• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계 학술대회논문집(수송기계편)
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• pp.156-160
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• 2005

The radiated noise of the excavator is composed of the various noise sources such as the diesel engine, cooling fan and hydraulic system, so the noise reduction for each noise source is required. In this study, the source contribution analysis for these principal noise sources is performed by using the noise source removal method. And to reduce the noise due to each one, the various experiments and analyses are studied. On the basis of these results, the proper reduction countermeasures are derived to develop the excavator satisfied the $2^{nd}$ noise regulation of EU.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1996년도 제11차 KACG 학술발표회 Crystalline Particle Symposium (CPS)
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• pp.87-107
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• 1996

The fine Co powder with an average particle sie of less than 1$\mu\textrm{m}$ was prepared by hydrothermal reduction with hydrogen from Co(OH)2 slurry obtained by mixing the solutons of CoSO4$.$7H2O and NaOH. A method to control pH of the end solution around neutrality was proposed. The reduction rate was found to be a function of pH, temperature, hydrogen pressure and the amount of catalyst.

• 한국염색가공학회지
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• 제15권3호
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• pp.140-145
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• 2003

The purpose of this study is searching the Elm-Bark dyes' dyeability and antibacterial activities according to the dyeing time, pH, a mordant and the method of mordancy. We used two kinds of Elm-Bark dyes which's extracted by the Electrolytic reduction water and Distilled water. Silk fabric and Cotton/nylon union fabric was used for this study. The results are as follow. K/S value is increased according to the dyeing time and the suitable pH level is pH 3. Dyeability is good with Iron(II) sulfate$(FeSO_4\cdot{7H}_2O)$ on the pre-mordancy and Potassium dichromate$(K_2Cr_2O_7)$ on the post-mordancy. The Elm-Bark dyes by the Electrolytic reduction water has good colorfastness more than by the Distilled water. Antibacterial activities is excellent and the ratio is over than 99.5%.

• 한국분말재료학회지
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• 제18권6호
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• pp.510-516
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• 2011

In the present study, potassium and caesium doped Ag/$Al_2O_3$ catalysts were synthesized by simple wet impregnation method and evaluated for selective catalytic reduction (SCR) of NOx using methane. TEM analysis and diffraction patterns demonstrated the finely dispersed Ag particles. BET surface measurements reveal that the prepared materials have moderate to high surface area and the metal amount found from ICP analysis was well matching with the theoretical loadings. The synthesized K-Ag/$Al_2O_3$ and Cs-Ag/$Al_2O_3$ catalysts exhibited a promotional effect on deNOx activity in the presence of $SO_2$ and $H_2O$. The long-term isothermal studies at $550^{\circ}C$ under oxygen rich condition showed the superior catalytic properties of the both alkali promoted samples. The crucial catalytic properties of materials are attributed to NO adsorption properties detected by the NO TPD.

• Biomolecules & Therapeutics
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• 제8권2호
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• pp.132-139
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• 2000

This study was performed far investigation of influence on renal function of idazoxan, $\alpha_{2}$-adrenergic antagonist, using the dog. Idazoxan, when giver. into vein, produced the decrease of urine volume(vol) accompanied with the reduction of free water clearance($C_{H2O}$), amounts of sodium excreted in urine($E_{Na}$), with the increase of potassium excreted in urine($E_{K}$), and so ratios of potassium against sodium($K^{+}/Na^{+}$) were elevated, at this time, greatened reabsorption rate of sodium and diministered that of potassium in renal tubules were appeared. Idazoxan administered into a renal artery elicited the augmentation of vol, glomerular filtration rate(GFR), renal plasma flow(RPF) and no change of filtration fraction(FF) in only ipsilateral kidney, whereas $E_{Na},\;E_{K}\;and\;K^{+}/Na^{+}$ were increased and $C_{H2O}$ was decreased in both control and experimental kidney. Idazoxan given into carotid artery showed partial increased vol, remarkable expanded RPF and unchanged GFR, and so filtration fraction(FF) was markedly reduced. Above results suggest that anti- diuretic action of idazoxan given into vein is mediated by reduction of $C_{H2O}\;and\;E_{Na}$, diuretic action only in the ipsilateral kidney by idazoxan given into a renal artery is caused by hemodynamic improvement through expansion of vas afferens in glomeruli.

• 한국농공학회논문집
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• 제55권2호
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• pp.47-57
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• 2013

This study is to assess the reduction of non-point source pollution loads for rice straw mulching of upland crop cultivation at a watershed scale. For Byulmi-cheon watershed (1.21 $km^2$) located in the upstream of Gyeongan-cheon, the HSPF (Hydrological Simulation Program-Fortran) and SWAT (Soil and Water Assesment Tool), physically based distributed hydrological models were applied. Before evaluation, the model was calibrated and validated using 9 rainfall events. The Nash-Sutcliffe model efficiency (NSE) for streamflow using the HSPF was 0.62~0.76 and the determination coefficient ($R^2$) for water quality (sediment, total nitrogen T-N, and total phosphorus T-P) were 0.72, 0.62, and 0.63 respectively. The NSE for streamflow using the SWAT were 0.43~0.81 and the $R^2$ for water quality (sediment, T-N, and T-P) were 0.54, 0.87, and 0.64 respectively. From the field experiment of 16 rainfall events, the rice straw cover condition reduced surface runoff average 10.0 % compared to normal surface condition. By handling infiltration capacity (INFILT) in HSPF model, the value of 16.0 mm/hr was found to reduce about 10.0 % reduction of surface runoff. For this condition, the reduction effect of sediment, T-N, and T-P loads were 87.2, 28.5, and 85.1 % respectively. By handling soil hydraulic conductivity (SOL_K) in SWAT model, the value of 111.2 mm/hr was found to reduce about 10.0 point reduction of surface runoff. For this condition, the reduction effect of sediment, T-N, and T-P loads were 80.0, 83.2, and 78.7 % respectively. The rice straw surface covering was effective for removing surface runoff dependent loads such as sediment and T-P.

• 한국환경보건학회지
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• 제49권5호
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• pp.275-288
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• 2023

Background: When basic local governments want to improve their air quality management policies, they need fundamental evidence, such as the effectiveness of current policies or scenario results. Objectives: The purpose of this study is to lay the groundwork for a process to calculate air pollutant reduction from basic local government air quality policies and provide numerical estimates of PM_2.5 concentrations following improved policies. Methods: We calculated the amount of air pollutant reduction that can be expected in the research region based on the Gyeonggi-do Air Environment Management Implementation Plan issued in 2021 and guidelines from the Korean Ministry of Environment. The PM_2.5 concentration variations were numerically simulated using the CMAQ (photochemical air quality model). Results: The research regions selected were Suwon, Ansan, Yongin, Pyeongtaek, and Hwaseong in consideration of population, air pollutant emissions, and geographical requirements. The expected reduction ratios in 2024 compared to 2018 are CO (3.0%), NO_x (7.9%), VOCs (0.7%), SO_x (0.1%), PM₁₀ (2.4%), PM_2.5 (6.1%), NH₃ (0.05%). The reduced PM_2.5 concentration ratio was highest in July and lowest in April. The expected concentration reduction of yearly mean PM_2.5 in the research region is 0.12 ㎍/m³ (0.6%). Conclusions: Gyeonggi-do is now able to quickly provide air pollutant emission reduction calculations by respective policy scenario and PM_2.5 simulation results, including for secondary aerosol particles. In order to provide more generalized results to basic local governments, it is necessary to conduct additional research by expanding the analysis tools and periods.

• 한국수소및신에너지학회논문집
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• 제27권4호
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• pp.412-420
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• 2016

Effect of $H_2S$ on reactivity of oxygen carrier was measured and discussed using fluidized bed reactor and SDN70 oxygen carrier. We could get 100% of fuel conversion and $CO_2$ selectivity even though $H_2S$ containing simulated syngas was used as fuel for reduction. Absorbed sulfur was released during oxidation and $N_2$ purge step after oxidation as $SO_2$ form. We could get 100% of fuel conversion and $CO_2$ selectivity during cyclic reduction-oxidation tests up to 10th cycle. However, only 6~7% of sulfur can be removed during oxidation and $N_2$ purge step and 93~94% of sulfur was accumulated in the oxygen carrier. Therefore we could conclude that total removal of sulfur was not possible. $SO_2$ emission during oxidation decreased as the number of cycle increased. Therefore we could expect that the reactivity of oxygen carrier will be decreased with time.

• 자원리싸이클링
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• 제27권5호
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• pp.23-29
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• 2018

일반적으로 탄산니켈을 제조하기 위한 원료로 $NiSO_4$ 및 $NiCl_2$가 사용되었다. 제조된 탄산니켈의 경우 표면 및 내부에 있어 $Na_2SO_4$ 및 NaCl이 생성되어 탄산니켈의 순도를 감소시키는 원인이 되고 있으며, 이러한 불순물의 제거정도에 따라 고순도 탄산니켈을 제조할 수 있다. 본 연구에서는 니켈MHP 용매추출 공정으로 제조된 $NiCl_2$를 이용하여 탄산니켈제조 연구를 진행하였다. 실험은 니켈염과 탄산염 당량비에 따른 제조, 탄산니켈 수세에 따른 탄산니켈 내 Na 및 Cl 감소 및 수세용수의 온도에 따른 Na 및 Cl의 감소에 대한 조건을 실험하여 고순도 탄산니켈을 제조할 수 있었다.

• 한국대기환경학회지
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• 제27권4호
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• pp.387-394
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• 2011

A study on the removal of sulfur dioxide and nitrogen oxide was carried out using a non-thermal nano-pulse corona discharger at different gas temperatures. Pulse voltage with a high voltage of 50 kV, a pulse rising time of about 100 ns, a full width at half maximum of about 500 ns and a frequency of 1 kHz was applied to a wire-cylinder corona reactor. Ammonia and propylene gases were added into the corona reactor as additives with a static mixer. Ammonia addition had less effect on $SO_2$ reduction at the higher temperature because of the retardation of ammonium sulfate formation. However, propylene addition enhanced NO reduction at higher temperature due to increased gas mixture. $SO_2$ was further removed at the mixed $SO_2$ and NO gas due to increased $NO_2$ by the conversion of NO. The addition of ammonia and propylene gases was more highly dominant for the removal of sulfur dioxide compared to the sole pulse corona without the additives. However, the specific energy density per unit concentration of pulse corona as well as propylene additive was an important factor to remove NO gas. Therefore, the specific energy density per unit concentration of 0.04 Wh/($m^3{\cdot}ppm$) was necessary for the NO removal of more than 80% with the concentration ratio of 2.0 for propylene and NO. Hydrogen peroxide was another alternative additive to remove both $SO_2$ and NO in the nano-pulse corona discharger.