검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 125

        101.
        2013.11 서비스 종료(열람 제한)
        K시의 소각장은 2000년 5월 시험가동으로 2기(스토거방식) 처리시설로 400ton/day의 생활쓰레기를 처리하면, 계통도는 쓰레기 반입, 쓰레기크레인, 소각로, 페열보일러, 반건식반응탐, 백필터, 탈질설비, 증기터빈발전기, 연돌소각처리 등으로 처리 하며, 소각과정에서 생성되는 폐열을 회수, 증기를 발생시켜 이 증기를 이용해서 장내 열원 및 소비전력을 보충하는 설비시설을 갖추고 있다. 그러나 그림 1과같이 사용 후 4 ~ 5년 후 부터는 산소농도가 증가하여 최근 3년간 급격히 상승해지고 있는 추세이며 2호기의 산소농도가 1호기 보다 높아지고 있어 배기가스 중 CO, SOx, HCl, NOx의 농도는 증가 하는 것으로 나타나고 있다. 본 연구는 소각로의 적정공기량을 투입하여 산소농도를 낮추어 대기배출 농도를 저감하기 위한 연구이다. 산소농도가 너무 높거나 너무 낮아도 문제가 되며 산소농도가 너무 높을 경우 모든 측정항목에 영향을 줌으로서 세심한 관심이 필요하다. 산소농도만 제어를 잘하면 CO는 물론 다른 항목의 제어 관리도 빨리 대처를 할 수 있다. 운전 중 가장 안정적인 범위는 이론상으로는 7 ~ 9%이나, K시의 소각설비는 10년 이상 운영으로 그동안에 많은 변화가 있어 산소농도는 약 9 ~ 13%로 높게 분석되었다. 1차 연소공기는 연소과정에는 직접적으로 영향을 주지만 연소실 내부의 유동장에는 큰 영향을 주지 않는 것으로 알려져 있고, 반면에 2차 연소공기는 불완전 연소물질의 2차 연소실에서의 연소를 촉진시키는 역할뿐만 아니라 연소실 내부의 유동형태를 크게 변화시키므로 미분입자의 이원방지, 화염높이의 적정유지, 연소가스 농도의 균일화 등 연소실내부의 연소상황을 제어하는 역할을 수행한다는 연구 문헌을 중심으로 본 연구 내용은 2차송풍량을 산소농도에 비례하여 송풍량이 자동으로 조절되어 소각로 내에 과잉송풍량이 들어가지 않고 산소농도에 맞게 송풍량을 주입하는 방법으로 DCS프로그램을 보완하였다. 그 결과 그림 2와 같이 대기배출 가스의 농도가 전년도에 비해 감소하였으며 약품사용량도 감소한 것으로 나타났다.
        102.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        SF6 (sulfur hexafluoride) gas has an extremely high global warming potential (GWP) because of strong absorption of infrared radiation and long atmospheric lifetime which cause the global warming effect. The objective of this study is to identify the effects of destruction and removal efficiency (DRE) of SF6 by the addition of oxygen, water vapor and hydrogen. The applied dose of ionization energy was 1,028 kGy(5 mA). The initial concentrations of SF6, O2, H2O and H2 gases were 1,000 ppm, 1,000 ppm, 3,000 ppm, 3,000 ppm, respectively. The DRE was increased about 2 times with O2 gas injection. The SF6 was completely removed with H2O and H2 gas injection. By-products formed by SF6 destruction were mainly HF and F2 gases. In addition, SF2, NF3, N2O, SO2, SO2F2, and NOx gases were produced.
        103.
        2012.04 KCI 등재 서비스 종료(열람 제한)
        Novel N2O2 tetradentate ligands, H-3BPD and H-2BPD were synthesized. Hydrochloric acid salts of Br-3BPD, Cl-3BPD, Br-2BPD and Cl-2BPD having Br and Cl substituents at the para position of the phenol hydroxyl group, were synthesized. The ligands were characterized by C. H. N atomic analysis, 1H NMR, 13C NMR, UV-visible, and mass spectra. The proton dissociation constants (logKn H) of the phenol hydroxyl group and secondary amine of the synthesized N2O2 ligands were shown by four step wise values. The orders of the calculated overall proton dissociation constants (logβp) were Br-3BPD < Cl-3BPD < H-3BPD in case of 3BPD and Br-2BPD < Cl-2BPD < H-2BPD in case of 2BPD respectively. The order agreed well with that of para Hammett substituent constants(δp). The stability constants(logKML) of the complexes between the synthesized ligands and transition metal(II) ions agreed with the order of logβp of the ligands. The order of the logKML value of the each transition metal (II) ion was Co(Ⅱ) < Ni(Ⅱ) < Cu(Ⅱ) > Zn(Ⅱ) > Cd(Ⅱ) > Pb(Ⅱ), which agreed well with that of Iriving-Williams series.
        105.
        2011.10 KCI 등재 서비스 종료(열람 제한)
        본 연구는 고해상도 디지털 X선 영상 검출기 적용을 위해 미세 Gd2O2S:Tb 형광체 분말을 저온 액상법을 이용하여 합성하였다. 제조된 형광체 분말을 이용하여 입자침전법을 이용하여 형광체 필름을 제작하여 발광특성을 조사하였다. 측정결과, Tb 첨가농도에 따른 상대적인 발광량 측정결과 5 wt%의 첨가농도에서 가장 높은 발광효율을 보였으며, 첨 가농도가 증가할수록 소광현상에 의한 발광강도가 급격히 감소하는 경향을 보였다. 또한 270 ㎛ 두께의 Gd2O2S:Tb에 서 2945 pC/cm2/mR의 발광 강도를 가졌으며, 발광 강도가 거의 포화되는 것을 관찰할 수 있었다. 끝으로 제조된 형광 체의 영상획득 성능을 평가하기 위해 상용화된 CMOS 센서를 이용하여 X선 영상을 획득하여 MTF, NPS를 측정하여 DQE 평가를 수행하였다. 측정결과, DQE(0)의 값은 37%로 다소 낮은 값을 보였다. 향후 필름 제조 공정상의 문제점 을 해결한다면, DQE를 개선할 수 있을 것으며, 고해상도 의료 방사선 영상 시스템 적용에 유용하게 적용 가능할 것으 로 판단된다.
        107.
        2011.06 KCI 등재 서비스 종료(열람 제한)
        new N3-O2 pentadentate ligand, H-BHPT, was synthesized. Hydrochloric acid salts of Br-BHPT, Cl-BHPT, CH3O-BHPT and CH3-BHPT, having Br-, Cl-, CH3- and CH3O- substituents at the para position of the phenol hydroxyl group of H-BHPT were synthesized. Hydrochloric acid salts of 3OH-BHPT and 4OH-BHPT, having different position of the phenol hydroxyl group of H-BHPT were also synthesized. The synthesis of each ligand was confirmed by C. H. N. atomic analysis and 1H NMR, 13C NMR, UV-visible, and mass spectra. The calculated proton dissociation constants (logKn H) of the phenol hydroxyl group and secondary amine group of the synthesized N3-O2 ligands showed five steps of the proton dissociations. The order of the overall proton dissociation constants (logβp) of the ligands was Br-BHPT < Cl-BHPT < H-BHPT < CH3O-BHPT < CH3-BHPT. The order agreed with that of Hammett substituent constants (δp). However, dissociation steps of 3OH-BHPT were four and that of 4OH-BHPT was three. The calculated stability constants (logKML) between the ligands and transition metal ions agreed with the order of logβp values of the ligands. The order of the stability constants between the transition metal ions with the synthesized ligands was Co(Ⅱ) < Ni(Ⅱ) < Cu(Ⅱ) > Zn(Ⅱ) > Cd(Ⅱ) > Pb(Ⅱ). The order agreed well with that of the Iriving-Williams.
        108.
        2010.07 KCI 등재 서비스 종료(열람 제한)
        A new N3O2 pentadentate ligand, N,N'-Bis(2-hydroxybenzyl)-ethylenetriamine(H-BHET․3HCl) was synthesized. The hydrochloric acid salts of Br-BHET․3HCl, Cl-BHET․3HCl, CH3O-BHET․3HCl and CH3-BHET․3HCl containing Br-, Cl-, H-, CH3O- and CH3- groups at the para-site of the phenol group of the H-BHEP were synthesized. The structures of the ligands were confirmed by C. H. N. atomic analysis and 1H NMR, 13C NMR, UV-visible and mass spectra. The calculated stepwise protonation constants(logKnH) of the synthesized N3O2 ligands showed six steps of the proton dissociation. The orders of the overall protonation constants(logβp) of the ligands were Br-BHET < Cl-BHET < H-BHET < CH3O-BHET < CH3-BHET. The orders agreed well with that of para Hammett substituent constants(δp). The calculated stability constants(logKML) between the ligands and heavy metal ions (Co(Ⅱ) , Ni(Ⅱ), Cu(Ⅱ), Zn(Ⅱ), Cd(Ⅱ) and Pb(Ⅱ)) agreed well with the order of the overall proton dissociation constants of the ligands but they showed a reverse order in para Hammestt substituent constants(δp). The order of the stability constants between the heavy metal ions with the synthesized ligands were Co(Ⅱ) < Ni(Ⅱ) < Cu(Ⅱ) > Zn(Ⅱ) > Cd(Ⅱ) > Pb(Ⅱ).
        112.
        2007.08 KCI 등재 서비스 종료(열람 제한)
        Hydrochloride acid salts of new N2O2 tetradentate ligands containing amine and phenol N,N'-bis(2-hydroxybenzyl)-o-phenylenediamine(H-BHP), N,N'-bis(5-bromo-2-hydroxybenzyl)-o-phenylenediamine(Br-BHP), N,N'-bis (5-chloro-2-hydroxybenzyl)-o-phenylene-diamine(Cl-BHP), N,N'-bis(5-methyl-2-hydroxybenzyl)-o-phenylene-diamine (Me-BHP) and N,N'-bis(5-methoxy-2-hydroxybenzyl)-o-phenylenediamine(MeO-BHP) were synthesized. The ligands were characterized by elemental analysis, mass and NMR spectroscopy. The elemental analysis showed that the ligands were isolated as dihydrochloride salt. The potentiometry study revealed that the proton dissociation constants(logKnH) of ligands and stability constants (logKML) of transition and heavy metals complexes. The order of the stability constants of each metal ions for ligands was Br-BHP < Cl-BHP < H-BHP < MeO-BHP < Me-BHP.
        113.
        2006.03 KCI 등재 서비스 종료(열람 제한)
        Advanced oxidation processes involving O3/H2O2 and O3/catalyst were used to compare the degradability and the effect of pH on the oxidation of 1,4-dioxane. Oxidation processes were carried out in a bubble column reactor under different pH. Initial hydrogen peroxide concentration was 3.52 mM in O3/H2O2 process and 115 g/L (0.65 wt.%) of activated carbon impregnated with palladium was packed in O3/catalyst column. 1,4-dioxane concentration was reduced steadily with reaction time in O3/H2O2 oxidation process, however, in case of O3/catalyst process, about 50~75% of 1,4-dioxane was degraded only in 5 minutes after reaction. Overall reaction efficiency of O3/catalyst was also higher than that of O3/H2O2 process. TOC and CODCr were analyzed in order to examine the oxidation characteristics with O3/H2O2 and O3/catalyst process. The results of CODCr removal efficiency and ΔTOC/ΔThOC ratio in O3/catalyst process gave that this process could more proceed the oxidation reaction than O3/H2O2 oxidation process. Therefore, it was considered that O3/catalyst advanced oxidation process could be used as a effective oxidation process for removing non-degradable toxic organic materials.
        115.
        2003.09 KCI 등재 서비스 종료(열람 제한)
        리튬2차전지용 양극소재 개발을 위해 Li[L ixM n1-x-yC ry ] O2를 공침법(co-p.ecipitation method)을 적용하여 각각 650℃(CR650)와 850℃(CR850)에서 합성하였다. 리트벨트 구조분석 결과 계산의 정밀도를 나타내는 R 지수값을 보면 Rexp에 대한 Rwp값( Rwp/ Rexp)은 CR650과 CR850의 각각에 대해 19.2%/10.1%과 15.9%/9.76%를 보여주며, Rb값은 각각 10.9%와 8.54%, 그리고 S(GofF)값은 각각 1.9와 1.6으로 계산되었다. 합성된 양극소재는 공간군 R3m의 층상구조(LiMn O2)가 존재하였으며, 전이금속 층 내의 Mn이 Li로 치환되면서(Li[L i13/M n23/] O2) 단사구조(C2/c)의 거대격자(Superlattice) 구조현상도 관찰되었다. 계산된 단위포는 공간군 R3m, CR650이 a=2.8520(2)a, c=14.248(2)a, V=100.40(1)a3이며, CR850은 a=2.8504(1)a, c=14.2371(7)a, V=100.179(8)a3으로 각각 계산되었다. 또한 최종 결정된 화학식은 CR650은 Li[L i0.35M n0.56C r0.09] O2, CR850은 Li[L i0.27M n0.61C r0.13] O2으로 각각 구해졌다.다...다..구해졌다.다...다..
        117.
        2002.06 KCI 등재 서비스 종료(열람 제한)
        Selective catalytic reduction and selective non-catalytic reduction processes are mainly used to treat nitrogen oxidants generated from fossil-fuel combustion. Especially, the selective non-catalytic reduction process can be operated more economical and designed more simply than the selective catalytic reduction. For this reason, many researchers carried out to increase the removal efficiency of nitrogen oxidants in the condition of low oxygen concentration by using the selective non-catalytic reduction process. However, this study was flue gas contained high oxygen concentration of 20(v/v%) with ammonia as a reducing agent. Moreover, it carried out experiment with many factors that are reaction temperature, retention time, initial NO concentration, NSR(normalized stoichiometric ratio). It was determined optimal operating conditions to improve NO removal efficiency with SNCR process. The De-NOx efficiency was increasesd with NSR, initial NO concentration and retention time increasement. This study has NO removal efficiency over 80% in the high oxygen concentration as well as low oxygen concentration. The injection of reducing agent may be considered for SNCR process and facility operation in 850℃ of optimal condition.
        6 7