The purpose of this experimental research is to evaluate the workability and strength properties of hybrid fiber reinforced concrete containing amorphous steel fiber and organic fiber. For this purpose, the hybrid fiber reinforced concrete containing amorphous steel fiber(ASF) with polyamide(PA) and polyvinyl alcohol(PVA) fiber, respectively were made according to their total volume fraction of 0.5% for water-binder ratio of 33%, and then the characteristics such as the workability, compressive strength, and flexural strength of those were investigated. It was observed from the test results that the workability and compressive strength at 7 and 28 days were decreased and the flexural strength at 7 and 28 days was increased with increasing ASF and decreasing organic fiber.
Electrochemical charateristics of activated carbon fiber cloth(ACFC) electrode were studied with propylene carbonate(PC), γ-butyrolactone(GBL) and N,N-dimethyl-formamide(DMF) as a solvent and tetraethylammoniumtetrafluoroborate(TEABF4), tetraethylammoniumhexafluorophosphate(TEABF6), tetrabutylammoniumtetrafluoroborate(TBABF4) and tetrabutylammonium hexafluorophosphate(TBAPF6) as an electrolytes(active material). The concentrations of electrolytes were in the range of 0.2~1.2 N, the volume ratios of PC and DMF as a mixed solvent system, were 90:10, 80:20, 70:30, 60:40, 50:50, and 40:60 vol%. Electrochemical characteristics such as electric conductivity, internal resistance, and electric capacitance of fabricated unit cells were measured after the moisture of activated material was removed with molecular sieve. Electrochemical characteristics were better in mixed solvents system than in mono solvent system. The mono solvent system of 1.0 N electrolyte of GBL/TEABF4 with activated carbon cloth electrodes showed better result but the mixed solvent system with PC and DMF/TEABF4(50:50 vol%) and the concentration of 1.0 N electrolyte showed the best characteristics. Internal resistance was 3.47 Ω and specific capacitance was 19.1 F/g respectively.y.
열가소성 고분자 복합재료 개발을 위하여 매트릭스 수지로는 폴리프로필렌섬유(PP)를 사용하고 유기계 강화소재로 폴리비닐알코올(비닐론, VF), 아라미드(케블라-49, KF) 및 폴리아미드섬유(PAF)등을 사용하였다. 복합매트제조장치로서 복합매트를 제조하고 가열.압축하여 고분자 복합재료를 성형하였다. 제조한 고분자 복합재료의 형태학, 유변학적 및 기계적특성 등을 측정하였다. 형태학에서 미트릭스와 강화섬유 간의 젖음성은 강화섬유의 함량이 증가함에 따라 감소하는 경향을 보였다. PAF/PP와 VF/PP 복합재료에 대한 점성도는 낮은 주파수 영역에서 강화섬유의 함량이 증가됨에 따라 증가하였으나, 높은 주파주 영역에서 5-20wt%로 강화된 복합재료는 매트릭스인 PP에 근접하게 감소된 점성도를 나타냈다. 기계적 특성은 강화 섬유의 함량에 따라 변하였으며, VF/PP 및 KF/PP 복합재료가 PAF/PP 계에 비해 우수한 현상을 보였다.
The purpose of this experimental research is to evaluate the mechanical properties of high performance concrete using amorphous steel fiber and organic fiber. For this purpose, the hybrid fiber reinforced concrete containing amorphous steel fiber(ASF) and polyamide(PA) fiber were made according to their total volume fraction of 0.5% for water-binder ratio of 33%, and then the characteristics such as the workability, compressive strength, and direct tension strength of those were evaluated. It was observed from the test results that the workability and compressive strength was decreased with increasing ASF and decreasing PA fiber. but the direct tension strength was on the whole increased with increasing ASF and decreasing PA fiber.
본 연구에서는 유기성 슬러지와 섬유폐기물의 물성, 열적 특성을 파악하여 고형연료탄을 제작하여 고형연료탄에 대한 공업분석, 발열량분석등을 통해 고형연료로서의 활용가능성을 평가하였다. 제조된 고형연료탄의 공업분석결과 하수 슬러지 건조물과 섬유폐기물 혼합 연료탄(ST)은 평균 수분 3.5%, 휘발분 65.58%, 회분 9.12%, 고정탄소 25.30% 이며, 하수슬러지 건조물(S) 연료탄은 수분 10.2%, 휘발분 56.75%, 회분 33.73%, 고정탄소 9.52%로 측정되었다. 발열량의 경우 ST 연료탄 의 경우 평균 고위발열량 5,820 Kcal/kg, 저위발열량 5,520 Kcal/kg으로 나타나 슬러지 연료탄의 경우 평균 고위발열량 3,732 Kcal/kg(저위발열량 3,350 Kcal/kg) 보다 높게 나타났다. 국내 무연탄과 하수슬러지 고형연료탄의 기본적 물성치를 비교하면, 주 가연분에는 하수슬러지는 휘발분이 대부분이며, 무연탄에는 고정탄소가 대부분임을 알 수 있다. 때문에 하수슬러지 고형연료탄을 석탄의 보조연료로 사용할 시 휘발분에 대한 연소특성을 고려해야 할 것으로 사료된다. 더하여 발열량은 유사한 범위를 보였고, 원소분석 비교에서 석탄에 비해 N, S의 함량 비가 다소 높은 것으로 나타나 연소시 배가스 중 질소화합물과 황화합물의 양이 증가할 것으로 판단되며 이를 효과적으로 관리할 수 있는 배가스 저감시설에 대한 고려가 필요하다.
The simulated dyes solution containing Basic Red 46(BR 46), Yellow 21(Y 21), and Maxilon Blue 30(MB 30) were electrochemically oxidized using carbon fiber as an anode. The electrolyses were performed in a electrolytic flow cell constructed by Vycor glass tube. The carbon fiber was positioned in the inside of Vycor glass tube and platinum wire coiled around outside of tube as a cathode. Several operating variables, such as current, time, pH and flow rate of solution were studied. Increasing current density would lead to a corresponding increase in the dye removal efficiency 99.2 % at a 200 mA. The electrolyses time could also improve and removal efficiency was about 99 % after 1.5 hours of electrolyses. The removal efficiency was increased with the increase of flow rate of solution and optimum flow rate was 5 mL/min. THe pHs of solution affect the removal efficiency. The removal efficiency was decreased with the increase of pH of solution and optimum pH was 5.05 (0.1 M KNO3).
The purpose of this study was to investigate the characteristics of removal efficiency for aromatic hydrocarbons using a high-temperature fiber filter on a laboratory scale. The main elemental compositions of a high-temperature fiber filter are aluminium and silica, which can act as the catalysts. Benzene, toluene and o-xylene among aromatic hydrocarbons were used in this experiment. For 3㎝ thickness of fiber filter, these compounds were removed more than 90% at the face velocities of 3㎝/sec and 5㎝/sec above 450℃. For 4㎝ thickness of it, the removal efficiencies of these compounds were almost 90% from 400℃ at the same face velocities, suggesting that it may be due to increasing the contact time between the fiber filter and aromatic hydrocarbons. The pressure drop ranged from 22 to 48㎜H2O for 3㎝ thickness of fiber filter. However, for 4㎝ thickness of it, it was about two times(41-89㎜H2O) higher than that for 3㎝ fiber thickness.