검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 6

        1.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In water treatment process using microfiltration membranes, manganese is a substance that causes inorganic membrane fouling. As a result of analysis on the operation data taken from I WTP(Water Treatment Plant), it was confirmed that the increase of TMP was very severe during the period of manganese inflow. The membrane fouling fastened the increase of TMP and shortened the service time of filtration or the cleaning cycle. The TMP of the membrane increased to the maximum of 2.13 kgf/cm2, but it was recovered to the initial level (0.17 kgf/cm2) by the 1st acid cleaning step. It was obvious that the main membrane fouling contaminants are due to inorganic substances. As a result of the analysis on the chemical waste, the concentrations of aluminum(146-164 mg/L) and manganese(110-126 mg/L) were very high. It is considered that aluminum was due to the residual unreacted during coagulation step as a pretreatment process. And manganese is thought to be due to the adsorption on the membrane surface as an adsorbate in feed water component during filtration step. For the efficient maintenance of the membrane filtration facilities, optimization of chemical concentration and CIP conditions is very important when finding the abnormal level of influent including foulants such as manganese.
        4,200원
        2.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, it is estimated that ceramic membrane process which can operate stably in harsh conditions replacing existing organic membrane connected with coagulation, sedimentation etc. . Jar-test was conducted by using artificial raw water containing kaolin and humic acid. It was observed that coagulant (A-PAC, 10.6%) 4mg/l is the optimal dose. As a results of evaluation of membrane single filtration process (A), coagulation-membrane filtration process (B) and coagulation-sedimentation-membrane filtration process (C), TMP variation is stable regardless of in Flux 2 m3/m2・day. But in Flux 5 m3/m2・day, it show change of 1-89.3 kpa by process. TMP of process (B) and (C) is increased 11.8, 0.6 kpa each. But, the (A) showed the greatest change of TMP. When evaluate (A) and (C) in Flux 10 m3/m2・day, TMP of (A) stopped operation being exceeded 120 kpa in 20 minutes. On the other hand, TMP of (C) is increased only 3 kpa in 120 minutes. Through this, membrane filtration process can be operated stably by using the linkage between the pretreatment process and the ceramic membrane filtration process. Turbidity of treated water remained under 0.1 NTU regardless of flux condition and DOC and UV254 showed a removal rate of 65-85%, 95% more each at process connected with pretreatment. Physical cleaning was carried out using water and air of 500kpa to show the recovery of pollutants formed on membrane surface by filtration. In (A) process, TMP has increased rapidly and decreased the recovery by physical cleaning as the flux rises. This means that contamination on membrane surface is irreversible fouling difficult to recover by using physical cleaning. Process (B) and (C) are observed high recovery rate of 60% more in high flux and especially recovery rate of process (B) is the highest at 95.8%. This can be judged that the coagulation flocs in the raw water formed cake layer with irreversible fouling and are favorable to physical cleaning. As a result of estimation, observe that ceramic membrane filtration connected with pretreatment improves efficiency of filtration and recovery rate of physical cleaning. And ceramic membrane which is possible to operate in the higher flux than organic membrane can be reduce the area of water purification facilities and secure a stable quantity of water by connecting the ceramic membrane with pretreatment process.
        4,000원
        4.
        1999.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        알긴을 액상제품에 이용하기 위하여 algin의 농도와 수용액의 pH, 온도 변화에 의한 algin의 유동특성과 산미제, 감미제, 기타 첨가물이 algin의 점성에 미치는 영향을 조사하였다. 알긴 용액은 회전속도가 동일할 때는 농도가 높을수록 점도가 증가하였고 0.4% 농도까지는 dilatant형, 0.5% 이상에서는 pseudoplastic형 유체의 특성을 나타냈다. 알긴 용액의 pH가 5.5일 때 점도가 가장 높았고 pH 5.5 이하에서는 산성일수록 점도가 낮아졌으며, pH 7.0 이상에서는 점도의 변화가 없었다. 온도가 낮을수록 점도가 높았고, 가열함에 따라 용해시간이 단축되었으며 80℃이상의 가열에 의하여 점도가 다소 낮아졌다. 산미제에 의해 알긴의 점도는 pH 의존적으로 pH 3.2∼3.3에서 점도가 가장 낮았고 pH 3.0 이하에서는 gel이 형성되었다. 감미제는 알긴 용액의 점도에 영향을 주지 않았다. 무기염류 중 NaCl과 KCl은 점도를 감소시켰으며 MgCl_2와 CaCl_2는 점도를 증가시켰고, FeCl_3 첨가는 점도 증가효과가 커서 0.1% 첨가에 의햐여 gel이 형성되었다. 아미노산 중 glutamic acid는 1.0% 첨가 시에 점도 감소효과가 있었으며 다른 아미노산은 변화를 나타내지 않았다.
        4,000원
        6.
        2010.06 KCI 등재 서비스 종료(열람 제한)
        정세관은 매우 복잡한 조직으로 마우스의 정자 발생 과정은 12단계로 구성되어 있다. Glutathione peroxidase(GPx)는 glutathione을 이용하여 과산화물(hydroperoxide)을 환원시키는 대표적인 항산화효소로서 포유류 정자 발생 과정에 관여하는 것으로 알려져 있다. 본 연구에서는 laser capture microdissection(LCM)을 이용하여 마우스 정소에서 발생 단계별로 정세관을 채취하여 real-time PCR로