• 제목/요약/키워드: electro discharge

검색결과 253건 처리시간 0.018초

미세금형 가공을 위한 전기화학식각공정의 유한요소 해석 및 실험 결과 비교

  • 류헌열;임현승;조시형;황병준;이성호;박진구
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2012년도 춘계학술발표대회
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    • pp.81.2-81.2
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    • 2012
  • To fabricate a metal mold for injection molding, hot-embossing and imprinting process, mechanical machining, electro discharge machining (EDM), electrochemical machining (ECM), laser process and wet etching ($FeCl_3$ process) have been widely used. However it is hard to get precise structure with these processes. Electrochemical etching has been also employed to fabricate a micro structure in metal mold. A through mask electrochemical micro machining (TMEMM) is one of the electrochemical etching processes which can obtain finely precise structure. In this process, many parameters such as current density, process time, temperature of electrolyte and distance between electrodes should be controlled. Therefore, it is difficult to predict the result because it has low reliability and reproducibility. To improve it, we investigated this process numerically and experimentally. To search the relation between processing parameters and the results, we used finite element simulation and the commercial finite element method (FEM) software ANSYS was used to analyze the electric field. In this study, it was supposed that the anodic dissolution process is predicted depending on the current density which is one of major parameters with finite element method. In experiment, we used stainless steel (SS304) substrate with various sized square and circular array patterns as an anode and copper (Cu) plate as a cathode. A mixture of $H_2SO_4$, $H_3PO_4$ and DIW was used as an electrolyte. After electrochemical etching process, we compared the results of experiment and simulation. As a result, we got the current distribution in the electrolyte and line profile of current density of the patterns from simulation. And etching profile and surface morphologies were characterized by 3D-profiler(${\mu}$-surf, Nanofocus, Germany) and FE-SEM(S-4800, Hitachi, Japan) measurement. From comparison of these data, it was confirmed that current distribution and line profile of the patterns from simulation are similar to surface morphology and etching profile of the sample from the process, respectively. Then we concluded that current density is more concentrated at the edge of pattern and the depth of etched area is proportional to current density.

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이온 교환막에서 이온의 비 평형 정상상태 이동을 이용한 단일 전해액의 배출만을 가지는 pH 조절용 연속식 전해 반응기 개발 (Development of a Continuous Electrolytic System for pH-control with Only One Discharge of Electrolytic Solution by Using Non-equilibrium Steady State Transfer of Ions across Ion Exchange Membranes)

  • 김광욱;유제욱;김인태;박근일;이일희
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2005년도 춘계 학술대회
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    • pp.101-109
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    • 2005
  • 본 논문에서는 불필요한 용액의 발생이 없이 전해 반응계로 주입되는 용액을 오직 pH 만을 조절시켜 배출시키기 위한 연속식 이온 교환막 전해 시스템을 개발하였다. 여기서는 전해 반응기 앞에 한 pH-조정조를 두고 대상 용액을 pH-조정조로 주입하면서 pH-조정조의 용액의 일부를 이온 교환막에 따라 음극방 또는 양극방으로 거처 다시 pH-조정조로 순환하게 하고. 또한 pH-조정조의 용액의 일부는 상대극방을 통과시킴으로써 pH가 산성 또는 알카리로 조절되어 배출되게 하였다. 이러한 전해반응기에서 pH 조절 과정은 음극과 양극 사이에 전압 차가 형성될 시, 이온 교환막을 통한 용액에 존재하는 이온의 전기이동 현상에 의해 유발되는 음극방과 양극방에서 용액의 전하 비 평형 현상과 이에 따른 물의 전해 분해 과정에 의해 설명되었다.

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슬관절 전치환술 후 한방병원에 입원한 환자 20명에 대한 후향적 분석 (Effects of Korean Medicine on 20 Post-TKR Inpatients: A Retrospective Observational Study)

  • 임지성;김지은;정영진;강도영;박은상;김종규;송용선
    • 동의생리병리학회지
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    • 제36권4호
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    • pp.138-142
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    • 2022
  • This study aimed to evaluate the effectiveness of Korean rehabilitation treatement for patients with post-TKR. The medical records of inpatients undergoing Korean rehabilitation treatment after TKR from 2016.01.01. to 2021.12.31. during the admission, were analyzed retrospectively. The effect of treatment was evaluated by using a numeric rating scale(NRS) and range of motion(ROM) of knee. Statistical analysis was done using the IBM SPSS statistics 26 program. If the period of hospitalization was within 7 days or change of NRS and ROM was not recorded properly, the case was excluded. All inpatients received acupuncture treatment, Electro-acupuncture. Soyeom pharmaco-acupuncture were used at a high rate. Blood letting cupping therapy, dry cupping therapy, Interferential Current Therapy(ICT) continuous passive motion(CPM), cryotherapy were used at a high rate. A significant improvement was noted when comparing the NRS and knee ROM results at the time of admission and discharge. Korean medical rehabilitation can be effectively used for patients who have undergone TKR, to relieve pain and enable returning to daily activities. It is expected to be helpful in future studies of post-TKR in Korean Medicine. Also It can be used for medical treatment of post-TKR in Korean Medicine Hospital and clinic. However, further research with a high level of evidence is necessary to support this finding.