• 제목/요약/키워드: galvanic

검색결과 349건 처리시간 0.025초

승마시뮬레이터 훈련과 평류안뜰자극이 자세균형능력과 고유수용성감각에 미치는 영향 (The Effects of Ability to Balance Posture and Proprioception by Horse Riding Simulator and Galvanic Vestibular Stimulation)

  • 조운수;김용남;박장성;진희경
    • 한국전문물리치료학회지
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    • 제19권2호
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    • pp.39-47
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    • 2012
  • The purpose of this study is to examine the influence of a horse riding simulator and galvanic vestibular stimulation on improving the ability to balance posture and proprioception. Thirty healthy adults participated and were randomly assigned to a horse riding simulator group ($n_1$=10), galvanic vestibular stimulation (GVS) group ($n_2$=10), control group ($n_3$=10). Experiment groups were trained 3 times per week over 6 weeks. The ability to balance posture was measured by force plate and proprioception was measured by Joint position sense. The following results were obtained. the changes of balance index were significant interaction in each group in accordance with the experiment time in 0, 3 and 6 weeks (p<.05). All groups showed the most decreasing pattern compared with the control group. But was not statistically significant. Proprioception was significant interaction in each group in accordance with the experiment time (p<.05). All groups showed the most decreasing pattern compared with the control group. The above results indicated that the 6 weeks horse riding simulator and galvanic vestibular stimulation training demonstrated positive effects in the ability to balance posture and proprioception. These results suggest that the horse riding simulator and galvanic vestibular stimulation training could be therapeutic intervention that can improve balance and postural control.

An Electrochemical Evaluation on the Corrosion of Weld Zone in Cold Arc Welding of the Cast Iron

  • Moon, Kyung Man;Kim, Jin Gyeong;Lee, Myung Hoon;Kim, Ki Joon
    • Corrosion Science and Technology
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    • 제7권2호
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    • pp.134-137
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    • 2008
  • Cold arc welding of cast iron has been widely used with repair welding of metal structures. However its welding is often resulted in the galvanic corrosion between weld metal zone and heat affected zone(HAZ) due to increasing of hardness. In this study, corrosion properties such as hardness, corrosion potential, surface microstructures, and variation of corrosion current density of welding zone with parameters of used electrodes for cast iron welding were investigated with an electrochemical evaluation. Hardness of HAZ showed the highest value compared to other welding zone regardless of kinds of used electrodes for cast iron welding. And its corrosion potential was also shifted to more negative direction than other welding zone. In addition, corrosion current density of WM in polarization curves was qualitatively smaller than that of HAZ. Therefore galvanic corrosion may be apparently observed at HAZ. However galvanic corrosion may be somewhat controlled by using an optimum welding electrode.

수직배양된 고집적 CdTe-Si 나노구조체의 제조방법 (Facile Synthesis of Vertically Aligned CdTe-Si Nanostructures with High Density)

  • 임진호;황성환;정현성
    • 한국전기전자재료학회논문지
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    • 제30권3호
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    • pp.185-191
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    • 2017
  • Cadmium compounds with one dimension (1D) nanostructures have attracted attention for their excellent electrical and optical properties. In this study, vertically aligned CdTe-Si nanostructures with high density were synthesized by several simple chemical reactions. First, l D Te nanostructures were synthesized by silver assisted chemical Si wafer etching followed by a galvanic displacement reaction of the etched Si nanowires. Nanowire length was controlled from 1 to $25{\mu}m$ by adjusting etching time. The Si nanowire galvanic displacement reaction in $HTeO_2{^+}$ electrolyte created hybrid 1D Te-branched Si nanostructures. The sequential topochemical reaction resulted in $Ag_2Te-Si$ nanostructures, and the cation exchange reaction with the hybrid 1D Te-branched Si nanostructures resulted in CdTe-Si nanostructures. Wet chemical processes including metal assisted etching, galvanic displacement, topochemical and cation exchange reactions are proposed as simple routes to fabricate large scale, vertically aligned CdTe-Si hybrid nanostructures with high density.

Mg 합금유전양긍에 의한 온수보일러의 음극방식거동에 관한 연구 (Study on the Cathodic Protectioin Behavior of Hot Water Boiler by Mg-Alloy Galvanic Anode)

  • 정기철
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2000년도 춘계학술대회 논문집(Proceeding of the KOSME 2000 Spring Annual Meeting)
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    • pp.115-121
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    • 2000
  • As the development of industry water quality of river is going to bad because of waste water of an industrial complex and general home agricultural chemicals exhaust of $SO_3$ and CO gas acid rain and so on. Corrosion damage of boiler factory equipment and so forth occur quickly due to using of the polluted water resulting in increasing leak accident. Especially working life of hot water boiler using the polluted water becomes more short and energy loss increases. The cathodic protection method is the most economical and reliable one to prevent corrosion damage of steel structures. Mg-base alloys galvanic anode protection of cathodic protection method is suitable for than application of hot water boiler using water with high specific resistance such as tap water. This paper is studied on the cathodic protection characteristics of how water boiler. In tap water and 0.001mol/$\ell$ NaCl solution the characteristics of anodic polarization of Mg-base alloys galvanic anode and tube material is investigated the measurement of cathodic protection potential according to the time elaspsed is carried out.

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Hydrogen Evolution Ability of Selected Pure Metals and Galvanic Corrosion Behavior between the Metals and Magnesium

  • Luo, Zhen;Song, Kaili;Li, Guijuan;Yang, Lei
    • Journal of Electrochemical Science and Technology
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    • 제11권4호
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    • pp.323-329
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    • 2020
  • The cathodic hydrogen evolution ability of different pure metals and their long term galvanic corrosion behavior with pure Mg were investigated. The hydrogen evolution ability of pure Ti, Al, Sn and Zr is weak, while that of Fe, W, Cr, and Co is very strong. Initial polarization test could not completely reveal the cathodic behavior of the tested metals during long term corrosion. The cathodic hydrogen evolution ability may vary significantly in the long term galvanic tests for different metals, especially for Al whose cathodic current density reduced to 1/50 of the initial value. The anodic polarization shows that Al and Sn as alloying elements are supposed to provide relatively good passive effect for Mg alloy, while Ag can provide a slight passive effect and Zn has little passive effect.

A Galvanic Sensor for Monitoring the External and Internal Corrosion Damage of Buried Pipelines

  • Choi, Yoon-Seok;Kim, Jung-Gu;Hwang, Woon-Suk
    • Corrosion Science and Technology
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    • 제4권5호
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    • pp.178-190
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    • 2005
  • In order to develop a new corrosion sensor for detecting and monitoring the external and internal corrosion damage of buried pipeline, the electrochemical property of sensors and the correlation of its output to corrosion rate of steel pipe, were evaluated by electrochemical methods in two soils of varying resistivity (5,000 ohm-cm, 10,000 ohm-cm) and synthetic tap water environments. In this paper, two types of galvanic probes were manufactured: copper-pipeline steel (Cu-CS) and stainless steel-pipeline steel (SS-CS). The corrosion behavior in synthetic groundwater and synthetic tap water for the different electrodes was investigated by potentiodynamic test. The comparison of the sensor output and corrosion rates revealed that a linear relationship was found between the probe current and the corrosion rates. In the soil resistivity of $5,000{\Omega}-cm$ and tap water environments, only the Cu-CS probe had a good linear quantitative relationship between the sensor output current and the corrosion rate of pipeline steel. In the case of $10,000{\Omega}-cm$, although the SS-CS probe showed a better linear correlation than that of Cu-CS probe, the Cu-CS probe is more suitable than SS-CS probe due to the high current output.

족삼리(足三里) 침자(鍼刺)가 인체(人體)의 Skin temperature, Galvanic skin response 및 Heart rate에 미치는 영향(影響) (Effect of Acupuncture ST36 on Skin Temperature, Galvanic Skin Response and Heart Rate in Humans)

  • 윤대환;나창수
    • Korean Journal of Acupuncture
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    • 제20권3호
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    • pp.29-34
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    • 2003
  • Objectives : The purpose of this study was to investigate the Effect of Acupuncture Chok-samni(ST36) on Skin temperature(ST), Galvanic skin response(GSR) and Heart rate(HR) in humans. ST36 is used in uneasiness, high fever, stroke, paralysis on oriental medicine. Methods : Subjects were 18 healthy oriental medical students volunteers(15male, 3female, mean age-28). Under sequence of ST36 acupuncture, the first group was observed ST, the second group was observed GSR and the third group was observed HR. Skin temperature was measured on Haegye acupoint(ST41) before and after acupuncture stimulation. Each test took 15minutes. This test was performed twice in order to increase the statistical authenticity. Results : Our result indicates that acupuncture stimulation of ST36 statistically decreased skin temperature on ST41. Also statistically decreased in HR. The change of GSR after ST36 acupuncture was decreased, but there is no statistical. Conclusions : These results suggested that acupuncture stimulation of ST 36 has effect on ST and HR in human body, and may be used by treatment as control the nerve system.

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PCB 구리 에칭 용액의 에칭 특성에 대한 전기화학적 고찰 (Electrochemical Evaluation of Etching Characteristics of Copper Etchant in PCB Etching)

  • 이서향;이재호
    • 마이크로전자및패키징학회지
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    • 제29권4호
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    • pp.77-82
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    • 2022
  • PCB 기판의 구리 식각 시 전기도금된 배선과 기지층의 전도층은 다른 에칭 특성을 가지며 이로 인한 배선의 과에칭과 배선기저부의 언터컷 현상이 보고되고 있다. 본 연구에서는 구리 에칭의 조성 변화에 따른 구리 에칭 특성에 대하여 연구하였다. 분극법과 OCV (open circuit voltage)를 이용하여 에칭액의 전기도금 구리와 기지층 구리의 최적 과산화수소와 황산의 농도를 얻었다. OCV와 ZRA (zero resistance ammeter)분석법을 이용하여 억제재의 효과를 비교하였다. 구리배선과 기지층간의 갈바닉 전류를 ZRA 방법을 이용하여 측정 비교하였다. 갈바닉 전류를 최소화하는 억제재를 ZRA를 이용한 갈바닉 쌍으로부터 선택할 수 있었다.