• Title/Summary/Keyword: Residual Current

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Method of Reducing Residual Vibration at the LCD Transfer Robot (디스플레이 반송로봇 잔류진동 저감방안)

  • Moon, Sung Bae;Rim, Kyung-Hwa
    • Journal of the Semiconductor & Display Technology
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    • v.16 no.2
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    • pp.98-105
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    • 2017
  • In the display industry, the residual vibration of the transfer robot can increase the process time and cause the breakage of the glass substrate, which is critical to productivity of display manufacturing. In this paper, the natural frequencies of transfer robot are analyzed by finite element method. On the basis of the analyzed data, we investigated the response characteristics of input shaping control with or without the glass presence on the hand of the transfer robot using MATLAB program, and compared with the current response characteristics of input shaping control applied to the industry. Based on this, we suggest an optimal residual vibration control method for the practical application in display industry.

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Current structures and Diffusion characteristics in Youngil Bay (영일만의 해수유동 구조 및 확산특성)

  • 이종섭;김차겸
    • 한국해양학회지
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    • v.30 no.5
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    • pp.467-479
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    • 1995
  • To investigate the current structures and diffusion characteristics in Youngil Bay, a systematic field observations of current velocity, drogue tracking, dye diffusion experiment and aerial photographing were performed. The flow patterns in the surface layer of the bay depend more strongly on the wind and ocean current than the tidal current, and the patterns in the middle are predominated by the ocean current. The residual currents in the surface generally flow toward the inner bay through the western and central areas of the bay, and then the currents go toward the ocean along the eastern shore of the bay with anti-clock-wise circulation. The residual currents in the surface of the eastern cease are not nearly influenced by the wind, and the currents always move northward to northeastward. However, the currents in the western shore depend strongly on the wind and the outflow of the Huntsman River, that is, the residual currents go northward to northeastward when the southerly to westerly winds blow or a large amount of flow from the river discharge. The residual currents in the middle layer flow toward the inner bay along the western shore of the bay, and the incomed currents go out to the ocean along the eastern shore with anticlockwise circulation. The diffusion of dye patch by the instantaneous point source shows a similar pattern to the drogue trajectory, and the apparent diffusion coefficients of the dye patch by Fick's theory is 1.14${\times}$10$^4$ cm$^2$/s. The behavior of the river discharges in flood shows a band type's effluent pattern toward the outer bay along the western coast.

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Effect of Deposition Conditions on Properties of Cu Thin Films Electrodeposited from Pyrophosphate Baths (피로인산구리용액으로부터 전기도금 된 Cu 필름의 특성에 미치는 도금조건의 영향)

  • Shin, Dong-Yul;Sim, Chulyong;Koo, Bon-Keup;Park, Deok-Yong
    • Journal of the Korean Electrochemical Society
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    • v.16 no.1
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    • pp.19-29
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    • 2013
  • Effects of current density, electrodeposition temperature and solution pH on properties of Cu thin films electrodeposited from pyrophosphate bath were investigated. Current efficiency was decreased with increasing current density and increased with increasing temperature. But solution pH slightly influenced on current efficiency and current efficiency was measured to be above 90% at both room temperature and $55^{\circ}C$. Residual stress of Cu thin film electrodeposited at room temperature was decreased with increasing current density, while current density reaches to 60 $mA/cm^2$ or more, stress became close to zero. Cu thin films electrodeposited at $55^{\circ}C$ exhibited the residual stress range of 0~40 MPa. At room temperature, dendritic surface morphology was observed above the current density of 30 $mA/cm^2$ and at $55^{\circ}C$, above the current density of 100 $mA/cm^2$. Cu thin films electrodeposited from bath solution with room temperature and $55^{\circ}C$ mainly consisted of (111) peaks. Specially, Cu thin film electrodeposited at 30 $mA/cm^2$ and $55^{\circ}C$ exhibited strong preferred orientation of (111) peaks.

Numerical experiments for the changes of currents by reclamation of land in Kwangyang Bay (매립으로 인한 광양만의 유동변화 수치실험)

  • 추효상
    • Journal of Environmental Science International
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    • v.11 no.7
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    • pp.637-650
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    • 2002
  • This study presents an investigation of the changes of the currents in Kwangyang Bay due to the construction of harbor, reclamation and coastal developments. Currents were simulated by the numerical experiments with a diagnostic multi-level model and using the seasonal oceanographic data of temperature, salinity and ocean current. The values of kinetic and potential energies for the currents were calculated in cases of three topographical changes; before coastal developments, the existing state and after completion of the development project in Kwangyang Bay. The changes of currents due to the coastal developments are as follow; Kinetic energies of tide induced residual currents and wind driven currents decreased by 35~40 percent and 5 percent respectively, however those of density currents increased by 10 percent since the decrease of the coastal areas. Kinetic energy of residual currents including tide induced residual currents, density currents and wind driven currents reduced by 10 percent compared with before the coastal developments. Decrease of current velocity was greatest in summer. Therefore, in summer it was assumed that the Kwangyang Bay is more easily polluted by stratification and decrease of residual current than before the coastal developments carried out.

Insufficient radiofrequency ablation-induced autophagy contributes to the rapid progression of residual hepatocellular carcinoma through the HIF-1α/BNIP3 signaling pathway

  • Xu, Wen-Lei;Wang, Shao-Hong;Sun, Wen-Bing;Gao, Jun;Ding, Xue-Mei;Kong, Jian;Xu, Li;Ke, Shan
    • BMB Reports
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    • v.52 no.4
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    • pp.277-282
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    • 2019
  • Currently speaking, it is noted that radiofrequency ablation (RFA) has been the most widely used treatment for hepatocellular carcinoma (HCC) occurring in patients. However, accumulating evidence has demonstrated that the incidence of insufficient RFA (IRFA) may result in the identified rapid progression of residual HCC in the patient, which can greatly hinder the effectiveness and patient reported benefits of utilizing this technique. Although many efforts have been proposed, the underlying mechanisms triggering the rapid progression of residual HCC after IRFA have not yet been fully clarified through current research literature reviews. It was shown in this study that cell proliferation, migration and invasion of residual HepG2 and SMMC7721 cells were significantly increased after the IRFA was simulated in vitro. In other words, it is noted that IRFA could do this by enhancing the image of autophagy of the residual HCC cell via the $HIF-1{\alpha}/BNIP3$ pathway. Consequently, the down-regulation of BNIP3 may result in the inhibition of the residual HCC cell progression and autophagy after IRFA. Our present study results suggest that IRFA could promote residual HCC cell progression in vitro by enhancing autophagy via the $HIF-1{\alpha}/BNIP3$ pathway. For this reason, it is noted that the targeting of the BNIP3 may be useful in preventing the rapid growth and metastasis of residual HCC after IRFA.

Residual capacity assessment of post-damaged RC columns exposed to high strain rate loading

  • Abedini, Masoud;Zhang, Chunwei
    • Steel and Composite Structures
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    • v.45 no.3
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    • pp.389-408
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    • 2022
  • Residual capacity is defined as the load carrying capacity of an RC column after undergoing severe damage. Evaluation of residual capacity of RC columns is necessary to avoid damage initiation in RC structures. The central aspect of the current research is to propose an empirical formula to estimate the residual capacity of RC columns after undergoing severe damage. This formula facilitates decision making of whether a replacement or a repair of the damaged column is adequate for further use. Available literature mainly focused on the simulation of explosion loads by using simplified pressure time histories to develop residual capacity of RC columns and rarely simulated the actual explosive. Therefore, there is a gap in the literature concerning general relation between blast damage of columns with different explosive loading conditions for a reliable and quick evaluation of column behavior subjected to blast loading. In this paper, the Arbitrary Lagrangian Eulerian (ALE) technique is implemented to simulate high fidelity blast pressure propagations. LS-DYNA software is utilized to solve the finite element (FE) model. The FE model is validated against the practical blast tests, and outcomes are in good agreement with test results. Multivariate linear regression (MLR) method is utilized to derive an analytical formula. The analytical formula predicts the residual capacity of RC columns as functions of structural element parameters. Based on intensive numerical simulation data, it is found that column depth, longitudinal reinforcement ratio, concrete strength and column width have significant effects on the residual axial load carrying capacity of reinforced concrete column under blast loads. Increasing column depth and longitudinal reinforcement ratio that provides better confinement to concrete are very effective in the residual capacity of RC column subjected to blast loads. Data obtained with this study can broaden the knowledge of structural response to blast and improve FE models to simulate the blast performance of concrete structures.

A Study on Cabbage Salting Brine Reuse Technology Combining an Electrochemical Method and Activated Carbon Adsorption (전기화학적 방법과 활성탄 흡착 연계 공정을 이용한 절임염수 재이용 기술 연구)

  • Lee, Eun-Sil;Kim, Daegi
    • Journal of the Korean Society for Environmental Technology
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    • v.19 no.6
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    • pp.536-542
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    • 2018
  • A system combining an electrochemical method and an adsorption system using activated carbon was assessed to facilitate the reuse of cabbage-salting brine. IrOx/Ti insoluble catalyst electrodes were used in the experiment. The results were analyzed to identify any changes in the residual chlorine concentration according to variations in the current density at a salinity of 10 %, as well as the capacity of the activated carbon to adsorb the residual chlorine and organic matter. For current densities of $500A/m^2$ and $1,000A/m^2$, the residual chlorine concentration did not increase, instead stabilizing once the current reached 0.33 Ah/L. To assess the adsorption efficiency according to the residual chlorine concentration, the unit amount of the adsorption can be estimated from $Y=0.0066+2.087{\times}10^{-4}b$. For both residual chlorine generation using an electrochemical method and chlorine removal through activated-carbon adsorption, the unit amount of adsorption was 0.33 g/g. The maximum amount of $COD_{Cr}$ organic matter adsorbed by the activated carbon was 0.021 g/g, while for $COD_{Mn}$, the value was 0.004 g/g.

Effects of Storage Condition on Degradation of Automotive Polymer Electrolyte Membrane Fuel Cells (보관상태가 자동차용 고분자전해질 연료전지의 성능 감소에 미치는 영향)

  • Cho, Eun-Ae
    • Journal of the Korean Electrochemical Society
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    • v.13 no.4
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    • pp.277-282
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    • 2010
  • Durability of automotive polymer electrolyte membrane fuel cell (PEMFC) strongly depends the startup/shutdown procedure. Formation of hydrogen/air boundary in the anode gas channel, so-called reverse current condition, particularly induces fast degradation of the cathode. Under the reverse current condition, high voltage is present at the cathode facing air in the anode gas channel and is a function of residual oxygen concentration in the gas channels, that increases with storage time and reaches 21% (air) eventually. In this study, effects of residual oxygen concentration in a PEMFC on degradation of the PEMFC.

Development of Improved 5th Order Motion Profile for Low Vibration and High Speed (저진동, 고속특성을 가지는 개선된 5차 모션 프로파일의 설계)

  • So, Byeong-Kwan;Tae, Won-Hyeong;Kim, Jung-Han
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.10
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    • pp.1110-1118
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    • 2012
  • In this study, for reducing the residual vibration in high speed motion control stage, an improved 5th order polynomial motion profile was developed. When a stage is moving, the current through the motor coils has the same profile of input motion profile of acceleration, therefore the characteristics of the acceleration input profile directly affect on the performance of the amplifier that includes the current control loop. Commonly low cost amplifier and motor has a narrow current control bandwidth, therefore the proposed algorithm was designed based on this practical constraint. Simulation and experimental results showed that the proposed algorithm clearly has low residual vibration characteristics than conventional 5th order polynomial motion profile on the same drive condition.