• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2017년도 추계학술논문요약집
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• pp.73-73
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• 2017

Pyroprocessing at KAERI (Korea Atomic Energy Research Institute) consists of pretreatment, electroreduction, electrorefining and electrowinning. SFR (Sodium Fast Reactor) fuel is prepared from the electrowinning process which is composed of LCC (Liquid Cadmium Process) and Cd distillation et al. LCC is an electrochemical process to obtain actinides from spent fuel. In order to recover actinides inert anodes such as carbon material are used, where chlorine gas ($Cl_2$) evolves on the surface of the carbon material. And, stainless steel (SUS) crucible should be installed in large-scale electrowinning system. Therefore, the effect of chlorine on the SUS material needs to be studied. LiCl-KCl-$UCl_3$-$NdCl_3$-$CeCl_3$-$LaCl_3$-$YCl_3$ salt was contained in 2 kinds of electrolytic crucible having an inner diameter of 5cm, made of an insulated alumina and an SUS, respectively. And, three kinds of electrodes such as cathode, anode, reference were used for the electrochemical experiments. Both solid tungsten (W) and LCC were used as cathodes. Cd of 45 g as the cathode material was contained in alumina crucibles for the deposition experiments, where the crucible has an inner diameter of 3 cm. Glassy carbon rod with the diameter of 0.3 cm was employed as an anode, where shroud was not used for the anode. A pyrex tube containing LiCl-KCl-1mol% AgCl and silver (Ag) wire having a diameter of 0.1cm was used as a reference electrode. Electrodeposition experiments were conducted at $500^{\circ}C$ at the current densities of $50{\sim}100mA/cm^2$. In conclusion, Fe ions were produced in the salt during the electrodeposition by the reaction of chlorine evolved from the anode and Fe of the SUS crucible and thereby LCC system using SUS crucible showed very low current efficiencies compared with the system using the insulated alumina crucible. Anode shroud needs to be installed around the glassy carbon not to influence surrounding SUS material.

• Physical Therapy Rehabilitation Science
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• 제11권1호
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• pp.8-15
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• 2022

Objective: Post stroke motor recovery is facilitated by the brain reorganization or the neuroplastic changes. The therapeutic approach mentioned in the current case is one of the approaches for enhancing motor recovery by stimulating the damaged neural networks directing the motor behaviour of a person. The aim of the present study was to establish the changes in the balance and gait pattern of an individual through multi target stimulation of areas of cerebral cortex by utilising multichannel trans cranial direct current stimulation (M-tDCS) in a sub-acute stroke survivor. Design: A Case Report Methods: The present patient was the participant of the trial (CTRI/2021/02/031044).The patient was intervened with M-tDCS (anodes over left primary motor cortex that is C3 point and left dorsolateral prefrontal cortex i.e., F3 point and cathodes over supraorbital areas, Intensity - 1.2mA) for the duration of 20 minutes along with turbo med extern - an AFO to facilitate ankle dorsi flexion and conventional physiotherapy rehabilitation. The Fugl-Meyer assessment lower extremity (FMA-LE), Berg Balance Scale (BBS), Wisconsin Gait Scale (WGS) and the Stroke Specific Quality of Life (SSQOL) measures were used for outcome assessment. Baseline assessment was done on day 0 followed by assessment on 10 and 20 post intervention. Results: Improvement was seen in all the tools i.e. (FMA -LE), BBS, SSQOL and WGS over the time period of 20 days. Conclusions: M-tDCS resulted in improvement in gait parameters, balance and motor functions of lower extremity of the patient.

• Journal of Electrochemical Science and Technology
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• 제12권2호
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• pp.246-256
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• 2021

Mo,Cu-doped CeO₂ (CMCuO) nanopowders were synthesized by the nitrate-fuel combustion method aiming to improve the electrical and electrochemical properties of its Mo-doped CeO₂ (CMO) parent by the addition of copper. An electrical conductivity of ca. 1.22·10^-2 S cm^-1 was measured in air at 800℃ for CMCuO, which is nearly 10 times higher than that reported for CMO. This increase was associated with the inclusion of copper into the crystal lattice of ceria and the presence of Cu and Cu₂O as secondary phases in the CMCuO structure, which also could explain the increase in the charge transfer activities of the CMCuO based anode for the hydrogen and carbon monoxide electro-oxidation processes compared to the CMO based anode. A maximum power density of ca. 120 mW cm^-2 was measured using a CMCuO based anode in a solid oxide fuel cell (SOFC) with YSZ electrolyte and LSM-YSZ cathode operating at 800℃ with humidified syngas as fuel, which is comparable to the power output reported for other SOFCs with anodes containing copper. An increase in the area specific resistance of the SOFC was observed after ca. 10 hours of operation under cycling open circuit voltage and polarization conditions, which was attributed to the anode delamination caused by the reduction of the Cu₂O secondary phase contained in its microstructure. Therefore, the addition of a more electroactive phase for hydrogen oxidation is suggested to confer long-term stability to the CMCuO based anode.

• 한국건설순환자원학회논문집
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• 제10권1호
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• pp.66-73
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• 2022

동절기 콘크리트 포장체의 블랙아이스 발생위험을 낮추고 동결에 의한손상을 방지할 목적으로 콘크리트의 전도저항성을 활용하여 자기 히팅 콘크리트를 개발하고자 하였다. 이를 위하여 분말형과 액상형 폐CNT와 전도촉진을 위해 폐음극재를 사용하여 강도변화와 온도 발열특성을 평가하고자 하였다. 액상형 폐CNT가 모르타르내에서 분산정도가 효과적이고, 강도저하가 작게 발생하는 것으로 분석되었다. 또한 모르타르에 스틸매쉬, 구리포일과 구리선을 전극으로 적용하여 DC 24 V를 공급하였으며, 폐CNT, 폐음극재과 탄소섬유 혼입율에 따른 온도변화 특성을 평가하였다. 또한 선정된 최적배합으로부터 전극간격에 따른 온도 특성을 평가하여 AC 50 V 까지는 전극간격 100 mm 까지는 충분한 발열 특성을 갖는 것을 확인하였다.

• Advances in nano research
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• 제13권6호
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• pp.513-525
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• 2022

In this study, it was aimed to evaluate direct oxidation of aqueous solution containing cefalexin antibiotic with new generation Sn/Sb/Ni: 500/8/1 anode. The fact that there is no such a study on treatment of cefalexin with these new anode made this study unique. According to the operating parameters evaluation COD graphs showed clearer results compared to TOC and CLX and thus, it was it was chosen as major parameter. Furthermore, pseudo-first degree kd values were calculated from CLX results to show more accurate and specific results. Experimental results showed that after 60 min of electrochemical oxidation, complete removal of COD and TOC was accomplished with 750 mg L^-1 KCl, at pH 7, 50 mA cm^-2 current density and 1 cm anode-cathode distance. Also, the stability of the Sn/Sb/Ni anode was evaluated by taking SEM and AFM images and XRD analysis before and after of electrochemical oxidation processes. According to the results, it was not occurred too much change on the anode surface even after 300 h of electrolysis. Thus, it was thought that the anode material was not corroded to a large extent. Furthermore, the removal efficiencies were very high for almost all the time and conditions. According to the results of the study, electrochemical oxidation with new generation Sn/Sb/Ni anodes for the removal of cefalexin antibiotic was found very successful and applicable due to require less reaction time complete mineralization and doesn't require pH adjustment step compared to other studies in literature. In future studies, different antibiotic types should be studied with this anode and maybe with real wastewaters to test applicability of the process in treatment of pharmaceutical wastewaters containing antibiotics, in a better way.

• 한국전기전자재료학회논문지
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• 제36권1호
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• pp.10-15
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• 2023

The carbonaceous materials have attracted much attention for utilization of anode materials for lithium-ion batteries. Among them, hollow carbon spheres have great advantages (high specific capacity and good rate capability) to replace currently used graphite anode materials, due to their unique features such as high surface areas, high electrical conductivities, and outstanding chemical and thermal stability. Herein, we have synthesized various sizes of hollow carbon spheres by a facile hardtemplate method and investigated the anode properties for lithium-ion batteries. The obtained hollow carbon spheres have uniform diameters of 350 ~ 600 nm by varying the template condition, and they do not have any cracks after the optimization of the process. Increasing the diameter of hollow carbon spheres decreases their specific capacities, since the larger hollow carbon spheres have more useless spaces inside that could have a disadvantage for lithium storage. The hollow carbon spheres have outstanding rate and cyclic performance, which is originated from the high surface area and high electrical properties of the hollow carbon spheres. Therefore, hollow carbon spheres with smaller diameters are expected to have higher specific capacities, and the noble channel structures through various doping approaches can give the great possibility of high lithium storage properties.

• Nuclear Engineering and Technology
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• 제54권12호
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• pp.4441-4448
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• 2022

The electrochemical oxidation process has been widely studied in the field of wastewater treatment for the decomposition of organic materials through oxidation using ·OH generated on the anode. Pt anode electrodes with high durability and long-term operability have a low oxygen evolution potential, making them unsuitable for electrochemical oxidation processes. Therefore, to apply Pt electrodes that are suitable for long-term operation and large-scale processes, it is necessary to develop a new method for improving the decomposition rate of organic materials. This study introduces a method to improve the decomposition rate of organic materials when using a Pt anode electrode in the electrochemical oxidation process for the treatment of organic decontamination liquid waste. Electrochemical decomposition tests were performed using sodium dodecylbenzenesulfonate (SDBS) as a representative organic material and a Pt mesh as the anode electrode. Y₂O₃ particles were introduced into the electrolytic cell to improve the decomposition rate. The decomposition rate significantly improved from 21% to 99%, and the current efficiency also improved. These results can be applied to the electrochemical oxidation process without additional system modification to enhance the decomposition rate and current efficiency.

• Journal of Electrochemical Science and Technology
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• 제14권2호
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• pp.162-173
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• 2023

Aqueous zinc-ion batteries are considered as promising alternatives to lithium-ion batteries for energy storage owing to their safety and cost efficiency. However, their lifespan is limited by the irreversibility of Zn anodes because of Zn dendrite growth and side reactions such as the hydrogen evolution reaction and corrosion during cycling. Herein, we present a strategy to restrict direct contact between the Zn anode and aqueous electrolyte by fabricating a protective layer on the surface of Zn foil via phosphidation method. The Zn₃(PO₄)₂ protective layer effectively suppresses Zn dendrite growth and side reactions in aqueous electrolytes. The electrochemical properties of the Zn₃(PO₄)₂@Zn anode, such as the overpotential, linear polarization resistance, and hydrogen generation reaction, indicate that the protective layer can suppress interfacial corrosion and improve the electrochemical stability compared to that of bare Zn by preventing direct contact between the electrolyte and the active sites of Zn. Remarkably, MnO₂ Zn₃(PO₄)₂@Zn exhibited enhanced reversibility owing to the formation a stable porous layer, which effectively inhibited vertical dendrite growth by inducing the uniform plating of Zn²⁺ ions underneath the formed layer.

• Korean Chemical Engineering Research
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• 제59권4호
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• pp.557-564
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• 2021

페로브스카이트 구조를 갖는 Sr_0.92Y_0.08Ti_1-xV_xO_3-δ (SYTV)는 고체산화물 연료 전지(Solid oxide fuel cell, SOFC)에서 H₂S를 포함하는 연료를 사용하기 위한 대체 연료극으로 연구되었다. Sr_0.92Y_0.08TiO_3-δ (SYT)의 전기화학적 성능을 향상시키기 위해 페로브스카이트의 B-사이트에 위치한 티타늄을 바나듐으로 치환하였다. 페치니법을 통해 합성된 SYTV는 작동 온도 조건에서 추가적인 부산물의 형성 없이 YSZ(yttria-stabilized zirconia) 전해질과 화학적으로 안정했다. 바나듐의 치환량이 증가함에 따라 산소 공공 결함(Oxygen vacancy)이 증가하였으며, 생성된 산소 공공 결함으로 인해 연료극의 이온 전도도가 증가했다. 전지 성능은 850 ℃ 순수한 H₂ 연료 조건에서 바나듐 치환 정도에 따라 1 mol.%의 바나듐이 치환된 경우 19.30 mW/cm² 이고 7 mol.%의 바나듐이 치환된 경우 34.87 mW/cm²이다. 1000 ppm의 H₂S를 포함하는 H₂ 연료조건에서 cell의 최대 전력밀도는 1 mol.%의 경우 22.34 mW/cm²이고 7 mol.%의 경우 73.11 mW/cm²로 증가하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.134-134
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• 2010

Fuel cell is a device that directly converts chemical energy in the form of a fuel into electrical energy by way of an electrochemical reaction. In the anode for a high temperature fuel cell, nickel or nickel alloy has been used in consideration of the cost, oxidation catalystic ability of hydrogen which is used as fuel, electron conductivity, and high temperature stability in reducing atmosphere. Most MCFC stacks currently operate at an average temperature of $650^{\circ}C$. There is some gains with decreased temperature in MCFC to diminish the electrolyte loss from evaporation and the material corrosion, which could improve the MCFC life. However, operating temperature has a strong related on a number of electrode reaction rates and ohmic losses. Baker et al. reported the effect of temperature (575 to $650^{\circ}C$). The rates of cell voltage loss were 1.4mV/$^{\circ}C$ for a reduction in temperature from 650 to $600^{\circ}C$, and 2.16mV/$^{\circ}C$ for a decrease from 600 to $575^{\circ}C$. The two major contributors responsible for the change in cell voltage with reducing operation temperature are the ohmic polarization and electrode polarization. It appears that in the temperature range of 550 to $650^{\circ}C$, about 1/3 of the total change in cell voltage with decreasing temperature is due to an increase in ohmic polarization, and the electrode polarization at the anode and cathode. In addition, the oxidation reaction of hydrogen on an ordinary nickel alloy anode in MCFC is generally considered to take place in the three phase zone, but anyway the area contributing to this reaction is limited. Therefore, in order to maintain a high performance of the fuel cell, it is necessary to keep this reaction responsible area as wide as possible, that is, it is needed to keep the porosity and specific surface area of the anode at a high level. In this study effective anodes are prepared for low temperature MCFC capable of enhancing the cell performance by using zirconium hydride at least in part of anode material.