• Title/Summary/Keyword: Liquid-solid

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A Review of Surface Energy of Solid Electrodes with Emphasis on Its Controversial Issues in Interfacial Electrochemistry

  • Go Joo-Young;Pyun Su-Il
    • Journal of the Korean Electrochemical Society
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    • v.7 no.4
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    • pp.211-219
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    • 2004
  • A classical Lippmann equation valid for liquid electrodes can not describe the interfacial properties of solid electrodes due to the elastic surface strain on solid electrodes. Although there have been many attempts to derive the thermodynamic equations for solid electrodes Outing the past few decades, their validity has been still questioned by many researchers. In practice, although there are various experimental techniques to measure surface energy of solid electrodes, the results obtained by each technique are rather inconsistent due to the complexity of the surface strain on solid electrodes. This article covers these controversial issues in surface energy of solid electrodes. After giving brief summaries of the definition of the important thermodynamic parameters and the derivation of the thermodynamic equations for solid electrodes, the several experimental methods were introduced for the measurement of surface energy of solid electrodes. And then we discussed in detail the inconsistent results in the measurement of the potential of zero charge (pac) and the potential of electrocapillary maximum (ecm).

Mixing Effect by the Geometry of Static Mixer with Turbulent In-Situ Mixing Process (난류 용탕 In-Situ 합성법을 위한 스태틱 믹서의 형상에 따른 혼합 효과)

  • Lee, Dae-Sung;Kim, Hyo-Geun;Ha, Man-Yeong;Park, Yong-Ho;Park, Ik-Min
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.29 no.12 s.243
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    • pp.1307-1312
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    • 2005
  • Turbulent in-situ mixing process is a new material process technology to get dispersed phase in nanometer size by controlling reaction of liquid/liquid, liquid/solid and liquid/gas, flow and solidification speed simultaneously. In this study mixing, the key technology to this synthesis method will be studied by computational fluid dynamics. For the simulation of mixing of liquid metal, static mixers will be investigated. Two inlets for different liquid metal meet and merge like 'Y' shape tube. The tube has various shapes such as straight and curved. Also, the radius of curve will be varied. The performance of mixer will be evaluated with quantitative analysis with coefficient of variance of mass fraction. Also, detailed plots of intersection will be presented to understand effect of mixer shape on mixing.

Role of Liquid Biopsies in Colorectal Cancer (대장암에서 액체 생검의 역할)

  • Kim, Sang Hyun;Keum, Bora
    • Journal of Digestive Cancer Research
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    • v.8 no.1
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    • pp.56-60
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    • 2020
  • In recent years, liquid biopsy has received immense attention. Liquid biopsy is a minimally invasive method used for obtaining biological fluids including urine, pleural fluid and, mostly, peripheral blood. Liquid biopsy involves various targets including circulating tumors cells (CTCs), circulating cell-free tumor DNA (ctDNA), and microRNA (miRNA). Colorectal cancer (CRC), like other solid tumors, shed tumor cells into the bloodstream. Analysis of these CTCs, as well as ctDNA is the primary objective of the liquid biopsy. Evaluation of CTC or ctDNA offers information about early tumor release, development of tumor metastasis and also about mechanisms involved in tumor resistance to treatment.

Visualization and Analysis of the Dynamic Behavior of Splashes and Residuals of Droplets Continuously Colliding with a Vertical Wall (수직벽으로 연속 충돌하는 액적들의 비산/잔류 동적 거동 가시화 및 분석 연구)

  • Jaehyeon Noh;Hoonseok Lee;Taeyeong Park;Seungho Kim
    • Journal of the Korean Society of Visualization
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    • v.22 no.2
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    • pp.82-89
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    • 2024
  • In this study, experiments were conducted to visualize and analyze the dynamic characteristics of splash and residual liquid film formation during and after the injection of water droplets onto vertically situated solid substrates with varying surface wettability, elasticity, and microtexture. As wettability decreased (higher contact angle), more splash droplets formed, and the residual liquid film decreased. Low contact angles resulted in thin residual films and less splash. Surface elasticity absorbed the impact forces of droplets, thereby decreasing splash phenomena and significantly reducing the formation of residual liquid films due to surface vibration. Surfaces with microtextures demonstrated control over droplet splash direction, guiding the liquid along desired pathways. High-speed imaging provided detailed insights, showing that surface properties critically influence splash dynamics and residual liquid film formation.

Detailed Representation of Liquid-Solid Mixed Surfaces with Adaptive Framework Based Hybrid SDF and Surface Reconstruction (적응형 프레임워크 기반의 하이브리드 부호거리장과 표면복원을 이용한 액체와 고체 혼합 표면의 세밀한 표현)

  • Kim, Jong-Hyun
    • Journal of the Korea Computer Graphics Society
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    • v.23 no.4
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    • pp.11-19
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    • 2017
  • We propose a new pipeline of fluid surface reconstruction that incorporates hybrid SDF(signed distance fields) and adaptive fluid surface techniques to finely reconstruct liquid-solid mixed surfaces. Previous particle-based fluid simulation suffer from a noisy surface problem when the particles are distributed irregularly. If a smoothing scheme is applied to reduce the problem, sharp and detailed features can be lost by over-smoothing artifacts. Our method constructs a hybrid SDF by combining signed distance values from the solid and liquid parts of the object. We also proposed a method of adaptively reconstructing the surface of the fluid to further improve the overall efficiency. This not only shows the detailed surface of the solid and liquid parts, but also the detail of the solid surface and the smooth fluid surface when both materials are mixed. We introduce the concept of guiding shape and propose a method to get signed distance value quickly. In addition, the hybrid SDF and mesh reconstruction techniques are integrated in the adaptive framework. As a result, our method improves the overall efficiency of the pipeline to restore fluid surfaces.

Performances of Anaerobic Sequencing Batch Reactor for Digestion of Municipal Sludge at the Conditions of Critical Solid-liquid Separation (혐기성 연속 회분식 공정에 의한 도시하수슬러지 소화시 고액분리 특성에 따른 처리효율평가)

  • Hur, Joon-Moo;Park, Jong-An
    • Journal of Environmental Health Sciences
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    • v.28 no.5
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    • pp.77-85
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    • 2002
  • The objective of this study was to evaluate the performances of the ASBR under critical conditions of solid-liquid separation, caused by extremely high solids concentration, for wider application of the ASBR to various wastes. The ASBRs and completely-mixed daily-fed control runs were operated using a municipal mixed sludge at 35$^{\circ}C$ and 55$^{\circ}C$. Conversion of completely-mixed daily-fed reactor to sequencing batch mode and changes in HRT of all ASBRs were easily achieved without adverse effect, regardless of digestion temperature. Solids accumulation was remarkable in the ASBRs, and directly affected by settleable solids concentration of the feed sludge. Noticeable difference in solids-liquid separation was that flotation thickening occurred in the mesophilic ASBRs, while gravity thickening was a predominant solid-liquid separation process in the thermophilic ASBRS. Solids profiles at the end of thickening step dramatically changed at solid-liquid interface, and slight difference in solids concentrations was observed within thickened sludge bed. Organics removals based on subnatant or supernatant after thickening always exceeded 80% in all reactors. Thickened sludge volume and gas production of the ASBRs affected mutually. Gas production increased as thickened sludge accumulated, and continuous gas evolution during thickening could cause thickened sludge to expand or resuspend. Thickened sludge volume exceeding a predetermined withdrawal level resulted in loss of organic solids as well as biomass during withdrawal step, leading to decrease in gas production ind SRT. Such an adverse mutual effect was significant in gravity thickening, while it was not sensitive in flotation thickening. Changes in organic loading had no significant effect on organic removals and gas production after build-up of solids in the ASBRs.

Numerical study on conjugate heat transfer in a liquid-metal-cooled pipe based on a four-equation turbulent heat transfer model

  • Xian-Wen Li;Xing-Kang Su;Long Gu;Xiang-Yang Wang;Da-Jun Fan
    • Nuclear Engineering and Technology
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    • v.55 no.5
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    • pp.1802-1813
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    • 2023
  • Conjugate heat transfer between liquid metal and solid is a common phenomenon in a liquid-metal-cooled fast reactor's fuel assembly and heat exchanger, dramatically affecting the reactor's safety and economy. Therefore, comprehensively studying the sophisticated conjugate heat transfer in a liquid-metal-cooled fast reactor is profound. However, it has been evidenced that the traditional Simple Gradient Diffusion Hypothesis (SGDH), assuming a constant turbulent Prandtl number (Prt,, usually 0.85 - 1.0), is inappropriate in the Computational Fluid Dynamics (CFD) simulations of liquid metal. In recent decades, numerous studies have been performed on the four-equation model, which is expected to improve the precision of liquid metal's CFD simulations but has not been introduced into the conjugate heat transfer calculation between liquid metal and solid. Consequently, a four-equation model, consisting of the Abe k - ε turbulence model and the Manservisi k𝜃 - ε𝜃 heat transfer model, is applied to study the conjugate heat transfer concerning liquid metal in the present work. To verify the numerical validity of the four-equation model used in the conjugate heat transfer simulations, we reproduce Johnson's experiments of the liquid lead-bismuth-cooled turbulent pipe flow using the four-equation model and the traditional SGDH model. The simulation results obtained with different models are compared with the available experimental data, revealing that the relative errors of the local Nusselt number and mean heat transfer coefficient obtained with the four-equation model are considerably reduced compared with the SGDH model. Then, the thermal-hydraulic characteristics of liquid metal turbulent pipe flow obtained with the four-equation model are analyzed. Moreover, the impact of the turbulence model used in the four-equation model on overall simulation performance is investigated. At last, the effectiveness of the four-equation model in the CFD simulations of liquid sodium conjugate heat transfer is assessed. This paper mainly proves that it is feasible to use the four-equation model in the study of liquid metal conjugate heat transfer and provides a reference for the research of conjugate heat transfer in a liquid-metal-cooled fast reactor.

Review of seismic studies of liquid storage tanks

  • Zhao, Ming;Zhou, Junwen
    • Structural Engineering and Mechanics
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    • v.65 no.5
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    • pp.557-572
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    • 2018
  • The academic research works about liquid storage tanks are reviewed for the purpose of providing valuable reference to the engineering practice on their aseismic design. A summary of the performance of tanks during past earthquakes is described in this paper. Next, the seismic response of tanks under unidirectional earthquake is reported, supplemented with the dynamic response under multidirectional motions. Then, researches on the influence of soil-structure interaction are brought out to help modify the seismic design approach of tanks in different areas with variable properties of soils. Afterwards, base isolation systems are reported to demonstrate their effectiveness for the earthquake-resistant design of liquid storage tanks. Further, researches about the liquid-structure interaction are reviewed with description of simplified models and numerical analytical methods, some of which consider the elastic effect of tank walls. Moreover, the liquid sloshing phenomenon on the hydrodynamic behaviors of tanks is presented by various algorithms including grid-based and meshfree method. And then the impact of baffles in changing the dynamic characteristics of the liquid-structure system is raised, which shows the energy dissipation by the vortex motion of liquid. In addition, uplifting effect is given to enhance the understanding on the capacity of unanchored tanks and some assessment of their development. At last, the concluding remarks and the aspects of extended research in the field of liquid storage tanks under seismic loads are provided, emphasizing the thermal stress analysis, the replaceable system for base isolation, the liquid-solid interaction and dynamic responses with stochastic excitations.

Effects of binary conductive additives on electrochemical performance of a sheet-type composite cathode with different weight ratios of LiNi0.6Co0.2Mn0.2O2 in all-solid-state lithium batteries

  • Ann, Jiu;Choi, Sunho;Do, Jiyae;Lim, Seungwoo;Shin, Dongwook
    • Journal of Ceramic Processing Research
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    • v.19 no.5
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    • pp.413-418
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    • 2018
  • All-solid-state lithium batteries (ASSBs) using inorganic sulfide-based solid electrolytes are considered prospective alternatives to existing liquid electrolyte-based batteries owing to benefits such as non-flammability. However, it is difficult to form a favorable solid-solid interface among electrode constituents because all the constituents are solid particles. It is important to form an effective electron conduction network in composite cathode while increasing utilization of active materials and not blocking the lithium ion path, resulting in excellent cell performance. In this study, a mixture of fibrous VGCF and spherical nano-sized Super P was used to improve rate performance by fabricating valid conduction paths in composite cathodes. Then, composite cathodes of ASSBs containing 70% and 80% active materials ($LiNi_{0.6}Co_{0.2}Mn_{0.2}O_2$) were prepared by a solution-based process to achieve uniform dispersion of the electrode components in the slurry. We investigated the influence of binary carbon additives in the cathode of all-solid-state batteries to improve rate performance by constructing an effective electron conduction network.

Interfacial Degradation Reaction between Cathode and Solid Electrolyte in All-Solid-State Batteries (고체전해질과 양극의 계면 열화 반응)

  • Jae-Hun Kim
    • Corrosion Science and Technology
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    • v.23 no.4
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    • pp.334-342
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    • 2024
  • The need for efficient and sustainable energy storage solutions has emerged due to a rapidly increasing energy demand and growing concerns about environmental issues. Among various energy storage methods, lithium secondary batteries are widely used in a variety of electronic devices such as smartphones, laptops, electric vehicles, and large-scale power storage systems due to their high energy density, long lifespan, and cost competitiveness. Recently, all-solid-state batteries (ASSBs) have attracted great attention because they can reduce the risk of fire associated with liquid electrolytes. Additionally, using high-capacity alternative anodes and cathodes in ASSBs can enhance energy density. However, ASSBs that use solid electrolytes experience a degradation in their electrochemical performances due to resistance at solid-solid interfaces. These interfaces can also result in poor physical contact and the presence of products formed from chemical and electrochemical reactions. Solving this interface problem is a critical issue for the commercialization of ASSBs. This review summarizes interfacial reactions between the cathode and solid electrolyte, along with research aimed at improving these interactions. Future development directions in this field are also discussed.