• Title/Summary/Keyword: regeneration process

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Hydraulic Cleaning Effect on Fouling Mechanisms in Pressurized Membrane Water Treatment (가압식 멤브레인 수처리에서 수리학적 세정이 파울링 기작에 미치는 영향)

  • Charfi, Amine;Jang, Hoseok;Kim, Jeonghwan
    • Membrane Journal
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    • v.27 no.6
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    • pp.519-527
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    • 2017
  • Membrane fouling is the main issue hindering the expansion of low pressure membrane processes for surface water treatment. Therefore, applying periodic hydraulic cleaning for fouling control should be well optimized. Better understanding of membrane fouling associated with periodic hydraulic cleaning would be useful to optimize membrane cleaning strategies. By comparing experimental permeability data with the classical Hermia blocking laws, this study aims at analyzing membrane fouling and understanding dominant fouling mechanisms occurring when filtering a synthetic surface water solution with a pressurized membrane process during six filtration cycles of 30 min each, separated with cyclic cleaning of 1 min by backwashing and forward flushing separately and combined. When applying single cleaning technique, membrane fouling during the first cycles was controlled by complete blocking mechanism while the last cycles were dominated by cake formation. Nevertheless, when combining cleaning technique better membrane regeneration was obtained and fouling was mainly due to cake formation.

A review of smart exsolution catalysts for the application of gas phase reactions (기상 반응용 스마트 용출 촉매 연구 동향)

  • Huang, Rui;Kim, Hyung Jun;Han, Jeong Woo
    • Ceramist
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    • v.23 no.2
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    • pp.211-230
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    • 2020
  • Perovskite-type oxides with the nominal composition of ABO3 can exsolve the B-site transition metal upon the controlled reduction. In this exsolution process, the transition metal emerges from the oxide lattice and migrates to the surface at which it forms catalytically active nanoparticles. The exsolved nanoparticles can recover back to the bulk lattice under oxidation treatment. This unique regeneration character by the redox treatment provides uniformly dispersed noble metal nanoparticles. Therefore, the conventional problem of traditional impregnated metal/support, i.e., sintering during reaction, can be effectively avoided by using the exsolution phenomenon. In this regard, the catalysts using the exsolution strategy have been well studied for a wide range of applications in energy conversion and storage devices such as solid oxide fuel cells and electrolysis cells (SOFCs and SOECs) because of its high thermal and chemical stability. On the other hand, although this exsolution strategy can also be applied to gas phase reaction catalysts, it has seldomly been reviewed. Here, we thus review recent applications of the exsolution catalysts to the gas phase reactions from the aspects of experimental measurements, where various functions of the exsolved particles were utilized. We also review non-perovskite type metal oxides that might have exolution phenomenon to provide more possibilities to develop higher efficient catalysts.

Improvement of Functional Recovery by Cell Transplantation after Spinal Cord Injury (척수손상 후 세포이식에 의한 운동기능의 회복증진)

  • 이배환;이경희;성제경;황세진;김계성
    • Science of Emotion and Sensibility
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    • v.7 no.2
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    • pp.179-186
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    • 2004
  • Acute spinal cord injury can produce neurologic injury with many physical, psychological and social ramifications. It has been shown that two separate components combine to produce neurologic damage in acute spinal cord injury : the primary and secondary injuries. The primary mediators of spinal cord injury include the actual mechanical tissue disruption which is a passive process that occurs immediately following the trauma. A secondary injury cascade follows which appears mediated by cellular and molecular processes working through complex mechanisms. Both the primary and secondary injury cascades produce cell death both in neuronal and supporting cell tissues. Recovery from central nervous system(CNS) disorders is hindered by the limited ability of the vertebrate CNS to regenerate injured cells, replace damaged myelin sheath, and re-establish functional neuronal connections. Of many CNS disorders including multiple sclerosis, stroke, and other trauma, spinal cord injury is one of the important diseases because of the direct association with the functional loss of the body. Previous studies suggest that substantial recovery of function might be achieved through regeneration of lost neuronal cells and remyelination of intact axon in spinal cord injury which is occurred frequently. As a therapeutic approach in spinal cord injury, recently, cell transplantation provides a potential solution for the treatment of spinal cord injury. This review describes the characteristics of spinal cord injury and presents some evidence supporting functional recovery after cell transplantation following spinal cord injury.

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A Study on the Collection Based on Personal History for the Archiving of Industrial Heritage (산업유산 아카이빙을 위한 개인 생애서사 기반 수집 연구)

  • Ryu, Hanjo
    • The Korean Journal of Archival Studies
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    • no.66
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    • pp.37-67
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    • 2020
  • Recently, industrial heritages have been transformed into cultural facilities in the wake of urban Regeneration. This focus is mainly on appearance, and the explanation is often abbreviated as a master narrative, and the placeness is not sufficiently inherited. The placeness of industrial heritage contains not only historical but also personal memories. Place memory must be collected and managed in order for the placeness that can be the source of identity to be preserved and utilized. To this end, this study suggested collecting place memories based on personal life histories. Using the case of collecting Andong Station and Cheongju Tobacco Factory, the life narrative was broken down into an event and the process of reinterpreting it as a place memory was proposed to implement archiving of industrial heritage sites. This methodology means that it can be supplemented rather than replaced.

Removal of Phenol Loaded with Activated Carbon by Potentiostatic Method (정전위전해에 의한 활성탄에 함유된 페놀 제거)

  • 김성우;박승조
    • Resources Recycling
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    • v.10 no.4
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    • pp.18-23
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    • 2001
  • Air pollutants, phenol was generated in case of thermal regeneration of used activated carbon loaded with phenol and because of this problem, removal process of phenol were studied. Electrolytic oxidation of samples, used S.company granular activated carbon (WS-GAC), used C.company granular activated carbon (WC-GAC) and used L.company granular activated carbon (WL-GAC) loaded with phenol carried out by potentiostatic method in this study. In case of experiment was to come into operation in condition of samples containing 100 mg/g phenol, supporting electrolyte was 1.0% sodium chloride solution, Ti-Ir (10$\times$10$\textrm{cm}^2$) electrode and electrode distance was 2 cm, current density was $1.25 A/dm^2$, Obtained from the results of electrolytic oxidation experiments were not detected residual phenol. And then we knew about reaction time of electrolytic oxidation, current density, concentration of supporting electrolyte and electrode and electrode distance were 60 minutes, 1.25 A/dm$^2$, 1.0%, 2 cm.

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Study on the Status Change in Rural Landscape Planning and Landscape Project in the General Agriculture Fishing Village Development Project (일반농산어촌개발사업에 있어 농촌경관계획과 경관사업부문의 위상변화에 관한 연구)

  • Lee, Su Hyun;Cho, Tong Buhm
    • Journal of Korean Society of Rural Planning
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    • v.25 no.4
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    • pp.119-128
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    • 2019
  • Although the General Agricultural Fishing Village Development Project had a significant impact on the landscape formation and management in rural area, the rural landscape planning and project sectors was not stable by fluctuation variables. On the basic understanding the institutional status of rural landscape planning, some conclusions could be discussed as follows through the analysis of quantitative and qualitative changes and the background factors. The rural landscape plan lacked its own legal and institutional foundations, and the landscape project of the General Agricultural Fishing Village Development Project was mainly focused on the environment-improving H/W project for expanding the basic living infrastructures. In order to reflect the characteristics of the region and become independent rural landscape management, it is necessary to change the contents so that the S/W business such as the deepening landscape awareness and empowerment linked with improving the physical landscape. To this end, it is necessary to establish a foundation for the rural landscape planning system to have its own status, and it seems to seek to supplement with what is included S/W contents reflecting the context of higher level landscape planning. The landscape sector of the General Agricultural Fishing Village Development Project proved to be in the process of shrinking in both quantity and quality, despite the temporary expansion in the past. In addition, considering the distortion of the contents of landscape projects in rural sites, it seems that the rural landscape-related public project are now in a position to seek a new phase change beyond quantitative expansion. In particular, along with institutional improvements to secure the independent status of rural landscape planning that contributes to village community regeneration and social sustainability through the role of intermediary support organizations in landscape management activities. Through the integrated landscape plan, which is established in advance and led by the residents in the early stages, there is a need to change the direction to enhance meaning of the landscape planning goes beyond the facility design or space improvement.

The Effect of the Moutan Radicis Cortex on Expression of CD81 and GFAP in Injured Astrocyte (목단피(牧丹皮)가 손상된 성상신경세포의 CD81 및 GFAP의 발현에 미치는 영향)

  • Moon, Sung-Jin;Seon, Ki-Moon;Lim, Jin-Young;Song, Bong-Keun
    • The Journal of Internal Korean Medicine
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    • v.30 no.1
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    • pp.24-35
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    • 2009
  • Object : In conditions of brain infarction, irreversible axon damage occurs in the central nerve system (CNS), because gliosis makes physical and mechanical barriers. If gliosis formation could be suppressed, irreversible axon damage would be reduced. This could mean that an injured CNS could be regenerated. CD81 and GFAP have close relationships to gliosis. The increase in glial cells at CNS injury gives rise to the expression of CD81 and GFAP. CD81 was postulated to play a central role in the process of CNS scar formation. Method : In this study, the author investigated the effect of the water extract of the Moutan Radicis Cortex on regulation of CD81 and GFAP expression in injured CNS cells. MTT assay was used to examine cell viability, while RT-PCR and ELISA methods were carried out to measure the expression of CD81 and GFAP in the astrocyte. Results : We observed that water extract of the Moutan Radicis Cortex increased cell viability under hypoxia induced by $CoCl_2$ and suppressed the expression of CD81 and GFAP up-regulated by hypoxia. Conclusion : These results suggest that the Moutan Redicis Cortex could promote neural regeneration as a consequence of protecting CNS cells from hypoxia and suppressing the reactive gliosis following CNS injury.

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Effect of Propofol Preconditioning on Hypoxic-Cultured Human Osteoblast

  • Yoon, Ji Uk;Shin, Sang Wook;Park, Bong Soo;Kim, Yong Ho;Woo, Mi Na;Yoon, Ji Young;Kim, Cheul Hong
    • Journal of The Korean Dental Society of Anesthesiology
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    • v.14 no.2
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    • pp.107-114
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    • 2014
  • Background: Angiogenesis has been recognized an essential precondition for osteogenesis. Because reduction and disruption of the blood supply to tissue cause tissue hypoxia, pathological bone loss affected by hypoxia often can occur in various clinical conditions. The effects of propofol on the process of osteogenesis have received little direct attention. Therefore, we investigated the effect of propofol on the growth and function of osteoblasts under hypoxic condition. Methods: After propofol (3, 30, $300{\mu}M$) preconditioning for 2 hours, hFOB 1.19 human osteoblast cells were cultured under 1 % oxygen tension for 48 hours. Using real time PCR and western blot analysis, we analyzed the expression of, BMP-2, TGF-${\beta}1$, type I collagen, osteocalcin, HIF-1s and Akt. Cell viability was also determined by MTT assay. Results: Propofol preconditioning on hypoxic-cultured osteoblast promoted the expressions of BMP-2, TGF-${\beta}1$, type I collagen and osteocalcin and induced hypoxia-mediated HIF-1 activation and the expression of Akt protein. Propofol with $300{\mu}M$ significant decreased cell viability compared to control. Conclusions: Clinically relevant concentrations of propofol are not cytotoxic to hypoxic osteoblasts in vitro. Propofol preconditioning on hypoxic-cultured osteoblast stimulates proliferation and differentiation of osteoblast through induced expression of BMP-2, TGF-${\beta}1$, type I collagen and osteocalcin. Propofol might promote angiogenesis and bone regeneration under hypoxic condition.

Recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF) could accelerate burn wound healing in hamster skin

  • Heo, Si-Hyun;Han, Kyu-Boem;Lee, Young-Jun;Kim, Ji-Hyun;Yoon, Kwang-Ho;Han, Man-Deuk;Shin, Kil-Sang;Kim, Wan-Jong
    • Animal cells and systems
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    • v.16 no.3
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    • pp.207-214
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    • 2012
  • Burns are one of the most devastating forms of trauma and wound healing is a complex and multicellular process, which is executed and regulated by signaling networks involving numerous growth factors, cytokines, and chemokines. Recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF) was specifically produced from rice cell culture through use of a recombinant technique in our laboratory. The effect of rhGM-CSF on promotion of deep second-degree burn wound healing on the back skin of a hamster model was evaluated through a randomized and double-blind trial. As macroscopic results, hamster skins of the experimental groups showed earlier recovery by new epidermis than the control groups. Immunohistochemical reactions of proliferating cell nuclear antigen and transforming growth factor-b1, which are indicators of cell proliferation, were more active in the experimental group, compared with the control group. On electron microscopy, basal cells in the epidermis of the experimental group showed oval nuclei, prominent nucleoli, numerous mitochondria and abundant free ribosomes. In addition, fibroblasts contained well-developed rough endoplasmic reticulum with dilated cisternae. Bundles of collagen fibrils filled the extracellular spaces. Particularly, ultrastructural features indicating active metabolism for regeneration of injured skin at 15 days after burn injury, including abundant euchromatin, plentiful free ribosomes, and numerous mitochondria, were observed. These findings suggest that use of rhGM-CSF could result in accelerated deep second-degree burn wound healing in animal models.

A experimental Study on Insulation Breaking Fire Case of Starter Motor B Terminal (스타트모터 B단자 절연파괴 화재사례에 대한 실험적 연구)

  • Woo, Seung Woo;Park, J.M.;Hyun, B.S.;Nam, J.W.;Park, W.S.;Kim, J.P.;Cho, Y.J.;Goh, J.M.;Park, N.K.
    • Journal of the Korean Society of Safety
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    • v.34 no.5
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    • pp.55-62
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    • 2019
  • In this paper, we introduce a case of a fire accident during parking of a large truck that is repeatedly occurring. The shape and location of the combustion and electrical singularity commonly found in other vehicle fire accidents could limit the starter motor as the ignition section. In addition, it was possible to confirm the electrical melting singularity that could act as a cause of ignition between the start motor B terminal and the start motor enclosure. By combining the above investigations and investigations, it was possible to estimate the electric fire expressed from insulation breaking of the starter motor B terminal, and by using the renewable starter motor comparison product mounted on the fire vehicle, an experiment was performed to reproduce the ignition process from the starter motor under specific conditions. So. It is hoped that this will raise awareness about vehicle fires, which can lead to large fires or casualties, share the risks of using starter motors for regeneration, and help in the rapid and accurate investigation of similar vehicle fires in the future.