• Title/Summary/Keyword: Key recovery

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The Study of Key Elements to Establish Natural Disaster Preparedness Plan in Libraries and Archives (도서관과 기록관의 자연재난 대비 계획수립 핵심 요소 고찰)

  • Lee, Sangbaek
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.30 no.1
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    • pp.101-119
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    • 2019
  • This study reviewed important elements that should be considered in developing natural disaster plan in libraries and archives. In Korea, research on natural disaster planning in libraries and archives was rarely conducted. Therefore, it was necessary to study and analyse overseas literature for natural disaster preparedness planning. The key elements for establishing a natural disaster preparedness plan commonly identified in overseas research can be divided into six factors. 'The disaster preparedness committee and roles of staff' should be designated for starting disaster preparedness, and 'Risks' vulnerable to disaster should be assessed and managed in advance. A 'Handbook for immediate response' should be produced for all employees to respond promptly in the event of disaster, and 'Recovery and business continuity plan' should be reviewed for strategic recovery based on disaster scale and return to work after disaster. Also, in order to strengthen the capacity of all staff related to disaster preparedness and to improve plan for disaster, 'Training' is needed, and 'Cooperation activities' between related organisations should be taken into consideration in order to obtain various perspectives for disaster preparedness and to cope with and recover from large-scale disasters. This study can help Korean libraries and archives to establish natural disaster preparedness plan for serious natural disaster that can likely occur in the future.

Self-Regeneration of Intelligent Perovskite Oxide Anode for Direct Hydrocarbon-Type SOFC by Nano Metal Particles of Pd Segregated (Pd 나노입자의 자가 회복이 가능한 지능형 페로브스카이트 산화물 음극의 직접 탄화수소계 SOFC 성능 평가)

  • Oh, Mi Young;Ishihara, Tatsumi;Shin, Tae Ho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.31 no.5
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    • pp.345-350
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    • 2018
  • Nanomaterials have considerable potential to solve several key challenges in various electrochemical devices, such as fuel cells. However, the use of nanoparticles in high-temperature devices like solid-oxide fuel cells (SOFCs) is considered problematic because the nanostructured surface typically prepared by deposition techniques may easily coarsen and thus deactivate, especially when used in high-temperature redox conditions. Herein we report the synthesis of a self-regenerated Pd metal nanoparticle on the perovskite oxide anode surface for SOFCs that exhibit self-recovery from their degradation in redox cycle and $CH_4$ fuel running. Using Pd-doped perovskite, $La(Sr)Fe(Mn,Pd)O_3$, as an anode, fairly high maximum power densities of 0.5 and $0.2cm^{-2}$ were achieved at 1,073 K in $H_2$ and $CH_4$ respectively, despite using thick electrolyte support-type cell. Long-term stability was also examined in $CH_4$ and the redox cycle, when the anode is exposed to air. The cell with Pd-doped perovskite anode had high tolerance against re-oxidation and recovered the behavior of anodic performance from catalytic degradation. This recovery of power density can be explained by the surface segregation of Pd nanoparticles, which are self-recovered via re-oxidation and reduction. In addition, self-recovery of the anode by oxidation treatment was confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM).

Recovery of High-Purity Methane from Piggery Wastewater in the Phase-Separated Anaerobic Process (상분리 혐기성공정에 의한 양돈폐수로부터 고순도 메탄회수)

  • Jung, Jin-Young;Chung, Yun-Chul;Yoo, Chang-Bong
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.05a
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    • pp.210-213
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    • 2008
  • The purpose of this study is to investigate the performances of organic removal and methane recovery in the full scale two-phase anaerobic system. The full scale two-phase anaerobic system was consists of an acidogenic ABR (Anaerobic Baffled Reactor) and a methanognic UASB (Upflow Anaerobic Sludge Blanket) reactor. The volume of acidogenic and methanogenic reactors is designed to 28.3 $m^3$ and 75.3 $m^3$. The two-phase anaerobic system represented 60-82% of COD removal efficiency when the influent COD concentration was in the range of 7,150 to 16,270 mg/L after screening (average concentration is 10,280 mg/L). After steady-state, the effluent COD concentration in the methanogenic reactor showed 2,740 $\pm$ 330 mg/L by representing average COD removal efficiency was 71.4 $\pm$ 8.1% when the operating temperature was in the range of 19-32$^{\circ}C$. The effluent SCOD concentration was in the range of 2,000-3,000 mg/L at the steady state while the volatile fatty concentration was not detected in the effluent. Meanwhile, the COD removal efficiency in the acidogenic reactor showed less than 5%. The acidogenic reactor played key roles to reduce a shock-loading when periodic shock loading was applied and to acidify influent organics. Due to the high concentration of alkalinity and high pH in the effluent of the methanogenic reactor, over 80% of methane in the biogas was produced consistently. More than 70 % of methane was recovered from theoretical methane production of TCOD removed in this research. The produced gas can be directly used as a heat source to increase the reactor temperature.

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Performance Analysis of Pilot Symbol Assisted Trellis-Coded 8PSK with Timing Recovery Circuits on the Frequency-Nonselective Rayleigh Fading Channel (주파수 비선택적 레일리 페이딩 채널에서의 타이밍 복구회로를 고려한 PSA-TC-8PSK의 성능 분석)

  • 이병로
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.3
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    • pp.419-425
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    • 2001
  • In land mobile communications, multipath fading is one of the key factors which affect the system performance. Some extensive studies have been carried out to improve the degraded performance under this fading channels. The PSAM channel compensation method using channel fading estimation is widely used and TCM is a combined coding and modulation technique that has been shown to provide significant coding gain without increasing the transmission bandwidth. In this paper, we analyze the performance of PSA-TC-8PSK which combines PSAM and TCM over frequency nonselective fading channels. To estimate channel fading, Wiener filter which minimizes error variance is used as compensation method and we analyze the affects on the system performance of the number of filter taps, period of the pilot symbol frame, and the Doppler frequency. In addition, we consider the symbol timing recovery circuit which can be implemented in the full-digital method and analyze the effects of symbol timing error on the system performance.

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Analysis of R&D investment of waste reduce, recycle and energy recovery technology (폐기물 저감·재활용·에너지화 기술의 R&D 투자 현황 분석)

  • Hong, Jung Suk;Kim, Hyung-Gun
    • Journal of Energy Engineering
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    • v.21 no.3
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    • pp.315-324
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    • 2012
  • Waste reduce, recycle, energy recovery technology is one of 27 key green technology by 2012, the government should increase R&D investment, despite the period 2008 to 2010 average annual growth rate was decreased. Accordingly, this area of government investment in R&D status analyzed in detail and as a result, total government investment in R&D decreased, but in these fields to define strategic product services investment in technology is increasing centralization trend that appears to be investment in the quality of determined that the good is. In particular, in 2010, strategic product service of the technologies 3 technology groups ((1) waste energy equipment (2) waste resource recycling facilities (3) waste based materials production facilities) the proportion of 24-28% relatively evenly invested, government R&D is judged that adequate investment in quality.

Economic Feasibility Study for CO2 Ocean Sequestration (CO2 해양격리시스템의 기술.경제적 가능성평가)

  • Park, Se-Hun;Oh, Wee-Yeong;Kwon, Moon-Sang
    • Ocean and Polar Research
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    • v.27 no.4
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    • pp.451-461
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    • 2005
  • The $CO_2$ storage in geologic and oceanic reservoirs is considered to be one of the carbon management strategies for responding to global climate change. Ocean carbon sequestration is purposeful storage acceleration into the ocean of large amounts of carbon that would accumulate in the atmosphere and naturally enter the ocean over a longer timespan. Some technologies for $CO_2$ ocean sequestrations have been developed as a nation project. However, $CO_2$ ocean sequestrations are attractive because they have the advantage of vast capacity sequestration far away from industrial areas, and offer easier monitoring whereas less economic advantage has been indicated as one of the key barriers compared with $CO_2$ geosphere sequestration, which is produced as a byproduct. In this paper, a conceptual design for $CO_2$ ocean sequestration is introduced, and the preliminary examination is described. As a result, the $CO_2$ price, US$ 24/t shows far away from the economics. The causes come from the expensive $CO_2$ recovery cost and the low $CO_2$ price. The expensive $CO_2$ recovery cost is because too much electricity and water are consumed. In order to look for an economic balance point for $CO_2$ ocean sequestration, NPV=0, it is increases the $CO_2$ price. Finally 60.4$ per ton is found to be the balance price.

Two-Step Oxidation of Refractory Gold Concentrates with Different Microbial Communities

  • Wang, Guo-hua;Xie, Jian-ping;Li, Shou-peng;Guo, Yu-jie;Pan, Ying;Wu, Haiyan;Liu, Xin-xing
    • Journal of Microbiology and Biotechnology
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    • v.26 no.11
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    • pp.1871-1880
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    • 2016
  • Bio-oxidation is an effective technology for treatment of refractory gold concentrates. However, the unsatisfactory oxidation rate and long residence time, which cause a lower cyanide leaching rate and gold recovery, are key factors that restrict the application of traditional bio-oxidation technology. In this study, the oxidation rate of refractory gold concentrates and the adaption of microorganisms were analyzed to evaluate a newly developed two-step pretreatment process, which includes a high temperature chemical oxidation step and a subsequent bio-oxidation step. The oxidation rate and recovery rate of gold were improved significantly after the two-step process. The results showed that the highest oxidation rate of sulfide sulfur could reach to 99.01 % with an extreme thermophile microbial community when the pulp density was 5%. Accordingly, the recovery rate of gold was elevated to 92.51%. Meanwhile, the results revealed that moderate thermophiles performed better than acidophilic mesophiles and extreme thermophiles, whose oxidation rates declined drastically when the pulp density was increased to 10% and 15%. The oxidation rates of sulfide sulfur with moderate thermophiles were 93.94% and 65.73% when the pulp density was increased to 10% and 15%, respectively. All these results indicated that the two-step pretreatment increased the oxidation rate of refractory gold concentrates and is a potential technology to pretreat the refractory sample. Meanwhile, owing to the sensitivity of the microbial community under different pulp density levels, the optimization of microbial community in bio-oxidation is necessary in industry.

Impact of Patients' Level of Participation in Rehabilitation on Functional Outcome in Patients With Stroke (뇌졸중 환자의 재활참여가 기능회복에 미치는 영향)

  • Won, Jong-im
    • Physical Therapy Korea
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    • v.27 no.1
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    • pp.63-69
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    • 2020
  • Background: Stroke recovery is a long and complex process. Successful stroke recovery seems to be strongly associated with patients' high motivation and committed participation. Patients' motivation is a key determinant of successful rehabilitation outcomes, but it is difficult in defining and measuring. Patients' participation is defined as the degree or extent to which subjects take part in rehabilitation activities and can be measured by observable behavior. Objects: The purpose of this study was to investigate the impact of patients' level of participation in rehabilitation on functional outcomes in patients with stroke. Methods: Forty post-stroke inpatients participated in this study. The level of rehabilitation participation was measured by the Hopkins Rehabilitation Engagement Rating Scale (HRERS). Other measures used for the evaluation were the Rivermead Mobility Index (RMI) and Korean version of the Modified Barthel Index (K-MBI). Overall measurements were made at early intervention and late intervention. Spearman correlation and multiple regression were used to measure the relationships between HRERS, RMI, and K-MBI. Results: The correlation found between HRERS total scores at early intervention and RMI total scores of late intervention was above moderate (r = 0.607, p < 0.01). RMI total scores at early intervention (p < 0.000), HRERS total scores at early intervention (p < 0.001), and disease duration (p < 0.003) were significant predictors of RMI total scores at late intervention. Conclusion: The level of participation at early intervention was associated with improvement in mobility. The level of mobility at early intervention, disease duration, and patients' participation at early intervention were important determinants of functional outcome. These findings suggest that patients' participation should be encouraged in order to achieve successful stroke recovery.

A Study on Risk Assessments and Protection Improvement for Electric Power Infrastructures against High-altitude Electromagnetic Pulse (전력기반시설의 고 고도 핵 전자기파에 대한 위험성 검토 및 방호 개선방안 연구)

  • Chung, Yeon-Choon
    • Convergence Security Journal
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    • v.19 no.3
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    • pp.43-50
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    • 2019
  • In a hyper-connected society, electric power infrastructures and information and communication infrastructures are the core of critical national infrastructures. However, electric power infrastructure is very deadly to high-frequency nuclear electromagnetic pulse (HEMP) threats recently issued by North Korea, so the resilience through rapid recovery after attack is directly related to the survivability of our country. Therefore, electric power infrastructure should take precedence over any other key infrastructure, with preemptive protection measures and fast recovery plans. In this paper, the characteristics of the HEMP threats was examined, and the risks and effective major protection measures of the electric power infrastructures are discussed. In the future, it is expected that it will be able to help establish the direction of enactment and revision of legal schems related to the 'high power EMP infringement prevention' for Korea's electric power infrastructures.

Studies on In Vivo Embryo Production by FSH-P and SUPER-OV in Korean Native Cattle III. The Factors Influencing In Vivo Embryo Production on Days and Seasons of Flushing (한우에서FSH-P와SUPER-OV에 의한 체내 수정란 생산에 관한 연구 II.계절 및 채란일에 따른 체내 수정란 생산에 영향을 미치는 요인)

  • 김흥률;김덕임;박철진;김창근;정영채;이종완
    • Journal of Embryo Transfer
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    • v.12 no.1
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    • pp.57-66
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    • 1997
  • This study was carried out to establish an effective and practical system for commercialization of embryo production techniques by analyzing several factors influencing in vivo embryo production on days and seasons of flushing in Korean native cattle. In vivo embryos were flushed 226 times from 128 donors. The results obtained for the factors influencing in vivo embryo production on days and seasons of flushing were as follows :1.The percentages of fertilized, transferable and freezable embryos by seasons were significantly different in both FSR-P and SUPER-OV(P<0.01). The percentages of them were highest in sunrrner with FS H-P and highest in autumn with SUPER -OV.2. The production of transferable and freezable embryos by flushing days was highest in 8 days with FSH-P, and there was no difference between 7 and 8 days for SUP ER-OV. 3. The failure rates of recovery were 17.0% in SUPER-OV and 21.2% in FSH-P, respectively. The donors superovulated but failed recovery were 8.5% in SUPER-OV and 12.9% in FSH-P, respectively. Nonsuperovulated donors was 8.4% and donors giving less than 2 eggs at recovery was 8.4% in both FSH -P and SUPER-OV 4. The donors returned to normal estrus after superovulation were 34.1% after 1 cycle,39.4% after 2 cycles, and 16.7% after 3 cycles by FSH-P, respectively. For SUPER-OV, they were 55.3, 33.0 and 9.6%, respectively. Generally, normal estrus after the treatment of superovulation was earlier and the occurrence of ovarian cyst was also lower in SUP ER-OV than in FSH-P.5.The percentages of blastocyst in embryos flushed at 7~8 days after estrus were 21. 9% and 54.3% in FSH -P and SUPER-OV, respectively. The development of embryos was faster in SUPER-OV than in FSH-P.(Key words : in vivo embryo, flushing days, superovulation, FSH-P, SUPER-OV)

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