• Title/Summary/Keyword: Global synthesis

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A Capstone Design Case Study for Offshore Wind Power (해상풍력발전 캡스톤 디자인 사례 연구)

  • Woo, Jinho;Na, Won-Bae
    • Journal of Fisheries and Marine Sciences Education
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    • v.25 no.1
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    • pp.167-180
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    • 2013
  • A capstone design is regarded as one of cap courses in undergraduate engineering education because it requires most prerequisites and makes students experience real engineering design processes. There have been case studies to show how this subject should be organized, practiced, and optimized. This study shows one of the case studies by focusing offshore wind power, one of newly recognized renewable energy resources, especially targeting for the design of wind turbine foundation and submarine power cable protectors mainly because of current energy and global warming crisis. To pinpoint engineering design, the students'activities during the project and design procedures are monitored, evaluated, and recommended; hence, core factors are addressed to develop successful aim, theory, practice, and other necessities. These factors include creative problem solving abilities; recognition of engineering curriculum; selection of project theme based on significance, ripple effect, and education purpose; team organization by the full brain model; systematization of project process; realization of engineering design; and synthesis of evaluation. In the end, the aftermath and future works are discussed.

Synthesis and High Photocatalytic Activity of Zn-doped TiO2 Nanoparticles by Sol-gel and Ammonia-Evaporation Method

  • Nguyen, Thanh Binh;Hwang, Moon-Jin;Ryu, Kwang-Sun
    • Bulletin of the Korean Chemical Society
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    • v.33 no.1
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    • pp.243-247
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    • 2012
  • Photocatalysis has been applied to decompose the waste and toxic materials produced in daily life and in the global environment. Pure $TiO_2$ (Zn-$TiO_2$-0) and Zn-doped $TiO_2$ (Zn-$TiO_2$-x, x = 3-10 mol %) samples were synthesized using a novel sol-gel and ammonia-evaporation method. The Zn-doped $TiO_2$ samples showed high photocatalytic activity for the degradation of methylene blue (MB). The physicochemical properties of the samples were investigated using XRD, SEM, ICP, DLS and BET methods. In addition, the most important measurement of photocatalytic ability was investigated by a UV-vis spectrophotometer. The effects of the mol % of zinc ion doping in $TiO_2$ on photocatalytic activity were studied. Among the mol % Zn ions investigated, the Zn-$TiO_2$-9 sample showed the highest photoreactivity. This sample removed 91.4% of the MB after 4 h, while the pure $TiO_2$ only removed 46.4% of the MB.

Near-IR Quantum Cutting Phosphors: A Step Towards Enhancing Solar Cell Efficiency

  • Jadhav, Abhijit P.;Khan, Sovann;Kim, Sun Jin;Cho, So-Hye
    • Applied Science and Convergence Technology
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    • v.23 no.5
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    • pp.221-239
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    • 2014
  • The global demand for energy has been increasing since past decades. Various technologies have been working to find a suitable alternative for the generation of sustainable energy. Photovoltaic technologies for solar energy conversion represent one of the significant routes for the green and renewable energy production. Despite of remarkable improvement in solar cell technologies, the generation of power is still suffering with lower energy conversion efficiency, high production cost, etc. The major problem in improving the PV efficiency is spectral mismatch between the incident solar spectrum and bandgap of a semiconductor material used in solar cell. Luminescent materials such as rare-earth doped phosphor materials having the quantum efficiency higher than unity can be helpful for photovoltaic applications. Quantum cutting phosphors are the most suitable candidates for the generation of two or more low-energy photons for the absorption of every incident high-energy photons. The phosphors which are capable of converting UV photon to visible and near-IR (NIR) photon are studied primarily for photovoltaic applications. In this review, we will survey various near IR quantum cutting phosphors with respective to their synthesis method, energy transfer mechanism, nature of activator, sensitizer and dopant materials incorporation and energy conversion efficiency considering their applications in photovoltaics.

Prospect of plant molecular cytogenetics in the 21st century

  • Mukai, Yasuhiko
    • Proceedings of the Korean Society of Life Science Conference
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    • 2003.10a
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    • pp.14-27
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    • 2003
  • The genomes of Arabidopsis and rice have been fully sequenced. Genomic sequencing provides global information about genome structure and organization. A comprehensive research account of our recent studies conducted on genome painting, comparative genomics and genome fusion is provided in order to project the prospects of plant cytogenetic research in post-genomics era. Genome analysis by GISH using genome painting is demonstrated as an excellent means suitable for visualization of a whole genome, since total genomic DNA representing the overall molecular composition of the genome is used as a probe. FISH on extended DNA fibers has been developed for high-resolution FISH and has contributed to determining the copy number and order of genes. We have also mapped a number of genes involving starch synthesis on wheat chromosomes by FISH and compared the position of these genes on linkage map of rice. Macro synteny between wheat and rice can be observed by comparing the location of these genes in spite of the fact that the size of DNA per chromosome differs by 20 fold in two. Moreover, to approach our goal towards making bread and udon noodles from rice flour in future by incorporating bread making and the noodle qualifies in rice, we have been successful in introducing large genomic DNA fragments containing agronomically important genes of wheat into a rice by successive introduction of large insert BAC clones, there by expanding genetic variability in rice. We call this method genome fusion.

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Methionyl-tRNA Synthetase Regulates Lifespan in Drosophila

  • Suh, Yoon Seok;Yeom, Eunbyul;Nam, Jong-Woo;Min, Kyung-Jin;Lee, Jeongsoo;Yu, Kweon
    • Molecules and Cells
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    • v.43 no.3
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    • pp.304-311
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    • 2020
  • Methionyl-tRNA synthetase (MRS) is essential for translation. MRS mutants reduce global translation, which usually increases lifespan in various genetic models. However, we found that MRS inhibited Drosophila reduced lifespan despite of the reduced protein synthesis. Microarray analysis with MRS inhibited Drosophila revealed significant changes in inflammatory and immune response genes. Especially, the expression of anti-microbial peptides (AMPs) genes was reduced. When we measured the expression levels of AMP genes during aging, those were getting increased in the control flies but reduced in MRS inhibition flies age-dependently. Interestingly, in the germ-free condition, the maximum lifespan was increased in MRS inhibition flies compared with that of the conventional condition. These findings suggest that the lifespan of MRS inhibition flies is reduced due to the down-regulated AMPs expression in Drosophila.

A Study on Pitch Period Detection of Speech Signal Using Modified AMDF (변형된 AMDF를 이용한 음성 신호의 피치 주기 검출에 관한 연구)

  • Seo, Hyun-Soo;Bae, Sang-Bum;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.515-519
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    • 2005
  • Pitch period that is a important factor in speech signal processing is used in various applications such as speech recognition, speaker identification, speech analysis and synthesis. So many pitch detection algoritms have been studied until now. AMDF which is one of pitch period detection algorithms chooses the time interval from valley point to valley point as pitch period. In selection of valley point to detect pitch period, complexity of the algoritm is increased. So in this paper we proposed the simple algorithm using modified AMDF that detects global minimum valley point as pitch period of speech signal and compared existing methods with it through simulation.

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Low-Level Laser Therapy including Laser Acupuncture for Non-Specific Chronic Low Back Pain : Protocol for a Systematic Review

  • Yeum, Hyewon;Nam, Dongwoo
    • Journal of Acupuncture Research
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    • v.36 no.4
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    • pp.251-255
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    • 2019
  • Background: Low-level laser therapy (LLLT) including laser acupuncture (LA) has been widely used to treat chronic low back pain (CLBP), but there is no critically appraised evidence of the potential benefits. The purpose of this protocol for a systematic review was to enable the evaluation of the effectiveness of LLLT including LA for non-specific CLBP to identify the potential benefits. Methods: The electronic databases MEDLINE (PubMed), Embase (Ovid), the Cochrane Central Register of Controlled Trials (CENTRAL), Korean medical databases (KoreaMed, KMBASE, KISS, NDSL, KISTI, OASIS), the Chinese database (CNKI), and Japanese databases (CiNII, J-STAGE) are recommended. Results: Randomized controlled trials in LLLT including LA should be included in the searches. All data synthesis and subgroup analyses should be conducted using a Review Manager software. The Cochrane risk of bias tool can be used to evaluate methodological quality of the studies. A risk ratio or mean difference with a 95% confidence interval will show the effects of LLLT including LA. Conclusion: The primary outcome would be pain intensity and functional status/disability due to low back pain. The secondary outcome would be a global measurement of recovery or improvement, quality of life and adverse event.

Inter-Territorial Collaboration in the Context of Strengthening Its Economic Security

  • Hlazov, Oleksandr;Kalashnikova, Khrystyna;Zolotarov, Volodymyr;Levchenko, Iaroslava;Britchenko, Igor;Losonczi, Peter
    • International Journal of Computer Science & Network Security
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    • v.21 no.12spc
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    • pp.675-683
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    • 2021
  • An article is devoted to developing the concept of inter-territorial collaboration in the context of strengthening its economic security. This concept is based on the study of international experience and successful OTG functioning in Ukraine. The idea includes directions, forms, tools, procedures, and financial sources for joint projects that strengthen territorial associations' economic security. The research consists of assessing the state of economic development of territorial communities and forms of their cooperation with other territorial communities. Analysis, synthesis, induction, and deduction are the main methods of scientific knowledge used to summarize statistical information, normative and legal support, and global experience of cooperation of territorial communities. The study results include the main areas of cooperation of territorial communities in Ukraine, including long-term collaboration. The study also contains successful examples of collaboration between different territorial communities, applying practical aspects and tools to form effective interaction. The main points of discussion concern various forms of interaction between territorial communities, which allow achieving the economic goal more quickly and effectively.

A Mechanism Study on Formation and Reduction of Residual Li of High Nickel Cathode for Lithium-ion Batteries (층상계 하이니켈 양극재의 잔류 리튬 생성 및 저감 메커니즘 연구)

  • MinWook, Pin;Beom Tak, Na;Tae Eun, Hong;Youngjin, Kim
    • Journal of Industrial Technology
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    • v.42 no.1
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    • pp.7-12
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    • 2022
  • High nickel layered oxide cathodes are gaining increasing attention for lithium-ion batteries due to their higher energy density and lower cost compared to LiCoO2. However, they suffer from the formation of residual lithium on the surface in the form of LiOH and Li2CO3 on exposure to ambient air. The residual lithium causes notorious issues, such as slurry gelation during electrode preparation and gas evolution during cell cycling. In this review, we investigate the residual lithium issues through its impact on cathode slurry instability based on deformed polyvinylidene fluoride (PVdF) as well as its formation and reduction mechanism in terms of inherently off-stoichiometric synthesis of high nickel cathodes. Additionally, new analysis method with anhydrous methanol was introduced to exclude Li+/H+ exchange effect during sample preparation with distilled water. We hope that this review would contribute to encouraging the academic efforts to consider practical aspects and mitigation in global high-energy-density lithium-ion battery manufacturers.

Structural Insights for β-Lactam Antibiotics

  • Dogyeoung, Kim;Sumin, Kim;Yongdae, Kwon;Yeseul, Kim;Hyunjae, Park;Kiwoong, Kwak;Hyeonmin, Lee;Jung Hun, Lee;Kyung-Min, Jang;Donghak, Kim;Sang Hee, Lee;Lin-Woo, Kang
    • Biomolecules & Therapeutics
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    • v.31 no.2
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    • pp.141-147
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    • 2023
  • Antibiotic resistance has emerged as a global threat to modern healthcare systems and has nullified many commonly used antibiotics. β-Lactam antibiotics are among the most successful and occupy approximately two-thirds of the prescription antibiotic market. They inhibit the synthesis of the peptidoglycan layer in the bacterial cell wall by mimicking the D-Ala-D-Ala in the pentapeptide crosslinking neighboring glycan chains. To date, various β-lactam antibiotics have been developed to increase the spectrum of activity and evade drug resistance. This review emphasizes the three-dimensional structural characteristics of β-lactam antibiotics regarding the overall scaffold, working mechanism, chemical diversity, and hydrolysis mechanism by β-lactamases. The structural insight into various β-lactams will provide an in-depth understanding of the antibacterial efficacy and susceptibility to drug resistance in multidrug-resistant bacteria and help to develop better β-lactam antibiotics and inhibitors.