• Title/Summary/Keyword: decay function

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Photochemical Kinetics of Maleic to Fumaric Acid on Silver Nanoparticle Surfaces

  • Jang, Nak-Han;Jeong, Dae-Hong;Suh, Jung-Sang
    • Bulletin of the Korean Chemical Society
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    • v.26 no.5
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    • pp.791-794
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    • 2005
  • A visible photochemistry of maleic to fumaric acid adsorbed on silver nanoparticle surfaces was investigated as probed by SERS using a simple flow method. Photoisomerization of maleic to fumaric acid was consecutively observed in the condition of various flow rates, which varied the exposure time of laser beam. The sequential SERS spectra of maleic acid indicated that the photochemical isomerization and desorption took place simultaneously on silver nanoparticle surfaces as a function of laser fluency and wavelength. For 530.9nm laser line excitation, the rate constant coefficients were obtained with a = 5.9 $sec^{-1}$ mW for isomerization and b = 13.9 $sec^{-1}$ mW for desorption, which $k_1\;=\;aI^n\;and\;k_2\;=\;bI^m$. Both reactions were one photon process (n = 1, m = 1) of a visible light and relatively fast process whose decay time was in the range of milli-second for 50 mW laser power. The rate of photochemical reaction increased on going toward the blue and photodesorption was a dominant process. A simple flow method used in this study was very useful to study a relatively fast photochemical reaction of molecules adsorbed on silver nanoparticle surfaces.

A Case of Acute Hydrogen Sulfide Intoxication Caused Rapid Loss of Consciousness (급속한 의식 변화를 초래한 급성 황화수소 중독 1례)

  • Ahn, Jung-Hwan;Jung, Yoon-Seok
    • Journal of The Korean Society of Clinical Toxicology
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    • v.2 no.2
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    • pp.147-150
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    • 2004
  • Hydrogen sulfide is a colorless, and malodorous 'rotten eggs' gas that results from the decay of organic material. It is a byproduct of industry and agriculture. The mechanism of its toxicity is primarily related to inhibition of oxidative phosphorylation, which causes a decrease in available cellular energy. Because there is no rapid method of detection that is of clinical diagnostic use, management decisions must be made based on history, clinical presentation, and diagnostic tests that imply hydrogen sulfide's presence. Although there is some anecdotal evidence to suggest that the early use of hyperbaric oxygen is beneficial, supportive care remains the mainstay of therapy. We describe an occupational exposure to hydrogen sulfide gas in 51-year-old man. While cleaning the sewage of pigs. he became unconscious. When he arrived in the emergency department, he had irritability and confused mentality. The typical smell of rotten eggs on clothing and exhaled air were enough to be considered to be exposed to hydrogen sulfide. Hyperbaric oxygen therapy was performed. He had a recovery to normal function.

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A Case Study on Conversion of Idle Industrial Facilities - Focus on Tate Modern, Baltic Center for Contemporary Art, and Ruhr Museum - (유휴 산업시설의 컨버전 사례 분석 - 테이트모던, 발틱 현대미술센터, 루르박물관을 중심으로 -)

  • Cho, Youn-Joo;Shin, Kyung-Joo
    • Korean Institute of Interior Design Journal
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    • v.20 no.3
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    • pp.59-68
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    • 2011
  • As society alters and building ages, many industrial facilities lost their function and abandoned in central city areas, and sometimes creating many problems. However, many European countries successfully transformed those urban decay to vivid cultural hub. The purpose of this study was to analyze a concept and methods of converting idle industrial facilities to successful cultural spaces. A case study of Tate Modern, Baltic Center for Contemporary Art, and Ruhr Museum was conducted using literature review, site visit, and interview methods. Findings indicated that converting historically significant idle industrial facilities to cultural center had not only reused abandoned site but also helped regenerating adjacent urban areas. This article demonstrates the key factors of successful conversion strategies as convenience, participation, placeness, historicity, and accessibly; and thus an effort to actively enhance the strategic factors were demanded in future conversion projects. A continuous studies on exploring extensive cases in various perspectives are required for further generalization in future studies.

POSITIVE RADIAL SOLUTIONS FOR A CLASS OF ELLIPTIC SYSTEMS CONCENTRATING ON SPHERES WITH POTENTIAL DECAY

  • Carriao, Paulo Cesar;Lisboa, Narciso Horta;Miyagaki, Olimpio Hiroshi
    • Bulletin of the Korean Mathematical Society
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    • v.50 no.3
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    • pp.839-865
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    • 2013
  • We deal with the existence of positive radial solutions concentrating on spheres for the following class of elliptic system $$\large(S) \hfill{400} \{\array{-{\varepsilon}^2{\Delta}u+V_1(x)u=K(x)Q_u(u,v)\;in\;\mathbb{R}^N,\\-{\varepsilon}^2{\Delta}v+V_2(x)v=K(x)Q_v(u,v)\;in\;\mathbb{R}^N,\\u,v{\in}W^{1,2}(\mathbb{R}^N),\;u,v&gt;0\;in\;\mathbb{R}^N,}$$ where ${\varepsilon}$ is a small positive parameter; $V_1$, $V_2{\in}C^0(\mathbb{R}^N,[0,{\infty}))$ and $K{\in}C^0(\mathbb{R}^N,[0,{\infty}))$ are radially symmetric potentials; Q is a $(p+1)$-homogeneous function and p is subcritical, that is, 1 < $p$ < $2^*-1$, where $2^*=2N/(N-2)$ is the critical Sobolev exponent for $N{\geq}3$.

A Study on the crisis of Monumentality (현대건축에서 기념비성의 위기에 관한 연구)

  • Khang, Hyuk;Chung, Yong-Soo
    • Journal of architectural history
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    • v.12 no.1 s.33
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    • pp.7-24
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    • 2003
  • Considering on the crisis and dilemma of monumentality in Modern architecture, this study analyse the historic reason of decay and new possibility of monumentality within the context of contemporary socio-cultural context. Historically monumentality has been considered as a main substance of High architecture in e tradition of Western Architecture. Difference between building and architecture mainly lies in monumentality which brings about esthetic quality. Usually architects take it granted that the physical and formal characteristics automatically cause the monumentality, But since the modem period the decline of communicative and representative function of architecture made this belief questionable. As Monumentality itself faced the dilemma with the modernity, ironically architects has to response to the task to handle the increasing social demands of monumental building. This study firstly shows the dilemma of monumentality in depth in case of the holocaust museum. Then we analyse the concept of monumentality itself by means of theoretical view of A. Loos and A Riegl We also analyse the change of role which monumental building played in history. Cultural and social change of context, and fundamental change of architecture old way of building a monument impossible. In conclusion this study proposes the new concept and searches new horizon of monumentality with a finding of the otherness of monumentality. Conventional monumental building language has to give way to new approaches. With some examples we already can find a new possibility.

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Epitranscriptomic regulation of transcriptome plasticity in development and diseases of the brain

  • Park, Chan-Woo;Lee, Sung-Min;Yoon, Ki-Jun
    • BMB Reports
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    • v.53 no.11
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    • pp.551-564
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    • 2020
  • Proper development of the nervous system is critical for its function, and deficits in neural development have been implicated in many brain disorders. A precise and predictable developmental schedule requires highly coordinated gene expression programs that orchestrate the dynamics of the developing brain. Especially, recent discoveries have been showing that various mRNA chemical modifications can affect RNA metabolism including decay, transport, splicing, and translation in cell type- and tissue-specific manner, leading to the emergence of the field of epitranscriptomics. Moreover, accumulating evidences showed that certain types of RNA modifications are predominantly found in the developing brain and their dysregulation disrupts not only the developmental processes, but also neuronal activities, suggesting that epitranscriptomic mechanisms play critical post-transcriptional regulatory roles in development of the brain and etiology of brain disorders. Here, we review recent advances in our understanding of molecular regulation on transcriptome plasticity by RNA modifications in neurodevelopment and how alterations in these RNA regulatory programs lead to human brain disorders.

The integration of genomics approaches for lettuce (Lactuca sativa L.) improvements on the disease resistances and other agronomic qualities.

  • Kim, Tae-Sung;Kim, Jeong-Haw;Kim, Jung-Bun;Jang, Suk-Woo
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.114-114
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    • 2017
  • The aim of this research is to improve Korean lettuce varieties in terms of Fusarium wilt, bolting under hot weather and nutritional function applying genomics approaches. To find related gene/molecular markers, we selected 96 lettuce varieties which are popular in domestic fresh vegetable markets. To construct frame works of the genomic approaches, we exploited GBS(Genotyping by Sequencing) and found total 61,407 SNPs from lettuce whole genomes (MAF>0.02). We observed that Three SNPs array per 100kb of lettuce genome. Average LD decay is expected to expand up to 3.9M(million)bp. Thus, we concluded that about 104 SNPs exist within a LD, which is sufficient to use GWAS(Genome-wide Association Study) to explore the useful gene/molecular markers. In addition, we optimized mass screening method to evaluate disease resistance levels against Fusarium wilt and are testing the bolting sensitivity during summer growing season for those lettuce allele mining set.

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Assessing conservation priorities of unexecuted urban parks in Seoul using ecological network and accessibility analyses (생태네트워크와 접근성 분석에 의한 서울시 미집행 도시공원의 보전 우선순위 평가)

  • Kang, Wan-Mo;Song, Young-Keun;Sung, Hyun-Chan;Lee, Dong-Kun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.21 no.2
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    • pp.53-64
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    • 2018
  • This study aims to quantitatively evaluate the conservation priorities of unexecuted urban parks in Seoul both from an ecological and public perspective. To this end, two methodologies, ecological network analysis based on graph and circuit theory and accessibility analysis, were employed in order to assess ecological connectivity of and public accessibility to unexecuted parks, respectively. This study applied linkage-mapping methods (shortest path and current flow betweenness centrality) of connectivity analysis to an integrated map of landscape permeability. The population-weighted accessibility to unexecuted parks was measured based on a negative exponential distance decay function. As a result, for both ecological connectivity and accessibility, Gwanaksan, Suraksan, and Bulamsan urban natural parks are found to be the most important (rank 1-3) to be conserved. For these sites, inner park areas with conservation priorities for connectivity and accessibility were identified. The findings of the study can be used for giving conservation priority to the unexecuted urban parks in terms of long-term sustainable urban planning.

Development of a potential evaluation method for urban expansion using GIS and RS technologies (GIS와 RS를 이용한 도시확산 포텐셜 평가기법의 개발)

  • Kim, Dae-Sik;Chung, Ha-Woo
    • Journal of Korean Society of Rural Planning
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    • v.10 no.3 s.24
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    • pp.41-51
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    • 2004
  • This study aims to develop a potential evaluation method for urban spatial expansion using remote sensing (RS) and geographic information system (GIS). A multi-criteria evaluation method with several criteria and their weighting values was introduced to evaluate the score and quantification of the potential surface around the existing cities. The six criteria with one geographic factor, slope, and five accessibility factors, time distance from center of the city, national road, interchange of expressway, a big city, and station, were defined for the potential. RS techniques were applied for classification of the actual urban expansion maps between two periods, and GIS functions were used for score of accessibility criteria with a distance decay function from geographic, road and several point maps, which was developed in this study. The new methodology was applied to a test area, Suwon, between 1986 and 1996. In order to optimize the six weighting values, this study made new findings to search the optimal combination of the weighting values from new methodology, weighted scenario method for intensity order (WSM), combined with intensity order and AHP method, including a trial and error method for sensitivity analysis to make the intensity order. The optimal combination of the weighting values by the new method generated the optimal potential surface, considering spatial trend of urban expansion in the test area.

Numerical Study on the Improvement of the Motion Performance of a Light Buoy

  • Son, Bo-Hun;Jeong, Se-Min
    • Journal of Ocean Engineering and Technology
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    • v.34 no.2
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    • pp.66-76
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    • 2020
  • A light buoy is equipped with lighting functions and navigation signs. Its shape and colors indicate the route to vessels sailing nearby in the daytime, with its lights providing this information at night. It also plays a role in notifying the presence of obstacles such as reefs and shallows. When a light buoy operates in the ocean, the visibility and angle of light from the lantern installed on the buoy changes, which may cause them to function improperly. Therefore, it is necessary for the buoy to have stable and minimal motions under given environmental conditions, mainly waves. In this study, motion analyses for a newly developed lightweight light-buoy in waves were performed to predict the motion performance and determine the effect of the developed appendages for improving the motion performance. First, free decay tests, including benchmark cases, were performed using computational fluid dynamics (CFD) to estimate the viscous damping coefficients, which could not be obtained using potential-based simulations. A comparison was made of the results from potential-based simulations with and without considering viscous damping coefficients, which were estimated using CFD. It was confirmed that the pitch and heave motions of the buoy became smaller when the developed appendages were adopted.