• Title/Summary/Keyword: Synthetic Environments

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Structural Changes of the Spinach Photosystem II Reaction Center After Inactivation by Heat Treatment

  • Jang, Won-Cheoul;Tae, Gun-Sik
    • BMB Reports
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    • v.29 no.1
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    • pp.58-62
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    • 1996
  • The structural changes in the electron donor side of the PSII reaction center have been monitored since heat treatment ($45^{\circ}C$ for 5 min) of thylakoids is known to decrease the oxygen evolving activity. In heat-treated spinach chloroplast thylakoids, the inhibitory effect of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) on the electron transport activity of the PSII reaction center from diphenyl carbazide to dichlorophenolindophenol became reduced approximately 3.8 times and [$^{14}C$]-labeled DCMU binding on the D1 polypeptide decreased to 25~30% that of intact thylakoid membranes, implying that the conformational changes of the DCMU binding pocket, residing on the D1 polypeptide, occur by heat treatment. The accessibility of trypsin to the $NH_2$-terminus of the cytochrome b-559 ${\alpha}$-subunit, assayed with Western blot using an antibody generated against the synthetic peptide (Arg-68 to Arg-80) of the COOH-terminal domain, was also increased, indicating that heat-treatment caused changes in the structural environments near the stromal side of the cytochrome b-559 ${\alpha}$-subunit, allowing trypsin more easily to cleave the $NH_2$-terminal domain. Therefore, the structural changes in the electron donor side of the PSII reaction center complexes could be one of the reasons why the oxygen evolving activity of the heat-treated thylakoid membranes decreased.

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The effect of phosphate corrosion inhibitor on steel in synthetic concrete solutions

  • Sail, L.;Ghomari, F.;Khelidj, A.;Bezzar, A.;Benali, O.
    • Advances in materials Research
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    • v.2 no.3
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    • pp.155-172
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    • 2013
  • The study of the corrosion inhibition of armatures made of steel conceived for reinforced concrete by sodium phosphate is the aim object of our experimental tests. Gravimetric and electrochemical measurements were carried in three different Mediums contaminated by chlorides (3% NaCl) with addition of increasing concentrations of sodium phosphate. Inhibitory efficiency reached 80% at an optimal concentration of $7,5{\times}10^{-3}M$, the results obtained using the gravimetric measurements are in good agreement with those obtained by electrochemical methods. However, the monitoring of the pH evolution after 24h shows in the three studied environments, that the pH decreases slightly at 24 hours from the initial pH at $t_0$, due to the presence of corrosion products which change the state of the final solution. Also, scanning electron microscopy revealed the existence of layers of apatite on the metal surface previously treated with the sodium phosphate which confirms the formation of a protective film around the surface of the metal.

A clutter reduction algorithm based on clustering for active sonar systems (능동소나 시스템을 위한 군집화 기반의 클러터 제거 기법)

  • Kwak, ChulHyun;Cheong, Myoung Jun;Ahn, Jae-Kyun
    • The Journal of the Acoustical Society of Korea
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    • v.35 no.2
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    • pp.149-157
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    • 2016
  • In this paper, we propose a new clutter reduction algorithm, which rejects heavy clutter density in shallow water environments, based on a clustering method. At first, it applies the density-based clustering to active sonar measurements by considering speed of targets, pulse repetition intervals, etc. We assume clustered measurements as target candidates and remove noise, which is a set of unclustered measurements. After clustering, we classify target and clutter measurements by the validation check method. We evaluate the performance of the proposed algorithm on synthetic data and sea-trial data. The results demonstrate that the proposed algorithm provides significantly better performances to reduce clutter than the conventional algorithm.

A comparative study for adsorption of carbolic acid by synthetic resins

  • Uslu, Hasan;Bamufleh, Hisham S.
    • Membrane and Water Treatment
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    • v.6 no.6
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    • pp.439-449
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    • 2015
  • Carbolic Acid which is called phenol is one of the important starting and/or intermediate materials in various industrial processes. However, its excessive release into environment poses a threat to living organisms, as it is a highly carcinogens and hazardous pollutant even at the very low concentration. Thus removal of phenol from polluted environments is very crucial for sustainable remediation process. We developed a low cost adsorption method for separating phenol from a model aqueous solution. The phenol adsorption was studied using two adsorbents i.e., Amber lite XAD-16 and Amber lite XAD-7 HP with a constant amount of resin 0.1 g at varying aqueous phenol concentrations ($50-200mgL^{-1}$) at room temperature. We compared the efficacy of two phenol adsorbents for removing higher phenol concentrations from the media. We investigated equilibrium and kinetics studies of phenol adsorption employing Freundlich, Temkin and Langmuir isotherms. Amberlite XAD-16 performed better than Amberlite XAD-7 HP in terms of phenol removal efficiency that amounted to 95.52%. Pseudo second order model was highly fitted for both of the adsorption systems. The coefficient of determination ($R^2$) with Langmuir isotherm was found to be 0.98 for Amberlite XAD-7 HP. However, Freundlich isotherm showed $R^2$ value of 0.95 for Amberlite XAD-16, indicating that both isotherms could be described for the isotherms on XAD-7 HP and Amberlite XAD-16, respectively.

A Study on the Invention of Synthetic Visual Analysis Model for Joseon Royal Tombs (조선 왕릉의 경관관리를 위한 통합적 시각구조분석모델 모색방안)

  • Hong, Youn-Soon;Lee, Ai-Ran;Paek, Chong-Chul
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.33 no.2
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    • pp.49-57
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    • 2015
  • The purpose of this study is to provide the visual landscape modelling on Josun royal tombs and surrounding. The visual landscape of traditional heritage is illustrated by the main view points of analysis. This analysis examines limited view points and cannot reflect a reality of environments. Nowadays various equipments and methodologies are developed for the visual landscape research. This study used new tools for analysis which are Sketch up (3D simulation) and mini helicopter (UAV). With those tools, this research examines not only view points of the analysis but also axis views and disincentive environments as a complex analysis. First of all, the research examined 3D modelling for the virtual simulation and drew coordinates and routes for the UAV operating. Secondly, UAV followed this routes and took linear and continuous views that are real scenes. As a result, it drew 3D simulation could illustrate and control the changing of environments such as the forest density and seasonal variations. Thus, comparing both of them shows efficiently landscape analysis. Thirdly, the study compared virtual and real landscape. Using this 3D modelling, this paper able to elaborate heritage environment and surrounding which omitted by view point analysis. Although this study has limitation practice and exercise on the field, the results and suggestions contribute to the various historic heritage managements and conservations. Moreover, it helps to explain the complex and dimensional landscape analysis.

Application of SAR DATA to the Study on the Characteristics of Sedimentary Environments in a Tidal Flat (SAR 자료를 이용한 갯벌 퇴적환경 특성 연구)

  • Kim, Kye-Lim;Ryu, Joo-Hyung;Kim, Sang-Wan;Choi, Jong-Kuk
    • Korean Journal of Remote Sensing
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    • v.26 no.5
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    • pp.497-510
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    • 2010
  • In this study, comparisons of the backscattering coefficients and the coherence values which had been extracted from SAR (Synthetic Aperture Radar) images such as JERS-1, ENVISAT and ALOS satellites with surface roughness, surface geometric and soil moisture content were carried out. As the results of analysis using the backscattering coefficient and coherence values from SAR images, the coherence was shown high in the region containing more of mud fraction due to higher viscosity of fine grain-size. A lot of tidal channels were well developed in the Ganghwa tidal flat, affecting the drainage of seawater and subsequent soil moisture content by exposure time of tidal flat. The backscattering coefficient. consequently, appeared to be lower in sand flat and mix flat with decrease of soil moisture. In contrast, most mud flats were distributed at high elevation so that soil moisture was not much influenced by seawater. The backscattering coefficient in mud flat seemed to have a relationship with the density of tidal channel. In addition, lowering backscattering coefficients in the all Ganghwa tidal flat was observed when surface remnant water increased according to the amount of rainfall. The correlation between backscattering coefficient, coherence and sediment environment factors in the Ganghwa tidal flat was investigated. In the future, more quantitative spatial analysis will be helpful to well understand the sedimentary influence of various sediment environment factors.

Abstracted Partitioned-Layer Index: A Top-k Query Processing Method Reducing the Number of Random Accesses of the Partitioned-Layer Index (요약된 Partitioned-Layer Index: Partitioned-Layer Index의 임의 접근 횟수를 줄이는 Top-k 질의 처리 방법)

  • Heo, Jun-Seok
    • Journal of Korea Multimedia Society
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    • v.13 no.9
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    • pp.1299-1313
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    • 2010
  • Top-k queries return k objects that users most want in the database. The Partitioned-Layer Index (simply, the PL -index) is a representative method for processing the top-k queries efficiently. The PL-index partitions the database into a number of smaller databases, and then, for each partitioned database, constructs a list of sublayers over the partitioned database. Here, the $i^{th}$ sublayer in the partitioned database has the objects that can be the top-i object in the partitioned one. To retrieve top k results, the PL-index merges the sublayer lists depending on the user's query. The PL-index has the advantage of reading a very small number of objects from the database when processing the queries. However, since many random accesses occur in merging the sublayer lists, query performance of the PL-index is not good in environments like disk-based databases. In this paper, we propose the Abstracted Partitioned-Layer Index (simply, the APL-index) that significantly improves the query performance of the PL-index in disk-based environments by reducing the number of random accesses. First, by abstracting each sublayer of the PL -index into a virtual (point) object, we transform the lists of sublayers into those of virtual objects (ie., the APL-index). Then, we virtually process the given query by using the APL-index and, accordingly, predict sublayers that are to be read when actually processing the query. Next, we read the sublayers predicted from each sublayer list at a time. Accordingly, we reduce the number of random accesses that occur in the PL-index. Experimental results using synthetic and real data sets show that our APL-index proposed can significantly reduce the number of random accesses occurring in the PL-index.

A Geodesign Methodology for Landscape Design (조경설계를 위한 Geodesign 방법론)

  • Ko, Jae Yong;Kim, Eun Hyung
    • Spatial Information Research
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    • v.23 no.6
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    • pp.77-87
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    • 2015
  • A design methodology for sustainable on the earth requires a synthetic, and holistic perspective to understand natural processes and urban environments. The apperceptive, holistic landscape design methodology includes one united environment combining analysis, planning and design. In addition, the individual process needs to provide enough spatial information and demands evaluation and understanding on the impact of a design result. The perspective and vision of Ian Mcharg, as asserted in his book, Design with Nature (1969), that the earth is one superorganism is being realized with Geodesign technologies. This paper made the following research efforts which can overcome the limit of the present GIS technologies for the sustainable landscape design: Review of the previous researches, analysis of foreign Geodesign cases and applied theories, suggestion of a Geodesign methodology for landscape design, selection of Geodesign tools and technologies for the implementation of the methodology, and finally the demonstration of effectiveness and potentiality by the application of the methodology.

Three-dimensional porous graphene materials for environmental applications

  • Rethinasabapathy, Muruganantham;Kang, Sung-Min;Jang, Sung-Chan;Huh, Yun Suk
    • Carbon letters
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    • v.22
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    • pp.1-13
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    • 2017
  • Porous materials play a vital role in science and technology. The ability to control their pore structures at the atomic, molecular, and nanometer scales enable interactions with atoms, ions and molecules to occur throughout the bulk of the material, for practical applications. Three-dimensional (3D) porous carbon-based materials (e.g., graphene aerogels/hydrogels, sponges and foams) made of graphene or graphene oxide-based networks have attracted considerable attention because they offer low density, high porosity, large surface area, excellent electrical conductivity and stable mechanical properties. Water pollution and associated environmental issues have become a hot topic in recent years. Rapid industrialization has led to a massive increase in the amount of wastewater that industries discharge into the environment. Water pollution is caused by oil spills, heavy metals, dyes, and organic compounds released by industry, as well as via unpredictable accidents. In addition, water pollution is also caused by radionuclides released by nuclear disasters or leakage. This review presents an overview of the state-of-the-art synthesis methodologies of 3D porous graphene materials and highlights their synthesis for environmental applications. The various synthetic methods used to prepare these 3D materials are discussed, particularly template-free self-assembly methods, and template-directed methods. Some key results are summarized, where 3D graphene materials have been used for the adsorption of dyes, heavy metals, and radioactive materials from polluted environments.

Genomic Analysis of a Freshwater Actinobacterium, "Candidatus Limnosphaera aquatica" Strain IMCC26207, Isolated from Lake Soyang

  • Kim, Suhyun;Kang, Ilnam;Cho, Jang-Cheon
    • Journal of Microbiology and Biotechnology
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    • v.27 no.4
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    • pp.825-833
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    • 2017
  • Strain IMCC26207 was isolated from the surface layer of Lake Soyang in Korea by the dilutionto-extinction culturing method, using a liquid medium prepared with filtered and autoclaved lake water. The strain could neither be maintained in a synthetic medium other than natural freshwater medium nor grown on solid agar plates. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain IMCC26207 formed a distinct lineage in the order Acidimicrobiales of the phylum Actinobacteria. The closest relative among the previously identified bacterial taxa was "Candidatus Microthrix parvicella" with 16S rRNA gene sequence similarity of 91.7%. Here, the draft genome sequence of strain IMCC26207, a freshwater actinobacterium, is reported with the description of the genome properties and annotation summary. The draft genome consisted of 10 contigs with a total size of 3,316,799 bp and an average G+C content of 57.3%. The IMCC26207 genome was predicted to contain 2,975 protein-coding genes and 51 non-coding RNA genes, including 45 tRNA genes. Approximately 76.8% of the protein coding genes could be assigned with a specific function. Annotation of the IMCC26207 genome showed several traits of adaptation to living in oligotrophic freshwater environments, such as phosphorus-limited condition. Comparative genomic analysis revealed that the genome of strain IMCC26207 was distinct from that of "Candidatus Microthrix" strains; therefore, we propose the name "Candidatus Limnosphaera aquatica" for this bacterium.