• Title/Summary/Keyword: environmental modification

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Surface Modification and Anchoring Titanium Dioxide on Mesoporous Activated Carbons (다공성 활성탄의 표면 개질 및 이산화티탄 고정)

  • 주창식;박흥재;정갑섭
    • Journal of Environmental Science International
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    • v.12 no.9
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    • pp.1005-1010
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    • 2003
  • For the purpose of surveying any possibility of anchoring titanium dioxide on activated carbons to promote their activities as catalysts and/or adsorbents, two activated carbons were oxidized with ammonium peroxydisulfate and followed by anchoring titanium dioxide. The anchoring of titanium dioxide on the oxidized activated carbons were performed via the adsorption of tetrabutyltitanate, hydrolysis with deionized water, and calcination. The effect of oxidizing and anchoring treatment on the surface element composition, surface area, and pore texture were analyzed by XPS, BET and TPD. The oxidation of activated carbons with ammonium peroxydisulfate introduced carboxyl groups on the surface of activated carbons and these carboxyl groups promoted the anchoring of titanium oxide on the activated carbons. However, the treatments affected the surface area and the porosity of activated carbons.

Study on Rapid Removal of Suspended Solid by Modified Magnetite Powder (마그네타이트 분말의 표면개질화에 의한 부유물질의 고속 제거)

  • 이혁희;박상원
    • Journal of Environmental Science International
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    • v.12 no.9
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    • pp.1017-1023
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    • 2003
  • The high speed elimination process of suspended solid was investigated to treat the pulp waste water by using surface modified magnetite particle and magnetic power. The effects of the various aluminum salts such as Al(NO$_3$)$_3$ㆍ9$H_2O$, AlC1$_3$ㆍ6$H_2O$, $Al_2$(SO$_4$)$_3$ㆍ13∼14 on the COD, BOD and suspended solid were systematically studied. It has been found that the 2.0 wt% of Al was most effective for the modification of Fe$_3$O$_4$ powder and then best for the treatment of pulp waste water, Optimum quantity of modified magnetite in this study was 12 wt%, and aging time was found to be 12 hours. Comparing with the conventional process, the required time for SS removal was drastically decreased. BOB and COD were also effectively removed when applied to the pulp wastewater.

A Study on Development of Advanced Environmental-Resistant Materials Using Metal Ion Processing

  • Fujita Kazuhisa;Kim Hae-Ji
    • Journal of Mechanical Science and Technology
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    • v.20 no.10
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    • pp.1670-1679
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    • 2006
  • The development of the oxidation, wear and corrosion resistant materials that could be used in severe environmental conditions is needed. The elementary technologies for surface modification include ion implantation and/or thin film coating. Furthermore, in order to develop ion implantation technique to the specimens with three-dimensional shapes, plasma-based ion implantation (PBII) techniques were investigated. As a result, it was found that the ion implantation and/or thin film coating used in this study were/was effective for improving the properties of materials, which include implantations of various kinds of ions into TiAl alloy, TiN films formed on surface of base material and coatings in high-temperature steam. The techniques proposed in this study provide useful information for all of the material systems required to use at elevated temperature. For the practical applications, several results will be presented along with laboratory test results.

Oxidative Stress, Nrf2, and Epigenetic Modification Contribute to Anticancer Drug Resistance

  • Kang, Kyoung Ah;Hyun, Jin Won
    • Toxicological Research
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    • v.33 no.1
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    • pp.1-5
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    • 2017
  • Nuclear factor E2-related factor 2 (Nrf2), a transcription factor, controls the expression of genes encoding cytoprotective proteins, including antioxidant enzymes that combat oxidative and electrophilic stress to maintain redox homeostasis. However, recent studies demonstrated that, in cancer, aberrant activation of Nrf2 by epigenetic alterations promotes high expression of cytoprotective proteins, which can decrease the efficacy of anticancer drugs used for chemotherapy. In this review, we summarize recent findings regarding the relationship between oxidative stress, Nrf2, epigenetic modification, and anticancer drug resistance, which should aid in development of new strategies to improve chemotherapeutic efficacy.

Post-Translational Modification of Proteins in Toxicological Research: Focus on Lysine Acylation

  • Lee, Sangkyu
    • Toxicological Research
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    • v.29 no.2
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    • pp.81-86
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    • 2013
  • Toxicoproteomics integrates the proteomic knowledge into toxicology by enabling protein quantification in biofluids and tissues, thus taking toxicological research to the next level. Post-translational modification (PTM) alters the three-dimensional (3D) structure of proteins by covalently binding small molecules to them and therefore represents a major protein function diversification mechanism. Because of the crucial roles PTM plays in biological systems, the identification of novel PTMs and study of the role of PTMs are gaining much attention in proteomics research. Of the 300 known PTMs, protein acylation, including lysine formylation, acetylation, propionylation, butyrylation, malonylation, succinylation, and crotonylation, regulates the crucial functions of many eukaryotic proteins involved in cellular metabolism, cell cycle, aging, growth, angiogenesis, and cancer. Here, I reviewed recent studies regarding novel types of lysine acylation, their biological functions, and their applicationsin toxicoproteomics research.

A Study on the Development of TCM Urban-Mode (도시형-TCM 개발에 관한 연구)

  • 장영기;조경두
    • Journal of Korean Society for Atmospheric Environment
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    • v.9 no.2
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    • pp.132-139
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    • 1993
  • TCM has been used for many environmental impact assessments and many case studies in Korea. TCM was applied to urbvan areas and rolling terrains. But original TCM was developed for rural area, and this model could not reflect the characteristcs of these study sites. This paper analyzed the characteristics of TCM, and modified the algorithm of area source, and modified the vertical wind speed profile exponents and diffusion parameter to make it applicable in urban area. In the process of modification, an important error in area source calculation of original TCM program was found. So that was corrected as follows. $$ Before modification $QC = 0.79788456^*(0.5^*GRID)^**BA/(U(IA, IRUN)^*AA^*BA TCM09310$ After modification $QC = 0.79788456^*(500^*GRID)^**BA/(U(IA, IRUN)^*AA*BA) modified$ $$ Then original TCM and modified TCM-urban mode were compared, and it was found that predicted mean value by original TCM was 7 times higher than observed mean value. But mean value by modified TCM-urban mode was very similar to observed value.

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Seismic behavior factors of buckling-restrained braced frames

  • Kim, Jinkoo;Park, Junhee;Kim, Sang-Dae
    • Structural Engineering and Mechanics
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    • v.33 no.3
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    • pp.261-284
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    • 2009
  • The seismic behavior of a framed structure with chevron-type buckling restrained braces was investigated and their behavior factors, such as overstrength, ductility, and response modification factors, were evaluated. Two types of structures, building frame systems and dual systems, with 4, 8, 12, and 16 stories were designed per the IBC 2003, the AISC LRFD and the AISC Seismic Provisions. Nonlinear static pushover analyses using two different loading patterns and incremental dynamic analysis using 20 earthquake records were carried out to compute behavior factors. Time history analyses were also conducted with another 20 earthquakes to obtain dynamic responses. According to the analysis results, the response modification factors turned out to be larger than what is proposed in the provision in low-rise structures, and a little smaller than the code-values in the medium-rise structures. The dual systems, even though designed with smaller seismic load, showed superior static and dynamic performances.

RNA Modification and Its Implication in Plant Pathogenic Fungi

  • Jeon, Junhyun;Lee, Song Hee
    • The Plant Pathology Journal
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    • v.37 no.6
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    • pp.505-511
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    • 2021
  • Interaction of a pathogen with its host plant requires both flexibility and rapid shift in gene expression programs in response to environmental cues associated with host cells. Recently, a growing volume of data on the diversity and ubiquity of internal RNA modifications has led to the realization that such modifications are highly dynamic and yet evolutionarily conserved system. This hints at these RNA modifications being an additional regulatory layer for genetic information, culminating in epitranscriptome concept. In plant pathogenic fungi, however, the presence and the biological roles of RNA modifications are largely unknown. Here we delineate types of RNA modifications, and provide examples demonstrating roles of such modifications in biology of filamentous fungi including fungal pathogens. We also discuss the possibility that RNA modification systems in fungal pathogens could be a prospective target for new agrochemicals.

The Effect of a Convergence Approach of Home Environment Modification and Task-oriented Intervention on Fall Efficacy and Activity Level of Person with Stroke in the Community (가정환경 수정과 과제기반 중재의 융복합 접근이 지역사회 뇌졸중 환자의 낙상 효능감 및 활동 수준에 미치는 영향)

  • Kim, Su-Kyoung
    • Journal of the Korea Convergence Society
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    • v.13 no.2
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    • pp.39-46
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    • 2022
  • The purpose of this study is to determine the effect of a convergence approach, which applies both home environment modification applied with assistive technology and task-oriented intervention using a fall safety checklist, on the fall efficacy and activity level of stroke patients. 41 persons with stroke(21 experimental groups and 20 control groups) were divided into experimental and control groups. The experimental group was applied environmental modification and the task-oriented intervention using the fall safety checklist for 4 weeks. The control group was provided only the environmental modification. Before and after the intervention, the Korean Activity Card Sort (KACS) and the Korean Falls Efficacy Scale-Korean version (FES-K) were used for evaluation. There was no significant difference in fall efficacy and activity level change between the experimental group and the control group. Both the experimental group and the control group significantly improved the fall efficacy and activity level after the intervention. By applying the results of this study to the clinical field, it will be possible to support stroke patients to live safely and actively participate in the community.