• Title/Summary/Keyword: physical and chemical effects

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Analysis of Prediction Results and Grid Size Dependence According to Changes in Fire Area (화원면적 변화에 따른 격자 크기 의존도 및 예측결과 분석)

  • Yun, Hong-Seok;Hwang, Cheol-Hong
    • Fire Science and Engineering
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    • v.33 no.6
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    • pp.9-19
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    • 2019
  • In fire simulations for building fire safety evaluation, changes in the fire area and grid size can significantly influence the prediction results. Therefore, the effects of area changes of the fire source with identical maximum heat release rates on the prediction results of a compartment fire were investigated. The dependence of the prediction results on the grid size using the identical fire area was also examined. No significant changes were observed in the thermal and chemical characteristics of the fires with variable grid sizes, even though the fire area was changed when six or more grids were set based on the fire diameter. In addition, changes in the fire area caused significant differences in the prediction of major physical quantities associated with available safety egress time (ASET) within a compartment. However, the fire area changes did not considerably influence the overall fire characteristics outside the compartment after reaching a certain distance from the opening.

Study on removal method of Brownish black and White crust on Mural in Koguryo Tomb (고구려 고분벽화 오염물질 제거에 관한 연구)

  • Han, Kyeong-Soon;Lim, Kwon-Woong
    • Journal of Conservation Science
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    • v.22
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    • pp.99-108
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    • 2008
  • This research aimed to provide a scientific methodology for removing white and black/brown coloured stains on the wall paintings of tombs of Jinpari No 1 and No 4. in the Democratic People's Republic of Korea. For the analysis of chemical composition of stains of the samples from the wall paintings, a microscope and SEM/EDX were used. The analysis confirmed that the fomula of white coloured stains should be $CaSO_4$ or $CaCO_3$ and the black/brown coloured stains should be $CaSO_4$ or $CaCO_3$ with soil deposition. Because of the difficulties of testing several cleaning solutions on sample patches of large area of the painting, the author considered a risk-free cleaning solution as being the most appropriate one, with Ammonium bicarbonate and Anion exchange resin showing satisfactory cleaning effect without visible side effects. For the removal of dense layer of stains, the research suggested that physical cleaning should be followed by applying a cleaning solution.

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Synthesis and Properties of Aromatic Poly(ether-ether-ester)s having Flexible Side Chain (유연한 곁사슬을 갖는 방향족 Poly(ether-ether-ester)의 합성 및 성질)

  • Bang, Moon-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.11
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    • pp.3060-3065
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    • 2009
  • A series of wholly aromatic Poly(ether-ether-ester)s with flexible side chain was synthesized by direct polycondensation from ether linkaged triad diol and 2,5-dialkoxyterephthalic acid. The chemical structures and physical properties of these polymers were investigated by using $^1H$-NMR, FT-IR, DSC and TGA. As results of investigations, the inherent viscosities($\eta$inh) measured at $40^{\circ}C$ in 1,1,2,2-tetrachloroethane(TCE) were 0.45~0.86 dl/g and initial decomposition(Td) in TGA occurred at 378~418 $^{\circ}C$ in N2 gas. The majority of these polymers were soluble in organic solvents used in this experiments at elevated temperatures. Melting temperatures(Tm) decreased with increasing the length of the side chain and showed odd-even effects.

Development of Three-Dimensional Knit Models through Rib & Purl Structures (리브편 조직과 펄편 조직을 이용한 입체 니트 구조의 개발)

  • Choi, Won-Seok;Lee, Youn-Hee
    • The Research Journal of the Costume Culture
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    • v.18 no.1
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    • pp.109-117
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    • 2010
  • Knit fabrics are created on diverse machines with diverse knit loops and conditions to make different patterns and fabric types. Dimensional modifications of knit fabrics can also be achieved by numerous methods such as different knit-loop structures, different types of yarns, or different finishing processes including heat setting, steaming, chemical treatment et cetera. This research develops and explores sophisticated three-dimensional knit fabrics by combining the several different knit stitches including rib and purl. This study focuses on 3D knit models created on modern electronic weft (flat V-bed) knitting machines which have capability of individual needle selection. Several samples of the 3D knitted fabrics are also examined in this research. This research furthermore suggests new types of knitted fashion garment made by using the interesting physical effects.

CND41, a DNA-binding protein in chloroplast nucleoid, and its function

  • Sato, Fumihiko;Murakami, Shinya;Chatani, Hiroshi;Nakano, Takeshi
    • Proceedings of the Botanical Society of Korea Conference
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    • 1999.07a
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    • pp.51-56
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    • 1999
  • Plastids, which are organelles unique to plant cells, bear their own genome that is organized into DNA-protein complexes (nucleoids). Regulation of gene expression in the plastid has been extensively investigated because this organelle plays an important role in photosynthesis. Few attempts, however, have been made to characterize the regulation of plastid gene expression at the chromosomal structure, using plastid nucleoids. In this report, we summarize the recent progress in the characterization of DNA-binding proteins in plastids, with special emphasis on CND41, a DNA binding protein, which we recently identified in the choloroplast nucleoids from photomixotrophically cultured tobacco cells. CND41 is a protein of 502 amino acids which consisted of a transit peptide of 120 amino acids and a mature protein of 382 amino acids. The N-terminal of the 'mature' protein has lysine-rich region which is essential for DNA-binding. CNA41 also showed significant identities to some aspartyl proteases. Protease activity of purified CND41 has been recently confirmed and characterized. On the other hand, characterization of accumulation of CND41 both in wild type and transgenic tobacco with reduced amount of CND41 suggests that CND41 is a negative regulator in chloroplast gene expression. Further investigation indicated that gene expression of CND41 is cell-specifically and developmentally regulated as well as sugar-induced expression. The reduction of CND41 expression in transgenic tobacco also brought the stunted plant growth due to the reduced cell length in stem. GA3 treatment on apical meristem reversed the dwarf phenotype in the transformants. Effects of CND41 expression on GA biosynthesis will be discussed.

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Rapid Thermal Annealing for Ag Layers on SiO2 Coated Metal Foils (이산화규소 증착된 스테인레스 기판위에 형성된 은 금속 박막의 급속 열처리에 대한 효과)

  • Kim, Kyoung-Bo
    • Journal of Convergence for Information Technology
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    • v.10 no.8
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    • pp.137-143
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    • 2020
  • This study examined the effects of rapid thermal annealing (RTA) on the physical and chemical characteristics of thin silver (Ag) layers on SiO2 coated metal foils. Ag layers were annealed at various temperatures of the range between 150 ℃ and 550 ℃ for 20 min. The surface roughness and resistivity are increased at the annealing temperatures of 550 ℃. We also found that oxygen (O) and silicon (Si) atoms exist at the Ag film surface by using compositional analysis in the annealing temperatures of 550 ℃. The total reflectance is decreased with increasing temperature. These phenomena are due to an out-diffusion of Si atoms from SiO2 layers during the RTA annealing. The results offer the possibility of using it as a substrate for various flexible optoelectronic devices.

Introduction of Various Amine Groups onto Poly(glycidyl methacrylate)-g-MWNTs and their Application as Biosensor Supports (폴리(글리시딜 메타크릴레이트)가 그래프트된 다중벽 탄소나노튜브에 다양한 아민 그룹의 도입과 바이오센서 지지체로서의 응용)

  • Chung, Da-Jung;Kim, Ki-Chul;Choi, Seong-Ho
    • Polymer(Korea)
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    • v.36 no.4
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    • pp.470-477
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    • 2012
  • A tyrosinase-immobilized biosensor was developed based on various amine-modified multi-walled carbon nanotube (MWNT) supports for the detection of phenolic compounds. MWNTs with various amine groups were prepared by radiation-induced graft polymerization of glycidyl methacrylate (GMA) onto MWNT supports and the subsequent amination of poly(GMA) graft chains. The physical and chemical properties of the poly(GMA)-grafted MWNT supports and the aminated MWNT supports were investigated by SEM, XPS, and TGA. Furthermore, the electrochemical properties of the prepared tyrosinase-modified biosensor based on MWNT supports with amine groups were also investigated. The response of the enzymatic biosensor was in the range of 0.1-0.9 mM for the concentration of phenol in a phosphate buffer solution. Various parameters influencing biosensor performance have been optimized: binder effects, pH, temperature, and the response to various phenolic compounds. The biosensor was tested on phenolic compounds contained in two different commercial red wines.

Manufacture of $\alpha-Al_2O_3$ from aluminous Shale (반토혈암으로부터 $\alpha-Al_2O_3$제조에 관한 연구)

  • 한오형;마동철;최경수
    • Resources Recycling
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    • v.3 no.3
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    • pp.21-26
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    • 1994
  • In present study an attempt has been made to extract the high purity $Al_2O_3$from domestic aluminous shale. The processes of the salt roasting with ammonium sulfate, extraction with sulfuric acid and calcination were adopted. In the extraction of alumina, the effects of the sulfuric acid concentration, the reaction time and the temperature has been investigated. The reaction products were analyzed by X-ray diffraction, DTA-TG, chemical analysis and SEM. The results are summerized as follows: 1)The pretreatment conditions were 0.6M-$(NH_4)_2SO_4$and $650^{\circ}C$ in sintering temperature. 2) The optimum extraction conditions were $10%-H_2SO_4$ and 240 minutes in acid treating time. 3)Physical properties of sintering materials were confirmed as $\alpha-Al_2O_3$ by X-ray diffraction method and the purity of $\alpha-Al_2O_3$ was 99.23%.

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Effects of Ethylene Oxide Fumigation and Gamma Irradiation on the Quality of Dried Agricultural Products (Ethylene Oxide 처리와 Gamma가 조사가 건조 농산물의 품질에 미치는 영향)

  • 조한옥;권중호;변명우;양재승;김영재
    • Journal of Food Hygiene and Safety
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    • v.1 no.2
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    • pp.133-141
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    • 1986
  • Gamma irradiation as a new physical treatment was applied to comparative researches with a conventional chemical fumigant on the microbiologicai and physicochemical qualities of selected agricultural products such as powdered hot pepper soybean paste,. oyste.mushroom powder, carrot flake, and raw sesame. The microorganisms contaminated in the sample, including total bacteria, thermophiles, acid tolerant bacteria, fungi, osmophilic molds and coliforms were sterilized with irradiation doses of 7-10 kGy, while ethylene oxide (E.O) fumigation proved insufficient for the destruction of them. An optimum dose of irradiation was less detrimental than E.O. fumigation to the physicochemical properties of the sample. Sensory evaluation after three months of storage at room temperatures showed that the overall acceptability of irradiated sample was higher than that of the non treated control as well as E.O. fumigated samples.

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A Study of Extracting Appropriate Conditions for Efficient Desalination for the Underwater Archaeological Ceramics from Ma Island in Taean (태안 마도출토 도자기의 효율적 탈염처리를 위한 조건도출 연구)

  • Nam, Byeong-Jik;Park, Dae-Woo;Kang, Hyun-Mi;Jang, Sung-Yoon;Jung, Yong-Hwa
    • Journal of Conservation Science
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    • v.26 no.2
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    • pp.133-142
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    • 2010
  • This paper focused on desalination method for the underwater archaeological ceramics. The desalination method applied in this study takes additional conditions such as the amount of desalting water, temperature, and agitation conditions and compares the effects of desalt process. The result of efficiency rate appears that the twenty-times of the object weight of desalting water is more effective than that of ten-times one, but shows less economic compared to the cost. In addition, the research shows that the efficiency rate has been improved around 20 to 30 %, yet such improvement is not taken into account as an effective result considering the risk of damage from the physical and chemical impact and the consumption of energy in applying additional method.