• Title/Summary/Keyword: morphology change

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The Effect of Solvent Treatment on the Microstructure and Surface Morphology of PET POY (폴리에스테르 부분배향사의 용매처리에 따른 내부구조 및 표면형태의 변화)

  • 신혜원;유효선
    • Journal of the Korean Society of Clothing and Textiles
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    • v.20 no.3
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    • pp.467-480
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    • 1996
  • Interactions between PET POY and solvents were estimated by the changes in microstructure and surface morphology. Changes in microstructure and surface morphology by the solvent treatments were: an increase in crystallite size, a decrease in interplanar spacing, a change in degree of orientation of crystalline region, a change in surface characteristics.

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The Changes of Microstructure, Morphology, and Mechanical Properties of Solvent Treated PET POY (Partially Oriented Yarn) (폴리에스테르 부분배향사의 용매처리에 따른 내부구조 및 인장성질의 변화)

  • Shin, Hae Won;Ryu, Hyo Seon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.17 no.1
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    • pp.63-75
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    • 1993
  • Partially oriented polyester yarn (PET POY) was treated in the unrestrained state using various solvents at different temperatures. Interactions between PET POY & solvents were estimated by the changes of microstructure, morphology and mechanical properties. The correlation between the changes of microstructure & morphology and the changes of mechanical properties was also studied. TCE, Dioxane, O-DCB, DMF, and BA were found to be active solvents, while Iso-AA and water were found to be weak solvents. PET POY was affected mainly by the solvents when treated with active solvents and affected mainly by heat when treated with weak solvents. Changes by the solvent treatment in microstructure and morphology were : an increase in crystallinity, a change in birefringence, a shrinkage in length, and a change in DSC curve. As for the changes in mechanical properties, findings in the PET POY when treated with solvents were : a decrease in stress-at-break, a change in yield stress, an increase in strain-at-break & yield strain, and a decrease in initial modulus. Changes in microstructure and morphology directly affected the mechanical properties.

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Structural Transcription of Organogels to Mesoporous Silicas: A Chain-length Dependent Morphology and Pore Texture

  • Huang, Yaqun
    • Bulletin of the Korean Chemical Society
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    • v.33 no.11
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    • pp.3711-3718
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    • 2012
  • Here, we report a chain-length dependent morphology and pore structure tailing of mesoporous silica templated from organogels, which is formed by primary alkylamine and ethylene glycol at room temperature. As the chain length of alkylamine changes from 12 to 18, the resulted materials exhibit a morphology change from layers to spheres and platelets, respectively. SEM and TEM observation revealed that these shapes appear to be inherited from their parent organogels. Further pore structure characterization by nitrogen sorption analysis demonstrates that all the resulted silicas exhibit typical IV isotherms indicative of uniform mesopores, and their pore sizes are dependent on the chain length of alkylamine used.

Characteristic Change of Fiber Depending on the Refining Conditions of Reconstituted Tobacco Process (판상엽 고해조건에 따른 섬유특성 변화 평가)

  • Han young-Rim;Sung Yong-Joo;Kim Sam-Kon;Kim Kun-Soo;Han In-Ho
    • Journal of the Korean Society of Tobacco Science
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    • v.27 no.2
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    • pp.195-200
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    • 2005
  • The goal of refining is to treat fibers so they meet the requirements of the papermaking process. The refining process in papermaking has great influence on the quality of the final product by changing the fiber properties, such as fiber length, shape, fine contents and so on. In this study, the effect on the morphological change of fibers by the refining conditions were investigated using the fiber morphology analyzer. Fiber morphology analyzer used to determine which pulps are suitable for producing particular products. Furthermore it is widely used in paper mills to monitor paper quality. The morphological change of fibers according to refining conditions were evaluated out by measuring fiber, shive and fine. In the fiber morphology, the domestic reconstituted tobacco fiber has the bigger average fiber length value than that of the foreign reconstituted tobacco.

환경적 스트레스에 의한 Helicobacter pylori의 형태 변화

  • 이학성;최태부
    • Microbiology and Biotechnology Letters
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    • v.25 no.3
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    • pp.240-247
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    • 1997
  • Bacillary is the most common form of H. pylori observed during human infection. However, it is known that the morphology change of H. pylori from bacillary to coccoid can be occurred with a response to the environmental stresses such as the nutrient depletion, accumulation of toxic metabolites, pH alteration, and exposure to antimicrobial agents. The coccoid form of H. pylori, which is viable but non-culturable in vitro, seems to be the major cause of antibiotic resistancy and high reinfectability of H. pylori. In this regard, we studied the environmental factors that can induce the morphological change in vitro of H. pylori, and the change of fatty acid composition of plasma membrane. The morphological change from bacillary to coccoid could be observed with the depletion of nutrients, pH variation and reactive oxygen species added in the culture media. This morphologic conversion was paralleled by a dramatic decrease in unsaturated fatty acids and an increase in saturated fattv acids of plasma membrane. The change in composition of membrane fatty acid seems to be a kind of protection mechanism of H. pylori against these environmental stresses.

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Temperature-dependent Morphology of Self-assembled InAs Quantum Dots Grown on Si Substrates (Si 기판 위에 형성된 InAs 양자점의 열처리에 의한 표면 상태의 변화)

  • Yoo, Choong-Hyun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.10
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    • pp.864-868
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    • 2007
  • Effect of high-temperature annealing on morphology of fully coherent self-assembled InAs quantum dots' grown on Si (100) substrates at $450^{\circ}C$ by atmospheric pressure metalorganic chemical vapor deposition(APMOCVD) was investigated by atomic force microscopy(AFM). When the dots were annealed at 500 - 600$^{\circ}C$ for 15 sec - 60 min, there was no appreciable change in the dot density but the heights of the dots increased along with the reduction in the diameters. In segregation from the InAs quantum dots and/or from the 2-dimensional InAs wetting layer which was not transformed into quantum dots looked responsible for this change in the dot size. However the change rates remained almost same regardless of annealing time and temperature, which may indicate that the morphological change due to thermal annealing is done instantly when the dots are exposed to high temperature annealing.

Surface morphology modification of vertically-aligned carbon nanotubes by water vapor exposure

  • Adil, Hawsawi;Jeong, Goo-Hwan
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.238.2-238.2
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    • 2015
  • Surface modification of vertically-aligned carbon nanotube (VACNT) is essential in order to meet specific demands for particular applications such as field emission displays, heat dissipation device and potential sun energy conversion due to their superior electrical and thermal conductivity and strong light absorption. In this study, we observe the effect of exposure to water vapor on a different lengths of the surfaces of VACNT. The study was conducted on three different lengths of the VACNT: short length around $200{\mu}m$, medium-length around $500{\mu}m$, and high length around 1 mm. Water exposure time ranges between 2-10 min and temperature of the water ranges from 60 to 120 oC. The result of water vapor exposure mainly show that increasing the exposure time and water temperature give rise to increase of the speed of change on the surface of the VACNT. Especially, the shorter VACNT change their surface morphology most rapidly.

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An Experimental Study on the Water Repellent Property of Mortar Applied Water Repellent Agent of Inorganic Polymer Type (무기질 폴리머계 흡수방지재를 도포한 모르터의 발수성능 평가에 관한 실험적 연구)

  • 김영삼;양승도;유재강;오상근
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2002.05a
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    • pp.31-36
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    • 2002
  • Recently, more interests in surface treatment of structure with water repellent agent are steadily increased, But, investigation of its properties such as protection, durability, morphology of micro structure is not sufficient. Therefore, This paper is aimed for the investigation of water repellent property and change of morphology of micro pores in mortar that is treated by water repellent agent(Inorganic polymer based material). Water repellent property, water absorption coefficient, air permeability, porosity and the observation of micro structure was investigated in different water repellent agent type. The test results indicated that water repellent treated mortar showed low absorption coefficient and air permeability(breathing effect). This is why inorganic polymer is coated at the wall of capillary and micro pores, also, the volume of micro pore is reduced without the change of morphology in micro structure.

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New Evaluation Method for The Particle Size and Morphology Via Change of Ground Particle During a Grinding Process (분쇄공정에서 변화된 입자크기 및 형상특성의 평가방법에 관한 새로운 제언)

  • Choi, Heekyu;Lee, Jehyun;Choi, Junewoo
    • Particle and aerosol research
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    • v.9 no.1
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    • pp.1-6
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    • 2013
  • New evaluation method for the particle size and morphology via change of ground particle during a grinding process was investigated. The grinding experiments were carried by a planetary ball mill. The relationship between the particle outline of the scanning electron microscopy photograph and measurement line, the measurement contact number was evaluated. The value of contact number decreased with the increase in the particle size of the ground sample, and varied with the experimental conditions. The value of contact number, which is related to the particle size of the raw sample, changed at the various experimental conditions.

Regulation of mitochondrial morphology and metabolism by Jak-STAT pathway

  • Rhee, Kun Do
    • Journal of Animal Reproduction and Biotechnology
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    • v.36 no.4
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    • pp.189-193
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    • 2021
  • Jak-STAT pathway is required for embryogenesis, female gametogenesis, cytokine-mediated neuroprotection, diabetes, obesity, cancer, stem cell, and various tissues. The noncanonical role of Jak-STAT in mitochondria function was supported by the detection of STAT protein in mitochondria, however, several studies show that STAT protein is detected in the endoplasmic reticulum (ER), and not in mitochondria. STAT protein may alter mitochondria function without entering mitochondria, this involves regulation of fission and fusion proteins to change mitochondria morphology. However, how changes in mitochondria morphology lead to changes in mitochondria metabolism needs further investigation.