• Title/Summary/Keyword: Molecular Characteristics

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Analysis for Scalar Mixing Characteristics using Linear Eddy Model (Linear Eddy Model을 이용한 스칼라의 혼합특성 해석)

  • Kim, H.J.;Ryu, L.S.;Kim, Y.M.
    • Journal of ILASS-Korea
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    • v.11 no.1
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    • pp.1-6
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    • 2006
  • The present study is focused on the small scale turbulent mixing processes in the scalar Held. In order to deal with molecular mixing in turbulent flow, the linear eddy model is addressed. In each realization, the molecular mixing term is implemented deterministically, and turbulent stirring is represented by a sequence of instantaneous, statistically independent rearrangement event called by triplet map. The LEM approach is applied with relatively simple conditions. The characteristics of scalar mixing and PDF profiles are addressed in detail.

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A Study on Nano-Motor of Giga-hertz level Resonance Characteristics (나노모터의 기가급 공진 특성에 대한 연구)

  • Song, Young-Jin;Lee, Jun-Ha
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.1
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    • pp.1-4
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    • 2010
  • We investigated a linear carbon nanotube motor serving as the key building block for nano-scale motion control by using molecular dynamics simulations. This linear nano-motor, is based on the electrostatically telescoping multi-walled carbon-nanotube with ultralow intershell sliding friction, is controlled by the gate potential with the capacitance feedback sensing. The resonant harmonic peaks are induced by the interference between the driving frequencies and its self-frequency. The temperature is very important factor to operate this nanomotor.

Characteristics of the Water Soluble Browning Reaction of Korean Red Ginseng as Affected by Heating Treatment (열처리에 따른 고려홍삼의 수용성 갈변물질의 특성)

  • 이종원;이성계
    • Journal of Ginseng Research
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    • v.22 no.3
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    • pp.193-199
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    • 1998
  • The purpose of this study was to Investigate characteristics of the water soluble browning reaction products (WS-BRPs) from Korean red ginseng by heat treatment. Absorbance of WS- BRPs was increased with increases of heating temperature and time, but pH value were decreased In Muter color value L and b value were decreased, while a value was increased. and absorbance at 280 nm in spectrum of the WS-BRPs was increased according to the increase of heating temperature. When the WS-BRPs were applied on Bio-Gel P-30 column after heating and pH treatment, two majors browning products increased according to the progress on time. And pH 3.0 increased in quantity of high molecular fractions and pH 8.0 increased in quantity of low molecular fractions.

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Culture Characteristics of Streptomyces spp. on Improved Polyacrylamide Gel and Agar Media

  • Han, Hong ui;Baek, Ji-Ho;Yang, Moon
    • Journal of Microbiology
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    • v.34 no.4
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    • pp.384-386
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    • 1996
  • Application of polyacrylamide gel (PAG) instead of agar to solid cultures of Streptomyces spp. was studied. The improved media were prepared by 1) gelling 20 ml of 5% acrylamide in a glass petri dish at room temperature, 2) washing by running water for more than 8 hr to remove residual reaction reagents, 3) drying at 5$0^{\circ}C$ for 12 hr to make a gel film, 4) autoclaving at 121$^{\circ}C$ for 15 min, and 5) swelling gel for about 4 hr by adding sterile liquid medium. In PAG media there were no differences from the observation of morphological characteristics showing during the cellular differentiation on agar media, whereas the ability to utilize carbohydrates differed somewhat from agar media. Agar media thus were little favorable for biochemical tests which the growth was determined depending on the formation of colony, but washed PAG was superior to serve as a solidifying agent.

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Study on Fluid Flow and Thermal Characteristics in a Nanoscale Channel Using MD Simulation (분자 동역학 시뮬레이션을 이용한 나노 스케일 채널 내에서의 유체 유동 및 열적 특성에 관한 연구)

  • Choi, Yong-Seok;Kim, Sung-Jin
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1880-1884
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    • 2004
  • To analyze the fluid flow and thermal characteristics in a nanoscale system, the planar Poiseuille flow of a Lennar-Jones liquid through parallel plates formed by fixed atoms is studied using nonequilibrium molecular dynamics simulations. The role of important simulation parameters such as the channel width, the magnitude of external field, the temperatures of the top and bottom plates, and the interaction potential parameter between fluid and wall atoms, which affect flow patterns and heat transfer rate inside the channel, are investigated. Under the various simulation conditions, interesting phenomena deviated from the continuum predictions have found.

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Cultural Characteristics of a Seedborne Fungus, Bipolaris spicifera Detected from Imported Grass Seeds into Korea

  • Koo, Han-Mo;Lee, Sang-Hun;Chung, Il-Min;Chun, Se-Chul
    • Mycobiology
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    • v.32 no.4
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    • pp.186-189
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    • 2004
  • The study on the cultural characteristics of Bipolaris spicifera was conducted to provide with information for the identification, and inoculation studies, etc. B. spicifera grew well at $30{\sim}35^{\circ}C$ and wide range of pH $5.0{\sim}9.0$. However, the fungal growth was retarded at pH 4.0 and 10.0, respectively. Conidia were germinated with 70% at $30^{\circ}C$ but maintained 50% germination even at $40^{\circ}C$, indicating that this pathogen could infect plants at relatively high temperature. The pathogen could not produce conidia under 24 hr fluorescent light condition for 7 days. In contrast, it produced many more conidia at 24 hr dark condition.

Prevalence and molecular characteristics of 16s rRNA methylase gene rmtB in amikacin resistant Escherichia coli isolated from South Korea

  • Belaynehe, Kuastros Mekonnen;Won, Ho Geun;Yoon, In Joong;Yoo, Han Sang
    • Korean Journal of Veterinary Research
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    • v.59 no.3
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    • pp.157-160
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    • 2019
  • The production of rmtB-encoded 16S rRNA methylases has emerged as a novel mechanism promoting high-level resistance toward aminoglycosides in Gram-negative bacteria. Between 2015 and 2017, 636 distinct commensal Escherichia (E.) coli isolates were collected from different farms in South Korea to determine the prevalence and molecular characteristics of rmtB. The positive rates of rmtB between all the isolates and amikacin-resistant isolates were 1.1 and 100%, respectively. High-level aminoglycoside resistance could be transferred by conjugation from rmtB-positive donors to higher amikacin-resistance efficacies. This is the first report of 16S rRNA methylase-encoding genes in E. coli isolated from food-producing animals in Korea.

Comparison of sericin produced through laboratory- and plant-scale extraction

  • Ye Eun Kim;Chun Woo Kim;In Chul Um
    • International Journal of Industrial Entomology and Biomaterials
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    • v.47 no.1
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    • pp.63-71
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    • 2023
  • In this study, the structural characteristics of sericin recovered from wastewater released from the silk textile industry (Plant sericin) were comparatively analyzed with those of sericin extracted from a silkworm cocoon produced in a laboratory (Lab sericin). To prepare Plant sericin, ethanol was added to wastewater (i.e., a sericin aqueous solution) after the degumming process to remove nonprotein materials, affording a sericin precipitate. To prepare Lab sericin, nonprotein materials were removed from a silkworm cocoon and sericin was subsequently extracted from the cocoon. Lab sericin and Plant sericin exhibited similar solution viscosities, gel strengths, and crystallinity indices, indicative of the similar molecular weights (MWs) of the two sericin samples. In the case of sericin powder, Plant sericin was more crystalline than Lab sericin due to its treatment with ethanol. The findings of this study revealed that sericin recovered from industrial wastewater can be used equally as its MW is similar to that of sericin obtained through laboratory-scale extraction.

Computational approaches for molecular characterization and structure-based functional elucidation of a hypothetical protein from Mycobacterium tuberculosis

  • Abu Saim Mohammad, Saikat
    • Genomics & Informatics
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    • v.21 no.2
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    • pp.25.1-25.12
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    • 2023
  • Adaptation of infections and hosts has resulted in several metabolic mechanisms adopted by intracellular pathogens to combat the defense responses and the lack of fuel during infection. Human tuberculosis caused by Mycobacterium tuberculosis (MTB) is the world's first cause of mortality tied to a single disease. This study aims to characterize and anticipate potential antigen characteristics for promising vaccine candidates for the hypothetical protein of MTB through computational strategies. The protein is associated with the catalyzation of dithiol oxidation and/or disulfide reduction because of the protein's anticipated disulfide oxidoreductase properties. This investigation analyzed the protein's physicochemical characteristics, protein-protein interactions, subcellular locations, anticipated active sites, secondary and tertiary structures, allergenicity, antigenicity, and toxicity properties. The protein has significant active amino acid residues with no allergenicity, elevated antigenicity, and no toxicity.

Two new records of Laurencia decussata and L. pacifica from Korea based on morphological structures and molecular data

  • Paola Romero-Orozco;Boo Yeon Won;Tae Oh Cho
    • Korean Journal of Environmental Biology
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    • v.41 no.4
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    • pp.666-676
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    • 2023
  • Laurencia is a red algal genus that was described by J.V. Lamouroux in 1813. The main characteristics of this genus have been known as the presence of four pericentral cells in an axial segment, secondary pit connections between adjacent epidermal cells, and the presence of corps en cerise in both epidermal and trichoblast cells. Additionally, the tetrasporangia are arranged in a parallel manner, and male branches feature terminal cup-shaped spermatangial pits. Currently, sixteen Korean Laurencia species have been reported based on their morphological characteristics. In this study, Laurencia decussata and L. pacifica have been added as new records to the Korean algal flora based on a combination of morphological observations and molecular analyses of rbcL sequences. Laurencia decussata has expanded from Australia and New Zealand to Korea, while the distribution of L. pacifica has expanded from USA and Mexico to Korea.