• 제목/요약/키워드: molecular distribution

검색결과 1,397건 처리시간 0.026초

Molecular Dynamics in Paraelectric Phase of KH2PO4 Crystals Studied by Single Crystal NMR and MAS NMR

  • Paik, Younkee;Chang, Celesta L.
    • 한국자기공명학회논문지
    • /
    • 제17권1호
    • /
    • pp.19-23
    • /
    • 2013
  • The temperature dependences of the NMR spectrum and the spin-lattice relaxation times in $KH_2PO_4$ were investigated via single-crystal NMR and MAS NMR. The stretched-exponential relaxation that occurred because of the distribution of correlation times was indicative of the degree of the distribution of the double-well potential on the hydrogen bond. The behaviors responsible for the strong temperature dependences of the $^1H$ and $^{31}P$ spin-lattice relaxation times in the rotating frame $T_{1{\rho}}$ in $KH_2PO_4$ are likely related to the reorientational motion of the hydrogen-bond geometry and the $PO_4$ tetrahedral distortion.

반복 적응법에 의한 SAR 잡음 제거 (Adaptive Iterative Depeckling of SAR Imagery)

  • 이상훈
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2007년도 춘계학술대회 논문집
    • /
    • pp.126-129
    • /
    • 2007
  • In this paper, an iterative MAP approach using a Bayesian model based on the lognormal distribution for image intensity and a GRF for image texture is proposed for despeckling the SAR images that are corrupted by multiplicative speckle noise. When the image intensity is logarithmically transformed, the speckle noise is approximately Gaussian additive noise, and it tends to a normal probability much faster than the intensity distribution. The MRF is incorporated into digital image analysis by viewing pixel type s as states of molecules in a lattice-like physical system defined on a GRF. Because of the MRFGRF equivalence, the assignment of an energy function to the physical system determines its Gibbs measure, which is used to model molecular mteractions. The proposed adaptive iterative method was evaluated using simulation data generated by the Monte Carlo method. In the extensive experiments of this study, the proposed method demonstrated the capability to relax speckle noise and estimate noise-free intensity.

  • PDF

호알칼리성 목질분해 효소를 이용한 폐지 재생(제2보) - 알칼리성 목질분해 효소 정제 및 섬유 반응 특성 - (Recycling of Waste Paper with Alkaline Cellulolytic Enzyme (II) - Purification of alkaline cellulolytic enzymes and characteristics of reaction with fiber -)

  • 강석현;이중명;박성배;엄태진
    • 펄프종이기술
    • /
    • 제36권1호
    • /
    • pp.24-29
    • /
    • 2004
  • Alkaline cellulolytic enzymes from cultured medium of Coprinus cinereus 2249 were purified with gel and ion-exchange chromatography and characteristics of those enzyme proteins were investigated. A fiber length distribution and a crystallinity of cellulose and sugar composition of enzyme treated Mixed Office Wastepaper(MOW) and Unbleached Kraft Pulp(UKP) were analysed. The conclusion could summarized as follows; \circled1 Alkaline and acidic, endo- and exo-glucanases were purified from cultured medium of Coprinus cinereus 2249. \circled2 The approximate molecular weight of alkaline endo-glucanase was 42 kDa, and also that of alkaline exo-glucanase was 50 kDa. A fiber length distribution and a crystallization of cellulose and sugar composition of enzyme treated MOW and UKP were not so much changed with original paper and pulp.

First Record of Cleantioides planicauda (Crustacea: Isopoda: Holognathidae) from South Korea

  • Song, Ji-Hun;Kim, Min-Seop;Min, Gi-Sik
    • Animal Systematics, Evolution and Diversity
    • /
    • 제30권1호
    • /
    • pp.26-32
    • /
    • 2014
  • Cleantioides planicauda (Benedict, 1899) has previously been recorded in China and Japan. In the present study, to our knowledge, we report for the first time the occurrence of this species in South Korea. Here, we provide detailed descriptions and illustrations of the diagnostic characteristics of C. planicauda. Further, for the first time, we determined the partial sequence of mitochondrial cytochrome c oxidase subunit 1 (CO1) gene of C. planicauda for molecular characteristic. Additionally, we provide a key to the Korean species and distribution of the genus Cleantioides. As a result of this study, four species of the genus Cleantioides, including C. planicauda, have now been recorded in South Korea.

주사형 맥스웰응력 현미경에 의한 표면의 전기적 이미지 (Electrical Imaging of Thin Film Surface by Scanning Maxwell-stress Microscopy)

  • 신훈규;권영수
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1998년도 하계학술대회 논문집 D
    • /
    • pp.1508-1510
    • /
    • 1998
  • Recent development of scanning probe microscope techniques has made it possible to investigate, not only microscopic surface topography, but also physical and chemical properties on the nanometer-scale. The scanning Maxwell-stress microscopy (SMM) is surface characterization tool capable of mapping both the surface topography and electrical properties, such as surface potential, surface charge dielectric constant of thin films with a nanometer-scale resolution by means of the AC voltage driven oscillation of metal coated cantilever. In this study, we observed the surface potential distribution and molecular ordering in thin films. We have demonstrated that the SMM can be used for imaging surface potential distribution over the film surface and also be used for detecting surface changes in thin films. This is first step towards the understanding of electrical phenomena in organic and inorganic materials, biological system with SMM.

  • PDF

First Report of Gymnosporangium globosum Causing American Hawthorn Rust in Korea

  • Yun, Hye-Young;Lee, Kyung-Joon;Kim, Young-Ho;Lee, Seung-Kyu
    • The Plant Pathology Journal
    • /
    • 제24권1호
    • /
    • pp.84-86
    • /
    • 2008
  • Field surveys and specimen collections of the rust fungal pathogen Gymnosporangium were carried out for 15 years from 1985 through 1999 in various locations of Korea. Macroscopic and microscopic examinations of morphological characteristics of aecia from the collected specimens revealed that Gymnosporangium globosum is the causal agent of American hawthorn rust disease on Crataegus pinnatifida and C. pinnatifida varmajor. The host plants are new for this rust fungus. G. globosum was found only in Gyeonggi and Chungbuk provinces, indicating that its distribution in Korea is limited. This is a first full description on morphological characters of aecia of G. globosum in Korea.

First Record of Ulva pertusa Kjellman (Ulvales, Chlorophyta) in the Pacific Coast of Mexico

  • Aguilar-Rosasl, Racal;Aguilar-Rosas, Luis E.;Shimada, Satoshi
    • ALGAE
    • /
    • 제23권3호
    • /
    • pp.201-207
    • /
    • 2008
  • Based on samplings during 2006-2007 on the intertidal zone of Playa Tampico, Eréndira and Punta Baja, Baja California, Ulva pertusa Kjellman (Ulvales, Chlorophyta) was recorded for the first time for the Pacific coast of Mexico. An alga native to Asia, U. pertusa has just recently been recorded in the southern coast of California (USA). The identification of U. pertusa was based on the observation of the morphology and reproductive characters of the collected specimens. Furthermore, the species identity was confirmed by molecular comparison between nuclearencoded ITS2 sequences of the Mexican samples and those of other Ulva species in GenBnak data. Habitat and distribution of U. pertusa along the Pacific coast of North America are also described. Considering our new report of its occurrence in Mexico, we conclude that U. pertusa is expanding its geographical distribution by trans-ocean introductions.

국내 토양 휴믹물질의 특성 규명 및 DB 구축에 대한 연구 (Characterization of Humic and Fulvic Acids Extracted at the Soils of Korea and Its DB Establishment)

  • 이창훈;유지호;신현상;정근호;이창우
    • 한국지하수토양환경학회:학술대회논문집
    • /
    • 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
    • /
    • pp.397-400
    • /
    • 2003
  • In this study, humic and fulvic acids in soils at the vicinity of domestic atomic power plants(NPPs), located in Yungkwang(YK), Uljin(UJ), Kori(KR), Koseong(KS), Wolseong(WS) area, and in volcanic ash soils of the Cheju island(Mt. Hanla(HL), Manjanggul(MJ)) were isolated, and characterized using chemical(elemental analysis, proton exchange capacity, molecular size distribution) and spectroscopic(UV/Vis., IR, FL, $^{13}$ C NMR spectra) methods. The results were compared with one another and compiled for their DB establishments. The humic substances distribution (humic acid, fulvic acid, Humin) in the soils were also determined by IHSS standard method. Main purpose of this study was to provide a basic data needed to evaluate the effect of humic substances on the migrational behaviour of radioactive elements in contaminated surface soil.

  • PDF

Effects of Surface Charges on the Retention of Placenta-loaded Liposome Formulations Administered by Intramuscular Route

  • Noh, Sang-Myoung;Park, Da-Eui;Kim, Young-Bong;Oh, Yu-Kyoung
    • Journal of Pharmaceutical Investigation
    • /
    • 제39권5호
    • /
    • pp.333-337
    • /
    • 2009
  • We aimed to optimize the formulation of porcine placental extract (PPE)-loaded liposomes for intramuscular administration and to investigate the effect of surface charges on the muscular retention in mice. PPE-loaded liposomes were formulated to have neutral, anionic, or cationic surface charges. The in vitro release profiles were studied by spectrofluorometry. In vivo distribution patterns at mice were studied using molecular imaging technology. Among the three types of liposomes, 1,2-dioleoyl-3-trimethylammonium-propane and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-based cationic liposomes showed the most prolonged in vitro release profile. Consistent with the in vitro results, the in vivo distribution study revealed that the cationic liposomes were retained at the site of administration for the longest period. Our results suggest the potential of cationic PPE-loaded liposomes for sustained release of the components after intramuscular administration.

Evolutionary Signature of Information Transfer Complexity in Cellular Membrane Proteomes

  • Kim, Jong-Min;Kim, Byung-Gee;Oh, S.-June
    • Genomics & Informatics
    • /
    • 제7권2호
    • /
    • pp.111-121
    • /
    • 2009
  • Cell membrane proteins play crucial roles in the cell's molecular interaction with its environment and within itself. They consist of membrane-bound proteins and many types of transmembrane (TM) proteins such as receptors, transporters, channel proteins, and enzymes. Membrane proteomes of cellular organisms reveal some characteristics in their global topological distribution according to their evolutionary positions, and show their own information transfer complexity. Predicted transmembrane segments (TMSs) in membrane proteomes with HMMTOP showed near power-law distribution and frequency characteristics in 6-TMS and 7-TMS proteins in prokaryotes and eukaryotes, respectively. This reaffirms the important roles of membrane receptors in cellular communication and biological evolutionary history.