• 제목/요약/키워드: functional transfer

검색결과 564건 처리시간 0.025초

산지사면의 실측토양수분을 이용한 전이함수 모형의 적용 (Transfer Functional Modeling Using Soil Moisture Measurements at a Steep Forest Hillslope)

  • 김상현
    • 한국환경과학회지
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    • 제22권4호
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    • pp.415-424
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    • 2013
  • In this paper, time series of soil moisture were measured for a steep forest hillslope to model and understand distinct hydrological behaviours along two different transects. The transfer function analysis was presented to characterize temporal response patterns of soil moisture for rainfall events. The rainfall is a main driver of soil moisture variation, and its stochastic characteristic was properly treated prior to the transfer function delineation between rainfall and soil moisture measurements. Using field measurements for two transects during the rainy season in 2007 obtained from the Bumrunsa hillslope located in the Sulmachun watershed, a systematic transfer functional modeling was performed to configure the relationships between rainfall and soil moisture responses. The analysis indicated the spatial variation pattern of hillslope hydrological processes, which can be explained by the relative contribution of vertical, lateral and return flows and the impact of transect topography.

Single Electron Transfer Promoted Photocyclization Reactions of ($\omega$-Phthalimidoalkylthio) acetic Acids

  • Yoon, Ung-Chan;Lee, Sang-Jin;Oh, Sun-Wha;Cho, Dae-Won
    • Journal of Photoscience
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    • 제8권3_4호
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    • pp.99-104
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    • 2001
  • Studies have been conducted to explore single electron transfer (SET) promoted photocyclization reactions of ($\omega$-phthalimidoalkylthio)acetic acids (alkyl=ethyl, n-propyl, n-butyl, n -hexyl and n-nonyl). Photocyclizations occur in methanol in modest yields to produce cyclized products in which phthalimide carbonyl carbon is bonded to the carbon of side chain in place of the carboxylic group. The initially formed cyclized products undergo efficient water eliminations to produce enthiol ethers in secondary ground state reactions.

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Photocyclization Reactions of ($\omega$-Phthalimidoalkoxy)acetic Acids via Sequential Single Electron Transfer-Decarboxylation Pathways

  • Yoon, Ung-Chan;Lee, Chan-Woo;Oh, Sun-Wha;Oh, Sun-Wha;Hyun Jin kim;Lee, Sang-Jin
    • Journal of Photoscience
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    • 제7권4호
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    • pp.143-148
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    • 2000
  • Studies have been conducted to explore single electron transfer(SET) promoted photocyclization of ($\omega$-phthalimidoalkoxy)acetic acids(alkoxy=ethoxy, n-propoxy and n-butyloxy). Photocyclizations occur in methanol or acetone in high yields to produce cyclized products in which phthalimide carbonyl carbon is bonded to the carbon of side chain in place of the carboxylic group. These photocyclizations are thought to proceed through pathways involving intramolecular SET from oxygen in the $\alpha$-carboxymethoxy groups to the singlet excited state phthalimide moieties followed by decarboxylation of the intermediate $\alpha$-carboxymethoxy cation fadicals and cyclizations by radical coupling. The photocyclizations occur ca. three times faster in both methanol or acetone with one equivalent of sodium hydroxide added to the reactions and occur slower in acetone than in methanol. The efficient and regiselective cyclization reactions observed for photolyses in methanol represent synthetically useful processes for construction of heterocyclic compounds.

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기능성 분자재료의 발전 방향 (A Scope of Functional Molecular Materials)

  • 신동명;강도열
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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    • pp.136-138
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    • 1990
  • In developing, microscopic scale electrical and electronic devices, molecular level Insulators and functional electric conductors are fundamental. The properties of the electrical-insulating thin film materials are very much dependent on defects and electron transfer rate. There are number of companies which try to reduce defects and control electrical conductivity. Functional electrical conductors are more demanding subject in electrical fields. Reorganization energy around the sites that generate the electrons and holes are very important for the electron transfer in the organic thin layers.

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제과제빵기계의 열전달 해석 (Heat Transfer Analysis of Bakery Machine)

  • 이종선
    • 한국산학기술학회논문지
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    • 제13권10호
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    • pp.4405-4410
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    • 2012
  • 본 논문의 목적은 제과제빵기계인 다기능 도우 컨디셔너의 열전달 해석에 있다. 도우 컨디셔너는 제과제빵의 원료인 생지(dough)를 숙성시키는 중요한 기계로서 사용량이 증가하고 있다. 새로운 형태의 다기능 도우 컨디셔너를 제작하기 위하여 자동 설계프로그램인 Solidworks를 활용하여 설계하였으며 이를 근거로 3차원 유한요소 해석코드인 ANSYS를 활용하여 열전달 해석을 수행하였다. 해석결과로서 다기능 도우 컨디셔너의 내부온도와 열유속을 구하였으며 이 결과는 다기능 도우 컨디셔너의 제작에 활용되었다.

Reaction between Gas-phase Hydrogen Atom and Chemisorbed Bromine Atoms on a Silicon(001)-(2X1) Surface

  • Park, Jong-Keun;Ree, Jong-Baik;Lee, Sang-Kwon;Kim, Yoo-Hang
    • Bulletin of the Korean Chemical Society
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    • 제28권12호
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    • pp.2271-2278
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    • 2007
  • Electron transfer of a redox protein at a bare gold electrode is too slow to observe the redox peaks. A novel Nafion-riboflavin functional membrane was constructed during this study and electron transfer of cytochrome c, superoxide dismutase, and hemoglobin were carried out on the functional membrane-modified gold electrode with good stability and repeatability. The immobilized protein-modified electrodes showed quasireversible electrochemical redox behaviors with formal potentials of 0.150, 0.175, and 0.202 V versus Ag/AgCl for the cytochrome c, superoxide dismutase and hemoglobin, respectively. Whole experiment was carried out in the 50 mM MOPS buffer solution with pH 6.0 at 25 oC. For the immobilized protein, the cathodic transfer coefficients were 0.67, 0.68 and 0.67 and electron transfer-rate constants were evaluated to be 2.25, 2.23 and 2.5 s?1, respectively. Hydrogen peroxide concentration was measured by the peroxidase activity of hemoglobin and our experiment revealed that the enzyme was fully functional while immobilized on the Nafion-riboflavin membrane.

편마비 환자의 밀기증후군 유무에 따른 기능 회복의 특성 (Characteristics of Functional Recovery in Hemiplegia with and without Pusher Syndrome)

  • 김승원;장우남;황병용
    • The Journal of Korean Physical Therapy
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    • 제15권4호
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    • pp.34-45
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    • 2003
  • A 'pusher syndrome' encompassing postural imbalance and hemi-neglect is believed to aggravate the prognosis of stroke patients. The patients with pusher syndrome show a particular posture that pushing away from the unaffected side of the body. The objective of this study was to investigate associated proprioception, associated neuro-psychological symptoms and characteristics of functional outcome with and without pusher syndrome. The subjects of this study were 58 acute stroke patients who been rehabilitated at two university hospitals in Seoul and Buchun. Data were collected using proprioception test and line bisection test. The ability of ADL was assessed by the Modified Barthel Index, transfer by the Functional Independence Measure, and balance by the Modified Motor Assessment Scale. The results were that significant difference was found in the presence of proprioception, in the incidence of hemineglect and anosognosia, and in the score of ADL, transfer and balance between patients with and without pusher syndrome. Patients without pusher syndrome gained more motor score than patients with pusher syndrome. From improvement of view, patients with pusher syndrome gained the lowest score in ability of transfer. The finding suggest that the patients with pusher syndrome is a poorer functional outcome, be related to proprioception, hemineglect and anosognosia.

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Photoaddition Reactions of N-Methylthiophthalimide with $\alpha$-Silyl-n-electron Donors via Single Electron Transfer-Desilylation and Hydrogen Atom Abstraction Pathways

  • Yoon, Ung-Chan;Oh, Sun-Wha;Moon, Seong-Chul;Hyung, Tae-Gyung
    • Journal of Photoscience
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    • 제9권1호
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    • pp.17-22
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    • 2002
  • Studies have been conducted to explore photoaddition reactions of N-methylthiophthalimide with $\alpha$-silyl-n-electron donors Et$_2$NCH$_2$SiMe$_3$, n-PrSCH$_2$SiMe$_3$ and EtOCH$_2$SiMe$_3$. Photoaddition of $\alpha$-silyl amine Et$_2$NCH$_2$SiMe$_3$ to N-methylthiophthalimide occurs in $CH_3$CN and benzene to produce non-silicon containing adduct in which thiophthalimide thione carbon is bonded to $\alpha$-carbon of $\alpha$-silyl amine in place of the trimethylsilyl group. In contrast, photoaddition of EtOCH$_2$SiMe$_3$ to N-methylthiophthalimide generates two diastereomeric adducts in which thiophthalimide thione carbon is connected to $\alpha$-carbon of $\alpha$-silyl ether in place of u-hydrogen. Based on a consideration of the oxidation potentials of u-silyl-n-electron donors and the nature of photoadducts, mechanism for these photoadditions involving single electron transfer(SET) -desilylation and H atom abstraction pathways are proposed.

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