Service-Learning in Language for Specific Purposes: A Case of Korean Language Practicum

While service-learning has been greatly acknowledged as an effective instructional tool in education for the past two decades, it has not been extensively applied to the Korean classroom and Language for Specific Purposes (LSP) settings as of yet. The practical challenges of community-involved service-learning for the less commonly taught language (LCTL) programs such as Korean are discussed. Moreover, community engagement through the campus community combined with the language teaching practicum is suggested for service-learning as an alternative to address the challenges. This study explores the curriculum design of a service-learning for a small language group and offers practical ideas on how to expose the students to campus communities, thereby providing them with cross-cultural insights and language practicum competence that extend beyond classroom language learning. The outcome supports that the campus community engagement effectively provides a hands-on opportunity for the students to practice not only their academics but also their leadership skills through the experience of designing their own service details in collaboration with their campus community partners

Tuning the electronic band structure of PCBM by electron irradiation

Tuning the electronic band structures such as band-edge position and bandgap of organic semiconductors is crucial to maximize the performance of organic photovoltaic devices. We present a simple yet effective electron irradiation approach to tune the band structure of [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM) that is the most widely used organic acceptor material. We have found that the lowest unoccupied molecular orbital (LUMO) level of PCBM up-shifts toward the vacuum energy level, while the highest occupied molecular orbital (HOMO) level down-shifts when PCBM is electron-irradiated. The shift of the HOMO and the LUMO levels increases as the irradiated electron fluence increases. Accordingly, the band-edge position and the bandgap of PCBM can be controlled by adjusting the electron fluence. Characterization of electron-irradiated PCBM reveals that the variation of the band structure is attributed to the molecular structural change of PCBM by electron irradiation

Complex Capacitance Analysis of Porous Carbon Electrodes for Electric Double-Layer Capacitors

A new analytical methodology, complex capacitance analysis, is developed for porous carbons that are employed as electric double-layer capacitor ~EDLC! electrodes. Based on the transmission line model, the imaginary capacitance profiles (Cim vs. log f) are theoretically derived for a cylindrical pore and further extended to multiple pore systems. The theoretical derivation illustrates that two important electrochemical parameters in EDLCs can be estimated from the peak-shaped imaginary capacitance plots: total capacitance from the peak area and rate capability from the peak position. The usefulness of this analysis in estimating EDLC parameters is demonstrated by applying to two sets of practical porous carbon electrodes. In addition, the penetrability distribution curves that are derived from the experimental imaginary capacitance data using the log-normal assumption and discrete Fourier transform allow us to estimate the pore structure of carbon electrodes.This work was supported by KOSEF through the Research Center for Energy Conversion and Storage

Ride Quality Control of a Full Vehicle Suspension System Featuring Magnetorheological Dampers With Multiple Orifice Holes

This study proposes a relationship between the ride comfort of passenger vehicles and two different types of magnetorheological (MR) dampers, with and without orifice holes in the piston. To achieve superior ride comfort, two cylindrical-type MR dampers with identical dimensions (piston radius, pole lengths, and the distance between two poles) are proposed. One of the MR dampers adds the orifice holes in the piston bobbin to obtain a relatively low damping force slope in the low piston velocity region. To enhance the ride quality of a passenger vehicle, the damping force slope of the rear damper should be more gradual than that of the front damper. Thus, it can be inferred that identical semi-active vehicle systems require normal MR dampers in the front and MR dampers with orifice holes in the rear, with proper control strategies. To evaluate ride performance, a robust sliding mode controller was designed. It is demonstrated through simulation that the proposed vehicle system produces better ride comfort than vehicle systems equipped with only one type of MR damper

Fabrication of complete titania nanoporous structures via electrochemical anodization of Ti

We present a novel method to fabricate complete and highly oriented anodic titanium oxide (ATO) nano-porous structures with uniform and parallel nanochannels. ATO nano-porous structures are fabricated by anodizing a Ti-foil in two different organic viscous electrolytes at room temperature using a two-step anodizing method. TiO2 nanotubes covered with a few nanometer thin nano-porous layer is produced when the first and the second anodization are carried out in the same electrolyte. However, a complete titania nano-porous (TNP) structures are obtained when the second anodization is conducted in a viscous electrolyte when compared to the first one. TNP structure was attributed to the suppression of F-rich layer dissolution between the cell boundaries in the viscous electrolyte. The structural morphologies were examined by field emission scanning electron microscope. The average pore diameter is approximately 70 nm, while the average inter-pore distance is approximately 130 nm. These TNP structures are useful to fabricate other nanostructure materials and nanodevices

Improvement in the photoelectrochemical responses of PCBM/TiO2 electrode by electron irradiation

The photoelectrochemical (PEC) responses of electron-irradiated [6,6]-phenyl-C61-butyric acid methyl ester (PCBM)/TiO2 electrodes were evaluated in a PEC cell. By coating PCBM on TiO2 nanoparticle film, the light absorption of PCBM/TiO2 electrode has expanded to the visible light region and improved the PEC responses compared to bare TiO2 electrode. The PEC responses were further improved by irradiating an electron beam on PCBM/TiO2 electrodes. Compared to non-irradiated PCBM/TiO2 electrodes, electron irradiation increased the photocurrent density and the open-circuit potential of PEC cells by approximately 90% and approximately 36%, respectively at an optimum electron irradiation condition. The PEC responses are carefully evaluated correlating with the optical and electronic properties of electron-irradiated PCBM/TiO2 electrodes

Cathodic Activity and Interfacial Stability of Y0.8Ca0.2Co1–xFexO3/YSZ Electrodes for Solid Oxide Fuel Cells

The Fe-doped cobaltates, Y0.8Ca0.2Co1–xFexO3– (x = 0.1–0.7), were prepared and their high-temperature phase stability and cathodic activity were investigated. The perovskite/yttria-stabilized zirconia (YSZ) electrodes were fabricated via a silk printing technique. It was found that the undoped cobaltate (x = 0) is so thermally unstable that the preparation of pure perovskite phase was unsuccessful. The partial Fe-doping to Co (x = 0.1–0.7), however, gave us highly crystalline perovskite powders of an orthorhombic lattice. Among those samples of x = 0.1–0.7, the Y0.8Ca0.2Co0.7Fe0.3O3– showed the best cathodic activity which is superior to La0.9Sr0.1MnO3. The thermal expansion coefficient of this material (10.5 × 10–6 cm/cm-K at 25–1000°C) was very close to that of 8 mol % YSZ (10.8 × 10–6 cm/cm-K). As a result of interfacial reaction between Y0.8Ca0.2Co0.7Fe0.3O3– and YSZ electrolyte, a spinel-type oxide was produced. But the interfacial product formation proceeded mainly during the electrode adhesion period (1200°C) whereas its growth during the cell operation (900–1000°C) was negligible.This work was supported by Ssangyong Cement Industry and Korea Science and Engineering Foundation (966-0304-005-2)

A Study on the Flora of 15 Islands in the Western Sea of Jeollanamdo Province, Korea

AbstractThis study aims to investigate the flora of 15 islands in Yeonggwang, Shinan, and Mokpo of the Jeollanamdo province and the distribution of major plants in order to use the results as fundamental data for studies on plants in islands. Field surveys were performed 25 times from 2004 to 2010 to investigate the flora in these regions. A total of 793 taxa including 123 families, 421 genera, 695 species, 2 subspeices, 88 varieties, and 8 forms was found. Korean endemic plants including Hepatica insularis and Galium koreanum were 6 taxa. 25 taxa of rare plants including Trachomitum lancifolium, Daphne kiusiana, and Centranthera cochinchinensis var. lutea were confirmed 120 taxa floristic special plant species were confirmed; 11 taxa of the fifth class, four taxa of the fourth class, 28 taxa of the third class. 78 taxa of naturalized plants were confirmed

Biochemical characterization of a recombinant Japanese encephalitis virus RNA-dependent RNA polymerase

<p>Abstract</p> <p>Background</p> <p>Japanese encephalitis virus (JEV) NS5 is a viral nonstructural protein that carries both methyltransferase and RNA-dependent RNA polymerase (RdRp) domains. It is a key component of the viral RNA replicase complex that presumably includes other viral nonstructural and cellular proteins. The biochemical properties of JEV NS5 have not been characterized due to the lack of a robust <it>in vitro </it>RdRp assay system, and the molecular mechanisms for the initiation of RNA synthesis by JEV NS5 remain to be elucidated.</p> <p>Results</p> <p>To characterize the biochemical properties of JEV RdRp, we expressed in <it>Escherichia coli </it>and purified an enzymatically active full-length recombinant JEV NS5 protein with a hexahistidine tag at the N-terminus. The purified NS5 protein, but not the mutant NS5 protein with an Ala substitution at the first Asp of the RdRp-conserved GDD motif, exhibited template- and primer-dependent RNA synthesis activity using a poly(A) RNA template. The NS5 protein was able to use both plus- and minus-strand 3'-untranslated regions of the JEV genome as templates in the absence of a primer, with the latter RNA being a better template. Analysis of the RNA synthesis initiation site using the 3'-end 83 nucleotides of the JEV genome as a minimal RNA template revealed that the NS5 protein specifically initiates RNA synthesis from an internal site, U₈₁, at the two nucleotides upstream of the 3'-end of the template.</p> <p>Conclusion</p> <p>As a first step toward the understanding of the molecular mechanisms for JEV RNA replication and ultimately for the <it>in vitro </it>reconstitution of viral RNA replicase complex, we for the first time established an <it>in vitro </it>JEV RdRp assay system with a functional full-length recombinant JEV NS5 protein and characterized the mechanisms of RNA synthesis from nonviral and viral RNA templates. The full-length recombinant JEV NS5 will be useful for the elucidation of the structure-function relationship of this enzyme and for the development of anti-JEV agents.</p