Chonbuk National University

About: Chonbuk National University is a education organization based out in Jeonju, South Korea. It is known for research contribution in the topics: Apoptosis & Nanofiber. The organization has 14820 authors who have published 28884 publications receiving 554131 citations.

Price transmission dynamics between ADRs and their underlying foreign securities

Abstract: This paper extends previous research by considering three pricing factors for American Depository Receipts (ADRs): the price of the underlying shares in the local currency, the relevant exchange rate, and the US market index. Using both a vector autoregressive (VAR) model with a cointegration constraint and a seemingly-unrelated regression (SUR) approach, we examine the relative importance of, and the speed of adjustment of ADR prices to, these underlying factors. Our results show that while the price of the underlying shares is most important, the exchange rate and the US market also have an impact on ADR prices. While the bulk of the shocks to the pricing factors are reflected in the ADRs within the same calendar day, there are indications that the adjustments are not completed until the following day. Curiously, the ADRs appear to initially overreact to the US market index but underreact to changes in underlying share prices and exchange rates.

Formation of low-resistance ohmic contacts between carbon nanotube and metal electrodes by a rapid thermal annealing method

Abstract: The contact resistance between a carbon nanotube and metal electrodes decreases by several orders of magnitude and becomes long-term stable when the nanotube contacted by Ti-Au electrodes was annealed by a rapid thermal annealing method at 600-800 °C for 30 s. The contact resistances of the annealed samples are in the range 0.5-50 kΩ at room temperature, depending on the electrical properties of the nanotube. The short and relatively low-temperature annealing process enables us to make a surface Ti-nanotube contact suitable for electrical measurements. For the samples with relatively low contact resistances (0.5-5 kΩ) at room temperature, the contact resistance remained constant or decreased slightly as the temperature was lowered. Those with a relatively high contact resistance (5-50 kΩ), on the other hand, showed increasing contact resistance with a lowering of the temperature.

Effect of chemical treatment of Kevlar fibers on mechanical interfacial properties of composites.

Abstract: In this work, the effects of chemical treatment on Kevlar 29 fibers have been studied in a composite system. The surface characteristics of Kevlar 29 fibers were characterized by pH, acid–base value, X-ray photoelectron spectroscopy (XPS), and FT-IR. The mechanical interfacial properties of the final composites were studied by interlaminar shear strength (ILSS), critical stress intensity factor ( K IC ), and specific fracture energy ( G IC ). Also, impact properties of the composites were investigated in the context of differentiating between initiation and propagation energies and ductile index (DI) along with maximum force and total energy. As a result, it was found that chemical treatment with phosphoric acid solution significantly affected the degree of adhesion at interfaces between fibers and resin matrix, resulting in improved mechanical interfacial strength in the composites. This was probably due to the presence of chemical polar groups on Kevlar surfaces, leading to an increment of interfacial binding force between fibers and matrix in a composite system.