Moonsung Kang

Molecular engineering of organic sensitizers containing p-phenylene vinylene unit for dye-sensitized solar cells.

Three organic sensitizers containing bis-dimethylfluorenyl amino donor and a cyanoacrylic acid acceptor bridged by p-phenylene vinylene unit were synthesized. The power conversion efficiency was quite sensitive to the length of bridged phenylene vinylene groups. A nanocrystalline TiO2 dye-sensitized solar cell was fabricated using three sensitizers. The maximum power conversion efficiency of JK-59 reached 7.02%.

New efficient ruthenium sensitizers with unsymmetrical indeno[1,2-b]thiophene or a fused dithiophene ligand for dye-sensitized solar cells.

Two novel ruthenium sensitizers containing unsymmetrical indeno[1,2-b]thiophene or a fused dithiophene unit in the ancillary ligand have been designed and synthesized. The photovoltaic performance of JK-188 using an electrolyte consisting of 0.6 M 1,2-dimethyl-3-propylimidazolium iodide, 0.05 M I(2), 0.1 M LiI, 0.05 M guanidinium thiocyanate, and 0.5 M tert-butylpyridine in acetonitrile revealed a short-circuit photocurrent density of 18.60 mA/cm(2), an open-circuit voltage of 0.72 V, and a fill factor of 0.71, yielding an overall conversion efficiency of 9.54%. The cell exhibits a remarkable stability under 1000 h of light soaking at 60 °C using a quasi-solid-state electrolyte consisting of 5 wt % poly(vinylidenefluoride-co-hexafluoropropylene), 0.6 M 1-propyl-2,3-dimethylimidazolium iodide, 0.5 M N-methylbenzimidazole, and 0.1 M I(2) in 3-methoxypropionitrile, retaining 97% of the initial efficiency (7.38%).

Trade Policy Mix: IPR Protection and R&D Subsidies

perfect. By examining policy choices wherein a government chooses both R&D subsidies and IPR protection levels simultaneously, we show that it is optimal for a government to adopt sufficiently weak IPR protection and to subsidize R&D investments of domestic firms. Inducing R&D investment of foreign rival firms will increase the profits of domestic firms.

Area-Controllable Stamping of Semicrystalline Copolymer Ionogels for Solid-State Electrolyte-Gated Transistors and Light-Emitting Devices

Two types of thin-film electrochemical devices (electrolyte-gated transistors and electrochemical light-emitting cells) are demonstrated using area-controllable ionogel patches generated by transfer-stamping. For the successful transfer of ionogel patches on various target substrates, thermoreversible gelation by phase-separated polymer crystals within the ionogel is essential because it allows the gel to form a conformal contact with the acceptor substrate, thereby lowering the overall Gibbs energy of the system upon transfer of the ionogel. This crystallization-mediated stamping provides a much more efficient deposition route for producing thin films of ionically conductive high-capacitance solid ionogel electrolytes. The lateral dimensions of the transferred ionogels range from 1 mm × 1 mm to 40 mm × 40 mm. These ionogel patches are incorporated in organic p-type and inorganic n-type thin-film transistors and electrochemical light-emitting devices. The resulting transistors show sub-1 V device operation with high transconductance currents, and the optoelectronic devices emit orange light through a series of electrochemical redox reactions. These results demonstrate a simple yet versatile route to employ physical ionogels for various solid-state electrochemical device applications.

South Korea: Temporary Trade Barriers Before and During the Crisis

This paper examines Korea’s use of temporary trade barriers, mainly antidumping measures, before and during the global financial crisis of 2008-9. Using the Temporary Trade Barriers Database (Bown 2010b), we determined that the stock of imported products subject to antidumping duties in Korea has increased moderately over time. During the financial crisis of 2008-9, there were a relatively small number of initiations; however, we conclude that the Korea Trade Commission was active in imposing AD duties during the financial crisis. We also conclude that AD measures have functioned as a substitute for tariff protection measures in Korea during this period and that the Korean use of AD measures is consistent with the theory put forth by Grossman and Helpman (1994) that politically organized sectors tended to receive more protection than unorganized ones. In addition, our analysis of the practical use of Korea’s determinants of dumping margins suggests that the KTC has more frequently used ‘facts available’ than any other discretionary practices during the global financial crisis.

Nonvolatile Electric Double-Layer Transistor Memory Devices Embedded with Au Nanoparticles

We present nonvolatile transistor memory devices that rely on the formation of electric double layer (EDL) at the semiconductor-electrolyte interface. The two critical functional components of the devices are the ion gel electrolyte and gold nanoparticles (NPs). The ion gel electrolyte contains ionic species for EDL formation that allow inducing charges in the semiconductor-electrolyte interface. The gold NPs inserted between the ion gel and the channel layer serve as trapping sites to the induced charges to store the electrical input signals. Two different types of gold NPs were used: one prepared using direct thermal evaporation and the other prepared using a colloidal process. The organic ligands attached onto the colloidal gold NPs prevented the escape of the trapped charges from the particles and thus enhanced the retention characteristics of the programmed/erased signals. The low-voltage-driven EDL formation resulted in a programmed/erased memory signal ratio larger than 103 from the nonvolatile indium-gallium-zinc oxide transistor memory devices at voltages below 10 V, which could be held for >105 s. The utility of the electrolytes to operate memory devices demonstrated herein should provide an alternative strategy to realize cheap, portable electronic devices powered with thin-film batteries.

Structure–Property Relationships of Semiconducting Polymers for Flexible and Durable Polymer Field-Effect Transistors

We report high-performance top-gate bottom-contact flexible polymer field-effect transistors (FETs) fabricated by flow-coating diketopyrrolopyrrole (DPP)-based and naphthalene diimide (NDI)-based polymers (P(DPP2DT-T2), P(DPP2DT-TT), P(DPP2DT-DTT), P(NDI2OD-T2), P(NDI2OD-F2T2), and P(NDI2OD-Se2)) as semiconducting channel materials. All of the polymers displayed good FET characteristics with on/off current ratios exceeding 107. The highest hole mobility of 1.51 cm2 V-1 s-1 and the highest electron mobility of 0.85 cm2 V-1 s-1 were obtained from the P(DPP2DT-T2) and P(NDI2OD-Se2) polymer FETs, respectively. The impacts of the polymer structures on the FET performance are well-explained by the interplay between the crystallinity, the tendency of the polymer backbone to adopt an edge-on orientation, and the interconnectivity of polymer fibrils in the film state. Additionally, we demonstrated that all of the flexible polymer-based FETs were highly resistant to tensile stress, with negligible changes in their carrier mobilities and on/off ratios after a bending test. Conclusively, these high-performance, flexible, and durable FETs demonstrate the potential of semiconducting conjugated polymers for use in flexible electronic applications.

An Analysis of Economic Impacts of FTAs on Strategic Industries in Jordan

This paper analyzes the economic impacts of Jordans regional trade agreements on its major strategic industries. We calculate each individual industrys revealed comparative advantage (RCA) index to identify Jordans strategic industries showing comparative advantages. And then we analyze each individual industrys export performance before and after its regional trade agreements have entered into force. This paper found that the bilateral free trade agreement (FTA) between Jordan and the United States has shown a positive impact on the Jordanian export performance, mainly in the textiles and clothing industry. However, it has not been quite as effective in enhancing Jordanian export opportunities in other industries, such as chemicals, vegetable products, paper and paperboard, and prepared foodstuffs, although there has been a growing positive impact on precious stones. The positive impacts of the FTA with the United States on Jordans textiles and clothing industry have been heavily dependent upon its initiatives and programs of QIZs. Pan Arab Free-Trade Area (PAFTA) has shown a relatively positive impact on several industries, such as chemicals, vegetable products, paper and paperboard, precious stones, and prepared foodstuffs, although chemicals and vegetable products have shown a steady export performance no matter whether PAFTA enters into force. However, the bilateral FTA with the EC has failed to show any significant impact on the Jordanian export performances of its strategic industries having comparative advantages.

Korea's growth‐driven trade policies: Inclusive or exclusive?

We attempted to find whether the Koreas growth-driven trade policies during the period of its industrialisation has contributed to output growth together with income distribution by qualitatively analysing the performance of trade policies interacting with the multilateral trading system over time. In addition, we conducted a regression analysis to investigate the effect of Koreas trade growth on inclusive growth during its industrialisation period covering the period of 1976–2011. We found that the recent reform policies reported in the WTOs Trade policy review for Korea in 2016 have attempted to achieve more balanced distribution of gains from trade but not enough to lead the Korean economy to a well-balanced welfare state. More specifically, we found the positive effects of international trade on inclusive growth driven by strong output growth effect, not by the effect on income distribution. Even though income distribution measured by Gini indices has been worsened after the East Asian financial crisis, we could not find significant evidence that Koreas rapid international trade growth has been responsible for the deteriorating income inequality.

Relationships between Pork Quality Traits and Growth Factor Concentrations in Serum and Longissimus dorsi Muscle before and at Slaughter in Female Market Pigs

The present study was conducted to test a hypothesis that pork quality traits would be influenced by the systemic and/or local bioavailability of insulin-like growth factor-I (IGF-I), transforming growth factor-β 1( TGF-β1), or epidermal growth factor (EGF) before or at slaughter. To this end, 60 cross-bred female market pigs weighing approximately 110 kg were slaughtered, after which Longissimus dorsi muscle (LM) samples taken at slaughter (D 0) and blood samples taken at D -7 and D 0 were analyzed. The 60 carcasses rendered 36 RFN (reddish-pink, firm, and non-exudative), 16 RSE (reddish-pink, soft, and exudative), and 6 PSE (pale, soft, and exudative); 2 DFD (dark, firm, and dry) also were found but were excluded in subsequent experiments. The L* and drip loss were greater in PSE vs. RFN and RSE and in PSE and RSE vs. RFN, respectively, as they should (P<0.05). The pH45min was less in PSE vs. RFN (P<0.05); pH24h tended to be less in the former (P=0.09). The LM IGF-I and TGF-β1 as well as serum EGF concentrations were less in PSE than in RFN. None of the other LM and serum concentrations of the three growth factors differed across the three pork quality categories. The LM IGF-I and TGF-β1 concentrations and serum EGF concentration at D 0 were negatively correlated with drip loss (r =-0.36(P<0.01), -0.44 (P<0.01), and -0.32 (P<0.05), respectively). However, none of the serum and LM growth factor variables was correlated with L* or a* (redness) of LM. Taken together, results suggest that locally expressed IGF-I and TGF-β1 and blood-borne EGF may have a beneficial effect on postmortem water holding capacity of the muscle and that pork quality traits could be predicted to some extent from concentrations of IGF-I and TGF-β1 in muscle and EGF in serum at slaughter.