Ozobranchus jantseanus (Clitellata: Ozobranchidae) from Reeve's Turtle, Mauremys reevesii: New Annelid Fauna in Korea.

Turtle leeches have not been recorded in Korea, although they occur in geographically adjacent countries including China and Japan. This study describes a turtle leech, Ozobranchus jantseanus (Clitellata: Ozobranchidae), found from Reeve's turtle (Mauremys reevesii) in Korea. Of the 143 Reeve's turtles collected from the freshwater reservoir in Jinju City, Gyeongsangnam-do, Korea, 95 unidentified leeches were found in 8 (5.6%) individuals. The leeches had 22 somites with 11 pairs of externally exposed branchiae, body-sized posterior suckers, and spines on the dorsal surface. We identified these leeches as Ozobranchus jantseanus Oka, 1912 (Clitellata: Ozobranchidae). This species of turtle leeches found in Korea may fill the gap in the biodiversity of East Asian annulus.

Categorization of atomic mixing patterns in bimetallic nanoparticles by the energy competition.

The superior properties of bimetallic nanoparticles are strongly related to their morphology. A better understanding of the morphological details would be the first step to design bimetallic nanoparticles for target applications. In this study, we discussed three possible categories of the atomic mixing patterns of bimetallic nanoparticles using the concept of competition between bond energy and surface energy. The categorization was confirmed with the thermodynamically stable structures of AgPt, AuPt, CuPt, PdPt, AgPd, AuPd, and CuPd obtained using Monte Carlo simulations. This work also proposed the phase diagrams of AuPt, CuPt, and PdPt nanoparticles, which displayed the details of atomic arrangements depending on the changes in size and atomic composition. The population in low-coordination sites and temperature effects were also intensively studied. The comprehensive understanding of these factors would facilitate the rational design and wide applications of bimetallic nanoparticles.

Solution-processed graphene oxide electrode for supercapacitors fabricated using low temperature thermal reduction.

We present a low temperature and solution-based fabrication process for reduced graphene oxide (rGO) electrodes for electric double layer capacitors (EDLCs). Through the heat treatment at 180 °C between the spin coatings of graphene oxide (GO) solution, an electrode with loosely stacked GO sheets could be obtained, and the GO base coating was partially reduced. The thickness of the electrodes could be freely controlled as these electrodes were prepared without an additive as a spacer. The GO coating layers were then fully reduced to rGO at a relatively low temperature of 300 °C under ambient atmospheric conditions, not in any chemically reducing environment. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) results showed that the changes in oxygen functional groups of GO occurred through the heat treatments at 180 and 300 °C, which clearly confirmed the reduction from GO to rGO in the proposed fabrication process at the low thermal reduction temperatures. The structural changes before and after the thermal reduction of GO to rGO analyzed using Molecular Dynamic (MD) simulation showed the same trends as those characterized using Raman spectroscopy and XPS. An EDLC composed of the low temperature reduced rGO-based electrodes and poly(vinyl alcohol)/phosphoric acid (PVA/H3PO4) electrolyte gel was shown to have high specific capacitance of about 240 F g-1 together with excellent energy and power densities of about 33.3 W h kg-1 and 833.3 W kg-1, respectively. Furthermore, a series of multiple rGO-based EDLCs was shown to have fast charging and slow discharging properties that allowed them to light up a white light emitting diode (LED) for 30 min.