B.W. Lee

Analysis of traditional knowledge of medicinal plants from residents in Gayasan National Park (Korea)

BackgroundThe purpose of this study is to investigate and analyze the traditional knowledge of medicinal plants used by residents in Gayasan National Park in order to obtain basic data regarding the sustainable conservation of its natural plant ecosystem.MethodsData was collected using participatory observations and in-depth interviews, as the informants also become investigators themselves through attending informal meetings, open and group discussions, and overt observations with semi-structured questionnaires. Quantitative analyses were accomplished through the informant consensus factor (ICF), fidelity level, and inter-network analysis (INA).ResultsIn total, 200 species of vascular plants belonging to 168 genera and 87 families were utilized traditionally in 1,682 ethnomedicianal practices. The representative families were Rosaceae (6.5%) followed by Asteraceae (5.5%), Poaceae (4.5%), and Fabaceae (4.0%). On the whole, 27 kinds of plant-parts were used and prepared in 51 various ways by the residents for medicinal purposes. The ICF values in the ailment categories were muscular-skeletal disorders (0.98), pains (0.97), respiratory system disorders (0.97), liver complaints (0.97), and cuts and wounds (0.96). In terms of fidelity levels, 57 plant species showed fidelities levels of 100%. Regarding the inter-network analysis (INA) between ailments and medicinal plants within all communities of this study, the position of ailments is distributed into four main groups.ConclusionThe results of the inter-network analysis will provide a suitable plan for sustainable preservation of the national park through a continued study of the data. Particular species of medicinal plants need to be protected for a balanced plant ecosystem within the park. Consequently, through further studies using these results, proper steps need to be established for preparing a wise alternative to create a sustainable natural plant ecosystem for Gayasan National Park and other national parks.

Magnetic ZnFe 2 O 4 Nanocubes: Synthesis and Photocatalytic Activity With Visible Light/H 2 O 2

ZnFe₂O₄ nanocubes with high magnetization were prepared by a hydrothermal method. The structural, optical, morphology, and magnetic properties were investigated. The as-prepared sample exhibited a uniform cubic morphology with a high-saturation magnetization of 94.6 emu/g, therefore, can be easily collected from an aqueous solution using a magnet. Further investigation on the photocatalytic degradation of chlorotetracycline (CTC) using ZnFe₂O₄ nanocubes revealed a good photodegradation performance in a visible light/H₂O₂ system. The degradation efficiency of the ZnFe₂O₄ nanocubes on CTC remains above 45% even after three recycling circles. Therefore, the hydrothermally prepared ZnFe₂O₄ nanocubes can be considered as a promising magnetically retrievable photocatalyst under visible light irradiation.

Soft X-ray absorption spectroscopy study of multiferroic Bi-substituted Ba1−xBixTi0.9Fe0.1O3

The electronic structures of multiferroic oxides of Ba1−xBixTi0.9Fe0.1O3 (0 ≤ x ≤ 0.12) have been investigated by employing photoemission spectroscopy and soft X-ray absorption spectroscopy (XAS). The measured Fe and Ti 2p XAS spectra show that Ti ions are in the Ti4+ states for all x and that Fe ions are Fe2+-Fe3+ mixed-valent for x > 0. The valence states of Fe ions are found to be nearly trivalent for x=0 and decrease with increasing x from being nearly trivalent (v(Fe) ~ 3) for x = 0 to v(Fe) ~ 2.6 for x = 0.12. The valence states of both Ti and Ba ions do not change for all x ≤ 0.12. Based on the obtained valence states of Fe ions, the electronic and the magnetic properties of Ba1−xBixTi0.9Fe0.1O3 are explored.