X-ray diffraction is widely used as a non-destructive method for measuring residual stress in crystalline materials, and is particularly useful as a technique for controlling residual stress that has been introduced during the heat treatment or surface treatment of metallic materials. Neutron stress measurement is gaining attention as an internal material measurement method. It complements the demerits of the X-ray method in that it measures stress in a very thin surface layer. The neutron stress measurement method, like the X-ray method, is based on the principle of crystal diffraction, and its penetration depth is about 1,000 times greater than that of the X-ray method and is suitable for measuring the inside of a material. This study investigated the residual stress measurement method using the sin2ψ method using shot-peened mechanical structural carbon steel. The non-destructive measurement using high-energy X-rays was compared with the residual stress measured using conventional laboratory X-rays, and the following results were obtained. The high intensity diffraction angles using highenergy X-rays are low, but can be measured with sufficient precision. Interpreting the three diffractions 633, 552, and 721 as a single diffraction profile allowed stress measurements to be made, and the calculated value was close to the weighted average of the intensity ratios. The results of the high-energy X-ray residual stress measurements were in good agreement with the results from laboratory X-rays, confirming the usefulness of this method as a non-destructive method of assessing stress deep inside materials.
High-frequency soft magnetic Ni, Fe, and Co-based thin films have been developed, typically as nanocrystals and amorphous alloys. These Ni, Fe, and Co-based thin films exhibit remarkably good frequency dependence up to high frequencies of several tens of MHz. These properties arise from the moderate magnetic anisotropy and fairly high electrical resistivity that result from the microstructural characteristics of the nanocrystalline and amorphous states. In this paper, Al-Co/AlN-Co and Al-N/AlN-Co multilayer films were deposited using two-facing-target type sputtering (TFTS). Their microstructures, magnetic and electrical properties were studied with the expectation that inserting Al-Co or Al-N as an interlayer could effectively reduce the coercive force and produce films with relatively high resistivity. A new approach is presented for the fabrication of Al-Co (Al-N)/AlN-Co multilayer films, prepared with the TFTS system. The deposited films were isothermally annealed at different temperatures and investigated for microstructure, magnetic properties and resistivity. The TFTS method used in this experiment is suitable for fabricating Al-Co(Al-N)/AlN-Co multilayer films with different layer thickness ratio (LTR). The annealing conditions, thickness of the multilayer film, and LTR can control the physical properties as well as the microstructure of the manufactured film. Magnetization and resistance increased and coercivity decreased as LTR decreased. The thin film with LTR = 0.175 exhibited high resistivity values of 2,500 μΩ-cm, magnetization of 360 emu/cm3, and coercivity of 5 Oe. Results suggests that thin films with such good resistivity and magnetization would be useful as high-density recording materials.
This study aimed to investigate antioxidant activities from 11 forest plants, and determine their total phenolics, flavonoids and proantocyanidins contents. In addition, the antioxidant activities were correlated with antioxidant compounds. Among the samples, Cornus officinalis, Castanea crenata, Lindera erythrocarpa, Carpinus laxiflora and Pourthiaea villosa showed significantly higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) (IC50=21.12~28.93 μg/mL) and 2,2’-azino-bis(3-ethylbenzothia zoline-6-sulfonic acid) (ABTS) (IC50=28.18~52.55 μg/mL) radical scavenging ability with reducing power (IC50=59.91~93.64 μg/mL) than other plants; and C. crenata, L. erythrocarpa and Rubus coreanus showed strong nitric oxide (NO) inhibition activity (≥60%). In addition, L. erythrocarpa, C. laxiflora and P. villosa showed higher oxygen radical absorbance capacity (ORAC) values (≥1,100 μM TE/g sample) than other samples. High total phenolic contents were observed in C. crenata (429.11 mg GAE/g), L. erythrocarpa (437.11 mg GAE/g), C. laxiflora (408.67 mg GAE/g) and P. villosa (404.11 mg GAE/g). The DPPH and ABTS radical scavenging activity with reducing power were significantly correlated with total phenolic contents (R2=0.71~0.79), but total phenolic contents were not correlated with NO inhibition and ORAC (R2=0.35~0.43). Therefore, these results suggested that C. officinalis, C. crenata, L. erythrocarpa, C. laxiflora and P. villosa are potential natural antioxidative candidate ingredients.
Recently, a rapid movement of agricultural products with an extensive international trading and climate change have led to an increased attention to nematodes as having regulatory significance. With the increase of global dispersal of pests, new diagnosis methods are required for a rapid and reliable species and/or biotype identification to restrict introduction of the pests. Recently, novel molecular diagnostic techniques provide clues to solve taxonomic problems associated with conventional species identification. In this articles, we proposed various molecular diagnostic techniques to complement the limitation of morphological taxonomy.
Part of a field survey to assess the extent of damage by termite (Reticulitermes speratus kyushuensis Morimoto), termite samples were collected from various locations of Korea from 2009 to 2011. During the study period, we firstly discovered Reticulitermes species on Jeju island, and partial sequences of mitochondrial COII gene, which is proved useful to study phylogenetic relationships of termites were investigated. Also, morphological characteristics of the collected samples were compared with previous reports. According to the result of taxonomic study and comparative sequence analysis, it was identified as Reticulitermes speratus kyushuensis Morimoto, and this is first report of R. s. kyushuensis from Jeju island in Korea which can be used as estimation of population structure and tool of control strategy.
Field survey to estimate extent of damage to Reticulitermes species were conducted from 2009 through 2011 in the various locations of Korea. We discovered Reticulitermes species from three different locations of Jeju island. Partial COII sequences of mt DNA and morphological characters were collected and compared with previous reports. As result of comparative sequence analysis and taxonomic study, it was identified as Reticulitermes speratus kyushuensis Morimoto 1968 and this is first report of Reticulitermes speratus kyushuensis from Jeju island in Korea which can be used as estimation of population structure and tool of control strategy.
We amplified D1 and D3 expansion segments of the 28S ribosomal RNA from 10 Suanguina moxae populations found in Korea. The amplification of the D1-D3 expansion segments of 28S gene of all populations tested produced a single PCR product approximately 1.03kb in size, suggesting the lack of D1-D3 expansion region size polymorphism among populations. The secondary structure model of 28S expansion segments D2 and D3 for Subanguina Moxae was predicted based on free energy minimization with comparative sequence analysis and new sequence alignment was conducted based on predicted secondary structure model. The predicted model was compared with previous predicted models of plant and animal parasite nematode. This predicted secondary structure model will provide valuable information to allocate positional sequence homology and reconstruction of reliable phylogenetic trees.