A well-established characterization method is required in powder bed fusion (PBF) metal additive manufacturing, where metal powder is used. The characterization methods from the traditional powder metallurgy process are still being used. However, it is necessary to develop advanced methods of property evaluation with the advances in additive manufacturing technology. In this article, the characterization methods of powders for metal PBF are reviewed, and the recent research trends are introduced. Standardization status and specifications for metal powder for the PBF process which published by the ISO, ASTM, and MPIF are also covered. The establishment of powder characterization methods are expected to contribute to the metal powder industry and the advancement of additive manufacturing technology through the creation of related databases.

Powder characteristics, such as density, size, shape, thermal properties, and surface area, are of significant importance in the powder bed fusion (PBF) process. The powder required is exclusive for an efficient PBF process. In this study, the particle size distribution suitable for the powder bed fusion process was derived by modeling the PBF product using simulation software (GeoDict). The modeling was carried out by layering sintered powder with a large particle size distribution, with 50 μm being the largest particle size. The results of the simulation showed that the porosity decreased when the mean particle size of the powder was reduced or the standard deviation increased. The particle size distribution of prepared titanium powder by the atomization process was also studied. This study is expected to offer direction for studies related to powder production for additive manufacturing.

With increasing demand for resources worldwide, Korea has been negotiating with resource-holding countries to achieve conservation of energy resources. Among them, Russia is the third largest resource-producing and exporting nation in the world and has several resource materials such as nickel, platinum group metals, gold, and other reserves. As a result, there is growing interest in cooperation between Korea and Russia. The aim of this article is to summarize the current status of market flow of Russian energy resources as well as Russia’s economic cooperation with Korea. Notably, South Korea needs to focus on investing in overseas mines for a stable supply of rare metals. Nevertheless, securing rare metals is a major task by understanding the flow and policy direction of Russian material mines.

Since the ISO decided to deal with rare-earth elements at the 298th Technical Committee (TC) in 2015, Korea has participated in four plenary meetings and proposed four standards as of June 2019. The status of ISO TC 298, the standards covered by the TC, and the standardization strategies of Korea are summarized. Korean delegations are actively engaged in WG2, which deals with recycling, proposing four standards for fostering the rare-earth recycling industry. However, the participation of domestic experts is still low compared with the increase in the number of working groups and the number of standards in TC 298. The aim of this article is to summarize the current status of ISO international standards related to rare-earth elements, to encourage relevant experts to participate in standardization, and to develop international standards that accurately reflect the realities of the industry.

Methyl bromide (MB) has been still routinely used in quarantine fumigation on imported citrus, although there had been issuing chronic inhalation toxicity to fumigators and related workers as well as phytotoxic damages after fumigation. Ethyl formate (EF), is the only option to replace MB in terms of its safety for consumers (food additive and naturally occurred) and worker with higher threshold level limit (TLV = 100 ppm). Its application technology also provide cost effectiveness, good commercial practice in terms of application time (< 10 min) for 40 ft container. The replacement of MB with EF is recommended not to fumigate with hazardous and phasing-out MB on imported oranges.

The purpose of this study was to evaluate the effect of joint mobilization and manual stretching exercises in patients with hallux valgus. Twenty-three participants were divided into two groups; joint mobilization (n=11) and manual stretching exercises (n=12). The subjects participated in the experiment for 15minutes, three times a week, four weeks. The joint mobilization (Grade III, Maitland) was performed to experimental group for a minute and then rested for 10 seconds for each set. The manual stretching was performed to control group with three exercise session (preparatory and finishing exercises, agonist contraction exercises, agonist contraction and hold-relax exercises). In the results of the study, intragroup comparison of the deformity angles (DA) was shown to decrease from 15.18° to 13.09° in the joint mobilization group (p<.05) and from 19.00° to 16.83° in the stretching exercises group (p<.05). However, left static foot pressure (LSFP), right static foot pressure (RSFP), left dynamic foot pressure (LDFP) and right dynamic foot pressure (RDFP) did not significantly increase or decrease after the experiment. Intergroup differences also were not statistically significant in all variables (p>.05). The current study suggests that JM and MSE are effective in decreasing the DA in patients with hallux valgus.

There is growing interest in the various functions of urban green spaces that can improve urban resilience. Urban green spaces have an important role in wildlife habitat, climate and hydrological control, and recreation and outdoor activities. The connectivity of a green space network is known to control urban resilience by minimizing the disturbance caused by urbanization and climate change and strengthening the adaptation capacity. In this study, we analyzed the social-ecological network characteristics of green space in the city of Jeonju, South Korea. To analyze the ecological network, we defined wildlife habitat as the ecological node and used an index based on graph theory. We defined residential area as the social node, and we analyzed the accessibility of green space from the residential area to assess the social network. The results indicate that the green spaces in Jeonju are highly connected in the social and ecological perspectives on the fringe of the city. However, our founding also indicated that the social and ecological connectivity of the green space network in the downtown area should be improved. This study can be used as a basis for establishing an Urban Open Space Conservation Plan that considers the improvement of urban resilience in the future.

Rare earth elements (REEs) are considered to be vital to modern industry due to their important roles in applications such as permanent magnets, automobile production, displays, and many more. The imbalance between demand and supply of REEs can be solved by recycling processes. Regarding the needs of industry and society, the International Organization for Standardization, Technical Committee 298 (ISO/TC298) Rare Earths has been recently launched for developing international standards on rare earth elements. In accordance with the suggestion of its constituents, it is tentatively working to develop the appropriate standards under five working groups (WG) on terms and definitions (WG1), element recycling (WG2), environmental stewardship (WG3), packaging, labelling, marking, transport, and storage (WG4), and testing analysis (WG5). The scope and structure of ISO/TC298 on the topic of rare earths is discussed in this document.

The antioxidant and antitumor properties of natural products, often recognized in traditional medicine systems, represent therapeutic modalities to reduce or prevent uncontrolled oxidation processes which in turn potentially ameliorate or tumor based symptoms of chronic diseases. We have studied the antioxidant and antitumor effects of Amanita muscaria (A. muscaria) in vitro and examined whether the A. muscaria has synergistic effects on antioxidant and antitumor properties. Although A. muscaria induced a dose-dependent increase in antioxidant activity, the latter has a consistently higher antioxidant effect. In mouse monocytes, the lipopolysaccharide- (LPS-) induced tumor necrosis- (TNF-) synthesis was significantly inhibited by A. muscaria in a dose dependent manner and synergistic effects were clearly demonstrated with the A. muscaria on TNF- inhibition. A. muscaria effect was also evident on inhibition of nuclear factor-kappa B activity, cyclooxygenase-II activity, and lipid peroxidation in mouse monocytes. This presented results may be a starting point for a comprehensive characterization of biological effects of A. muscaria.

Russula compacta, a wild mushroom, belongs to Russulaceae, Russulales of Basidiomycota. This study was conducted to evaluate the free radical scavenging, anti-inflammatory, anticholinesterase and anti-α-glucosidase effects from fruiting bodies of R. compacta extracted with methanol and hot water. In 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging effects, the methanol and hot water extracts showed good scavenging effects comparable with positive control, BHT. The chelating effect of methanol and hot water extracts of the mushroom were significantly higher than the positive control, BHT. The reducing power of the methanol and hot water extracts of the mushroom were lower than the positive control at the concentrations tested. In the HPLC anaysis of phenolic acids profile of the mushroom extract, 7 phenolic acids such as gallic acid, vanillin, rutin hydrate, resveratol, quercetin formononetin, and biochanin-A were detected. Nitric oxide (NO) production in lipopolysaccahride (LPS) activated RAW 264.7 cells was inhibited by 1.5-fold with the treatment of methanol extract when compared with the control. In the anti-cholinesterase activity assay, the methanol extract inhibited the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) effects by 73.9% and 81.05% at the 1.0 mg/mL concentration, whereas galanthamine, the standard drug, inhibited the AChE and BChE activities by 97.80% and 81.12%, respectively at the same concentration. The methanol and hot water extracts of the mushroom inhibited the α-glucosidase activity by 55.44% and 62.00%, respectively at the 2.0 mg/mL concentration, while acarbose, the positive control inhibited the α-glucosidase activity by 81.81% at the 2.0 mg/mL concentration. From the experimental results, the fruiting bodies of R. compacta contained natural antioxidant, anti-inflammatory, anti-cholinesterase, and anti-diabetic substances, which might be used for health foods.

Coprinellus miaceus, belongs to Coprinaceae of Agaricales, Basidiomycota, has been used for an edible purposes in asian countries. This experiment was initiated to evaluate the free radical scavenging, free radical scavenging, anti-acetylcholinesterase, anti-inflammatory and α-glucosidase inhibitory activities of C. micaceus fruiting bodies extracted with methanol and hot water. In 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, the scavenging activities of methanol and hot water extracts were lower than that of positive control, BHT. The chelating effects of methanol and hot water extracts were significantly higher than positive control, BHT at the concentrations of 0.125-2.0 mg/mL. In the reducing power assay, methanol and hot water extracts exhibited the lower activities than the positive control, BHT at the 0.125-0.2 mg/mL concentration. In the HPLC analysis of phenolic acids profile of the mushroom fruiting bodies, 4 phenolic compounds including procatechuic acid, chlorogenic acid, (-)-epicatechin, and naringin were detected. The tyrosinase inhibitory activities of methanol and hot water extracts were 91.33% and 91.99% at 2.0 mg/mL concentration, while the inhibitory activity of kojic acid, the positive control, was 99.61%. Nitric oxide (NO) production in lipopolysaccahride (LPS) activated RAW 264.7 cells were inhibited by the methanol extract in a concentration dependent manner. In the acetylcholinesterase (AChE) inhibitory activity assay, methanol and hot water extracts of the mushroom inhibited the AChE by 94.64% and 74.19%, respectively at the 1.0 mg/mL concentration, whereas galanthamine, the standard drug inhibited the AChE activity by 97.80% at the same concentration. The methanol and hot water extracts of the mushroom inhibited the α-glucosidase activity by 62.26% and 67.59%, respectively at the 2.0 mg/mL concentration, while acarbose, the positive control inhibited the α-glucosidase activity by 81.81% at the same concentration. Therefore, it is concluded that fruiting bodies of C. micaceus contained natural antioxidant, anti-inflammatory, anti-acetylcholinesterase and α-glucosidase inhibitory substances which might be used for promoting human health.