In laser powder bed fusion (L-PBF), a metal powder–based additive manufacturing process, pure titanium powders rely on expensive gas-atomized spherical powders, which poses a significant limitation of material cost. In contrast, non-spherical titanium powders are more cost-effective but their application in L-PBF is restricted their use due to poor flow property and high oxygen content. In this study, a powder mixing strategy with spherical titanium and hydrophobic SiO2 nanoparticle is proposed to improve the flowability and process stability of non-spherical Ti powders. After evaluating flow properties at various mixing ratios, a spherical-to-non-spherical Ti ratio of 4:6 was selected, with SiO2 nanoparticles added during mixing. The uniform distribution of oxide nanoparticles on the powder surfaces was confirmed by SEM and EDS. A maximum relative density of 99.7% was shown by specimens made with L-PBF under various processing parameters. The specimens obtained a tensile strength of 762.6 ± 3.8 MPa and an elongation of 22.1 ± 0.7% at a volumetric energy density of 71.4 J/mm³. This study demonstrates the application of low-cost non-spherical Ti powders in L-PBF is feasible and presents an effective way to simultaneously increase process stability and economic efficiency in titanium additive manufacturing.

This study investigated the quality and antioxidant characteristics of rice morning bread prepared with the addition of apple peel powder (APP, 0, 4, 8, and 12% w/w). It sought to evaluate the influence of APP on the antioxidant capacity of rice morning bread. The findings are summarized as follows: First, as the APP content increased, the weight of the rice morning bread significantly increased, while the volume and specific volume decreased (p<0.001). Second, the Hunter color values showed that the L value (lightness) decreased, whereas the a (redness) and b (yellowness) values increased significantly. Third, texture profile analysis revealed that hardness and chewiness increased with increasing APP levels, whereas cohesiveness decreased (p<0.001). Fourth, antioxidant activities (measured with 2,2-diphenyl-1-picrylhydrazyl [DPPH], 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) [ABTS] radical scavenging ability, and ferric reducing antioxidant power [FRAP]) improved significantly. Fifth, the total phenolic content (TPC) of rice morning bread significantly increased with increasing levels of APP (p<0.05). In conclusion, although APP significantly enhances antioxidant properties, given the bread's physical characteristics, a 4% addition is most appropriate. This study suggests that apple peel powder, a sustainable byproduct, is a promising material for developing functional bakery products.

In this study, a particle shape control process was developed to fabricate flake-like SUS316L powders about 20 μm for application in semiconductor gas filters. The Flake powder was produced through a wet milling process using a Planetary Mill by varying the rotation speed, milling time, solvent, and polyvinylpyrrolidone (PVP) dispersant conditions. The fabricated powders were then characterized to evaluate their morphological and phase transformation behaviors. In the ethanol-based Planetary Milling process, as the rotation speed increased from 300, 400, 500 rpm, the powder morphology was observed to gradually change from spherical to flake-like due to the increase in milling energy. According to the XRD, as the rotation speed increased, a phase transformation from austenite to martensite occurred due to the increase in heat generation and collisions between the powder and balls. In addition, an increase in Full Width at Half Maximum (FWHM) was observed, indicating a decrease in crystallinity. Under different solvent and dispersant conditions, the addition of 5 wt% PVP to the deionized water (DI Water) solvent suppressed particle fracture and produced more uniform flake-like particles compared with the DI Water process without PVP. In addition, a smaller FWHM and reduced oxygen content were observed.

Silicon based anode materials offer high theoretical capacity but suffer from severe volume expansion and unstable interfacial properties during repeated lithiation and delithiation, resulting in rapid performance degradation. In this study, a thin aluminum oxide coating layer was deposited on Si/SiOx Carbon anode materials using a powder atomic layer deposition (PALD) process to address these limitations. EDS mapping and XRD analyses confirmed the uniform formation of an amorphous aluminum oxide coating with increasing thickness as the deposition cycles increased. Electrochemical evaluation showed that the electrode coated with 5 PALD cycles exhibited approximately 78% higher capacity retention after 100 cycles at 1 A g-1 and a higher initial Coulombic efficiency compared to the bare electrode. The coated electrode also delivered approximately 22% higher capacity at a high current density of 5 A g-1, indicating enhanced rate capability. Cyclic voltammetry analysis revealed increased surface controlled reaction contributions and improved reaction kinetics. These results demonstrate that PALD derived aluminum oxide coatings effectively stabilize the electrode electrolyte interface and enhance the electrochemical performance of silicon based anodes, highlighting their potential for next generation high capacity lithium ion batteries. generation high capacity lithium ion battery anode materials.

This study investigates the compaction behavior of anisotropic, plate-like powders used in axial flux motor cores through a combined FEM–DEM approach. A porous continuum FEM model captures stress and density evolution during die pressing, revealing strong gradients along the compaction direction, with higher stress and densification near the upper punch and reduced compaction in the lower region. Guided by these results, DEM simulations examine particle packing, orientation, and contact pressure in representative zones. The DEM analysis shows that higher local pressure promotes denser packing and in-plane particle alignment near the upper punch, while the lower region exhibits more random orientations and lower contact forces. As a result, the multi-scale FEM–DEM framework clarifies how anisotropic particle behavior governs local densification and offers practical guidance for die design and process optimization to achieve more uniform density and controlled magnetic-property-relevant particle alignment in axial flux motor cores.

The influence of process conditions on the microstructure of porous W-Cu, fabricated by freeze casting using tert-butyl alcohol as the freezing agent, was investigated. The slurries containing 10 vol% of WO3-CuO powder were prepared by milling with a small amount of citric acid and polyethylene glycol as dispersants. The slurries with dispersion stability were frozen in a mold with the lower part cooled to -20°C, followed by sublimation in a vacuum to remove the freezing agent. The sintered W-1 vol% Cu in a hydrogen atmosphere exhibited aligned pores with the size of 50 μm, which were generated by sublimation of directionally solidified tert-butyl alcohol crystals. In the cross-section of the specimen, hexagonal pores corresponding to the crystal structure of tert-butyl alcohol were observed. Microstructure analysis of the struts revealed that Cu was distributed non-uniformly due to the mutual insolubility and low wettability of the W-Cu system.

Ammonia (NH3) emitted from swine manure contributes to odor problems and environmental pollution in intensive livestock systems. Plant extracts containing natural saponins, such as Yucca schidigera (YS) and Quillaja saponaria (QS), are used as potential agents to reduce gaseous emissions. This study evaluated the effect of a YS–QS powdered extract on NH3 emissions from pig manure under controlled laboratory conditions. Nine cylindrical pots (23 cm diameter, 25 cm height) were filled with 5 kg of fresh pig manure and assigned to three treatments with three replicates each: untreated manure (T0), manure plus 250 mg/kg extract (T250), and manure plus 2,500 mg/kg extract (T2500). Pots were maintained at 30°C in insulated containers. The extract consisted of a commercially available YS–QS powder. Initial manure properties were pH 8.19 and oxidation-reduction potential –60 mV. Headspace NH3 concentrations were continuously measured using a multi-channel laser-based gas analyzer at ~67-second intervals. Based on the results, NH3 concentrations at day 0 for T0, T250, and T2500 were 35.31±11.07, 62.03±24.30, and 84.65±21.11 ppb, respectively. By day 2, the concentrations decreased to 29.40±12.69, 41.59±18.92, and 50.40±18.81 ppb. The overall reduction rates from day 0 to day 2 were 17% (T0), 33% (T250), and 40% (T2500), with T250 achieving approximately twice the reduction observed in T0. In conclusion, the YS–QS extract reduced NH3 emissions from pig manure, with treatments ≥250 mg/kg showing greater effectiveness than the untreated manure. These results support the potential use of plant-based additives to improve NH3 emission control in manure.

In this study, freeze-dried red beet powder was characterized for its physicochemical properties and functional components and subsequently incorporated into rice cookies at levels of 0%, 2%, 4%, 6%, and 8% to assess its effects on quality characteristics and antioxidant activity. As the level of red beet powder increased, moisture content decreased, whereas both the diameter and thickness of the rice cookies increased, resulting in a reduced spread ratio. In terms of color parameters, lightness and yellowness decreased, whereas redness significantly increased with increasing red beet powder content, indicating a distinct visual change in the cookies. Antioxidant activity increased proportionally with red beet powder levels. These findings demonstrate that incorporating red beet powder effectively enhances the antioxidant activity and functional properties of rice cookies.

This study aimed to enhance the value of traditional Korean sweet Dasik by incorporating citrus mandarin powder rich in functional components. Jinmal Dasik was prepared using citrus mandarin powder at concentrations of 0%, 8%, 16%, 24%, and 32%. Quality characteristics, sensory properties, and antioxidant activities of the samples were evaluated. As the citrus mandarin powder concentration increased, moisture and sugar content increased, while pH decreased. Color measurements revealed decreased lightness and increased redness and yellowness. Mechanical texture parameters showed no significant differences among the groups. In sensory evaluation, the 24% sample received the highest scores for appearance, taste, texture, and overall acceptability, while the 24% and 32% samples achieved the highest aroma scores. Quantitative descriptive analysis indicated that higher powder levels increased yellowness, citrus aroma, sweetness, sourness, bitterness, astringency, and moistness, though no significant differences were observed in terms of hardness and chewiness. Principal component analysis supported these trends. The antioxidant activity of Jinmal Dasik, including total phenol and flavonoid contents, DPPH radical scavenging activity, and reducing power, increased with higher levels of citrus mandarin powder. Overall, the addition of 24% citrus mandarin powder was optimal for improving the sensory acceptability, antioxidant activity, and quality attributes of Jinmal Dasik.

This study investigates the vitrification of blast furnace slag (BFS) by adjusting the content of steel slag and the added amount of E-glass. SaEb glasses were prepared with a composition of x wt% BFS and (100-x) wt% E-glass (x = 10, 20, 30, 40, and 50). Each composition was melted in a platinum crucible under atmospheric conditions at 1,500 °C for 2 h, and transparent glasses with a transmittance exceeding 75 % were fabricated. All SaEb glasses exhibit an amorphous pattern, indicating successful vitrification. We also analyzed their optical, thermal, and physical properties, including Fourier transform infrared spectroscopy (FT-IR), glass transition temperature (Tg), and x-ray pattern. As the E-glass content increased, the glass transition temperature of blast furnace slag-based glass decreased from 765 °C to 734 °C due to the weakening of the SiO4 unit structure. In all compositions, the glass transition–crystallization temperature difference exceeded 220 °C, confirming the glasses stability for slag fiber applications. The blast furnace slag-based glass exhibits potential for application in slag fiber production, and is expected to provide fundamental data for future studies on related materials.

The development of high-performance metal filters is essential for maintaining ultra-clean environments in semiconductor manufacturing. In this study, cross-sealed honeycomb filters were fabricated using STS316L powder via material extrusion additive manufacturing (MEAM) for semiconductor gas filtration. The effects of filter geometry (4 or 9 channels) and sintering temperature (850°C, 950°C, or 1,050°C) on performance were examined. First, 4-channel and 9-channel filters sintered at the same temperature (950°C) exhibited similar porosities of 50.08% and 50.57%, but the 9-channel filter showed a higher pressure-drop (0.26 bar) and better filtration-efficiency (3.55 LRV) than the 4-channel filter (0.19 bar and 3.25 LRV, respectively). Second, for filters with the same geometry (4-channel) increasing the sintering temperature reduced porosity from 64.52% to 40.33%, while the pressure-drop increased from 0.13 bar to 0.22 bar and filtration-efficiency improved from 2.53 LRV to 3.51 LRV. These findings demonstrate that filter geometry and sintering temperature are key factors governing the trade-off between air permeability, pressure-drop, and filtration efficiency. This work provides insights and data for optimizing MEAM-based high-performance metal powder filter design.

This study examined process–structure relationships in laser powder bed fusion of Al0.1CoCrFeNi + Cu composites, focusing on densification, elemental distribution, and solidification cracking. Mechanically mixed Al0.1CoCrFeNi and Cu powders were processed across a range of laser powers (100–250 W) and scan speeds (200–800 mm/s). Increased volumetric energy density (VED) improved densification, with a plateau near 200 J/mm3 yielding ~96% relative density; however, this value was still below application-grade thresholds. At low VED, insufficient thermal input and short melt pool residence times promoted Cu segregation, while higher VED facilitated improved elemental mixing. Elemental mapping showed partial co-segregation of Ni with Cu at low energies. Solidification cracks were observed across all processing conditions. In high VED regimes, cracking exhibited a minimal correlation with segregation behavior and was primarily attributed to steep thermal gradients, solidification shrinkage, and residual stress accumulation. In contrast, at low VED, pronounced Cu segregation appeared to exacerbate cracking through localized thermal and mechanical mismatch.

The recent development of small modular reactors (SMRs) and the adoption of higher-enrichment fuels have intensified the need for advanced burnable absorbers to ensure effective reactivity control and extended fuel cycles. Among various designs, UO2 fuels with high Gd2O3 (gadolinium oxide) content provide notable benefits; in particular, they are compatible with established fabrication methods for burnable absorber fuels. However, achieving a homogeneous dispersion of Gd2O3 at high loading levels remains challenging, and the frequent occurrence of phase segregation and non-uniform microstructures can limit fuel reliability and performance. Overcoming these limitations requires an understanding of the powder characteristics and mixing behaviors during fabrication. In this study, we investigate the effects of the initial particle size and mixing method of UO2 and Gd2O3 powders on the microstructure and mixing homogeneity of high-Gd2O3-content fuels. The findings indicate that both the mixing method and the preparation state of the starting powders significantly affect the resulting microstructure and mixing uniformity.

건설 자재와 건설 폐기물의 환경적 영향에 대한 사회적 관심이 높아지고 있다. 고강도 콘크리트의 필요성이 점차 커짐에 따라, 본 연구에서는 서로 연관된 환경 문제에 대한 두 가지 잠재적 해결책을 검토하였다. 첫째는 재활용 콘크리트 골재의 사용량 증가 가능성이고, 둘째는 고로 슬래그를 시멘트로 활용(재활용)할 가능성이다. 일반적으로 재활용 골재를 사용하면 고강도 콘크리트의 강도 가 저하되는 것으로 알려져 왔다. 따라서, 본 연구에서는 재활용 골재 콘크리트의 배합비와 함량 변화를 분석하여 고층 건축에 재활용 골재가 실용적인지, 그리고 어떤 방식으로 활용되는지를 규명하고자 하였다.

Since the first introduction of plastics, the issue of recycling has been repeatedly discussed. Plastics with limited biodegradability accumulate in the soil and ocean when deposited in landfills, causing environmental problems, and when incinerated emit a large amount of carbon. In particular, polyethylene terephthalate (PET) is now an indispensable material in daily life, and the waste it generates is also significant. In response, we sought a way to use PET waste as a concrete additive. Typically, adding PET damages the physical strength of concrete, and to solve this problem, gamma ray irradiation was first applied to the PET. The overall peak intensity of the fourier transform infrared spectroscopy (FT-IR) absorption spectrum of gamma-ray-irradiated PET increased, and the surface hydrophilicity of the material increased. In addition, it was confirmed that surface roughness increased when PET was irradiated with gamma rays. The strength of concrete mixed with gamma-irradiated PET was measured, and the compressive strength increased compared to concrete mixed with non-gamma-irradiated PET, and in the case of fibrous PET, the flexural strength increased.