This study investigated the quality characteristics and antioxidant activities of gluten-free cookies containing teff flour. By substituting 0% (control), 25% (TF25), 50% (TF50), 75% (TF75), and 100% (TF100) of wheat flour with teff flour, five samples were produced. Baking loss rate was the highest in TF25 at 13.76% and the lowest in TF75 at 4.03%. Spread factor was significantly higher in cookies made with teff flour (83.00~85.00) than in the control (81.33) (p<0.05). There was no significant difference in density among the samples at 1.17~1.25 g/mL (p<0.05); however, pH significantly decreased at 6.42~6.04 (p<0.05). While the L-value and b-value significantly decreased with the amount of teff flour, the a-value significantly increased (p<0.05). The ΔE value was the highest in the control at 31.31 and the lowest in TF100 at 58.69. Hardness was the highest in the control at 42.04 N than in cookies containing teff flour. The content of polyphenols was the highest in TF100 at 3.37 μg GAE/mg and the lowest in the control at 1.32 μg GAE/mg. The content of flavonoids was the highest in TF100 at 3.66 μg QE/mg and the lowest in controls at 0.45 μg QE/mg. The value of DPPH IC50 was the highest in the control at 3,723.00 μg/mL and the lowest in TF 100 at 405.27 μg/mL. The value of ABTS IC50 was the highest in the control at 1,822.32 μg/mL and the lowest in TF100 at 529.30 μg/mL. In sensory evaluation, while control, TF75, and TF100 had a higher score in appearance at 5.52~5.60, all samples had no significant differences in flavor, sweetness, savory taste, chewiness, and overall acceptability (p<0.05). These results showed that the gluten-free cookies containing teff flour can improve the quality characteristics and antioxidant activities of a cookie. We concluded that gluten-free cookies containing 100% teff flour are desirable.

Photoelectron-hole separation efficiency plays an important role in the enhancement of the photocatalytic activity of photocatalysts towards the degradation of organic molecules. In this study, TiO2/TiOF2 heterostructured composite powders with suitable band structures, which structures are able to separate photoelectron-hole pairs, have been synthesized using a simple and versatile ultrasonic spray pyrolysis process. In addition, their phase volume fractions have been controlled by varying the pyrolysis temperature from 400 oC to 800 oC. The structural and optical properties of the synthesized powders have been characterized by X-ray diffraction, scanning electronic microscopy and UV-vis spectroscopy. The powder with a phase volume ratio close to 1, compared with single TiOF2 and other composite powders with different phase volume fractions, was found to have superior photocatalytic activity for the degradation of rhodamine B. This result shows that the TiO2/TiOF2 heterostructure promotes the separation of the photoinduced electrons and holes and that this powder can be applicable to environmental cleaning applications.

We investigated the antioxidant, physicochemical, and sensory characteristics of dried type sodium-reduced bibimbap using dandelion complex powder (DCP). DCP is known to add moisture to the skin and relieve symptoms of atopic dermatitis. The sodium content of the standard sample was 1,110.87 mg per serving. The sodium was significantly reduced by 30%, resulting in 762.62 mg of sodium for the reduced sodium group (p<0.05). The ash contents of the standard sample group with DCP showed the highest value (3.17%) in all samples and was affected by minerals of DCP (p<0.05). The total flavonoid contents and ABTS radical scavenging activity, indicators of antioxidant, anticancer and antibacterial activities, showed significantly high activities with addition of DCP (p<0.05). In the sensory results, bulgogi and savory flavor of the samples with DCP showed significantly higher values, and samples with DCP received the highest scores for after-taste. All samples were confirmed to be microbiologically safe according to the food code applied to food manufacturers. Pathogenic microorganisms tests were either negative or not detected in all samples.

Purple-fleshed potato powder (PFPP) was investigated to determine optimal mixing ratio with milk powder and dextrin to produce a ready-to-eat mashed potato powder. The rheological characteristics, color, and anthocyanin contents were studied at a different concentration of ingredients. The power-law model was applied to explain the mechanical spectra of mashed potatoes which represented the change in structure induced by different mixing ratios. Mixture design was used to obtain the experimental points used to establish the empirical models to describe the effects of each ingredient on the characteristic of the mashed potato. The results of mechanical spectra showed that both storage and loss moduli (G' and G'') were significantly influenced by PFPP and milk powder concentration. The power law parameters n' and n'' showed higher values for the mashed potato with a lower concentration of PFPP and a higher concentration of milk powder, which showed that the gel networks involved in the mashed potato were weaker. The optimum mixing ratio with the highest redness and anthocyanin content, while maintaining the rheological properties similar to the commercial mashed potato, was determined as PFPP:milk powder:dextrin = 90.49:4.86:4.65 (w/w). The proportions of PFPP and milk powder in the formulation significantly changed the characteristics of mashed potato, whereas no significant effect of dextrin was observed in this formulation.

Purple-fleshed potato powder (PFPP) was investigated to determine optimal mixing ratio with milk powder and dextrin to produce a ready-to-eat mashed potato powder. The rheological characteristics, color, and anthocyanin contents were studied at a different concentration of ingredients. The power-law model was applied to explain the mechanical spectra of mashed potatoes which represented the change in structure induced by different mixing ratios. Mixture design was used to obtain the experimental points used to establish the empirical models to describe the effects of each ingredient on the characteristic of the mashed potato. The results of mechanical spectra showed that both storage and loss moduli (G' and G'') were significantly influenced by PFPP and milk powder concentration. The power law parameters n' and n'' showed higher values for the mashed potato with a lower concentration of PFPP and a higher concentration of milk powder, which showed that the gel networks involved in the mashed potato were weaker. The optimum mixing ratio with the highest redness and anthocyanin content, while maintaining the rheological properties similar to the commercial mashed potato, was determined as PFPP:milk powder:dextrin = 90.49:4.86:4.65 (w/w). The proportions of PFPP and milk powder in the formulation significantly changed the characteristics of mashed potato, whereas no significant effect of dextrin was observed in this formulation.

Transparent conducting electrodes (TCEs) are attracting considerable attention as an important component for emerging optoelectronic applications such as liquid crystal displays, touch panels, and solar cells owing to their attractive combination of low resistivity (< 10-3 Ω cm) and high transparency (>80%) in the visible region. The solutionbased process has unique properties of an easy fabrication procedure, scalability, and low cost compared to the conventional vacuum-based process and may prove to be a useful process for fabricating TCEs for future optoelectronic applications demanding large scale and flexibility. In this paper, we focus on the introduction of a solution-based process for TCEs. In addition, we consider the powder materials used to fabricate solution-based TCEs and strategies to improve their transparent conducting properties.

Harmonic structure materials are materials with a core–shell structure having a shell with a small grain size and a core with a relatively large grain size. They are in the spotlight because their mechanical properties reportedly feature strength similar to that of a sintered powder with a fine grain size and elongation similar to that of a sintered powder with a coarse grain size at the same time. In this study, the tensile properties, microstructure, and stretchflangeability of harmonic structure SUS304L made using powder metallurgy are investigated to check its suitability for automotive applications. The harmonic powders are made by mechanical milling and sintered using a spark plasma sintering method at 1173 K and a pressure of 50 MPa in a cylindrical die. The sintered powders of SUS304L having harmonic structure (harmonic SUS304L) exhibit excellent tensile properties compared with sintered powders of SUS304L having homogeneous microstructure. In addition, the harmonic SUS304L has excellent stretch-flangeability compared with commercial advanced high-strength steels (AHSSs) at a similar strength grade. Thus, the harmonic SUS304L is more suitable for automotive applications than conventional AHSSs because it exhibits both excellent tensile properties and stretch-flangeability.

복분자, 갈근 및 녹차 추출분말이 각각 1%(w/w)로 첨가된 조미액으로 제조된 한우 육포의 품질특성 및 항산화 활성을 비교하였다. 복분자, 갈근 및 녹차 추출분말이 첨가된 조미액의 항산화 활성은 무첨 가구에 비해 유의적으로 높았다. 식물류 추출분말이 첨가된 육포의 전단가는 대조구에 비해 유의적으로 낮았으며, 색차(ΔE)는 시료 간에 미미하였으며, 전반적인 기호도는 녹차 추출분말이 첨가된 육포 (G-BJ)에서 다소 높게 평가되었다. 육포의 저장과정 중 수분활성도는 저장 2주째에 대조구에서 유의적 으로 증가되었으나, 식물 추출분말이 첨가된 육포는 저장 1주에 비해 유의적인 증감을 보이지 않았다. 저장 4주 경과 후에는 모든 시료에서 수분활성도가 다소간 증가되는 경향이었다. 식물 추출분말이 첨가 된 육포를 4주간 실온에 저장하는 동안 지질과산화물의 함량은 유의적으로 증가하였다. G-BJ는 4주간 저장되었을 때 2주간 저장된 시료에 비해 유의적인 증가 현상을 보이지 않았다. 식물 추출분말이 첨가 된 육포의 항산화 활성은 대조구에 비해 유의적으로 높았으며, 특히 G-BJ에서 가장 높았다. 한우 육포 의 제조 시 식물 추출분말의 첨가는 육포의 전단가 감소와 항산화 활성을 증가시킴으로써 육포의 품질 향상에 효과적일 것으로 예상된다.

Porous polytetrafluoroethylene (PTFE) thin films are fabricated by spin-coating using a dispersion solution containing PTFE powders, and their crystalline properties are investigated after thermal annealing at various temperatures ranging from 300 to 500°C. Before thermal annealing, the film is densely packed and consists of many granular particles 200-300 nm in diameter. However, after thermal annealing, the film contains many voids and fibrous grains on the surface. In addition, the film thickness decreases after thermal annealing owing to evaporation of the surfactant, binder, and solvent composing the PTFE dispersion solution. The film thickness is systematically controlled from 2 to 6.5 μm by decreasing the spin speed from 1,500 to 500 rpm. A triboelectric nanogenerator is fabricated by spin-coating PTFE thin films onto polished Cu foils, where they act as an active layer to convert mechanical energy to electrical energy. A triboelectric nanogenerator consisting of a PTFE layer and Al metal foil pair shows typical output characteristics, exhibiting positive and negative peaks during applied strain and relief cycles due to charging and discharging of electrical charge carriers. Further, the voltage and current outputs increase with increasing strain cycle owing to accumulation of electrical charge carriers during charge-discharge.

Abstract Y2Ti2O7 nanoparticles (0.3 mol%) have been successfully synthesized by the co-precipitation process. The samples, adjusted to pH7 with ammonia solution as catalyst and calcined at 700~900 ℃, exhibit very fine particles with close to spherical shape and average size of 10-30 nm. It was possible to control the size of the synthesized Y2Ti2O7 particles by manipulating the conditions. The Y2Ti2O7 nanoparticles were coated on a glass substrate by a dipping coating process with inorganic binder. The Y2Ti2O7 solution coated on the glass substrate had excellent adhesion of 5B; pencil hardness test results indicated an excellent hardness of 6H. The thickness of the thick film was about 30 μm. Decomposition of MB on the Y2Ti2O7 thin film shows that the photocatalytic properties were excellent.