K0.5Bi0.5TiO3 (KBT) thin films were prepared by sol-gel processing for future use in piezoelectric generators. It is believed that the annealing temperature of films plays an important role in the output performance of piezoelectric generators. KBT films prepared on Ni substrates were annealed at 500 ~ 700 oC. Tetragonal KBT films were formed after annealing process. As the annealing temperature increased, the grain size of KBT films increased. KBT thin films show piezoelectric constant (d33) from 23 to 41 pC/N. The increase of grain size in KBT films brought about output voltage and current in the KBT generators. Also, the increase in the displacement of specimens during bending test resulted in increases in output voltage and current. Although KBT generators showed lower output power than those of generators prepared using NBT films, as reported previously, the KBT films prepared by sol-gel method show applicability as piezoelectric thin films for lead-free nanogenerators, along with NBT films.

본 연구에서는 전처리 방법별 건조 단호박의 이화학적 특성을 비교 분석하고 반응표면분석법을 이용하여 단호박 말랭이의 최적 건조 조건을 설정하였다. 단호박의 이취 제거와 가공적성을 위한 건열(굽기), 습열(증자), 마이크로웨 이브 처리의 전처리 방법을 비교하고자 호화 점도를 측정 하여 전처리 시간을 설정하였다. 각 전처리 방법별 열풍 건조 전후의 단호박 품질특성을 비교한 결과, 마이크로웨이브 처리에서 가용성 고형분, 과당, 포도당, 자당 함량이 건열과 습열 처리보다 높았고, 수분 함량, 강도 및 경도가 낮게 나타나 마이크로웨이브 처리를 단호박 열풍 건조를 위한 최적의 전처리 방법으로 설정하였고 반응표면분석법을 이용하여 최적의 열풍 건조 조건을 확인하였다. 반응표면분석은 중심합성 계획법으로 실험을 디자인하여 독립변수로서 건조 온도(30, 40, 50oC, X1)와 건조 시간(4, 6, 8 h, X2)을 설정하고, 종속변수로는 건조 단호박의 수분 함량, 수분활성도, 가용성 고형분, 강도, 경도, 과당, 포도당, 자당 함량, 색도(L*, a*, b*)를 측정하여 건조 조건을 최적화하였다. 최적화 변수로는 적합성 결여 검증에서 Pr> F 값이 0.05 이상인 수분 함량, 수분활성도, 가용성 고형분을 최적화 변수로 설정하였으며, 최적화 결과 43oC의 온도와 7.2시간이 최적 건조 조건으로 확인되었고, 예측값과 실험 값을 비교한 결과 90% 이상의 최적 비율을 보였으며, 해당하는 값이 95% 신뢰구간과 예측구간 범위에 들어 실험 디자인과 모델의 적합성 또한 검증되었다.

For the purpose of manufacturing a high efficiency TiO2 photocatalyst, B-doped TiO2 photocatalysts are synthesized using a plasma electrolytic oxidation method in 0.5 M H2SO4 electrolyte with different concentrations of H3BO3 as additive. For the B doped TiO2 layer fabricated from sulfuric electrolyte having a higher concentration of H3BO3 additive, the main XRD peaks of (101) and (200) anatase phase shift gradually toward the lower angle direction, indicating volume expansion of the TiO2 anatase lattice by incorporation of boron, when compared with TiO2 layers formed in sulfuric acid with lower concentration of additive. Moreover, XPS results indicate that the center of the binding energy peak of B1s increases from 191.45 eV to 191.98 eV, which suggests that most of boron atoms are doped interstitially in the TiO2 layer rather than substitutionally. The B doped TiO2 catalyst fabricated in sulfuric electrolyte with 1.0 M H3BO3 exhibits enhanced photocurrent response, and high efficiency and rate constant for dye degradation, which is ascribed to the synergistic effect of the new impurity energy band induced by introducing boron to the interstitial site and the improvement of charge transfer reaction.

In this study, vin chaud were manufactured with eight types of vin chaud-bomb containing different amounts of ingredients, and Campbell Early wine. Samples were analyzed for pH, total acidity, volatile acidity, ethanol content, total polyphenol, and anthocyanins, and radical scavenging activities for antioxidant effect. Based on the results of this study the pH of the samples ranged from 3.34 to 3.41 and the total acidity of wines ranged from 0.55 to 1.00%. The alcohol contents of the vin chaud samples ranged from 3.8~5.8% to and the color intensity of the vin chaud samples was higher than that of the wine. Total polyphenol content was 145.90~262.98 mg% and the tannin content of the C-1 (236.90 mg%) was the highest among the samples. The ABTS and DPPH radical scavenging activity of the samples were 57.39~75.10% and 63.71~80.00% respectively. α-Glucosidase inhibitory activity ranged from 21.54 to 33.49%, on the other hand, wine was not detected and tyrosinase inhibitory activity had the highest values (39.26%) in the C-1 sample. The findings of the present study provide insightful scientific information on vin chaud, and forms a basis for further innovations in the food and wine industry.

Here, we report the development of a new and low-cost core-shell structure for lithium-ion battery anodes using silicon waste sludge and the Ti-ion complex. X-ray diffraction (XRD) confirmed the raw waste silicon sludge powder to be pure silicon without other metal impurities and the particle size distribution is measured to be from 200 nm to 3 μm by dynamic light scattering (DLS). As a result of pulverization by a planetary mill, the size of the single crystal according to the Scherrer formula is calculated to be 12.1 nm, but the average particle size of the agglomerate is measured to be 123.6 nm. A Si/TiO2 core-shell structure is formed using simple Ti complex ions, and the ratio of TiO2 peaks increased with an increase in the amount of Ti ions. Transmission electron microscopy (TEM) observations revealed that TiO2 coating on Si nanoparticles results in a Si-TiO2 core-shell structure. This result is expected to improve the stability and cycle of lithium-ion batteries as anodes.

In the present work, Inconel 718 alloy is additively manufactured on the Ti-6Al-4V alloy, and a functionally graded material is built between Inconel 718 and Ti-6Al-4V alloys. The vanadium interlayer is applied to prevent the formation of detrimental intermetallic compounds between Ti-6Al-4V and Inconel 718 by direct joining. The additive manufacturing of Inconel 718 alloy is performed by changing the laser power and scan speed. The microstructures of the joint interface are characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and micro X-ray diffraction. Additive manufacturing is successfully performed by changing the energy input. The micro Vickers hardness of the additive manufactured Inconel 718 dramatically increased owing to the presence of the Cr-oxide phase, which is formed by the difference in energy input.