Al2O3 sol with long-term stability was prepared by mechanical milling. Thin films were evaluated and created for use as coating materials. The particle size of the manufactured sol was 98 nm when 2 wt% of nitric acid was added. This indicates that the viscosity of the sol is 12 cps and that it has long-term stability. The thickness of the thin films, which varied from 100 nm to 500 nm, could be managed by adjusting the draw rate and the amount of an organic additive. A thin film heated to 500˚C indicated a hydrophilic property against water and excellent permeability against a visible ray.
The development of soy cutlets containing textured soy protein (TSP) as a meat analog was studied. In order to decrease the beany flavor and to increase the texture, TSP was treated with 0.3% Flavourzyme or 0.1% Protamex for 10 or 20 min, respectively. The degree of hydrolysis for TSP treated with Protamex was higher than that treated with Flavourzyme. Hydrolysis was observed to increase as the reaction time was increased for both Flavourzyme and Protamex. The water holding capacity of TSP treated with Protamex for 10 min was the highest, and that treated with Flavourzyme for 20 min was similar to that of Protamex treatment for 20 min. The oil binding capacity of TSP treated with Protamex for 20 min was the highest. The hardness of the soy cutlets using TSP treated with Flavourzyme for 10 min was higher than that treated for 20 min, while that of Protamex treated for 20 min was higher than that treated for 10 min. The cohesiveness of the soy cutlets using TSP treated with Flavourzyme or Protamex for 10 min was higher than those treated for 20 min. The chewiness of the soy cutlets treated with Flavourzyme for 10 min was higher than for those treated for 20 min, while those treated with Protamex for 20 min was higher than those treated for 10 min. The springiness of TSP treated with Flavourzyme for 20 min was higher than those treated for 10 min, and higher than those treated with Protamex for 10 or 20 min. For sensory evaluation, the beany flavor of the soy cutlets treated with Protamex for 20 min was the weakest. The flavor and chewiness of both a pork cutlet and a soy cutlet treated with Protamex for 20 min were the best. In the overall quality, soy cutlets treated with Protamex for 20 min was the most desirable. In conclusion, soy cutlets treated with 0.1% Protamex for 20 min could be a reasonable substitute of pork cutlets.
Some biological activities such as an electron donating capacity, the contents of total polyphenol compounds and flavonoids, fibrinolytic activity and α-glucosidase inhibitory activity have been detected in hot water extracts of Ligularia fischeri and Angelica gigas Nakai. To increase the usefulness of the functional ingredients for prevention and improvement of some metabolic disorders, ethanol-treated hot water extracts of Angelica gigas Nakai were prepared. A hot water extract of Ligularia fischeri has 92% of electron donating capacity, 39.4 mg/g of total polyphenol compounds, 24.8 mg/g of flavonoids and 29.8% of α-glucosidase inhibitory activity, but no fibrinolytic activity. A hot water extract of Angelica gigas Nakai has 94.7% of electron donating capacity, 5.8 mg/g of total polyphenol compounds, 2.6 mg/g of flavonoids, 0.48 plasmin units of fibrinolytic activity and no α-glucosidase inhibitory activity. However, with partial purification using cold ethanol treatment, the α-glucosidase inhibitory activity of Angelica gigas Nakai was increased to 70.5%. Thus, we expected a more useful effect with the use of the addition of a cold ethanol-treated Angelica gigas Nakai extract. The L, b values of cold buckwheat noodles using a mixture of 0~3% of Ligularia fischeri powder and 0.5% of an ethanol-treated hot water extract of Angelica gigas Nakai were decreased with the addition of an increasing amount of Ligularia fischeri powder. Among the mechanical qualities, only adhesiveness was significantly higher in 3% Ligularia fischeri noodles. From sensory evaluation data, it was determined that these two functional ingredients did not ruin the color, texture, and overall acceptance of the cold buckwheat noodles. A higher amount of the extracts improved the quality of the product with little added cost.
Al-Ni alloy nano powders have been produced by the electrical explosion of Ni-plated Al wire. The porous nano particles were prepared by leaching for Al-Ni alloy nano powders in 20wt% NaOH aqueous solution. The structural properties of leached porous nano powder were investigated by nitrogen physisorption, X-ray diffraction (XRD) and transmission Microscope (TEM). The surface areas of the leached powders were increased with amounts of AI in alloys. The pore size distributions of these powders were exhibited maxima at range of pore diameters 3.0 to 3.5 nm from the desorption isotherm. The maximum values of those were decreased with amounts of Al in alloys.
doped (GDC) solid solutions have been considered as a promising materials for electrolytes in intermediate-temperature solid oxide fuel cells. In this study, the nano-sized GDC powder with average panicle size of 69nm was prepared by a high energy ball milling process and its sintering behavior was investigated. Heat-treatment at of nano-sized GDC powder mixture led to GDC solid-solution. The enhanced densification over 96% of relative density was obtained after sintering at for 2h. It was found that the sinterability of GDC powder could be significantly improved by the introduction of a high energy ball milling process
The Ni-based bulk metallic glass matrix composites were fabricated by spark plasma sintering of mixture of gas-atomized metallic glass powders and ductile brass powders. The successful consolidation of metallic glass matrix composite was achieved by strong bonding between metallic glass powders due to viscous flow deformation and lower stress of ductile brass powders in the supercooled liquid state during spark plasma sintering. The composite shows some macroscopic plasticity after yielding, which was obtained by introducing a ductile second brass phase in the Ni-based metallic glass matrix.
We report on the light-emitting diode (LED) characteristics of core-shell CdSe/ZnS nanocrystal quantum dots (QDs) embedded in TiO2thin films on a Si substrate. A simple p-n junction could be formed when nanocrystal QDs on a p-type Si substrate were embedded in ~5 nm thick TiO2 thin film, which is inherently an n-type semiconductor. The TiO2 thin film was deposited over QDs at 200˚C using plasma-enhanced metallorganic chemical vapor deposition. The LED structure of TiO2/QDs/Si showed typical p-n diode currentvoltage and electroluminescence characteristics. The colloidal core-shell CdSe/ZnS QDs were synthesized via pyrolysis in the range of 220-280˚C. Pyrolysis conditions were optimized through systematic studies as functions of synthesis temperature, reaction time, and surfactant amount.
Ba(Ti,Sn)O3 thin films, for use as dielectrics for MLCCs, were grown from Sn doped BaTiO3 sourcesby e-beam evaporation. The crystalline phase, microstructure, dielectric and electrical properties of films wereinvestigated as a function of the (Ti+Sn)/Ba ratio. When BaTiO3 sources doped with 20~50mol% of Sn wereevaporated, BaSnO3films were grown due to the higher vapor pressure of Ba and Sn than of Ti. However, itwas possible to grow the Ba(Ti,Sn)O3 thin films with ≤15mol% of Sn by co-evaporation of BTS and Ti metalsources. The (Ti+Sn)/Ba and Sn/Ti ratio affected the microstructure and surface roughness of films and thedielectric constant increased with increasing Sn content. The dielectric constant and dissipation factor ofBa(Ti,Sn)O3 thin films with ≤15mol% of Sn showed the range of 120 to 160 and 2.5~5.5% at 1KHz,respectively. The leakage current density of films was order of the 10−9~10−8A/cm2 at 300KV/cm. The researchresults showed that it was feasible to grow the Ba(Ti,Sn)O3 thin films as dielectrics for MLCCs by an e-beamevaporation technique.
Microstructure and mechanical properties of WC-3wt% Co cemented carbides, fabricated by a sparkplasma sintering (SPS) process, were investigated in this study. The WC-3wt%Co powders were sintered at900~1100oC for 5min under 40MPa in high vacuum. The density and hardness were increased as the sinteringtemperature increased. WC-3wt%Co compacts with a relative density of 97.1% were successfully fabricated at1100oC. The fracture toughness and hardness of a compact sintered at 1100oC were 21.6MPa·m1/2 and4279Hv, respectively.
High-energy mechanical milling (HEMM) and sintering into Al-Mg alloy melt were employed tofabricate an Al alloy matrix composite reinforced with submicron and micron sized Al2O3 particles. Al-basedmetal matrix composite (MMC) reinforced with submicron and micron sized Al2O3 particles was successfullyfabricated by sintering at 1000oC for 2h into Al-Mg alloy melt, which used high energy mechanical milled Al-SiO2-CuO-ZnO composite powders. Submicron/micron-sized Al2O3 particles and eutectic Si were formed by in situdisplacement reaction between Al, SiO2, CuO, and ZnO during sintering for 2h into Al-Mg alloy melt and werehomogeneously distributed in the Al-Si-(Zn, Cu) matrix. The refined grains and homogeneously distributedsubmicron/micron-sized Al2O3 particles had good interfacial adhesive, which gives good wear resistance withhigher hardness.
LaFeO3 powders were synthesized using a method involving solution combustion, and the surfaceproperties of these powders were examined by x-ray photoelectron spectroscopy. As the amount of fuelincreased during the synthesis, the LaFeO3 powders became amorphous with a large plate-like shape. It wasfound that the O 1s spectra were composed of two types of photoelectrons by deconvolutioning the spectra.Photoelectrons with higher binding energy come from adsorbed oxygen (O−) whereas those with lower energycome from lattice oxygen (O2−). The ratio of adsorbed and lattice oxygen increased as the ratio of the fuel andnitrate (Φ) increased. The binding energy of both types of oxygen increased as Φ increased due to the formationof carbonates.
In this paper, a novel non-vacuum technique is described for the fabrication of a CuInSe2 (CIS) absorber layer for thin film solar cells using a low-cost precursor solution. A solution containing Cu- and Inrelated chemicals was coated onto a Mo/glass substrate using the Doctor blade method and the precursor layer was then selenized in an evaporation chamber. The precursor layer was found to be composed of CuCl crystals and amorphous In compound, which were completely converted to chalcopyrite CIS phase by the selenization process. Morphological, crystallographic and compositional analyses were performed at each step of the fabrication process by SEM, XRD and EDS, respectively.
Porous HAp with three-dimensional network channels was prepared in a polymer foam process using a in-situ formation. HAp/polyol with various HAp solid contents was formed with an addition of isocyanate. Under all conditions, the obtained porous HAp had pore sizes ranging 50 μm to 250 μm. The influence of the HAp content on the physical and mechanical properties of porous HAp scaffolds was investigated. As the solid content increased, the porosity of the porous HAp decreased from 79.3% to 77.9%. On the other hand, the compressive strength of the porous HAp increased from 0.7 MPa to 3.7 MPa. With a HAp solid content of 15 g, the obtained porous HAp had physical properties that were more suitable for scaffolds compared to other conditions.
Adsorption is one of the most efficient method for the separation of low level carbon dioxide. In order to enhance the adsorption capacity, a few additives such as alkali hydroxides were combined with the zeolitic sorbents. As a result of the experimental examination by applying the CO2 flow of 3000 ppm, the composite sorbent showed the improved quality to a certain degree and the added binder was also found to contribute to better adsorption.
Measurement is used for evaluation of product or process exactly. If it couldn't measured correctly, Quality-cost must be raised and it would be hard to improve product quality. So, this study suggests improvement guide line for the multilateral problems of measuring instrument operation based on the investigation of 157 small and medium-sized enterprises in February, 2008. To use inspection gig correctly, man who treat it must be accustomed with the structure, the performance, the method. The inspection gig is selected properly for the measurement goal. If not, results couldn't be correctly or wasted time, efforts, and costs. When selecting a inspection gig, the locating, the clamping, and the efficiency must be considered.
직물의 결점은 원단손실을 가중시키기 때문에, 검단공정에서 결점부위를 제거한다. 실제공장에서 이뤄지는 검단공정은 육안판정방식과 전자동 방식 중 하나를 채택하는데, 두 방식 나름대로 장단점이 있다. 본 연구에서는 육안판정과 전자동 방식의 장점만을 모아 검출은 사람이 하지만, 결점위치 정보 제공 및 결점정보 기록을 컴퓨터가 하도록 반자동 검단기를 개발하였다. 본 연구에서 개발한 레이저 그리드는 결점의 위치를 검단자가 쉽게 파악하도록 돕는 역할을 하며, 야드미터는 자동으로 결점의 위치를 측정하는 역할을 한다. 컴퓨터는 야드미터로 측정된 직물의 길이와 사람이 검출한 결점의 위치정보를 받아들여 저장하고 직물의 결점정보를 한눈에 보여주는 역할을 한다. 실제 사용되는 직물을 대상으로 특정 패턴으로 재단했을 때의 손실률을 계산하여 개발된 시스템의 성능을 객관적으로 평가하였다.
본 연구에서 졸-겔 방법에 의하여 나노 기공을 가지는 세라믹막을 제조하여 단일 조성의 헬륨과 질소를 가지고 기체투과 실험을 수행하였다. 기공 크기 0.1 μm, 기공율 32%의 평막형 α-Al2O3 지지체를 제조하였으며, 지지체를 담지하여 코팅하는 방법으로 4nm의 기공 크기를 가지는 γ-Al2O3 중간층을 제조하였다. 실리카 졸은 TEOS의 산 촉매 가수분해와 축중합반응을 통하여 합성하였다. 막은 딥코팅과 소결과정을 거쳐 제조되었다. 졸-겔 법에 의해 합성된 세라믹 막을 통한 헬륨, 질소 투과 실험은 기체의 투과 특성을 파악하기 위하여 시행하였다. 질소에 대한 헬륨의 선택도는 100∼160 정도였으며 헬륨의 투과도는 303∼363 K의 온도 범위에서 10 -7 mol/m 2 ⋅s⋅Pa 정도였다.