Waste oyster shells create several serious problems; however, only some parts of them are being utilized currently. The ideal solution would be to convert the waste shells into a product that is both environmentally beneficial and economically viable. An experimental study is carried out to investigate the recycling possibilities for oyster shell waste. Bulk ceramic bodies are produced from the oyster shell powder in three sequential processes. First, the shell powder is calcined to form calcium oxide CaO, which is then slaked by a slaking reaction with water to produce calcium hydroxide Ca(OH)2. Then, calcium hydroxide powder is formed by uniaxial pressing. Finally, the calcium hydroxide compact is reconverted to calcium carbonate via a carbonation reaction with carbon dioxide released from the shell powder bed during firing at 550oC. The bulk body obtained from waste oyster shells could be utilized as a marine structural porous material.

This study investigated properties of bread utilizing extracts of ginseng powder. Ginseng powder bread was baked. Addition of 1~3% of ginseng powder extract to wheat flour was carried out. Rheological properties, dough pH, dough volume, bread volume, water absorption capacity, baking loss, bread color, bread texture, and sensory evaluation were tested to examine properties of bread baked with extracts of ginseng powder. The results are as follows. The dough pH decreased gradually with increasing ginseng powder extract concentration. The bread volume, baking loss, and bread weight increased with increasing use of ginseng powder extract, and springiness and cohesiveness increased as red ginseng powder additive concentration increased. Lightness of the L decreased while a and b increased. In the sensory evaluation, ginseng powder with 1% ginseng powder extract was evaluated as the best for taste, texture, flavor, and overall acceptability.

투명한 교류 분말형 전계발광 소자는 Electroluminescence (EL) 용 ZnS계 형광체와 시아노 에틸 유기바인더의 첨가량을 달리하여 제작하였다. 전면전극 indium thin oxide(ITO) glass 위에 약 3 μm 크기 의 형광체로 발광층을 형성하여 silver nanowire(Ag NW)를 스핀코팅으로 후면전극 형성 후 연구를 진행 하였다. 본 연구에 제작된 소자의 발광휘도와 투과도을 통해 등황색 계열의 약 585 nm의 주파장 스펙트 럼을 확인하였고 형광체의 첨가량이 낮아질수록 발광휘도가 약 80 %로 감소, 투과도는 약 30 % 증가하 는 것을 알 수 있었다.

To produce 4N grade high-purity silica powder from natural ore, the mineralogical characteristics of natural silica ore were investigated and their effects on the purification process were revealed. The Chinese silica mineral ore used was composed of iron and aluminum as main impurities and calcium, magnesium, potassium, sodium, and titanium as trace impurities; these trace impurities generally exist as either single oxides or complex oxides. It was confirmed that liberation and acidic washing of the impurities were highly dependent on the particle size of the ground silica ore and on its mineralogical characteristics such as the distribution and phases of existing impurities. It is suggested that appropriate size reduction of silica ore should be realized for optimized purification according to the origin of the natural silica ore. A single step purification process, the mechano-chemical washing (MCW) process, was proposed and verified in comparison with the conventional multi step washing process.

Cu-30 vol% SiC composites with relatively densified microstructure and a sound interface between the Cu and SiC phases were obtained by pressureless sintering of PCS-coated SiC and Cu powders. The coated SiC powders were prepared by thermal curing and pyrolysis of PCS. Thermal curing at 200 oC was performed to fabricate infusible materials prior to pyrolysis. The cured powders were heated treated up to 1600 oC for the pyrolysis process and for the formation of SiC crystals on the surface of the SiC powders. XRD analysis revealed that the main peaks corresponded to the α-SiC phase; peaks for β-SiC were newly appeared. The formation of β-SiC is explained by the transformation of thermally-cured PCS on the surface of the initial α-SiC powders. Using powder mixtures of coated SiC powder, hydrogen-reduced Cu-nitrate, and elemental Cu powders, Cu-SiC composites were fabricated by pressureless sintering at 1000 oC. Microstructural observation for the sintered composites showed that the powder mixture of PCS-coated SiC and Cu exhibited a relatively dense and homogeneous microstructure. Conversely, large pores and separated interfaces between Cu and SiC were observed in the sintered composite using uncoated SiC powders. These results suggest that Cu-SiC composites with sound microstructure can be prepared using a PCS coated SiC powder mixture.

In this study, the degree of particle melting in Y2O3 plasma spraying and its effects on coating characteristics have been investigated in terms of microstructural features, microhardness and scratch resistance. Plasma sprayed Y2O3 coatings were formed using two different powder feeding systems: a system in which the powder is fed inside the plasma gun and a system in which the powder is fed externally. The internal powder spraying method generated a well-defined lamellae structure that was characterized by a thin porous layer at the splat boundary and microcracks within individual splats. Such micro-defects were generated by the large thermal contraction of splats from fully-molten droplets. The external powder spraying method formed a relatively dense coating with a particulate deposition mode, and the deposition of a higher fraction of partially-melted droplets led to a much reduced number of inter-splat pores and intra-splat microcracks. The microhardness and scratch resistance of the Y2O3 coatings were improved by external powder spraying; this result was mainly attributed to the reduced number of micro-defects.

A powder injection molding process is developed and optimized for piezoelectric PAN-PZT ceramics. Torque rheometer experiments are conducted to determine the optimal solids loading, and the rheological property of the feedstock is evaluated using a capillary rheometer. Appropriate debinding conditions are chosen using a thermal gravity analyzer, and the debound specimens are sintered using sintering conditions determined in a preliminary investigation. Piezoelectric performance measures, including the piezoelectric charge constant and dielectric constant, are measured to verify the developed process. The average values of the measured piezoelectric charge constant and dielectric constant are 455 pC/N and 1904, respectively. Powder injection molded piezoelectric ceramics produced by the optimized process show adequate piezoelectric performance compared to press-sintered piezoelectric ceramics.

유과의 기능성 강화와 저장성 향상에 효과가 있는 소재를 개발하기 위하여 클로렐라 분말을 첨가한 유과를 제조하여 품질 특성을 조사한 결과는 다음과 같다. 유과반죽의 밀도는 클로렐라 분말 첨가군이 대조군보다 높게 나타났으며, pH는 대조군에 비해 첨가군이 낮게 나타났다. 유과의 퍼짐성과 수 분함량은 클로렐라 분말 첨가량이 증가할수록 증가되었으며, 부피 또한 증가하는 경향을 보였다. 색도에서 클로렐라 분말 첨가량이 증가될수록 L값과 a값은 낮게 나타났으며, b값은 높아지는 경향을 보였다. 유과의 조직감은 대조군에 비해 클 로렐라 분말 함량이 증가할수록 높아졌다. 유과의 관능평가 결과, 유과의 색과 맛은 클로렐라 분말 2% 첨가군이 가장 높게 나타났으며, 전반적인 기호도는 클로렐라 분말 1%, 클 로렐라 분말 2%, 클로렐라 분말 3%, 대조군으로 나타나, 클로렐라 분말 1% 첨가 유과의 기호도가 가장 높게 나타났다. 저장 기간에 따른 클로렐라 분말 유과의 산가는 대조군보다 클로렐라 분말 첨가군에서 훨씬 낮았으며, 특히 2%첨가 유 과에서 가장 낮게 나타나 클로렐라에 의한 지질의 산화 억제 효과를 확인할 수 있었다. 과산화물가는 저장 30일까지는 급격히 증가하다가 감소하였으며, 클로렐라 분말 2% 첨가군 에서 가장 낮은 과산화물가를 나타냈으며, 클로렐라 분말에 의한 과산화 지질의 산패억제 효과가 우수함을 알 수 있었 다. TBA가는 클로렐라 분말 2% 첨가 유과가 가장 낮은 증 가폭을 나타내어 클로렐라 분말이 malonaldehyde의 생성을 효과적으로 억제함을 알 수 있었고, 지방의 산화안정성에 효 과적인 것을 확인할 수 있었다.

In this paper, cerium doped lutetium pyrosilicate (LPS) powders with cerium content (0.05 and 0.07 mol%) were prepared by sol-gel process. The formation of lutetium pyrosilicate (LPS) phase was confirmed by XRD analysis for the powders heated at 1,200 oC; in these powders, a single phase of Lu2Si2O7 (LPS) was observed. Cerium doped lutetium pyrosilicate (LPS) powder was agglomerated and constituted of small spherical particles with diameters of about 300 nm. The photoluminescence spectra of the Lu2Si2O7:Ce3+ powders showed the characteristic of excitation and there was an emission spectrum for Ce3+ in the host of Lu2Si2O7. The emission spectrum shows a broad band in the range of 350-525 nm; the broad wavelength on the right side of the spectra should be ascribed to the same 5d-4f transitions of Ce3+, as in the case of cerium doped Lu2Si2O7 single crystals.

비열 처리 기술인 유전체 장벽 방전 저온 플라즈마(dielectric barrier discharge cold plasma, DBD-CP)를 이용하여 양 파 분말에 접종된 Salmonella Enteritidis, Escherichia coli O157:H7, 그리고 Listeria monocytogenes의 저해 효과를 조사 하였다. DBD-CP 처리 조건으로서 DBD-CP 형성 가스는 헬륨이었고, 독립 변인은 처리 전압(4, 5, 6, 7, 8, 그리고 9 kV)과 처리 시간(5, 10, 12, 15, 그리고 20분)이었다. 미생물 저해율과 양파 분말의 표면 온도를 종속 변인으로 하여 DBD-CP 최적화 조건을 확립하였고, 이를 바탕으로 S. Enteritidis 저해율에 대한 예측 모델을 구축하였다. 또한 양파 분말의 입자 크기와 수분활성도(Aw)에 따른 S. Enteritidis 저해 효과를 알아보았다. 또다른 처리 조건으로서 헬륨-물 혼 합 가스를 형성 가스로 사용하여 9 kV에서 5분 동안 주파수(15, 25, 그리고 35 kHz)에 따른 미생물 저해율과 시료 표면 온도에 대한 영향을 관찰하였다. DBD-CP 처리에 의해 양파 분말에 접종된 S. Enteritidis, E. coli O157:H7, 그리고 L. monocytogenes는 각각 ≤2.3 ± 0.1, ≤1.4 ± 0.2, 그리고 ≤0.7 ± 1.2 log CFU/cm 2까지 저해되었고, 시료의 최고 온도는 38.5 ± 1.52℃이었다. 양파 분말에 접종된 S. Enteritidis의 저해율에 대한 DBD-CP 최적 조건은 9 kV와 20분이었고, S. Enteritidis 저해율을 가장 적절하게 예측한 모델은 Fermi’s model (R 2 =0.93)이었다. 수분활성도가 0.4, 0.8인 양파 분말의 S. Enteritidis 저해율은 각각 2.3 ± 0.1, 1.8 ± 0.1 log CFU/cm 2로 유의적인 차이가 없었고(p>0.05), 입자 크기가 0.25, 1.00 cm 2인 양파 분말의 S. Enteritidis 저해율은 각각 2.3 ± 0.1, 1.0 ± 0.5 log CFU/cm 2로 입자의 크기가 작을수록 저해율이 높았다. 헬륨-물 혼합 가스로 DBD-CP 처리시 모든 식중독균에서 주파수가 작을수록 저해율이 증가하였고, 헬륨의 단 독 처리에 비해 미생물 저해율이 유의적으로 증가하였다(p<0.05). 현 연구를 통해 DBD-CP 처리 기술은 분말 식품의 품질 보존 및 미생물 안전성을 향상시키기 위한 살균 방법으로서의 가능성을 보여주었다.

This study was conducted to investigate the quality characteristics and antioxidant properties of cookies supplemented with 1-4% (w/w) persimmon leaf powder (PLP). pH and density of cookie dough increased significantly but moisture content decreased significantly with increasing levels of PLP (p<0.05). The spread ratio and loss rate of cookies decreased significantly with increasing levels of PLP (p<0.05). Lightness (L*), redness (a*), and yellowness (b*) decreased significantly with higher amount of PLP (p<0.05). The use of PLP significantly increased the hardness of cookies while 2,2-diphenyl- 1-picrylhydrazyl (DPPH) and 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging activities were significantly elevated (p<0.05). The consumer acceptance test indicated that the addition of PLP up to 2% had a favorable effect on the consumer preferences in most attributes. Based on the overall observations, cookies with 2% PLP can take advantage of the functional properties of PLP without sacrificing consumer acceptability.

The feasibility of incorporating licorice powder (LP) as a value-added food ingredient into convenient food products was investigated using yanggaeng as a model system. LP was incorporated into yanggaeng at amounts of 0, 2, 4, 6, and 8% (w/w) based on total weight of cooked white beans and LP. pH level decreased while moisture content and soluble solid content increased significantly with increasing levels of LP (P<0.05). In terms of color, lightness decreased while redness and yellowness increased significantly (P<0.05) with increasing levels of LP. Hardness also decreased significantly with higher amount of LP in the formulation (P<0.05). 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and 1,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities were significantly elevated by LP addition, and they increased significantly as LP concentration increased in the formulation (P<0.05). Finally, consumer acceptance test indicated that the highest levels of LP incorporation (8%) had an adverse effect on general consumer preferences. In contrast, yanggaeng with moderate levels of LP (2%) is recommended based on its overall scores to take advantage of the antioxidant properties of LP without sacrificing consumer acceptability.

Bioenergetics has been defined as the biology of energy transformations and energy exchanges within and between living organisms and their environment; this field now includes the concept of bioenergetic medicine, e.g., therapeutic approaches involving biophotons. QELBY® powder is a patented quantum energy-radiating material (patent No. 10-1172018), to be precise, a biologically active silicon dioxide-containing mineral powder that radiates reductive energy in infrared wavelength. In this study, we examined possible biological effects of indirect contact with QELBY® powder on various mammalian cell lines derived from macrophagic (MØ) and nonmacrophagic cells, including Raw 264.7 (mouse-derived MØ cell line), HD11 (chicken-derived MØ cell line), and HeLa (human cervical cancer cell line). Our comparison among the cells with and without indirect contact with QELBY® powder showed that this indirect contact significantly (i) increased the mitochondrial membrane potential (up to 1.36-fold) regardless of the cell type (p < 0.05), (ii) decreased the intracellular concentration of ATP in HeLa cells but not in the MØ-derived cells (p < 0.05), and (iii) protected DNA from damage during oxidative stress according to a standard comet assay (single-cell alkaline gel electrophoresis). Taken together, these results imply that indirect contact with QELBY® powder can make cells more metabolically active by increasing the mitochondrial membrane potential and by alleviating DNA damage caused by oxidative stress.

Powder injection molding (PIM), which combines the advantages of powder metallurgy and plastic injection molding technologies, has become one of the most efficient methods for the net-shape production of both metal and ceramic components. In this work, plasma display panel glass bodies are prepared by the PIM process. After sintering, the hot isostatic pressing (HIP) process is adopted for improving the density and mechanical properties of the PIMed glass bodies. The mechanical and thermal behaviors of the prepared specimens are analyzed through bending tests and dilatometric analysis, respectively. After HIPing, the flexural strength of the prepared glass body reaches up to 92.17 MPa, which is 1.273 and 2.178 times that of the fused glass body and PIMed bodies, respectively. Moreover, a thermal expansion coefficient of 7.816 × 10−6/oC is obtained, which coincides with that of the raw glass powder (7.5-8.0 × 10−6/oC), indicating that the glass body is fully densified after the HIP process.

This study evaluated the quality characteristics of dried noodles prepared with strawberry powder in order to determine the most preferred noodle recipe for children’s school meals. The proximate composition of strawberry powder used was as follows: moisture, 3.39%; crude protein, 1.53%; crude lipid, 0.97%; crude ash, 0.82%; and carbohydrates, 93.29%. When viscosity of the composite strawberry powder-wheat flours was measured by amylograph. Gelatinization point, maximum viscosity, viscosity at 95oC and viscosity at 95oC after 15 min decreased as the level of strawberry powder increased. As the level of strawberry powder increased, both L and b color values decreased, whereas a value increased. Weight, water absorption and volume of cooked noodles decreased, whereas turbidity of soup increased. For textural properties, addition of strawberry powder to cooked noodles reduced hardness, chewiness and brittleness. Overall preference according to the results of the sensory evaluation, noodles added with 6% strawberry powder were the most preferred. According to the results, the addition of strawberry powder can positively affect the overall sensory evaluation of dried noodles, and 6% is the optimal level for addition.

In this study, sponge cakes were prepared with replacement of 1, 3, and 5% spergularia marina griseb powder. The specific gravity tended to increase as the ratio of spergularia marina griseb powder increased. The control group had higher moisture content, volume, and specific volume than the spergularia marina griseb powder samples. As the amounts of spergularia marina griseb powder increased, L and b value increased. In terms of textural characteristics, Sponge cake levels of hardness, springiness, cohesiveness, chewiness and brittleness increased as the amount of spergularia marina griseb powder additive increased. In the sensory evaluation, overall acceptability of 3% spergularia marina griseb powder was the highest. Based on the above results, sponge cake, made by addition of 3% spergularia marina griseb could be helpful in improving physical quality as well as taste enhanc the functionality of the product.

Black tomato (Lycopersicum esculentum) is known to have more β-carotene, lycopene, and vitamin C than general redcolored tomatoes. In this study, we evaluated the quality properties, antioxidant activities and sensory characteristics of black tomato cookies. Cookies were prepared by replacing 0, 1, 3, 5, and 7% of flour with black tomato powder. Density of black tomato cookies tended to be decreased between control (1.20) and 3% added groups (1.12). pH value was decreased from control (6.66) to 7% added group (5.16). Spread factor and loss rate were increased with increasing amounts of black tomato powder. Hardness was gradually increased from 107.77 g/cm2 in control to 170.50 g/cm2 in 7% added group. Color measurement indicated that L-value (brightness) was highest in control (70.46) and lowest in 7% added group (45.23); whereas, a-value (redness) increased while b-value (yellowness) tended to decrease with increasing amounts of black tomato powder. Total polyphenol contents and DPPH radical scavenging activities were directly proportional to the amount of black tomato powder. Consumer preference scores in color and flavor of black tomato powder added group were higher than those of control. Characteristic strength test was not significantly different among the groups. Overall, the results indicated that adding 5% black tomato powder is desirable for making black tomato cookies.

This study focuses on fabricating silver flake powder by a mechanical milling process and investigating the formation of flake-shaped particles during milling. The silver flake powder is fabricated by varying the mechanical milling parameters such as the amount of powder, ball size, impeller rotation speed, and milling time of the attrition ballmill. The particle size of the silver flake powder decreases with increasing amount of powder; however, it increases with increasing impeller rotation speed. The change in the particle size of the silver flake powder is analyzed based on elastic collision between the balls, taking energy loss of the balls due to the powder into consideration. The change in the particle size of the silver flake powder with mechanical milling parameters is consistent with the change in the diameter of the elastic deformation contact area of the ball, due to the collision between the balls, with milling parameters. The flake-shaped silver particles are formed at the elastic deformation contact area of the ball due to the collision. Keywords: Flake powder, Milling, Ball collision, Elastic deformation

This study was performed to develop and evaluate cookies prepared with various amounts (0 g, 12.5 g, 25 g and 37.5 g) of mealworm powder to serve as not only sports snacks but also for the general population as a new protein source. In the chromaticity of mealworm cookies, lightness and yellowness decreased whereas redness increased with more mealworm powder. The hardness of the mealworm cookies increased as more mealworm powder was added. In sensory evaluation, higher preference was shown with the measure of color, taste, and overall preference for mealworm cookies prepared with 50% mealworm powder (MP2). For the general composition of MP2, the moisture, carbohydrate, crude protein, crude fat and crude ash were higher compared with the control cookie. For the mineral contents of MP2, the contents of Ca (33.44 mg/100 g), P (225.13 mg/100 g), Mg (82.21 mg/100 g), Na (246.22 mg/100 g), and K (503.49 mg/100 g) were higher compared with the control cookie. The essential amino acids (valine, isoleucine, leucine, methionine, threonine, phenylalanine, and histidine) in MP2 were also higher compared with the control cookie. It was concluded that MP2 can be used as a new protein source for not only the maintenance of muscle but also for the prevention of muscle loss in old people.