• 한국분말재료학회지
• /
• 제22권2호
• /
• pp.87-92
• /
• 2015

Metallic porous materials have many interesting combinations of physical and geometrical properties with very low specific weight or high gas permeability. In this study, highly porous Cu foam is successfully fabricated by a slurry coating process. The Cu foam is fabricated specifically by changing the coating amount and the type of polyurethane foam used as a template. The processing parameters and pore characteristics are observed to identify the key parameters of the slurry coating process and the optimized morphological properties of the Cu foam. The pore characteristics of Cu foam are investigated by scanning electron micrographs and micro-CT analyzer, and air permeability of the Cu foam is measured by capillary flow porometer. We confirmed that the characteristics of Cu foam can be easily controlled in the slurry coating process by changing the microstructure, porosity, pore size, strut thickness, and the cell size. It can be considered that the fabricated Cu foams show tremendous promise for industrial application.

• Preventive Nutrition and Food Science
• /
• 제20권3호
• /
• pp.204-209
• /
• 2015

To develop new type of sponge cake, the effects of partial (0~40%) replacement with Rubus coreanus powder (RCP) on the quality characteristics of sponge cakes were investigated. The pH level and moisture content ranged from 4.05~8.23 and 28.49~36.59, respectively, and significantly decreased upon addition of RCP (P<0.05). Baking loss rate and cake firmness significantly increased with higher RCP content in the formulation, whereas morphological characteristics of cakes such as height, volume, and symmetry indices significantly decreased (P<0.05). For crumb color values, $L^*$-and $b^*$-values significantly decreased while $a^*$-value significantly increased as a result of RCP substitution (P<0.05). Hedonic sensory results indicated that sponge cakes supplemented with 30~40% RCP showed the most favorable acceptance scores for most of the sensory attributes evaluated. Overall, Rubus coreanus sponge cake could be developed with comparable physicochemical qualities without sacrificing consumer acceptability.

• 대한본초학회지
• /
• 제21권4호
• /
• pp.183-187
• /
• 2006

Objectives : Southern, northern, and wild types of Osterici Radix, and Notopterigii Rhizoma et Radix imported from China are circulated in Korea. Morphological identification was attempted by comparing powder forms of these materials. Methods : To make the specimen, the samples were grinded, and the powder was mounted by a solution of Glycerin, Acetic acid and Water at the rate of 1 : 1 : 1. The specimen was mounted by optic microscope, photographs were taken and the characteristics were sketched in lines. Result : 1. Korean Osterici Radix was yellow-brown, but Chinese Notopterigii Rhizoma et Radix was dark-brown. 2. Oil ducts were mostly broken, and most of secretory cells were narrow and long, including yellow or light yellow secretion and starch grain. 3. Parenchyma cells were rectangular, and southern type of Osterici Radix and Chinese Notopterigii Rhizoma et Radix include lots of starch grain in parenchyma cells, while northern type of Osterici Radix and wild Osterici Radix include a little. 4. Vessels were usually reticulate vessel, and the diameter of the vessels of Korean Osterici Radix was $25{\sim}88{\mu}m$, while that of the vessels of Chinese Notopterigii Rhizoma et Radix was $13{\sim}52{\mu}m$. 5. The surface of accessory cells were light brown with the shape of irregular polygon. Conclusion : Southern type of Osterici Radix, nothern type of Osterici Radix, wild Osterici Radix, and Chinese Notopterigii Rhizoma et Radix were all alike, except the amount of starch grain in parenchyma cells.

• 한국세라믹학회지
• /
• 제32권1호
• /
• pp.37-44
• /
• 1995

TiO2 fine powders were synthesized using oxygenolysis and hydrolysis reaction of TiCl4 vapor in gas phase. The TiO2 powder synthesized showed morphological differences depending on reaction system as follows: TiCl4-O2 reaction system produced the monosized particles having polyhedral shape with well-defined crystal planes and the particles did not agglomerate into secondary particles. TiCl4-H2O reaction system, whereas, produced the spherical secondary particles which consisted of fine primary particles. Other powder characteristics such as particle size, impurity content and rutile content are also reported in this study.

• 생약학회지
• /
• 제26권4호
• /
• pp.411-418
• /
• 1995

In order to clarify the originality of several Alisma Rhizomes, we investigated the differences of their morphological, anatomical and physiochemical characteristics. Morphological observation shows the variability of Alisma shape and quality. The diversities in morphological shapes and qualities of tuber were observed among different origins. Chinese product looked like corm shape, but korean's irregular shape. The microscopic observation of korean Alisma revealed the presence of irregular vascular bundle which was scattered transversely and longitudinaly, which was different from that of the rhizome. This facts suggest that the portion of crude drug in Alisma should be the corm rather than the rhizome. In the physicochemical differences, chinese Alisma contains larger amount of mineral elements such as K, Na and Ca than korean Alisma. On the contrary, protein contents in lyophilized powder of aqueous extracts in korean Alisma rhizome was significantly higher than chinese Alisma rhizome. The leaves and stems contained larger amount of Ca and Na than tuber, and may be used as the osmotic diuretics for chinese traditional medicine.

• 소성∙가공
• /
• 제25권3호
• /
• pp.195-202
• /
• 2016

Direct laser melting(DLM) is an additive manufacturing process that can produce parts by solidification of molten metallic powder layer by layer. The properties of the fabricated parts strongly depend on characteristics of the metallic powder. Atomized powders having spherical morphology have commonly been used for DLM. Mechanical ball-milling is a powder processing technique that can provide non-spherical solid powders without melting. The aim of the current study was to investigate the effect of powder morphologies on the deposition quality in DLM. To characterize the morphological effect, the performances of spherical and non-spherical powders were compared using both single- and multi-track DLM experiments. DLM experiments were performed with various laser process parameters such as laser power and scan rate, and the deposition quality was evaluated. The surface roughness, cross-section bead shape and process defects such as balling or non-filled area were compared and discussed in this study.

• 생약학회지
• /
• 제27권4호
• /
• pp.378-382
• /
• 1996

We previously reported the morphological, physiochemical characteristics of Alismae Rhizoma. In this study, we examined the antimicrobial and antifungal activities of 85% ethanol and water extracts of Alismae Rhizoma using disc method. Ethanol extracts of Korean Alismae Rhizoma showed antimicrobial activity on B. subtilis and S. aureus on the concentration dependent manner, whereas, Chinese Alismae Rhizoma revealed antimicrobioal activity on E. coli and N. gonorrhoeae. The water solution(500 mg/ml) of each lyophilized powder of aqueous extracts didn't show any antimicrobial activity on B. subtilis, S. aureus and E. coli, on the contrary, they stimulated cell growth slightly. Ethanol extracts of Korean samples showed antifungal activity on A. niger, but not on C. albicans. Neither A. niger nor C. albicans were affected by Chineses samples.

• 한국분말재료학회지
• /
• 제19권3호
• /
• pp.210-214
• /
• 2012

Mass production-capable $Li_2MnSiO_4$ powder was synthesized for use as cathode material in state-of-the-art lithium-ion batteries. These batteries are main powder sources for high tech-end digital electronic equipments and electric vehicles in the near future and they must possess high specific capacity and durable charge-discharge characteristics. Amorphous silicone was quite superior to crystalline one as starting material to fabricate silicone oxide with high reactivity between precursors of sol-gel type reaction intermediates. The amorphous silicone starting material also has beneficial effect of efficiently controlling secondary phases, most notably $Li_xSiO_x$. Lastly, carbon was coated on $Li_2MnSiO_4$ powders by using sucrose to afford some improved electrical conductivity. The carbon-coated $Li_2MnSiO_4$ cathode material was further characterized using SEM, XRD, and galvanostatic charge/discharge test method for morphological and electrochemical examinations. Coin cell was subject to 1.5-4.8 V at C/20, where 74 mAh/g was observed during primary discharge cycle.

• 한국분말재료학회지
• /
• 제19권3호
• /
• pp.220-225
• /
• 2012

YAG:Ce yellow phosphor particles were synthesized by spray pyrolysis with changing the solution properties and their luminous properties, crystal structure, and morphological changes were studied by using PL measurement, XRD, and SEM analysis. It was clear that the solution properties significantly affected the crystal phase, crystallite size, the PL intensity, and the morphology of YAG:Ce particles. At low calcination temperature, the addition of urea only to the spray solution was helpful to form a pure YAG phase without any impurity phases, as the result, the highest luminescence intensity was achieved at the calcination temperature of $900^{\circ}C$. When the calcination temperatures were larger than $1300^{\circ}C$, however, the YAG particles prepared without any additive showed the highest luminescent intensity. Regardless of the solution conditions, the emission intensity of YAG:Ce particles prepared by spray pyrolysis showed a linear relation with the crystallite size. In terms of the morphology of YAG:Ce particles, the addition of both DCCA and $NH_4OH$ to the spray solution was effective to prepare a spherical and dense structured YAG particles.

• 한국미생물·생명공학회지
• /
• 제23권1호
• /
• pp.81-86
• /
• 1995

A Streptomyces strain YS-943, which produced amino acid antimetabolite, was isolated from soil. During the course of screening for new amino acid antimetabolites from the culture broth of Actinomycetes, we found that the strain produced a substance active against Gram-positive bacteria and its activity was reversed by L-methionine and L-histidine on the synthetic minimal agar medium in the culture broth.The morphological and cultural characteristics serve to identify the producing organism strain YS-943 as the genus Streptomyces. Fermentation was carried out in the synthetic medium at 28$\CIRC$C for 48 hours. The fermentation yield reached about 12 mg per liter of the broth. The YS-943 substance was obtained as white powder, mp 194$\CIRC$C and has the molecular formular of C$_{4}$H$_{8}$N$_{2}$O$_{4}$. Its structure was determined to be o-carbamyl-D-serine by spectroscopic data. It is active against some Gram-positive bacteria and reversed by L-methionine and L-histidine.