• International Journal of Industrial Entomology and Biomaterials
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• 제4권2호
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• pp.93-100
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• 2002

Cocoon production, which is a representative of traditional sericulture shifted into silkworm powder production in the spring of 1995. This, infect, signifies the change from the dress-centered textile business to the bio-industry and the functional resource industry. One of the most outstanding shifting is utilization of silkworm larvae for anti-diabetic agent. In Asian countries including Korea, silkworm powder derived from the domestic silkworm (Bombyx mori L.) has long been favored for anti-diabetic agent, but its efficacy was not tested until last decade by modern scientific methods. In this article, we reviewed the major researches on the silkworm powder as a blood glucose-lowering substance. After the beginning test of the efficacy of silkworm powder by a cooperative research between Department of Sericulture and Entomlogy, NIAST, RDA and Kyung Hee University, substantial data have been accumulated so far, In a serial experiment to select best condition, the fifth instar larvae prepared by freeze dry method turned out to have the best blood glucose-lowering effect. In the pharmacological experiment to understand the mechanism of silkworm powder in small intestine, the silkworm powder turned out to inhibit the activity of ${\alpha}$-glucosidase, by competitively binding to $\alpha$-type disaccharides. The animal experiment showed that the extract of silkworm powder prevents a rapid increase of blood glucose level after meal and prevents hunger and law blood glucose level during empty stomach. In the experiment to isolate the major component of silkworm powder, which exerts blood glucose-lowering effect, 1-deoxynojirimy-cin (DNJ) was eventually mass-purified, and it turned out that DNJ isolated from silkworm powder was excellent in its blood glucose-lowering effect. In the experiment to understand the personal difference of the efficacy of the silkworm powder, clinical candidates were divided on the basis of the criterion of traditional Chinese medicine: Tae-Yang, Tae-Um, So-yang, and So-Um. The result showed that silkworm powder has a tendency to reduce blood glucose level at fasting and at 2 hours after meal, and this trend was somewhat obvious in the Tae-Um body type. In summary, we reviewed scientific papers on the efficacy of silkworm powder and its purified DNJ as a blood glucose-lowering agent. These suggest that silkworm powder truly possesses blood glucose-lowering effect as documented in the traditional Chinese medicine, although further researches will be required to develop them as "medical" resource instead of functional food.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.990-991
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• 2006

• 한국표면공학회지
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• 제36권2호
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• pp.194-199
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• 2003

Polarization measurements were peformed to investigate the electrochemical behavior of copper ions and limiting current density in waste rinse water from copper electroplating processes. A newly designed cyclone type electrolyzer was tested to recover the copper powder. Synthetic solutions were prepared using analytical grade $CuSO_4$ to the desired waste water concentration and pH was adjusted with $H_2$$SO_4$. Electrowinning was peformed at room temperature and the solution was cycled with a pump. Results showed that more than 99 percent of Cu was recovered and the size of the recovered Cu powder ranges from 0.1 - $0.5\mu\textrm{m}$. The chemical composition of the Cu powder mainly consists of $Cu_2$O and Cu and can be easily reduced to pure Cu powder.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.844-845
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• 2006

For microelectronic circuits, the main type of failure is thermal fatigue. Therefore, the search for matched coefficients of thermal expansion (CTE) of packaging materials in combination with a high thermal conductivity is the main task for developments of heat sink materials electronics, and good mechanical properties are also required. The aim of this work is to develop copper matrix composites reinforced with carbon nanofibers to meet these requirements. In this paper, a technology for obtaining a homogeneous mixture of copper and nanofibers will be presented and the microstructure and properties of consolidated samples will be discussed.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.618-619
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• 2006

The binder phase for TiC reinforced steel matrix composite was added in the form of elemental powders and master alloy powders. The microstructures, binder phase variation with TiC content and mechanical properties were evaluated. The addition of a type of binder phase largely effects the microstructure and mechanical properties. The binder phase variation from starting composition was observed with increase in wt% TiC content and this variation was higher when the master alloy powders were used as a binder. The response to heat treatment was decreased with an increase in TiC content due to the shift of binder phase from the starting composition.

• 한국건설순환자원학회논문집
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• 제2권4호
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• pp.314-320
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• 2014

시멘트산업은 건설산업에의 기초소재를 공급하는 중추이지만 시멘트 제조시 고온의 소성이 필요하고 소성시의 원료 및 연료로부터 발생하는 $CO_2$와 구조물 해체시 발생하는 건설폐기물은 새로운 환경문제로 대두되고 있다. 본 연구는 폐콘크리트 미분말의 리사이클을 통해 시멘트로서 활용하기 위한 것이다. 기존의 불활성 충전재로서의 활용에서 벗어나 화학적 특성을 기반으로 배합조건을 조절하여 클링커 및 시멘트를 제조하고 미세조직 및 상분석을 실시하여 저탄소형 시멘트 개발 가능성을 타진하고자 한다. 연구결과 폐콘크리트 미분말을 활용한 저탄소형 시멘트 제조가 가능하며 유효활용을 위한 방안이 마련되어야 한다.

• 한국분말재료학회지
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• 제17권4호
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• pp.336-341
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• 2010

The present study focused on the synthesis of Bi-Sb-Te-based thermoelectric powder by an oxidereduction process. The phase structure, particle size of the synthesized powders were analyzed using XRD and SEM. The synthesized powder was sintered by the spark plasma sintering method. The thermoelectric property of the sintered body was evaluated by measuring the Seebeck coefficient and specific electric resistivity. The $Bi_{0.5}Sb_{1.5}Te_3$ powder had been synthesized by a combination of mechanical milling, calcination and reduction processes using mixture of $Bi_2O_3$, $Sb_2O_3$ and $TeO_2$ powders. The sintered body of the $Bi_{0.5}Sb_{1.5}Te_3$ powder synthesized by an oxide-reduction process showed p-type thermoelectric characteristics, even though it had lower thermoelectric properties than the sintered body of the $Bi_{0.5}Sb_{1.5}Te_3$ thermoelectric powder synthesized by the conventional melting-crushing method.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1181-1182
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• 2006

Y-type barium ferrite $(Ba_2Zn_2Fe_{12}O_{22})$ was prepared by the glass-ceramic method. Glasses with composition of $0.1ZnO{\cdot}0.9(0.3Fe_2O_3{\cdot}0.5BaO{\cdot}0.2B_2O_3)$ were prepared, and the precipitation behavior of Y-type ferrite from the glass matrix was investigated by heating glass specimens at various temperature. $\alpha-BaFe_2O_4$ which is a precursor of M-type ferrite $(BaFe_{12}O_{19})$ was precipitated at about 813 K and an unknown compound, phase X, was precipitated at about 850 K. M-type ferrite and Y-type ferrite started to form at about 923 K and 1103 K, respectively. The formation of Y-type ferrite was int erpreted as the result of the reaction of M-type ferrite with a melt of phase X.

• 한국분말재료학회지
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• 제12권3호
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• pp.186-191
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• 2005

A formation of aluminum hydroxide by hydrolysis of nano and micro aluminum powder has been studied. The nano aluminum powder of 80 to 100 nm in diameter was fabricated by a pulsed wire evaporation (PWE) method. The micro powder was commercial product with more than $10\;{\mu}m$ in diameter. The hydroxide type and morphology depending on size of the aluminum powder were examined by several analyses such as XRD, TEM, and BET. The hydrolysis procedure of micro aluminum powder was different from that of nano aluminum powder. The nano aluminum powder after immersing in the water was transformed rapidly to a nano fibrous boehmite, accompanying with a remarkable temperature increase, and then further transformed slowly to a stable bayerite. However, the micro powder was changed to the stable bayerite slowly and directly. The formation of fibrous aluminum hydroxide from nano aluminum powder might be due to the fine cracks which were formed by hydrogen gas pressure on the surface hydroxide layer during hydrolysis. The nano powder with large specific surface area and small size reacted more actively and faster than the micro powder, and transformed to meta-stable hydroxide in relatively short reaction time. Therefore, the formation of fibrous boehmite is special characteristic of hydrolysis of nano aluminum powder.

• 대한본초학회지
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• 제21권4호
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• pp.183-187
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• 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.