• 한국분말재료학회지
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• 제11권3호
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• pp.253-258
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• 2004

We report a carbothermal reduction process for massive synthesis of monolithic W$_{18}$O$_{49}$ phase from tungsten oxide in the presence of carbon source. Carbon black powder was used as a carbon source and added to WO$_3$ by 40 weight percent. Bundles of W$_{18}$O$_{49}$ rods were formed over the temperature range of 80$0^{\circ}C$$^{\circ}C$ to 90$0^{\circ}C$. Pure W$_{18}$O$_{49}$ bundles could be separated from the mixture of W$_{18}$O$_{49}$ and residual carbon black powder. Field emission character of W$_{18}$O$_{49}$ phase was determined using the extracted W$_{18}$O$_{49}$ rods. Flat lamp fabricated from the W$_{18}$O$_{49}$ rods showed the turn-on field of 9.3 V/${\mu}m$.

• 한국축산식품학회지
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• 제24권1호
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• pp.15-22
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• 2004

규격돈의 비육돈육(B 등급육)에 0.3%의 쑥 분말을 첨가한 수육(B$_{+}$ 수육)과 첨가하지 않은 수육(B$_{0}$ 수육), 그리고 종빈돈에서 생산된 육(E 등급육)에 쑥 분말을 첨가한 수육(E$_{+}$ 수육)과 첨가하지 않은 수육(B$_{0}$ 수육)을 제조하고, 도체등급과 쑥 분말이 이화학적, 관능적 특성에 미치는 영향을 검토하였다. 수육의 pH, 휘발성 염기질소 함량, 일반세균 수, 열량, 필수아미노산, 유리아미노산, 불포화지방산 조성, 황색도, 종합적 기호도는 원료육의 등급과 쑥 분말 첨가 유무에 관계없이 유의적 차이를 나타내지 않았다. B$_{0}$수육의 보수력, 탄성 및 명도는 E$_{0}$ 수육보다 높았다(p＜0.05). B$_{0}$ 수육의 적색도는 E$_{0}$수육보다 낮게 나타났다(p＜0.05). B$_{0}$ 수육의 맛과 연도는 E$_{0}$ 수육보다 현저히 우수하였다(p<0.05). 쑥 분말 첨가에 의하여 수육의 보수력, TBARS 값 및 아질산이온 잔류량이 낮아졌다.

• 자원리싸이클링
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• 제8권4호
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• pp.45-56
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• 1999

본 연구의 목적은 불순물들을 다량 함유한 mill scale과 ferro-Mn을 정제과정을 거쳐 불순물들의 함량을 100 ppm 이하로 감소시킨 후 이들을 원료로 사용하여 Mn-Zn ferrite 원료분말을 기존의 고상반응법이 아닌 분무배소 방법에 의해 제조하는데 있다. 이를 위하여 본 연구에서는 정제된 원료용액을 분무배소시킴으로써 고상의 미세한 복합산화물 분말을 형성시키며, 생성된 분말을 효율적으로 포집할 수 있을 뿐 아니라 유해 생성기체를 중화시킬 수 있는 분무배소로 system을 개발하였다. 또한 정제된 원료 용액을 본 연구에서 개발된 분무배소로 내로 투입시킴으로써 Mn-ferrite 및 $Fe_{2}O_{3}$와 $Mn_{2}O_{3}$의 복합산화물 분말을 제조하였으며, 이때 각각의 조건 하에서 생성된 분말들에 대해 조성, 비표면적 및 입도 분포 등의 물리적, 화학적 특성을 조사하였다. 분무 배소법에 의해 생성된 원료분말에 ZnO 및 기타 첨가제를 정해진 조성으로 혼합시킨 후 성형 및 엄격하게 제어된 소결과정에 의해 Mn-Zn ferrite core를 제조하였다. 또한 제조된 core에 대하여 손실값, 초투자율, 잔류자속밀도, 항자력 및 포화자속밀도의 자기적 특성을 측정하였으며, 이 결과들을 바탕으로 Mn-Zn ferrite 원료 분말을 제조하기 위한 분무배소방법의 타당성을 확인하였다.

• 한국축산식품학회지
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• 제31권1호
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• pp.122-128
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• 2011

제조 방법을 다르게 처리한 쑥을 유화형 소시지 제조 시 첨가하여 냉장온도($4{\pm}1^{\circ}C$)에서 4주간 저장하면서 pH, TBARS, 총 미생물수, 아질산염잔존량 및 육색을 조사하였다. 시험구는 쑥을 첨가하지 않은 대조구, 쑥 분말 첨가구는 T1, 쑥 즙 첨가구는 T2, 쑥 에탄올 추출물 첨가구는 T3, 쑥 중탕 추출물 첨가구를 T4 등 5개 처리구로 나누어 0, 1, 2, 3 및 4주간 저장하면서 실험하였다. pH는 저장기간이 경과하면서 모든 처리구에서 서서히 감소하는 경향으로 대조구와 T4는 유의성이 없었고, T1과 T2 및 T3는 저장기간 동안 다소 낮았다(p<0.05). TBARS는 저장기간 동안 증가하였으며, 쑥 즙과 에탄올 추출물을 첨가한 유화형 소시지는 대조구보다 낮아 쑥의 첨가는 지방산화를지연시켰고, 특히 에탄올 추출물 첨가구인 T3에서 TBARS값은 가장 낮은 경향이었다(p<005). 총 미생물수는 저장기간이 지나면서 모든 첨가구에서 증가하였고, 저장 0주에는 처리구간 유의성이 없었으며, 처리구간에는 T3가 유의적으로 낮은 미생물수를 나타내었다. 아질산염잔존량은 저장기간이 경과하면서 감소하였는데 T3에서 다른 시험구보다 유의하게 감소하였다. 육색은 저장기간이 지나면서 CIE $L^*$값과 CIE $b^*$값은 감소하였고 CIE $a^*$값은 증가하였으며, 처리구간에는 CIE $L^*$값과 CIE $a^*$값은 쑥 첨가구에서 낮았고, CIE $b^*$값은 대조구와 T1에서 높은 결과로 쑥 추출물의 첨가는 소시지 색을 어둡게 하는 경향이었다. 결론적으로 쑥 에탄올 추출물 첨가는 지방의 산화와 미생물 성장 억제 및 아질산염잔존량 감소에 효과가 있을 것으로 기대된다.

• Journal of Welding and Joining
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• 제11권4호
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• pp.91-102
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• 1993

The plasma sprayed $Cr_3C_2$-NiCr coatings are widely used as wear-resistant and corrosion-resistant materials. The mechanical and wear properties of the plasma sprayed $Cr_3C_2$-NiCr coating on steel plate were examined in this study. The pore in the coatings could be classified into two types, the one is the intrinsic pore originated from the spraying powder, the other is the extrinsic pore formed during spraying. During the tensile adhesion test, the fracture occured at the interface of top coating and bond coating. It is though that the compressive residual stress increases with the increase of the top coating thickness. From the wear test, it was found that the wear rate increased with the increase of the sliding velocity regardless of the temperature. It is thought that the fracture toughness reduces with the increase of the sliding velocity at $30^{\circ}C$ and that the adhesion amount increases with the increase of the sliding velocity at $400^{\circ}C$ It is concluded that the wear mechanism at $30^{\circ}C$ is the fracture and pull-out of the carbide particles due to the fatigue on sliding surface, while the wear mechanism at $400^{\circ}C$ is the adhesion of the smeared layer formed during wear process.

• 한국전기전자재료학회논문지
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• 제30권5호
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• pp.318-324
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• 2017

Powder compaction technology is widely used to prepare thermal battery components. This method, however, is limited by the size, thickness, and geometry of the battery components. This limitation leads to excessive cell capacity, overweight, and higher cost of the pellets, which decreases the specific capacities and delays the activation time of thermal batteries. $FeS_2$ thin-film cathodes were fabricated by tape-casting technology and analyzed by SEM and EDS in this paper. The residual organic binder of the $FeS_2$ thin-film cathodes decreased with the temperature of the heat treatment, which improved the specific capacity because of the lower resistance. Specific capacities of the $FeS_2$ thin-film cathodes decreased because of the higher residual binder and the restrictive reaction of active materials with molten salts as the thickness increased. $FeS_2$ thin-film cathodes showed much higher specific capacity (1,212.2 As/g) than pellet cathodes (860.7 As/g) at the optimal heat-treatment temperature ($230^{\circ}C$).

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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• pp.145-148
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• 2006

Cold gas dynamic spray is a relatively new coating process by which coatings can be produced without significant heating during the process. Cold gas dynamic spray is conducted by powder sprayed by supersonic gas jet, and generally called the kinetic spray or cold-spray. Cold-spray was developed in Russia in the early 1980s to overcome the defect of thermal spray method. Its low process temperature can minimize thermal stress and also reduce the deformation of the substrate. Most researches on cold-spray have focused on micro scale coating, but our research team tried to apply this method to macro scale deposition. The macro scale deposition causes deformation of a thin substrate which is usually convex to the deposited side. In this research, the main cause of the deformation was investigated using 6061-T6 aluminum alloy and properties of deposited aluminum layer such as coefficient of thermal expansion, Elastic modulus, hardness, electric conductivity were measured. From the result of the analysis, it was concluded that compressive residual stress was the main reason of substrate deformation while CTE had little effect.

• The Korean Journal of Ceramics
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• 제1권4호
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• pp.191-196
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• 1995

Using sol-gel processing method, thin films of lathanum modified lead titanate(PLT) on Corning 7059 glass were prepared. A differential thermal analysis (DTA/TG) curve of gel powder and infrared spectra (FT-IR) of the films were measured to estimate residual organices in them. The heat-treated films were characterized by X-ray diffraction(XRD). Microstructures of the films were observed by a scanning electron microscope (SEM). Optical properties of the films were determined by a UV-VIS spectrophotometer. The waveguiding properties and optical attenuation were measured with the end coupling method and the cut back method. Effects of the drying conditions on the transmittance and the propagation loss of the films were investigated. Experimemtal results showed that the content of residual organics in the film decreased as the drying temperature of the film increased. As the La content of the film increased, the grain size decreased and the transmittance increased. The transmittances of the films increased with the increasing of the drying temperature. The propagation losses in the film decreased as the drying temperature increased.

• 한국전기전자재료학회논문지
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• 제26권1호
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• pp.27-32
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• 2013

According to the composition of LTCC material, though it was thought that bulk defect which was made in forming process effects on the densification during the sintering, it was not reported systemically. In this study, we evaluated crystal structure, 3 point bending strength, hardness and microstructure of the samples by uniaxial pressing and tape casting using the commercial powders of the crystallizing glass and the glass/ceramic composite. In the case of glass/ceramic composite, Viox-001 powder with residual glass in the sintering, 3 point bending strength was similar regardless of forming process due to fill the bulk defect by residual glass. In the case of crystallizing glass, MLS-22, because glass phase was small in the sintering, glass did not fill the pore in the sample by uniaxial pressing process, therefore, the 3 point bending strength of it was 167 MPa. However, the 3 point bending strength of the sample by tape casting was 352 MPa and much higher. Meanwhile, crystal structure and hardness were similar regardless of forming process.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2001년도 제33회 춘계학술대회 개최
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• pp.346-353
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• 2001

Zirconia powder containing 3 mol% yttria(3Y-PSZ) with and with out Fe$_2$O$_3$ addition was coated on tile cast iron substrate by plasma spraying method. The erosion experiments were performed at temperatures from $25^{\circ}C$ to $600^{\circ}C$. A gas blast type erosion tester was used to examine erosion behavior of the specimens. The results of 3Y-PSZ coatings showed that tile erosion rate had maximum value at 40$0^{\circ}C$. It coincided with tile results of phase transformation tetragonal phase to monoclinic phase caused by low temperature thermal degradation. The tensile stress relaxation and the micro-hardness improvement significantly influenced on the erosion rate at $600^{\circ}C$. In the case of Fe$_2$O$_3$ added 3Y-PSZ coatings, the erosion rate of tested at $25^{\circ}C$ showed maximum value at 5.0 mol% Fe$_2$O$_3$ added coating. This tendency is caused by the improvement of mechanical properties and the tensile residual stress. The erosion rate at 200'c and 400'L showed significantly decrease by Fe203 addition. This decrease is believed to be the stabilization of the tetragonal phase and the increase of micro-hardness.