• 한국응용곤충학회지
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• 제39권2호
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• pp.99-103
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• 2000

소간냉동건조분말, 누에번데기냉동건조분말, 수벌가루를 각각 첨가하여 만든 인공사료들을 이용하여 칠성풀잠자리붙이(Chrysopa pallens(Rambur))를 사육한 결과 누에냉동건조분말을 1% 수준으로 첨가한 먹이에서만 효율이 증대되었으며, 유충발육기간이 15.6$\pm$0.99일, 고치무게가 $16.4\pm$2.94mg, 성충까지의 생존율이 89.3%로 나타났다. 또한 소간냉동건조분말, 소고기냉동건조분말, 달걀냉동건조분말 그리고 설탕을 각각 4/4/3/4의 비율로 놓고 비타민 C와 Vanderzant의 비타민 B 혼합물을 각각 50mg씩 넣은 먹이로 칠성풀잠자리붙이를 사육한 결과 유충발육기간이 $12.7\pm$1.45일, 고치무게가 $18.1\pm$2.24mg, 성충까지 생존율이 100%fh 나타났으며, 산란 시작후 20일간의 산란수가 $633\pm$70.4개에 달해서, 이 인공사료를 이용한 칠성풀잠자리붙이의 대량사육이 가능한 것으로 나타났다.

• Tribology and Lubricants
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• 제15권1호
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• pp.77-82
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• 1999

The processing conditions fur the synthesis of platelet W $S_2$ lubricant powder through a solid-gas reaction were optimized. The mixture of tungsten and sulfur powders were sealed in a vacuum of 10$^{-6}$ torr, prior to heat-treating at 85$0^{\circ}C$ fur 8 days. The reaction product showed a well-developed platelet W $S_2$ powder with an average size of 3.8 ${\mu}{\textrm}{m}$. The TGA/DTA analysis of the synthesized W $S_2$ powder was performed up to 120$0^{\circ}C$ at a rate of 1$0^{\circ}C$/min in flowing air (100 ${\mu}{\textrm}{m}$/min) atmosphere. The weight loss was about 6% up to 120$0^{\circ}C$ compared to the original weight. A rapid weight loss of about 5% occurred in the temperature range of 44$0^{\circ}C$ to 66$0^{\circ}C$ and an exothermic peak observed due to the transition of W $S_2$ to W $O_3$. The synthesized W $S_2$powder was coated on the commercial deep grooved ball bearing (No. 6203) to examine the effect of W $S_2$, coating layer on the noise and endurance of the ball bearing. The level of noise obtained from W $S_2$, coated-ball bearing (56 ㏈) was higher. than the value (32 ㏈) occurred in the case of greece lubrication. The endurance of the ball-bearing assembled after the coating of W $S_2$ powder onto each part increased 50 times compared to the non-coated ball-bearing..

• 한국분말재료학회지
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• 제21권3호
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• pp.185-190
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• 2014

$FeS_2$ has been widely used for cathode materials in thermal battery because of its high stability and current capability at high operation temperature. Salts such as a LiCl-KCl were added as a binder for improving electrical performance and formability of $FeS_2$ cathode powder. In this study, the effects of the addition of $Li_2O$ in LiCl-KCl binder on the formability of $FeS_2$ powder compact were investigated. With the increasing amount of $Li_2O$ addition to LiCl-KCl binder salts, the strength of the pressed compacts increased considerably when the powder mixture were pre-heat-treated above $350^{\circ}C$. The heat-treatment resulted in promoting the coating coverage of $FeS_2$ particles by the salts as $Li_2O$ was added. The observed coating as $Li_2O$ addition might be attributed to the enhanced wettability of the salt rather than its reduced melting temperature. The high strength of compacts by the $Li_2O$ addition and pre-heat-treatment could improve the formability of $FeS_2$ raw materials.

• 한국재료학회지
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• 제23권11호
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• pp.607-612
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• 2013

A powder in sheath rolling method was applied to the fabrication of a carbon nano tube (CNT) reinforced aluminum composite. A 6061 aluminum alloy tube with outer diameter of 31 mm and wall thickness of 2 mm was used as a sheath material. A mixture of pure aluminum powder and CNTs with a volume content of 5% was filled in the tube by tap filling and then processed to an 85% reduction using multi-pass rolling after heating for 0.5 h at $400^{\circ}C$. The specimen was then further processed at $400^{\circ}C$ by multi-pass hot rolling. The specimen was then annealed for 1 h at various temperatures that ranged from 100 to $500^{\circ}C$. The relative density of the 5vol%CNT/Al composite fabricated using powder in sheath rolling increased with increasing of the rolling reduction, becoming about 97% after hot rolling under 96 % total reduction. The relative density of the composite hardly changed regardless of the increasing of the annealing temperature. The average hardness also had only slight dependence on the annealing temperature. However, the tensile strength of the composite containing the 6061 aluminum sheath decreased and the fracture elongation increased with increasing of the annealing temperature. It is concluded that the powder in sheath rolling method is an effective process for fabrication of CNT reinforced Al matrix composites.

• 한국식품조리과학회지
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• 제24권1호
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• pp.76-83
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• 2008

The aim of this study was to use arrowroot powder to develop a recipe for a nutritional cookie having the optimal composition of ingredients and texture to elict a strong preference response in all age groups. Wheat flour was partially substituted with arrowroot powder to reduce the wheat flour content of the cookie. Measurements were made and analyzed according to the Response Surface Methodology technique, which showed 16 experimental points including 2 replicates for arrowroot powder, yellow sugar and butter. The compositional and functional properties of the test were measured, and the values obtained were applied to a mathematical model. A canonical form and perturbation plot showed the influence of each ingredient on the final mixture product. The result of sensory evaluation showed very significant values for color (p<0.01), appearance (p<0.001), texture (p<0.05), overall quality (p<0.05), and flavor (p<0.05). Instrumental analysis showed significant values for lightness (p<0.001), redness (p<0.01), yellowness (p<0.01) and spread ratio (p<0.001). The optimal sensory ratios were determined to be 15g for the arrowroot powder, 70 g for sugar and 80 g for butter.

• 한국세라믹학회지
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• 제48권5호
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• pp.418-425
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• 2011

In this study, a high energy ball milling process was introduced in order to improve the densification of direct nitrided AlN powder. The sintering behavior and thermal conductivity of the AlN milled powder was investigated. The mixture of AlN powder and 5 wt% $Y_2O_3$ as a sintering additive was pulverized and dispersed by a bead mill with very small $ZrO_2$ bead media. The milled powders were sintered at $1700^{\circ}C-1800^{\circ}C$ for 4 h under $N_2$ atmosphere. The results showed that the sintered density was enhanced with increasing milling time due to the particle refinement as well as the increase in oxygen contents. Appropriate milling time was effective for the improvement of thermal conductivity, but the extensive millied powder formed more fractions of secondary phase during sintering, resulted in the decrease in thermal conductivity. The AlN powder milled for 10min after sintering at $1800^{\circ}C$ revealed the highest thermal conductivity, of 164W/$m{\cdot}K$ in tne densified AlN sintered at $1800^{\circ}C$.

• 자원리싸이클링
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• 제26권1호
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• pp.16-21
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• 2017

본 연구는 SiC 결정 성장을 위한 원료 분말 합성법에 관한 것이다. ${\beta}-SiC$ 분말들은 높은 온도 조건(>$1400^{\circ}C$)에서 실리콘 분말과 탄소 분말의 반응에 의해서 합성 된다. 이 반응은 진공 상태(또는 Ar 가스 분위기)에서 실리콘+탄소 혼합물이 반응하고 다결정의 SiC 분말을 형성하기 충분한 횟수를 거쳐 그라파이트 도가니 안에서 진행된다. 최종 결과물의 특성들은 X-ray 회절, SEM/EDS, 입도 분석 및 ICP-OES을 통해 분석되었다. 또한, 최종 결과물의 순도는 the Korean Standard KS L 1612에 의거해서 분석했다.

• 폴리머
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• 제28권1호
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• pp.77-85
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• 2004

초고분자량 폴리에틸렌은 우수한 기계적 특성과 생체 적합성으로 인해 생체 재료 분야에서 널리 이용되어 왔다. 그러나, 다른 생체 고분자 재료와의 접착 시, 초고분자량 폴리에틸렌 분말의 표면 불활성으로 인해 접착력이 현저히 감소한다. 본 연구에서는 초고분자량 폴리에틸렌 분말을 첨가함으로써 상온 경화형 폴리(메틸 메타크릴레이트) 뼈 시멘트의 기계적 특성 및 열적 특성을 향상시키기 위해 메틸 메타크릴레이트와 자일렌의 혼합 용액으로 초고분자량 폴리에틸렌 분말의 표면 개질을 시도하였다. 개질 후, 표면 처리된 초고분자량 폴리에틸렌 분말은 적외선 분광기, 주사전자 현미경, 인장압축 시험기, 및 디지털 온도계로 특성을 결정하였다. 메틸 메타크릴레이트와 자일렌의 함량을 달리하여 표면 개질된 초고분자량 폴리에틸렌 분말을 함유한 폴리(메틸 메타크릴레이트) 뼈 시멘트의 기계적 특성을 측정해 본 결과, 메틸 메타크릴레이트/자일렌을 1 : 1 (부피 비율)로 표면 개질한 초고분자량 폴리에틸렌 분말을 첨가시킨 새로운 폴리(메틸 메타크릴레이트) 뼈 시멘트의 기계적 강도가 최대였으며, 중합 열은 103 $^{\circ}C$에서 58∼73 $^{\circ}C$로 감소함을 확인하였다. 또한, 초고분자량 폴리에틸렌 분말의 표면 개질방법의 메카니즘을 제안하였다.

• Journal of Pharmaceutical Investigation
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• 제39권1호
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• pp.29-36
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• 2009

Since the quality of final products is significantly affected by the homogeneity of powder mixture, the powder blending process has been regarded as one of the critical pharmaceutical unit processes, especially for solid dosage forms. Accordingly, the monitoring to determine a blending process' end-point based on a faster and more accurate in-line/on-line analysis has attracted enormous attentions recently. Among various analytical tools, NIR (near-infrared) spectroscopy has been extensively studied for PAT (process analytical technology) system due to its many advantages. In this study, NIR spectroscopy was employed with an optical fiber probe for the in-line monitoring of fluid-bed blending process. The position of the probe, the ratio of binary powder mixture, the powder size differential and the back-flush period of the shaking bag were examined as principal process parameters. During the blending process of lactose and mannitol powders, NIR spectra were collected, corrected, calibrated and analyzed using MSC and PLS method, respectively. The probe position was optimized. A reasonable end-point was predicted as 1,500 seconds based on 5% RSD value. As a consequence, it was demonstrated that the blending process using a fluid-bed processor has several advantages over other methods, and the application of NIRS with an optical fiber probe as PAT system for a fluid-bed blending process could be high feasible.

• 동아시아식생활학회지
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• 제11권5호
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• pp.386-392
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• 2001

일반국수와 유청분말의 첨가량을 달리하여 제조한 국수의 조리 특성과 관능적 특성을 통하여 제면 적성을 비교한 결과는 다음과 같다. 조리면의 기계적인 텍스쳐 특성 중 유청분말 첨가량의 변화에 따라 차이를 보이는 것은 경도와 검성, 씹힘성이었다. 경도의 경우 1% 첨가한 것, 부착성과 응집성, 씹힘성의 경우 3%를 첨가한 것, 탄력성은 7%를 첨가한 것이 가장 좋았다. 조리면의 탄성은 유청분말의 첨가로 인해 약간 향상된 경향을 보였다. 유청분말 첨가 국수의 신장도와 신장력은 일반국수에 비해서 약간 나아진 경향을 보였으나 유청분말 첨가량의 변화에 따라 신장도는 크게 변화하지 않았으나 첨가물에 의해 조금씩 향상된다고 판단되었다. 신장력은 3% 유청국수가 가장 컸으며 1%, 5%, 7%를 첨가한 순으로 나타났다. 국수국물의 색도를 측정한 결과 유청분말 첨가 국수의 국물은 황색도 값에 따라 녹황색을 띄었다. 국수국물의 탁도는 일반국수 국물에 비해 유청 국수 국물이 조금 더 높아 혼탁한 것으로 나타났다. 조리후의 일반국수와 유청분말 첨가 국수의 부피증가율과 무게 증가율 및 함수율은 유청국수 중 5% 유청국수의 부피가 가장 많이 증가하였고 일반국수가 가장 적게 증가하였다. 관능검사에 의한 국수의 텍스쳐 특성치로 볼 때 유청분말을 첨가한 국수 중 외관과 색에서는 7%를 첨가한 것이 가장 높은 점수를 받았으며 식감과 기호도에서는 5% 첨가한 것이 점수가 높은 것으로 나타났다. 위에 조사한 항목들에 대한 결론은 유청분말의 함량을 달리하여 첨가했을 때 국수는 유청분말을 첨가하지 않았을 때의 국수보다 국수 품질에 있어서 텍스쳐 측정 결과 견고성, 부착성, 검성, 씹힘성, 탄력성 등 모든 항목에서 향상되었고 밀가루의 중량에 대한 첨가비율은 5%가 가장 적합한 것으로 나타났다. 또한 국수의 색은 연하고 밝아 기호도 조사에서 선호하는 색으로 나타났다. 앞으로 유청분말 국수에 대한 연구가 점진적으로 이루어져야 할 것이며 유청분말을 첨가하는 범위를 빵이나 케이크, 과자로 넓혀 나아갈 수 있는 자료가 될 것이다. 또한 유가공업계는 유청 또는 유청분말의 소비로 인해 경제적 잇점을 추구할 수 있을 것으로 사료된다.