• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.879-880
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• 2006

Effect of phase transformation and grain-size variation of hot-pressed cobalt on its dry sliding wear was investigated. The sliding wear test was carried out against glass (83% $SiO_2$) beads at 100N load using a pin-on-disk wear tester. Worn surfaces, cross sections, and wear debris were examined by an SEM. Phases of the specimen and wear debris were identified by an XRD. Thermal transformation of the cobalt from the hcp $\varepsilon$ phase to the $\gamma$ (fcc) phase during the wear was detected, which was deduced as the wear mechanism of the sintered cobalt.

• Journal of the Korean Ceramic Society
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• v.37 no.11
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• pp.1071-1077
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• 2000

표면 윤활층을 가진 나노 알루미나를 진공중에서 가압성형함으로써 결함발생없이 높은 충전압력을 가할 수 있었으며, 높은 밀도, 미세기공, 좁은 기공경 분포를 가지는 성형체를 제조할 수 있었다. 윤활제의 화학 및 기계적 특성에 의하여 변하는 모세관 현상을 조정함으로써 충전효율을 증대하고 결함발생을 억제할 수 있다. 나노분말의 소결에서도 성형 미세구조의 균일도가 치밀화 거동에 여전히 지배적인 역할을 하였다.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.12
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• pp.1359-1367
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• 2003

본 연구에서는 실제 의복 관리와 생산 면에서 접할 수 있는 모 직물의 접착심과의 접착 후, 프레싱 처리 후, 드라이클리닝 및 프레스로 처리 후 직물의 형태안정성과 의복형성능의 변화를 살펴보았다. 겉감으로는 신사복 춘하용 모 100% 또는 모 혼방 직물 15종류를 사용하였으며 심지로는 신사복에 많이 쓰이는 3종류 심지를 사용하였다. FAST시스템과 KES시스템을 이용하여 직물의 접착 후, 프레싱 처리 후, 드라이크리닝과 프레싱 처리 후의 형태안정성과 의복형성능의 변화를 시험하였으며 다음과 같은 결과를 얻었다. 1) 모직물의 형태안정성에서 주요인자인 습윤팽창(HE)은 접착으로 크게 감소하였고 프레싱 처리와 드라이크리닝과 프레싱 처리 후는 접착 후보다 큰 변화를 보이지 않는다. 모직물의 습윤팽창(HE)의 조절시 접착심이 습윤팽창(HE)의 안정성에서 중요한 역할을 하는 것으로 나타났다. 2) 완화수축(RS)은 접착 후 조금 감소하였으나 큰 변화를 보이지 않고 프레싱 처리 후 현저한 감소를 보인다. 드라이크리닝과 프레싱 처리 후는 직물이 수축하고 볼륨감이 생김으로 완화수축(RS)은 더욱 감소하였다. 모직물의 완화수축(RS)의 조절시 프레싱이 중요한 역할을 하는 것으로 나타났다. 3) 모직물의 의복형성능(TAV)은 접착으로 크게 향상되었다. 드라이크리닝과 프레싱 처리 후 직물이 좀더 부드러워지고 볼륨감이 생기면서 의복형성능(TAV)은 적게 향상됨을 보인다. 이와 같이 3가지 처리는 서로 보완되어 모직물의 형태안정성과 의복형성능을 향상시키는 것으로 나타났다.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.6
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• pp.1010-1020
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• 1997

For this study, we did needlework of the sample considering practical aspects of production and consumption of silk, high-quality material for women's clothes, and then analyzed the state of the seam puckering after press and dry cleaning, estimated the Seam Puckering based on the mechanical properties of silk related to machine sewing, and examined the effects which Mechanical Properties have on Seam Puckering closely. Through this, we reach the following conclusion. 1. There are three types of seam puckering for each stage, which are caused bathe smoothness of the surface by press, and the difference between the shrinkage rates of fabric and sewing thread by Dry Cleaning. 2. In analyzing seam puckering classified by each step, seam puckering after sewing the fabric is related to WT negatively, while to RT and W positively. Seam puckering after sewing and pressing the fabric is related to WT, RC, MMD negatively and seam puckering after sewing, pressing anddry cleaning the fabric isrelated to WT negatively, too. 3. Concerning the mechanical properties of the sample with a little seam puckering, WT, LC, WC, RC, MMD, SMD is relatively large while RT, B, 2HB is small. 4. Judging from the result of estimating seam puckering based on mechanical properties, the estimate-formula is satisfied in this study.

• Journal of Animal Science and Technology
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• v.63 no.3
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• pp.510-519
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• 2021

One of the most pressing issues facing the dairy industry is drought. In areas where annual precipitation is low, irrigation for growing feed presents the greatest water-utilization challenge for dairy producers. Here, we investigated the effects of cultivar and harvest days after planting (DAP) on dry matter (DM) yield and nutritive value of teff (Eragrostis tef), a warm-season annual grass native to Ethiopia that is well adapted to drought conditions. Eighty pots were blocked by location in a greenhouse and randomly assigned to four teff cultivars (Tiffany, Moxie, Corvallis, and Dessie) and to five harvest times (40, 45, 50, 55, or 60 DAP). Cultivars had no effect on DM yield and nutritive value. As harvest time increased from 40 to 60 DAP, DM yield and ash-free neutral detergent fiber (aNDFom) concentrations increased, while crude protein (CP) concentrations and in vitro NDF digestibility decreased. To assess carryover effects of time of harvest on yield and nutritive value, two additional cuttings were taken from each pot. Increasing first-cutting harvest time decreased CP concentrations in the second cutting and reduced DM yields in the second and third cutting. Harvesting teff between 45 and 50 DAP best optimized forage yield and nutritive value in the first and subsequent cuttings.

• Journal of Powder Materials
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• v.26 no.6
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• pp.471-476
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• 2019

Additively manufactured metallic components contain high surface roughness values, which lead to unsatisfactory high cycle fatigue resistance. In this study, high cycle fatigue properties of selective laser melted Ti-6Al-4V alloy are investigated and the effect of dry-electropolishing, which does not cause weight loss, on the fatigue resistance is also examined. To reduce the internal defect in the as-built Ti-6Al-4V, first, hot isostatic pressing (HIP) is conducted. Then, to improve the mechanical properties, solution treatment and aging are also implemented. Selective laser melting (SLM)-built Ti64 shows a primary α and secondary α+β lamellar structure. The sizes of secondary α and β are approximately 2 ㎛ and 100 nm, respectively. On the other hand, surface roughness Ra values of before and after dry-electropolishing are 6.21 ㎛ and 3.15 ㎛, respectively. This means that dry-electropolishing is effective in decreasing the surface roughness of selective laser melted Ti-6Al-4V alloy. The comparison of high cycle fatigue properties between before and after dry-electropolished samples shows that reduced surface roughness improves the fatigue limit from 150 MPa to 170 MPa. Correlations between surface roughness and high cycle fatigue properties are also discussed based on these findings.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.10
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• pp.1809-1820
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• 2001

본 연구에서는 모 직물의 접착심과의 접착 후, 프레싱 처리 후, 드라이클리닝 처리 후 프레스로 처리한 실제의 의복의 관리와 생산 면에서 접할 수 있는 직물 변화에 대하여 물성 변화를 살펴보았다. 겉감으로는 신사복 춘하용 모 100% 또는 모혼방 직물 15종류를 사용하였으며 심지로는 신사복에 많이 쓰이는 3종류 심지를 사용하였다. KES시스템을 이용하여 직물의 접착후, 프레싱 처리 후, 드라이크리닝과 프레싱 처리 후의 물성 변화를 시험하였으며 다음과 같은 결과를 얻었다. 1) 접착 후 EM은 대체로 감소하지만 강성과 이력 현상은 증가하는 것으로 나타났다. 결과로 KOSHI, SHARI, HARI는 증가하고 THV는 감소하여 태는 접착으로 저하되었다. 2) 프레싱 처리 후는 접착 후와 큰 차이를 보이지 않는다. 마찰특성에서 좀더 매끄러워지고 마찰 계수는 증가하는 것으로 나타났다. 3) 드라이크리닝과 프레싱 처리 후의 물성의 변화에서는 위사 방향의 큰 값을 갖는 경우에 감소하는 것으로 나타났다. 굽힘 강성과 전단강성은 감소하였지만 이력은 증가하는 흥미로운 결과를 보인다. 드라이클리닝 용제의 효과로 여겨진다. 무게는 증가하여 직물이 처리 후 수축한 것으로 나타났다. 프레싱 처리 후와 비교시 KOSHI, SHARI, HARI와 FURAMl는 감소하고 THV는 증가하여 태가 향상하였다.

• Korean Journal of Food Science and Technology
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• v.10 no.1
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• pp.1-7
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• 1978

The wet soybean residue, a byproduct of soymilk industry having potential food value has been tried to dehydrate for the purpose of storage. The total solid of the byproduct was composed of 28.9% protein, 13.6% fat, 4.4% ash and 53.0% carbohydrates. The original water content of 593%(dry-weight basis) was reduced to 378% by pressing mechanically. The sufficient pressure and time for the pressing were found to be 0.5M/T and 5minutes, respectively. The partially dehydrated soybean residue was formed into pellets of 3mm in diameter and 10mm in length. By applying hot air on the thin layer of pellets the moisture could be further reduced to the level of 10% which is equivalent to that of the commercial wheat flour. No significant color deterioration in the product was observed if the hot air dehydration procedure was within the limit of 95 minutes at $120^{\circ}C$ under the air flow velocity of 160 feet per minute.

• Transactions of the Korean hydrogen and new energy society
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• v.16 no.2
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• pp.150-158
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• 2005

Added ratio of 8YSZ powder and organic compounds (solvent, plasticizer, dispersant, binder) properly. It manufactured electrolysis membrane by wet process that make slurry and dry process that do not use organic compounds. In the case of wet process, harmony combination and method of organic compound are an importance element in slurry manufacture. This slurry did calcine at temperature of 140$^{\circ}C$ in Furnace and manufactured electrolyte disk by Dry pressing method. Like this, manufacturing disk sintered at temperature of $1300^{\circ}C,\;1400^{\circ},\;1500^{\circ}C$ in Furnace and completed electrolysis membrane. Confirmed change of crystal structure and decision form through analysis of density, SEM, XRD according to change of sintering temperature, and considered relation with ion conductivity.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.701-710
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• 1996

Composting has gained rapid acceptance as a method of recyling relatively dry organic materials such as leaves and brush and , when alternative disposal costs are high, even moist materials such as grass clippings and dewatered sewage sludges. However, as moisture contents rise above 60% , the need for a dry bulking amendment increase the costs of composting , both by direct purchases of amendment and though increased reactor capacity and materials handling requirements. High moisture materials also present increased risks of anaerobic odor formation through reduced oxygen transport (Miller , 1991) . These costs and operational challengers often constrain the opportunities to compost high moisture materials such as agricultural manures. During the last several decades economies of scale in livestock production have been increasing livestock densities and creating manure management challenges throughout the world. This issue is particularly pressing in Korea, where livestock arms typically manage little or no cropland, and the nutrients and boichemical oxygen demand in manure pose a serious threat to water quality. Composting has recently become popular as a means of recycling manure into products for sale off the farm, but bulking amendments (usually sawdust) are expensive designed to minimize bulking agent requirements by using the energy liberated by decompostion. In this context the composting reactor is used as a biological dryer, allowing the repeated use of bulking amendment with several batches of manure.