• Asian-Australasian Journal of Animal Sciences
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• 제5권2호
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• pp.199-215
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• 1992

Sources of organic waste materials for aerobic and/or anaerobic degradation, or for composting of solid wastes in Germany were estimated. The basic microbiology and the energetics of these processes were compared with special emphasis on anaerobic degradation, for which a general degradation scheme of carbohydrates is presented. Advantages of anaerobic over aerobic treatment processes are pointed out and conditions for maintaining a highly stable anaerobic process as well as producing a sanitized, hygienic product are discussed. Reactor systems suitable for efficient treatment of wastes with a high or low proportion of suspended solids are principally compared and results of laboratory studies on the degradation of several wastes and animal manures summarized. Finally, a piggery slurry treatment factory for an ultimate slurry processing to obtain a dry fertilizer and a harmless, disposable liquid, as it is in operation in Helmond/Holland, is presented and preliminary process data are presented.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.431-432
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• 2006

In this study, the effect of the temperature of magnesium slurry was investigated by mechanical stirring method. The evaluations of rheological behavior of AM50A magnesium alloy were measuring of viscosity and microstructures in the semisolid state. The apparent viscosity was investigated at continuous cooling rate using a concentric cylinder viscometer. Measurement of viscosity measures torque that act to stirrer rotating in slurry doing continuous cooling using torque-meter and expressed by POWER-LAW. Microstructures were observed after mechanical stirring that enforce time at steady state temperature of solid fraction.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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• pp.1205-1210
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• 2000

In this research we made the mean cement particle size 4 $\mu\textrm{m}$ which can penetrate even minor cracks based on the theory of J.K. Michel who reported particles can penetrate the crack of width up to 3 times of maximum particle size. The cement slurries were produced by adding super plasticizer. The slurries were tested with slurry characterization methods and its rheological properties were characterized. The early hydrated phenomena of ultra fine cement were observed by SEM, XRD and DSC during 24 hours. Mechanical properties of hardened slurry with JIS molds were also tested in 3, 7 and 28 days. The cracked specimens which were repaired with slurries produced various conditions were tested after 3, 7 and 28 days curing in the air and adhesion properties were characterized.

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2893-2896
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• 2010

In this study, the optimal preparation conditions in the polymerization process of poly(ethylene terephthalate) (PET) were studied in detail. As a result, the dispersibility of $TiO_2$ was significantly improved by the addition of dispersant and steric hinderance additives into $TiO_2$/ethylene glycol (EG) slurry during the esterification step. The addition sequence of $TiO_2$/EG slurry and stirring also affected the dispersibility of $TiO_2$. The SEM results showed that some $TiO_2$ particles were agglomerated in the PET matrix. The full dull (FD) PET chip and fiber were prepared according to the optimal preparation conditions. The FD PET fiber exhibited a better dispersibility than that of the FD PET chip.

• 한국정밀공학회지
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• 제16권11호
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• pp.62-67
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• 1999

The RP&M(Rapid Prototyping and Manufacturing) is the most appropriate technology for the small-lot production system, in which the production cycle is getting shorter owing to various needs from consumers. Recently RP products which are made of plastics, wax, and paper are used to verify the design of samples. But these products cannot be applied to the real mold because the strength enough to be a mold cannot be given by soft materials such as plastics. So RP products are copied to AFR(Al powder Filled Resin) molds or metal molds, which is called the RP&M. In this paper, RP&M is applied to a casting process. A porous casting mold, which is made from ceramic powder and binder, is used for rapid tooling of aluminum shoes molds.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.546-546
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• 2008

Copper (Cu) Chemical mechanical polishing (CMP) has been an essential process for Cu wifing of DRAM and NAND flash memory beyond 45nm. Copper has been employed as ideal material for interconnect and metal line due to the low resistivity and high resistant to electro-migration. Damascene process is currently used in conjunction with CMP in the fabrication of multi-level copper interconnects for advanced logic and memory devices. Cu CMP involves removal of material by the combination of chemical and mechanical action. Chemicals in slurry aid in material removal by modifying the surface film while abrasion between the particles, pad, and the modified film facilitates mechanical removal. In our research, we emphasized on the role of chemical effect of slurry on Cu CMP, especially on the effect of amine functional group on removal rate selectivity between Cu and Tantalum-nitride (TaN) film. We investigated the two different kinds of complexing agent both with amine functional group. On the one hand, Polyacrylamide as a polymer affected the stability of abrasive, viscosity of slurry and the corrosion current of copper film especially at high concentration. At higher concentration, the aggregation of abrasive particles was suppressed by the steric effect of PAM, thus showed higher fraction of small particle distribution. It also showed a fluctuation behavior of the viscosity of slurry at high shear rate due to transformation of polymer chain. Also, because of forming thick passivation layer on the surface of Cu film, the diffusion of oxidant to the Cu surface was inhibited; therefore, the corrosion current with 0.7wt% PAM was smaller than that without PAM. the polishing rate of Cu film slightly increased up to 0.3wt%, then decreased with increasing of PAM concentration. On the contrary, the polishing rate of TaN film was strongly suppressed and saturated with increasing of PAM concentration at 0.3wt%. We also studied the electrostatic interaction between abrasive particle and Cu/TaN film with different PAM concentration. On the other hand, amino-methyl-propanol (AMP) as a single molecule does not affect the stability, rheological and corrosion behavior of the slurry as the polymer PAM. The polishing behavior of TaN film and selectivity with AMP appeared the similar trend to the slurry with PAM. The polishing behavior of Cu film with AMP, however, was quite different with that of PAM. We assume this difference was originated from different compactness of surface passivation layer on the Cu film under the same concentration due to the different molecular weight of PAM and AMP.

• 한국주조공학회지
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• 제17권1호
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• pp.67-75
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• 1997

The semisolid processing of two Al-Si alloys, A356 and Al-25wt%Si, was studied with using the rotor composed of permanent magnets. The semisolid slurry was agitated by the electromagnetic force induced from the rotating permant magnets. The round shaped primary ${\alpha}$ phases were formed in A356 alloy as a result of agitation. In Al25wt%Si alloy, spherodization of primary Si particles was not observed with the rotation of the magnets. The primary Si particles were segregated to the outer surface area of sample, which became pronounced with increasing the rotating speed of magnets.

• 한국재료학회지
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• 제10권10호
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• pp.659-664
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• 2000

연료극 지지체식 원통형 고체산화물 연료전지를 개방하기 위해 연료극 지지체와 전해질이 코팅된 연료극 원통관의 제조 및 그것의 특성에 대해 연구하였다- 연료극 지지체는 20-50vol.%의 탄소함량에 따라 만들어졌으며, 탄소량이 증가함에 따라 연 료극 지지체의 기공율도 점차 증가하였으며, 적절한 기공율을 가지기 위한 최적 탄소량은 30vol.%임을 확인하였다. 연료극 지지체 관은 압출법으로 제작하였으며, 전해질은 슬러리 코팅법으로 원통판의 바깥쪽에 코팅하였고, $1400^{\circ}C$에서 공소결을 성공적으로 실시하였다. 소결후 물리척특성과 미세구조를 조사하였으며, 연료극 지지체관의 기공율은 35%이었고 연료전지의 요구조건을 만족하였다. 기체투과율 시험을 통하여, 연료극 지지체관 자체는 충분히 다공성을 나타내었으나, 전해질층을 코팅한 경우에는 매우 낮은 기체부과율을 나타냄을 확인하였다. 이것은 코팅된 전해질층이 매우 치밀하다는 것을 의미하며, 본 연구를 통해서 연료극 지지체식 원통형 고체산화물 연료전지가 제조될 수 있음을 확인하였다.

• 한국분말재료학회지
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• 제13권5호
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• pp.336-339
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• 2006

Magnetic properties of nanostructured materials are affected in complicated manner by their microstructure such as pain size (or particle size), internal strain and crystal structure. Thus, studies on the synthesis of nanostructured materials with controlled microstructure are necessary fur a significant improvement in magnetic properties. In the present work, nanostructured Fe-Co alloy powders with a grain size of 50 nm were successfully fabricated from the powder mixtures of (99.9% purity) $FeCl_2$ and $CoCl_2$ by chemical solution mixing and hydrogen reduction.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2001년도 추계 학술발표회 논문집
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• pp.231-238
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• 2001