• 한국세라믹학회지
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• 제49권6호
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• pp.542-548
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• 2012

The viscosity of a ceramic slurry depends on the slurry concentration, particle shape and size, hydrodynamic interactions, temperature, shear rate, pre-treatment condition and the method of measurement with the selected equipment. Representative ceramic slurries with low to high viscosity levels are selected from colloidal silica, barium titanate slurry and glass frit paste. Rotational rheometers and vibrational viscometers are used to compare the measured viscosity for various ceramic slurries. The rotational rheometer measured the viscosity according to the change of the shear rate or the rotational speed. On the other hand, the vibrational viscometer measured one point of the viscosity in a fixed vibrational mode. The rotational rheometer allows the measurement of the viscosity of a ceramic paste with a viscosity higher than 100,000 cP, while the vibrational viscometer provides an easy and quick method to measure the viscosity without deformation of the ceramic slurry due to the measurement method. It is necessary to select suitable equipment with which to measure the viscosity depending on the purpose of the measurement.

• Geomechanics and Engineering
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• 제17권6호
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• pp.543-551
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• 2019

In China, serious environmental problems are induced by the extremely soft construction waste slurries in many urban areas, and there is no appropriate method to treat it presently. In this paper, four model tests were conducted to investigate the efficiency of waste slurry treatment by combining three conditioning agents which can change characteristics of the slurries with a traditional vacuum preloading method. The tests of size analysis of particle aggregate were conducted to investigate the influence of different conditioning agents on the size distributions of particle aggregate. During the model test, the discharged water volumes were monitored. The pore-size distribution and void ratio of the waste slurries after the vacuum preloading were measured by mercury intrusion porosimetry (MIP). It is found that 1) During the natural precipitation, volume of water out of the organic agent is higher than that of the mixed agent, but it is smaller than that of the mixed agent in the vacuum preloading stage; 2) the mixed agent has a higher total volume of water out than the organic agent and the inorganic agent after test, while the organic agent and the inorganic agent have little difference with respect to the drainage effect. The results demonstrate that the combination of mixed conditioning agent and vacuum preloading for the solid-liquid separation in waste slurry has a satisfactory effect and can be applied in engineering practice.

• Nuclear Engineering and Technology
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• 제11권3호
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• pp.203-212
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• 1979

Magnox 핵연료 재처리에서 발생되는 모의고준위 방사성폐액의 열분해와 이 폐액의 유리화를 위한 첨가제가 함유된 HARVEST 공급스러리 (SN과 SG)의 열분에 관하여 연구되었다. 폐액과 스러리는 500-55$0^{\circ}C$ 범위에서 거의 완전히 가소 처리된다. 90$0^{\circ}C$ 이하에서 스러리로부터 얻어지는 고화물들은 유사한 색체를 띄지만, 이 이상에서 대단히 짙은 색으로 변한다. 스러리는 90$0^{\circ}C$에서 유리화하기 시작하여 1000-105$0^{\circ}C$에서 완전히 유리화 된다. 한편, SN 스러리내에 불순물로 존재하는 황화물은 75$0^{\circ}C$ 이상에서 황색반점을 분리시키는 영향이 있다. 650-$700^{\circ}C$ 이하에서 얻어지는 고화물의 밀도는 대단히 낮고 700-80$0^{\circ}C$에서는 밀도가 2g/㎤로 급증됨으로서 650-$700^{\circ}C$에서 용융되기 시작하는 것같다. 50$0^{\circ}C$까지 온도가 상승함에 따라 고화물의 강도가 감소하고, 그 이상에서는 고화물의 소질현상으로 인하여 강도가 증가하게 된다. 50$0^{\circ}C$ 이하의 SN 고곡물은 SG 고화물에 비하여 강도가 훨씬 크고, 불순물로 존재하는 황화물은 silica의 반응도를높여 준다는 것을 암시하고 있다.

• 한국축산시설환경학회지
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• 제4권2호
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• pp.193-204
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• 1998

• Korea-Australia Rheology Journal
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• 제15권1호
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• pp.19-25
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• 2003

Since the microstructure of functional thin films depends on the dispersion characteristics of dense slurry, it is important to control the agglomerative nature of slurries under processing. The present authors have been discussing the model prediction of agglomerative nature and local rate of agglomeration in dense suspensions. The experiments have been peformed under shear flow using the nearly spherical and oblate type graphite particles. In this study, the experiment has been conducted using water and glycerol as dispersion media. Stress control type rheometer was used to measure the slurry rheology. Local agglomeration of graphite particles has been predicted by using Usui's model. The experimental results show that both the shape and slurry processing method affect on the local dispersion condition. The agglomeration formed by oblate type graphite particles seems to be more difficult to break up than that of spherical particles.

• 펄프종이기술
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• 제31권3호
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• pp.10-18
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• 1999

The influence of simple electrolyte or anionic trashes on cationic starch adsorption was examined using deinked pulp and bleached thermomechniical pulp. Adsorbed amounts of cationic starches increased slightly , then decreased abruptly as the concentration of simple electrolyte increased. This phenomenon was discussed based on the compression of electrical double layer and conformation change of starch molecules. Also, the effect of the type of simple electrolytes on starch adsorption was examined and discussed. Addition of sodium slilicate increased starch adsorption since it increased surface charge density of fibers. On the other hand, addition of kraft lignin decreased cationic demand of the pulp slurries and adsorbed amounts of cationic starches. Nonionic surfactant did not show any significant effect on the cationic demand of pulp slurries. When simple electrolytes were added to the stock , grater adsorption or cationic starches was obtained with starches of lower degree of substitution . On t도 other hand, amount of adsorbed starches decreased for lower DS starches when the concentration of anionic trashes increased.

• International Journal of Air-Conditioning and Refrigeration
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• 제10권1호
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• pp.31-39
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• 2002

Microencapsulated pcm (MPCM) particles are mixed with distilled water and utilized to evaluate its characteristics and performance as a thermal storage medium transporting heat. For the present study, tetradecane ($C_14$$H_30$, $T_m$=5.5$^{\circ}C$) is capsulated in the core, coated with the melamine for their surface. The size of particles is well-controlled under 10$\mu$m in the process of in-situ polymerization with melamine-formaldehyde resin. For the experiment, the concentractions of slurries are prepared for 20 wt%, 30 wt%, and 40 wt%. The results are compared with those of water and 100% tetradecane oil. The pure water and tetradecane start solidifying within 20 minutes after introducing cooling water into the thermal storage tank whose flow rates are varied by 125 cc/min, 250 cc/min, and 500 cc/min. However, MPCM slurries are required relatively longer period of time for their phase change than pure phase change materials. That is, the entrained MPCM particles restrict their heat transfer in terms of natural convection and conduction to them.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.92-95
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• 2002

Bioavailability study was conducted to elucidate the relationship between sorption/desorption and biodegradation of sorbed phenanthrene in seven different soils. Mineralization kinetics was determined for phenanthrene-sorbed soil slurries inoculated with Pseudomonas putida (ATCC strain 17484). Two biodegradation models were used to fit mineralization kinetics; (i) a first-order degradation model and (ii) a coupled degradation-desorption model. The biodegradation rates were in order of vermicompost >Bion peat > 50% organoclay > Pahokee > blank (no soil, medium only) > montmorillonite > Ohio shale. The mineralization rate constants increased as desorption-resistance of phenanthrene increased. Among the tested sorbents, active biodegradation of phenanthrene was observed in vermicompost and Bion peat. Biodegradation in these two sorbents exhibited little lag time and a high maximum mineralized capacity. The role of sorption/desorption in bioavailability of phenanthrene sorbed in soils was discussed.

• 한국세라믹학회지
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• 제35권12호
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• pp.1280-1285
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• 1998

Foaming method is presented the preparation of porous materials from high-concentrated kaolin silica and flyash slurries. The slurries were foamed dried and sintered respectively. The porosity of sintered ma-terials was about 70-75% Mean pore-size was the range of 70-150$\mu\textrm{m}$ and pore structure was continuous Sodium lauryl sulfate anionic surfactant was used as a foaming agent. The foaming ability and the froth sta-bility were increased with increasing the concentration of the foaming agent. But the size of the constituent bubble of froth after foaming process was not affected by the concentration of the foaming agent. These results showed that the mean pore-size of sintered materials was closely related to the froth stability which is related to the change of bubble-size during the drying process.

• 반도체디스플레이기술학회지
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• 제3권4호
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• pp.45-49
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• 2004

We examined large particles and filter size effects of Central Chemical Supplying (CCS) system for STI-CMP on Light Point Defects (LPDs) after polishing. As manufacturing process recently gets thinner below 0.1 um line width, it is very important to keep down post-CMP micro-scratch and LPDs in case of STI-CMP. Therefore, we must control the size distribution of large particles in a slurry. With optimization of final filter size, CCS system is one of the solutions for this issue. The oxide and nitride CMP tests were accomplished using nano-ceria slurries made by ourselves. The number of large particles in a slurry and the number of LPDs on the wafer surface after CMP were reduced with decrease of the final filter size. Oxide removal rates slightly changed according to the final filter size, showing the good performance of self-made nano ceria slurries.