• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2005.11a
• /
• pp.57-61
• /
• 2005

Cement paste is originally the basic material and crucial factor consisting concrete. This study investigates the relationship between flow apparatuses, which are ring flow(R-F), flow cone(F-C) and mini slump(M-S), in order to estimate the fluidity of cement Paste. For quantitatively evaluating the measured data this study also investigated the calibration of the rheology consistent, such as yield value and plastic viscosity, of cement paste using viscometer For this purpose the present work discussed the influence of 3 type of ordinary portland cement with different companies, affecting the fluidity of cement paste. and it also demonstrated the influence of the various kinds of mineral admixtures, such as fly ash(FA), blast furnace slag(BS) and silica fume(SF) and that of incorporating ratio. The author concluded that using R-F apparatus is the most effective flow test method of cement paste and it is exactly proportional to other apparatus' rheological properties.

• Bulletin of the Korean Chemical Society
• /
• v.29 no.4
• /
• pp.731-735
• /
• 2008

The fluid ensemble in the liquid lens, which is composed of electrolyte and silicone oil, is the key material system to vary the focal length processing of the electrochemical desorption. In order to characterize the capability of the liquid lens according to response time and optical range, we prepared a fluid ensemble comprising the electrolyte and oil. To elucidate the physical mechanism of the effective response time, we examined the viscosity dependency while satisfying the requirements for the density and refractive index of the electrolyte and oil, respectively. The characterization results indicated that the response time (up and down) is influenced by the viscosity of the electrolyte and oil. On this basis, we prepared a fluid ensemble capable of reversibly adjusting for the focal length of the liquid lens, as well as the response time. The ensemble is applicable to various systems such as micro-lens and optical sensors.

• Nuclear Engineering and Technology
• /
• v.41 no.7
• /
• pp.979-988
• /
• 2009

Tensioned metastable fluids provide a powerful means for low-cost, efficient detection of a wide range of nuclear particles with spectroscopic capabilities. Past work in this field has relied on one-component liquids. Pure liquids may provide very good detection capability in some aspects, such as low thresholds or large radiation interaction cross sections, but it is rare to find a liquid that is a perfect candidate on both counts. It was hypothesized that liquid mixtures could offer optimal benefits and present more options for advancement. However, not much is known about radiation-induced thermal-hydraulics involving destabilization of mixtures of tensioned metastable fluids. This paper presents results of experiments that assess key thermophysical properties of liquid mixtures governing fast neutron radiation-induced cavitation in liquid mixtures. Experiments were conducted by placing liquid mixtures of various proportions in tension metastable states using Purdue's centrifugally-tensioned metastable fluid detector (CTMFD) apparatus. Liquids chosen for this study covered a good representation of both thermal and fast neutron interaction cross sections, a range of cavitation onset thresholds and a range of thermophysical properties. Experiments were devised to measure the effective liquid mixture viscosity and surface tension. Neutron-induced tension metastability thresholds were found to vary non-linearly with mixture concentration; these thresholds varied linearly with surface tension and inversely with mixture vapor pressure (on a semi-log scale), and no visible trend with mixture viscosity nor with latent heat of vaporization.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2006.11a
• /
• pp.67-70
• /
• 2006

This study investigates the properties of light weight foamed concrete designed with various incorporating ratios of CKD and adding ratios of PS. Test showed that increase of CKD and PS decreased fluidity of fresh concrete, which need more addition of superplasticizer to secure proper fluidity. As for the sinking depth of specimens, using more CKD or PS decreased the value, due to the improvement of viscosity by micro particles of CKD and reduction of air loss by PS. Those methods are very effective to solve the sinking problem of light weight foamed concrete, which has been highly concerned. For the hardened concrete, compressive strength of specimens exhibited that using around 10% of CKD or 0.02% of PS increased the strength value, but decreased when incorporated or added more amounts of that, due to reduction of the sinking depth, caused by filling effect of the micro particle and improvement of the viscosity.

• Archives of Pharmacal Research
• /
• v.14 no.4
• /
• pp.298-304
• /
• 1991

Isoprinosine, an antiviral agent with a bitter taste, has been clinically used up to a maximum of 4 g daily in 4-8 doses. In this investigation, isoprinosine was microencapsulated with ethylcellulose 22 cps, 50 cps and 100 cps by means of polymer deposition from cyclohexane through temperature change. Complete removal of cyclohexane from the microcapsules was necessary, since ethylcellulose-coated microcapsules obtained from cyclohexane medium were heavily solvated with cyclohexane and formed lumps even after drying. The displacement of cyclohexane by n-hexane during isolation of microcapsules (Method III) or the freezing of the anal-washed microcapsules before drying (Mothod II) provided the dried products which were more discrete microcapsules than those which were simply dried in the air overnight (Method I). Method III was especially the most effective procedure in preparing finer and more discrete microcapsules. The drug-release from microcapsules was influenced by the ratio of core to wall, the viscosity grade of ethylcellulose and the overall microcapsule size. The release rate was adequately fitted to both the first-order and the diffusion-controlled processes. It is therefore possible to design the release-controlled microcapsules with ethylcellulose of different viscosity along with various core to wall ratio.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2011.05a
• /
• pp.127-130
• /
• 2011

The duplex waterproofing construction method has been investigated to improve various problems (how to fix the sheet, breaking, air/water pocket, and cracks caused by different materials) of the existing rooftop exposed waterproofing construction method. By using fiber sheet, Net PE fabric, and thixotropy urethane with high viscosity, the waterproofing construction method is to glue the ground and waterproof course by circular dot. The method is also to construct the waterproof course with high hardness by using waterproof membrane coatings in upper hybrid system. By gluing the ground and the waterproof course by circular dot, the study is expected to be useful to minimize the simultaneous breaking in the waterproof course as tensile stress is buffer in case of the ground crackling. Also, since the waterproofing construction method is good at moving and emitting vapor from the ground, it is considered to be effective to minimize any damages caused by air/water pocket and get loose of the waterproof course.

• Korean journal of food and cookery science
• /
• v.21 no.6 s.90
• /
• pp.776-781
• /
• 2005

Preparation of nectar using Kabocha squash was optimized and the quality changes during 7 weeks'storage were investigated. The paste for the nectar base could be effectively obtained by consecutive processes of steaming for 15 min, crude smashing and homogenization. To improve the mouth-feel of the nectar, various pectinases and cellulases were treated with Econase CE, Rapidase press, Macerozyme A, Sumizyme MC and Cytolase M102. Among them, Cytolase M102 was the most effective enzyme at $0.05\%$ for 90 min reaction in terms of the collective results as the residue of the nonsoluble solids, viscosity and alcohol test. The best ratio of the nectar ingredients was a ratio of water to paste of 1.5, $11^{o}$Brix of saccharinity, $0.025\%$ of citric acid and $0.15\%$ of xanthan gum. When the retort sterilized nectar in a can was stored in an incubator at $35^{\circ}C$ for 7 weeks, the color, pH, saccharinity, viscosity and total count plates remained almost unchanged.

• Tribology and Lubricants
• /
• v.31 no.5
• /
• pp.213-220
• /
• 2015

This study evaluates the effect of grooves on the stem part of a plunger on the lubrication characteristics of a fuel injection pump (FIP) by using hydrodynamic lubrication analysis. The current study uses the two-dimensional Reynolds equation to evaluate the changes in lubrication characteristics with variations in clearance, viscosity, and grooves for a laminar, incompressible, and unsteady state flow. This study investigates the lubrication characteristics by comparing the dimensionless minimum film thickness or the film parameter, which is the ratio of the minimum film thickness to surface roughness. The analysis method for the groove section differs depending on the depth of the groove. For instance, in the case of a shallow groove, the film thickness equation considers the depth of the groove, while in the case of a deep grove, it considers the flow continuity. The lubrication characteristics of the FIP are more sensitive to changes in the groove width than to changes in other design variables. Moreover, the application of a groove is more effective under low viscosity conditions. The smaller the distance from the edge of the stem part to the first groove in the case of shallow grooves, the better are the lubrication characteristics of the FIP. In contrast, in the case of deep grooves, the lubrication characteristics of the FIP improve as the distance increases. The application of shallow grooves is more effective for improving the lubrication characteristics than the application of deep grooves.

• Applied Biological Chemistry
• /
• v.38 no.1
• /
• pp.67-71
• /
• 1995

For the quality management of ginseng root extracts and their products, the effective constituents contents, physical properties (pH, turbidity, viscosity, optical density) and color intenties of the extracts from white ginseng roots of different cultivating years. The sugar contents, lightness and yellow intensity of extracts from white ginseng roots increased with increased their cultivating years. The crude ash contents turbidity and optical density of extracts from white ginseng roots decreased with increased their cultivating years. Therefore, the extracts from white ginseng root of 5 or 6 cultivated years showed higher quality than the extracts from ginseng root of 4 cultivated years.

• Korean journal of food and cookery science
• /
• v.23 no.3 s.99
• /
• pp.363-368
• /
• 2007

Jeung-pyun, a very popular fermented rice cake consumed in Korea, consists mainly of rice, rice wine (Tak-Ju), and sugar. The effects of addition of different beans on the quality characteristics of the batter and Jeung-pyun were investigated. Six different beans were mixed with the rice flour at levels of 5% and 10% of the rice flour weight, respectively. The addition of Back-tae, Huk-tae, Sori-tae, which are types of soybeans, and black gram significantly increased the batter volume and viscosity. However, the fermented Back-tae (Cheongguk-jang) was not effective at increasing the batter volume and viscosity. The buffering effect of the beans was very significant on the fermented batter, and the decrease in pH of the fermented batter made with beans was less than that of the control batter without beans. Additions of the soybeans and Cheongguk-jang were most effective for the buffering effect in the fermented batter. Although the Back-tae, Huk tae, and Sori-tae were different colors and shapes, they were all soybeans and exhibited similar effects on the Jeung-pyun batter. However, the effects of the beans were not significant on the Jeung-pyun. The volume and moisture content of the Jeung-pyun made with beans were not significantly different from the volume and moisture of the Jeung-pyun made without beans. The above results suggest that the addition of different soybeans, mung beans, and black gram significantly effects on the properties of Jeung-pyun batter, but not Jeung-pyun itself.