• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.2
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• pp.162-166
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• 1998

Synthetic fluid, class 7 group 2, as an insulating and cooling material is selected as. specimen, arid it is studied for the physical and electrical properties. Also, Benzotriazole(following as BT A) known as a suppressant of streaming electrification is added to it, and the change of physical and electrical properties by addition of BT A is investigated. From the spectrum of FT-IR, it is confirmed that the absorption peak in wavenumbers $3400{\sim}3450[cm^{-1}]$ is small or disappears when BTA is added. AC breakdown strength and volume resistivity of each specimen are investigated. It is considered that the effective content of BTA is about 10[ppm] for the suppression of electrification in this experiment.

• Development and Reproduction
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• v.23 no.4
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• pp.305-311
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• 2019

Small intestine has a structure called villi that increases the mucosal surface area for nutrient absorption. Intricate and tight epithelial-mesenchymal interactions are required for villi development. These interactions are regulated by signaling molecules, physical forces, and epithelial deformation. Signaling molecules include hedgehog (Hh), bone morphogenetic protein (BMP) and Wnt ligands. The Hh ligand is expressed from the epithelium and binds to the underlying mesenchymal cells, resulting in aggregation into mesenchymal clusters. The clusters express BMP and Wnt ligands to control its size and spacing between clusters. The clusters then form villi. Despite the fact that the villi formation is studied extensively, we do not have a complete understanding. In addition, the recent study shows there is a great relationship between the overexpression of the Hh signal and development of cancer in the gastrointestinal tract. Therefore, signaling between epithelial and mesenchymal cells and their physical interactions will be discussed on this review.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1244-1249
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• 2002

In this study, the physical characteristics of steel-wire sound absorbing materials with different thickness and bulk density is experimentally obtained in terms of the porosity and specific flow resistivity. Based on the experimental results, the following conclusions can be made. The porosities of steel-wire sound absorbing materials are smaller than those of general absorbing materials, which are inversely proportional to the volume densities. For the porosity measurement with a good accuracy, the dynamic correction based on the system compliance should be involved in porosity measurement. In addition, the flow condition for the precise measurement of the specific flow resistivity of steel-wire sound absorbing materials should be limited in the laminar flow region.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1333-1335
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• 1997

We have made disperse diazo black D(DBD) thin films using Langmuir-Blodgett(LB) and vacuum-evaporation technique. Physical and optical properties of the films were investigated. Solution was made with a concentration of $10^{-3}mol/{\ell}$ using chloroform. Moving wall apparatus, (NL-LB140S-MWC) was employed to make the LB films. X,Y and Z-type LB films were manufactured and studied UV/visible absorbance spectra and morphology of surface using atomic force microscopy(AFM). Vacuum-evaporated DB D thin films were made at a pressure of $10^{-5}$ torr. The absorption peaks were observed at 200 and 400 nm in the LB films and vacuum-deposited films. We have also studied photoluminescence spectrum of the DBD films.

• Journal of the Korean Applied Science and Technology
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• v.12 no.1
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• pp.59-67
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• 1995

Oil dispersants using polyoxyethylene monooleate, polyoxyethylene oleylether, and poly(oxypropylene-oxyethylene)glycol block copolymer were prepared, and oil dispersant efficiency was measured using vertical shaking flask method to 4 kinds of Bunker B oil with different physical properties by appling the prepared dispersants. Although the dispersant efficiency was differed according to the differences of physical properties of Bunker B oil, the dispersant prepared using polyoxyethylene oleylether was the most effective to disperse the oil into water. The impurities like surfur contained in sample oil have to be removed by filteration to obtain the correct degree of absorption using UV spectrophotometer.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.383-389
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• 1999

To determine the optimum condition for buckwheat noodle making, we prepared noodle from com posite flours of buckwheat, wheat and corn starch, and those physical properties and sensory evalua tion were investigated. The weights of cooked noodle became lower with increasing buckwheat content level indicating that elution of its components to soup was high. Wheat flour in the composite flours probably caused to drop gelatinization temperature and maximum viscosity compared to buck wheat flours. Corn starch in the composite flours increase gelatinization temperature and maximum viscosity compared to buckwheat flours. From the result of farinogram, buckwheat flour lower water absorption ability, and increased dough development time compared to composite flours. Adhesiveness of the cooked noodle with wheat flour was decreased. Cohesiveness of the cooked noodle was decrea sed with increasing buckwheat flour level. In sensory evaluation, chewing and softness of noodle with 100% buckwheat flour was evaluated the best. In taste, BW1 and BSW1 noodles showed slightly higher preference although there was no significant differences.

• YAKHAK HOEJI
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• v.39 no.6
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• pp.593-599
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• 1995

Erythromycin was formulated as enteric-coated pellets in order to reduce degradation in stomach and gastromtestmal irritation, and to maximize the absorption in intestine followmg its oral administration. Core pellets were prepared using fluid-bed granulator with two different methods (powder layering and solvent spraying) and enteric-coated with two different coating polymers (HPMCP and Eudragit E30D). Physical characteristics md dissolution rates of core pellets and enteric-coated pellets were evaluated to optimize the formulation. Powder layering method resulted in shorter initial dissolution time than solvent spraying method, but physicochmical properties of the product were worse than solvent spraying method with respect to hardness, ftiability and density. The dissolution rate of the drug was increased with the addition of surfactants, showing concentration-dependence. The scanning electron microscopic observation of pellets revealed significant differences on the surface appearances prepared with solvent spraying method. The core pellet made with powder layering method had crystals on the surface, which resulted in poor physical properties of the pellets. The dissolution profiles of erythromycin pellets coated with HPMCP or Eudragit L30D were close to that of commercially available erythromycin enteric-coated product.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.3
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• pp.379-383
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• 2007

The effects of phenolic acids on the physical properties of wheat flour extrudate were investigated. Ferulic acid, fumaric acid, and p-coumaric acid were mixed with hard wheat flour, respectively, and extruded under a twin screw extruder. We found that by adding the phenolic acids, longitudinal expansion at the die increased, textural hardness decreased, and the water absorption capacity of the extrudate decreased. The results showed that the addition of phenolic acids produced a softer textured, more longitudinally puffed and hydrophobic extrudate compared to the control extrudate. Moreover, the addition of phenolic acids did not significantly affect the color of the extrudate: oxidative browning of the phenolic acids was not observed, due to inactivation of the browning enzymes under the hot temperature and reduced oxygen conditions of the extrusion process.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.813-816
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• 2006

Recently, improvements in the standard of living in industrial area require the establishment of a convenient residential environment in order to enhance the quality of living. To achieve such an environment, it is necessary to effectively reduce or prevent various environmental problems occurring in and around residential areas. Although conventional concrete has been regarded as a destroyer of nature, water and air can pass freely through concrete when it is made porous concrete by forming continuous void. In view of the harmony between nature and concrete, various research paths are being taken focusing on coarse aggregates to make porous concrete having continuous voids so as to improve water and air permeability, acoustic absorption, water purification, and applicability to vegetation. In this study, the Physical and Mechanical Properties of porous concrete according to compaction method analyzed by void ratio, coefficient of permeability and compressive strength.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.853-856
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• 2006

It is known that cement production not only consumes large amount of energy but also contributes substantially to the green house gas emission. Therefore, there is a demand to develope a new technology to produce energy efficient and environmental conscious cements. The most recent, wood wool ceramic board is being applied in various building material field, for example thermal insulating and acoustic absorption material. This paper focused on improvement of the physical properties for wood wool ceramic board applied inorganic polymer binder. As the result of this experiment, what we could obtain better wood wool ceramic board's properties such as density, water contests, water resistance and band strength, was 0.46, $10{\sim}12%$, 1.9% and $40kgf/cm^2$. This result can be applicable to commercial wood wool ceramic board.