• Structural Engineering and Mechanics
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• v.49 no.1
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• pp.1-22
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• 2014

A seismic evaluation is made of the response to horizontal ground shaking of cantilever retaining walls using the finite element model in three dimensional space whose verification is provided analytically through the modal analysis technique in case of the assumptions of fixed base, complete bonding behavior at the wall-soil interface, and elastic behavior of soil. Thanks to the versatility of the finite element model, the retained medium is then idealized as a uniform, elastoplastic stratum of constant thickness and semi-infinite extent in the horizontal direction considering debonding behavior at the interface in order to perform comprehensive soil-structure interaction (SSI) analyses. The parameters varied include the flexibility of the wall, the properties of the soil medium, and the characteristics of the ground motion. Two different finite element models corresponding with flexible and rigid wall configurations are studied for six different soil types under the effects of two different ground motions. The response quantities examined incorporate the lateral displacements of the wall relative to the moving base and the stresses in the wall in all directions. The results show that the wall flexibility and soil properties have a major effect on seismic behavior of cantilever retaining walls and should be considered in design criteria of cantilever walls. Furthermore, the results of the numerical investigations are expected to be useful for the better understanding and the optimization of seismic design of this particular type of retaining structure.

• Journal of Pharmaceutical Investigation
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• v.39 no.2
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• pp.127-131
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• 2009

Hydrogels for medical devices such as hydrophilic dressing, moisturizing healing band, hydrophilic intravenous catheter and soft contact lens were evaluated for their cytotoxicity according to the International Organization for Standardization (ISO) procedures. To test indirect cytotoxicity of hydrogel products, dissolution medium and dissolution condition were selected based on the guideline for medical devices. Cytotoxicity was low in all the case of hydrogel products. Soft contact lens showed no significant difference in dissolution between complete medium and saline. Currently, there is no specific guidelineto test hydrogel for medical devices in Korea with consideration of characteristics of hydrogel. Thus, proper method of cytotoxicity evaluation should be selected depending on the characteristics and usages of hydrogels for medical devices.

• The Korean Journal of Mycology
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• v.20 no.3
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• pp.216-221
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• 1992

Aerial crystalline filaments emerged from dense type of mycelia on some monokaryotic transformants of Pleurotus florida, P. ostreatus and P. sajorcaju. Cytstals were not dissolved in water but soluble in ethanol or at the temperature of higher than $80^{\circ}C$. Crystals were detected in the mycelia grown on the mushroom minimal medium as well as the mushroom complete medium. They were produced on both liquid media and agar plate. Although the mycelia incubated at $15-20^{\circ}C$, produced crystals, the mycelia incubated at $30-35^{\circ}C$ did not. Furthermore, crystal forming mycelia were obtained from monokaryotic basidiospore of P. ostreatus and P. sajor-caju by mutations (UV irradiation).

• The Korean Journal of Mycology
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• v.13 no.2
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• pp.79-82
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• 1985

The experiment of protoplast regeneration and reversion were undertaken to provide a basic techniques for protoplast manipulation. Protoplasts of Pleurotus florida and Pleurotus ostreatus were reverted to normal hyphal growth and the reversion frequency of both fungal protoplasts were $0.24{\sim}3.19%$. Reversion medium stabilized with 0.6 M potassium chloride and sucrose was better than the other stabilized one. The protoplast reversion frequency was increased when various amino acid and vitamin compounds were added to the hypertonic mushroom complete agar medium.

• Macromolecular Research
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• v.15 no.7
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• pp.633-639
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• 2007

A variety of NMR techniques were applied to the micro-chemical structural characterization of polyanilines prepared via an efficient synthetic method in a self-stabilized dispersion medium in which the polymerization was conducted in a heterogeneous organic/aqueous biphasic system without any stabilizers. Here, the monomer and growing polymer chain were shown to function simultaneously as a stabilizer, imparting compatibility for the dispersion of the organic phase, and as a form of flexible template in an aqueous reaction medium. Polymerizations predicated on this concept generated polyanilines with a low defect content: solution state $^{13}C-NMR$ and solid $^{13}CDD/CP/MAS$ spectroscopy indicated that the synthesized HCPANi and its soluble derivative, HCPANi-t-BOC, evidenced distinctly different NMR spectra with fewer side peaks, as compared to conventionally prepared PANis, and the complete structural assignments of the observed NMR peaks could be determined via the combination of both 1D and 2D techniques. Ortho-linked defects in HCPANi were estimated to be as low as 7%, as shown by a comparison of the integration of the carbonyl carbon resonance peaks.

• The Korean Journal of Mycology
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• v.19 no.1
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• pp.27-31
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• 1991

Formation of conidium, an asexual organ on the hyphae, was examined from ten species of Pleurotus. Conidiospores of them were distinguished into two types of spores; an elliptical and a globose spores. Dikaryotic hyphae of ten species and monokaryotic hyphae of three species were observed to produce conidiospore. Conidia were observed on the hyphae grown on mushroom complete agar medium but were not on mushroom minimal agar medium. Two aconidial mutants were obtained by the ultraviolet irradiation.

• Preventive Nutrition and Food Science
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• v.8 no.1
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• pp.36-39
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• 2003

Many defined cell culture media were formulated over 3() years ago and may be deficient in certain micronutrients whose essentiality has only subsequently been recognised. The objective of this study was to evaluate whether alpha-minimal essential medium (MEM) supplemented with 10% foetal bovine serum contained sufficient selenium for optimal activity of the selenium containing enzymes cytosolic glutathione peroxidase (cGPx) and phospholipid hydroperoxide glutathione peroxidase (PHGPx) in cultured Chinese hamster ovary (CHO) cells. Additionally, the effect of zinc deficiency and metallothionein (MT) overexpression on cGPx and PHGPx activity was studied. The addition of 100 nM of selenous acid to the culture medium increased cGPx expression by 10-fold and PHGPx by about 2-fold in both wild-type CHO-K1 cells and CHO-K1 cells overexpressing mouse MT-1. Zinc deficiency had no significant effect on enzyme activity, but cells overexpressing mouse MT-1 had higher levels of cGPx activity. Zinc deficiency decreased cell survival but overexpression of MT-1 was partially protective, probably because its presence in quantity favoured the uptake, sequestration and cellular retention of any remaining zinc. This study demonstrates that selenium in complete alpha-MEM is insufficient for optimal cGPx and PHGPx activity and may compromise the cellular response to oxidative stress.

• Korean Journal of Microbiology
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• v.23 no.4
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• pp.297-301
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• 1985

The dependence of activities of Aspergillus phoenicis on the culture conditions in the progesterone transformation reaction was investigated. In the beginning of the reaction, $6{\beta},\;11{\alpha}-dihydroxyprogesterone$ was not produced even at high concentration of $11{\alpha}-hydroxyprogesterone$. However, large amount of the product was obtained after the complete exhaustion of progesterone. When spores of A.phoenicis replaced mycelia as enzyme source, $11{\alpha}-hydroxyprogesterone$ was produced after a considerably long indyction period, and its maximum production rate followed the exponential growth phase. The $6{\beta}-hydroxylation\;of\;11{\alpha}-hydroxyprogesterone$ continued, even after the stationary growth phase. A. phoenicis showed high enzyme activity for these reactions when the phosphate buffer solutions were used in place of the ordinary culture medium. The buffer solutions of low pH gave more yield of $11{\alpha}-hydroxyprogesterone$ than those of high pH. However, the addition of flucose to the buffer solutions did not activate the transformation reaction. The presence of progesterone seems to be necessary for the induction of enzymes for the $6{\beta}-hydroxylation\;of\;11{\alpha}-hydroxyprogesterone\;since\;6{\beta},\;11{\alpha}-dihydroxyprogesterone$ is not produced in the reaction medium containing only $11{\alpha}-hydroxyprogesterone$ as a substrate.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.4
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• pp.73-79
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• 2021

The objective of this study is to prevent or decrease condensation on the surface of aluminum butterfly valves used in high humidity air conditions. We proposed a new valve with an anti-condensation device, a heat resistance medium, instead of a conventional valve. We, then, compared the surface temperature distribution between the proposed and conventional valves using experimental and analytical methods. The size of the evaluated valve is 100A and fluid conditions are 35℃/RH 75% in the air outside the valve and 5℃ in the cooling water inside the valve. The experimental results show that the surface temperature of the proposed valve is 23~42% higher than that of a conventional valve, thereby exhibiting an anti-condensation effect. As a result, we observed the complete prevention of condensation on a gear box mounted to the proposed valve, showing surface temperature distribution above the dew point temperature of air. The analytical results are in agreement with the trends in experimental results.

• Journal of radiological science and technology
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• v.16 no.1
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• pp.89-94
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• 1993

However, technical advances in ultrasono imaging have had a remarkable impact on the study of biliary system oral cholecystography is a contrast of the gallbladder which is very frequently performed even with the application of Extra Shock Wave Lithotripsy(ESWL) in clinical use. Oral GB requires a stringent preparation if it is to be fully successful and a considerable amount of time to complete all its procedures and its objects of the radiographs. 1) to obtain a firm diagnosis of the presence of gallstones. 2) to essess function of the gallbladder that is, its ability to concentrate and store bile. After a times sequence of X-ray exposures taken in various positions to show the gallbladder to be satisfactorily filled, the patient is given a fatty meal, for instances two eggs or a cup of milk. The gallbladder which is drained by the cystic duct stores and concentrates the bile and is stimulated to contrast and excrete the bile by hormone "cholecystokinin" secreted in the intestinal mucosa. To evaluate the effect of the fatty meal which caused the gallbladder to constrict and empty, and by so doing the contrast medium passes through the cystic and bile ducts which are shown in radiographs exposed from 15-30 minutes after the variety practice of fattymeal, such as soft-boiled 2 eggs, raw 2 eggs, 100g of peanuts, and 200ml of milk. If the concentration of the opaque medium in the gallbladder is adequate, then not only the size, shape and position of the gallbladder will be shown from firms taken at intervals, the rate of concentration of the opaque medium and of the emptying of gallbladder has been measured and analyzed.