• Analytical Science and Technology
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• v.24 no.2
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• pp.94-104
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• 2011

Mesoporous silica was synthesized in a water solvent and in an ethanol solvent with the non and cationic cetyltrimethyl ammonium chloride (CTAC) by varying the amount of the amphiphilic acrylic urethane oligomer (AAU) and the pH of the solution. The adsorption of the MX (3-chloro-4 (dichloromethyl)-5-hydroxy-2-(5H)-furanone) in drinking water was studied using the synthesized mesoporous silica as an adsorbent. The most appropriate silica was synthesized in acidic conditions in the water solvent and in alkali conditions in the ethanol solvent. The average pore sizes of the synthesized mesosilica were 3 nm and more. The mesoporous silica synthesized by the addition of the AAU oligomer showed excellent adsorption characteristics. With respect to the co-surfactant, the best adsorption characteristics were obtained when the P64,a non-ionic surfactant with a high molecular weight, was used to synthesize the silica than when other co-surfactants were used. The adsorption rate decreased as the MX concentration in the water increased. Different adsorption equilibrium conditions were reached depending on the adsorbate MX concentration in the adsorbent and the solution. It was seen that perfect adsorption does not occur due to such equilibrium conditions.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.12
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• pp.2227-2238
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• 2000

The interfacial features of suspension system made of $CaCO_3$ particles have been investigated for the purpose of designing its effective treatment process. For the examination of variation of electrokinetic potential as a function of pH. the value of potential was observed to shift in the negative direction, which was thought to be due to the adsorption of hydroxide ion on the particle surface. Adsorption of surfactant on suspended particles resulted in the change of surface charge and shift in electrokinetic potential, which was dependent upon the sign of head charge and concentration of surfactant. Addition of inorganic salts affected stability of suspension greatly and sedimentation rate of suspension was influenced by the electric valence and amount of ions produced by dissolution of inorganic coagulants. DLVO theory made it possible to construct a energy profile diagram and a close correlation was found between experimental result and theoretically derived consequences. Non-specific adsorption of indifferent electrolyte resulted in the compression of electrical double layer and specific adsorption induced the shift of IEP and PZC in the opposite direction.

• The Journal of Korean Medicine
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• v.39 no.1
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• pp.63-74
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• 2018

Objectives: Periodontitis is an inflammatory disease with the destruction of periodontal ligament, alveolar bone loss and inflammation of gingva, leading to teeth loss. Eclipta prostrata L. (Ecliptae Herba) has been used to treat the inflammatory disease as a Korean traditional medicine. The aim of this study is to investigate the effects of E. prostrata L. on periodontitis. Methods: E. prostrata L. was extracted with water and lyophilized. The aqueous extract of E. prostrata L. (EP) was topically applied to the periodontal lesion for 2 weeks. To induce the periodontitis, a 3-0 nylon ligature was placed around the cervix of the lower first molar in rat. Rats were divided into 3 groups (n = 7); NL group (non-ligatured and non-treated), L group (ligatured and vehicle-treated) and EP group (ligatured and EP-treated). After sacrifice, the mandibles was dissected and stained with methylene blue solution to analyze the alveolar bone loss. The expression of MMP-9 was determined in gingival tissues. To confirm the effect of EP on recovery of gingiva, mRNA expressions of type I pro-collagen and MMP-9 levels were investigated in LPS-treated HS68 fibroblast cells. In addition, inflammatory mediators were evaluated in LPS-treated RAW264.7 cells. Results: Alveolar bone loss was significantly inhibited by EP treatment. The mRNA expression of MMP-9 was attenuated in rats treated with EP. In addition, treatment with EP increased the expression of type I pro-collagen, while the expression of MMP-9 was decreased in LPS-stimulated HS68 fibroblast cells. Furthermore, EP down-regulated the LPS-induced IL-6, $TNF-{\alpha}$, COX-2 and iNOS production in RAW264.7 cells. Conclusions: These results suggest that EP have ameliorative effects on periodontitis through inhibiting alveolar bone loss and modulating the inflammatory mediators. Therefore, E. prostrata L. may be an alternative on patients with periodontitis.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.324-329
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• 2001

This experimental study concerns the characteristics of a transitional flow in a concentric annulus with a diameter ratio of 0.52, whose outer cylinder is stationary and inner one rotating. The pressure losses and skin-friction coefficients have been measured for the fully developed flow of $0.1\sim0.4%$ aqueous solution of sodium carbomethyl cellulose (CMC), respectively at inner cylinder rotational speed of $0\sim600rpm$. The transitional flow has been examined by the measurement of pressure losses to reveal the relation of the Reynolds and Rossby numbers with the skin-friction coefficients. The present results show that the skin-friction coefficients have the significant relation with the Rossby numbers, only for laminar regime. The occurrence of transition has been checked by the gradient changes of pressure losses and skin-friction coefficients with respect to the Reynolds numbers. The increasing rate of skin-friction coefficients due to the rotation in uniform for laminar flow regime, whereas it is suddenly reduced for transitional flow regime and, then, is gradually declined for turbulent flow regime. Consequently, the critical(axial-flow) Reynolds number decrease as the rotational speed increases. Thus, the rotation of inner cylinder promotes the early occurrence of transition due to the onset of taylor vortices.

• Animal cells and systems
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• v.6 no.1
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• pp.75-80
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• 2002

A study on the effects of bisphenol A (BPA) on sex differentiation and gonadal development in medaka, Oryzias latipes, was investigated by histological examination. The fish were exposed to aqueous solutions of BPA at nominal concentrations of 50, 100, and 200 $\mu\textrm{g}$/L from newly-hatched larvae stage to 70 d. The ovaries of female fish were composed of oocytes at the chromatin nucleolus and peri-nucleolus stages at 20 d after the exposure. The testes contained a number of spermatogonia and spermatocytes at 30 d. In the process of sex differentiation. gonadal development was not different in all experimental groups until 30 d after the exposure. At 70 d after the exposure, however, advanced development of oocytes in the ovary and inhibition of spermatogenesis in the testis were observed in the BPA-treated groups compared to the non-treated controls. More females than males were identified in the 50 and 100 $\mu\textrm{g}$/L BPA-treated groups, in comparison to the 200 $\mu\textrm{g}$/L BPA-treated group and non-treated controls. Medaka exposed to 200 $\mu\textrm{g}$/L BPA were bigger compared to other experimental groups. The present study suggests that BPA may lead to problems in either mating or sexual behavior due to the difference in growth and disparity of sexual maturation between male and female fish.

• Journal of Energy Engineering
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• v.18 no.2
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• pp.87-92
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• 2009

An experimental investigation is conducted to study a 2-phase vertically upward hydraulic transport of solid particles by water and non-Newtonian fluids in a slim hole concentric annulus with rotation of the inner cylinder. Rheology of particulate suspensions in viscoelastic fluids is of importance in many applications such as particle removal from surfaces, transport of proppants in fractured reservoir and cleaning of drilling holes, etc. In this study, a clear acrylic pipe was used in order to observe the movement of solid particles. Annular velocities varied from 0.3 m/s to 2.0 m/s. The mud systems included fresh water and CMC solutions. Main parameters considered in the study were inner-pipe rotation speed, fluid flow regime and particle injection rate. A particle rising velocity and pressure drop in annulus have been measured for fully developed flows of water and of aqueous solutions. For both water and 0.2% CMC solutions, the higher the concentration of the solid particles is, the larger the pressure gradients become.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.29-32
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• 2004

Gaseous partitioning tracer test has been used for determining the volume and spatial distribution of residual non-aqueous phase liquid (NAPL) in the unsaturated soils. In this study, an experimental method for measuring the content of gas-exposed NAPL as well as that of total NAPL in a sand during air sparging was developed. Two different gaseous phase NAPL-partitioning tracers were used; n-pentane, with very low water solubility, was used as the tracer that partitions into NAPL that is only in contact with the mobile gas, and chloroform, with fairly good water solubility, was selected for detecting total NAPL content in the sand. Helium and difluromethanewere used as the non- reactive tracer and water-partitioning tracers, respectively. Using n-decane as a model NAPL (NAPL saturation of 0.018), 25.6% of total NAPL was detected by n-pentane at the water saturation of 0.68. Oniy 9.1% of total NAPL was detected by n-pentane at the water saturation of 0.84. This result implies that the quantity of gas-exposed NAPL increased about three times when the water saturation decreased from 0.84 to 0.68. At the water saturation of 0.68, more than 90% of total NAPL was detected by chloroform while 65.8% of total NAPL was detected by chloroform at the water saturation of 0.84. Considering that the removal rate of NAPL during air sparging for NAPL-contaminated aquifer is expected to be greatly dependent upon the spatial arrangement of NAPL phase with respect to the mobile gas, this new approach may provide useful information for investigating the mass transfer process during air-driven remedial processes fer NAPL-contaminated subsurface environment.

• Journal of the Korean Applied Science and Technology
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• v.29 no.1
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• pp.19-32
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• 2012

Pharmaceutical use accounts for a great part of articles and papers on crosslinking of polymers. Crosslinking of polymers used for tissue engineering and drug delivery respects non-cytotoxicity and in situ gelling. The crosslinking of polymers is aimed not only at the improvement of modulus, chemical resistance, and thermal resistance, but also at endowing them with such functions as metal adsorption, antifouling, and ion exchange via crosslinked segments. Smart polymers responding to environmental change, and cosslinking mediated by light, enzyme, natural compound and in aqueous medium in consideration of environment are being studied. Developing new polymeric materials is essential along with the pharmaceutics aiming at the longevity of 120 years old. Functionalization and property adjustment of polymers through crosslinking will be done more delicately. Hydrogels will be focused on injectable and in situ gel forming. In the coating industry crosslinking system with low non-toxicity and low energy consumption will be developed in consideration of workers and environment.

• The Korea Journal of Herbology
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• v.35 no.6
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• pp.35-41
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• 2020

Objectives : The object of this study was to observe anticancer and immunomodulatory effects of Formosa plum aqueous extracts (PLe) on non-small cell lung carcinoma (squamous epithelial carcinoma), NCI-H520, xenograft Balb/c nu-nu nude mice. Method : Three different dosages of PLe, 50, 100 and 200 mg/kg were orally administered once a day for 28 days from 11 days after tumor cell inoculation. Five groups, each of seven mice per group were used in the present study as follows. Tumor volume and weights, serum interferon (IFN)-γ levels, serum IL-6 were observed with tumor mass and lymphatic organ histopathology to detect anticancer and immunomodulatory effects. Result : Although no meaningful changes on the tumor weights and volumes were observed after treatment of all three different dosages of PLe, decreases of tumor cell volumes in tumor masses were dose-dependently decreased mediated by increases of apoptosis among tumor cells by treatment of PLe 100 and 200 mg/kg as compared with tumor-bearing control. In addition, decreases on the body weight and gains were also demonstrated in tumor-bearing control with increases of serum IL-6 levels. Conclusion : The results obtained in this study suggest that over 50 mg/kg of PLe showed favorable immunomodulatory and anticachexic effects with anticancer effects in 100 and 200 mg/kg of PLe treated groups on the NCI-H520 cell xenograft. However, detail mechanism studies should be conducted in future with the screening of the biological active compounds in this herb.

• Journal of Korean Society on Water Environment
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• v.36 no.1
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• pp.48-54
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• 2020

This paper presents a screening protocol for the selection of solvents available for the solvent extraction desalination process. The desalination solvents hypothetically and theoretically require the capability of (1) Forming hydrogen bonds with water, (2) Absorbing some water molecules into its non-polar solvent layer, (3) Changing solubility for water-solvent separation, and (4) Rejecting salt ions during absorption. Similar to carboxylic acids, amine solvents are solvent chemicals applicable for desalination. The key parameter for selecting the potential solvent was the octanol-water partitioning coefficient (Kow) of which preferable value for desalination was in the range of 1-3. Six of the 30 amine solvents can absorb water and have a variable, i.e., temperature swing solubility with water molecule for water-solvent separation. Also, the hydrogen bonding interaction between solvent and water must be stronger than the ion-dipole interaction between water and salt, which means that the salt ions must be broken from the water and only water molecules absorbed for the desalination. In the final step, three solvents were selected as desalination solvents to remove salt ions and recover water. The water recovery of these three solvents were 15.4 %, 2.8 %, 10.5 %, and salt rejection were 76 %, 98 %, 95 %, respectively. This study suggests a new screening protocol comprising the theoretical and experimental approaches for the selection of solvents for the desalination method which is a new and challenges the desalination process in the future.