• Elastomers and Composites
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• v.46 no.4
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• pp.335-342
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• 2011

The virgin and recycled polyethylene composites with various ratio of fly ash were manufactured by using a fully intermeshing co-rotating twin screw extruder for the reuse of fly ash from power plant and post-consumed polyethylene. Fly ash were blended with virgin HDPE and recycled polyethylene at the weight fraction of 0 to 40 wt.%. Mechanical properties such as yield strength, abrasion resistance, and slow crack resistance were measured with ISO and ASTM standards. The experimental results for the various composites showed that the elongation at break and the yield stress of the composites decreased with increasing fly ash contents. Generally, the abrasion resistance of PEs decreased with increasing sandpaper grits but the abrasion resistance of the composites increased with fly ash content at finer abrasive surface. The slow crack growth resistance of virgin HDPE, recycled JRPE and the JRPE composite showed higher slow crack growth resistance up to 50% of load at notch depth of 20% and 30%, but KRPE and the KRPE composite showed much lower resistance than virgin HDPE, JRPE and the JRPE composite. Time to break, measured with NCLS test method, of all PEs and the composites satisfies the regulation of Korean Industrial Specification for sewer pipe and support application.

• Journal of Adhesion and Interface
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• v.21 no.3
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• pp.101-106
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• 2020

In this study, epoxy-modified acrylate was synthesized. The synthesized acrylate was added to the composition for sheet molding compound (SMC) in the range of 5 phr to 15 phr. The prepared SMC prepreg was molded at high temperature and pressure to produce a glass fiber reinforced composite. Physical properties such as tensile and impact strength of the composite were measured, respectively. Experimental data show that the composite with 5 phr of synthesized acrylate has 20% improved tensile strength and 12% improved impact strength than that of the reference sample.

• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.425-430
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• 2015

ZSM-5 crystals grew by hydrothermal synthesis method on the surface of foam type porous silicon carbide ceramics which fabricated by polymer replica method. Oxide layer was developed on the surface of the porous silicon carbide ceramics to induce growth of ZSM-5 from the surface. In this study, hydrothermal synthesis was carried out for 7 h at $150^{\circ}C$ using TEOS, $Al(NO_3){\cdot}9H_2O$ and TPAOH as raw materials in the presence of the porous silicon carbide ceramics. X-ray Powder Diffraction (XRD) and Scanning Electron Microscope (SEM) analyses were confirmed $1{\sim}3{\mu}m$ sized ZSM-5 crystals have grown on the surface of porous silicon carbide ceramics. BET data shows that small pores about $10{\AA}$ size drastically enhanced and surface area increased from $0.83m^2/g$ to $30.75m^2/g$ after ZSM-5 synthesis on the surface of foam type porous silicon carbide ceramics.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.2
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• pp.283-299
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• 2017

The leakage of tunnel causes the long-term durability of the structures such as concrete lining to deteriorate. The cause of durability degradation can be various substances contained in groundwater such as chloride, sulphate, water, and gas. In this study, a series of test were carried out to determine the watertightness performance and the resistance to salt water of the spray-applied membrane used as non-structural rock support or as a waterproof material for tunnels. As a result, it was found that the penetration of water could occur in a specimen, and the reason was that the internal pores generated by the mixing of the liquid polymer and the powder material and the internal pores were connected by the water pressure. The tensile strength of the test specimens immersed in distilled water and saline water was found to be reduced to less than half of the tensile strength in normal condition. In addition, The elongation was measured to be higher in distilled water than in salt water. However, this result will require further investigation.

• Journal of Life Science
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• v.23 no.12
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• pp.1471-1476
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• 2013

The present study deals with the immobilization of Kluyveromyces lactis ${\beta}$-galactosidase on a weak ionic exchange resin (Duolite A568) as polymer support. ${\beta}$-Galactosidase was immobilized using the adsorption method. A kinetic study of the immobilized enzyme was performed in a packed-bed reactor. The adsorption of the enzyme followed a typical Freundlich adsorption isotherm. The adsorption parameters of k and n were 14.6 and 1.74, respectively. The initial rates method was used to characterize the kinetic parameters of the free and immobilized enzymes. The Michaelis-Menten constant ($K_m$) for the immobilized enzyme (120 mM) was higher than it was for the free enzyme (79 mM). The effect of competitive inhibition kinetics was studied by changing the concentration of galactose in a recycling packed-bed reactor. The kinetic model with competitive inhibition by galactose was best fitted to the experimental results with $V_m$, $K_m$, and $K_I$ values of 46.3 $mmolmin^{-1}mg^{-1}$, 120 mM, and 24.4 mM, respectively. In a continuous packed-bed reactor, increasing the flow rate of the lactose solution decreased the conversion efficiency of lactose at different input lactose concentrations. Continuous operation of 11 days was conducted to investigate the stability of a long-term operation. The retained activity of the immobilized enzymes was 63% and the half-life of the immobilized enzyme was found to be 15 days.

• Journal of Pharmacopuncture
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• v.9 no.2
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• pp.17-37
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• 2006

Objectives : To observe the changes in the serum proteins after intravenous injection of cultivated wild ginseng pharmacopuncture. Methods : Blood was collected before and after the administration of cultivated wild ginseng pharmacopuncture and only the serum was taken. Then differences in the spots on the scanned image after carrying out 2-Dimensional electrophoresis were located and conducted mass analysis and protein identification. Results : Following results were obtained from the comparative analysis of serum proteins before and after the administration of cultivated wild ginseng pharmacopuncture. 1. 28 spots were identified before and after the administration. 2. In confirming manifestation degree, spots with more than two-times increase were 204, 1302, 2205, 3105, 7104, 8006, spots with more than one-time increase were 1101, 1505, 2013, 2403, 3009, 3010, 4002, 4009, 6704, 8101, and spots with decrease were 205, 801, 803, 3205, 5202, 6105, 6106, 7103, 9001, 9003. 3. After conducting protein identification, proteins 205, 804, 1302, 4009, 6105, 6106 are unidentified yet, and 1l01 is unnamed protein. Protein 204 is identified as complement receptor CR2-C3d, 801 as YAPl protein, 803 as antitrypsin polymer, 1505 as PRO0684, 2013 and 3010 as proapolipoprotein, 2205 as USP48, 2403 as vitamin D binding protein, 3009 as complement component 4A preprotein, 3105 as immunoglobulin lambda chain, 3205 as transthyretin, 4002 as Ras-related protein Ral-A, 4204 as beta actin, 5202 and 7104 as apolipoprotein Ll, 6704 as alpha 2 macroglobulin precursor, 7103 as complement component 3 precursor, 8006 as testis-specific protein Y, 8101 as transferrin, 9001 as (Alpha-Oxy, Beta-(Cl12g)deoxy) T-State Human Hemoglobin, and 9003 as human hemoglobin. 4. Immune protein CR2-C3d(204), which acts against microbes and pathogenic organisms, was increased by more than two-times after the administration of pharmacopuncture. 5. Antitrypsin(803), which is secreted with inflammatory response in the lungs, was reduced after the administration of pharmacopuncture. 6. Proapolipoprotein(2013, 3010) and apolipoprotein(7104), key components of the HDL-cholesterol which plays an important role in preventing arteriosclerosis, were increased after the administration of pharmacopuncture. 7. Vitamin D binding protein(DBP, 2403), protecting the lung at the time of inflammatory response, was increased after the administration of pharmacopuncture. 8. Transthyretin(TTR, 3205), which is the main protein causing familial amyloid polyneuropathy(FAP), was decreased after the administration of pharmacopuncture. 9. Ras-related protein Ral-A(4002) that controls phospholipid metabolism, cytoskeletal formation, and membrane traffic, was increased after the administration of pharmacopuncture. 10. Testis-specific protein Y(8006), which takes part in determination of the gender, was increased by more than two-times after the administration of pharmacopuncture. 11. Transferrin(8101), which balances the iron level in the body, was increased after the administration of pharmacopuncture. Conclusion : Above results support the notion that intravenous injection of cultivated wild ginseng pharmacopuncture induce changes in serum proteins and this research can be a pioneer work in finding biomarkers.

• Archives of Plastic Surgery
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• v.38 no.4
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• pp.438-444
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• 2011

Purpose: Adipose-derived stromal cells (ASCs) are readily harvested from lipoaspirated tissue or subcutaneous adipose tissue fragments. The stromal vascular fraction (SVF) is a heterogeneous set of cell populations that surround and support adipose tissue, which includes the stromal cells, ASCs, that have the ability to differentiate into cells of several lineages and contains cells from the microvasculature. The mechanisms that drive the ASCs into the osteoblast lineage are still not clear, but the process has been more extensively studied in bone marrow stromal cells. The purpose of this study was to investigate the osteogenic capacity of adipose derived SVF cells and evaluate bone formation following implantation of SVF cells into the bone defect of human phalanx. Methods: Case 1 a 43-year-old male was wounded while using a press machine. After first operation, segmental bone defects of the left 3rd and 4th middle phalanx occurred. At first we injected the SVF cells combined with demineralized bone matrix (DBM) to defected 4th middle phalangeal bone lesion. We used P (L/DL)LA [Poly (70L-lactide-co-30DL-lactide) Co Polymer P (L/DL)LA] as a scaffold. Next, we implanted the SVF cells combined with DBM to repair left 3rd middle phalangeal bone defect in sequence. Case 2 was a 25-year-old man with crushing hand injury. Three months after the previous surgery, we implanted the SVF cells combined with DBM to restore right 3rd middle phalangeal bone defect by syringe injection. Radiographic images were taken at follow-up hospital visits and evaluated radiographically by means of computerized analysis of digital images. Results: The phalangeal bone defect was treated with autologous SVF cells isolated and applied in a single operative procedure in combination with DBM. The SVF cells were supported in place with mechanical fixation with a resorbable macroporous sheets acting as a soft tissue barrier. The radiographic appearance of the defect revealed a restoration to average bone density and stable position of pharyngeal bone. Densitometric evaluations for digital X-ray revealed improved bone densities in two cases with pharyngeal bone defects, that is, 65.2% for 4th finger of the case 1, 60.5% for 3rd finger of the case 1 and 60.1% for the case 2. Conclusion: This study demonstrated that adipose derived stromal vascular fraction cells have osteogenic potential in two clinical case studies. Thus, these reports show that cells from the SVF cells have potential in many areas of clinical cell therapy and regenerative medicine, albeit a lot of work is yet to be done.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.17-21
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• 2019

The redox flow battery (RFB) is a large-capacity energy storage equipment, and the vanadium redox flow cell is a typical RFB, but VRFB is expensive. Iron-chrome RFBs are economical because they use low-cost active materials, but their low performance is an urgent problem. One of the reasons for the low performance is the crossover of the active materials. In this study, the sulfonated Poly (ether ether ketone) (sPEEK) membrane, which is a hydrocarbon membrane, was used instead of the fluorine membrane to reduce the crossover of the active materials. The chromium ion permeability of the sPEEK membrane was $1.8{\times}10^{-6}cm^2/min$, which was about 1/33 of that of the Nafion membrane. Thus, it was shown that the use of the sPEEK membrane instead of the fluorine membrane could solve the high active material crossover problem. The activation energy of iron diffusion through the sPEEK membrane was 24.9 kJ/mol, which was about 66% of Nafion membrane. And that the e-PTFE support in the polymer membrane reduces the active material crossover through Iron-Chrome Redox Flow Battery (ICRFB).

• Membrane Journal
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• v.33 no.6
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• pp.427-438
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• 2023

In this study, in order to improve the performance of the reverse osmosis membrane with high water flux and high salt rejection, a study was conducted on the evaluation of characteristics according to the curing temperature and time during various additives and interfacial polymerization. The morphology of the membrane with no additives and the membrane with additives both showed a "rigid-and-valley" structure, confirming that the polyamide layer was successfully polymerized on the surface of the porous support layer. In addition, the additive of 2-Ethyl-1,3-hexanediol (EHD) had improved hydrophilicity and water flux, which was confirmed by measuring the contact angle. Finally, a highly permeable TFC membrane with NaCl and MgSO₄ salt rejection of 97.78% and 98.7% and a high water flux of 3.31 L/(m²⋅h⋅bar) was prepared.

• Journal of Advanced Technology Convergence
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• v.3 no.2
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• pp.25-31
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• 2024

In recent industrialization and development due to information and communication technology, modern women in modern society are exposed to physical and mental health due to numerous stresses. Popular inflammations are attributable to a decrease in lactic acid bacteria, frequent antibiotic use, and a decrease in immunity. It is necessary to develop products that are helpful and reflected. The inner care gel currently introduced on the market can increase beneficial bacteria and maintain a healthy y-zone. The inner gel contains a hydrogel component. 90% is made up of water, and other components act as support for supporting water and are formed through crosslinking between polymer chains. Hydroxyethyl cellulose (HEC) is a hydroxyethyl ethylenetel of cellulose. The purpose of use is to act as a binder, an emulsion stabilizer, a viscosity enhancer (water-soluble), and a film forming agent. CA (crosslinker) is a crosslinking agent and serves to bind. Hydrogel in the beauty field acts as a film forming agent that gently wraps around the skin by forming a thin film and serves as an emulsion stabilizer that helps to prevent separation of other raw materials. It also acts as a thickener by increasing viscosity in cosmetics. In addition, it is used for glucose monitoring, nursing care, cell transplantation, and wound treatment in the bio field. Currently, it is understood that no products using functional hydrogel have been released, so in this study, a Y zone care hydrogel solution was manufactured to find out the antibacterial properties of the functional hydrogel, and a new solution was developed. As a result, it was confirmed that the appropriate Ph was applied to the Y zone, and after culturing Candida albicans in PDB medium, all three products of the Y zone care hydrogel solution showed an antibacterial effect of 0.5-1.0mm