• The Journal of Korean Medicine
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• v.24 no.3
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• pp.35-44
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• 2003

Objective : This study was performed to evaluate the effects of Palmijihwang-hwan (Baweidehuang-wan) and Obaeja (Galla Rhois) on the regeneration of periodontal tissue. Methods : In this study, we used MC3T3-El cells, such as osteoblast-like cell lines and human periodontal ligament fibroblasts, for experimental material. We separated each type of cells into a control group and an experimental group. In the control group, the cells were cultivated for 48 hours with distilled water and media which contained 10% fetal bovine serum (FBS) and penicillin (l00unit/ml)-streptomycin ($l00{\mu\textrm{g}}/ml$) at $37^{\circ}$ in 5% $CO_2$ gas. In the experimental group, the cells were cultivated for 48 hours with Palmijihwang-hwan extract and Obaeja extract (concentrations $1{\mu\textrm{g}}/ml,{\;}25{\mu\textrm{g}}/ml,{\;}50{\mu\textrm{g}}/ml$) under the same conditions as the control group. Investigating the regeneration of periodontal tissue was performed by evaluating proliferation, the activity of alkaline phosphatase and the synthetic ability of proteins using those cultivated cells by means of microculture tetrazolium (MTT) assay, alkaline phosphatase substrate kit and protein assay kit. Results : 1. In vitro, Palmijihwang-hwan extract increased the proliferation of MC3T3-El cells. 2. In vitro, Obaeja extract increased the activity of alkaline phosphatase and the synthetic ability of protein in MC3T3-El cells and human periodontal ligament fibroblasts depending on Obaeja extract's concentration. Conclusion : Obaeja extract can be developed as a subsidiary medicine for the regeneration of periodontal tissue. Further studies to evaluate the different concentrations the Obaeja extract and clinical trials in vivo are suggested.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.30-38
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• 2008

Dental pulp cells are assumed to possess the capacity to elaborate both bone and dentin matrix under the pathological conditions following tooth injury. The purpose of this study is to examine the effects of mineral trioxide aggregate (MTA) on various gene expression regarding dentinogenesis and cell viability assay in cultured primary human dental pulp cells. The author also examined the effects of this material on cellular alkaline phosphatase activity as a potential indicator of dentinogenesis. For gene expression on MTA, reverse transcriptase polymerase chain reaction was performed using primer sets of glyceraldehyde-3-phosphate dehydrogenase, type I collagen, alkaline phosphatase(ALP), osteonectin, and dentin sialoprotein after 2 and 4 days. Cell viability assay showed that the proportion of MTA-treated pulp cells which had been exposed for 5 days to MTA was higher than that of the control cells. Among the genes investigated in this study, ALP and osteonectin(SPARC) were increased in MTA treated group than in control. These findings suggest that this dental pulp culture system may be useful in the future as a model for studying the mechanisms underlying dentin regeneration after the treatment with MTA. Exposure to MTA material would not induce cytotoxic response in the dental pulp cells. In addition, MTA could influence the behavior of human pulp cells by increasing the ALP activity and SPARC synthesis.

• Journal of the Korea Institute of Building Construction
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• v.12 no.6
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• pp.566-574
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• 2012

To address the problem of global warming, consumption of cement, the main material of concrete, should be decreased. Unfortunately, when industrial by-products are used in large quantities as admixture, the early age strength of concrete will be decreased, reducing its viability for use in concrete structures. Therefore, in this study, the application of an ionization accelerator and alkaline activator as addition agent of superplasticizer were investigated to secure a similar early age strength to that of normal concrete, thus increasing the viability of low cement concrete. Through the investigation, it was found that specimens that used a combination of Alkaline-activator (Na2Sio3) and ionization accelerator (Amine) had the highest early and long-age compressive strength. From this, we can determine an appropriate range of application of superplasticizer to improve early-age compressive strength of low cement concrete.

• Journal of the Korean Ceramic Society
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• v.51 no.2
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• pp.64-71
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• 2014

Accelerated carbonation is a technique that can be used as a CCS technology for $CO_2$ sequestration of approximately 5~20% in a stable solid through the precipitation of carbonate. An alkaline inorganic waste material such as ash, slag, and cement paste are generated from incinerators, accelerated carbonation offers the advantage of lower transport and processing costs at the same generation location of waste and $CO_2$. In this study, we evaluated an amount of $CO_2$ sequestration in various types of inorganic alkaline waste processed by means of accelerated carbonation. A quantitative evaluation of $CO_2$ real sequestration based on a TG/DTA analysis, the maximum 118.88 $g/kg_{-waste}$ of $CO_2$ in paper sludge fly ash, the maximum 134.46 $g/kg_{-waste}$ of $CO_2$ in municipal solid waste incinerator bottom ash, the maximum 9.72 $g/kg_{-waste}$ of $CO_2$ in industrial solid waste incinerator fly ash, and the maximum $18.19g/kg_{-waste}$ of $CO_2$ in waste cement paste.

• Advances in concrete construction
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• v.2 no.1
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• pp.29-37
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• 2014

Increasing emphasis on energy conservation and environmental protection has led to the investigation of the alternatives to customary building materials. Some of the significant goals behind understaking such investigations are to reduce the greenhouse gasemissions and minimize the energy required formaterial production.The usage of concrete around the world is second only to water. Ordinary Portland Cement (OPC) is conventionally used as the primary binder to produce concrete. The cement production is a significant industrial activity in terms of its volume and contribution to greenhouse gas emission. Globally, the production of cement contributes at least 5 to 7 % of $CO_2$. Another major problem of the environment is to dispose off the fly ash, a hazardous waste material, which is produced by thermal power plant by combustion of coal in power generation processes. The geopolymer concrete aims at utilizing the maximum amount of fly ash and reduce $CO_2$ emission in atmosphere by avoiding use of cement to making concrete. This paper reports an experimental work conducted to investigate the effect of curing conditions on the compressive strength of geopolymer concrete prepared by using fly ash as base material and combination of sodium hydroxide and sodium silicate as alkaline activator.

• The Journal of Korean Medicine
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• v.38 no.4
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• pp.1-10
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• 2017

Objectives: The aim of the present study is to evaluate the effects of the extract of Pongamia pinnata on the morphology, viability, and differentiation potential of human stem cells derived from the gingiva. Methods: Stem cells obtained from gingivae were cultured in an osteogenic medium in the presence of methanol extract of Pongamia pinnata (PPT) at concentrations ranging from 0.001 to 1%. Evaluations of cell morphology and cellular viability were done at Day 1. Alkaline phosphatase activity assays and Alizarin red S staining were performed to evaluate the osteogenic differentiation of stem cells. Results: The morphology of stem cells in the presence of PPT at final concentrations of 0%, 0.001%, 0.01%, 0.1%, and 1% did not produce any noticeable changes when compared with the untreated control group. Application of PPT produced a significant increase in alkaline phosphatase activity when compared to the control group. The results of the Alizarin Red S staining showed a significant increase of absorbance with the 0.001% group. Conclusions: Based on these findings, it was concluded that PPT could produce beneficial effects on mesenchymal stem cells with enhanced osteogenic differentiation.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06a
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• pp.51-59
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• 2006

The surface of various mechanical pulp fibres including thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), and alkaline peroxide mechanical pulp (APMP) fibres, were characterized using SEM, AFM, and XPS. With SEM and AFM, middle lamella material was observed to be non-fibrillar, patch-like, while fibre secondary wall was observed to have a microfibrillar structure. It was found that after the first-stage refiner, lignin-rich middle lamella remainders are present on the fibre surface of all three pulps, although most of the fibre surfaces expose microfibrillar structure. After the final-stage refining, large amounts of granules are present on the TMP fibre surface. In contrast, most middle lamella remainders remain on the surface of CTMP fibres after final stage refining and even after peroxide bleaching. XPS results have confirmed that the non-fibrillar surface material is the lignin-rich middle lamella remainder., and the remainders of middle lamella contribute to the high surface lignin concentration.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.77-78
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• 2020

An alkaline activator was synthesized by dissolving waste glass powder (WGP) in NaOH-4M solution to explore its effects on the Class-C fly ash (FA) and ground granulated blast furnace slag (GGBS) based alkali-activated material (AAM). The compressive strength and porosity were measured, and (SEM-EDX) were used to study the hydration mechanism and microstructure. Results indicated that the composition of alkali solutions was significant in enhancing the properties of the obtained AAM. As the amount of dissolved WGP increased in alkaline solution, the silicon concentration increased, causing the accelerated reactivity of FA/GGBS to develop Ca-based hydrate gel as the main reaction product in the system, thereby increasing the strength. Further increase in WGP dissolution led to strength loss, which were believed to be due to the excessive water demand of FA/GGBS composites to achieve optimum mixing consistency. Increasing the GGBS proportion in a composite also appeared to improve the strength which contributed to develop C-S-H-type hydration.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.167-168
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• 2009

Phase pure barium magnesium tantalate $Ba(Mg_{1/3}Ta_{2/3})O_3$(BMT) nanopowders were synthesized at temperature as low as $220^{\circ}C$ through glycothermal reaction by using $Ba(OH)_2{\cdot}8H_2O$, $Mg(NO_3){\cdot}6H_2O$, and $TaCl_5$ as precursors and 1,4-butandiol as solvent. XRD, SEM, and TGA data support that glycothermal processing method provides a simple low temperature route for producing fine grained BMT nanopowders without alkaline mineralizers. BMT nanopowders synthesized at $220^{\circ}C$ showed more homogenous with rounded morphologies.

• Analytical Science and Technology
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• v.13 no.3
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• pp.297-303
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• 2000

Isotope-dilution inductively coupled plasma mass spectrometry was used to determine trace amounts of Cd, Cu, Pb, Ni and Zn in sediment. Sediment samples were dissolved by microwave digestion with addition of mixed acid ($HNO_3$, HF and $HClO_4$). Lead was determined after separation of alkaline and alkaline earth metals by an ammonium pyrrolidenedithiocarbarmate (APDC) solvent extraction. The other elements were determined after separation of iron, tin and titanium by hydroxide precipitation. Recovery efficiency of the analyte elements was not satisfactory, but most of matrix elements causing the isobaric interference could be effectively eliminated by the separation. Good agreement was achieved with the certified values in the analysis of the two sediment reference materials.