• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.698-701
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• 2011

Over recent several years, researches for the less sensitive gun propellant development have been carried out with promising the product of propellants which have temperature independent characteristics using the new energetic plasticizing mixture as Di-nitro-diaza-alkanes. During this study, the promising propellant formulation having temperature ballistic properties as well as better behaviors concerning the cold brittleness of the materials was confirmed by results in tests of a closed bomb and 40mm Gun firing. On-going research on the optimized shape, formulation and processes of the propellant is progressing. From now on it should be done present study to establish the better composition and processes.

• Safety and Health at Work
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• v.2 no.1
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• pp.57-64
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• 2011

Objectives: Although phthalates like dibutyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP) are commonly used as plasticizers and their metabolites are especially suspected of reproductive toxicity, little is known about occupational exposure to those phthalates. The aim of this study was to assess the utility of measuring the metabolite concentrations of DBP and DEHP in serum and urine samples as an indicator of occupational exposure to those phthalates. Methods: Phthalate metabolites were analyzed by using column-switching high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS). Results: We detected phthalate metabolites in serum and urine matrices at approximately 10-fold lower than the limit of detection of those metabolites in the same matrix by LC-MS/MS without column switching, which was sufficient to evaluate concentrations of phthalate metabolites for industrial workers and the general population. Conclusion: The accuracy and precision of the analytical method indicate that urinary metabolite determination can be a more acceptable biomarker for studying phthalate exposure and adverse health outcomes.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.5
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• pp.40-50
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• 2016

Energetic plasticizers containing explosophore groups such as $-NO_2$, $-ONO_2$, and $-N_3$ group are susceptible to impact, shock, heat, etc, finally deteriorating the insensitivity of PBXs. In this study, in an attempt to investigate the feasibility of replacing sensitive explosophore groups to fundamentally inactive but potentially (latent) energetic fluorine group which was known to have an exothermic thermite reaction with aluminum, nano-aluminum/fluorinated polyurethane binders were prepared by simultaneous polyurethane and catalyst-free azide-alkyne click reaction in the presence of nano-aluminum. Thermal characteristics of nano-aluminum/fluorinated polyurethane binders were monitored by using DSC with high pressure crucible pan.

• Archives of Pharmacal Research
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• v.26 no.11
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• pp.973-978
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• 2003

A polymeric film composed of Carbopol, Poloxamer and hydroxypropyl methylcellulose was prepared to develop a buccal patch and the effects of composition of the film on adhesion time, swelling ratio, and dissolution of the film were studied. The effects of plasticizers or penetration enhancers on the release of triamcinolone acetonide (TAA) were also studied. The hydrogen bonding between Carbopol and Poloxamer played important role in reducing swelling ratio and dissolution rate of polymer film and increasing adhesion time. The swelling ratio of the composite film was significantly reduced and the adhesion time was increased when compared with Carbopol film. As the ratio of Poloxamer to hydroxypropyl methylcellulose increased from 0/66 to 33/33, the release rate of TAA decreased. However, no further significant decrease of release rate was observed beyond the ratio of 33/33. The release rate of TAA in the polymeric film containing polyethylene glycol 400, a plasticizer, showed the highest release rate followed by triethyl citrate, and castor oil. The release rate of TAA from the polymeric film containing permeation enhancers was slower than that from the control without enhancers. Therefore, these observations indicated that a preparation of a buccal patch is feasible with the polymeric film composed of Cabopol, Poloxamer and hydropropyl methylcellulose.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.25 no.4 s.34
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• pp.51-55
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• 1999

Cosmetic mask is one of the traditional cosmetic product and is used to keep skin healthy and beautiful through moisturizing effect, cleansing effect and acceleration effect on microcirculation. There are several types of cosmetic mask such as peel-off type, tissue-off type, wash-off type and cotton sheet type immersed in cosmetic water. It is important for cosmetic formulators to develop an adequate type of cosmetic mask that meets the needs of the target consumers because each type of cosmetic mask has benefits and problems in its usage and efficacy. Polyvinyl alcohol (PVA) is widely used as an active ingredient of peel-off type cosmetic mask and the physical property of the PVA film changes with the usage of other ingredients. We studied the change of physical properties of the film containing PVA by formulating peel-off type cosmetic mask with the variation of humectants. Methylguceth-20 and glycereth-26 reduce the interaction between skin surface and PVA film without serious weakening of tensile strength and they can alleviate irritation. Glycerin, urea and betaine help PVA film soften and they also have excellent efficacy as humectants.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.4
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• pp.195-202
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• 2004

In this study, it was founded to make the optimal mixture for producing concrete which is self-compacting, yet, and generates low heat of hydration by using flyash, blast furnace slags and limestone powders as binders in addition to cement while using super-plasticizers and viscosity agents as admixture agents. The structural behaviors of the concrete produced with the selected mixture were compared with those of the concrete currently using for construction of nuclear power plants. The study shows that the blended high fluidity concrete including limestone is better in workability and durability than the concrete currently in use for nuclear power plants.

• Environmental Engineering Research
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• v.25 no.4
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• pp.506-514
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• 2020

The current study stresses on the reuse of waste lignocellulose biomass (rice husk and sugarcane bagasse) for the synthesis of carboxymethyl cellulose (CMC) and further conversion of this CMC into a biodegradable film. Addition of commercial starch was done to form biodegradable film due to its capacity to form a continuous matrix. Plasticizers such as Glycerol and citric acid were used to provide flexibility and strength to the film. Biopolymer film obtained from sugarcane bagasse CMC showed maximum tensile strength and elongation in comparison to the film synthesized from commercial CMC and CMC obtained from rice husk. It has been observed that an increase in sodium glycolate/NaCl content in CMC imposed an adverse effect on tensile strength. Opacity, moisture content, and solubility of the film increased with a rise in the degree of substitution of CMC. Therefore, CMC obtained from sugarcane bagasse was better candidate in preparing biopolymer/biocomposite film.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.365-370
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• 2014

Objectives: The major objective is development of an eco-friendly non-phthalate plasticizer using crude glycol derived from the biodiesel process. Methods: Glycerol monolaurate(GML) was synthesized from glycol and triglyrcerides. Glycerol diacetomonolaurate(GDAL) was synthesized from GML and acetic acid. Results: The synthesis of the GDAL plasticizer was measured with nuclear magnetic resonance spectroscopy(NMR). Mechanical properties were measured by universal testing machine(UTM) and the experimental values were compared with phthalate plasticizers such as dioctyl phthalate(DOP). In particular, the values for tensile strength and elongations with GDAL were higher than with DOP. Conclusions: We confirmed the development of an eco-friendly non-phthalate plasticizer by NMR. Based on our results, applicability for food and drug packaging materials was found.

• Polymer(Korea)
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• v.26 no.6
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• pp.778-784
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• 2002

Chemical modification of a dextran film to improve its physical properties was carried out by addition of plasticizers and crosslinking agents. Moreover, low-temperature plasma treatment with acetylene gas was done. The dextran film showed high mechanical strength but was brittle and vulnerable to moisture. When plasticizer was added, it became very soft but with large reduction of mechanical strength. However, a flexible film with fairly high mechanical strength and water resistance was prepared when the film was crosslinked by adding crosslinking agent with or after the addition of plasticizer. Treatment with an acetylene plasma changed the dextran film surface from hydrophilic to hydrophobic with little influence on the bulk properties of the film.

• Bulletin of the Korean Chemical Society
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• v.25 no.10
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• pp.1484-1488
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• 2004

The thiocyanate-selective PVC membrane electrodes based on 5,10,15,20-tetrakis(2,4,6-trimethylphenyl)-porphyrinatomanganese(III) chloride [Mn(TMP)Cl] and 5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrinatomanganese(III) chloride $[Mn(Cl_8TPP)Cl]$ as ion carriers were investigated. The effect of ionophores, membrane compositions, plasticizers, and solution pHs on the response characteristics were studied. The Mn(TMP)Cl as an ionophore shows the best potentiometric sensitivity with a slope of -58.7 mV/decade and a detection limit of $log[SCN^-]$ = -6.90, and selectivity for thiocyanate over strong hydrophobic interfering anions such as ${ClO_4}^-$ and salicylate. The potentiometric response is affected by the electronic effect of the substituents and solution pHs. The presence of substituents with electron donating and more liphophilic characters around the ligated metal center produces an improved response toward $SCN^-$.