• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.10
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• pp.952-959
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• 2004

The hybrid liquid desiccant air conditioning system has been in use for many years, primarily in industrial process applications requiring dehumidification and humidity control. In this study, the hybrid dehumidifier has been designed to study the dehumidification characteristic of the aqueous triethylene glycol (TEG) solution. The experimental results show energy efficient characteristics of hybrid liquid desiccant air conditioning system compared with the refrigeration system in terms of energy use, the difference of pressure loss between hybrid liquid desiccant air conditioning system and refrigeration system. Data obtained are useful for design guidance and performance analysis of the hybrid air conditioning system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.7
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• pp.630-638
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• 2004

Liquid desiccant dehumidification systems have the ability to provide efficient humidity and temperature control while saving the electrical energy requirement for air conditioning as compared to a conventional system. The dehumidifier and the regenerator form the heart of this system. The latent part of the cooling load is overcome using liquid desiccant. The model regenerator has been designed to study the absorption characteristic of the aqueous triethylene glycol (TEG) solution which is in the flow range from 20 to 50 LPM. Also, this system designed that was able to change the height of the regenerator and dehumidifier. Because the effect of performance have different result according the height. The effect of performance factors of the regenerator with inlet solution flow rate, air flow rate, solution concentration, solution temperature, brine temperature, air temperature and inlet air relative humidity have been analyzed. Data obtained are useful for design guidance and performance analysis of the hybrid air conditioning system.

• Textile Coloration and Finishing
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• v.8 no.3
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• pp.16-23
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• 1996

In order to know the change of weight loss, crystallinity, crystallite size(010) plane, and thermal properties of PET films which had before drawn and annealed at various temperature. It were treated in sodium triethylene glycolate-triethylene glycol(STEG-TEG) were prepared. The following results were abtain. The weight loss of PET films were increasing with increaing treated time in STEG-TEG solution and It showed a linear rlationship to the treated time. The crystallinity and crystallite size(010) plane of PET films decreased with increasing decomposition ratio when PET films were treated with before annealed under 16$0^{\circ}C$. The crystalline region on the surface of samples were decompose to thermal unstable crystalline structure

• Journal of Environmental Health Sciences
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• v.39 no.6
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• pp.483-491
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• 2013

Objectives: Electronic cigarettes are battery powered devices that convert a nicotine-containing liquid into an inhalable vapor. The device aerosolizes nicotine so that it is readily entrained into the respiratory tract, from where it enters the bloodstream. Information on the safety of E-cigarettes is required. Methods: Seventeen articles on studies analyzing toxic substances in the liquid and gas phases of electronic cigarettes were reviewed. Results: Tobacco-specific nitrosamines, bis(2-ethylhexyl) phthalate, formaldehyde and acetaldehyde, known to be carcinogenic agents in humans or animals, were detected in the liquid and gas phases. In addition, diethyl phthalate, acetone, ethanol, cresol, xylene, propylene, styrene, triethylene glycol, tetraethylene glycol, pentaethylene glycol cis-3-hexen-1-ol, methyl cinnamate and undecane were identified in the liquid and gas phases of E-cigarettes. Propylene glycol, glycerin, 1-methoxy-2-propanol, 1-hydroxy-2- propanone, acetic acid, 1-menthone, 2,3-butanediol, menthol, carvone, maple lactone, benzyl alcohol, 2-methyl-2-pentanoic acid, ethyl mantel, ethyl cinnamate, myosamine, benzoic acid, 2,3-bipyridine, cotinine, hexadecanoic acid, and 1'1-oxybis-2-propanol were detected in the vapors of E-cigarettes. Conclusion: The hazardous compounds identified in the liquid and gas phases of E-cigarettes should be controlled for the lowest concentrations in the raw materials and production procedures.

• Clean Technology
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• v.20 no.2
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• pp.123-129
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• 2014

A green procedure is described for the preparation of a series of ionic liquids where two 3-methylimidazolium cations were bridged with ethylene glycol chain as linkers. Diethylene glycol-bis(3-methylimidazolium) ditosylate, triethylene glycolbis(3-methylimidazolium) ditosylate, and tetraethylene glycol-bis(3-methylimidazolium) ditosylate were heated with 3-methylimidazole under solvent-free condition to give the corresponding bis(3-methylimidazolium) ditosylate ionic liquids efficiently in a short time.

• Journal of the Korean Applied Science and Technology
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• v.7 no.1
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• pp.49-62
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• 1990

In order to synthesize N,N-di-(polyoxyethylene) perfluoroacyl amines and the surface active monoperfluoroacyl aza crown ethers, it is performed as follow. Six of N,N-di(polyoxyethylene) perfluoro acyl amines were synthesized from perfluoroalkanoic acids with ethanol followed by oxyethylation with triethylene glycol mono chloride or tetra ethylene glycol mono chloride and six of N-perfluor acyl monoaza crown ethers by cyclization of corresponding N,N-di(polyoxy ethylene} perfluoro acyl amines with p-toluene suflonic chloride-NaOH/dioxane, p-toluene sulfonyl chloride KOH/dioxane and benzene sulfonic chloride-KOH/dioxane systems.

• Journal of Korean society of Dental Hygiene
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• v.14 no.5
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• pp.775-781
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• 2014

Objectives : The purpose of the study is to investigate the protective effect of coenzyme $Q_{10}$ on cytotoxicity effect of dental monomers in odontoblast(MDPC-23). Methods : MDPC-23 was incubated with the(co)monomers triethylene glycol dimethacrylate (TEGDMA) with and without addition of coenzyme $Q_{10}$. The cell proliferation and survival was determined using WST-1 assay. The level of reactive oxygen species(ROS) was measured by immunofluorescent staining for DCF-DA. Results : TEGDMA treatment decreased the cell proliferation by dose dependently(0.1, 1, 2.5, 5, 10 mM) on the growth of MDPC-23 cells. Coenzyme $Q_{10}$ showed cell proliferation from 5 to $500{\mu}M$ by WST-1 assay. Pre-treatment coenzyme $Q_{10}$ showed the antioxidant effect on proliferation and viability of MDPC-23 after 48h(p<0.05). The positive cells were observed in non-coenyme $Q_{10}$ treatment group(group 2) in comparison with coenyme $Q_{10}$ pre-treatment group(group 1) by DCF-DA. The fluorescence positive cells showed 14.715(group 1) and 19.788(group 2) using image J system. Conclusions : TEGDMA induced cytotoxicity. The MDPC-23 cell death was associated with the increasing ROS. Coenyme $Q_{10}$ showed the antioxidant effects by decreasing ROS. This effects may contribute to the treatment of periodontal disease induced by TEGDMA after operation.

• Polymer(Korea)
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• v.31 no.6
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• pp.491-496
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• 2007

In the polymeric dental restorative composites, the resin matrix mainly contains 70 wt% 2,2-bis[4-(2-hydroxy-3-methacryloyloxy propoxy) phenyl] propane (Bis-GMA), as a base resin and 30 wt% triethylene glycol dimethacrylate (TEGDMA) as a diluent. Even though the viscosity of the resin matrix is rapidly decreased by adding TEGDMA, addition of TEGDMA to the Bis-GMA results in reduction in the mechanical properties and increase in the curing shrinkage of the dental composite. In order to fabricate dental composite exhibiting excellent properties by reducing TEGDMA content in the resin matrix, in this study, Bis-GMA derivatives, which do not contain hydroxyl groups, were used instead of Bis-GMA. The curing characteristics of Bis-GMA derivatives were similar with those of Bis-GMA, while the former exhibited lower viscosity and water absorption than the latter. Comparing the curing shrinkage of the dental composite containing Bis-GMA derivative with that prepared from Bis-GMA, the reduction in curing shrinkage was about 25%. Dental composites prepared from new resin matrices also exhibited low water uptake and better properties in mechanical strength.

• Journal of the Korean Chemical Society
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• v.64 no.2
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• pp.74-78
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• 2020

A push-pull conjugated dye (DCMP) was covalently immobilized on a silanized glass surface to produce a high sensitivity pH sensor film for operating in the acidic region. A pH-sensitive sensor film was prepared by photo-initiating copolymerization of a modified DCMP (DCMA), 2-hydroxyethyl methacrylate (HEMA) and triethylene glycol dimethacrylate on the silanized glass surface. The absorbance of the sensor film increased with increasing pH between pH 2.0 and 5.0, and the fluorescence intensity of the film also increased about 50 times with increasing pH in the same pH range. The sensor film was reversible and reproducible under acidic conditions. The sensor film showed a relatively short response time between 20-50 seconds and high selectivity for proton in the presence of various metal ions.

• Journal of Korean society of Dental Hygiene
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• v.19 no.2
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• pp.173-181
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• 2019

Objectives: The resin infiltration technique is a promising alternative therapy for arresting the early dental caries. However, there are very few reports on the safety and biocompatibility of this technique. We evaluated various properties of resin infiltrant (RI) based on a triethylene glycol dimethacrylate (TEGDMA).The water sorption (Wsp) and water solubility (Wsl) was assessed. Additionally, the cytotoxicity of RI against both animal and human fibroblast cell lines was investigated. Methods: The RI of the $Icon^{(R)}$, the first product developed for resin infiltration, is mainly composed of TEGDMA in the resin matrix. The Wsp and Wsl for the RI were measured in accordance with ISO 4049 specifications. Fourier-transform infrared spectroscopy (FTIR) was used for analyzing the polymerization before and after curing of RI. The cytotoxicity of RI against the mouse fibroblasts (L929) and human gingival fibroblasts (hTERT-hNOF) was evaluated using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and the data were analyzed using one-way analysis of variance. Results: Wsp and Wsl of the RI specimens were $53.37{\mu}g/mm^3$ and $10.6{\mu}g/mm^3$, respectively. FTIR analysis revealed a slightly higher degree of curing with longer irradiation time. The degree of conversion for RI was high (80.9%) after 40 seconds of light curing. There was a significant decrease in the viability of L929 and hTERT-hNOF cells at RI extraction solution concentrations above 50%, respectively, compared to that in the negative control (p< 0.05). Conclusions: Even though the RI exhibited positive effect on the early prevention of dental caries, the clinicians should also consider the toxicity of RI on periodontal tissues.