• Applied Chemistry for Engineering
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• v.25 no.4
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• pp.418-424
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• 2014

The improved thermal stability and anti-oxidation properties of Lyocell fiber were studied based on flame retardant treatment by using NaCl/$H_3PO_4$ solution. The optimized conditions of flame retardant treatment were studied on various maxing ratio of NaCl and $H_3PO_4$ and the mechanism was proposed through experimental results of thermal stability anti-oxidation. The IPDT (integral procedural decomposition temperature), LOI (limited oxygen index) and $E_a$ (activation energy) increased 23, 30 and 24% respectively via flame retardant treatment. It is noted that thermal stability and anti-oxidation improved based on char and carbon layer formation by dehydrogenation and dissociation of C-C bond resulting the hindrance of oxygen and heat energy into polymer resin. The optimized conditions for efficient flame retardant property of Lyocell fiber were provided using NaCl/$H_3PO_4$ solution and the mechanism was also studied based on experimental results such as IDT (initial decomposition temperature), IPDT, LOI and $E_a$.

• Clean Technology
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• v.17 no.3
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• pp.259-265
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• 2011

The textile industry is suffered from air pollution problems which must be resolved. In particular, white smoke and odor after the tenter process require abatement. The major air pollution problem in the textile industry occurs during the finishing stages, where various chemicals are used for coating the fabrics. Lubricating oils, plasticizers, and water repellent chemicals are the fabric treatment chemicals. The coated fabrics are cured by heating in tenter facility. In this process, most of air pollutants emitted into the air. White smoke is basically made up of tiny solid or liquid particles of VOCs less than one micron in size. The oil mist can be carried over long distance from their point of origin. The most effective method of removing odor from tenter process is to get rid of tiny oil mist at the emitted gas. For this reason, the full-scale EFC (Electric Fume Collector) of 700 CMM was tested for removing odorous substances emitted from tenter facility. As a result of this study, odor and white smoke can be eliminated effectively and quite large amounts of oil can be recovered.

• Elastomers and Composites
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• v.46 no.3
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• pp.195-203
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• 2011

Eco-friendly materials or bio-composites were made with poly(lactic acid) (PLA) as matrix polymer and kenaf fibers as filler. Also, acetylated kenaf fibers and compatibilizer were adopted in order to improve the interfacial adhesion between fiber and polymer. In this study, the effect of chemical modification and compatibilizer on the mechanical-viscoelastic and morphology properties of the bio-composites was discussed. The hydrophobic fibers by acetylation were known to show better interfacial bonding with the matrix polymer and resulted in improved performance and morphology. Viscoelastic property and glass transition temperature, however, were not nearly enhanced.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.3
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• pp.55-61
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• 1987

This study was carried out to investigate the changes in the pH, extractability of protein, ATPase activity of myofibrillar protein, myofibrillar fragmentation, freezing loss and drip loss during storage at $4^{\circ}C$ and $-20^{\circ}C$ in breast and leg muscle of spent-hen meat. pH values ill pectoral and leg muscle were lowest ell tile 1st day and 1st week during cold and frozen storage, respectively. The extractabilities of myofibrillar proteins were increased graduall during cold storage and were highest on the 1st week during frozen storage, The $Mg^{2+}-ATPase$ activities of myofibrillar proteins were highest on the 1st day and 1st week during cold and frozen storage, respectively. The myofibrillar fragmentations were greatly changed on the 1st day during cold storage and 1st week during frozen storage. Freezing losses and drip losses were increased gradually during frozen storage. pH values in breast muscle were lower than those of leg muscle, and the extractabilities, $Mg^{2+}-ATPase$ activities, fragmentations of myofibrillar proteins, and drip losses in breast muscle were higher than those of leg muscle during storage, but the patterns of the changes in both muscles were similar during storage.

• Polymer(Korea)
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• v.36 no.4
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• pp.531-535
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• 2012

Conductive polyaniline (PANI) nanofibers in UV-curable resin were used for a transparent conductive film. The emeraldine-salt PANI (ES-PANI) nanofibers were prepared by chemical oxidation polymerization of aniline, which could be changed into emeraldine-base PANI by dedoping. EB-PANI nanofibers as a precursor for conductive fillers were thereby transformed into re-dpoed PANI (rES-PANI) by dodecylbenzenesulfonic acid in the UV-curable resin solution. rES-PANI nanofibers have high conductivity and long-term stability in the solution without a defect of nanostructure. The resulting conductive resin solution was proved to be highly stable where no precipitation of rES-PANI fillers was observed over a period of 3 months. The transparent film was spin-casted on a poly(methyl methacrylate) sheet of thickness ca. $5{\mu}m$. A surface resistance of $6.5{\times}10^8{\Omega}/sq$ and transmittance at 550 nm of 91.1% were obtained for the film prepared with a concentration of 1.4 wt% rES-PANI nanofibers in the solution. This transformation process of rES-PANI from ES-PANI by dedoping-redoping can be an alternative method for the preparation of an antistatic protection film with controllable surface resistance and optical transparencies with the PANI concentration in UV-curable solution.

• Food Engineering Progress
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• v.22 no.4
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• pp.344-352
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• 2018

The effects of chemical compositions (protein, lipid, and dietary fiber) on the physical properties of dried biji powders were investigated. The raw biji was freeze-dried (control) and hot-air dried (untreated). The untreated biji was further defatted and deproteinated. The prepared biji powders were analyzed for the proximate composition, total dietary fiber (TDF), water absorption index (WAI), water solubility index (WSI), swelling power, solubility (including the quantification of soluble carbohydrate and protein fractions), and final viscosity (using a rapid visco analyzer). Control and untreated biji powders exhibited the similar chemical compositions. The defatted biji possessed higher TDF, although its protein content did not significantly differ for control and untreated ones. The deproteinated biji consisted mainly of TDF. WAI and swelling power increased in the order: deproteinated > defatted > control > untreated biji powders. WSI and solubility increased in the order: control > untreated > defatted > deproteinated biji powders. The similar patterns were observed for soluble carbohydrate and protein fractions. The deproteinated biji revealed the highest viscosity over applied temperatures, while the untreated one was lowest. Overall results suggested that the physical properties of the dried biji powder were reduced by protein and fat, but enhanced by dietary fiber.

• Journal of the Korea Concrete Institute
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• v.23 no.4
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• pp.441-448
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• 2011

In this study, experimental tests of chemical and autogenous shrinkage were performed to evaluate the early age shrinkage behaviors of ultra high performance cementitious composites (UHPCC) with various replacement ratios of silica fume (SF), shrinkage reducing agent (SRA), expansive admixture (EA), and superplasticizer (SP). Starting time of self-desiccation, was analyzed by comparing the setting times and the deviated point of chemical and autogenous shrinkage strains. The test results indicated that both SF and SRA augment the early age chemical shrinkage, whereas SP delays the hydration reaction between cement particles and water, and reduces chemical shrinkage. About 49% of autogenous shrinkage was depleted by synergetic effect of SRA and EA. The hardening of UHPCC was catalyzed by containing EA. Self-desiccation of UHPCC occurred prior to the initial setting due to the high volume fraction of fibers and low water-binder ratio (W/B).

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.1
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• pp.79-91
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• 2012

A curved fiber reinforced polymer (FRP) panel is produced with a certain width depending on allowances of manufacturing processes and facilities. An targeted arch-shaped structure could be built by sequential connection of series of the FRP panels. The connection manner between the FRP panels could be given by chemical treatment, mechanical treatment and hybrid method. Among those, the connection between the panels by chemical treatment is commonly adopted. Therefore, For an optimized design of the connected part between FRP pannels, a number of direct shear tests have been undertaken in terms of a number of parameters: surface treatment conditions, bonding materials, etc.. As results, surface grinding condition by sand paper or surface treatment by sand blasting appear properly acceptable methods, and epoxy and acryl resins are shown to be effective bonding materials for the purpose in this study.

• Journal of Chest Surgery
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• v.31 no.5
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• pp.549-551
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• 1998

Although dysphagia in patients with acute leukemia is usually related to reflux esophagitis, infectious esophagitis, chemotherapy1) and leukemic infiltration2), acute esophageal stricture resulting from chemotherapy in the patient with leukemia is very rare. A 40-year-old man with acute myelogenous leukemia was admitted for operation of esophageal stricture which was developed within 1 month of chemotherapy. An esophagectomy and esophagogastrostomy with pyloroplasty was carried out. Histology showed mucosal infiltration of mononuclear cells and transmural fibrosis involving submucosa and the muscle layer.

• Journal of Engineering Education Research
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• v.21 no.6
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• pp.99-107
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• 2018

The purpose of this study is to establish and propose educational vision of chemical engineering field in order to search for academic identity and future education direction in chemical engineering field. In order to achieve this research purpose, we investigate the literature and data on the vision, educational goals, and curriculum of the department of chemical engineering in domestic and foreign universities. We also analyze the SWOT of internal and external environmental factors respectively. The validity of the proposal was verified through delphi survey with delphi panels and the vision was developed by revising and improving upon the opinions of professionals. The vision is comprised of the value and mission of learning, the educational purpose, and the educational goal. The first stage is value and mission of chemical engineering. The educational purposes and the educational goals are divided into 'Department of Chemical Engineering' and 'Department of Chemical and Biological Engineering'. The application of the educational vision of chemical engineering field is as follows. First, we expect that the vision to be a valuable, philosophical, and theoretical basis for establishing educational objectives and goals in the field of chemical engineering. Hopefully, it will be used as a general education goal for the top-level education. Second, we hope that the vision will be used to develop customized vision, customized educational purpose, and educational goals that reflect the characteristics of region, departments, graduates, and educational needs in the field of chemical engineering. Finally, we hope that these results will be the starting point to discuss the educational vision in the department of chemical engineering.