• Textile Coloration and Finishing
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• v.27 no.2
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• pp.149-154
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• 2015

To investigate the biodegradation of the cellulose powder(CP) derived from Styela clava tunics(SCT), some physico-chemical properties and biodegradability of SCT-CP were measured after the incubation for 45 days. The particles size of SCT-CP prepared with washing, bleaching, drying, and grinding processes was $150-400{\mu}m$ although most of particles (70%) was more than $400{\mu}m$. The cellulose structures of SCT-CP detected using the X-ray diffraction and DSC analysis was very similar with that of wood pulp powder(WP-CP). The glass transition temperature was not detected in both samples. Furthermore, more than 90% of the SCT-CP was degraded, whereas only over 70% of the WP-CP was degraded after the incubation for 45 days. Therefore, these results suggest the possibility that SCT-CP is particularly applicable to prepare medical fiber and film for disease treatment.

• Environmental Analysis Health and Toxicology
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• v.22 no.1 s.56
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• pp.27-36
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• 2007

Cyanides and dichlorophenols were important pollutants in industrial effluents of steel, petroleum, plastics, pesticides, synthetic dye and/or fiber manufacturing. The toxic effects of cyanide and 3, 5-dichlorophenol in the unary and binary solutions to Vibrio fischeri were determined using the newly developed $N-tox^{(R)}$ bioassay system. This bioassay system relies upon the attenuation of light intensity emitted by Vibrio fischeri exposed to various pollutants including metals and organic compounds. Most of studies dealing with toxicity of pollutants concerned single chemical species, while the organisms were typically exposed to pollutant mixtures. The present study showed that the toxicity of some binary combinations of cyanide and 3, 5-dichlorophenol significantly was lower than the predicted toxicity from the addicted model. This antagonistic interaction was well explained by chemical interaction model presented in this study.

• Journal of Korean Tunnelling and Underground Space Association
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• v.7 no.3
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• pp.187-195
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• 2005

When a tunnel is excavated below groundwater table, the groundwater flow occurs towards the tunnel resulting in the seepage pressure. In this paper, the effect of groundwater flows on the behavior of shotcrete lining installed between ground-liner interfaces was studied considering permeability ratio between the ground and the shotcrete into account. Three-dimensional coupled finite element analysis was performed for this assessment. Seepage forces will seriously affect the shotcrete behavior since arching phenomena do not occur in seepage forces. A parametric study was conducted on the various tunnelling situations including interfacial properties between ground and shotcrete lining, the shape of tunnel cross-section and the thickness of liner, etc. Moreover, the convergence-confinement method (CCM) of a NATM tunnel considering seepage forces was proposed. The result showed that the more water tight is the shotcrete, the smaller is the convergence and the larger is the internal pressure. Therefore, the watertight fiber-reinforced shotcrete is found to be even more advantageous when used in under water tunnel.

• Environmental Analysis Health and Toxicology
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• v.22 no.2 s.57
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• pp.119-128
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• 2007

The present study was conducted to find out effect of PFOS on survival, activity, growth and organ structure of the melania snail, Semisulcospira gottschei. Experimental groups were composed of one control condition and four PFOS exposure condition (0.1, 0.5, 1.0 and 5.0 mg/L). After 16 week exposure, survival rate and activity were not significantly influenced at the two lower exposure groups, 0.1 and 0.5 mg/L, but they were significantly reduced in 1.0 and 5.0 mg/L groups. Total weight and meat weight rate (MWR) were reduced in PFOS exposure group in comparison to control group. Also, histological degenerations such as acidification of mucous, necrosis and split of muscular fiber bundle, atrophy of anterior pedal gland were recognized in the foot. Hepatopancreas showed the atrophy and degeneration of the digestive cell, vacuolation of digestive gland and closure of lumen in digestive gland.

• Journal of Conservation Science
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• v.35 no.5
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• pp.385-391
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• 2019

In order to examine the material characteristics of a black and white photograph of the Borobudur temple, in Indonesia, several analyses were conducted. A sample was taken from a black and white photograph; microscopy, Fourier transform-infrared spectroscopy, scanning electron microscopy/energy dispersive spectroscopy, X-ray diffraction, and X-ray fluorescence analyses showed that the black and white photograph was composed of four layers including a paper substrate, baryta, binder and surface layers. It was confirmed that the substrate was paper made of cellulose fiber from Cannabis sativa, the baryta layer was made of barium sulfate(BaSO₄) in powder form, the binder was an emulsion containing silver halide, and the surface protective layer was made of gelatin. Since photographs have different characteristics and require different preservation environments depending on the material of construction, it is necessary to study various black and white photographic material characteristics corresponding to each time period.

• The Journal of the Korea Contents Association
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• v.15 no.8
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• pp.397-407
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• 2015

Concrete is a attractive construction material, however durability problem occur due to steel corrosion, which leads propagation to structural safety problem. The recently developed FRP (Fiber Reinforced Plastic) Hybrid Bar has an engineering merit of both structural steel and FRP. Accelerated corrosion test for RC (Reinforced Concrete) samples with normal steel and FRP Hybriud Bar are performed and their flexural capacity is evaluated. Furthermore UV(Ultrasonic Velocity) measurement is attempted for analysis of variation of UV due to corrosion condition. After corrosion test, there is no significant reduction in RC beam with FRP hybrid bar but 11.5% of reduction in the case of normal steel is evaluated with 3.3% of UV reduction. For commercial production of FRP hybrid bar, bond strength evaluation through long-term submerged corrosion is required.

• Nutritional Sciences
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• v.2 no.2
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• pp.71-75
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• 1999

Epidemiologic studies consistently demonstrate an inverse relationship between risk for colon canter and consumption of fruits and vegetables. Wheat bran, flax and soy contain dietary fiber and phytochemicals, such as lignans and isoflavones, that may inhibit colon carcinogenesis. Orange juice contains hesperidin, a flavanone glucoside that protects against colon carcinogenesis. This study determined if feeding orange juice, wheat bran, soy and flaxseed (combined diet) would inhibit azoxymethane (AOM) induced colon cancer. Cancer was initiated in male Fisher 344 rats by injecting 15 mg AOM/kg of weight at 22 and 29 days of age. One week after the second AOM injection, rats (N = 30) in the combined diet group received dry diet containing wheat bran (4%), soy with ethanol soluble phytochemirals(13%) and flaxseed (8%) and orange juice replaced drinking water. The control group remained on the control diet and received distilled water to drink. The rats were killed 28 weeks later, and colon tissues and tumors were removed for histologic analysis. Feeding the combined diet significantly reduced tumor incidence (p < 0.05), however tumor multiplicity was not changed (p > 0.05, 0.9 tumors/rat fed the combined diet vs 1.2 for controls). Also, tumor burden was only marginally reduced in rats fed the combined diet vs control rats (65 vs 210 mg of tumor/rats, respectively). The reduction in tumor incidence was associated with a decreased labeling index and proliferation zone in normal appearing colon mucosa. Therefore, this study shows that phytochemicals in wheat bran, soy, flax and orange juice reduce colon carcinogenesis, presumably by decreasing cell proliferation and enhancing cell differentiation.

• Nutrition Research and Practice
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• v.10 no.4
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• pp.433-441
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• 2016

BACKGROUND/OBJECTIVES: The purpose of this study was to develop a dish-based semiquantitative food frequency questionnaire (FFQ) for Korean adolescents and evaluate its reproducibility and validity. SUBJECTS/METHODS: Based on 24-hour dietary recall data from the 4th Korean National Health and Nutrition Examination Survey (KNHANES), we developed a FFQ with 71 items. From a quota sample of 160 adolescents recruited using gender and age group as stratification variables, 153 participated in the complete data collection process. The FFQ was administered to each subject twice, at an interval of 3-4 weeks, to evaluate the test-retest reliability. The validity of the FFQ was assessed relative to 8-day food record data. RESULTS: The study findings demonstrated the FFQ's satisfactory reproducibility. Spearman correlation coefficients ranged from 0.64(for ${\beta}-carotene$) to 0.81(for protein). From cross-classification analyses, the proportion of subjects in the same intake quartile was highest for protein (65.4%) and lowest for vitamin A(47.1%). With regard to validity analysis, Spearman correlation coefficients ranged from 0.27(for vitamin A and fiber) to 0.90 (for energy). The proportions of subjects in the opposite categories between the first FFQ and the 8-day food record data were generally low within the range from 0.74% (for energy and carbohydrate) to 13.2% (for ${\beta}-carotene$). CONCLUSIONS: In conclusion, the dish-based semiquantitative FFQ developed in this study can be useful for grouping Korean adolescents according to major macro- and micronutrient intakes with reasonable reproducibility and validity.

• Journal of Nutrition and Health
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• v.44 no.3
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• pp.203-211
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• 2011

Previous studies have shown that plant-based vegetarian diets, which typically contain a variety of antioxidants and dietary fiber, help reduce the risk of heart disease, diabetes, obesity, and cancer. However, some studies have reported that vegetarian diets can lead to deficiencies in protein and trace minerals compared to non-vegetarian diets. This study was conducted to compare anthropometric measurements, blood parameters, dietary intake, and hair mineral status in long-term vegetarians (MV; moderate vegan, LV; lacto-ovo vegetarian) and non-vegetarians (NV). Thirty MV (12 males, 18 females; mean age, $50.58{\pm}5.05$ years), 15 LV (11 males, four females; mean age, $49.45{\pm}4.97$ years), and 30 NV (15 males, 15 females; mean age, $48.90{\pm}3.62$ years) participated. No significant differences were observed for age, height, weight, or body mass index, but body fat was significant lower in MV and LV males than that in NV males. White blood cell counts of MV, LV, and NV male subjects were significantly different. Dietary intake data showed that plant protein and plant iron intake were significantly higher in MV and LV than those in NV. Animal protein, animal fat, and animal iron intake were significantly higher in NV than those in MV and LV. A hair mineral analysis showed that calcium and iron were higher in the hair of MV and LV than those in NV. Zinc concentration in hair was not significantly different among the groups. The results suggest that vegetarian diets are adequate to sustain mineral status to at least the same degree as that of non-vegetarian diets.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.426-434
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• 2010

This study is experimentally performed to evaluate the strength reduction behavior and its statistical properties of plain woven glass/epoxy composites. The results indicate that the major impact damage of plain woven glass/epoxy composites is the fiber breakage and matrix crack, whereas the dominant impact damage of unidirectional carbon/epoxy laminates is the delamination, which depends on the stacking sequence. The residual strength prediction models, previously proposed on unidirectional laminates, are applied to evaluate the residual strength of plain woven glass/epoxy composites with impact damage. Among these models, the results by Caprino and Avva's model have a good agreement with the experimental results. To investigate the variability of residual strength of the impacted composite materials, a statistical model was proposed and its results were in conformance with the experimental results regardless of their thickness.