• Economic and Environmental Geology
• /
• v.52 no.6
• /
• pp.627-635
• /
• 2019

Cement-asbestos slate is the main asbestos containing material. It is a product made by combining 10~20% of asbestos and cement components. Man- and weathering-induced degradation of the cement-asbestos slates makes them a source of dispersion of asbestos fibres and represents a priority cause of concern. When the asbestos enters the human body, it causes cellular damage or deformation, and is not discharged well in vitro, and has been proven to cause diseases such as lung cancer, asbestos, malignant mesothelioma and pleural thickening. The International Agency for Research on Cancer (IARC) has designated asbestos as a group 1 carcinogen. Currently, most of these slats are disposed in a designated landfill, but the landfill capacity is approaching its limit, and there is a potential risk of exposure to the external environment even if it is land-filled. Therefore, this study aimed to exam the possibility of detoxification of asbestos-containing slate by using exothermic reaction and heat treatment. Cement-asbestos slate from the asbestos removal site was used for this experiment. Exothermic catalysts such as calcium chloride(CaCl₂), magnesium chloride(MgCl₂), sodium hydroxide(NaOH), sodium silicate(Na₂SiO₃), kaolin[Al₂Si₂O₅(OH)₄)], and talc[Mg₃Si₄O₁₀(OH)₂] were used. Six catalysts were applied to the cement-asbestos slate, respectively and then analyzed using TG-DTA. Based on the TG-DTA results, the heat treatment temperature for cement-asbestos slate transformation was determined at 750℃. XRD, SEM-EDS and TEM-EDS analyses were performed on the samples after the six catalysts applied to the slate and heat-treated at 750℃ for 2 hours. It was confirmed that chrysotile[Mg₃Si₂O₅(OH₅)] in the cement-asbestos slate was transformed into forsterite (Mg₂SiO₄) by catalysts and heat treatment. In addition, the change in the shape of minerals was observed by applying a physical force to the slate and the heat treated slate after coating catalysts. As a result, the chrysotile in the cement-asbestos slate maintained fibrous form, but the cement-asbestos slate after heat treatment of applying catalyst was broken into non-fibrous form. Therefore, this study shows the possibility to safely verify the complete transformation of asbestos minerals in this catalyst- and temperature-induced process.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.9
• /
• pp.1529-1536
• /
• 2004

This study was designed to determine total trans fatty acids (tFAs) content of processed foods commonly consumed in the Korean diet and to prepare the database for the estimation of tFAs intake in Koreans. Total fat and tFAs content was determined by Soxhlet extraction method and attenuated total reflection infrared spectroscopy (ATR-IR), respectively. The tFAs positional isomers were analyzed using GC/MS spectrometer. In margarines, the content of tFAs ranged from 8.27% to 28.53%. Shortenings contained higher levels of tFAs (1.98~11.33%) than lards (1.83~1.96%). The content of tFAs in grilled confectioneries was wide (7.37~26.54%). Instant popcorns contained the highest amount of tFAs. Fried chickens had 0.44 to 14.85% of tFAs and french fries had 5.18 to 27.01% of tFAs. In fried snacks (crispy) and chocolates, tFAs were not detected. The amount of tFAs per serving size was the highest in instant popcorn, followed by french fries, fried snack (tortilla), doughnuts, and grilled confectioneries. TFAs isomer of margarines was mostly C18:1${\Delta}$9t. In shortenings and lards, the most abundant positional isomer of tFAs was C18:1${\Delta}$9t and C18:2${\Delta}$9t ${\Delta}$12t. Correlation coefficient of tFAs content between IR and GC/MS method was $r^2$=0.91.

• Applied Microscopy
• /
• v.36 no.3
• /
• pp.141-153
• /
• 2006

The purpose of this study is to find out how soft contact lens multi-purpose solution (MPS), often used for medical treatment, effects the inhibition on cell growth and research the result of using MPS, suspected to demage eye cells, on rabbit eye's corneal epithelium and endothelium tissue. In this treatise, $ReNu^{(R)}$ (Baush & Lomb, USA), Opti-free $express^{(R)}$ (Alcon, USA), Free-sol $plus^{(R)}$ (Hanamedicon, Korea) had been selected among the MPS. After culturing L929 roil line, cell growth inhibition rate was measured by MTT assay, and by making Hematoxylin and Eosin stain specimen. the morphology was observed by optical microscope. In the In vivo experiment,9 white rabbit eyes (18 eyes) were classified into 3 groups. The experimental group is left eyes (9 eyes) of rabbit, and MPS were dropped; however. the control group, the right eyes (9 eyes), were only used a saline solution without preservatives. After the dropping within the period, the cornea surface of rabbit eyes were stained by Rose bengal and observed. To figure out the changes of the corneal epithelium and endothelium tissue scanning electron microscopy (SEM) has been used. As the result, the rate of cell growth inhibition was 54%. 73% and 36%, respectively. Morphological changes represented that the shape has been changed into oval or round shape and those are not considered as a common formation of L929 cell line. When it comes to staining Rose bengal, each experiment group was stained red which is not shown in controls. The polygonal mosaic pattern of a corneal epithelium was disturbed in the picture taken by SEM; furthermore, the shape of the corneal endothelium was irregular. In conclusion, as we consider antimicrobial effect and the safety on living cells, it is necessary that we should improve concentration of preservatives and study continuously to develop a new preservatives without a toxic effect on the cornea surface.

• Food Science and Preservation
• /
• v.21 no.1
• /
• pp.82-90
• /
• 2014

This study was conducted in order to analyze the polyphenol contents and antioxidant activities of hot-water extracts of Aster scaber in the wild field and cultivated field, and through the drying methods for the comparison on the quality characteristics of Aster scaber, according to cultivation and drying methods, and the development of functional materials. The extraction yield was higher in the Aster scaber cultivated field than those of the Aster scaber in the wild field, and high from the dried Aster scaber. The total polyphenol and flavonoid contents of Aster scaber hot-water extracts from the wild field were higher than those in the cultivated field. The total polyphenol contents were high in the extract of blanched and dried Aster scaber, and the flavonoid content was high in the non-treated Aster scaber. The electron donating ability (EDA) values of Aster scaber hot-water extracts were increased along with the increase of extract concentration, while the EDA of the blanched and dried Aster scaber extracts was higher than the other extracts. Furthermore, the SOD-like activity was increased by the extract concentration, and was high in the extract of the non-treated Aster scaber. The nitrite scavenging ability in pH 1.2 was high in the non-treated, blanched, dried, and natural dried Aster scaber. The xanthine oxidase inhibitory activities were increased through the increase of extract concentrations, and higher in the hot-water extract from Aster scaber in the wild field (WRA) than those in the other extracts. The inhibition of tyrosinase and reduction of power were increased by the increased extract concentration, and high in the extracts of blanched and dried Aster scaber. The reduced power was higher in the Aster scaber hot-water extracts of cultivated field, and was higher in the extracts of blanched and dried Aster scaber than those in the extracts dried through the use of other drying methods. Aster scaber has a high content of polyphenol and flavonoid, and antioxidant activities, which were developed as functional materials.

• Food Science and Preservation
• /
• v.21 no.2
• /
• pp.264-275
• /
• 2014

This study evaluated the improving efficacy of Lespedeza cuneata ethanol extract on skin photoaging induced by ultraviolet (UV) irradiation. The total polyphenol and flavonoid contents of the extract were respectively $134.98{\pm}1.70$ and $16.20{\pm}0.05$ mg/g, respectively. The superoxide anion radical scavenging activity and electron-donating ability of the extract were shown to be dependent on concentration, and the antioxidant ability was shown to be more effective in superoxide anion radical scavenging activity than in electron-donating ability under the same concentration conditions. In the in vivo test conducted using hairless mouse with skin photoaging induced by UVB irradiation, the skin erythema of the groups treated with the extract (AS) reduced to 28% of the control, and the skin moisture content increased to 131%.. The extract treatment of the UV-damaged skin improved the morphological and histopathological state of the skin. Furthermore, the SOD, GST and CAT activities in the skin tissue of the AS group increased, and the XO activity and TBARS generation decreased. With regard to the genes related to the photoaging skin, the expression of PAK, p38, c-Fos, c-Jun, TNF-${\alpha}$ and MMP-3 in the skin of the AS group were found to have decreased. It was therefore concluded that Lespedeza cuneata ethanol extract can reduce wrinkle formation in the skin due to the regulation of the gene expression caused by the exposure to UVB light.

• Korean Business Review
• /
• v.17 no.2
• /
• pp.63-87
• /
• 2004

To create and maintain comparative supremacy as a strategic tool of business, many organizations have introduced informational technology and system. By using this system, Some companies got a beneficial value for achieving organizational goals but others could not obtain their effectiveness and efficiency. In particular, a lot of organizations that tried to make strategic supremacy with e-commercial trade are under hard condition because of poor profit. It implies that it is essential to identify and analyse the consumer who uses e-commercial trade. This paper, therefore, focusing on internet shopping malls between business and consumer as one of areas of e-commercial trades, shows the difference between consumer expectation and performance. The results of this study are as follows: First, as for the significant difference of influencing factors to consumer satisfactions according to the types of internet shopping malls, there is a meaningful difference in consumer anxiety and internet usefulness, but not in consumer service. Prior to verify the differences in detail on consumer's anxiety and internet usefulness, we examined that there is any difference between expectation and performance. T-test was used for the variants of consumer anxiety and internet usefulness, and its meaningful probability was 0.000, which means that both showed statistically significant difference. Based on the results, we also found that regardless of the types of internet shopping malls, consumer expectation was greater than performance. although the difference between expectation and performance was not equal according to the internet shopping malls. Second, a regression analysis was performed to understand the relation between consumer service, internet usefulness, consumer anxiety, and consumer satisfaction, it was found that consumer service, internet usefulness, consumer anxiety had significantly effected on consumer satisfaction. Third, To verify the relation between consumer satisfaction and repurchase-intentions, intentions to spread out, Pearson correlation analysis was used. it was found that consumer satisfaction had positive effect on both intentions. This study has some limitations because of the shorts of money and time. since the sample of this study was consumers who have ever bought one or more products via internet shopping mall, this sample was appropriate. but the major parts of sample were college students, and the sample size was so small. therefore this results should carefully be generalized. For further study, it is required to select more precise samples and to include more variables.

• Journal of Life Science
• /
• v.18 no.4
• /
• pp.474-481
• /
• 2008

This research was performed to determine the proximate compositions, mineral contents, alginic acid, antioxidative activities and amino acids of sea tangles collected from Gijang and Wando area. Crude protein and ash contents were higher in Gijang sea tangle, whereas carbohydrate and moisture were higher in Wando in general. Mineral contents of Gijang sea tangle were higher than Wando. Especially, Na and K was the most abundant in both Gijang and Wando sea tangles. Alginic acid content was almost similar in both sea tangles. The major free amino acids were glutamic acid, aspartic acid, alanine, proline and hydroxyproline in both Gijang and Wando sea tangles. Antioxidative activity of methanol extract of sea tangle was measured by using DPPH radical scavenging and SOD-like activity. DPPH radical scavenging and SOD-like activity were about 17% ($40\;{\mu}g/ml$) and 7% ($5\;{\mu}g/ml$) higher, respectively, in Wando sea tangle. When stimulate the macrophages RAW264.7 cells with lipopolysaccharide (LPS), inhibition of NO synthesis of the methanol extract was 11% higher in Wando sea tangle comparing with Gijang samples.

• Food Science and Preservation
• /
• v.19 no.6
• /
• pp.909-918
• /
• 2012

The phenolic compounds which were extracted with 70% ethanol from Ulmus pumila for 12 hr were the highest as $17.9{\pm}1.0\;mg/g$. DPPH scavenging activity of 70% ethanol extracts was also the highest as $89.5{\pm}1.9%$ and it was confirmed to be high as 80% over in both of water and 70% ethanol extracts containing $50{\mu}g/mL$ over phenolic concentration. ABTS radical cation decolorization activities of water and 70% ethanol extracts were higher as $96.8{\pm}2.9%$, antioxidant protection factor (PF) was 2.0 PF in 70% ethanol and showed higher activities in both of water and 70% ethanol extracts containing $200{\mu}g/mL$ phenolic concentration as 2.5 PF than BHA. TBARs of 70% ethanol extracts was $86.5{\pm}4.6%$, it showed high anti-oxidative activity in $50{\sim}200{\mu}g/mL$ phenolic concentrations of water and 70% ethanol extracts as 80% over. The angiotensin converting enzyme (ACE) inhibitory activity of Ulmus pumila extracts against hypertension was 77.4% and 90.6% in water and 70% ethanol extracts of $200{\mu}g/mL$ phenolic concentration. Xanthine oxidase inhibitory activity of Ulmus pumila extracts for anti-gout effect was not observed in water extracts, but it showed 30% inhibitory activity in 70% ethanol extracts, and 48.1% at $200{\mu}g/mL$ phenolics concentration.

• Journal of IKEEE
• /
• v.27 no.1
• /
• pp.122-126
• /
• 2023

In this paper, a control system for a complex microbial incubator was proposed. The proposed control system consists of a control unit, a communication unit, a power supply unit, and a control system of the complex microbial incubator. The controller of the complex microbial incubator is designed and manufactured to convert analog signals and digital signals, and control signals of sensors such as displays using LCD panels, water level sensors, temperature sensors, and pH concentration sensors. The water level sensor used is designed and manufactured to enable accurate water level measurement by using the IR laser method with excellent linearity in order to solve the problem that existing water level sensors are difficult to measure due to foreign substances such as bubbles. The temperature sensor is designed and used so that it has high accuracy and no cumulative resistance error by measuring using the thermal resistance principle. The communication unit consists of two LAN ports and one RS-232 port, and is designed and manufactured to transmit signals such as LCD panel, PCT panel, and load cell controller used in the complex microbial incubator to the control unit. The power supply unit is designed and manufactured to supply power by configuring it with three voltage supply terminals such as 24V, 12V and 5V so that the control unit and communication unit can operate smoothly. The control system of the complex microbial incubator uses PLC to control sensor values such as pH concentration sensor, temperature sensor, and water level sensor, and the operation of circulation pump, circulation valve, rotary pump, and inverter load cell used for cultivation. In order to evaluate the performance of the control system of the proposed complex microbial incubator, the result of the experiment conducted by the accredited certification body showed that the range of water level measurement sensitivity was -0.41mm~1.59mm, and the range of change in water temperature was ±0.41℃, which is currently commercially available. It was confirmed that the product operates with better performance than the performance of the products. Therefore, the effectiveness of the control system of the complex microbial incubator proposed in this paper was demonstrated.

• Journal of Intelligence and Information Systems
• /
• v.24 no.2
• /
• pp.85-109
• /
• 2018

Recommender system recommends the items expected to be purchased by a customer in the future according to his or her previous purchase behaviors. It has been served as a tool for realizing one-to-one personalization for an e-commerce service company. Traditional recommender systems, especially the recommender systems based on collaborative filtering (CF), which is the most popular recommendation algorithm in both academy and industry, are designed to generate the items list for recommendation by using 'overall rating' - a single criterion. However, it has critical limitations in understanding the customers' preferences in detail. Recently, to mitigate these limitations, some leading e-commerce companies have begun to get feedback from their customers in a form of 'multicritera ratings'. Multicriteria ratings enable the companies to understand their customers' preferences from the multidimensional viewpoints. Moreover, it is easy to handle and analyze the multidimensional ratings because they are quantitative. But, the recommendation using multicritera ratings also has limitation that it may omit detail information on a user's preference because it only considers three-to-five predetermined criteria in most cases. Under this background, this study proposes a novel hybrid recommendation system, which selectively uses the results from 'traditional CF' and 'CF using multicriteria ratings'. Our proposed system is based on the premise that some people have holistic preference scheme, whereas others have composite preference scheme. Thus, our system is designed to use traditional CF using overall rating for the users with holistic preference, and to use CF using multicriteria ratings for the users with composite preference. To validate the usefulness of the proposed system, we applied it to a real-world dataset regarding the recommendation for POI (point-of-interests). Providing personalized POI recommendation is getting more attentions as the popularity of the location-based services such as Yelp and Foursquare increases. The dataset was collected from university students via a Web-based online survey system. Using the survey system, we collected the overall ratings as well as the ratings for each criterion for 48 POIs that are located near K university in Seoul, South Korea. The criteria include 'food or taste', 'price' and 'service or mood'. As a result, we obtain 2,878 valid ratings from 112 users. Among 48 items, 38 items (80%) are used as training dataset, and the remaining 10 items (20%) are used as validation dataset. To examine the effectiveness of the proposed system (i.e. hybrid selective model), we compared its performance to the performances of two comparison models - the traditional CF and the CF with multicriteria ratings. The performances of recommender systems were evaluated by using two metrics - average MAE(mean absolute error) and precision-in-top-N. Precision-in-top-N represents the percentage of truly high overall ratings among those that the model predicted would be the N most relevant items for each user. The experimental system was developed using Microsoft Visual Basic for Applications (VBA). The experimental results showed that our proposed system (avg. MAE = 0.584) outperformed traditional CF (avg. MAE = 0.591) as well as multicriteria CF (avg. AVE = 0.608). We also found that multicriteria CF showed worse performance compared to traditional CF in our data set, which is contradictory to the results in the most previous studies. This result supports the premise of our study that people have two different types of preference schemes - holistic and composite. Besides MAE, the proposed system outperformed all the comparison models in precision-in-top-3, precision-in-top-5, and precision-in-top-7. The results from the paired samples t-test presented that our proposed system outperformed traditional CF with 10% statistical significance level, and multicriteria CF with 1% statistical significance level from the perspective of average MAE. The proposed system sheds light on how to understand and utilize user's preference schemes in recommender systems domain.