• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.127.1-127.1
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• 2011

In this paper, ZnO:Al thin films with c-axis preferred orientation were prepared on Soda lime glass substrates by RF magnetron sputtering technique. AZO thin film were prepared in order to clarify optimum conditions for growth of the thin film depending upon process, and then by changing a number of deposition conditions and substrate temperature conditions variously, structural and electrical characteristics were measured. For the manufacture of the AZO were vapor-deposited in the named order. It is well-known that post-annealing is an important method to improve crystal quality. For the annealing process, the dislocation nd other defects arise in the material and adsorption/decomposition occurs. The XRD patterns of the AZO films deposited with grey theory prediction design, annealed in a vacuum ambient($2.0{\times}10-3$Torr)at temperatures of 200, 300, 400 and $500^{\circ}C$ for a period of 30min. The diffraction patterns of all the films show the AZO films had a hexagonal wurtzite structure with a preferential orientation along the c-axis perpendicular to the substrate surface. As can be seen, the (002)peak intensities of the AZO films became more intense and sharper when the annealing temperature increased. On the other hand, When the annealing temperature was $500^{\circ}C$ the peak intensity decreased. The surface morphologies and surface toughness of films were examined by atomic force microscopy(AFM, XE-100, PSIA). Electrical resistivity, Gall mobility and carrier concentration were measured by Hall effect measuring system (HL5500PC, Accent optical Technology, USA). The optical absorption spectra of films in the ultraviolet-visibleinfrared( UV-Vis-IR) region were recorder by the UV spectrophotometer(U-3501, Hitachi, Japan). The resistivity, carrier concentration, and Hall mobility of ZnS deposited on glass substrate as a function of post-annealing.

• Korean Journal of Community Nutrition
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• v.15 no.3
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• pp.329-341
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• 2010

The purpose of this study was to examine vegetable & fruit (V/F) intakes, beliefs and self-efficacy regarding V/F consumption, nutrition knowledge and eating behavior of elementary students. A survey was conducted to the 4th graders (n = 234) at two elementary schools in Guri, Kyunggi-do. About one-fourth of subjects were overweight or obese. Subjects had 4.2 servings of V/F a day, consuming 340.2 g of V/F. Girls consumed significantly more amounts of vegetables than boys (p < 0.05). Girls were more favorable regarding V/F consumption (p < 0.01), and believed more strongly on advantages of having V/F such as “good for skin” constipation prevention (p < 0.001) and cancer prevention (p < 0.05). Boys felt more strongly in disadvantages or barriers of eating V/F, including mother's cooking time constraints (p < 0.01), lack of past experience of eating V/F, and family members' disliking of V/F (p < 0.05). Girls felt more confident in eating V/F (p < 0.05) than boys; they also felt more confident in specific items of "eating fruits/salads instead of cookies/chips for snack" and "eating fruit juice/vegetable juice instead of soda"(p < 0.01). Subjects showed low level of nutrition knowledge, especially in items such as balanced meals, recommended servings of V/F and vitamin deficiency. Compared to boys, girls had more desirable eating behavior such as eating adequate amount of meals (p < 0.001), having a variety of foods, eating fruits daily, and having fatty foods less frequently (p < 0.05). Intakes of Ca and K were quite below the recommended level, while the intakes of protein, Na and vitamin A intake were much above the Dietary Reference Intakes (DRI) for 9-11 old children. Nutrient intakes expressed as %DRI was higher in girls for vitamin A (p < 0.01), energy and riboflavin (p < 0.05). High V/F consumption group (${\geq}5$ servings of V/F a day) compared to the counterparts showed higher self-efficacy and had better eating behaviors. Nutrition education for children should focus on increasing consumption of V/F, by helping them to increase self-efficacy for eating V/F and to recognize the benefits and reduce the barriers of eating V/F, especially in boys. It is also needed to provide nutrition information for balanced meals or increasing V/F consumption, and help the children to adopt desirable eating behavior.

• Journal of Korean Ophthalmic Optics Society
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• v.4 no.2
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• pp.123-128
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• 1999

This paper reports the preparation and characterization of colored coatings of $Al_2O_3$-CoO. Films of 25mol% CoO doped $Al_2O_3$, have been prepared on soda-lime-silica slide glasses by the sol-gel process from Al-alkoxide and Co-nitrate. The films have been characterized by a photospectroscopy and hardness tester. The color, spectral reflectance and spectral transmittance of the films was expressed in Lab color chart and on spectra plot. Microhardness of the films increased with increasing of the heating temperature. Transmittance and reflectance of the films decreased with increase of the heating temperature and coating times. The coating films showed various light-yellow, deep-yellow, greenish-yellow color as a function of the coating times and heating temperature.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.27-30
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• 2008

Purpose: This research is that $V_2O_5$ cathode's composition is possible in low temperature. Methods: Transparent in visible spectra range and crystallographically amorphous $V_2O_5$ thin films were prepared by simple vacuum thermal evaporation on soda-lime-silica slide glass substrate. After annealing at 100$^{\circ}C$, 150$^{\circ}C$ and 200$^{\circ}C$ for 10 minutes in air, the surface morphology and the fracture-cross section of the films were investigated by field emission - scanning electron microscope. Transmittance in visible spectra range and surface roughness of the films were analyzed by ultra violet - visible spectrophotometer and scanning probe microscope, respectively. Results: As the increase of annealing temperature from 100$^{\circ}C$ to 150$^{\circ}C$ and 200$^{\circ}C$, transmittance of the $V_2O_5$ films decreased. Optical properties will be fully discussed on the basis of the surface morphological results. Conclusions: Optical transmissivity was superior in case of 100$^{\circ}C$, and could make amorphous $V_2O_5$ thin film that surface quality of thin film did homogeneity.

• The Journal of Engineering Geology
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• v.10 no.1
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• pp.51-62
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• 2000

The $CO_2$-richrich water pumps or springs out at two sites (Sinchon and Kohran) consisting of Cretaceous sedimentary rocks in Kyungpook area. The water has been long known as its soda pop-liketaste and therapeutic effect against calcium deficit, stomach and skin troubles, etc. The water arecharacterized by a high $CO_2$ concentration $(P_{CO2}=0.29~l.01 atm)$ and electrical conductance (1,093~2,810$\mu$S/cm). The $CO_2$-rich water belongs to Ca(Na)-$HCO_3$ type in chemical classification. The contents of Ca, Mg, Na, HCO$_3$ and Fe of $CO_2$-rich water show much higher values than those of general groundwater Environmental isotopic data $(^2H/^1H, ^{18}O/^{16}O and ^3H/^1H)$ indicate that the water is ofmeteoric origin recharged after 1950s. The $CO_2$ in the springs seems to be originated from deep-seatedsource related to acidic porphyry and granite nearby sedimentary rocks. Carbonate minerals and albiteare likely to be the major source minerals of the dissoved inorganic constituents in the $CO_2$-rich water.The equilibrium state between major minerals and $CO_2$-rich water was calculated by a thermodynamicprogram.

• Journal of The Korean Association For Science Education
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• v.35 no.4
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• pp.537-548
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• 2015

This study aims to identify and compare the patterns of scientific questions generation among elementary science-gifted and general students when conducting observational tasks. The pattern in generating scientific questions, which is distinguished from other types of scientific questions, is the manner that students generate a variety of types of questions in an inquiry process. To analyze the patterns in generating scientific questions, the task of observing dry grapes in soda pop, candlelight, and dyed celery were selected as suitable tasks. The subjects were 26 science-gifted students participating in a gifted education program and 27 general students in an elementary school in the same city. They were all sixth graders. The results of this study are as follows: First, the patterns of scientific questions generation among gifted students and general students during observational tasks were classified into five patterns: [Pattern 1] single, [Pattern 2] sequential, [Pattern 3] repetitive, [Pattern 4] circulative, [Pattern 5] repetitive, and circulative. Second, gifted students and general students presented all of the five patterns, but the frequency of the patterns indicated differences between the two groups. The gifted students primarily presented [Pattern 3] and [Pattern 5]. On the other hand, the general students mainly presented [Pattern 1], [Pattern 2], and [Pattern 3]. These results suggest that the ways of generating scientific questions are very much as important as the types of questions. Teachers can establish teaching-learning strategies for generating scientific questions appropriate to learner's characteristics.

• Advances in environmental research
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• v.6 no.3
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• pp.159-171
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• 2017

A successful oil well drilling depends largely on a good mud Program. During drilling, mud provides sufficient hydrostatic pressure, removes drill cuttings and cools drill bits. Mud additives are always required to provide sufficient hydrostatic pressure to ensure borehole stability. Barium Sulphate ($BaSO_4$) also known as barite is the prevalent weighting material but there is needed to develop local materials to augment the use of Barite. The present search is concerned on the early Carboniferous succession exposed in Um Bogma Formation, west central Sinai, Egypt as a new weighting agent in drilling fluids. The increases in the cost of drilling fluids and a shortage of using barite have introduced the locale dolomite as alternative weighting materials. The rheological properties of mud drilling samples weighted by local dolomite samples are being examined and investigated to know its potential to be used as a weighting material in drilling mud. Two mud samples were prepared which comprised of fresh water, caustic soda, bentonite and the weighting material. The weighting materials are added to achieve the required density. The first sample: Water-based mud with commercial barite of density between 10.00 lb/gm and 18.00 lb/gm. The second sample: Water-based mud with dolomite of density between 10.00 lb/gm and 18.00 lb/gm. These samples were analyzed and the density, rheological properties, aging of barite and dolomite and solid contents were investigated. At 10.00 lb/gm, the yield point of dolomite was $20.00lb/100ft^2$ and barite $22.00lb/100ft^2$ while the 10 second gel strength of dolomite was $30.00lb/100ft^2$ and $22.00lb/100ft^2$ for barite. Similarly, little difference was observed in plastic and apparent viscosities. At 10.00 lb/gm, the plastic and apparent viscosities of dolomite were 8.00 cp and 20.00 cp while barite was 8.00 cp and 24.00 cp. The result show that dolomite mud sample gave a little higher yield point and gel strength than barite mud sample. Therefore, dolomite has the potential to be used as weighting material in drilling mud in place of barite thereby enhancing the local content initiative of the government. When dolomite is sourced locally and used it will reduce overall mud and drilling costs.

• Journal of the Mineralogical Society of Korea
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• v.22 no.2
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• pp.107-114
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• 2009

In present study, an alternative process for manufacturing ultra marine blue by using kaolin, sulfur, sodium carbonate, silica, and rosin was investigated. From the experiments, it was found in the reductive calcination process that the temperature variation with the bed height of input materials is relatively high due to the inadequate thermal conductivity of them. It was also found that the color of the ultramarine blue manufactured is sensitive for the shape of the input materials and the calcinations conditions, and specially the heating rate is very important to form ultramarine. For manufacturing green ultramarine by using sulfur, sodium carbonate, silicon, and pine resin, an optimum condition was investigated to be the heating rate region below $0.6^{\circ}C/min$, the reaction temperature of $850^{\circ}C$ and the reaction time of 4 hr. At the oxidative calcination process to manufacture ultra marine blue from green ultramarine, the optimum flow rate of air is $500{\sim}550\;{\ell}/kg$ (green ultramarine) and the reaction temperature is $500{\sim}550^{\circ}C$.

• The Korean Journal of Quaternary Research
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• v.24 no.1
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• pp.11-24
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• 2010

Seongnyu Cave have developed along the NE-SW direction in carbonate rocks of the Joseon Supergroup. The cave mostly shows horizontal passages and contains three lakes. The main passage is about 330 m long with 540 m-long branches, thus the total length of the cave is about 870 m. Through cave diving, about 85 m-long new passages were discovered. Numerous speleothems such as soda straws, stalactites, stalagmites, columns, flowstones, rimstones, cave shields, cave corals, curtains (and bacon sheets), cave pearls, cave flowers, helictites and calcite rafts can be found in the cave. Especially, some speleothems which were believed to have grown in the past were discovered in the submerged passage, and a few stalactites, stalagmites, flowstones and columns were eroded (or corroded) by the cave stream that flowed on the floor. Because these speleothems only grow in subaerial environments within limestone caves, it appears that they grew when there was no lake in the cave and became submerged as the lake level rose in the cave. The presence of these speleothems in the lakes indicate that they only grew during glacial periods when sea-level was lower. Therefore, detailed investigation of these speleothems will provide invaluable information on paleoclimatic evolution around the Korean peninsula in the future.

• Korean Journal of Community Nutrition
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• v.21 no.3
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• pp.274-283
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• 2016

Objectives: The purpose of the study was to examine dietary life characteristics such as knowledge, self-efficacy and dietary behavior of preschoolers in Namyangju, Kyunggi-province, Korea. Methods: The survey questionnaire was developed based on literature review. Preschoolers aged 4-5 years (n=208) responded to the questionnaire to measure knowledge, self-efficacy, food preference, and dietary behavior. After excluding incomplete responses, the data of 197 subjects were used for analysis. Results: Mean score of dietary life knowledge was 8.0 out of 12, showing a low level of knowledge. Two out of 12 knowledge items were significantly different by gender. Percentage of correct answer on items of 'foods to make bones strong' and 'kinds of fast foods' was higher in girls than in boys (p<0.05). Total score of self-efficacy regarding dietary life was 40.1 (possible score: 12~48), on average. Compared to girls, boys had more confidence in 'not over-eating', and 'eating balanced meals with meat, fish and vegetables' (p<0.05). Boys scored higher on total score of food preference than girls (p<0.01). The preference for fruits was quite high. Among food items, boys scored higher on the preference for rice (p<0.01), fish (p<0.01), pork (p<0.05), beef (p<0.05), milk (p<0.01), and ice cream (p<0.05) than girls. Boys also liked fast foods more than girls did, showing preference for chicken (p<0.01) and soda (p<0.05). Compared to girls, boys showed more desirable behavior in 'eating breakfast everyday' (p<0.01). Dietary behavior was significantly correlated with self-efficacy (r=0.52, p<0.01), food preference (r=0.35, p<0.01), and knowledge (r=0.25, p<0.01) of subjects. Conclusions: In this study, we observed differences in food preference by gender. Dietary behavior of preschoolers was correlated with several factors, including dietary life related knowledge, self-efficacy and food preference. Thus, it is needed to develop nutrition education programs focusing on increasing dietary life related knowledge and self-efficacy, and consider the differences in food preference of preschoolers by gender.