• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.920-926
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• 2011

In this paper, a solar power emotional LED lightening street lamps with multi control sun tracker is presented. The proposed system has a multiple control sun tracking function and high quality emotional LED lamps. The system is designed to absorb maximum sun lights by temperature sensor and humidity sensor of control circuits. A battery charge-discharge controller is developed for high efficient usage of battery charger for utilization of new and renewal energy. An interface circuit for remote monitoring and controlling is included in the developed system. The proposed multi tracking solar power emotional LED street lamps is better than conventional systems in aspect of tracking operation and energy efficiency, and expected to be a leading model for next generation solar power street lamp system, because it is a new technology combining sun tracking solar power system and emotional lightening system.

• Korean Journal of Metals and Materials
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• v.56 no.12
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• pp.910-914
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• 2018

Since catalyst technology is one of the promising technologies to improve the working performance of next generation energy and electronic devices, many efforts have been made to develop various catalysts with high efficiency at a low cost. However, there are remaining challenges to be resolved in order to use the suggested catalytic materials, such as platinum (Pt), gold (Au), and palladium (Pd), due to their poor cost-effectiveness for device applications. In this study, to overcome these challenges, we suggest a useful method to increase the surface area of a noble metal catalyst material, resulting in a reduction of the total amount of catalyst usage. By employing block copolymer (BCP) self-assembly and nano-transfer printing (n-TP) processes, we successfully fabricated sub-20 nm Pt line and cross-bar patterns. Furthermore, we obtained a highly ordered Pt cross-bar pattern on a Ni thin film and a Pt-embedded Ni thin film, which can be used as hetero hybrid alloy catalyst structure. For a detailed analysis of the hybrid catalytic material, we used scanning electron microscope (SEM), transmission electron microscope (TEM) and energy-dispersive X-ray spectroscopy (EDS), which revealed a well-defined nanoporous Pt nanostructure on the Ni thin film. Based on these results, we expect that the successful hybridization of various catalytic nanostructures can be extended to other material systems and devices in the near future.

• Animal Bioscience
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• v.34 no.1
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• pp.36-47
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• 2021

Objective: This study determined the optimal ratio of whole plant corn silage (WPCS) to corn stover (stems+leaves) silage (CSS) (WPCS:CSS) to reach the greatest profit of dairy farmers and evaluated its consequences with corn available for other purposes, enteric methane production and milk nitrogen efficiency (MNE) at varying milk production levels. Methods: An optimization model was developed. Chemical composition, rumen undegradable protein and metabolizable energy (ME) of WPCS and CSS from 4 cultivars were determined to provide data for the model. Results: At production levels of 0, 10, 20, and 30 kg milk/cow/d, the WPCS:CSS to maximize the profit of dairy farmers was 16:84, 22:78, 44:56, and 88:12, respectively, and the land area needed to grow corn plants was 4.5, 31.4, 33.4, and 30.3 ha, respectively. The amount of corn available (ton DM/ha/yr) for other purposes saved from this land area decreased with higher producing cows. However, compared with high producing cows (30 kg/d milk), more low producing cows (10 kg/d milk) and more land area to grow corn and soybeans was needed to produce the same total amount of milk. Extra land is available to grow corn for a higher milk production, leading to more corn available for other purposes. Increasing ME content of CSS decreased the land area needed, increased the profit of dairy farms and provided more corn available for other purposes. At the optimal WPCS:CSS, MNE and enteric methane production was greater, but methane production per kg milk was lower, for high producing cows. Conclusion: The WPCS:CSS to maximize the profit for dairy farms increases with decreased milk production levels. At a fixed total amount of milk being produced, high producing cows increase corn available for other purposes. At the optimal WPCS:CSS, methane emission intensity is smaller and MNE is greater for high producing cows.

• Korean Journal of Community Nutrition
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• v.21 no.2
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• pp.190-199
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• 2016

Objectives: The purpose of this study was to identify the differences in nutrient intake according to using diuretics, symptom severity and degree of physical functioning in heart failure patients. Methods: A secondary data analysis was conducted by using baseline data of an intervention study for heart failure patients. In this study, 131 heart failure patients were included. Data were collected using medical records, NYHA (New York Heart Association functional classification) class, and 6-minute-walking test and 24-hour diet recall. Data were analyzed using descriptive statistics and Chi-square test by SPSS 21.0. Nutrient intake was assessed using CAN-pro 2.0. Results: Majority of the participants consumed total calorie less than Estimated Energy Requirement (EER) and consumed carbohydrates more than 65% of their total calorie intakes. 24.4% of the participants consumed fat more than 30% of their total calorie intakes and 23.7% consumed saturated fat more than 7% of their total calorie intakes. 100.0% of the participants consumed protein less than 7% of their total calorie intakes and 73.3% of the participants consumed more than recommended intakes of sodium. More than 90.0% of the participants consumed less than adequate intakes of potassium (90.1%) and Vitamin D (91.6%), respectively. 100% and 62.6% of the participants consumed less than Estimated Average Requirement (EAR) of magnesium and Vitamin $B_1$, respectively. Nutrient intakes in heart failure patients were different for potassium intake according to the usage of diuretics. The participants with symptom severity tended to intake protein less properly and the participants walking more than 300.0 m tended to intake sodium improperly high. Conclusions: The findings of this study indicated the need for screening nutrient intakes of heart failure patients. It is necessary to increase the intake of total calories and most nutrients and to restrict sodium intakes among heart failure patients.

• Korean Journal of Construction Engineering and Management
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• v.18 no.1
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• pp.74-82
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• 2017

It is known that energy usage from Korean Universities was growing rapidly in the early 2000s. But since 2011, the change was caused by GHG emissions regulation enforced by the government. The purpose of this research was to find the characteristics and trends of greenhouse gas emissions from major universities in Korea according to the each university's data and information. The result shows that GHG emissions from University have increased steadily prior to enforcement by 4-5% annually, but the rate of increase marked 0.5~1% in 2011~2013 is the season of emission regulation and the total amount of emissions decreased 3%~5% in 2014~2015 while preparing an emissions trading scheme. Therefore we can say that the enforcement of GHG reduction such as energy target management system makes a visible effect at least in the University sector that level of GHG emissions is from $75kg/m^2$ to $58Kg/m^2$ for seven years. Another result says that the size of research fund is the main factor that affects the amount of GHG emissions before 2011, but the size of building area has been a new factor influencing the GHG emission since 2013. Thus we suggest that the criteria for evaluating the level of GHG emission from University is suitable if it is based on the building area intensity.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.271-277
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• 2021

In this study, experiments of local heating on crown and supplying warm nutrient for energy saving and improving growth of 'Seolhyang' strawberry were conducted. The temperature of inside and crown in greenhouses which were control (space heating 8℃) and test (space heating 5℃+crown heating) was measured. In the control greenhouse, the average of temperature and humidity in December was 7.1℃, 87.2%, respectively. In the test greenhouse, the average of temperature and humidity in December was 5.7℃, 88.7%. The temperature of crown and inside the bed were 7.9℃, 10.8℃ in control, 9.3℃, 12.7℃ in test. During the test period, the total 16,847×10³ kcal of energy was consumed in control greenhouse including space heating. In test greenhouse including space heating, crown heating and warm water supplying, total 9,475.7×10³ kcal of energy was consumed. So, energy consumption in test was 43.8% less than in the control. The total yields of strawberry during test period were 412.7g/plant for test greenhouse and 393.3g/plant for control greenhouse respectively.

• Journal of Energy Engineering
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• v.28 no.3
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• pp.65-79
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• 2019

The study attempted to estimate the optimal facility capacity by combining renewable energy sources that can be connected with gas CHP in industrial complexes. In particular, we reviewed industrial complexes subject to energy use plan from 2013 to 2016. Although the regional designation was excluded, Sejong industrial complex, which has a fuel usage of 38 thousand TOE annually and a high heat density of $92.6Gcal/km^2{\cdot}h$, was selected for research. And we analyzed the optimal operation model of CHP Hybrid System linking fuel cell and photovoltaic power generation using HOMER Pro, a renewable energy hybrid system economic analysis program. In addition, in order to improve the reliability of the research by analyzing not only the heat demand but also the heat demand patterns for the dominant sectors in the thermal energy, the main supply energy source of CHP, the economic benefits were added to compare the relative benefits. As a result, the total indirect heat demand of Sejong industrial complex under construction was 378,282 Gcal per year, of which paper industry accounted for 77.7%, which is 293,754 Gcal per year. For the entire industrial complex indirect heat demand, a single CHP has an optimal capacity of 30,000 kW. In this case, CHP shares 275,707 Gcal and 72.8% of heat production, while peak load boiler PLB shares 103,240 Gcal and 27.2%. In the CHP, fuel cell, and photovoltaic combinations, the optimum capacity is 30,000 kW, 5,000 kW, and 1,980 kW, respectively. At this time, CHP shared 275,940 Gcal, 72.8%, fuel cell 12,390 Gcal, 3.3%, and PLB 90,620 Gcal, 23.9%. The CHP capacity was not reduced because an uneconomical alternative was found that required excessive operation of the PLB for insufficient heat production resulting from the CHP capacity reduction. On the other hand, in terms of indirect heat demand for the paper industry, which is the dominant industry, the optimal capacity of CHP, fuel cell, and photovoltaic combination is 25,000 kW, 5,000 kW, and 2,000 kW. The heat production was analyzed to be CHP 225,053 Gcal, 76.5%, fuel cell 11,215 Gcal, 3.8%, PLB 58,012 Gcal, 19.7%. However, the economic analysis results of the current electricity market and gas market confirm that the return on investment is impossible. However, we confirmed that the CHP Hybrid System, which combines CHP, fuel cell, and solar power, can improve management conditions of about KRW 9.3 billion annually for a single CHP system.

• Journal of Environmental Science International
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• v.15 no.7
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• pp.677-688
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• 2006

Currently, the application of $TiO_2$ photocatalyst has been focused on purification and treatment of wastewater. However, the use of conventional $TiO_2$ slurry photocatalyst results in disadvantage of stirring during the reaction and of separation after the reaction. And the usage of artificial UV lamp has made the cost of photocatalyst treatment system high. Consequently, we studied that solar light/$TiO_2$ film system was designed and developed in order to examine disinfection characteristics of sewage wastewater treatment. The optimum conditions for disinfection such as solar light intensity, characteristic of sewage wastewater, amounts of $TiO_2$ and comparison of solar ligth/$TiO_2$ systems with UV light/$TiO_2$ system was examined. The results are as follows: (1) photocatalytic disinfection process with solar light in the presence of $TiO_2$ film more effectively killed total coliform (TC) than solar light or $TiO_2$ film absorption only. (2) The survival ratio of TC and residual ratio of organic material (BOD, CODcr) decreased with remain resistant material. (3) The survival ratio of TC and residual ratio of organic material (BOD, CODcr) decreased with the increase of amounts of $TiO_2$. (4) TC survival ratio decreased linearly with increasing UV light intensity. (5) The disinfection effect of solar light/$TiO_2$ slurry system decreased more than UV light/$TiO_2$ film systems. (6) The disinfection reaction followed first-order kinetics. We suggest that solar light instead of using artificial UV light was conducted to investigate the applicability of alternative energy source in the disinfection of TC and the degradation of organic material.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.10
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• pp.1478-1483
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• 2006

This experiment was carried out to determine the effects of supplementation of L-carnitine and humic substances alone or in combination in laying hen diets on performance, egg traits and blood parameters. A total of 180 IGH type brown laying hens aged 22 weeks were employed in a completely randomized block design with one control group and three treatment groups. Each group was divided into five replicates as subgroups, each comprising 9 hens. The diets of the first, second and third treatment groups were supplemented with 0.1 g/kg L-carnitine, 1.5 g/kg humic substances (Farmagulator$^{(R)}$ Dry Plus) and 0.1 g/kg L-carnitine+1.5 g/kg humic substances, respectively. The experimental period lasted 18 weeks. Feeding supplemental carnitine, humic substances or carnitine+humic substances resulted in increases in body weight gain (p<0.05). Dietary treatments did not significantly affect daily feed intake, daily metabolizable energy intake, egg production, egg weight, feed efficiency, mortality, egg shape index, egg breaking strength, egg shell thickness, egg albumen index, egg yolk index, egg Haugh unit and the percentages of egg shell, albumen and yolk. Supplementation of humic substances reduced egg yolk cholesterol as mg per g yolk and mg per yolk (p<0.05). Blood serum parameters were not affected by the supplementation of carnitine, humic substances or carnitine+humic substances. The results in this study demonstrated that humic substances supplementation reduced egg cholesterol without adverse effects on performance, egg traits and blood parameters of laying hens. It was concluded that the usage of L-carnitine alone or in combination with humic substances in diets had no beneficial effects in laying hens.

• Journal of the Korean Home Economics Association
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• v.48 no.2
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• pp.121-134
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• 2010

This study was performed to develop the semi-quantitative food frequency questionnaire (SQFFQ) for assessing the usual dietary intake of Korean adolescents. For that, we used 24 hour recall data from the 2005 NHANES(the Third Korean National Health and Nutrition Examination Survey). The cumulative percent contribution and cumulative multiple regression coefficients of 17 nutrients(energy, protein, fat, carbohydrate, fiber, calcium, phosphorus, iron, sodium, potassium, vitamin A, retinol, ${\beta}$-carotene, thiamin, riboflavin, niacin, vitamin C) of each food were computed. Among 687 food items, 265 food items were selected and grouped depending on similarities in ingredients, nutrient profiles, and/or culinary usage and re-added food items which were excluded for seasonal effect. Finally, total 19 food groups, 87 food items, were included in SQFFQ. Food intake frequency was quantified using nine categories. The portion size was classified depending on the average size of each selected food item. Each portion size was then categorized as one of three amounts: small (0.5 times), medium (1 times), and large (1.5 times). The SQFFQ covered 91.9% of the intake of 17 nutrients in 2005 NHANES and 86.6% in 2001 NHANES. Therefore, by testing the validity of developed SQFFQ using nutrient intakes, this list was valid to evaluate the usual daily intake in Korean adolescents.