• Membrane Journal
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• v.30 no.3
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• pp.158-172
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• 2020

In the aspect of saving energy and water, facilitating the separation membrane for the water treatment has been rising recently as one of the possible solutions. However, microbial biofouling effect is the biggest obstacle that hinders reaching higher permeability over a prolonged period of nanofiltration operation. To solve this problem and fully utilize the filtration membranes with enhanced performance, largely two kinds of solutions are studied and the first and the most commonly mentioned type is the one using the silver nanoparticles. Since silver nanoparticles are important to be well tailored on membrane surface, various methods have been applied and suggested. Using silver nanoparticles however also has the drawbacks or possible toxicity risks, raising the need for other types of utilizing non silver particles to functionalize the membrane, such as copper, graphene or zinc oxides, and amine moieties. Each attempt included in either kind has produced some notable results in killing, preventing, or repelling the bacteria while at the same time, left some unsolved points to be evaluated. In this review, the effects of metal nanoparticles and other materials on the antifouling properties of water treatment membranes are summarized.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.25 no.4
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• pp.79-108
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• 2014

The purpose of this study was to research instances of green library construction and recognition in order to increase awareness of green libraries. To this end, we investigated the green library's outline and green building, evaluated cases of G-SEED certified libraries, and surveyed the employees at the 16 different G-SEED certified libraries. Results showed that the employees' knowledge of green libraries and the green certification system was low, whereas their interest and needs regarding the green library concept were very high. Second, the respondents were able to recognize as a whole the factors of green library construction based on the evaluation items for G-SEED and place particular emphasis on 'recyclable resources & recycling bins.' However, only a few recognized 'water reclamation/reuse system establishment' as a green library factor. Third, the respondents largely agreed upon an evaluation of items on the suitability of G-SEED, and their ranked reasons for build a green library were preventing environmental pollution, energy-saving, environment, ecology, and indoor environmental factors. Fourth, a lack of 'awareness about the concept of the green library' was thought to most affect the awareness of difficulties in green library construction, and the respondents agreed with the need for 'library image enhancement' to better manage expectations of the green library.

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.714-721
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• 2008

Chemical plants which consume lots of energy are not operating in the best conditions due to their own peculiar nonlinearity, instability, and diverse disturbances. In order to improve this, the plant wide optimization was performed. It is important to select the most appropriate number of decision variables which strongly affect the operating cost because there are too many decision variables which economically have an effect on plant wide. For instance, if all decision variables which can economically affect are applied in optimization and then the result of the optimization is applied to operation, a lot of operating conditions should be going to be changed. As a result of changing a plenty of operating conditions, the cost of the change will absolutely increase. Thus, in this study, the method of selecting the most appropriate decision variables which can influence on saving operation costs was presented in order to optimize plant wide. TPA (Terephthalic-acid) plant is considered as a case study. In other word, after modeling, the most proper decision variables was selected by examining the degree which decision variables influence on operating costs through sensitivity analysis. In TPA process, the three decision variables were selected by the presented method in this study. Then the plant was optimized by selected the decision variables. Consequently, it was seen that the plant are expected to save the 350 million won of energy annually without additional investment for facilities or remodeling of the plant.

• Korean Journal of Food Science and Technology
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• v.44 no.6
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• pp.704-710
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• 2012

This study was designed to investigate the effect of pulsed electric fields on the drying of ginseng and extraction of dried ginseng to reduce energy-consumption. Fresh ginseng was treated in a PEF system of 1 and 2 kV/cm electric field strength, 25 and 200 Hz of frequency, $30{\mu}s$ of pulse width and pulse number of 175. The samples were subsequently dried for 26 h at $55{\pm}1^{\circ}C$, and the characteristic of hot-water extraction on dried ginseng was investigated. The ginseng pretreated with an intensity of 2 kV/cm (200 Hz, n=175) resulted in a reduction of approximately 38% for drying time. The influence of PEF treatment on the water extraction of dried ginseng at $95{\pm}1^{\circ}C$ was also investigated. The application of an electric field intensity of 2 kV/cm (25 and 200 Hz, n=175) increased soluble solid content, significantly reducing sugar content and free sugar content of the extract compared to non-PEF-treated samples.

• 대한공업교육학회지
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• v.44 no.2
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• pp.86-103
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• 2019

The purpose of this study is to provide basic data on the development of education and training programs for training 'mechanical facilities maintenance manager'. To this end, the DACUM technique was used for job analysis and education and training programs were developed through expert consultation meetings. The job analysis was based on the 10-member DACUM Committee to derive the job definition, job model, job description, and task description of the 'mechanical facilities maintenance manager'. The main findings are as follows. First, the 'mechanical facilities maintenance manager' was defined as those who operate, inspect, diagnose, and repair mechanical facilities to provide the best performance and efficient operation management, provide a safe and pleasant environment, and perform energy saving and facility life extension tasks. Second, the duties of the 'mechanical facilities maintenance manager' analyzed in the job model consist of the comprehensive plan for operation of mechanical facilities, energy management of mechanical facilities, operation management of mechanical facilities, maintenance of mechanical facilities, safety environment management of mechanical facilities, and customer support management of mechanical facilities. Considering the nature and content of the duties, 4 to 11 tasks per duty were derived and a total of 33 tasks were presented as job model. Third, the curriculum for the 'mechanical facilities maintenance manager' was set up in two courses: Practice I for Mechanical Facilities Maintenance and Practice II for Mechanical Facilities Maintenance. Considerations and policy suggestions were presented when applying and implementing education and training programs based on the results of the research.

• Clean Technology
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• v.24 no.4
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• pp.315-322
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• 2018

Industrial use of waste oyster shells is limited because of requiring excessive energy for converting natural oyster shells in the form of calcium carbonate ($CaCO_3$) into calcium oxide (CaO) for this purpose. This study aimed to develop energy-saving process for producing solidifying agent using waste oyster shells for backfill materials. It was suggested that oyster shells were converted to calcium sulfates which were mixed with sodium hydroxide solution and red clay, forming solid specimen. The optimal concentrations of sulfuric acid for sulfation of oyster shell and sodium hydroxide to generate calcium hydroxide ($Ca(OH)_2$), were determined. Unconfined compressive strength of solid specimen increased with increasing the content of solidifying agent while it increased also with increasing ratio of natural oyster shells to coal ash. The result clearly demonstrates that solidifying agent consisting of sulfuric acid-treated oyster shell, coal ash, and sodium hydroxide solution, can be effectively utilized for preparing backfill materials using natural oyster shell and coal ash. Sulfuric acid-treated oyster shell-based solidifying agent has not been previously developed and will contribute to broaden industrial application of waste oyster shells.

• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.8-13
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• 2022

This study was carried out to investigate the proper wattage and installation distance for the efficient use of nano-carbon fiber infrared heating lamp (NCFIHL), a heating device advantageous for heating energy saving, when the production of watermelon plug seedlings in the plug seedling nursery in winter season. Six small beds were divided into plastic film, and 700 W and 900 W nano-carbon fiber infrared heating lamps were installed at 100 cm above the bed. 1 lamp at central (control), 60 cm interval (2 lamps), and 40 cm interval (3 lamps) heating lamps were installed in each bed inside the greenhouse. All treatments, except the control, were set to keep the night air temperature at 20℃ after lighting the NCFIHL. The leaf temperature showed a tendency to increase fast as the install distance was narrow. The leaf length and leaf width tended to increase as the installation distance of the 700 W heating lamp was narrow. The compactness was high in 700 W heating lamp with 40 cm of installation distance. Therefore, in consideration of maintaining the set temperature at night, installing 700 W electric lamps at 40 cm was an efficient power and installation distance for watermelon grafted seedlings considering economic feasibility.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.278-286
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• 2021

In this study, based on the Computational Fluid Dynamics (CFD) simulation model developed through previous study, inner environmenct of the modified glass greenhouse was predicted. Also, suggested the optimal shape of the greenhouse and location of the heat exchangers for heat energy management of the greenhouse using the developed model. For efficient heating energy management, the glass greenhouse was modified by changing the cross-section design and the location of the heat exchanger. The optimal cross-section design was selected based on the cross-section design standard of Republic of Korea's glass greenhouse, and the Fan Coil Unit(FCU) and the radiating pipe were re-positioned based on "Standard of greenhouse environment design" to enhance energy saving efficiency. The simulation analysis was performed to predict the inner temperature distribution and heat transfer with the modified greenhouse structure using the developed inner environment prediction model. As a result of simulation, the mean temperature and uniformity of the modified greenhouse were 0.65℃, 0.75%p higher than those of the control greenhouse, respectively. Also, the maximum deviation decreased by an average of 0.25℃. And the mean age of air was 18 sec. lower than that of the control greenhouse. It was confirmed that efficient heating energy management was possible in the modified greenhouse, when considered the temperature uniformity and the ventilation performance.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.4
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• pp.45-56
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• 2016

In this study, an analysis has been conducted on the evaluation criteria of current G-SEED(Green Standard for Energy and Environmental Design) and on the 78 buildings, certified by G-SEED, for 3 years from November, 2012 to November, 2015. Based on the results of this analysis, four issues are driven and proposed hereinafter. Issue 1 : Nowadays, the psychological proportion of landscape architecture in building is getting greater than ever so that it shows reliable reduction of carbon dioxide. Therefore, so far as the eight kinds of buildings are concerned, the evaluation items of G-SEED must include those of landscape architecture mandatorily through its enlargement. Issue 2 : It is undesirable factor that inhibits precise evaluation on landscaping area to let other areas appraise landscape architecture because it requires outstanding professionalism. So, G-SEED should not only ensure landscaping professionalism for the correct evaluation but also let landscape area participate in assessing other areas. Issue 3 : Many previous researches turned out that landscape planting technique has excellent effect on saving energy and reducing temperature of buildings. Thus, landscape planting technique of landscape area is required to be one of the evaluation items of energy sector. Issue 4 : Tree management also has to be newly included as one of the evaluation factor for the maintenance relating to the landscape architecture. G-SEED, enacted and enforced by the Green Building Creation Support Act in 2013, surely is effective system to reduce carbon dioxide in buildings. This is a special Act in its nature that is superior to Construction Law and must be observed by all means to construct buildings. Under the umbrella of this legal system, various of researches and products are contributing to creating new jobs in construction area. However, it is a well-known fact that landscape architecture area has shown less interest on this Act than that of construction area. In conclusion, it is necessary that landscape industry should conduct continuous researches on G-SEED and pay more attention to the Act enough to harvest related products and enlarge its work area.

• Journal of Climate Change Research
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• v.2 no.2
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• pp.93-106
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• 2011

Republic of Korea officially announced its mid term reduction target which reduce about 30% of BAU GHG emission by 2020 in the 15th meeting of UNFCCC(COP 15) held in Copenhagen, Denmark 2009. To achieve this goal, it is necessary to understand the serious of climate change and take part in GHG reduction not only industry but also the nation. However, such positive participation in green life which may cause inconvenient of the life of the people. It should be accomplished with providing reliable information. This study suggests the scientific potentialities of GHG emission by guideline on low carbon life and green life to form and change a lifestyle suitable for coping with climate change. And also, this study quantitate the GHG reduction which may reduce demand for air conditioning by cool biz and warm biz. In Korea, this campaign has become known as 'CoolMaebsi' by Ministry of Environmental of Korea. 'CoolMaebsi' is a compound word of 'Cool' which means feel refreshed, and 'Maebsi' is a Korean word which means attire. Though this campaign is effective and significant to reduce the GHG emission yet there were no study on quantitative analysis. Therefore this study calculated reduced energy consumption and potential GHG emission by measuring variation of skin temperature. As the result, wearing warm biz and cool biz have an effect of reducing not only the energy consumption but also GHG emission. To achieve the low carbon society, it is necessary to improve the energy saving system and introduce the policy which guide to change a life style.