• Journal of the Korea Institute of Building Construction
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• v.14 no.4
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• pp.301-307
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• 2014

In order to reduce the emission of carbon dioxide($CO_2$), this research use blast furnace slag in concrete manufacture, as 100% replacement of cement. The aim of this study is to investigate the density and strength properties of alkali-activated lightweight composites with alkali activators of different types and different amounts. The bubble for achieving the lightweight of alkali-activated lightweight composites was generated in the reaction between the paper ash and the alkali activators instead of using a foaming agent. Lightweight formed concrete was conducted basic experimental for determining replacement ratio of paper ash. Then, the density and strength were measured according to the types and the contents of the alkali accelerator that can react with the paper ash. As results, the optimum replacement ratio of the paper ash was 5%. The alkali activator containing NaOH 12.5% obtained the lowest weight of $1.13g/cm^3$. Also, compressive strength were relatively high. Therefore, this study demonstrated that alkali accelerator with a certain amount of NaOH can achieve relatively high strength and lightweight alkali-activated lightweight composites.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.6
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• pp.1274-1279
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• 2011

The purpose of this paper is to present the manufacturing defect and damage pattern of a 3 phase 22.9/3.3kV oil immersed transformer, as well as to present an objective basis for the prevention of a similar accident and to secure data for the settlement of PL related disputes. It was found that in order to prevent the occurrence of accidents to transformers, insulating oil analysis, thermal image measurement, and corona discharge diagnosis, etc., were performed by establishing relevant regulation. The result of analysis performed on the external appearance of a transformer to which an accident occurred, the internal insulation resistance and protection system, etc., showed that most of the analysis items were judged to be acceptable. However, it was found that the insulation characteristics between the primary winding and the enclosure, those between the ground and the secondary winding, and those between the primary and secondary windings were inappropriate due to an insulating oil leak caused by damage to the pressure relief valve. From the analysis of the acidity values measured over the past 5 years, it is thought that an increase in carbon dioxide (CO2) caused an increase in the temperature inside the transformer and the increase in the ethylene gas increased the possibility of ignition. Even though 17 years have passed since the transformer was installed, it was found that the system's design, manufacture, maintenance and management have been performed well and the insulating paper was in good condition, and that there was no trace of public access or vandalism. However, in the case of transformers to which accidents have occurred, a melted area between the upper and the intermediate bobbins of the W-phase secondary winding as well as between its intermediate and lower bobbins. It can be seen that a V-pattern was formed at the carbonized area of the transformer and that the depth of the carbonization is deeper at the upper side than the lower side. In addition, it was found that physical bending and deformation occurred inside the secondary winding due to non-uniform pressure while performing transformer winding work. Therefore, since it is obvious that the accident occurred due to a manufacturing defect (winding work defect), it is thought that the manufacturer of the transformer is responsible for the accident and that it is lawful for the manufacture to investigate and prove the concrete cause of the accident according to the Product Liability Law (PLL).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.4
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• pp.284-291
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• 2010

A simulation modeling for predicting the harvesting date with high potato solids consists of development of mathematical models. The mathematical model on potato growth and its development should be obtained by using agricultural elements which analyze relations of solar radiation quantity, temperature, photon quantity, carbon dioxide exchange rate, water stress and loss, relative humidity, light intensity, and wind etc. But more reliable way to predict harvesting date against climatic change employs in vivo energy consumption for growth and induction shape in a slight environmental adaptation. Therefore, to calculate in vivo energy loss, we take a concept of estimate of the amount of basal metabolism in each tuber on the basis of $Wm={\int}^m_tf(x)dt$ and $Tp=\frac{Tm{\cdot}Wm^{Tp}}{Wm^{Tm}}$. In the validation experiments, results of measuring solid accumulation of potato harvested at simulated date agreed fairly well with the actual measured values in each regional field during the growth period of 2005-2009. The calculation method could be used to predict an appropriate harvesting date for a production of high potato solids according to weather conditions.

• Resources Recycling
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• v.18 no.3
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• pp.11-19
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• 2009

Recently the problem of global environment is became by social issue. Accordingly the interests to recycling and saving of resources are growing from daily life to varieties field of industry. To preserve the global environment, prevent global warming, environmental destruction, environmental pollution by wastes, the drain of aggregate, plasticity energy of cement and decrease in carbon dioxide are an urgent problem that must be resolved. So there is to a field of building industry and stands but on the inside of the building the many double meaning resources usefully, applies. Also the seller masterpiece building where the service life is long planned is safe and comfortably, maintenance, suppresses the construction which is not necessary is unnecessary. Also the seller masterpiece building where the service life is long planned is safe and comfortably, maintenance, suppresses the construction which is not necessary is unnecessary. By revitalizing effective use of limited earth resources, recycling and controling production of construction waste, this study introduced to a method for Long-Term Durability of Construction Structure and Effective Use of Technology for Construction Waste considering architectural demand and earth environment. It is for reduction of an earth environment load from the side of construction production and performance design of a structure.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.3
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• pp.187-195
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• 2019

The needs for precise diagnostics and farm management-decision aids have increased to reduce the risk of climate change and environmental stress. Crop simulation models have been widely used to search optimal solutions for effective cultural practices. However, limited knowledge on physiological responses to environmental variation would make it challenging to apply crop simulation models to a wide range of studies. Advanced research facilities would help investigation of plant response to the environment. In the present study, the sunlit controlled environment chambers, known as Korean SPAR (Soil-Plant-Atmosphere-Research) system, was developed by renovating existing SPAR system. The Korean SPAR system controls and monitors major environmental variables including atmospheric carbon dioxide concentration, temperature and soil moisture. Furthermore, plants are allowed to grow under natural sunlight. Key physiological and physical data such as canopy photosynthesis and respiration, canopy water and nutrient use over the whole growth period are also collected automatically. As a case study, it was shown that the Korean SPAR system would be useful for collection of data needed for understanding the growth and developmental processes of a crop, e.g., soybean. In addition, we have demonstrated that the canopy photosynthetic data of the Korean SPAR indicate the precise representation of physiological responses to environment variation. As a result, physical and physiological data obtained from the Korean SPAR are expected to be useful for development of an advanced crop simulation model minimizing errors and confounding factors that usually occur in field experiments.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.1
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• pp.31-38
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• 2022

Due to the increasing consumer demands for the safety, shelf life, and quality of food, the application and development of active packaging in the food and packaging industry have been improved. According to the standards and specifications of the Republic of Korea for utensils, containers, and packages, the function of active packaging is to remove or alleviate factors that degrade food quality. Although extensive reviews regarding the development and commercialization of active packaging have been conducted, the legal regulations and safety assessments concerning active packaging have rarely been examined. This review provides information regarding the definition, structure, components, operational mechanisms, and applications for active packaging that actively removes oxygen, moisture, carbon dioxide, and ethylene. Furthermore, the legal regulations and research results related to the development of test methods for safety assessments of active packaging are investigated.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.28 no.3
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• pp.95-120
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• 2023

Methane (CH₄) is a key greenhouse gas in the atmosphere with 85 times greater greenhouse potent relative to carbon dioxide (CO₂). The atmospheric concentration of CH₄ is rapidly increasing due to the intensive usage of CH₄ and the thawing of the cryosphere. Additionally, with the current warming of ocean water, the dissociation of gas hydrates, an ice-like compound and the largest reservoir of CH₄ on Earth, is expected to occur, resulting in the release of CH₄ from the seafloor into the overlying water and atmosphere. Moreover, bottom water hypoxia is another concern that potentially introduces greenhouse gases into the atmosphere. With ongoing global warming and eutrophication, the size and duration of bottom water hypoxia are rapidly increasing. These low-oxygen conditions would relocate the redox zone shallower in sediment or in the water column, causing the release of CH₄ into the atmosphere and thereby intensifying global warming. However, there exists a gap in the understanding of CH₄ dynamics including its generation in relation to bottom water hypoxia. Therefore, this review article aims to understand the relationship between CH₄ and bottom water hypoxia and to draw attention to CH₄ investigation in Korea.

• The Korean Journal of Mycology
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• v.10 no.2
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• pp.75-83
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• 1982

As a primary study for cell growth and alcohol production of a cider yeast, Saccharomyces sp. R-11, cultural and nutritional characteristics of the strain were investigated. The results obtained were as follows: The optimum culture medium for this strain was a synthetic medium, Henneberg B, and sucrose was the best carbon source for yeast growth and alcohol production. Optimum sugar concentrations for yeast growth and alcohol production were 15% and 25%, respectively. Optimum pH and temperature of the basal medium for growth of this strain were 4.5 and $30^{\circ}C$ respectively. The yeast growth was enhanced by the addition of 100 ppm of $Mg^{2+}$, but significantly inhibited by the addition of 100 ppm of $Co^{2+}$. Lower temperature and maintenance of optimum pH for yeast growth increased the final alcohol concentration. Under optimum condition for cell growth at stationary culture, generation time and specific growth rate of the strain were 7.5 hr and 0.092 $hr^{-1}$, respectively. At 8% initial alcohol concentration, yeast growth was inhibited about 50% and this strain could not be grown at more than 12% initial alcohol. The strain could be grown at less than 125ppm $SO_2$without alcohol addition, and at less than 75 ppm $SO_2$ with 8% initial alcohol. The higher sulfur dioxide concentration of a medium, the longer lag phase in yeast growth was observed. This strain could induced alcoholic fermentation at less than 10% initial alcohol concentration with 0 and 25 ppm $SO_2$, at less than 8% initial alcohol with 50 and 75 ppm $SO_2$, and at less than 6% initial alcohol with 100 and 125 ppm $SO_2$.

• Journal of Bio-Environment Control
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• v.18 no.3
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• pp.291-296
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• 2009

This study was conducted to compare the storability of 6 chicory cultivars for producing chicon; 'Vintor', 'Focus', 'Metafora', 'Kibora', 'Nobus', and 'Redoria Red' grown in 2 regions: Chuncheon (plain region) and Pyeongchang (high land region). Chicons were produced from chicory roots that grown for 120days and then stored for over 120days at $2^{\circ}C$ and 90% of RH conditions. To produce chicon, chicory root was forced at $18^{\circ}C$ for 22days with suppling the nutrient solution ($KNO_30.54g{\cdot}L^{-1}$, $Ca(NO_3)_2\;1.02g{\cdot}L^{-1}$, $MgSO_4\;0.36g{\cdot}L^{-1}$, $KH_2PO_4\;0.21g{\cdot}L^{-1}$, $K_2SO_4\;0.10g{\cdot}L^{-1}$, pH 7.0). Chicons produced from 6 different chicory cultivars packed with $25{\mu}m$ ceramic film and stored for 25days at $8^{\circ}C$. The fresh weight of chicon in MAP was maintained to 99.5% of pre-storage weight. The fresh weight of 'Redoria Red' was lowest in all cultivars, and that of Chuncheon region cultivated treatment was lower than Pyeongchang treatment. The $CO_2$ and $O_2$ concentration in chicon MAP were 2% and $10{\sim}17%$. There were not significantly different among cultivars and between regions, although 'Redoria Red' cultivar showed highest $CO_2$ and lowest $O_2$ concentrations. The ethylene concentration in chicon MAP was $1.0{\mu}{\iota}{\cdot}{\iota}^{-1}$ and also didn't show any significant difference among all treatments. Chicon detoriorated visual quality with appearing russet spotting that result from ethylene gas. The visual quality of 'Redoria Red' cultivar decreased faster than the other cultivars. 'Metafora', 'Focus', and 'Kibora' maintained higher firmness of their leaf than the others, and the firmness was higher grown in Pyeongchang region cultivated treatments than in Chuncheon region.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.202-209
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• 1996

The environment in composting greenhouse is very different with the traditional greenhouse by biothermal energy and $CO_2$ concentration. This experiment aimed to investigate the environmental effects on the growth and development of tomato grown at composting greenhouse. The room temperature is not different between two greenhouses because of heating and ventilation, but the soil temperature in composting greenhouse is about 7$^{\circ}C$ to 15$^{\circ}C$ higher than that of traditional greenhouse. The emission concentration of ammonia gas is the highest, 117.3ppm, at the 6th day starting the digest, and were gradually lowered from 7th day, 11 became 15.7ppm at the 16th day. The concentration of $CO_2$ in composting greenhouse were 250 to 2000ppm higher than that of traditional greenhouse for 4 months starting digest. The growth and development of tomato grown at composting greenhouse was better than that of traditional greenhouse. The yield in composting greenhouse was also better than that of traditional greenhouse. The sugar contents of tomato grown at composting greenhouse became about 1 $^{\circ}$Brix higher than that of traditional greenhouse.