• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.34-50
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• 2022

Since the Paris climate agreement, reducing greenhouse gases has been the most important global issue. In particular, it is necessary to reduce fossil fuels in the mobility sector, which accounts for a significant portion of total greenhouse gas emissions. In this paper, we investigated the economic feasibility of green mobility energy supply chains, which supply hydrogen as fuel to hydrogen vehicles based on electricity from renewable energy sources. The design and operation costs were analyzed by evaluating nine scenarios representing various combinatorial possibilities such as renewable energy generation, hydrogen production through water electrolytes, hydrogen storage and hydrogen refueling stations. Simulation calculations were made using Homer Pro, widely used commercial software in the field. The experience gained in this study could be further utilized to construct actual hydrogen energy systems.

• Journal of Bio-Environment Control
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• v.25 no.3
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• pp.212-217
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• 2016

This study was conducted to investigate the effect of nursery period on growth and yield attribute of green papaya (var. Red lady). The nursery period was 3, 5, 7, 9, 11 and 13 months and the green papaya was transplanted on 15 April, 2015 in a non-heated greenhouse. The plant height, node number and fresh weight of nursery plant were increased as the nursery periods increased. The growth of green papaya with 13 months nursery period was better than those of other treatments. First harvest after transplanting was increased as the nursery periods were shorten. It took 137 days (18 August) at 13 months treatment, and 184 days (2 October) at 3 months treatment. The fruit length and diameter were smallest at 3 months treatment and there was no significant difference among other treatments. The fruit yield was also influenced by the nursery periods, the commercial yield was also increased as the nursery periods increased. The commercial yield was highest at 13 months treatment (3,172kg/10a), followed by 11 (2,247kg/10a) and 9 months treatment (2,357kg/10a). At 7 and 5 months treatment were 1,942kg/10a and 1,787kg/10a, respectively and the yield was lowest at 3 months treatment (1,443kg/10a). The commercial yield was significantly decreased under 7 months treatment. Although the harvest time of 11 months treatment was earlier than that of other treatments in non-heated greenhouse, 9 month treatment will be more recommendable for green papaya production because of operating costs.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.577-582
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• 2011

Greenhouse satsuma mandarins (Citrus unshiu Marc., cv. Gungchun) of an early harvesting cultivar were treated by hot water showering at 65$^{\circ}C$ for 10 s at a commercial scale in a packing house and then stored at 5$^{\circ}C$ for 3 weeks and subsequently at 18$^{\circ}C$ for 1 week (simulated shelf-life) to examine the potential use of hot water treatment (HWT) as an environmentally benign method to maintain mandarin quality characteristics during postharvest storage and sale. The respiration rate just after heat treatment or during storage was at a similar level in both the treated and untreated fruit. HWT also had no detrimental effects on quality attributes including pH, titratable acidity, soluble solids content, weight loss, firmness, and peel color. The development of stem-end rot, mold decay, and black rot was lower in the heat-treated fruit compared to those in the untreated control. A sensory evaluation showed that HWT markedly improved fruit appearance, making the fruit cleaner and glossier. The results suggested that HWT can be applied to satsuma mandarin as an effective pretreatment to maintain postharvest quality during storage and marketing.

• Journal of Bio-Environment Control
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• v.24 no.2
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• pp.57-62
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• 2015

Manual grafting is a labor-intensive operation and highly susceptible to human error. Development of grafting robot has been considered as an effective alternative to manual grafting. The study was conducted to investigate the grafting efficiency between the domestically produced automated grafting robot and traditional manual grafting performed in a commercial plug seedling greenhouse. Plug seedlings of pepper (Capsicum annuum L.) 'Buchon' and 'Anseongmatchum' were sown as scions and rootstocks, respectively on March 29, 2013. The grafting was performed by a grafting robot, amateur grafters, and professional grafters on May 31, 2013. After grafting, the seedling efficiencies and seedling characteristics were compared in terms of plant height, the number of success as well as failure of seedling grafts produced in an hour. The results showed that plant heights were most uniform in the grafts performed by the professionals that had a 0.6 cm difference whereas an uneven difference of 2.1 cm difference was observed in plug seedling grafted by an amateur. However, plug seedlings grafted by the grafting robot were found to be uniform with 1 cm plant height difference. Moreover, the maximum number of grafting processed plug seedlings per hour (667 plants) was achieved by the grafting robot on compared with the seedlings grafted (466 plants) by the professionals. Furthermore, the least failure rate of 21.7% was noted upon the usage of grafting robot than the manual grafters. Thus, the results demonstrate that the technology of automated grafting robots is the most appealing and can be employed in commercial plug seedling greenhouses to overcome the drawbacks of manual grafting.

• Journal of Bio-Environment Control
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• v.18 no.3
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• pp.244-252
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• 2009

This research aims at comparison of climatic conditions of sweet pepper's greenhouse between Korea (KOR) and the Netherlands (NL) to find out the reason of much lower yield in KOR than NL focus-ing on greenhouse climatic conditions. Hence, greenhouse climate data were obtained from each one commercial glasshouse in both countries. The crops (cv. 'Derby') were grown on rockwool slab with two stems per plant with 3.75plants/$m^2$ in KOR and three stems per plant with 2.5plants/$m^2$ or four stems per plant with 1.875plants/$m^2$ in NL. Even though plant density was differed but stem density was on the same to 7.5stems/$m^2$. There was no significantly difference on weekly growth of sweet pepper plant both countries, whereas harvested nodes to whole nodes of NL's plant was more than two times higher compared to KOR. The averaged daily global radiation during the whole growing periods was 14.5MJ/$m^2$/day in KOR and l2.1MJ/$m^2$/day in NL. Averaged 24h temperature was similar to both glasshouse as $21.6^{\circ}C$ in KOR and $21.2^{\circ}C$ in NL during the whole growing periods, however the variance was higher in KOR than NL. Humidity deficit (HD) was observed higher in KOR during the whole growing periods. Averaged day $CO_2$ concentration was measured contrary pattern in both countries because of heating to greenhouse on NL winter season. Averaged 24h temperature and day $CO_2$ concentration to daily global radiation was regular pattern in NL, whereas there are large scatter in KOR. Consequently, more irregular greenhouse climate condition in KOR could be induced irregularly crop growth.

• Journal of the Korean Wood Science and Technology
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• v.45 no.5
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• pp.650-660
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• 2017

In this study, simplified LCA (life cycle assessment) tool was developed to increase accessibility and availability on LCA timber construction. The result of simplified LCA was compared with commercial program on LCA (Simapro.7) to verify its availability. As a result of evaluating environmental impacts with the Life Cycle Inventory of all processes, gap between LCA and simplified LCA tools of timber construction was about 1%. Therefore, the simplified LCA tool could analyse greenhouse gas emissions of timber construction and to expand number of data set through improved conveniency of users for developing database of timber construction in Korea. The reduction effects of greenhouse gas emissions of timber construction was about 53% of total emission offset up to construction phase. The results of this study would support decision making process to expand to timber construction policy to showcase environmental friendliness of timber construction. It was expected to contribute to response to the New climate regime in forestry.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.5
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• pp.350-355
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• 2013

Little information is available for emission pathway even if HFC-134a that is known as one of the major greenhouse gases has been broadly used in Korea. This paper attempts to clarify the emission characteristics of HFC-134a used for refrigerant of cold drinking vending machines (CDVMs) at the use- and disposal-phase. We measured the residual amounts in the scrap CDVMs of 47 by applying commercial recover for refrigerant. The first-order kinetic model was introduced and the emission rate would be proportional to the remaining quantity of refrigerant. The emission factor at the use-phase was determined indirectly to be $6.9{\pm}0.7$ %/yr within a confidence interval of 95%, using information on residual amount and elapsed operation time at the disposal point. Correspondingly, the annual emission rate of HFC-134a per CDVM was determined to be 11.6 g. The average residual rate of HFC-134a in scrap CDVMs was assessed to be $62.5{\pm}2.2%$, leading to a potential emission amount of 144.8 g per scrap CDVM. The chemical compositions of refrigerants from scrap passenger vehicles are quite similar to those of new refrigerants, suggesting that the refrigerants from scrap passenger vehicles could be reused. During the recovering process of refrigerant, the recovered refrigerant was contaminated by compressor lubricant that accounted for about 30% in weight. It is necessary to separate the refrigerant from the recovered material contaminated by lubricant for recycling and reuse the refrigerant.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.375-381
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• 2018

This study was performed to investigate the residual characteristics of the insecticide dinotefuran in asparagus under greenhouse conditions from July to August and consequentially to obtain basic data for guidelines on the safe use of this pesticide in asparagus. Residues of dinotefuran in young stem of asparagus before and after growing mother stem were analyzed from samples collected at 0, 1, 3, 5, and 7 days after single application of a commercial formulation of dinotefuran (wettable powder, 10%) at the recommended dose (2,000 times dilution). The residue of dinotefuran in young stem of asparagus was analyzed by HPLC-UVD, and recovery of dinotefuran in young stem was tested at 0.5 and 1.0 mg/kg concentrations. As a result, the limit of quantitation (LOQ) of dinotefuran was 0.01 mg/kg, and the recovery of dinotefuran was in the range of 83.3-94.0% with a coefficient of variation less than 10%. Residues of dinotefuran in young stem of asparagus before and after growing the mother stem were lower than the tentative limit (0.05 mg/kg) from 5 and 3 days after single application, respectively. Based on these results, single application of dinotefuran (wettable powder, 10%) at the recommended dose at 7 days before harvest would have no deleterious effects on safety issues concerning pesticide residue. This result might provide basic information to construct guidelines for the safe use of dinotefuran in asparagus.

• Korean Journal of Medicinal Crop Science
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• v.27 no.6
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• pp.397-403
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• 2019

Background: Oplopanax elatus is widely distributed at high altitudes (about 1,100 m) in China, Russia and Korea. It is hard to propagate, breed, and difficult to grow. Hence, it has been designated as a rare and endangered medicinal plant. A study was conducted to establish a system for large scale seedling production of Oplopanax elatus in vitro and to find the ideal environment for its seedling growth. Methods and Results: In this study, the explants produced under in vitro conditions during our previous study were grouped into three categories (under 10 mm, 10 mm - 30 mm and above 30 mm) based on plant height and were transferred to the growth-chamber and greenhouse for two weeks in each setting for acclimatization. The plantlet category of above 30 mm showed good performance, and was further evaluated under three acclimatization methods as follows: three different growth media (commercial soil, commercial soil + perlite, commercial soil + sand), four shading levels (0%, 50%, 70%, 90%) and four altitude levels (157 m, 218 m, 601 m, 870 m) in Gangwon province of South Korea. As results, O. elatus seedlings showed better growth characteristics at 870 m of altitude, 70% shading level and in the commercial soil compared to other treatments. Conclusions: The regenerated seedlings of Oplopanax elatus obtained through plant tissue culture would be advantageous for use in large scale seedling production systems paired with a good acclimation method. For obtaining optimal results, it is recommended that seedling be acclimatized in a high altitude environment.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.677-691
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• 2016

To assess South Korean commercial tomato cultivars, regular and cherry tomato cultivars were grown in the greenhouse and evaluated for color attributes, titratable acidity, pH, total soluble solids, carotenoids (lycopene and ${\beta}$-carotene), total phenols, flavonoids, vitamin C, and antioxidant activity. Significant differences (p < 0.05 using Duncan's multiple range test (DMRT)) were observed in the levels of most phytochemicals, quality parameters, and antioxidant activity among the twenty South Korean tomato cultivars tested. Lycopene and ${\beta}$-carotene contents varied significantly (p < 0.05 using DMRT), from $0.95mg{\cdot}100g^{-1}$ to $5.12mg{\cdot}100g^{-1}$ and $0.65mg{\cdot}100g^{-1}$ to $3.56mg{\cdot}100g^{-1}$ of fresh weight, respectively. ${\beta}$-carotene contents exhibited the highest genetic variation (59.2%), followed by naringenin (52.8%) and other phytochemicals. Most of the cherry tomato cultivars had statistically higher levels (p < 0.05 using DMRT) of carotenoids, phenols, flavonoids, vitamin C, and antioxidant activity compared to the regular tomato varieties, suggesting their higher nutritional value. Lycopene content was highest in the cultivars YoYo, Jicored, Titi-Chal, TY-Endorphin, and Rubyking. Cultivars Rubyking, TY-Endorphin, and Titi-Chal also showed relatively higher antioxidant activities in three assays: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ferric ion reducing antioxidant power (FRAP) assays. All the antioxidants, except luteolin, were positively correlated with antioxidant activities; the highest correlation was observed between total phenol and antioxidant activities, followed by the correlation between rutin and vitamin C. Cultivars identified to have superior nutritional status would be useful in tomato breeding programs to further improve quality and health benefits of tomatoes for the fresh and processed markets.