• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.1225-1231
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• 2006

Recently, as the climate of temperature change has happened worldwide, To solve this problem, Kyoto protocol was taken to regulate global warming on Feb. 2005 and each country is making efforts to prevent global warming. In the automotive industry, R-134a refrigerant is widely used most these days because it has zero ODP(Ozone Depletion Potential). But R-134a GWP(Global Warming Potential) is so high. Therefore, replacement refrigerant desperately is needed as a alternative refrigerant. So, R-l52a is considered as one of the alternative refrigerants due to zero ODP and lower GWP against as required on Europe Committee. In this paper, performance of the air conditioning system between R-134a and R-152a is investigated experimentally. In the bench level, cooling capacity, condensing capacity, COP of automotive air conditioning system are ovaluated by means of air velocity entering the condenser and compressor revolution speed with optimized charge refrigerant quantity. Result of this study, R-152a refrigerant shows the possibility as alternative refrigerant of current R-134a in automotive air conditioning system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.sup1
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• pp.28.2-28.2
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• 2009

• Journal of Korean Society of Water and Wastewater
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• v.27 no.2
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• pp.197-206
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• 2013

Recently, climate change causes climatic anomaly such as global warming, the typhoon and severe rain storm etc. and it brings damage frequently. Climate change and global warming are prevalent all over the world in this century and many researchers including hydrologists have studied on the climate change. In this study, Seonakdong river watershed in the Nakdong river basin was selected as a study area. Real-time monitoring system was used to draw the rating curves, which has 0.78 to 0.96 of $R^2$. To predict runoff change in Seonakdong river watershed caused by climate change, the change in hydrologic runoff were predicted using the watershed model, SWAT. As a result, the runoff from the Seonakdong river watershed was increased by up to 45 % in summer. Because of the non-point sources from the farmland and the urban area, the water quality will be affected by the climate change. In this study, the operating plan of the water gates in Seonakdong river will be suggested by considering the characteristics of the watershed runoff due to the climate change. The optimal watergate opening plan will solve the water pollution problems in the reservoir-like river.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.11
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• pp.547-552
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• 2014

As global warming in recent years has raised ever more critical concern, refrigerants with high global warming potentials (GWP) are facing the challenge of being phased out. R410A, with a GWP of 2,088, has been widely used in residential air-conditioning and heat pump systems. A potential substitute for R410A is R32, which has a GWP of 675. The present study presents experimental results of an inverter heat pump system that uses R32 as an alternative refrigerant to R410A. Drop-in tests with R32 indicated that the energy efficiency ratio of the system increased by 5.3% in cooling standard mode, and by 4.2% in heating standard mode at the same capacity; and that the cooling and heating capacity increased by about 12% at the same compressor operating frequency, while the annual performance factor (APF) of the system increased by 5.3%.

• Clinical and Experimental Reproductive Medicine
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• v.43 no.1
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• pp.31-37
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• 2016

Objective: The aim of this study was to investigate associations between the morphology score of blastocysts and blastocoele re-expansion speed after warming with clinical outcomes, which could assist in making correct and cost-effective decisions regarding the appropriate time to vitrify blastocysts and to transfer vitrified-warmed blastocysts. Methods: A total of 327 vitrified-warmed two-blastocyst transfer cycles in women 38 years old and younger were included in this retrospective study. Results: The clinical pregnancy rate (CPR) and implantation rate (IR) of transfers of two good-morphology grade 4 blastocysts vitrified on day 5 (64.1% and 46.8%, respectively) were significantly higher than the CPR and IR associated with the transfers of two good-morphology grade 3 blastocysts vitrified on day 5 (46.7% and 32.2%, respectively). No significant differences were found in the CPR and IR among the transfers of two good-morphology grade 4 blastocysts regardless of the day of cryopreservation. Logistic regression analysis showed that blastocoele reexpansion speed after warming was associated with the CPR. Conclusion: The selection of a good-morphology grade 4 blastocyst to be vitrified could be superior to the choice of a grade 3 blastocyst. Extending the culture of grade 3 blastocysts and freezing grade 4 or higher blastocysts on day 6 could lead to a greater likelihood of pregnancy. Since re-expansion was shown to be a morphological marker of superior blastocyst viability, blastocysts that quickly re-expand after warming should be prioritized for transfer.

• Journal of the Korea Institute of Building Construction
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• v.18 no.4
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• pp.347-354
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• 2018

This paper verifies the superiority of warming work in winter by applying the insulation gang-form to the apartment housing site and analyzes the economic feasibility of the application. According to the experimental results, the actual cost of warming work was about 52 million won less than planned, and 160 million won less than the existing average.(Note - The cost of gang form material increased from 260 million won to 310 million won after the change) As a result, the construction cost could be reduced by about 110 million won. As the costs of warming work can change depending on the number of floors, the building number, and the area of each site, it is deemed necessary to conduct a thorough review in advance at the site where the cost of warming work is to be applied.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.1
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• pp.9-16
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• 2021

The present study was conducted to accomplish management efficiency by preparing preemptive measures for consumer dissatisfaction and overcome risks caused by Global Warming through studies of model cases in packaging. Through this study, we made it possible to find a way for companies to prepare for Global warming and consumer dissatisfaction. By contributing to eco-friendly packaging, we are trying to preemptively respond to recent major issues through packaging. Through this experiment, we tried to measure the degree of penetration of Plodia interpunctella H. larva into the insect repellent film produced by printing Ink containing a natural repellent. The control experiment was conducted with an untreated LDPE film to which no insect repellent was applied. The numbers decreased from 17 to 7 when the film was processed with repellent to show experimental results verifying effects of repellent by decrease in 10 (58.8% Decrease). Such results show that it is safe when the film is unfolded but in the case where the film is folded, the Plodia interpunctella H. punches through the film to lead to consumer dissatisfaction and it suggests that this can bring on risks to corporate management. Considering that most of the film is folded in the case of PE bag packaging, the direction which the corporations should take in terms of preparing for climate change countermeasures and consumer dissatisfaction has been clarified. Due to it receiving satisfactory results in safety rest results for printing film applied with pest repellent as well as the Quality analysis to test repellent contents of repellent film, it is certain that the importance of repellent method in packaging will increase in preparing for consumer dissatisfaction and actions against climate change henceforth.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1624-1629
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• 2008

The governing equations in generalized curvilinear coordinates for a 3D pulsatile flow are the Incompressible Navier-Stokes (INS) equations with the artificial dissipative terms and continuity equation discretized using a second-order accurate, finite volume method on the nonstaggered computational grid. This method adopts a dual or pseudo time-stepping Artificial Compressibility (AC) method integrated in pseudo-time. The computational technique implements the implicit approximate factorization method of the Beam and Warming method (1978), which is the extension of the Alternate Direction Implicit (ADI) method. The algorithm yields practically identical velocity profiles and secondary flows that are in excellent overall agreement with an experimental measurement (Rindt & Steenhoven, 1991).

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.711-714
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• 2001

A new technology to make fluoride gas such as NF$_3$contained in the exhaust gas from semiconductor manufacturing plants convert directly into a harmless substance have been established and new concept on the disposal treatment of global warming gases were presented. Experimental results verify that the chemical reactions can be take place at substantially lower temperature of 80-40$0^{\circ}C$ as compared with the combustion treatment method. Reaction product is mainly metal fluoride which is a harmless and a valuable chemical material as one of new resources. The other favorable characteristics are that the continuous treatment is possible at a low temperature under atmospheric pressure. Furthermore this process is compact, easily controllable and safely operable at low running cost. This paper concerns with a new harmless disposal treatment of toxic global warming gas.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.3
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• pp.255-263
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• 2011

Projected increases in atmospheric $CO_2$ concentration ([$CO_2$]) and temperature ($T_a$) have the potential to alter in rice growth and yield. However, little is known about whether $T_a$ warming with elevated [$CO_2$] modify plant architecture. To better understand the vertical profiles of leaf area index (LAI) and the flag leaf morphology of rice grown under elevated $T_a$ and [$CO_2$], we conducted a temperature gradient field chamber (TGC) experiment at Gwangju, Korea. Rice (Oryza sativa L. cv. Dongjin1ho) was grown at two [$CO_2$] [386 (ambient) vs 592 ppmV (elevated)] and three $T_a$ regimes [26.8 ($\approx$ambient), 28.1 and $29.8^{\circ}C$] in six independent field TGCs. While elevated $T_a$ did not alter total LAI, elevated [$CO_2$] tended to reduce (c. 6.6%) the LAI. At a given canopy layer, the LAI was affected neither by elevated [$CO_2$] nor by elevated $T_a$, allocating the largest LAI in the middle part of the canopy. However, the fraction of LAI distributed in a higher and in a lower layer was strongly affected by elevated $T_a$; on average, the LAI distributed in the 75-90 cm (and 45-60 cm) layer of total LAI was 9.4% (and 35.0%), 18.8% (25.9%) and 18.6% (29.2%) in ambient $T_a$, $1.3^{\circ}C$ and $3.0^{\circ}C$ above ambient $T_a$, respectively. Most of the parameters related to flag leaf morphology was negated with elevated [$CO_2$]; there were about 12%, 5%, 7.5%, 15% and 21% decreases in length (L), width (W), L:W ratio, area and mass of the flag leaf, respectively, at elevated [$CO_2$]. However, the negative effect of elevated [$CO_2$] was offset to some extent by $T_a$ warming. All modifications observed were directly or indirectly associated with either stimulated leaf expansion or crop phenology under $T_a$ warming with elevated [$CO_2$]. We conclude that plant architecture and flag leaf morphology of rice can be modified both by $T_a$ warming and elevated [$CO_2$] via altering crop phenology and the extent of leaf expansion.