• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.539-546
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• 2019

Global warming has mentioned as one of the international problems and these researches have conducted. Carbon Capture, Utilization and Storage (CCUS) technology has improved due to increasing importance of reducing emission of carbon dioxide. Among of various CCUS technologies, mineral carbonation can converted $CO_2$ into high-cost materials with low energy. Existing researches has been used ions extracted solid wastes for mineral carbonation but the procedure is complicated. However, the procedure using seawater is simple because it contained high concentration of metal cation. This research is a basic study using seawater-based wastewater for mineral carbonation. 3 M Monoethanolamine (MEA) was used as $CO_2$ absorbent. Making various concentrations of seawater solution, simulated seawater powder was used. Precipitated metal carbonate salts were produced by mixing seawater solutions and $rich-CO_2$ absorbent solution. They were analyzed by X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Thermogravimetric Analysis (TGA) and studied characteristic of producing precipitated metal carbonate and possibility of reusing absorbent.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.76-76
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• 2001

The objective of this study was to optimize the vitrification method of in vitro produced bovine embryos. Thus, in vitro produced embryos at 8 cell, morula and blastocyst stages were vitrified on electron microscope grids (EM grids) or in open pulled straws (OPS) with EG5.5 (5.5 M ethylene glycol, 1.0 M sucrose and 10% FBS in m-DPBS medium) freezing solution and their survival rates after thawing were compared. The embryos on EM grids or in OPS were briefly exposed to EG5.5 freezing solution and plunged directly into liquid nitrogen within 30 to 35 sec. Post-thawed embryos were serially diluted in 0.5, 0.25 and 0.125 M sucrose in m-DPBS, each for 1 min, and then cultured in CRI aa medium supplemented with 10% FBS. Embryonic survival rate was assessed as re-expanded and hatched rates of those embryos after warming. The rates of re-expansion embryos did not significantly different between EM grid (8 cell: 42.10%, morula: 66.66% and blastocyst: 77.08%) and OPS (8 cell: 47.36%, morula: 61.90% and blastocyst: 83.33%) methods. In addition, the hatched rates in EM grid (8 cell: 31.57%, morula: 57.14% and blastocyst: 72.91%) were similar to those in OPS (8 cell. 34.21%, morula: 50.00% and Blastocyst: 77.08%). Interestingly, even at the same blastocyst stage, the in vitro survival of day 7 embryos (EM grid: 79.48 and OPS: 87.18%) was higher than those of day 8 embryos (EM grid: 72.10 and OPS: 82.06%). The total cell number of blastocyst developed in vitro after vitrification was examined with Hoechst 33342 staining to compare the embryo quality among different treatment groups. The total cell number of blastocyst was not significantly different between vitrified groups (EM grid: 162.4$\pm$8.0 and OPS: 158.4$\pm$7.1) and unvitrified control (168.0$\pm$5.6). These results indicate that both vitrification containers can provide the high rate of embryo survival. Moreover, the OPS container may not need a cap to protect the container from floating after immersion in L$N_2$. Therefore, this study suggest that bovine embryos can be cryopreserved easily, effectively and successfully by vitrification method using EM grid or OPS with EG5.5 freezing solution. In the future, the Pregnancy rate would be investigated after transfer of our vitrified embryos into the appropriated recipients.

• Journal of Embryo Transfer
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• v.13 no.3
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• pp.313-321
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• 1998

This study was conducted to investigate the effects of equilibration and dilution methods on the survival rate of vitrified IVM-IVF bovine blastocysts. Vitrification solution was composed with 20% glycerol, 20% ethylene glycol, 3/8 M sucrose and 3/8 M dextrose in D-PBS supplemented with 20% FBS (GESD). Embryos were equilibrated in 1 of 3 methods: 3-step (El), 2-step (E2), or 1-step (E3), and after loading into 0.25-ml straws, were plunged into liquid nitrogen. After warming in water bath at 2$0^{\circ}C$, cryoprotectants were diluted in 1 of 3 methods: 1) D1(VS+1/2 M sucrose, 1/2 M sucrose and l/4 M sucrose), 2) D2 (1/2 M sucrose and 1/4 M sucrose), or 3) D3(1/2 M sucrose only). All procedures except warming were conducted at room temperature. Survival and hatching rates of blastocysts and expanded blastocysts following equilibration methods were 50 and 83.6%, and 27.8 and 67.3%, respectively in El, which were significantly higher (P〈0.01) than those of E2 (16.7 and 23.2%, and 7.4 and 12.5%, respectively) and 23 (0 and 3.7%, and 0 and 0%, respectively). Survival and hatching rates of expanded blastocysts were significantly (P〈0.01) higher than those of blastocysts in El. Survival rates of blastocysts and expanded blastocysts following dilution methods were 52% and 80.6% in D2, which were significantly higher (P〈0.05) than those of D1 (29.6 and 48.3%) and D3 (47.2 and 63.8%). Hatching rates of blastocysts were similar in D1, D2 and D3, however in expanded blastocysts, that of D2(61.3%) was significantly higher (P〈0.01) than that of D1(34.5%). Survival rates of expanded blastocysts in D1 and D2, and hatching rates in D2 and D3 were significantly higher(P〈0.01) than those of blastocysts. These results indicate that the viability of vitrified blastocysts was improved by the several steps of equilibration, and by 2-steps dilution after warming, independently of their stage of development. The results also indicated that the expanded blastocysts are more profitable to vitrification than blastocysts.

• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.1002-1007
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• 2012

The considerable portion of energy demand has been satisfied by the combustion of fossil fuel and the consequent $CO_2$ emission was considered as a main cause of global warming. As a technology option for $CO_2$ emission mitigation, absorption process has been used in $CO_2$ capture from large scale emission sources. To set up optimal operating parameters in $CO_2$ absorption and solvent regeneration units are important for the better performance of the whole $CO_2$ absorption plant. Optimal operating parameters are usually selected through a lot of actual operation data. However theoretical approach are also useful because the arbitrary change of process parameters often limited for the stability of process operation. In this paper, a theoretical approach based on vapor-liquid equilibrium was proposed to estimate optimal operating conditions of $CO_2$ absorption process. Two $CO_2$ absorption processes using 12 wt% aqueous $NH_3$ solution and 20 wt% aqueous MEA solution were investigated in this theoretical estimation of optimal operating conditions. The results showed that $CO_2$ loading of rich absorbent should be kept below 0.4 in case of 12 wt% aqueous $NH_3$ solution for $CO_2$ absorption but there was no limitation of $CO_2$ loading in case of 20 wt% aqueous MEA solution for $CO_2$ absorption. The optimal regeneration temperature was determined by theoretical approach based on $CO_2$ loadings of rich and lean absorbent, which determined to satisfy the amount of absorbed $CO_2$. The amount of heating medium at optimal regeneration temperature is also determined to meet the difference of $CO_2$ loading between rich and lean absorbent. It could be confirmed that the theoretical approach, which accurately estimate the optimal regeneration conditions of lab scale $CO_2$ absorption using 12 wt% aqueous $NH_3$ solution could estimate those of 20 wt% aqueous MEA solution and could be used for the design and operation of $CO_2$ absorption process using chemical absorbent.

• Industrial Engineering and Management Systems
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• v.13 no.3
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• pp.289-296
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• 2014

With society becoming more advanced and complex, the required management engineering makes essential the development of human resources that can propose solutions for problems of new phenomena from a different perspective. As an example of such phenomena, we note a consumer electronics 'Eco-point' system campaign in this study. To mitigate global warming, revitalize the economy, and encourage the adoption of terrestrial digital compatible TVs, the consumer electronics Eco-point system campaign was implemented in May 2009 in Japan. In this study, we note a model which is constant term with exponential curve with notion of the growth phenomenon (Nakagiri and Kurita, Journal of the Operations Research Society of Japan, 2002). In our study, we call this model the 'differential equation model of the growth phenomenon.' This model represents a phenomenon with a hierarchical structure for capturing the properties of n species. In this study, we propose a new model which can represent not only the impact of largescale campaigns but also seasonal factors. Accordingly, we understand the phenomenon of fluctuation of sales of some products caused by large-scale campaigns and predict the fluctuation of sales. The final goal of this study is to develop human resources that can propose provision and solution for pre-consumption and reactionary decline in demand by understanding the impact of large-scale campaigns. As the first step of this goal, our objective is to propose a new regression method with different conventional perspective that can describe the fluctuation of sales caused by large-scale campaigns and show the possibility of new management engineering education.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.1
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• pp.130-136
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• 2011

Methane is known to be one of the major greenhouse gases. On a global scale, livestock farming may contribute 18% of total greenhouse gas emissions. Though methane contribution is less than 2% of all the factors leading to global warming, it plays an important role because it is 21 times more effective than carbon dioxide. Methane emission is a direct result of the fermentation process performed by ruminal microorganisms and, in particular, the archael methanogens. Reducing methane emission would benefit both ruminant production and the environment. Methane generation can be reduced by electron-sink metabolic pathways to dispose of the reducing moieties. An alternative way for methane control in the rumen is to apply inhibitors against methanogens. Generating methane from manure has considerable merit because it appears to offer at least a partial solution to two pressing problems-environmental crisis and energy shortage. An obvious benefit from methane production is the energy value of the gas itself. Control of methane emission by rumen microbes in Korea has mainly been focused on application of various chemicals, such as BES and PMDI, that inhibit the growth and activity of methanogens in the rumen. Alternatives were to apply long-chain polyunsaturated fatty acids and oils with or without organic acids (malate and fumarate). The results for trials with methane reducing agents and the situation of biogas production industries and a typical biogas plant in Korea will be introduced here.

• Journal of Environmental Science International
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• v.21 no.1
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• pp.113-123
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• 2012

A unit emission reduction of nitrous oxide ($N_2O$) from anthropogenic sources is equivalent to a 310-unit $CO_2$ emission reduction because the $N_2O$ has the global warming potential (GWP) of 310. This greatly promoted very active development and commercialization of catalysts to control $N_2O$ emissions from large-scale stationary sources, representatively nitric acid production plants, and numerous catalytic systems have been proposed for the $N_2O$ reduction to date and here designated to Options A to C with respect to in-duct-application scenarios. Whether or not these Options are suitable for $N_2O$ emissions control in nitric acid industries is primarily determined by positions of them being operated in nitric acid plants, which is mainly due to the difference in gas temperatures, compositions and pressures. The Option A being installed in the $NH_3$ oxidation reactor requires catalysts that have very strong thermal stability and high selectivity, while the Option B technologies are operated between the $NO_2$ absorption column and the gas expander and catalysts with medium thermal stability, good water tolerance and strong hydrothermal stability are applicable for this option. Catalysts for the Option C, that is positioned after the gas expander thereby having the lowest gas temperatures and pressure, should possess high de$N_2O$ performance and excellent water tolerance under such conditions. Consequently, each de$N_2O$ technology has different opportunities in nitric acid production plants and the best solution needs to be chosen considering the process requirements.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.8
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• pp.1061-1068
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• 2012

These days, world wide interest about global warming and environmental pollution and exhausting fossil fuel which have been main energy source in all around the world. So many country have tried to find out the solution by investing new & renewable and clean energy. Therefore LNG have been widely used as a substitution of fossil fuel and clean energy that emits less pollutant like SOx, NOx. Therefore LNG consumption has been quickly raised and LNG carriers have been getting larger for decades. In this study, high power fiber laser was used for welding of stainless steel for LNG carrier to increase its productivity. Used material was STS316L which has low carbon less than 0.03% and its thickness was 8 mm. We carried out bead, lap and butt welding by using the fiber laser which has maximum power up to 5kW. As a result, we could find out that lap and butt joint was possible at welding speed of 2.0m/min and 3.0m/min respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.435-436
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• 2008

Dye-sensitized Solar Cells(DSSCs) which convert incident sun light into electricity were expected to overcome global warming and depletion of fossil fuels. And it is one of study that is lately getting into the spotlight because manufacturing method is more simple and inexpensive than existing silicon solar cells. In this respect, DSSCs are in the limelight as the next generation solar cells. DSSCs are generally composed of a dye-modified $TiO_2$ photoelectrode, a Pt counter electrode, and an electrolytes containing a redox couple$(I^-/I_3^-)$. Among these elements, pt electrode were prepared by applying electric potential to FTO substrate in the $H_2PtCl_6$ solution. In this study, we report the solar cell efficiency depending on $PtCl_4$ concentration change. $PtCl_4$ concentration was 1mM, 5mM, 10mM, and 20mM, and adhered on FTO glass substrate by sintering process. When applied each $PtCl_4$ counter electrode on DSSC, the best efficiency was found at 10mM of $PtCl_4$ concentration. The catalyst promotes the movement of electron from the counter electrode to the electrolyte the higher the molarity, the better the efficiency. However, in case of 20mM, it is estimated that over-deposited $PtCl_4$ tends to restrict the movement of electron due to its bundle formation.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.4
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• pp.95-104
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• 2013

As global warming and depletion of fossil fuel are considered as urgent problems, the development of electric vehicle (EV) is getting more attention by automobile industry. However, the wide adoption of EVs is not coming yet, because of many issues such as long recharging time and high cost of batteries etc. As an alternative solution to the conventional battery charging EV, the idea of battery exchanging EV is introduced. To realize the battery exchanging business model, one should solve the issues of ownership and reliability of battery. To address such issues, the concept of battery sharing should be considered together with good traceability system. In this study, we studied RFID code structure to provide better visibility and traceability for shared EV batteries. The proposed RFID code and code generation system is based on GRAI-96 of EPCglobal and included factors such as chemical, physical, and manufacturing features. The designed code can be also used as the ID of each battery.