• Journal of Sensor Science and Technology
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• v.15 no.5
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• pp.323-327
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• 2006

Manganese, copper and chlorine-doped ZnS phosphors (ZnS:Mn,Cu,Cl) were synthesized through solid-state reaction. Manganese was added in the range of amount $1.4{\sim}5.3$ mol % to ZnS phosphors containing 0.2 or 1.0 mol % of copper and a small amount of chlorine. As-synthesized phosphors showed a spherical morphology with a mean size of ${\sim}20\;{\mu}m$ and structural properties of Wurtzite, which were identified by SEM and XRD, respectively. Optical properties of ZnS:Mn,Cu,Cl synthesized with various concentrations of activators were analysed by both of PL and EL spectra. Samples mainly showing only 580 nm-orange emission by 380 nm-UV excitation gave different EL spectra of blue, green, and orange emissions at 450, 480 and 580 nm, respectively, depending on concentrations of $Cu^{2+}$ and $Mn^{2+}$.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.2
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• pp.121-125
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• 2010

Carbon Capture and Storage (CCS) technology mitigates the emission amount of carbon dioxide into the atmosphere and can reduce green house effect which causes the climate change. Deep saline aquifer or obsolete oil/gas storage etc. in the marine geological structure are considered as the candidates for the storage. The injection and storage relating technology have been interested in the global society, however the adverse effect caused by leakage from the system failure. Even the safety level of the CCS is very high and there is almost no possibility to leak but, still the risk to marine ecosystem of the high concentrated carbon dioxide exposure is not verified. The present study introduces the system and environmental risk assessment methods. The feature, event and process approach can be a good starting point and we found the some possibility from the fault tree analysis for evaluation. From the FEP analysis, we drove the possible scenario which we need to concentrate on the construction and operation stages.

• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.459-465
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• 2012

We had synthesized a green dopant material based on the binaphthyl group, 7,7'-(2,2'dimethoxy-1,1'-binaphthyl-3,3'-diyl) bis(4-(thiophen -2-yl) benzo[e][1,2,5] thiadiazole (TBT). We also fabricated the white organic light emitting diode (OLED) with a phosphorescent blue emitter : iridium(III)bis[(4,6-di-fluoropheny)-pyridinato -N,C2]picolinate (FIrpic) doped in N,N'-dicarbazolyl-3,5-benzene (mCP) of hole transport type host material and both TBT and bis(2-phenylquinolinato)- acetylacetonate iridium(III) (Ir(pq)2acac) doped in 1,3,5-tris(N-phenylbenzimidazole -2-yl)benzene (TPBi) of electron transport type host material. As a result, the property of white OLED using TBT, which demonstrated a maximum luminous efficiency and external quantum efficiency of 5.94 cd/A and 3.23 %, respectively. It also showed the pure white emission with Commission Internationale de I'Eclairage (CIE) coordinates of (0.34, 0.36) at 1000 nit.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.1370-1376
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• 2012

This study tried to analyze $CO_2$ emission volume as green-house gases by application of land use patterns and transport policies in District Unit Design. It is postulated a Toy network and various scenarios which are combined land use patterns and transport policies for analyzing $CO_2$ gas reduction. As results, this study shows best District Unit Design technique is the policy that develop mid block and introduction of car free zone to inner 2 way streets. Worst design technique is the policy that make hierarchical network and introduction of access control to outer roads that have been known as a best road policy till nowadays. Therefore, we need more carefully introduce design technique for reduction of $CO_2$ in District Unit.

• Environmental and Resource Economics Review
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• v.16 no.4
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• pp.923-946
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• 2007

The goal of this study is to analyse the effects of financial support by governmental on KERRP (Korea Emission Reduction Registration Project) in the case of descending clock auction. Result shows that about 60% of total reduction (612,000ton) can be achieved at the price of 8,000 Won/ton with the budget amount of 5 billion Won, if the benefit from energy saving by the project is not included. Also 100% of total reduction (1,015,713ton) can be achieved at the price of 4,900Won/ton, if the benefit from energy saving by the project is included. Because most projects get some benefits from the energy saving occurred by project performance, the financial support by government may not be needed. However, this type of support would be meaningful from the aspect of encouraging GHG (Green House Gas) reduction to be prepared for the potential obligation of national GHG reduction from 2013.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.1
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• pp.83-95
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• 2020

The economic issue of the period of return versus investment has emerged to efficiently utilize the thermal energy of public resource recovery facilities using waste and private thermal source facilities using BIO-SRF. Accordingly, the optimum temperature and pressure facilities are required beyond the traditional designed, constructed and operated. In this study, we analyzed current energy output by different heat and pressure model in domestic facilities, and calculated the characteristics of green-house gas emission. In order to, utilize the thermal energy producing facilities using waste and biomass fuel more efficiently, it is temperature and pressure, which will lead to more lucrative investment and return as well.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.4
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• pp.393-402
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• 2017

In this study, greenhouse gas (GHG) reductions from bioenergy (biogas, biomass) have been estimated in Korea, 2015. This study for construction of reduction inventories as direct and indirect reduction sources was derived from IPCC 2006 guidelines for national greenhouse gas inventories, guidelines for local government greenhouse inventories published in 2016, also purchased electricity and steam indirect emission factors obtained from KPX, GIR respectively. As a result, the annual GHG reductions were estimated as $1,860,000tonCO_{2eq}$ accounting for 76.8% of direct reduction (scope 1) and 23.2% of indirect reduction (scope 2). Estimation of individual greenhouse gases (GHGs) from biogas appeared that $CO_2$, $CH_4$, $N_2O$ were $90,000tonCO_2$ (5.5%), $55,000tonCH_4$ (94.5%), $0.3tonN_2O$ (0.004%), respectively. In addition, biomass was $250,000tonCO_2$ (107%), $-300tonCH_4$ (-3.2%), $-33tonN_2O$ (-3.9%). For understanding the values of estimation method levels, field data (this study) appeared to be approximately 85.47% compared to installed capacity. In details, biogas and biomass resulting from field data showed to be 76%, 74% compared to installed capacity, respectively. In the comparison of this study and CDM project with GHG reduction unit per year installed capacity, this study showed as 42% level versus CDM project. Scenario analysis of GHG reductions potential from bioenergy was analyzed that generation efficiency, availability and cumulative distribution were significantly effective on reducing GHG.

• Korean Journal of Materials Research
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• v.8 no.7
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• pp.616-620
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• 1998

Zn_{0.994}Mn_{0.006}Ga_2O_4$ green phosphor powders were synthesized using polymerized complex and solution combustion methods, and their powder and luminescence properties were characterized by XRD, SEM, BET, PL, etc. The properties were compared with those of the powders prepared by a solid state reaction method. The powders prepared by polymerized complex and solution combustion methods showed only a single spinel phase at 50$0^{\circ}C$ and 40$0^{\circ}C$, respectively. Their particle sizes were smaller than that of a solid state reaction method. Emission intensity of the phosphor powders prepared by both methods were highest at 90$0^{\circ}C$ and 40$0^{\circ}C$, respectively.

• Clean Technology
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• v.23 no.1
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• pp.34-41
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• 2017

The scrubber wastewater should be replaced frequently to maintain efficiency. Most chemical companies consign scrubber wastewater, because there are no wastewater treatment facilities. So scrubber wastewater is not frequently replaced because of high treatment cost. For this reason, the most scrubber exhaust gas exceeds the odor emission limit or has a phenomenon that the odor intensity of exhaust gas becomes higher. Therefore we have developed a scrubber wastewater cleaning system consisting of filtration and adsorption processes. The scrubber wastewater cleaning system was applied two chemical companies. We evaluated the water quality and odor reduction effect before and after system application. As a result, scrubber wastewater quality improved by 50% or more, odor reduction efficiency of scrubber exhaust gas improved by 20% or more. And the total operating costs of the scrubber could be reduced by 40% or more.

• Journal of Environmental Science International
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• v.27 no.9
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• pp.737-742
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• 2018

Livestock manure treatments have become a more serious problem because massive environmental pollutions such as green and red tides caused by non-point pollution sources from livestock manures have emerged as a serious social issue. In addition, more food wastes are being produced due to population growth and increased income level. Since the London Convention has banned the ocean dumping of wastes, some other waste treatment methods for land disposal had to be developed and applied. At the same time, researches have been conducted to develop alternative energy sources from various types of wastes. As a result, anaerobic digestion as a waste treatment method has become an attractive solution. In this study has three objectives: first, to identify the physical properties of the mixture of livestock wastewater and food waste when combining food waste treatment with the conventional livestock manure treatment based on anaerobic mesophilic digestion; second, to find the ideal ratio of waste mixture that could maximize the collection efficiency of methane ($CH_4$) from the anaerobic digestion process; and third, to promote $CH_4$ production by comparing the biodegradability. As a result of comparing the reactors R1, R2, and R3, each containing a mixture of food waste and livestock manure at the ratio of 5:5, 7:3, and 3:7, respectively, R2 showed the optimum treatment efficiencies for the removal of Total Solids (TS) and Volatile Solids (VS), $CH_4$ production, and biodegradability.