• Journal of the Korea Institute of Building Construction
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• v.15 no.2
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• pp.193-199
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• 2015

As a solution of both environmental issue of reducing carbon dioxide emission and sustainable issue of exhausting natural resources, in concrete industry, many research on recycling various by-products or industrial wastes as the concrete materials has been conducted. The aim of this research is feasibility analysis of additional reaction with ordinary Portland cement and flue gas desulfurization gypsum based on the blast furnace slag and recycled fine aggregate based mortar to achieve the normal strength range. Consequently, in the case of mortar replaced 10% FGD and 30% OPC for BS, 80% of plain OPC mortar's compressive strength was achieved. Furthermore, when the water-to-binder ratio is decreased to keep the practically similar level of flow, it is expected to be achieve the equivalent compressive strength to plain OPC mortar.

• Applied Chemistry for Engineering
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• v.31 no.6
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• pp.596-602
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• 2020

Blending process of adhesive production has a cooling process to cool down the temperature of the solution which was heated up to 76 ℃ with a mineral insulated (MI) cable by 30 ℃ at room temperature. Using a MI cable in the adhesive production process makes the production inefficient because it takes about 10 h for the cooling process. If a jacketed vessel is used instead of the MI cable, it would shorten the cooling downtime without any additional cooling system by using cold water. However, there are various types of jacketed vessels, and thus the most suitable type should be found before set up. In this study, we designed the optimized jacketed vessel for the adhesive production process by calculating the cooling downtime, which impacts production efficiency, as a function of the jacket types using computational fluid dynamics. As a result, the cooling performance of the plain jacket was 32.7% superior to that of the half-pipe coil jacket with the same height. In addition, the plain jacket with 60% spiral baffle reduced the cooling downtime and operating time by 80.4% and 25.1%, respectively.

• Clean Technology
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• v.24 no.4
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• pp.371-379
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• 2018

The objective of this study is to develop a platinum/hexaaluminate pellet catalyst for the decomposition of eco-friendly liquid propellant. Pellet catalysts using hexaaluminate prepared by ultrasonic spray pyrolysis as a support and platinum as an active metal were prepared by two methods. In the case of the pellet catalyst formed by loading the platinum precursor onto the hexaaluminate powder and then adding the binder (M1 method catalyst), the mesopores were well developed in the catalyst after calcination at $550^{\circ}C$. However, when this catalyst was calcined at $1,200^{\circ}C$, the mesopores almost collapsed and only a few macropores existed. On the other hand, in the case of a catalyst in which platinum was supported on pellets after the pellet was produced by extrusion of hexaaluminate (M2 method catalyst), the surface area and the mesopores were well maintained even after calcination at $1,200^{\circ}C$. Also, the catalyst prepared by the M2 method showed better heat resistance in terms of platinum dispersion. The effects of preparation method and calcination temperature of Pt/hexaaluminate pellet catalysts on the decomposition of liquid propellant composed mainly of ammonium dinitramide (ADN) or hydroxyl ammonium nitrate (HAN) were investigated. It was confirmed that the decomposition onset temperature during the decomposition of ADN- or HAN- based liquid propellant could be reduced significantly by using Pt/hexaaluminate pellet catalysts. Especially, in the case of the catalyst prepared by the M2 method, the decomposition onset temperature did not show a large change even when the calcination temperature was raised at $1,200^{\circ}C$. Therefore, it was confirmed that Pt/ hexaaluminate pellet catalyst prepared by M2 method has heat resistance and potential as a catalyst for the decomposition of the eco-friendly liquid propellants.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.85-93
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• 2011

This study experimented to evaluate the environment friendly high performance ternary cement concrete deck overlay pavement using mineral admixture such as fly ash and ground granulated blast-furnace slag. It was measured to find best binder mixing according to replacement rate of mineral admixture with compressive strength and flexural strength. After finding best binder, it is also experimented to evaluate durability on chloride penetration resistance, freezing- thawing resistance, scaling resistance of deicing chemicals, abrasion resistance, alkali-silica reactivity test and bonded environment friendly high performance ternary cement concrete deck overlay pavement experimented to evaluate bonded old deck and new concrete overlay pavement using special polymer cement mortar. In additions, bonded environment friendly high performance ternary cement concrete deck overlay pavement by experimental construction was evaluated at interchange bridge of North Yeoju. Result, examination was indicated better binding with binder replacement of cement 70%, ground granulated blast-furnace slag 15% and fly ash 15%. And special polymer cement mortar used in old deck and new overlay concrete was indicated better bonding both laboratory and construction.

• Applied Chemistry for Engineering
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• v.23 no.1
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• pp.1-7
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• 2012

In this article, I will introduce recent developments of environmental-friendly materials fabricated using atomic layer deposition (ALD). Advantages of ALD include fine control of the thin film thickness and formation of a homogeneous thin fim on complex-structured three-dimensional substrates. Such advantages of ALD can be exploited for fabricating environmental-friendly materials. Porous membranes such as anodic aluminum oxide (AAO) can be used as a substrate for $TiO_2$ coating with a thickness of about 10 nm, and the $TiO_2$-coated AAO can be used as filter of volatile organic compound such as toluene. The unique structural property of AAO in combination with a high adsorption capacity of amorphous $TiO_2$ can be exploited in this case. $TiO_2$ can be also deposited on nanodiamonds and Ni powder, which can be used as photocatalyst for degradation of toluene, and $CO_2$ reforming of methane catalyst, respectively. One can produce structures, in which the substrates are only partially covered by $TiO_2$ domains, and these structures turns out to be catalytically more active than bare substrates, or complete core-shell structures. We show that the ALD can be widely used not only in the semiconductor industry, but also environmental science.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1220-1230
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• 2010

The purposes of this study were to compare price sensitivity analysis for using environmental-friendly agricultural products in university foodservice between Jeonnam and Gyeongnam areas in Korea and to suggest the optimum guideline for price increase. The questionnaires were distributed to 600 university students respectively in Jeonnam and Gyeongnam area from July 15 to July 25, 2008; among them, 570 students from Jeonnam area and 490 students from Gyeongnam area responded. The results of this study were as follows. First, Indifference price (IDP) were 890 won (Jeonnam area) and 1,050 won (Gyeongnam area); Optimum price point (OPP) were 1,030 won (Jeonnam area) and 1450 won (Gyeongnam area). Price stress range were 140 won (890~1030 won) in Jeonnam area and 400 won (1050~1450 won) in Gyeongnam area. Second, point of marginal cheapness (PMC) were 500 won (Jeonnam area) and 790 won (Gyeongnam area) whereas point of marginal expensiveness (PME) were 1,170 won (Jeonnam area) and 1820 won (Gyeongnam area). Range of acceptable price (RAP) were 670 won (500~1170 won) in Jeonnam area and 1030 won (790~1820 won) in Gyeongnam area. Third, on the basis of IDP percentage and RAP, students in Jeonnam area were more sensitive to meal price increase than students in Gyeongnam area. In contrast, on the basis of Price Stress, students in Gyeongnam area were more sensitive to meal price increase than students in Jeonnam area. Hence, when using environmental-friendly agricultural products in university foodservice, in Jeonnam area, meal price increase should be recommended to be in RAP (500~1170 won), and in Gyeongnam area, meal price increase should be recommended to be in RAP (790~1820 won).

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.269-272
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• 2009

Catalytic decomposition of nitrous oxide was investigated experimentally. Two noble metal catalyst (Pt, Ir) were chosen to decompose nitrous oxide. Each catalyst was tested with different chamber pressure and preheating temperature. Ir decomposed $N_2O$ at lower temperature ($230^{\circ}C$) and suitable for $N_2O$ decomposition. In addition, the minimum required preheating temperature decreased as the chamber pressure increased. However, deactivation of Ir catalyst was observed during the experiments.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06d
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• pp.416-419
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• 2010

본 논문은 친환경 운전(Eco Driving)에 대한 사회적, 기술적 관심이 고조되고 있는 현 상황에서 차량에서 제공하는 차량 정보 가운데 MAF 센서 값을 이용하여 차량의 주행 연비를 추정하고자 하였다. MAF는 화학반응에서 연료 1g당 혼합되는 공기의 양을 의미하며, g/s의 단위를 사용한다. 휘발유 차량의 경우 엔진 ECU에서 폐회로 제어를 통해 혼합비를 14.7:1로 일정하게 유지하는 동작을 수행하므로 우리는 MAF 값을 통해 차량의 주행 연비 추정이 가능하다. 본 논문에서는 국내에서 생산중인 차종들에 대해 MAF 값을 이용한 실제 주행 테스트 수행하였으며, 이에 대한 연비 결과를 종합적으로 비교 분석하였다.

• Korean Chemical Engineering Research
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• v.57 no.5
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• pp.743-748
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• 2019

This study focuses on the simulation of wet flue gas desulfurization process for improving the production of gypsum by the utilization of low-grade limestone. At present, high-grade limestone with a $CaCO_3$ content of 94% is used for producing merchantable gypsum. In modeling process, a lot of reactions are considered to develop model. First, the limestone dissolution is simulated by RSTOIC model. Second, SOx absorption and crystallization is used by RCSTR model. Finally the gypsum is separated by using SEPERATORS model. Modeling steps make it easy to reflect further side reactions and physical disturbances. In optimization condition, constraints are set to 93% purity of gypsum, 94% desulfurization efficiency, and total use of limestone at 3710 kg/hr. Under these constraints, the mass flow of low-grade limestone was maximized. As a result, the maximum blending quantity of low-grade limestone for 2,100 kg of high-grade limestone that satisfies constraints is about 1,610 kg.

• Clean Technology
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• v.26 no.2
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• pp.91-95
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• 2020

A new eco-friendly synthetic method for N-hydroxysuccinimide (NHS), widely used in the pharmaceutical and fine chemical industries, is developed. Conventional synthesis method yields NHS of about 70% after its reaction with NH₂OH to succinic acid. In this method, NHS can be obtained using low-cost succinic acid, but a great deal of solvents are required as an extraction method to purify NHS, while the work-up process is complicated, resulting in low yield. In addition, there is a safety risk due to the high reaction temperature for commercial production, and it is not economical due to the high cost of production from the generation of much waste because of an acid catalyst and the use of various solvents. In order to make up for this shortcoming, this study used succinic anhydride as a raw material under low temperature reaction and developed a new eco-friendly industrial synthesis method using isobutyl alcohol for a single solvent and non-catalytic reaction. The economic evaluation confirms that there is a cost reduction effect of about 20%. In the future, based on this result, studies may establish a commercial production technology through scale-up research and proceed with foreign technology transfer.