• The Korean Journal of Food & Health Convergence
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• v.6 no.5
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• pp.19-25
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• 2020

The purpose of this study was to research and develop a step-type chemical liquid deodorizer including a liquid catalyst that can prevent civil complaints due to odor due to its excellent deodorizing performance. The main composition of chemical liquid deodorizer including liquid catalyst is cleaning deodorization, catalyst deodorization, chemical deodorization, water film plate, deodorization water circulation device, deodorization water injection device, catalyst management system, gas-liquid separation device, chemical supply device, deodorizer control panel, etc. It consists of a device. The air flow of the step-type liquid catalyst chemical liquid deodorizer is a technology that firstly removes basic odor substances, and the liquid catalyst installed in the subsequent process stably removes sulfur compounds, which are acidic odor substances, to discharge clean air. The efficiency of treating the complex odor of the prototype was 98.5% for the first and 99.6% for the second, achieving the target of 95%. The hydrogen sulfide treatment efficiency of the prototype was 100% for the first and 99.9% for the second, which achieved 95%, which was the target of the project. As a result, ammonia was removed by the reaction of ammonia and hydrogen sulfide.

• Particle and aerosol research
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• v.9 no.4
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• pp.261-269
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• 2013

The chemical mechanical polishing (CMP) process is widely used in semiconductor manufacturing process for planarization of various materials and structures. Point-of-use (POU) filters are used in most of the CMP processes in order to reduce the unwanted micro-scratches which may result in defects. The performance of the POU filter is depends on type and size of the abrasives used during cleaning process. For this reason, there is a need to evaluate POU filters for their filtration efficiency (FE) with different types of abrasives. In this study, we developed filter test system to evaluate the FE of POU using ceria and silica abrasives (slurry). The POU filter is roll type capsule filter with retention size of 0.2 ${\mu}m$. Two POU filters of different make are evaluated for FE. We observed that both POU filters show similar filtration efficiency for silica and ceria slurry. Results reveal that the ceria slurry and the colloidal silica particle are removed not only by mechanical way but also hydrodynamic and electrostatic interaction way.

• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.234-241
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• 2007

To achieve safe operation and to improve economics it is imperative to monitor and analyse demand and supply of utilities and to meet utility needs in time. The main objective of motor/turbine processes is to manipulate steam and electricity balances in utility plants. The optimal operation of motor/turbine processes is by far the most important to improve economics in the utility plant. In order to analyse motor/turbine processes, we need steady state models for steam generation equipments and steam distribution devices as well as turbine generators. In addition heuristics concerning various operational situations are required. The motor/turbine optimal operation system is based on utility models and operational knowledgebase and provides optimal operating conditions when the amount of steam demand from various steam headers is changed frequently. The optimal operation system also produces optimal selection of driving devices for utility pumps to reduce operating cost.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.3
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• pp.88-95
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• 2019

The hydrogen torch ignition system has been widely used to ignite a pure aluminum for aluminum powder combustion system because of its simple ignition method. However, the conventional hydrogen torch ignition system has a disadvantage that requires a high-pressure tank to supply hydrogen, which leads to the increase of the weight. In order to solve this problem, a hydrogen ignition system using $NaBH_4$, a solid chemical hydride, was designed in this study. The thermal decomposition of $NaBH_4$ was initiated approximately at $500^{\circ}C$ and hydrogen was generated. The parameters affecting the thermal decomposition characteristics of $NaBH_4$ were analyzed and the aluminum combustion test was carried out using $NaBH_4$-based hydrogen ignition system to study the applicability to a practical aluminum-combustion propulsion system.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.183-194
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• 2013

Liquid urea based SCR has been used in the market to reduce NOx in the exhaust emission of the diesel engine vehicle. This system has several problems at low temperature, which are freezing below $-12^{\circ}C$, solid deposit formation in the exhaust, and difficulties in dosing system at exhaust temperature below $200^{\circ}C$. Also, it is required complicated exhaust packaging equipment and mixer due to supply uniform ammonia concentration. In order to solve these issues, solid urea, ammonium carbonate, and ammonium carbamate are selected as ammonia sources for the application of solid SCR. In this paper, basic research on reaction rate of three ammonia-transporting materials was performed. TGA (Thermogravimetric Analysis) and DTA (Differential Thermal Analysis) tests for these materials are carried out for various heating conditions. From the results, chemical kinetic parameters such as activation energy and frequency factor are obtained from the Arrhenius plot. Additionally, from test results of DSC (Differential Scanning Calorimeter) for these materials, chemical kinetic parameters using the Kissinger method are calculated. Activation energies of solid SCR from this experiment are compared with proper data of literature study, then obtained data of this experiment are used for the design of reactor and dosing system for candidate vehicle.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.571-576
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• 2002

Electromagnetic analysis has been made for the design of 3 MJ Compulsator (Compensated Pulsed Alternator, CPA) that will be used as the power supply system of the electrothermal-chemical launcher system. using finite element method with ANSYS/Emag. From the analysis results, it was possible to decide the excitation MMF and the rotor/stator size to obtain the desired output current. And using electromagnetic forces from the analysis results. the stresses on the components of 3 MJ CPA could be analyzed. The detailed design based on the analysis results has been made and the fabrication of 3 MJ CPA is in progress. Before assembling components into 3 MJ CPA. an experiment is being made to check the correspondence between analysis results and measurements.

• Journal of Power System Engineering
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• v.7 no.1
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• pp.20-24
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• 2003

Boiler is one of the most important utilities providing steam to turbine in order to supply mechanical energy in thermal power plant. It is composed of thousands of tubes for high efficient heat transfer. Water is converted to steam inside the waterwall tubes. Many chemical components dissolved in boiler water come out of itself, deposit to the tube wall surface, prohibit heat transer, raise tube metal temperature, eventually fail the boiler tubes. Several tasks such as fracture surface study, tensile test, hardness test, metallurgical test, composition analysis of sticking elements were conducted to identify the root cause of tube failure.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2179-2181
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• 2005

An experimental study on the water plasma characteristics of removal efficiency for organic contaminants in dye waste water has been investigated. In this study, dielectric barrier discharging electrodes with round shape have disposed cross each other in reactor, and pulse power was supplied to between each electrodes. Its output pulse voltage range is from 0[V] to 30[kV] and output frequency range is from 100[Hz] to 2[kHz]. Using proposed system, High frequency discharge is tested in the mixed Tone(air and water) and the space distribution of streamer corona plasma is observed. In spite of the increasement of voltage and frequency, the proposed system have a stable operation characteristics. It is verified by the experimental results.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.284-284
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• 2009

EFA production systems have through necessity resulted in the development of innovative practices for weed, pest and diseases control, for example, using ducks and snails for weed control in paddy fields. These practices began to be introduced in the early 1990's and the techniques have become more popular and have been adapted to suit regional conditions. In this study, the production practices, productivity and economic performances of organic and non-chemical rice farming adopting ducks and snails for weed control were compared. In the production practices, Korean organic and non-chemical farming seem to have several concerns in terms of sustainability. It comprises lack of resistant variety use and rotational cropping system as well as high dependency upon external inputs such as organic fertilizer and farming materials for pest control. The production level of organic farming is approximately similar level but 20% higher income than non-chemical farming, while, when it was compared with conventional farming organic farming showed 20% lower productivity but 20% higher income. Organic farming shows 15% to 18% higher profits than non-chemical farming as the snail-using organic farming tends to have higher income and lower input costs than duck-using organic farming. This may encourage more farmers to convert to organic production using these techniques than simply non-chemical farming in the future. This organic conversion could be more promoted by policy intervention. However, it may result in increased supply and therefore decreased prices for organic rice in the long term unless further market demand occurs. Balanced policy measures considering production as well as marketing and consumption are urgently required for the sustainable development of organic farming.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.3
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• pp.294-301
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• 2020

Man-In-Simulant Test(MIST) provides a test method to evaluate chemical protective equipments such as protective garments, gloves, footwear and gas mask. The MIST chamber is built to control concentration of chemical vapor that has a activity space for two persons. Non-toxic methyl-salicylate(MeS) is used to simulate chemical agent vapor. We carried out to measure inward leakage MeS vapors by using passive adsorbent dosimeter(PAD) which are placed on the skin at specific locations of the body while man is activity according to the standard procedure in MIST chamber. But more time is required for PADs and there is concern of contamination in PADs by recovering after experiment. Therefore detector for measuring in real time is necessary. In order to analyze in real time the contamination of the personal protective equipment inside the chemical environment, we have developed a wireless real-time gas detector. The detector consists of 8 gas-sensors and 1 control-board. The control-board includes a CPU for processing a signal, a power supply unit for biasing the sensor and Bluetooth-chipset for transmission of signals to external PC. All signals from gas-sensors are converted into digital signals simultaneously in the control-board. These digital signals are stored in external PC via Bluetooth wireless communication. The experiment is performed by using protective equipment worn on manikin. The detector is mounted inside protective equipment which is capable of providing a real-time monitoring inward leakage MeS vapor. Developed detector is demonstrated the feasibility as real-time detector for MIST.