• Journal of Ocean Engineering and Technology
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• v.10 no.3
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• pp.117-124
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• 1996

A fluidized bed combustion chamber is widely used to incinerate waste material. The most important factor designing the incinerator is the flow characteristics in a fluidized bed, because combustion efficiency is influenced by the flow characteristics. This paper has invesitigated the flow characteristics of bubbles in fluidized bed by means of meassuring a pressure fluctuation in the fluidized bed. A pressure probe system has used to measure the pressure. The data concerned with bubble rising velocity, bubble size, distribution of bubbles and frequency of bubble generation or decay are obtained to find the flow characteristics of bubbles in the fluidized bed. The result obtained from this experimental study can be used to design the fuel feeding system of fluidized bed combustion type incinerator. And it is possible to predict the mixing of waste material and fluidizing material.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.02a
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• pp.182-190
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• 2004

An unique extraction chromatographic column (TOA: Tri-n-octylamine on Teflon powder) with a two-stage sample loading was prepared to separate Np and Pu from the environmental matrix. Np and Pu were efficiently retained in 4 M $HNO_3$ medium on the column and easily eluted with 0.02 M oxalic acid in 0.16 M HNO$_3$at $95^{\circ}C$. The separated solutions were free from most of the matrix elements and were aspirated into the ICP-MS directly. The decontamination factor for 238U is more than 104. The instrumental detection limit for 237Np was 0.46 pg mL-l ($1.2{\times}10_{-5}$Bq mL-l), and for 239Pu was 0.48 pg mL-l ($1.1{\times}10_{-3}$ Bq mL-l). The feasibility for the determination of both elements was proved by analysing IAEA-135 reference samples, the measured values agreed with the recommended reference value.

• Journal of Industrial Technology
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• v.16
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• pp.45-50
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• 1996

An experimental study os performed to examine the feasibility of using wastes steel furnace slag construction materials and its utility as a replacement for the natural resources to prevent the economic loss was investigated. A half factorial exprements was performed with the variables of W/C ratio, S/A, Coarse aggrigate/Slag ratio and slump as a preliminary study for optimum mix design of concrete. The results show that the W/C ratio and Slump ratio are the most important factor to the concrete strength. The substitute of waste Slag up to 100% has little influence, saying that it can substitute the coarse aggregate without damaging the concrete properties.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.196-199
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• 2005

The centrifuge system in liquid radwaste system(LRS) is composed of several skids including Decanter and Separator. The decanter separates the sludge over 5mm in size within liquid radwaste by centrifuge force and drops it into 55gallon drum. The separator separates the sludge over $0.1{\mu}m$ in size within the liquid radwaste processed by Decanter by centrifuge force. The process of separating the sludge from the LRS keeps the resin in Ion Exchanger from being damaged and improves the performance of Ion Exchanger, and satisfies the decontamination factor suggested in Uljin 5,6 FSAR to safety discharge into the outer environment.

• Journal of the Korean Society of Food Culture
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• v.17 no.3
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• pp.252-259
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• 2002

The purpose of this study examined important factor of performance on Contract Foodservice management. Three contract Foodservice companies were selected which were located in Seoul & kuonggi province. 300 units were chose. The questionnaire was composed of seven part. There were the operation of food management, the operation of menu, the operation of equipment and facilities management, the operation of solid waste and safety management, the operation of waiting time management. As a result of the survey B&I foodservice was listed higher than University foodservice as food hygiene, FIFO and food shelf life. University foodservice employees worked 4 hour longer than B&I foodservice employees, so turnover rate was higher than it. Comparing the number of feeding, B&I foodservice equipment and facilities scale was bigger than University foodservice equipment and facilities. The rate of solid waste on B&I foodservice was 11.468% and the rate of University foodservice was 16.23%, the waiting time of University foodservice was about 8mins longer than B&I foodservice.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11C
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• pp.133-139
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• 2001

The economical detection of dual-tone multi-frequency(DTMF) signals is an important factor when developing cost-effective telecommunication equipment. Each channel has independently a DTMF receiver, and it informs the detected signal to processors. In order to detect the DTMF signals, this paper analyze the power spectra of the DTMF receiver by using the QFT algorithm. As experimental result, by analyzing 2$\^$M/ real data in terms of ITU-T specification, it show that the QFT algorithm improve the performance of the DTMF receiver and can save memory waste and can the real-time processing.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.12
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• pp.1209-1214
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• 2006

This paper presents an application of Dividing Wall Column(DWC) to the recovery of the waste solvent from the film making processes. The waste solvent feed contains MEK(Methyl-Ethyl-Ketone), Toluene, Cyclohexanone, and water. The commercial software $HYSYS^{TM}$ was used for rigorous simulation and analysis. Sensitivity analysis for several major design variables were carried out to achieve the optimal design of the process. Distribution of the internal vapor and liquid flows to the prefractionator and main sections is shown to be the most dominant design factor for energy saving efficiency in the DWC process. The simulation results also show that the solvent recovery process using the DWC significantly improves both the energy efficiency and the compactness of the solvent recovery process.

• Advances in environmental research
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• v.6 no.1
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• pp.25-33
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• 2017

This paper discussed plurality in urban governance in Nigeria and its implication on delivery of urban environmental services, with a focus on water supply, sanitation and solid waste disposal. Conceptually, it explained urban governance as the sum total of the ways of achieving an inclusive city and expressed the urban governance system of Nigeria based the legal framework set for them. The paper explored the environmental implications of urban governance in Nigeria. It concluded that urban governance has several implications on delivery of urban environmental services in Nigeria. The dualism in urban governance is a factor contributing towards inefficient delivery of environmental services such as water supply, sanitation and solid waste management in Nigeria. The paper recommended, among others, a constitutional reform that will guarantee efficient urban governance and delivery of environmental services in Nigeria.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.1
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• pp.45-52
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• 2023

The power generation method using expensive diesel has operation problems such as high cost diesel generator and a lack of reserved power due to increase of power demand in some islands, requiring expansion of power generation facilities. To solve this problems, it is necessary to improve the efficiency of power generation facilities through an ORC(Organic Rankin Cycle) system application that uses waste heat as a heat source. Therefore, localized application technology of price competitive and highly reliable ORC power generation system is needed, and optimization technology of generators is having great effect, so this study performed two generator designs to get a high-efficiency generator with an optimized 30kW output. The comparison of simulation data for two designed models showed that a generator with SPM factor of 46.2% had an efficiency of 92.1% and a power ouput of about 23.2kW based on 12,000rpm, a generator with SPM factor of 44.46%, had a power output of 27.9kW and efficiency of 93.6% based on above rpm. For the verification of improved design model with SPM factor of 44.46%, the prototype test system with 110kW motor dynamometer was installed and got to the efficiency of 92.08% with conditions of the rated capacity 25kW at 12,000rpm, the test results of prototype generator showed the validity of generator design.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.12
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• pp.865-872
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• 2014

The study was conducted to evaluate the effect of addition of food waste in brown water for anaerobic hydrogen production. Batch experiment was carried out to determine appropriate food waste to brown water mixing ratio. Maximum hydrogen yield of $6.92mmol\;H_2/g\;COD_{removed}$ was obtained at 70% food waste and 30% brown water. Semi-pilot scale reactor was operated based on result of batch experiment. Semi-pilot reactor operated, mixing 70% food waste and 30% brown water showed significant increment in butyric acid concentration. B/P (Butyric to propionic acid ratio) which is considered as governing factor for hydrogen production was found high (52.64). Maximum hydrogen yield of $25.03mmol\;H_2/g\;COD_{removed}$ was obtained. Result of this study concluded that mixing of food waste to brown water at appropriate ratio assists in enhanced hydrogen fermentation.