• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.168-169
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• 2002

본 연구에서는 Tank model의 이론과 구조를 설명하고, 형산강 수계의 강우-증발-유량관측자료를 사용하여 모형의 매개변수를 산정하고 이를 기준값으로 하여 각 매개변수들의 특성을 파악하고자 민감도 분석을 실시하였다. 민감도 분석을 통해서 얻어진 Tank model 매개변수들의 특성은 앞으로 형산강에 대한 하천 유출량 산정시 도움을 줄 수 있을 것이다. 이상과 같이 검증되어진 Tank모델을 사용하여 1997년부터 2001년까지의 5년간의 강우량, 증발산량 자료를 바탕으로 형산강 일별 하천 유출량을 산정하고 계절별, 권역별 하천수의 유하 특성에 대해서 고찰하였다. (중략)

• Journal of Environmental Health Sciences
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• v.20 no.2
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• pp.28-38
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• 1994

New problems have been recently posed on the abnormal foaming (Scum) in an aeration tank and the sludge flotation in a final sedimentation tank during the activated sludge process. However, the activities of the causing bacteria, Nocardia-amarae in an aeration tank have not been searched out at all. Therefore, in this article the activities of Nocardia-amarae in an aeration tank have been closely examined by means of the changes of (F/M) ratio, SRT and inflowing substrate using continuous type and fed-batch type. Summarized results of experiments are as follows. 1. Regrading continuous culture when synthetic wastewater was used substrate neither the increase in the number of Nocardia-amarae in the aeration tank nor the Occurrence of Scum was observed. 2. In the case of fed-batch culture, Nocardia-amarae in the aeration tank increased due to the partial change in substrate and the effect of SRT was significant. 3. Once the scum was formed and the quantity of added Nocardia-amarae and substrate were not changed, the effect of STR was not significant.

• 한국전산유체공학회:학술대회논문집
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• 2004.10a
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• pp.33-36
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• 2004

The ballast tank of a ship is a system that realizes the required shipping condition and controls the draft of a ship. The loading/unloading of the ballast tank is frequently operated during navigation and the accurate prediction of the loading/unloading time is very important. A numerical algorithm that predicts the loading/unloading time of the ballast tank has been developed and applied to the prediction of the loading/unloading time of the ballast tank with various piping systems. This algorithm can be useful in optimizing the ballast tank system in early design stage.

• 한국전산유체공학회:학술대회논문집
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• 2004.10a
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• pp.131-136
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• 2004

Thermal control of satellite propellant tank is achieved by patch heaters enabled by thermostat's behavior. It is important to attach the thermostat on the appropriate position of the propellant tank. However its position cannot be given with exact numerics because tank is spherical. Actually the position for thermostat is designated in relevant drawing approximately, therby, the engineer practices depending on his own experience and intuition. The sensitivity analysis for the position of thermostat is performed such that the influence on the thermal behavior and control of tank is examined quantatively. When assembling tank module, the reasonable performance on the thermal control is believed with possible human errors if the uncertainty in the position of thermostat is not quite large.

• Journal of Environmental Health Sciences
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• v.34 no.6
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• pp.446-451
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• 2008

In this study, the removal characteristics of organic components and nutrients of sewage taken from the Suwon area were investigated in a lab-scale modified DNR (Daewoo Nutrient Removal) process. The modified DNR process consisted of a sludge denitrification tank, an anaerobic tank, an anoxic tank, an aerobic tank, a secondary anoxic tank and a secondary aerobic tank. The proposed process with the average C/N ratio of 3.5 was performed for the sewage treatment. The results were compared with other existing DNR processes. The organic fractions in sewage were analyzed by measuring the oxygen uptake rate. The resulting removal efficiencies of SS, BOD, COD, TN and TP were 93.1%, 95.5%, 86.1%, 67.8% and 80.6%, respectively.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2000.02a
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• pp.48-51
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• 2000

The behavior of cryogenic liquid stored in a closed cryogenic tank has been studied at various liquid levels, as a function of pressure and temperature on time, assuming heat leak(NER) is 0.7%/day. The pressure depends, as expected, on the liquid-vapor ratio in a tank. The calculation shows that if liquid level is as high as 90%,much higher than the critical volume ration, in a closed tank of designed pressure 11 bar, it takes 5.4 to 15days for the entire volume of the tank to be filled with liquid and 11 to 22 days for the tank to be exploded. If a closed tank is full of liquid, it is extremely dangerous because of abrupt pressure increase so that the safety devices are necessary to vent out pressurized gas. These phenomena can be explained with the liquid heat capacity, latent heat and compressibility.

• Solar Energy
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• v.18 no.4
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• pp.59-66
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• 1998

It was compared with experimental data to verify TRNSYS Model of the thermosyphon hot water system and the various simulations were conducted to optimize the component parameters of the system. To obtain consistent simulation results the system model, which could accurately describ the thermal storage tank temperature stratification and the friction head for mass flow rate, was used. The optimization of collector parameters(collector aspect ratio, riser numbers per header unit length), thermal storage tank parameters(ratio of tank length to tank diameter, heat exchanger type), system parameters(ratio of tank volume to collector area) was simulated by TRNSYS program. The simulation results indicate that the system performance is more effected by collector aspect ratio and the ratio of tank volume to collector area than the othor parameters.

• Fire Science and Engineering
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• v.34 no.2
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• pp.86-93
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• 2020

This study aims to maintain the safety of an outdoor storage tank through the fundamental case analysis of explosion and fire accidents in the storage tank. We consider an accident caused by the explosion of fire inside the tank, as a result of the gradual spreading of the residual fire generated by wind lamps flying off a workplace in the storage tank yard. To determine the cause of the accident, atmospheric diffusion conditions were derived through CCTV image analysis, and the wind direction was analyzed using computational fluid dynamics. Additionally, the amount of oil vapor inside the tank when the floating roof was at the lowest position, and the behavior of the vapor inside the tank when the floating roof was at the highest position were investigated. If the cause of the explosion in the storage tank is identified and the level of the storage tank is maintained below the internal floating roof, dangerous liquid fills the storage tank, and the vapor in the space may stagnate on the internal floating roof. We intend to improve the operation procedure such that the level of the storage tank is not under the Pontoon support, as well as provide measures to prevent flames from entering the storage tank by installing a flame arrester in the open vent of the tank.

• Journal of Korean Society on Water Environment
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• v.23 no.3
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• pp.403-409
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• 2007

This study was carried out to recommend the systematic improving practice for the effective operation of septic tank, and the evaluation of its BOD and nutrient removal efficiency depending on process, the survey of characteristics of FRP material, and the suggestion of optimum septic tank model within sewage treatment area. The average BOD concentration and BOD removal efficiency of septic tank which was carried out the cleaning periodically in 63.9 mg/L and 77.8%, shows good quality better than the septic tank which was not carried out the cleaning regularly. Maximum load of tensile, flexural and compressive strength increased in proportion to its thickness, and the contents standard 25% of glass fiber required upgrade over than 30%. Configuration and performance for the optimum of the septic tank suggests that over $0.75m^3$ of the effective total volume, adding to over $0.25m^3$ a man for more than 5 men of the treated person, retention time should be within one day. Improving plans about facility and materials quality of the septic tank have an obligation that protective wall ought to install on the concrete bottom and side faces to prevent crumble or transform from loading of the ground or upper part of the structure on the tank setting. And it is eliminated the uneffective resisting pressure and it keeps off circulate imperfect products by strengthening of the test methods such as stretching strength, pressing strength, glass fiber contents and thickness.

• Fashion & Textile Research Journal
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• v.14 no.2
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• pp.261-268
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• 2012

The purpose of this study is to investigate problems of design, fitness, suitability for movement, and wearing comfort of jumper for Korean military tank drivers through analysis of actual wearing condition by questionnaire and field evaluation and to provide basic data for developing its improved design. The survey was done for 477 military tank drivers and evaluation was performed using thermal manikin to measure insulation. The overall satisfaction for design of jumper for military tank driver was over 3.5(likert scale). The overall satisfaction for fitness of jumper for military tank driver was also over 3.5. The satisfactions for material was between 2.39 and 3.13 and the satisfaction for pilling property was the lowest, followed by static property and shape stability after laundering. The satisfactions for movement suitability were standing(3.81), sitting(3,38), raising hand(forward: 2.90, sideward: 3.01), respectively. In insulation evaluation of jumper for military tank drivers and outwears(jacket, jumper), the insulation of jumper for military tank drivers was lower than outwear(jumper) and same with outwear(jacket). The insulation in dynamic and still condition(without wind) of jumper for military tank driver was 0.37clo and 0.31clo, respectively. Its decreation rate in dynamic condition comparing to still condition was 59% which was lower than jacket(0.73clo) and jumper(1.15clo).