• Journal of Environmental Science International
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• v.14 no.9
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• pp.827-835
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• 2005

A three-dimensional ecological model (EMT -3D) was applied to Nonylphenol in Tokyo Bay. EMT -3D was calibrated with data obtained in the study area. The simulated results of dissolved Nonylphenol were in good agreement with the observed values, with a correlation coefficient(R) of 0.7707 and a coefficient of determination (R2) of 0.5940. The results of sensitivity analysis showed that biodegradation rate and bioconcentration factor are most important factors for dissolved Nonylphenol and Nonylphenol in phytoplankton, respectively. In the case of Nonylphenol in particulate organic carbon, biodegradation rate and partition coefficient were important factors. Therefore, the parameters must be carefully considered in the modeling. The mass balance results showed that standing stocks of Nonylphenol in water, in particulate organic carbon and in phytoplankton are $8.60\times 10^5\;g,\;2.19\times 10^2\;g\;and\;3.78\times 10^0\;g$ respectively. With respect to the flux of dissolved Nonylphenol, biodegradation in the water column, effluent to the open sea and partition to particulate organic carbon were $6.02\times10^3\;g/day,\;6.02\times10^2\;g/day\;and\;1.02\times10^1\;g/day$, respectively.

• Applied Chemistry for Engineering
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• v.2 no.4
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• pp.393-398
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• 1991

An experimental reactor system was devised and employed to examine catalytic coal gasification. A 4-kw tungsten halogen lamp heater combinded with a graphite sample basket coated with silicon nitride film made rapid heating and cooling possible. Also a small graphite cap on the thermocouple tip which located just beneath the sample basket helped remarkably to read real temperatures. Silicon nitride film on the basket and the cap showed very good protection against the reaction between graphite and oxidant gases during the experiments. The weight of specimen could be continuously measured without disturbance.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1361-1364
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• 1990

In order to tackle global environmental problems such as destruction of the ozone layer or climatic changes due to atmospheric temperature increase, the acquisition of plentiful and precise data is necessary. Therefore, a means of conducting long-lasting high-resolution measurements over broad areas is required. A feasibility study has been made on a high altitude (20km), super-pressured helium-filled PLTA (Powered Ligher-than-Air) vehicle as an ideal platform for environmental observation. It has a long service life and carries a larger payload than an artificial satellite. This PLTA platform uses an electric propulsion system to maintain position in space against wind currents. The thruster is driven by solar power acquired from solar cells. For night use, solar energy is stored in regenerative fuel cells. This study focuses on energy balance and structural analysis of the hull and platform. The platform is capable of conducting high resolution remote sensing as well as having the capability to serve as a telecommunications relay. The platform could replace a number of ground-based telecommunications relay facilities, guaranteeing sufficient radio frequency intensity to secure good quality telecommunication transmittal. The altitude at which the platform resides has the lowest wind flow in the lower stratosphere, and permits viewing from the ground within a 1,000km range. Because this altitude is much lower than that required of an artificial satellite, the measuring resolution is a couple of thousand times higher than with artificial satellites. The platform can also be used to chase typhoons and observe them from their sources in tropical regions.

• Journal of the Korean Society for Heat Treatment
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• v.13 no.5
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• pp.346-354
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• 2000

Effect of Nb addition on the phase transformation behavior was studied through continuous cooling transformation tests after reheating(reheating CCT) and deforming(deforming CCT) the 0.07%C-1.3%Mn-0.015%Ti-(0~0.08)% Nb steels. Transformation temperatures for deforming CCT were lower than those for reheating CCT, and the critical cooling rate for bainite transformation during deforming CCT was lower than that during reheating CCT. These enhanced hardenability for deforming CCT was considered to come from the sufficient solid solution of Nb in austenite during high temperature reheating before deformation. With Nb addition, the phase transformation temperature decreased, the bainite formation was enhanced, and the hardness of steel increased. Furthermore, these phenomena were more remarkable for deforming CCT than for reheating CCT. From the results, Nb-Ti bearing low carbon steel was considered to be a very favorable alloy system with good strength/toughness balance by recrystallization control rolling process.

• Journal of Biosystems Engineering
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• v.37 no.2
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• pp.82-89
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• 2012

Purpose: The simulation model of a pneumatic conveying drying (PCD) for sawdust was developed and verified with the experiments. Method: The thermal behavior and mass transfer of a PCD were modeled and investigated by comparing the experimental results given by a reference (Kamei et al. 1952) to validate the model. Momentum, energy and mass balance, one dimensional first order ordinary differential equations, were coded and solved into Matlab V. 7.1.0 (2009). Results: The simulation results showed that the moisture content reduced from 194% to 40% (dry basis), air temperature decreased from $512^{\circ}C$ to $128^{\circ}C$ with the particle residence time of 0.7 seconds. The statistical indicators, root mean square error and R-squared, were calculated to be 0.079, and 0.998, respectively, between the measured and predicted values of moisture content. The relative error between the measured and predicted values of the final pressured drop, air temperature, and air velocity were only 8.96%, 0.39% and 1.05% respectively. Conclusions: The predicted moisture content, final temperature, and pressure drop values were in good agreement with the experimental results. The developed model can be used for design and estimation of PCD system for drying of wood dust particles.

• Spatial Information Research
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• v.14 no.1 s.36
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• pp.115-128
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• 2006

The aim of the study is to select and verify for development of groundwater resources using Geographic Information System(GIS). The water balance, land cover, forest, soil, elevation, slope, hydrogeology and lineament were analyzed. Using GIS, relationship between the data and groundwater yield data was analyzed and the groundwater resources potential map was made for selecting suitable area for groundwater development. Then groundwater resource potential map was verified using groundwater yield data. The verified result showed the good agreement between the potential map and groundwater yield data. The potential map can be used for groundwater management which is related to groundwater development.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.1106-1114
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• 2006

Good health and longevity are the goal of human beings. Dietary treatment for the improvement of health and chronic diseases therapy has been occupied an important position in Oriental and Western medicine. In this paper, the viewpoints of dietary treatment in Oriental and Western medicine were compared. The principle of Yin-Yang and five elements, as a standing rule that establishes the theory of Oriental medicine and origin of the oriental philosophy, it provides the based of the Oriental medicine's outlook of the world. The principles of dietary treatment in Oriental medicine was reasonable combination of food, balance of Oh-Mi and temperance of food. Nutritional therapy in Oriental medicine has done the phase of Bian Zheng by individual characteristics. The theory of Yin-Yang and five elements, Ki-Mi, Sasang Constitution Medicine and Kyi-Kyung were obviously recognized the theory of nutrition therapeutics in Oriental medicine. In Western medicine, dietary treatment supplies individuals with a recipe of calorie and specific nutrients. The Food Exchange System was very convenient way of practice in nutrition therapy. But each of dietary treatment in Oriental and Western nutrition has strong and week points. So we need to study enough materials to treatment of Oriental nutrition and Western nutrition for the improvement of health and chronic diseases therapy.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.3
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• pp.177-186
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• 2003

In the present study, the flow characteristics of developing turbulent flows are investigated at the exit region of a square cross-sectional 180" curved duct with dimensions of 40mm$\times$40mm$\times$4000mm (height $\times$ width $\times$length). Smoke particles produced from mosquito coils were used as seed particles for the LDV measurement. Experiments were carried out to measure axial velocity profiles, shear stress distributions and entrance lengths by using an LDV system and Rotating Machinery Resolver RMR with PHASE software. Experimental results clearly show that the time-averaged Reynolds number does not affect oscillatory flow characteristics because the turbulent components tend to balance the oscillatory components in the fully developed flow region. Also, the velocity profiles are in good agreement with 1/7power law such as the results of steady turbulent flows. The turbulent intensity linearly increases along the walls and is slightly higher, especially in the period of deceleration. On the other hand, the LDV measurements show that shear stress values in slightly higher in the period of deceleration due to the flow characteristics in the exit region. The entrance length where flows become stable appears at the point that is 40 times the length of hydraulic diameter.eter.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.1
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• pp.97-119
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• 2023

The number of industrial Internet of Things (IoT) users is increasing rapidly. Lightweight block ciphers have started to be used to protect the privacy of users. Hardware-oriented security design should fully consider the use of fewer hardware devices when the function is fully realized. Thus, this paper designs a lightweight block cipher IIoTBC for industrial IoT security. IIoTBC system structure is variable and flexibly adapts to nodes with different security requirements. This paper proposes a 4×4 S-box that achieves a good balance between area overhead and cryptographic properties. In addition, this paper proposes a preprocessing method for 4×4 S-box logic gate expressions, which makes it easier to obtain better area, running time, and power data in ASIC implementation. Applying it to 14 classic lightweight block cipher S-boxes, the results show that is feasible. A series of performance tests and security evaluations were performed on the IIoTBC. As shown by experiments and data comparisons, IIoTBC is compact and secure in industrial IoT sensor nodes. Finally, IIoTBC has been implemented on a temperature state acquisition platform to simulate encrypted transmission of temperature in an industrial environment.

• Nuclear Engineering and Technology
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• v.56 no.3
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• pp.1002-1012
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• 2024

To remove insoluble fission products, which could possibly cause reactor instability and significantly reduce heat transfer efficiency from primary system of molten salt reactor, a helium bubbling method is employed into a passive molten salt fast reactor. In this regard, two-phase flow behavior of molten salt and helium bubbles was investigated experimentally because the helium bubbles highly affect the circulation performance of working fluid owing to an additional drag force. As the helium flow rate is controlled, the change of key thermal-hydraulic parameters was analyzed through a two-phase experiment. Simultaneously, to assess the applicability of numerical model for the analysis of two-phase flow behavior, the numerical calculation was performed using the OpenFOAM 9.0 code. The accuracy of the numerical analysis code was evaluated by comparing it with the experimental data. Generally, numerical results showed a good agreement with the experiment. However, at the high helium injection rates, the prediction capability for void fraction of helium bubbles was relatively low. This study suggests that the multiphaseEulerFoam solver in OpenFOAM code is effective for predicting the helium bubbling but there exists a room for further improvement by incorporating the appropriate drag flux model and the population balance equation.