• Journal of the Korean Society of Marine Environment & Safety
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• v.6 no.1
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• pp.69-76
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• 2000

Bubble boom may be a good alternative for the prevention of oil spill pollution due to its easy deployment and clean post-process tasks. The present work is focused on the experimental investigation of air bubble movement for the bubble boom by visualization and quantitative PIV measurements. Bubble plume was generated by adjusting the pressure of pressure vessel ranging 6.7 kpa to 14.7 kpa. The results showed at lower inlet velocity and higher supply air flow rate that bubble boom maintained its containing capability reasonably well up to the maximum containing limit.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1078-1083
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• 2000

A high speed rotor balancing machine was developed, which is capable of balancing a flexible rotor in high speed. The machine is largely consisted of vacuum chamber, oil supply system and vacuum pump system. And, in order to investigate performances of the machine, various tests were carried. After high speed rotor balancing of gas turbine engine rotor using influence coefficient method, the flexible engine rotor passed smoothly through its critical speed.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.32-36
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• 2003

The mining industry of Japan had rapidly grown after the World War II with the economic growth. There existed more than 350 mines all over Japan in the 1960’s. The mines however had been closed one after another under the influence of the world and domestic economic events such as the mining-related pollution in Japan after the middle of the 60’s, the Oil Crisises in 73 and 79 and the Strong Yen in 85 (Fig. 1). (omitted)

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.164-173
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• 2015

This study aims to design energy supply systems from various energy sources for transportation sectors and comparatively analyze the life cycle cost of different scenario-based systems. For components of the proposed energy supply system, we consider a typical oil refinery, byproduct hydrogen system, renewable energy source (RES)-based electric generation system and existing electricity grid. We also include three types of vehicles in transportation sector such as internal combustion engine vehicle (ICEV), electric vehicle (EV), fuel cell vehicle (FCV). We then develop various energy supply scenarios which consist of such components and evaluate the economic performance of different systems from the viewpoint of life cycle cost. Finally we illustrate the applicability of the proposed framework by conducting the design problem of energy supply systems of Jeju, Korea. As the results of life cycle cost analysis, EV fueled by electricity from grid is the most economically feasible. In addition, we identify key parameters to contribute the total life cycle cost such as fuel cost, vehicle cost, infra cost and maintenance cost using sensitivity analysis.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.1
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• pp.24-34
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• 2015

Domestic companies supplying electricity must increase obligatory duty to use renewable energy annually. If not met with obligatory allotment, the electricity-supply companies must pay RPS (Renewable Portfolio Standards) penalty. Although the power plants using a pulverizing coal firing boiler could co-fire up to around 3 per cent with wood pellets mixed in with coal feedstock without any major equipment revamps, they recorded only about 60 per cent fulfillment of RPS. Consequently, USD 46 million of RPS penalty was imposed on the six power supplying subsidiaries of GENCOs in 2014. One of the solutions to reduce the RPS penalty is that the power supply companies adopt the co-firing of torrefied lignocellulosic biomass in coal plants, which may contribute to the use of over 30 per cent of torrefied biomass mixed with bituminous coals. Extra binder was required to form pellets using torrefied biomass such as wood chips, PKS (Palm Kernel Shell) and EFB (Empty Fruit Bunch). Instead of corn starch, 30, 50 and 70 per cent of Larix saw dusts were respectively added to the torrefied feedstocks such as Pinus densiflora chips, PKS and EFB. The addition of saw dusts led to the decrease of the calorific values of the pellets but the forming ability of the pelletizer was exceedingly improved. Another advantage from the addition of saw dusts stemmed from the reduction of ash contents of the pellets. Finally, it was confirmed that torrefied oil palm biomass such as PKS and EFB could be valuable feedstocks in making pellets through improved binding ability.

• Journal of Aquaculture
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• v.7 no.4
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• pp.225-237
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• 1994

Survival and growth rates of flounder larvae fed rotifers and Artemia nauplii enriched by various bio-enrichment techniques were investigated. Enriched materials used in the study were $12\omega-yeast$, 2 commercial emulsified oil and microparticulated products. $\omega-yeast$ were added with one kinds of oils (cuttlefish liver oil, sardine oil, Alaska pollock liver oil, linseed oil) at the level of $5\%,\;15\%\;and\;25\%$. The results are as follows: 1. The growth rate of rotifers cultured with $\omega-yeast$ added $15\%$ cuttlefish liver oil was the best among 12 kinds of $\omega-yeast$ and this performance was almost the same with that of rotifers fed on Chlorella. 2. Survival and growth rates of flounder larvae fed on rotifers and Artemia nauplii enriched with $\omega-yeast$ and the other commercial products were higher than that those of larvae cultured with only Chlorella and non-enriched Artemia. The optimum contents of the cuttlefish liver oil in $\omega-yeast$ for rotifers and Artemia enrichment were $15\%\;and\;25\%$, respectively. 3. Optimum enrichment time and supply amount of $\omega-yeast$ for Artemia nauplii were 6 hr., 1.5 g/g cyst, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.10
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• pp.1030-1034
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• 2005

The purpose of this study was to clarify the penetration behavior of particulate matters by wave and tidal actions in sandy beach located in enclosed bay and to evaluate the effect of stranded oil on penetration of particulate matters. Experiments were rallied out using a model sandy beach facility. The particulate matters penetrated into saturated sediments by wave action from breaking wave run-up point with a semi-circular forming in low energy beach as enclosed bay. On the other hand, the penetration velocity of the particulate matters was to be faster according to the increase of slope and breaking wave height. The particulate matters by tidal action penetrated into the sediments at an angie of 45 degrees in the direction of porous water flow. The stranded oil completely blocked the penetration of the particulate matters into the sediments. These results indicate that the penetrated oil prevents the penetration of the particulate matters into the sediments and, therefore, results in the reduction in the supply of plankton, bacteria and organic detritus for the benthic organisms in the sandy beach.

• Tribology and Lubricants
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• v.33 no.2
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• pp.37-44
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• 2017

A DE-side LBP tilting pad journal bearing of a 1-stage overhung heat-pump compressor in a propylene process exhibited abnormal high-temperature behavior. Its temperature had been relatively high at $78^{\circ}C$ from the beginning of operation. In 2014, after three years of operation, it increased suddenly and reached $103^{\circ}C$. Installing a varnish removal equipment and others managed to stabilize the temperature at $95^{\circ}C$. We undertook a troubleshooting approach for reviewing the comprehensive status and integrity of the temperature design of the bearing. We performed lubrication and heat-balance analysis, based on the design engineering data and documents supplied by the OEM. For the base design data of DE-side TPJB, evaluating the effects of key design variables on bearing metal temperature showed that firstly, increasing the bearing clearance and supply oil flow-rate, and next, changing the oil type, and finally, increasing the machined pad clearance and offset, are more effective in reducing the bearing metal temperature. Furthermore, a clarification meeting with the OEM revealed that an incorrect decision had been made to decrease the bearing clearance to eliminate the SSV harshness issue, while not maintaining a sufficient oil flow-rate. We conducted a detailed retrofit design analysis, wherein we increased the oil flow-rate and bearing clearance by decreasing the preload. We predicted that the bearing temperature would decrease to $63^{\circ}C$ from $75.7^{\circ}C$ even at the rerate condition. Finally, after installing and operating a retrofit replacement bearing in 2015, the bearing temperature stabilized at a low temperature of $65^{\circ}C$. Currently (January. 2017), two year later, the bearing metal temperature remains at $65^{\circ}C$. Therefore, we can conclude that the abnormal high-temperature behavior of the bearing has been resolved completely.

• Environmental Analysis Health and Toxicology
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• v.27
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• pp.8.1-8.10
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• 2012

Objectives: The goal was to model and quantify the atmospheric concentrations of volatile organic compounds (VOCs) as the result of the Hebei Spirit oil spill, and to predict whether the exposure levels were abnormally high or not. Methods: We developed a model for calculating the airborne concentration of VOCs that are produced in an oil spill accident. The model was applied to a practical situation, namely the Hebei Spirit oil spill. The accuracy of the model was verified by comparing the results with previous observation data. The concentrations were compared with the currently used air quality standards. Results: Evaporation was found to be 10- to 1,000-fold higher than the emissions produced from a surrounding industrial complex. The modeled concentrations for benzene failed to meet current labor environmental standards, and the concentration of benzene, toluene, orthometa- para-xylene were higher than the values specified by air quality standards and guideline values on the ocean. The concentrations of total VOCs were much higher than indoor environmental criteria for the entire Taean area for a few days. Conclusions: The extent of airborne exposure was clearly not the same as that for normal conditions.

• Advances in concrete construction
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• v.16 no.1
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• pp.69-78
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• 2023

This investigation delves into the adverse repercussions stemming from the impact of arsenic on steel pipes concealed within soil designated for rice cultivation. Simultaneously, the study aims to ascertain effective techniques for detecting arsenic in the soil and to provide strategies for mitigating the corrosion of steel pipes. The realm of nanotechnology presents promising avenues for addressing the intricate intersection of renewable energy, oil, and environmental pollution from a novel perspective. Nanostructured materials, characterized by distinct chemical and physical attributes, unveil novel pathways for pioneering materials that exert a substantial impact across diverse realms of food production, storage, packaging, and quality control. Within the scope of the food industry, the scope of nanotechnology encompasses processes, storage methodologies, packaging paradigms, and safeguards to ensure the safety of consumables. Of particular note, silver nanoparticles, in addition to their commendable antibacterial efficacy, boast anti-fungal and anti-inflammatory prowess, environmental compatibility, minimal irritability and allergenicity, resilience to microbial antagonism, thermal stability, and robustness. Confronting the pressing issue of arsenic contamination within both environmental settings and the food supply is of paramount importance to preserve public health and ecological equilibrium. In response, this study introduces detection kits predicated upon silver nanoparticles, providing an expeditious and economically feasible avenue for identifying arsenic concentrations ranging from 0.5 to 3 ppm within rice. Subsequent quantification employs Hydride Atomic Absorption Spectroscopy (HG-AAS), which features a detection threshold of 0.05 ㎍/l. A salient advantage inherent in the HG-AAS methodology lies in its capacity to segregate analytes from the sample matrix, thereby significantly reducing instances of spectral interference. Importantly, the presence of arsenic in the soil beneath rice cultivation establishes a causative link to steel pipe corrosion, with potential consequences extending to food contamination-an intricate facet embedded within the broader tapestry of renewable energy, oil, and environmental pollution.