• Journal of Korean Society of Water and Wastewater
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• v.19 no.5
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• pp.537-546
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• 2005

This study was carried out to evaluate EPS and SMP variation of sludge and effluent in nitrification and denitrification process with zeolite addition, a possible reduction of effluent DOC by URC(Ultra Rapid Coagulation) process. As a biological wastewater treatment result, EPS formation of both aeration and anoxic sludges are not affect by SRT variation. However, EPS concentration of sludges is higher in aeration tank than in anoxic tank by 6~8 mg EPS/ g VSS. Linear relationship between SMP to DOC indicates that SMP of bulk solution contributes to most of the biological treatment effluent DOC. DOC and turbidity removal efficiency was more improved with URC process than in a conventional coagulation. For pretreatment of UF filtration DOC removal was advanced by URC process than only UF filtration.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2003.10a
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• pp.165-169
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• 2003

Current volume reduction methods for wasted expandable polystyrene (EPS) foam are summarized and compared each other. Wasted EPS foam has not been recycled effectively because of its large volume to weight ratio. This has prevented from its proper recycling because of high cost of transportation to recycling plant. Successful recycling of wasted EPS foam results directly from successful, i.e. economically and environmentally, volume reduction of wasted EPS foam. This paper deals with various methods for volume reduction methods of wasted EPS foam. Five typical methods of volume reduction are introduced and they are compared each other in terms of expected PS properties after volume reduction, cost effectiveness of each process, possible effects on environment caused by the volume reduction process, and possible recycled products. The methods include thermal, solvent, far infrared and mechanical compaction. Comparison in this paper is made mostly in qualitative manner. The focus in this study is concentrated on summarizing and comparing existing methods of volume reduction for wasted EPS foam.

• Journal of the Korean Geotechnical Society
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• v.23 no.10
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• pp.151-161
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• 2007

EPS provides a superb self-sufficient stability. Studies on the process of EPS construction method focus on the inchoate phase of general construction, which is increasingly applied to construction sites throughout the world. Unfortunately, there has been little study on the durability and long-term soil behavior involving EPS materials. In this study, the boring, in-site and laboratory tests were conducted to examine the long-term soil behavior in the back-filling of alternating behind the side to which EPS was applied. And results of finite element analysis considering various test results and the soil behavior data measured during the construction show that EPS construction method is a superb process that relieves the load and consequently reduces the settlement, alleviates the stress on the abutment, and prevents lateral flow.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.152-153
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• 2013

Based on the Fire Service Act of mandatory provision, new buildings are strictly forced to use fire protection materials. Flame resistant EPS is one of those materials. Unlike conventional EPS that can be fused to make EPS ingot and be recycled for various purposes, flame resistant EPS waste cannot be recycled due to the presence of protective coating that is applied to increase the fire protection properties of EPS. A suitable alternative that can process large amount of flame resistant EPS wastes needs to be developed, and one of the possible alternative is to use them as construction materials. In this research, experiments were designed to observe whether the flame resistant EPS wastes can be utilized as partial replacements of fine aggregates in cement mortar. The replacement ratio of waste EPS was varied, and its effect on compressive strength and absorption capacity was investigated. According to the experimental results, both compressive strength and absorption capacity met the Korean Standard specification for cement bricks and blocks, indicating that flame resistant EPS wastes can be used for construction purposes.

• Journal of Welding and Joining
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• v.21 no.5
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• pp.525-533
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• 2003

The dimensional accuracy and global roughness between successive layers of VLM-s, which is a new rapid prototyping process using hotwire cutter and EPS foam, depend significantly on the operating parameters of hotwire cutter. In the present study, the effect of cutting angle on the kerf width and edge shape in hotwire cutting of EPS foam for the case of single-sloped cutting with one cutting angle was investigated. Through single-sloped cutting tests, the modified relationship between kerf width and effective heat input, considering the effect of the cutting angle, and the relationship between the melted area and the cutting angle were obtained. In order to investigate the effect of cutting angles on the thermal field in EPS foam, transient heat transfer analyses using single-sloped volumetric heat flux model and locally-conformed mesh were performed. Through the comparison between experimental and numerical results, it was shown that the proposed analysis model is needed to estimate the three-dimensional temperature distribution of the EPS foam for the case of single-sloped hotwire cutting.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1119-1122
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• 2004

In the UV-NIL process using an elementwise patterned stamp (EPS), which includes channels formed to separate each element with patterns, low-viscosity resin droplets with a nano-liter volume are dispensed on all elements of the EPS. Following pressing of the EPS, the EPS is illuminated with UV light to cure the resin; and then the EPS is separated from several thin patterned elements on a wafer. Experiments on UV-NIL were performed on an EVG620-NIL. 50 － 70 nm features of the EPS were successfully transferred to 4 in. wafers. Especially, the wafer deformation during imprint was analyzed using the finite element method (FEM) in order to study the effect of the wafer deformation on the UV-NIL using EPS.

• Journal of Microbiology and Biotechnology
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• v.32 no.12
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• pp.1599-1604
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• 2022

Storage stability of freeze-dried lactic acid bacteria is a critical factor for their cost-effectiveness. Long-term storage of lactic acid bacteria enables microbial industry to reduce distribution costs. Herein, we investigated the effect of cold adaptation under supercooling conditions at -5℃ on the viability of Leuconostoc mesenteroides WiKim32 during the freeze-drying process and subsequent storage. Cold adaptation increased the thickness of exopolysaccharides (EPS) and improved the viability of freeze-dried Leu. mesenteroides WiKim32. Compared to non-adapted cells, cold-adapted cells showed a 35.4% increase in EPS thickness under supercooling conditions. The viability of EPS-hydrolyzed cells was lower than that of untreated cells, implying that EPS plays a role in protection during the freeze-drying process. Cold adaptation increased the storage stability of freeze-dried Leu. mesenteroides WiKim32. Fifty-six days after storage, the highest viability (71.3%) was achieved with cold adaptation at -5℃. When EPS-containing broth was added prior to the freeze-drying process, the viability further increased to 82.7%. These results imply that cold adaptation by supercooling pretreatment would be a good strategy for the long-term storage of Leu. mesenteroides WiKim32.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.4
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• pp.452-459
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• 2007

Nutrient removal hybrid process to use suspended and attached growth microorganisms and apply the contact and stabilization process was process obtaining good results to HRT within 6 hours to dominate nitrifier and to promote separation and growth of autotrophs and heterotrophs to pack with EPS(Expanded Poly-Styrene) media in nitrification reactor. An average effluent quality of this process was below 5.2 mg/L, 7.3 mg/L, 4.9 mg/L as $BOD_5,\;COD_{Mn}$, SS concentration and 6.8 mg/L, 0.6 mg/L as T-N, T-P concentration. Also, An average removal efficiency of this process was 94.6%, 79.8%, 94.9% as $BOD_5,\;COD_{Mn}$, SS and 70.8%, 76.9% as T-N, T-P. 16S-rRNA analysis result of microorganisms attached to EPS media was researched Nitrosomonas and Nitrosococcus blown to ammonia-oxidizing bacteria cluster to include Gallionella and these microorganisms were researched to involve about 6% of biofilm attached EPS media. Consequently, this process was treated below 10 mg/L and 1.0mg/L as T-N, T-P concentration at short hydraulic retention time(about 6 hr) to dominate nitrifier.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.3
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• pp.627-631
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• 2007

The factors affecting on sludge sedimentation are reported as F/M ratio, ingredient, composition of influent substrate, dissolved oxygen concentration, temperature, pH, filamentous bacteria and SRT. Aeration tank applying Bacillus sp. has an important role for maintaining the dominant microorganism species to make steady progress for spore growth affecting sedimentation. This research aims to investigate the affecting factor for the sedimentation in B3 system and RABC system with aeration tank applying tapered aeration. Extracellular polymeric substances(EPS), protein and carbohydrate can be produced for the extreme condition, that is down to 0.2 mg/L of dissolved oxygen in the aeration tank. This research found out the relation between the sedimentation and the EPS production, especially the ratio of protein/carbohydrate. The spore of Bacillus sp. was formed at the low DO then microorganisms produced EPS. The results showed that the production of EPS was 109.95 mgEPS/gSS at 1.6 mg/L of DO, however it was 131.77 mgEPS/gSS at 0.5 mg/L of DO. The sedimentation was affected by protein content in EPS and the ratio of protein and carbohydrate. The settleability of sludge was not affected by the ratio of protein/carbohydrate in B3 process, meanwhile settleability was affected by the ratio of it in RABC process, respectively.

• Journal of the Korean Society for information Management
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• v.24 no.3
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• pp.67-82
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• 2007

The purpose of this paper is to imply for the assessing framework of next generation Enterprise Portals'(EPs) function through the lens of organizational knowledge creation. As the emerging "suite" products such as Smart Enterprise Suite (SES) converges EPs with collaboration and content management, EPs are no longer just a gateway to information and content. EPs are emerging as the center of convergence for many complementary technologies. Considering that this trend is common and knowledge creation is one of key goals of EPs, it is important to assess EPs' function through the knowledge creation process. This paper reviews literatures to set initial assessing elements of EPs' function, then adopts Delphi Technique to prove and categorize the elements according to the knowledge creation process. The samples are consisted of 7 professional knowledge management consultants at Entrue Consulting Partners, LG CNS. This paper may be significant in providing a new vision to the evaluation of EPs by combining a theoretical model with a practical situation.