• 한국지반신소재학회논문집
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• 제9권3호
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• pp.57-65
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• 2010

본 연구의 주된 목적은 반복적인 하중조건하에서 연성포장체의노반재료로써, EPS블럭의 시간의존적 변형을 연구하는데 있다. 반복하중 조건에서의 EPS블럭의 거동을 이해하기 위해서 본 연구에서는 실험적 방법 및 수치모형을 제시하였다. 이 수치모델링을 위해서 반복하중 조건하에서 관찰된 변형거동과 단위중량, 변형 그리고 적용된 하중과의 상관관계의 조사가 행해졌다. 실험결과는 핀들레이 이론과 반복하중 조건에서의 연구결과의 모델 분석등과 비교되었고, 보완된 핀들레이 모델과 본 연구에서 제시한 모델은 반복하중에서의 EPS블럭의 변형거동을 나타내는데 이용될 수 있는 것으로 기대된다.

• 항공우주기술
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• 제1권1호
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• pp.72-83
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• 2002

본 논문은 다목적실용위성 전력시스템의 초기 설계과정으로, 2000년 11월 ASTRIUM과 KARI에서 진행한 다목적실용위성 2호기 전력시스템의 용량설계와 태양전지 어레이의 설계를 기술하였다. ASTRIUM은 다목적실용위성 2호기 전력시스템의 기본설계를 위하여, ASTRIUM의 기존 위성 프로그램인 CHAMP 위성과 GlobalStar 위성에 적용한 전력설계 개념을 고려하였다. 그러나 전력시스템의 설계는 전력운용 개념, 각 전장품 및 전력원의 특성에 따라 설계가 다르다. 그리고 ASTRIUM사의 전력시스템 운용개념은 다목적실용위성 1호기와 다르며, 전력시스템에 사용한 전력원과 각 전장품의 상이한 특성으로 전력시스템의 설계에 근본적인 차이가 있음을 미리 밝혀둔다. 따라서 본 논문은 2호기의 제안서에 기술된 내용을 중심으로 ASTRIUM과 KARI에서 수행한 2호기 전력시스템의 기본설계를 요약하였다.

• 한국지반공학회논문집
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• 제20권1호
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• pp.91-99
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• 2004

지중매설구조물의 하중저감과 관련하여 미국과 캐나다에서는 점토, 이토, 지푸라기 등의 압축재를 이용한 유도고랑 관거(induced-trench)기법에 대한 연구가 진행되어 왔으며, 일본과 노르웨이 등에서는 압축재로서 EPS 블럭을 이용한 하중 저감 방안에 대한 현장 시험시공을 통한 연구가 수행된 바 있다. 이와 같이 아칭효과를 극대화시키는 재료인 EPS 블록을 이용한 고성토 매설구조물 구축공법은 작용하중 저감에 따른 경제적인 구조물 단면의 선정, 구조물의 안정성 증대, 시공의 용이성 등 많은 장점을 갖고 있다. 본 논문에서는 연성 관거인 파형강관에 대한 토압 저감을 대상으로 아칭재인 EPS의 아칭 효과에 따른 토압 저감 효과를 분석하였다. 일련의 EPS를 이용한 하중 저감 평가시험이 수행되었으며, 현장 시험을 기초로 한 수직 토압 저감효과는 일반적인 연성관거에 비해 약 35∼40% 정도인 것으로 평가되었다.

• 한국포장학회지
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• 제27권3호
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• pp.175-180
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• 2021

Although it has recently been regulated for use as an eco-friendly policy in Korea, the use of EPS (Expanded Polystyrene) cooling boxes, which are used as cold chain delivery insulation boxes for fresh agricultural and livestock products, is also increasing rapidly as e-commerce logistics such as delivery have increased rapidly due to COVID-19. Studies were conducted to optimize the EPS cooling container through internal air heat flow of CFD (Computational Fluid Dynamics) analysis and FEM (Finite Element Method) random vibration analysis using domestic PSD (Power Spectral Density) profile of the EPS cooling box to which the refrigerant is applied in this study. In the analysis of the internal air heat flow by the refrigerant in the EPS cooling box, the application of vertical protrusions inside was excellent in volume heat flow and internal air temperature distribution. In addition, as a result of random vibration analysis, the internal vertical protrusion gives the rigid effect of the cooling box, so that displacement and stress generation due to vibration during transport are smaller than that of a general cooling container without protrusion. By utilizing the resonance point (frequency) of the EPS cooling box derived by the Model analysis of ANSYS Software, it can be applied to the insulation and cushion packaging design of the EPS product line, which is widely used as insulation and cushion materials.

• 상하수도학회지
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• 제18권5호
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• pp.619-627
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• 2004

Purposes of this study were to examine closely the extracellular polymeric substances (EPS) which was a membrane fouling contaminant, to control detected EPS by powdered activated carbon (PAC) dosage etc. and to evaluate the possibility of practical reuse facility. With high removal efficiency of general pollutants, when the PAC is added to MBR, improvement of removal efficiency of $COD_{cr}$, and color was expected and treated wastewater can be reused. It was judged that the correlation between EPS and membrane fouling was very high. Carbohydrate and DNA in the EPS were judged to be cause of membrane fouling. If EPS could be controled, not only membrane fouling would be decreased but also operation time would be extended. In experiment of powdered activated carbon (PAC), characteristics of the best PAC for membrane fouling control were the particle size of $7{\mu}m$, lodine Number of 1,050, surface area of peat of $1,150m^2/g$. In lab test, operation time of MBR by PAC dosage of 200mg/gVSS was longer than one of MBR by without PAC dosage. Because EPS, especially carbohydrate and DNA, was controled successfully by PAC, membrane fouling in MBR could be decreased.

• Geomechanics and Engineering
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• 제14권6호
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• pp.533-544
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• 2018

The importance of using materials cost effectively to enhance the strength and reduce the cost, and weight of earth fill materials in geotechnical engineering led researchers to seek for modifying the soil properties by adding proper additives. Lightweight fill materials made of soil, binder, water, and Expanded polystyrene (EPS) beads are increasingly being used in geotechnical practices. This paper primarily investigates the behavior of sandy soil, modified by EPS particles. Besides, the mechanical properties of blending sand, EPS and the binder material such as fly ash and cement were examined in different mixing ratios using a number of various laboratory studies including the Modified Standard Proctor (MSP) test, the Unconfined Compressive Strength (UCS) test, the California Bearing Ratio (CBR) test and the Direct Shear test (DST). According to the results, an increase of 0.1% of EPS results in a reduction of the density of the mixture for 10%, as well as making the mixture more ductile rather than brittle. Moreover, the compressive strength, CBR value and shear strength parameters of the mixture decreases by an increase of the EPS beads, a trend on the contrary to the increase of cement and fly ash content.

• KSBB Journal
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• 제14권1호
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• pp.66-70
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• 1999

A pullulans와 S Cerevisiae의 납 제거 특성을 비교하고, 미생물이 분비하는 세포외고분자물질의 영향에 대해 고찰하였다. A pullulans의 경우에 미생물의 보관시간이 증가할수록 미생물이 분비하는 세포외고분자물질의 양도 증가하였으며, 납 제거능도 우수해졌다. 그러나 세포외고분자물질을 제거한 A pullulans세포에서는 납 흡착량이 약 10%로 매우 적었다. S Cerevisiae의 경우에는 세포외고분자물질은 거의 분비되지 않았으며, 보관시간에 따른 납 흡착량의 변화는 거의 없었다. 또한 보관시간이 경과할수록 흡착 평형에 도달하는 시간은 점점 짧아졌다. 따라서 A pullulans와 S Cerevisiae의 납제거 기작은 세포외고분자물질의 유무에 따라 매우 달라짐을 알 수 있었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2002년도 학술논문발표회
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• pp.91-96
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• 2002

This study is to investigate the insulation performance of lightweight concrete using recycled lightweight aggregate, to develop lightweight concrete products which have an excellence on the insulation performance are satisfied with properties of building materials. As a result of this study, recycled EPS aggregate is considered to have an independent pores which is closed by dense partitions. So, it is showed that the insulation performance of lightweight concrete using recycled EPS aggregate are excellent. Especially, in the case of lightweight concrete under conditions of replacement ratio over 100%, it is considered that insulation performance is very excellent as thermal conductivity is showed about 0.2kcal/mh$^{\circ}C$. According to considering the relation between ultrasonic pulse velocity, unit weight and thermal conductivity through the graph, the result of relation between ultrasonic pulse velocity, unit weight and thermal conductivity on the graph expressed their high interaction shown as direct proportion on the graph. So that it is possible to extract the insulation performance of lightweight concrete using recycled EPS aggregate by ultrasonic pulse velocity and unit weight.

• Journal of Microbiology and Biotechnology
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• 제21권12호
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• pp.1287-1293
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• 2011

The extracellular polysaccharide (EPS) was isolated from mycelial cultures of Laetiporus sulphureus var. miniatus and purified by DEAE cellulose and Sephadex G-50 column chromatography. The purified EPS (EPS-2-1) was composed of only glucose units and its molecular mass was 6.95 kDa. The chemical structure of EPS-2-1 consisted of a main chain containing ($1{\rightarrow}4$)-Glcp units with branches at the C-6 position of the chain carrying-Glcp-($1{\rightarrow}4$)-linked residues. The effect of purified EPS on immunomodulatory genes and proteins of the Bcl-2 family was observed using cultured U937 human leukemia cells. Of note, the levels of Bax and Bad proteins treated with the EPS (4 mg/ml) were approximately 23- and 18-times higher than those in non-treated cells, respectively. These results may suggest that the EPS purified from the mushroom L. sulphureus is associated with the activation of immunomodulatory mediators, Bax and Bad proteins.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.220-223
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• 2006

The COMS(Communication, Ocean and Meteorological Satellite) EPS(Electrical Power Subsystem) is derived from an enhanced Eurostar 3000 EPS which is fully autonomous operation in normal conditions or in the event of a failure and provides a high level of reconfiguration capability and flexibility. This paper introduces the COMS EPS preliminary design result. The COMS EPS consists of a battery, a solar array wing, a PSR(Power Supply Regulator), a PRU(Pyrotechnic Unit), a SADM(Solar Array Drive Mechanism) and relay and fuse brackets. This can offer a bus power capability of 3 kW. The solar array is made of a deployable wing with two panels. One type of solar cells is selected as GaAs/Ge triple junction cells. Li-ion battery is base lined with ten series cell module of five cells in parallel. PSR associated with battery and solar array generates a power bus fully regulated 50 V. Power bus is centralised protection and distribution by relay and fuse brackets. PRU provides power for firing actuators devices. The solar array wing is routed by the SADM under control of the AOCS(Attitude Orbit Control Subsystem). The control and monitoring of the EPS especially of the battery, is performed by the PSR in combination with on-board software.