• Tribology and Lubricants
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• 제40권2호
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• pp.61-66
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• 2024

Micro-plastics are synthetic high-differentiation chemicals of less than 5mm in size, and are deposited not only on the sea surface but also on the coast. If these micro-plastics are not properly separated from the sand, they can threaten marine ecosystems. Thus, in the present study, we aimed to apply cyclone separator to the micro-plastic retrieval in order to predict the movement of particles according to the formation of the cyclone separator by applying the centrifugal force of the particle in accordance with the rotational movement of the air. The cyclone separator has three shapes, the first one is a typical interconnected cyclone separator. The second is the horn form, except for the cylinder in a regular cyclone separator, and the third is a form that increases the horn's height twice in the second. The numerical analysis simulation of the Cyclone separator used the Fluent software package. The output speed of the Cyclone separator was 5 to 13m/s at 1m/s intervals. The simulated particles include sand, Styrofoam, PET, PP, and PU. Sand particles are assigned a fixed diameter of 2mm, while other particles have a diameter of 3mm. As a result of the analysis, the first form was not separated from plastic. The Styrofoam separation efficiency in the second showed its highest efficiency at 72.7% at 7m/s, and the efficiency decreased after 12m/s as the sand particles were mixed into the plastic attachment location. In the third form, the separation efficiency of Styrofoam at 12m/s was highest at 67.9%.

• 한국화재소방학회논문지
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• 제29권4호
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• pp.49-56
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• 2015

본 연구에서는 건물 실내에서 주로 사용되고 있는 합판, 실내 마감용 목재(루바; 소나무), 압축 스티로폼 단열재, 강화마루 및 PVC 장판 5 종류의 연소가스 유해성을 분석하였다. 연소가스의 유해성 분석은 Naval Engineering Standard(NES) 713 규격 및 미국국방성 규격(MIL-DTL)을 적용하였다. $CO_2$의 방출량은 5종의 내장재 모두 NES 713 규격 한계치인 100,000 ppm을 초과하지 않았다. CO 방출량의 경우 압축 스티로폼 단열재가 6,098 ppm으로 규격 한계치인 4,000 ppm을 초과하는 값을 나타내었다. 포름알데히드는 PVC 장판과 압축 스티로폼 단열재에서 각각 25 ppm, 49 ppm 방출되었다. $NO_X$는 합판에서 955 ppm으로 가장 높은 양이 방출되었으며, 규정 한계치 250 ppm에 비하여 높은 값으로 나타났다. 독성 지수는 합판 5.19, PVC 장판 4.13, 압축 스티로폼 단열재가 2.35, 강화마루 2.34, 그리고 실내 마감용 목재 1.22로 산출되었다. 본 연구에서는 화재 시 발생되는 연소가스 측정 및 유해가스 농도를 확인하여, 향후 건축 내장재의 화재 안전성을 평가하기 위한 기초 데이터로 활용하고자 한다.

• 한국식품저장유통학회지
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• 제8권3호
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• pp.286-290
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• 2001

PE필름과 스티로폴 상자를 이용한 생강 저장시 탄산가스 흡착제 및 저장 온 .습도가 생강의 저장성에 미치는 영향을 구명하기 위하여 PE필름이나 스티로폴 상자에 생강을 저장하여 온 습도와 환기공수 및 탄산가스 흡착제 처리에 따른 효과를 검토해 본 결과는 다음과 같다. PE 필름 포장에 의해 중량감소가 현저하게 억제되었으며 0.05 mm보다 0.08 mm에서 중량감소율은 낮았으나 부패율 및 곰팡이발생율이 높았고, 저장온도별로는 15$^{\circ}C$에 비하여 1$0^{\circ}C$에서 중량감소율이 낮고 건전율이 높았으며 저장중 발아가 되지 않아 저장성이 양호하였다. PE필름 두께가 얇고 환기공수가 많을수록 중량감소율은 높았으나 건전율은 0.05 mm에서는 직경 6 mm 크기의 환기공 1개 처리구가, 0.08 mm에서는 환기공 3개 처리구에서 높았으며, 탄산가스 흡착제를 넣어 줌으로써 무처리에 비해 포장내 $CO_2$ 농도가 낮아지고, 부패율 및 곰팡이 발생율이 낮았다. 스티로폴 상자를 이용할 때에도 탄산가스 흡착제 처리로 건전율이 높아졌으며 활성탄이 나 소석회간에 큰 차이는 없었고 상대습도 65%에 비하여 92%에서 건전율이 높았으나, 10% 내외의 발아율을 나타냈다. 이상의 결과로 생강저장 적정 온.습도는 1$0^{\circ}C$, 92% 이며, 저장시 소석회를 처리하므로서 저장성을 높일 수 있을 것으로 사료된다.

• 디지털산업정보학회논문지
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• 제11권3호
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• pp.145-158
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• 2015

Disposable marine product packaging materials such as wooden, Styrofoam, and corrugated cardboard boxes have a very low reuse rate, thus causing the logistics costs to rise and making it difficult to establish a unit load system for marine products. Disposable packing containers to be discarded are accompanied by resource and environmental issues home and abroad. Transportation vehicles for marine products have to return empty without loading different kinds of products after delivery due to the smell and properties of marine products, thus posing as an obstacle to logistics rationalization. In an effort to overcome those limitations, this study examined the stages of transportation including "producer-wholesale market in the producing area-commission merchant-wholesale market in the consumption area-commission merchant-quasi-wholesale market-consumer" and also analyzed the utilization and distribution of disposable packaging materials currently used in the circulation of marine products including wooden, Styrofoam, and corrugated cardboard boxes. Based on the analysis results, the investigator developed a logistics rationalization model capable of promoting semi-permanent reuse and lowering empty vehicle rate on return routes as an alternative to address environmental issues caused by disposable packaging materials, which have been an obstacle to the logistics rationalization of marine products, packaging costs in the process of repeating packing and unpacking at each stage of marine products circulation, and empty vehicle rates on return routes after marine products delivery.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2005년도 춘계 학술기술논문발표대회 논문집
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• pp.17-20
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• 2005

This paper reported the temperature history of concrete placed at deck plate slab under cold climate condition by varying with surface insulating type. No curing sheet and simple insulation curing including non-woven fabric, double layer bubble sheet, the combination of double layer bubble sheet and non-woven fabric dropped temperature below zero within 24 hours, which caused frost damage at early age. On the other hand, the combination of double layer bubble sheet and non-woven fabric and double layer bubble sheet and styrofoam maintained minimum temperature above $4^{\circ}C\;and\;8^{\circ}C$, respectively. Based on core test results compressive strength of concrete with the combination of double layer bubble sheet and non-woven fabric and double layer bubble sheet and styrofoam was higher than those with other curing method due to good insulation effect.

• 전자공학회논문지 IE
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• 제48권4호
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• pp.7-12
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• 2011

본 논문은 금속 표면에서 안정적으로 동작하는 메탈 접착 RFID 태그를 제안한다. 제안한 방법은 일반 상용 RFID 태그를 이용하는 것으로, 스티로폼103.7을 RFID 태그 뒷면에 부착하였다. 비유전율 1.03인 스티로폼103.7을 2.5mm 두께로 RFID 태그 뒷면에 부착하였다. 제안한 방식의 성능을 확인하기 위하여 RFID를 적용한 변압기 물류 시스템을 제안하여 실험을 수행하였다. 변압기 물류 시스템의 실험에서 제안한 태그는 2m 이상에서 리더기와 통신이 가능하였다. 인식율에서도 일반 금속용 태그와 유사한 성능을 나타내었다.

• 수산해양교육연구
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• 제14권1호
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• pp.43-56
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• 2002

(1) This study was carried out to obtain seasonal fluctuations of marine debris in 5 beaches near the Southern Coast of Korea during May, 1999 - April, 2000. The results are as follows: 1. The density of marine debris was remarkably highest at Namhae beach among 5 beaches. The major part of debris in the beach was styrofoam, with the density of 348.5${ea/km}^2$. But, it was Songjung where the largest amount of resin pellets existed. 2. The composition of styrofoam consisted of 51% of the marine debris, wood& papers was 11%, resin pellets & plastics were 8% and others were 16%. 3. Seasonal fluctuations irregularly change in each beach, but the amount of resin pellets were found to be large only in September. It is estimated that resin pellets are beached upon the coastal beaches by the strong warm currents(Tushima currents) during the summer season. 4. Debris fabrication materials that were found had most of parts made up of PE 71.2%, PP 21.2% and EVA 7.7% through these surveys. 5. In the polluted state, the medium one among the 3 specifications(o1d, medium and new state) occupied 88.5% or so.

• 디지털산업정보학회논문지
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• 제10권3호
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• pp.261-272
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• 2014

Home appliances go through a couple of packaging stages from the plant to consumers. The primary packaging, inner packaging for each part, happens for protection after products leave the plant. The secondary packaging happens in the unit of product, ensuring cushioning packaging to protect products from movement. The final tertiary packaging is for transportation and delivery. Each stage of product packaging, however, costs a lot of money because of disposable packaging materials used in each stage including vinyl, tapes, Styrofoam, and corrugated cardboards. Discarded packaging materials also cause environmental problems. In an effort to come up with a measure to solve those problems, this study proposed a plan to minimize logistics costs with semi-permanent packaging materials to replace disposable ones including Styrofoam, vinyl, and corrugated cardboards in the stages of inner packaging, cushioning packaging, product unit-based packaging, and transportation. The study also developed a model to cut down logistics costs by reducing various packaging stages including the primary, secondary, and tertiary stage only to the secondary one through module-type products instead of the transportation- and delivery-type ones, as well as demonstrated the excellence of the study through numerical analysis.

• 한국가구학회지
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• 제19권5호
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• pp.319-327
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• 2008

As art of lamination by plywood got to be generally used, it became a suitable material for expressing live curves that were not able to be expressed on wood furniture made of plank and timber, as well as, openwork deep in curved space, heavy quality of material, and changing contour line-looking wave lines with different process angles. As an alternative, it would be good to build a full scale model, since it would provide practice in form-building and it would also provide a chance to correct the form. Less material can be used and reduce the cutting process by Properly trimming models made of soft formal structure such as Styrofoam Iso-pink and adhesive Styrofoam, and separating the layers and using them on shape cutting of plywood with the same thickness. And by attaching the model veneer that was used in shape cutting of the model and using it as a cutting guide, we can reduce the error of work and successively build the planned form. Since this study is about the need of a full scale model for a laminated wood model and an efficient process, this study concentrates more on process.

• 콘크리트학회지
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• 제9권1호
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• pp.165-172
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• 1997

경량기포콘크리트란 시멘트슬러리 속에 미리 생성된 기포를 혼합시켜 양생시킴으로써 동일한 체적의 보통콘크리트보다 가볍게 만든 콘크리트를 의미한다. 본 연구의 목적은 고분자기포제를 이용하여 초경량성과 타설에 충분한 유동성을 확보하면서 소요강도를 갖는 최적의 선기포방식의 경량기포콘크리트를 개발하는데 있다. 연구결과 실리카흄, 플라이애쉬 등의 혼화재와 산업부산물인 발포포리스티렌비드의 혼합으로 경량기포콘크리트의 역학적 특성을 개선시켜 기존의 선기포방식으로 제조된 경량기포콘크리트보다 유동성 , 경량성과 강도특성이 우수한 경량기포콘크리트를 개발하였다. 본 논문에서는 개발된 경량기포콘크리트의 여러 가지 배합인자에 따른 유동성 및 압축강도를 규명하였으며 최적 배합비를 도출하였다.