• 제목/요약/키워드: styrofoam

검색결과 159건 처리시간 0.028초

Experimental research on sagging bending resistance of steel sheeting-styrofoam-concrete composite sandwich slabs

  • Cao, P.Z.;Lu, Y.F.;Wu, Kai
    • Steel and Composite Structures
    • /
    • 제15권4호
    • /
    • pp.425-438
    • /
    • 2013
  • A new-styrofoam-concrete composite sandwich slab with function of heat insulation is designed. Four full-scale simply supported composite sandwich slabs with different shear connectors are tested. Parameters under study are the thickness of the concrete, the height of profiled steel sheeting, the influence of shear connectors including the steel bars and self-drilling screws. Experimental results showing that four specimens mainly failed in bending failure mode; the shear connectors can limit the longitudinal slippery between the steel profiled sheeting and the concrete effectively and thus guarantee the good composite action and cooperative behavior of two materials. The ultimate sagging bending resistance can be determined based on plastic theory. This new composite sandwich slab has high sagging bending resistance and good ductility. Additionally, these test results help the design and application of this new type of composite sandwich slab.

초고주파 가열을 이용한 스티로폼 제조기술 연구 (A Study on the Styrofoaming Method by UHF Heating)

  • 한두희
    • 한국산학기술학회논문지
    • /
    • 제6권1호
    • /
    • pp.94-103
    • /
    • 2005
  • 고강도 저발포 스티로폼을 고온고압 수증기를 사용하지 않고 초고주파를 사용하여 제조하는 공법을 개발하였다. 주파수 13.6 MHz이고 출력 7kW의 전자기파와 3배 발포분을 원료로 사용하였다. 유전가열방식이 스팀방식보다 내부 융착성에서 우수하였으며, 모분 온도 $105-110^{\circ}C$에서 내부 융착성이 가장 우수하였다.

  • PDF

다층형 단열재의 구성 형식에 따른 강도 특성 연구 (Strength Properties of Multi-layered Insulation according to the Type of Configuration)

  • 류화성;신상헌;송성용;김득모
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2019년도 춘계 학술논문 발표대회
    • /
    • pp.141-142
    • /
    • 2019
  • As part of the recent low-energy policy, insulation standards for buildings are increasing every year. In addition, the conventional styrofoam heat insulation material has a problem in that the thickness of the heat insulation material to achieve the standard heat transmission rate is rapidly increased. Although the risk of spreading the structure vulnerable to fire due to insufficient spacing between buildings due to thickened insulation is increasing, the high cost of high efficiency insulation is difficult to solve. On the other hand, it is known that the method to be used as a formwork using insulation is excellent in cost reduction effect by reducing the amount of formwork used and simplifying the subsequent insulation work. The purpose of this study is to evaluate the strength characteristics of multi - layered insulation materials with appropriate strength by reducing the thickness of the insulation by appropriately combining high performance phenolic foam insulation and styrofoam insulation.

  • PDF

PPS(PAD POOL SYSTEM) 도입에 의한 섬유업계 물류비 절감에 관한 연구 (A study on the logistics cost reduction in textile industries by introducing Pad Pool System)

  • 권안식;박인술
    • 대한안전경영과학회지
    • /
    • 제7권2호
    • /
    • pp.95-106
    • /
    • 2005
  • Many Korean companies are challenged to reduce logistics cost and meet environmental-friendly logistics. The textile companies in harsh competition are requested to make improvement on their logistics environment to cut down the total cost. However, they have reached the limit on improving the manufacturing process. We believe that the logistics department is the most improvable part at present. Improving logistics will be highly effective to cut down the total cost. In this study, we present Pad Pool System(PPS) as the solution to save their logistics cost. PPS, which means the shared use of Styrofoam pads, will enable the textile companies to cut down their cost and strengthen enterprise competitiveness. Also, PPS will be helpful reducing environmental disruption because the system reuses retrieved Styrofoam pads many times.

다층형 단열재를 사용한 영구거푸집의 처짐 특성 (Deflection Characteristics of Permanent Formwork Using Multi-layer Insulation)

  • 류화성;신상헌;송성용;김득모
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2019년도 추계 학술논문 발표대회
    • /
    • pp.130-131
    • /
    • 2019
  • As part of recent low-energy policies, thermal insulation standards for buildings are being tightened every year. In addition, the conventional styrofoam insulating material has a problem that the thickness of the heat insulating material to achieve a standard heat permeability is rapidly increased. Due to the thick insulation, there is a high risk of spreading vulnerable structures such as fire due to lack of space between buildings. On the other hand, the method of using the insulation as a formwork is known to be excellent cost saving effect through the reduction of the formwork usage and the simplification of the external insulation work. In order to solve this problem, this study aims to fabricate a multi-layered insulator that combines high-performance phenolic foam insulation and styrofoam insulation and evaluate the deflection characteristics for use as formwork.

  • PDF

Perlite 단용 및 혼용처리를 이용한 과채류 양액재배 기술 개발 I. 재배용기와 배지의 종류가 양액재배 오이의 생장과 과실품질에 미치는 영향 (Development of Hydroponic Technique of Fruit Vegetables Using Perlite and Mixtures with Perlite as a Substrate I. Effects of Containers and Substrates on the Growth and Fruit Quality of Hydroponically Grown Cucumber)

  • 정순주;서범석;강종구;김홍기
    • 생물환경조절학회지
    • /
    • 제4권2호
    • /
    • pp.159-166
    • /
    • 1995
  • 본 실험은 배수성과 통기성이 우수한 양액 재배 배지로써 perlite와 구입이 용이한 왕겨 및 훈탄의 혼합배지를 이용하여 스티로폼 성형베드 및 상자, 플라스틱 자루, 폿트 등의 재배용기의 차이와 배지의 종류에 따른 양액재배 오이의 생육 및 수량반응을 구명하고자 수행하였 다. 1. 스티로폼베드와 상자가 다른 용기보다 초장이 높게 나타났으며, 스티로폼 상자를 용기로 사용할 때 펄라이트 단용처리구가 275.5cm, 왕겨 혼합처리구가 277.0cm로 초장이 가장 높았다. 2. 엽면적은 스티로폼 성형베드와 상자가 가장 높게 나타났고, 자루재배, 폿트재배의 순으로 나타났다. 스티로폼 성형베드와 상자의 경우에는 펄라이트 단용>왕겨 혼합배지>훈탄 혼합배지의 순으로 나타났으나, 자루재배에서는 왕겨, 폿트재배에서는 왕겨 혼합배지에서 엽면적이 높게 나타났다. 3. 과실수량은 스티로폼 상자를 용기로 한 펄라이트 단용구가 2097.1g으로 가장 많았으며 과수도 13.4개로 높게 나타났다. 4. 상품과율은 스티로폼 베드와 상자에서 70%이상을 나타냈으나 자루재배와 폿트재배에서는 70%이하로 나타났다. 5. 곡과율과 선세과는 자루재배에서 10%이상으로 높게 나타난 반면 스티로폼 상자에서는 낮게 나타났다.

  • PDF

하계 동해의 해양폐기물 분포와 조성에 관한 연구 (Distribution and Composition of Floating Debris in the East Sea during the Summer Season)

  • 김종화;김민석;김용복
    • 수산해양교육연구
    • /
    • 제17권1호
    • /
    • pp.58-66
    • /
    • 2005
  • Floating debris was observed using a training ship, KAYA, of Pukyong National University with cruising speed of about 10-12 knot during July 12~25, 2003. The area sampled was the East Sea enclosed by 3 nations, namely, Korea, Japan and Russia, and was divided into 68 unit segments on survey routes [Fig. 1]. Debris fabrication materials were categorized with 6 items, e.g., man-made or natural wood items, paper and cardboard, nylon rope, styrofoam, vinyl and plastic, floating metal and glass containers. All identified items within $100{\pm}10 m$ wide band were recorded but ignored if beyond this boundary. The results of this study are as follows: 1. The average numbers of debris per unit area, $1km^2$, were found as 16.3 pieces (items) in the sea. 2. The highest densities of numbers, $32.3pieces/km^2$, were discovered in vicinity of the Oki strait of Japan, area of 'NEK' in Fig. 1. 3. Especially, styrofoam item only was composed to 63.6% of all in the sea of 'SD', located in the southern part of Dokdo Island, Korea. The item seems to be derive from the Southern Sea of Korea. 4. Therefore, comparing the distribution of debris numbers (the results of above 2 and 3) with flow patterns of Kuroshio currents, it was shown that their relation was good agree each other. Further more surveys are being conducted and a much wider coverage can be achieved with other countries, then it can be obtained that the East Sea is polluted to some extent, where is the origin of debris, and the finding of floating routes and stationary sea.

Performance of a Recirculating Aquarium System for the Culture and Holding of Marine Fish

  • Peng Lei;Jo Jae-Yoon
    • Fisheries and Aquatic Sciences
    • /
    • 제7권2호
    • /
    • pp.76-83
    • /
    • 2004
  • To supply fresh and quality quarantined seafood in live seafood specialty restaurants, facilities for short-term culture or holding of live marine fish and shellfish are a necessity. In this study, the performance of a simple recirculating aquarium system for the culture and holding of marine fish was evaluated. The aquarium system consisted of a culture tank, a foam fractionator for solids removal, and a Styrofoam bead filter for nitrification and solids trapping. In the first trial, the aquarium was stocked with a total of 12 kg Korean rockfish, which were fed approximately $0.5\%$ of the total fish body weight daily. During the 2-month culture period, total ammonia nitrogen (TAN) and nitrite nitrogen $(NO_2-N)$ concentrations remained below 1mg/L and 2mg/L, respectively. The chemical oxygen demand (COD) fluctuated between 13.6 and 31.2 mg/L on selected sampling days. The total suspended solids (TSS) removed by the foam fractionator was between 2.7 and 4.6g daily. The Styrofoam bead filter not only reduced TAN and $NO_2-N$ in the culture tank water, but also trapped solids equivalent to 8.3-26.7\% of the weight of feed supplied. In Trial 2, 30kg of live fish were held in the aquarium without feeding for a 24-hour period and the water quality parameters were monitored. TAN and $NO_2-N$ concentrations first increased and then decreased to around 0.3mg/L. These results demonstrate that the recirculating aquarium system is a functional option for the short-term culture or holding of marine fish.

시판 보냉팩 개수에 따른 진공포장 냉동 넙치(Paralichthys olivaceus) 및 고등어(Scomber japonicus) 필렛의 상온유통 중 선도유지능 비교평가 (Comparative Assessment of Freshness Preservation in Vacuum-Packed Frozen Olive Flounder Paralichthys olivaceus and Mackerel Scomber japonicus Fillets During Room Temperature Distribution Using Varied Quantities of Commercially Available Cold Packs)

  • 김소희;이지운;전은비;김진;;박신영;이정석
    • 한국수산과학회지
    • /
    • 제56권6호
    • /
    • pp.818-825
    • /
    • 2023
  • The surge in online seafood consumption has increased parcel delivery, leading to a need to implement effective preservation methods. As the cold chain system is not fully established in Korea, styrofoam boxes and cold packs are commonly used for low-temperature seafood distribution. The impact of cold packs on product preservation depends on the number utilized. Herein, the freshness of vacuum-packed frozen fish fillets (Paralichthys olivaceus and Scomber japonicus) stored at 25±0.5℃ for up to 84 h was measured. Chemical (pH and volatile base nitrogen), microbiological (viable cell count), and physical (odor intensity) properties were assessed using 2 or 4 cold packs in a styrofoam box. Four cold packs yielded lower values, indicating superior freshness, and extended fish freshness by approximately 12 h compared with two cold packs. Therefore, it is recommended to use a minimum of 4 cold packs (-350 g/cold pack) in a styrofoam box for distributing approximately 300 g of frozen fish fillets at room temperature during the summer, considering an average delivery period of 2 days in Korea.