• Journal of Bio-Environment Control
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• v.13 no.4
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• pp.251-257
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• 2004

This experiment was carried out to investigate the effects of different covering materials and methods on heat insulation of a plastic greenhouse, growth and yield of tomato. Night air and soil temperatures in a double-layer greenhouse with external multifold thermal cover (MTC; eight-ounce cassimere+four-fold polyform+double-fold non-woven fabric+single-fold polypropylene covering were about $1^{\circ}C$ lower than in that with internal MTC covering, but about $3^{\circ}C$ higher than in that with an EVA film screen. Tomato yield in the external MTC covering increased by $2\%\;and\;19\%$ as compared to that in the internal MTC covering and the non-covering of MTC, respectively, due to its high light transmission and insulation effect. Night air temperatures in a double-layer greenhouse with external MTC covering and with thermal screen (polyester plus aluminium) were $2.2^{\circ}C\;and\;4.5^{\circ}C$ higher than those in a double-layer greenhouse with an external MTC covering and in a double-layer greenhouse equipped an EVA film screen, respectively. Tomato yield in the treatment with external MTC covering and a thermal screen was $18\%\;and\;37\%$ greater than that in the external MTC covering and in an EVA film screen, respectively. Results indicate that tomato could be grown without heating or with minimal heating in a double-layer greenhouse covered with MTC and a thermal screen during the winter season in sourthern regions of Korea.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.05a
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• pp.185-190
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• 2005

Safe, economical and environment-friendly tunnel construction are required again along with social continuous development, the importance of waterproof work that is portion that actually all of user and builder can find that is embossed by tunnel construction's one of important construction. Also, ECB (Ethylen Copolymer Bitumen) sheet that is used in existing tunnel waterproofing method (ECB waterproofing method) being black because asphalt (Bitumen) is added, by purpose that make illumination of tunnel interior brightly and scar discovery eases in sheet with coating white film, but ECB that is used present according as ECB that asphalt is added does not satisfy high tensile strength of construction field, quality standard of extension. Also ECB denigrates color of black M/B that asphalt is excepted.

• Journal of the Korean Society of Safety
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• v.14 no.2
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• pp.83-89
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• 1999

The electrical properties due to mixture ratio of linear low density polyethylene(LLDPE) and ethylene vinyl acetate(EVA) films are studied. An experimental specimen is selected as LLDPE/EVA of thickness 200${\mu}{\textrm}{m}$ produced by mixture ratio of 50 : 50, 60 : 40, 70 : 30 and 80 : 2 wt%. In temperature range from $25^{\circ}C$ to 12$0^{\circ}C$, the measurement of volume resistivity using a highmegohm meter is performed within 10 minutes since each voltage of DC 100 V, 250 V, 500 V and 1000 V is applied, according to the step voltage method. From FT-IR spectrum for an analysis of physical properties, it can be confirmed that LLDPE blended with EVA shows an absence of carbonyl groups(1735 $cm^{-1}$, C=0) and ether groups(1242 $cm^{-1}$, C-O). The peak of LLDPE and EVA made of mixture ratio of 70 : 30 at 2$\theta$ =21.4$^{\circ}$ in the results of XRD is higher than the others. In the experiment for volume resistivity characteristics in order to investigate the electrical properties of specimen, it is confirmed that volume resistivity is decreased with the increase of the molecular motion and temperature.

• Polymer(Korea)
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• v.29 no.2
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• pp.127-134
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• 2005

The relationships among mechanical properties, rheological properties, and morphology by reactive extrusion based on commingled pckaging film wastes contains polypropylene (PP) pckaging film system [PP/polyethylene (PE)/aluminum (Al)/poly(ethylene terephthalate) (PET)] and Nylon packaging film system[Nylon/PE/linear-low density polyethylene (LLDPE)] were investigated to improve the compatibility and toughness of these wastes using various compatibilizers such as ethylene vinylacetate (EVA), styrene-ethylene/butylene-styrene triblock copolymer (SEBS), styrene-ethylene/butylene-styrene-graft-maleic anhydride copolymer (SEBS-g-MA), polyethylene-graft-maleic anhydride (PE-g-MA), polypropylene-graft-maleic anhydride (PP-g-MA) , polyethylene-graft-acrylic acid (PE-g-AA) and polypropylene-graft-acrylic acid (PP-g-AA). Compared with simple melt blend system, the blends showed improvement of about $50\%$ increase in physical properties when SEBS and EVA were added. However, SEBS-g-MA thermoplastic elastomer which is highly reactive with amine terminal group of nylon, resulted in about $200\%$ increase in impact strength. This compatibilization effect resulted from the increase of interfacial adhesion and the reduction of domain size of dispersed phase in PP/Nylon blend system.

• Smart Media Journal
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• v.12 no.5
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• pp.36-45
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• 2023

Recently, in digital agriculture, the types and utilization of greenhouses based on IoT are spreading, and greenhouses are being modernized, enlarged, and even factoryized using smart technology. However, a specific standardization plan has not been proposed according to the equipment for data collection in the smart greenhouse and the size or shape of the greenhouse. In other words, there is a lack of standard data for facility equipment, such as the type and number of sensors and equipment according to the size of the greenhouse, the type of greenhouse construction film and materials suitable for crops and carbon neutrality. Therefore, in this study, the suitability of the implementation, installation and quantity of IoT equipment for data collection was tested, and some standard technologies were presented through the implementation of data collection and communication methods. In addition, impact strength, tensile, tear, elongation, light transmittance, and lifespan issues for PE, PVC, and EVA, which account for about 90% of existing greenhouses, were presented, and the shape, size, and environmental problems of greenhouses made of films were presented. presented in the text. In this research paper, a standardized carbon-neutral modular smart greenhouse using nano-material film was implemented as a solution to environmental problems such as greenhouse size, farm crop type, greenhouse lifespan, and film, and its performance with existing greenhouses was analyzed and presented. Through this, we propose a modularized greenhouse that can be expanded or reduced freely without distinction in the size of the greenhouse or the shape of farmhouse crops, and the lifespan is extended and standardized. Finally, the average characteristics of greenhouses using existing PE, PVC, and EVA films and the characteristics of greenhouses using new carbon-neutral nanomaterials are compared and reviewed, and a plan to implement an expandable IoT greenhouse that supports carbon neutrality is proposed.

• Journal of the Korea Concrete Institute
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• v.15 no.6
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• pp.888-893
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• 2003

The purpose of this study is to make clear the durability of the polymer films formed in the autoclaved polymer-modified mortars and concretes. The polymer films prepared with polymer dispersions such as a styrene-butadiene rubber (SBR) latex, a poly (ethylene-vinyl acetate)(EVA) emulsion and a polyacrylic ester (PAE) emulsion for polymeric admixtures are exposed to autoclaving at 18$0^{\circ}C$ in temperature and 1.01 MPa in vapor pressure, and subjected to tensile test and infrared spectroscopy. The durability of the polymer films is evaluated from the application of autoclaving to the polymer films under saturated Ca(OH)$_2$ solution immersion causes no degradation for SBR films and a significant degradation due to the saponification of the polymers for EVA and PAE films. Accordingly, in the application of autoclaving to polymer-modified mortars and concretes, it is suggested that SBR-modified mortars and concretes are hardly degraded but EVA- and PAE-modified mortars and concretes are markedly degraded by the saponification of the polymers.

• Applied Chemistry for Engineering
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• v.18 no.1
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• pp.58-63
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• 2007

The aim of the present work is to study the effect of gallium addition to HZSM-5 on recovery rates of gaseous and liquid products and carbon number distribution in the catalytic cracking of a polymer mixture, LDPE, LLDPE, and EVA copolymer, with a composition similar to that found in real agricultural film wastes. Ga/HZSM-5 system produced a larger amount of aromatic hydrocarbons than HZSM-5. The yield of aromatic compound in vapor phase contact was higher than that in liquid phase contact. The yield of aromatic compound increased with the amount of catalyst and with the reaction temperature of catalyst bed. The effect of gallium addition on the carbon number distribution was not great.

• Elastomers and Composites
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• v.33 no.5
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• pp.324-334
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• 1998

SBR, polyurethane, acryl and epoxy latex were seperately mixed with ethylene-vinylacetate emulsion(EVA) in the range of $0{\sim}50%$ (wt.% ). For the mixtures, the various physical properties were examined. The viscosity of mixtures was mainly influenced by compatability with EVA emulsion, was decreased within 20% (wt.% ) of latex content, and showed the similar values over 20% (wt.% ) of latex content. The workable time of cement mixtures was mainly depended on the reactivity with cement. The formation of film could be only within $30{\sim}40$ minutes from mixing cement. The tack-free time of mixtures was influenced by the sorts of resin and the quantity of cement. The slow order of tack-free time was epoxy mixtures>SBR mixtures>urethane mixtures>acryl mixtures. The pencil hardness of mixtures was $4B{\sim}2H$, represented higher value in cement mixtures than in emulsion state.

• Textile Coloration and Finishing
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• v.35 no.3
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• pp.159-168
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• 2023

Polyolefin elastomer (POE) is widely used in a variety of applications, particularly in the manufacture of composites, due to its excellent mechanical properties, chemical resistance, and flexibility. However, POE has a high processing temperature, which causes damage to the fiber during the manufacturing process when impregnating the fiber. Therefore, ethylene vinylacetate (EVA), which has a low melting point and excellent adhesion properties, is blended with POE to reduce the processing temperature, and POE-g-MAH (Polyolefin elastomer-grafted-maleic anhydride) is used as a compatibilizer to further improve the POE/EVA blend properties. The compatibility of POE/EVA blends is observed by SEM, and the interaction between each polymer is confirmed by DSC and FT-IR. In addition, the effect of adding the compatibilizer is analyzed through mechanical properties such as tensile strength and elongation. The optimal content of compatibilizer for POE/EVA blends considering physical properties and moldability is sought, and 20 phr is determined to be the most appropriate.

• Journal of Electrochemical Science and Technology
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• v.12 no.3
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• pp.330-338
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• 2021

An integral electrode-bipolar plate assembly, which is composed of electrode, conductive adhesive film (CAF) and bipolar plate, has been developed and evaluated for application with a vanadium redox flow battery (VRB) to decrease contact resistance between electrode and bipolar plate. The CAF, made of EVA (ethylene-vinyl-acetate) material with carbon black or CNT (Carbon Nano Tube), is applied between the electrode and the bipolar plate to enable an integral assembly by adhesion. In order to evaluate the integral assembly of VRB by adhesive film, the resistivity of integral assembly and the performance of single cell were investigated. Thus, it was verified that the integral assembly is applicable to redox flow battery. Through resistance and contact resistance of bare EVA and CAF films on bipolar plate were changed. Among the adhesive films, CAF film coated with carbon black showed the lowest value in through resistance, and CAF film coated with CNT showed the lowest value in contact resistance, respectively. The efficiency of VRB single cell was improved by applying CAF films coated with carbon black and CNT, resulting in the reduced overvoltage in charging process. Therefore, the energy efficiency of both CAF films, about 84%, were improved than that of blank cell, about 79.5 % under current density at 40 mA cm^-2. The energy efficiency of the two cells were similar, but carbon black coated CAF improved the coulomb efficiency and CNT coated CAF improved the voltage efficiency, respectively.