• Horticultural Science & Technology
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• v.31 no.2
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• pp.179-185
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• 2013

This study was carried out to find a reasonable irrigation method of a nutrient solution for the phenolic foam slab (foam LC) used in a trial experiment to substitute the rockwool slab in the production of paprika (Capsicum annuum 'Veyron'). 100, 90, and 80 mL of a nutrient solution was supplied per plant each time when the accumulated radiation reached to 100, $90J{\cdot}cm^{-2}$, and they were named as the 100-100, 90-90, and 90-80 treatment, respectively. The drain percentage per plant of the 100-100 treatment was high by 33.8% in rockwool and 36.7% in foam LC (Lettuce Cube) and that of 90-80 treatment was low by 30.4% and 33.7%. The water content and EC of the rockwool slab were maintained in the range of 63.6-68.9% and $4.4-5.1mS{\cdot}cm^{-1}$, while those of the foam LC slab were in the range of 52.9-58.8% and $5.5-6.5mS{\cdot}cm^{-1}$. The plant height and leaf size of the 100-100 and 90-90 treatments increased in a similar manner, while those of the 90-80 treatment decreased and those of the rockwool were greater than those of the foam LC. The fruit size and weight of the 100-100 and 90-90 treatments were similarly bigger and heavier than those of the 90-80 treatment. The number of fruits harvested per plant was the greatest in the 90-80 treatment with 8 and 8.3 fruits in the rockwool and foam LC. The number of marketable fruits in the rockwool and foam LC was the greatest with 18.1 and 18.2, respectively, in the 90-90 treatment, while that in the 90-80 treatment was 17.2 and 16.8, respectively. The number of unmarketable fruits of the 90-80 treatment was the greatest (1.7-1.8 fruits per plant) in both the rockwool and foam LC, and most of them were small sized or blossom end rot fruits. The yield of the 90-90 treatment was the greatest among the irrigation.

• Fire Science and Engineering
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• v.15 no.3
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• pp.7-13
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• 2001

In this paper, we had analyzed comsbustion gases according to pyrolysis $600^{\circ}c$, $800^{\circ}c$ and $1000^{\circ}c$ for polymeric material using a GASTEC colorimetric gas detector tube in order to combustion gases toxicity evaluation for flame retardant untreated ply wood, flame retardant treated ply wood, flexible polyvinyl chloride and flexible polyurethane foam of polymeric material. As a result, comsbustion gases producted from small specimens of polymeric material had reached fatal to man at a 30 minute exposure time that had possesed toxicity index. Toxicity index at pyrolysis $800^{\circ}c$ of flexible polyvinyl chloride was 31.74. Flexible polyvinyl chloride was the highest toxicity index of flame retardant untreated ply wood, flame retardant treated ply wood, flexible polyvinyl chloride and flexible polyurethane foam. The comsbustion gases producted commonly no concern with pyrolysis temperature had analyzed carbon dioxide($CO_2$) and carbon monoxide(CO). Toxicity index had investigated differently according to pyrolysis temperature even a similar materal.

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.260-266
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• 2006

For the synthesis of polyurethane memory foam stabilizer with fine cells, hydrosilylation reaction with various polyalkyleneoxides and hydrogen functional group of polymethylhydrogensiloxane (D = 75, D' = 15) was conducted. Polyalkyleneoxides (PAO) used in this research were ethylene oxides or ethylene-co-propylene oxides with terminal groups of hydroxides or methyl groups. To analyze the molecular structures and molecular weights as well as the reaction yields (98%), NMR and GPC analysis were executed. Synthesized siloxane surfactants modified with polyalkylene (EO = 12 units) were applied to producing flexible polyurethane fine memory foams from 0.6 pphp to 2.0 pphp. By controlling the amount of the surfactant, physical characteristics, the polyurethane memory foam with cell size (minimum $0.868{\mu}m$), air flows (-78 KPa), and recovery times (8 sec) were achieved.

• Applied Chemistry for Engineering
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• v.30 no.2
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• pp.241-246
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• 2019

In this paper, reactive surfactants were synthesized by using acrylic acid or 3-butenoic acid as nonionic surfactants, polyoxyethylene(23) lauryl ether (Brij 35) and polyoxyethylene(20) stearyl ether (Brij S20). The synthesis of surfactants was confirmed by FT-IR and $^1H$-NMR. The surface tension, emulsifying property, and foam power and stability were also measured. The surface tension value was 35~41 dyne/cm at an critical micelle concentration (cmc) which was measured as $1.0{\times}10^{-4}{\sim}9.7{\times}10^{-5}mol/L$ using a surface tension method. The emulsifying power of synthesized surfactant was measured with benzene, soybean oil and monomer. Also, the initial height of the bubbles and the height after 5 minutes were measured and the values were compared with each other.

• Elastomers and Composites
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• v.52 no.3
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• pp.211-215
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• 2017

Thermally expandable microspheres were used as post-treatment initiators of potassium persulfate, sodium bisulfite, and sodium sulfide in order to improve the foaming ability and whiteness when foaming a mixture of thermally expandable microsphers and poly(vinyl chloride). Potassium persulfate showed no significant influence on the foaming behavior, foam expansion, whiteness, and yellowing, whereas in the case of using sodium bisulfite. In particular, sodium bisulfite demonstrated the best efficiency with 2 wt% treatment. The thermally expandable microspheres prepared herein can provide excellent foamability and whiteness, and are expected to be applicable in various fields such as general coating and wallpaper.

• Transactions of the Society of Information Storage Systems
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• v.9 no.1
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• pp.22-27
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• 2013

In this paper we are presenting a architecture of Co ion decorated graphene oxide as an electrode for supercapacitor application. Graphene oxide, which is exfoliated by oxidant from graphite, is the material for solving the problem of mass production and coating on the surface of working electrode. The $Co^{2+}$ ions are coated by using layer by layer(LBL) method on graphene oxide foam. The metal ion decorated graphene oxide shows enhanced capacitance performance when tested as supercapacitor electrode, showing the specific capacitance of $827Fg^{-1}$.

• Journal of the Korean Institute of Gas
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• v.8 no.2 s.23
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• pp.1-7
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• 2004

The physical properties of rigid polyurethane foam(PUF) synthesized using various types of blowing agents such as water, HFC-365mfc, HFC-245fa, HCFC-l4lb, CFC-11 and n-pentane were studied. The blending effect of blowing agents were also studied. The thermal conductivity, reaction rate, and cell morphology of the PUF with various blending ratio of blowing agents were investigated. The PUF blown by water shows the highest compressive strength among other single blowing agents. The thermal conductivity of PUFs blown by HFC-245fa and HFC-365mfc are close to that of PUFs blown by CFC-11. When HFC-365mfc was mixed with HFC-245fa(30mo1e$\%$) as coblowing agent, the mechanical property shows the highest value among other coblowing agents. It is that the thermal conductivity of PUFs depends on cell size of PUFs as well as thermal conductivity of blowing agent in gaseous form.

• Transactions of the Korean hydrogen and new energy society
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• v.24 no.1
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• pp.1-11
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• 2013

Additives such as glycerol, methanol, acetone, and ethanol were used to prevent $NaBO_2$ from precipitation, and their effects on hydrogen generation properties of $NaBH_4$ hydrolysis were investigated. When the concentration of additives was 5 wt%, the additives such as methanol, acetone, and ethanol could not prevent $NaBO_2$ precipitation. Although glycerol prevented $NaBO_2$ precipitation, conversion efficiency decreased to 78.0% due to its viscosity. Based on test results, hydrogen generation tests were also performed at various concentration of glycerol and methanol to investigate the concentration effects on hydrogen generation properties. As the concentration of glycerol increased from 1 wt% to 3 wt%, conversion efficiency increased owing to additive effect. When its concentration increased to 5 wt%, conversion efficiency decreased due to its viscosity. As the concentration of methanol increased from 5 wt% to 10 wt%, conversion efficiency increased owing to additive effect. When its concentration increased to 15 wt%, conversion efficiency decreased due to $NaB(OCH_3)_4$ precipitate. Although conversion efficiency decreased about 1% when 3 wt% glycerol was added, $NaBO_2$ precipitation was prevented. Consequently, addition of 3 wt% glycerol to $NaBH_4$ solution improves stability of hydrogen generation system.

• Transactions of the Korean hydrogen and new energy society
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• v.35 no.2
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• pp.152-161
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• 2024

In this study, a fuel cell system for future defense unmanned vehicles was designed and validated. A Co/Al₂O₃-Ni foam catalyst for NaBH₄ hydrolysis was characterized using several analytical methods. A NaBH₄ hydrogen generation system with the Co/Al₂O₃-Ni foam catalyst continuously generated hydrogen at elevated reaction temperatures. The fuel cell system with the NaBH₄ hydrogen generation system was designed and tested. The performance of the fuel cell system was comparable to that of the fuel cell system using pure hydrogen. Therefore, the fuel cell system with the NaBH₄ hydrogen generation system is a suitable power source for future defense unmanned vehicles owing to its easy refueling and simple system.

• Journal of the Korean institute of surface engineering
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• v.56 no.5
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• pp.299-308
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• 2023

In this study, phosphorus (P)-doped nickel cobaltite (P-NiCo₂O₄) and nickel-cobalt layered double hydroxide (P-NiCo-LDH) were synthesized on nickel (Ni) foam as a conductive support using hydrothermal synthesis. The thermal properties, crystal structure, microscopic surface morphology, chemical distribution, electronic state of the constituent elements on the sample surface, and electrical properties of the synthesized P-NiCo₂O₄ and P-NiCo-LDH samples were analyzed using thermogravimetric analysis-differential scanning calorimetry (TGA-DSC), X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). The P-NiCo₂O₄ electrode exhibited a specific capacitance of 1,129 Fg^-1 at a current density of 1 Ag^-1, while the P-NiCo-LDH electrode displayed a specific capacitance of 1,012 Fg^-1 at a current density of 1 Ag-1. When assessing capacity changes for 3,000 cycles, the P-NiCo₂O₄ electrode exhibited a capacity retention rate of 54%, whereas the P-NiCo-LDH electrode showed a capacity retention rate of 57%.