• Fashion & Textile Research Journal
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• v.21 no.3
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• pp.363-369
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• 2019

This study developed electroconductive textiles by coating polypyrrole to PET nonwoven-based Polyvinyl Alcohol (PVA) nanoweb made by electrospinning and applying the developed electrotextiles as ECG Electrodes. To find the optimum coating conditions for high electrical conductivity, the ratios of 2.6-Naphthalenedisulfonic acid with Disodium Salt (NDS) vs Ammonium Persulfate (APS) as an oxidant and a doping agent in the solution were changed from 3:7 to 7:3; the immersion time of the specimen in the solution was 1 hour. PVA nanowebs coated with polypyrrole under various conditions were filmed with FE-SEM. FT-IR analysis was also performed to examine the presence of polypyrrole nanoparticles in the PVA nanoweb. The electrical resistance of the treated specimens were measured with a Multimeter. Consequently, the PVA Nano Web was undamaged even after heat treatment that allowed for coating. Uniform polypyrrole nanoparticles then formed on the surface of the PVA nanoweb after coating. The measured electrical resistance was shown to be at least $12K{\Omega}/{\Box }$ from a maximum of $3,456K{\Omega}/{\Box }$. The proper amount of NDS content had a positive effect on the conductivity improvement of electroconductive textiles; in addition, the highest electrical conductivity was achieved with a ratio of 3:7 between NDS and APS.

• Food Science of Animal Resources
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• v.39 no.1
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• pp.23-34
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• 2019

Fat reduction in the formulation of cheese emulsion causes problems in its flowability and functional characteristics during spray-dried cheese powder production. In order to eliminate these problems, the potential of using microparticulated whey protein (MWP) in cheese emulsions was examined in this study. Reduced-fat white-brined cheese emulsions (RF) with different dry-matters (DM) (15%, 20%, and 25% excluding emulsifying salt) were produced using various MWP concentrations (0%-20% based on cheese DM of emulsion). Their key characteristics were compared to full-fat cheese emulsion (FF). MWP addition had no influence on prevention of the phase separation observed in the instable group (RF 15). The most notable effect of using MWP was a reduction in apparent viscosity of RF which significantly increased by fat reduction. Moreover, increasing the amount of MWP led to a decrease in the values of consistency index and an increase in the values of flow behavior index. On the other hand, using high amounts of MWP made the emulsion more liquid-like compared to full-fat counterpart. MWP utilization also resulted in similar lightness and yellowness parameters in RF as their full-fat counterparts. MWP in RF increased glossiness and flowability scores, while decreased mouth coating scores in sensory analyses. Fat reduction caused a more compact network, while a porous structure similar to FF was observed with MWP addition to RF. In conclusion, MWP showed a good potential for formulation of reduced-fat cheese emulsions with rheological and sensorial characteristics suitable to be used as the feeding liquid in the spray drying process.

• Membrane and Water Treatment
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• v.10 no.4
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• pp.287-298
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• 2019

Lotus leaf has a special dual micro and nano surface structure which gives its highly hydrophobic surface characteristics and so-called self cleaning effect. In order to endow PVDF hollow fiber membrane with this special structure and improve the hydrophobicity of membrane surface, PVDF hollow fiber composite membranes was obtained through the immersion coating of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) dilute solution on the outside surface of PVDF support membrane. The prepared PVDF composite membranes were used in the vacuum membrane distillation (VMD) for the desalination. The effects of PVDF-HFP dilute solution concentration in the dope solution and coating time on VMD separation performance was studied. Membranes were characterized by SEM, WCA measurement, porosity, and liquid entry pressure of water. VMD test was carried out using $35g{\cdot}L^{-1}$ NaCl aqueous solution as the feed solution at feed temperature of $30^{\circ}C$ and the permeate pressure of 31.3 kPa. The vapour flux reached a maximum when PVDF-HFP concentration in the dilute solution was 5 wt% and the coating time was kept in the range of 10-60 s. This was attributed to the well configuration of micro-nano rods which was similar with the dual micro-nano structure on the lotus leaf. Compared with the original PVDF membrane, the salt rejection can be well maintained which was greater than 99.99 % meanwhile permeation water conductivity was kept at a low value of $7-9{\mu}S{\cdot}cm^{-1}$ during the continuous testing for 360 h.

• Membrane Journal
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• v.29 no.3
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• pp.140-146
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• 2019

In this study, a selective layer of poly styrene sulfonic acid (PSSA) and polyethyleneimine (PEI) was formed by layer-by-layer method onto a porous polyacrylonitrile (PAN) hollow fiber membrane as the suppoter membrane. The salting out method was used by adding Mg salt to the coating solution. Several experimental conditions of the ionic strength, polymer concentration, and coating time were investigated, and the flux and rejection were measured at the operating pressure of 2 atm for 100 mg/L of NaCl, $MgCl_2$, and $CaSO_4$ as the feed solution. The membranes coated with PSSA 20,000 ppm, coating time 3 minutes, ionic strength 1.0, PEI 30,000 ppm, coating time 1 minute, and ionic strength 0.1 were observed the best. In the 100 ppm NaCl, $MgCl_2$, and $CaSO_4$ feed solutions, the flux of 20.4, 19.4, and 18.7 LMH, and the rejection of 67, 90, and 66.6%, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.10
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• pp.1603-1610
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• 2019

Objective: The purpose of this study was to investigate the effect of fermented spinach derived nitrite and sodium nitrite on cured pork loin. Methods: The following treatments were prepared using brine (8% [w/v] salt): Control (-), no nitrite added; Control (+), 0.08% (w/v) sodium nitrite brine; T1, 0.04% (w/v) nitrite fermented spinach juice in 0.04% (w/v) sodium nitrite brine; T2, spinach juice in 0.04% (w/v) sodium nitrite brine; T3, 0.04% (w/v) nitrite fermented spinach juice used as sodium nitrite free brine; and T4, spinach juice used as sodium nitrite free brine. T2 and T4 were incubated to allow to reduce nitrate to nitrite. Results: Spinach juice did not affect cooking loss and pH but negatively influenced flavor and overall acceptability (p<0.05). T1 samples containing synthetic and natural nitrites showed the highest redness values. Spinach juice negatively affected volatile basic nitrogen; however, thiobarbituric acid reactive substance values of T1 and T3 were similar to those of controls (+) (p>0.05). Residual nitrite content decreased with decreasing synthetic nitrite levels. T1 and control samples showed no significant differences in overall acceptability (p>0.05). Conclusion: Thus, combined synthetic and natural nitrites improved the quality of cured pork loin.

• Journal of the Korean Society of Safety
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• v.33 no.6
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• pp.15-21
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• 2018

Ships may collide with reefs or other objects during operation, when arriving or departing ports. The hull plate may be damaged due to the contact with other ships. The total number of domestic powered fishing vessels has decreased, but that of FRP fishing vessels has increased by 0.7% and the ratio of FRP fishing vessels to the total fishing vessels increased to 96%. Recently, fishing vessels has been used as fishing boats for income of non-fishermen as well as fishermen. Therefore, safety management for repair and maintenance is necessary. The penetration of moisture and moisture in the composite material such as FRP may deteriorate the mechanical properties and the salt (NaCl) component of the damaged portion may cause a relatively high deterioration in material strength. The gel coat painting is the final stage of repairs ans maintenance of FRP fishing vessels. The thickness criteria in the domestic and foreign gel coat is 0.3~0.762 mm. The joint specimens, which was immersed in seawater for 120 days, were compared with those without seawater immersion. As a result, the tensile strength was 83 ~ 121.8% and the flexural strength was 83 ~ 113% compared with the specimens without seawater immersion. According to the previous study the tensile strength decreased by more than 29% and the flexural strength decreased by more than 50% when the composite material was immersed in seawater for 1,083 hours without coating. As a result, it was found that the gel coat with 0.5 mm thickness is very effective in preventing the strength decrease of the composite material.

• Journal of the Korean GEO-environmental Society
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• v.20 no.1
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• pp.51-56
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• 2019

This paper presents a method to deice concrete pavement with carbon nanotube(CNT) as an heating material so as to avoid the adverse effects of conventional deicing method such as salt on the structure, function and environment. To this end, laboratory tests integrated with numerical simulations were conducted. In the laboratory tests, the CNT was embedded inside the concrete slab and generated the heat up to the target temperature of $60^{\circ}C$ in the freezer at temperature of $-10^{\circ}C$. Then, the surface temperature was measured to investigate how far the heat transfers on the surface at temperature of above $0^{\circ}C$. Also, three different spacings of 15, 20 and 30cm between CNTs were conducted to determine the maximum allowable spacing of CNT. Along with these experimental tests, heat transferring analysis conducted to validate the test results.

• Journal of Korean Society on Water Environment
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• v.35 no.5
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• pp.418-424
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• 2019

In this study, $TiO_2$ nanotubes with different morphologies were prepared in the electrolyte consisting of ethylene glycol, ammonium fluoride($NH_4F$), and deionized water($H_2O$) by controlling the voltage and time in the anodization method. Thicknesses and pore sizes of these $TiO_2$ nanotubes were measured to interpret the relationship between anodization conditions and $TiO_2$ nanotube morphologies. Element contents in the $TiO_2$ nanotubes were detected for further analysis of $TiO_2$ nanotube characteristics. Photoelectrolyticdecolorization efficiencies of the $TiO_2$ nanotube plates with various morphologies were tested to clarify the morphology that a highly active $TiO_2$ nanotube plate should have. Influences of applied voltage in photoelectrolysis processes and sodium sulfate($Na_2SO_4$) concentration in wastewater on the decolorization efficiency were also studied. To save the equipment investment cost in photoelectrolysis methods, a two-photoelectrode system that uses the $TiO_2$ nanotube plates as photoanode and photocathode instead of adding other counter electrodes was studied. Compared with single-photoelectrode system that uses the $TiO_2$ nanotube plate as photoanode and titanium plate as cathode on the view of the treatment of dye wastewater containing different amounts of salt. As a result, a considerably suitable voltage was strictly needed for enhancing the photoelectrolyticdecolorization effect of the two-photoelectrode system but if salts exist in wastewater, an excellent increase in the decolorization efficiency can be obtained.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.1021-1027
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• 2020

The amount of food waste generated in Republic of Korea has been increasing alongside an increasing population and booming economy as such, research on effective treatment and recycling is required. Food waste recycling is complicated by its inferior characteristics such as high levels of water and concern that its continuous application to farmland can lead to salt accumulation and concomitant damage crops. In the present study, therefore, dehydrated food waste powder (FWP), which contains a large amount of organic matter and nutrients, but which may require additional improvements was mixed in various ratios with organic fertilizers and the mixtures were tested for their effects on the growth of the leaf lettuce. A control was set up with inorganic fertilizers alone while a treatment with only FWP was also included. The mixture of FWP and organic fertilizers produced better leaf lettuce growth in all the treatments than the control and FWP. The fresh weight of the leaf lettuce produced with a mixture containing 60% FWP was 50% higher than that of the control. The results from this study indicate, therefore, that FWP mixed with other organic supplements in appropriate amounts positively impacts crop growth and development.

• Korean Journal of Metals and Materials
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• v.48 no.1
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• pp.49-56
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• 2010

This study investigated how the surface of Al-12wt.%Si alloy modified by the plasma electrolytic oxidation process (PEO). The PEO process was performed in an electrolyte with sodium hexametaphsphate as a conducting salt, and the effect of ammonium metavanadate on variations in the morphology of electrochemically generated oxide layers on the alloy surface was investigated. It is difficult to form a uniform passive oxide layer on Al alloys with a high Si content due to the differences in the oxidation behavior of the silicon-rich phase and the aluminum-rich phase. The oxide layer covered the entire surface of the Al-12WT.%Si alloy uniformly when ammonium metavanadate was added to the electrolyte. The oxide layer was confirmed as a mixture of $V_2O_3$ and $V_2O_5$ by XPS analysis. In addition, the oxide layer obtained by the PEO process with ammonium metavanadate exhibited a black color. Application of this surface modification method is expected to solve the problem of the lack of uniformity in the coloring of oxide layeres caused by different oxidation behaviors during a surface treatment.