• Membrane Journal
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• v.15 no.1
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• pp.62-69
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• 2005

SEBS-clay hybrid membranes were prepared by melt intercalation method with internal mixer. In the hybrid, the amount of clay content was fixed to 5 phr. MMT was intercalated or exfoliated by the ionomer and it was confirmed by X-ray diffraction method. D-spacing of the characteristic peak from MMT plate in SAXD was moved and diminished. Gas permeability, mechanical properties and thermal properties of the SEBS-clay hybrid membranes were investigated. Gas permeability through the SEBS-clay hybrid membranes decreased due to increased tortuosity made by intercalation of clay in SEBS.

• Korean Journal of Agricultural Science
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• v.44 no.3
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• pp.332-338
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• 2017

This study was conducted to investigate the effect of 1-methylcyclopropene (1-MCP), a known ethylene action inhibitor, on fruit quality and incidence of physiological disorders during a simulated marketing period in new mid-season Asian pear (Pyrus pyrifolia Nakai) 'Changjo'. Flesh firmness of untreated control fruits was maintained with a hardness of 20.2 N until day 14 of simulated marketing but decreased rapidly to 6.2 N at day 21 of simulated marketing; losing its commercial quality. However, the firmness of 1-MCP treated fruits remained high (> 20.7 N) during the same period. Quality indices such as soluble solids content and titratable acidity in 'Changjo' pear did not show any significant differences during simulated marketing period regardless of 1-MCP treatment. For the difference in skin color, redness ($a^*$) tended to increase as simulated marketing period became longer, and 1-MCP treatment delayed this change by 7 days compared to the untreated fruits. No decrease occurred in ethylene production level with 1-MCP treatment in 'Changjo' pear. Meanwhile, 1-MCP treated pears showed a significantly lower respiration rate compared to the untreated fruits. Also, 1-MCP treatment effectively reduced the incidence of physiological disorders including internal flesh browning and mealiness symptoms during simulated marketing periods of 21 and 14 days, respectively. Therefore, we conclude that the use of 1-MCP is recommended for quality maintenance and for prevention of physiological disorders during simulated marketing periods of ${\geq}7days$ for mid-season Asian pear 'Changjo'.

• Korean Journal of Agricultural Science
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• v.25 no.1
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• pp.19-25
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• 1998

This study was conducted to develop an appropriate postharvest technique to extend the shelf-life of an early cultivar, 'Tsugaru' apples. The general quality of stored fruit was more affected by maturity at harvest than postharvest treatments. When firmness and internal quality were considered, fruits harvested at the medium stage of color development showed better results. Between postharvest treatments examined in this study, a simple polyethylene film(PE) wrapping (30um) was excellent on inhibition of weight loss but this treatment revealed no clear effect on other quality factors including firmness and acidity. Ethylene scrubber(ES) in polyethylene wrapping showed a positive effect on keeping fruit quality in general. Especially acid content was higher in fruit stored with PE + ES, thus, fruit seemed to be better in freshness. A physiological disorder was observed regardless postharvest treatments. The symptom was associated with incidence of pitting on surface and breakdown of the effected tissue. And much more symptoms were developed near the calyx end. Thus, future studies concerning 'Tsugaru' storage should include an examination of the optimum storage temperature.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.521-529
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• 2022

This study evaluated the effects of agricultural reflective film and HANSPEK film on the fruit quality attributes and peel color variables of 'Fuji' apples. The reflective films were applied under the tree canopies at 20 and 30 days before harvest (DBH), and a tree with no films was used as the control. Depending on the measurement locations, the light intensity was 7.4 - 14.6% higher in the reflective film treatments than that of the control. However, no difference in the light intensity was observed between the reflective and HASPEK films. In addition, the light intensity was not also different between the 20 and 30 DBH. At harvest, the flesh firmness, fruit weight, soluble solids content, titratable acidity, and internal ethylene concentration were not different regardless of the type of reflective film and treatment time. In addition, the peel color variables were not affected in the equatorial region. However, in the calyx region, the L* and b* values were decreased, and the a* value was increased by the reflective and HANSPEK films compared with the control. Hence, the hue angle was decreased to near 0^o (red), and the peel color was improved. Therefore, this study suggests that the application of the HANSPEK film under a tree canopy could improve the fruit peel color of 'Fuji' apples.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.279-283
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• 2013

This work was carried out to evaluate the effect of preharvest sprayable 1-methylcyclopropene (1-MCP: $Harvista^{TM}$) treatment on the fruit quality attributes in cold stored 'Gamhong' (Malus domestica Borkh) apples. Preharvest sprayable 1-MCP treatment did not affect fruit qualities at harvest but titratable acidity (TA) was higher in fruit treated 10 days before harvest (DBH) than in control. During cold storage, fruit firmness and TA were higher in 1-MCP treated fruit than in control fruit as storage duration progressed, while SSC was not affected. Internal ethylene concentration (IEC) levels were not different among treatments at harvest. While the IEC level in control fruit reached to $58.3{\mu}L{\cdot}L^{-1}$ after 6 month cold storage, the IEC levels in 1-MCP treated fruit ranged from 18.2 to $25.0{\mu}L{\cdot}L^{-1}$. Therefore, this result indicates that preharvest sprayable 1-MCP treatment should be another promising approach to retain fruit quality attributes in long-term cold stored 'Gamhong' apples.

• Polymer(Korea)
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• v.27 no.6
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• pp.562-568
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• 2003

Environmental problems due to waste tire and waste plastics let us develop practical and economically feasible products. For this purpose, the characteristics of waste tire/plastic composites including various additives were examined using internal mixer. Experimental results indicated that the tensile strength and the flexural strength of waste tire/plastic composites decreased with the waste tire content. When 20 wt% of PP was added to the waste tire (60 wt%)/HDPE composites, the tensile strength was 1.5 times higher than the composite without PP, It was also found that the strain at break of composites increased by 2.5 times with 10 wt% addition of ethylene vinyl acetate and styrene ethylene butylenes styrene respectively. When 10 wt% of glass fiber was added to waste tire (60 wt%)/ HDPE composites, the tensile strength was 63% higher than the composite without glass fiber.

• Horticultural Science & Technology
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• v.32 no.2
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• pp.193-201
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• 2014

We investigated the effect of preharvest spray of aminoethoxyvinylglycine (AVG) on the fruit quality and incidence of physiological disorders during shelf-life of 'Hanareum' and 'Wonhwang' pear (Pyrus pyrifolia Nakai). AVG applications (0, 75, 150 and $300mg{\cdot}L^{-1}$) made 30 days before anticipated harvest of respective cultivar. AVG did not influence the fruit development and quality parameters including starch content, soluble solids and acidity at harvest time in two pear cultivars although the flesh firmness of the fruits treated with $300mg{\cdot}L^{-1}$ AVG were higher than that of control in 'Hanareum' pear. Among the three AVG concentrations, only $300mg{\cdot}L^{-1}$ AVG showed effectiveness on maintaining flesh firmness in 'Hanareum' pear during shelf-life. Meanwhile, competitive high flesh firmness was attained in 'Wonhwang' pear treated with $150mg{\cdot}L^{-1}$ AVG (27.7 N) and $300mg{\cdot}L^{-1}$ AVG (28.2 N) when compared with untreated control (17.8 N) during 21 days of shelf-life at $25^{\circ}C$. AVG did not cause any significant difference at skin color development relative to control in two pear cultivars. AVG decreased ethylene production and respiration rate at $300mg{\cdot}L^{-1}$ level in two pear cultivars during the entire shelf-life. During shelf-life, low incidence of physiological disorders including internal and core browning and mealiness were attained in the fruits treated at $300mg{\cdot}L^{-1}$ AVG in two cultivars when we compared with the untreated control.

• Korean Journal of Agricultural Science
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• v.38 no.2
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• pp.205-212
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• 2011

The potential factors for quality loss of cleaned fresh ginseng and technology to be associated with the improvement of marketability through pre-packaging fumigation were examined. Major microorganisms isolated from fresh ginseng included Botrytis cinerea, and Erwinia sp. Others such as Cylindrocarpon sp., Fusarium spp., Pennicilium spp., Bacillus spp. were also found at relatively low frequency. The bacterial density of vacuum packaged fresh ginseng rapidly increased during simulated marketing. Little correlation between bacterial growth and package swelling was found. In order to improve packaging method of fresh ginseng, pre-packaging treatment of 2-phenylethyl alcohol (PE, 100 uL/L, 4 hr) was examined. The fumigation treatment effectively inhibited the growth of bacteria density and also effective on keeping firmness of ginseng root, especially in cortical portion. The internal gas compositions of plastic container packaged for ginseng were approximately ranged between 6 to 8% $O_2$and 3 to 4% $CO_2$. The $O_2$ level of fumigation treatment was lower than control whereas $CO_2$ level was higher. The upsurge of ethylene evolution I day after simulated marketing was found only in fumigation treatment but it returned to ordinary level at day 2. The sucrose content of 2-PE treatment was significantly reduced at 5 days after simulated marketing but reducing sugars like glucose and fructose remained at higher level. The difference in sugar levels was reduced after 10 days of simulated marketing. The decay of fresh ginseng began at the lateral or fine root, which is weak to physical damage, in general. The epidermis was more damaged. Plastic container packaging with PE fumigation could be an alternative to vacuum packaging, which allows an aerobic environment and prevents anaerobic respiration. Further study of pre-package fumigation is required to improve technology of fresh ginseng marketing.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.4
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• pp.11-19
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• 2015

The important properties of EVA (ethylene vinyl acetate) redispersible polymer was waterproof, densification of internal pore space of concrete and ball bearing and micro filler. Also, the significant role of polypropylene(PP) fiber was crack control and blockade of movement for deterioration factors. The most studies for EVA were limited in the field of mortar and PP fiber reinforced concrete had been studied in the state of being restricted unit water content, rich mix and mixing much of the fiber without considering construction site. Therefore, the control mix design were applied in ready mixed concrete using 10 % fly ash of total cement weight used in batch plant. On the basis of control mix design, EVA contents ranging from 0 % to 10 % of total cement weight and PP fiber contents ranging from 0 % to 0.5 % of EVA concrete volume were used in the mix designs. The results showed the maximum compressive strength value was measured at EVA 5.0 % and PP fiber 0.1 %, the minimum water absorption ratio was at EVA 10 % and PP fiber 0 %, the durability factor for freezing and thawing resistance was at EVA 5.0 % and PP fiber 0.3 % and the minimum weight reduction ratio of resistance to sulfuric acid attack was at EVA 10 % and PP fiber 0.5 % after curing age 42days. Meanwhile, From these results, PP fiber reinforced EVA concrete would be very benefit, if each optimal mix types were used in hydraulic structures, underground utilities and agricultural structures.

• Food Science and Preservation
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• v.23 no.4
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• pp.453-458
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• 2016

'Jonathan' apples are relatively small size which contributes to enhancing fruit consumption and gaining popularity. Thus, this study was carried out to evaluate the effects of AVG (aminoethoxyvinylglycine, ReTain$^{(R)}$), sprayable 1-MCP (1-methylcyclopropene, Harvista$^{TM}$), and fumigation 1-MCP (SmartFresh$^{TM}$) applications on fruit quality attributes and storability in 'Jonathan' apple fruits during cold-stored. The Jonathan fruits were dipped with either ReTain (75 mg/L) or Harvista (125 mg/L) solutions for 5 min, or fumigated with SmartFresh (1 mg/L) for 18 hr before storage at $0{\pm}1^{\circ}C$ for 75 days. Flesh firmness and titratable acidity remained higher in all pre-treated apples than control ones during cold storage period. Flesh firmness was higher for apples treated with ReTain and SmartFresh than samples treated with Harvista, while soluble solid content and respiration rate were not affected by sample pretreatment. Internal ethylene concentration (IEC) of all pretreated apples remained below about $4.5{\mu}L/L$ during the entire storage period while that of control sample greatly increased to $10.29{\mu}L/L$. Ethylene production was much higher in control fruits than in treated ones during cold storage. These results indicated that ReTain and 1-MCP treatments would be considerably effective in retention of fruit quality attributes of 'Jonathan' apple during cold-stored.