• Resources Recycling
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• v.3 no.1
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• pp.17-24
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• 1994

Recovery of precious metal values from petrochemical spent catalyst is important from the viewpoint of environmental protection and resource recycling. Two types of spent catalysts were used in this study. One used in the manufacture of ethylene contains 0.3% Pd in the alumina substrate. The other used in oil refining contains 0.3% Pt and 0.3% Re. Both spent catalysts are roasted to remove volatile matters as carbon and sulfur. Then, metallic Pd powder from Pd spent catalyst is obtained in the course of grinding, hydrochloric acid or aqua regia leaching and cementation with iron. For the recovery of Pt and Re from Pt-Re spent catalyst, Pt and Re are leached with either HCI or aqua regia, first. Metallic Pt powder is recovered from the leach solution by cementation with Fe powder. Re in sulfide form is precipitated by the addition of sodium sulfide to the solution obtained after Pt recovery. It is found that 6N HCI can be successfully used as leaching agent for both types of spent catalyst. 6N HCI is considered to be better than aqua regia in consideration of reagent and equipment cost.

• Food Science and Preservation
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• v.17 no.5
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• pp.595-601
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• 2010

We investigated the effects of 1-methylcyclopropene (1-MCP) treatment (0, 0.5, and 1.5 ppm) for 16 hours, followed by storage at ambient temperature, on the qualities of pears (Pyrus pyrifolia c.v. "Hwasan"). Color differences, as measured using the Hunter L, a, and b values, showed the greatest decreases before storage, and 8 weeks after storage, when fruit was exposed to 1.5 ppm 1-MCP. The sensory qualities of c.v. "Hwasan" pears were good until 4 weeks of storage after treatment with 0 ppm 1-MCP, until 6 weeks when 0.5 ppm 1-MCP was employed, and until 7 weeks when 1.5 ppm 1-MCP treatment was performed. Fruit and storage quality in terms of all of hardness, sugar content, PPO activity, respiration amount, and ethylene production increased in the 8 weeks after application of 1.5 ppm 1-MCP. Consequently, it seems that 1-MCP treatment, especially at 1.5 ppm, before storage of pears at ambient temperature, effectively improves the quality of pears of c.v. "Hwasan".

• Journal of the Korean Geotechnical Society
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• v.22 no.9
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• pp.5-14
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• 2006

Generally, the sediments contain significant water, clay, colloidal fraction and contaminants, and can result in soft strata with high initial void, and its potential hazards in subsurface environments exist. Electrokinetic technique has been used in sedimentation for volume reduction of slurry tailing wastes and in remediation for extraction of contaminants from contaminated soils. In this research, the coupled effects of sedimentation and remediation of contaminated sediments are focused using electrokinetic sedimentation and remediation techniques from experimental aspects. A series of laboratory experiments including variable conditions such as initial solid content of the specimen, concentration level of the contaminant, and magnitude of applied voltage are performed with the contaminated sediment specimens mixed with ethylene glycol. Commercially available high specification Kaolin was used to simulate slurried sediment. From the test results, the settlement of specimen increases with increasing of applied voltage and decreasing of solid content and contamination level. The density of specimen increases due to settlement of specimen in the process of electrokinetic sedimentation and decreases due to extraction of organic contaminant in the process of electrokinetic remediation.

• Composites Research
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• v.20 no.3
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• pp.1-7
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• 2007

Manufacturing process of the shear thickening fluid(STF) and evaluation of the ballistic penetration resistance performance of the Kevlar-STF composites were studied. STF was made from silica and ethylene glycol, and the Kevlar-STF composite was made by impregnating the STF into the Kevlar fabric. Specimens including neat Kevlar woven fabrics and Kevlar-STF composites with two types of silica were prepared and carried out the ballistic tests. From the results STFs represented shear thickening behavior irrespective of the silica type, and Kevlar-STF composite with spherical silica showed best ballistic penetration resistance performance among them. Especially the specimens of Kevlar-STF composites with spherical silica showed radial fiber deformation by the projectile during the tests, that was somewhat different deformation behavior from those of the neat Kevlar fabrics shown fiber pull-out phenomena or fracture.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.427-431
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• 2013

Paprika fruits should be stored and distributed at above $7^{\circ}C$ to prevent chilling injury but the small amount of paprika that transports with other horticultural products in refrigerated container by ship usually stored less than $5^{\circ}C$ for other products. In this case, paprika fruits cannot help exposing chilling temperature, so that the paprika must be lost marketable value during a long period of transfer. This study was conducted to compare the alleviated effects of high $CO_2$ treatment (passive MAP), heat (hot water dipping), and UVc treatment on chilling injury of paprika fruits due to low temperature storage, and also to decide if these treatments can be used for transporting under $5^{\circ}C$. After each treatment the paprika were put in the low temperature storage ($4^{\circ}C$) for 20 days and afterwards change the in room temperature ($20^{\circ}C$) for 5 days. The fresh weight loss of all the treatments except the high $CO_2$ treatment showed around 7~12% after 25 days of storage and the ethylene concentration showed periodical increases and decreases as around 3 ${\mu}l/l$. The $CO_2$ concentration was rapidly increased 33% carbon dioxide in high $CO_2$ treatment during room temperature storage after cold storage for 20 days. The firmness which is key quality characteristics during storage and is decreasing caused by chilling injury was not significantly different among all treatments. However, the firmness of stored paprika was maintained highest in the treated with hot water dipping. Therefore, HWD and UVc treatment that showed 60% of electrolyte leakage in the $4^{\circ}C$ control (chilling injury control) and similar level with the $7^{\circ}C$ control (non-chilling injury control) would be effective to alleviate chilling injury in the stored paprika.

• Journal of Bio-Environment Control
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• v.19 no.2
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• pp.88-92
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• 2010

This study was conducted to compare the quality characters of 15 different tomato cultivars ('Dotearang Dia', 'Super Dotearang', 'Super sunroad', 'Hoyong', 'Mirokku', 'Baccuhs', 'Mascara', 'Poseidon', 'Radido', 'Madison', 'Rapsodie', 'Solomon', 'Amaral', 'Picasso', 'Tymaxx') and find out the correlation among the quality characters in order to get basic informations for exporting tomato. The $a^*/b^*$ value of fruit surface showed from 2.8 to 4.8, but there was no significant difference in fruit surface color value, such as $a^*$, $b^*$ and $a^*/b^*$ among the cultivars. The respiration and ethylene production rate also were not shown any significantly difference among cultivars. The firmness of fruit was higher in 'Picasso', 'Tymaxx' and 'Madison' cultivars. The contents of soluble solids was higher in 'Hoyong' and 'Dotearang Dia' cultivars. The vitamin C content was higher in 'Super Sunroad' and 'Dotearang Dia' cultivars. The titratable acidity was higher in 'Hoyong' cultivars. The sugar/acid ratio that depended on soluble contents was lower in 'Amaral', 'Picasso', 'Tymaxx' cultivars that showed lower soluble contents. Conclusionally, The firmness that was one of the most important quality character in exporting tomato was higher in European cultivars, but soluble solide and vitamin C content were higher in Japanese cultivars. The significant correlation coefficient values were determined (more than p = 0.05) between $a^*/b^*$ and other quality characters. The results suggested that surface color was the most suitable character represented tomato qualities. The high coefficient value (r = 0801) between $a^*/b^*$ and the contents of soluble solids. The firmness and the contents of soluble solids that is the most important factor for exporting showed significant negative correlation (r = -0.611).

• Horticultural Science & Technology
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• v.30 no.6
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• pp.725-733
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• 2012

Effects of postharvest 1-methylcyclopropene (1-MCP) treatment, controlled atmosphere (CA) storage, and shelf temperature on quality of 'Gamhong' apples were analyzed during export simulation. Fruits were harvested at the optimum maturity for long-term storage, treated with $1{\mu}L{\cdot}L^{-1}$ 1-MCP for 16 hours, and then stored for 6 months under air and CA conditions at $0^{\circ}C$. Poststorage export procedure was performed by applying additional 2-week refrigerated storage and 7-day shelf-life test at 7 and $20^{\circ}C$, which simulated container shipment and local distribution, respectively. After storage and during export simulation, rates of respiration and ethylene evolution were significantly lower in 1-MCP treated and CA-stored apples. For the reduction of respiration, CA storage was more effective than 1-MCP treatment. Soluble solids content was maintained higher in 1-MCP treated apples, while titratable acidity was maintained better both in the 1-MCP treated and CA-stored apples. Effects of 1-MCP treatment and CA storage were highly significant in maintaining flesh firmness and sensory texture ratings. Additive effects from combined application of 1-MCP treatment and CA storage were occasionally observed. Shelf temperature during the local distribution simulation seemed not to significantly influence quality changes only showing limited effects on flesh firmness. Overall results suggest that storage potential of 'Gamhong' apples is shorter than 4 months in control fruit under refrigerated air conditions, whereas the potential can be extended to longer than 6 months by 1-MCP treatment and CA storage. Postharvest program should be provided considering the time of export, i.e. period of storage, and duration of local distribution.

• Journal of Bio-Environment Control
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• v.21 no.2
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• pp.88-94
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• 2012

This study was carried out in order to investigate the effect of temperature of treatment and storage on the longevity of 'Unicorn' tomatoes of light red maturity stage during commercial handling conditions encountered while exporting over long distances. Tomato stored at $5^{\circ}C$ and $11^{\circ}C$ temperature with 85% relative humidity by pre-treating handling temperature that was using from field to before shipment as a winter temperature $5^{\circ}C$, spring temperature $11^{\circ}C$ and summer temperature $25^{\circ}C$ for 3 days. On the final storage day, $25^{\circ}C/11^{\circ}C$ (treated/stored) tomatoes showed the highest respiration and ethylene production rate; whereas the lowest respiration and ethylene production rate was found for $5^{\circ}C/5^{\circ}C$ treated and stored tomatoes. Tomatoes treated and stored at $5^{\circ}C/5^{\circ}C$ showed higher marketability, without evidence of fungal rot, decay or spots for 23 days. The fresh weight loss under all treatment conditions increased gradually during $5^{\circ}C$ and $11^{\circ}C$ storage temperatures. The higher firmness and soluble solids were determined from $5^{\circ}C/5^{\circ}C$ and $5^{\circ}C/11^{\circ}C$ treated and stored tomatoes repectively, than from others tomatoes on the final day of storage. In addition, $5^{\circ}C/5^{\circ}C$ tomatoes showed higher vitamin C contents than tomatoes stored at other temperatures, on the final day of storage. As the ripening and storage period progressed, the titratable acidity increased, but declined (P < 0.05) thereafter, due to over ripe tomatoes under all treatment conditions. These results show that $5^{\circ}C/5^{\circ}C$ treated and stored light red maturity stages of 'Unicorn' tomatoes are optimum to export because they show the highest storability and marketability. Moreover, the marketability of light red maturity stage of 'Unicorn' tomato maintained for 2 weeks in $25^{\circ}C/11^{\circ}C$ treated and stored temperature that might be the export temperature from Korea to Japan in summer season. This research result could be useful in helping tomato growers and exporters to get optimum market value by satisfying the buyer and consumer with a fresher product.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.192-198
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• 2006

Treatment effects of grape fruit stem extracts (GFSE) containing trans-resveratrol on the storage property of fresh jujube (Zizyphus jujube) were investigated. Fresh jujubes were packed in different storage containers [polyethylene terephthalate (PET) and polyethylene (PE)], and treated with GFSE containing trans-resveratrol of 10, 30 and 50 ppm, respectively. The storage vessels filled with $N_2$ gas, and stored in refrigerator $(0{\pm}1^{\circ}C)$ during 18 weeks, and then quality characteristics during storage period were analysed. Ethylene gas increased until 8 weeks and decreased afterward. Decaying of jujube started at $6\~8$ weeks in control, but it did at 14 week storage for the fruits at $50\%$ maturity treated with 10 ppm of GFSE and packed in PE vessel. Soluble solid (Brix degree) and total acidity of fresh jujube slightly increased in all the treatments during storage period. Hardness slightly increased until 4 weeks and decreased afterward. Vitamin C content was at the highest content of $86.8\~273.4$ mg/100g for most of treatments at 2 weeks and decreased afterward. Storage stability was higher for $50\%$ maturity fruits than for the $70\%$ maturity, and higher for PE vessels than PET containers. Storage period of fresh jujube in this experiment ranges in $10\~12$ weeks for $50\%$ maturity fruits treated with 10 ppm of GFSE and packed in PE vessel.

• Food Science and Preservation
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• v.30 no.1
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• pp.78-87
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• 2023

This study was conducted to evaluate the effect of different 1-methylcyclopropene (1-MCP) concentrations on fruit quality of small-sized RubyS apples during cold storage. After harvesting, the fruits were treated with 1-MCP at 0.5 or 1 µL/L concentrations and, subsequently, stored at 0℃ for 6 months. After 6 months, the flesh firmness of untreated fruits, which was 85.4 N at harvest, had gradually decreased to 46.5 N; however, that of 1-MCP-treated fruits was maintained at 59.1 and 59.5 N. Titratable acidity (TA) of untreated fruits had also decreased from 0.42 to 0.24%, whereas that of 1-MCP-treated fruits was maintained at 0.26 and 0.27%. Soluble solids content (SSC) did not differ in all fruits. However, the 1-MCP-treated fruits had lower levels of SSC/TA ratio than untreated fruits. Moreover, after 6 months, the ethylene production had increased to 47.0 µL/kg/h in the untreated fruits, whereas 1-MCP blocked the ethylene production at 1.4 and 1.7 µL/kg/h. The weight loss and peel color variables remained unaffected by 1-MCP treatments. Thus, these results indicated that, for RubyS apples, the storability was only 2 months at 0℃ without treatment, which can be extended to 6 months with 1-MCP treatments. The application of 1-MCP at 0.5 µL/L concentration is effectively and economically sufficient to maintain the quality of RubyS apples.