• Clean Technology
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• v.17 no.2
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• pp.124-133
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• 2011

In addition to six substances regulated in EU RoHS including lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBB) and polybrominated diphenyl ethers (PBDE), priority substances are identified in new RoHS II as hexabromocyclododecane (HBCDD), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP) and diethylhexyl phthalate (DEHP). In this study, 20 plastic samples were collected from 12 domestic electrotechnical companies and levels of four restricted substances were determined by gas chromatography-mass spectrometry, Among 20 parts that compose washer, refrigerator or microwave oven, HBCDD was detected in three samples of NBR material with the amount of 42~381 mg/kg while DBP and BBP was not detected in any samples collected respectively, implying that these substance may not be used widely in plastic materials for EEE. However, DEHP was detected in all samples of NBR, PP, PBT, EPDM and PVC materials with the amount of 42 up to 59,400 mg/kg that exceeds the limit value of 0.1 wt% (1,000 mg/kg). Presence of a restricted substance in polymer material makes a great negative influence on a number of final product. To cope with coming RoHS II as well as REACH, action not to use DEHP in plastic material or the relevant notification in case of REACH seems to be needed. Screening test of Arsenic compounds such as diarsenic pentaoxide, diarsenic trioxide, lead hydrogen arsenate, triethyl arsenate that are included in REACH SVHC was done by ICP measurement Arsenium was detected in four samples made of NBR and PBT materials in the level of 15~700 mg/kg. By considering the screening method used in this study, the amount of arsenium compounds in the thermistor made of PBT material has a high chance of exceeding the regulated limit value.

• Korean journal of food and cookery science
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• v.16 no.6
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• pp.577-583
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• 2000

The purpose of this study was to investigate the effectiveness of various quality preservative treatments for extending shelf life and maintaining good quality of minimally processed fruit and vegetables produced in Korea. To determine the suitable treatments for delaying quality deterioration, fresh Asian pears and Chinese cabbages were sliced and treated with various quality preservatives (1% CaCl$_2$, 1% NaCl, 3% sucrose, 1% Ca-lactate, 1% vitamin C, 0.05% chitosan ＋1% vitamin C, 0.1% Sporix＋1% vitamin C, hot water (60$\^{C}$), 0.2% L-cysteine), packed with polyethylene film (60㎛-thick), and stored at 4$\^{C}$/0$\^{C}$ or 20$\^{C}$. Various biological and sensory tests were performed to evaluate the quality changes in minimally processed products. Results indicated that Chinese cabbages treated with 1% CaCl$_2$ at 4, and 1% CaCl$_2$ and 1% NaCl at 20$\^{C}$ were most effective in maintaining the quality and minimizing the biochemical changes during storage. For sliced Asian pears, 0.2% L-cysteine and 1% NaCl treatments were effective to reduce browning, and 1% CaCl$_2$ treatment was the most effective to prevent softening during storage at 20$\^{C}$ and 0$\^{C}$. Modified atmosphere packaging of Pleurotus ostreatus and Lentinus edodes had a significantly different shelf life depending on packaging material, packaging thickness and storage temperature. Sealed packaging with polyethylene film (60㎛-thick) for two kinds of mushrooms maintained a good quality with an extended shelf life by 30-50% at 20$\^{C}$ and by 30-130% at 0$\^{C}$. To minimize the quality deterioration which appeared in the condition of polyethylene film packaging, quality preservatives such as KMnO$_4$ and KHSO$_2$＋K$_2$S$_2$O$\_$5/ for SO$_2$ generation were added inside of mushroom packaging. The best condition for maintaining good quality longer was packaging with polyethylene film+SO$_2$ which showed 5080% extended shelf life for both Pleurotus ostreatus and Lentinus edodes at 20$\^{C}$ and 0$\^{C}$.

• Horticultural Science & Technology
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• v.31 no.2
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• pp.186-193
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• 2013

Potential of consumer unit packaging was investigated for quality maintenance during export simulation in king oyster mushrooms (Pleurotus eryngii). Mushrooms were harvested in late May, precooled to $4^{\circ}C$ within 6 hours, and then packaged for shipping in two ways: 2 kg bulk packaging in a polyethylene (PE) bag or three types of unit packaging methods such as 400 g in polypropylene film bag (PPB), 200 g on styrofoam tray + PE shrinkage film wrapping (STW), and 200 g in polyethylene terephthalate (PET) containers (PETC). For local distribution of bulk-packaged commodity, mushrooms were sorted again and packaged into 3 consumer units in the same way as for the initial shipping packages. Simulation of refrigerated container shipping was performed in a walk-in type pilot storage at $0.5^{\circ}C$ for 5 weeks, while local marketing simulation was carried out on the shelf at $7^{\circ}C$ for 7 days. During the shipment simulation, creation of modified atmosphere (MA) was substantial in 2 kg bulk packages with low $O_2$ below 2% and high $CO_2$ over 15% whereas, in PPB and PETC unit packages, relatively higher $O_2$ concentrations were observed. On the shelf at $7^{\circ}C$, $CO_2$ concentrations rapidly increased in PPB and PETC packages despite the short marketing period. Overall marketability evaluated by off-flavor, browning, and texture rating was maintained at excellent level when 2 kg bulk packaging in PE or unit packaging in PPB and PETC were used for shipment. In contrast, establishment of MA was very slight in STW packages during shipment and local distribution resulting in poor quality after export simulation. The results suggested that shipment using adequate consumer unit packaging is more practical and economically beneficial than using bulk packaging in the export program consisting of 5-week shipment and 7-day local distribution.

• Journal of Chest Surgery
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• v.34 no.9
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• pp.698-703
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• 2001

Background: Endovascular stent-graft insertion in aortic diseases is now generally accepted as an attractive alternative treatment modality. We reviewed our clinical experiences of endovascular stent-graft insertion in thoracic aorta. Material and Method: Since 1995, we performed 8 cases of endovasclar stent-graft insertion. Preoperative diagnoses were aortic aneurysms in 4, traumatic aortic ruptures in 3, and ruptured aortic pseudoaneurysm in 1. All procedures were performed in angiography room with the guidance of fluoroscopy. The stent-graft device is a custom-made 0.35mm thickness Z-shaped stainless steel wires, intertwined with each other using polypropylene suture ligation. It is covered with expanded Dacron vascular graft. Result: All procedures were performed successfully. Follow-up studies revealed 2 minimal perigraft leakages. There was no significant leakage or graft migration. 2 patients expired due to multiple organ failure and fungal sepsis. Other survivors(6) are doing well. Conclusion: Endovascular stent-graft insertion is relatively saft and effective treatment modality in the managment of various types of aortic diseases. In may be an effective alternative in aortic diseases of great surgical risk.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.3 no.2
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• pp.1-15
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• 1983

This paper has concentrated on estimating the possibility and mathematical analysis for the application of BFB to the treatment of nightsoil with low dilution rate. The experiment for the study of this purpose was conducted by continuous type reactor at $20^{\circ}C$, varying F/M ratio from 0.12 to 0.37 and dilution ratio from 2 to 10, and in it provided matted reticulated polypropylene sheets for the solid supports. The obtained results showed that the application of BFB to the treatment of nightsoil would be more effective than any other biological treatment process. Also, it has observed that the optimum dilution ratio was about 5 times and the optimum HRT was about 17 hours, and then it was estimated that the reactor volume and the quantity of weak water could be reduced to the extent of 70 percent and 80 percent. The experimental results of BFB could be analysed by the mathematical models applied to complete mixing activated sludge process. The substrate removal rates which were obtained by McKinney's($K_m$) and EcKenfelder's($K_e$) equation was 1.784/hr and $2.0{\times}10l/mg{\cdot}day$, and substrate was removed very rapidly compared to those of conventional type biological treatment processes. The biomass yield coefficient($a_5$), the endogeneous respiration rate(b), the synthesis oxygen demand rate($a{_5}^{\prime}$), and the endogeneous respiration oxygen demand rate(b') were 0.349, 0.0237/day, 0.495 and 0.0336, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.2
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• pp.49-58
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• 1989

For the effective utilization of anchovy as a food source, this work was undertaken the com-parison in food quality of anchovy snacks and its changes during storage at room temperature ($24\pm4^{\circ}C$). Chopped anchovy was mixed with soft flour($340.0\%$, w/w), corn starch($10.0\%$, w/w), sodium chloride($2.5\%$, w/w), monosodium glutamate($0.1\%$, w/w), sodium bicarbonate ($2.5\%$, w/w), water($5.6\%$, w/w), onion powder($0.3\%$, w/w), garlic powder($0.3\%$, w/w), red pepper powder($0.3\%$, w/w) and sodium erythorbate($0.2\%$, w/w), The mixture were rolled, aged, co沇ed, dried and finally parched or deep-fried at $190\pm10^{\circ}C$. The anchovy snacks were packed in the casted polypropylene film bag ($16cm{\times}14cm$), The changes in moisture contents, water activity, pH, volatile basic nitrogen, contents of amino acid and color values of products were negligible during storage. The results of TBA value and peroxide value showed that lipid oxidation can be retarded by adding antioxidant and spices. Judging from contents of amino acid and mineral, the products were more nutritive than the sold shrimp snack on the market. From the results of sensory evaluation and chemical experiments, the product prepared with sodium erythorbate could be preserved in good quality during storage of 120 days.

• Journal of Chest Surgery
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• v.36 no.2
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• pp.63-72
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• 2003

Although a variety of synthetic vascular grafts are available in modern vascular surgery, no ideal prosthesis ha,4 yet been developed. Small-caliber vascular grafts with low flow, as used in the lower extremity, continue to become thrombosed at unacceptable rates. We have developed and evaluated the new antithrombogenic blood contacting surfaces in canine model. Material and Method: Two now antithrombogenic blood contacting surfaces(Polyvinylalcohol -Polyurethane(PVA-PU) blend and natural Graphite-polyurethane(G-PU) blend) have been developed and evaluated in canine model, using vascular grafts and patches. The luminal surfaces of the test vascular grafts(5 mm ID) were fabricated by dipping a glass rod in PVA-PU blend solution(50 % PVA) using phase separation method. Mongrel dogs of either sex weighing 18-22 kg were anesthetized by endotracheal intubation using halothane and their lungs were ventilated with a volume-cycled ventilator, Maintenance anesthesia with 0.5-1.0% halothane and supplemental oxygen was used. Two pairs were used for comparison in the bilateral femoral arteries for both vascular grafts(PVA-PU vs. PU) and vascular patches(G-PU vs. PU). Bilateral groin incisions were made and the arteries were exposed and clamped. After an excision of 1 cm of the artery between clamps, a grail of 2.5 cm in length was implanted end-to-end using 6-0 polypropylene suture. The vascular patch was implanted as a form of on-lay patch. Animals were sacrificed at 1, 2, 4, 6, 8 and 16 weeks for vascular grafts and 1, 2. 4 and 6 weeks for vascular patches. Result The vascular grafts of PVA-PU blends showed patent lumina in the 2 and 16 weeks animals, while those of PU showed a patent lumen in 2 weeks animal. PVA-PU graft of 16 weeks showed a fairly clean luminal surface. A light microscopic finding of this graft demonstrated good tissue infiltration through porosity, The animals with vascular patches showed patent arteries in both groups except 2 weeks animal. Scanning electron microscopy of the luminal surfaces of G-PU patches in 4 and 6 weeks animals showed endothelial cell covering with microvilli. PU patches showed qualitatively less endothelial cell covering. Conclusion: In conclusion, PVA-PU and G-PU blends can be a promising blood contacting surfaces for application in a synthetic vascualr graft. However, further animal study is needed to determine the real long-term effects of these methods of surface modifications.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.834-844
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• 2014

Postharvest browning of mushroom (Agaricus bisporus) reduces the shelf life of harvested mushrooms. Here, mushrooms were dipped in various solutions (distilled water; DW, 0.25% rice bran extract; RB, 0.1% ascorbic acid; AA, RB + AA) for 3 min. After air-drying at room temperature, the dipped mushrooms were packaged in a polypropylene (PP) films and stored at 4 or $15^{\circ}C$. The quality changes of mushrooms were measured in terms of color, gas composition, firmness, and sensory evaluation during storage. Rice bran extract was measured for total polyphenol content, total flavonoid content, DPPH, ABTS radical scavenging, chelating activity and PPO inhibition activity. No difference in firmness were found in the mushroom samples regardless of dipping solution or storage temperature. At both 4 and $15^{\circ}C$ storage temperatures, RB + AA solution-dipped samples showed the highest L value and lowest delta E value. During the storage period, sensory evaluation showed that overall acceptability of mushrooms treated with RB and RB + AA solution was higher than that of the untreated mushrooms. Total polyphenol and flavonoid contents of 0.25% rice bran extract were $36.42mg\;GAE{\cdot}g^{-1}$ and $4.85mg\;QE{\cdot}g^{-1}$, respectively. The DPPH and ABTS radical scavenging activity of 0.1% ascorbic acid was higher than that of 0.25% rice bran extract. The highest copper ($Cu^{2+}$) chelating activity was found in the 0.25% rice bran extract. The PPO inhibition activity of 0.1% ascorbic acid was higher than that of 0.25% rice bran extract. Our results suggest that 0.25% rice bran extract with 0.1% ascorbic acid is effective anti-browning agent for maintaining quality of Agaricus bisporus during storage.

• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.944-948
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• 1999

The morphological properties of four binary blends of polyethylene synthesized by metallocene catalyst(MCPE) and four polyolefins prepared by Ziegler-Natta catalyst have been investigated to interpret the effect of micro-molecular structure on the phase morphology and interfacial behavior; four binary blend systems studied are high density polyethylene(HDPE)-metallocene polyethylene (MCPE), polypropylene(PP)-MCPE, poly(propylene-co-ethylene) (CoPP)-MCPE, and poly(propylene-co-ethylene-co-1-butylene) (TerPP)-MCPE, and they are all phase separated. The HDPE-MCPE blend shows evenly growing homogeneous HDPE domain on the continuous MCPE phase, on the other hand, the rest of three blends show complex heterogeneous phase behavior. The PP-MCPE blend shows that PP and MCPE and completely phase separated and phase inversion takes place at 50% MCPE. The CoPP-MCPE and TerPP-MCPE show enhanced interface due to the same micro-molecular structure of ethylene, and phase inversion takes place at 40% MCPE. In particular, TerPP-MCPE blend shows improved phase morphology between interfaces, and this may be arisen from the comonomer contents in TerPP, which are 1-butene and ethylene having the same chemical structure as that of MCPE. The enhancement of the phase morphology in the TerPP-MCPE blend is correlated with the mechanical and morphological properties. Thus, although the four blend systems are phase separated, the phase morphology suggests that the order of interfacial adhesion strength be HDPE-MCPE > TerPP-MCPE > CoPP-MCPE > PP-MCPE and that micro-molecular structure between constituents be one of major factors giving enhanced interfacial adhesion.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.655-665
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• 2014

The effect of modified atmosphere packaging (MAP) on kohlrabi (Brassica olerace L. gongulodes group)'s quality and antioxidant molecule during storage was examined to determine the optimal film package for maintaining freshness. To extend shelf life, MAP was tested using PE $50{\mu}m$ and oriented polypropylene (OPP) films with oxygen transmission rate (OTR) at 3,000, 10,000, $15,000mL/m^2/day/atm$. The OPP film packaging with modified oxygen transmission rate showed a delay in a weight loss and extended storage period. The package with OTR 3000 attained the desired gas composition of $O_2$ 3.2-6.7 kPa and $CO_2$ 13.1-19.8 kPa, in storage at room temperature. Kohlrabi stored in this package showed the lowest weight loss and the highest visual quality. Deterioration and off-odor were developed more rapidly in PE $50{\mu}m$ towards the end of the storage at room temperature. However, there are no differences among OTR films in visual quality and off-odor until 60 days at cold storage. Vitamin C content of kohlrabi was reduced rapidly in OTR 15000 with high transmission rate and showed less loss in PE $50{\mu}m$ and OTR 3000 in both room temperatures and cold storage. Results revealed that an OPP film with OTR 3000 extended the shelf life of kohlrabi in storage with maintained quality and vitamin C.