• Progress in Superconductivity and Cryogenics
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• v.24 no.4
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• pp.1-5
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• 2022

We investigate the effect of surface disorder on the lower critical field (H_c1) of MgB₂ thin films with a thickness of 850 nm, where the disorder on the surface region is produced by the irradiation of 140 keV Co ions with the dose of 1 × 10¹⁴ ions/cm². The thickness of the damaged region by the irradiation is around 143 nm, corresponding to ~17% of the whole thickness of the film, thereby forming the disordered MgB₂ overlayer on the pure MgB₂ layer. The magnetic field dependence of magnetization, M(H), for the pristine MgB₂ thin film and the film with overlayer is measured at various temperatures, and H_c1 is determined from the difference (△M) between the Meissner line and magnetization signal with the criterion of △M = 10^-3 emu. Intriguingly, the film with the disordered overlayer shows a remarkably large H_c1(0) = 108 Oe compared to the H_c1(0) = 84 Oe of pristine film, indicating that the disordered MgB₂ overlayer on the pure MgB₂ layer serves to prevent the penetration of vortices into the sample. These results provide new ideas for improving the superheating field to design high-performance superconducting radio-frequency cavities.

• Progress in Superconductivity
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• v.4 no.2
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• pp.153-156
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• 2003

We have studied fabrication of $MgB_2$ thin film on $SrTiO_3$ (001) and r-cut $A1_2$$O_3$ substrates by rf magnetron sputtering method using and $ MgB_2$ single target and two targets of Mg and B, respectively. Based on P -T phase diagram of $MgB_2$ and vapor pressure curves of Mg and B, a three-step process was employed. B layer was deposited at the bottom to enhance the film adhesion to the substrate. Secondly, co-sputtering of Mg and B was done. Finally, Mg was sputtered on top to compensate fur the loss of Mg during annealing. Subsequently, $MgB_2$ films were in-situ annealed in various conditions. The sample fabricated using the three-step process showed $T_{c}$ of 24 K and formation of superconducting $MgB_2$ phase was confirmed by XRD spectra. In case of co-sputtering deposition, $T_{c}$ depended on annealing time and argon pressure. However, those made by single-target sputtering showed non-superconducting behavior or low transition temperature, at best.est.

• Food Science of Animal Resources
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• v.32 no.4
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• pp.483-490
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• 2012

Ready-to-eat chicken breasts were packaged in a multilayer, gas-tight tray with top film and various quality changes were investigated during the 24 wk of storage at $10^{\circ}C$. Over the storage period, total aerobes, mesophilic aerobic and anaerobic spore formers, and Clostridium spp. were not detected above 1.0 log CFU/g (detection limit). The residual oxygen ratio in the head space of tray and pH values tended to decrease with storage time, namely from initial values of 5.7% and 6.56 to 3.3% and 6.34 at week 24, respectively. Thiobarbituric acid reactive substances and volatile basic nitrogen values increased from 0.52 mg malonaldehyde (MA)/kg and 2.1 mg/100 g initially, to 3.70 mg MA/kg and 39.9 mg/100 g at week 24, respectively. In terms of the change in meat color during storage, the samples showed a slight increasing trend of CIE $a^*$, $b^*$, and ${\Delta}E$ values over the storage period until week 24 (p<0.05). The change in brine color showed a similar trend with meat of which Hunter $b^*$ and ${\Delta}E$ values increased slightly during storage during 24 wk (p<0.05). The values for the transmittance degree of brine in the samples tended to decrease. Moreover, values for the absorbance degree tended to increase with storage time until week 24. The sensory scores for color, texture, odour, and flavour were evaluated below 5.0 (marketability level) after 24 wk of storage. Based on this sensory evaluation, it could be concluded that retorted RTE chicken breast could remain marketable for at least 20 wk at $10^{\circ}C$.

• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.2
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• pp.265-270
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• 2013

Dialysis is the rate-limiting step in the preparation of aqueous silk fibroin (SF) solution. However, the traditional practice of dialyzing SF solution for at least 48 h to remove LiBr is not based on empirical evidence. The aim of the present study was to systematically measure LiBr content in SF solutions dialyzed for varying lengths of time and assess the potential toxicity of residual lithium ions in cells. Complete removal of lithium ions was not achieved even after 72 h of dialysis, with a residual lithium ion content in the solution of 22.85 mg/l. SF films prepared from solutions dialyzed for 8 and 24 h had predominantly random coil or b-sheet structures, respectively. The residual lithium had little cytotoxicity in NIH3T3 fibroblast cells, but viability was compromised in cells grown on SF film prepared from solution dialyzed for 24 h.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.3
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• pp.200-207
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• 2011

Abstract: The effect of lead free glass frit compositions on the properties of thick film conductor and resistor pastes were investigated. Two types lead free frits, HBF-A(without $Bi_2O_3$) and HBF-B(with $Bi_2O_3$) were made from $SiO_2$, $B_2O_3$, $Al_2O_3$, CaO, MgO, $Na_2O$, $K_2O$, ZnO, MnO, $ZrO_2$, $Bi_2O_3$. And Ag based conductor pastes and $RuO_2$ based resistor paste were prepared by mixed with these frits and functional phase(Ag and $RuO_2$), and organic vehicle. The properties of thick film conductor and resistor sintered at $850^{\circ}C$ were studied after printing on $Al_2O_3$ substrate. The morphology of the sintered films surface were SEM and EDS were carried out to analysis the chemical composition on resistor surface and state of Ru atom in frit matrix.

• Tuberculosis and Respiratory Diseases
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• v.54 no.5
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• pp.510-521
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• 2003

Background : The surfactant specific proteins, SP-B and SP-C are believed to be important regulators of the surfactant function and homeostasis. Since acute respiratory distress syndrome(ARDS) is usually viewed as the functional and morphological expression of a similar underlying lung injury caused by a variety of insults, and since abnormalities in the surfactant function have been described in ARDS, the authors investigated the different effects of endotoxin and thiourea on the accumulation of mRNA encoding SP-B and SP-C. Methods : Sprague-Dawley rats were given 5 mg/kg of an intraperitoneal endotoxin from Salmonella enteritidis and 3.5 mg/kg intraperitoneal thiourea and were sacrificed at different time periods. Results : 1. The SP-B mRNA levels 6 and 24 hours after the 5 mg/kg endotoxin treatment was significantly reduced by 26.1% and 50%, respectively(P<0.01, P<0.001). 2. The SP-B mRNA levels 24 hours after the 3.5 mg/kg thiourea treatment was reduced by 9.8% and 12.5%, respectively. 3. The SP-C mRNA levels 6 and 24 hours after the 5 mg/kg endotoxin treatment was significantly reduced by 38.7% and 53.6%, respectively(P<0.01, P<0.001). 4. The SP-C mRNA level 6 hours after the 3.5 mg/kg thiourea treatment was reduced by 22.8%(P<0.05). Conclusion : These results indicate that the differential regulation of the hydrophobic surfactant proteins in vivo is evident, and suggest that the hydrophobic surfactant proteins might be differentially regulated during lung injury at different time periods without altering the lung wet to dry ratios. The mechanism of these alternations at the different time periods and the different kinds of etiology remain to be determined.

• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.65-69
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• 1998

In order to evaluate the utility of bituminous coal fly ash, gypsum, oyster shell as soil amendments, aadic clayloam paddy soils with low calaum content were amended in the upper 15㎝ with amendments, and then Chinese cabbage was cultivated under plastic film house. Amendments treated were, in metric tons per hectare, i) none(Check) ; ii) 80 fly ash(FA) ; iii) 4 shell(SH) ; iv) 56 fly ash+24 gypsum (FG) ; v) 40 fly ash+24 gypsum+0.8 shell(FGS). On the whole, soil chemical properties were improved by amendments treatments. Amongst treatments, FA prominently neutralized soil pH and increased contents of Av. $P_2O_5$, Ex. K, and Av. B in soils. Besides, it showed the highest ratio in bacteria/fungi and (bacteria+actinomycetes)/fungi. FGS also affected the neutralization of soil pH and the increment of Ex. Mg. Amendments plants appeared alkaline damages only at early growing stage, but showed positive responses in fresh weight yields : 23% for FGS : 21% for FG : 19 18% for SH. At harvesting, leaves both of FA and FGS plants had higher values in contents of N, P, K, Ca, Mg, Fe, Mn, Zn, B, reduang-sugar, and vitamin-C than of others. In especial, Check plants appeared the heart rot symptoms owing to calaum defiaency differently from amendments plants. Taken together, FGS was an effective combination enable to maximize the utility of fly ash, gypsum, shell as soil amendments, espeaally in cabbage yield and quality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.45-49
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• 2002

This study was conducted to enhance the value of chamnamul (Pimpinella brachycarpa (Komarov) $N_{AKAI}$) as an useful food resource. Hunter L, a, b values (lightness, redness, yellowness) of chamnamul leaf were 33.28$\pm$1.94, -10.98$\pm$0.74, 14.05$\pm$1.29 and shearing force was 2745.2g. Contents of tannin and dietary fiber were 100.9 mg%, 24.0% (freeze drying base). The minerals identified in chamnamul were Ca 7.85 g/kg, K 76.31 g/kg, Mg 4.78g/kg, Fe 0.35g/kg, Na 2.35 g/kg. Chamnamul kimchi was packed in polyethylene film (200g) and fermented at 2$0^{\circ}C$ and 4$^{\circ}C$. In color changes kimchi fermented at 2$0^{\circ}C$ showed more increase in Hunter L, a, b values than kimchi fermented at 4$^{\circ}C$. The pH of kimchi decreased and acidity increased with storage time at both temperature. Ascorbic acid contents decreased sharply with storage time. Loss of ascorbic acid contents was about 81.9% in kimchi fermented at 2$0^{\circ}C$ after 5 days, and kimchi fermented 4$^{\circ}C$ lost 77.3% of ascorbic acid after 30 days. Also reducing sugar contents decreased with storage time at 2$0^{\circ}C$ and 4$^{\circ}C$. The results of sensory evaluation showed that optimum ripening time of chamnamul kimchi was 1~3 days at 2$0^{\circ}C$ and more than 20 days at 4$^{\circ}C$.>.

• Food Science and Preservation
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• v.24 no.5
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• pp.565-575
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• 2017

This study was carried out to investigate shelf-life and quality of fresh-cut Dungkunma (Dioscorea bulbifera) in order to elevate utilization of Dungkunma a fresh food. Before vacuum-packaging (in polyethylene/polypropylene film ($100{\mu}m$, $15{\times}20cm$, $75{\pm}2cmHg$) and storaging at $2^{\circ}C$, Dungkunma was peeled out and cut to dice type ($2.0{\pm}0.5cm^3$), and then washed and blanched using hot water (at $90{\pm}2^{\circ}C$ with 2% NaCl solution for 30 sec). Blanched Dungkunma was pre-dried at room temperature, $40^{\circ}C$ and $50^{\circ}C$ for removing surface water. Each peeled dice Dungkunma was packed 50 g in polyethylene/polypropylene film ($100{\mu}m$, $15{\times}20cm$) with vacuum treatment ($75{\pm}2cmHg$) and stored at $2^{\circ}C$ for 90 days. Hardness and adhesiveness of Dungkunma blanched by 2% NaCl and pre-dried at $50^{\circ}C$ (SB50) were the highest, but changes were the least during storage. Lightness and yellowness of stored Dungkunma in all treatments decreased slightly while redness increased during storage. Changes of color of SB50 was the least. Total concentration of aerobic bacteria in SB50 was $1.88{\pm}0.18log\;CFU/g$ during 90 days and E. coli was detected in all treatments during whole storage periods. Dioscin and allantoin contents of SB50 were virtually unchanged during the storage. Consequently, the results of this study suggest that vacuum packaged Dungkunma after blanching using 2% NaCl solution could be effective to prolong the quality of fresh-cut Dungkunma.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.3
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• pp.67-74
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• 1979

Peanut was cultured with varying planting density and sowing date with and without vinyl-film mulching. Vinyl-film mulching raised soil temperature 4.6$^{\circ}C$ higher than the non-mulched during April and early May, but later-on the soil temperature was similar between the two treatments. The ripening and slender grain ratio increased with closer spacing and earlier sowing. Compared with ordinary cultural practices of May 10th sowing without mulching the peanut yield increased by 9% by mulching sown May 10th, and by 49% by mulching and early sowing April 20th.