• Food Science of Animal Resources
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• v.27 no.2
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• pp.171-178
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• 2007

This study was conducted to investigate the effect of ageing temperature(0 and $4^{\circ}C$) and time(2, 7, 14, 21, 28, and 49 days) on the meat quality of longissimus muscle from Hanwoo steer. The pH, Warner-Bratzler shear force(WBSF), myofibrillar fragmentation index(MFI), cooking and purge loss, sensory, morphological changes, and amino acid composition were assessed. The pH of longissimus muscle increased significantly(p<0.05) for 21 days at $0^{\circ}C$ and 14 days at $4^{\circ}C$, but decreased thereafter. Longissimus muscle aged from 14 days to 28 days at $4^{\circ}C$ had a lower WBSF than longissimus muscle aged at $0^{\circ}C$(p<0.05). The WBSF of longissimus muscle decreased significantly(p<0.05) with ageing time. The MFI, cooking and purge loss, tenderness, and juiciness scores were higher for longissimus muscle aged at $4^{\circ}C$ than at $0^{\circ}C$. As ageing time increased, the MFI, cooking and purge loss, tenderness, juiciness, and amino acid composition of longissimus muscle increased significantly(p<0.05) with ageing at 0 or $4^{\circ}C$. Transmission electron microscopy showed Z-disk degradation and morphological changes of the myofibrils correlating with increased tenderness during the ageing time. Based on these results, the proper ageing conditions of longissimus muscle of Hanwoo steer were 14 days of ageing at $0^{\circ}C$ or 7 days of ageing at $4^{\circ}C$. However, further study on the application of ageing technology to this industry is necessary for the optimization of ageing conditions for the sub-primals or muscles from Hanwoo beef.

• Food Science of Animal Resources
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• v.35 no.6
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• pp.721-730
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• 2015

The objective of this study was to examine the effect of ginger extract (GE) combined with citric acid on the tenderness of duck breast muscles. Total six marinades were prepared with the combination of citric acid (0 and 0.3 M citric acid) and GE (0, 15, and 30%). Each marinade was sprayed on the surface of duck breasts (15 mL/100 g), and the samples were marinated for 72 h at 4℃. The pH and proteolytic activity of marinades were determined. After 72 h of marination, Warner Bratzler shear force (WBSF), myofibrillar fragmentation index (MFI), pH, cooking loss, moisture content, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and protein solubility were evaluated. There was no significant (p>0.05) difference in moisture content or cooking loss among all samples. However, GE marination resulted in a significant (p<0.05) decrease in WBSF but a significant (p<0.05) increase in pH and MFI. In addition, total protein and myofibrillar protein solubility of GE-marinated duck breast muscles in both WOC (without citric acid) and WC (with citric acid) conditions were significantly (p<0.05) increased compared to non-GE-marinated duck breast muscles. SDS-PAGE showed an increase of protein degradation (MHC and actin) in WC condition compared to WOC condition. There was a marked actin reduction in GE-treated samples in WC. The tenderization effect of GE combined with citric acid may be attributed to various mechanisms such as increased MFI and myofibrillar protein solubility.

• Applied Chemistry for Engineering
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• v.8 no.1
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• pp.140-145
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• 1997

Carbon dioxide hydrogenation reaction was carried out over hybrid catalyst composed of $Cu/ZnO/ZrO_2$, and MFI zeolites such as HZSM-5, H-Ga-Silicate and H-Fe-Silicate. The hybrid catalyst composed of $Cu/ZnO/ZrO_2$, catalyst and HZSM-5 showed the highest yield and selectivity to $C_2{^+}$ hydrocarbon, which seemed to be due to the largest amount of Br nsted acid sites. Higher yield to $C_2{^+}$ hydrocarbon was obtained over HZSM-5 with lower $SiO_2/Al_2O_3$ ratio and also with longer ion exchange time, which showed larger amount of Br nsted acid sites, respectively. When a metal ion was exchanged into HZSM-5, the highest yield to $C_2{^+}$ hydrocarbon was obtained with descending order $Ga/HZSM-5{\simeq}HZSM-5>Zn/HZSM-5$, i.e., with the amount of $Br\ddot{o}nsted$ acid sites.

• Polymer(Korea)
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• v.37 no.1
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• pp.5-14
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• 2013

In this paper the effect of UV (ultraviolet) exposure on HDPE (high density polyethylene)-smooth and f-PP (flexible polypropylene) geomembranes is evaluated under UVB-313 (ultraviolet wavelength 290-315 nm) exposure. Tensile property, melt flow index (MFI), oxidation induction time (OIT), both standard-OIT and high pressure-OIT and Fourier transform infrared spectroscopy/attenuated total reflectance (FTIR/ATR) results are discussed. Although tensile properties of the exposed geomembrane samples remained unchanged, the depletion of antioxidants was found higher for f-PP than for HDPE geomembrane. Arrhenius model by extrapolation was used on the data to predict the antioxidant lifetime to a typical site temperature of $20^{\circ}C$. There was no significant difference between the MFI value of the virgin and UV exposed HDPE geomembrane samples but a decrease in MFI was found in f-PP geomembrane that signifies that crosslinking has occurred. From FTIR spectra, the small peak (near $1750\;cm^{-1}$) observed in the spectrum of UV exposed sample corresponds to a carbonyl (C=O) linkage, which suggests that oxidation has occurred in the polymer structure, and another new band for f-PP between 3100 and $3500\;cm^{-1}$ is attributed to a hydroxyl bond and/or hydroperoxide bond.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.11a
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• pp.166-171
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• 2002

폐자원의 재활용은 현재 미래산업을 발전시키는데 중요한 변수로 작용하고 있으며, 폐플라스틱의 경우 통신 케이블 덕트, 고속전철용 케이블 덕트, 선박용 구조체등 고부가가치 제품으로의 기술개발이 활발히 진행되고 있다. 폐 Polyolefin 계열의 수지는 성형가공이 적절한 MFI(Melt flow index)와 뛰어난 기계적 물성, 가공 성형성 등으로 인해 다양한 형태와 용도로 recycling되고 있으나, 재생시 다수 Grade에 의한 분별, 분리수거의 어려움, 상용성결여, 난연성 부재 그리고 70% 대의 기계적 물성 회복율로 인해 그 용도가 제한되고 있는 실정이다.(중략)

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.120.2-120
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• 2003

• ALGAE
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• v.31 no.4
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• pp.373-378
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• 2016

Cochlodinium polykrikoides is a red-tide forming dinoflagellate that causes significant worldwide impacts on aquaculture industries and the marine ecosystem. There have been extensive studies on managing and preventing C. polykrikoides blooms, but it has been difficult to identify an effective method to control the bloom development. There is also limited genome information on the molecular mechanisms involved in its various ecophysiology and metabolism processes. Thus, comprehensive genome information is required to better understand harmful algal blooms caused by C. polykrikoides. We estimated the C. polykrikoides genome size using flow cytometry, with detection of the fluorescence of DNA stained with propidium iodide (PI). The nuclear genome size of C. polykrikoides was 100.97 Gb, as calculated by comparing its mean fluorescence intensity (MFI) to the MFI of Mus musculus, which is 2.8 Gb. The exceptionally large genome size of C. polykrikoides might indicate its complex physiological and metabolic characteristics. Our optimized protocol for estimating the nuclear genome size of a dinoflagellate using flow cytometry with PI can be applied in studies of other marine organisms.

• Food Science of Animal Resources
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• v.29 no.1
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• pp.55-61
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• 2009

The objective of this study was to examine the effects of high and low chilling temperature on the water-holding capacity (WHC) and tenderness of hot-boned breast meat of broiler chickens. Breast meat was obtained from 32 broiler chickens within 15 min post-mortem (PM), and then divided into two groups. One group was chilled at $-1^{\circ}C$ and the other group was stored at $30^{\circ}C$ for 3 hr, and then all the samples were chilled at $2^{\circ}C$ until 24 hr PM. During the storage, their physicochemical characteristics were tested at 15 min, 3 hr and 24 hr PM. These included pH, R-values, cooking losses, sarcomere length, MFI, and shear force of the breast meat, none of which was different (p>0.05) between the two temperature treatments at $-1^{\circ}C$ and $30^{\circ}C$. However, sarcomere length was shortened more at $-1^{\circ}C$ than at $30^{\circ}C$, MFI was larger at $30^{\circ}C$ than at $-1^{\circ}C$, drip loss was greater at $30^{\circ}C$ than at $-1^{\circ}C$, and WHC was lower at $30^{\circ}C$ than at $-1^{\circ}C$(p<0.05). In brief, in terms of yield and tenderness, broiler breast meat stored at $-1^{\circ}C$ was superior to that stored at $30^{\circ}C$.

• Membrane Journal
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• v.16 no.2
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• pp.159-166
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• 2006

MFI(Mobil Five) structured hydrophobic ZSM-5 zeolite membrane was used for selective pervaporation of trichlorinated organic compounds(trichloromethane, trichloroethane, trichloroethylene) from their aqueous solutions. ZSM-5 zeolite membrane was hydrothermally synthesized on the inside of a porous stainless steel tube by secondary growth employing ZSM-5 seed powders. Separation factors for each binary mixtures were observed $16{\sim}66$ for trichloromethane/water, $3.3{\sim}4.6$ for trichloroethane/water and $1.4{\sim}8$ for trichloroethylene/water at the experimental conditions of the feed mole fraction from 0.0001 to 0.001 with temperature ranged $25{\sim}35^{\circ}C$.

• Applied Chemistry for Engineering
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• v.19 no.2
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• pp.214-221
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• 2008

The production of biodiesel by transesterification of waste frying oil was conducted on various zeolite catalysts with different acidity and pore structure. $H^+$ ion exchanged MOR, MFI, FAU, and BEA zeolites were employed in the reaction with silicalite which has no strong acid sites. $H^+$ ion exchanged MOR(10) zeolite, which has more acid sites and stronger acid strength than other zeolites, exhibited the highest methyl esters yield as 95%. Dealumination to the HMOR zeolite induced decreasing of acid amount and acid strength. It brought about the decrease of fatty acid methyl esters (FAME) yield. The yield increased linearly with enhancing of acid strength and increasing of amount of strong acid sites. The yields were independent on pore structure of the zeolites.