• Journal of the Korean Ceramic Society
• /
• v.31 no.12
• /
• pp.1437-1442
• /
• 1994

Self propagating synthesis and thermal explosion of combustion reactions were applied to Al/K2Cr2O7/Al2O3 system as the first stage for a production of magnesia-chromium refractory. Several factors related to products made by two combustion reactions were considered and properties of products were characterised. Two processes were required to preheat upto at least 80$0^{\circ}C$ for the thermal explosion and the self propagating synthesis. These processes were so violent and explosive that alumina as diluent was added to the system in order to absorb the reaction heat and reduce the reaction rate. The products consisted of crystal phases of KAl5O8, Cr2O3, Al2O3, K2CrO4, and K2Al2O4.3H2O. The amount of KAl5O8 and K2Al2O4.3H2O crystal phases of products were decreased with further addition of alumina.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.23 no.4
• /
• pp.625-633
• /
• 1994

In this study, processing of dried products of adcidian , Haocynthia roretzi, were investigated, which has been cultured in the south and east coast of Korea in recent years. Raw ascidians were shucked , gutted, soaked and then drained. Seven kinds of dried ascidian meats were prepared : boiled in 5% slat solution for 10 min and hot-air dried (A)-sun dried (B) or hot-air dried (C) after soaking for 1 min in 0.2% NaHSO3 solution , sun dried (D) or hot -air dried (G) after treating for 15 sec in 5% liquid smoke solution, and sun dried (E) or hot -air dried (F) after blanching for 30 sec in boiling 5% salt solution added with 0.2% NaHSO3. The moisture contents, water activity of the products showed little change and VBN gradually increased during storage at 25 $\pm$2$^{\circ}C$. The TBA and POV values of the liquid smoked dried ascidian (product D, G0 were considerably lower than those of others, In fatty acid composition 22 : 6 , 20 : 5 : 16: 0 and 18 : 1 acid were predominant. Conditions adopted in products D and G had a good antioxidative effect on highly unsatuated fatty acids during the storage. The contents of inosine and AMP of products were higher than those of other nucleotide and their related compounds. Judging from the results of chemical experiments and sensory evaluation, the sample A, D and G were most desirable and they could be preserved more than 120 days at room temperature(25$\pm$2$^{\circ}C$).

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.21 no.6
• /
• pp.361-365
• /
• 1988

Thermal diffusivities of white muscled fish meat paste products were measured and an experimental equation for prediction of the thermal diffusivity was suggested. The thermal diffusivities of products with water contents of 43.03 to $82.49\%$ and lipid contents of 0.50 to $14.88\%$ could be deduced as following equations ; $$\alpha_{80.39^{\circ}C}=0.0832{\cdot}10^{-6}{\cdot}X_w+0.0797{\cdot}10^{-6},\;m^2{\cdot}s^{-1}$$ $$\alpha_{100.63^{\circ}C}=0.0873{\cdot}10^{-6}{\cdot}X_w+0.0830{\cdot}10^{-6},\;m^2{\cdot}s^{-1}$$ $$\alpha_{120.09^{\circ}C}=0.0842{\cdot}10^{-6}{\cdot}X_w+0.0901{\cdot}10^{-6},\;m^2{\cdot}s^{-1}$$ From these equations, an experimental equation was derived for the prediction of thermal diffusivities of white muscled fish meat paste products ; $$\alpha=(1.308+0.1324{\cdot}X_w){\cdot}\alpha_w-0.0626{\cdot}10^{-6}{\cdot}X_w-0.1355{\cdot}10^{-6},\;m^2{\cdot}s^{-1}$$ The errors of the thermal diffusivities predicted with this equation were less than ${\pm}\;0.30\%$ compared with those measured.

• Journal of Applied Biological Chemistry
• /
• v.64 no.1
• /
• pp.49-55
• /
• 2021

The diet plays a fundamental role in the formation of the gut microbiota, determining the interrelationship between the gut microbiota and the host. The current study investigated the effect of Chlorella vulgaris on the gut microbiota by using simulated in vitro digestion and colonic fermentation. Bioaccessibility was measured after in vitro digestion, and SCFAs and microbial profiling were analyzed after colonic fermentation. The bioaccessibility of C. vulgaris was 0.24 g/g. The three major SCFAs (acetate, propionate, and butyrate) increased significantly when compared to the control group. In microbial profiling analysis, microorganisms such as Faecalibacterium, Dialister, Megasphaera, Dorea, Odoribacter, Roseburia, Bifidobacterium, Butyricmonas, and Veillonella were high in C. vulgaris group. Among them, Faecalibacterium, Dialister, Megasphaera, Roseburia, and Veillonella were thought to be closely associated with the increased level of SCFAs. Finally, it can be expected to help improve gut microbiota and health through ingestion of C. vulgaris. However, further studies are vital to confirm the changes in the gut microbiota in in vivo, when C. vulgaris is ingested.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.58 no.7
• /
• pp.1418-1423
• /
• 2009

This paper describes the design and implementation of a System-on-a-Chip (SoC) for image processing applications to use in wearable/mobile products. The target Soc consists of LEON 2 core, AMBA/APB bus-systems and custom-designed controllers. A new FPGA-based prototyping platform is implemented and used for design and verification of the target SoC. To ensure that the implemented SoC satisfies the required performances, an image processing application is performed.

• Food Science of Animal Resources
• /
• v.21 no.2
• /
• pp.156-162
• /
• 2001

The quality changes of UHT market milk product were investigated by the season and storage conditions. Throughout the year, standard plate counts(SPC) wasnt increased significantly during storage at 5$\pm$1 and 7$\pm$1$^{\circ}C$ for 10 days. And except for summer, SPC was lower than 20,000 cfu/ml after storage at 10$\pm$1$^{\circ}C$ or 10 days. But SPC was rapidly increased from 3 days at 15$\pm$1$^{\circ}C$, and there was gas forming by yeast growth after storage at 30$\pm$1$^{\circ}C$. Values of pH and titratable acidity of market milk products were 6.49 to 6.71 and 0.155 to 0.16%, respectively. pH and titratable acidity were a lot changes at the temperature over 15$\pm$1$^{\circ}C$, and milk products showed a curd at 30$\pm$1$^{\circ}C$. Carbohydrate of market milk product had little difference throughout the year, whereas fat, protein and total solids of market milk products in autumn showed a little higher value than that of other seasons. There were no changes of milk composition during storage periods, but carbohydrate was decreased a little after storage over 20$\pm$1$^{\circ}C$.

• Korean Chemical Engineering Research
• /
• v.52 no.2
• /
• pp.247-255
• /
• 2014

$La_{0.8}Sr_{0.2}CuO_3$ powder with the perovskite structure was prepared as electrode catalyst using citrate method. Porous electrode was made with as-prepared catalyst, carbon as supporter and polytetrafluoroethylene (PTFE) as hydrophobic binder. As results of potentiostatic electrolysis with potential of -1.5~-2.5 V vs. Ag/AgCl in 0.1, 0.5 and 1.0 M KOH at 5 and $10^{\circ}C$ on the porous electrode, liquid products were methanol, ethanol, 2-propanol and 1, 2-butanol regardless reaction temperature, while gas products were methane, ethane and ethylene at $5^{\circ}C$, and methane, ethane and propane at $10^{\circ}C$ respectively. Optimal potentials for $CO_2$ reduction in the view of over all faradic efficiency were high values (-2.0 and -2.2 V) for gas products whereas low potential (-1.5 V) for liquid products regardless of concentration and temperature.

• The Korean Journal of Physiology and Pharmacology
• /
• v.8 no.2
• /
• pp.95-100
• /
• 2004

Ischemic preconditioning (IPC) has been accepted as a heart protection phenomenon against ischemia and reperfusion (I/R) injury. The activation of ATP-sensitive potassium $(K_{ATP})$ channels and the release of myocardial nitric oxide (NO) induced by IPC were demonstrated as the triggers or mediators of IPC. A common action mechanism of NO is a direct or indirect increase in tissue cGMP content. Furthermore, cGMP has also been shown to contribute cardiac protective effect to reduce heart I/R-induced infarction. The present investigation tested the hypothesis that $K_{ATP}$ channels attenuate DNA strand breaks and oxidative damage in an in vitro model of I/R utilizing rat ventricular myocytes. We estimated DNA strand breaks and oxidative damage by mean of single cell gel electrophoresis with endonuclease III cutting sites (comet assay). In the I/R model, the level of DNA damage increased massively. Preconditioning with a single 5-min anoxia, diazoxide $(100\;{\mu}M)$, SNAP $(300\;{\mu}M)$ and 8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphate (8-pCPT-cGMP) $(100\;{\mu}M)$ followed by 15 min reoxygenation reduced DNA damage level against subsequent 30 min anoxia and 60 min reoxygenation. These protective effects were blocked by the concomitant presence of glibenclamide $(50\;{\mu}M)$, 5-hydroxydecanoate (5-HD) $(100\;{\mu}M)$ and 8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphate, Rp-isomer (Rp-8-pCPT-cGMP) $(100\;{\mu}M)$. These results suggest that NO-cGMP-protein kinase G (PKG) pathway contributes to cardioprotective effect of $K_{ATP}$ channels in rat ventricular myocytes.

• Preventive Nutrition and Food Science
• /
• v.5 no.4
• /
• pp.234-238
• /
• 2000

The cleavage products formed by autoxidation of phytofluene were evaluated in order to elucidate possible oxidation products of phytofluene under oxidative conditions. Phytofluene solubilized at 50$\mu$M in liposomal suspension was oxidized by incubating at 37$^{\circ}C$ for 72 h. Among a number of oxidation products formed, five products in the carbonyl compound fraction were identified as 6, 10, 14-trimethylpentadeca-3,5,9,13-tetraen-2-one, phytapentaenal, 5,9,13,17-tetramethyloctadeca-2,4,6,8,12,16-hexaenal, 5,9,13,17-tetramethyloctadeca-2,4,8,12,16-pentaenal, 2,7,11,15,19-pentamethylicosa-2,4,6,10,14,18-hexaenal and 4,9,13,17,21-pentamethyldocosa-2,4,6,8,12,16,20-heptaenal. These correspond to a series of products formed by cleavage in the respective eight conjugated double bonds of phytofluene. Also, 4,5-didehydorgeranyl geranoic acid was formed by autoxidation of phytofluene in liposomal suspension. The pig liver homogenate had the ability to convert phytapentaenal to 4,5-didehydrogeranyl geranoic acid, comparable to the conversion of all-trans-retinal to all-trans-retinoic acid. These results suggest that phytofluene is cleaved to a series of long-chain and short-chain carbonyl compounds under the oxidative condition in vitro and that phytapentaenal is further enzymatically converted to 4,5-didehydrogeranyl geranoic acid.

• Korean Journal of Agricultural Science
• /
• v.42 no.4
• /
• pp.369-374
• /
• 2015

This study was conducted to compare the glucose, lactate, and nucleotide degradation products content of cooked beef steaks from Korean Hanwoo (quality grade: 1) and Australian cattle (Bos indicus, grain-fed for 100 d) by internal temperature. The loins (M. longissimus dorsi) and top rounds (M. semimembranosus) from two cattle breeds were cut into about 2 cm thickness and then cooked in a $180^{\circ}C$ electronic oven until internal temperature attained to 50, 70, or $90^{\circ}C$. Regardless of internal temperature, glucose content was higher (P<0.05) in cooked loin and top round steaks from Hanwoo compared to those from Australian cattle. Lactate content was shown to be lower (P<0.05) in cooked steaks from Hanwoo than in those from Australian cattle. Lower (P<0.05) hypoxanthine and higher (P<0.05) guanosine 5'-monophosphate, inosine 5'-monophosphate, inosine contents were observed in cooked steaks from Hanwoo. Furthermore, glucose content tended to be decreased by internal temperature but nucleotide degradation products content was not changed by internal temperature. Therefore, these findings suggest that cooked Hanwoo beef steaks had higher flavor precursors related to sweet and umami tastes than cooked Australian beef steaks