• Food Science of Animal Resources
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• v.40 no.3
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• pp.415-425
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• 2020

It is believed that two main proteolytic systems are involved in the tenderization of meat: the cathepsins and the calpains. Many researchers consider the calpain system to be the major contributor to meat tenderness during post-mortem storage. However, the role and activity of cathepsins during post-mortem storage or low temperature meat processing is unclear, particularly for the tough meat cuts like brisket. Thus, the study was designed to investigate the effects of cold (refrigerated and frozen) storage and sous vide processing on the activities of cathepsin B, H, and L in beef brisket. There were no significant changes in pH and cathepsin H activity throughout the 18 d of storage at both temperatures. However, an increase in cathepsin B activity was observed during the first 4 d at both storage temperatures, but subsequently the activity remained unchanged. Cathepsins B and L were found to be more heat stable at sous vide temperatures (50℃ for 24 h, 55℃ for 5 h and at 60℃ and 70℃ for 1 h) compared to cathepsin H. Cathepsin B+L activity was found to increase after sous vide cooking at 50℃ for 1 h but decreased to about 47% relative to the uncooked control after 24 h of cooking. These results suggest that cathepsins B and L may contribute to the improved meat tenderness usually seen in sous vide cooked brisket meat.

• Journal of fish pathology
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• v.24 no.1
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• pp.29-37
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• 2011

Effects of temperature ($13{\pm}1.5^{\circ}C$, $23{\pm}1.5^{\circ}C$) on the pharmacokinetic properties of nalidixic acid (NA) and piromidic acid (PA) were studied after oral administration to cultured black rockfish, Sebastes schlegeli. Serum concentrations of NA and PA were determined using HPLC-UV detector after a single dosage of 60 mg/kg body weight. At $23{\pm}1.5^{\circ}C$, the peak serum concentrations of NA and PA, which attained at 24 h post-dose, were 5.87 and $0.43\;{\mu}g/ml$, respectively. At $13{\pm}1.5^{\circ}C$, the peak serum concentrations of NA and PA, which attained at 10 h post-dose, were 6.22 and $1.57\;{\mu}g/ml$, respectively. Better absorption of PA was noted at $13{\pm}1.5^{\circ}C$ compared to $23{\pm}1.5^{\circ}C$. However, absorption of NA was not affected significantly by temperature. The elimination of NA and PA from serum of black rockfish was considerably faster at $23{\pm}1.5^{\circ}C$ than at $13{\pm}1.5^{\circ}C$. The kinetic profile of absorption, distribution and elimination of NA and PA in serum were analyzed by fitting to a one compartment model, with WinNonlin program. The AUC, $T_{1/2}$, $T_{max}$ and $C_{max}$, respectively, were: $161.25\;{\mu}g{\cdot}h/ml$, 0.15 h, 12.29 h and $8.91\;{\mu}g/ml$ at $23{\pm}1.5^{\circ}C$, and $134.12{\mu}g{\cdot}h/ml$, 0.18 h, 8.79 h and $5.00\;{\mu}g/ml$ at $13{\pm}1.5^{\circ}C$ with NA; $41.57\;{\mu}g{\cdot}h/ml$, 0.58 h, 8.24 h and $0.21\;{\mu}g/ml$ at $23{\pm}1.5^{\circ}C$, and $40.36\;{\mu}g{\cdot}h/ml$, 0.59 h, 5.04 h and $1.20\;{\mu}g/ml$ at $13{\pm}1.5^{\circ}C$ with PA.

• Atmosphere
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• v.24 no.4
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• pp.523-532
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• 2014

In this study, thermal tropopause height defined from WMO (World Meteorological Organization) using temperature profile derived from Advance Microwave Sounding Unit-A (AMSU-A; hereafter named AMSU) onboard EOS (Earth Observing System) Aqua satellite is retrieved. The temperature profile of AMSU was validated by comparison with the radiosonde data observed at Osan weather station. The validation in the upper atmosphere from 500 to 100 hPa pressure level showed that correlation coefficients were in the range of 0.85~0.97 and the bias was less than 1 K with Root Mean Square Error (RMSE) of ~3 K. Thermal tropopause height was retrieved by using AMSU temperature profile. The bias and RMSE were found to be -5~ -37 hPa and 45~67 hPa, respectively. Correlation coefficients were in the range of 0.5 to 0.7. We also analyzed the change of tropopause height and temperature in middle troposphere in the extreme heavy rain event (23 October, 2003) associated with tropopause folding. As a result, the distinct descent of tropopause height and temperature decrease of ~8 K at 500 hPa altitude were observed at the hour that maximum precipitation and maximum wind speed occurred. These results were consistent with ERA (ECMWF Reanalysis)-Interim data (potential vorticity, temperature) in time and space.

• Journal of Plant Biology
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• v.36 no.2
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• pp.133-140
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• 1993

The photosynthetic activities in relation to oxygen evolution rates, quantum yield, CO2 uptake rates and room temperature chlorophyll fluorescence were investigated in cotyledons of cucumber seedlings exposed to low temperature (at 4$^{\circ}C$) for 24 h. Light-chilling caused more inhibition on light-saturated maximum oxygen evolution rates, quantum yield, and CO2 uptake rates than dark-chilling did in the cucumber plant. Light-chilling induced more marked increase in Fo and decrease in (Fv)m/Fm than dark-chilling did in the room temperature chlorophyll induction kinetics. The above results affected by chilling in the light are considered to be associated with the partial damage of the reaction center of PS II and the decreased photosynthetic activities. There occurred a large decrease in qQ with little change in qNP in the light-chilling plant. When light- and dark-chilled plants were recovered at room temperature for 24 h and their chlorophyll fluorescences were induced with light doubling technique, light-chilled plants showed more smaller magnitude and rate of fluorescence relaxation than dark-chilled plants. These suggest that light-chilling might cause some alterations in transthylakoid pH formation, and that photosynthetic apparatus of cucumber cotyledons is more susceptible to light-chilling. In the fast fluorescence induction kinetics, FR was decreased by 60% in the light-chilled plants with reference to $25^{\circ}C$ light-grown plants, while the dark-chilled plants showed a decreased rate of only 20% with reference to $25^{\circ}C$ dark-treated plants for 24 h, indicating that cucumber seedling is very sensitive to chilling stress. So, it is certain that chilling injury to the photosynthetic apparatus is strongly dependent on the presence of light in cucumber seedlings.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.8
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• pp.1085-1096
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• 2000

An experimental study was performed to examine the heat and mass transfer characteristics of $LiBr-H_2O$ solution flowing over a single horizontal tube with the water vapor absorption. Effects of the flow rate and the temperature of the solution at the top of the tube, the absorber pressure and the drainage pattern were considered. The absorption rate depends highly on the absorber pressure at the low flow rate condition while on the solution inlet temperature at the high flow rate condition. Also, when the flow rate is low, the absorption performance with the sheet flow drainage appeared to be higher than that with the dripping/jet drainage. However, at the high flow rate condition, the case became reversed. The liquid film became wavy with the higher absorption rate. The waves were more probable to form with the lower flow rate and temperature of the solution, and with the higher absorber pressure.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.11
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• pp.70-77
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• 1998

Ni/SiC Schottky diodes have been fabricated using epitaxial 4H-SiC and 6H-SiC wafers. The epitaxial n-type layers were grown on $n^{+}$ substrates, with a doping density of 4.0$\times$10$^{16}$ c $m^{-3}$ and a thickness of 10${\mu}{\textrm}{m}$. Oxide-termination has been adopted in order to obtain high breakdown voltage and low leakage current. The fabricated Ni/4H-SiC and Ni/6H-SiC Schottky barrier diodes show excellent rectifying characteristics up to the measured temperature range of 55$0^{\circ}C$. In case of oxide-terminated Schottky barrier diodes, breakdown voltage of 973V(Ni/4H-SiC) and 920V(Ni/6H-SiC), and a very low leakage current of less than 1nA at -800V has been observed at room temperature. On non-terminated Schottky barrier diodes, breakdown voltages were 430V(Ni/4H-SiC) and 160v(Ni/6H-SiC). At room temperature, SBH(Schottky Barrier Height), ideality factor and specific on-resistance were 1.55eV, 1.3, 3.6$\times$10$^{-2}$ $\Omega$.$\textrm{cm}^2$ for Ni/4H-SiC Schottky barrier diodes, and 1.24eV, 1.2, 2.6$\times$10$^{-2}$$\Omega$.$\textrm{cm}^2$/ for Ni/SH-SiC Schottky barrier diodes, respectively. These results show that both Ni/4H-SiC and Ni/6H-SiC Schottky barrier diodes are very promising for high-temperature and high power applications.s..

• Journal of the Korean Society of Clothing and Textiles
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• v.38 no.4
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• pp.540-556
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• 2014

This research investigated the effective conditions to dye cotton with commercial indigo leaf powder. We tested dyeing conditions of: pH of dyebath (6.5, 9-12), heating ($20^{\circ}C$, $50^{\circ}C$, $70^{\circ}C$, $90^{\circ}C$), ageing (0, 0.5, 1, 4, 24 hours), reduction time (0, 30, 60 min), and dyeing temperature ($2^{\circ}C$, $10^{\circ}C$, $20^{\circ}C$, $50^{\circ}C$, $70^{\circ}C$, $80^{\circ}C$), dyeing was conducted for 20 minutes. The highest K/S value was obtained when cotton was dyed using pH 11 dyebath, heated at $50^{\circ}C$ for 30 minutes, aged for 24 hours at room temperature ($20^{\circ}C$), reduction carried out for 30 minutes, and dyed at $50^{\circ}C$. It is proposed that the K/S value is primarily influenced by the dyebath pH and dyeing temperature, followed by the presence or absence of ageing time and reduction time. The color of cotton with high K/S values was B type by Munsell hue value, which was similar to the color obtained in previous studies by freshly made indigo leaf powder and indigo leaf juice. The results indicate that the dyeing conditions established in this research are suitable to maximize the dyeability of commercial indigo leaf powder and that the indigo leaf powder can be used as a substitute for fresh indigo leaf juice.

• Clean Technology
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• v.29 no.1
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• pp.39-45
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• 2023

To investigate the effects of Mg addition at different aging times and temperatures, Cu/MgO/Al₂O₃ catalysts were synthesized for the low-temperature water gas shift (LT-WGS) reaction. The co-precipitation method was employed to prepare the catalysts with a fixed Cu amount of 30 mol% and varied amounts of Mg/Al. Synthesized catalysts were characterized using XRD, BET, and H₂-TPR analysis. Among the prepared catalysts, the highest CO conversion was achieved by the Cu/MgO/Al₂O₃ catalyst (30/40/30 mol%) with a 60 ℃ aging temperature and a 24 h aging time under a CO₂-rich feed gas. Due to it having the lowest reduction temperature and a good dispersion of CuO, the catalyst exhibited around 65% CO conversion with a gas hourly space velocity (GHSV) of 14,089 h-1 at 300 ℃. However, it has been noted that aging temperatures greater or less than 60 ℃ and aging times longer than 24 h had an adverse impact, resulting in a lower surface area and a higher reduction temperature bulk-CuO phase, leading to lower catalytic activity. The main findings of this study confirmed that one of the main factors determining catalytic activity is the ease of reducibility in the absence of bulk-like CuO species. Finally, the long-term test revealed that the catalytic activity and stability remained constant under a high concentration of CO₂ in the feed gas for 19 h with an average CO conversion of 61.83%.

• Korean Journal of Food Science and Technology
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• v.27 no.5
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• pp.742-747
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• 1995

The effect of storage temperature and period on the contents of tin, iron, lead and vitamin C, browning index and pH was studied for canned and bottled orange juices currently sold in Korean market, which were stored for 24 weeks at 20, 30, 40 and $50^{\circ}C$ and analyzed at 4 week intervals. The change of metal content in bottled juices was negligible but metal release in canned juices was remarkably affected by storage temperature. Tin content after 16 weeks increased by $2.7{\sim}13.1$ times, iron content after 24 weeks increased by $4.3{\sim}5.2$ times and lead content after 24 weeks increased by $1.1{\sim}2.9$ times. Retention of total ascorbic acid in canned juices after 24 weeks at $30{\sim}50^{\circ}$ decreased to $13{\sim}76%$, while that in bottled juices decreased to $4{\sim}80%$. Browning index in canned juices after 24 weeks below $40^{\circ}C$ increased slightly with serious discoloration at $50^{\circ}C$ while that in bottled juices increased a little rapid. pH change in canned and bottled juices during storage below $40^{\circ}C$ was not observed regardless of container type but a great change of pH was accompanied with swelling of container ends in the case of canned juices after 24 weeks at $50^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.33 no.4
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• pp.432-440
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• 1996

ZrO2 gel was prepared under pH 10 alkaline condition by sol-gel process and was investigated as a function of calcination temperature and effect of calcination temperature on cobalt adsorption capacity. The ZrO2 powder prepared by sol-gel process was calcined at 600, 800, 1000, 1200, 140$0^{\circ}C$ and analyzed by X-ray diffractometry. SEM specific surface area by BET nitrogen adsorption FT-IR and TG-DTA technique. It was shown that cobalt adsorption capacity of ZrO2 prepared under pH 10 alkaline condition and then calcined at $600^{\circ}C$ in high temperature was determined to be larger than that of ZrO2 at various calcination temperature. The specific surface area of ZrO2 calcined at $600^{\circ}C$ was 24.03m2/g and cobalt adsorption capacity at 25$0^{\circ}C$ high-temperature water was 0.16m-eq/g.