• Korean journal of food and cookery science
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• v.32 no.3
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• pp.316-324
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• 2016

Purpose: This study chose Vaccinium oldhamii as a material to complement the redness of Sansuyu, which is unstable to heat, to Sansuyu pudding. Methods: The level of browning and hunter color of Corni fructus juice supernatant (CFS) and Vaccinium oldhamii extract (VOE) were examined and dependent on heating time and storage period. Results: A value (redness) of VOE was high, browning was moderate during the storage period, and though the storage period was extended, the value stayed stable, meaning overall redness was maintained. With the increase in the amount of added VOD, the color preference of Sansuyu pudding, and D (VOE 10.0%) was marked the highest at 5.80. As for the preference of texture, B (VOE not added) was the highest at 5.35, but C (VOE 5.0%) was marked the highest at 5.10 for overall preference. The DPPH radical scavenging ability of Sansuyu pudding was 15.86-21.39% at a concentration of 1,000 ppm, and the total polyphenol content was 136.76-139.62 mg/100 g. Since the redness of Sansuyu is unstable to heat and then is heated, its degree of browning and b value (degree of yellowness) increases. Conclusion: So if a material with a red color that is stable to heat is added to Sansuyu, the preference of Sansuyu products will improve.

• Korean journal of food and cookery science
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• v.24 no.2
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• pp.206-211
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• 2008

This study investigated the feasibility of manufacturing a low-sugar wild vine jam by examining viscosity, water content, and pH, as affected by sugar and pectin content. The jams were prepared by adding various amounts of sucrose, glucose, or fructose (1.89 M, 2.34 M, 2.63 M, or 2.92 M) and/ or pectin (0%, 0.3%, 0.5%, 0.8%, or 1%) to wild vine juice and heating at $90^{\circ}C$ for 3 hrs. A higher viscosity was shown for the jam manufactured with sucrose as compared to those made with glucose or fructose, and the greater the sucrose level the higher the viscosity of the jam. The jam with 50% reduced sugar content showed a similar viscosity to the control jam, which contained only 2.92 M sucrose, when the sugar was co-added with pectin at 0.5% for the low sucrose jam, and at 0.8% for the low glucose or low fructose jams, respectively. The water content of the low sucrose jam was lower than that of the low glucose or low fructose jams, and adding pectin had no significant effect on the water content of the low sugar jam. The pH levels of the jams were not significantly different, regardless of the type and concentration of sugar, temperature, or pectin addition, and ranged between 3.6 and 3.8. Overall, the results clearly show that wild vine jam with 50% reduced sugar content and having the same viscosity as control jam, can be manufactured when pectin and sugar are added together.

• Food Science and Biotechnology
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• v.14 no.3
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• pp.305-310
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• 2005

Flaxseed is outstanding for lignans and oil rich in ${\alpha}$-linolenic acid which protect against several major illnesses. Better understanding of processing and storage characteristics of flaxseed will increase options for food use. Lignans and oil are found in the hull and embryo, respectively. Comparison of pearling and impact-dehulling processes for separation of lignan and oil-rich fractions showed the impact process was less effective, but easier to scale-up. Screw-pressing embryo reduced oil yield compared to whole seed, but doubled productivity and sharply reduced frictional heating of the oil. Flaxseed hull and embryo, also whole, ground and steamed-ground samples, were stable up to 30 weeks in closed containers at $23^{\circ}C$. Steamed-ground samples in open trays at $40^{\circ}C$ deteriorated markedly (peroxide value > 100 by 22 weeks); yet, whole seed remained stable. Incorporation of 18% flaxseed embryo into yellow perch feed increased ${\alpha}$-linolenic acid to 13 to l4% of muscle and liver lipids, compared to 0.5 to 0.7% in the no-embryo control. Feed conversion ratio, weight gain, and survival were similar. These studies are helping to establish the technological base for processing and utilizing flaxseed and flaxseed fractions to improve human diets.

• Resources Recycling
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• v.9 no.6
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• pp.15-22
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• 2000

There are many intensive efforts to develop the recycling technologies of waste plastics in steel works to tackle the saving of resources and the protection of the natural environment. In this study, the thermogravimetric analyses for three kinds of plastics, the combustion experiments and the theoretical approach for calculating the flame temperature in the blast furnace had been performed to understand the behavior of plastics in the raceway. The thermal decompositions of plastics were studied using thermogravimetric analyzer under the atmospheric condition. The starting temperature of thermal decomposition and the maximum weight loss point were increased in proportion to the logarithmic values of heating rate. The combustion characteristics of plastics were simulated in a coke-bed combustor. The combustion efficiency of plastics was lower than that of pulverized coal. The oxygen enrichment was found out to be one of the useful methods to increase the combustibility of plastics in raceway. The maximum injection rate of plastics was calculated based on the flame temperature.

• Journal of the Korean Wood Science and Technology
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• v.46 no.3
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• pp.285-296
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• 2018

As a study for the verification of heat treated wood according to ISPM No. 15, the spectroscopic characteristics of the heat treated wood surface were analyzed. Various functional groups were observed on the IR spectrum, but it was difficult to find any particular difference between wood species, heat treatment time and storage period. HBI (hydrogen-bonding intensity) shows the change of the heat treated wood according to the storage time, but the change of wood with the heat treatment time was hard to be observed. On the PCA score plot, however, it was possible to sort the wood according to the heat treatment time of 60 minutes or 90 minutes in the species. The standards for classification of heat-treated wood in PCA were aromatic rings in lignin and C-H bending in cellulose, and these components were able to classify heat-treated wood by ISPM No. 15.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.4
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• pp.80-86
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• 2012

This study is for figuring out a possibility of realization of the thermal protection system(TPS) for temporary use under high temperature condition and improving a design of the future TPS. On this purpose, environmental condition of the system has been simplified: the boundary conditions consist of a internally heating surface and a externally heated surface which is simulating the external high temperature condition. Configuration of the system is simplified as a hexahedon. Melting characteristics of the phase change material(PCM) and air temperature variation of TPS with or without connector have been numerically analyzed and compared. As a result of numerical analysis, the heat from the internally heated surface could not be effectively transferred. Therefore, temperature of inner space has been increased.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.8
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• pp.325-330
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• 2016

This study was conducted to develop a heating system for a fuel cell-driven electric vehicle. The system consists of a compressor, an expansion device and three heat exchangers. A conventional air source heat exchanger is used as primary heat exchanger of the system, and an additional water source heat exchanger is used as a pre-heater to supply heat to the upstream air of the primary heat exchanger. On the other hand, the third heat exchanger consists of a water-to-refrigerant heat exchanger. The heat source of the pre-heater and the water-refrigerant heat exchanger is the waste heat from the fuel cell's stack. In the experiment, the indoor and the outdoor air temperature were fixed, and the compressor speed, EEV opening and waste heat temperature were varied. The results indicate that the $COP_h$ of the proposed system is 3.01 when the system is operating at a 1,200 rpm compressor speed, 50% EEV opening, and $50^{\circ}C$ waste heat source temperature in air pre-heater operation. However, when the system uses a water-refrigerant heat exchanger, the $COP_h$ increases to up to 9.42 at the same compressor speed and waste heat source temperature with 75% EEV openings.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.5
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• pp.225-232
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• 2013

Heat pump systems have been widely adopted in buildings for cooling and heating, due to their higher energy efficiency. Recently, the demand for hot water supply from the heat pump system has been increasing. To increase the water supply temperature with higher system efficiency and reliability, a heat pump water heater adopting cascade cycle was investigated in this study. The cascade heat pump water heater consisted of a low-stage cycle using R410A, and a high-stage cycle using R134a. A simulation program for the cascade heat pump water heater was developed, and verified by comparison with experimental data. The performance of the cascade heat pump water heater was optimized, by varying the compressor rotating speeds of the low- and high-stage cycles. At low ambient temperatures, the performance of the cascade cycle was compared with that of the single-stage cycle. The system efficiency of the cascade cycle was higher than that of the single-stage cycle, showing a lower compression ratio and compressor discharge temperature.

• Journal of the Optical Society of Korea
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• v.16 no.4
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• pp.349-353
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• 2012

Uniform spreading of injection current in light-emitting diodes (LEDs) is one of the crucial requirements for better device performances. It is reported that non-uniform current spreading leads to low output power, high current crowding, heating, and reliability degradation of the LED device. This paper reports on the effects of different surface and electrode geometries in the LEDs. To increase the output power of LEDs and reduce the series resistance, a rectangular-type LED (RT-LED) with a centered island cathode has been fabricated and investigated by comparison with a conventional LED (CV-LED). The performances of RT-LEDs were prominently enhanced via uniform current spreading and low current crowding. Performances in terms of increased output power and lower forward voltage of simulated RT-LEDs are much superior to those of CV-LEDs. Based on these results, we investigated the correlation between device geometries and optical characteristics through the fabricated CV and RT-LEDs. The measured output power and forward voltage of the RT-LEDs at 100 mA are 64.7% higher and 8% smaller compared with those of the CV-LEDs.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.539-548
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• 2019

This study investigated the influence of ultrasound treatment on the quality properties of chicken breast meat and the broth from Korean chicken soup (Baeksuk). In this study, the internal temperature, malondialdehyde content, textural profile, color, dry matter, protein content, phenolic content and sensory properties of chicken breast meat broth from chicken soup with ultrasound treatment were analyzed. The chicken, plants, salt, and water were vacuum packaged in a retort pouch. The chicken soup was manufactured with ultrasound treatment (45 kHz and $1.6W\;cm^{-2}$) in a water bath at $85^{\circ}C$. The texture properties, color, and lipid oxidation of the chicken breast meat from the chicken soup were not affected by the ultrasound treatment. There was no significant difference in the lipid oxidation in the broth of the chicken soup between the control and ultrasound treatment. The dry matter and crude protein contents of the broth were significantly increased by the ultrasound treatment. The broth flavor of the chicken soup manufactured with the ultrasound treatment received a higher score than that of the control in the sensory analysis. There were no differences in the sensory properties of the chicken breast meat from the chicken soup between the control and ultrasound treatment Therefore, the broth quality of the chicken soup can be improved by heating with ultrasound treatment. Additionally, to apply ultrasound technology to the production chicken breast meat and the broth from chicken soup, it is necessary to further study the quality characteristics of the breast meat and broth according to various frequencies and strengths.