• Journal of the East Asian Society of Dietary Life
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• v.27 no.5
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• pp.529-539
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• 2017

The aim of this work was to make acorn bread containing natural antioxidants as healthy food. The amylographic characteristics, loaf volume, color, texture, and subjective preference of the acorn bread containing 5~25% of acorn flour were measured during storage at room temperature and in a freezer. The results were as follows: The loaf volume decreased with increasing the addition of acorn flour from 5% to 25%. The onset gelatinization temperature and the value at the peak point of the bread decreased according to the amount of acorn flour added. L-value decreased with the increase of acorn flour contents, but the a- and b- values increased. During the storage period at room temperature, the L, a, and b- value decreased, whereas in the freezer, the L-value decreased except for the bread containing 5~11% acorn flour. In sensory evaluation, color and taste achieved high scores at 18% addition, but low scores at 25% addition. The bitter aftertaste showed low scores according to the addition of acorn flour. The softness and chewiness decreased, but the overall acceptance increased according to the addition of acorn flour except for the bread added with 25% acorn flour. The textural measurements showed that the hardness, springiness, gumminess, and brittleness increased significantly during the storage periods. The cohesiveness, gumminess, and brittleness in room temperature storage decreased with the increase of acorn flour contents. In freezer storage, the addition of acorn flour resulted in the increase of hardness, springiness, gumminess, and brittleness during storage periods. On the other hands, the cohesiveness decreased with the addition of acorn flour. Moreover the addition of acorn flour increased significantly the hardness, gumminess, and brittleness during storage periods. As a result, the bread containing acorn flour showed reasonable textural properties during storage periods.

• Journal of Power System Engineering
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• v.7 no.2
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• pp.17-22
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• 2003

As side-by-side refrigerators came into existence, there has been a growing concern about the free%ins-up of the vital equipment in a walk-in freezer. Due to a bad performance, customers are experiencing too much frustration. In order to minimize the freezing phenomena, the numerical simulation has been performed on the characteristics of cold air flow in a side-by-side refrigerator. The flow field has been simulated with a standard $k-\varepsilon$ turbulent model and a SIMPLE algorithm based on the finite volume method. Through the results of the analysis of the pattern of cold air flow, finally the shape of outlet for cold air flow was modified. The present model was compared with the modified model. The latter was better than the former in minimizing the freezing phenomena.

• Journal of Pharmaceutical Investigation
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• v.32 no.3
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• pp.173-179
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• 2002

Solid dispersions of ipriflavone with PVP were prepared by a spray-drying method in order to improve the bioavailability. They were measured with scanning electron microscopy, differential scanning calorimetry, x-ray powder diffraction, and Fourier transform infrared spectroscopy to evaluate the physicochemical interaction between ipriflavone and PVP and study the correlation between these physicochemical characteristics and bioavailability. Ipriflavone exhibited crystallinity, whereas PVP was almost amorphous. The area of the endotherm $({\Delta}H)$ of freezer milled ipriflavone, freezer milled ipriflavone physically mixed with freezer milled PVP, and physically mixed ipriflavone with PVP was almost the same, whereas ${\Delta}H$ of the solid dispersed ipriflavone with PVP was much smaller than that of the other preparation types. Also, the crystallinity and the crystal size of ipriflavone in the solid dispersed ipriflavone with PVP were much smaller than those of the other preparation types. From the in vivo test, the AUC of the solid dispersed ipriflavone with PVP was approximately 10 times higher than that of the physically mixed ipriflavone with PVP. The solid dispersion using the spray-drying method with a water-soluble polymer, PVP, may be effective for the improvement of the bioavailability.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.804-809
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• 2009

The present study measured frost pattern on a cylinder to propose empirical correlation equations for the local and average frost thickness, frost density and frost mass. The key parameters were diameter of the cylinders (7mm, 20mm), cooling surface temperature of the circular tube, absolute humidity of air, air temperature and air velocity. A 50% ethylene glycol aqueous solution was applied as a coolant. The frost thicknesses at both front and rear were larger than those at the other parts, while they were increased as diameter of the cylinder was increased. The local frost thicknesses at high air velocity were more uniform than those at low air velocity. The values predicted by Kim et al. under the freezer condition showed larger by the maximum of $30{\sim}50%$ than the measured data under heat pump condition. The empirical correlations for the local and average frost thickness and frost mass were proposed. The correlation equations for the frost thickness and frost mass under the heat pump condition in the present study might predict more accurate than the other correlation equations. The proposed correlations might be applied for the freezer condition within the maximum 15% deviation from the previous correlations under freezer condition.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.517-522
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• 2005

A cold storage refrigerator using phase change material(PCM) has been developed and its performance test results are provided here. The inner temperature of the refrigerator is controlled with forced convection driven by a fan using a DC battery. At the first, to freeze all the PCM of the ambient temperature by a built-in refrigerating machine, it took about 8 and 10 hours respectively at the refrigerator and the freezer mode. Then, without external power supply, the inner temperature of the cold storage refrigerator has been maintained at $-18{\pm}1^{\circ}C$ during 14 hours at the freezer mode and maintained at $3{\pm}^{\circ}C$ during 34 hours at the refrigerator mode. Just after the end of its valid usage as a refrigerator or a freezer, it took about 6 hours to refreeze the PCM for its reuse. During the test, the ambient temperature was kept at $30^{\circ}C$.

• Journal of the Korean Applied Science and Technology
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• v.35 no.2
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• pp.357-366
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• 2018

In this study, if the set temperature of the refrigerator differs from the set temperature of the refrigerator, the temperature distribution of food in the refrigerator is estimated by measuring the temperature in the refrigerator and in the refrigerator room. In addition, based on the set temperature of the refrigerator and the freezer, the temperature range of the heat is large and the time required to recover to the set temperature is to be determined. And the optimal setting temperature for home refrigerators is to be shown by measuring the amount of power consumed to recover to the set temperature. As a result, the conditions in which the temperature in the freezer realized $-18^{\circ}C$ were only appropriate in case 3, Case 6, Case 8, and Case 9 when the set temperature in the refrigerator was lower than that in the freezer. Under these conditions, the minimum temperature in the refrigerator was $-1.1^{\circ}C$, Case 6 was $-1.5^{\circ}C$, Case 8 was $-1.1^{\circ}C$ and Case 9 was $-0.8^{\circ}C$, respectively. Also, the total power consumption during the 10 hours operation time of each case was greater than the setting temperature of the freezer and the refrigerator except case 4, since case 4 started operation around 13:30 in the morning.

• 한국전자현미경학회:학술대회논문집
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• 1999.11a
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• pp.70-71
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• 1999

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.4 no.4
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• pp.277-288
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• 1992

Numerical simulations are made of the refrigeration cycle in a domestic refrigerator/freezer. The main purpose of the present study is to predict the steady-state cycle performance with various specifications of cycle components and cabinet under the continuous running conditions. The detailed mathematical models are constructed for both the cycle components and cabinet, which are strongly coupled with each other. The simultaneous equations are solved by simple iteration method, and the results obtained are examined to assess the effect of the cycle components and cabinet modification on the system performance.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.333-334
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• 2010

In this paper, quality variations of commercially available anti-freezers manufactured in Korea are studied. This study is focused on the effect of the use of anti freezer on strength recovery of cement mortar under low curing temperature. As expected, regardless of types of anti freezer, the use of antifreezer protects the water from freezing under low curing temperature.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.6
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• pp.319-325
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• 2009

The purpose of this study is to investigate the performance characteristics of a bypass two-circuit refrigerator. A bench scale refrigeration system was designed and constructed to estimate possible performance improvement of the bypass two-circuit refrigerator. The experiments were conducted in the bench scale refrigeration system by varying capacity of the condenser and refrigerant charge amount with an adoption of a refrigerant storage vessel. The COPs of the bypass two-circuit refrigeration system in the refrigerator and freezer (RF)-mode and freezer(F) only-mode were increased by 10% and 17%, respectively, with increasing the capacity of the condenser. Besides, the COP of the system in the F only-mode was increased by 10% by adopting the refrigerant storage vessel.