• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.11
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• pp.889-894
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• 2003

The objectives of this study are to present a proper mathematical model for a thermoelectric cooler equipped with the spacer and to investigate the effect of its geometries by heat transfer analysis. In order to enhance the efficiency of the thermoelectric cooler, the spacer is inserted between TEM (thermoelectric module) and cold plate. The theoretical results show that the COP (coefficient of performance) increases nonlinearly as high as 0.63 with increasing the depth of spacer and the depth of TEM and with decreasing the area of insulator.

• Food Science of Animal Resources
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• v.31 no.1
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• pp.74-80
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• 2011

The objective of this study was to determine the shelf-life effects and residual nitrite content of emulsified sausages added with pine needles during cold storage. The sausage consisted of four types: no pine needles added (control), pine needle juice added (T1), ethanol extract of pine needles added (T2), and boiling extract of pine needles added (T3). Each sausage type was tested in triplicate and assigned to one of four storage periods: 0, 10, 20, or 30 d. As storage time increased, the presence of pine needles resulted in decreased pH, meat color (CIE $L^*$, $a^*$ and $b^*$), residual nitrite value, and increased thiobarbituric acid reactive substances (TBARS) values and total plate counts (TPC). Values for pH, TBARS, residual nitrite, total plate counts and CIE $L^*$ and $a^*$ decreased significantly with added pine needles relative to the control (p<0.05). In particular, T2 was significantly (p<0.05) more effective for delaying lipid oxidation than the other treatment groups. In conclusion, the results demonstrate that adding an ethanol extract of pine needles (T2) to emulsified sausages tended to improve antioxidative and antimicrobial effects and reduce residual nitrite content during storage compared to the other treatment groups.

• Journal of Animal Science and Technology
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• v.53 no.5
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• pp.461-467
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• 2011

The objective of this study was to determine the shelf-life effects and residual nitrite contents of mugwort and pine needle extracts addition in emulsified sausage during cold storage. The sausages were of five types: no mugwort and pine needle extracts added (Control), mugwort water extract added (T1), mugwort ethanol extract added (T2), pine needle water extract added (T3), and pine needle ethanol extract added (T4). Each sausage type was tested in triplicate and assigned to one of four storage periods: 0, 10, 20 and 30 days. As storage time increased, the presence of mugwort and pine needle extracts resulted in decreased pH, CIE $L^*$, and residual nitrite value, but increased TBARS (thiobarbituric acid reactive substance) values, and total plate counts (TPC). Values for pH, TBARS, residual nitrite contents and total plate counts were significantly decreased by the addition of mugwort and pine needle extracts compared to the control (P<0.05). Among all treatments, T4 was more (P<0.05) effective in delaying lipid oxidation compared to other treatment groups. In conclusion, this study demonstrates that addition of pine needle ethanol extract to emulsified sausages tended to improve antioxidant and antimicrobial effects and residual nitrite contents during storage than other treatment groups.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.382-389
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• 2019

A novel folding process is proposed using a repeated cold-die forging and annealing to form a sterling silver ring. Sterling silver plate was cut into a doughnut shape, and lattices with 0.43-mm line-width were imprinted on it. The sample was folded by forging using dies with slopes of $45^{\circ}$, $60^{\circ}$, and $75^{\circ}$ and annealing. For comparison, samples were also fabricated without annealing. Strain was identified by measuring the length of lattices. Vernier calipers, a Vickers hardness tester, an optical microscope, and a UV-VIS colorimeter were used to determine the size, hardness, microstructure, and body color. Without annealing, cracks occurred. However, successful deformation was possible when annealing was used. The results of macro strain measurements show that the outer diameter and width decreased, while the inner diameter and thickness increased after the final process. The maximum strain was increased 0.128 toward the parallel direction. The Vickers hardness decreased after annealing and increased after the folding process. The microstructure results showed that the grain size increased after annealing but decreased after folding. The color difference based on the Lab index was under 10 for all processes. Eventually, a doughnut-shaped silver plate was successfully deformed into a ring shape by the folding process.

• Journal of the Korean Dietetic Association
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• v.14 no.1
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• pp.87-96
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• 2008

The purposes of this research were to investigate in-patients' perception on foodservice quality and to examine factors influencing their meal consumption at hospitals. Three general hospitals with over 400 beds in Seoul and Chon-An agreed to participate in the research. A total of 516 in-patients of the hospitals were surveyed on their meal consumptions, reasons of plate wastes, perceptions of foodservice quality, and demographic information. A response rate was 76% after excluding responses with significant missing data. On average the regular diet patients consumed 72%, 69%, and 68% of rice, soups, and side dishes served, respectively; the therapeutic diet patients consumed less than 70% of the meals they were served. The consumption rates did not differ significantly by diet type, gender, age, and hospitalization period. Among the therapeutic diet patients, those who had nutrition education consumed significantly more rice than the others (p<0.05). The main reasons why the patients did not eat all food served were 'lack of energy' and 'not tasty'. The patients' perception on foodservice quality was low; the therapeutic diet patients perceived more negatively than the regular diet patients in 'keeping hot food hot, cold food cold(p<0.05)', 'maintaining consistency of taste(p<0.01)', and 'providing nutrition information(p<0.01)'. To achieve the goal of the foodservice at hospitals, the dietitians can use the findings of the research in developing and implementing strategies to improve the patients' meal consumption. Recipe standardization, employee training, and production management will be useful for improving food quality and nutrition education on therapeutic diets for the patients will improve their meal consumption at hospitals.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.10
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• pp.102-111
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• 2004

The procedure of design and manufacture of sub-scale combustor using bipropellant swirl injector with external mixing for a liquid rocket engine are described. The results of cold flow test, ignition test and combustion test of the sub-scale combustor are also given in this paper. The sub-scale combustor uses liquid oxygen(LOx) and kerosene as propellants and has a injector head, an ablative material combustor wall and a water cooled nozzle. The injector head has LOx manifold, fuel manifold, fire face plate, one center swirl injector and 18 main swirl injectors. The cold flow, ignition and combustion tests were successfully performed without damage of combustor. Results of hot firing tests show that combustion efficiency meets the target of design and operations of start and stop cyclogram are stable and high frequency combustion instability does not occur.

• Journal of Korean Society of Steel Construction
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• v.24 no.4
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• pp.443-450
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• 2012

In this study, This study investigates the axial load behavior of concrete-filled steel columns using seismic rectangular steel tube with the width-to-thickness and slenderness ratio. Due to cold-roll forming and cold-press forming of steel tube, the flat part and the corner part of the rectangular steel tubes are changed in the material properties compared to SN-steel plate. It was showed the tendency to increase yield strength, tensile strength and upper limit of yield ratio This phenomenon affects the nonlinear behavior after local buckling of the steel tube. Therefore, the coupon test was performed by the processing of rectangular steel tube, in order to assess forming performance. And a total of 6 CFT-columns were tested under monotonic loading condition. Main parameters were the width-thickness ratio and the slenderness ratio.

• Journal of the Korean Society for Heat Treatment
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• v.28 no.5
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• pp.239-249
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• 2015

Various amount of NbC carbide was intentionally formed in a matrix-type cold-work tool steel by controlled amount of Nb and C addition. And the effect of NbC addition on the mechanical properties was investigated. Four alloys with different Nb and C contents were cast by vacuum induction melting, then hot forging and spheroidizing annealing were conducted. The machinability of the annealed specimens was examined with 3 different cutting tools. And tensile tests at room temperature were conducted. After quenching and tempering, hardness and impact toughness were measured, while wear resistance was evaluated by disk-on-plate type wear test. The increasing amount of NbC addition resulted in degraded machinability with increased strength, whereas the absence of NbC also led to poor machinability due to high toughness. After quenching and tempering, the additional NbC improved wear resistance with increasing hardness, whereas it deteriorated impact toughness. Therefore, it could be found that a moderate addition of NbC was desirable for the balanced combination of mechanical properties.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.1
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• pp.7-13
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• 2003

A hot press method was use for the optimal manufacturing condition for a shape memory alloy(SMA) composite. The bonding between the matrix and the reinforcement within the SMA composite by the hot press method was strengthened by cold rolling. In this study, the objective was to develop an on-line monitoring system for the prevention of the crack initiation and propagation by shape memory effort of SMA composite. Shape memory effect was used to prevent the SMA composite from cracking. For the system to be developed, an optimal hE parameter should be determined based on the degree of damage and crack initiation. When the SHA composite was heated by the plate heater attached at the composite, the propagating cracks appeared to be controlled by the compressive force of SMA.

• Journal of Advanced Marine Engineering and Technology
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• v.11 no.3
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• pp.45-52
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• 1987

Generally the factors affected largely by the cold cracking sensitivity of the weld are the quantity of the diffusible hydrogen, the brittleness and hardness of the bond area and the tensile restraint stress. These factors have relation each other, and if we can reduce one of these factors, it becomes instrumental to the root cracks prevention of weld. This study deals with the gravity type-underwater-welding of KR Grade A-3 marine steel plate using E4303 welding electrode in order to compare wet-underwater-welding with in-air- welding, resulting in obtaining the tensile restraint characteristics, the hardness distribution, the quantity of diffusible hydrogen and the macro- and micro-crack properties in both underwater and in-air welds. The main results obtained are as follows: 1) The quantity of diffusible hydrogen measured for 48 hours is about 18cc/100g-weld-metal for the in-air-weld of one pass and about 48cc/100g-weld-metal for the underwater-weld of one pass which is about 3 times penetration of diffusible hydrogen compairing with the case of the in-air-weld. However, it was experimentally confirmed that, by the multi-pass welding of 2 to 5 passes, the diffusible hydrogen in the underwater weld metal can be reduced as much as 27 to 49%. 2) The hardness of the weld metal indicates the highest value in the heat affected zones of underwater weld for more rapid cooling rate, resulting in the higher sensitivity of cold cracking. So, it is desirable to soften the higher hardness in the HAZ by tempering effect such as the multi-pass welding in the underwater welding. 3) At the bond vicinity of the underwater weld HAZ, micro cracks were found as resulted by both more rapid cooling rate and more diffusible hydrogen and also by the stress corrosion cracking under the tensile restraint stress in the underwater. But this could be prevented by the tempering effect of the following weld bead such as the multi-pass welding.