• The Journal of Advanced Prosthodontics
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• v.7 no.1
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• pp.47-50
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• 2015

PURPOSE. This study aimed to discover a way to increase the bond strength between bis-acryl resins, using a comparison of the shear bond strengths attained from bis-acryl resins treated with light curing, pressure, oxygen inhibition, and heat. MATERIALS AND METHODS. Self-cured bis-acryl resin was used as both a base material and as a repair material. Seventy specimens were distributed into seven groups according to treatment methods: pressure - stored in a pressure cooker at 0.2 Mpa; oxygen inhibition- applied an oxygen inhibitor around the repaired material,; heat treatment - performed heat treatment in a dry oven at $60^{\circ}C$, $100^{\circ}C$, or $140^{\circ}C$. The shear bond strength was measured with a universal testing machine, and the shear bond strength (MPa) was calculated from the peak load of failure. A comparison of the bond strength between the repaired specimens was conducted using one-way ANOVA and Tukey multiple comparison tests (${\alpha}$=.05). RESULTS. There were no statistically significant differences in the shear bond strength between the control group and the light curing, pressure, and oxygen inhibition groups. However, the heat treatment groups showed statistically higher bond strengths than the groups treated without heat, and the groups treated at a higher temperature resulted in higher bond strengths. Statistically significant differences were seen between groups after different degrees of heat treatment, except in groups heated at $100^{\circ}C$ and $140^{\circ}C$. CONCLUSION. Strong bonding can be achieved between a bis-acryl base and bis-acryl repair material after heat treatment.

• Journal of the Korean Society of Food Culture
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• v.24 no.1
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• pp.69-76
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• 2009

This study was conducted to determine the optimal cooking conditions for brown rice using an electric pressure rice cooker. The effects of steeping conditions and cooking pressure on the hydration, gelatinization, texture and palatable properties of cooked brown rice were evaluated. Based on water uptake and DSC data, the optimal steeping time and temperature for brown rice were determined to be 25 minutes and ${\sim}60^{\circ}C$, respectively. The cooking conditions for brown rice were then divided into the following 6 categories: steeping at $25^{\circ}C$ for 25 minutes and cooking at an atmospheric pressure of 1.7 (25P) or 1.9 (25HP), steeping at $57^{\circ}C$ for 25 minutes and cooking at an atmospheric pressure of 1.7 (57P) or 1.9 (57HP), steeping at $85^{\circ}C$ for 15 minutes and cooking at an atmospheric pressure of 1.7 (85P) or 1.9 (85HP). The susceptibility of cooked brown rice starch to degradation into maltose by ${\alpha}$-amylase, which is related to the degree of gelatinization and in vitro digestibility, were then determined. The amount of maltose produced by cooked brown rice samples was highest in the 57HP group, followed by the 57P and 85HP groups. Storing cooked brown rice at $73^{\circ}C$ for 24 hours resulted in significantly higher amounts of starch being degraded into maltose in the 57P, 57HP and 85HP groups than in the other groups. Textural analysis demonstrated that the 57P, 57HP and 85HP groups had significantly lower gumminess and chewiness values when compared to the other groups, and that 57HP received had the lowest hardness of all treatments. These results were confirmed by the results of the sensory evaluations. Furthermore, the 57P and 57HP groups were found to have a higher glossiness, stickiness aroma and taste score than the other groups. These findings were taken to indicate that steeping conditions and pressure exerted a positive synergistic effect on the cooking quality of brown rice. The texture analyzer also revealed that storing the cooked rice at $73^{\circ}C$ for 24 hours only led to significantly lower scores in gumminess, hardness and chewiness in the 57P and 57HP groups, which indicates that these groups underwent a lesser degree of retrogradation than other groups. Taken together, the results of the present study demonstrate that steeping brown rice at $57^{\circ}C$ for 25 minutes and a higher cooking pressure improved the palatability and in vitro digestibility of brown rice significantly.

• Proceedings of the Korean Reliability Society Conference
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• 2001.06a
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• pp.337-337
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• 2001

High voltage ceramic capacitors are widely applied in power electronic circuits, such as filters, snubbers, and resonant circuits, due to their excellent features of high voltage endurance and low aging. This paper presents a result of failure analysis and reliability evaluation for high voltage ceramic capacitors. The failure nodes and failure mechanisms were identified in order to understand the failure physics in a component. The causes of failure mechanisms for zero resistance phenomena under withstanding voltage test in high voltage ceramic capacitors molded by epoxy resin were studied by establishing an effective closed-loop failure analysis. Also, the condition for dielectric breakdown was investigated. Particular emphasis was placed on breakdown phenomena at the ceramic-epoxy interface. The validity of the results in this study was confirmed by the results of accelerated testing. Thermal shock test as well as pressure cooker test for high voltage ceramic capacitor mounted on a magnetron were implemented. Delamination between ceramic and epoxy, which, might cause electrical short in underlying circuitry, can occur during curing or thermal cycling. The results can be conveniently used to quickly identify defective lots, determine mean time to failure (MTTF) of each lot at the level of Inspection, and detect major changes in the vendors processes.

• Journal of Electrical Engineering and Technology
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• v.8 no.3
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• pp.603-609
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• 2013

In this paper, we describe the analysis of inkjet-printed silver (Ag) patterns on epoxy-coated substrates according to several reliability evaluation test method guidelines for conventional printed circuit boards (PCB). To prepare patterns for the reliability analysis, various regular test patterns were created by Ag inkjet printing on flame retardant 4 (FR4) and polyimide (PI) substrates coated with epoxy for each test method. We coated the substrates with an epoxy primer layer to control the surface energy during printing of the patterns. The contact angle of the ink to the coated epoxy primer was $69^{\circ}$, and its surface energy was 18.6 $mJ/m^2$. Also, the substrate temperature was set at $70^{\circ}C$. We were able to obtain continuous line patterns by inkjet printing with a droplet spacing of $60{\mu}m$. The reliability evaluation tests included the dielectric withstanding voltage, adhesive strength, thermal shock, pressure cooker, bending, uniformity of line-width and spacing, and high-frequency transmission loss tests.

• Korean journal of food and cookery science
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• v.23 no.5
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• pp.761-769
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• 2007

The purpose of this study was to provide the sensory profiles for cooked rice varieties, with 3 types of functional rice and 4 types of ready -to -eat rice, using descriptive analysis. Eighteen descriptors as well as reference standards were developed. The cooked functional rice, ready-to-eat rice, and plain cooked rice were separated into 4 groups by PCA. PC1 & PC2 explained 65% of the total valiance. PC 1 was responsible for the highest percentage of separation based on the texture intensities. The cooked functional rice showed higher intensity for hardness and roughness. The ready-to-eat rice A, B, and C samples had higher intensities in terms of moistness, glossiness, and moisture content, as well as sour and raw rice flavor. The ready-to-eat rice D sample had low grain wholesomeness, and high intensity for raw rice flavor. Finally, the plain cooked rice had more roasted and burnt rice flavor.

• Korean journal of food and cookery science
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• v.23 no.4 s.100
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• pp.452-460
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• 2007

As a preliminary study for developing cooking techniques to improve cooked rice flavor, we surveyed consumer perceptions on purchasing rice and the consumption of cooked rice. The quantity of rice purchased by consumers was in the range of $1O{\sim}20$ kg. The purchase criterion for 50% of the subjects was the taste of the cooked rice, and half of the subjects bought their rice at a supermarket. A majority (90%) of the subjects consumed the rice within 1 to 4 months, storing it raw in the package (32.4%) or in a container at room temperature. The rice was cooked for 2 to 5 persons (65%), 1 to 2 times a day (70%) with a pressure cooker (76%). The rice and water volume were measured by eye. The cooked rice was eaten immediately (41.8%) or in 1 to 2 days (48.6%) by keeping it in an electric cooker (63.6%). The subjects perceived the rice cultivar (37.9%) as the major factor for the cooked rice flavor, as well as the region of origin (21.3%), and storage period (11.9%); the cultivars of Ilmi, Ilpoom and Chuchung were preferred. In conclusion, the consumers regard rice as a principal food; however, the methods to measure rice and water are not standardized. To improve the taste of cooked rice, consumers depend on cooking equipment and the rice cultivar.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.249-249
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• 2017

This study was carried out to compare the antioxidant components and antioxidant activity of brown rice according to addition rate (0, 10, 20, 30, 50, and 100%) and cooker. Brown rice was cooked using general and high pressure cookers with and without fermented alcohol. Pasting characteristics with addition rate of brown rice decreased with increasing amounts of brown rice. Total polyphenol and flavonoid contents increased with increasing amounts of brown rice. DPPH and ABTS radical scavenging activities increased with increasing amounts of brown rice. Moreover, brown rice cooked by the general cooking method with fermented alcohol showed higher antioxidant effects compared to other cooking methods. In this study, antioxidant components and antioxidant activity of cooking brown rice with addition rate and cooking method can be used as basic data on processed manufactured products.

• Korean Journal of Food Science and Technology
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• v.18 no.4
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• pp.319-324
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• 1986

The characteristics of cooked rice were investigated with variation in amount of water added and different cooking methods of pressure and electric cookers. Samples added with 1.3, 1.5, and 1.7 times of water were evaluated for sensory characteristics and for degree of gelatinization by enzyme digestion method upon one hour cooling at room temperature. Samples were reheated by microwave oven and then compaired with fresh samples through sensory evaluation under the same condition. Sensory attributes of rice cooked with 1.3, 1.5, and 1.7 times of water addition showed significant differences among the groups in most properties except in stickiness. Degree of gelatinization in fresh samples also indicated significant differences between the two cookers in varied rice to water ratio. There were significant differences among the samples, fresh and reheated by microwave oven. Revealed differences, however, were not great in the same type of cooker groups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1027-1033
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• 1998

Stewed pumpkin juice(SPJ) has recently become popular as a health drink, and its consumption is growing rapidly. Well ripened pumpkin was heated in a pressure cooker and squeezed to an extract and then packed in retort pouches. The ingredient of ginger, onion, jujube and boxthorn was added to samples of SPJ in order to observe the effect on the composition of SPJ during production and storage at 28oC for 60 days. The level of the main mineral(K) in pumpkin varied when the ingredients were added. The pH of control SPJ showed more changes than the SPJs with ingredients added, and there was almost no change in the samples with boxthorn. During storage, titrable acidity decreased in all samples, and the SPJs with ginger and jujube showed relatively little change compared to the samples of control SPJ and SPJ with onion. As for soluble solid and reducting sugar, the SPJs with jujube and boxthorn showed the highest reading. For carotenoid, the SPJs with jujube, ginger, boxthorn and onion listed according to the amount of carotenoid contained more total carotenoid than the control SPJ. Most of the carotenoid in pumpkin and its extract was found to be carotene by HPLC and Chandler's method. Sensory evaluation of the SPJ samples with ingredients revealed preference for the taste of the SPJs with jujube, ginger and boxthorn in declining order of preference. The taste of SPJs with ingredients added was generally preferent over the control SPJ except the case of SPJ with onion.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.1
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• pp.7-18
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• 2008

This paper reviews the current development of an ultra-slim SiP for Radio Frequency (RF) application, in which three flip chips, additional passive components and Surface Acoustic Wave (SAW) filters are integrated side-by-side. A systematic investigation is carried out for the design optimization, process and reliability improvement of the package, which comprises several aspects: a design study based on the 3D thermo-mechanical finite element analysis of the packaging, the determination of stress, warpage distribution, critical failure zones, and the figuration of the effects of material properties, process conditions on the reliability of package. The optimized material sets for manufacturing process were determined which can reduce the number of testing samples from 75 to 2. In addition the molded underfilling (MUF) process is proposed which not only saves one manufacturing process, but also improves the thermo-mechanical performance of the package compared with conventional epoxy underfilling process. In the end, JEDEC's moisture sensitivity test, thermal cycle test and pressure cooker tests have also been carried out for reliability evaluation. The test results show that the optimized ultra-slim SiP has a good reliability performance.