• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.604-609
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• 2000

This study was carried out to investigate the possibilities of adopting xanthangum, guargum and ${\kappa}-carrageenan$ as cryprotectant by examining the rheological and structural properties of dough. Results of farinography showed that water absorption, development time and mechanical tolerance index in dough with the gums increased more than those of the control. It was also found that resistance in dough with the gums increased greatly, but extensibilities were similar to that of the control, resulting in increasing R/E values in the dough with the gums through extensograph. According to amylogram, gelatinization temperature of dough was $59.5^{circ}C$ and those of the dough with the gums were $58^{circ}C$. Even though maximum viscosity of the dough was 550 B.U in the control, those were 690 B.U, 780 B.U and 760 B.U in the dough with xanthangum, guargum, and ${\kappa}-carrageenan$, respectively. The control deeply increased the pH during frozen storage but the addition of ${\kappa}-carrageenan$ and xanthangum increased the pH slightly. The dough with the gums had more stable spaces than control in the microstructure through SEM.

• Korean Journal of Food Science and Technology
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• v.42 no.6
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• pp.705-713
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• 2010

This study was carried out to investigate the physicochemical properties of bread dough with added mulberry leaf powder. The crude protein, fiber and ash contents of the mulberry leaf powder were 21.25%, 7.70% and 9.27% respectively. The mulberry leaf-mixed powder showed low lightness and redness values and high yellowness. Farinograph water absorption increased as the mulberry leaf powder content increased. Both arrival and development times of the mulberry leaf powder-added dough were longer than those of wheat flour dough. As the mulberry leaf powder content increased, the degree of weakness increased. Maximum viscosity by amylograph analysis increased gradually with the addition of mulberry leaf powder, while gelatinization temperature was not affected. Degree of extension decreased as shown in extensograph analysis with increasing content of mulberry leaf powder.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.53-58
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• 2013

The effect of baking on the physicochemical and sensory properties was investigated using a model system of sponge cakes incorporated with pine leaf powder (PLP) as a value-added food ingredient. PLP was incorporated into cake batter at 5 levels (0, 2, 4, 6, and 8%, w/w) by adding an equivalent amount based on the weight of wheat flour. After appropriate mixing, sponge cakes were baked at $170^{\circ}C$ for 30 min in an oven. The baked cakes were cooled to room temperature for 1 h prior to all measurements. The pH, moisture content, specific volume, height, volume index, and symmetry index decreased significantly with the increase in PLP content (p<0.05). On the contrary, specific gravity of the batter and baking loss increased (p<0.05). The lightness of the cakes decreased, whereas redness increased significantly with the higher amount of PLP in the formulation (p<0.05). Hardness also increased significantly (p<0.05). Both total polyphenol content and DPPH (1,1-diphenyl-2-picryl hydrazyl) radical scavenging activity increased significantly by the addition of PLP (p<0.05). The consumer acceptance test indicated that the addition of PLP up to 4% did not cause a significant unfavorable effect on the consumer acceptances in all attributes. The sponge cakes with 2-4% PLP would be recommended with respect to the overall acceptance score while taking advantage of the functional properties of PLP without sacrificing the consumer acceptability.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.4
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• pp.53-58
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• 2018

Since the scaling-down of IC devices has been reached to their physical limitations, several innovative packaging technologies such as 3D packaging, embedded packaging, and fan-out wafer level packaging (FOWLP) are actively studied. In this study the fabrication of organic-inorganic dielectric material was evaluated for the use of multi-structured redistribution layers (RDL) in FOWLP. Compared to current organic dielectrics such as PI or PBO an organic-inorganic hybrid dielectric called polysilsesquioxane (PSSQ) can improve mechanical, thermal, and electrical stabilities. polysilsesquioxane has also an excellent advantage of simultaneous curing and patterning through UV exposure. The polysilsesquioxane samples were fabricated by spin-coating on 6-inch Si wafer followed by pre-baking and UV exposure. With the 10 minutes of UV exposure polysilsesquioxane was fully cured and showed $2{\mu}m$ line-pattern formation. And the dielectric constant of cured polysilsesquioxane dielectrics was ranged from 2.0 to 2.4. It has been demonstrated that polysilsesquioxane dielectric can be patterned and cured by UV exposure alone without a high temperature curing process.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.2
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• pp.245-253
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• 2010

The reliability problems of flip chip packages subjected to temperature change during the packaging process mainly occur due to mismatches in the coefficients of thermal expansion as well as features with time-dependent material properties. Resin molding compounds like glass fiber reinforced epoxy composites used as the dielectric layer in printed circuit boards (PCB) strongly exhibit viscoelastic behavior, which causes their Young's moduli to not only be temperature-dependent but also time-dependent. In this study, the stress relaxation and creep tests were used to characterize the viscoelastic properties of the glass fiber reinforced epoxy composite. Using the viscoelastic properties, finite element analysis (FEA) was employed to simulate thermal loading in the pre-baking process and predict thermal warpage. Furthermore, the effect of viscoelastic features for the major polymeric material on the dielectric layer in the PCB (the glass fiber reinforced epoxy composite) was investigated using FEA.

• Korean journal of food and cookery science
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• v.22 no.2 s.92
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• pp.147-157
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• 2006

To improve the properties of non-waxy rice flours for baking, soaked-wet milled rice flour (SWRF) was adjusted moisture content (MC) to 30 and 50 % and heated at 50 and $70^{\circ}C$ in a shaking water bath for 6 and 18 hrs, respectively. Moisture-heat treated rice flours were investigated with regard to particle size distribution, and morphological, physicochemical and pasting properties for comparing dry and wet milled flours. The particle size of rice flour treated with 30% MC was distributed between $4-20{\mu}m\;and\;100-200{\mu}m$, like SWRF. The particles above $200{\mu}m$ in the flour were produced at higher heating temperature. By SEM, starch granules were found in the rice flours treated with 30% MC, who whereas aggregated starch granules were shown in the flours treated with 50% MC. Moisture-heat treatment using higher MC and heating temperature decreased the lightness and increased the yellowness of non-waxy rice flours. Water binding capacity of 30% moisture treated rice flour was similar to that of SWRF. In the same moisture treated rice flour, swelling power was higher, but solubility was lower at $50^{\circ}C$ than at $70^{\circ}C$. The initial pasting temperature by RVA increased after moisture-heat treatment. The peak viscosity of moisture-heat treated rice flour was higher for 30% moisture than that of the others. The rice flour treated with 30% MC and heated at $50^{\circ}C$ showed low setback and increased stability for retrogradation.

• Food Engineering Progress
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• v.15 no.4
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• pp.332-337
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• 2011

Physicochemical properties of hydroxypropylated and cross-linked (HPCL) rice starch were investigated. Dual modification of rice starch was carried out by hydroxypropylation using propylene oxide (2, 6, and 12%) and then crosslinking using phosphorus oxychloride (0.005% and 0.02%). Swelling power of dual-modified rice starch increased at lower temperature (60$^{\circ}C$) than that of native rice starch (70$^{\circ}C$). HPCL rice starch showed slightly lower solubility (1.6-6.1%) than native rice starch (2.2-13.8%). Solubility and swelling power tended to gradually increase with increasing phosphorus oxychloride contents. RVA pasting temperature (66.2-70.8$^{\circ}C$) and peak viscosity (160.6- 171.1 RVU) of HPCL rice starch were lower than that of those of native starch (71.3$^{\circ}C$, 190.4 RVU) and decreased with increasing propylene oxide concentration. DSC thermal transitions of HPCL rice starches shifted to lower temperature and show less amylopectin melting enthalpy (11.8-9.8 J/g) than that of native rice starch (11.9 J/g). Overall, physicohemical properties of HPCL rice starches were highly dependent on hydroxypropylation rather than crosslinking.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.5
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• pp.842-849
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• 2015

The purpose of this study was to determine the optimal mixing ratio of hot-air dried loquat leaf powder and optimum conditions for making Jeolpyun containing hot-air dried loquat leaf powder (LLP). Samples of Jeolpyun were prepared with different contents of hot-air dried LLP (0%, 3%, 6%, 9%, 12%) followed by analysis of chemical properties, moisture contents, color, mechanical quality characteristics, amylograph, and sensory tests. Chemical analysis showed that hot-air dried LLP consisted of 11.41% water, 8.34% crude protein, 1.90% crude fat, 7.74% crude ash, and 16.95% crude fiber, with $^{\circ}Brix$ of 2.07, and pH of 5.78. Moisture contents of samples ranged from 52.22 to 50.06%. L-value decreased with addition of hot-air dried LLP, whereas a-value increased with increasing amount of hot-air dried LLP, and no significant differences were observed regarding b-value. In the mechanical evaluation of physical properties, hardness deceased with increasing amount of hot-air dried LLP. The starting temperature amylograph of Jeolpyun was higher in samples with hot-air dried LLP than those without hot-air dried LLP. Set back was slower with increasing amount of hot-air dried LLP, an increasing amount of hot-air dried LLP made set back of Jeolpyun slower. In the sensory test, Jeolpyun with 6% hot-air dried LLP was the most preferred with less bitterness and proper softness, moisture and chewiness. Therefore, addition of 6% hot-air dried LLP to Jeolpyun made with rice flour showed the best overall preference. Based on the results of this experiment, samples with hot-air dried LLP showed slower hardening than those without hot-air dried LLP in textural changes during storage, and Jeolpyun with 6% hot-air dried LLP is expected to increase quality and preference of Jeolpyun.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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• pp.1783-1789
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• 2017

Thermostability is an important property of xylanase because high temperature is required for its applications, such as wood pulp bleaching, baking, and animal feedstuff processing. In this study, XynB from Thermobacillus composti, a moderately thermophilic gram-negative bacterium, was modified via site-directed mutagenesis (based on its 3D structure) to obtain thermostable xylanase, and the properties of this enzyme were analyzed. Results revealed that the half-life of xylanase at $65^{\circ}C$ increased from 10 to 50 min after a disulfide bridge was introduced between the ${\alpha}$-helix and its adjacent ${\beta}$-sheet at S98 and N145. Further mutation at the side of A153E named XynB-CE in the C-terminal of this ${\alpha}$-helix enhanced the half-life of xylanase for 60 min at $65^{\circ}C$. Therefore, the mutant may be utilized for industrial applications.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.325-330
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• 2001

One of the principal components of the KSTAR (Korea Superconducting Tokamak Advanced Research) tokamak structure is the vacuum vessel, which acts as the high vacuum boundary for the plasma and also provides the structural support for internal components. Hyundai Heavy Industries Inc. has performed the engineering design of the vacuum vessel. Here the overall configuration of the KSTAR vacuum vessel was briefly described and then the design methodology and the analysis results were presented. The vacuum vessel consists of double walls, several ports, leaf spring style supports. Double walls are separated by reinforcing ribs and filled with baking/shielding water. The overall external dimensions of the main body are 3.39 m high, 1.11 m inner radius, 2.99 m outer radius, and made of SA240-316LN. The vacuum vessel was designed to be capable of achieving the base pressure of $1\times10^{-8}$ Torr, and also to be structurally capable of sustaining the vacuum pressure, the electromagnetic and thermal loads during plasma disruption and bakeout, respectively. The vacuum vessel will be baked out maximum $150^{\circ}C$ by hot pressurized water through the channels formed between double walls and the reinforcing ribs. A 3-D temperature distribution and the resulting thermal loads in the vessel were calculated during bakeout. It was found that the vacuum vessel and its supports were structurally rigid based on the thermal stress analysis. The maximum electromagnetic loads on the vacuum vessel induced by eddy and halo currents resulting from the engineering plasma radial and vertical disruption scenarios have been estimated. The stress analyses have been performed based on these electromagnetic loads and the resulting stresses at he critical locations of the vacuum vessel were within the allowable stresses.