• Food Engineering Progress
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• v.21 no.1
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• pp.72-78
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• 2017

The objective of this study was to investigate the effects of combinations of tofu paste and non-starch polysaccharides (NSP) on the oil uptake reduction (OTR) of deep-fat fried cake doughnuts. OTR agents were tofu paste (from grinding tofu with deionized water, followed by passage through a 60 mesh sieve), and five neutral and nine anionic NSPs. A control doughnut (without tofu paste or NSP), tofu doughnut (with tofu paste) and NSP-tofu doughnut (with tofu paste and NSP) were prepared. The moisture and total lipid (TL) content, cross-section image, color characteristic, and specific volume were measured. The tofu and NSP-tofu doughnuts exhibited higher moisture and lower TL content than the control. OTR was 10.8% for the tofu doughnut, and between 13.2% and 41.2% for the NSP-tofu doughnut. The highest OTR (41.2%) was found in the NSP-tofu doughnut with a combination of tofu paste and sodium alginate (NaA). The specific volume of the NSP-tofu doughnuts with combinations of tofu paste with NaA (2.5 mL/g), locust bean gum (2.5 mL/g), and ${\kappa}$-carrageenan (2.4 mL/g) was very close to that of the control (2.6 mL/g). Considering the OTR and specific volume of doughnuts, the combination of tofu paste and NaA would be most effective in reducing the oil uptake of doughnuts during deep-fat frying.

• 지역과문화
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• v.6 no.3
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• pp.79-105
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• 2019

In the Geumseongsan Tumulus of the Uiseong area where the Jomunguk was existed in the Three Han Period, many relics such as metal craft ornaments and Uiseong-style earthernware were excavated. However, it is hard to find cases where the excavated relics were used to develop cultural products. In this study, symbolic relics which can express the culture of Uiseong Jomunguk were selected from excavated relics. Then, the basic design that can be applied to various cultural products were derived from symbolic relics. In order to select symbolic relics, the formative characteristics of the metal craft relics excavated from the Tablili Tumulus and the Dali Tumulus were examined. As a result, a gilt-bronze crown excavated from the Tablili Tumulus was selected as a symbolic relics. And then the basic desin was derived from the gilt-bronze crown. The basic design is expressed in the form of birds based on the bird's feather shape at the edge of the standing ornaments and the record of the Bongdae(鳳臺), the phoenix's habitat. And the application design that changed the expression of the birds' face was presented. The earthenware excavated from the Uiseong area was designed as a soil pot and applied various indoor air purification plants. The result of this study, which reinterprets and reconstructs the historical and cultural resources of the region in accordance with the modern sense, can be used as useful data for the development of cultural products of Jomunguk. Furthermore, if the design derived from the Jomunguk relics is used as a representative symbol of the area, it will be possible to derive an image of a differentiated region from other regions. Finally, it is expected that the result of this study will be a chance to re-evaluate the value of the historical and cultural resources in the region.

• Applied Chemistry for Engineering
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• v.31 no.1
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• pp.73-83
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• 2020

As electronic devices become more advanced and smaller, one of the biggest problems to solve is the heat affecting the efficiency and lifetime of instruments. High thermal conductivity materials, in particular, metal or ceramic ones, have been used to reduce the heat generated from devices. However, due to their low mechanical properties and high weight, thermally conductive composites composed with polymers having a light-weight and good mechanical properties as a matrix and carbon materials having high thermal conductivity as a thermally conductive filler have been attracting great attention. To improve the thermal conductivity of the composites, a phonon scattering must be suppressed to move phonon effectively. In this review, we classified researches related to phonon migration and scattering inhibition of carbon/polymer composites, and discussed various methods to improve thermal conductivity.

• Journal of Life Science
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• v.29 no.1
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• pp.76-83
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• 2019

In this study, the optimal growth and poly(3-hydroxybutyrate) (PHB) biosynthesis of Pseudomonas sp. EML2 were established using waste frying oil (WFO) as a cheap carbon source. The fatty acid composition of WFO and fresh frying oil (FFO) were analyzed by gas chromatography. The unsaturated and saturated fatty acid contents of the FFO were 82.6% and 14.9%, respectively. These contents changed in the WFO. The compositional change in the unsaturated fatty acid content in the WFO was due to a change in its chemical and physical properties resulting from heating, an oxidation reaction, and hydrolysis. The maximum dry cell weight (DCW) and PHB yield (g/l) of the isolated strain Pseudomonas sp. EML2 were confirmed under the following culture conditions: 30 g/l of WFO, 0.5 gl of $NH_4Cl$, pH 7, and $20^{\circ}C$. Based on this, the growth and PHB yield of Pseudomonas sp. EML2 were confirmed by 3 l jar fermentation. After the cells were cultured in 30 g/l of WFO for 96 h, the DCW, PHB content, and PHB yield of Pseudomonas sp. EML2 were 3.6 g/l, 73 wt%, and 2.6 g/l, respectively. Similar results were obtained using 30 g/l of FFO as a carbon source control. Using the FFO, the DCW, PHB content, and PHB yield were 3.4 g/l, 70 wt%, and 2.4 g/l, respectively. Pseudomonas sp. EML2 and WFO may be a new candidate and substrate, respectively, for industrial production of PHB.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.331-338
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• 2014

Myxococcus stipitatus KYC4013 extract exhibited the most potent antifungal activity among the extracts of 207 Myxococcus strains isolated in Korea. High-resolution LC-MS analysis revealed that M. stipitatus KYC4013 produces five antifungal substances and three other secondary metabolites that were predicted to be melithiazol and phenalamide derivatives, respectively. The putative melithiazol derivatives were best produced in CYS medium and the putative phenalamide derivatives were best produced in VY3 medium.

• Korean Chemical Engineering Research
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• v.49 no.4
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• pp.400-404
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• 2011

Many studies on polydiacetylene(PDA) have been investigated to apply to chemical and biological sensors due to their unique optical properties of color change from blue to red and fluorescence change from non-fluorescence to red fluorescence. Especially, high sensitivity against specific molecules is very important to apply polydiacetylenes to various sensors. In this study, we examined the effect of sensitivity enhancement of 10,12-pentacosadynoic acid(PCDA) vesicles in detection ${\alpha}$-cyclodextrin(CD) according to control of vesicle size by filters with different pore sizes and polymerization temperature. Colorimetric response(CR) was calculated using visible spectrometer. In order to investigate the effect of vesicle size on sensitivity of PDA vesicles, two PCDA vesicles were filtered without filtration and with 0.22 ${\mu}m$ filter. The two PCDA vesicles were polymerized at $25^{\circ}C$ and were incubated with ${\alpha}$-CD(5 mM) for 30 min. The CRs of the former and latter vesicles were 31.4% and 74.0%, respectively. Then, two PCDA vesicles filtered with 0.22 ${\mu}m$ filter were polymerized at $25^{\circ}C$ and $5^{\circ}C$ and were reacted with ${\alpha}$-CD(5 mM) for 30 min to examine the effect of polymerization temperature. The CRs of the former and latter vesicles were 74.0 and 99.2%, respectively. This suggests that vesicle sizes and polymerization temperature are key factors in enhancing the sensitivity of PDA vesicles. In addition, these results are expected to be useful to apply the PDA vesicles as biosensors to detect DNA, protein, and cells.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.2
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• pp.113-119
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• 2022

In order to improve the mechanical reliability of next-generation electronic devices including flexible, wearable devices, a high level of mechanical reliability is required at various flexible joints. Organic adhesive materials such as epoxy for bonding existing polymer substrates inevitably have an increase in the thickness of the joint and involve problems of thermodynamic damage due to repeated deformation and high temperature hardening. Therefore, it is required to develop a low-temperature bonding process to minimize the thickness of the joint and prevent thermal damage for flexible bonding. This study developed flexible laser transmission welding (f-LTW) that allows bonding of flexible substrates with flexibility, robustness, and low thermal damage. Carbon nanotube (CNT) is thin-film coated on a flexible substrate to reduce the thickness of the joint, and a local melt bonding process on the surface of a polymer substrate by heating a CNT dispersion beam laser has been developed. The laser process conditions were constructed to minimize the thermal damage of the substrate and the mechanism of forming a CNT junction with the polymer substrate. In addition, lap shear adhesion test, peel test, and repeated bending experiment were conducted to evaluate the strength and flexibility of the flexible bonding joint.

• Journal of Life Science
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• v.28 no.11
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• pp.1339-1346
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• 2018

In Korea, edible mushrooms are produced largely on commercial artificial media, so the annual production of spent mushroom substrate (SMS), as a by-product of the mushroom industry, is estimated at over 200 million tons. This SMS is assumed to contain abundant fungal mycelia and pre-fruiting bodies, as well as various nutritive and bioactive compounds that are presently discarded. This study examined the physico-chemical, nutritional, and enzymatic characteristics of uninoculated sterilized medium (USM) and SMS of shiitake mushrooms with the aim of developing a high-value added product from SMS. The contents of crude protein, crude lipid, and ash were higher after the third SMS harvest ($SMS-A-3^{rd}$) than in USM or $SMS-A-1^{st}$. The contents of Ca, Mg, and P in $SMS-A-3^{rd}$ were 2.95, 2.35, and 2.1-fold higher compared than in USM. No As or Cd was detected in USM or SMS. The pH, Brix, and acidity were 4.6, 20.0, and 1.4, respectively in $SMS-A-3^{rd}$, but 5.6, 6.0, and 0.0, respectively, in USM. These results suggest a highly active production of soluble components and organic acids in $SMS-A-3^{rd}$. The distinct color differences noted for USM, $SMS-A-1^{st}$, and $SMS-A-3^{rd}$ could be used as a mycelial growth indicator. Enzyme activity assays using the APIZYM system showed that SMS is a potent source of hydrolysis-related enzymes, especially esterase (C4) and ${\beta}$-glucuronidase. Our results suggested that the SMS of shiitake has a high potential for use in environmental, agricultural, and stock-breeding industries, for example, as active ingredients for sewage treatment, waste-polymer degradation, and feed additives.

• Clean Technology
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• v.13 no.4
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• pp.293-299
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• 2007

Direct coating of catalyst layer on the $Nafion^{(R)}$ membrane has been optimized in the process of fabrication of membrane electrode assembly (MEA) to enhance the performance of direct methanol fuel cell (DMFC). In this method, the contact resistance at the interface of the catalyst layer and the membrane was found to be low. The effect of catalyst loading, thickness of membrane and the gas diffusion layer (GDL) with or without the presence of micro-porous layer (MPL) on the performance of the MEA was also investigated. The MEA fabricated by the above-mentioned method exhibited a performance of $147\;mW/cm^2$ and $100\;mW/cm^2$ at $80^{\circ}C$ and $60^{\circ}C$, respectively, with the catalysts loading of $4\;mg/cm^2$.

• The Korean Journal of Food And Nutrition
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• v.16 no.4
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• pp.430-436
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• 2003

Coating treatment with 120 kDa of chitosan on bread was decreased growth rate of bacteria and not detected growth of any fungi during storage period. Bread with coating by 1% and 2% of 120 kDa chitosan have had the high antioxidant. Change in the water content was lawered as the higher concentration of chitosan coating on bread. water activity has a low variance untill 2% of chitosan concentration and so there result are expected on inhibition effect of retrogradation in bread during storage period. The change of pH was not detected in bread. And the color of bread have not effected on treatment with below 2% of chitosan but had a little effect by 2% of chitosan coating.