• The Korean Journal of Community Living Science
• /
• v.26 no.3
• /
• pp.447-456
• /
• 2015

To develop functional bread and improve the quality of gluten-free bread, this study investigates the quality characteristics of gluten-free rice bread made from soft-type rice (Bodeurami) flour mixed with black rice at different levels (0%, 10%, 20%, 30%, and 40%, w/w). An increase in the mix level of black-rice flour increased the weight of rice bread but reduced its volume, baking loss, volume expansion, and specific volume. The results for Hunter's color value and texture measurements indicate that an increase in the content of black-rice flour reduced the L-value, the b-value, hardness, gumminess, and chewiness but increased the a-value, adhesiveness, and springiness. According to the sensory analysis, rice bread formulated with a mixture of soft-type rice flour (80%) and black-rice flour (20%) showed the highest scores in color, taste, texture, and overall preferences. With respect to flavor and appearance, bread samples with 20% and 30% black-rice flour were preferred to those with 0%, 10%, and 40% black-rice flour. These results suggest that gluten-free rice bread mixed with wet-milling rice flour and black-rice flour can be used to develop functional and gluten-free bread.

• Composites Research
• /
• v.24 no.5
• /
• pp.9-16
• /
• 2011

This paper describes the crashworthiness evaluation and performance improvement of tilting train made of sandwich composites. The applied sandwich composite of carbody structure was composed of aluminum honeycomb core and glass/epoxy & carbon/epoxy laminate composite facesheet. Crashworthiness analysis of tilting train was carried out using explicit finite element analysis code LS-DYNA 3D. The 3D finite element model and 1D equivalent model were applied to save the finite element modeling and calculation time for crash analysis. The crash conditions of tilting train were conducted according to four crash scenarios of the Korean railway safety law. It found that the crashworthiness analysis results were satisfied with the performance requirements except the crash scenario-2. In order to meet the crashworthiness requirements for crash scenario-2, the stiffness reinforcement for the laminate composite cover and metal frames of cabmask structure was proposed. Consequentially, it has satisfied the requirement for crash scenario-2.

• Journal of Korean Society of Forest Science
• /
• v.17 no.1
• /
• pp.17-22
• /
• 1973

A study on the wood quality from planted Pinus koraiensis Sieb. et Zucc. has been undertaken by the University Forest in order to gain results of the gross structural features of stem. For this study some groups of trees were felled and several characteristics such as the degree of stem, slenderness, eccentric growth, heartwood diameter, height of butt sweep and butt-swell were analyzed. The results of the study are as follows. 1) The relation between diameter of log and its height in sample trees are nearly parallel to each other. But their degrees of slenderness in logs cut from intermediate and codominant trees are some what gentle as compared with that of logs from dominant tree. 2) The eccentric growth at transverse section of sample trees is generally decreased with the increase of tree height on all sample trees. 3) On the eccentric growth at transverse section of tree, a rather distinct tendency was noticed that all of sample trees showed the direction of eccentric growth in $R_2$ side. 4) Heartwood diameter appeares to become larger as tree growth decrease under same diameter of logs and log diameter in which heartwood appeares is larger in rapid growth rate trees. 5) The maximum height of butt-sweep generally shows that the larger the breast height diameter of tree is, the smaller its height becomes. On the contrary it was noticed that the larger the breast height diameter of trees, the higher the maximum height of butt-swell became. The direction of butt-sweep and butt-swell were shown in $R_1$ side in all sample trees.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.41 no.10
• /
• pp.820-826
• /
• 2013

In this paper, a compact and wideband CLAS(Conformal Load bearing Antenna Structure) was studied using smart skin technique. In order to satisfy the electrical performance of the CLAS antenna, the proposed CLAS antenna is composed of conductive mesh, face-sheet, radiator, honeycomb, housing. Especially, radiator is composed of composite magneto-dielectric material and radiating element etched on the PCB (Printed Circuit Board). The radiating element is inserted into the composite magneto-dielectric material and has sloted Folded LP(Log Periodic) structure. By fabricated composite magneto-dielectric, the resonance frequency is decreased and the impedance matching characteristics is improved. We verified that the antenna has wideband characteristics and compact size using the antenna test results.

• Korean Journal of Environmental Agriculture
• /
• v.3 no.2
• /
• pp.23-29
• /
• 1984

Agricultural soil samples collected from 121 sites (plastic film house 59, up-land 30 and orchard 32 sites) were evaluated by steam distillation and GLC-ECD analysis for organochlorine pesticides (${\gamma}-BHC$, heptachlor, p,p'-DDE, dieldrin, p,p'-DDD, and p,p'-DDT) in Jeollanam-Do area. Total residues of organochlorine pesticide in orchard, plastic film house and up-land were 0.415, 0.234 and 0.156ppm, respectively. Ninety-four percent of total residue was p,p'-DDT and its homologues (p,p'-DDE and p,p'-DDD). ${\gamma}-BHC$ was detected in all soil samples at $trace{\sim}0.050ppm$ range. Residue levels of organochlorine pesticide increased in the order of p,p'-DDE, ${\gamma}-BHC$, heptachlor, dieldrin, p,p'-DDT and p,p'-DDD.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.30 no.7
• /
• pp.44-50
• /
• 2002

Low-velocity impact on composite sandwich panel has been investigated. Contact force is computed from a proposed modified Hertzian contact law. The Hertzian contact law is constructed by adjusting numerical value of the exponent and reducing the through-the- thickness elastic constant of honeycomb core. The equivalent transverse elastic constant is calculated from the rule of mixture. Nonlinear equation to calculate the contact force is solved by the Newton-Raphson method and time integration is done by the Newmark-beta method. A finite element program for the low-velocity impact analysis is coded by implementing these techniques and an 18-node assumed strain solid element. Behaviors of composite sandwich panels subjected to low-velocity impact are analyzed for various cases with different geometry and lay-ups. It has been found that the present code with the proposed contact law can predict measured contact forces and contact times for most cases within reasonable error bounds.

• Journal of the Korean Wood Science and Technology
• /
• v.25 no.1
• /
• pp.15-22
• /
• 1997

The effectiveness of presteaming for improving CCA treatability on refractory Japanese larch heartwood was investigated in this study. Presteaming was effective on improving treatability, and the extent of improvement was dependent on moisture contents of wood specimen and steaming conditions. Green wood showed higher average value in both preservative retention and penetration than dry wood, and steaming under pressure conditions also had higher treatability than steaming at atmospheric conditions. The degree of improvement for treatability was increased with the extension of steaming period. Treatability of dry wood pres teamed under pressure conditions more than 6 hours and green wood for 3 hours was similar to that enhanced by conventional incising. Presteaming green wood under pressure conditions more than 6 hours was more effective than conventional incising in improvement of CCA treatability, and resultant treatability satisfied a minimum value required for CCA-treated wood for being used at the regions of hazard class H3 and H4. In addition, an improvement of treatability by presteaming was due to an increase in permeability resulted from the degradation of hemicelluloses within aspirated pit membrane and cell wall, not the removal of extractives from pit membrane. The reduction in strength, measured as longitudinal compressive strength, due to pres teaming was related with the degradation of hemicelluloses, and was increased as steaming conditions were severe. The degree of strength reduction associated with presteaming treatment to obtain required treatability could be quantified from the relatively good relation between the increase in treatability and the decrease in strength.

• Fire Science and Engineering
• /
• v.29 no.6
• /
• pp.84-90
• /
• 2015

Multi-layered material (sandwich panel) consists of double-sided steel plate which is incombustible material or similar material and core material which is not incombustible material. In case of sandwich panel which uses combustible material as insulation, flames spread inside the steel plate at the time of fire so that it is difficult to extinguish fire from the outside and flames spread rapidly and may cause the building to collapse. The current Building Act requires the sandwich panel to secure fire-retardant performance according to the purpose and size of building. In this study, the fire spreading prevention structure applied to partial exterior walls was applied to multi-layered material and its effect was measured through full scale fire test and the possibility to secure fire safety of buildings by applying the fire spreading prevention structure to multi-layered material in future was presented.

• Journal of the Korean Wood Science and Technology
• /
• v.36 no.4
• /
• pp.52-57
• /
• 2008

In this study, the effects of carbonization temperature on the physico-chemical properties of porous wood charcoal are studied by FT-IR and Raman spectroscopies. IR studies showed that cellulose and hemicellulose are mostly decomposed in the precarbonization stage at $500^{\circ}C$, while the decomposition reaction of relatively more stable lignin lasts up to $700^{\circ}C$. Above $900^{\circ}C$, the peak at $1575cm^{-1}$ disappears and a new peak at $1630cm^{-1}$, which seems to be related to the new carbon deposit phase, is evolved. The results of Raman studies, which show the red-shift of D-band and the increase in the relative intensity of D- to G-band, indicate that the size of the crystalline becomes smaller with increasing the carbonization temperature.

• Korean Journal of Medicinal Crop Science
• /
• v.26 no.3
• /
• pp.233-239
• /
• 2018

Background: Inflammation plays an important role in various diseases, including ulcerative colitis, Behcet's disease, and rheumatoid arthritis. In this study, we investigated the anti-inflammatory effects of Morus alba L. extracts obtained using different extraction methods (water extraction or high temperature extraction) on RAW264.7 cells. Methods and Results: Extracts from the central part (including the heartwood, sapwood, cambiun, and phloem) and bark (including the periderm and cortex) of Morus alba L. were obtained using either water or high temperature extraction. The following extract were obtained: MA1, water extract from the central part of Morus alba L., MA2, high temperature extract from the central part of Morus alba L., MA3, water extract from the bark of Morus alba L., and MA4, high temperature extract from the bark of Morus alba L. None of these extracts was observed to be cytotoxic to RAW264.7 cells. The MA2 extract reduced the production of LPS-induced NO (nitric oxide), $PGE_2$ (prostaglandin $E_2$), $TNF-{\alpha}$, IL-6, and $IL-1{\beta}$ production in LPS-stimulated RAW264.7 cells. Conclusions: These results indicated that the inflammatory response was moderated by MA2. Treatment with MA2 could be used as a natural medicine for treating diseases involving inflammation. However, further experiments are required to determine how the high temperature extraction method alters the active ingredients in the extract and influences the anti-inflammatory effects of Morus alba L..