• Journal of the Korean Wood Science and Technology
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• v.27 no.1
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• pp.37-49
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• 1999

The effect of fire-retardant treatment and redrying on the mechanical properties of radiata pine sapwood were evaluated. Small, clear specimens were treated with three different fire-retardant(FR) chemicals, borax-boric acid(BRX), minalith(MIN), and pyresote(PYR), with target retentions of 30 and 60kg/$m^3$, and then redried at maximum dry-bulb temperature of $25^{\circ}C$, $60^{\circ}C$, $80^{\circ}C$ or $110^{\circ}C$. Each specimen, including untreated and water-treated controls, was tested in static bending and in compression parallel to grain. The extent of strength reduction was dependent on the type of FR chemicals, retention, and redrying temperature, and a highly significant interaction existed between FR treatment and redrying temperature. Modulus of rupture(MOR) and work to maximum load(WML) were significantly decreased by FR treatment and redrying. None of three FR chemicals adversely affect modulus of elasticity (MOE) and maximum crushing strength(MCS). MOE of BRX treatment and MCS of both BRX and PYR treatment increased significantly compared to untreated controls. No significant differences existed between retention levels except for MOE and MCS of some combinations of FR chemicals and redrying temperatures. Although MOE and MCS was not significantly affected by any of the redrying temperatures, these properties were generally decreased with the increase in redrying temperature. The significant reduction in MOR and WML was observed in BRX treatment when dried at temperatures of $60^{\circ}C$ and above, and in MIN and PYR treatment when dried at temperatures of $80^{\circ}C$ and above. Consequently, BRX-treated radiata pine should not be redried at temperatures >$60^{\circ}C$, and MIN- and PYR-treated radiata pine should not be redried at temperatures > $80^{\circ}C$ where bending strength and energy-related properties are important design considerations.

• Korean Journal of Food Science and Technology
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• v.2 no.2
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• pp.8-16
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• 1970

Exploitation of leaf protein concentrates for human consumption is very important. Leaf protein concentrates can be easily prepared by mechanically mincing leaves material and press it for getting the juice. Crude protein can be separated from the juice by aging, adjusting the pH, or heating to $75-80^{\circ}C$ etc. This report deals with the extractability of total-N from 69 species of fresh leaves by mechanical process, and then compared the recovery of leaf protein concentrates from leaf extracts by treating with TCA, pH adjustment and heating. Results are summarized as follows. 1. In general, the greater the content of total-N of leaves the greater the percentage extraction. Extraction of the juice from leaves is needed at least two times. The simple equations are constituted between the total-N (T; %) and the first and second extractability ($E_1,\;E_2;\;%$) of the total-N of leaves, as follows: $E_1=0.8168T\;E_2=0.1830T$ 2. The optimum pH value for coagulating protein from extracts is considered to be 3.5 to 4.5. However, the products of leaf protein concentrate by the pH adjustment of extracts are generally dull in color with rich elasticity. 3. Recoveries of the leaf protein concentrate from extracts by treating methods were in the following order of TCA treatment> pH 4 treatment> pH 3 treatment> heat treatment. The yield of leaf protein concentrates decreased bout 10% with pH 4 treatment, 11.4% with pH 3 treatment, and 14.8% with heat treatment compared with the TCA treatment. 4. The heat treatment is the most benifitial method for the production of leaf protein concentrates with regard to properties of texture, color and yield of products and easiness of the treatment method.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.2
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• pp.179-184
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• 2020

Elasticity and softness of the skin depend on the level of moisture present in the stratum corneum, which is known to be affected by various environmental changes, such as cold and hot winds and dry environments. However, not many studies have been conducted on changes in skin moisture and the degree of recovery due to individual skin differences. In the present study, we aimed to investigate the effect of warm air heating on skin hydration levels and develop moisturizing formulas to improve lowered skin hydration levels. In order to deliver warm air heating condition, heating dryer (40 ℃, 6 m/s, 30 cm apart from forearm) was applied into inner forearm of healthy subjects (male: 10, female: 39, age: 25 - 63) Among 49 subjects, 26 subjects showed significantly lowered skin hydration levels until 30 min after warm air heating exposure (lowered group). In addition, moisturizing cream with high water holding capacity was applied to forearm of 10 subjects in lowered group for 3 weeks and skin hydration levels after warm air heating were significantly improved at the levels of before application of warm air heating. From this study, we found out that there is a skin type that skin hydration levels are significantly decreased under warm air heating condition (dehydrated skin) and this dehydrated skin can be improved by moisturizing formulas with high water holding capacity.

• Journal of dental hygiene science
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• v.15 no.3
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• pp.259-264
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• 2015

For this experiment, specimen was manufactured by injecting polymer and monomer into silicon mold with volume ratio of 2.5:1 based on ISO 20795-2 so that average thickness, width and length of specimen would be maintained as 3.3 mm, 10.0 mm and 65.0 mm, respectively depending on spray on technique. Specimen was divided into 3 groups ($25^{\circ}C$, $40^{\circ}C$, $70^{\circ}C$) depending on polymerization temperature and 10 specimen was manufactured for each group and it was polymerized in water tank of ${\pm}1^{\circ}C$ under the setting condition of polymerization time of 15 minutes and pressure of 3 bar. After keeping specimen in distilled water of $37^{\circ}C$ for over 48 hours before experiment, flexural strength (FS) and elasticity modulus (EM) of specimen being tested by using Intron (3344; Instron; Instron). SPSS ver. 16.0 was used for analysis and post-hoc test of Scheffe was performed after using one-way ANOVA. When comparing mean value of FS of resin for orthodontics, it was represented in the range of 71.500 MPa for $25^{\circ}C$ group, 74.920 MPa for $40^{\circ}C$ group and 76.880 MPa for $70^{\circ}C$ group and difference was shown in the order of $25^{\circ}C$ group <$40^{\circ}C$ group <$70^{\circ}C$ group but such difference was not significant statistically (p=0.052). Result of EM mean value of resin for orthodontics was more polymerization temperature was high, the more was significant difference represented in the order of $25^{\circ}C$ group <$40^{\circ}C$ group <$70^{\circ}C$ group (p<0.039).

• Restorative Dentistry and Endodontics
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• v.26 no.4
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• pp.332-340
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• 2001

Flowable composite resin has lower filler content, increased flow, and lower modules of elasticity. It is suggested that flowable composite resin can be bonded to the tooth structure intimately and absorb or dissipate the stress. Therefore, it may be advantageous to use flowable composite resin for the base material of class II restoration and for the class V restoraton. The purpose of this study was to evaluate the microleakage and shear bond strength of four flowable composite resins (Aeliteflo, Flow-It, Revolution, Ultraseal XT Plus) compared to Z100 using Scotchbond Multi Purpose dentin bonding system. To evaluate the microleakage, notch-shaped class V cavities were prepared on buccal and lingual surfaces of 80 extracted human premolars and molars on cementum margin. The teeth were randomly divided into non-thermocycling group (group 1) and thermocycling group (group 2) of 40 teeth each. The experimental teeth of each group were randomly divided onto five subgroups of eight samples (sixteen surfaces). The Scotchbond Multi-Purpose and composite resin were applied for each group following the manufacturer's instructions. the teeth of group 2 were thermocycled five hundred times between 5$^{\circ}C$ and 55$^{\circ}C$. The teeth of group 2 were placed in 2% methylene blue dye for 24 hours, then rinsed with tab water. The specimens were embedded in clear resin, and sectioned longitudinally with a diamond saw. The dye penetration on each of the specimen were observed with a stereomicioscope at $\times$20 magnification. To evaluate the shear bond strength, 60 teeth were divided into five groups of twelve teeth each. The experimental teeth were ground horizontally below the dentinoenamel junction, so that no enamel remained. After applying Scotchbond Multi-Purpose on the dentin surface, composite resin was applied in the shape of cylinder. The cylinder was 4mm in diameter and 2mm in thickness. Shear bond strength was measured using Instron with a cross-head speed of 0.5mm/min. After shear bond strength measurement, mode of failure was evaluated with a stereomicroscope at $\times$30 magnification. All data were statistically analyzed by One Way ANOVA and Student-Newman-Keuls method. The correlation between microleakage and shear bond strength was analyzed by linear regression. The results of this study were as follows ; 1. In non-thermocycling group, the leakage value of Z100 was significantly lower than those of flowable composite resins at the enamel and dentin margin, margin, except that Revolution showed the lower leakage value than that of Z100 at the dentin margin (p<0.05). 2. In thermocycling group, the leakage values of Z100 and Ultraseal XT Plus were lower than those of other subgroup at the enamel and dentin margin, except that Flow-It showed the lower leakage value than that of Ultraseal XT Plus at the dentin margin (p<0.05). 3. The leakage value of Z100 and Ultraseal XT Plus in thermocycling group were not higher than that in non-thermocycling group at the enamel margin. The leakage value of Z100 in thermocycling group was not higher than that in non-thermocycling group at the dentin margin (p<0.05). 4. As for the shear bond strength measurement, there were no statistically significant differences among groups (p<0.05). The shear bond strengths given in descending order were as follows: Z100(16.81$\pm$2.98 MPa), Flow-It(14.8$\pm$4.43 MPa), Aeliteflo(14.34$\pm$3.69 MPa), Revolution(13.46$\pm$4.23 MPa), Ultraseal XT Plus(12.83$\pm$3.16 MPa). 5. Failure modes of all specimens were adhesive failures. 6. There was no correlation between microleakage and shear bond strength.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.149-157
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• 2001

The purpose of this study was to investigate the property of a new Korean stainless steel wire(Jinsung Ind.) comparing with other foreign Products. Five types of stainless steel wires (Standard, Resilient, HI-T of Unitek, Stainless steel of Ormco and Jinsung Ind.) in 0.016x0.022 and 0.019x0.02 were tested to observe for Composition analysis, size difference, tensile properties, flexure bending property, tortion property, surface hardness and surface topography by means of SEM. The findings suggest that: 1. In maximum tensile strength of tensile properties, Unitek Hi-T showed the greatest value, followed by Unitek Resilient, Jinsung Stainless Steel, Ormco Stainless Steel, Unitek Standard in 0.016x0.022, and Unitek Hi-T showed highest value, followed by Jinsung Stainless Steel, Ormco Stainless Steel, Unitek Resilient, Unitek Standard in 0.019x 0.025. 2. In elongation rate, Unitek Standard showed the greatest value, fellowed by Ormco Stainless Steel, Unitek Hi-T, Unitek Resilient, Jinsung Stainless Steel in 0.016x0.022, and Unitek Hi-T showed the highest value, followed by Unitek Standard, Ormco Stainless Steel, Jinsung Stainless Steel, Unitek Resilient in 0.019x0.025. 3. In modulus of elasticity, Jinsung Stainless Steel showed the greatest value, followed by Unitek Hi-T, Unitek Resilient, Ormco Stainless Steel, Unitek Standard in 0.016x0.022, and Unitek Resilient showed the highest value followed by Jinsung Stainless Steel, Ormco Stainless Steel, Unitek Hi-T, Unitek Standard in 0.019x0.025. 4. In bending fatigue test, Jinsung Stainless Steel showed the greatest fracture resistance, followed by Unitek Hi-T, Unitek Standard, Unitek Resilient, Ormco Stainless Steel in 0.016x0.022, and Unitek Hi-T showed the greatest fracture resistance followed by Jinsung Stainless Steel, Unitek Resilient, Unitek Standard, Ormco Stainless Steel in 0.019x0.025. 5. In twist test, Unitek Resilient showed the greatest fracture resistance, followed by Jinsung Stainless Steel, Unitek Hi-7, Ormco Stainless Steel, Unitek Standard in 0.016x0.022, and Jinsung showed the greatest fracture resistance, followed by Unitek Resilient, Unitek Standard, Ormco Stainless Steel, Unitek Hi-T. 6. In surface topography, every products showed indentation and pitting. Jinsung stainless steel wire showed long thin indentation and relatively smooth surface. Unitek wires showed indentation and pitting and Ormco wire showed a lot of irregular pittings.

• Journal of Korean Society of Forest Science
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• v.96 no.4
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• pp.455-461
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• 2007

This research was processed on morphological and physical characteristics of 'Yongdong' cultivar nuts. (1)Morphological properties of 'Yongdong' cultivar nuts were significantly different from the control, native species, in respect of all properties. (2) 'Yongdong' cultivar nuts showed higher figures than the native species on 9 items of morphological properties (kernel weight, size, length and width of pad on suture and etc.), whereas other 6 items (height of pad on suture, thickness of shell and septem, fragment numbers of isolated kernel, roundness index, and etc.) showed lower figures than those of the control. (3) In physical properties of the nut shells, 'Yongdong' cultivar was superior to the control at all items with the exception of compressive prove distance. Accordingly, it was also verified as effective cultivar of shelled walnut with suture line direction applied the minimum strength. (4) 'Yongdong' cultivar, 21.9 kg, was approximately twice lower than the control, 42.6 kg, on maximum compressive weight. It was demonstrated that the 'Yongdong' cultivar characterized by easily crushing shell by small strength was great in cracking properties. (5) On the study of yield strength, the native species being twice higher than 'Yongdong' cultivar showed the properties of the small elasticity and the shell hardness. While, the suture line of 'Yongdong' cultivar having the lowest yield strength 15.6 kg and 16.0 kg was identified the shell crushed easily. (6) The movement distance of the compressive prove of 'Yongdong' cultivar, 4.2 mm, was longer than that of the control, 2.7 mm. Subsequently, it means that the amount of loss possibly occurring to distribution process was not great, whereby productive value was high. (7) The compressive strength of the suture line of 'Yongdong' cultivar, $9.1kg/cm^2$, was much lower than total average of that $12.4kg/cm^2$. It was also statistically different with other properties. (8)The hardness examination by the compressive position revealed that the suture line of 'Yongdong' cultivar, $149.8kg/cm^2$, was lowest in contrast with the control, $300.9kg/cm^2$.

• Journal of Korean Home Economics Education Association
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• v.18 no.3 s.41
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• pp.61-79
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• 2006

The purpose of this research was to evaluate concretely how the 7th Technology Home Economics(HE) curriculum was operated In school fields by using context evaluation, input evaluation using the CIPP model focusing HE. In this research. a questionnaire survey was done targeting HE teachers in charge of technology and home economics subject for the 7th curriculum implementation at 250 randomly selected middle schools in Gpoungsangnamdo, and 109 returned questionnaire papers were used for the final analysis. The frequency, percent, mean and standard deviation of these data were obtained by using the SPSS 10.0 for Windows Program. The results of this research were outlined below: First, with a regard to the context evaluation (evaluating educational contexts), the requirement degree of seeking for career appeared to be the highest at the requirement survey of the education goal and character of HE area, and the requirement degree of elevating understanding home living' were very low. Interest and concern of students towards these subject as well as the self-confidence of HE teachers in charge were low. Second, as for the input evaluation (evaluating education plans), time allocation, content level, and content amount were not regarded to be not proper, and the composition of HE educational curriculums and the class guideline of teachers also were not so faithful from the aspect of school level. Among surveyed items, establishing plans in school level towards evaluation was relatively sincere, but discussions about curriculums were not so faithful, suggesting various kinds of content are not fully discussed. As shown by the results above, it is difficult to say that the operation of the 7th HE educational curriculums has secured its position perfectly. It is necessary to examine systematically the educational goals. character of the 7th HE educational curriculum and the appropriateness of curriculum content, and to seek various methods to elevate the self confidence of teachers and the interests of students. Because how to operate national level educational curriculums in school levels with self-regulation and elasticity will be an important variable in realizing educational goals, teachers, the main body of educational curriculums and direct performers, should establish and perform educational plans in school levels to elevated the satisfaction of teachers and educational effects for normally operating educational curriculums. In addition, educational curriculums should be operated and evaluated mainly by teachers at school fields to make it possible to confirm and check the achievement of the goals of educational curriculums qualitatively.

• Food Science and Preservation
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• v.24 no.1
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• pp.93-99
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• 2017

Collagen synthesis is decreased and matrix metalloproteinase-1 (MMP-1) levels are increased in naturally aged human skin, and these alterations cause changes such as skin wrinkling and decreased elasticity. As a part of our ongoing search for bioactive ingredients, MMP-1 inhibitory and type-1 procollagen synthesis inducing activities of aqueous methanolic extract of manufactured gambir product from Uncaria gambir were investigated in in vitro bioassay systems. In addition, total phenolic contents were quantified using a spectrophotometric method. Among tested samples, 40% MeOH eluate from 80% methanolic extract of manufactured U. gambir using open column chromatography packed with Diaion HP-20 resin showed significant MMP-1 inhibitory activities with an $IC_{50}$ value of $15.6{\pm}1.3{\mu}g/mL$. Furthermore, type-1 procollagen synthesis promoting property of 40% MeOH eluate ($IC_{50}$ value; $6.9{\pm}0.7{\mu}g/mL$) from 80% methanolic extract of manufactured gambir was higher than other eluates. Additionally, the present investigation revealed that 40% MeOH eluate of manufactured gambir product contained a high level of total phenolic compounds. The result suggests a distinct relationship between anti-wrinkle activity and total phenolic contents, and manufactured gambir product could be considered a new effective source of natural bioactive ingredients. Systematic investigation of manufactured gambir product will be performed for further development of its biological properties.

• Korean Journal of Plant Resources
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• v.24 no.4
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• pp.413-418
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• 2011

This study was carried out to establish a proper cultivation site and diagnose the drought-tolerance of Aster scaber and Synurus deltoides leaves by using Pressure-volume curves. In order to measure pressure-volume (P-V) curves, Aster scaber and Synurus deltoides were cut off above ground part and the tip of the cutting were placed in water, which was covered with a plastic bag. Samples were kept overnight (about 12 hours) in darkness at room temperature (20~25$^{\circ}C$) to achieve maximal turgor (full saturation). The pressure in the chamber was gradually increased from 0.3MPa to 1.8MPa by nitrogen gas. After measured, leaf samples were dried at 80$^{\circ}C$ for 48 hours and dry weight of each samples were determined. The result of the original bulk osmotic potential at maximum turgor ${\Psi}^{sat}_o$ sat was lower -0.8 MPa in Aster scaber leaves than -0.7 MPa Synurus deltoides leaves. Also the osmotic potential at incipient plasmolysis ${\Psi}^{tlp}_o$ in Aster scaber leave was -0.9 MPa. In contrast, the value of maximum bulk modulus of elasticity $E_{max}$ of Aster scaber leaves were approximately two folds higher than that of Synurus deltoides leaves. The values of the relative water content at incipient plasmolysis $RWC^{tlp}$ are all above 90% showing that the function of osmoregulation is somewhat better, and Vo/DW, Vt/DW, Ns/DW of Synurus deltoides leaves were approximately 1~2 times higher than that of Aster scaber leaves. Thus, responses to water relations of Aster scaber and Synurus deltoides such as ${\Psi}^{sat}_o$, ${\Psi}^{tlp}_o$, $E_{max}$, ${\Psi}_{P,max}$, $RWC^{tl}$ were shown that the Aster scaber leaves was slightly higher drought-tolerance than Synurus deltoides leaves. However, in both of Aster scaber and Synurus deltoides, occurring incipient plasmolysis at the high water content, have a relatively lower drought-tolerance property indicating that growth of these plants are cultivated appropriate in high moisture soil sites.