• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.3
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• pp.81-87
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• 2014

Conditions of paper manufacturing process should be changed depending on the end use and paper properties. Most of the case, mixed pulps with long softwood fibers and short hardwood fibers are used to achieve proper qualities of product with reasonable production cost. For specialty paper manufacture the wood pulp and cotton linter pulp are usually mixed together. The objectives of this study is to analyze physical, mechanical and fracture mechanical properties of paper depending on SwBKP, HwBKP and cotton linter pulp(CLP) mixing. When the mixing ratio of SwBKP was increased, strength properties, such as tensile, tear, and folding endurance, were also increased. When the mixing ratio of SwBKP and HwBKP was increased, stress concentration index was decreased and fracture toughness was increased.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.6
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• pp.151-157
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• 2018

In this study, we have developed a composite pressure vessel that is compact and can store refrigerant at high pressure to increase the refrigerant volume. The composite pressure vessel is made of aluminum-based duralumin, which has high rigidity and excellent elongation in the inner liner, considering the characteristics of products in the aerospace and defense industry, where the safety of the applied product is considered as a priority. High strength carbon fiber was applied to the outside. In order to evaluate the performance of the developed product, burst test and cycling test were carried out. In burst test, an excellent safety margin equivalent to 2.7 times the operating pressure was obtained. In cycling test, a stable failure mode in which 'pre-burst leak' occurs is proved and the soundness of the product is proved.

• The Korean Journal of Mycology
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• v.3 no.2
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• pp.1-6
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• 1975

Various enzymes produced by the Basidiomycetes, i.e. Pleurotus ostreatus, Pholiota nameko and Flammulina velutipes have been analysed. The purpose of the analyses is to produce a nutritious fertilizer from saw dust, sweet potato stems, corn stems and barley stems which are known as the farm product waste materials. The results of the analyses are as follows: 1. In order for P. ostreatus, Pho. nameko and F. velutipes to grow properly, the saw dust of broad-leaved trees, poplar and chestnut were mixed with sweet-potato stems, corn stems and barley straws at the ratio of $42{\sim}49\;:\;30$, and then to this mixture was added rice bran at the ratio of $18{\sim}35\;:\;30$ The following proved to be optimum conditions for the growth in this test: the parcentage of water content $60{\sim}70%$, $24{\sim}26^{\circ}C$ degrees of temperature. 2. We analyzed the fiber contained in the above materials after 20 days growth in various media. We found out that the fiber was decomposed up to $47{\sim}50%$ and polysaccharified. Lignin was decomposed up to $20{\sim}25%$ and about three times as much protein was contained in the product as in the original materials. 3. Our analyses revealed the possibility of producing concentrated feed from the crude fiber.

• The Korean Journal of Rheology
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• v.10 no.4
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• pp.217-226
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• 1998

The anisotropy caused by the fiber orientation, which is inevitably generated by the flow during injection molding of short fiber reinforced polymers, greatly influences dimensional accuracy, mechanical properties, and other quality of the final product. Since the filling stage of the injection molding process plays a vital role in determining fiber orientation, an accurate analysis of flow field for the filling stage is needed. Unbalanced filling occurs when a complex or a multi-cavity mold is used leading to development of regions where the fiber suspension is under compression. It is impossible to make an accurate calculation of the flow field during filling with the analysis assuming incompressible fluid. A mold with four cavities with different filling times was produced to compare the numerical analysis results with the experimental data. There was a good agreement between the experimental and theoretical results when the compressibility of the polymer melt was considered for the numerical simulation. The fiber orientation states for compressible and incompressible fluids were also compared qualitatively as well as quantitatively in this study.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.1
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• pp.43-59
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• 2017

This study used data from a survey of adult Korean women in their twenties to learn their current practices for wearing and purchasing tight-fit jeans available on the market as well as perceptions regarding size measurements and satisfaction levels. We then determined product sizes and pattern measurements for the type of jeans worn. This study also analyzed discrepancies in product size measurements among brands to determine whether the measurements were generally suitable for average body shapes and measurements of women in their twenties. The study results were as follows. First, the survey asked women in their twenties about current practices in wearing jeans. Many respondents answered that their preferred fit is "a perfectly snug fit" and that the most common fit style of jeans was the skinny fit. Second, we selected a test pair of jeans with an identical fiber content from brands that women prefer to wear, according to the survey results. We researched the product measurements of the size respectively labeled 27 inches for each of the 8 brands' test jeans; consequently, the results showed that there were significant differences among the brands in the product measurements of each part of jeans. Third, we analyzed the pattern measurements of 8 selected brands for each area and identified pattern characteristics by brand.

• Analytical Science and Technology
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• v.35 no.4
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• pp.169-180
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• 2022

Tomato has a limited shelf life and is highly perishable due to its high moisture content. As fruit leather, is a traditional food of Nepal, it can be beneficial to move towards value addition and diversification of the traditional product. The main aim was to analyze the nutritional values and phytochemicals of the tomato pulp and prepared leather, and sensory evaluation of prepared tomato leather. Five samples A, B, C, D and E were prepared with 80:20, 72.5:27.5, 95:5, 87.5:12.5 and 65:35 fruit pulp: sugar ratio respectively. Analysis of raw tomato pulp and all the five samples was performed. Sensory quality of the product sample A was found superior to that of other samples but chemical and phytochemical properties of product sample C was found superior than that of other prepared samples. Therefore, we had two best products, in terms of sensory properties and in terms of nutritional properties. The best product on the basis of nutrients (sample C) had acidity (%), TSS (°Bx), pH, total ash content (%), crude protein (%), crude fat (%), crude fiber (%), carbohydrate (%), vitamin C (mg/100 g), total energy (Kcal/100 g), TPC (mg GAE/g of dry extract), TFC (mg QE/g of dry extract), DPPH scavenging activity (% of inhibition) and lycopene content (mg/100 g) was found to be 3.70.1, 20 ± 0.02, 3 ± 0.1, 2.30 ± 0.05, 2.69 ± 0.04, 0.87 ± 0.02, 5.46 ± 0.01, 69.68 ± 0.02, 25.17 ± 1.25, 297.31 ± 0.01, 85.35 ± 0.02, 65.39 ± 0.02, 59.23 ± 0.03 and 98.57 ± 0.02 respectively. A tasty and nutritious product of tomato, leather can be prepared which can be more appealing to the consumer.

• Applied Biological Chemistry
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• v.46 no.4
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• pp.323-328
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• 2003

Wheat bran, a milling by-product of domestic wheat grains, containing approximately 42% of the total dietary fiber, was tested for the effects on bread-making properties. The amylograph peak viscosity and set bark values considerably decreased with increasing levels $(0{\sim}30%)$ of wheat bran. Adding wheat bran somewhat increased water absorption and showed no consistent effect on mixing time. Yeast-leavened breads were baked with wheat flour with up to 30% of the flour substituted with domestic wheat bran. Adding domestic wheat bran exerted detrimental effect on loaf volume and decreased sensory acceptability such as crust and crumb color, crumb grain, texture, and flavor. Wheat bran decreased lightness and imparted red and yellow tint. It was suggested that domestic wheat bran could be substituted for wheat flour at levels up to 15% without significantly depressing bread quality in the preparation of high-fiber bread. Crumb firmness of bread containing 15% wheat bran was significantly higher than that of the control bread (100% wheat flour) and increased rapidly at $2{\sim}3$ days during storage.

• Polymer(Korea)
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• v.38 no.6
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• pp.708-713
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• 2014

Most plastics products are being produced by injection molding process. However, mold shrinkage is inevitable in injection molding process and it deteriorates dimensional quality through deflections and warpages. Mold shrinkage depends upon the material property of resin as well as injection molding condition. In this study, material property of resin has been predicted for glass fiber reinforced polycarbonate to control the warpage, and computer simulation of injection molding has been performed using predicted property. It was observed that the deflection of part decreased by the glass fiber reinforced resin. In order to verify the validity of this method and confidence of results, experiments of injection molding were performed. The results of experiments and computer simulations showed good agreement in their tendency of deflections. Consequently, it was concluded that the method of designing the material property of resin conducted in this study can be utilized to control the dimensional accuracy of injection molded products.

• Korean Journal of Optics and Photonics
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• v.10 no.3
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• pp.248-253
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• 1999

In this paper, we have investigated a fiber type active coupler which utilizes the mode coupling between the side polished single mode optical fiber and the active multimode planar waveguide. The proposed device can be used for not only tunable wavelength filter or optical intensity modulator but also a tool for measuring optical properties of guiding material such as refractive index, birefringence, electro-optic coefficient, and thermo-optic coefficient. We gave designed and optimized a coupler structure using the BPM and fabricated the device using thermo-optic polymer as active planar waveguide overlay. The device showed that insertion loss was less then 0.5 dB, extinction ratio was -13 dB at the resonance wavelength, and the wavelength tunablity due to thermo-optic effect was -1.5 nm/$^{\circ}C$. The active coupler using thermo-optic effect can be used as a wavelength tunable filer, an optical intensity modulator and an optical sensor. pulses that are subsequently compressed by a dispersive optical fiber. Experimental results show that $sech^2$ shape pulses with a pulse width of ~14 ps and a time bandwidth product of ~0.34 are successfully generated at 10 GHz repetition rate. In contrast to other methods, such as higher order soliton compression, this approach does not depend on the optical power and thus shows promise for application to low-power lasers.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.1
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• pp.59-64
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• 2019

In recent years, the HP-CRTM method, which has the ability to produce carbon fiber-reinforce plastic composites at high speeds, has come into the spotlight in the automotive parts industry, which demands high productivity. Multi-axial carbon fabric, an intermediate material used in this HP-CRTM molding process, consists of layered fibers without crimp, which makes it better in terms of tensile and shear strength than the original woven fabrics. The NCF (non-crimp fabric) can form the layers of the carbon fiber, which have different longitudinal and lateral directions, and ${\pm}{\theta}$ degrees, depending on the product's properties. In this research, preforms were made with carbon fibers of ${\pm}45^{\circ}$ and $0/90^{\circ}$, which were lamination structures under seven different conditions, in order to create the optimal laminated structure for automobile reinforcement center floor tunnels. Carbon fiber composites were created using each of the seven differently laminated preforms, and polyurethane was used as the base material. The specimens were manufactured in accordance with the ASTM D3039 standards, and the effect of the NCF lamination structure on the mechanical properties was confirmed by a tensile test.