• Fashion & Textile Research Journal
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• v.1 no.2
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• pp.154-159
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• 1999

In this study, for different test methods of the performance of sewing threads were used to evaluate the sewability of 10 different industrial threads. Sewability evaluations related to the breakage of thread during sewing operation were investigated by seam length and fabric thickness method (Test 1), thread tension method (Test 2), strength retention method (Test 3), and backward sewing method(Test 4), and discussed. Two of the methods, Test 1 and Test 2, simulated very harsh sewing conditions which each thread could accept as an evaluation of its sewability. Core spun thread ranked with the best sewability generally and followed by air jet textured (ATY) thread. Spun thread was superior to the filament thread in sewing thread type. In general, there was a high degree of correlation in the results of Test 1 and Test 2. The order of sewing thread by sewability test 1 was polyester spun thread, cotton thread, and p/c core spun thread. The order of sewing thread by test 2 was polyester spun thread, and p/c core spun thread. Cotton threads and cotton blended threads performed better in Test 3, and ATY threads and core spun threads in Test 4.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.8
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• pp.1141-1149
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• 1998

Tencel fabrics were treated with NaOH, mechanically prefibrillated, and hydrolyzed by cellulase. Softner was applied to improve hand of the treated Tencel fabrics after prefibrillation and cellulase treatment. Kawabata's Evaluation System for Fabrics(KES-FB) was used to evaluate effects of NaOH pretreatment, prebifrillation, and cellulase and softner treatments on fabric hand of the treated fabrics. Primary hand values of women's medium thick fabrics such as KOSHI, NUMERI, FUKURAMI, and SOFUTOSA, and total hand values were evaluation parameters. As the treatments of prefibrillation, cellulase, and softner progressed, values in bending and shearing properties decreased and softness and elasticity were imparted to the treated fabrics. Specifically, compressional linearity, compressional energy, and thickness of the treated fabrics increased by prefibrillation, providing bulkiness to the treated fabrics. Values indicating surface properties increased owing to fibrils formed by prefibrillation treatment, but removal of fibrils by cellulase treatment enhanced smoothness. As the fabrics were exposed to various treatments such as NaOH pretreatments, prefibrillation, and cellulase and softner treatments, NUMERI, FUKURAMI, SOFUTOSA, and total hand values increased with the exception of KOSHI, Consequently, the treated fabrics became softer, smoother, and more elastic. Especially, the NaOH pretreatment provided superior SOFUTOSA to Tencel fabrics.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.8
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• pp.870-879
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• 2007

In this study, various damage modes in bending unimorph piezoelectric composite actuators with a thin sandwiched PZT plate during bending fracture tests have been evaluated by monitoring acoustic emission (AE) signals in terms of waveform and peak frequency as well as AE parameters. Three kinds of actuator specimens consisting of woven fabric fiber skin layers and a PZT ceramic core layer are loaded with a roller and an AE activity from the specimen is monitored during the entire loading using an AE transducer mounted on the specimen. AE characteristics from a monolithic PZT ceramic with a thickness of $250{\mu}m$ are examined first in order to distinguish different AE signals from various possible damage modes in piezoelectric composite actuators. Post-failure observations and stress analyses in the respective layers of the specimens are conducted to identify particular features in the acoustic emission signal that correspond to specific types of damage modes. As a result, the signal classification based on waveform and peak frequency analyses successfully describes the failure process of the bending piezoelectric composite actuator exhibiting diverse failure mechanisms. Furthermore, it is elucidated that when the PZT ceramic embedded actuators are loaded mechanical bending loads, the failure process of actuator specimens with different lay-up configurations is almost same irrespective of their lay-up configurations.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.3
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• pp.468-486
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• 2017

In this study, three kinds of wearable fashion prototypes were developed using 3D printers with the goal of developing a practical production method for daily clothes. Prototypes were modeled using Rhinoceros software and developed using FDM 3D printers and TPU filaments. The results of this study are as follows. First, it confirmed the possibility of FDM-type entry-level 3D printers as a tool to develop wearable fashion products. Second, TPU filaments that are soft and ductile are highly likely to be used as a clothing material. Third, patterns designed through the 3D modeling process can be sampled directly to a 3D printer and easily corrected and supplemented. Fourth, it was confirmed that TPU prints of about 1.00mm thickness can be sewn with fabric using sewing machines through the development of 'Prototype 1' and 'Prototype 2'; in addition, hand stitching is also possible. Fifth, as in the case of 'Prototype 3', it is possible to fabricate a garment fit enough to the body if the clothing configuration is designed to connect the basic module using TPU filaments. In the future, the development of wearable fashion prototypes using various materials and 3D printing technology will help diversify everyday clothes.

• Advances in concrete construction
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• v.13 no.5
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• pp.367-376
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• 2022

Theoretical study of vibration distinctiveness of rotating cylindrical are examined for three volume fraction laws viz.: polynomial, exponential and trigonometric. These laws control functionally graded material composition in the shell radius direction. Functionally graded materials are controlled from two or more materials. In practice functionally graded material comprised of two constituent materials is used to form a cylindrical shell. For the current shell problem stainless steel and nickel are used for the shell structure. A functionally graded cylindrical shell is sanctioned into two types by interchanging order of constituent materials from inner and outer side for Type I and Type II cylindrical shell arrangement. Fabric composition of a functionally graded material in a shell thickness direction is controlled by volume fraction law. Variation of power law exponent brings change in frequency values. Influence of this physical change is investigated to evade future complications. This procedure is capable to cater any boundary condition by changing the axial wave number. But for simplicity, numerical results have been evaluated for clamped- simply supported rotating cylindrical shells. It has been observed from these results that shell frequency is bifurcated into two parts: one is related to the backward wave and other with forward wave. It is concluded that the value of backward frequency is some bit higher than that forward frequency. Influence of volume fraction laws have been examined on shell frequencies. Backward and forward frequency curves for a volume fraction law are upper than those related to two other volume fraction laws. The results generated furnish the evidence regarding applicability of present shell model and also verified by earlier published literature.

• Fashion & Textile Research Journal
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• v.1 no.4
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• pp.358-362
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• 1999

Twenty-three fabrics of varying thicknesses and weights were subjected to the maximum pressures of 10, 20, 35, 50 and 70 $gf/cm^2$ to yield pressure-thickness curves. Compression property values were plotted according to the amount of pressure applied to the samples. Pressure increases resulted in decreases in LC (compressional curve linearity), increases in WC (compressional energy) and no change in RC (compressional resilience). The best-fit lines are found separately according to pressures. The thickest fabrics exhibited the highest LC and WC values. The slopes varied different according to the pressure applied, with a pressure 50 $gf/cm^2$ exhibiting the steepest slope at We. The pressure of 20 $gf/cm^2$ correlated most closely with the hand-evaluation test results, yielding Spearmans correlation coefficients of .86 and .82 respectively for the LC and WC.

• Membrane Journal
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• v.9 no.1
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• pp.51-62
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• 1999

The recovery of trace volatile organic components from water by pervaporation was investigated. Permeation experiments through homogeneous polydimethylsiloxane(PDMS) membrane was carried out and the effect of feed concentrations and membrane thicknesses on the permeation characteristics were investigated. A solution-diffusion model is used to describe the pervaporation transport mechanism. In homogeneous PDMS membrane it appeared that the selectivities of MEK and toluene are constant, and that organic flux has a linear relationship with feed concentration. These results indicate that the coupling effects between organics were negligible. The selectivity of PDMS membranes is invariant with respect to the membrane thickness. The intrinsic membrane permeability of organic components determined by using a solution-diffusion model. Comparing with various composite type membrane, the membrane using PEG treated nonwoven fabric as sublayer showed the best performance in VOC recovery by pervaporation.

• Composites Research
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• v.32 no.1
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• pp.65-70
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• 2019

The aircraft composites wing parts are usually integrated with adhesive or fastener. These laminated composites have weak interlaminar strength, which can lead to delamination. In order to compensate the disadvantages of laminated composites, it is possible to improve the strength, durability, shock and fatigue resistance by reinforcing the fiber in the thickness direction. In addition, using a single structure near-net-shape saves the manufacturing time and the number of fasteners, thus can reduce the overall cost of the composite parts. In this study, compression test, tensile test and open-hole tensile test are carried out for three structural architecture of 3D (three-dimensional) textile preforms: orthogonal(ORT), layer-to-layer(LTL) and through-the-thickness(TTT) patterns. Among these, the orthogonal textile composite shows the highest Young's modulus and strength in tensile and compression. The notch sensitivity of the orthogonal textile composite was the smallest as compared with UD (unidirectional) and 2D (two-dimensional) fabric laminates.

• Journal of Mushroom
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• v.16 no.3
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• pp.231-235
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• 2018

Arthrographis cuboidea is a wood rot fungus found in soil. It causes disease in repeated cultivation areas of Ganoderma lucidum, which damage the mushroom logs and causes considerable loss of income to mushroom farmers. This study aimed to investigate the physicochemical properties of soil and characteristics of the growth environment such as the temperature of the Ganoderma lucidum cultivated land. The time required for primordia initiation was 12-13 days. In the chromaticity survey, the degree of redness (a) was 19.5 for vinyl, 20.2 for control, and 19.5 for nonwoven. The yellowness index (b) was 12.7 for vinyl, 13.3 for control, and 12.4 for nonwoven. In the study of growth characteristics, in case of no treatment (control), the length and thickness of the pileus were measured as 145.7 mm and 23.6 mm and those of the stipe were 73.9 mm and 11.5 mm, respectively, and the weight was 130 g. Treatment with non-woven fabric resulted in 157 mm and 93.3 mm long and 22.3 mm and 11.9 mm thick pileus and stipe, respectively, and the weight was 164 g. This result indicates that treatment with non-woven fabric is better than no treatment with respect to Ganoderma lucidum growth.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.3
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• pp.508-512
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• 1998

The NTC thermistors were sintered by using microwave hybrid heating method at $1100^{\circ}C$~$1300^{\circ}C$ and those electrical properties were investigated. The obtained $B_{25^{\circ}C/85^{\circ}C}$ values from temperature dependence of electrical resisitivity were around 3100~3200 K which were almost the same values as conventionally sintered ones. Compared with conventional sintering process, this process could complete whole sintering process within 20 minutes. This the processing time and energy consumption could be reduced through this rapid heating by using microwave hybrid heating.t there were showed only two peaks, glycolide melting peak and lower molecular weight melting peak without lauryl alcohol. Conversion increased slowly with the reaction time up to 50 minutes, and then gave a sudden increase above that. The reaction time to disappear in glycolide melting peak during polymerization was shortened with the increase of lauryl alcohol content. Zero-shear viscosity of polyglycolic acid decreased with the increase of free acid content in glycolide.ssional energy and bending hysteresis increased. \circled3 Surface characteristics such as friction coefficient and thickness variation of highly shrinkage fabrics became relatively roughened state. \circled4 Since stiffened and roughened characteristics of highly shrinkage fabrics, drapabilities of them were significantly lowered. Additionally thermal insulation property of high shrinkage fabric was higher than that of low shrinkage fabric due to bulky and thickened feature. From the results, it is considered that the silk fabrics with high filling shrinkage have the good bulkiness and heat keeping properties and thus they have the suitable characteristics for high quality men's and women's formal garments.