• Journal of the Korean Home Economics Association
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• v.45 no.2
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• pp.91-103
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• 2007

The purpose of this study is to investigate the types and functions of brand labels on clothing. We surveyed the materials and manufacturing methods for brand labels by visiting the label stores and label manufacturers. 200 pieces of children's wear were surveyed. The label attributes that were studied were: the number of labels, the location of the labels, the attachment system for the labels, the color of the labels, the materials used to make the labels, manufacturing methods, and the size of the labels. From this investigation a brand label was classified into a main label and a point label. The main results were: 1. Materials such as fabrics, nonwovens, leather, suede, rubber, PVC, silicone, and metals are used for brand labels. The manufacturing methods for brand labels are weaving, printing, high frequency, heating, and molding. 2. More than 54% of clothes have more than two brand labels attached. This percentage exceeds the attaching of only one brand label in rate. An inside brand label is located at a certain place. This inside label uses only fabric material reflecting inherent brand color and design. The outside brand label is located at several places with consideration of the clothes design. This label uses various materials, colors, and characters matching with the clothes. As for the size, an inside label is mainly medium in size, whereas an outside label is small. 3. A brand label is classified into a main label (first label) and a point label (second label), which are defined as follows. A main label indicates the brand name and is located inside at a certain place using an inherent brand design and a fabric material. A point label is an additional label to express brand image and is located outside at various places for decoration using various characters and design and materials.

• Elastomers and Composites
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• v.47 no.4
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• pp.282-291
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• 2012

Control of shape/volume, mechanical, optical, electrical, and chemical switching of materials by external stimuli such as light, temperature, pH, electric field, and pressure has attracted great attention. Among these materials, photo-responsive materials containing photochromic compounds such as azobenzene, spiropyran, and cinnamic acid groups have been the subject of intense interest in recent years. In this review, we describe the recent progress in the area of azobenzene containing polymer materials that can convert light energy into mechanical energy directly. Especially we focus our attention on light-driven actuators such as artificial muscle, motor, and valve. We summarize the photomechanical effects in liquid crystal elastomer, amorphous polymer, monolayer, and supramolecules containing azobenzene, respectively.

• Elastomers and Composites
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• v.45 no.1
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• pp.25-31
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• 2010

We used activated carbon (AC), activated carbon fiber (ACF) and multi-walled carbon nanotube (MWCNT) as carbon sources and titanium n-butoxide as titanium source to prepare carbon-$TiO_2$ composites. For characterization their properties, scanning electron microscopy (SEM), transmission electron microscopy (TEM), BET surface area, X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDX) were used. And the photoactivity of the carbon-$TiO_2$ composites, under UV irradiation, was tested using the fixed concentration of methylene blue (MB, $C_{16}H_{18}N_3S{\cdot}Cl{\cdot}3H_2O$) in aqueous solution. After UV irradiation for a certain time, the concentration of MB solution was determined by UV-vis absorption spectroscopy.

• Elastomers and Composites
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• v.58 no.1
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• pp.32-43
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• 2023

The worldwide use of polyurethane foam products generates large amounts of waste, which in turn has detrimental effects on the surroundings. Hence, finding an economical and environmentally friendly way to dispose of or recycle foam waste is an utmost priority for researchers to overcome this problem. In that sense, the glycolysis of waste flexible polyurethane foam (WFPF) from automotive seat cushions using different industrial-grade glycols and potassium hydroxide as a catalyst to produce recovered polyol was investigated. The effect of different molecular weight polyols, catalyst concentration, and material ratio (PU foam: Glycols) on the reaction conversion and viscosity of the recovered polyols was determined. The obtained recovered polyols are obtained as single or split-phase reaction products. Besides, the foaming characteristics and physical properties such as cell morphology, thermal stability, and compressive stress-strain nature of the regenerated flexible foams based on the recovered polyols were discussed. It was observed that the regenerated flexible foams displayed good seating comfort properties as a function of hardness, sag factor, and hysteresis loss compared to the reference virgin foam. With the growing demand for a sustainable and circular economy, a global valorization of glycolysis products from polyurethane scraps can be realized by transforming them into profitable substances.

• Elastomers and Composites
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• v.58 no.1
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• pp.44-56
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• 2023

Additive manufacturing (AM) or three-dimensional (3D) printing of metals has been drawing significant attention due to its reliability, usefulness, and low cost with rapid prototyping. Among the various AM technologies, fused deposition modeling (FDM) or fused filament fabrication is receiving much interest because of its simple manufacturing processing, low material waste, and cost-effective equipment. FDM technology uses metal-filled polymer filaments for 3D printing, followed by debinding and sintering to fabricate complex metal parts. An efficient binder is essential for producing polymer filaments and the thermal post-processing of printed objects. This study involved an in-depth investigation of and a fabrication route for a novel multi-component binder system with steel alloy powder (45 vol.%) ranging from filament fabrication and 3D printing to debinding and sintering. The binder system consisted of polyvinyl pyrrolidone (PVP) as a binder and thermoplastic polyurethane (TPU) and polylactic acid (PLA) as a carrier. The PVP binder held the metal components tightly by maintaining their stoichiometry, and the TPU and PLA in the ratio of 9:1 provided flexibility, stiffness, and strength to the filament for 3D printing. The efficacy of the binder system was examined by fabricating 3D-printed cubic structures. The results revealed that the thermal debinding and sintering processes effectively removed the binder/carrier from the cubic structures, resulting in isotropic shrinkage of approximately 15.8% in all directions. The scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) patterns displayed the microstructure behavior, phase transition, and elemental composition of the 3D cubic structure.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.6
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• pp.65-71
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• 2010

The aim of the study intends to investigate wearing practice of personal protective equipment for firefighter in gyeongnam province and to provide the base data for the safety and health of firefighter. The results of the study are as follows. The overall reliability of fire personal protection equipment has been investigated by 3.19 and an overall improvement in the personal protective equipment is needed. Firefighter showed such a low satisfaction leather fire boots(2.68), glove(2.67) and rubber fire boots(2.59) in personal protective equipment and rubber fire boots(2.75), glove(2.77) and leather fire boots(2.97) has been investigated by the state of the poor. For personal protective equipment, firefighters have been experiencing many difficulties on the fit and weight. To overcome this problem, it is necessary to be designed ergonomically and to develop high-performance, lightweight materials.

• Elastomers and Composites
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• v.36 no.4
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• pp.237-245
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• 2001

A study was made on the chemical treatment of silica and silane coupling agents, bistriethox ysilylpropyltetrasulfide(Si 69) and ${\gamma}$-mercaptopropyltrimethoxy silane (MPS) for reinforcement of silica formulation. The effects of chemical treatment method and the most popular two coupling agents were examined. The results clearly indicate that the wet method, coupling agent is combined chemically with the silica prior to mixing, has more dispersion, wetting ability, dynamic properties and stability than the dry method, coupling agent is premixed directly with the silica. The mixing was done using a bench-type kneader having two mixing cam and a two-roll mill, under approximately similar conditions. The physical properties of SBR vulcanizates give rise to marked improvements by addition of Si 69 and MPS in comparison with without silane coupling agents. The optimum amount of Si 69 and MPS was 2 w/w% by experiments in the dry method but was 4 w/w% by EA and TGA analysis in the wet method.

• The Journal of Advanced Prosthodontics
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• v.5 no.3
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• pp.234-240
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• 2013

PURPOSE. This study evaluated the effectiveness of various methods for removing provisional cement from implant abutments, and what effect these methods have on the retention of prosthesis during the definitive cementation. MATERIALS AND METHODS. Forty implant fixture analogues and abutments were embedded in resin blocks. Forty cast crowns were fabricated and divided into 4 groups each containing 10 implants. Group A was cemented directly with the definitive cement (Cem-Implant). The remainder were cemented with provisional cement (Temp-Bond NE), and classified according to the method for cleaning the abutments. Group B used a plastic curette and wet gauze, Group C used a rubber cup and pumice, and Group D used an airborne particle abrasion technique. The abutments were observed using a stereomicroscope after removing the provisional cement. The tensile bond strength was measured after the definitive cementation. Statistical analysis was performed using one-way analysis of variance test (${\alpha}$=.05). RESULTS. Group B clearly showed provisional cement remaining, whereas the other groups showed almost no cement. Groups A and B showed a relatively smooth surface. More roughness was observed in Group C, and apparent roughness was noted in Group D. The tensile bond strength tests revealed Group D to have significantly the highest tensile bond strength followed in order by Groups C, A and B. CONCLUSION. A plastic curette and wet gauze alone cannot effectively remove the residual provisional cement on the abutment. The definitive retention increased when the abutments were treated with rubber cup/pumice or airborne particle abraded to remove the provisional cement.

• Composites Research
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• v.16 no.2
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• pp.18-25
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• 2003

The tensile properties of short nylon6 fiber reinforced NR and SBR have been investigated as functions of fiber aspect ratio(AR), diameter ratio(DR), interphase condition, and fiber content. The tensile strength increased with increasing fiber AR(20 min.) and good interphase conditions. The short-fiber(DR=3 and AR=20 min.) reinforced SBR did not show the dilution effect for all interrhase conditions. And the short-fiber(DR=3 and AR=20min.) reinforced NR did not show the dilution effect except for the no-coating. The tensile moduli were significantly improved due to fiber AR. fiber content, and good interphase at same DR. The better interphase condition showed the higher pull-out force at same DR. Also, the stress analysis near the fiber end carried out using axisymmetric FEA to be convinced of the reinforcing mechanism. It is found that the fiber AR, interphase and DR have an important effect on tensile properties.

• Journal of radiological science and technology
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• v.33 no.2
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• pp.121-126
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• 2010

Traditionally, lead has been primarily used to shield the radiation in the hospital, because of its soft texture, durability and cost effectiveness. However, lead can be dangerous because of its toxicity when exposed to the human body, and it is classified as a heavy metal like cadmium, mercury, and arsenic etc. In order to compensate its noxious properties on the human body, researchers are trying to develop a radiation shield which has similar shielding efficiency and can also be manufactured in any form. In this study, sulfuric acid barium was mixed with fiber, rubber, and silicon all of which are harmless to the human body, tested, and evaluated for its ability of medical radiation shield. The result of this study showed that the sheet containing silicon and barium has the strongest shielding abilities.