• Membrane Journal
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• v.14 no.1
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• pp.53-56
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• 2004

Direct Methanol Fuel Cell (DMFC) is considered as a candidate technology for applications in stationary, transportation as well as electronic power generation purposes. To develop a high performance direct methanol fuel cell(DMFC), a competent electrolyte membrane is needed. The electrolyte membrane should be durable and methanol crossover must be low. One of the approaches to increase the stability of generally used polymer electrolyte membranes such as Nafion against swelling or thermal degradation is to bond it with an inorganic material physically or chemically. In Noritake Company, we have developed a novel method of reinforcing the polymer electrolyte matrix with inorganic fibers. Methanol crossover values measured were significantly lower than the original polymer electrolyte membranes. These fiber reinforced electrolyte membranes (FREM) were used for DMFC study and stable power output values as high 160 mW/$\textrm{cm}^2$ were measured. The details of the characteristics of the membranes as well as I-V data of fuel cell stacks are detailed in the paper.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.386-387
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• 2003

Titania-silica hybrid inorganic materials are interesting subjects and many researchers have been studying.$\^$1-3)/ In general, the titania-silica hybrid materials are used as film and catalyst. Sol-gel method has widely been used as an alternative technology to prepare a wide variety of applications including monoliths, powders, coatings, and fibers.$\^$4-6)/ The typical sol-gel method is hydrolysis and condensation of tetraethyl orthosilicate (TEOS), Si(OCH$_2$CH$_3$)$_4$. (omitted)

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.2
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• pp.67-73
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• 2015

This study evaluated the effects of fibers on the void ratio, compressive strength and repeated freezing and thawing resistance of porous vegetation concrete with binder type (non-sintering inorganic binder and blast furnace slag cement) and natural jute fiber volume fraction (0.0 %, 0.1 % and 0.2 %). The natural jute fiber volume fraction affected the void ratio, compressive strength and repeated freezing and thawing resistance. Added of natural jute fiber resulted in improved properties of the void ratio, compressive strength and freezing and thawing resistance. Also, the both compressive strength and freezing and thawing resistance increased with natural jute fiber volume fraction up to 0.1 % and then decreased with fiber volume fraction at 0.2 %.

• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3206-3212
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• 2023

We developed a miniaturized multi-dimensional radiation sensor system consisting of an inorganic scintillator array and plastic optical fibers. This system can be applied to remotely obtain the radioactivity distribution and identify the radionuclides in radioactive waste by utilizing a scanning method. Variation in scintillation light was measured in two-dimensional regions of interest and then converted into radioactivity distribution images. Outliers present in the images were removed by using a digital filter to make the hot spot location more accurate and cubic interpolation was applied to make the images smoother and clearer. Next, gamma-ray spectroscopy was performed to identify the radionuclides, and three-dimensional volume scanning was also performed to effectively find the hot spot using the proposed array sensor.

• Journal of Environmental Science International
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• v.24 no.7
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• pp.927-937
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• 2015

This study was performed to identify and quantify the asbestos fibers released from two types of asbestos-cement slate roofs. One is a plant roof installed in 1987 which contained 15% chrysotile, and the other is a residential roof installed before 1983 which contained 12% chrysotile. The concentrations of asbestos fibers in air surrounding asbestos-cement slate roofs and in the falling water harvested from the same roofs on rainy days ranged from 0.0012 to 0.0018 f/mL and from 1,764 f/L to 10,584 f/L, respectively. The concentration of inorganic fibers in the soil around asbestos-cement slate roofs was from 217 to 348 f/g. With the above results, the excess lifetime cancer risk (ELCR) for the risk assessment of the asbestos fibers released from asbestos-cement slate based on US EPA IRIS (Integrated risk information system) model is within 5.5E-06 ~ 6.5E-06 levels which indicates that the levels do not exceed "the acceptable risk(1.0E-05)" recommended by WHO. The asbestos concentration in air, drained rainfall and soil around the plant slate roof was higher than that around residential slate roof, but the excess lifetime cancer risk (ELCR) from residential slate was higher than that from plant slate. This suggested that the enclose and encapsulation of residential roofs have priority in removal policy to minimize the exposure risk.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.271-272
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• 2003

Electrospinning is a novel process for forming fibers with submicron scale diameters through the action of electrical force. In the previous study, we performed study on the ultrafine PVDF nanofiber production in the stable spinning condition. Recently it would be great interest to fabricate IP(inorganic particle) assemblies in nanofibe. since such IP/nanofiber hybrid materials might be used in a nonwoven form as nanowires, medical gauges for bums healing and cell growing, sensors, chemical and gas filteration. (omitted)

• Membrane and Water Treatment
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• v.14 no.2
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• pp.85-93
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• 2023

Membrane separation is widely used for several applications such as water treatment, membrane reactors and climate change. Cross-linked organic-inorganic hybrid polyvinylidene fluoride (PVDF) / Tetraethyl orthosilicate (TEOS) was adopted for the preparation of optimized hollow membrane (HFM) for membrane distillation or other low pressure separators for mechanical properties and permeability under varying pretreatment schemes. HFMs were prepared on semi-pilot membrane fabrication system. Novel adopted post-treatment schemes involved soaking in glycerol, magnesium sulphate (MgSO₄), sodium hypochlorite (NaOCl), and isopropanol for different durations. All fibers were characterized for morphology using a scanning electron microscope (SEM), surface roughness using atomic force microscope (AFM), elemental composition by examining Energy Dispersive Spectroscopy (EDS), water contact angle (CA°) and porosity. The performance of the fibers was evaluated for pure water permeation flux (PWF). Post-treatment with MgSO₄ gave the highest both tensile modulus and flux. Assessment of properties and performance revealed comparable results with other organic-inorganic separators, HF or flat. In spite of few reported data on post treatment using MgSO₄ in presence of TEOS, this proves the potential of low cost treatment without negative impact on other membrane properties. The flux is also comparable with hypochlorite which manifests substantial precaution requirements in actual industrial use.The relatively high values of flux/bar for sample treated with TEOS, post treated with MgSO₄ and hypochlorite are 88 and 82 LMH/bar respectively.

• Journal of Adhesion and Interface
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• v.3 no.4
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• pp.44-52
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• 2002

Composite materials are created by combining two or more component to achieve desired properties which could not be obtained with the separate components. The use of reinforcing fillers, which can reduce material costs and improve certain properties, is increasing in thermoplastic polymer composites. Currently, various inorganic fillers such as talc, mica, clay, glass fiber and calcium carbonate are being incorporated into thermoplastic composites. Nevertheless, lignocellulose fibers have drawn attention due to their abundant availability, low cost and renewable nature. In recent, interest has grown in composites made from lignocellulose fiber in thermoplastic polymer matrices, particularly for low cost/high volume applications. In addition to high specific properties, lignocellulose fibers offer a number of benefits for lignocellulose fiber/thermoplastic polymer composites. These include low hardness, which minimize abrasion of the equipment during processing, relatively low density, biodegradability, and low cost on a unit-volume basis. In spite of the advantage mentioned above, the use of lignocellulose fibers in thermoplastic polymer composites has been plagued by difficulties in obtaining good dispersion and strong interfacial adhesion because lignocellulose fiber is hydrophilic and thermoplastic polymer is hydrophobic. The application of lignocellulose fibers as reinforcements in composite materials requires, just as for glass-fiber reinforced composites, a strong adhesion between the fiber and the matrix regardless of whether a traditional polymer matrix, a biodegradable polymer matrix or cement is used. Further this article gives a survey about physical and chemical treatment methods which improve the fiber matrix adhesion, their results and effects on the physical properties of composites. Coupling agents in lignocellulose fiber and polymer composites play a very important role in improving the compatibility and adhesion between polar lignocellulose fiber and non-polar polymeric matrices. In this article, we also review various kinds of coupling agent and interfacial mechanism or phenomena between lignocellulose fiber and thermoplastic polymer.

• Fibers and Polymers
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• v.2 no.3
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• pp.135-140
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• 2001

Organic-inorganic hybrid composites consisting of poly(vinylidene fluoride) (PVDF) and SiO$_2$ were prepared through a sol-gel process and the crystallization behavior of PVDF in the presence of $SiO_2$ networks was investigated by spectroscopic, thermal and x-ray diffraction measurements. The hybrid composites obtained were relatively transparent, and brittleness increased with increasing content of tetraethoxysilane (TEOS). It was regarded from FT-lR and DSC thermal analyses that at least a certain interaction existed between PVDF molecules and the $SiO_2$ networks. X-ray diffraction measurements showed that all of the hybrid samples had a crystal structure of PVDF ${\gamma}$-phase. Fresh gel prepared from the sol-gel reaction showed a very weak x-ray diffraction peak near 2$\theta$=$21^{\circ}$ due to PVDF crystallization, and Intensity increased grade-ally with time after gelation. The crystallization behavior of PVDF was strongly affected by the amount of $SiO_2$ networks. That is, $SiO_2$ content directly influenced preference and disturbance fur crystallization. In polymer-rich hybrids, $SiO_2$ networks had a favorable effect on the extent of PVDF crystallization. In particular, the maximum portent crystallinity of PVDF occurred at the content of 3.7 wt% $SiO_2$ and was higher than that of pure PVDF. However. beyond about 10 wt% $SiO_2$, the crystallization of PVDF was strongly confined.

• Journal of the Korean Society of Tobacco Science
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• v.32 no.1
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• pp.12-18
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• 2010

The parcel wrapper for cigarettes has been used as the package and media materials for protection and design of product brands. The design of parcel wrapper has been contributed to the delivery of brand image and motivated consumer to purchase the brand. Therefore, the properties of parcel wrapper have been paid attention to highlight the design image, and increasing opacity of media materials has been one of the effective ways to obtain clear design on the paper surface. This study was carried out to improve the opacity of parcel wrapper for cigarettes. The effects of pulp composition and inorganic fillers in the furnish on the optical and mechanical properties were investigated. The use of hardwood in the stock preparation gave the increased opacity of paper than that of softwood. The application of higher refractive indices of fillers was effective to improve opacity. Brightness, tensile strength and stiffness were affected by the retained filler amount on the paper. Increase of filler contents decrease the tensile strength and stiffness due to the lesser bonding ability of fibers.