• Archives of Metallurgy and Materials
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• v.65 no.3
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• pp.993-996
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• 2020

In this study, we demonstrate a facile and cost-effective way to synthesize Nd-Fe-B of various shapes such as powders, rods and fibers using electrospinning, heat-treatment and washing procedures. Initially Nd-Fe-B fibers were fabricated using electrospinning. The as-spun Nd-Fe-B fibers had diameters ranging 489 to 630 nm depending on the PVP concentration in reaction solutions. The different morphologies of the Nd₂Fe₁₄B magnetic materials were related to the difference in thickness of the as-spun fibers. The relationships between the as-spun fiber thickness, the final morphology, and magnetic properties were briefly elucidated. The intrinsic coercivity of Nd₂Fe₁₄B changed with the change in morphology from powder (3908 Oe) to fiber (4622 Oe). This work demonstrates the effect of the Nd-Fe-B magnetic properties with morphology and can be extended to the experimental design of other magnetic materials.

• Textile Coloration and Finishing
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• v.18 no.4
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• pp.37-42
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• 2006

Two kinds of sea-island type polyester ultramicro fibers (fiber fineness : 0.01 and 0.05 denier) were treated with NaOH varying time and concentration. Surface morphology of the treated fibers with alkaline weight loss was observed by SEM. The treated effects were investigated by measuring density, melting temperature, and X-ray diffraction patterns. The surface morphology of the polyester ultramicro fiber was changed by NaOH concentration. Weight loss of 0.01d fiber was much larger than that of 0.05d fiber. Density and crystallinity were increased with weight loss of fiber. After the weight loss had finished, the density and crystallinity were decreased because of attack of island partition of the fiber. A melting temperature$(T_m)$ is $250^{circ}$ at untreated fiber on the whole and in 0.05d fiber the $(T_m)$ is $252^{circ}$ at untreated. In 0.01d fiber the $(T_m)$ was increased with weight loss of fiber.

• Polymer(Korea)
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• v.27 no.4
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• pp.299-306
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• 2003

It is well known that the interaction and adhesion between the glass fiber (GF) and polymer matrix has a significant effect in determining the properties of fiber-reinforced materials. Therefore, it is one of important considerations to modify the surface of glass fiber with an appropriate sizing. We investigated the treatment method of glass fiber with coupling agent to improve the interaction of the interfacial region. The correlation between interfacial property and interphase microstructure was also examined in an attempt to realize a proper morphology at the glass fiber surfaces.

• Proceedings of the Korean Fiber Society Conference
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• 1993.06a
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• pp.50-51
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• 1993

• Proceedings of the Korean Fiber Society Conference
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• 1992.06b
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• pp.56-57
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• 1992

• Proceedings of the Korean Fiber Society Conference
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• 1991.06b
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• pp.22-22
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• 1991

• Carbon letters
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• v.12 no.3
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• pp.131-137
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• 2011

Kenaf fibers, cellulose-based natural fibers, were used as precursor for preparing kenafbased carbon fibers. The effects of carbonization temperature ($700^{\circ}C$ to $1100^{\circ}C$) and chemical pre-treatment (NaOH and $NH_4Cl$) at various concentrations on the thermal change, chemical composition and fiber morphology of kenaf-based carbon fibers were investigated. Remarkable weight loss and longitudinal shrinkage were found to occur during the thermal conversion from kenaf precursor to kenaf-based carbon fiber, depending on the carbonization temperature. It was noted that the alkali pre-treatment of kenaf with NaOH played a role in reducing the weight loss and the longitudinal shrinkage and also in increasing the carbon content of kenaf-based carbon fibers. The number and size of the cells and the fiber diameter were reduced with increasing carbonization temperature. Morphological observations implied that the micrometer-sized cells were combined or fused and then re-organized with the neighboring cells during the carbonization process. By the pre-treatment of kenaf with 10 and 15 wt% NaOH solutions and the subsequent carbonization process, the inner cells completely disappeared through the transverse direction of the kenaf fiber, resulting in the fiber densification. It was noticeable that the alkali pre-treatment of the kenaf fibers prior to carbonization contributed to the forming of kenaf-based carbon fibers.

• Nutritional Sciences
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• v.3 no.1
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• pp.3-10
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• 2000

The present study was aimed at investigating the nutritional and physiological significance of rice bran as a source of dietary fiber as compared to pectin and wheat bran. The parameters for comparison included hypertrophy and morphology of intestines, stool weights and villus marker enzyme activity. For 6 weeks, 10 Sprague Dawley male rats were given one of six experimental diets: 1% cellulose control (CC), 5% pectin (P5), 5% rice bran(RB5), 10% rice bran(RB10), 5% wheat bran (WB5) or 10% wheat bran (WB10) based on the level of dietary fiber. Among experimental groups, food efficiency ratio and body weight gain was comparable. RB10 increased cecal and colonic tissue weights and content weights of cecum and colon as much as P5 did. Stool weight was positiviely correlated with colonic tissue weight (r=0.727, P<0.001), with colonic content weight(r=0.647, P<0.001). Small intestine length increased most in the P5 group, followed by the RB10 group. The scanning electron micrograph of jejunal villi from rice bran groups showed a leaf-shaped, smooth and regular pattern, whereas that of CC group produced a rather long shape. The wheat bran groups showed an irregular leafshaped pattern, and the pectin group typically produced leaf-shaped villi with surface damage. The activities of villus marker enzymes (maltase and sucrase) were higher in the bran-fed rats than in the control or pectin-fed rats. The results indicate than not only dietary fiber amounts but also fiber sources are closely related to the physiology and morphology of the large and small intestines in rats. Rice bran exerted effects on fecal output and trophic effects on the intestines similar to those of pectin.

• Journal of the Korean Society of Tobacco Science
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• v.26 no.1
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• pp.57-63
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• 2004

A comparative analysis of characteristics of domestic and foreign reconstituted tobacco based on papermaking was conducted to evaluate the quality of reconstituted tobacco and to utilize as basic data for improvement of domestic reconstituted tobacco. In the formation, which is key factor to quality and physical properties of product, foreign reconstituted tobacco has better uniform formation than those of domestic one. These result was attributed to distribution of large floc size in the domestic one unevenly. In the fiber morphology, domestic reconstituted tobacco has larger average fiber length and width than those of foreign one. They indicated that fiber morphology of domestic one will exert structural properties of paper such as formation and permeability. Tensile strength of domestic one has lower than those of foreign one by basis weight. In the air permeability, domestic one was remarkably reduced because base web was over sized. It also will affect the combustibility of reconstituted tobacco. In summary, we conclude that the physical and structural properties of domestic reconstituted tobacco result in quality deviations compared with foreign reconstituted tobacco.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.1
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• pp.47-56
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• 2011

This study was carried out to investigate the characteristics of the Hanji which had been used for movable types printing volumes of the Joseon Dynasty. A total 29 volumes which had printed with metal and wooden movable types, were examined on the physical properties, fiber morphology, and color reactions. The grammage of all of the Hanji which had been used for movable types printing volumes were $13.10-51.65g/m^2$ and on the average was $25g/m^2$. The apparent density of the Hanji was $0.23-1.65g/cm^3$ and on the average was $0.4g/cm^3$. In almost all movable types printing volumes, the Hanji had undergone Dochim which is a processing of printability improvement. Through the examination on fiber morphology and color reactions, Hanji was investigated into that all of those were made from paper mulberry bast fiber.