• Proceedings of the KIEE Conference
• /
• 1997.07e
• /
• pp.1887-1889
• /
• 1997

This paper reports the principle, design, configuration, and test results of the fiber optic security system using multimode fiber. In this system, optical fiber works as a sensing element. The length of sensing element may be from several meters to several killometers. Physical principle of this system is the dependence of interferometric pattern on the end of the fiber on mechanical perturbation in the area, where this fiber is situated. Near and far field patterns of the output light for multimode fiber are speckle pattern. A number of speckles on the fiber depends on mode numbers. Light intensity in each point of the fiber end depends on phase difference of modes. Finally we introduced a "Fiber Optic Security System based on Multimode" Fiber which we developed, it may be available in the field of the important area and building.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.11
• /
• pp.1995-1997
• /
• 2007

In this paper we propose a wavelength-switchable fiber ring laser that employs a polarization-dependent fiber band stop filter. The fiber filter was fabricated by inscribing a long-period fiber grating on a high birefringent fiber. Dual-wavelength switching operation was accomplished by controlling the rotatable linear polarizer which rotated the polarization plane of the light circulating through the fiber laser cavity. The amplitude variation of both laser lines was measured to be less than 0.5 dB and the signal-to-amplified spontaneous emission ratio was more than 55 dB.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2007.05a
• /
• pp.19-32
• /
• 2007

A new generation of fiber-based papermaking chemicals were presented for the first time at the PTS Pulp Technology Symposium 2005, and then several articles were published in various magazine in Asia ("Paper Asia"), the US ("Pulp & Paper"), and Europe ("Wochenblatt fuel Papierfabrikation"). The information generated quite an interest in the paper industry. Extensive studies of these papermaking additives have been made recently, new information obtained, and the compounds have gained more recognition in the industry. The company J. Rettenmaier und Soehne developed of a group of fiber-based papermaking additives. They includ combination of fibers with sizing agents, starch, fluorochemicals, minerals, biocides and some others. This article presents in-depth study of the AKD modified micronized cellulose as an example of the fiber-based papermaking chemicals cocept. The material of the present paper is based mostly on the results of the pilot paper machine study at the Paper Research Institute PTS (Heidenau, Germany), and includes case studies from the mills, which used $ARBOCELPLUS^{(R)}-AKD$ compounds. It should be noted that the $ARBOCELPLUS^{(R)}$ compounds were not designed to replace traditional additives in paper industry. They should rather be used in those areas, where application of "normal" chemicals is especially problematic.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.43 no.4
• /
• pp.1-10
• /
• 2011

Beating or refining is an energy intensive process in paper industry. In India, most of the paper industries blend long fibered softwood pulps with short fibered hardwood or agro based pulps to get the paper properties of competitive level. Refining characteristics of the blend of pulps is very crucial with respect to freeness and strength properties. This study has been carried out to understand the refining behavior of three hardwood pulps and a softwood pulp. The hardwood and softwood pulps are blended in different proportions in two different ways; a) blending after their separate refining, and b) blending before refining followed by mixed refining of the blended pulps. Freeness of pulp, strength, optical and surface properties of paper along with formation have been determined and compared for both the refining methods. The fiber classification of refined pulps was also carried out to analyze the effect of refining method on fiber morphology. The mixed refining of hardwood and softwood pulps marginally affects the fiber morphology in comparison to separate refining of pulps. The strength and other properties of paper prepared from mixed refining of pulps are either better or comparable than those of separately refined pulps.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.47 no.6
• /
• pp.49-56
• /
• 2015

To investigate fiber orientation of Korean traditional paper, Hanji, the fiber arrangements on the surface and cross section of Hanji were observed by scanning electron microscope (SEM). The surface observation showed that the fibers of traditional paper were arranged in vertical and horizontal directions, and those of ssangbal sheet forming were arranged more in vertical direction. The fibers of machine made Hanji and copying paper were usually arranged in vertical direction. As for the observation of cross section of traditional paper, fibers arranged in horizontal direction tended to be increased with the increase of thicknesses. The thick traditional paper have cracks in the middle part of structural section of paper. They were larger in cross section in horizontal direction than in vertical direction. The horizontal arrangement of traditional paper seemed to be about 8% to 14% higher to the vertical arrangement, which is very lower to other papers.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.31 no.3
• /
• pp.54-59
• /
• 1999

This study was to quantify fiber distributions in thickness direction of kenaf handsheets as a fiber distribution index (FDI) and to analyze the relationship between FDI and the handsheet properties. The images of fiber distribution in z-direction were obtained by Confocal Laser Scanning Microscope (CLSM) and analyzed by image analysis technique. The proposed FDI had a good correlation with high R2 vlaues with various properties of paper, such as apparent density, scattering coefficient , burst index, tear index, tensile index, and folding endurance. The proposed FDI was shown as a good index to quantify paper properties.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.37 no.2 s.110
• /
• pp.1-10
• /
• 2005

Removal of fines from fiber furnish by fractionation improves drainage, but decreases fiber bonding in paper. Fines can be again classified by their size such as the fines that passed 150 and 400 mesh screen, respectively. A hypothesis of different properties between these two kinds of fines was tested. Four different furnishes (SwBKP, HwBKP, KOCC, and BCTMP) were refined in two levels, and all their furnish and handsheet properties were compared in respect of their fines. KOCC fines gave the slowest drainage and least contribution to breaking length while BCTMP fines the fastest drainage and the highest contribution to breaking length. Removal of the fines that passed 400 mesh screen gave high improvement in drainage and large decrease in breaking length. Only KOCC fines removal gave more positive results where there were large improvement in drainage but only small decrease in breaking length.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1993.10a
• /
• pp.150-155
• /
• 1993

The use of polypropylene fibers in concrete has been widely advertised by the fiber manufacturers. However, the behavior of concrete containing plastic fibers has not been fully understood. The effects of fiber on concrete have been forcused on shrinkage crack control mainly from field observation, and the mechanism and the side effect of fiber such as workability reduction have been neglicted. In this paper, the effect of fiber on workability and shrinkage properties have been studied. The addition of fiber significantly reduce workability and requires additional water to maintain the workability, which causes adversal effects on concrete properties.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1993.10a
• /
• pp.156-161
• /
• 1993

This paper is to develop steel fiber reinforced polymer-impregnated concrete(SFPIC) by impregnation polymer impregnate into hardened steel fiber reinforced concrete(SFRC). Steel fiber induces ductile behavior and polymer impregnant increase compressive strength. Steel fiber reinforced polymer-impregnated concrete specimens are prepared with fiber contents of 0.0, 1.5, 2.0, 2.5% and tested to obtain uni-axial and bi-axial compression strengths, tensile strength and flexural strength. The strength and mechanical properties of normal concrete, SFRC, SFPIC are compared.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1995.10a
• /
• pp.89-92
• /
• 1995

For the development of lilght weight cement concrete with high durability, this study used perlite and paper sludge ash by the light weight material, and polypropylene fiber by the reinforcment, and poly-acrylic ester emulsion by the matrix improvement. According to the increasing mixture ratio of fiber and use of polymer, the light weight polypropylene fiber reinforced polymer cement ratio of fiber and use of polymer, the light weight polypropylene fiber reinforced polymer cement concrete were showed high resistance for frost damage.