• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.30 no.1
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• pp.7-17
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• 1998

With the advent of CLSM in the end of 1980s, it has been applied to the field of pulp and paper science in various ways. This study showed the potentials of CLSM In analyzing a change of pulp fiber and paper properties before and after mechanical treatment. In particular, a quantification of internal fibrillation has been done using cross-sectional images of fibers and image analysis technique, then evaluated the effects of fiber wall delamination on fiber and paper properties. It showed that the delaminated fibers were closely associated to development of the interfiber bonding in a fiber network. The CLSM made it possible to investigate a density profile along the sheet thickness, which was created by some papermaking processes like pressing, drying and calendering. Through the attempt to observe the forming procedure of a fiber network during handsheet making, the CLSM images showed that the pressing stage was considered greatly to contribute to generation of interfiber bonding with removing a free water and partly a bound water between fibers. In addition, the CLSM could be used to illustrate not only a surface profile of paper showing the extent of smoothness or roughness, but also a density profile in a B-direction of the network. Finally it became evident that the CLSM could be used as an excellent tool to predict development in fiber and paper properties before and after mechanical treatment during papermaking processes.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.3
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• pp.18-23
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• 2015

In this study, the effects of cationic fatty acid bulky promotor on the properties of BCTMP (bleached chemithermomechnical pulp) handsheet including bulk and strength were elucidated. As results, it was observed that the bulk of BCTMP handsheet increased with the increases of the concentration of cationic fatty acid bulky agent, while mechanical properties such as tensile strength and burst strength decreased. The opacity of BCTMP handsheet also increased with the increases of the concentration of cationic fatty acid bulky agent, while brightness was almost not changed. The effectiveness of bulky agent with SwBCTMP (softwood) was higher than that with HwBCTMP (hardwood). Compared with previous research on the effect of bulky agent on BKP handsheet, the bulk increase of BCTMP handsheet was greater compared to that of BKP handsheet. However, the reduction of mechanical property in BCTMP handsheet was lower than that of BKP handsheet.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.2
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• pp.61-66
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• 2002

This study was carried out to investigate sheet properties of Indian mallow hanji, made by different pulping methods such as alkali and sulfomethylated pulpings, and different stock compositions, various mixing ratios of bast fiber and woody core fibers. Effect of morphological properties of pulp stocks on the sheet formation and their optical properties were also evaluated using an image analyzer and confocal laser scanning microscope(CLSM). In addition, the effect of fiber distribution index(FDI), which was calculated based on the image in a z-direction of a sheet from CLSM, on the sheet properties of Indian mallow hanji was discussed. The proposed FDI had a good correlation with various properties of paper, such as apparent density, opacity, tear index, breaking length and zero-span tensile strength. Especially, sulfomethylated pulp sheets＇FDI was higher than alkali pulp sheets.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2008.04a
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• pp.129-134
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• 2008

Properties of newly developed paper from Red Algae Pulp (RAP) were examined. The paper samples were prepared by mixing RAP fiber with wood fibers, HwBKP and SwBKP, to form a paper with $60g/m^2$ in weight. It was prepared in three to four different levels of refining degree and pressure so that it can reveal different bulk level in order to clearly compare the opacity at equivalent bulk for each furnish compositions. Printability of RAP fiber revealed superior effect on print through repression and initial ink absorption. Those properties are expected to improve further if printability improvement effect due to smoothness improvement is added.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.205-208
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• 2006

Existing gas fired burners work in the medium wave IR range at $1000^{\circ}C$ and an energy density of $200kW/m^{2}$. The patented porous burner technology reaches the short wave IR spectrum ($1450^{\circ}C$) and comes up to an energy density of $1000kW/m^{2}$. This technology is of great interest for various applications in paper industry. Speeding up existing coating lines can be realized without a major revamp of the line. Main characteristics of this new developed technology enable a better process control. In this paper the porous burner technology for paper industry is evaluated.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.30 no.4
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• pp.42-48
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• 1998

The bacterial cellulose(BC) has many unique properties that are potentially and commercially beneficial. In order to enhance inherently inferior physical property of chemithermomechanical pulp(CTMP) sheet, chemical pulp has been used widely. Bacterial cellulose also has an enhanced sheet strength because of its unique physical and morphological features. This study was carried out to inverstigate the effect of BC addition on physical properties of CTMP sheets. The effect of BC addition on its optical properties was also discussed. The apparent density, internal bond strength, Young's modulus, tensile strength and folding endurance of CTMP sheet are increasing with increase of BC contents. This strength increase would be attributed to the increase of relative bonding sites among pulp fibers by addition of BC which has microfibrillar structure with very high specific surface areas. There were not so significant changes in opacity of CTMP sheet upto 20% addition level of BC, while over 40% addition, the opacity gradually decreased and levelled off. Porosity is decreased with addition of BC. This decrease would be attributed to densification of sheet by fine and filamentous structure of BC fibers.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.3
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• pp.67-73
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• 2004

Effect of calendering on structural and surface properties of sheets made of various pulp was investigated. BKP, BCTMP and KOCC were used as raw materials for handsheets and sheets were calendered at the different calendering temperature and pressure conditions. Caliper, air permeability, and PPS roughness were reduced by calendering, but their effects were a little different depending on pulp type and calendering condition. Increase of density with increase of calendering Pressure was remarkable on sheet made of BCTMP or KOCC, and the effect of temperature was more significant than pressure. PPS roughness of sheet made of BCTMP or KOCC was reduced by calendering, but BKP sheet showed little reduction of roughness at higher calendering pressure. The compressibility of sheet increased logarithmetically with calendering pressure and surface compressibility of KOCC sheet was relatively higher than other pulps.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.2
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• pp.34-41
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• 1999

Adsorption of cationic polyacrylamide dry strength resins onto the surface of papermaking fibers and fines is critical for their effective utilization. Since dry strength resins are frequently employed when recycled fibers containing a great deal of fines are used as a raw material, their adsorption characteristic onto the recycled fiber fines is of great importance. In this study, effects of recycling on adsorption characteristics of cationic polyacrylamide onto primary and secondary fines were examined. Never dried bleached hardwood kraft pulp was beaten and dried for recycling. In each recycling step the adsorption characteristic of a cationic PAM onto primary and secondary fines was evaluated by kjeldahl nitrogen analysis method. The influence of recycling on water retention value and carboxyl content along with the sheet density and tensile strength was examined. Secondary fines of never dried pulp adsorbed twice as much of C-PAM as the primary fines, however, the adsorption capacity of the secondary fines decreased rapidly during the course of recycling and showed lower adsorption capacily than primary fines.

• KSBB Journal
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• v.11 no.2
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• pp.238-245
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• 1996

Microbial desulfurization characterlstics of a bituminous coal have been determined by using Thiobacillus ferrooxidans. The effects of process variables (such as coal pulp density, particle size and addition of surfactants) on pyrite removal have been investigated in both shake and airlift-bioreactor culture experiments. In shake experiments, pyrite could be removed over 78% for pulp densifies below 20% (w/v) and removed below 40% for pulp densities over 30% (w/v) in 8 days. Pyrite removal decreased with increasing pulp densities, and it also decreased sharply with increasing particle sizes. In airlift bioreactor experiments, pyrite at 50% (w/v) pulp density could be removed about 50%. Its value is much higher than 15% at the same pulp density in a shake experiment. With addition of surfactants, pyrite removal was enhanced in shake experiments significantly, whereas it was slightly decreased in an airlift bioreactor experiment.

• Journal of Oral Medicine and Pain
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• v.41 no.3
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• pp.85-90
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• 2016

Purpose: The aim of this study was to develop an automated software to extract tooth and pulpal area from sectional cone-beam computed tomography (CBCT) images, which can guarantee more reproducible, objective and time-saving way to measure pulp/tooth volume ratio. Methods: The software program was developed using MATLAB (MathWorks). To determine the optimal threshold for the region of interest (ROI) extraction, user interface to adjust the threshold for extraction algorithm was added. Default threshold was determined after several trials to make the outline of extracted ROI fitting to the tooth and pulpal outlines. To test the effect of starting point location selected initially in the pulpal area on the final result, pulp/tooth volume ratio was calculated 5 times with different 5 starting points. Results: Navigation interface is composed of image loading, zoom-in, zoom-out, and move tool. ROI extraction process can be shown by check in the option box. Default threshold is adjusted for the extracted tooth area to cover whole tooth including dentin, cementum, and enamel. Of course, the result can be corrected, if necessary, by the examiner as well as by changing the threshold of density of hard tissue. Extracted tooth and pulp area are reconstructed three-dimensional (3D) and pulp/tooth volume ratio is calculated by voxel counting on reconstructed model. The difference between the pulp/tooth volume ratio results from the 5 different extraction starting points was not significant. Conclusions: In further studies based on a large-scale sample, the most proper threshold to present the most significant relationship between age and pulp/tooth volume ratio and the tooth correlated with age the most will be explored. If the software can be improved to use whole CBCT data set rather than just sectional images and to detect pulp canal in the original 3D images generated by CBCT software itself, it will be more promising in practical uses.