• 펄프종이기술
• /
• 제42권3호
• /
• pp.37-42
• /
• 2010

The properties of paper are very susceptible to moisture content originated from relative humidity. This propensity of PVA impregnated paper was investigated in this study. Especially the hardening effect of borax treatment after PVA impregnation on the response of paper sample to the relative humidity was evaluated. When the moisture content was increased with the relative humidity, tensile stretch and tear resistance were increased while tensile strength and stiffness were decreased. A great increase in folding endurance of PVA impregnated paper sample was found at the higher relative humidity. The borax treatment could reduce the response of PVA impregated paper to the relative humidity.

• Advanced Composite Materials
• /
• 제18권4호
• /
• pp.315-326
• /
• 2009

PCC (precipitated calcium carbonate) and ground calcium carbonate have been widely used in alkaline papermaking. Unfortunately, although increasing filler level in papers can improve the paper properties such as brightness, opacity, stiffness gloss, smoothness, porosity, and printability, as well as decrease cost, some strength of the paper is negatively affected. In this research, needle-like aragonite was synthesized using $Ca(OH)_2$ and $CO_2$ as reactants in the presence of $MgCl_2$ and characterized with scanning electronic microscopy (SEM) and X-ray diffraction (XRD). The physical and optical properties of the paper handsheets containing these needle-like aragonite fillers were evaluated. Results indicated that tensile strength, Z-direction tensile strength and folding endurance of the paper were improved by the needle-like aragonite crystals compared to the paper using commercial PCC (precipitated calcium carbonate) as filler. The stiffness of the paper handsheet on the machine direction was increased, but no evident difference in the cross direction was found. The improvement of paper strength mainly resulted from the twining effect between the aragonite whiskers and paper fibers. The optical properties of the paper were slightly decreased with the use of the needle-like aragonites compared to commercial PCC. These results suggest that paper cost can be decreased by increasing the content of needle-like aragonite filler while paper strength will not be decreased compared to PCC filler.

• 한국사회복지학
• /
• 제61권3호
• /
• pp.179-204
• /
• 2009

본 연구는 사회복지학에서의 실행연구 이해와 적용을 높이기 위해 실행연구의 연구 설계 과정에 따라 실행연구 사례를 소개하면서, 사회복지학에서의 유용성을 논의하고자 한 것이다. 즉, '장애인거주시설에서의 이용자 참여 매뉴얼 개발 연구'의 수행 과정을 설명하고, 실행연구과정에서 연구참여자들에게 어떠한 변화가 나타나는지 질적 양적 자료 분석을 통해 실행연구의 효과를 살펴보았다. 이와 함께 실행연구의 사회복지학에의 유용성은 무엇인지를 논의하였다. 이 연구는 국내 최초로 사회복지학에서의 실행연구를 적용한 연구 수행과정 및 그 효과를 탐색함으로써, 사회복지학 실행연구의 이해 및 확산에 기여할 것으로 본다.

• 한국펄프종이공학회:학술대회논문집
• /
• 한국펄프종이공학회 1999년도 Proceedings of Pre-symposium of the 10th ISWPC
• /
• pp.164-171
• /
• 1999

A new technique for recycling process water was developed in order to reduce the calcium hardness of the closed OCC recycling system. Calcium ions present in the white water were precipitated as calcium carbonate by a reaction with sodium carbonate and the CaCO$_3$precipitates were easily removed from the system by a dissolved air flotation(DAF) method. After the DAF stage, CO$_2$-gas was purged into the water because the pH of Na$_2$CO$_3$-treated white water was reduced to neutral by CO$_2$gas. Since CaCO$_3$precipitate tends to stick onto the fine fiber surface and then is selectively removed from the water, a proper amount of suspended solid in the process water acts as an important factor in deciding the removal efficiency. By the application of Na$_2$CO$_3$addition - DAF - CO$_2$purging to the short circulated white water the calcium hardness was significantly reduced by 92% and more. The removal of calcium ions with fine fibers led to drainage improvement, reduction of fresh water consumption, and enhanced efficiency of wet-end chemicals.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
• /
• pp.817-820
• /
• 2005

Legibility of electronic paper was evaluated by using the method of letter-search task and subjective visual comfort scaling. The results show that legibility depends on the illumination level, and conventional paper has a higher visual comfort rating than electronic paper although they have the similar performance in the letter-search task.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2007년도 정기 학술대회 논문집
• /
• pp.188-192
• /
• 2007

This paper presents a current perspective on advanced fusion research trends in the construction industry as reflected in the proceedings of International Symposium on Automation and Robotics in Construction (ISARC) which has focused on advanced fusion technology in last decades. The paper reports the results of a 7-year analysis of papers between 2000 and 2006. The analysis focused on such data as research topics of the proceedings. The paper summarizes the data extracted from the paper and uses it to analyze advanced fusion research trends. The research result shows that the top research topics in advanced fusion research areas are construction robots and automation and intelligent construction management. The research also found that research related to advanced fusion technology is increasing throughout the world and topics are changing as current needs change.

• 펄프종이기술
• /
• 제29권2호
• /
• pp.46-50
• /
• 1997

• 펄프종이기술
• /
• 제41권2호
• /
• pp.64-69
• /
• 2009

Cultural heritages represent the histories and intellectual level of a country. The Annals of Joseon Dynasty are regarded as the most valuable resources containing the record of Korean history. In some periods, wax-treated paper was used as the material of the Annals of Joseon Dynasty. Many previous studies have focused on the development of paper used as the material of the Annals of Joseon Dynasty, but the manufacture method of wax-treated volumes and the degradation mechanism of wax have been not fully understood yet. The purposes of the present study are to produce various kinds of wax-treated paper using by different coating methods and to analyse the morphological properties of wax-treated paper. The analysis of SEM demonstrates that beeswax treated paper made by brushing method produces flatter surface and more excellent penetration. Wax layer is produced on the cross section of beeswax treated paper as the increase of coating amount.

• 펄프종이기술
• /
• 제40권5호
• /
• pp.27-35
• /
• 2008

In order to determine the most appropriate recycling line to treat old corrugated container (OCC) to substitute unbleached kraft pulp (UKP) for the manufacture of kraft paper, three recycling lines were evaluated in pilot scale tests. The recycling line consisting of kneading, flotation, washing, dispersion and screening steps was able to produce pulp with acceptable appearance. Kneading was shown to be more efficient treatment to reduce specks than dispersion. In addition, 0.2 mm slot screen was very effective to remove specks. Severe damages on fiber morphology such as shortening of fiber and formation of fines were not observed during mechanical treatments such as kneading and dispersion. Most of strength properties of the kraft paper produced with the recycled pulp were found to be slightly increased after treated in the recycling lines.

• 한국펄프종이공학회:학술대회논문집
• /
• 한국펄프종이공학회 2008년도 추계학술발표논문집
• /
• pp.96-106
• /
• 2008