• The Journal of Engineering Geology
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• v.18 no.4
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• pp.459-470
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• 2008

Types of slope failure related to cut slope stability are interpreted through case analyses, and also factors affecting structurally controlled instability investigated, which are developed by geologic structures along a national road No. 25 across the Cheongwon and Boeun-Guns, Chungbuk. Engineering properties such as orientation, persistence, roughness and uniaxial compressive strength of joints are analyzed by square-inventory method in three areas with well-preserved outcrops. The study area is located in Ogcheon folded bet, and are composed of quartz-schist and quartzite in the Midongsan Formation and phyllite in the Ungyori Formation. Flexural beds by folding, schistosity and cleavage besides joints are developed due to slight metamorphism. Various types of joints developed by folding are formed such as strike-parallel, strike-perpendicular, wedge and wrench joint sets by both initially regional and later superposed folding. Factors of slope instability are created by crossing the orientations of joint, cleavage, bedding and slope one another. In the case that the orientation of a slope is coincident with one of beds, factors causing large-scale failure including plane failure are increased greatly. Also in the region that orientations of the slope and bed are crossed each other at high angle, only local and minor failures are shown in the slope.

• Journal of the Korean Society of Safety
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• v.19 no.2
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• pp.125-129
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• 2004

In masive concrete placement, cracking problem due to hydration heat is frequently encountered. One of measure to solve this problem is to make a construction joint. However, it is cumbersome to make it by chipping the surface of joint. In this study, push-out test for 18 specimens was conducted to compare the interface shear strength of consturction joints whose surfaces were prepared with three methods; chipping, rib-lath, folded rib-lath. Compared to the specimens made with conventional surface chipping, those with rib-lathe showd excellent preformance increasing shear resistance capacity and the role of shear key conceived by folding rib-lath played important role in enhancing shear resistance.

• The Research Journal of the Costume Culture
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• v.22 no.2
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• pp.339-345
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• 2014

This study analyzes and compares Hanji made with loess to Hanji made with kaolin, two yellow-based inorganic pigments, in terms of its physical properties, optical properties, and color fastness to light with the aim of using it as a fashion material. Hanji made by adding inorganic pigments showed an approximately 20% retention ratio on average. This figure was similar to those of loess and kaolin. Physical properties were analyzed, with the following results. A higher amount of additives lowered the apparent density and increased thickness and bulk. In general, inorganic pigment-added Hanji had lower tensile strength, bursting strength, and folding endurance compared to non-additive Hanji. The analysis of optical properties showed a lower brightness index for Hanji made with inorganic pigments compared to non-additive Hanji. When comparing the two inorganic pigments, the brightness of Hanji made with kaolin was higher. Regarding color fastness to light, loess showed level 4 and kaolin showed level 5 when 25% inorganic pigments on pulp were added to Hanji. Thus, Hanji made by adding inorganic pigments during the manufacturing process may perform well as materials for fashion because the additives enhanced both the color fastness to light and the bulk while maintaining the strength. In addition, Hanji dyed with inorganic pigments may have the potential to serve as materials for the fashion industry while still retaining the characteristics of Hanji.

• Food Science of Animal Resources
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• v.39 no.3
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• pp.503-509
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• 2019

The aim of this study was to compare the effects of number of washes and salt addition on the meat quality in protein recovered from Alaska Pollock compared with pork leg. Various properties of protein recovered from Alaska Pollock (C, washed twice, no salt) and pork leg (T1, washed twice, no salt; T2, two washes, salt added; T3, washed four times, no salt; and T4, washed four times, salt added) were assessed in this study. Pork leg samples exhibited better color (more whiteness, less yellowness) than Alaska Pollock samples. In pork leg samples, four washes (T3, T4) during processing yielded whiter, less yellow protein than two washes (T1, T2). Overall, the textural property measures were higher in pork leg samples (T2, T3, and T4) than in other samples. Breaking force, jelly strength, and folding resistance were significantly higher in salt-treated pork leg samples (T2, T4) than in the other samples. Our findings demonstrate that protein recovered from pork leg has better color parameters, and physical strength compared with Alaska Pollock-derived protein. A higher number of wash steps and treatment with salt during processing were furthermore found to yield better color, and physical strength in the protein samples.

• Transactions of Materials Processing
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• v.30 no.4
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• pp.165-171
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• 2021

This study was conducted on the manufacturing method of high-strength aluminum bolts. We obtained the displacement-load information by tensile test of the Al 6056 raw material and the T6 heat-treated material and calculated the precise flow stress and fracture limit using repetitive finite element analysis for before and after heat treatment. We designed a multi-stage forging process for T6 heat-treated material, and calculated that the accumulated damage value does not exceed fracture limits by finite element method. We produced the prototype forgings without any harmful defects such as cracks and folding occurring. Bolts made of T6 heat treated material show 9.6%higher tensile strength than T6 heat treated material after wire drawing.

• Journal of the Korean Wood Science and Technology
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• v.27 no.1
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• pp.88-104
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• 1999

This study was carried out to classify the Hanjis into three groups that were indigenous Hanji, traditional Hanji, and improved Hanji handmade by paper making method according to the physical properties of each paper sheet such as tensile, bursting and tearing strength, folding endurance and fiber orientation in each layer. The results obtained were summarized as follows: 1. The multi-layered Hanjis made by "Oebal" Hanji making method in different direction of fiber orientation have good properties in tearing resistance. 2. The multi-layered Hanji in different direction of fiber orientation has good properties in the tearing resistance, but the burst index and the breaking length results were lower than the single layered Hanjis. 3. The different fiber orientation and multi-layered method didn't increase, the three indexes(burst index, tear index, breaking length). Only, the different direction of fiber orientation decreased the difference of width and length strength (tensile, tear) of the Hanji. 4. "Dochim"(Korean finishing touch process for indigenous Hanji by fulling round sticks) greatly increase folding endurance(double folds, not $log_{10}$) and good effect to tensile strength and burst strength. 5. The today's Oebal Hanji were the maximum of 2 layers and the indigenous Oebal Hanji were 16 layers the maximum. In addition, average of the indigenous Oebal Hanji was 4 layers(all 4-layer Hanji were the different fiber orientation of each layer). 6, The indigenous Hanji(multi-layered, and different fiber orientation) was good condition with "Dochim". Dochim increased tensile strength and burst strength of the indigenous Hanji. So the three-strength indexes were similar level("--"). 7. When the number of layer which were same fiber orientation increase, the increased Hanji became similar strength pattern("V", breaking length and burst index was higher than tear index) with "Ssangbal" Hanji. 8. The single layered papers that made by "Oebal" Hanji making method were similar strength pattern with Ssangbal Hanji. 9. There was no way to find the width and length direction of multi-layered Hanji by comparison between the difference of tensile strength and the difference of tearing resistance. 10. The compared pattern of tensile strength and tearing resistance of indigenous Oebal Hanji was different from today's Oebal Hanji. Especially, the tearing resistance of all indigenous Oebal Hanji(16 samples) was stronger on width of tearing resistance. And in the half of indigenous Oebal Hanji samples, the width of tensile strength and tearing resistance was stronger than length strength (Indigenous Oebal: '$\ulcorner\lrcorner$' 50%, '$\bigcup$' 50% $\leftrightarrow$ Today's Oebal: '$\ulcorner\lrcorner$' 12%, '$\bigcup$'6%, '$\llcorner\urcorner$'17%, '$\bigcap$'65%). In 65% today's Oebal, the length direction of tensile strength and tearing resistance was stronger than the width direction.

• 보존과학연구
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• s.32
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• pp.5-24
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• 2011

Neunghwaji(Embossed patterned paper) is a unique paper used for a traditional book cover in Korea. The research was carried out to investigate Neunghwaji's features. Physical property was studied through a test of tensile strength and folding endurance. Also, comparative analysis of virus resistance and waterproof ability was undertaken on Neunghwaji. 1. Folding endurance test showed that strength of non-embossed CB and HB decreased during deteriorating duration. Embossed CN and HN showed the strength increasing at early stage and decreasing from the 27th day of the deteriorating duration. Tensile strength was decreasing in both cases as deterioration progressed. 2. Growth of Arthrinium sp. fungus on embossed paper was 10% less than plain paper while Cladosporium sp. showed 20~30% less growth. Amur cork dyeing(H) showed 10~30% lower fungi growth than Gardenia seed dyeing(C). The result indicated that embossed paper has better virus resistance than Hanji, and Amur cork dyeing has better virus resistance than Gardenia seed dyeing. 3. Average contact angle of CN, CB, HN, and HB was $85{\sim}92^{\circ}$ and NON-N and NON-B was $59{\sim}63^{\circ}$. In detail, CN's contact angle was $1{\sim}7^{\circ}$ higher than CB's; HN was $1{\sim}6^{\circ}$ higher than HB. Therefore, it was found that embossed paper has higher contact angle than Hanji thus the former has better waterproof ability. The research suggested production technique of Neunghwaji and studied its features related to the technique. Neunghwaji was confirmed to have superior quality to Hanji though further study regarding above test result is needed to complement the research.

• Advanced Composite Materials
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• v.18 no.4
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• pp.315-326
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• 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.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2007.04a
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• pp.380-390
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• 2007

The purpose of this study is to make a functional Hanji treated with an oriental lacquer which has various functionalities. The raw oriental lacquer produced in China was used in this study This lacquer was diluted with ethanol and terpene in different solvent ratios. The diluted lacquer in the solvents had two layers. The upper layer was solvent soluble and the lower contained precipitates. Hanji was treated with the solvent solubles and the mixture containing precipitates, and then properties of the Hanji were evaluated. The oriental lacquer consisted of 25.04% of water, 60% of urushiol, 3.13% of nitrogen-containing compounds, and 5.66% of gum. The pH of oriental lacquer was 5.3 and the viscosity was 1680 cP. The average weight, thickness, and density of Hanji treated with oriental lacquer tended to gradually decreased as the lower concentration of lacquer was used and as the solvent soluble was treated. Tensile strength of the treated Hanji decreased when the diluted lacquer was used and Hanji treated with terpene dilutes at the ratio of lacquer to solvent of 1:5 (v/v) showed higher tensile strength than ones treated with ethanol dilutes. The folding endurance decreased as the less concentrated lacquer was used and the highest value was obtained when 1:40 (v/v) of lacquer to solvent ratio in both ethanol and terpene mixture. Absorption ratio was higher in the Hanji treated with ethanol mixture, treated with the lacquer in higher concentration, and treated with ethanol mixture. Hanji treated with ethanol dilutes at 1:20 (v/v) and the lower ratio of lacquer to solvent showed a hydrophobic property. Amount of the bound dye materials tended to be decreasing as the concentration of lacquer becomes lower and it was higher in Hanji treated with ethanol mixture than with terpene mixture. Color of Hanji treated with the solvent diluted mixture was Y to YR-type, whereas that of Hanji treated with raw oriental lacquer was Y-type, terpene

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.4
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• pp.1-8
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• 2013

High loading of printing and writing grades with fillers has many advantageous aspects in papermaking because it allows decreasing fiber use and reducing manufacturing cost. High loading technology, however, has some disadvantageous aspects as well. It decreases physical properties of papers, especially strength properties. The problem associated with high loading can be reduced by applying surface sizing starch solution onto paper surface. It is important to control the penetration of the surface sizing starch solution into paper web to obtain the desired property improvement. In this study, the effect of the addition of two polymers into starch solution on paper properties has been examined. PVOH and polyDADMAC were used as polymeric additives for surface sizing with oxidized starch. Viscosity of starch solutions and surface roughness of dried starch films on glass slides showed that some interactions between polymeric additives and oxidized starch have been occurred and the most extensive interaction with starch solution was obtained with high molecular weight polyDADMAC. Low molecular weight PVOH was most effective in improving folding endurance and internal bond strength. On the other hand, polymer addition showed no effect on surface strength of paper. This indicates that not the level of starch holdout but the bonding strength of starch itself has predominant influence on surface strength of paper.