• 한국농촌건축학회논문집
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• 제21권1호
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• pp.37-44
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• 2019

Recently, various tourist products using hanok have increased rapidly. In the meantime, there is a steady demand for Hanok architecture. However, there are many negative perceptions about wood deformation and biodeterioration. Wood deformation and biodeterioration are related to moisture content. And the cracks occur in the process of removing water from the wood. Therefore, this study investigates the moisture content and cracks of dried hanok made of wood according to the drying method of wood. Drying methods include natural seasoning and artificial seasoning. There was a difference in moisture removal depending on drying period and method of natural seasoning. Drying time should be about 3 years for natural seasoning, so the moisture content of the wood is stable. In addition, the moisture absorption rate was low even in a humid environment where the voids were removed. However, natural seasoning is time consuming. Artificial seasoning, on the other hand, can quickly remove moisture from the wood and reduce porosity, but it is costly. Cracks that occur during the drying of wood may become problematic in appearance and stability due to wider spacing over time. As a result, the difference in the moisture content of the timber depending on the drying method and drying period of the wood was maintained even after the formation. These gaps appeared to be differences in moisture absorption in a wet environment.

• Journal of Biosystems Engineering
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• 제33권4호
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• pp.253-259
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• 2008

In this paper an optimum design of a lab-scale biofilter for absorbing ammonia has been proposed and analyzed. This biofilter is using pine chaff and wood shaving as filter materials. It is assumed that the biofilter can be used as a storage tank of swine manure slurry or swine stall. To evaluate the biofilter performance, the ammonia, mainly offensive odor ingredient, was measured. Swine compost was mixed with filter materials in ratio of 1:1 on weight base. Each test continued for 20 days. The ammonia emissions were reduced by 97.9% and 98.3% in case of using biofilter filled with pine chaff and compost, and wood shaving and compost, respectively. The system was tested with and without adding compost. It was found that the biofilter with wood shaving and compost has an ammonia removal efficiency of 94.1%, while biofilter with wood shaving only has 85.3%. The biofilter with wood shaving and compost showed 8.8% higher removal efficiency than that of wood shaving only. By mixing the compost, the number of microorganism was found to be about 2.3 times more than that of wood shaving only. Therefore it can be concluded that adding compost has a positive effect on the formation of microorganism.

• 한국가구학회지
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• 제19권5호
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• pp.358-364
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• 2008

Wood-inorganic material composite (WIC) was prepared by impregnating wood with copper sulfate ($CuSO_4\;5H_2O$) solution and by immersed wood in sodium carbonate($Na_2CO_3$) solution in order to introduce insoluble copper compounds {copper carbonate hydroxide, $CuCO_3\;Cu(OH)_2$} into the wood to give fungicidal effects in treated-wood. The weight percent gains (WPGs) of treated wood reached maximum value by impregnation of 20% copper sulfate solution and immersion in about 15% sodium carbonate solution for 24 hrs. Inorganic substances were present mainly in the lumina and cross-field pitting of tracheides. These substances were proved to be the insoluble copper carbonate hydroxide against water by the energy dispersive X-ray analyzer in conjunction with a scanning electron microscope (SEM-EDXA). The treated specimens showed high preservative effectiveness because the weight losses were hardly occurred by the fungi degradation test.

• 유기물자원화
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• 제18권3호
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• pp.87-91
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• 2010

목재 및 비목재 재료는 여과재료로 광범위하게 사용되고 있다. 작은 입자(${\sim}5{\mu}m$)를 여과하는데 사용될 수 있는 구조를 가지기 때문이며, 상대적으로 원가가가 저렴한 재료이다. 이 화이버 필터는 비점오염원을 여과하는데 있어서 목재 및 비목재 재료의 몇 가지 물리적 성질, 특히 입자의 여과에 관하여 주목을 받는 차별화되는 특성을 가지고 있다. 또한, 이들 재료는 각각의 섬유들이 가지는 다양성과 형태로 인하여 비정형성과 복잡한 다공성구조를 형성한다.

• 한국가구학회지
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• 제23권1호
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• pp.26-37
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• 2012

This is the study about the New Formation Developement, the Changeable Table Design with Units that made of Wasted Wood to use restricted material rationally and to improve the space efficiency in the Table Design. We made some changeable table design with units that made of laminated wood wasted. And we found out the following formative characteristic and physical merits through this study. First, the space efficiency can be improve technically through the unit combination and organic transfomation of the specific form and a new method by laminated wood make the personal originality and the structral stability be built up. Second, there are some merits, moveable convenience and variable layout by the combination or transformation or personal fondness so that economical efficiency and variable of design can be improved. Third, we can remove original faults inside wood like a knot or not-uniform of wood organ when we laminate wood so that we use proper units that have original beauty of wood and can represent mild mood of furniture wholly. Fourth, much more strengthen tensile strength by the reciprocal action among the units that be made of laminated wood reduces wood's metamorphosis like bending or twisting so that the uniformity of wood can be gain and furniture's metamorphosis can be reduced. According to changes of nature environment, the difficulty of supply and demand for wood may be happen. According to changes of life style these days, supply and demand for environment friendly material, processing technique and developement of design to improve the efficiency of using space must be very important factor in morden furniture design. So we propose changeable furniture design by using new environment friendly meterial and processing method from this study.

• 펄프종이기술
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• 제42권2호
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• pp.41-45
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• 2010

This study was performed to evaluate the effect of paper property changes by internal addition of surface strength agent on printability. Advances in printing technique has required the development of paper qualities in many aspects. Basically paper structure is composed of hydrogen bonds which induce many problems in high speed printing machine because of weak bonding strength. One of the important printing problems is surface picking when mechanical pulp or recycled pulp are used. It was caused by the ink-stained blanket in printing process because accumulations of pollutant in white water and other elements which are bonded weakly or do not have hydrogen bonds. Debris at paper surface adheres to blanket which deteriorates printing efficiency and causes various problems. To complement these problems, Pennocel 5137 of polysaccharide structure was used as an agent to improve paper's surface property, strength and printability. Paper surface picking was analyzed by RI-1 test. As the dosage amount increased tensile strength, fiber bonding strength and ZDT strength were improved. Further more formation, smoothness and surface picking resistance were improved. It was confirmed that when adding polysaccharide structure polymers to improve surface strength such as surface picking resistance, it was also possible to improve tensile strength, fiber bonding strength, formation and smoothness.

• 한국축산식품학회지
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• 제43권5호
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• pp.826-839
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• 2023

This study investigated the effects of different charcoals on the occurrence of 16 polycyclic aromatic hydrocarbons (PAHs) in grilled beef steaks and beef patties. Seven different charcoals were used as follows: from oak wood (C1), from orange wood (C2), from Valonia oak wood (C3), from Marabu wood (C4), extruded charcoal from beech wood (C5), from coconut shells (C6), and from hazelnut shells (C7). The grilling times for each charcoal type were 6 min for the beef patties and 7 min for the beef steaks, until the internal temperature reached at least 74℃. The total concentration of 16 PAHs (PAH16) in beef steaks grilled with C1 (35.75 ㎍/kg) and C7 (36.39 ㎍/kg) was higher than that of C3 (23.80 ㎍/kg) and C6 (24.48 ㎍/kg; p<0.05). The highest amounts of PAH16 (216.40 ㎍/kg) were determined in the beef patty samples grilled using C5 (p<0.05). The summation of benzo[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene, referred to as PAH4, was not detected in any of the beef steaks, whereas it was determined in the beef patties grilled with C2 (7.72 ㎍/kg) and C5 (22.95 ㎍/kg; p<0.05). The PAH16 concentrations of the beef patty samples in each charcoal group were significantly higher compared to the beef steaks (p<0.05). To avoid the formation of high PAH levels, the use of extruded charcoal and hazelnut shell charcoal should therefore be avoided when charcoal grilling beef steaks and beef patties, and low-fat meat products should be preferred.

• Journal of the Korean Wood Science and Technology
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• 제51권6호
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• pp.493-508
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• 2023

Round timber materials of 600 mm length, cut from large-cross-section round timber of red pine (Pinus densiflora S. et Z.) of 450 mm width and 4.2 m length, were prepared as the target of kiln drying in this study. After treating the target materials through end sealing (ES), end sealing - kerfing (ES-K), lateral sealing - end sealing - boring (LS-ES-B), or lateral sealing - partial end sealing (LS-PES), the effects of the treatment on the incidence of drying defects were determined. The target materials with exposed lateral surface and sealed cross surface were steamed at the initial temperature of 65℃ above the official pest control temperature of 56℃, followed by kiln drying toward the final temperature of 75℃. The target materials with sealed lateral surfaces, on the other hand, were dried at the initial temperature of 90℃ at almost the maximum temperature of conventional kiln drying, as there is no risk of early check formation caused by surface moisture evaporation. The final temperature was set at approximately 100℃. The drying time, taken for the target materials with initial moisture content of 70%-80% to reach the target moisture content of 19%, varied across treatment conditions. The measured drying time was 1,146 hours (approximately 48 days) for the timber with sealed cross surface and 745 hours (approximately 31 days) for the timber with sealed lateral surface, until the moisture content reached the target level. The formation of surface checks could not be prevented in the control and ES groups, but a definite preventive effect was obtained for the LS-ES-B and LS-PES groups.

• Journal of Plant Biology
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• 제33권4호
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• pp.285-292
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• 1990

In order to elucidate the formation of reaction tissues during the transition from primary to secondary growth, the developmental anatomy was conducted in the first internode of Ginkgo biloba seedling in horizontal position. The righting of the horizontal first internode took place at the middle portion and gradually proceeded to the base during the primary growth. Reaction tissues were formed corresponding to the righting movement in the horizontal first internode. During the transition from primary to secondary growth, compression wood was gradually developed on the lower side only. The anatomical features of compression wood also extended longitudinally to the lower side of the vertical portion where it coincided with the lower side of the horizontal first internode occurs acropetally from basal to apical portion. Eventually, some of the anatomical features of compression wood occurred at the primary growth. And the typical compression wood is gradually established during the secondary growth. On the other hand, the lower side tracheid and ray were longer and higher than those of the upper side in the horizontal first internode. However, difference in the width of ray was not observed between the lower and upper sides.

• Journal of the Korean Wood Science and Technology
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• 제40권2호
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• pp.71-77
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• 2012

Cellulose nanowhisker (CNW) isolated from hardwood bleached kraft pulp (HW-BKP) using sulfuric acid hydrolysis was suspended in polyvinyl alcohol (PVA) and electrospun into composites nanofibers. Transmission electron microscopy (TEM) revealed the CNW to be rod-like, approximately of $16.1{\pm}4.6$ nm wide and $194{\pm}61$ nm long, providing an aspect ratio of about 12, with a particle size distribution range of $662.2{\pm}301.2$ nm. Uniform and high quality CNW/PVA composite nanofibers were successfully manufactured by the electrospinning method. As the CNW loading increases, the viscosity of CNW/PVA solutions shows a minimum at 1% CNW level which subsequently results in the smallest diameter (193 nm) of electrospun nanofibers. The average diameter of the nanofibers increased up to 284 nm with increasing CNW loading. These results suggest that the electrospinning method provides a great potential of manufacturing consistent and reliable nanofibers from CNW/PVA solution for the formation of scaffolds with potentials in future application.