• Title/Summary/Keyword: lumber

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A Study on the Ignitibility of Wooden Flooring (목질바닥재의 착화특성에 관한 연구)

  • Kim, Hae-Rim;Kim, Young-Tak;Park, Young-Ju;Lee, Hae-Pyeong
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.11a
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    • pp.397-402
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    • 2008
  • In this study, we analyzed the ignitibility of the wooden floorings used as the finishing materials for interior with the flammability tester and the ignition point tester. Also we analyzed the limit oxygen index(LOI) using the oxygen index tester and the flame resistance of the wooden floorings. We confirmed that all of the samples had a excellent flame resistance. The ignitibility of the floorings were ranked as the material lumber>the strengthening flooring>the veneer board(1)>the veneer board(2).

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Allowable Stress Calculation of Domestic Japanese Larch Small Diameter Lumbers (국내산 낙엽송 소경각재의 허용응력 산출)

  • Kim, Yun-Hui;Shin, Il-Joong;Yang, Jung-Mo;Jang, Sang-Sik
    • Journal of the Korea Furniture Society
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    • v.23 no.2
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    • pp.214-221
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    • 2012
  • Sustainable energy consumption and increasing $CO_2$ emissions stimulate Eco-friendly industry. Wood has positive various properties as alternative energy such as solar, wind and water. Wood provide lumber, pallet, paper, pulp and fuel through production process. Even Korea republic has 63.7% of forest rates, weather condition makes low forestry production capacity. For utilization of domestic small diameter log needs study mechanical properties. In this study, various properties tested on domestic Japanese Larch small diameter lumbers and make mechanical properties table for allowable stress calculation. Result of compressive test, allowable compressive stress is 13 MPa. Allowable bending stress is 12 MPa.

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A Study on Performance of Old Lumber Member in Different Material Joint (이질재료와 결합된 노후화된 목재 부재 성능에 관한 연구)

  • Shim, Hak-Bo;Park, Soon-Jeon
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2009.04a
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    • pp.504-507
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    • 2009
  • 구조용 재료중에서 목재는 비중에 비하여 강도가 크고. 가공성이 우수하며, 뛰어난 미관을 가지고 있다는 장점이 있지만 다른 건축 구조재료에 비하여 연소와 부식의 우려뿐만 아니라, 쉽게 부패하고 변형이 되는 단점도 가지고 있는 것이 사실이다. 이러한 단점에 의해 생긴 심각한 결함은 건물을 붕괴할 수도 있다. 따라서, 오늘날 목재가 사용된 건축물의 경제적인 유지관리가 중요시 되고 있다. 본 연구는 이질재료와 접합된 노후화된 목재 부재의 성능을 분석하여 쉽게 부패하고 변형이 되는 목재의 효율적인 유지관리방향의 기초를 확립하고자 하는 것을 목표로 하고 있다.

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Effect of specific gravity and annual ring width on the acoustical properties of European lumber used in violin making (유럽산 바이올린 용재의 비중과 년륜폭이 소재의 음향적 성질에 미치는 영향)

  • 정우양;홍병화
    • Journal of the Korea Furniture Society
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    • v.10 no.1
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    • pp.57-63
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    • 1999
  • This study was carried out to analyze the relationship between basic physical properties and acoustical characteristics of imported violin wood and to offer the information on raw material procurement and incoming-material quality control to domestic violin makers which have purchased most raw materials from European exporting countries at high expense. Equilibrium moisture content of European spruce with lower specific gravity after the prolonged storage was rather higher than that of European maple with higher specific gravity. The specific gravity of spruce increased with decreasing annual ring width, however, that of narrower annual ring. Increasement in specific gravity enhanced the dynamic Young's modulus of both wood species, but influenced the vibration energy loss by internal friction differently between two species. For dynamic MOE, qurater-sawn spruce was higher than the flat-sawn, but maple showed the reverse directional characteristics. Consequently, it would be well for violin makers to establish the standard for materials and quality control system to assure the quality of their violin products.

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Properties of 3-layered Laminated Veneer Lumber with Crack and Grain Angle from Stress Wave Tested Veneers (응력파 실험에 의해 예측된 단판으로 제작한 할열과 목리를 지닌 3매 단판적층재의 특성)

  • Cha, Jae-Kyung
    • Journal of the Korean Wood Science and Technology
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    • v.18 no.3
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    • pp.17-25
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    • 1990
  • 양표면은 무결점재를, 가운데 단판은 경사목리 및 목리방향의 할열을 가진 단판을 사용하여 제조한 3매 단판 적충재에 있어서 목리방향과 할열의 인장탄성계수 및 인장강도에 미치는 영향에 대하여 조사하였다. 또한, 비파괴 시험 방법인 응력파 실험에 의하여 각단판의 탄성계수를 측정하고, 이들 단판의 탄성계수로부터 단판적층재의 탄성계수를 예측하여 실측치와 비교하였다. 응력파에 의해 예측된 탄성계수는 인장실험으로부터 얻어진 결과와 거의 일치하였으며 인장탄성계수와 인장강도간에도 높은 상관관계를 나타내었다($r^2$=0.681). 인장강도에 있어서는 가운데 단판 할열의 영향은 나타나지 않았으나 목리의 경우 경사각이 증가함에 따라 인장강도가 감소하는 경향을 나타내었다.

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Prevention of Mold Growth on CCA-treated Radiata Pine Lumber by Incorporation of Moldicide into the CCA Solution

  • Kang, Sun-Mi;Kim, Gyu-Hyeok
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.2
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    • pp.79-84
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    • 2007
  • Surface mold fungi growing on CCA-treated wood could be inhibited effectively by the incorporation of moldicide into treating solution. In this study, moldicides compatible with the CCA solutions from various commercial moldicides were screened, and then their optimum concentrations for controlling surface mold on CCA-treated radiata pine sapwood were examined through both the laboratory and the field trials. Among nine commercial moldicdes tested, two substituted isothiazolinones, moldicide A containing 2-n-octyl-4-isothiazoline-3-one and moldicide B containing 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one, were chemically compatible with CCA solution. The optimum concentration to be incorporated into 2% CCA treating solution was determined to be 0.001% for moldicide A and 0.003% for moldicide B.

Analysis of Solar Radiation and Heat-Efficiency in Semi-Greenhouse Type Solar-Dehumidification Lumber Dryer (반온실형(半溫室型) 제습(除濕).태양열(太陽熱) 목재(木材)드라이어의 일사량(日射量)과 열효율분석(熱效率分析)에 관(關)한 연구(硏究))

  • Lee, Hyoung-Woo
    • Solar Energy
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    • v.9 no.3
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    • pp.3-12
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    • 1989
  • Semi-greenhouse type solar-dehumidification drying of oak was carried out to investigate the possibility to dry wood using solar energy in Korea. The energy balance equation was set up, considering all the energy requirements, and the solar radiation was calculated to analyze the efficiencies of solar dryer with and without the dehumidifier. The average temperature inside dryer and collector rose up to $52^{\circ}C$ and $70^{\circ}C$, respectively. The average daily total beam, diffuse, and ground-reflected radiations were 7.27MJ, 8.70MJ, and 0.33MJ on the roof and 2.08MJ, 4.84MJ, and 5.37MJ on the south wall collector, respectively. Heat efficiency of solar dryer was 14.04% with dehumidifier and 13.13% without dehumidifier. The energy required to remove 1g of water from wood was 0.0289MJ/g in solar-dehumidification drying and 0.0310 MJ/g in semi-greenhouse type solar drying.

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The Effect of Electrical Stimulation on Bacterial Growth (전기자극이 세균성장에 미치는 영향)

  • Park Young-Han;Kim Jin-Sang;Park Rae-Joon
    • The Journal of Korean Physical Therapy
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    • v.6 no.1
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    • pp.109-119
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    • 1994
  • The study was carried out to investigate the change of bacterial growth in vitro according to polarity, current intensity and time, to prepare the basic data for electrotherapy and clinical research. The Gram positive Staphylococcus aureus and Gram negative Escherichia coli 1mm infect wound were cultured in Trypticase Soy Brath and Trypticase Soy Agar. The results were as followings. 1. The current stimulated group was changed in bacterial growth according to polarity, current intensity and time respectively. 2. The bacteriolytic effect revealed in the anode but the inhibitory effect of bacterial growth revealed in the cathode. 3. The lumber of E. coli reduced after 6-hours but the numbers of S. aureus reduced after 2 hours in Trypticase Soy Brath. 4. The anode showed acid reaction and cathode showed alkaline reaction in Trypticase Soy Agar.

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A Study on the Finishing Material terms analyzed the Building Specifications in Chosun Dynasty - limit the palace construction work - (조선조 영건의궤를 통한 수장재 용어에 관한 연구 - 궁궐건축을 중심으로 -)

  • Hong Seok-Joo
    • Korean Institute of Interior Design Journal
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    • v.14 no.2 s.49
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    • pp.12-19
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    • 2005
  • After an important construction work in Chosun dynasty, the appropriate government made out the building specification as it called 營建儀軌. They are recorded about variety matters as the appointed days, various official documents, managers and craftsmen, etc.. Sometimes we can see the attached pictures about some building or furniture. specifications in Chosun dynasty about the unit of materials and history of each terms. The results are as followings: (1) The interior materials are classified to several units such as Gai(箇;the unit of square lumber or log), Rip(立;the unit of plates), Boo(部;the unit of assembled materials), etc.. (2) The terms are defined and enlightened how to use and how to change. Particularly, the terms are different positively in constituent units of wooden floor. So, it is expected to continuant study.

Visualization of Vortex Lock-on to Oscillatory Incident Flow in the Cylinder Wake Using Time-Resolved PIV (고속 PIV계측에 의한 실린더 근접후류 공진 유동 가시화)

  • 송치성
    • Journal of Advanced Marine Engineering and Technology
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    • v.25 no.6
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    • pp.1353-1361
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    • 2001
  • Vortex lock-on or resonance behind a circular cylinder is visualized using a time-resolved PW when a single frequency oscillation is superimposed on the mean incident velocity. For vector processing, a cross-correlation algorithm in conjunction with a recursive correlation and interrogation window shifting techniques is used. Measurements are made of the Karmas and streamwise vertices in the wake-transition regime at Reynolds lumber 360. When lock-on occurs, the vortex shedding frequency is found to be half the oscillation frequency as expected from previous experiments. At the lock-on state, the Karman vortices are observed to be more disordered by the increased strength and spanwise wavelength of the streamwiee vortices, which lead? to a strong three-dimensional motion.

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