• Title/Summary/Keyword: MOE

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The Practice of Bending Deflection using Non-destructive MOE of Glulam (비파괴 탄성계수를 이용한 집성재의 휨변형 예측)

  • Park, Jun-Chul;Hong, Soon-Il
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.1
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    • pp.48-55
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    • 2009
  • In the glulam beam deflection it is necessary to check the reliability of theory formula, because of wood anisotropy and wood qualities (knot, slop of grain). In this experiment, when bending stress occurred on glulam, practice deflection of glulam measuring with AICON DPA-Pro 3D system were compared with prediction deflection calculated as substituting MOE through non-destructive testing and static MOE through bending test in differential equation of deflection curve. MOE using ultrasonic wave tester of laminae, MOE using natural frequencies of longitudinal vibrations ($E_{cu}$, $E_{cf}$), MOE using ultrasonic wave tester of glulam ($E_{gu}$) and MOE using natural frequencies of longitudinal vibrations ($E_{gf}$) were substituted in this experiment. When practice deflection measured by 3D system was compared with prediction deflection calculated with differential equation of deflection curve, within proportional limit the ratio of practice deflection and prediction deflection was similar as 1.12 and 1.14, respectively. Deflection using ultrasonic wave tester was 0.89 and 0.95, Deflection using natural frequencies of longitudinal vibrations was 1.07 and 1.10. The results showed that prediction deflection calculated by substituting using non-destructive MOE of glulam having anisotropy in differential equation of deflection curve was agreed well with practice deflection.

Effects of Finger Joint and Strength of Lamination on the Estimation of Strength Properties of Glulam (집성재의 강도적 성질 예측에 대한 핑거 조인트와 라미나의 강도의 영향)

  • Kim, Gwang-Chul;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.28 no.1
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    • pp.8-17
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    • 2000
  • Structural glued laminated timbers were manufactured from Japanese larch(Larix leptolepis) lumber. The effect of various factors, such as finger joint, strength of lamination, on the strength properties of glulam was investigated. When only MOE of lamina was used as input variable for the estimation of strength properties of glulam, the deviations between actual and simulated results were increased with the number of lamination, because the effects of variance of lamina properties on the strength estimation of glulam were cumulated with the number of lamination. Therefore, to estimate the MOR of glulam more careful approach was needed. Besides, both MOE and MOR of lamination were used as input variable to compare the effect of input variable. In the case of finger jointed lamination was located in tension zone, MOE of glulam was some effected, because of the variation of MOE of lamination and the deficiency of information for knot. In the case of finger jointed lamination wasn't located in tension zone, more exact estimation was possible than the case of finger jointed lamination was located in tension zone. From the results, it was concluded that more exact estimation of strength properties of glulam could be obtained by considering effects of both finger joint and knot.

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The Bending Performances of Sloped Finger-Jointed Rhus verniciflua (옻나무 경사핑거접합재의 휨강도성능)

  • 변희섭;이원희;홍병화
    • Journal of the Korea Furniture Society
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    • v.10 no.1
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    • pp.65-71
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    • 1999
  • The bending performance of sloped finger-jointed Rhus verniciflua were tested in order to improve the strength properties of finger-joint. Sloped finger-cut pieces were jointed with three kinds of adhesives (polyvinyl acetate, polyvinyl-acryl acetate and oilic resin). The slope ratios of finger joints were 0, 1.0, 1.5, and 2.0. The MOE, MOR and deflection to maximum load in bending of sloped finger-joints and solid wood specimen were measured. The results were : 1) The efficiencies of MOE to finger and sloped finger-joints to the solid wood were almost same in the three kinds of adhesives(polyvinyl acetate, polyvinyl-acryl acetate and oilic urethane resin) and there were some effect of slope on the MOE in a sloped finger-joint for three kinds of resin adhesives. 2) There was the effect of slope on the MOR in sloped finger-joints in every kind of adhesive. The efficiencies of MOR in slope ratios of 0 and 2.0 ranged 65-79%, respectively. There was also a slight effect of the kinds of adhesives on the MOR. However, the efficiencies of deflection to the urethane resin adhesive were much less than those of polyvinyl acetate, polyvinyl-acryl acetate resin adhesives except the slope ratio of 0. 3) It might be impossible to estimate the bending stregth of sloped finger-jointed Rhus verniciflua by using MOE. The correlation coefficient(0.192) between MOE was very low and not significant at 5% level.

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Estimating MOE of Thermal Degraded Wood by Stress Wave Method (Stress wave법에 의한 열적 열화된 목재의 휨탄성계수 예측)

  • Lee, Jun-Jae;Kim, Jeong-Won
    • Journal of the Korean Wood Science and Technology
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    • v.26 no.3
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    • pp.9-15
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    • 1998
  • The strength and stiffness of structures would be weakened by thermal degradation of wood members which are exposed to a variety of heat including a fire. For this reason, thermal degraded wood members can't pertinently support the load. However, it is easy to repair or rehabilitate wood structures. So, the degraded wood members which can't support the load can be replaced with new members. For the sake of this advantage, there is a need for nondestructive evaluation(NDE) technique, which is very effective to assess wood members in service. In this paper, it was considered whether the stress wave method is adequate to estimate static bending MOE of thermal degraded wood. As the result, the relationship between static bending MOE and MOEsw in elevated temperature was found out significant. Therefore, the application of stress wave method for estimating static bending MOE of thermal degraded zzwood would be possible. However, it is thought that further research for the effects of exposure temperature, time, and thermal degradation on the relationship between static bending MOEb and MOEsw would be needed.

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A Study on the Harmonization of Poisonous Substance Used in Paint Manufacture (도료제조업종에서 취급하는 유독물의 GHS 분류 통일화 방안 연구)

  • Lee, Jong Han;Hong, Mun Ki;Kim, Hyun Ji;Park, Sang Hee
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.23 no.2
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    • pp.156-163
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    • 2013
  • Objectives: Numerous poisonous substances are used in paint manufacture, but there are differences in the results of GHS classification between the Ministry of Labor(MOL) and the Ministry of Environment(MOE). Therefore, paint manufacturers suffer confusion as to how to classify a given chemical's risk and hazard level. This paper was designed to compare the classification results of chemicals by the MOL and the MOE and suggest a harmonization measure. Methods: After selecting 25 poisonous substances from among the organic solvents, pigments, and additives used in paint manufacturer, the GHS classification results by MOL and MOE were compared. Further the logic and classification of the GHS proposed by each Ministry was analyzed. Based on the derived results, a harmonization plan was proposed. Results: Based on the GHS classification of the poisonous substances, the concordance is 10.0-66.6 %, excluded flammable liquid. The GHS classifications differed based on the suggested building blocks, the sub-classification method used, the references(data sources), and subjective judgment of the experts from each Ministry. In order to pursue the harmonization plan, cooperation is demanded from the MOL and MOE.

The Nimby Syndrome and Basic Plan for Waste Treatment Facilities in 1994 (님비와 폐기물처리시설 설치 방향)

  • 신현국
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.59-64
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    • 1994
  • In order to democractically resolve the "not-in-my-backyard" (Nimby syndrome) which is widespread in Korea, the policy of the Ministry of Environmnt(MOE) is that the MOE is willing to negotiate with local inhabitants who refuse to allow the establishment of waste treatment facilities, and that such facilities will be safety and effectively constructed and managed. According to this policy, the MOE has developed a basic plan to construct 255 incinerators by the year 2001, and establish 42 sanitary landfill sites and 5 specific waste treatment facilities in 1994.s in 1994.

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Effect of Acetylation on Ultrasonic Velocity of Bamboo (아세틸화 처리가 대나무재의 초음파 전달 속도에 미치는 영향)

  • Kang, Ho-Yang;Lee, Gwan-Young
    • Journal of the Korean Wood Science and Technology
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    • v.25 no.3
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    • pp.8-15
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    • 1997
  • The ultrasonic velocity and dynamic MOE of acetylated bamboos were investigated using PUNDIT, a transit time measuring device for longitudinal ultrasonic propagation. Bamboo specimens were boiled in acetic anhydride for 2, 4 and 6 hours, and the maximum average WPG (Weight Percentage Gain) of 19% was obtained at 6 hours. The volumes of acetylated bamboos increase with boiling time and WPG, while as WPG increases their oven-dry densities generally increase with a concave around 5% WPG. This oven-dry density pattern likely influences the trends of ultrasonic velocity and dynamic MOE. which generally decrease with a convex around 5% WPG. It is postulated that during boiling extractives in a bamboo move and aggregate at its surfaces transiently, resulting in the increase of ultrasonic velocity and dynamic MOE. To explain the fact that ultrasonic velocity varies with WPG a simple model was proposed and some ultrasonic properties of a transmitted wave were examined.

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Correction of King-Moe Type V Scoliosis with Optimization Method in a FE Model (King-Moe Type V 형태의 척추측만증 유한 요소 모델에서 최적화 기법을 적용한 교정 방법)

  • 김영은;손창규;박경열;정지호;최형연
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.701-704
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    • 2003
  • Scoliosis is a complex musculoskeletal dieses requiring 3-D treatment with surgical instrumentation. Conventional corrective surgery for scoliosis was done based on empirical knowledge without information of the optimum position and operative procedure. Frequently, post operative change of rib hump increase and shoulder level imbalance caused serious problems in the view of cosmetics. To investigate the effect of correction surgery, a reconstructed 3-D finite element model for King-Moe type V was developed. Vertebrae, clavicle and other bony element were represented using rigid bodies. Kinematic joints and nonlinear bar elements used to represent the intervertebral disc and ligaments according to reported experimental data. With this model, optimization technique was also applied in order to define the optimal magnitudes of correction. The optimization procedure corrected the scoliotic deformities by reducing the objective function by more than 94%. with an associated reduction of the scoliotic descriptors mainly on the frontal thoracic curve.

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Geft is dispensable for the development of the second heart field

  • Fan, Xiongwei;Hou, Ning;Fan, Kaiji;Yuan, Jiajia;Mo, Xiaoyang;Deng, Yun;Wan, Yongqi;Teng, Yan;Yang, Xiao;Wu, Xiushan
    • BMB Reports
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    • v.45 no.3
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    • pp.153-158
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    • 2012
  • Geft is a guanine nucleotide exchange factor, which can specifically activate Rho family of small GTPase by catalyzing the exchange of bound GDP for GTP. Geft is highly expressed in the excitable tissue as heart and skeletal muscle and plays important roles in many cellular processes, such as cell proliferation, migration, and cell fate decision. However, the in vivo role of Geft remains unknown. Here, we generated a Geft conditional knockout mouse by flanking exons 5-17 of Geft with loxP sites. Cre-mediated deletion of the Geft gene in heart using Mef2c-Cre transgenic mice resulted in a dramatic decrease of Geft expression. Geft knockout mice develop normally and exhibit no discernable phenotype, suggesting Geft is dispensable for the development of the second heart field in mouse. The Geft conditional knockout mouse will be a valuable genetic tool for uncovering the in vivo roles of Geft during development and in adult homeostasis.