• 제목/요약/키워드: Wood's Function

검색결과 55건 처리시간 0.025초

공진주파수에 의한 목재의 동적탄성계수 추정 (Estimation of the Dynamic MOE in Woods with Resonance Frequency)

  • 이원희;황권환
    • Journal of the Korean Wood Science and Technology
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    • 제25권1호
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    • pp.42-49
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    • 1997
  • The purpose of this study was to investigate the relationships among density, moisture content, and modulus of elasticity in which are important characteristics in physical and mechanical properties of woods. In this study, the dynamic MOE was calculated through the combination with resonance frequency of transverse vibration method and density, and the estimated moisture contents were calculated with two different equations (1, 2) in order to compare with experimental moisture contents. The following results from this study were obtained: 1. According to the regression analysis with two different parameters (E and density), the two regression lines appeared to be straight intersecting at 0.6 density. As another factor, moisture contents in wood also influenced on the analysing regression at the below F.S.P. 2. When considering the relationship between moisture contents and E, the tendency of each moisture content and E showed very similar pattern suggesting that moisture contents in addition to density are very important parameter. 3. When together with moisture contents and density as parameters for multiple regression analysis, coefficiences of determinations are dramatically improved. Interestingly, the coefficiences of determinations are further increased when analysing at the below point of F.S.P. and when analysing higher and lower density separately. In summary, more correct estimation of the dynamic MOE of woods can be possible with only transverse vibration and density in wood. Therefore, with this indirect method, the calculation of MOE in all kinds of woods including timber, live tree and wood products can be feasible resulting in accelerating the efficiency of time and labor.

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유기용매 전처리에 의한 목재의 흡음성능 변화 (Changes of Sound Absorption Capability of Wood by Organosolv Pretreatment)

  • 강춘원;최인규;곽기섭;여환명;이남호;강호양
    • Journal of the Korean Wood Science and Technology
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    • 제40권4호
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    • pp.237-243
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    • 2012
  • 유기용매 전처리에 의한 목재 횡단면의 흡음성능과 구조적 특징의 변화를 관찰하고자 낙엽송과 백합나무로부터 원반형 시험편을 채취하였다. 탈 섬유소처리를 한 후 처리목재의 구조적 특징 변화를 관찰하고, 전달함수법을 이용하여 섬유방향 흡음율을 측정하여 이를 무처리 시의 결과와 비교하였다. 측정주파수범위(50~6,400 Hz)에서 유기용매 전처리 시험편이 무처리 시험편보다 높은 흡음율을 나타내었으며, 특히 2~4 kHz의 주파수영역에서는 90% 정도 높은 흡음율을 나타내었다. $70{\sim}120^{\circ}C$에서 유기용매 전처리한 목재는 무처리 목재와 비교하여 1.0% 미만의 중량 감소율을 보였고, 현미경에 의해 해부학적 구조 변화를 관찰할 수 있었다. 측정주파수영역에서의 흡음율 증가는 유기용매 전처리에 의한 목재의 구조적 변화에 의한 것으로 판단되었다.

폐닥나무 섬유를 혼입한 목모보드 제조 및 조습특성 분석 (Manufacturing of Wood Wool Board Mixed with Waste Paper-Mulberry Fiber and Analysis of Humidity Characteristics)

  • 김남일;조정훈;서성관;이오규;이형원;배성철;추용식
    • 자원리싸이클링
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    • 제30권4호
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    • pp.35-45
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    • 2021
  • 본 연구에서는 폐닥나무 섬유를 사용한 목모보드의 제조 및 조습 특성 분석을 수행하였다. 목모보드 제조를 위해 폐닥나무 섬유의 분쇄 시간을 30, 60, 120, 180초로 제어하였으며, 혼합량을 시멘트 대비 0, 3, 6, 9% 수준으로 외할 첨가하여 제어하였다. 분쇄시간 제어 조습섬유 혼입 목모보드의 흡·방습 특성 분석 결과, 60초 분쇄 섬유 혼합 목모보드가 흡·방습 성능이 뛰어난 것으로 확인되었으며, 이는 분쇄 섬유의 손상이 적어 소재 자체의 흡·방습 성능이 보드 혼합 시에도 발현되었기 때문이다. 또한 섬유 혼합량 제어 목모보드의 흡·방습 특성 분석 결과, 6% 혼합 목모보드가 흡·방습 특성이 가장 뛰어났으며, 흡습 및 방습량은 각각 291.00g/m2 및 108.75g/m2으로 확인되었다.

Antitimor Activity of Some Phytobased Polysaccharides and their Effects on the Immune Function

  • Moon, Chang-Kiu;Sim, Kyl-Soon;Lee, Soo-Hwan;Park, Kwang-Sik;Pyo, Yun-Yeo;Ha, Bae-Jin;Lee, Chong-Chul
    • Archives of Pharmacal Research
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    • 제6권2호
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    • pp.123-131
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    • 1983
  • Polysaccharide fractions were prepared from Ginseng root, Mori Radicis Cortex (M. R. C. ), Phellodendri Cortex (Ph. C. ), Sappan Wood (S. W. ) and Tigli Semen (T. S.). Water extract was also prepared from the mixture of ph. C., S. W. and T. S. Ginseng polysaccharide and water extract of the mixture showed marked antitumor activity against sarcoma 180. Ginseng polysaccharide showed a mild increasing effect on the number of circulating leucocytes and a marked increasing effect on the number leucocytes and a marked increasing effect on the number of plaque forming cells (PEC). Polysaccharides from ginsing root, S. W., Ph. C. + T. S. and water extract of the mixture showed dramatic inducing activities of periotoneal exudate cells (PEC), polymorphonuclear leucocytes (PMN) and macrophages. These results suggest the possibility that water extract of the mixture may have the lentinan like effect and ginseng polysaccharide may have stimulating effects on the general immune system.

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Fourier-Galerkin Moment Method를 이용한 접지된 2개 유전체층 위의 완전도체띠 격자구조에 의한 TE 산란의 해 (Solution of TE Scattering by a Perfectly Conducting Strip Grating Over the Grounded Two Dielectric Layers Applying Fourier-Galerkin Moment Method)

  • 윤의중
    • 한국항행학회논문지
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    • 제16권4호
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    • pp.635-640
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    • 2012
  • 본 논문에서는 접지된 2개의 유전체층 위의 도체띠 격자구조에 의한 TE (Transverse Electric) 산란문제를 도체경계조건과 수치해석 방법인 FGMM (Fourier-Galerkin Moment Method)를 적용하여 해석하였으며, 이 때 유도되는 표면전류밀도는 미지의 계수와 단순한 함수인 지수함수의 곱의 급수로 전개하였다. 전반적으로, 제안된 구조에서 영역-2의 유전체층의 비유전율 ${\epsilon}_{r2}$과 유전체 층의 두께 $t_2$가 증가함에 따라 반사전력이 증가하였다. 반사전력의 급변점들은 공진효과에 기인한 것으로 과거에 wood's anomaly라고 불리워졌으며, 수치계산 결과들은 기존 논문의 결과들과 일치하였다.

황원어(黃元御) 의학사상의 도서역학적 연구 (Study for Medical Thinkings of Huang Yuan-Yu on Tu Shu Yi)

  • 김영목
    • 동의생리병리학회지
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    • 제23권2호
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    • pp.308-318
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    • 2009
  • This study makes clear Huang Yuan-Yu(黃元御)'s medical thoughts Yi-philosophically. Yi-philosophy(易學) since ancient times is occupied by fundamental problems of various fields of Oriental Science. Confusian Medicine Reseachers of Zhang Jie-Bin(張介賓), Zhang Nan(章楠), Zhu Zhen-Heng(朱震亨) was seriously affected by Yi-philosophy(易學) and Confucianism(儒學). But I don't think that the majority of their medicine theories are occupied by Yi-philosophy(易學) and Confucianism(儒學). But Huang Yuan-Yu(黃元御) studied medicine thoughts on the basis of Tu Shu Yi(圖書易) in almost whole medicine theories and clinical contents. Therefore this study researched medical thinkings of Huang Yuan-Yu(黃元御) on Yi-philosophical medical viewpoint Tu Shu Yi(圖書易)-scientifically. Especially in this paper the author examined a characteristic point in medical thoughts of Huang Yuan-Yu(黃元御), the difference of existing medicine on Nei-Jing(內經) and Yi-medicine of Huang Yuan-Yu(黃元御), a commonness of medicine principles of Huang Yuan-Yu(黃元御) and Li Ji-Ma(李濟馬)), medicine theories of Huang Yuan-Yu(黃元御) on Tu Shu Yi(圖書易) and a background of Yi-philosophical medical standpoint. The results was summarized as follows; First, Huang Yuan-Yu(黃元御)'s standpoint on five phase is that the relation of earth and wood fire metal water is form and use(體用). Huang Yuan-Yu(黃元御) insists that the earth represents existence itself and wood fire metal water is concepts that represents actual states. Second, the concept of Four-Constitution of Huang Yuan-Yu(黃元御) and Li Ji-Ma(李濟馬) is same. Third, Huang Yuan-Yu(黃元御) doesn't have a standpoint of five-phase on Nei-Ching Medicine, but a standpoint of five-phase on Yi-philosophy. Fourth, water, fire, metal, wood is Four-Constitution that middle qi transformed. Fifth, the middle qi is yang-earth and yin-earth of the spleen and stomach, the physiological function of four viscera is maintained by the movement of ascending and descending of yin and yang earth. Sixth, The middle qi is main role of Four-Constitution. Exchanging of water and fire and the movement of ascending and descending of metal and wood depends on the earth. Seventh, generally medicine researchers speak that human mind is a main role of psycho-function of heart, but Huang Yuan-Yu has the standpoint of spleen-stomach oriented seven emotions not human-mind oriented viewpoint. It represents that a existing thinking of heart-earth center is changed to medical viewpoint of spleen-earth center. Eighth, There is enough ground for controversy on where is the middle point of human in five viscera. Is that spleen or heart? Huang Yuan-Yu(黃元御) insists that the spleen and stomach is middle point, but the standpoint in Four-Constitution medicine of Li Ji-Ma(李濟馬) is that middle point is heart.

한국 가구 하드웨어 변화 연구 - 조선시대부터 현대까지 - (A Study on Changes of Furniture Hard Ware in Korea - From the Joseon Era to Modern Times -)

  • 조숙경;문선옥
    • 한국가구학회지
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    • 제23권2호
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    • pp.122-129
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    • 2012
  • This article was intended as fundamental materials to recognize the current status of furniture hard ware in Korean market and to fix the identity of Korean furniture, by investigating and comparing the furniture hard ware used in the Joseon era and in modern times by type, function, shape and material. The analysis of furniture hard ware of the Joseon era and modern times from the view of functional aspects was oriented to the hard ware necessary to open and close the door & drawer on one side, and to that being attached to the main body of furniture not to scratch the wood by another wood on the other side, and from this the following conclusion was drawn. First of all, "Gwangdoojung" - a kind of spike- and metal decoration on the edge of the furniture disappeared, while the function-oriented hard wares have been diversified in modern times, from the perspective of the change of kinds. Second, the functional aspect of the furniture hard ware was emphasized in modern times than the Joseon era. In other words, the hard wares of the Joseon era came into view due to their strong appeal to decoration, whereas those of modern times were mostly hidden or moderated, keeping the function substantially. Third, the hard wares from the Joseon era were shown in concrete and detailed shape motivated by natural objects and furthermore even gloriously, but the modern hard wares are simple & basic geometry, from a formative point of view. Fourth, the material aspects present that the Joseon era's hard ware was mainly cast iron, whereas that of modern times shows the diversification from metal to even plastic. Finally, the recent trend in naming of the hard wares is the words of foreign origin. This resulted from that the foreign names of hard wares are valid also after import process in Korean market, so the domestic development of hard ware as the essential factor for the furniture design is urgently necessary to establish the identity of Korean modern furniture.

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접지된 다층 유전체위의 저항띠 격자구조에 의한 TE 산란의 해 (Solution of TE Scattering by a Resistive Strip Grating Over Grounded Dielectric Multilayers)

  • 윤의중
    • 한국통신학회논문지
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    • 제31권9A호
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    • pp.913-919
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    • 2006
  • 본 논문에서는 스트립 폭과 격자주기, 비유전율, 유전체 층의 두께, 그리고 TE(transverse electric) 평면파의 입사각에 따른 접지된 다층 유전체위의 저항띠 격자구조에 의한 TE 산란 문제를 수치해석 방법인 FGMM(Fourier-Galerkin Moment Method)을 이용하여 해석하였다. 유도되는 표면전류밀도는 간단한 함수인 지수함수를 사용하여 Fourier 급수로 전개하였다. 전반적으로 다층유전체의 비유전율과 두께가 증가함에 따라 반사전력이 증가하였고, 반사전력의 급변점들은 공진효과에 기인한 것으로 과거에 wood's anomallies$^{[7]}$라고 불리워졌다. 제안된 방법의 검증을 위하여 기존의 완전도체 경우인 균일 저항율 R = 0에 대한 정규화된 반사전력의 수치결과는 기존 논문들과 일치하였다.

접지된 유전체 평면위의 저항띠 격자구조에 의한 TE 산란 해석 (Analysis of the TE Scattering by a Resistive Strip Grating Over a Grounded Dielectric Plane)

  • 윤의중
    • 한국항행학회논문지
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    • 제10권3호
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    • pp.198-204
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    • 2006
  • 본 논문에서는 스트립 폭과 격자주기, 유전체 층의 비유전율과 두께, 그리고 TE(transverse electric) 평면파의 입사각에 따른 접지된 유전체 평면위의 저항띠 격자구조에 의한 TE 산란 문제를 수치해석 방법인 FGMM(Fourier-Galerkin Moment Method)를 이용하여 해석하였다. 유도되는 표면전류밀도는 간단한 함수인 지수 함수를 사용하여 Fourier 급수로 전개하였다. 유전체층의 비유전율과 두께가 증가함에 따라 반사전력이 증가하였고, 반사전력의 급변점들은 공진효과에 기인한 것으로 과거에 wood's anomallies[7]라고 불리워졌다. 제안된 방법의 검증을 위하여 기존의 완전도체 경우인 균일 저항율 R = 0에 대한 정규화된 반사전력의 수치결과는 기존의 논문들과 일치하였다.

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MPTP로 유도된 신경 독성에 대한 NXP031의 개선 효과 (Ameliorative Effects of NXP031 on MPTP-Induced Neurotoxicity)

  • 이주희;송민경;김연정
    • Journal of Korean Biological Nursing Science
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    • 제23권3호
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    • pp.199-207
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    • 2021
  • Purpose: The purpose of this study was to investigate effects of NXP031, an inhibitor of oxidation by specifically binding to the complex of DNA aptamer/vitamin C, on dopaminergic neurons loss and the reaction of microglia in an animal model of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced subchronic Parkinson's disease (PD). Methods: A subchronic PD mouse model was induced via an intraperitoneal (IP) injection of MPTP 30 mg/kg per day for five days. NXP031 (vitamin C/aptamer at 200 mg/4 mg/kg) and vitamin C at 200 mg/kg were administered via IP injections at one hour after performing MPTP injection. This process was performed for five days. Motor function was then evaluated with pole and rotarod tests, after which an immunohistochemical analysis was performed. Results: NXP031 administration after MPTP injection significantly improved motor functions (via both pole and rotarod tests) compared to the control (MPTP injection only) (p<.001). NXP031 alleviated the loss of dopaminergic neurons in the substantia nigra (SN) and striatum caused by MPTP injection. It was found to have a neuroprotective effect by reducing microglia activity. Conclusion: NXP031 can improve impaired motor function, showing neuroprotective effects on dopaminergic neurons in the SN and striatum of MPTP-induced subchronic Parkinson's disease mouse model. Results of this study suggest that NXP031 has potential in future treatments for PD and interventions for nerve recovery.