• Title/Summary/Keyword: Strength Gain

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The Study of the Changeable Table Design with Units that made of Wasted Wood (소경단목재(小輕短木材) 접목을 활용한 유니트 가변형 테이블디자인 연구개발)

  • Kim, Myeong-Tae;Seo, Seok-Min
    • Journal of the Korea Furniture Society
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    • v.23 no.1
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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.

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General Response for Lateral-Torsional Buckling of Short I-Beams Under Repeated Loadings (반복하중을 받는 짧은 I형 보의 횡-비틀림 좌굴의 일반적 응답에 관한 고찰)

  • 이상갑
    • Computational Structural Engineering
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    • v.5 no.1
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    • pp.119-132
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    • 1992
  • The objective of this study is to perform extensive parametric studies of the lateral-torsional buckling of short 1-beams under repeated loadings, and to gain a further insight into the lateral-torsional beam buckling problem. A one-dimensional geometrically (fully) nonlinear beam model is used, which includes superposed infinitesimal transverse warping deformation in addition to finite torsional warping deformation. A multiaxial cyclic plasticity model is also implemented to better represent cyclic metal plasticity in conjunction with a consistent return mapping algorithm. The general response for the lateral-torsional buckling of short I-beams under repeated loadings is examined through several parametric studies around the standard case : the material yield strength, the yield plateau, the strain hardening, the kinematic hardening, the residual stresses, the load eccentricity with respect to the shear center, the height of the load with respect to the cross-section of the beam, the location of the load along the length of the beam, the dimensions of the cross-section of the beam and the fixity of the supported end remote from the load.

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Osteosarcopenic Obesity in Elderly: The Cascade of Bone, Muscle, and Fat in Inflammatory Process

  • Du, Yang;Oh, Chorong;No, Jae-kyung
    • Culinary science and hospitality research
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    • v.23 no.6
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    • pp.173-183
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    • 2017
  • Conditions related to body composition and aging, such as osteopenic obesity, sarcopenia/ sarcopenic obesity, and the newly termed osteosarcopenic obesity(triad of bone, muscle and adipose tissue impairment), are beginning to gain recognition. Currently, it has begun to attract the attention of scholars from all over the world, however, for this disease, it still needs a more clear understanding and perception. Therefore, this article considered the osteoporosis, muscle depression, and obesity, these diseases as a gate to study the relationship among muscle, bone, and fat. In addition, in the aging process, the formation of IGF-cortisol, testosterone, and estrogen is sensitive. These hormones can not only absorb muscle protein metabolism, but also affect alienation. The decrease in IGF-cortisol in the elderly resulted in increased visceral fat, decreased muscle mass and bone mineral density, and then affected decreased skeletal muscle atrophy and decreased quality. The reduction of skeletal muscle quality and strength and increase body fat affected the adipose tissue to produce inflammatory cytokines, thereby reduced skeletal muscle, promoted cardiovascular disease, metabolic syndrome and insulin resistance in chronic diseases. Almost all chronic inflammatory diseases were associated with bone, muscle and fat. These mechanisms were complex and interrelated. Inflammation reduces bone formation, increases fat and reduces muscle mass. And thus not only had a significant impact on the motor system, but also made the incidence increase of fracture, osteoporosis, fragile syndrome, fall, osteomalacia and other bone disease. This article aimed to start from the interaction between the muscles and bones of the elderly, extended to obesity, muscle deficiency, osteoporosis and other diseases, finally, from a nutritional point of view, to discuss how to treat osteoporosis obesity.

Existential Philosophic at Approach to Nursing Science (간호학의 실존철학적 접근-서양의 실존주의와 동양의 불교사상을 중심으로-)

  • 최연자
    • Journal of Korean Academy of Nursing
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    • v.26 no.4
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    • pp.759-767
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    • 1996
  • This study was done to provide an understanding of nursing in relation to the existential philosophy of the West and Buddhistic philosophy, It examined how human beings and death are interpreted and understood in existential philosophy as well as in Buddhistic philosophy. Then the study suggested that nursing should focus on helping the sufferer to find meaning and a sense of responsibility in his or her existence. When people have the opportunity to realize certain important but painful truths about their existence, they develop internal strength and control of their lives. Just as people learn to face their being, so can they come to terms with their non-being. According to the causal process in Buddhism, Human Being is not always annihilation of self. Therefore, birth, aging, disease and death go through the process of natural change and it is the appearance of human existence which is inherent in the health of every human being. To promote our health we must gain an insight about this phenomenon. This study viewed nurses' clients as 〈good friend〉 rather than 〈patient〉 which focuses on a disease-oriented concept. The concept of 〈good friend〉 views nurses' clients as active participants to create their life and as responsible persons in a constantly changing life. The study also examined the concept of recovery which means to come back to the previous healthy state and it suggested that the concept of recovery should be changed to 〈good change〉, because in existential philosophy, human beings are viewed as never going back to the past but moving on to the future by creating their existence. This study also suggested that nursing should help 〈good friend〉enlighten their existence to be free from pain and death and to get control over their existence.

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Axisymmetric Nonlinear Consolidation Analysis for Drainage-installed Deposit Considering Secondary Compression (배수재가 설치된 연약지반의 2차압축을 고려한 축대칭 비선형 압밀해석)

  • Kim Yun-Tae
    • Journal of the Korean Geotechnical Society
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    • v.21 no.3
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    • pp.133-140
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    • 2005
  • In order to accelerate the rate of consolidation settlement and gain a required shear strength for a given soft clay deposit, vertical drain method combined with a preloading technique has been widely applied. In this paper, a theory of axisymmetric nonlinear consolidation fer drainage-installed deposit, which considers secondary compression (or creep) during primary consolidation, as well as the variations of compressibility and permeability during the consolidation process, has been developed. A computer program named AXICON based on Hypothesis B fur the analysis of axisymmetric nonlinear consolidation was developed by adopting finite difference method. The results of AS(ICON were compared with Hansbo's solution based on Hypothesis A, as well as in-situ settlements and pore pressures measured in test embankment of Ska-Edeby. The results indicated that Hypothesis A usually underestimated the in-situ settlement and Hypothesis B was considered to be logically correct. It was also shown that one may able to appropriately predict the real in-situ behaviors using the proposed program.

Development of Eco-Block for Grass Growth based on Expanded Vermiculite Absorbing Bacteria (박테리아 흡착 팽창질석 기반 친생태 잔디블록의 개발)

  • Yoon, Hyun-Sub;Jung, Seung-Bae;Yang, Keun-Hyeok;Lee, Sang-Seob;Lee, Jae-Yeung
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.3
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    • pp.316-321
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    • 2016
  • This study developed an eco-block for grass growth using the expanded vermiculites that absorb bacteria selected considering for the high pH and dry environments and plant growth. For the developed eco-block, a fundamental properties including compressive strength gain and water absorption and ecology characteristics were tested. The selected bacteria was Bacillus alcalophilus a nd Rhodoblastus acidophilus and had high concentration of $10^9cell/mL$. The expanded vermiculite that was used for shelter of bacteria was added by 7.5% and 10% replacement of the natural aggregates by volume. The developed eco-block achieved the minimum requirements specified in SPS provision and significantly effective in reducing chemical Chemical Oxygen Demand(COD) concentration and enhancing the growth of fish and plant.

Foamed Concrete with a New Mixture Proportioning Method Comparable to the Quality of Conventional ALC Block (ALC 블록성능의 기포콘크리트 배합설계 연구)

  • Yang, Keun-Hyeok
    • Journal of the Korea Institute of Building Construction
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    • v.15 no.1
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    • pp.1-7
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    • 2015
  • The objective of this study is to develop a high-performance foamed concrete made with a new mixture proportioning as an alternative of autoclaved lightweight concrete (ALC) block. For the early-strength gain of the foamed concrete under an atmospheric curing condition, the binders and chemical agents were specially contrived as follows: 3% anhydrous gypsum was added to ordinary portland cement (OPC) in which $3CaO{\cdot}SiO_2$ content was controlled to be above 60%; and the content of polyethylene glycol alkylether in a polycarboxylate-based water-reducing agent was modified to be 28%. Using these binders and chemical agents, 11 mixes were prepared with the parameters of W/B ratio (30% to 20% in a interval of 2.5%) and unit binder content ($400kg/m^3$ to $650kg/m^3$ in a interval of $50kg/m^3$). The quality and availability of the mixed foamed concrete were examined according to the minimum requirements specified in the KS for ALC block and existed conventional foamed concrete. The measured properties satisfied the minimum requirement of KS for ALC block and proved that the developed high-performance foamed concrete had considerable potential for practical application.

Investigation of the Color Change and Physical Properties of Heat-treated Pinus koraiensis Square Lumbers (열처리 잣나무 정각재의 재색 변화 및 물성 조사)

  • Lim, Ho-Mook;Hong, Seung-Hyun;Kang, Ho-Yang
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.1
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    • pp.13-19
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    • 2014
  • Three heat-treatment schedules were applied to $90{\times}90mm$ dimension square lumber of Pinus koraiensis, one of major domestic species, and their colors and physical properties were investigated for obtaining an optimum schedule. Each square lumber was heat-treated three times. The temperatures of $170^{\circ}C$ and $190^{\circ}C$, and the time of 9 hours and 13 hours were used for the first heat-treatment. The schedule of $190^{\circ}C$ and 7 hours were used for the next two heat-treatments. The averages of brightness $L^*$ decreased linearly as the heat-treatment repeated and its standard deviations also decreased slightly. While the averages of color difference ${\Delta}E^*$ increased linearly as the heat-treatment repeated and its standard deviations also increased slightly. The average compressive strength of the heat-treated specimen was higher than that of the control by 9%, which deviates from previous reports. ASE and WPG of the heat-treated specimens were measured to confirm that heat-treatment improved dimensional stability significantly.

Simulated Optimum Substrate Thicknesses for the BC-BJ Si and GaAs Solar Cells

  • Choe, Kwang-Su
    • Korean Journal of Materials Research
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    • v.22 no.9
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    • pp.450-453
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    • 2012
  • In crystalline solar cells, the substrate itself constitutes a large portion of the fabrication cost as it is derived from semiconductor ingots grown in costly high temperature processes. Thinner wafer substrates allow some cost saving as more wafers can be sliced from a given ingot, although technological limitations in slicing or sawing of wafers off an ingot, as well as the physical strength of the sliced wafers, put a lower limit on the substrate thickness. Complementary to these economical and techno-physical points of view, a device operation point of view of the substrate thickness would be useful. With this in mind, BC-BJ Si and GaAs solar cells are compared one to one by means of the Medici device simulation, with a particular emphasis on the substrate thickness. Under ideal conditions of 0.6 ${\mu}m$ photons entering the 10 ${\mu}m$-wide BC-BJ solar cells at the normal incident angle (${\theta}=90^{\circ}$), GaAs is about 2.3 times more efficient than Si in terms of peak cell power output: 42.3 $mW{\cdot}cm^{-2}$ vs. 18.2 $mW{\cdot}cm^{-2}$. This strong performance of GaAs, though only under ideal conditions, gives a strong indication that this material could stand competitively against Si, despite its known high material and process costs. Within the limitation of the minority carrier recombination lifetime value of $5{\times}10^{-5}$ sec used in the device simulation, the solar cell power is known to be only weakly dependent on the substrate thickness, particularly under about 100 ${\mu}m$, for both Si and GaAs. Though the optimum substrate thickness is about 100 ${\mu}m$ or less, the reduction in the power output is less than 10% from the peak values even when the substrate thickness is increased to 190 ${\mu}m$. Thus, for crystalline Si and GaAs with a relatively long recombination lifetime, extra efforts to be spent on thinning the substrate should be weighed against the expected actual gain in the solar cell output power.

Microstructure Control and Mechanical Properties of Continuously Porous SiC-Si3N4 Composites (연속다공질 SiC-Si3N4 복합체의 미세구조 및 기계적 특성)

  • Paul Rajat Kanti;Gain Asit Kumar;Lee Hee-Jung;Jang Hee-Dong;Lee Byong-Taek
    • Korean Journal of Materials Research
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    • v.16 no.3
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    • pp.188-192
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    • 2006
  • The microstructures and mechanical properties of continuously porous $SiC-Si_3N_4$composites fabricated by multi-pass extrusion were investigated at different Si levels added. Si-powder with different weight percentages (0%, 5%, 10%, 15%, 20%) was added to the SiC powder to make the raw mixture powders, with $6wt%Y_2O_3-2wt%Al_2O_3$ as sintering additives, carbon ($10-15{\mu}m$) as a pore-forming agent, ethylene vinyl acetate as a binder and stearic acid ($CH_3(CH_2)_{16}COOH$) as a lubricant. In the continuously porous $SiC-Si_3N_4$ composites, $Si_3N_4$ whiskers like the hairs of nostrils were frequently observed on the wall of the pores. In this study, the morphology of the $Si_3N_4$ whiskers was investigated with the silicon addition content. In the composites containing of 10 wt% Si, a large number of $Si_3N_4$ whiskers was found at the continuous pore regions. In the sample to which 15 wt% Si powder was added, maximum values of about 101 MPa bending strength and 57.5% relative density were obtained.