• Journal of Biosystems Engineering
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• 제40권3호
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• pp.201-211
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• 2015

Purpose: Designing equipment for processing, sorting, and other post-harvest operations of agricultural products requires information about their physical properties. This study was conducted to investigate some of the mechanical and physical properties of Moringa oleifera L. pods and seeds. Methods: Properties such as the length, width, thickness, bulk density, porosity, mass, static coefficient of friction, and angle of repose were determined as a function of moisture content. Statistical data and force-deformation curves obtained at each loading orientation and moisture level were analyzed for bioyield point, bioyield strength, yield force, rupture point, and rupture strength using a testrometric machine. Result: The basic dimensions (length, width, and thickness) of moringa pods and seeds were found to increase linearly from 311.15 to 371.45 mm, 22.79 to 31.22 mm, and 22.24 to 29.88 mm, respectively, in the moisture range of 12 to 49.5% d.b. The coefficient of friction for both pods and seeds increased linearly with an increase in moisture content on all the surfaces used. The highest value was recorded on mild steel, with 0.581 for pods and 0.3533 for seeds, and the lowest on glass for pods, with a value of 0.501, and of 0.2933 for seeds on galvanized steel. The bioyield and rupture forces, bioyield and rupture energies, and deformation of the pods decreased with an increase in moisture content to a minimum value, then increased with further decrease within the moisture content range, while the yield force increased to a maximum value and then decreased as the moisture content increased. Conclusion: These results will help to determine the most suitable conditions for processing, transporting, and storing moringa pods, and to provide relevant data useful in designing handling and processing equipment for the crop.

• 동굴
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• 제63호
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• pp.21-43
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• 2004

본 연구에서는 동굴의 민속학적인 접근을 통해 선조들이 어떤 용도로 동굴을 이해하고 활용했는지 주거지로서의 동굴, 그리고 동굴관련 신화와 설화, 속담과 민간신앙, 생활민속으로서의 동굴의 이용을 통해 파악해보고자 하였다. 선사시대 동굴에서 주로 주거 및 식생활을 하였음을 고고학 자료를 통해 파악해 볼 수 있었고, 동굴관련 단군신화가 있어 동굴의 의미를 되새길 수 있으며 동굴마다 신비경과 관련된 동굴 설화가 많아 동굴에 대한 이해를 깊게 하고 있고, 미지의 세계와 관련한 속담, 기도처ㆍ수양처로서의 동굴, 또 현대 생활민속과 관련하여 식품 저장소로서, 군사시설로써의 활용뿐만 아니라, 유희공간인 관광지로써 현대에는 크게 각광받고 있다.

• Geomechanics and Engineering
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• 제24권1호
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• pp.91-103
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• 2021

This paper concerns with forced dynamic response of thick functionally graded (FG) beam resting on viscoelastic foundation including porosity impacts. The dynamic point load is proposed to be triangle point loads in time domain. In current analysis the beam is assumed to be thick, therefore, the two-dimensional plane stress constitutive equation is proposed to govern the stress-strain relationship through the thickness. The porosity and void included in constituent is described by three different distribution models through the beam thickness. The governing equations are obtained by using Lagrange's equations and solved by finite element method. In frame of finite element analysis, twelve-node 2D plane element is exploited to discretize the space domain of beam. In the solution of the dynamic problem, Newmark average acceleration method is used. In the numerical results, effects of porosity coefficient, porosity distribution and foundation parameters on the dynamic responses of functionally graded viscoelastic beam are presented and discussed. The current model is efficient in many applications used porous FGM, such as aerospace, nuclear, power plane sheller, and marine structures.

• 전기화학회지
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• 제6권4호
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• pp.236-241
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• 2003

Magnetic CoW thin film alloys were electrodeposited from citrate baths to investigate the resulting microstructure and magnetic properties. Deposit tungsten (W) content in the films electrodeposited at $70^{\circ}C$ were independent of current density, while coercivity decreased from hard $(H_{c,//}\~150\;Oe\;and\;H_{c.{\bot}}\;\~240\;Oe)$ to soft magnetic properties $(H_{c,//}\~20\;Oe\;and\;H_{c.{\bot}}\;\~30\;Oe)$ with increasing current densities from $10\;to\;100mA{\cdot}cm^2$, with deposit W content $(\~40\%)$ relatively unaffected by the applied current density. X-ray diffraction analysis indicated that hcp $Co_3W$ phases [(200), (201) and (220) planes] in the CoW films electrodeposited at $70^{\circ}C\;and\;10mA{\cdot}cm^{-2}$ were dominant, whereas amorphous CoW phases with small amount of hcp $Co_3W$ [(002) planes] were dominant with deposition at $70^{\circ}C\;and\;100mA{\cdot}cm^{-2}$. At intermediate current densities $(25\;and\;50mA{\cdot}cm^{-2}),\;hop\;Co_3W$ phases [(200), (002), (201) and (220)] were observed. The average grain size was measured to be 30 nm from Sheller formula. It is suggested that the change of the deposit coercivities in the CoW thin films electrodeposited at $70^{\circ}C$ is attributed to the change of microstructures with varying the current density. Nanostructured $Co_3W/amorphous-CoW$ multilayers were fabricated by alternating current density between 10 and $100 mA{\cdot}cm^{-2}$, varying the individual layer thickness. The magnetic properties of $Co_3W/amorphous-CoW$ multilayers were strongly dependent on the thickness of the alternating hard and soft magnetic thin films. The nanostructured $Co_3W/amorphous-CoW$ multilayers exhibited a shift from low to high coercivities suggesting a strong coupling effect.

• 한국생활과학회지
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• 제10권4호
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• pp.379-390
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• 2001

The purpose of this study is to investigate the fitness according to drafting method of the block patterns for women in Korea. The major findings of this study are as follows: 1. According to comparative analysis of required measurements, two measurements of back length and bust girth are used in Proportional Drafting Method (Munhwa). In case of Compromise Drafting Methods are used across chest, across back, bust length, bust width, full length in front, across shoulder and shoulder length in addition to back length and bust girth. The type of Armstrong as a Short Measure Drafting Method uses 10 measurements for the drafting the bodice. 2. While Esmod block pattern arid Armstrong's block pattern are the lightest in full width and other widths. Rasara block pattern is the most ample. In Lee, Myung-hee's block pattern and Lee, Hyung-sook's block pattern, amounts of drooping are decided $3{\sim}4cm$, but drooping amounts of other block patterns are decided corresponding to real measurements. While cap height in Esmod and Armstrong's sleeve patterns are directly measured Armhole length of the block pattern, cap height of other sleeve patterns are used armhole depth and cap height length as well as armhole length. 3. When analyzing to indirect measurements, Esmod block pattern shows the least different between full length of block pattern and that of body form. Munhwa block pattern and Kim, Hyosook's block pattern are mostly same to body form back length. However all of the block patterns are sheller than body form length. In case of Suh, Wansuk's block pattern, across back and across chest are same size, but other block patterns show difference between across back and across chest. Most block patterns' neck width in front and bach bodice are almost same. Front neck width is generally bigger than back neck width in some cases.