• Title/Summary/Keyword: Texture properties

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Effect of Deformation Temperature on Crystal Texture Formation in Hot Deformed Nanocrystalline SmCo5 Permanent Magnets

  • Ma, Q.;Yue, M.;Lv, W.C.;Zhang, H.G.;Yuan, X.K.;Zhang, D.T.;Zhang, X.F.;Zhang, J.X.;Gao, X.X.
    • Journal of Magnetics
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    • v.21 no.1
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    • pp.25-28
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    • 2016
  • In the present study, bulk anisotropic nanocrystalline $SmCo_5$ magnets were prepared by hot deformation. The effect of deformation temperature on the texture and magnetic properties are presented, based on which the mechanism of plastic deformation and texture formation during the hot deformation process is discussed. Our analyses reveal that deformation temperature is one of the most important parameters that determine the texture of $SmCo_5$ grains. We suggest that diffusion creep plastic deformation occurs during hot deformation, which is very sensitive to the energy gain provided by an increase in temperature.

Prediction of Texture Evolution in Equal Channel Angular Extrusion (ECAE) Using Rate-Independent Crystal Plasticity with Rigid-Plastic Finite Element Method (결정 소성학과 강소성 유한요소해석을 연계한 ECAE 공정에서의 변형 집합 조직 발달에 대한 연구)

  • Kim, Kyung-Jin;Yoon, Jeong-Whan;Yang, Dong-Yol
    • Journal of the Korean Society for Precision Engineering
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    • v.32 no.11
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    • pp.937-944
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    • 2015
  • Recently, the change of mechanical properties and microstructural evolution during severe plastic deformation (SPD), such as Equal Channel Angular Extrusion (ECAE), has been the subject of intensive investigation because of the unique physical and mechanical properties of severely deformed materials. In this study, two types of ECAE processes were considered, dies with intersection angles ${\Phi}$ of $90^{\circ}$ and $120^{\circ}$, using experiments and simulations. The decoupled method, in which the rigid-plastic finite element method is incorporated with the rate-independent crystal plasticity model, was applied to predict the texture evolution in commercially pure aluminum during the ECAE processes with $120^{\circ}$ and $90^{\circ}$ dies. The simulated textures were compared with a measured texture via an EBSD OIM analysis. The comparison showed that the simulated textures generally were in good agreement with the experimentally measured texture.

Optimization of Rheological Properties for the Processing of Omija-pyun(Omija jelly) by Response Surface Methodology (반응표면 분석법을 이용한 오미자편의 물성특성)

  • 정희선;주나미
    • Korean journal of food and cookery science
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    • v.19 no.4
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    • pp.429-438
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    • 2003
  • The optimization of Omija-pyun as a traditional dessert, with the most European taste and year round availability, was studied with regard to its texture. The response surface methodology was used to determine the optimal composition of Omija-pyun as a European style dessert. The texture, including the springiness, gumminess, cohesiveness, adhesiveness, hardness and chewiness, was measured using TPA parameters (TA-HD Texture Analyser, stable micro system, UK). The texture of Omija-pyun was influenced by pectin and sucrose to the first linear order. The properties of springiness and adhesiveness were influenced by pectin x pectin to the second quadratic order. No cross product effects between ingredients were found from the analysis. The maximum springiness was obtained with 42g of pectin, 450g of sucrose, 110g of glucose syrup and 4.8g of tartaric acid. The maximum chewiness was with 55g of pectin, 330g of sucrose, 140g of glucose syrup and 5.7g of tartaric acid. The maximum adhesiveness was achieved using 17g of pectin and 400g of sucrose. The gumminess and hardness increased with increasing pectin content, and a cross product effect was observed(Eds note: you said earlier that no cross product effects between the ingredients was found\ulcorner) between sucrose and glucose syrup.

Improvement of Mechanical Properties of Mg alloys through Control of Grain Size and Texture (결정립크기와 집합조직제어를 통한 마그네슘 합금의 기계적 성질 개선)

  • Kim, W.J.;Lee, J.B.;Kim, W.Y.;Jeong, H.G.;Park, J.D.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2006.05a
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    • pp.57-58
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    • 2006
  • The effects of lowering ECAP temperature during ECAP process and Post-ECAP annealing on microstructure, texture and mechanical properties of the AZ31 alloys have been investigated in the present study. The as-extruded materials were ECAP processed to 2 passes at 553K prior to subsequent pressing up to 6 passes at 523K or 493K. When this method of lowering ECAP temperature during ECAP was used, the rods could be successfully deformed up to 6 passes without any surface cracking. Grain refinement during ECAP process at 553K might have helped the material to endure further straining at lower deformation temperatures probably by increasing the strain accommodation effect by grain boundary sliding, causing stress relaxation. Texture modification during ECAP has a great influence on the strength of Mg alloys because HCP metals have limited number of slip systems. As slip is most prone to take place on basal planes in Mg at room temperature, the rotation of high fraction of basal planes to the directions favorable for slip as in ECAP decreases the yield stress appreciably. The strength of AZ31 Mg alloys increases with decrease of grain size if the texture is constant though ECAP deformation history is different. A standard positive strength dependence on the grain size for Mg alloys with the similar texture (Fig. 1) supports that the softening of ECAPed Mg alloys (a negative slope) typically observed despite the significant grain refinement is due to the texture modification where the rotation of basal planes occurs towards the orientation for easier slip. It could be predicted that if the original fiber texture is restored after ECAP treatment yielding marked grain refinement, yield stress as high as 500 MPa will be obtained at the grain size of ${\sim}1{\mu}m$. Differential speed rolling (DSR) with a high speed ratio between the upper and lower rolls was applied to alter the microstructure and texture of the AZ31 sheets. Significant grain refinement took place during the rolling owing to introduction of large shear deformation. Grain size as small as $1.4{\mu}m$ could be obtained at 423K after DSR. There was a good correlation between the (0002) pole intensity and tensile elongation. This result indicates that tensile ductility improvement in the asymmetrically rolled AZ31 Mg alloys is closely related to the weakening of basal texture during DSR. Further basal texture weakening occurred during annealing after DSR. According to Hall-Petch relation shown in Fig. 1, the strength of the asymmetrically rolled AZ31 is lower than that of the symmetrically rolled one when compared at the same grain size. This result was attributed to weakening of fiber texture during DSR. The DSRed AZ31, however, shows higher strength than the ECAPed AZ31 where texture has been completely replaced by a new texture associated with high Schmid factors.

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The Physicochemical Properties of Hand-Peeled and Flame-Peeled Chestnuts (수작업 박피밤과 화염박피 밤의 물리화학적 특성)

  • 김종훈;박재복;최창현
    • Journal of Biosystems Engineering
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    • v.24 no.5
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    • pp.407-414
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    • 1999
  • To evaluate the quality of flame-peeled chestnuts, their physical and chemical properties were analyzed. The physicochemical properties of flame-peeled chestnuts, including geometrical shape, texture and chemical composition, were compared to those of hand-peeled ones. For the flame-peeled chestnuts, some properties in heated and non-heated sections were separately analyzed. The color, texture such as springness, cohesiveness, adhesiveness, hardness and chewiness, moisture content, and reducing sugar of the heated section of the flame-peeled chestnuts were significantly different with their non-heated section. But the physicochemical properties of the non-heated section of the flame-peeled chestnuts were similar to those of the hand-peeled ones.

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Texture development in cold-roiled and heat-treated Ni tapes (냉간가공과 열처리한 Ni 테이프에서의 집합조직 발달)

  • 이동욱;지봉기;임준형;주진호;정충환;박순동;전병혁;홍계원;김찬중
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.535-538
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    • 2002
  • Cube-textured Ni substrates for YBCO coated conductors were fabricated by cold-rolling and annealing of Ni powder compacts. To establish the optimum sintering temperature, tensile test was performed for the Ni rod sintered at various temperatures. The Ni rods prepared at above 100$0^{\circ}C$ showed good mechanical properties due to the complete densification of the Ni rods. The Ni rods were rolled to final thickness of 100 ${\mu}{\textrm}{m}$ and then annealed at 100$0^{\circ}C$ for various annealing time for texture development. The texture analysis made by 2 $\theta$ scan and pole-figure showed that the cube texture was developed in a short time of a few munitues. The FWHM of in-plane and out of plane texture of the prepared Ni tapes was 8-10$^{\circ}$. The AEM surface roughness of the Ni tapes was as smooth as 3 nm.

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Comparison of the Explanation on Visual Texture of Cotton Textiles using Regression Analysis and ANFIS - on Warmness (회귀분석과 ANFIS를 활용한 면직물의 시각적 질감에 대한 해석 비교 - 온난감을 중심으로)

  • 주정아;유효선
    • Science of Emotion and Sensibility
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    • v.7 no.3
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    • pp.15-25
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    • 2004
  • The regression analysis and Adaptive -Network based Fuzzy-inference system (ANFIS) were applied to the explanation on human's visual texture of cotton fabrics with 7 mechanical properties. The ANFIS uses the structure with fuzzy membership function and neural network. The results obtained by the statistical analysis through the coefficient of correlation and regression analysis showed that subjective texture had a linear relationship with mechanical properties. But It had a relatively low coefficient of determination and was difficult that the statistical analysis explained other relationship with the exception of a lineality and interaction among mechanical properties. Comparing the statistical analysis, the ANFIS was an effective tool to explain human's non-linear perceptions and their interactions. But to apply ANFIS to human's perceptions more effectively, it is necessary to discriminate effective input variables through controlling the properties of samples.

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Comparison of Soil Pore Properties between Anthropogenic and Natural Paddy Field Soils From Computed Tomographic Images

  • Chun, Hyen Chung;Jung, Ki-Yuol;Choi, Young Dae;Jo, Su-min;Lee, Sanghun;Hyun, Byung-Keun;Shin, Kooksik;Sonn, Yeonkyu;Kang, Hang-Won
    • Korean Journal of Soil Science and Fertilizer
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    • v.48 no.5
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    • pp.351-360
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    • 2015
  • Human influence on soil formation has dramatically increased with human civilization and industry development. Increase of anthropogenic soils induced researches on the anthropogenic soils; classification, chemical and physical characteristics of anthropogenic soils and plant growth from anthropogenic soils. However there have been no comprehensive analyses on soil pore or physical properties of anthropogenic soils from 3 dimensional images in Korea. The objectives of this study were to characterize physical properties of anthropogenic paddy field soils by depth and to find differences between natural and anthropogenic paddy field soils. Soil samples were taken from two anthropogenic and natural paddy field soils; anthropogenic (A_c) and natural (N_c) paddy soils with topsoil of coarse texture and anthropogenic (A_f) and natural (N_f) paddy soils with topsoil of fine texture. The anthropogenic paddy fields were reestablished during the Arable Land Remodeling Project from 2011 to 2012 and continued rice farming after the project. Natural paddy fields had no artificial changes or disturbance in soil layers up to 1m depth. Samples were taken at three different depths and analyzed for routine physical properties (texture, bulk density, etc.) and pore properties with computer tomography (CT) scans. The CT scan provided 3 dimensional images at resolution of 0.01 mm to calculate pore radius size, length, and tortuosity of soil pores. Fractal and configuration entropy analyses were applied to quantify pore structure and analyze spatial distribution of pores within soil images. The results of measured physical properties showed no clear trend or significant differences across depths or sites from all samples, except the properties from topsoils. The results of pore morphology and spatial distribution analyses provided detailed information of pores affected by human influences. Pore length and size showed significant decrease in anthropogenic soils. Especially, pores of A_c had great decrease in length compared to N_c. Fractal and entropy analyses showed clear changes of pore distributions across sites. The topsoil layer of A_c showed more degradation of pore structure than that of N_c, while pores of A_f topsoil did not show significant degradation compared with those of N_f. These results concluded that anthropogenic soils with coarse texture may have more effects on pore properties than ones with fine texture. The reestablished paddy fields may need more fundamental remediation to improve physical conditions.

Texture Properties of Acorn Starch Gels -Puncture test, Back extrusion test and Retrogradation test- (도토리묵의 텍스쳐 특성 -관통시험, 역압출시험, 노화특성시험-)

  • 김영아
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.20 no.2
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    • pp.173-178
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    • 1991
  • The rheological properties of acorn crude starch gel and refined starch gel were investigated by puncture test, back-extrusion test and retrogradation test. Puncture test was a useful method to compare the different gel type and concentration, and to calculate the compression and shear coefficient. Maximum extrustion force and adhesiveness were also examined by performing back-extrustion test. The retrogradation rate was analysed by Avrami equation in retrogradation test.

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Effect of soil physical properties on infiltration rate

  • Sajjadi, Sayed-Abdul-Hamid;Mirzaei, Maryam;Nasab, Afsaneh Fayyaz;Ghezelje, Amin;Tadayonfar, Gholamreza;Sarkardeh, Hamed
    • Geomechanics and Engineering
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    • v.10 no.6
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    • pp.727-736
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    • 2016
  • Excessive rainfall can cause runoff flows over the soil surface and as a consequence some amount of water will infiltrate into the soil. From a hydrologic modeling perspective it is necessary to estimate infiltration rate in order to calculate the actual runoff discharge. There are many parameters that can affect the infiltration rate such as soil texture, moisture and compaction. However, the most common equations used in hydrological calculations for estimating the infiltration rate do not consider the soil properties directly and estimate infiltration rate without any soil properties expressions. The purpose of this research was to investigate the relations between infiltration rate and soil texture, moisture and compaction. To achieve this purpose an experimental study was performed to show the effect of soil properties and their relations on infiltration rate by using non-linear regression.