• Title/Summary/Keyword: Grain Texture

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Morphological and Textural Characteristics of the Beach-dune System in South Korea, with the Possibility of a Dune Type Scheme Based on Grain-size Trend (국내 해안의 해빈-해안사구 지형 및 퇴적물 특성과 입도기반 사구유형 분석)

  • Rhew, Hosahng;Kang, Jihyun
    • Journal of The Geomorphological Association of Korea
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    • v.27 no.3
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    • pp.53-73
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    • 2020
  • Morphology and grain size distribution of coastal dunes should be well documented because they are critical to dune's buffering capacity and resilience against storm surges. The nationwide coastal dune survey produced the dataset, including beach-dune topographic profiles and grain size parameters for frontal beaches, foredunes, and inland dunes. This research investigated the dataset to describe geomorphic and textural properties of coastal dunes: foredune slopes, dune heights above approximately highest high water, mean size, and sorting, together with associated variables of coastal setting that influence coastal dunes. It also explores the possibility of a dune type scheme based on gran size trends. The results are as follows. First, the coast in which dunes are developed is the primary control on foredune morphology and sediment texture. Coastal dunes on the east coast were developed more alongshore rather than inland, with gentler slopes on the higher ground and out of coarser sand. The shore aspect contributes to this pattern because the east coast cannot benefit from prevailing northwesterly. Second, grain size trends from beaches through foredunes to inland dunes were little identified. Third, 12 dune types were identified from 69 dunes, showing the indicative capability for the status of beaches and dunes. We confirmed that the dataset could increase our understanding of the overall characteristics of coastal dune morphology and texture, though there is something to be improved, for example, establishing the refined and comprehensive field survey protocol.

Texture of Asymmetric Rolled Aluminum sheets (알루미늄 비대칭압연 집합조직)

  • Akramov, S.;Kim, In-Soo
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.05a
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    • pp.477-479
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    • 2008
  • Drawability and other mechanical properties of sheet metals are strongly dependent on their crystallographic orientations. In this paper the formability of the AA 5052 Al alloy sheets was investigated after asymmetric rolling and subsequent heat treatment. In most cases, after asymmetric rolling specimens showed a fine grain size and subsequent heat treated specimens showed that the ND//<111> texture component were observed. The anisotropy of formability is often described by the plastic strain ratios (r-value) as a function of the angle to the rolling direction in sheet metal. For a good formability, a high r-value is required in sheet metals. In the asymmetry rolled and subsequent heat treated Al alloy sheet, the variation of the plastic strain ratios have been investigated in this study. The plastic strain ratios of the asymmetry rolled and subsequent heat treated AA 5052 Al alloy sheets were higher than those of the original Al sheets. These could be related to the formation of ND//<111> texture components through asymmetric rolling in Al sheet.

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Relations of Whole Grain Consumption with Predisposing, Reinforcing, and Enabling Factors among Korean Adults (일부 한국 성인의 전곡류 섭취빈도와 동기부여, 행동강화, 행동가능 요인간의 연관성)

  • Chae, Da-Hae;Yum, Jin-Hee;Lee, Seung Min
    • Journal of the Korean Dietetic Association
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    • v.20 no.2
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    • pp.133-148
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    • 2014
  • This study compared levels of whole grain consumption-related predisposing, reinforcing, and enabling factors according to socio-demographic variables, and examined how these factors are associated with whole grain consumption frequency among Korean adults. A survey questionnaire was administered to a convenience sample of adult males and females aged 20~59 years (n=300). The questionnaire included questions on predisposing, reinforcing, and enabling factors in relation to whole grain consumption as well as a brief whole grain food frequency questionnaire. Female subjects showed a significantly higher level of negative beliefs on health nutrition taste texture while showing a significantly lower level of social support compared to that of males. The age group of 40~59 years showed a significantly higher social support level than the age group of 20~39 years. Results from multivariate regression analyses showed that different combinations of predisposing, reinforcing, and enabling variables were significant in predicting whole grain consumption frequency according to sex and age. The study findings can be used for developing specific target-oriented nutrition intervention programs for promotion of whole grain intake among Korean adults.

Effects of Hot Rolling on Microstructures and Magnetic Properties

  • Hong, Byung-Deug;Kim, Jae-Kwan;Cho, Kyung-Mox
    • Journal of Magnetics
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    • v.11 no.3
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    • pp.111-114
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    • 2006
  • We electroplated copper-cobalt thin films on a silicon substrate, which had 150 nm thick copper seed layer. The adhesion between the two metallic layers could be increased by utilizing a proper organic additive, pulse plating technique, and high temperature annealing. The thin films exhibited columnar growth of the deposits and enhanced adhesion. This is attributed to the grain growth mechanism introduced by the additive and annealing.

A Study on Change of Texture During Thermal Cycling in Cu-Zn-AI Shape Memory Alloy (Cu-Zn-AI 형상기억 합금의 열사이클에 따른 집합조직의 변화에 관한 연구)

  • Hong, D.W.;Park, Y.K.
    • Journal of the Korean Society for Heat Treatment
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    • v.5 no.3
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    • pp.179-185
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    • 1992
  • The shape memory effect results from the martensite transfomation of each individual grain. Thus it is necessary to study the texture and its variation. In this study the change of texture during thermal cycling and it's effect on shape memory ability are investigated. The major component of the rolling texture in the parent phase is identified (001) [110], and minor components are (112) [110], (111) [112], {hkl}<100> fiber texture is developed at $45^{\circ}$ from rolling direction. In the case of martensite phase, it is estimated that the major component is (011) [100] and the minor components are (105) [501], (010) [101] and (100) [001]. According to thermal cycling. severity of texture, especially (001) [110] component in parent phase and (011) [100] component in martensite phase are increased. The shape memory ability is increased with increase of thermal cycles and also increased as the direction of specimen approach to $45^{\circ}$ from rolling direction. After first thermal cycling the temperature of transformation can be define clearly and Ms and As are raised by thermal cycling.

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Changes in Microstructure and Texture during Annealing of 0.015% C-1.5% Mn-0~0.5% Mo Steels (0.015% C-1.5% Mn-0~0.5% Mo 강의 어닐링과정에서 미세조직과 집합조직의 변화)

  • Jeong, Woo Chang
    • Journal of the Korean Society for Heat Treatment
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    • v.24 no.5
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    • pp.251-261
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    • 2011
  • The changes in microstructure and texture during annealing were examined in a series of 0.015% C-1.5% Mn cold-rolled sheet steels with 0~0.5% Mo. Orientation distribution function data were calculated from the (110), (200), (211) pole figures determined on the rolled plane of cold-rolled and annealed steel sheets. Regardless of Mo content and annealing conditions, martensite volume fraction was less than 1.0%, not affecting the texture evolution. Textural change at the cooling stage after heating at $820^{\circ}C$ for 67 sec was not observed. Increasing the Mo content and annealing temperature markedly strengthened the intensities of ${\gamma}$-fiber texture, resulting in the increase in $r_m$ value. The desirable texture evolution for deep drawability in the 0.5% Mo steel may be mainly caused by the grain refining effect of Mo carbide in the hot-rolled steel sheet.

Fabrication of Ni substrates made by powder metallurgy and casting method (초기시편 제조법에 따른 Ni substrate의 특성비교)

  • 임준형;김규태;김정호;장석헌;주진호;나완수;지봉기;전병혁;김찬중
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2003.10a
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    • pp.55-58
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    • 2003
  • We fabricated the textured Ni substrate and evaluated the effects of processing variables on microstructural evolution and texture transformation. Ni-rods as an initial specimen were prepared by two different methods, i.e., powder metallurgy(P/M) and plasma arc melting(PAM) The texture of the substrate was characterized by pole-figure and surface condition was evaluated by atomic force microscopy. It was observed that the texture of substrate made by P/M did not significantly varied with annealing temperature of 800~120$0^{\circ}C$ and the full-width at half-maximums (FWHM) of both in-plane and out-of-plane were 9$^{\circ}$~10$^{\circ}$. On the other hand, the texture of substrate made by PAM was more dependent on the annealing temperature and the FWHMs of in-plane texture was 9$^{\circ}$~13$^{\circ}$ at the temperature range. In addition, twin texture, (221)<221>, was formed as the temperature increased further. The grain size of substrate made by P/M was smaller than that made by PAM and this difference was correlated to the microstructure of initial specimens.

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Microstructures and Mechanical Behavior of 2024 Al Alloys Deformed by Equal Channel Angular Pressing (2024 Al 합금의 ECAP 공정에 따른 미세조직 변화와 강도특성)

  • Kim, Seon-Hwa;Choi, Yong-Lak
    • Korean Journal of Materials Research
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    • v.16 no.1
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    • pp.68-74
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    • 2006
  • 2024 Al alloys were severely deformed by equal channel angular pressing(ECAP) to obtain an ultrafine grain structure. The more deformation amount increased, the more grain size decreased. Most of the grain structure were changed from elongated to equiaxed shape with increasing pass number. The morphology of S' phases was also changed from rod-type to spherical type. The grain size of 6 passed specimen was 100 to 200 nm, and the size of S' phases was about 10 nm in the microstructure. XRD measurements have revealed that the texture formed by plastic deformation disappeared in the 6 passed specimen. SP test results described that the start of crack propagation occurred at the transition zone between plastic bending and membrane stretching because of small elongation. The maximum strength of ECA pressed specimen increased 1.9 GPa to 2.9 GPa with increasing pass number.

Quality characteristics of non-fried Yackwa according to the methods of baked-in-oven and peanut addition (오븐가열 및 땅콩첨가 제조방법이 구운 약과의 품질특성에 미치는 영향)

  • Jang, So-Young;Lee, Min-Kyung;Lee, Sook-Young
    • Journal of the Korean Society of Food Culture
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    • v.22 no.4
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    • pp.434-440
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    • 2007
  • Yackwa is used as one of foods prepared for traditional rituals and holidays and enjoyed as snacks. Since Yackwas are fried, they contain oil, which can cause rancidity and undermines the freshness of Yackwas during distribution to retailers, not to mention a high level of calories. The study aims to develop baked Yackwas and analyze the quality in terms of calorie levels and characteristics by baking Yackwas in oven. Calorie level was 4.65 kcal/g in fried Yackwa, 3.96 kcal/g in baked Yackwa, and 2.95 kcal/g in baked peanut Yackwa prior to dip coating of grain syrup. baked Yackwa showed hardness of 13476.33 $g/cm^2$ before dipping in grain syrup, which was harder than 1912.56 $g/cm^2$ of fried Yackwa. After grain syrup coating, hardness of baked Yackwa reduced more significantly, compared with that of fried Yackwa, as grain syrup permeated through texture of Yackwa. And less hardness makes baked Yackwa tastier. Sensory evaluation was measured in a 5-point scale. Scores for texture and taste of baked Yackwa outpaced those of fried Yackwa. Score for the overall quality was 3.65 in baked Yackwa and 3.25 in baked peanut Yackwa, compared to 2.85 of fried Yackwa, indicating a higher potential of commercializing(p<0.05).

Effects of Strain Annealing Grain Size on the Magnetic Properties of Extra-Low Carbon Steel (극저탄소강판의 자성에 미치는 변형소둔 결정립도의 영향)

  • An, S.K.;Jeong, W.S.;Park, J.U.
    • Journal of the Korean Society for Heat Treatment
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    • v.19 no.4
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    • pp.208-218
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    • 2006
  • The effects of the grain size on the magnetic properties in extra-low carbon steel after strain annealing were investigated. Two kinds of sample were prepared. One is the annealed sheet, which was annealed at $670^{\circ}C$ and $850^{\circ}C$ for various time periods after cold rolling. The other is the strain annealed sheet, which was temper rolled by 0.4% and subsequently strain annealed at the temperature ranging between $670^{\circ}C$ and $850^{\circ}C$ for various time periods. The grains after strain annealing became more coarse than those after primary annealing. The grains were coarsened due to the strain induced grain boundary migration (SIGM). It was found that the permeability tended to be increased and coercivity tended to be decreased with the increase of grain size. The optimum magnetic properties was achieved after strain annealing at $850^{\circ}C$ for 30 minites. Under this condition, the coercivity was measured to be 0.6 and the permeability was measured up to be 13000.