• Title/Summary/Keyword: Cross-sectional dimension

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Multi-Step Reheating Process of Metal Matrix Composites for Thixoforming (Thixoforming을 위한 금속 복합재료의 다단 재가열 공정)

  • 허재찬;강충길
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.180-183
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    • 1997
  • The forming process of metal matrix composites by the die casting and squeeze casting process are limited in size and dimension in term of final parts without machining. The thixoforming process for metal matrix composites has numerous advantages compared to die casting, squeeze casting and compocasting. The characteristics of thixoforming process can decrease the liquid segregation because of he improvement in fluidity in a globular microstructure state and utilizes flow without air entrapment. Therefore, in order to obtain the sound parts of metal matrix composites by using thixoforming process which as co-existing solidus-liquidus pahse, it si very important to obtain reheating condition. However, for he thixoforming process, the billet with the desired volume fraction must be heated to obtain a uniform temperature distribution over the entire cross-sectional areas. To obtain the reheating conditions of composites, the particulate reinforced metal matrix composites for thixoforming were fabricated by combined stirring process which is simultaneously performed with electro-magnetic stirring process which is simultaneously performed with electro-magnetic stirring and mechanical stirring process.

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Relationship between Spiritual Health, Mindfulness and Emotion Regulation among French Emerging Adults

  • Papillon, Pascal;Rajesh, Sasidharan K.
    • CELLMED
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    • v.10 no.1
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    • pp.3.1-3.4
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    • 2020
  • Spirituality is the dynamic and inherent dimension of humanity. This study aimsto evaluate the relationship between Spiritual Health, Mindfulness and Emotion Regulation among French Emerging Adults. An online cross-sectional survey design consisted of four hundred and twenty-one samples were recruited from different universities at Strasbourg, France. Participant's age ranged from 18 to 28 years with a mean age of 20.77 years (SD=2.22). The results, highlights that Spiritual Health Measure was significant and positive association with Mindfulness (r=.45, p < .01) and Reappraisal (r=.22, p < .01). Further, the significant negative correlation observed with Spiritual Dissonance (r=.44, p < .01) and Suppression (r=.24, p < .01). These findings support emerging literature on Spiritual Health. Future studies should evolve an intervention model to promote Spiritual Health and Positive Health.

Modeling and Simulation of Human Knee Joint in Three Dimension By Using the Method of Optimal Triangular Patches (최단 거리 삼각형 패치 형성법을 이용한 무릎 관절의 3차원 형상 모델링과 시뮬레이션)

  • Moon, Byung-Young;Son, Kwon;Kim, Kwang-Hoon;Seo, Jung-Tak
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.12
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    • pp.205-212
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    • 2003
  • Many people are exposed to accidents by vehicles or sports. The most frequent injuries by these accidents is concerned with a knee joint. The three-dimensional surface model of a knee is needed for dynamic analysis of knee motion and knee reconstruction. three-dimensional motion data of a knee joint were obtained using X-ray and precise magnetic sensors. The surface data of a femur and a tibia were obtained using cross-sectional pictures by CT. The three-dimensional surface models of a femur and a tibia were made by the method of optimal triangular patch. Using obtained motion data, we simulated the motion of three-dimensional knee joint model.

Effect of cross-sectional vortex formation on magnetization reversal in rectangular shaped Permalloy nanowires

  • Khan, Imran;Hong, Jisang;Hwang, Chanyong
    • Proceedings of the Korean Magnestics Society Conference
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    • 2013.12a
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    • pp.115-115
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    • 2013
  • In order to pinpoint the different factors responsible for magnetization reversal, we performed simulation using OOMMF micromagnetic package for rectangular shaped permalloy element having length of $1{\mu}m$, width 50-100 nm and thickness 15-80 nm with length to width ratio L/W>4. Interestingly an increase in coercivity with thickness is found for every width below a critical thickness. With increasing width and thickness, the distinct behavior of coercivity, hysteresis loops and reversal mechanism are presented. Vortex end domains are observed during the magnetization reversal beyond particular thickness, where the three dimension reversal mechanism is expected to begin, causing a sudden increase in coercivity.

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Shape Design of Initial Section for Non-circular Shaped Mold Spring (비원형 단면을 갖는 금형스프링의 단면설계)

  • Lee, Hyoungwook;Choi, Hwaryong
    • Journal of Institute of Convergence Technology
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    • v.1 no.1
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    • pp.24-28
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    • 2011
  • The purposes of this study are predictions of the changes in the section geometry and determination of the initial cross section so that opposite side in height direction is exactly parallel after coiling process. Finite element analysis is carried out for the calculation of the sectional changes for mold spring item. Analysis results reveal that the slope of the top and bottom sides varies in the range of 5 to 8 degrees and the amount depends on the dimension of the outer diameter. The slopes of the sides should be defined first among design variables.

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Reheating Process of Metal Matrix Composites Fabricated by Combined Stirring Process for Thixoforming (복합교반법으로 제조한 금속복합재료의 Thixoforming용 재가열공정)

  • 이동건;강충길
    • Transactions of Materials Processing
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    • v.11 no.1
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    • pp.45-53
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    • 2002
  • The forming process of metal matrix composites by die casting and squeeze casting process are limited in size and dimension In term of final parts. The melt strirring method have the problems that the homogeneous distribution of the reinforcements is difficult due to the low weldability and the density difference between the molten metal and the reinforcement. The thixoforming process for metal matrix composites has numerous advantages compacted to die casting, squeeze casting and compocasting. However, for the thixofoming process, the billet with the desired volume fraction must be heated to obtain a uniform temperature distribution over the entire cross-sectional areas. To obtain the reheating conditions of composites, the particulate reinforced metal matrix composites for thixoforming were fabricated by combined stirring process which is simultaneously performed with electro-magnetic stirring and mechanical stirring process. The matrix alloy and reinforcement are used to aluminum alloy(A357) and SiCp with diameter 14, $25{\mu}m$, respectively. The microstructure characteristics were investigated by changing the volume fraction and reinforcement size. The heating conditions to obtain the uniform temperature distribution in cross section area of fabricated metal matrix composites billet are proposed with heating time, the heating temperature and the holding time.

Effects of Starvation in Rock Bream, Oplegnathus fasciatus and Olive Flounder, Paralichthys olivaceus

  • Park, In-Seok;Gil, Hyun Woo;Yoo, Gwang Yeol;Oh, Ji Su
    • Development and Reproduction
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    • v.19 no.2
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    • pp.97-109
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    • 2015
  • We assessed the effects of various dietary conditions on the growth, phenotypic traits, and morphometric dimensions of rock bream, Oplegnathus fasciatus and on the morphometric dimensions of sectioned olive flounder, Paralichthys olivaceus. Rock bream in the fed group increased in body weight, standard length, and condition factor, but these parameters decreased significantly for fish in the starved group (P < 0.05). The head connection dimensions of fish in the fed group decreased, while for starved fish there was increase in external morphometric dimensions (P < 0.05). In both species, sectioned morphometric analysis revealed that fish in the fed group had a larger body circumference and cross-cut sectional area, and greater cross-cut section height, relative to the starved group (P < 0.05).

Micro-Mechanical Approach for Spanwise Periodically and Heterogeneously Beam-like Structures

  • Lee, Chang-Yong
    • Journal of the Korean Solar Energy Society
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    • v.36 no.3
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    • pp.9-16
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    • 2016
  • This paper discusses a refined model for investigating the micro-mechanical behavior of beam-like structures, which are composed of various elastic moduli and complex geometries varying through the cross-section directions and are also periodically-repeated and heterogeneous along the axial direction. Following the previous work (Lee and Yu, 2011), the original three-dimensional static problem is first formulated in a unified and compact form using the concept of decomposition of the rotation tensor. Taking advantage of the smallness of the cross-sectional dimension-to-length parameter and the micro-to-macro heterogeneity, while also performing homogenization along the dimensional reduction simultaneously, the variational asymptotic method is rigorously used to construct a total energy function, which is asymptotically correct up to the second order. Furthermore, through the transformation procedure based on the pure kinematic relations and the linearized equilibrium equations, a generalized Timoshenko model is systematically established. For the purpose of dealing with realistic and complex geometries and constituent materials at the microscopic level, this present approach is incorporated into a commercial analysis package. A few examples available in literature are used to demonstrate the consistency and efficiency of this proposed model, especially for the structures, in which the effects of transverse shear deformations are significant.

The Relationship among Structure, Process, and Outcome Dimensions of Nursing Department in Hospitals (병원 간호조직의 구조, 과정, 결과적 차원의 관계)

  • Cho, Mee-Kyung
    • Journal of Korean Academy of Nursing Administration
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    • v.6 no.1
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    • pp.19-29
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    • 2000
  • The purpose of this study was to analyze the relationship and the importance of relevant variables among structure, process, and outcome dimensions of nursing department in hospitals. The subject for this study was the registered nurses(N=400) working in medical, intensive care, and surgical units at 5 general hospitals with more than 500beds in Chungnam and Chungbuk. The research design was cross-sectional correlation among the variables based on their self description. The survey instrument was based on eleven structured questionnaires. The data were collected from April 26 to May 26, 1999. The SPSS/PC+ program and LISREL 8.12a program were used to analyze the data. Based on the data collected, the following results were obtained. The relationship among structural, procedural, and outcome dimensions 1. Structural dimension had a relationship with procedural dimension relating to decision-making of caregiving and working conditions, in particular, participation of the problem identification. 2. The extent of participation in decision-making had a relationship with organizational commitment and group effectiveness through the selection process among the total decision-making processes. 3. The structural dimension had a large direct effect rather than indirect effect through decision making processes on organizational commitment and group effectiveness. The relationship of structure, process, outcome dimensions was partially supported by this study. The information obtained from surveys in the field form the basis for the following recommendations for improving organizational effectiveness with in the nursing department in an hospitals. 1) Establishment of decentralized structure, environment, and culture in organizational settings would be desirable so that their members may actively participate in decision-making process. 2) Continuous education and training of nurses with theoretical Knowledge and skill of decision making, practical knowledge, and upright role perception should be highly emphasized for persons in nursing schools and in on-the-job training.

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A Study on the Evaluation of Smear Zone by In-situ Tests (현장시험에 의한 Smear Zone의 평가)

  • 이장덕;구자갑
    • Journal of the Korean Geotechnical Society
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    • v.19 no.6
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    • pp.207-216
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    • 2003
  • To evaluate the smear zone caused by the drain installation, 10 piezometers were installed in the typical soft ground in the western coastal area of Korea. The dynamic pore water pressure developed during the drain installation was monitored using piezometers installed at a distance of 10cm, 20cm, 30cm, 40cm and 50cm from the location of the drain. The decay of pore pressure with time after pushing piezometers to depths of 5 meters and 7 meters during the drain installation was monitored to assess flow and consolidation characteristics of the soil after disturbance of the soil due to the drain installation. The drain installation results in shear strain and displacement of the soil and it decreases the permeability of the soil. Hence, the comparison between dissipation of the pore water pressure process in 10 pieszometers before as well as after installation of the drain indicated the diameter of disturbance zone and smear zone, which is related to the cross-sectional dimension of the mandrel. In addition, Cone-pressuremeter(CPM) tests were performed to obtain rigidity index of the soil for an interpretation of the dissipation processes. It has been evaluated by in-situ tests that the smear zone is from 3.0 to 3.6 times of the cross-sectional dimension of the mandrel. The hydraulic conductivity expressed in terms of the coefficient of consolidation after the drain installation was calculated from 3 to 8 times decrease evaluated by Teh & Houlsby equation and CPM test results.