• Title/Summary/Keyword: shape formation

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Electrochemically Fromed Nanotube Shape on Ternary Ti Alloy with Hf Content

  • Kim, Jeong-Jae;Choe, Han-Cheol
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.05a
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    • pp.106-106
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    • 2015
  • In this study, we investigated electrochemically formed nanotube shape on ternary Ti-25Ta-xHf alloys with Hf contents. Ti-25Ta-xHf (x=0~15 wt.%) alloys were manufactured by vacuum arc-melting furnace. The obtained ingots were homogenized in an argon atmosphere at $1050^{\circ}C$ for 2h and then water quenching. The specimens were cut from ingots to 4 mm thickness and first ground and polished using SiC paper (grades from #100 to #2000). The anodization treatments on Ti-25Nb-xHf alloys were carried out at room temperature for experiments. The formation of nanotubular film was conducted by electrochemical method in mixed electrolytes with 1 M $H_3PO_4$ + 0.8 wt. % NaF at 30 V for 2 h. The morphologies of nanotube depended on the Hf content in Ti-25Ta-xHf ternary system.

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Genetic analysis and characteristics in the crescent-egg mutant, cre, of Bombyx mori. (신돌연변이잠 cre(반월형란)의 유전자 연관분석과 유전형질)

  • 홍선미;노시갑
    • Journal of Sericultural and Entomological Science
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    • v.43 no.2
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    • pp.67-76
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    • 2001
  • The "crescent-egg" a new spontaneous mutant was detected in a white egg strain k37. Studies were carried out the linkage analysis, to investigate phenotypic characteristics and biochemical analysis of haemolymph and ovarian protein. The mutant, ore was independent from 20 linkage groups P(2), Ze(3),L(4), oc(5), sn8), Ia(9), w-1(10), K(11), ch(13), U(14), bl(15), cts(16), bts(17), mln(18), nb(19), oh(20),Lan(21), or(22), tub(23) and Xan(27). The fertilization, hatchability and larval growth were not different from the those of normal eggs. The content and composition of yolk protein were similared to normal eggs. Scanning electron microscopy revealed the areal specific structure in dorsal region of egg-shell of cre mutant. Analysis of chorion protein by isoelectrofocusing(IEF), was resolved no difference in the composite of the chorion protein. We conclude that the egg mutant ere is expressed only in the egg-shape formation and region specific determination.

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Developed Low-priced 3kW Small Hydro Power Generation System using Composite Material (복합소재를 이용한 저가형 3kW 소수력 발전시스템 개발)

  • So, Byung Moon;Kim, Sung Hee;Han, Woo Yong
    • Journal of the Semiconductor & Display Technology
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    • v.17 no.1
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    • pp.84-87
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    • 2018
  • As the propeller end speed increases, the propeller surface is damaged in the process of bubble formation and dropout. It is intended to prevent the corrosion of the propeller by modifying the shape of the end through the winglet structure to mitigate the cavitation phenomenon. In the case of conventional SUS materials, the cost of production is so high that plastic materials are used to prevent corrosion. This paper aims to mitigate the cavitation by deforming the shape of the end through the winglet structure by using the SMC composite material of the propeller using the existing SUS.

DYNAMICAL AND STATISTICAL ASPECTS OF GRAVITATIONAL CLUSTERING IN THE UNIVERSE

  • SAHNI V.
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.19-21
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    • 1996
  • We apply topological measures of clustering such as percolation and genus curves (PC & GC) and shape statistics to a set of scale free N-body simulations of large scale structure. Both genus and percolation curves evolve with time reflecting growth of non-Gaussianity in the N-body density field. The amplitude of the genus curve decreases with epoch due to non-linear mode coupling, the decrease being more noticeable for spectra with small scale power. Plotted against the filling factor GC shows very little evolution - a surprising result, since the percolation curve shows significant evolution for the same data. Our results indicate that both PC and GC could be used to discriminate between rival models of structure formation and the analysis of CMB maps. Using shape sensitive statistics we find that there is a strong tendency for objects in our simulations to be filament-like, the degree of filamentarity increasing with epoch.

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The Identification of drilling chatter on the machining accuracy (Drill가공의 형상정도에 의한 Chatter발생 규명)

  • Park, Jong-Kweon;Seong, Hwal-Gyeong
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.5
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    • pp.18-24
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    • 1995
  • Drilling chatter is regenerative type self-excited vibration and can be predicted by the measurments of the dynamic compliance between tool and workpiece based on structural dynamics and cutting dynamics. This paper describes the theoretical prediction about drilling chatter and the mechanism of the formation of multi-coner shape in holes by drilling chatter. By the experiments and theoretical study, it is found that the odd number of multi-coner shape is always generated by drilling chatter.

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Developing an Observation System for Body Movements and Clothes (몸의 움직임과 의상의 관찰체계 연구)

  • Soyung Im;Jisoo Ha
    • Journal of the Korean Society of Clothing and Textiles
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    • v.47 no.3
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    • pp.531-543
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    • 2023
  • Unlike a still body in a photograph, the concept of time applies to a moving body wearing clothes. Clothes change shape according to movement, and multidimensional formative observation elements are required to perceive this. Thus, the purpose of this research is to develop a system for observing body movements and clothing. This experimental study was designed based on embodiment research. The first stage of the study derived body movement and clothing observation items from theory. In the second stage, 11 fashion personnel participated in experimental research to verify the observation items and identify those that needed correction or supplementation. The results showed that body movement and clothing observation items can be classified as follows: large moving bodies, moving clothes, body and clothes movement, and body and clothes space. The observation system for body movement and clothes presented can be used to construct the formation of moving clothes.

Interpretation of the Asymmetric Color and Shape of Brownish Ring in Quartz Crucible

  • Jung, YoonSung;Choi, Jae Ho;Min, Kyung Won;Byun, Young Min;Im, Won Bin;Kim, Hyeong-Jun
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.4
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    • pp.50-52
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    • 2022
  • Brownish rings (BRs) with white interiors are formed during the manufacture of silicon ingots in quartz glass crucibles. These BRs inhibit the yield of silicon ingots. However, the composition and mechanism of the formation of these BRs remain unclear thus far. Therefore, in this study, we analyzed the color and shape of these BRs. Raman analysis revealed that the brown and white colors appear owing to oxygen deficiency rather than crystallization from excess oxygen supply as previously assumed. Moreover, the dark shade of the brown areas depends on the degree of oxygen deficiency and the asymmetrical width of the brown areas is attributed to the direction of the molten silicon flow, which is influenced by the rotation and heat of the ingot crucible.

Measurement of Crystal Formation Using a Quartz Crystal Sensor

  • Joung, Ok-Jin;Kim, Young-Han
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1659-1661
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    • 2004
  • Measurement of supersaturation is important in crystallization processes, because it is one of key factors to control crystal size distribution and shape determining product quality. A monitoring system of the supersaturation using a quartz crystal sensor is applied to the supersaturation measurement. From the variation of resonant frequency, the beginning of the formation of salt crystal on the sensor surface is detected while the sensor is directly cooled down. The degree of supersaturation is computed from the solubility difference at the temperatures of the salt solution and the sensor. The performance of the propsed system of the supersaturation measurement is examined by applying the system to the crystallization of three different salt solutions. The experimental outcome compared with eye observation result and photographic analysis indicates that the proposed system is effective and useful to determine the supersaturation in the crystallization process. In addition, the microscopic monitoring of the initial stage crystallization is available with the sensor system.

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Measurement of Crystal Formation in Supersaturated Solution

  • Kim, Byung-Chul;Kim, Young-Han
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1196-1200
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    • 2003
  • The degree of supersaturation is an important measure for the operation of crystallization processes, because it is directly related to the control of crystal size distribution and shape. A conventional technique utilizing solution composition and temperature has a variety of problems caused from the measurement error and the handling of analyzing samples. A monitoring system of the supersaturation using a quartz crystal sensor is proposed here, and its performance is examined applying different manipulations of coolant temperature. The experimental outcome and photographic examination indicate that the measurements of resonant frequency and resistance of the sensor can be used for the prediction of the formation and growth of solid crystal from the crystallization process. The monitoring system eliminates the intrinsic error source of the conventional system to give the improved measurement and on-line application availability.

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Effects of Time and Current Density in Anodizing of Mg-Al Alloy in Alkaline Solution (알카리 수용액에서 Mg-Al 합금의 양극산화시 전류밀도와 양극산화 시간의 효과)

  • Jang Seok-Ki;Kim Seong-Jong;Kim Jeong-Il
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.1
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    • pp.107-115
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    • 2005
  • The effects on the formation of anodic oxide films on Mg-Al alloy (AZ91) in 1M-NaOH solution was investigated using parameters of current density and time during anodizing The general tendency has been confirmed that the increase of anodizing time improves the corrosion resistance. It is considered that the formation of anodic oxide film was increased by increasing the applied current and the anodizing time to generate active dissolution reaction In anodizing at constant current density. passivity potentials shifted to noble direction with increasing current densities. It was confirmed that oxygen quantify in anodic oxide films increased with anodizing time. The compact films above 4 $mA/cm^2$ were formed with the shape of an island in grooves at early stage and then grew with combination of the islands