• Title/Summary/Keyword: Different Parts

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The Droplet Size Distribution of Fan Spray at Different Surrounding Conditions (팬형분무의 주변조건에 따른 입자분포 변화)

  • Moon, Seok-Su;Choi, Jae-Joon;Bae, Choong-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.7 s.262
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    • pp.611-619
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    • 2007
  • In this study, the droplet size distribution of a slit injector at different surrounding conditions, such as air flow and fuel temperature, were investigated. Phase Doppler anemometry (PDA) was utilized to investigate the initial droplet size distribution and the effect of fuel temperature and air flow on droplet size distribution. The entrained air motion was also evaluated by the temporal velocity profile of droplets. When the air flow velocity increased, the small droplets were more entrained to the upper and central parts of the spray and this tendency was confirmed by plotting the temporal velocity profile of droplets. This entrainment of small droplets at high airflow velocities caused relatively small mean droplet size at upper and central parts of the spray and the large mean droplet size at downstream and edge of the spray, compared to that of low airflow velocities. The total mean droplet size, obtained by averaging the size of all droplets measured at all test locations, decreased when the high airflow velocities were applied. The increased fuel temperature, with an airflow velocity of 10m/s, caused reduced droplet size at all test locations. However, the decreased value of mean droplet size at high fuel temperatures was relatively higher at upper parts of the spray, compared to downstream, as a result of enhanced entrainment of small droplets to upper parts of the spray.

Unit Cell FEM Analysis Using I-Fiber Single Stitch with Different Thickness

  • Tapullima, Jonathan;Park, Gyu Yeong;Yoon, Dong Hwan;Choi, Jin Ho
    • Composites Research
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    • v.34 no.1
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    • pp.30-34
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    • 2021
  • This paper present a three-dimensional unit cell finite element analysis to predict the pull-out behavior of a single stitch in a composite laminate. The stitching process used for this study correspond to the I-fiber stitching method that has been studied by the Composite Structures Lab (CSL) as a new through-thickness reinforced method. A total of six cases were analyzed, which were divided in two groups by the stitching yarn used, 6k and 12k. Each group of cases have three different thickness according to the amount of plies; 16 plies, 32 plies and 64 plies. The finite element analysis used the cohesive zone method to characterize the single stitch reinforcement in the interface. Due to the complexity of the load vs displacement curves taken from the experimental results, a bilinear and trilinear bridging laws were implemented in the models. The cohesive parameters used for each case showed a good agreement with the experimental data and can be used for future studies.

Investigation into the Effects of Process Parameters of DED Process on Deposition and Residual Stress Characteristics for Remanufacturing of Mechanical Parts (기계 부품 재제조를 위한 DED 공정 조건에 따른 적층 및 잔류응력 특성 분석)

  • Kim, D.A.;Lee, K.K.;Ahn, D.G.
    • Transactions of Materials Processing
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    • v.30 no.3
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    • pp.109-118
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    • 2021
  • Recently, there has been an increased interest in the remanufacturing of mechanical parts using metal additive manufacturing processes in regards to resource recycling and carbon neutrality. DED (directed energy deposition) process can create desired metallic shapes on both even and uneven substrate via line-by-line deposition. Hence, DED process is very useful for the repair, retrofit and remanufacturing of mechanical parts with irregular damages. The objective of the current paper is to investigate the effects DED process parameters, including the effects of power and the scan speed of the laser, on deposition and residual stress characteristics for remanufacturing of mechanical parts using experiments and finite element analyses (FEAs). AISI 1045 is used as the substrate material and the feeding powder. The characteristic dimensions of the bead shape and the heat affected zone (HAZ) for different deposition conditions are obtained from the experimental results. Efficiencies of the heat flux model for different deposition conditions are estimated by the comparison of the results of FEAs with those of experiments in terms of the width and the depth of HAZ. In addition, the influence of the process parameters on residual stress distributions in the vicinity of the deposited region is investigated using the results of FEAs. Finally, a suitable deposition condition is predicted in regards to the bead formation and the residual stress.

Study on Contents Comparison of Foenumoside B in Different Parts of Lysimachia foenum-graecum (영릉향으로부터 분리된 Foenumoside B의 부위별 함량비교 연구)

  • Um, Young Ran;Mok, So Youn;Shin, Jae-Hyuck;Kim, Seul-Ki;Cho, Byoung-Heon;Cho, Yong Baik
    • Korean Journal of Pharmacognosy
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    • v.45 no.1
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    • pp.88-92
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    • 2014
  • Lysimachia foenum-graecum (LF) has been used for home remedy of common cold and headache in China. Foenumoside B from LF has been reported for anti-obesity effects. We used foenumoside B as a marker for content evaluation of different parts of LF. Ethanol extract of LF was used for isolation of foenumoside B and purified further by column chromatography. The structure was identified as foenumoside B by interpretation of spectroscopic analysis, including $^1H$-, $^{13}C$-NMR and FT-ICR-MS. High-performance liquid chromatography (HPLC) method was used to compare the quantitative level of foenumoside B in different parts of LF. Foenumoside B contents in the leaf, stem, and aerial part showed significant differences. Contents of foenumoside B was detected highly in the leaf extracts. The results would be useful for efficient extraction of foenumoside B in LF.

Prediction of Phase Transformation of Boron Steel Sheet during Hot Press Forming using Material Properties Modeler and DEFORMTM-HT (보론 강판의 핫 프레스 포밍 공정 시 재료 물성 모델러와 DEFORMTM-HT를 활용한 상 변태 예측)

  • Kang, K.P.;Lee, K.H.;Kim, Y.S.;Ji, M.W.;Suh, Y.S.
    • Transactions of Materials Processing
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    • v.17 no.4
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    • pp.249-256
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    • 2008
  • Combined phase transformation and heat transfer was considered on the simulation of hot press forming process, using material properties modeler, $JMatPro^{(R)}$ and a finite element package, $DEFORM^{TM}$-HT. In order to obtain high temperature mechanical properties and flow curves for different phases, a material properties modeler, $JMatPro^{(R)}$ was used, avoiding expensive and extensive high temperature materials tests. The results successfully show that the strength of hot press forming parts may exhibit different strength in the same parts, depending on the contact of blank with tooling. It was also shown effectively that the strength of the parts can be controlled by designing appropriate cooling paths and coolants. This was shown in terms of different heat convection coefficient in the calculation. Overall, current combination of software was shown to be an effective tool for the tool and process design of hot forming process, although the material modeler needs to be additionally verified by an appropriate set of high temperature materials test.

Nutritional Composition and Antioxidative Activity of Different Parts of Taraxacum coreanum and Taraxacum officinale (흰민들레와 서양민들레의 부위별 영양성분 및 항산화효과)

  • Lee, Jae-Joon;Oh, Hee-Kyung
    • Journal of the Korean Society of Food Culture
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    • v.30 no.3
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    • pp.362-369
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    • 2015
  • This study compared the nutritional composition and antioxidative activities of different parts (aerial part and root) of Taraxacum coreanum and Taraxacum officinale. To identify the nutrient composition of different parts of Daedelion species, nutrient contents were analyzed. Crude ash, protein, and fat contents of T. coreanum and T. officinale were higher in the aerial part compared to the root. There was no significant difference in crude ash, protein, or carbohydrate content of the aerial part depending on the Daedelion species. Aerial part contents of vitamin A, E, and C were significantly higher in T. coreanum than T. officinale. The K content of the aerial part of T. coreanum and T. officinale was highest, although there was no significant difference among Daedelion species. Contents of oxalic acid, citric acid, and acetic acid in the aerial part of T. coreanum were highest. Contents of total polyphenols, total flavonoids, and DPPH radical scavenging activity of the aerial part were significantly higher in T. coreanum than T. officinale. In conclusion, the aerial part of T. coreanum and T. officinale could be used as antioxidative functional food sources.

The Total Phenolic Contents and DPPH Radical Scavenging Activities of Korean Potatoes according to Physical Characteristics and Cooking Methods (한국산 감자의 기관별, 품종별, 중량별, 분포별 및 조리 방법에 따른 총 페놀 함량과 DPPH 라디칼 소거능에 관한 연구)

  • Im, Hyo-Won;Suh, Bong-Soon
    • Journal of the East Asian Society of Dietary Life
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    • v.19 no.3
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    • pp.375-383
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    • 2009
  • This study was conducted to measure the total polyphenol contents and DPPH radical scavenging activities of different potato plants parts, varieties, and grades, and by distribution and different cooking conditions. The results were as follows. For the plant parts, total phenolic content and DPPH radical scavenging activity were highest in the flowers followed by leaves and stems, respectively. Among 5 potato varieties, 'Jasim' had the highest DPPH radical scavenging activity and the activity of its pulp was lower than that of its cortex(peel). Regardless of potato grade, the cortexes(peel) of samples had two-fold higher DPPH radical scavenging activity than pulp, and the Grade SS potato had the highest phenolic content. It was also found that the bud ends and stem ends had comparably larger amounts of phenolic compounds in horizontally cut potatoes. Finally, the descending order for DPPH radical scavenging activity, according to different cooking conditions, was as follows: gas oven range-baking, frying, microwave-heating, sauteing, boiling in 1% saline solution, steaming, and boiling in 3% saline solution.

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Anatomical and Physical Properties of Pitch Pine (Pinus rigida Miller) - The Characteristics of Stem, Branch, Root and Topwood - (리기다소나무(Pinus rigida Miller)의 목재해부학적(木材解剖學的) 및 물리학적성질(物理學的性質)에 관(關)한 연구(硏究) - 간(幹), 지(枝), 근(根), 초두목(梢頭木)의 특성(特性)을 중심(中心)으로 -)

  • Lee, Phil Woo
    • Journal of Korean Society of Forest Science
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    • v.16 no.1
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    • pp.33-62
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    • 1972
  • Pitch pine (Pinus rigida Miller) in Korea has become one of the major silvicultural species for many years since it was introduced from the United States of America in 1907. To attain the more rational wood utilization basical researches on wood properties are primarily needed, since large scale of timber production from Pitch Pine trees has now been accomplishing in the forested areast hroughout the country. Under the circumustances, this experiment was carried out to study the wood anatomical, physical and mechanical properties of Pitch Pine grown in the country. Materials used in this study had been prepared by cutting the selected pitch pine trees from the Seoul National University Forests located in Suwon. To obtain and compare the anatomical and physical properties of the different parts of tree such as stem, branch, top and rootwood, this study had been divided into two categories (anatomical and physical). For the anatomical study macroscopical and microscopical features such as annual ring, intercellular cannal, ray, tracheid, ray trachid, ray parenchyma cell and pit etc. were observed and measured by the different parts (stem, branch, root and topwood) of tree. For the physical and mechanical properties the moisture content of geen wood, wood specific gravity, shrinkage, compression parallel to the grain, tension parallel and perpendicular to the grain, radial and tangential shear, bending, cleavage and hardness wree tested. According to the results this study may be concluded as follows: 1. The most important comparable features in general properties of wood among the different parts of tree were distinctness and width of annual ring, transition from spring to summerwood, wood color, odor and grain etc. In microscopical features the sizes of structural elements of wood were comparable features among the parts of tree. Among their features, length, width and thickness of tracheids, resin ducts and ray structures were most important. 2. In microscopical features among the different parts of tree stem and topwood were shown simillar reults in tissues. However in rootwood compared with other parts on the tangential surface distinctly larger ray structures were observed and measured. The maximum size of unseriate ray was attained to 27 cell ($550{\mu}$) height in length and 35 microns in width. Fusiform rays were formed occasionally the connected ray which contain one or several horizontal cannals. Branchwood was shown the same features like stemwood but the measured values were very low in comparing with other parts of tree. 3. Trachid length measured among the different parts of tree were shown largest in stem and shortest in branchwood. In comparing the tracheid length among the parts the differences were not shown only between stem and rootwood, but shown between all other parts of tree. Trachid diameters were shown widest in rootwood and narrowest in branchwood, and the differences among the different parts were not realized. Wall thickness were shown largest value in rootwood and smallest in branchwood, and the differences were shown between root and top or branchwood, and between stem and branch or top wood, but not shown between other parts of tree. 4. Moisture contents of green wood were shown highest in topwood and lowest in heartwood of stem. The differences among the different parts were recognized between top or heartwood and other parts of tree, but not between root and branchwood or root and sapwood. 5. Wood specific gravities were shown highest in stem and next order root and branchwood, but lowest in topwood. The differences were shown clearly between stemwood and other parts of tree, but not root and branchwood. However the significant difference is realized as most lowest value in topwood. 6. In compression strength parallel to the grain compared among the different parts of tree at the 14 percent of moisture content, highest strength was appeared in stem, next order branch and rootwood, but lowest in topwood. 7. In bending strength compared among the different parts of tree at the 14 percent of moisture content clearly highest strength was shown in branchwood, next order stem and root, but lowest in topwood. Though the branchwood has lower specific gravity than stemwood it was shown clearly high bending strength.

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Study of Parts Integration in Product Including Parts having Same Function (동일 기능을 갖는 부품들이 포함된 제품의 부품 통합에 관한 연구)

  • Choi, Jun Ho;Lee, Kun Sang
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.2
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    • pp.193-198
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    • 2013
  • In general, a product consists of one or more parts. Different parts of a product can perform the same function. According to "the design hypothesis of an integrated part", parts having the same function may be integrated into one part. A part can also perform more than one function. The form or material characteristic of a part may perform its function. In this study, we develop a method for defining the functions of components and for integrating parts having the same functions. We have successfully integrated some parts of a three-hole punch using the proposed method. The results satisfy axiomatic design.

A Comparison of Recognition by Gender of Sexy Body Parts and Apparel Designs (성적 자극을 유발하는 신체부위와 관능적 디자인의 인지도에 관한 성별 비교)

  • Lee Jeong-Min;Park Sook-Hyun;Kwon Mi-Jeong
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.9_10 s.146
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    • pp.1316-1328
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    • 2005
  • The purpose of this study was to compare the differences in recognition of sexy body parts and apparel designs by gender and correlations between sexy body parts and apparel designs. Data were collected through a survey of 265 males and 303 females. Data were analyzed by included t-tests, f-tests, and Pearson's correlations. The results were as follows: 1. Females found male body parts were sexier than males did. Males found female body parts were sexier than females did. 2. Females found men's clothing designs were sexier than males did. Also, males recognized women's clothing designs as sexier than females did. 3. Males found see-through and body-consciousness, the methods of designing sexy styles, were sexier than females did. Differences in sexy color recognition by gender were also found. 4. There were correlations between most of sexy body parts and designs which emphasized that body parts. The results of this study shows the differences in recognition and correlation by gender. The results may be applied to develope sexy designs for different genders.