• Title/Summary/Keyword: low dimensional materials

Search Result 431, Processing Time 0.024 seconds

Physical Properties and Virtual Cloth Images of Cotton Fabrics Treated with Chitosan, 1,2,3,4-Butanetetracarboxylic Acid and Citric Acid (키토산과 1,2,3,4-Butanetetracarboxylic Acid, Citric Acid로 가공된 면직물의 역학적 특성과 가상 봉제 이미지)

  • Kim, Kyung-Sun;Jeon, Dong-Won;Kim, Jong-Jun
    • Journal of Fashion Business
    • /
    • v.13 no.1
    • /
    • pp.102-114
    • /
    • 2009
  • Chitosan is a polysaccharide with cationic amino groups in its structure and has useful properties as functional materials. Various end-use developments of chitosan are in progress. When the cotton fabric is pretreated with chitosan, the hand property of cotton fabric may be improved expecially for the summer apparel. In this study, as a cross-linking agent to introduce chitosan into cotton, BTCA(butane-1,2,3,4-tetracarboxylic acid) or CA(citric acid) was added in order to prevent detachment of chitosan by the cross-linking. During the cross-linking procedure, via the padding-drying-heat setting, amino groups of chitosan and hydroxyl groups of cotton, carboxyl groups of BTCA/CA are cross-linked by forming anhydrous cyclic rings. Since BTCA has four carboxyl groups, cross-linking by thermal treatment is easy, leading to the trials in wrinkle-recovery treatment of cotton fabrics. However, the high price of the BTCA reagent has been a shortcoming in the actual application for industrial use. Therefore, in this study, we tried the application of CA having three carboxyl groups, which is relatively low priced, as the substituting cross-linking agent. The hand of the treated fabrics were evaluated by measuring physical properties. In addition, based on the physical properties, three-dimensional images were introduced by using 3D CAD systems and results were compared.

Investigation of Cutting Characteristics of Linear Hotwire Cutting System and Bonding Characteristics of Expandable Polystyrene Foam for Variable Lamination Manufacturing(VLM) Process (가변 적층 쾌속 조형 공저 개발을 위한 발포 폴리스티렌폼의 선형 열선 절단시스템 절단 특성 및 접착강도 특성에 대한 연구)

  • Ahn, Dong-Gyu;Lee, Sang-Ho;Yang, Dong-Yol;Shin, Bo-Sung;Lee, Yong-Il
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.17 no.12
    • /
    • pp.185-194
    • /
    • 2000
  • Rapid Prototyping(RP) techniques have their unique characteristics according to the working principles: stair-stepped surface of parts due to layer-by-layer stacking, low build speed caused by line-by-line solidification to build one layer, and additional post processing to improve surface roughness, so it is required very high cost to introduce and to maintain of RP apparatus. The objective of this study is to develop a new RP process, Variable Lamination Manufacturing using linear hotwire cutting technique and expandable polystyrene foam sheet as part material(VLM-S), and to investigate characteristics of part material, cutting characteristics by using linear hotwire cutting system and bonding. Experiments were carried out to investigate mechanical properties of part material such as anisotropy and directional tensile strength. In order to obtain optimal dimensional accuracy, surface roughness, and reduced cutting time, addition experiments were performed to find the relationship between cutting speed and cutting offset of hotwire, and heat generation of hotwire per unit length. So, adhesion strength tests according to ASTM test procedure showed that delamination did not occur at bonded area. Based on the data, a clover-shape was fabricated using unit shape part(USP) it is generated hotwire cutting. The results of present study have been reflected on the enhancement of the VLM-S process and apparatus.

  • PDF

Dosimetric comparison between modulated arc therapy and static intensity modulated radiotherapy in thoracic esophageal cancer: a single institutional experience

  • Choi, Kyu Hye;Kim, Jina;Lee, Sea-Won;Kang, Young-nam;Jang, HongSeok
    • Radiation Oncology Journal
    • /
    • v.36 no.1
    • /
    • pp.63-70
    • /
    • 2018
  • Purpose: The objective of this study was to compare dosimetric characteristics of three-dimensional conformal radiotherapy (3D-CRT) and two types of intensity-modulated radiotherapy (IMRT) which are step-and-shoot intensity modulated radiotherapy (s-IMRT) and modulated arc therapy (mARC) for thoracic esophageal cancer and analyze whether IMRT could reduce organ-at-risk (OAR) dose. Materials and Methods: We performed 3D-CRT, s-IMRT, and mARC planning for ten patients with thoracic esophageal cancer. The dose-volume histogram for each plan was extracted and the mean dose and clinically significant parameters were analyzed. Results: Analysis of target coverage showed that the conformity index (CI) and conformation number (CN) in mARC were superior to the other two plans (CI, p = 0.050; CN, p = 0.042). For the comparison of OAR, lung V5 was lowest in s-IMRT, followed by 3D-CRT, and mARC (p = 0.033). s-IMRT and mARC had lower values than 3D-CRT for heart $V_{30}$ (p = 0.039), $V_{40}$ (p = 0.040), and $V_{50}$ (p = 0.032). Conclusion: Effective conservation of the lung and heart in thoracic esophageal cancer could be expected when using s-IMRT. The mARC was lower in lung $V_{10}$, $V_{20}$, and $V_{30}$ than in 3D-CRT, but could not be proven superior in lung $V_5$. In conclusion, low-dose exposure to the lung and heart were expected to be lower in s-IMRT, reducing complications such as radiation pneumonitis or heart-related toxicities.

Modeling of Carbon Plume in PLAD Method Assisted by Ar Plasmas (Ar 플라즈마 상태에서 PLAD법에 의한 탄소 입자의 운동 모델링)

  • So, Soon-Youl;Lim, Jang-Seob
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.19 no.4
    • /
    • pp.24-31
    • /
    • 2005
  • A plused laser ablation deposition(PLAD) technique has been used for producing fine particle as well as thin film at relatively low substrate temperatures. However, in order to manufacture and evaluate such materials in detail, motions of plume particles generated by laser ablation have to be understood and interactions between the particles by ablation and gas plasma have to be clarified. Therefore this paper was focused on the understanding of plume motion in laser ablation assisted by hi plasmas at 100[mTorr]. One-dimensional hybrid model consisting of fluid and particle models was developed and three kinds of plume particles which are carbon atom(C), $ion(C^+)$ and electron were considered in the calculation of particle method. It was obtained that ablated $C^+$ was electrically captured in Ar plasmas by strong electric field(E). The difference between motions of the ablated electrons and $C^+$ made E strong and the collisional processes active. The energies of plume particles were investigated on a substrate surface. In addition the plume motion in Ar gas was also calculated and discussed.

The Visual Image Evaluation for the Dot Pattern Size and the Variation of Coloration in the Achromatic Color (무채색 물방울무늬의 크기와 배색변화에 따른 시각적 이미지 평가)

  • Kim, Sun-Mi;Jeong, Su-Jin
    • Journal of Fashion Business
    • /
    • v.12 no.4
    • /
    • pp.114-130
    • /
    • 2008
  • The purpose of this study is to investigate the effect of Dot Pattern Size(0.8, 1.8, 2.5, 5, 8), color combination(W/Bk, Bk/Gr, Gr/W), Area-Ratio(Background/Dot, Dot/Background) on wearing dot-printed dresses image. Sets of stimulus and response scales(7 point semantic) were used as experimental materials. The stimuli were 30 color pictures manipulated with the combination of Dot Pattern Size, color combination, and Area-Ratio using computer simulation. The subjects were 180 female undergraduates living in Gyeongnam-do. The data was analyzed by using SPSS program. Analyzing methods were ANOVA and LSD test. Image factor of the stimulus was composed of 5 different components, visibility, chastity, attractiveness, cuteness and feminity. Among them, the visibility and chastity were important. Each dimensional image was affected by dot pattern size, color combination and Area-Ratio. In the visibility image, color combination(W/Bk is the most effective) is more influential, the larger size is effective pattern. In the cuteness and feminity image, area ratio(low-brightness dot pattern is the more effective) is more effective than color combination or dot pattern size. Even the same dot pattern size and area was recognized as different image depending on the area ratio. According to the variation of dot pattern size, color combination and area-ratio, it was investigated that the images for a dress wearer were expressed diversely, were shown differently in image dimensions, and could be produced to different images.

Design of 3-D resonator for improvement of interference in ETCS (ETCS 신호 간섭 개선을 위한 3-D 공진기 설계)

  • Kim Ho-Yong;Lee Hong-Min
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.43 no.9 s.351
    • /
    • pp.99-104
    • /
    • 2006
  • In this paper, the conventional 2 dimensional metamaterial structure has degeneration of shielding characteristic in cross polarization effect. The proposed 3-D resonator is designed for reduction of cross polarization effect. The proposed 3-D resonator using LTCC consists of 2-D parallel resonators on X-axis, Y-axis and Z-axis. The 2-D parallel resonator consists of two plate and one via. When the co-polarization electric filed is excited, the resonance frequency of 3-D resonator is 5.024GHz. The stop bandwidth is 19MHz. When the cross-polarization electric field is excited, the resonance frequency of 3-D resonator is 4.825GHz. The stop bandwidth is 19MHz. The proposed 3-D resonator achieve reduction of cross-polarization effect. The concrete consists of proposed 3-D resonator and absorbtion materials. The concrete will be applied for reduction or interference signal of ETCS(Electric Toll collection system).

Analysis of Consumer's Perception and Product Satisfaction·Dissatisfaction with Urban Outdoor Wear based on Kano Model: Focused on University Students (어반 아웃도어웨어에 대한 소비자 인식과 Kano 모델을 적용한 제품 만족·불만족에 대한 연구: 대학생을 중심으로)

  • Jun, Daegeun;Kim, Heekyoung;Kim, Hyeran;Park, Soonjee
    • Fashion & Textile Research Journal
    • /
    • v.18 no.1
    • /
    • pp.103-112
    • /
    • 2016
  • This research was designed to figure out the perception and attitude of university students toward urban outdoor wear and to provide the guidelines for product quality improvement using Kano model. A total of 270 responses were analyzed by SPSS 20.0 through frequency and factor analysis. Respondents' levels for outdoor activity & outdoor products possession being still low, steady growth in urban outdoor wear market is expected. A total of eight quality factors were identified through factor analysis; suitability, production quality, functionality, ease of care, fabric performance, portability, fashionability, and symbolism. Based on Kano model, quality factors of urban outdoor wear were categorized into three groups: one-dimensional; indifferent; and must-be quality factor. It was found that consumers were satisfied with urban outdoor wear only when it meets the needs for suitability for body types and ease of care, meaning that manufactures should be cautious not to lose these features. Being must-be quality factor, production quality(form stability, quality of subsidiary materials), and fabric performance such as colorfastness should be basically satisfied. The relative importance of each quality feature on satisfaction/dissatisfaction was investigated using CSC(customer satisfaction coefficient). Based on the CSC, every item was classified again. Attractive quality features with large CSC were shown in suitability factor. Must-be quality features with small CSC were mainly shown in functionality and fabric performance factors. These findings imply that manufactures of urban outdoor wear should not only maintain the production quality but also focus on suitability features to differentiate their product with previous products.

Accuracy of Intraoperative Gross Examination of Myometrial Invasion in Stage I-II Endometrial Cancer

  • Sethasathien, Prauk;Charoenkwan, Kittipat;Siriaunkgul, Sumalee
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.17
    • /
    • pp.7061-7064
    • /
    • 2014
  • Background: To assess the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of intraoperative gross examination (IGE) of uterine specimens in determining deep myometrial invasion and cervical invasion compared to final histology. Materials and Methods: The clinical, surgical and histological data of all FIGO stage I-II endometrial cancer (EC) patients who had primary surgery were reviewed. Results of the IGE for myometrial invasion and cervical invasion were compared to the final histology. The sensitivity, specificity, PPV, NPV, and accuracy of the IGE in determining deep myometrial invasion and cervical invasion were calculated. Association between clinico-pathological factors and discrepancy between IGE and final histology in the determination of myometrial invasion was also assessed. A p-value of <0.05 was considered significant. Results: From January 2007 to December 2012, 179 patients diagnosed with clinical stage I-II endometrial cancer underwent surgical staging. The sensitivity and specificity of IGE in detecting deep myometrial invasion were 42.4% and 90.0%, respectively, and the PPV and NPV were 67.6% and 76.1%. The overall accuracy of IGE was 74.3%. The sensitivity and specificity of IGE in identifying cervical invasion were 28.6% and 97.5%, respectively, while the PPV and NPV were 60.0% and 91.1%. The overall accuracy of IGE was 89.4%. Conclusions: The sensitivity of IGE for detecting deep myometrial invasion and cervical invasion in early-stage EC is too low to be used alone. Alternative methods including intraoperative frozen section analysis, preoperative three dimensional ultrasound, and preoperative magnetic resonance imaging should be strongly considered.

Development of Methodology for Fracture Network Analysis in the Unsaturated Zone using MINC Approach in TOUGH2 Code (TOUGH2 전산코드의 MINC 기법을 이용한 불포화 암반 내 단열 해석 방법론 개발)

  • Ha, Jaechul;Cheong, Jae-yeol;Kim, Soogin;Yoon, Jeonghyoun
    • The Journal of Engineering Geology
    • /
    • v.26 no.3
    • /
    • pp.325-330
    • /
    • 2016
  • The second phase of low- and intermediate-level waste (LILW) disposal facility is under planned on the sedimentary rock in unsaturated zone. In this study, we created two meshes which were a matrix continuum mesh and a fracture continuum mesh to carry out 2 dimensional numerical modeling for groundwater flow in the unsaturated zone containing fractures focused on the second phase of LILW disposal facility. Two continuum meshes were developed using MINC in meshmaker module of TOUGH2 code. A fracture continuum mesh was included the k-field distribution of the permeability derived from the Discrete Fractured Network (DFN) modeling. To apply the unsaturated zone for the modeling, the gridding steps to generate mesh were developed. Each step to generate a mesh consisted of definition of materials, setting the initial conditions and creating grids using MINC. The methodology development of meshes in this study will be applied for more precise modeling of groundwater flow and mass transport.

Development of Variable Deposition manufacturing for Ethylene Vinyl Acettecopolymer (EVA를 이용한 가변 용착 쾌속 조형 공정의 개발)

  • Lee, Sang-Ho;Sin, Bo-Seong;Jeong, Jun-Ho;An, Dong-Gyu;Yang, Dong-Yeol
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.17 no.9
    • /
    • pp.189-195
    • /
    • 2000
  • RP techniques have their unique characteristics according to the working principles : star-stepped surface of parts due to layer-by-layer stacking low build speed caused by line-by-line solidification to fish one layer and post processing to improve surface finish etc The objective of this study is to propose a new RP technique Variable Deposition Mnanufacturing (VDM) which can make up for the disadvantages of the existing RP techniques and to develop an apparatus to implement the technique. The proposed process can greatly reduce the build time and improve the surface finish of parts generated. Experiments are carried out to obtain the range of temperature of molten material to maintain its fluidity and to investigate the effect of gas cooling on the preservation of the slopes. Some simple shapes such as a line-shape an S-shape and a circle-shape are fabricated from Ethylene Vinyl Acetatecopolymer(EVA) In order to examine the applicability of VDM to more general shapes a tensile specimen and a yo-yo shape were manufactured by the proposed RP method using EVA material as a trial approach. The current basic study shows a high potential of practical use of the proposed VDM process to prototyping of a general three-dimensional shape.

  • PDF