• Title/Summary/Keyword: Material Selection

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Fabrication of Organic-Inorganic Nanocomposite Blade for Dicing Semiconductor Wafer (반도체 웨이퍼 다이싱용 나노 복합재료 블레이드의 제작)

  • Jang, Kyung-Soon;Kim, Tae-Woo;Min, Kyung-Yeol;Lee, Jeong-Ick;Lee, Kee-Sung
    • Composites Research
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    • v.20 no.5
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    • pp.49-55
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    • 2007
  • Nanocomposite blade for dicing semiconductor wafer is investigated for micro/nano-device and micro/nano-fabrication. While metal blade has been used for dicing of silicon wafer, polymer composite blades are used for machining of quartz wafer in semiconductor and cellular phone industry in these days. Organic-inorganic material selection is important to provide the blade with machinability, electrical conductivity, strength, ductility and wear resistance. Maintaining constant thickness with micro-dimension during shaping is one of the important technologies fer machining micro/nano fabrication. In this study the fabrication of blade by wet processing of mixing conducting nano ceramic powder, abrasive powder phenol resin and polyimide has been investigated using an experimental approach in which the thickness differential as the primary design criterion. The effect of drying conduction and post pressure are investigated. As a result wet processing techniques reveal that reliable results are achievable with improved dimension tolerance.

Evaluation of Cryogenic Performance of Adhesives Using Composite-Aluminum Double Lap Joints (복합재-알루미늄 양면겹치기 조인트를 이용한 접착제의 극저온 물성 평가)

  • Kang, Sang-Guk;Kim, Myung-Gon;Kong, Cheol-Won;Kim, Chun-Gon
    • Composites Research
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    • v.19 no.4
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    • pp.23-30
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    • 2006
  • In the development of a cryogenic propellant tank, the proper selection of adhesives to bond composite and metal liner is important for the safety of operation. In this study, 3 types of adhesives were tested for the ability to bond CFRP composites developed for cryogenic use and aluminum alloy (Al 6061-T6) for lining the tank using double-lap joint specimens. The double-lap joint specimens were tested inside an environmental chamber at room temperature and cryogenic temperature ($-150^{\circ}C$) respectively to compare the bond strength of each adhesive and fracture characteristics. The material properties with temperature of component materials of double-lap joints were measured. In addition, ABAQUS was used for the purpose of analyzing the experimental results.

A Survey on the Wearing Status and Satisfaction of Golf Wear -Focusing on Men and Women in Their 40s, 50s, and 60s- (골프웨어 착용실태 및 만족도 조사 -40~60대 남·여를 중심으로-)

  • Kyung Ja Paek
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.4
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    • pp.717-726
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    • 2023
  • This study collected basic data for the design of and research and development for golf wear with an eye toward various consumer needs such as design, activity, function, comfort, and durability as requirements for golf wear. 64 men and women in their 40s, 50s, and 60s were surveyed on the state of wearing golf wear and their satisfaction of the garments. As a result, it was confirmed that the quality of golf wear participants currently possessed did not sufficiently satisfy the research group consumers. Therefore, research and development of golf wear for these consumers should be advanced, while considering reasonable price, age-appropriate design, pattern development, and material selection with keeping in mind the intended activity level as well as comfort. It was thought that the development of functional golf wear would contribute to more comfortable golf activities.

Behavior of High-elastic Stress Absorbing Interlayer for Reflective Cracking Resistance (고탄성 응력흡수층의 반사균열 저항특성 연구)

  • Park, Tae Soon;Lee, Yo Seop
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.3D
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    • pp.445-451
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    • 2006
  • This study was conducted to develop the interlayer mixture that absorbs the stress between the old concrete pavement and the asphalt overlay pavement layer. The elasticity, the flexibility, the consistency and the impermeability is required for high-elastic Stress Absorbing Interlayer(HSAI) to absorb and disperse the stress that causes the flexural and horizontal movements of the joint and the crack. The HSAI developed from foreign product was satisfied with the design criteria. The specimens using the HSAI showed the significant reduction of the reflective crack compared those not using the HSAI. The significance included that the life of shear failure and horizontal displacement resistance increased 4 times. The life of the share failure increased to 5 times and the horizontal displacement increased to 9 times according to the selection of surface course material which showed the excellence of the HSAI.

A Study on Bag Purchasing Behaviors and Design Preferences - Focusing on Comparative analysis by Sex and Age group - (가방 구매행동과 디자인 선호도 연구 - 성별과 연령집단에 따른 비교분석을 중심으로 -)

  • Mi-sook Lee
    • Journal of the Korea Fashion and Costume Design Association
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    • v.25 no.3
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    • pp.1-16
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    • 2023
  • The purposes of this study were to investigate bag purchasing behaviors and design preferences of male and female adult consumers, and to find the differences depending on sex and age variable. A survey was conducted on 400 male and female adults from 20s to 50s. The questionnaire consisted of bag purchase behaviors, bag design preferences, and the subjects' demographic characteristics. The data were analyzed by Cronbach's α, factor analysis, x2 test and t-test using SPSS. The results were as follows. First, as bag selection criteria, four factors (practicality, symbolism, aesthetics, and economics) were derived, and adult consumers considered economics as the most important among the factors. As for purchasing information sources, three factors (media, human resources, and store) were derived, and adult consumers considered human resources and store information sources more important than media. The main motive for purchasing bags was age and damage of the owned products, and Internet shopping malls were the most common purchasing place. The average annual cost of purchasing bags was 100,000 to 300,000 won, and the frequency of purchase was about once a year. Second, as bag preference images, four factors (individual, romantic, active, and classic image) were derived, and adult consumers preferred classic images the most. The shoulder bag was the most preferred as the bag shape, and black was the most preferred bag color. For the material, natural leather was the most preferred, and for the size, medium size was the most preferred. Third, bag purchasing behaviors and design preferences showed many significant differences according to the sex and age of the consumers. Therefore, the results of this study suggests that bag companies need to establish product development and marketing strategies in consideration of differences according to the sex and age group of adult consumers.

Modern Concepts of Restructured Meat Production and Market Opportunities

  • Abdul Samad;AMM Nurul Alam;Swati Kumari;Md. Jakir Hossain;Eun-Yeong Lee;Young-Hwa Hwang;Seon-Tea Joo
    • Food Science of Animal Resources
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    • v.44 no.2
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    • pp.284-298
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    • 2024
  • Restructured meat (RM) products are gaining importance as an essential component of the meat industry due to consumers' interest in health benefits. RM products imply the binding or holding of meat, meat by-products, and vegetable proteins together to form a meat product with meat's sensory and textural properties. RM products provide consumers with diversified preferences like the intake of low salt, low fat, antioxidants, and high dietary fiber in meat products. From the point of environmental sustainability, RM may aid in combining underutilized products and low-valued meat by adequately utilizing them instead of dumping them as waste material. RM processing technique might also help develop diversified and new hybrid meat products. It is crucial to have more knowledge on the quality issues, selection of binding agents, their optimum proportion, and finally, the ideal processing techniques. It is observed in this study that the most crucial feature of RM could be its healthy products with reduced fat content, which aligns with the preferences of health-conscious consumers who seek low-fat, low-salt, high-fiber options with minimal synthetic additives. This review briefly overviews RM and the factors affecting the quality and shelf life. Moreover, it discusses the recent studies on binding agents in processing RM products. Nonetheless, the recent advancements in processing and market scenarios have been summarized to better understand future research needs. The purpose of this review was to bring light to the ways of sustainable and economical food production.

Optimizing cement replacement with rice husk ash and eggshell ash for enhanced mechanical properties of geopolymer concrete: A comparative study with and without admixture

  • Yashwanth Pamu;Venkata Sarath Pamu;Praveen Samarthi;Mahesh Kona
    • Computers and Concrete
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    • v.33 no.6
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    • pp.707-724
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    • 2024
  • This paper proposes a study of cement replacement with rice husk ash (RHA) and eggshell ash (ESA) for enhanced mechanical properties of geopolymer (GP) concrete with and without admixture. The main objective is to investigate the mechanical properties of GP with various replacement levels of Pozzolana Portland cement by RHA and ESA. The GP resistance to durability is examined and impact of ash materials on concrete's durability performance is determined. The environmental benefits of using agricultural waste materials in GP manufacturing minimize cement usage and CO2 emissions. The goal is to assess value of RHA-ESA of building material, paving stones for structures to lessen environmental impact. The novelty lies in use of ESA and RHA as partial replacements for cement and investigation of admixtures to enhance concrete properties, and reduce environmental impact. The research contributes by introducing a novel approach to reducing cement consumption by using ESA and RHA to address environmental concerns. It also explores the potential benefits of admixtures improving concrete performance and reducing environmental pollution. A study is carried with and without impacts of admixture to find compressive strength of GP cubes. The cement has been replaced by RHA and ESA in the range of (2.5%+7.5%, 5%+5%, 7.5%+2.5) by weight of cement for M20 mix. The compressive strength (CS) and split tensile strength (STS) at 7days, 14 days and 28 days is obtained as 21 N/mm2 at 7.5%RHA+2.5%ESA and 2.3 at 7.5%RHA+2.5%ESA, 24 N/mm2 at 7.5%RHA+2.5%ESA and 2.3 at 7.5%RHA+2.5%ESA, 28 N/mm2 at 7.5%RHA+2.5%ESA and 2.8 at 7.5%ESA respectively with normal curing condition.

Exploring the phenomenon of veganphobia in vegan food and vegan fashion (비건 음식과 비건 패션에서 나타난 비건포비아 현상에 대한 탐구)

  • Yeong-Hyeon Choi;Sangyung Lee
    • The Research Journal of the Costume Culture
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    • v.32 no.3
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    • pp.381-397
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    • 2024
  • This study investigates the negative perceptions (veganphobia) held by consumers toward vegan diets and fashion and aims to foster a genuine acceptance of ethical veganism in consumption. The textual data web-crawled Korean online posts, including news articles, blogs, forums, and tweets, containing keywords such as "contradiction," "dilemma," "conflict," "issues," "vegan food" and "vegan fashion" from 2013 to 2021. Data analysis was conducted through text mining, network analysis, and clustering analysis using Python and NodeXL programs. The analysis revealed distinct negative perceptions regarding vegan food. Key issues included the perception of hypocrisy among vegetarians, associations with specific political leanings, conflicts between environmental and animal rights, and contradictions between views on companion animals and livestock. Regarding the vegan fashion industry, the eco-friendliness of material selection and design processes were seen as the pivotal factors shaping negative attitudes. Furthermore, the study identified a shared negative perception regarding vegan food and vegan fashion. This negativity was characterized by confusion and conflicts between animal and environmental rights, biased perceptions linked to specific political affiliations, perceived self-righteousness among vegetarians, and general discomfort toward them. These factors collectively contributed to a broader negative perception of vegan consumption. In conclusion, this study is significant in understanding the complex perceptions and attitudes that con- sumers hold toward vegan food and fashion. The insights gained from this research can aid in the design of more effective campaign strategies aimed at promoting vegan consumerism, ultimately contributing to a more widespread acceptance of ethical veganism in society.

Bioactivity-Guided Fraction from Viscera of Abalone, Haliotis discus hannai Suppresses Cellular Basophils Activation and Anaphylaxis in Mice

  • Kap Seong Choi;Tai-Sun Shin;Ginnae Ahn;Shin Hye Kim;Jiyeon Chun;Mina Lee;Dae Heon Kim;Han-Gil Choi;Kyung-Dong Lee;Sun-Yup Shim
    • Journal of Microbiology and Biotechnology
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    • v.34 no.2
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    • pp.379-386
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    • 2024
  • Basophils and mast cells are specialized effector cells in allergic reactions. Haliotis discus hannai (abalone), is valuable seafood. Abalone male viscera, which has a brownish color and has not been previously reported to show anti-allergic activities, was extracted with acetone. Six different acetone/hexane fractions (0, 10, 20, 30, 40, and 100%) were obtained using a silica column via β-hexosaminidase release inhibitory activity-guided selection in phorbol myristate acetate and a calcium ionophore, A23187 (PMACI)-induced human basophils, KU812F cells. The 40% acetone/hexane fraction (A40) exhibited the strongest inhibition of PMACI-induced-β-hexosaminidase release. This fraction dose-dependently inhibited reactive oxygen species (ROS) production and calcium mobilization without cytotoxicity. Western blot analysis revealed that A40 down-regulated PMACI-induced MAPK (ERK 1/2, p-38, and JNK) phosphorylation, and the NF-κB translocation from the cytosol to membrane. Moreover, A40 inhibited PMACI-induced interleukin (IL)-1β, IL-6, and IL-8 production. Anti-allergic activities of A40 were confirmed based on inhibitory effects on IL-4 and tumor necrosis factor alpha (TNF-α) production in compound (com) 48/80-induced rat basophilic leukemia (RBL)-2H3 cells. A40 inhibited β-hexosaminidase release and cytokine production such as IL-4 and TNF-α produced by com 48/80-stimulated RBL-2H3 cells. Furthermore, it's fraction attenuated the IgE/DNP-induced passive cutaneous anaphylaxis (PCA) reaction in the ears of BALB/c mice. Our results suggest that abalone contains the active fraction, A40 is a potent therapeutic and functional material to treat allergic diseases.

Analysis of Elementary School Teachers' Experiences with Using the Unity Physics Engine to Develop Augmented Reality Science Educational Materials (초등학교 교사의 유니티 물리엔진을 활용한 증강현실 과학교육 자료개발 경험 분석)

  • Kim, Hyunguk
    • Journal of Korean Elementary Science Education
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    • v.43 no.3
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    • pp.385-401
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    • 2024
  • This study presents a step-by-step analysis of the experiences and discussions of five elementary school teachers while developing the Augmented Reality (AR) science educational materials, using the Unity Physics Engine. In the preparation phase to develop the AR materials, the teachers explored the features of the AR technology and decided to create AR materials for experiments related to magnetic fields in the magnetism unit, based on discussions about the unit selection. In addition, they complained about difficulties arising out of the lack of background knowledge about the C# programming language in the preparation phase. During the material development stage, there were difficulties in operating the unfamiliar interface and other functions of the software. However, this was overcome through knowledge sharing and collaborative communication among the teachers. The final materials developed were marker-type AR materials to perform experimental activities by changing the position of the magnet and the compass markers. Based on the developed materials, the teachers discussed their smooth utilization during the classroom activities.