• Title/Summary/Keyword: e-Manufacturing

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An Experimental Study on Early Strength and Drying Shrinkage of High Strength Concrete Using High Volumes of Ground Granulated Blast-furnace Slag(GGBS) (고로슬래그 미분말을 대량 사용한 고강도 콘크리트의 조기강도 및 길이변화 특성에 관한 실험적 연구)

  • Yang, Wan-Hee;Ryu, Dong-Woo;Kim, Woo-Jae;Park, Dong-Cheol;Seo, Chee-Ho
    • Journal of the Korea Institute of Building Construction
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    • v.13 no.4
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    • pp.391-399
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    • 2013
  • For high strength concrete of 40~60 MPa, the effects on the early strength and concrete dry shrinkage properties replacing 60~80% of Ordinary Portland Cement with Blast Furnace Slag Powder and using the Alkali Activator (Modified Alkali Sulfate type) are considered in this study. 1% Alkali Activator to the binder, cumulative heat of hydration for 72 hours was increased approximately 45%, indicating that heat of hydration contributes to the early strength of concrete, and the slump flow of concrete decreased slightly by 3.7~6.6%, and the 3- and 7- strength was increased by 8~12%, which that the Alkali Activator (Modified Alkali Sulfate type) is effective for ensuring the early strength when manufacturing High Strength Concrete (60%) of Blast Furnace Slag Powder. Furthermore, the dry shrinkage test, both 40 MPa and 60 MPa specimens had level of length changes in order of BS40 > BS60 > BS60A > BS80A, and the use of the Alkali Activator somewhat improved resistance to dry shrinkage.

Study on a recipe of recycled bumper and pristine materials for application of vehicle parts (재활용 범퍼의 효율적인 적용을 위한 신재의 최적 배합비율에 관한 연구)

  • Son, Younggon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.1
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    • pp.175-180
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    • 2016
  • Waste bumpers from out-of-service vehicles are recycled in the manufacturing process of plastic parts by incorporating pristine materials after removing the coated paint on a bumper. This study examined the chemical properties and mechanical properties of a mixture of recycled bumper and pristine materials as a function of the mixing ratio. When the pristine materials and the recycled bumper pieces were mixed, the stiffness (tensile strength and the flexural modulus) was provided by their composition averages. On the other hand, the toughness (Izod impact strength and the elongation-at-break) was lower than their composition averages (i.e., negative deviation). FTIR analysis showed that these results were due to the absence of the compatibility between the pristine materials and recycled bumper pieces. When the recycled bumper pieces were loaded at more than 30 wt. %, the toughness decreased drastically. A previous study showed that a paint removal efficiency up to 80 wt.% was easily attainable. The other 20 wt.% of paint on the bumper is very difficult to remove. Therefore, this study examined the mechanical properties of a mixture of recycled bumper pieces containing the unremoved paint and recycled bumper pieces without paint. When the recycled bumper pieces containing the unremoved paint were incorporated in only small quantities, the mechanical properties were decreased to a great extent. These results show that the paint removal efficiency is very important in the recycled bumper industry.

Numerical Analysis of Flow Characteristies inside innes part of Fluid Control Valve System (유동해석을 통한 유체제어벨브 시스템의 내부 유동 특성 분석)

  • Son, Chang-Woo;Seo, Tae-Il;Kim, Kwang-Hee;Lee, Sun-Ryong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.6
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    • pp.160-166
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    • 2018
  • The worldwide semi-conductor market has been growing for a long time. Manufacturing lines of semi-conductors need to handle several types of toxic gases. In particular, they need to be controlled accurately in real time. This type of toxic gas control system consists of many different kinds of parts, e.g., fittings, valves, tubes, filters, and regulators. These parts obviously need to be manufactured precisely and be corrosion resistant because they have to control high pressure gases for long periods without any leakage. For this, surface machining and hardening technologies of the metal block and metal gasket need to be studied. This type of study depends on various factors, such as geometric shapes, part materials, surface hardening method, and gas pressures. This paper presents strong concerns on a series of simulation processes regarding the differences between the inlet and outlet pressures considering several different fluid velocity, tube diameters, and V-angles. Indeed, this study will very helpful to determine the important design factors as well as precisely manufacture these parts. The EP (Electrolytic Polishing) process was used to obtain cleaner surfaces, and hardness tests were carried out after the EP process.

Sol-gel deposited TiInO thin-films transistor with Ti effect

  • Kim, Jung-Hye;Son, Dae-Ho;Kim, Dae-Hwan;Kang, Jin-Kyu;Ha, Ki-Ryong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.200-200
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    • 2010
  • In recent times, metal oxide semiconductors thin films transistor (TFT), such as zinc and indium based oxide TFTs, have attracted considerable attention because of their several advantageous electrical and optical properties. There are many deposition methods for fabrication of ZnO-based materials such as chemical vapor deposition, RF/DC sputtering and pulsed laser deposition. However, these vacuum process require expensive equipment and result in high manufacturing costs. Also, the methods is difficult to fabricate various multicomponent oxide semiconductor. Recently, several groups report solution processed metal oxide TFTs for low cost and non vacuum process. In this study, we have newly developed solution-processed TFTs based on Ti-related multi-component transparent oxide, i. e., InTiO as the active layer. We propose new multicomponent oxide, Titanium indium oxide(TiInO), to fabricate the high performance TFT through the sol-gel method. We investigated the influence of relative compositions of Ti on the electrical properties. Indium nitrate hydrate [$In(NO^3).xH_2O$] and Titanium isobutoxide [$C_{16}H_{36}O_4Ti$] were dissolved in acetylacetone. Then monoethanolamine (MEA) and acetic acid ($CH_3COOH$) were added to the solution. The molar concentration of indium was kept as 0.1 mol concentration and the amount of Ti was varied according to weighting percent (0, 5, 10%). The complex solutions become clear and homogeneous after stirring for 24 hours. Heavily boron (p+) doped Si wafer with 100nm thermally grown $SiO_2$ serve as the gate and gate dielectric of the TFT, respectively. TiInO thin films were deposited using the sol-gel solution by the spin-coating method. After coating, the films annealed in a tube furnace at $500^{\circ}C$ for 1hour under oxygen ambient. The 5% Ti-doped InO TFT had a field-effect mobility $1.15cm^2/V{\cdot}S$, a threshold voltage of 4.73 V, an on/off current ratio grater than $10^7$, and a subthreshold slop of 0.49 V/dec. The 10% Ti-doped InO TFT had a field-effect mobility $1.03\;cm^2/V{\cdot}S$, a threshold voltage of 1.87 V, an on/off current ration grater than $10^7$, and a subthreshold slop of 0.67 V/dec.

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A Study on the Consumption of Korean Traditional Rice Cakes by College Students (전통 떡류에 대한 대학생들의 이용 현황에 관한 연구)

  • 정효선;서경화;신민자
    • Korean journal of food and cookery science
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    • v.20 no.1
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    • pp.26-33
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    • 2004
  • The purpose of this study was to investigate the consumption patterns of traditional Korean rice cake among college students. Self administered questionnaires were collected from 512 college students in the Seoul, Kyunggi, Chungchung, Kyungsang, Junla and Gangwondo areas. The data were statistically analysed using frequency analysis, chi-squared and t-tests and a one-way ANOVA. By examining the results of the student's perceptions of traditional Korean rice cake, it was found that most know little, or only a moderate amount, about this type of food. Meanwhile, more than half the students liked traditional Korean rice cake, as this type of food satisfied their need for a traditional Korean taste, while the reason for disliking was that they were more familiar with western-style confectionary. Most students answered that they only ate traditional Korean rice cake on special occasions, such as big holidays or ceremonies for the dead ancestors. Most answered that they bought those foods at conventional markets, the mile in the neighborhood, (Eds note: I dont't understand, do you mean, “within a mile of their neighborhood”\ulcorner) or atbig malls. The factor they considered the most important at the time of purchase was the quality (taste), which demonstrates the need for the development of traditional Korean rice cakes, with new tastes and shapes, which still satisfy the Korean's taste, whilemaintaining the traditional taste. For the questions that asked about the problems faced by the traditional Korean rice cake manufacturing industry, and the reasons for low consumption, the students responded that buying this type of food was difficult as the outlets selling themwere not easy to find. Our results seem to suggest that there are almost no specialty stores for the sale of traditional Korean rice cake compared to the other types of cakes that are scattered all over the country. (Eds note: this is only my opinion, and I maybe wrong, but I would have thought that trying to market traditional Korean rice cakes at local convenience stores, rather than speciality stores, would make them more available to the general public. Their marketing at speciality stores will maintain the status quo, i.e. people will go to the speciality stores to purchase product for holidays and special occasions, whereas they will go to the local convenience stores to buy general everyday snacks etc.)

A Study on Measures to Achieve Performance and Safety of Air Respirators for Fire Fighters (소방대원용 공기호흡기의 성능안전확보 대책에 관한 연구)

  • Son, Bong-Sei;Oh, Suk-Hwan;Kim, Yeop-Rae
    • Fire Science and Engineering
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    • v.26 no.4
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    • pp.77-81
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    • 2012
  • This study of aims to provide basic data for improve the performance of air respirators that generate by bad influencing elements in fire emergency field. With three types of conditions set up for these tests, the pressures of containers have been extracted; the ambient temperatures have been checked, and the generation of moisture inside and outside container have been checked and identified. Specifically, these tests have been conducted at temperatures ranging between $-20{\sim}40^{\circ}C$. The pressures of containers have been extracted to reach between 0.4~0.8 MPa, using a pressure regulating valve. These tests have resulted in no change in the temperature and moisture outside the containers and no generation of moisture inside the containers as well. Although moisture has been generated inside the pressure gauge, the amount of moisture has not exceeded 25 $mg/m^3$, i.e. the limit suggested by the Korean Government. Therefore, it is judged that the moisture generated inside air respirators, which can be the most critical issue in the equipment, is likely to be caused in the process of managing the equipment or replacing air in the equipment at places of end-users, rather than in the process of manufacturing and production of the equipment.

Development of Lightweight Composite Sub-frame in Automotive Chassis Parts Considering Structure & NVH Performance (구조 및 NVH 성능을 고려한 복합재료 서브프레임 개발)

  • Han, Doo-Heun;Ha, Sung
    • Composites Research
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    • v.32 no.1
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    • pp.21-28
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    • 2019
  • Recently, according to environmental regulations, the automobile industry has been conducting various research on the use of composite materials to increase fuel efficiency. However, there has not been much research on lightweight chassis components. Therefore, in this research, the purpose of this study is to apply composite materials to the sub-frame of chassis components to achieve equivalent levels of stiffness, strength, NVH performance and 50% lightweight compared to the steel sub-frame. First, the Natural frequency of steel and composite specimens was compared to the damping characteristics of composite materials. Then, in this study, the Lay-up Sequence was derived to maximize the stiffness and strength of the sub-frame by applying composite materials. And this lay-up Sequence is proposed to avoid heat shrinkage due to curing during manufacturing. This process was designed based on a FEM structural analysis, and a Natural frequency and frequency response function graph was confirmed based on a modal analysis. The prototype type composite sub-frame was manufactured based on the design and the F.E.M analysis was verified through a modal experiment. Furthermore, it was fitted to the actual vehicle to verify the natural frequency and the indoor noise vibration response, including idling and road noise. This result was confirmed to be equivalent to the steel sub-frame. Finally, the composite sub-frame weight was confirmed to be about 50% of the steel sub-frame.

Change of Physical Property of Alaska Pollack Gadus chalcogrammus Surimi with Addition of Polysaccharide Alginic Acid for Applying to 3D Printing (3D 프린팅을 위한 수리미 제조 시 다당류 알긴산 첨가에 따른 물성 변화)

  • Kim, Han-Ho;Choi, Ye-Hui;Park, Ye-Lin;Park, Jeong-Cheol;Han, Hyeon-Su;Kang, Yoo-Seok;Kim, Soo-Hyeong;Seo, Hun-Seo;Kang, Woo-Sin;Kim, Su-Ryong;Ryu, Si-Hyeong;Lee, Ji-Eun;Xu, Xiaotong;Lee, Ga-Hye;Jeong, So-Mi;Ahn, Dong-Hyun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.54 no.2
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    • pp.145-151
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    • 2021
  • When manufacturing Alaska pollack Gadus chalcogrammus surimi for 3D printing, it examined the characteristics of physical properties and sensuality by adding polysaccharides alginic acid [0, 1, 2, 3% (w/w)]. As a result of the color value of surimi by adding alginic acid, it showed that the lightness of heated surimi containing 2% (w/w) alginic acid was the highest and ∆E value was the lowest. In the changes in physical properties, the heated surimi of 3% (w/w) alginic acid content showed the lowest values of hardness, springiness, cohesiveness, gumminess, chewiness and resilience, but the highest adhesiveness. In the case of fried surimi, its hardness, cohesiveness, gumminess, chewiness and resilience were the lowest at the content of 3% (w/w) alginic acid. After 7 days of cold storage, the hardness, gumminess, and chewiness of heated surimi with an alginic acid content of 2% (w/w) were significantly higher, and fried surimi was also the same. In the results of the sensory evaluation, there were significant differences according to the alginic acid content in hardness and fishy smell, and as the alginic acid content increased, it felt more fishy smell, resulting in poor preference.

A Study on the Manufacturing and Applicability of Rosin-based Epoxy Adhesives and Filling Material for Conservation of Wood Crafts (목공예품 보존용 송진 기반 에폭시 접착제 및 메움제의 제조와 적용성에 관한 연구)

  • Wi, Koang-Chul;Han, Won-Sik;Oh, Seung-Jun
    • Journal of Conservation Science
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    • v.36 no.6
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    • pp.475-482
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    • 2020
  • In this study, we synthesized rosin-based epoxy resin and manufactured two components adhesives and epoxy putty using this epoxy resin. This study manufactured main element of adhesives for enabling it to form epoxide group by letting epichlorohydrin react to maleic anhydride modified rosin, and used room temperature curing type triethylenetetramine for hardener. The ratio between main element and hardener of of manufactured adhesives was 100 : 20, and main element and hardener of filling material were manufactured as clay type by mixing them with filler. Manufactured undiluted adhesives and filling material showed very stable result in the adhesive strength (3.06 MPa) and ultraviolet irradiation, showing outstanding result comparing to existing restoration adhesives. And it is considered a material having reversibility as it was dissolved in organic solvents such as acetone and toluene after being hardened, which showed a result that solved part of possible problems caused by restoration. As a result of use and application of manufactured adhesives and filling material for actual wood crafts, they showed excellent results in workability, stability, removability etc., and this study confirmed that the material can be used for and applied to various fields.

A Study on Geospatial Information Role in Digital Twin (디지털트윈에서 공간정보 역할에 관한 연구)

  • Lee, In-Su
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.3
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    • pp.268-278
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    • 2021
  • Technologies that are leading the fourth industrial revolution, such as the Internet of Things (IoT), big data, artificial intelligence (AI), and cyber-physical systems (CPS) are developing and generalizing. The demand to improve productivity, economy, safety, etc., is spreading in various industrial fields by applying these technologies. Digital twins are attracting attention as an important technology trend to meet demands and is one of the top 10 tasks of the Korean version of the New Deal. In this study, papers, magazines, reports, and other literature were searched using Google. In order to investigate the contribution or role of geospatial information in the digital twin application, the definition of a digital twin, we investigated technology trends of domestic and foreign companies; the components of digital twins required in manufacturing, plants, and smart cities; and the core techniques for driving a digital twin. In addition, the contributing contents of geospatial information were summarized by searching for a sentence or word linked between geospatial-related keywords (i.e., Geospatial Information, Geospatial data, Location, Map, and Geodata and Digital Twin). As a result of the survey, Geospatial information is not only providing a role as a medium connecting objects, things, people, processes, data, and products, but also providing reliable decision-making support, linkage fusion, location information provision, and frameworks. It was found that it can contribute to maximizing the value of utilization of digital twins.