• 제목/요약/키워드: supplementary materials

검색결과 263건 처리시간 0.02초

Fabrication of nitrogen doped ordered mesoporous carbon derived from glucosamine with hybrid capacitive behaviors

  • Zhang, Deyi;Han, Mei;Li, Yubing;Wang, Bing;Wang, Yi;Wang, Kunjie;Feng, Huixia
    • Carbon letters
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    • 제23권
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    • pp.9-16
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    • 2017
  • This paper introduces a nitrogen-doped ordered mesoporous carbon (NOMC) derived from glucosamine with hybrid capacitive behaviors, achieved by successfully combining electrical double-layer capacitance with pseudo-capacitance behaviors. The nitrogen doping content of the fabricated NOMC reached 7.4 at% while its specific surface area ($S_{BET}$) and total pore volume reached $778m^2g^{-1}$ and $1.17cm^3g^{-1}$, respectively. A dual mesoporous structure with small mesopores centered at 3.6 nm and large mesopores centered at 9.9 nm was observed. The specific capacitance of the reported materials reached up to $328Fg^{-1}$, which was 2.1 times higher than that of pristine CMK-3. The capacitance retention rate was found to be higher than 87.9% after 1000 charge/discharge cycles. The supplementary pseudocapacitance as well as the enhanced wettability and conductivity due to the incorporation of nitrogen heteroatoms within the carbon matrixes were found to be responsible for the excellent capacitive performance of the reported NOMC materials.

조선후기 사랑방 목가구의 표현과 의미 구조 분석 (Analysis of Expressive Features and Structural Meanings in Korean Men's Furniture of the 19th century)

  • 김은정;박영순
    • 한국실내디자인학회논문집
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    • 제21권6호
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    • pp.147-157
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    • 2012
  • This paper aims to examine the fundamental relationship of what principles cause the aesthetic shapes in Korean sarangbang furniture of the $19^{th}$ century. Focusing on the Greimas' isotopic and semantic structure analysis, this research analyzed the traditional Korean men's furniture in four steps; signifier analysis, isotopic analysis, semantic structure analysis, and comprehensive interpretation. The results show that the expressive qualities of sarangbang furniture included visual symmetric aesthetics, and the hues of natural materials with dark tones. The manufacturing process emphasized the characteristics of natural materials; while diversity was respected in decorations, function as restrained form was also important with a concise image. Through these characteristics, sarangbang furniture revealed a balance, a harmony of contrastive elements, and a restrained aesthetics. Within these qualities, it was seen that aesthetic principles, such as "severance and communication," "artifice and nature," "restraint and manifestation," "toughness and softness," "filling and emptying" and "decoration and utility" were in a mutually supplementary relationship. At the basis of this aesthetic thought appears to be Confucianism, which had been the model for seonbi politics and scholarship.

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A software-assisted comparative assessment of the effect of cement type on concrete carbonation and chloride ingress

  • Demis, S.;Papadakis, V.G.
    • Computers and Concrete
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    • 제10권4호
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    • pp.391-407
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    • 2012
  • Utilization of supplementary cementing materials (SCM) by the cement industry, as a highly promising solution of sustainable cement development aiming to reduce carbon dioxide emissions, necessitates a more thorough evaluation of these types of materials on concrete durability. In this study a comparative assessment of the effect of SCM on concrete durability, of every cement type as defined in the European Standard EN 197-1 is taking place, using a software tool, based on proven predictive models (according to performance-related methods for assessing durability) developed and wide-validated for the estimation of concrete service life when designing for durability under harsh environments. The effect of Type II additives (fly ash, silica fume) on CEM I type of cement, as well as the effect of every Portland-composite type of cement (and others) are evaluated in terms of their performance in carbonation and chloride exposure, for a service life of 50 years. The main aim is to portray a unified and comprehensive evaluation of the efficiency of SCM in order to create the basis for future consideration of more types of cement to enter the production line in industry.

Influence of supplementary cementitious materials on strength and durability characteristics of concrete

  • Praveen Kumar, V.V.;Ravi Prasad, D.
    • Advances in concrete construction
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    • 제7권2호
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    • pp.75-85
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    • 2019
  • The present study is focused on the mechanical and durability properties of ternary blended cement concrete mix of different grades 30 MPa, 50 MPa and 70 MPa. Three mineral admixtures (fly ash, silica fume and lime sludge) were used as a partial replacement of cement in the preparation of blended concrete mix. The durability of ternary blended cement concrete mix was studied by exposing it to acids HCl and $H_2SO_4$ at 5% concentration. Acid mass loss factors (AMLF), acid strength loss factor (ASLF) and acid durability factor (ADF) were determined, and the results were compared with the control mix. Chloride ions penetration was investigated by conducting rapid chlorination penetration test and accelerated corrosion penetration test on control mix and ternary blended cement concrete. From the results, it was evident that the usage of these mineral admixtures is having a beneficiary role on the strength as well as durability properties. The results inferred that the utilization of these materials as a partial replacement of cement have significantly enhanced the compressive strength of blended concrete mix in 30 MPa, 50 MPa and 70 MPa by 42.95%, 32.48% and 22.79%. The blended concrete mix shown greater resistance to acid attack compared to control mix concrete. Chloride ion ingress of the blended cement concrete mix was low compared to control mix implying the beneficiary role of mineral admixtures.

Influence of plastic viscosity of mix on Self-Compacting Concrete with river and crushed sand

  • Rama, J.S. Kalyana;Sivakumar, M.V.N.;Kubair, K. Sai;Vasan, A.
    • Computers and Concrete
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    • 제23권1호
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    • pp.37-47
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    • 2019
  • In view of the increasing utility of concrete as a construction material, the major challenge is to improve the quality of construction. Nowadays the common problem faced by many of the concrete plants is the shortage of river sand as fine aggregate material. This led to the utilization of locally available materials from quarries as fine aggregate. With the percentage of fines present in Crushed Rock Fines (CRF)or crushed sand is more compared to river sand, it shows a better performance in terms of fresh properties. The present study deals with the formulation of SCC mix design based on the chosen plastic viscosity of the mix and the measured plastic viscosity of cement pastes incorporating supplementary cementitious materials with CRF and river sand as a fine aggregate. Four different combinations including two binary and one ternary mix are adopted for the current study. Influence of plastic viscosity of the mix on the fresh and hardened properties are investigated for SCC mixes with varying water to cement ratios. It is observed that for an increasing plastic viscosity of the mix, slump flow, T500 and J-ring spread increased but V-funnel and L-box decreased. Compressive, split tensile and flexural strengths decreased with the increase in plastic viscosity.

운동 치료 연구에 영향을 주는 연구대상자의 참여도와 충실도 조사 (Investigation of frequency and fidelity of the participants affecting the study of exercise therapy)

  • 최보람
    • 대한물리치료과학회지
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    • 제28권1호
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    • pp.54-61
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    • 2021
  • Background: The present study was performed to examine the factors required for active engagement of participants in exercise therapy by surveying the frequency of participation, fidelity of performance, and supporting materials and rewards provided to encourage participation in the study. Design: Cross-sectional study. Methods: The survey was conducted in a population of 103 participants in at least one exercise treatment study. A 12-item questionnaire was designed to determine the frequency of exercise participation and fidelity of participant performance. Results: The results were subjected to frequency analysis and Pearson's correlation analysis. The subjects were less likely to exercise with the therapist and less likely to exercise at home. In addition, the provision of supplementary materials, to be considered when exercising at home, was insufficient. A strong positive correlation was found between the frequency of exercise in the presence of a therapist and the fidelity of participant performance (r=0.812, p=0.001), whereas a weak negative correlation was found between the frequency of unperformed exercises and the fidelity of participant performance (r=-0.523, p=0.023). Conclusion: The results of the present study suggested that it is necessary to increase the number of times that exercises are performed with the therapist to motivate increased frequency of exercise participation and fidelity of participant performance. In addition, appropriate rewards and periodic management are required.

상업용 리튬 배터리의 수명 예측을 위한 고속대량충방전 데이터 정규화 선형회귀모델의 적용 (Application of Regularized Linear Regression Models Using Public Domain data for Cycle Life Prediction of Commercial Lithium-Ion Batteries)

  • 김장군;이종숙
    • 한국수소및신에너지학회논문집
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    • 제32권6호
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    • pp.592-611
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    • 2021
  • In this study a rarely available high-throughput cycling data set of 124 commercial lithium iron phosphate/graphite cells cycled under fast-charging conditions, with widely varying cycle lives ranging from 150 to 2,300 cycles including in-cycle temperature and per-cycle IR measurements. We worked out own Python codes which reproduced the various data plots and machine learning approaches for cycle life prediction using early cycles and more details not presented in the article and the supplementary information. Particularly, we applied regularized ridge, lasso and elastic net linear regression models using features extracted from capacity fade curves, discharge voltage curves, and other data such as internal resistance and cell can temperature. We found that due to the limitation in the quantity and quality of the data from costly and lengthy battery testing a careful hyperparameter tuning may be required and that model features need to be extracted based on the domain knowledge.

의류 DIY 패키지의 소비자 현황조사 연구 (Research on Customer Survey for Clothing DIY Packages)

  • 이은혜
    • 패션비즈니스
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    • 제27권2호
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    • pp.108-123
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    • 2023
  • Recent increase of eco-conscious trends and pleasure from Do It Yourself (DIY) activities have led to a surge in sales of package products bundling together clothing patterns and raw materials. However, a well-structured market system is yet to be established. We surveyed 460 women with sewing as a hobby who had purchased these DIY clothing pattern packages. The survey revealed that majority of respondents had their hobby for over five years. Choosing the right fabric to match clothing patterns presented a common challenge. Most participants owned a sewing machine and an overlocker, with price being the primary concern when purchasing a package. For guidance during the sewing process, participants preferred print materials featuring real-life images. Those with less sewing experience leaned towards video tutorials. Items of interest or those commonly created included blouses, shirts, and dresses. Desire for further learning in sewing and pattern-making was prominent, with a clear preference for online classes. Several strategies are recommended to enhance the appeal of DIY clothing package products, including broadening range of packages that incorporate fabric, offering supplementary educational resources to improve users' skills, implementing affordable pricing structures, supplying comprehensive creation guidelines, and making available design modification guides. These considerations could significantly boost customer satisfaction. This research intends to lay groundwork for understanding DIY clothing creation market, ultimately fostering production of highly desirable products. Insights of this study will prove instrumental in refining product development and devising effective marketing tactics, leading to a more rewarding consumer experience.

Blended Instructional Practices in Higher Education Institutions

  • OH, Eunjoo
    • Educational Technology International
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    • 제8권1호
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    • pp.101-126
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    • 2007
  • The purpose of this study was to investigate current practices in blended instruction. In particular, the study explored (1) the types of instructional delivery methods, technologies, and instructional components, (2) the reasons why faculty apply blend instruction, and (3) the advantages and challenges in delivering blended instruction. This study focused on the practices in the Universities that have the extensive doctoral research programs classified by the Carnegie Foundations. The survey was performed with the sample of faculty from 30 universities and the survey data included 133 faculties out of the total 1,000 randomly selected faculty members. Of the 133 responses, 111 (77.7%) participants had certain degree of experience, while 17 faculty (or instructors) (13.3%) did not have any practice with blended instruction. The most common instructional delivery format in the participating universities was blended instruction that added supplementary online instructional components in the class. Online Course Management Systems (CMS) and multimedia presentation tools were common technology for course delivery, and "discussion" was the most general instructional activity for the class. The participating faculty often preferred the blended format since it provides students and faculty with convenience, flexibility, active engagement, efficiency in using resource materials, and a feeling of connection between/among students and instructor. Benefits to the class were availability of more authentic experience and diverse curricular materials, and the instructional format that meets the needs of remediation and enhancement of students. This study addressed not only advantages and challenges of blended instruction, but also suggestions based on the comments by the participating faculty.

Design and Implementation of Mathematics Textbooks in Support of Effective Teaching for Secondary Schools: A Chinese Case

  • PENG, Aihui;SONG, Naiqing
    • 한국수학교육학회지시리즈D:수학교육연구
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    • 제19권4호
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    • pp.247-265
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    • 2015
  • Mathematics textbook plays a significant role in shaping students' learning of mathematics. Logic, rigor and abstraction as typical features of the formalization of mathematics, dominate mathematics textbooks around the world, which is regarded as one of the important origins of students' learning difficulties in mathematics. An innovative series of Chinese mathematic textbooks is presented in this paper. Supported by the supplementary materials excerpts from the textbooks, it gives a comprehensive theoretical analysis of the principles of design and implementation of this series of mathematics textbooks. The effectiveness of this series of textbooks is demonstrated by student achievement and secondary research data. It shows that series of Chinese mathematic textbooks has largely decreased students' learning difficulties in mathematics and enhance classroom teaching efficiency. It suggests that prioritizing the essence of mathematics and reducing abstraction is an important notion for mathematics textbook design and implementation.