• Title/Summary/Keyword: Stemming material

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A System Theory Approach to Social Support for Multi-cultural Families with a Focus on Formal Support Systems (다문화가족의 사회적 지지에 대한 체계론적 접근 - 공적 지원체계를 중심으로 -)

  • Hong, Sung-Hee
    • Journal of Family Resource Management and Policy Review
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    • v.19 no.1
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    • pp.23-47
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    • 2015
  • The purpose of this study was to investigate social workers' personal experiences providing social support to multi-cultural family in a multi-cultural family center. The data were collected through in-depth interviews with 14 social workers at the multi-cultural family center, and were analyzed using a phenomenological research method. The major findings were as follows : The social workers' personal experiences with and understanding of social support were classified as 4 categories : 'source of emotional support to the multi-cultural family', 'diverse and systematic educational support', 'excessive demands on material support', and 'daily life support and connection with community network'. The social workers recognized emotional and educational support as essential factors in providing social support to multi-cultural family. However, the social workers' perceptions of material support derived from negative personal experiences stemming from excessive demands and misunderstanding for material support. These results showed that social workers at the multi-cultural family center provided multi-cultural families with social support and that they interacted with community support system and multi-cultural families to increase their satisfaction.

Pitch based carbon fibers for automotive body and electrodes

  • Yang, Kap Seung;Kim, Bo-Hye;Yoon, Seong-Ho
    • Carbon letters
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    • v.15 no.3
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    • pp.162-170
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    • 2014
  • Pitch is an attractive raw material for carbon fiber precursors due to its low cost stemming from its availability as a residue of coking and petroleum processes. Ford Motor Company reported a carbon fiber target price of $11.0/kg by using a fast cycle-time manufacturing method with carbon fiber in an inexpensive format, allowing for an average retail price of gasoline of $3.58/gallon. They also recommended the use of carbon fiber with strength of 1700 MPa, modulus of 170 GPa, and 1.5% elongation. This study introduced a ca. $5.5{\mu}m$ carbon fiber with 2000 MPa tensile strength obtained from a precursor through simple distillation of petroleum residue. Petroleum pitch based carbon nanofibers prepared via electrospinning were characterized and potential applications were introduced on the basis of their large specific surface area and relatively high electrical conductivity.

Multi-cracking modelling in concrete solved by a modified DR method

  • Yu, Rena C.;Ruiz, Gonzalo
    • Computers and Concrete
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    • v.1 no.4
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    • pp.371-388
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    • 2004
  • Our objective is to model static multi-cracking processes in concrete. The explicit dynamic relaxation (DR) method, which gives the solutions of non-linear static problems on the basis of the steady-state conditions of a critically damped explicit transient solution, is chosen to deal with the high geometric and material non-linearities stemming from such a complex fracture problem. One of the common difficulties of the DR method is its slow convergence rate when non-monotonic spectral response is involved. A modified concept that is distinct from the standard DR method is introduced to tackle this problem. The methodology is validated against the stable three point bending test on notched concrete beams of different sizes. The simulations accurately predict the experimental load-displacement curves. The size effect is caught naturally as a result of the calculation. Micro-cracking and non-uniform crack propagation across the fracture surface also come out directly from the 3D simulations.

Mechanical properties and deformation behavior of carbon nanotubes calculated by a molecular mechanics approach

  • Eberhardt, Oliver;Wallmersperger, Thomas
    • Smart Structures and Systems
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    • v.13 no.4
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    • pp.685-709
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    • 2014
  • Carbon nanotubes are due to their outstanding mechanical properties destined for a wide range of possible applications. Since the knowledge of the material behavior is vital regarding the possible applications, experimental and theoretical studies have been conducted to investigate the properties of this promising material. The aim of the present research is the calculation of mechanical properties and of the mechanical behavior of single wall carbon nanotubes (SWCNTs). The numerical simulation was performed on basis of a molecular mechanics approach. Within this approach two different issues were taken into account: (i) the nanotube geometry and (ii) the modeling of the covalent bond. The nanotube geometry is captured by two different approaches, the roll-up and the exact polyhedral model. The covalent bond is modeled by a structural molecular mechanics approach according to Li and Chou. After a short introduction in the applied modeling techniques, the results for the Young's modulus for several SWCNTs are presented and are discussed extensively. The obtained numerical results are compared to results available in literature and show an excellent agreement. Furthermore, deviations in the geometry stemming from the different models are given and the resulting differences in the numerical findings are shown. Within the investigation of the deformation mechanisms occurring in SWCNTs, the basic contributions of each individual covalent bond are considered. The presented results of this decomposition provide a deeper understanding of the governing deformation mechanisms in SWCNTs.

Sensitivity and accuracy for rheological simulation of cement-based materials

  • Kim, Jae Hong;Jang, Hye Rim;Yim, Hong Jae
    • Computers and Concrete
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    • v.15 no.6
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    • pp.903-919
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    • 2015
  • The flow of freshly mixed cement-based material shows thixotropy, which implies some difficulties on robust measurement of its rheological properties: The flow curve of thixotropic materials depends on the used protocol. For examples, higher viscosity is obtained when the rate of shear strain is more quickly increased. Even though precise measurement and modelling of the concrete rheology needs to consider the thixotropic effect, engineers in the concrete field prefer considering as a non-thixotropic Herschel-Bulkley fluid, even more simply Bingham fluid. That is due to robustness of the measurement and application in casting process. In the aspect of simplification, this papers attempts to mimic the thixoropic flow by the non-thixotropic Herschel-Bulkley model. Disregarding the thixotropy of cement based materials allows us to adopt the rheological concept in the field. An optimized protocol to measure the Bingham parameters was finally found based on the accuracy and reproducibility test of cement paste samples, which minimizes the error of simulation stemming from the assumption of non-thixotropy.

Nanoplasmonics: Enabling Platform for Integrated Photonics and Sensing

  • Yeo, Jong-Souk
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.75-75
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    • 2015
  • Strong interactions between electromagnetic radiation and electrons at metallic interfaces or in metallic nanostructures lead to resonant oscillations called surface plasmon resonance with fascinating properties: light confinement in subwavelength dimensions and enhancement of optical near fields, just to name a few [1,2]. By utilizing the properties enabled by geometry dependent localization of surface plasmons, metal photonics or plasmonics offers a promise of enabling novel photonic components and systems for integrated photonics or sensing applications [3-5]. The versatility of the nanoplasmonic platform is described in this talk on three folds: our findings on an enhanced ultracompact photodetector based on nanoridge plasmonics for photonic integrated circuit applications [3], a colorimetric sensing of miRNA based on a nanoplasmonic core-satellite assembly for label-free and on-chip sensing applications [4], and a controlled fabrication of plasmonic nanostructures on a flexible substrate based on a transfer printing process for ultra-sensitive and noise free flexible bio-sensing applications [5]. For integrated photonics, nanoplasmonics offers interesting opportunities providing the material and dimensional compatibility with ultra-small silicon electronics and the integrative functionality using hybrid photonic and electronic nanostructures. For sensing applications, remarkable changes in scattering colors stemming from a plasmonic coupling effect of gold nanoplasmonic particles have been utilized to demonstrate a detection of microRNAs at the femtomolar level with selectivity. As top-down or bottom-up fabrication of such nanoscale structures is limited to more conventional substrates, we have approached the controlled fabrication of highly ordered nanostructures using a transfer printing of pre-functionalized nanodisks on flexible substrates for more enabling applications of nanoplasmonics.

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A Study on Cultural Appropriation of Fashion Design in the Era of Globalization - Focusing on Traditional Culture - (세계화 시대의 패션디자인 문화적 전유에 관한 연구 - 전통문화를 중심으로 -)

  • Yu HE Chen;Chahyun Kim
    • Journal of Fashion Business
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    • v.28 no.3
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    • pp.69-89
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    • 2024
  • In the era of globalization, cultural appropriation, stemming from the interaction and clash of diverse cultures, remains inadequately defined, leading to controversy in many designs. This study aims to provide a theoretical basis for understanding cultural appropriation by comparing similar concepts and examining specific cases. It proposes methods for the rational use of traditional cultures in apparel to minimize controversy. Firstly, the study investigates the concept of cultural appropriation by exploring differences among related terms. Secondly, it examines instances of cultural appropriation in fashion through form, color, pattern, and material, drawing from papers and Google searches over the past decade. Thirdly, it categorizes representative cases by domestic and foreign fashion brands, analyzing the underlying reasons. The goal is to establish a theoretical foundation for developing culturally sensitive clothing products. Based on the findings, several measures are proposed: understanding and respecting cultural backgrounds through in-depth research on the history and significance of elements; collaborating with cultural groups and consulting experts for feedback; explaining the source of design inspiration to help consumers understand the cultural elements' meanings; avoiding the reinforcement of stereotypes and respecting cultural diversity and complexity; respecting intellectual property and ensuring moral and legal appropriateness; and learning from case studies of other designers' and brands' successes and failures.

Introduction to the Technology, Applications, Products, Markets, R&D, and Perspectives of Nanofoods in the Food Industry

  • Kim, Dong-Myong;Lee, Gee-Dong
    • Preventive Nutrition and Food Science
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    • v.11 no.4
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    • pp.348-357
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    • 2006
  • Nano is a unit that designates a billionth; accordingly nanotechnology could be described as the study and applications of the unique characteristics and phenomena of nanometer size materials. Applications of nanotechnology fall into two categories (one is top-down and the other is bottom-up). Currently, most products are the results of the top-down approach. Nanofoods have distinct functional characteristics stemming from the size, mass, chemical combinations, electrolytic features, magnetic properties of food sources at the nano level and which can be applied for safe absorption and delivery into the body. The greatest advantage of nanofood is that it permits the efficient use of small quantities of nutritional elements by increasing digestive absorption ability and by delivering natural elements without any change in their original characteristics. On the other hand, there are still unsolved problems, such as questions about safety and introduction of harmful material. The demand for new commercial food products is increasing, and commercial food producers are gradually combining nanotechnology and traditional food preparation methods. Nanofoods will improve our eating habits remarkably in the future. Tomorrow we will design nanofoods by shaping molecules and atoms. It will have a big impact on the food and food-processing industries. The future belongs to new products and new processes with the goals of customizing and personalizing consumer products. Nanotechnology is expected to be applied to not only foods themselves, but also to food packaging, production, safety, processing and storage. Also, it is believed that nanotechnology will be applied tracking finished products back to production facilities and even to specific processing equipment in those facilities. The aim of this study is the introduction of technology, applications, products, markets, R&D, and perspectives of nanofoods in the food industry.

Study on Blast Effects of Stemming Materials by Trauzl Lead Block Test and Numerical Analysis (트라우즐 연주시험과 수치해석에 의한 전색 매질별 발파효과 영향에 관한 연구)

  • Ko, Young-Hun;Kim, Seung-Jun;Baluch, Khaqan;Yang, Hyung-Sik
    • Explosives and Blasting
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    • v.35 no.4
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    • pp.19-26
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    • 2017
  • The most widely used method for determining the blast effects of explosives is the Trauzl lead block test. This test is used to measure the explosive power (strength) of a substance by determining volume increase, which is produced by the detonation of a test explosive charged in the cavity of a lead block with defined quantity and size. In this paper, Trazul lead block test and AUTODYN numerical analysis were conducted to evaluate the coupling medium effect of blast hole. The effects of coupling materials can be expressed as the expansion of the cavity in a standard lead block through explosion of the explosives. The tests were conducted with emulsion explosives. The coupling mediums used as the filling material around a explosive charge were air, sand, water and gelatine. Results of test and numerical analysis showed that expansion of lead block were much more affected by water&gel than by sand and air. The water and gel showed similar results. As expected, the transmitted pressure and dynamic strain was higher in water and gelatine coupled blast hole than in air and sand.

Relationship between Children's Perceived Competences and the Expressive Disposition of Interpersonal Relations and Parents' Social Support (아동의 자기역량지각과 대인표현성향 및 부모의 사회적 지지간의 관계)

  • Choi, Kyung-Ho;Lee, Kyu-Mee;Choi, In-Sook
    • The Journal of Korean Society for School & Community Health Education
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    • v.7
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    • pp.59-74
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    • 2006
  • Objectives: The purpose of this research is to find out the relations among children‘s perceived competences, expressive disposition of interpersonal relations, and parents’ social support, which influence their self image. Methods: The samples to achieve the purpose of this research are composed of 294 students in G elementary school, OO city, Kyounggido, the number of male students in the fifth year being 71, female 77, and male students in the sixth year being 73, female 73. After having excluded the data of 9 students among them due to their insincere reply, this research analyzed the data of 285 students by using SPSS WIN Ver. 13.0. Results: First, after having observed the average difference stemming from each method, this research found that there is no sexual difference in parents‘ social support. (p<.05). In children's perceived competences, female students is higher only in active aspect than male students, but there is no meaningful difference in other aspects. In expressive disposition of interpersonal relations, the showing-off and narcissistic expressive tendency of female students is higher than that of male students, but there is no meaningful difference in other aspects. Second, this research found out the meaningful static correlation among parents' social support, children's perceived competences, and expressive disposition of interpersonal relations. Parents' emotional, appreciative, and informative support has the static correlation with all the other aspects of children's perceived competences, and material support has the static correlation with children's academic, active, and general self-esteeming sense (p<.05, p<.01). Third, this research observed, of all the aspects of parents' social support and expressive disposition of interpersonal relations, what variable is affecting children's perceived competences, and found that parents' appreciative support, showing-off and narcissistic expressive tendency, material support, and informative support, each in order, has meaningful influence (p<.05, p<.01). This fact shows that the further the children recognize these supports of their parents', the more affirmatively they recognize their competences, and the further the children of showing-off and narcissistic expressive disposion recognize their competences. Conclusions: First, sampling was conducted of the fifth and sixth male and female students of OO elementary school, and so the result of this research has the applicative limitation in the generalization for all the elementary school students. Therefore this research suggests further researches by broad sampling for the more advanced generalization. Second, this research only observed the differnce of perception deriving from gender and school year, but the parents' social support levels perceived by children reveal many differnces according to children's characters or their families' variables. Therefore this research suggests subsequent researches on various variables.

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