• Title/Summary/Keyword: silica hybrid

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Preparation of UV-Curable Hydrophilic Coating Films Using Colloidal Silica (콜로이드 실리카를 이용한 UV 경화형 친수성 코팅 도막 제조)

  • Yang, Jun Ho;Song, Ki Chang
    • Korean Chemical Engineering Research
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    • v.55 no.6
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    • pp.754-761
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    • 2017
  • UV-curable hydrophilic coating solutions were prepared by mixing colloidal silica dispersed in alcohol with an acrylic monomer, pentaerythritol triacrylate (PETA). Hydrophilic coating films were also prepared by spin coating the hydrophilic coating solutions on PC substrates and UV curing for 10 minutes subsequently. The effect of the amount of colloidal silica in the coating solutions, which was varied from 10 g to 50 g, was investigated on the hydrophilic properties of UV-cured coating films. The results showed that the amount of colloidal silica had a great influence on the hydrophilic properties of UV-cured coating films and the coating film prepared with 30 g of colloidal silica showed a lowest contact angle of $37^{\circ}$ and an excellent pencil hardness of H.

Experimental and numerical studies on flexural behavior of high strength concrete beams containing waste glass

  • Haido, James H.;Zainalabdeen, Marwa A.;Tayeh, Bassam A.
    • Advances in concrete construction
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    • v.11 no.3
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    • pp.239-253
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    • 2021
  • The behavior of concrete containing waste glass as a replacement of cement or aggregate was studied previously in the most of researches, but the present investigation focuses on the recycling of waste glass powder as a substitute for silica fume in high strength concrete (HSC). This endeavor deals with the efficiency of using waste glass powder, as an alternative for silica fume, in the flexural capacity of HSC beam. Thirteen members with dimensions of 0.3 m width, 0.15 m depth and 0.9 m span length were utilized in this work. A comparison study was performed considering HSC members and hybrid beams fabricated by HSC and conventional normal concrete (CC). In addition to the experiments on the influence of glass powder on flexural behavior, numerical analysis was implemented using nonlinear finite element approach to simulate the structural performance of the beams. Same constitutive relationships were selected to model the behavior of HSC with waste glass powder or silica fume to show the matching between the modeling outputs for beams made with these powders. The results showed that the loading capacity and ductility index of the HSC beams with waste glass powder demonstrated enhancing ultimate load and ductility compared with those of HSC specimens with silica fume. The study deduced that the recycled waste glass powder is a good alternative to the pozzolanic powder of silica fume.

Silica-Based Planar Lightwave Circuits for WDM Applications

  • Okamoto, Katsunari;Inoue, Yasuyuki;Tanaka, Takuya;Ohmori, Yasuji
    • Electrical & Electronic Materials
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    • v.11 no.11
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    • pp.53-65
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    • 1998
  • Planar lightwave circuits (PLCs) provide various important devices for optical wavelength division multiplexing (WDM) systems, subscriber networks and etc. This paper reviews the recent progress and future prospects of PLC technologies including arrayed-waveguide grating multiplexers, optical add/drop multiplexers, programmable dispersion equalizers and hybrid optoelectronics integration technologies.

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Hybrid fuzzy model to predict strength and optimum compositions of natural Alumina-Silica-based geopolymers

  • Nadiri, Ata Allah;Asadi, Somayeh;Babaizadeh, Hamed;Naderi, Keivan
    • Computers and Concrete
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    • v.21 no.1
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    • pp.103-110
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    • 2018
  • This study introduces the supervised committee fuzzy model as a hybrid fuzzy model to predict compressive strength (CS) of geopolymers prepared from alumina-silica products. For this purpose, more than 50 experimental data that evaluated the effect of $Al_2O_3/SiO_2$, $Na_2O/Al_2O_3$, $Na_2O/H_2O$ and Na/[Na+K] on (CS) of geopolymers were collected from the literature. Then, three different Fuzzy Logic (FL) models (Sugeno fuzzy logic (SFL), Mamdani fuzzy logic (MFL), and Larsen fuzzy logic (LFL)) were adopted to overcome the inherent uncertainty of geochemical parameters and to predict CS. After validating the model, it was found that the SFL model is superior to MFL and LFL models, but each of the FL models has advantages to predict CS. Therefore, to achieve the optimal performance, the supervised committee fuzzy logic (SCFL) model was developed as a hybrid method to combine the benefits of individual FL models. The SCFL employs an artificial neural network (ANN) model to re-predict the CS of three FL model predictions. The results also show significant fitting improvement in comparison with individual FL models.

Preparation of UV-Curable Polyurethane Modified $Acrylate/SiO_2$ Hybrid Film Using Sol-Gel Process (졸-젤 공정을 이용한 광경화형 폴리우레탄 변형 아크릴레이트/실리카 하이브리드 필름의 제조)

  • Nam, Dae-Woo;Nam, Byeong-Uk;Cha, Bong-Jun;Kim, Baek-Jin
    • Polymer(Korea)
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    • v.31 no.2
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    • pp.111-116
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    • 2007
  • Polyurethane modified acrylate $(PUA)/SiO_2$ hybrid films were prepared by ultraviolet curing and their surface properties were investigated by hardness and adhesion test. The films were examined by the manipulation of mole-ratio of organic to inorganic components. Under the silica content controlled, highly desirable films were achieved and scratch resistance and hardness property of film were also enhanced, which indicates that the crosslinked silica particles are homogeneously dispersed within PUA film.