| 1. |
- Fan, Y., et al.
(författare)
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Mechanical preparation of nano titanium dioxide powder and its optical properties
- 2007
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Ingår i: Journal of the Chinese Ceramic Society. - 0454-5648. ; 35:7, s. 832-837
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Tidskriftsartikel (refereegranskat)abstract
- mechanical preparation of the nano-sized particles of TiO2 powder by a stirred bead mill was investigated. The particle sizes of the ground products were determined by the acoustic particle sizer, the nitrogen gas adsorption method and a scanning electron microscopy. The diameter of the nano-sized particles, which were obtained after milling for 7 h, is about 50 nm and the specific surface area is up to 70 m2/g. The surface and structure of the samples have been investigated with X-ray diffraction. It is indicated that an intense comminution in the mill leads to a progressive loss in crystallinity of TiO2. The catalytic degradation of methyl orange in water was also studied by a photometer. The results show that the nano-sized particles of TiO2 powder prepared by milling possess photocatalysis effect and are capable of absorption of ultraviolet radiation
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| 2. |
- Pan, Zhidong, et al.
(författare)
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Mechanically activated slag cement
- 2005
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Ingår i: Journal of the Chinese Ceramic Society. - 0454-5648. ; 33:10, s. 1248-1254
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Tidskriftsartikel (refereegranskat)abstract
- Mechanical activation of cement blended with metallurgical wastes (blast furnace slag and silica fume) in a high energy vibrating mill was investigated. The results show that the mechanical activation of the solids led to a reduction of the ground product fineness and an effective dispersion/interaction of ultra-fine silica particles within cement particles, resulting in an increased rate of the hydration reactions of the slag cement. The hardened paste samples after activation possess higher bending and compressive strengths. Fourier transform infrared spectroscopy and nuclear magnetic resonance studies indicate the mechanism of the mechanical activation on the slag cement.
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| 3. |
- Tang, Luping, 1956, et al.
(författare)
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Durability and service life prediction of reinforced concrete structures
- 2015
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Ingår i: Kuei Suan Jen Hsueh Pao/ Journal of the Chinese Ceramic Society. - : Chinese Ceramic Society. - 0454-5648. ; 43:10, s. 1408-1419
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents some durability and service life models for reinforced concrete structures with regard to chloride ingress, carbonation and frost attack. In the past years a number of models for durability design of concrete structures have been suggested by relevant organisations or international committees. It is necessary to validate these models against long-term field data for their applicability with respect to exposure climate in order to satisfactorily use the models in the durability design and redesign of concrete structures. In this study, various potential models for concrete resistance to chloride ingress, carbonation and frost attack were briefly reviewed. Three models including the simple ERFC, the DuraCrete and the ClinConc, for prediction of chloride ingress were evaluated using the infield data collected from both the field exposure site after over 20 years exposure and the real road bridges of about 30 years old. A physicochemical model for prediction of carbonation depth was evaluated using the infield data collected from the field exposure site after 11 years exposure and the limited data from the real structures with the age of 7-13 years. For the modelling of frost attack, some problems in measurement of critical saturation degree and actual degree of saturation are discussed. According to the comparison results, the simple ERFC overestimates whilst the DuraCrete model underestimate the chloride ingress in most cases. The ClinConc model on the other hand gives reasonable good prediction for both the short-term (one year) and the long-term (21 years) exposure. The Papadakis model for carbonation also gives fairly good prediction of carbonation depth when compared with the Norwegian infield data classified as exposure class XC3, but underestimates the carbonation depths when compared with the infield data from Norwegian structures in exposure class XC4. For the frost attack, it is premature to apply the models to the service life prediction so far.
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| 4. |
- Wang, Yanmin, et al.
(författare)
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Centrifugal classification of ultrafine calcium carbonate
- 2006
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Ingår i: Journal of the Chinese Ceramic Society. - 0454-5648. ; 34:8, s. 927-931
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Tidskriftsartikel (refereegranskat)abstract
- The experimental results on wet classification of ultra-fine calcium carbonate below 8 μm using an industrial scale disc-stack nozzle centrifuge system are presented. The parameters such as G-force, disc geometry, nozzle size, split, feed rate have been analysed by a statistical approach. The results show that the centrifuge is capable to efficiently classify the micron-sized material at 40% in mass. The product size distribution becomes finer and steeper after removing the undesired coarser particles from the feed. In addition, the centrifugal classification performance is empirically correlated to the parameters used.
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| 5. |
- Wang, Yanmin, et al.
(författare)
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Computer simulation for particle packing phenomena
- 2003
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Ingår i: Journal of the Chinese Ceramic Society. - 0454-5648. ; 31:2, s. 169-178
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Tidskriftsartikel (refereegranskat)abstract
- Computer simulation of particle packing in various material engineering areas (mainly in ceramics, cement, pharmaceuticals, powder metallurgy, polymer, etc.) provides very useful engineering tools in order to economically and efficiently analyse/optimise the properties of material and design the advanced materials as well. Recent major developments is represented on this aspect for the past 15 years. Computer simulation of particle packing processes has been advanced, especially for the packing dynamics. Some developed computer softwares have been applied to simulate the particle packing processes of various materials like ceramics and concrete. A new concept for simulation of packing phenomena based on the discrete element method (DEM) has been recently proposed. Also, in order to simplify the simulation process, a new type of Monte Carlo one-dimensional algorithm has been developed instead of the complex three-dimensional strategy in the existing computer systems. In addition, the limitations/problems of developed simulation algorithms and the possible future developments are discussed
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| 6. |
- Yanmin, Wang, et al.
(författare)
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Mechano-chemical effects on synthesis of ceramic materials and its compositions
- 2005
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Ingår i: Journal of the Chinese Ceramic Society. - 0454-5648. ; 33:4, s. 506-515
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Tidskriftsartikel (refereegranskat)abstract
- This paper reviews recent developments on mechano-chemical synthesis of various ceramic materials and compositions (such as oxide ceramics, biomaterial ceramics, electronic and electric intermetallics, microwave dielectric composite, battery compounds, and sialon ceramic composites). The method of soft mechano-chemical synthesis has a considerable potential for low cost, large scale production of various ceramic materials. The technique can be extended to the synthesis of a very wide range of various powders of advanced inorganic materials by the suitable selection of starting materials and milling conditions. The method accelerates and simplifies the process of the synthesis, decreases the energy expenses and the cost of the materials, thus being more economically efficient and ecologically clean. The mechano-chemical procedure permits an unique preparative flexibility allowing for rapid solid-phase crystallisation of nano-structured ceramic materials. Further studies in this aspect are also proposed
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