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Online since: August 2013
Authors: Jing Long Bu, Rui Sheng Wang, Li Xue Yu, Yong Wu He, Zhi Fa Wang, Jun Xing Chen, Dong Mei Zhao
A greater number of fused silica is transformed from amorphous state to crystalline state with big volume expansion, at 1400℃, which causes microcrack leading to decrease the bending strength.
That reveals that nano-zirconia possessing large surface area and high surface energy effectively improve driving force of atomic motion, which is beneficial to hole among grain-boundaries shrinking and vacancy cluster submerging, and promote the effect of sintering composite ceramic.
Increasing sintering temperature can promote composite ceramic sintering, but a greater number of crystallization from amorphous state to crystalline state appears at 1400˚C and causes plenty of microcrack leading to strength of composite ceramic declining.
That reveals that nano-zirconia possessing large surface area and high surface energy effectively improve driving force of atomic motion, which is beneficial to hole among grain-boundaries shrinking and vacancy cluster submerging, and promote the effect of sintering composite ceramic.
Increasing sintering temperature can promote composite ceramic sintering, but a greater number of crystallization from amorphous state to crystalline state appears at 1400˚C and causes plenty of microcrack leading to strength of composite ceramic declining.
Online since: October 2011
Authors: Majid Karimian, M.H. Idris, Ali Asghar Niakan, A. Ourdjini
Experimental Procedure
The pattern used in the study was a step-like shape sized 100×250mm withstep thickness of 3, 6, 12, and 18 and 24 mm (Figure 1) The pattern made of polystyrene foam with a density of 20Kg/m3 was cut using hot wire to an accuracy of ±0.5 mm.
3
100
50
250
24
Figure1: The dimensions of the pattern used in this study
The patterns were then dipped for 60 seconds into slurry of Zircon (ZR-A) and colloidal silicate mixture with the viscosity controlled at27 secondsusing Zahn flow cup number 5.
The mould was prepared by placing the pattern in a flask as shown in Figure 2and unbounded silica sand with a grain fineness number of 60-100 was introduced manually into the flask.Compaction of the sand was made by vibrating the sand-filled flask for the duration of 60 secondsat a frequency of50 Hz.The flask was then placed in the pressure vessel as shown in (Figure2).
The mould was prepared by placing the pattern in a flask as shown in Figure 2and unbounded silica sand with a grain fineness number of 60-100 was introduced manually into the flask.Compaction of the sand was made by vibrating the sand-filled flask for the duration of 60 secondsat a frequency of50 Hz.The flask was then placed in the pressure vessel as shown in (Figure2).
Online since: July 2014
Authors: Qi Hong Wu, Shi Ming Wan, Qing Xu
The dynamic component is computed as the product of the pile velocity times the damping factor (a soil parameter related to soil grain size).
Table 1 Stratum character serial number Stratum name Average thickness(m) serial number Stratum name Average thickness(m) ① silty clay 3.92 140 ⑤ Medium-Coarse sand 6.78 230 ② silty clay 4.77 150 ⑥ silty clay 5.90 250 ③ medium sand 3.30 180 ⑦ medium-Coarse sand 6.42 310 ④ silty clay 5.29 170 ⑧ Coarse sand 4.37 320 4.2.1 Static load test results analysis Chart 1 shows the Q~s curve and chart 2 shows the s~lgt curve.
Table 1 Stratum character serial number Stratum name Average thickness(m) serial number Stratum name Average thickness(m) ① silty clay 3.92 140 ⑤ Medium-Coarse sand 6.78 230 ② silty clay 4.77 150 ⑥ silty clay 5.90 250 ③ medium sand 3.30 180 ⑦ medium-Coarse sand 6.42 310 ④ silty clay 5.29 170 ⑧ Coarse sand 4.37 320 4.2.1 Static load test results analysis Chart 1 shows the Q~s curve and chart 2 shows the s~lgt curve.
Online since: July 2014
Authors: Rayid Muneer Rayid Muneer, S. Ramachandran, Ramdoss Vithya Sagar
Table I: Main Geometrical Features of The Analyzed Barrel
Denominator
Value
Diameter [mm]
1000
1000 (2D simulation)
Length [mm]
Blade angle
36 degree
Number of blades
10
As the aim of the present work was to reproduce the operation of a rotating machine, the use of moving sub-grids was necessary.
Table 3.1: Summary of material options for model turbine blades Material Comments Disposition Solid Wood Difficult to maintain isotropic structure due to grain structure of wood Not used Laminated wood Labour-intensive but cheap.
DESIGN DIMENSIONS Figure 5.1 Flow analysis for flow velocity 0.5m/s (pipe) Length= 1000 mm Diameter=1000 mm Number of blades= 12 Type of foil = newly designed Chord length, C= 16.19 mm Blade inclination angle, φ, from the horizontal, where φ = tan-1(nlπd) = tan-1(37.68) = 89.90 Solidity, σ, defined as σ = nCπd = 610.0392 The heb turbine design described in this report has a diameter of 1 m and a length of 1 m.
Table 3.1: Summary of material options for model turbine blades Material Comments Disposition Solid Wood Difficult to maintain isotropic structure due to grain structure of wood Not used Laminated wood Labour-intensive but cheap.
DESIGN DIMENSIONS Figure 5.1 Flow analysis for flow velocity 0.5m/s (pipe) Length= 1000 mm Diameter=1000 mm Number of blades= 12 Type of foil = newly designed Chord length, C= 16.19 mm Blade inclination angle, φ, from the horizontal, where φ = tan-1(nlπd) = tan-1(37.68) = 89.90 Solidity, σ, defined as σ = nCπd = 610.0392 The heb turbine design described in this report has a diameter of 1 m and a length of 1 m.
Online since: March 2017
Authors: Ekaterina K. Krivonosova, Dmitriy Trushnikov, Ekaterina A. Krivonosova
Thus, the initial numbered image of the structure consists of a matrix containing 0 and 1;
• treatment of the resultant sets of the digital values (matrices) by division of the matrix to larger cells with the dimensions Li× Li(i=1,..., 32);
• construction, for each of division, of the characteristic measure in the form of the probability of distribution of units Ni, required for covering the ferrite field;
• the approximation of the dependence of lnPi on lnLi by the method of least squares and the determinationof fractal dimensions Df from the relationship:
P(Li) = const×Li-Df, (1)
Fractal structure formation analysis and assessment of cold resistance of the weld metal of low-carbon steel for welding with coated electrodes
Engaging the concept of fractals allowed to quantify the degree of homogeneity (dispersion, fragmentation) of the structure of weld metal.
Comparison of the values of Df with the topography of the structure shows that for a coarser structure with wide fragments of Widmannstatten ferrite extending through all fields of the grains of primary austenite, the value of Df is lower and the structure is more homogeneous, approaching the conventional ferritic–pearlitic structure, with the higher values of Df.
The distribution density can be calculated more efficiently by counting the number of cells P required to cover the fractal.
Comparison of the values of Df with the topography of the structure shows that for a coarser structure with wide fragments of Widmannstatten ferrite extending through all fields of the grains of primary austenite, the value of Df is lower and the structure is more homogeneous, approaching the conventional ferritic–pearlitic structure, with the higher values of Df.
The distribution density can be calculated more efficiently by counting the number of cells P required to cover the fractal.
Online since: October 2024
Authors: Oleksandr Kireev, Dmytro Tregubov, Ilgar Dadashov, Olena Borsuk, Evgen Slepuzhnikov
Liquids modeling and their properties is carried out on the molecules coarse-grained model basis within the statistical associative theory by replacing the molecule with a solid balls limited number, by which fill the matrices [6], that allows predicting many substance properties and internal force fields.
The factor of 200 to the atoms number determines the electron density redistribution total path in the crystal (in contrast to the hydrocarbons linear structure).
In addition, in the equivalent length and molar mass, it is necessary to take into account a oxygen atoms certain number that could be cluster part as peroxide groups.
Methane requires 9.52 moles of air for the 1 mole combustion, for longer n-alkanes this number decreases to 7.3 per one molecular link.
Sanket, Development of New Transferable Coarse-Grained Models of Hydrocarbons, J.
The factor of 200 to the atoms number determines the electron density redistribution total path in the crystal (in contrast to the hydrocarbons linear structure).
In addition, in the equivalent length and molar mass, it is necessary to take into account a oxygen atoms certain number that could be cluster part as peroxide groups.
Methane requires 9.52 moles of air for the 1 mole combustion, for longer n-alkanes this number decreases to 7.3 per one molecular link.
Sanket, Development of New Transferable Coarse-Grained Models of Hydrocarbons, J.
Online since: August 2011
Authors: Sai Yu Wang, Shao Jiang Lin
The results also indicate that the initial porosity has a great effect on the number of pores, pore size, pore shape and the distribution of pores during post sintering process.
Compared with conventional post-sintering, microwave processing offers unique advantages, which include saved energy, enhanced densification and suppressed grain growth owing to very rapid heating rates and cycles.
At the beginning of densification, the initial large pores quickly break down into a large number of smaller pores.
Compared with conventional post-sintering, microwave processing offers unique advantages, which include saved energy, enhanced densification and suppressed grain growth owing to very rapid heating rates and cycles.
At the beginning of densification, the initial large pores quickly break down into a large number of smaller pores.
Online since: October 2006
Authors: Roland Weiss
It will be demonstrated during
the presentation that the manufacturing depends on one hand side on the material which has to be
manufactured and on the other side on the structural component and the number of parts which are
required.
The manufacturing process of CMCs depends on the shape and size, numbers, requirements (mechanical, thermal, chemical and physical) and cost effectiveness of structural components.
One of the key factors in respect to the processing costs is the impregnation technology, whereas the final properties like ductility, grain size and purity are controlled by the final heat treatment temperature (HTT) and the post treatments.
The manufacturing process of CMCs depends on the shape and size, numbers, requirements (mechanical, thermal, chemical and physical) and cost effectiveness of structural components.
One of the key factors in respect to the processing costs is the impregnation technology, whereas the final properties like ductility, grain size and purity are controlled by the final heat treatment temperature (HTT) and the post treatments.
Online since: May 2013
Authors: Xi Fang Zhu, Chen Lei, Xiao Jin, Xiong Chao, Zhang Yan, Hong Chun Yuan, Li Hua Ding, Xiang Cai Zhou
The results suggest the existence of a large number of interface states in ZnO/p-Si heterojunction, and the interface states can be reduced and the photoelectric properties can be further improved.
The preferential orientation of the ZnO grains is observed along the (101) axis aligning with the growth direction.
The presence of a number of peaks in XRD pattern is the indication of polycrystalline nature of the ZnO.
The preferential orientation of the ZnO grains is observed along the (101) axis aligning with the growth direction.
The presence of a number of peaks in XRD pattern is the indication of polycrystalline nature of the ZnO.
Online since: May 2011
Authors: A.N. Ramakrishna, A.V. Pradeep Kumar, Keerthi Gowda
The possible training parameters
are number of iterations (epoch) learning rate, error goal and number of hidden layers.
However the numbers of neurons in the input layer and output layer are determined based on the problem domain depending up on number of input variables and number of output or target variables.
Tested: Properties tested BC Soil RHA Specific gravity 2.67 1.92 Liquid limit (%) 64.86 128.34 Plastic limit (%) 28.89 - Shrinkage limit (%) 11.48 - Plasticity index (%) 35.97 Non plastic Grain sizes Gravel fraction (%) - - Sand fraction (%) Coarse (%) 1.5 - Medium (%) 4 2.84 Fine (%) 12.54 31.45 Silt fraction (%) 26 52.35 Clay fraction (%) 55.96 13.36 MDD (KN/m2) 14.75 7.09 OMC (%) 26.53 74.24 Free swell index (%) 109.12 - Properties tested Value Grade 43 Specific gravity 3.12 Normal consistency (%) 32 Initial setting time (min) 96 Final setting time (min) 364 Fineness (%) 5.5 Compressive strength 3 days strength (Mpa) 25.5 7 days strength (Mpa) 36.7 28 days strength (Mpa) 41.5 Table 3 Chemical Properties of Soil Elements BC soil (%) RHA (%) SiO2 38.32 83.32 Fe2O2 2.69 0.8 SO3 0.034 0 CaO 3.05 0.71 MgO 2.69 0 Al2O3 5.93 0.8 Ignition loss 11.04 5.23 pH 8.06 9.69 Table 4 CBR of Soil-RHA-Cement
Mixes and RHA Mix proportion (%) Soaked CBR Soil RHA Cement (%) 100 0 0 1.88 (1.89) 95 5 0 4.08(4.08) 90 10 0 5.84(5.83) 85 15 0 5.14(5.36) 96 0 4 25.56(25.53) 92 0 8 48.57(48.53) 88 0 12 58.16(58.15) 91 5 4 28.16(28.18) 87 5 8 54.68(54.73) 83 5 12 63.09(63.04) 86 10 4 30.82(32.73) 82 10 8 60.56(59.11) 78 10 12 68.49(68.84) 81 15 4 25.85(25.85) 77 15 8 56.62(57.55) 73 15 12 67.06(67.34) Fig: 1 Illustrative topology to prognosticate CBR values BC soil- RHA-Cement mix Hidden layer CBR values Fig. 2 Effect of RHA and Cement on Soaked CBR Value of BC Soil Fig.3 Convergence curve The number of hidden layers and neurons in hidden layer are fixed during the training process.
A significant number of reports have been published in application of ANN for the prediction of future events in Civil engineering problems [1,2,3].
However the numbers of neurons in the input layer and output layer are determined based on the problem domain depending up on number of input variables and number of output or target variables.
Tested: Properties tested BC Soil RHA Specific gravity 2.67 1.92 Liquid limit (%) 64.86 128.34 Plastic limit (%) 28.89 - Shrinkage limit (%) 11.48 - Plasticity index (%) 35.97 Non plastic Grain sizes Gravel fraction (%) - - Sand fraction (%) Coarse (%) 1.5 - Medium (%) 4 2.84 Fine (%) 12.54 31.45 Silt fraction (%) 26 52.35 Clay fraction (%) 55.96 13.36 MDD (KN/m2) 14.75 7.09 OMC (%) 26.53 74.24 Free swell index (%) 109.12 - Properties tested Value Grade 43 Specific gravity 3.12 Normal consistency (%) 32 Initial setting time (min) 96 Final setting time (min) 364 Fineness (%) 5.5 Compressive strength 3 days strength (Mpa) 25.5 7 days strength (Mpa) 36.7 28 days strength (Mpa) 41.5 Table 3 Chemical Properties of Soil Elements BC soil (%) RHA (%) SiO2 38.32 83.32 Fe2O2 2.69 0.8 SO3 0.034 0 CaO 3.05 0.71 MgO 2.69 0 Al2O3 5.93 0.8 Ignition loss 11.04 5.23 pH 8.06 9.69 Table 4 CBR of Soil-RHA-Cement
Mixes and RHA Mix proportion (%) Soaked CBR Soil RHA Cement (%) 100 0 0 1.88 (1.89) 95 5 0 4.08(4.08) 90 10 0 5.84(5.83) 85 15 0 5.14(5.36) 96 0 4 25.56(25.53) 92 0 8 48.57(48.53) 88 0 12 58.16(58.15) 91 5 4 28.16(28.18) 87 5 8 54.68(54.73) 83 5 12 63.09(63.04) 86 10 4 30.82(32.73) 82 10 8 60.56(59.11) 78 10 12 68.49(68.84) 81 15 4 25.85(25.85) 77 15 8 56.62(57.55) 73 15 12 67.06(67.34) Fig: 1 Illustrative topology to prognosticate CBR values BC soil- RHA-Cement mix Hidden layer CBR values Fig. 2 Effect of RHA and Cement on Soaked CBR Value of BC Soil Fig.3 Convergence curve The number of hidden layers and neurons in hidden layer are fixed during the training process.
A significant number of reports have been published in application of ANN for the prediction of future events in Civil engineering problems [1,2,3].