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Online since: January 2006
Authors: Ying Li Gao, Jian Yin, Shi Qiong Zhou
The UFA's effects attribute to figuration effect, activation effect and tiny aggregation effect
during cement hydration[2]: (1)The figuration effect of UFA is named the effect resulted from its
physical properties such as particle shape, internal structure, surface nature and grain size
distribution, etc. (2)The activation effect of UFA represents the reaction ability between fly ash's
activation component such as SiO2, Al2O3 and alkali activator Ca(OH)2, and these reactions can
produce C-S-H gel and C-A-H crystal. (3)The tiny aggregation effect of UFA represents that UFA
can even distribute in cement paste phase and looks like tiny aggregation.
Meanwhile, the solution and hydration of CaSO4 accelerate UFA's activity, then make the pozzolanic effect of UFA play earlier and increase Table 4 The Preferential Design of Mix Proportion of Cement-UFA- Fluoro gypsum and Strength Test Compression Strength (MPa) Serial Number C [%] UFA [%] Fluoro gypsum [%] W [g] W/B B [g] Superplasticizer [g] 1d 3d 7d 28d 0 100 0 0 135 0.25 540 2.16 40.7 58.5 65.9 93.1 1 80 10 10 118 0.22 540 2.16 40.1 57.7 71.6 107.5 2 78 10 12 118 0.22 540 2.16 36.0 48.4 60 90.6 3 80 12 8 118 0.22 540 2.16 36.4 53.6 68.2 90.6 4 75 12 13 118 0.22 540 2.16 35.4 51.3 53.1 89.1 5 70 15 15 108 0.2 540 2.16 34.7 52.8 60.9 102.2 6 65 15 20 108 0.2 540 2.16 33.2 50.6 52.5 89.7 7 70 20 10 97.2 0.18 540 2.16 38.1 60.1 68.8 105.9 8 75 20 5 97.2 0.18 540 2.16 32.2 45.2 52.6 91.6 Notes: 1) Added superplasticizer is 0.4% of the total binding materials, which can make the system keep need workability. 2) The sizes of molded
Table 5 The Mix Proportion of Highway Repair Concrete with UFA-Fluoro gypsumand and Mixture Performance Serial Number C [kg/m 3] UFA [%] Fluoro gypsum [%] W/B W [kg/m 3] B [kg/m 3] Superplasticizer [kg/m 3] S [kg/m 3] G [kg/m 3] Slump [mm] 0 400 0 0 0.29 116 400 1.68 577 1345 15 1 320 10 10 0.28 112 400 1.68 577 1345 20 2 280 15 15 0.28 112 400 1.68 577 1345 25 3 280 20 10 0.26 104 400 1.68 577 1345 30 Note: Concrete adopt the standard curing, the sizes of compression and splitting-tensile specimens are 100mm×100mm×100mm, the sizes of flexural specimens are 100mm×100mm×400mm, the data of Table 5 are the values of measuring value multiplying correspondent size conversion factor. 0 5 10 15 20 25 30 20 25 30 35 40 45 50 55 60 65 70 Compression Strength( MPa) Age ( d) Ref er ence Concr et e 80% +10% UFA+10% CaSO4 70% +15% UFA+15% CaSO4 70% +20% UFA+10% CaSO4 0 5 10 15 20 25 30 3.5 4.0
(as shown in Table 6) Table 6 The Experiment Results of Wearability of Repair Concrete Serial Number C [kg/m 3] UFA [%] Fluoro gypsum [%] W/B 28d Wearing Value [kg/m 2] Relative Wearing Ratio [%] 0 400 0 0 0.29 3.62 100 1 320 10 10 0.28 2.71 74.8 2 280 15 15 0.28 2.85 78.7 3 280 20 10 0.26 2.62 72.4 Notes: The wearability specimen sizes is 150㎜×150 ㎜×150 ㎜, adopting the standard curing.
Meanwhile, the solution and hydration of CaSO4 accelerate UFA's activity, then make the pozzolanic effect of UFA play earlier and increase Table 4 The Preferential Design of Mix Proportion of Cement-UFA- Fluoro gypsum and Strength Test Compression Strength (MPa) Serial Number C [%] UFA [%] Fluoro gypsum [%] W [g] W/B B [g] Superplasticizer [g] 1d 3d 7d 28d 0 100 0 0 135 0.25 540 2.16 40.7 58.5 65.9 93.1 1 80 10 10 118 0.22 540 2.16 40.1 57.7 71.6 107.5 2 78 10 12 118 0.22 540 2.16 36.0 48.4 60 90.6 3 80 12 8 118 0.22 540 2.16 36.4 53.6 68.2 90.6 4 75 12 13 118 0.22 540 2.16 35.4 51.3 53.1 89.1 5 70 15 15 108 0.2 540 2.16 34.7 52.8 60.9 102.2 6 65 15 20 108 0.2 540 2.16 33.2 50.6 52.5 89.7 7 70 20 10 97.2 0.18 540 2.16 38.1 60.1 68.8 105.9 8 75 20 5 97.2 0.18 540 2.16 32.2 45.2 52.6 91.6 Notes: 1) Added superplasticizer is 0.4% of the total binding materials, which can make the system keep need workability. 2) The sizes of molded
Table 5 The Mix Proportion of Highway Repair Concrete with UFA-Fluoro gypsumand and Mixture Performance Serial Number C [kg/m 3] UFA [%] Fluoro gypsum [%] W/B W [kg/m 3] B [kg/m 3] Superplasticizer [kg/m 3] S [kg/m 3] G [kg/m 3] Slump [mm] 0 400 0 0 0.29 116 400 1.68 577 1345 15 1 320 10 10 0.28 112 400 1.68 577 1345 20 2 280 15 15 0.28 112 400 1.68 577 1345 25 3 280 20 10 0.26 104 400 1.68 577 1345 30 Note: Concrete adopt the standard curing, the sizes of compression and splitting-tensile specimens are 100mm×100mm×100mm, the sizes of flexural specimens are 100mm×100mm×400mm, the data of Table 5 are the values of measuring value multiplying correspondent size conversion factor. 0 5 10 15 20 25 30 20 25 30 35 40 45 50 55 60 65 70 Compression Strength( MPa) Age ( d) Ref er ence Concr et e 80% +10% UFA+10% CaSO4 70% +15% UFA+15% CaSO4 70% +20% UFA+10% CaSO4 0 5 10 15 20 25 30 3.5 4.0
(as shown in Table 6) Table 6 The Experiment Results of Wearability of Repair Concrete Serial Number C [kg/m 3] UFA [%] Fluoro gypsum [%] W/B 28d Wearing Value [kg/m 2] Relative Wearing Ratio [%] 0 400 0 0 0.29 3.62 100 1 320 10 10 0.28 2.71 74.8 2 280 15 15 0.28 2.85 78.7 3 280 20 10 0.26 2.62 72.4 Notes: The wearability specimen sizes is 150㎜×150 ㎜×150 ㎜, adopting the standard curing.
Online since: March 2024
Authors: Temitayo Mufutau Azeez, Saheed Akande, Omolayo M. Ikumapayi, Tuoyo Ikomi
There are two damage variables that need to be considered for tertiary softening: grain boundary cavity nucleation and growth, and the multiplication of mobile dislocations.
Labelling of the Samples Sample Label Tensile Test (Sample) Hardness Test (Sample) Creep Test (Sample) Control C 3 1 3 Heat Treated (Air Cooled) A 3 1 3 Heat Treated (Furnace Cooled) T 3 1 3 Total number of samples = 21 9 3 9 The heat treatment was carried out using a KSL-1400X Muffle Furnace in Nigeria.
The results shows that Sample C has the highest average hardness number HRC 98, followed by sample T (HRC 80).
The sample A has the least hardness number HRC 64.
Labelling of the Samples Sample Label Tensile Test (Sample) Hardness Test (Sample) Creep Test (Sample) Control C 3 1 3 Heat Treated (Air Cooled) A 3 1 3 Heat Treated (Furnace Cooled) T 3 1 3 Total number of samples = 21 9 3 9 The heat treatment was carried out using a KSL-1400X Muffle Furnace in Nigeria.
The results shows that Sample C has the highest average hardness number HRC 98, followed by sample T (HRC 80).
The sample A has the least hardness number HRC 64.
Online since: March 2023
Authors: Abideen Ganiyu, Hilal Salim Al-Alawi, Morsaleen Chowdhury, Atef Badr
A number of recent studies have also attempted to use waste materials such as coir waste, fly ash, rice husk ash, glass powder, calcium carbide residue, alum sludge, olive etc. for soil stabilization and propose altervative soils to be utilized as construction materials [24, 25].
Utilizing construction wastes for the stabilization of expansive soil is a relatively novel idea, and will lead to a reduction in the cost of handling the waste and most significantly it is environmentally friendly as this will reduce the number of toxic wastes and products released into the environment.
In addition, an increase in the number of curing days also resulted in an increase in the compressive strength for all the soil samples, with the highest values obtained at 28 days of curing.
Dulaimi, "Incorporating of two waste materials for the use in fine-grained soil stabilization," Civil Engineering Journal, vol. 6, no. 6, pp. 1114--1123, 2020
Utilizing construction wastes for the stabilization of expansive soil is a relatively novel idea, and will lead to a reduction in the cost of handling the waste and most significantly it is environmentally friendly as this will reduce the number of toxic wastes and products released into the environment.
In addition, an increase in the number of curing days also resulted in an increase in the compressive strength for all the soil samples, with the highest values obtained at 28 days of curing.
Dulaimi, "Incorporating of two waste materials for the use in fine-grained soil stabilization," Civil Engineering Journal, vol. 6, no. 6, pp. 1114--1123, 2020
Online since: July 2009
Authors: Graeme E. Murch, Alexander V. Evteev, Elena V. Levchenko, Irina V. Belova
In a situation where the vacancies are maintained at equilibrium everywhere in the diffusion
zone, vacancies are created and annihilated as required 1) by the process of dislocation climb
(in alloy systems) and/or 2) at grain boundaries and/or 3) at free surfaces.
Time dependencies of: upper panel - the average vacancy compositions inside the core and diffusion zone of the nanoparticle model as well as the ratio ε 3 of the number of virtual lattice sites within the void to the total number of lattice sites inside the whole of the nanoparticle, and lower panel - the average composition of A atoms inside the 'diffusion zone'.
For a hollow nanosphere (and nanotube) with internal radius ir and external radius er , the variation of vacancy composition near the surfaces with the number of vacancies in the void void VN is given by the Gibbs-Thomson equation: kTNG cc void VS eq VV exp , (3) SG SΔ is the change in the free energy of the spherical surface with a principal radius of curvature r ( irr or err ) and S is the surface area.
Time dependencies of: upper panel - the average vacancy compositions inside the core and diffusion zone of the nanoparticle model as well as the ratio ε 3 of the number of virtual lattice sites within the void to the total number of lattice sites inside the whole of the nanoparticle, and lower panel - the average composition of A atoms inside the 'diffusion zone'.
For a hollow nanosphere (and nanotube) with internal radius ir and external radius er , the variation of vacancy composition near the surfaces with the number of vacancies in the void void VN is given by the Gibbs-Thomson equation: kTNG cc void VS eq VV exp , (3) SG SΔ is the change in the free energy of the spherical surface with a principal radius of curvature r ( irr or err ) and S is the surface area.
Online since: July 2004
Authors: Xiaoying Zhu, Edward L. Dreizin, Mirko Schoenitz
On controlled heating, a number of exothermic transitions were observed below the onset of eutectic melting.
A number of experimental and theoretical studies on mechanical alloying of Al3Ti have been published.
A number of exothermic peaks are observed below 600 °C.
The remaining Ti is contained in x-ray amorphous phases, or in extended grain boundaries.
A number of experimental and theoretical studies on mechanical alloying of Al3Ti have been published.
A number of exothermic peaks are observed below 600 °C.
The remaining Ti is contained in x-ray amorphous phases, or in extended grain boundaries.
Online since: July 2025
Authors: Salsabila Firdausi Zahra, Tri Mulyono, Zulfikar Zulfikar, Yeni Maulidah Muflihah, Siswoyo Siswoyo, Asnawati Asnawati
The resolution value depends on three factors such as selectivity (the degree of separation between two peaks), retention (the time a compound spends in the column), and number of plates (a measure of column efficiency) [18].
System Suitability Test Results of GC-FID to Determine the Caffeine Content of Sidomulyo Robusta Coffee Parameters Result %RSD of retention time 0,0132 %RSD Area 1,1179 Theoretical Number of Plates 1472101 Tailing Factors 1,2034 Resolution 67,561 As show in the Table 2, all required parameters have met the acceptance limit.
Results of Robustness Analysis of Methods with Changes in Oven Initial Temperature and Flow Rate Parameters Change Retention Time (min) Area (pA) Theoretical Number of Plates (N) Tailing Factors (Tf) Resolution (Rs) Initial Oven Temperature 98 °C 35,378 2,2738 1582913,000 1,3573 69,544 100 °C 34,967 2,2933 1472100,667 1,2034 67,561 102 °C 34,581 2,3234 1563340,000 1,2713 67,481 Average 34,976 2,2970 1539451,222 1,2773 68,195 SD 0,325 0,0204 - - - %RSD 0,930 0,8883 - - - Flow Rate 1,1 mL/min 35,813 2,2525 1067191,667 1,1848 62,931 1,2 mL/min 34,967 2,2933 1472101,000 1,2034 67,561 1,3 mL/min 34,225 2,3002 1769822,000 1,2383 70,551 Average 35,002 2,2820 1436371,444 1,2090 67,014 SD 0,649 0,0211 - - - %RSD 1,853 0,9235 - - - Precision, Accuracy, and Recovery Intra-day and inter-day precision were determined based on the %RSD of the area and retention time of three replicate injections at three different concentrations of spike solution.
Development of a Rapid Method for the Determination of Caffeine in Coffee Grains by GC-FID — A Fully Validated Approach, 4–9. https://doi.org/10.3390/antiox6030067 [7] Misra, B.
System Suitability Test Results of GC-FID to Determine the Caffeine Content of Sidomulyo Robusta Coffee Parameters Result %RSD of retention time 0,0132 %RSD Area 1,1179 Theoretical Number of Plates 1472101 Tailing Factors 1,2034 Resolution 67,561 As show in the Table 2, all required parameters have met the acceptance limit.
Results of Robustness Analysis of Methods with Changes in Oven Initial Temperature and Flow Rate Parameters Change Retention Time (min) Area (pA) Theoretical Number of Plates (N) Tailing Factors (Tf) Resolution (Rs) Initial Oven Temperature 98 °C 35,378 2,2738 1582913,000 1,3573 69,544 100 °C 34,967 2,2933 1472100,667 1,2034 67,561 102 °C 34,581 2,3234 1563340,000 1,2713 67,481 Average 34,976 2,2970 1539451,222 1,2773 68,195 SD 0,325 0,0204 - - - %RSD 0,930 0,8883 - - - Flow Rate 1,1 mL/min 35,813 2,2525 1067191,667 1,1848 62,931 1,2 mL/min 34,967 2,2933 1472101,000 1,2034 67,561 1,3 mL/min 34,225 2,3002 1769822,000 1,2383 70,551 Average 35,002 2,2820 1436371,444 1,2090 67,014 SD 0,649 0,0211 - - - %RSD 1,853 0,9235 - - - Precision, Accuracy, and Recovery Intra-day and inter-day precision were determined based on the %RSD of the area and retention time of three replicate injections at three different concentrations of spike solution.
Development of a Rapid Method for the Determination of Caffeine in Coffee Grains by GC-FID — A Fully Validated Approach, 4–9. https://doi.org/10.3390/antiox6030067 [7] Misra, B.
Online since: October 2010
Authors: Antonio Luque, Antonio Martí
As the number of layers containing quantum dots is increased, the accumulated strain tends to produce dislocations that end up degrading the quality of the material and, in particular, the quality of the emitter of the cell [16].
Researchers at NREL [18], Rochester Institute and NASA [19-21] have investigated the use of GaAs1-xPx compensating layers to reduce the strain induced by the dots and therefore allow possiblely for an increased number of QD layers to be grown.
However, the improvement seems finally be due, not to the presence of the intermediate band, but to a better passivation of the grain boundary.
It must be remembered in this respect that the quantum efficiency at a given wavelength is nothing else than the ratio between the photons converted into photocurrent at that given wavelength and the total number of incident photons.
Researchers at NREL [18], Rochester Institute and NASA [19-21] have investigated the use of GaAs1-xPx compensating layers to reduce the strain induced by the dots and therefore allow possiblely for an increased number of QD layers to be grown.
However, the improvement seems finally be due, not to the presence of the intermediate band, but to a better passivation of the grain boundary.
It must be remembered in this respect that the quantum efficiency at a given wavelength is nothing else than the ratio between the photons converted into photocurrent at that given wavelength and the total number of incident photons.
Online since: August 2002
Authors: Santiago Suriñach, Maria Dolores Baró, J. Nogués, J. Sort, N.M. Mateescu
According to Warren's formulae, 1/α and 1/β indicate the average number of layers between two
deformation and twin faults, respectively [24].
It is noteworthy that, already before the milling, there are a certain number of stacking faults in the particles.
This is due to the limited number of slip systems in hcp crystals [26].
Furthermore, numerous studies reveal that, due to surface energy considerations, Tt can be also significantly lowered when the grain size is reduced to a few nm.
It is noteworthy that, already before the milling, there are a certain number of stacking faults in the particles.
This is due to the limited number of slip systems in hcp crystals [26].
Furthermore, numerous studies reveal that, due to surface energy considerations, Tt can be also significantly lowered when the grain size is reduced to a few nm.
Online since: January 2021
Authors: Madjda Mokhtari, Aicha Ziouche, Mouna Boulahbal, Moulay Abderrahmane Malouki, Aicha Kourim
In the O-H stretching region, the natural clay shows two prominent bands the first one at 3620cm-1 and the second one at the wave number 3693 cm-1 correspond vibration of OH- stretching which bonded with Al on the surface.
This fastness is due to the fact that there were a large number of vacant sites for metal on the external surface of clay particles.
This is due to the increase in surface area and hence more available adsorption sites competing for the same number of initial ion concentration [22].
Teixeria, "Chormium (III) biosorption onto spent grains residual from brewing industry: equilibrium, kinetics and column studies," Int.
This fastness is due to the fact that there were a large number of vacant sites for metal on the external surface of clay particles.
This is due to the increase in surface area and hence more available adsorption sites competing for the same number of initial ion concentration [22].
Teixeria, "Chormium (III) biosorption onto spent grains residual from brewing industry: equilibrium, kinetics and column studies," Int.
Online since: March 2021
Authors: Kenji Kikuchi
Polishing the surface of material components may strengthen material endurance in lead bismuth environment to guard materials surface from dissolution of main elements of steel into lead bismuth, followed by grain drops.
In this case grain drops will be caused by the dissolution of elements. [6] A purification device is equipped for avoiding lead bismuth flow from clogging in tube or precipitation on the components in liquid lead-bismuth circulation-loop.
Calculational model is based on high Reynolds type k-ε and the number volume elements is one million, using STAR-CD code [18], a flow velocity distribution at 104.5[mm] apart from the left edge is calculated.
In this case grain drops will be caused by the dissolution of elements. [6] A purification device is equipped for avoiding lead bismuth flow from clogging in tube or precipitation on the components in liquid lead-bismuth circulation-loop.
Calculational model is based on high Reynolds type k-ε and the number volume elements is one million, using STAR-CD code [18], a flow velocity distribution at 104.5[mm] apart from the left edge is calculated.