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Online since: April 2015
Authors: S.V. Akarachkin, A.A Sivkov, N.V. Martyushev, Aleksander S. Ivashutenko
The obtained data are presented in table 1.
Application of yttria (Y2O3) as a stabilizer allows obtaining a tetragonal modification of zirconium dioxide in the amount of » 70 mas. % [4] at the stage of nanopowder plasmochemical synthesis, which coincided with experimental data (see table 1).
According to X-ray diffraction analysis data, CSR (of crystallites) amounts to 50 nm.
From literature data [9] we know the results on radial magnetoimpulse pressing of composition ZrO2 + 9,8 mol. % Y2O3, obtained by the method of laser evaporation, close in chemical composition to C2, used in the work.
In RMI-compacts with zirconium dioxide the magnitude of internal stresses is low due to their low density, this explains the absence of the effect of high-temperature decompaction in the process of sintering, which is confirmed by dilatometric data (Netzsch 402PC).
Application of yttria (Y2O3) as a stabilizer allows obtaining a tetragonal modification of zirconium dioxide in the amount of » 70 mas. % [4] at the stage of nanopowder plasmochemical synthesis, which coincided with experimental data (see table 1).
According to X-ray diffraction analysis data, CSR (of crystallites) amounts to 50 nm.
From literature data [9] we know the results on radial magnetoimpulse pressing of composition ZrO2 + 9,8 mol. % Y2O3, obtained by the method of laser evaporation, close in chemical composition to C2, used in the work.
In RMI-compacts with zirconium dioxide the magnitude of internal stresses is low due to their low density, this explains the absence of the effect of high-temperature decompaction in the process of sintering, which is confirmed by dilatometric data (Netzsch 402PC).
Online since: November 2016
Authors: Siyabulela Hamnca, Meryk Ward, Priscilla Gloria Lorraine Baker, Xolani Terrance Ngema, Emmanuel Iheanyichukwu Iwuoha
As far as some metal ions with a preferred redox state and their transformation into the metallic state are studied, a clear description of the chemical entity might be possible from electrochemical data.
From the CV data, the electrochemistry of PAA thin film onto ITO electrode showed the similar behaviour as the electrochemistry of PAA on the glassy carbon electrode (Fig. 2), in terms of the number of oxidation and reduction peaks.
The second reduction peak (Epc2) was due to a stable quinoid type dication poly(amine- amide)2+.
ITO/PAA thin films has the same number of oxidation and reduction peaks as GCE/PAA.
Catalytic Reduction of Hexavalent Chromium Using Flexible Nanostructured Poly(amic acids).
From the CV data, the electrochemistry of PAA thin film onto ITO electrode showed the similar behaviour as the electrochemistry of PAA on the glassy carbon electrode (Fig. 2), in terms of the number of oxidation and reduction peaks.
The second reduction peak (Epc2) was due to a stable quinoid type dication poly(amine- amide)2+.
ITO/PAA thin films has the same number of oxidation and reduction peaks as GCE/PAA.
Catalytic Reduction of Hexavalent Chromium Using Flexible Nanostructured Poly(amic acids).
Online since: January 2016
Authors: András Zöld, Flóra Szkordilisz
If no other comment is given the data relate to the height of the pedestrian zone (0.8 m above the pavement).
The reduction of the velocity along the street axis is the consequence of the hydraulic resistance of the boundary surfaces.
The reduction of the velocity in Base scenario along the street axis is 2,5 m/s or 28% on 50 m length.
Along the street the reduction of the velocity is more radical in comparison with the empty variant.
The reduction of maximum values by 0,51 m/s The reduction of maximum values by 0,51 m/s crossroad There is still air (no ventilation) in the crossroad.
The reduction of the velocity along the street axis is the consequence of the hydraulic resistance of the boundary surfaces.
The reduction of the velocity in Base scenario along the street axis is 2,5 m/s or 28% on 50 m length.
Along the street the reduction of the velocity is more radical in comparison with the empty variant.
The reduction of maximum values by 0,51 m/s The reduction of maximum values by 0,51 m/s crossroad There is still air (no ventilation) in the crossroad.
Online since: June 2011
Authors: Zong Cai Deng, Jian Hui Li, Ying Li, Zhao Zhong Chang
Test phenomena are described, experimental data are analyzed and compared, and the effect of the axial compression ratio and stirrup reinforcement ratio on the seismic behavior is studied.
Table 2 summarizes the results of the cyclic tests, it can be seen from Table 2 that (1) the rebar corrosion causes the reduction of bearing capacity for the un-strengthened columns, however, the yield load of the corroded columns strengthened with hybrid FRP sheets is decreased by 7.8%~10.4% compared to the corresponding strengthened un-corroded columns, but the maximum load is slightly increased by 1.2%~6.1%, which indicate that strengthening with hybrid FRP sheets can make up the reduction of bearing capacity caused by rebar corrosion, and lead to the maximum bearing capacity of the strengthened corroded column up to same level with the strengthened un-corroded column, even higher. (2) With the increase of axial compressive ratio, the strengthening effect of hybrid FRP sheets is more remarkable. (3) When the axial compressive ratio is same, with the increase of stirrup space, the bearing capacity of the specimens is decreased by 5.0%~14.8%.
Fig. 1 shows the hysteresis curves, it can be observed from Fig.1 that the un-strengthened corroded columns show poor hysteresis response due to rebar corrosion resulting in low lateral load and ductility, especially under high axial compressive ratio, the reduction of bearing capacity and rigidity is very distinct after the maximum lateral load is obtained, the failure of the corroded columns may change from ductile failure of the un-corroded column to brittle failure.
Table 2 summarizes the results of the cyclic tests, it can be seen from Table 2 that (1) the rebar corrosion causes the reduction of bearing capacity for the un-strengthened columns, however, the yield load of the corroded columns strengthened with hybrid FRP sheets is decreased by 7.8%~10.4% compared to the corresponding strengthened un-corroded columns, but the maximum load is slightly increased by 1.2%~6.1%, which indicate that strengthening with hybrid FRP sheets can make up the reduction of bearing capacity caused by rebar corrosion, and lead to the maximum bearing capacity of the strengthened corroded column up to same level with the strengthened un-corroded column, even higher. (2) With the increase of axial compressive ratio, the strengthening effect of hybrid FRP sheets is more remarkable. (3) When the axial compressive ratio is same, with the increase of stirrup space, the bearing capacity of the specimens is decreased by 5.0%~14.8%.
Fig. 1 shows the hysteresis curves, it can be observed from Fig.1 that the un-strengthened corroded columns show poor hysteresis response due to rebar corrosion resulting in low lateral load and ductility, especially under high axial compressive ratio, the reduction of bearing capacity and rigidity is very distinct after the maximum lateral load is obtained, the failure of the corroded columns may change from ductile failure of the un-corroded column to brittle failure.
Online since: November 2011
Authors: Kun Hu, Zhen Zhong Li, Yong Guo, Wei Xing Huang
Finally, a kinetics model of the continuous treatment process was derived based on mass balance and Monod equations, and the kinetic constants were determined by the experimental data at steady operating OLR.
Besides, a kinetics model for the steady and continuous treatment process was proposed based on the Monod equations and mass balance, and the kinetic constants were determined by the experimental data at steady operating OLR.
Under every air supply condition, with the increase of reaction time, the COD concentration decreases and the reduction rate is gradually slowed down.
Eq. 5 can be transformed to linear expression as, (6) The experiments at the steady operation OLR are approximate to a steady and continuous process, so the experimental data are used to calculate the 1/q and corresponding 1/Se, and the calculated 1/q is plotted versus 1/Se in Fig. 8.
The kinetic constants determined by the experimental data under steady-state operation are in good agreement with literature values.
Besides, a kinetics model for the steady and continuous treatment process was proposed based on the Monod equations and mass balance, and the kinetic constants were determined by the experimental data at steady operating OLR.
Under every air supply condition, with the increase of reaction time, the COD concentration decreases and the reduction rate is gradually slowed down.
Eq. 5 can be transformed to linear expression as, (6) The experiments at the steady operation OLR are approximate to a steady and continuous process, so the experimental data are used to calculate the 1/q and corresponding 1/Se, and the calculated 1/q is plotted versus 1/Se in Fig. 8.
The kinetic constants determined by the experimental data under steady-state operation are in good agreement with literature values.
Online since: November 2014
Authors: Mei Juan Shan, Xin Hong Shi
Introduction
In pursuit of remarkable structural weight reduction in aircraft industries, the primary structural materials of aircrafts are inclined to nonmetallic materials such as composite materials, honeycomb and PMMA, etc [1-3].
(a) (b) Fig 2 Fatigue testing machine Instron-8803 and clamping state of specimens According to ASTM D3479-2002 [7], by using staircase fatigue tests, the conditioned fatigue limit was obtained with five pairs of effective test data.
Experimental results Fig.3 shows the staircase diagrams of all specimens with four stress levels, follow from which five pairs of test data are available.
For specimens without scratches, the S-N curve obtained by the contained fatigue limit and logarithm fatigue median life at each stress level, among which the latter is calculated from the five experimental data of the fatigue life, is illustrated in Fig.4.
In addition, with the increase of the scratch depth from 0.0mm to 0.4mm, an initial gentle decrease turns into a rapid reduction of the fatigue life, in which the turning point is about 0.2mm.
(a) (b) Fig 2 Fatigue testing machine Instron-8803 and clamping state of specimens According to ASTM D3479-2002 [7], by using staircase fatigue tests, the conditioned fatigue limit was obtained with five pairs of effective test data.
Experimental results Fig.3 shows the staircase diagrams of all specimens with four stress levels, follow from which five pairs of test data are available.
For specimens without scratches, the S-N curve obtained by the contained fatigue limit and logarithm fatigue median life at each stress level, among which the latter is calculated from the five experimental data of the fatigue life, is illustrated in Fig.4.
In addition, with the increase of the scratch depth from 0.0mm to 0.4mm, an initial gentle decrease turns into a rapid reduction of the fatigue life, in which the turning point is about 0.2mm.
Online since: August 2014
Authors: Zai Yuan Li, Feng Pan, Chun Ji Li
(6)
Using the DTA curve data, according to equation (6) the reaction progression n can be obtained.
The mensuration condition that rise temperature velocity was 10℃·min-1 and reduction reaction gas is N2 gas.
Fig.2TG-DTA-DTG curvers of nano-Ni(OH)2 power The DTA-TG-DTG curves data and equation (2) allow the calculation for apparent activation energy E and pre-exponential factor A of nano-Ni(OH)2 power.
Fig.3 Plot of LnK~1/T of nano-Ni(OH)2 power The Figure 3 shown that relation of lnK and 1/T was linear and indicated that the reduction reaction was Arrhenius type.
-E/R E(J·mol-1) LnA A n Ni(OH)2 -8805.724 73.210 28.485 2.349×1012 1.2767 Based on all above data, the kinetics equation of nano-Ni(OH)2 power was: Conclusions The conclusions were as followed: (1) In process of nano-Ni(OH)2 powders decomposition, the apparent activation energy of nano-Ni(OH)2 is 73.210kJ·mol-1, the frequency gene is 2.349×1012
The mensuration condition that rise temperature velocity was 10℃·min-1 and reduction reaction gas is N2 gas.
Fig.2TG-DTA-DTG curvers of nano-Ni(OH)2 power The DTA-TG-DTG curves data and equation (2) allow the calculation for apparent activation energy E and pre-exponential factor A of nano-Ni(OH)2 power.
Fig.3 Plot of LnK~1/T of nano-Ni(OH)2 power The Figure 3 shown that relation of lnK and 1/T was linear and indicated that the reduction reaction was Arrhenius type.
-E/R E(J·mol-1) LnA A n Ni(OH)2 -8805.724 73.210 28.485 2.349×1012 1.2767 Based on all above data, the kinetics equation of nano-Ni(OH)2 power was: Conclusions The conclusions were as followed: (1) In process of nano-Ni(OH)2 powders decomposition, the apparent activation energy of nano-Ni(OH)2 is 73.210kJ·mol-1, the frequency gene is 2.349×1012
Online since: October 2007
Authors: Dong Nyung Lee
(a) β-fiber intensity lines
of Cu-16% Mn alloys after
various rolling reductions and
(b) (111) pole figures of Cu-16%
Mn alloy after complete
recrystallization (97.5% rolled,
annealed at 450 °C for 1000 s)
( experimental data: (a) from ref
Fig. 6. (111) pole figures of (a) rolled and (b) recrystallized of Cu-1%P alloy (measured data [14]).
Fig. 7. (111) pole figures of 95% rolled Cu-22%Zn brass (a) before and (b) after annealing (experimental data [14]).
Textures of (a) and (b) can be approximated by {110}<112> and {236}<385>, respectively (experimental data [15]).
The mobility data of tilt grain boundaries in aluminum show that the average mobility of a <111> tilt boundary is increasingly higher than that of a <100> boundary with increasing temperature [22].
Fig. 6. (111) pole figures of (a) rolled and (b) recrystallized of Cu-1%P alloy (measured data [14]).
Fig. 7. (111) pole figures of 95% rolled Cu-22%Zn brass (a) before and (b) after annealing (experimental data [14]).
Textures of (a) and (b) can be approximated by {110}<112> and {236}<385>, respectively (experimental data [15]).
The mobility data of tilt grain boundaries in aluminum show that the average mobility of a <111> tilt boundary is increasingly higher than that of a <100> boundary with increasing temperature [22].
Online since: September 2013
Authors: Muammer D. Arif, A.K.M. Nurul Amin, Asan Gani Bin Abdul Muthalif, Ummu Atiqah Khairiyah B. Mohammad
An accelerometer was attached at the bottom of the tool holder of 120 mm overhang and connected to the vibration data acquisition system.
The vibration amplitude data were recorded at in the frequency range of 0 to 5 kHz.
Fig. 1: Experimental set up for turning operation The data acquisition system comprised a vibration sensor (KISTLER accelerometer Type 8774A50) and a signal conditioning unit.
The best condition for chatter suppression occurred at run number 1 with cutting speed of 125m/min, feed rate of 0.16mm/rot and depth of cut of 2.21mm with a reduction of 89.44%.
Table 1: Comparison of peak vibration amplitudes at two frequency ranges in the absence and presence of magnets Run Speed (m/min) Feed (mm/rot) D.O.C (mm) Vibration Amplitude (m/s2) Without Magnet at 1kHz With Magnet at 1kHz Without Magnet at 5kHz With Magnet at 5kHz 1 125 0.16 2.21 49.28 5.202 5.202 3.637 2 200 0.10 2.00 37.15 15.53 37.15 7.512 3 50 0.22 2.00 63.34 34.03 49.81 93.83 4 125 0.08 1.50 26.68 16.05 26.68 10.31 5 125 0.16 1.50 42.03 15.99 42.03 5.499 6 125 0.16 1.50 40.39 6.877 40.39 1.918 7 125 0.24 1.50 27.07 13.40 37.26 7.058 8 18.93 0.16 1.50 27.76 22.69 27.76 1.680 9 231 0.16 1.50 38.75 23.89 18.87 10.82 10 200 0.22 1.00 45.09 16.64 45.09 8.917 11 50 0.10 1.00 25.17 7.441 25.17 2.540 12 125 0.16 0.80 31.10 11.93 31.10 9.592 Average Percentage of Reduction - 56.75% - 65.36% Fig. 2: Vibration amplitude in the absence of magnet Fig. 3: Vibration amplitude with present of magnet In order to predict the peak acceleration amplitudes for magnet
The vibration amplitude data were recorded at in the frequency range of 0 to 5 kHz.
Fig. 1: Experimental set up for turning operation The data acquisition system comprised a vibration sensor (KISTLER accelerometer Type 8774A50) and a signal conditioning unit.
The best condition for chatter suppression occurred at run number 1 with cutting speed of 125m/min, feed rate of 0.16mm/rot and depth of cut of 2.21mm with a reduction of 89.44%.
Table 1: Comparison of peak vibration amplitudes at two frequency ranges in the absence and presence of magnets Run Speed (m/min) Feed (mm/rot) D.O.C (mm) Vibration Amplitude (m/s2) Without Magnet at 1kHz With Magnet at 1kHz Without Magnet at 5kHz With Magnet at 5kHz 1 125 0.16 2.21 49.28 5.202 5.202 3.637 2 200 0.10 2.00 37.15 15.53 37.15 7.512 3 50 0.22 2.00 63.34 34.03 49.81 93.83 4 125 0.08 1.50 26.68 16.05 26.68 10.31 5 125 0.16 1.50 42.03 15.99 42.03 5.499 6 125 0.16 1.50 40.39 6.877 40.39 1.918 7 125 0.24 1.50 27.07 13.40 37.26 7.058 8 18.93 0.16 1.50 27.76 22.69 27.76 1.680 9 231 0.16 1.50 38.75 23.89 18.87 10.82 10 200 0.22 1.00 45.09 16.64 45.09 8.917 11 50 0.10 1.00 25.17 7.441 25.17 2.540 12 125 0.16 0.80 31.10 11.93 31.10 9.592 Average Percentage of Reduction - 56.75% - 65.36% Fig. 2: Vibration amplitude in the absence of magnet Fig. 3: Vibration amplitude with present of magnet In order to predict the peak acceleration amplitudes for magnet
Online since: May 2012
Authors: Xiao Jie Chen
Fig. 1 Aircraft price relative to aircraft operational mass (source Avmark data).
The component mass estimating methods presented below are derived from statistical data of existing aircraft.
In general, the aircraft on which the data is based will be of conventional layout with a semi-monologue aluminum alloy structural framework.
As the design unfolds and more detailed geometric data are known it is possible to use formulae which include specific wing parameters.
This landing gear mass data shows a 99% correlation by the function Eq. 2 Muc = 0.0445 MTOM (i.e. 4.45%) (2) The data above does not take into account recent improvements in undercarriage materials and wheel brake design.
The component mass estimating methods presented below are derived from statistical data of existing aircraft.
In general, the aircraft on which the data is based will be of conventional layout with a semi-monologue aluminum alloy structural framework.
As the design unfolds and more detailed geometric data are known it is possible to use formulae which include specific wing parameters.
This landing gear mass data shows a 99% correlation by the function Eq. 2 Muc = 0.0445 MTOM (i.e. 4.45%) (2) The data above does not take into account recent improvements in undercarriage materials and wheel brake design.