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Online since: September 2014
Authors: Amirreza Yaghoobi, Hamid Baseri, Abdolhamid Gorji, Mohammad Bakhshi-Jooybari
This process composed of two steps: training the model using data generated by finite element simulations and testing the model.
In all, 25 such data sets were used based on L25 orthogonal array. 21 data sets were selected randomly and used for training purposes, while the remaining 4 data sets were presented to the trained network as new application data to verify the predictive accuracy of the network model.
Thus, the network was evaluated using data that had not been used for training.
It can be seen that there is a good agreement between the neural network model predictions and FE simulations for the train and the test data.
Comparison of the predicted and simulated data for (A) training (B) test Optimization of Pressure Path Using Simulated Annealing.
In all, 25 such data sets were used based on L25 orthogonal array. 21 data sets were selected randomly and used for training purposes, while the remaining 4 data sets were presented to the trained network as new application data to verify the predictive accuracy of the network model.
Thus, the network was evaluated using data that had not been used for training.
It can be seen that there is a good agreement between the neural network model predictions and FE simulations for the train and the test data.
Comparison of the predicted and simulated data for (A) training (B) test Optimization of Pressure Path Using Simulated Annealing.
Online since: November 2012
Authors: Rui Barbosa, Nuno Lapa, Diogo Dias, Benilde Mendes
The substitution of 10% cement by fly ashes has not promoted the reduction of the compressive strength of concrete.
Results and Discussion Compressive strength data.
The overall analyses of the formulations revealed a tendency for the reduction of the compressive strength with the increasing substitution of cement by fly ashes.
The substitution of 10% cement by fly ashes (F2, F3, F4, F5) has not promoted the reduction of the compressive strength of the concrete.
Results and Discussion Compressive strength data.
The overall analyses of the formulations revealed a tendency for the reduction of the compressive strength with the increasing substitution of cement by fly ashes.
The substitution of 10% cement by fly ashes (F2, F3, F4, F5) has not promoted the reduction of the compressive strength of the concrete.
Online since: September 2015
Authors: Michal Kotoul, Ivo Dlouhy, Petr Skalka
We show that the superposed bridging mechanism strongly interacts with the inherent rigidity effect of gradient elasticity, hence the total reduction of the J-integral will be likely more pronounced than a mere sum of these two contributions.
To this end a homogenized cracked Bioglass® foam is analyzed using the strain/stress-based Ru-Aifantis [4] approach which is extended to enforce the equilibrium of nonlocal stresses via the Lagrange multiplier method, since the original Ru-Aifantis approach does not provide us with data concerning the cups-like closure of crack caused by the inherent rigidity effect of gradient elasticity.
Thus, the total reduction of the J-integral calculated along a remote path is given by the resisting force arising from the bridging traction and the reduction of the crack tip extension force.
To this end a homogenized cracked Bioglass® foam is analyzed using the strain/stress-based Ru-Aifantis [4] approach which is extended to enforce the equilibrium of nonlocal stresses via the Lagrange multiplier method, since the original Ru-Aifantis approach does not provide us with data concerning the cups-like closure of crack caused by the inherent rigidity effect of gradient elasticity.
Thus, the total reduction of the J-integral calculated along a remote path is given by the resisting force arising from the bridging traction and the reduction of the crack tip extension force.
Online since: October 2012
Authors: Ya Qun Zhou, Wei Ping Wang, Hai Yan Deng
The recharge volume
Based on the analysis of rainwater quantity and quality, the available rainfall of roof is calculated by the following formula [2]:
Q=Ψ·α·β·A(H·10-3)
Where: Q is the annual average available rainfall of roof (m3); Ψ is the runoff coefficient, which equals 0.9; α is the seasonal reduction coefficient; β is the initial rainwater removal coefficient; A is the horizontal projection of roof area (m2); H is the average annual rainfall (mm).
The seasonal reduction coefficient (α) must be determined by the analysis of multi-year statistics of local Weather Bureau.
Considering the factors such as climate, seasons and so on, the seasonal reduction coefficient of the available rainfall in Jinan was determined as 0.85.
Based on the data of rainfall and water quality, the initial rainwater removal coefficient was decided as 0.85.
The seasonal reduction coefficient (α) must be determined by the analysis of multi-year statistics of local Weather Bureau.
Considering the factors such as climate, seasons and so on, the seasonal reduction coefficient of the available rainfall in Jinan was determined as 0.85.
Based on the data of rainfall and water quality, the initial rainwater removal coefficient was decided as 0.85.
Online since: January 2005
Authors: Shi Fang Xiao, Yu Hu Wang
The obtained data are listed in
table 1.
From Fig.2, we can also see the flow 2.0 2.5 3.0 3.5 4.0 4.5 2 3 4 5 6 7 8 9 10 11 12 Stress (GPa) Mean grain size (nm) Compression flow stress Tension flow stress Compression yield stress Tension yield stress Fig. 1 The yield and flow stress variation along with mean grain size in tension and compression simulation 0.0 -0.2 -0.4 -0.6 -0.8 -1.0 0 -5 -10 -15 -20 Stress (GPa) Strain 4.23 nm 3.55 nm 2.66 nm 2.13 nm Ⅰ Ⅱ Ⅲ Fig. 2 The stress-strain curves of nanocrystalline Fe under compression condition stress decrease with the reduction of mean grain size.
It is possible the grain boundary as a special phase and the function of grain boundary as shear sliding band disappears as the reduction of systematic order degrees resulted in region Ⅰ.
Summary (1) The yield and flow stress of nanocrystalline Fe decrease with reduction of grain size in tension and compression.
From Fig.2, we can also see the flow 2.0 2.5 3.0 3.5 4.0 4.5 2 3 4 5 6 7 8 9 10 11 12 Stress (GPa) Mean grain size (nm) Compression flow stress Tension flow stress Compression yield stress Tension yield stress Fig. 1 The yield and flow stress variation along with mean grain size in tension and compression simulation 0.0 -0.2 -0.4 -0.6 -0.8 -1.0 0 -5 -10 -15 -20 Stress (GPa) Strain 4.23 nm 3.55 nm 2.66 nm 2.13 nm Ⅰ Ⅱ Ⅲ Fig. 2 The stress-strain curves of nanocrystalline Fe under compression condition stress decrease with the reduction of mean grain size.
It is possible the grain boundary as a special phase and the function of grain boundary as shear sliding band disappears as the reduction of systematic order degrees resulted in region Ⅰ.
Summary (1) The yield and flow stress of nanocrystalline Fe decrease with reduction of grain size in tension and compression.
Online since: January 2014
Authors: Alžbeta Sapietová, Richard Petrech, Matej Petrovic
An analytical calculation of dynamic forces in mechanism was solved by the method of mass reduction and force parameters [3].
The method of the mass reduction and force parameters is based on the balance of the flow of mass, momentum, and energy of multi-body systems.
Reduction of force effects is realized through the equal the power of work forces and reduced system performance of work forces of the initial multi-body system, which neglects gravitation forces.
Pressure [MPa] a) b) Fig. 9 a) Equivalent (von-Mises) stress, b) Curve of equivalent (von-Mises) stress Sumary The outputs of the simulations contain a large amount of data on individual parts of the virtual prototype (speeds, accelerations, position, interactions of the force, etc.).
The method of the mass reduction and force parameters is based on the balance of the flow of mass, momentum, and energy of multi-body systems.
Reduction of force effects is realized through the equal the power of work forces and reduced system performance of work forces of the initial multi-body system, which neglects gravitation forces.
Pressure [MPa] a) b) Fig. 9 a) Equivalent (von-Mises) stress, b) Curve of equivalent (von-Mises) stress Sumary The outputs of the simulations contain a large amount of data on individual parts of the virtual prototype (speeds, accelerations, position, interactions of the force, etc.).
Online since: December 2014
Authors: Kai Ming Wang, Shou Shan Gao, Wei Liang Huan, Hong Bao Jia, Xiao Qi Li
The following methods are used to prepare nitride: direct nitrizing method, carbon thermal reduction method, benzene thermal method[5, high temperature self-spreading method[6], gas phase method, and aminolysis method etc.[7], while direct nitrizing method including high energy ball milling[8] and mechanical activation methods[9].
But if nitrizing is carried under normal pressure, reduction process using tubular furnace, and materials putting on ceramic plate, the raw material layer cannot be thicker (less than 5 millimeter), otherwise the temperature cannot be lowered, time cannot be shorten, the nitrizing will be incomplete, and the grain sizes can be larger.
Mixing and contacting of reacting gas (ammonia and hydrogen) with nanopowder are improved greatly, thus resultant nanograin size reduction becomes possible.
The data is in agreement with gas-solid reaction mechanism analysed by Szekely [12] and Qingyin Ge [13], and proves that system pressure has large effects on aminolysis temperature and pressure.
But if nitrizing is carried under normal pressure, reduction process using tubular furnace, and materials putting on ceramic plate, the raw material layer cannot be thicker (less than 5 millimeter), otherwise the temperature cannot be lowered, time cannot be shorten, the nitrizing will be incomplete, and the grain sizes can be larger.
Mixing and contacting of reacting gas (ammonia and hydrogen) with nanopowder are improved greatly, thus resultant nanograin size reduction becomes possible.
The data is in agreement with gas-solid reaction mechanism analysed by Szekely [12] and Qingyin Ge [13], and proves that system pressure has large effects on aminolysis temperature and pressure.
Online since: November 2015
Authors: Bo Wei Chen, Xing Yu Liu, Ming Jiang Zhang, Wen Yan Liu, Chun Yu Meng, Jian Kang Wen
The potential for Fe(III) reduction seems to be widespread among acidophilic heterotrophs.
The utilization of Fe(III) and reduction of schwertmannite Fe(III) and reduce schwertmannite by genus Alicyclobacillus was reported previously[8].
Our research also finds that when Alicyclobacillus was present, the formation of jarosite was diminished in chalcopyrite bioleaching at high temperature (unpublished data).
Considering the Fe(III) reduction ability, it seems under high temperature, that the presence of Alicyclobacillus may: a. help to reduce jarosite; b. help to reduce Fe(III) coupled with sulphur oxidation.
The utilization of Fe(III) and reduction of schwertmannite Fe(III) and reduce schwertmannite by genus Alicyclobacillus was reported previously[8].
Our research also finds that when Alicyclobacillus was present, the formation of jarosite was diminished in chalcopyrite bioleaching at high temperature (unpublished data).
Considering the Fe(III) reduction ability, it seems under high temperature, that the presence of Alicyclobacillus may: a. help to reduce jarosite; b. help to reduce Fe(III) coupled with sulphur oxidation.
Online since: March 2013
Authors: Jun Jie Zhang, Xian Ming Zhu, Zhi Zhong Liu
Ko [4] investigated the structure-borne noise reduction for infinite elastic cylindrical shell with elasticity equation, and utilized the insertion loss of the pressure to describe the effect of coated layer.
The baseline data used for the calculations is in reference [4,5].
The explanations are as follows: When thicknesses of coated layer is equal to integral multiple of half wavelength plus one-quarter wavelength[4,5], the maximum amount of the noise reduction is obtained.
(8) And when thicknesses of coated layer is equal to integral multiple of half wavelength[4,5], the minimum amount of the noise reduction is obtained.
The baseline data used for the calculations is in reference [4,5].
The explanations are as follows: When thicknesses of coated layer is equal to integral multiple of half wavelength plus one-quarter wavelength[4,5], the maximum amount of the noise reduction is obtained.
(8) And when thicknesses of coated layer is equal to integral multiple of half wavelength[4,5], the minimum amount of the noise reduction is obtained.
Online since: December 2013
Authors: Franciszek Grosman, Marek Tkocz
This approach offers important benefits such as improved structural stiffness of an aircraft, reduction of labor, time and tooling costs required for assembly operations, reduction of inventory etc. [1].
A schematic diagram of the device for incremental forming equipped with sensors of the control and data acquisition system: 1 - punch, 2 - pressure plate, 3 - working rolls, 4 - segmental punch, 5 - press table, 6 - die, 7 - workpiece, 8 - punch retainer Fig.2.
Division of a punch into segments and pressing them by moving rolls causes temporary load exertion only on a small fragment of the workpiece surface, enabling significant reduction of the required press load.
A schematic diagram of the device for incremental forming equipped with sensors of the control and data acquisition system: 1 - punch, 2 - pressure plate, 3 - working rolls, 4 - segmental punch, 5 - press table, 6 - die, 7 - workpiece, 8 - punch retainer Fig.2.
Division of a punch into segments and pressing them by moving rolls causes temporary load exertion only on a small fragment of the workpiece surface, enabling significant reduction of the required press load.