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Online since: December 2016
Authors: Vasile Danut Cojocaru, Ion Cinca, Elisabeta Mirela Cojocaru, Nicolae Serban, Mariana Lucia Angelescu, Doina Raducanu, Doina Margareta Gordin
In order to obtain data concerning twinning deformation one set of samples were processed by cold-rolling, with a thickness reduction of 10%.
In figure 3 one can observe that twinning deformation occurred in a large number of grains even at 10% thickness reduction.
Only crystal orientation data contained in the selected area (see Fig. 5b) was used in order to obtain Inverse Pole Figure (IPF) and Pole Figure (PF) of parent grain – twin system.
Fig. 6 shows the distribution of rolling direction (RD), transverse direction (TD) and normal direction (ND) in respect to reference frame of the crystal, in the case of Ti-31.7Nb-6.21Zr-1.4Fe alloy cold-rolled with a 10% thickness reduction.
(hkl)[uvw] 332 113 332 113 332 113 332 113 233 311 232 311 233 311 233 311 323 131 323 131 323 131 323 131 Schmid Factor (SF) -0.122 -0.141 0.295 0.200 0.305 0.052 0.305 0.012 -0.451 -0.108 -0.016 -0.392 Conclusions The main results can be summarized as follows: (1) at 10% thickness reduction twins are observed in a large number of grains; (2) for all observed twins a CSL close to 50.47° is observed, indicating a {332}<113> twinning system; (3) computed SF’s suggest that the primary activated twinning variant is 323131 (SF = -0.451); a possible secondary twinning variant being 323131 (SF = - 0.392).
In figure 3 one can observe that twinning deformation occurred in a large number of grains even at 10% thickness reduction.
Only crystal orientation data contained in the selected area (see Fig. 5b) was used in order to obtain Inverse Pole Figure (IPF) and Pole Figure (PF) of parent grain – twin system.
Fig. 6 shows the distribution of rolling direction (RD), transverse direction (TD) and normal direction (ND) in respect to reference frame of the crystal, in the case of Ti-31.7Nb-6.21Zr-1.4Fe alloy cold-rolled with a 10% thickness reduction.
(hkl)[uvw] 332 113 332 113 332 113 332 113 233 311 232 311 233 311 233 311 323 131 323 131 323 131 323 131 Schmid Factor (SF) -0.122 -0.141 0.295 0.200 0.305 0.052 0.305 0.012 -0.451 -0.108 -0.016 -0.392 Conclusions The main results can be summarized as follows: (1) at 10% thickness reduction twins are observed in a large number of grains; (2) for all observed twins a CSL close to 50.47° is observed, indicating a {332}<113> twinning system; (3) computed SF’s suggest that the primary activated twinning variant is 323131 (SF = -0.451); a possible secondary twinning variant being 323131 (SF = - 0.392).
Online since: March 2017
Authors: Stefan Szczepanik, Piotr Nikiel, Piotr Bednarczyk
Some specimens were then cold drawn with a linear velocity of 1 m/min to 16 % area reduction, and one specimen in 3 passes to 51 % reduction in area.
Drawing was done on a carriage drawing machine at linear speed of 1 m/min with a 16 mm diameter drawing die to 16.4 % reduction in area.
Young’s modulus, yield stress and hardness data are summarised in Table 1.
Table 2 lists also some of our previous data in an attempt to identify the various contributions to overall strengthening of Al and Al-l8.8Cu-6.3%Si-0.7Mg alloy [10].
Drawing was done on a carriage drawing machine at linear speed of 1 m/min with a 16 mm diameter drawing die to 16.4 % reduction in area.
Young’s modulus, yield stress and hardness data are summarised in Table 1.
Table 2 lists also some of our previous data in an attempt to identify the various contributions to overall strengthening of Al and Al-l8.8Cu-6.3%Si-0.7Mg alloy [10].
Online since: February 2014
Authors: Shi Hua Li
Currently, data mining in the commercial and industrial areas has been widely used.
Replacing experts, the starting point of DM is to dig out knowledge from massive data.
The dilemma of “massive data, but lack of information” is getting worse.
In essence, data mining, in a given condition, is a process of dimensionality reduction and characterization to the complex problem.
SPRINT: A scalable parallel classifier for data mining.
Replacing experts, the starting point of DM is to dig out knowledge from massive data.
The dilemma of “massive data, but lack of information” is getting worse.
In essence, data mining, in a given condition, is a process of dimensionality reduction and characterization to the complex problem.
SPRINT: A scalable parallel classifier for data mining.
Online since: March 2014
Authors: Bao Dong Chen, Feng Guo, Jing Wen
In order to improve the understanding deformation behaviors of thermal compressive of ZK30 magnesium alloy, carried out a series of thermal compressive tests with height reduction 60% of specimens were performed at deformation temperature range of 523-673 K, and strain rates range of 0.001-1 s−1 on Gleeble-1500 thermo-mechanical simulator.
The reduction in height is 60% at the end of the thermal compression test.
Comparing these flow curves with one another, thus it can be seen that flow stress decreases markedly with increases in deformation temperature for a particular strain rate, over 62% reduction.
Based on the experimental data, the main points resulted from the present work are presented as follows: (1) At constant strain rate, the deformation behavior of ZK30 magnesium alloy is characterized by the typical dynamic recrystallization and recovery softening mechanisms occur simultaneously.
(2) The parameters of constitutive model in the whole range of deformation conditions were determined by linear fitting test data, such as the apparent activation energy (Q) was estimated to be on average 144.072 KJmol−1, the stress exponents (n) were measured to be 5.386.
The reduction in height is 60% at the end of the thermal compression test.
Comparing these flow curves with one another, thus it can be seen that flow stress decreases markedly with increases in deformation temperature for a particular strain rate, over 62% reduction.
Based on the experimental data, the main points resulted from the present work are presented as follows: (1) At constant strain rate, the deformation behavior of ZK30 magnesium alloy is characterized by the typical dynamic recrystallization and recovery softening mechanisms occur simultaneously.
(2) The parameters of constitutive model in the whole range of deformation conditions were determined by linear fitting test data, such as the apparent activation energy (Q) was estimated to be on average 144.072 KJmol−1, the stress exponents (n) were measured to be 5.386.
Online since: May 2016
Authors: Peter Paulík
In order to simplify the task, the article introduces a new proposal based on theory of elasticity, which have a good accuracy, with minimal experimental data needed.
At first the coefficient ka has been derived from experimental data [2], [3], measured on non-loaded specimens for different types of concrete used in their research.
Once the basic constants were determined the deterioration function has been applied to experimental data at various load levels.
Table 1 and table 2 shows the data adopted from scientific papers published by Schneider and Chen [2], [3], and the data predicted by the theoretical model.
Results of the theoretical model and the experimental data are in good correlation.
At first the coefficient ka has been derived from experimental data [2], [3], measured on non-loaded specimens for different types of concrete used in their research.
Once the basic constants were determined the deterioration function has been applied to experimental data at various load levels.
Table 1 and table 2 shows the data adopted from scientific papers published by Schneider and Chen [2], [3], and the data predicted by the theoretical model.
Results of the theoretical model and the experimental data are in good correlation.
Online since: July 2011
Authors: Yong Jiu Shi, Yun Lin, Yan Nian Zhang, Yuan Qing Wang
Moreover, a Boltzmann function fitting analysis was applied to the experimental data, and the ductile-brittle transition temperature and the changing regularity were obtained.
Test required sampling in the steel plate rolling direction perpendicular, and setting different temperature points, to get the related impact on low-temperature variation, trying to provide effective technical parameters and data for amendment of GB50017 -2003 the Chinese code for design of steel structures[6].
The experiment data was plotted as the Fig.13 to Fig.15.
However, it was almost impossible to obtain such a typical curve, for the experimental data dispersion was greater.
These data results were not enough to complete the fitting, and their value decreased ranging from -40 °C to -60 °C.
Test required sampling in the steel plate rolling direction perpendicular, and setting different temperature points, to get the related impact on low-temperature variation, trying to provide effective technical parameters and data for amendment of GB50017 -2003 the Chinese code for design of steel structures[6].
The experiment data was plotted as the Fig.13 to Fig.15.
However, it was almost impossible to obtain such a typical curve, for the experimental data dispersion was greater.
These data results were not enough to complete the fitting, and their value decreased ranging from -40 °C to -60 °C.
Online since: July 2016
Authors: Sivakumar Ramakrishan, Ahmad Fauzi Mohd Noor, Sheikh Abdul Rezan, Norlia Baharun, Ismail Hanafi, Hazman Haji Seli, Ali Yaraghi, Eltefat Ahmadi, Mohammad Hanif Abang Sapri, Noor Izah Shoparwe, Hareyani Zabidi, Kamar Shah Ariffin
The common carbon source used for reduction was coke and coal.
Computer programs were used to fit the measured (x-ray/neutron) diffraction pattern of the sample and performs cyclic calculations to minimize the difference between a given structure model and the experimental data. [9].
The morphology of ilmenite sand changed in the process of reduction.
Reduction of ilmenite in inert gases resulted in formation of coarse grains of metallic iron with a denser particle structure in comparison with reduction in hydrogen [12].
Li, “Carbothermal Solid State Reduction of Stable Metal Oxides,” steel Res.
Computer programs were used to fit the measured (x-ray/neutron) diffraction pattern of the sample and performs cyclic calculations to minimize the difference between a given structure model and the experimental data. [9].
The morphology of ilmenite sand changed in the process of reduction.
Reduction of ilmenite in inert gases resulted in formation of coarse grains of metallic iron with a denser particle structure in comparison with reduction in hydrogen [12].
Li, “Carbothermal Solid State Reduction of Stable Metal Oxides,” steel Res.
Online since: May 2012
Authors: Jun Wang, Xue Wen He, Peng Ju He
The information monitoring center receives real-time data from all list subsystems through the GSM/GPRS network, function in the original data storage, statistics and analysis.
The gateway collects real-time data from each sensor node through the ZigBee network, gathers the original data for data encapsulation and protocol conversion, and then uploads data to the information monitoring center through the GSM/GPRS network.
CC2430 controls the MC35i terminal and transports data via RS-232 interface.
Next, the gateway packages the original data according to TCP data format and then establishing a TCP connection to send the data packets to the monitoring center database.
The application management software receives the original data from each subsystem, realizes the function of user management, data management, system parameters configuration, search, printing and etc.
The gateway collects real-time data from each sensor node through the ZigBee network, gathers the original data for data encapsulation and protocol conversion, and then uploads data to the information monitoring center through the GSM/GPRS network.
CC2430 controls the MC35i terminal and transports data via RS-232 interface.
Next, the gateway packages the original data according to TCP data format and then establishing a TCP connection to send the data packets to the monitoring center database.
The application management software receives the original data from each subsystem, realizes the function of user management, data management, system parameters configuration, search, printing and etc.
Online since: October 2013
Authors: Qin Liu, Xiao Na Zhang
Based on regression analysis of test data, the formulas for estimating the shrinkage deformation of recycled coarse aggregates concrete are given out, which provide the basis for engineering applications.
With zero growth period, the cement hydration gradually slowed, and pre-hydration resulting hydrate filled pore structure, allowing cement increased compactness, porosity reduction, hydration shrinkage decreases [3].
Because the volume of hardened cement paste is not stable when the relative humidity of external environment is less than 100%, the cement paste will be dehydration, and will be volume reduction [3].
According to experimental data, regression analysis, shrinkage estimation formulas are obtained under different curing conditions in the natural strength grade 100% of recycled coarse aggregate concrete.
Based on regression analysis of test data, the formulas for estimating the shrinkage of recycled coarse aggregate concrete cured in natural environment are given out to provide the basis for engineering applications.
With zero growth period, the cement hydration gradually slowed, and pre-hydration resulting hydrate filled pore structure, allowing cement increased compactness, porosity reduction, hydration shrinkage decreases [3].
Because the volume of hardened cement paste is not stable when the relative humidity of external environment is less than 100%, the cement paste will be dehydration, and will be volume reduction [3].
According to experimental data, regression analysis, shrinkage estimation formulas are obtained under different curing conditions in the natural strength grade 100% of recycled coarse aggregate concrete.
Based on regression analysis of test data, the formulas for estimating the shrinkage of recycled coarse aggregate concrete cured in natural environment are given out to provide the basis for engineering applications.
Online since: July 2010
Authors: M.G. Manjunatha, Airody Vasudeva Adhikari, Pramod Kumar Hegde
The molecular weight data of the polymer is summarized in Table 1.
The UV-Visible absorption spectrum of the polymer was recorded both in solution and in thin film and the corresponding spectral data are summarized in Table 1.
Electrochemical data of the polymer P is summarized in Table 2.
When the polymer was swept cathodically, it showed a reduction peak at -1.24 V (Fig. 5) with onset reduction potential at -0.78 V.
Fig. 5, Oxidation and reduction cyclic voltammetry waves of the polymer P.
The UV-Visible absorption spectrum of the polymer was recorded both in solution and in thin film and the corresponding spectral data are summarized in Table 1.
Electrochemical data of the polymer P is summarized in Table 2.
When the polymer was swept cathodically, it showed a reduction peak at -1.24 V (Fig. 5) with onset reduction potential at -0.78 V.
Fig. 5, Oxidation and reduction cyclic voltammetry waves of the polymer P.