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Online since: May 2011
Authors: Ming Huang, Xin Rong Liu
Considering the external influences on rock deformation as instantaneous elastic deterioration defined by the reduction of instantaneous elastic modulus and long-term creep deterioration defined by the reduction of long-term creep modulus, kBurgers model with deterioration is presented too.
When considering the impact of rock deformation caused by these external factors, it is thought that the deterioration can be divided into instantaneous elastic deterioration and long-term creep deterioration, and the instantaneous elastic deterioration is defined by the reduction of instantaneous elastic modulus and long-term creep deterioration is defined by the reduction of long-term creep modulus. ① Instantaneous elastic deterioration For the definition of deterioration variable, deterioration can be defined by the reduction of elastic modulus in the view of energy damage theory, and it is considered that material properties deterioration is the main factor causing material damage.
There are two reasonable solutions for the above issues; one is processing the test data directly by using the creep equation iunder the assumption of constant bulk modulus, in order to avoid the conversion of model parameters.
The other is still processing the creep test data by conventional modeling method not considering any assumptions, and then achieving the assumption of conventional modeling by the exact relationship between the model parameters under several assumptions.
The instantaneous elastic deterioration is defined by the reduction of instantaneous elastic modulus, while long-term creep deterioration is defined by the reduction of creep modulus.
When considering the impact of rock deformation caused by these external factors, it is thought that the deterioration can be divided into instantaneous elastic deterioration and long-term creep deterioration, and the instantaneous elastic deterioration is defined by the reduction of instantaneous elastic modulus and long-term creep deterioration is defined by the reduction of long-term creep modulus. ① Instantaneous elastic deterioration For the definition of deterioration variable, deterioration can be defined by the reduction of elastic modulus in the view of energy damage theory, and it is considered that material properties deterioration is the main factor causing material damage.
There are two reasonable solutions for the above issues; one is processing the test data directly by using the creep equation iunder the assumption of constant bulk modulus, in order to avoid the conversion of model parameters.
The other is still processing the creep test data by conventional modeling method not considering any assumptions, and then achieving the assumption of conventional modeling by the exact relationship between the model parameters under several assumptions.
The instantaneous elastic deterioration is defined by the reduction of instantaneous elastic modulus, while long-term creep deterioration is defined by the reduction of creep modulus.
Online since: July 2012
Authors: Zhong Lin Cai, Shan Mao Li, Ji Zhang Wang, Wei Li, Wei Ping Jiang, Xin Wang
The kinetic process of the reduction reaction between phosphorous acid and adamsite has been studied to determine the reaction rate equation and to deduce the reaction mechanism, providing the theoretical basis for destroying adamsite by phosphorous acid.
At last, reaction is conducted under the best reaction conditions and the process is followed by test; on the basis of trial and error method, try to model experimental data through several potential reaction rate equations and finally determine the reaction rate equation, and furthermore to deduce the possible reaction mechanism according to literatures[7,8].
Results and discussions According to the experiment, it is found that during the reduction reaction course between phosphorous acid and adamsite, the reaction rate accelerates with the increasing quantity of phosphorous acid, which illustrates that the overall reaction rate not only relates to the quantity of adamsite, but also relates to the quantity of phosphorous acid.
Based on the theory that the trimolecular or tetramolecular collision probability at the same time is very low, and there is hardly any elementary reaction concerning larger molecular than trimoleculars, trial and error method can be considered; firstly, assume the reaction orders of phosphorous acid and adamsite are all order 1, and the experimental data is modeled with rate equation; if the model analysis results do not conform to experimental data, it is better to adopt other reaction rate equations to model data, eg, take the reaction order of phosphorous acid as order 1 and adamsite as order 2, or take the reaction order of adamsite as order 2 and take phosphorous acid as order 1.
Make analysis based on the chromatographic conditions mentioned in foregoing statement, and model the analysis data to validate the above reaction rate equation, and finally determining the rate equation and obtaining the reaction rate constant k.
At last, reaction is conducted under the best reaction conditions and the process is followed by test; on the basis of trial and error method, try to model experimental data through several potential reaction rate equations and finally determine the reaction rate equation, and furthermore to deduce the possible reaction mechanism according to literatures[7,8].
Results and discussions According to the experiment, it is found that during the reduction reaction course between phosphorous acid and adamsite, the reaction rate accelerates with the increasing quantity of phosphorous acid, which illustrates that the overall reaction rate not only relates to the quantity of adamsite, but also relates to the quantity of phosphorous acid.
Based on the theory that the trimolecular or tetramolecular collision probability at the same time is very low, and there is hardly any elementary reaction concerning larger molecular than trimoleculars, trial and error method can be considered; firstly, assume the reaction orders of phosphorous acid and adamsite are all order 1, and the experimental data is modeled with rate equation; if the model analysis results do not conform to experimental data, it is better to adopt other reaction rate equations to model data, eg, take the reaction order of phosphorous acid as order 1 and adamsite as order 2, or take the reaction order of adamsite as order 2 and take phosphorous acid as order 1.
Make analysis based on the chromatographic conditions mentioned in foregoing statement, and model the analysis data to validate the above reaction rate equation, and finally determining the rate equation and obtaining the reaction rate constant k.
Online since: February 2018
Authors: Lian Jin Li, Si Qi Liu, Xing Han
The blank pipe initially produces flattening deformation, height reduction, width increase.
The deformation is mainly plastic reduction of the wall[10] and the deformation ends at the outlet section.
And then the two are added together to get the total rolling force: (19) in the formula, is the average unit pressure of the reduced-diameter area(MPa); is the total area of the rolling contact zone(); is the average unit pressure of the reduction of wall area(MPa); is the contact area of the reduction of wall area().
Calculation Results of Rolling Mill Parameters Roller speed [rad/s] Plastic deformation stress [MPa] Friction Coefficient Crushing strength [MPa] The reduced-diameter area The reduction of wall area Rolling Force [kN] Unit Pressure[MPa] Contact area [mm²] Unit pressure [MPa] Contact area [mm²] 1.804 105.5 0.32 18.9 158.2 4217.7 139.3 7833.1 1758.4 2.029 115.6 0.32 18.9 171.5 4217.7 152.6 7833.1 1918.7 2.255 119.3 0.32 18.9 176.4 4217.7 157.5 7833.1 1977.7 2.481 112.1 0.32 18.9 166.9 4217.7 148.0 7833.1 1863.2 2.706 110.9 0.32 18.9 165.3 4217.7 146.4 7833.1 1844.0 Comparison of the calculated value of the rolling force in Table 1. and the average value of the actual rolling force is done and the data is shown in Table 2.
A rolling force prediction model based on support vector regression for double cold reduction, J.
The deformation is mainly plastic reduction of the wall[10] and the deformation ends at the outlet section.
And then the two are added together to get the total rolling force: (19) in the formula, is the average unit pressure of the reduced-diameter area(MPa); is the total area of the rolling contact zone(); is the average unit pressure of the reduction of wall area(MPa); is the contact area of the reduction of wall area().
Calculation Results of Rolling Mill Parameters Roller speed [rad/s] Plastic deformation stress [MPa] Friction Coefficient Crushing strength [MPa] The reduced-diameter area The reduction of wall area Rolling Force [kN] Unit Pressure[MPa] Contact area [mm²] Unit pressure [MPa] Contact area [mm²] 1.804 105.5 0.32 18.9 158.2 4217.7 139.3 7833.1 1758.4 2.029 115.6 0.32 18.9 171.5 4217.7 152.6 7833.1 1918.7 2.255 119.3 0.32 18.9 176.4 4217.7 157.5 7833.1 1977.7 2.481 112.1 0.32 18.9 166.9 4217.7 148.0 7833.1 1863.2 2.706 110.9 0.32 18.9 165.3 4217.7 146.4 7833.1 1844.0 Comparison of the calculated value of the rolling force in Table 1. and the average value of the actual rolling force is done and the data is shown in Table 2.
A rolling force prediction model based on support vector regression for double cold reduction, J.
Online since: October 2011
Authors: Jun Qi Dong, Qian Chen, Wu Jie Wei
The reason is that the experimental data of different type fin are mostly come from different literature and researchers, the data reduction methods and fin geometry parameters are not all the same.
Especially for little experimental data of wavy fin surface can be obtained in the open literature.
Experimental and data reduction 1)Test apparatus Fig.1 shows a schematic diagram of the wind tunnel apparatus in the study.
All the experimental data were obtained on basis of the heat balance which was less than 3%.
(a) Plain fin (b) wavy fin (c) louvered fin (d) offset fin Fig.2 Photo of the four types fin 3)Data reduction Effectiveness-NTU method can be bused for obtaining air-side heat transfer coefficient.
Especially for little experimental data of wavy fin surface can be obtained in the open literature.
Experimental and data reduction 1)Test apparatus Fig.1 shows a schematic diagram of the wind tunnel apparatus in the study.
All the experimental data were obtained on basis of the heat balance which was less than 3%.
(a) Plain fin (b) wavy fin (c) louvered fin (d) offset fin Fig.2 Photo of the four types fin 3)Data reduction Effectiveness-NTU method can be bused for obtaining air-side heat transfer coefficient.
Online since: May 2020
Authors: Xian Zheng Gong, Li Wei Hao, Yu Liu, Xiao Qing Li, Feng Gao, Ning Liu, Yan Zheng
The LCI mainly includes the steps of data collection, data calculation, allocation of flows and releases.
The data need to be associated with the functional unit by calculation, and describe the calculation program in writing.
The inventory data of building materials are collected according to the unit process within the boundary of the system.
The data come from spot investigation, database and literature.
In addition, according to the purpose and scope, some optional elements are also include: normalization, groping, weighting, data quality analysis.
The data need to be associated with the functional unit by calculation, and describe the calculation program in writing.
The inventory data of building materials are collected according to the unit process within the boundary of the system.
The data come from spot investigation, database and literature.
In addition, according to the purpose and scope, some optional elements are also include: normalization, groping, weighting, data quality analysis.
Online since: February 2014
Authors: J.S. Zhao, J.H. Dai
The data at different cyanide concentrations, temperature and oxygen pressure are obtained.
However, platinum and palladium can not be dissolved in the cyanide solutions at room temperature and atmospheric pressure, although it is possible from their thermodynamic data[2], To elevate reaction temperature and/or oxygen pressure, the dissolution reaction kinetics of cyanides with platinum and palladium can be improved.
The combined experimental and computational data provide direct insight into the electronic structure of these complexes.
The electrochemical reduction of oxygen on platinum electrodes has been studied.
It is the cathode reaction in pressure-cyanide dissolution, and the four-electron reduction to water is the desired reaction and the two-electron reduction to hydrogen peroxide is to be avoided.
However, platinum and palladium can not be dissolved in the cyanide solutions at room temperature and atmospheric pressure, although it is possible from their thermodynamic data[2], To elevate reaction temperature and/or oxygen pressure, the dissolution reaction kinetics of cyanides with platinum and palladium can be improved.
The combined experimental and computational data provide direct insight into the electronic structure of these complexes.
The electrochemical reduction of oxygen on platinum electrodes has been studied.
It is the cathode reaction in pressure-cyanide dissolution, and the four-electron reduction to water is the desired reaction and the two-electron reduction to hydrogen peroxide is to be avoided.
Online since: April 2018
Authors: Rohitha Keerthiwansa, Jakub Javořík, Jan Kledrowetz, Pavel Nekoksa
Adding a positive constant k to a function would lead the function f(x) to move vertically upward while reduction of same would make it move downward (Fig.1).
The secondary data.
Once, a particular data set was selected as alternative to the biaxial data, it is then used together with uniaxial data for data fitting.
Firstly data was fitted only with uniaxial data and secondly with both uniaxial and generated biaxial data.
Fig. 7 Resulting graphs of data fitting done with combined data Conclusions To minimize the error generated as a result of data fitting using only one set of data, i.e. uniaxial data, in this work, combined data fitting which can be done with secondary data set generated from initial data set was proposed.
The secondary data.
Once, a particular data set was selected as alternative to the biaxial data, it is then used together with uniaxial data for data fitting.
Firstly data was fitted only with uniaxial data and secondly with both uniaxial and generated biaxial data.
Fig. 7 Resulting graphs of data fitting done with combined data Conclusions To minimize the error generated as a result of data fitting using only one set of data, i.e. uniaxial data, in this work, combined data fitting which can be done with secondary data set generated from initial data set was proposed.
Online since: April 2013
Authors: Alan G. Leacock, Desmond Brown, Gregor Volk
There is also benefit to be accrued from the residual stress reduction obtained during artificial ageing.
The data was used to calculate the radius of a specimen by least squares method in comparison to a perfect circle.
These changes are indicative of a reduction in the solid state diffusion by entrapment of the mobile copper in the precipitate form.
For both the 1hr and 7hrs naturally aged specimens, the high strain level (5.0%) led to a reduction in springback.
The lack of change is indicative of a reduction in the kinetics of the artificial ageing process.
The data was used to calculate the radius of a specimen by least squares method in comparison to a perfect circle.
These changes are indicative of a reduction in the solid state diffusion by entrapment of the mobile copper in the precipitate form.
For both the 1hr and 7hrs naturally aged specimens, the high strain level (5.0%) led to a reduction in springback.
The lack of change is indicative of a reduction in the kinetics of the artificial ageing process.
Online since: October 2013
Authors: Versiane Albis Leao, Nayara Carolina Quites, Lucas Antônio Melgaço, Sueli Moura Bertolino
Glycerol, which is a by-product from biodiesel production, is a potential choice as substrate for sulphate reduction.
In addition, data scattering was more pronounced in the UASB reactor as compared to the FBR, confirming the lower operational stability of the former.
Glycerol is a potentially inexpensive substrate for sulphate reduction with a smaller production of end-products [6].
Sulphate reduction with glycerol showed efficiencies of 90%, with average residual sulphate concentrations of 200mg.L-1 (figure 2B).
Conclusions The FBR performed better than the UASB reactor during sulphate reduction with lactate.
In addition, data scattering was more pronounced in the UASB reactor as compared to the FBR, confirming the lower operational stability of the former.
Glycerol is a potentially inexpensive substrate for sulphate reduction with a smaller production of end-products [6].
Sulphate reduction with glycerol showed efficiencies of 90%, with average residual sulphate concentrations of 200mg.L-1 (figure 2B).
Conclusions The FBR performed better than the UASB reactor during sulphate reduction with lactate.
Online since: September 2008
Authors: Lucia Calcagno, Francesco La Via, Gaetano Izzo, Grazia Litrico, Gaetano Foti
In fact point
defects introduce deep levels in the semiconductor gap
which affect the electrical properties of diodes and a
simple interpretation of data is difficult: Schottky
barrier and carrier concentration result completely
modified; the concentration of vacancy, as calculated
by TRIM simulation (using version STRIM2000) [7], is
rather uniform in the measured layer (1.2 - 3.5 µm) and
for this fluence is 5×10
15 cm-3.
The slope of the data allows to determine the efficiency of carrier reduction (compensation/vacancy).
The obtained results are shown in Fig.3 versus the nitrogen concentration, together with the data reported by Aberg et al. [8, 9].
The literature data are also reported.
Indeed these point defects cause also a change in the I-V characteristics of the diodes mainly related to the strong reduction of carrier concentration around the end ion range.
The slope of the data allows to determine the efficiency of carrier reduction (compensation/vacancy).
The obtained results are shown in Fig.3 versus the nitrogen concentration, together with the data reported by Aberg et al. [8, 9].
The literature data are also reported.
Indeed these point defects cause also a change in the I-V characteristics of the diodes mainly related to the strong reduction of carrier concentration around the end ion range.