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Online since: May 2014
Authors: Barry Dixon, John Santamaria, Mehrdad Behnia, Seyed Pezhman Payami, Masud Behnia
Comparison of the CFD results with previously obtained experimental data shows a satisfactory agreement.
According to manufacturer’s data [18] and literature [19]-[20], material properties are summarised in Table I.
Results and Discussion In this study, available data in literature for similar designs and conditions are used to discuss the model.
For instance, the measured flow resistance in Hygrovent S (Medisize, Hillegom, The Netherlands) at the baseline and after 24 hours confirms our data [21].
The data on expiratory temperature for the current design could not be found through the literature.
According to manufacturer’s data [18] and literature [19]-[20], material properties are summarised in Table I.
Results and Discussion In this study, available data in literature for similar designs and conditions are used to discuss the model.
For instance, the measured flow resistance in Hygrovent S (Medisize, Hillegom, The Netherlands) at the baseline and after 24 hours confirms our data [21].
The data on expiratory temperature for the current design could not be found through the literature.
Online since: October 2012
Authors: Gen Da Chen, Fu Jian Tang, Xiao Ming Cheng, Richard K. Brow, Jeffery S. Volz, Michael Koenigstein
An equivalent electrical circuit model was established to extract corrosion-indicative dielectric properties of enamel and FBE coatings from the EIS data.
EIS data was obtained at the open-circuit potential using a Gamry Reference 600 potentiostat/galvanostat/ZRA instrument.
Aspx ) was used to fit the equivalent electrical circuit model into the impedance spectra test data.
However, the reduction in corrosion resistance in the FBE coating is more significant than that in the enamel coating
EIS data was obtained at the open-circuit potential using a Gamry Reference 600 potentiostat/galvanostat/ZRA instrument.
Aspx ) was used to fit the equivalent electrical circuit model into the impedance spectra test data.
However, the reduction in corrosion resistance in the FBE coating is more significant than that in the enamel coating
Online since: May 2014
Authors: Jesper Hattel, Ismet Baran, Gaetano S. Palazzo, Pierpaolo Carlone, Remko Akkerman
The predicted temperature and degree of cure profiles in the three dimensional (3D) thermo-chemical analysis are found to agree well with the measured data.
The rheological behavior is herein modeled following the well-recognized three parameters correlation model, which is expressed as: η=η∞exp∆EηRT+Kα, (8) where R is the gas constant, T is the absolute temperature, η∞, ∆Eη and K are material parameters provided by experimental data fitting.
However, due to the lack of thorough experimental data, generally averaged values are utilized.
The increase of the contact area with radius compensates the slight reduction of contact pressure.
The rheological behavior is herein modeled following the well-recognized three parameters correlation model, which is expressed as: η=η∞exp∆EηRT+Kα, (8) where R is the gas constant, T is the absolute temperature, η∞, ∆Eη and K are material parameters provided by experimental data fitting.
However, due to the lack of thorough experimental data, generally averaged values are utilized.
The increase of the contact area with radius compensates the slight reduction of contact pressure.
Online since: August 2013
Authors: Chang Bin Hu, Zeng Hua Sun, Li Juan Wang
China
ahuchb@sohu.com, bfzuszh@sina.com, clijuan2014@sina.com
Keywords: JPCP; Built-in temperature difference; Built-in basic temperature; Climate conditions; Geography
Abstract: To understand the characteristics of early-age built-in temperature in JPCP, the actual data of construction climate conditions of typical regions in China were investigated.
Construction climate condition According to Natural Zoning of China, the historical meteorological data that represents the typical cities in the natural partition during the period from 2000 to 2010 are obtained.
According to the regulation that the construction should be terminated when the minimum temperature of the construction site is lower than -3℃ or the average temperature is below 5℃ in 5 consecutive days and minimum night temperature is lower than -3℃ in night hours, statistical meteorological data in recent ten years are obtained.
The decrease of climate effect factors may lead to the reduction of negative BITD variation
Construction climate condition According to Natural Zoning of China, the historical meteorological data that represents the typical cities in the natural partition during the period from 2000 to 2010 are obtained.
According to the regulation that the construction should be terminated when the minimum temperature of the construction site is lower than -3℃ or the average temperature is below 5℃ in 5 consecutive days and minimum night temperature is lower than -3℃ in night hours, statistical meteorological data in recent ten years are obtained.
The decrease of climate effect factors may lead to the reduction of negative BITD variation
Online since: December 2010
Authors: Yang Liu
During the modal test, total 8 accelerometer sensors (PCB 3801G3FB3G) are applied to measure modal parameters of this bridge, and the SCADASIII data acquisition system (LMS company) is used to acquire the acceleration signal.
The sensor and data acquisition system are shown in Fig. 4.
Figure 4 Photo of accelerometer sensor and data acquisition system Figure 5 Measured acceleration signal and auto-power spectrum of acceleration response The acceleration data collected at each hour are identified by the ERA (eigen-system realization algorithm) [9] combining NExT (natural excitation technique) [10], and five identified frequencies during the period of 20/10/2009-30/10/2009 are obtained (Table 2) Table 2 Comparison between analytical frequencies and measured frequencies (Temperature: 19°C) Mode Analytical frequency (Hz) Identified results by ERA method Frequency (Hz) Error (%) MAC 1 1.31 1.20 8.40 0.88 2 1.93 1.71 11.39 0.89 3 2.14 2.22 -3.74 0.99 4 2.83 2.59 9.26 0.91 5 2.97 2.82 5.05 0.92 According to the comparison between measured and analytical modal parameters, the following conclusion are drawn: (1) ERA combining NExT is an effective method to identify the modal parameters of practical bridges; (2) The difference between measured and analytical frequencies
An Eigensystem Realization Algorithm for Modal Parameter Identification and Model Reduction.
The sensor and data acquisition system are shown in Fig. 4.
Figure 4 Photo of accelerometer sensor and data acquisition system Figure 5 Measured acceleration signal and auto-power spectrum of acceleration response The acceleration data collected at each hour are identified by the ERA (eigen-system realization algorithm) [9] combining NExT (natural excitation technique) [10], and five identified frequencies during the period of 20/10/2009-30/10/2009 are obtained (Table 2) Table 2 Comparison between analytical frequencies and measured frequencies (Temperature: 19°C) Mode Analytical frequency (Hz) Identified results by ERA method Frequency (Hz) Error (%) MAC 1 1.31 1.20 8.40 0.88 2 1.93 1.71 11.39 0.89 3 2.14 2.22 -3.74 0.99 4 2.83 2.59 9.26 0.91 5 2.97 2.82 5.05 0.92 According to the comparison between measured and analytical modal parameters, the following conclusion are drawn: (1) ERA combining NExT is an effective method to identify the modal parameters of practical bridges; (2) The difference between measured and analytical frequencies
An Eigensystem Realization Algorithm for Modal Parameter Identification and Model Reduction.
Online since: October 2013
Authors: Qi Chu Chen, Jing Yi Lin, Bin Li, Chang Liu
To realize the goal of energy-saving and emission-reduction and the goal of economic structure reform, series of policies have been released to encourage and promote the development of electric vehicle industry, not only on public transportation, but also on private electric vehicles.
They meter the actual discharged amount, and transmit the data to the on-board terminals.
And this imposes more demands to electric vehicle manufacturers to reserve enough spaces to accommodate ammeters and equip vehicles with terminals that can collect data from ammeters.
As to the battery exchanging mode, which takes minutes to replace battery, it cannot afford enough long time to acquire the metering data.
Therefore, it cannot spread before unified standards on installation, wiring, data collection and communications are issued and supported by all sorts of vehicle suppliers.
They meter the actual discharged amount, and transmit the data to the on-board terminals.
And this imposes more demands to electric vehicle manufacturers to reserve enough spaces to accommodate ammeters and equip vehicles with terminals that can collect data from ammeters.
As to the battery exchanging mode, which takes minutes to replace battery, it cannot afford enough long time to acquire the metering data.
Therefore, it cannot spread before unified standards on installation, wiring, data collection and communications are issued and supported by all sorts of vehicle suppliers.
Online since: October 2013
Authors: Zhen Li, Wei Wei Wang
Introduction
The application of renewable energy in buildings is one of six fields of energy-saving construction with maximum potential, and is the strategic core and advancing front of energy-saving and emission-reduction in construction.
Therefore the government attaches importance to actual operation effect of renewable energy application in buildings, and successively promulgates the Testing Guidance on Demonstration Projects with Renewable Energy Application in Buildings and the Technical Guidance on Data-monitoring System to Demonstration Projects with Renewable Energy Application in Buildings to guide the operation and acceptance of projects[1-3].
From the data of property management department, we can only get the power consumption per square meter during the heating supply.
For being short of data on total cooling and heating volume, the government authorities can not calculate the normal energy substitution correctly, and can not make corresponding policies according to the data.
Therefore the government attaches importance to actual operation effect of renewable energy application in buildings, and successively promulgates the Testing Guidance on Demonstration Projects with Renewable Energy Application in Buildings and the Technical Guidance on Data-monitoring System to Demonstration Projects with Renewable Energy Application in Buildings to guide the operation and acceptance of projects[1-3].
From the data of property management department, we can only get the power consumption per square meter during the heating supply.
For being short of data on total cooling and heating volume, the government authorities can not calculate the normal energy substitution correctly, and can not make corresponding policies according to the data.
Online since: January 2012
Authors: Chang De Hu, Mei Rong Zhao, Xiao Bei Deng, Sha Zhu
Therefore once the micro-cantilever surface absorbing the molecules to be tested, the micro-cantilever quality increasing, this causes a reduction in the frequency response .Then the measured substance could be quantitatively analyzed by detecting changes of micro-cantilever resonance frequency.
detection circuit computer micro- cantiliver piezoelectric film excitation signal voltage signal u current signal i data acquisition Fig.2 The block diagram of piezoelectric micro-cantilever system As Fig.2 shown, the system working process is described as follows: with the piezoelectric micro-cantilever fixed on the stent, sine voltage excitation signal is applied to piezoelectric film of the micro-cantilever through the analog output ports of a data acquisition card.
To keeps invariant for the amplitude of the excitation signal, then do a frequency scan[7] for the data acquisition card output signals controlled by computer, at a given frequency range by a small enough frequency interval, for a certain time at each frequency.
Finally, the voltage signal is recorded in computer through data acquisition card.
detection circuit computer micro- cantiliver piezoelectric film excitation signal voltage signal u current signal i data acquisition Fig.2 The block diagram of piezoelectric micro-cantilever system As Fig.2 shown, the system working process is described as follows: with the piezoelectric micro-cantilever fixed on the stent, sine voltage excitation signal is applied to piezoelectric film of the micro-cantilever through the analog output ports of a data acquisition card.
To keeps invariant for the amplitude of the excitation signal, then do a frequency scan[7] for the data acquisition card output signals controlled by computer, at a given frequency range by a small enough frequency interval, for a certain time at each frequency.
Finally, the voltage signal is recorded in computer through data acquisition card.
Online since: June 2018
Authors: Eddy Aeloiza, Arun Kadavelugu, Pietro Cairoli, Rostan Rodrigues
These features of SiC devices allow significant reduction in size and weight of power conversion systems, while increasing their efficiency, performance and reliability.
Extensive field data on long-term short-circuit capability of SiC MOSFETs is not currently available in the literature or in device datasheets, which makes it further difficult to design a reliable gate driver and protection circuit.
Also, these short circuit results are in consistent with the data published in [8].
The test data of the SiC MOSFET after 100 short-circuit tests (with fast protection) is compared with the data before the device is subjected to any short-circuit condition.
Extensive field data on long-term short-circuit capability of SiC MOSFETs is not currently available in the literature or in device datasheets, which makes it further difficult to design a reliable gate driver and protection circuit.
Also, these short circuit results are in consistent with the data published in [8].
The test data of the SiC MOSFET after 100 short-circuit tests (with fast protection) is compared with the data before the device is subjected to any short-circuit condition.
Online since: February 2019
Authors: Liudmila Shtirc, Svetlana G. Vlasova, Dmitry Meshcherskikh
The increase of the foaming coefficient indicates a volume mass reduction of the sample.
Analyzing the data received, it can be concluded that in order to obtain a lighter foamed glass, the SO3 content should be not less than 0.3% in the primary composition with more than 4% of iron oxide content.
Dependence of the foaming coefficient on the initial temperature in the furnace* Тinitial, [оС] in the furnace Gassing agent, [wt. %] Foaming time, [min] Foaming coefficient (Kv) 27.5 silica, 0.5 30 1.5 100 silica, 0.5 30 1.61 200 silica, 0.5 30 1.75 300 silica, 0.5 30 1.88 * example from composition #2 Analyzing the data received, it can be concluded that when the initial temperature in the lab furnace increases, the foaming kinetics changes.
Analyzing the data received, it can be concluded that to obtain a foam material with the most equal porous structure, it is necessary to use a 25% NaOH solution as a foaming agent and to maintain the maximum foaming temperature in a lab furnace of 890°C.
Conclusion According to the experimental data, in order to obtain a lighter foam material it is necessary to have a SO3 content in the original glass composition of at least 0.3% with an iron oxide content of more than 4%.
Analyzing the data received, it can be concluded that in order to obtain a lighter foamed glass, the SO3 content should be not less than 0.3% in the primary composition with more than 4% of iron oxide content.
Dependence of the foaming coefficient on the initial temperature in the furnace* Тinitial, [оС] in the furnace Gassing agent, [wt. %] Foaming time, [min] Foaming coefficient (Kv) 27.5 silica, 0.5 30 1.5 100 silica, 0.5 30 1.61 200 silica, 0.5 30 1.75 300 silica, 0.5 30 1.88 * example from composition #2 Analyzing the data received, it can be concluded that when the initial temperature in the lab furnace increases, the foaming kinetics changes.
Analyzing the data received, it can be concluded that to obtain a foam material with the most equal porous structure, it is necessary to use a 25% NaOH solution as a foaming agent and to maintain the maximum foaming temperature in a lab furnace of 890°C.
Conclusion According to the experimental data, in order to obtain a lighter foam material it is necessary to have a SO3 content in the original glass composition of at least 0.3% with an iron oxide content of more than 4%.