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Online since: November 2013
Authors: Xiu Ping Zhao, Zhi Qiang Gao
The Internet of Things technology used in agricultural products, such as food safety traceability management is taking the technological advantages of the Internet of Things-RFID (Radio Frequency IDentification) is non-contact automatic fast read and write data encryption, in order to achieve a unified management and efficient flow of work in coordination.This thesis reports a production method of conductive nano-silver jet ink.
Obtain the dispersion of silver nanoparticles through chemical reduction reaction.
Take 0.2 mo1·L-1solution of hydrazine hydrate N2H4 • H2O 10 ml, 0.2 mo1·L-1 solution of silver nitrate 10ml, silver nitrate and PVP in the mass ratio of 2 times, respectively, in 20 ℃, 40 ℃, 60 ℃, 80 ℃ under the conditions of the reduction reaction, the experimental results shown in Fig.2.
Obtain the dispersion of silver nanoparticles through chemical reduction reaction.
Take 0.2 mo1·L-1solution of hydrazine hydrate N2H4 • H2O 10 ml, 0.2 mo1·L-1 solution of silver nitrate 10ml, silver nitrate and PVP in the mass ratio of 2 times, respectively, in 20 ℃, 40 ℃, 60 ℃, 80 ℃ under the conditions of the reduction reaction, the experimental results shown in Fig.2.
Online since: August 2013
Authors: Jian Hua Li, Mei Lin Jia, Meng Jie Feng
A series of mesoporous TiO2 supports were synthesized by the sol-gel template method by using different surfactant and Au/TiO2 catalysts were prepared by the solution reduction method.
In recent years, gold clusters supported on titania (Au/TiO2) have been shown to be very active catalysts for selective oxidation of propene, nitrogen oxide reduction, and relatively low-temperature CO oxidation [9,10].It has been well established that the catalytic properties of gold for CO oxidation are not only determined by the particle size but also largely dependent on the nature of the support and the preparation procedures, which give the very complex nature of gold catalysis [11].
For comparison, P25 was purchased from Degussa. 2.1.2 Catalyst Preparation The Au/TiO2 catalyst was prepared by solution reduction method with chloroauric acid tetrahydrate (HAuCl4, AR, Sinopharm Chemical Reagent Co., Ltd) as the precursor and mesoporous titania as the support.
Data were evaluated using the BET and BJH methods to calculate the surface area and pore size, respectively.
In recent years, gold clusters supported on titania (Au/TiO2) have been shown to be very active catalysts for selective oxidation of propene, nitrogen oxide reduction, and relatively low-temperature CO oxidation [9,10].It has been well established that the catalytic properties of gold for CO oxidation are not only determined by the particle size but also largely dependent on the nature of the support and the preparation procedures, which give the very complex nature of gold catalysis [11].
For comparison, P25 was purchased from Degussa. 2.1.2 Catalyst Preparation The Au/TiO2 catalyst was prepared by solution reduction method with chloroauric acid tetrahydrate (HAuCl4, AR, Sinopharm Chemical Reagent Co., Ltd) as the precursor and mesoporous titania as the support.
Data were evaluated using the BET and BJH methods to calculate the surface area and pore size, respectively.
Online since: January 2012
Authors: Ozgen U. Colak, Ardavan Zandiatashbar
Thermal reduction of graphite oxide is the method used to obtain bulk quantities of graphene platelets (GPL) which comprise multiple graphene sheets.
In this work, thermal reduction of graphite oxide was used to obtain bulk quantities of graphene platelets (GPL) which comprise multiple graphene sheets.
b) a) Fig.2. a) Load-depth response of elastic-plastic material during nanoindentation, b) AFM image of nanoindented Epoxy sample Atomic Force Microscopy (AFM) image of the indented site in epoxy are shown in Fig. 2b The Procedure to Calculate the Hardness and Reduced Modulus: The procedure was developed by Oliver and Pharr [2] to measure the hardness and elastic modulus of a material from indentation load–displacement data obtained during one cycle of loading and unloading.
Reduced modulus, elasticity modulus and hardness of graphene platelet (GPL)-epoxy nanocomposite measured from force-depht curve under load controlled nanoindentation Load (µN) Loading rate (µN/s) Er (GPa) E (GPa) Hardness (MPa) 2000 200 2.86 2.61 174 4000 200 2.22 2.02 135 6000 200 1.79 1.63 118 8000 200 1.63 1.49 112 Conclusions and Comments Thermal reduction of graphite oxide was used to obtain bulk quantities of graphene platelets (GPL).
In this work, thermal reduction of graphite oxide was used to obtain bulk quantities of graphene platelets (GPL) which comprise multiple graphene sheets.
b) a) Fig.2. a) Load-depth response of elastic-plastic material during nanoindentation, b) AFM image of nanoindented Epoxy sample Atomic Force Microscopy (AFM) image of the indented site in epoxy are shown in Fig. 2b The Procedure to Calculate the Hardness and Reduced Modulus: The procedure was developed by Oliver and Pharr [2] to measure the hardness and elastic modulus of a material from indentation load–displacement data obtained during one cycle of loading and unloading.
Reduced modulus, elasticity modulus and hardness of graphene platelet (GPL)-epoxy nanocomposite measured from force-depht curve under load controlled nanoindentation Load (µN) Loading rate (µN/s) Er (GPa) E (GPa) Hardness (MPa) 2000 200 2.86 2.61 174 4000 200 2.22 2.02 135 6000 200 1.79 1.63 118 8000 200 1.63 1.49 112 Conclusions and Comments Thermal reduction of graphite oxide was used to obtain bulk quantities of graphene platelets (GPL).
Online since: June 2013
Authors: Artur Chrobak, Grzegorz Haneczok, Julian Kubisztal, Jozef Stabik, Agnieszka Dybowska, Marian Kubisztal
The influence of size reduction of SrFe12O19 powder particles on magnetic parameters of the studied nanocomposites were discussed in detail.
b) a) Fig. 3 Magnetic data for nanocomposite pellets containing nano Ni and SrFe12O19 (as received and milled) powder versus concentration c: a) saturation magnetization Ms, b) residual magnetism Mr.
It seems, that the size reduction effect results in higher disorder in magnetic moment structure of the strontium ferrite particles, so an increase in (m)SrFe12O19 concentration gives a slight decreases in Ms (from 51 to 46 emu/g, see Fig.3a).
Concluding remarks Main conclusions can be formulated as follows: i) presence of Ni nanopowder in A-E+SrFe12O19 composite improves its elastic properties, e.g. for 36 wt. % of Ni the observed increase of Ea is about 80 % ii) size reduction of the SrFe12O19 powder particles causes an increase of coercive field Hc from 1 to 1.8 kOe and iii) replacement of the as received micron size strontium ferrite particles by the milled ones results in the significant decrease in saturation magnetization Ms and residual magnetism Mr.
b) a) Fig. 3 Magnetic data for nanocomposite pellets containing nano Ni and SrFe12O19 (as received and milled) powder versus concentration c: a) saturation magnetization Ms, b) residual magnetism Mr.
It seems, that the size reduction effect results in higher disorder in magnetic moment structure of the strontium ferrite particles, so an increase in (m)SrFe12O19 concentration gives a slight decreases in Ms (from 51 to 46 emu/g, see Fig.3a).
Concluding remarks Main conclusions can be formulated as follows: i) presence of Ni nanopowder in A-E+SrFe12O19 composite improves its elastic properties, e.g. for 36 wt. % of Ni the observed increase of Ea is about 80 % ii) size reduction of the SrFe12O19 powder particles causes an increase of coercive field Hc from 1 to 1.8 kOe and iii) replacement of the as received micron size strontium ferrite particles by the milled ones results in the significant decrease in saturation magnetization Ms and residual magnetism Mr.
Online since: October 2014
Authors: Gheorghe Brabie, Bogdan Chirita, Gheorghe Mustea
The cutting followed by burnishing, used like a combined process, leads to the improvement of the part surface quality (roughness, hardness, microstructure etc.) and to reduction of the costs and manufacturing times as a function of different working parameters.
Introduction The cutting followed by burnishing, used like a combined process, leads to the improvement of the part surface quality (roughness, hardness, microstructure etc.) and to reduction of the costs and manufacturing times as a function of different working parameters.
The burnishing- turning combined process determines the following effects on the machined surface quality: the considerable reduction of the surface roughness, the increase of the material microhardness, the elongation of the material grains in the rolling direction, the occurrence of the compressive residual stresses in the surface layers, the occurrence of the cracks in the surface strata for a pressing pressure of 150 bar [1, 2].
The strain gauges used for determination of residual stresses were of HBM 1.5/120RY61S type, their signal being captured by a SPIDER 8-30 data acquisition device and processed using the Residual Stress Management System.
Introduction The cutting followed by burnishing, used like a combined process, leads to the improvement of the part surface quality (roughness, hardness, microstructure etc.) and to reduction of the costs and manufacturing times as a function of different working parameters.
The burnishing- turning combined process determines the following effects on the machined surface quality: the considerable reduction of the surface roughness, the increase of the material microhardness, the elongation of the material grains in the rolling direction, the occurrence of the compressive residual stresses in the surface layers, the occurrence of the cracks in the surface strata for a pressing pressure of 150 bar [1, 2].
The strain gauges used for determination of residual stresses were of HBM 1.5/120RY61S type, their signal being captured by a SPIDER 8-30 data acquisition device and processed using the Residual Stress Management System.
Online since: December 2013
Authors: Ta Chung Yang, Sheng Shian Tsai
The cavity between the microperforated plate and the back plate also provides resonant effects for noise reduction.
If double layers of microperforated plates are used, wide frequency ranges of noise reduction can be achieved [2].
Compared with the total noise level of condition (2), a significant noise reduction of 33dBA is achieved.
Data analysis is performed using a commercial software of statistics.
The S/N ratio is defined as (1) where is the experimental data, is the data number,is the standard deviation.
If double layers of microperforated plates are used, wide frequency ranges of noise reduction can be achieved [2].
Compared with the total noise level of condition (2), a significant noise reduction of 33dBA is achieved.
Data analysis is performed using a commercial software of statistics.
The S/N ratio is defined as (1) where is the experimental data, is the data number,is the standard deviation.
Online since: December 2011
Authors: Zhao Mei Wang, Kai Jun Xiao, Jian Yong Wu
Data was processed with the MAS OPTION Software.
In the first 1 min (0~1 min), a sharp reduction of hSP occurred with a reduction rate of 51%.
It suggested that low ultrasonic power was favorable for the reduction of viscosity in consideration of energy saving.
A B C D Fig. 1 Effect of ultrasound irradiation duration on the association of EPS in aqueous solution Note:DLS data were collected without filtration for samples.
Note:Data are shown for native and ultrasonic irradiated EPS solutions several days after filtration with 450 nm pore size filters.
In the first 1 min (0~1 min), a sharp reduction of hSP occurred with a reduction rate of 51%.
It suggested that low ultrasonic power was favorable for the reduction of viscosity in consideration of energy saving.
A B C D Fig. 1 Effect of ultrasound irradiation duration on the association of EPS in aqueous solution Note:DLS data were collected without filtration for samples.
Note:Data are shown for native and ultrasonic irradiated EPS solutions several days after filtration with 450 nm pore size filters.
Online since: October 2015
Authors: Emilian Ghicioi, Attila Kovacs, Edward Gheorghiosu, Gabriel Dragos Vasilescu, Ciprian Jitea, Daniela Rus, Tiberiu Csaszar
The document for safety to professional vibration – overview
Data and information included in the document for safety to professional vibration
The evaluation of risk of exposure to professional vibration, regarding the increasing of occupational safety rate, for the economic agents whose activities are performed in the presence of sources generating vibrations, can be accomplished through “The document for safety to professional vibration’’, comprising the following sections [1,2,5]:
Document name and date:
‘’The document for safety to professional vibration’’ (DSVP) from DD/MM/YYYY;
Applicant: The beneficiary of order and/ or the subscriber of the contract regarding the assessment of risk of exposure to professional vibration or the beneficiary of order and/ or the subscriber of the contract regarding the assessment of risk of exposure to global vibration;
- Address: Data and information regarding the applicants location and/ or work place where it will be performed the evaluation
containing the procedure for analysis and assessment of vibration risk; - List of control to vibration: A list containing questions regarding the review of activities performed in the presence of sources generating vibration; - Declared values of vibration on work equipment located at the analyzed work places: The name of the section comprising sequences regarding the work places for which the risk assessment is done (job name; declared value of specific vibration of equipment; limit values of exposure in accordance with the applicable regulations; observations on the workers time of exposure to vibration) and the flowchart for performing an assessment for risk to exposure on vibrations, in accordance with the regulations; - Chart of risk of exposure to professional vibrations: Graphical representation of risk levels regarding the exposure to professional vibration using the iso-curves of risk (equal level curves); - Matrix of estimation and assessment of risk of exposure to vibration: Data
Start Analyze of vibration The evaluation of exposure to vibration The control of vibration 2,5¸5 m/s2 > 2,5 m/s2 < 2,5 m/s2 End The vibration reduction > 5 m/s2 Fig.1.
Start Analyze of vibration The evaluation of exposure to vibration The control of vibration 0,5¸1,15 m/s2(9,1¸21 m/s1,75) > 0,5 m/s2(9,1 m/s1,75) End The vibration reduction > 1,15 m/s2(21 m/s1,75) < 0,5 m/s2(9,1 m/s1,75) m/s1,75) Fig.2.
Program of prevention and reduction of risk to vibration Avoiding or reducing the exposure to vibration Yes No 1.
containing the procedure for analysis and assessment of vibration risk; - List of control to vibration: A list containing questions regarding the review of activities performed in the presence of sources generating vibration; - Declared values of vibration on work equipment located at the analyzed work places: The name of the section comprising sequences regarding the work places for which the risk assessment is done (job name; declared value of specific vibration of equipment; limit values of exposure in accordance with the applicable regulations; observations on the workers time of exposure to vibration) and the flowchart for performing an assessment for risk to exposure on vibrations, in accordance with the regulations; - Chart of risk of exposure to professional vibrations: Graphical representation of risk levels regarding the exposure to professional vibration using the iso-curves of risk (equal level curves); - Matrix of estimation and assessment of risk of exposure to vibration: Data
Start Analyze of vibration The evaluation of exposure to vibration The control of vibration 2,5¸5 m/s2 > 2,5 m/s2 < 2,5 m/s2 End The vibration reduction > 5 m/s2 Fig.1.
Start Analyze of vibration The evaluation of exposure to vibration The control of vibration 0,5¸1,15 m/s2(9,1¸21 m/s1,75) > 0,5 m/s2(9,1 m/s1,75) End The vibration reduction > 1,15 m/s2(21 m/s1,75) < 0,5 m/s2(9,1 m/s1,75) m/s1,75) Fig.2.
Program of prevention and reduction of risk to vibration Avoiding or reducing the exposure to vibration Yes No 1.
Online since: September 2013
Authors: Cheng Jiang Zhang, Zheng Qi Xu, Hao Song
Results and discussion
The profile measured on site in field is as thick as 31.52m and has 85 layer. 82 radioactive spots are actually measured on site. 410 γ energy spectrum data are obtained and the statistic results are listed in Table 1.
Content(10-6) URa 18.39 6.77 9.67 1.75 Th 28.5 0.08 13.55 1.76 K(%) 2.95 0.47 1.80 0.25 External irradiation ratio Ir 1.1 0.26 0.67 0.06 Internal irradiation ratio Ira 1.14 0.42 0.60 0.11 γ energy spectrum geophysical profile maps of Xigeda Formation are made according to the actual measurement data for URa, Th, K, Ir and Ira.
The black in the figure represents the reduction environment and the grey represents the oxidation environment.
The figure clearly shows that the data got by γ energy spectrum measurement have obvious regularity and the stratums can generally be divided into 22 layer and 6 macro cycles.
Generally speaking, the bottom is of reduction environment (blue gray, thin granularity) and the top is of oxidation environment (gray yellow, thick granularity).
Content(10-6) URa 18.39 6.77 9.67 1.75 Th 28.5 0.08 13.55 1.76 K(%) 2.95 0.47 1.80 0.25 External irradiation ratio Ir 1.1 0.26 0.67 0.06 Internal irradiation ratio Ira 1.14 0.42 0.60 0.11 γ energy spectrum geophysical profile maps of Xigeda Formation are made according to the actual measurement data for URa, Th, K, Ir and Ira.
The black in the figure represents the reduction environment and the grey represents the oxidation environment.
The figure clearly shows that the data got by γ energy spectrum measurement have obvious regularity and the stratums can generally be divided into 22 layer and 6 macro cycles.
Generally speaking, the bottom is of reduction environment (blue gray, thin granularity) and the top is of oxidation environment (gray yellow, thick granularity).
Online since: October 2014
Authors: Pierre Marie Geffroy, Eric Blond, Thierry Chartier, Camille Gazeau, Nicolas Richet, Mickaël Reichmann
This model assumed that the oxygen flux is governed by the association/dissociation of adsorbed oxygen and by the high energetic cost of oxygen reduction/oxidation.
Introduction Due to the increasing need of pure oxygen at high temperature and cost reduction policy in energy industries, catalytic membrane reactors are promising technologies to replace usual cryogenic separation of oxygen form air.
Local hypothesis Thermodynamic balance: - Global reaction OO×+*kS1ex2h∙+O*+ VO× - Reaction mechanism Mathematical relations Dirichlet boundary condition : Neumann boundary condition : Neumann boundary condition: Comparison with experimental data Conclusions Over-estimates the oxygen activity gradient inside the membrane, so overestimates the chemical strains Underestimates the oxygen activity gradient inside the membrane, so underestimates the chemical strains Can reproduce the measures but cannot predict the oxygen permeation fluxes.
The oxidation/reduction reaction describes the charge transfer phenomena.
This model reproduced qualitatively the kinetic difference between oxidation and reduction but it should be refined to obtain quantitative prediction.
Introduction Due to the increasing need of pure oxygen at high temperature and cost reduction policy in energy industries, catalytic membrane reactors are promising technologies to replace usual cryogenic separation of oxygen form air.
Local hypothesis Thermodynamic balance: - Global reaction OO×+*kS1ex2h∙+O*+ VO× - Reaction mechanism Mathematical relations Dirichlet boundary condition : Neumann boundary condition : Neumann boundary condition: Comparison with experimental data Conclusions Over-estimates the oxygen activity gradient inside the membrane, so overestimates the chemical strains Underestimates the oxygen activity gradient inside the membrane, so underestimates the chemical strains Can reproduce the measures but cannot predict the oxygen permeation fluxes.
The oxidation/reduction reaction describes the charge transfer phenomena.
This model reproduced qualitatively the kinetic difference between oxidation and reduction but it should be refined to obtain quantitative prediction.