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Online since: September 2012
Authors: José Carlos Bressiani, Ana Helena Almeida Bressiani, Marcio W.D. Mendes
One way for production of metallic alloys is powder metallurgy (PM) that is an excellent tool for the near net-shape fabrication of surgical implants due to some inherent advantages, including the capability of precisely adjusting chemical compositions, feasibility, modulus reduction through the inclusion of pores and also and reduction of costs [1].
The XRD patterns were compared with the database PDF-2 of the International Centre for Diffraction Data (ICDD).
The significant reduction in D50% is due increased milling time and consequently greater number of collisions (impact) between the balls of crucible and the alloy particles promoting the breakage of larger particles by processes as microforging, fracture, agglomeration and deagglomeration [9].
milling Time [h] D10% [µm] D50% [µm] D90% [µm] 2 10.60 39.7 94.10 6 3.20 9.0 15.9 10 1.4 4.6 9.10 The variation green density of samples is in Fig. 3, as seen there is decrease on density due the reduction on particle size.
The treatment applied in samples with 10 milling hours exhibit modulus and hardness according data of ti-13Nb-13-Zr alloy, density of 90.44 % of theoretical density and smaller porosity.
The XRD patterns were compared with the database PDF-2 of the International Centre for Diffraction Data (ICDD).
The significant reduction in D50% is due increased milling time and consequently greater number of collisions (impact) between the balls of crucible and the alloy particles promoting the breakage of larger particles by processes as microforging, fracture, agglomeration and deagglomeration [9].
milling Time [h] D10% [µm] D50% [µm] D90% [µm] 2 10.60 39.7 94.10 6 3.20 9.0 15.9 10 1.4 4.6 9.10 The variation green density of samples is in Fig. 3, as seen there is decrease on density due the reduction on particle size.
The treatment applied in samples with 10 milling hours exhibit modulus and hardness according data of ti-13Nb-13-Zr alloy, density of 90.44 % of theoretical density and smaller porosity.
Online since: June 2010
Authors: Wei Ke, Shan Na Xu, Nan Chen, Junhua Dong
However, thermodynamic data [12]
showed that magnesium hydride could exist in the film of magnesium corrosion product.
It is well-known that mercury droplet has very high overpotential and low exchange current density for the reduction of H +.
They also exhibited low exchange current density and higher overpotential for H + reduction[16].
This indicates that the addition of Cd restrans both the reduction of H + and the formation of magnesium hydride.
In the weak-polarized region, the measured data equals to the absolute difference between the anodic current density and the cathodic current density of the matrix, which can be written as |Ia-Ic|.
It is well-known that mercury droplet has very high overpotential and low exchange current density for the reduction of H +.
They also exhibited low exchange current density and higher overpotential for H + reduction[16].
This indicates that the addition of Cd restrans both the reduction of H + and the formation of magnesium hydride.
In the weak-polarized region, the measured data equals to the absolute difference between the anodic current density and the cathodic current density of the matrix, which can be written as |Ia-Ic|.
Online since: January 2005
Authors: Takahito Ohmura, Kaneaki Tsuzaki
In the case of the tempering temperature at or above 723 K, the data
approaches those of single crystals.
The increase of the ratio indicates a significant reduction of the grain boundary effect on the martensite.
The reduction of the grain boundary effect corresponds to a decrease in the second term of the Hall-Petch relation that is composed of the grain size term d -n and the locking parameter k.
Thus, the significant increase of the ratio Hn/Hv corresponding to the reduction of the grain boundary effect at 723 K is mainly attributed to the disappearance of the film-like cementite on the boundaries.
In this way, a rocking parameter k can be semiquantitatively evaluated using data of nanohardness and grain size for just one sample without changing a grain size to have a Hall-Petch plot.
The increase of the ratio indicates a significant reduction of the grain boundary effect on the martensite.
The reduction of the grain boundary effect corresponds to a decrease in the second term of the Hall-Petch relation that is composed of the grain size term d -n and the locking parameter k.
Thus, the significant increase of the ratio Hn/Hv corresponding to the reduction of the grain boundary effect at 723 K is mainly attributed to the disappearance of the film-like cementite on the boundaries.
In this way, a rocking parameter k can be semiquantitatively evaluated using data of nanohardness and grain size for just one sample without changing a grain size to have a Hall-Petch plot.
Online since: July 2015
Authors: Payoon Senthongkaew, Ratchatee Techapiesancharoenkij, Weerawat Terdthaichairat
The representative results of the DSC temperature scans and the corresponding melting-temperature data are shown in Fig. 2 and Table 1, correspondingly.
The potentiodynamic polarization curves are shown in Fig. 3, and the corresponding data of the corrosion potentials (Ecorr) and current densities (Icorr) are summarized in Table 2.
The reduction of zinc content from 9 wt% to 7 wt% increased the Ecorr values from -924 mV to -903 mV.
Apparently, the reduction of Zn content and the increase of Cu content improved the corrosion resistance of the Sn-Zn-Cu solder alloys.
Therefore, a reduction of a Zn-to-Cu ratio apparently improved the corrosion resistance of the alloys.
The potentiodynamic polarization curves are shown in Fig. 3, and the corresponding data of the corrosion potentials (Ecorr) and current densities (Icorr) are summarized in Table 2.
The reduction of zinc content from 9 wt% to 7 wt% increased the Ecorr values from -924 mV to -903 mV.
Apparently, the reduction of Zn content and the increase of Cu content improved the corrosion resistance of the Sn-Zn-Cu solder alloys.
Therefore, a reduction of a Zn-to-Cu ratio apparently improved the corrosion resistance of the alloys.
Online since: June 2012
Authors: Jing Xia Cao, Bao Wang, Xu Huang, Chun Xiao Cao, Huan Ying Sun
The purpose of this paper is to reveal the deformation mechanism of burn resistant titanium alloy (Ti-35V-15Cr-Si-C) at the elevated temperatures by studying of the flow behavior and microstructure evolution of differently hot compressed samples, based on compression testing data of as-cast and as-extruded burn resistant titanium alloy.
The height reduction is 50%.
Fig.3 Cracking in as-cast state alloy, occurring at 1s-1 and 0.01s-1, 50% reduction Fig.4 Cracking in as-extrude state alloy, occurring at 1s-1, 50% reduction Hot deformation activation energy The work-hardening and softening of alloys occur at the same time and compete between contenting aspects during hot deformation.
The work-hardening is a phenomenon that flow stress increases with increment of the upset reduction, because of pile-up of dislocation forms around original grain boundaries and carbide branches.
The Arrhenius hyperbolic sine equation can be written in the form: (6) The solution formula of the deformation activation energy can be obtained from Eq.(6) (7) Since the peak flow stress σp and strain rate and deformation temperature T are known based on hot compression testing data, using Eq.(3) and Eq.(4) and Eq.(6), the parameter of k and n1 can be obtained by linear fitting, and deformation activation energies can be calculated.
The height reduction is 50%.
Fig.3 Cracking in as-cast state alloy, occurring at 1s-1 and 0.01s-1, 50% reduction Fig.4 Cracking in as-extrude state alloy, occurring at 1s-1, 50% reduction Hot deformation activation energy The work-hardening and softening of alloys occur at the same time and compete between contenting aspects during hot deformation.
The work-hardening is a phenomenon that flow stress increases with increment of the upset reduction, because of pile-up of dislocation forms around original grain boundaries and carbide branches.
The Arrhenius hyperbolic sine equation can be written in the form: (6) The solution formula of the deformation activation energy can be obtained from Eq.(6) (7) Since the peak flow stress σp and strain rate and deformation temperature T are known based on hot compression testing data, using Eq.(3) and Eq.(4) and Eq.(6), the parameter of k and n1 can be obtained by linear fitting, and deformation activation energies can be calculated.
Online since: January 2015
Authors: Raushan Alzhanova, Alisher Akhatuly, Kirill Romanov, Pavel Grigorev
Developments of construction require a reduction of building time, improvement of working efficiency and quality.
Data presented in Table 2.
Name / period Cargo-passenger hoist Cargo hoist Full period of equipment operation for the 15-storey building,months 6 6,5 Full period of equipment operation for the 15-storey building,shifts 248 270 Full period of equipment operation for the 25-storey building,months 9 9,5 Full period of equipment operation for the 25-storey building,shifts 372 394 [25] Based on data in tables 1, 2 and 3 total expenses were calculated for each equipment.
[18] Sorensen, K.L., Singhose, W., Dickerson, S.A., Controller enabling precise positioning and sway reduction in bridge and gantry cranes (2007) Control Engineering Practice, Vol. 15, 7, pp. 825-837
[22] Sorensen, K.L., Singhose, W., Dickerson, S.A., Controller enabling precise positioning and sway reduction in bridge and gantry cranes (2007) Control Engineering Practice, Vol. 15, 7, pp. 825-837
Data presented in Table 2.
Name / period Cargo-passenger hoist Cargo hoist Full period of equipment operation for the 15-storey building,months 6 6,5 Full period of equipment operation for the 15-storey building,shifts 248 270 Full period of equipment operation for the 25-storey building,months 9 9,5 Full period of equipment operation for the 25-storey building,shifts 372 394 [25] Based on data in tables 1, 2 and 3 total expenses were calculated for each equipment.
[18] Sorensen, K.L., Singhose, W., Dickerson, S.A., Controller enabling precise positioning and sway reduction in bridge and gantry cranes (2007) Control Engineering Practice, Vol. 15, 7, pp. 825-837
[22] Sorensen, K.L., Singhose, W., Dickerson, S.A., Controller enabling precise positioning and sway reduction in bridge and gantry cranes (2007) Control Engineering Practice, Vol. 15, 7, pp. 825-837
Online since: December 2014
Authors: Ling Qiang Yang, Yan Wang
Determination of compressive strength by means of destructive testing methods results in a reduction in the cross section of structural elements, and therefore a reduction in load bearing capacity.
In this paper, numerical analysis is performed on test results of concrete strength data to future understand the stress field and the yielding mechanism of concrete specimens.
Simulate laboratory compressive strength tests boundary conditions: Upper and lower surfaces of the specimen without friction reduction are in contact with the loading panel, lower boundary fixed in x, y and z directions, upper boundary fixed in x and y direction.
If the loading capacity of the specimen is taken as the measure for strength, then specimens with friction reduction should be used in testing when it is a plane stress problem; if it is a plane strain problem, confinement should be used in the testing.
In this paper, numerical analysis is performed on test results of concrete strength data to future understand the stress field and the yielding mechanism of concrete specimens.
Simulate laboratory compressive strength tests boundary conditions: Upper and lower surfaces of the specimen without friction reduction are in contact with the loading panel, lower boundary fixed in x, y and z directions, upper boundary fixed in x and y direction.
If the loading capacity of the specimen is taken as the measure for strength, then specimens with friction reduction should be used in testing when it is a plane stress problem; if it is a plane strain problem, confinement should be used in the testing.
Online since: December 2014
Authors: Xiao Zhong Ge
According to the analysis of force and acquirement of installing mechanical, achieve the transmission for adjusting position of roller using SEW motor and reduction gearbox with high reduction ratio.
Table 1 System configuration chart No System element No System element No System element 1 S7-400 4 ET-200 7 BD1\BD2\BD3\BD4 \RVS\ CL1\CL2\CL3\FP1\FP2 2 MM440 5 TP270 8 SEW motor 3 Absolute encoder 6 DP repeater 9 Reduction gearbox Implementation of system MM440 and absolute value encoder implement the function of positioning.According to the configuration of system, the position of each roller is controlled using absolute value encoder and SEWS motor driven by MM440.
According to the reduction gear ratio i and pitch P, compute the actual distance Sp=[6],which is described by each pulse in encoder.
Fig.4 Schematic diagram of data definition of fixed position control program HMI frame structure and optimization According to the mechanism character and the technological requirements of NA welded pipe forming machine, the HMI frame structure is designed as shown in Fig.5.
Table 1 System configuration chart No System element No System element No System element 1 S7-400 4 ET-200 7 BD1\BD2\BD3\BD4 \RVS\ CL1\CL2\CL3\FP1\FP2 2 MM440 5 TP270 8 SEW motor 3 Absolute encoder 6 DP repeater 9 Reduction gearbox Implementation of system MM440 and absolute value encoder implement the function of positioning.According to the configuration of system, the position of each roller is controlled using absolute value encoder and SEWS motor driven by MM440.
According to the reduction gear ratio i and pitch P, compute the actual distance Sp=[6],which is described by each pulse in encoder.
Fig.4 Schematic diagram of data definition of fixed position control program HMI frame structure and optimization According to the mechanism character and the technological requirements of NA welded pipe forming machine, the HMI frame structure is designed as shown in Fig.5.
Online since: July 2014
Authors: Ying Quan Wang
Using the data calculated by the equation to get the C to A’s comprehensive weight vector that is N=DT.
Through various energy-saving measures, the calculated values and reduction rate of energy consumption can be drawn from the residential reasonable distribution of energy saving, as shown.
Table 1 Calculation and analysis of the effect of residential reasonable distribution of energy saving design Energy use Calculation method Design value Standard value Energy consumption reduction rate /GJ /GJ /% Heating 11.8×0.55×0.9×0.6 3.5 12.8 73 Air condition 2.3×0.8×0.53×0.6 0.55 2.4 77 Aeration 4.6×0.6 2.7 4.7 43 Hot water Supply 23.5×0.5 11.7 24.5 52 lighting 10.4×0.94×0.6 5.87 10.7 45 Household appliances 22.8×0.6 13.7 23.7 42 Other 4.4 4.4 0 Total 44.2 83.2 47 Energy consumption reduction rate = (1 - energy consumption design value of residential energy saving / standard value of energy consumption) Calculated as shown in Table1, for example, the effect of rural residential reasonable distribution of energy saving design is analyzed.
Through various energy-saving measures, the calculated values and reduction rate of energy consumption can be drawn from the residential reasonable distribution of energy saving, as shown.
Through various energy-saving measures, the calculated values and reduction rate of energy consumption can be drawn from the residential reasonable distribution of energy saving, as shown.
Table 1 Calculation and analysis of the effect of residential reasonable distribution of energy saving design Energy use Calculation method Design value Standard value Energy consumption reduction rate /GJ /GJ /% Heating 11.8×0.55×0.9×0.6 3.5 12.8 73 Air condition 2.3×0.8×0.53×0.6 0.55 2.4 77 Aeration 4.6×0.6 2.7 4.7 43 Hot water Supply 23.5×0.5 11.7 24.5 52 lighting 10.4×0.94×0.6 5.87 10.7 45 Household appliances 22.8×0.6 13.7 23.7 42 Other 4.4 4.4 0 Total 44.2 83.2 47 Energy consumption reduction rate = (1 - energy consumption design value of residential energy saving / standard value of energy consumption) Calculated as shown in Table1, for example, the effect of rural residential reasonable distribution of energy saving design is analyzed.
Through various energy-saving measures, the calculated values and reduction rate of energy consumption can be drawn from the residential reasonable distribution of energy saving, as shown.
Online since: January 2016
Authors: Rutanachai Thaipratum
Silver nanoparticles, nanoparticles of silver of between 1 nm to 100 nm in size, with different shapes, sizes and their anti-bacterial activities can be prepared by reduction of silver nitrate with different reducing agents such as glucose, sodium borohydride, sodium citrate and ascorbic acid [1].
A simple and economic method of synthesis of silver colloid nanoparticles with controlled size by reduction of [Ag(NH3)2]+ complex in sodium dodecyl sulfate (SDS) micellar solution with three various reducing agents (hydrazine, formalin and ascorbic acid) has been report [2].
Data points shown are averages of three measurements ±SE.
WARSZYŃSKI, PREPARATION OF SILVER NANOPARTICLES VIA CHEMICAL REDUCTION AND THEIR ANTIMICROBIAL ACTIVITY, Physicochem.
Rashid, Green Synthesis of Silver Nanoparticles through Reduction with Solanum xanthocarpum L.
A simple and economic method of synthesis of silver colloid nanoparticles with controlled size by reduction of [Ag(NH3)2]+ complex in sodium dodecyl sulfate (SDS) micellar solution with three various reducing agents (hydrazine, formalin and ascorbic acid) has been report [2].
Data points shown are averages of three measurements ±SE.
WARSZYŃSKI, PREPARATION OF SILVER NANOPARTICLES VIA CHEMICAL REDUCTION AND THEIR ANTIMICROBIAL ACTIVITY, Physicochem.
Rashid, Green Synthesis of Silver Nanoparticles through Reduction with Solanum xanthocarpum L.