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Online since: September 2013
Authors: Li Zhou, Hui Jie Liu, Duo Liu, Lin Zhi Wu
A large number of researches have been focused on the effect of hydrogen as an alloying element on phase compositions, development of metastable phases, and kinetics of phase transformations in titanium alloys.
The Ti-6Al-4V-0.1H alloy also shows a simple XRD pattern of HCP α phase and BCC β phase, but the number and intensity of β phase peak increase (Fig. 2b).
The δ hydride decomposes and fine recrystallized α grains are formed, but δ hydride also precipitates in βH phase of Ti-6Al-4V-0.5H alloy and fine recrystallized α grains are developed in transformed β of dehydrogenated Ti-6Al-0.5H alloy.
The Ti-6Al-4V-0.1H alloy also shows a simple XRD pattern of HCP α phase and BCC β phase, but the number and intensity of β phase peak increase (Fig. 2b).
The δ hydride decomposes and fine recrystallized α grains are formed, but δ hydride also precipitates in βH phase of Ti-6Al-4V-0.5H alloy and fine recrystallized α grains are developed in transformed β of dehydrogenated Ti-6Al-0.5H alloy.
Online since: July 2004
Authors: Marcello Baricco, Mauro Palumbo
Modelling
The homogeneous nucleation frequency of crystals (I
s
) in a liquid (amorphous) matrix can be
obtained from [6]:
−
=
RT
G
exp
aND
I
*
2 vns ∆
(1)
where Dn is a diffusion coefficient for nucleation, Nv is the number of atoms per unit volume, a is
the atomic radius, T is the temperature and R is the gas constant.
Hopfler et al. [18] have measured the diffusion of B in FeB grain boundaries.
Lacking data of B diffusion in an amorphous alloy and because grain boundaries can be considered as a twodimensional model for an amorphous phase [19,20], these data have been used for B diffusion in the amorphous matrix.
Because of the huge number of intermetallic compounds in the binary and in the ternary systems, a full assessment of the Al-NiCe system is not yet available.
Hopfler et al. [18] have measured the diffusion of B in FeB grain boundaries.
Lacking data of B diffusion in an amorphous alloy and because grain boundaries can be considered as a twodimensional model for an amorphous phase [19,20], these data have been used for B diffusion in the amorphous matrix.
Because of the huge number of intermetallic compounds in the binary and in the ternary systems, a full assessment of the Al-NiCe system is not yet available.
Online since: September 2018
Authors: Sergei A. Kitan, Nikolay G. Galkin, Konstantin Nickolaevich Galkin, Sergei Andreevich Dotsenko, Evgeniy Anatolievich Chusovitin, Dmitrii L. Goroshko
The film consists of contacting grains of round shape with a diameter up to 15 nm.
Sample Sn concentration [%] Film thickness [nm] Composition Root-mean-square roughness [nm] A 0 213 α-Si 0.32 B 14 604 Si1-xSnx 1.36 C 19 285 Si1-xSnx 0.43 D 17 261 Si1-xSnx 0.32 E 40 336 Si1-xSnx+β-Sn 26.8 F 20 270 Si1-xSnx 0.23 At the 604 nm thickness of grown Si-Sn film (sample B), the rms roughness increased to 1.36 nm, which indicates the coagulation processes of individual grains in the film (from 15 nm to 30 nm) and increasing their height.
It is believed that a large number of broken bonds on the boundaries of nanocrystals form a high density in the tails of states of the silicon band gap.
This indicates an increase in the number of silicon crystallites with dimensions of 8-10 nm, but not an increase in the average size of the silicon crystallite.
Sample Sn concentration [%] Film thickness [nm] Composition Root-mean-square roughness [nm] A 0 213 α-Si 0.32 B 14 604 Si1-xSnx 1.36 C 19 285 Si1-xSnx 0.43 D 17 261 Si1-xSnx 0.32 E 40 336 Si1-xSnx+β-Sn 26.8 F 20 270 Si1-xSnx 0.23 At the 604 nm thickness of grown Si-Sn film (sample B), the rms roughness increased to 1.36 nm, which indicates the coagulation processes of individual grains in the film (from 15 nm to 30 nm) and increasing their height.
It is believed that a large number of broken bonds on the boundaries of nanocrystals form a high density in the tails of states of the silicon band gap.
This indicates an increase in the number of silicon crystallites with dimensions of 8-10 nm, but not an increase in the average size of the silicon crystallite.
Online since: July 2004
Authors: Andrzej Calka, David Wexler
The effect of spark discharge milling condition on
particle size and surface morphology was investigated for a number of different materials including;
alumina, NiZr, Ni plus Si, Mg-Zn alloy of eutectic composition, and FeSiB metallic glass ribbons.
and is little literature on materials processing under conditions which predominantly involved arc discharges, although there is much interest in a related technique involving consolidation of fine grained and nanostructural powders under an arc discharge [4-6].
For small amplitude vibrations, the number fraction of fine particles increased with increasing amplitude (Fig. 2(b) and Fig 2(d)).
Journal Title and Volume Number (to be inserted by the publisher) 7 In hexagonal alumina, fracture was significantly speeded up compared with milling without electrical discharge.
For vibrational amplitudes of 0.4mm and 0.6 mm the number fraction of fine particles increased with increasing amplitude, however, doubling this amplitude to 1.2 mm resulted in agglomeration and increases in average particle size.
and is little literature on materials processing under conditions which predominantly involved arc discharges, although there is much interest in a related technique involving consolidation of fine grained and nanostructural powders under an arc discharge [4-6].
For small amplitude vibrations, the number fraction of fine particles increased with increasing amplitude (Fig. 2(b) and Fig 2(d)).
Journal Title and Volume Number (to be inserted by the publisher) 7 In hexagonal alumina, fracture was significantly speeded up compared with milling without electrical discharge.
For vibrational amplitudes of 0.4mm and 0.6 mm the number fraction of fine particles increased with increasing amplitude, however, doubling this amplitude to 1.2 mm resulted in agglomeration and increases in average particle size.
Online since: October 2010
Authors: Lei Wang, Dong Sheng Li, Jin Ping Ou
Regional Panel Report
].In recent years, with increasing numbers of implementations of SHMS, more researchers have realized the significant temperature effect, which even affect more than traffic load.
Fig. 5 Temperature sensor on Dongying Yellow River Bridge Fig. 6 Optical sensing interrogator SM125 Table. 1 Temperature sensors integrated into monitoring system Section number 3 7 11 12 17 18 20 26 28 Sensors on upper-bridge t2, t3 t3, t4 d4, d13, d18 d7, d11 d15, d18 t3, t4 d7, d11, d15 t3 d16, t1, t3 Sensors on down-bridge t3, d12 d4, d10, d14, d18 d1, d11, d15 d8, d11, d15 t2, t3, t4 d5, d10, d14, d18 d16 d15 Table. 2 Dimensions of cross sections integrated with temprature sensors Section number 3 7 11 12 17 18 20 26 28 Average height of section[cm] 806.9 428.5 657.9 412.5 610.7 1056 624 412.5 414.9 Web thickness[cm] 70 50 50 50 50 70 50 50 50 Bottom slab thickness[cm] 75 32 35 32 32 75 32 32 32 Temperature distribution of DYRB Temperature history at different sections of DYRB.
Also, the top slab is covered by a 17cm thick pavement consisted by 4cm modified asphalt concrete face layer, 5cm thick median grain concrete and 8cm thick waterproof concrete, which reduce thermal conduction in the top slab.
Acknowledgement This work has been supported by the Key Projects in the National Science & Technology Pillar Program during the Eleventh Five-Year Plan Period, numbered 2006BAJ03B05, and named Health Monitoring and Diagnosis Technology of Major Buildings and Structures.
Fig. 5 Temperature sensor on Dongying Yellow River Bridge Fig. 6 Optical sensing interrogator SM125 Table. 1 Temperature sensors integrated into monitoring system Section number 3 7 11 12 17 18 20 26 28 Sensors on upper-bridge t2, t3 t3, t4 d4, d13, d18 d7, d11 d15, d18 t3, t4 d7, d11, d15 t3 d16, t1, t3 Sensors on down-bridge t3, d12 d4, d10, d14, d18 d1, d11, d15 d8, d11, d15 t2, t3, t4 d5, d10, d14, d18 d16 d15 Table. 2 Dimensions of cross sections integrated with temprature sensors Section number 3 7 11 12 17 18 20 26 28 Average height of section[cm] 806.9 428.5 657.9 412.5 610.7 1056 624 412.5 414.9 Web thickness[cm] 70 50 50 50 50 70 50 50 50 Bottom slab thickness[cm] 75 32 35 32 32 75 32 32 32 Temperature distribution of DYRB Temperature history at different sections of DYRB.
Also, the top slab is covered by a 17cm thick pavement consisted by 4cm modified asphalt concrete face layer, 5cm thick median grain concrete and 8cm thick waterproof concrete, which reduce thermal conduction in the top slab.
Acknowledgement This work has been supported by the Key Projects in the National Science & Technology Pillar Program during the Eleventh Five-Year Plan Period, numbered 2006BAJ03B05, and named Health Monitoring and Diagnosis Technology of Major Buildings and Structures.
Online since: July 2011
Authors: Wen Bo Tang, Yun Gang Guo, Hon Grui Wang
Table 1: Chemical composition (wt %) of materials used
Number
C
Cr
Nb
Mo
Si
Mn
Ti
Ni
V
P
S
A
2.00
17.4
-
-
4.09
2.80
0.11
0.11
0.06
0.13
0.01
B
0.61
2.37
1.54
0.59
1.29
1.17
0.6
06
-
0.02
0.01
H08A
≤0.10
≤0.20
-
-
≤0.30
0.30~0.5
-
≤0.30
-
≤0.03
≤0.03
Q235
0.15
-
-
-
0.30
0.30
-
-
-
0.050
0.045
The hardfacing alloys were deposited by shielded manual arc welding (SMAW) under direct current with a reverse polarity.
In the procedure, the carbide size, the substrate's distribution and the grain size are discussed.
(Modle:ML-100,CHINA) Table 2: Parameters of abrasive wear test Diameter of wheel [mm] Speed of rotation [rpm] Sliding distance [m] radial feed [mm/ r] 260 60 250 1 Table 3: The hardness of hardfacing layer and result of wearability test Number HRC Mass loss [g] Relative wear resistance Load/20 N Load/30 N Load/40 N A 56.4 0.0633 0.0889 0.1189 1 B 59.7 0.0396 0.0523 0.0712 1.7 Results and Discussion The characterization of microstructure has been studied with optical microscopy after etching with the admixture of nitric acid and alcohol.
In the SEM image of Fig. 3, it can be seen more clearly that there are a number of small white particles with sizes about 5–10μm embedded in the layer.
In view of the foregoing, the developed hardfacing deposits of the Fe–Cr–C–Nb/Ti system can be said to have improved wear resistance when the number of NbC increase.
In the procedure, the carbide size, the substrate's distribution and the grain size are discussed.
(Modle:ML-100,CHINA) Table 2: Parameters of abrasive wear test Diameter of wheel [mm] Speed of rotation [rpm] Sliding distance [m] radial feed [mm/ r] 260 60 250 1 Table 3: The hardness of hardfacing layer and result of wearability test Number HRC Mass loss [g] Relative wear resistance Load/20 N Load/30 N Load/40 N A 56.4 0.0633 0.0889 0.1189 1 B 59.7 0.0396 0.0523 0.0712 1.7 Results and Discussion The characterization of microstructure has been studied with optical microscopy after etching with the admixture of nitric acid and alcohol.
In the SEM image of Fig. 3, it can be seen more clearly that there are a number of small white particles with sizes about 5–10μm embedded in the layer.
In view of the foregoing, the developed hardfacing deposits of the Fe–Cr–C–Nb/Ti system can be said to have improved wear resistance when the number of NbC increase.
Online since: December 2012
Authors: Zhi Gang Wen, Shan Li, Chun Xiao Fan, Jun Wei Zou, Xiao Ying Zhang
A number of projects and research [3]-[7] have developed building control applications.
The Building Control Prototype System In designing a building control prototype system based on wireless sensor-actuator networks, we had a number of design goals that we were trying to accomplish.
To improve the network layer routing algorithm, we reduce the redness of information and forwarding number to control the network routing status as much as possible, based on the update frequency of the network and signal quality.
When the number of retransmissions is more than 10 times, the packet is discarded and the next packet is transported immediately.
Deborah: “Fine-grained network time synchronization using reference broadcasts”, The 5th Symposium on Operating Systems Design and Implementation (2002).
The Building Control Prototype System In designing a building control prototype system based on wireless sensor-actuator networks, we had a number of design goals that we were trying to accomplish.
To improve the network layer routing algorithm, we reduce the redness of information and forwarding number to control the network routing status as much as possible, based on the update frequency of the network and signal quality.
When the number of retransmissions is more than 10 times, the packet is discarded and the next packet is transported immediately.
Deborah: “Fine-grained network time synchronization using reference broadcasts”, The 5th Symposium on Operating Systems Design and Implementation (2002).
Online since: April 2023
Authors: R.K. Zhdanov, Y.Y. Bozhko, V.R. Belosludov, K.V. Gets
Sea water contain a number of different salts dissolved: NaCl, KCl, etc.
This approach gives reliable data but could fail for complex multi-component systems with different number of guests molecules involved.
MD methods of calculating are time consuming and only the very limited number of points could be obtained at reasonable time especially when temperature dependence is also required.
Acknowledgments The reported study was funded by RFBR and MOST, project number 21-52-52001.
Zajcev, Effective Fine-Grained Concrete with High-Dispersed Additive Based on the Natural Mineral Wollastonite, FarEastСon - Materials and Construction: Materials International Scientific Conference «FarEastCon». 945 (2018) 85-90
This approach gives reliable data but could fail for complex multi-component systems with different number of guests molecules involved.
MD methods of calculating are time consuming and only the very limited number of points could be obtained at reasonable time especially when temperature dependence is also required.
Acknowledgments The reported study was funded by RFBR and MOST, project number 21-52-52001.
Zajcev, Effective Fine-Grained Concrete with High-Dispersed Additive Based on the Natural Mineral Wollastonite, FarEastСon - Materials and Construction: Materials International Scientific Conference «FarEastCon». 945 (2018) 85-90
Online since: September 2020
Authors: Khairul Anuar Shariff, Shah Rizal Kasim, Lynette Wei Ling Chan, Muhammad Syahir Juhari
Decreasing bulk density value of this specimen is most likely due to the increase in the number and/or size of closed pores in the porcelain body due to bloating effect [10].
As mentioned that during final stage of sintering, the remaining open pores are transformed into closed pore by grain growth or presence of a small amount of liquid phase [10].
As a general trend of Fig. 4, it shows that the increase of the firing temperature involves in decreasing of number of pores and at the same time increase in the thermal conductivity of the fired tiles.
At the same time, C1 specimen fired at 1150 °C shows lowest thermal conductivity due higher number of pores (higher water absorption).
This low thermal conductivity was contributed by high number of pores formation which trapped air that can inhibits the heat to flow throughout the ceramic tile body as well as low bulk density.
As mentioned that during final stage of sintering, the remaining open pores are transformed into closed pore by grain growth or presence of a small amount of liquid phase [10].
As a general trend of Fig. 4, it shows that the increase of the firing temperature involves in decreasing of number of pores and at the same time increase in the thermal conductivity of the fired tiles.
At the same time, C1 specimen fired at 1150 °C shows lowest thermal conductivity due higher number of pores (higher water absorption).
This low thermal conductivity was contributed by high number of pores formation which trapped air that can inhibits the heat to flow throughout the ceramic tile body as well as low bulk density.
Online since: April 2015
Authors: Sheng Quan Dong, Yan Feng Liang, Gao Hong Li
The quality of adhesion was ranked by different numbers ranging from 0 to 5 according to GB/T9286 (eqv.
One can rank the cross-cut adhesion number as excellent (0), very good (1), good (2), moderate (3), poor (4), and very poor (5).
The porosity of each coating was examined by submerging the sample in an aqueous solution containing 10g/L sodium chloride, 100g/L ethanol, and 0.01g/L phenolphthalein, and determining the number of red spots formed in the pores due to the chemical reaction between the solution and the composite substrate.
The porosity is expressed in terms of the number of red spots per square centimeter.
Here, the amorphous structure was free from crystal defects such as grain boundaries and dislocations.
One can rank the cross-cut adhesion number as excellent (0), very good (1), good (2), moderate (3), poor (4), and very poor (5).
The porosity of each coating was examined by submerging the sample in an aqueous solution containing 10g/L sodium chloride, 100g/L ethanol, and 0.01g/L phenolphthalein, and determining the number of red spots formed in the pores due to the chemical reaction between the solution and the composite substrate.
The porosity is expressed in terms of the number of red spots per square centimeter.
Here, the amorphous structure was free from crystal defects such as grain boundaries and dislocations.