Search Options

Sort by:

Sort search results by

Publication Type:

Publication Type filter

Open access:

Publication Date:

Periodicals:

Periodicals filter

Search results

Online since: June 2012
Authors: Wan Qi Jie, Qi Tang Hao, Qiang Li
,is widely used in the production of large sized complex thin walled castings in aerospace and automotive manufacturing, and other fields [1] because the parts produced by this method are of high quality, low shrinkage porosity, fine grains, etc.
In recent years, with the rapid development of intelligent control technology, as the representative of the control object in a number of complexes, nonlinear, time-varying and large inertia of the system, fuzzy control intelligent control technology has been widely used.
The fuzzy inference rule is if X1 is A1i and X2 is A2i then Y is Bi (3) where X1 and X2 respectively represent the error and error change rate; Y is the opening output; A1, A2 and B are the fuzzy language value; iis the number of statements, as shown in Table 3.
The total number of rules is 49.
Thus, the results of KP (KI and KD are similar) are Rx,y=i-1n(A1i×A2i)×Bi (4) Defuzzification of output The centroid method is used to implement defuzzification, and the value of the fuzzy control output is given by u*=jkjuj/jkj (5) wherej is the rule number.
Online since: January 2020
Authors: Xing Sheng Li, Yong Sun, Hua Guo
Introduction A great number of researches have been conducted on the application of Thermally Stable Diamond Composite (TSDC) in making rock cutting tips [1-7], because TSDC has much higher wear resistance than Tungsten Carbide (WC) [2] and much higher thermal stability than polycrystalline diamond composite (PCD) [3].
The properties of the high thermal stability and wear resistance of TSDC is due to that TSDC is made of synthetic diamond grains using ceramic-based silicon as the binder material during the sintering process [2-3].
Directly estimate the reliability of the tips, R, by calculating the relative frequency of tip failures and using the relationship between the failure probability and reliability: RL=1-FL=ns/Np , (1) where, RL and FL are the reliability and failure probability of the tip after cutting L mm long rock, respectively; ns is the number of the survived tips after cutting L mm long rock and Np is the number of the total tips used in the cutting tests. 3.
Nevertheless, to improve the estimation accuracy, both approaches require a large number of failure data based on accelerated life tests, which are often costly and time-consuming.
Online since: April 2020
Authors: Wei Li, Dong Yang Li, Yu Hao Song, Cheng Liu
At this time, due to the increase in the crystallization rate of amorphous silicon, the number of nanocrystalline Si particles increases and the micro- nanostructures in the surface morphology of the film are mainly clusters of Si nanoparticles (Fig. 2(c)).
At this time, the size of Si particles and the crystallization rate also gradually decrease from the center to the edge of the laser spot area, the grain size of Zone I is 9.2 nm and the crystallization rate is 43.6 %.
When the laser energy is further increased to 600 mJ/cm2, the intensity of Si (111) in the diffraction peak increases to some extent, indicating the number of Si particles increases.
If we continue to apply 600 mJ/cm2 laser energy on a-Si:Al thin film, the crystallization rate of a-Si:Al thin film can further be enhanced, and the number of Si particles increases obviously, while the size of Si particles does not significantly increase (kept at about 10 nm).
It can be understood that with the increase of femtosecond laser energy, the number of crystal silicon particles in a-Si:Al thin film gradually increases, and the refractive index of the thin film as a whole is gradually close to the poly-crystalline silicon, so that the interference peak is gradually suppressed.
Online since: July 2024
Authors: Lucy W. Kariuki, Bernard W. Ikua, Samuel K. Karanja, Stephen P. Ng'ang'a
In their study, two FDM parameters were taken into account, namely, the building direction and the number of contours.
Due to the large number of printing parameters involved in FFF, optimizing the printing parameters for all viable materials using experimental methods would be challenging.
The pseudo grains are comprised of fibres aligned in the same direction.
Illustration of pseudo-grain material modelling for short fibre-reinforced composites Design of the structural models.
This can be attributed to a reduction in the overall number of layers required to build the part, thus less occurrence of thermal gradients between layers.
Online since: June 2009
Authors: Siddhartha Shrivastava, Debabrata Dash
The number of functional foodstuff delivery systems is expected to increase sharply over the next few years.
The word "Kam" means deep purple, and the rice variety is known for its purple stem, leaves and grains.
Using nanotechnology, the scientists changed the colour of the leaves and stems of Khao Kam from purple to green and the grain becomes whitish.
This bar code is essentially a sticker having a number of black and white bars with certain digits written at the bottom.
Lack of finances also limits the number of inspectors that can be employed at these critical control points.
Online since: December 2012
Authors: Yi Lian Li, Telesphore Kabera
The Corey function was used to get the relative permeability for free CO2 phase; krg = (1-Sˆ )2(1-Sˆ 2) (3) S^ = (Sl-Slr)/(1-Slr-Sgr) (4) For the capillary pressure between the two phases the following equation was used: Pcap = -P0([S*]-1/λ – 1)1-λ (5) P0 = √(ø/k) (6) Table 1 Aquifer Properties Used in Flow Simulations Rock grain density (kg m-3) 2600 Aquifer horizontal distance (km) 21 Aquifer nett thickness (m) 110 Porosity (%) 15.4 Formation heat conductivity under fully liquid-saturated conditions (W/m°C) 2.51 Rock grain specific heat (J/kg°C) 920 Aquifer initial temperature (°C) 89 CO2 injection temperature (°C) 45 Aquifer initial pressure (bar) 220 CO2 injection pressure (bar) 270 Salinity (mass fraction) 0.29 Rock compressibility (Pa-1) 4.5 x 10-10 Liquid relative permeability, krl √S*{1-(1-[S*]1/m)m}2, S* = (Sl-Slr)/(1-Slr) Residual water saturation, Srl 0.30 Gas relative permeability, krg (1-Sˆ )2(1-Sˆ 2), S^ = (Sl-Slr)/(1-Slr-Sgr) Residual gas saturation
Figure 5 Gas saturation spatial distribution during CO2 sequestration (Left frames present only injection case, and the right frames represent one injection and two production case) (0.1 cut-off) Results and Discussion As it was mentioned above, while placing production wells, one has to be careful in order to prevent the risk of producing CO2, in order to achieve this, a number of simulations were performed such as placing the production well at a distance of about 7.5km from the injection, this case showed that after 200 years the CO2 mobile migrating horizontally will reach the production but when the distance was increased to about 9.5km from the injection well, even after 700 years the CO2 mobile will not reach the production well ( Figure 5).
As it is shown in figure 6 the effect of shale layers is to retard migration of CO2 mobile phase front normally depending on the number of shale layers.
Online since: May 2012
Authors: Hai Dong Wu, Mei Li Zhou, Hai Fan, Ya Zhang, Tong Lou Ding, Bao Shan Wang
As a result China neither allows cultivating biomass energy plants in crop lands, nor translating crop grains into bio-fuels.
Furthermore, the number of bacteria, salt-tolerant bacteria, and actinomycetes all increased with the application of fertilizers (treatment IV=treatment III>treatment II> control), but the number of salt-tolerant actinomycetes did not change significantly.
Additional fertilizer can be applied at the shooting stage and booting stage, while leaf surface fertilizer can be applied at the grain filling stage to increase sorghum juice Brix.
Online since: July 2011
Authors: Lei Wang, Xue Tao Yuan, Zhi Qiang Hua, Dong Bai Sun, Song Lin Chen
It may lead to settle down and make available smaller number of nano-particles adjacent to the electrode surface for incorporation.
Amorphous alloys offer better corrosion resistance than equivalent polycrystalline materials because of the freedom from grain or grain boundaries and because of the glassy film, which formed on and passivate their surfaces.
The main causes for deterioration of corrosion resistance of NiP-Al2O3 composite coating when the concentration of nano-particles increased from 4 to 10 g/L are: ① with the increase of Al2O3 particles in the composite coating, interface between metal matrix and particles enlarged, the discontinuous interface surrounded particles have interspace, the agglomerates of particles leaded to uneven surface, and the particles had not been effectively covered by NiP alloy; ②a large amount of added Al2O3 nano-particles wedged in and fragmented the original integrated and uniform coating and passive film, enlarging the interface area of coating, increasing interface energy and increasing the number of corrosion microcell.
Online since: January 2019
Authors: Yong Mao, Kai Xiong, Shun Meng Zhang, Ying Jie Sun
(9) In these formulas, h indexes Planck’s constants, k is Boltzmann’s constants, NA indexes Avogadro’s number, ρ is the density, M stands for the mass of unit cell, n is the number of atoms in the unit cell, νm is the averaged elastic wave velocity, νl and νt point to the longitudinal sound velocity and transverse sound velocity.
[4] FuZhi Dai, Yanchun Zhou, Wei Sun, Segregation of solute atoms (Y, Nb, Ta, Mo and W) in ZrB2 grain boundaries and their effects on grain boundary strengths: A first-principles investigation.
Online since: April 2009
Authors: David J. Young, M.A.A. Motin, J. Zhang
The precipitate distributions are consistent with such a process: the precipitate-free zones beneath the scale-metal interfaces and surrounding grain boundaries reflect preferred nucleation at these internal surfaces.
Carbon dissolves in and supersaturates the metal, leading to graphite precipitation at or immediately beneath the surface and at interior grain boundaries.
Assuming the effect of copper is to reduce catalytic activity by replacing nickel, and that each catalytic site involves a number of near neighbours nickel atoms [31-33], then the number of atoms is given by n.
Showing 24491 to 24500 of 28673 items