Search results

In the present study, uniaxial tensile test of aluminum alloy casting containing defects was simulated and analysed, and the effect of types and number of defects on mechanical properties was studied by finite element analysis software.
The number of pores and oxides is in equal portion in the defects d) In order to study the influence of different defects in shape to mechanics properties of aluminum alloy castings, this paper use circular, square and rectangular approximate to simulate the casting defect and establish aluminum alloy casting uniaxial tensile test finite element model under the conditions of the defect rate in 3% based on the statistical results.
Although the number of pores is less than that of oxides based on the simulation results, just as oxides, pores could be observed in Aluminum ally castings with degassing or not.
The oxidation inclusion's increases improve the tensile strength of casting in some way, when the number of pores and oxides is in equal portion in the defects, along with the increase of the defect, the tensile strength of casting increases slightly.
SIMULATION OF COARSE-GRAINED LY-12 QUASI-SUPERPLASTIC UNIAXIAL TENSION.

The number of survival bacteria after treatment was evaluated with spread plate techniques.
The number of survival bacteria after treatment was evaluated with the spread plate technique.
After colonies are grown, they are counted and the number of bacteria in the original sample is calculated.
The number of viable bacteria was determined by using the spread plate technique after passing through reactor of each cycle.
The survival rating of E. coli was determined by counting the number of viable cells in terms of CFU.

Let us turn to formula (8), which describes the magnitude of the fluctuations of the number of nuclei.
Calculating the number of these nuclei and predicting their future lives is the purpose of the kinetic theory of new phase nucleation.
The quantity i is understood here as the number of structural units of the old phase.
Let the temperature , and (i.e. the pore is semi-spherical and form on the boundary grain).
Rice, et al., Non-equilibrium models for diffusive cavitation of grain interfaces, Acta Met. 27 (1979) 265-284

The changing contact conditions result in a varying number of transmission points of the grinding force, which leads to a different tool load.
If the number of contact points located on the left and right flanks is even, a substantially uniform distribution of force is present.
If the number of contact points is odd, an uneven distribution of forces occurs and can lead to a characteristic profile-form deviation [1].
The number of contact points depends on workpiece normal module mn, number of teeth z, normal pressure angle αn and helix angle β as well as on the geometry and size of the grinding worm.
The hypothesis can be made that more sharp grains are used to machine the same material volume, which potentially results in a more effective cut with less friction and thus less power is consumed during grinding.

The flood and drought disasters are evaluated by LiuYaBin etc. in China's major grain producing areas[6].From the perspective of system theory, this paper considerate the interaction mechanism of disaster-inducing factors, hazard inducing environment and hazard-affected body comprehensively.
Serious flooding disasters often cause large areas of farmland and crops have been destroyed, and a large number of cultivated lands also had been destroyed.
For larger relief amplitude area, the secondary disasters such as landslides and debris flows caused by tiny change of underlying surface factors, destroying a large number of cultivated land.
Acknowledges: This work is supported by the special fund of the Ministry of Land and Resources of the PRC (Project Number: 201311002-01).
Risk assessment of flood and drought in major grain-producing areas based on information diffusion theory [J].

AWJ subsurface, as well as common machined features such as grain deformation, possess certain characteristics linked to the AWJ process which have been less explored.
The mathematical model, presented as regression coefficients in Fig. 1 had a good experimental design with a condition number of 1.15, an excellent fit as indicated by the R2 parameter (0.900) and a very good prediction power with a high Q2 (0.817).
A fast traverse rate does not allow the jet of water to penetrate the material and minimises the number of particles that strike the material, increasing the kerf width at the bottom of the sample.
The mathematical model had a good experimental design as evaluated by the low condition number (2.28), a very good fit (R2=0.859) and good prediction power (Q2=0.572).
Acknowledgement The authors acknowledge the support of the European Commission through the 7th Framework Programme Transport (including Aeronautics) Call, Project number 234325 - ADMAP-GAS.

Step 4: auxiliary iterative localization If the number of anchors within two hops of an unknown node is less than 3, the unknown node cannot be localized directly.
IF the number of anchor nodes≥3 THEN 13.
IF the number of beacons(include anchor nodes and localized nodes) ≥3 THEN 27.
The number of anchors is 20; we take the latter 20 nodes as anchors.
Srivastava: Dynamic fine-grained localization in ad-hoc networks of sensors, in ACM MOBICOM(2001) 166-179

We can see from this micrograph that the Zn-Al solder rigidly joined the SiC die to the Cu foil without any cracking and that an off-eutectoid structure containing big hcp-Zn grains formed in the solder layer, as expected from the Zn-Al binary phase diagram [6].
Fig. 6 The results of a thermal cycle test between –40°C and 200°C where the average shear strength is plotted as a function of the number of cycles.
Figure 6 shows the results of the thermal cycle tests, with the change in the average shear strength plotted as a function of the number of cycles.
Although the shear strength gradually declined with an increasing number of cycles, our attachment maintained a sufficient and acceptable strength level of 78 MPa even after 1500 cycles.
A considerable number of cracks and their length can be seen in the Zn-Al solder layer.

The quality of information is related to the possibility of focusing within a certain depth of field, which provides acquiring images in such a way that cells approach the volumic dimension; the higher accuracy of data is reflected in the lower standard deviations, for a similar number of measurements.
When the images are acquired by an electron microscope the grey levels represent either surface topography (secondary electron images) or phases with different mean atomic numbers (backscattered electron images); therefore electronic signals make it possible to discriminate a wider range of materials and/or features within a sample [3].
For this purpose, several parallel lines (equally spaced by 0.35 mm) were superposed on the micrographs and the number of cell walls intersected by unit length, PL, was determined.
Most cells possess faces with five edges and a number of closed faces, suggesting that they can be classified as semiclosed-cell type foams.
Vander Voort: Grain Size Measurement, in “Practical applications of quantitative metallography”, Ed.

After water toughening treatment at 1050℃, the organization of the manganese steel is even austenitic grains, the hardness reaches to 170 ~ 230HB.
The emerging of a large number of high-density twins decrease the casting defects such as gas holes and so on.
(a) (b) (c) (d) (e) (f) Fig.1 Typical microstructure of high manganese steel before and after asynchronous rolling a) structure with water toughening treatment b) with 8.51% cold rolling c) with 15.25% cold rolling d) with 18.83% cold rolling e) with 22.48% cold rolling f) with29.63% cold rolling It can be seen from Figure 2 that: in the small deformation case, a lot of flat deformation zone and deformation twins appear in the organization, dislocation configuration performance is the flat band; with deformation increase, the twins number increase significantly; when the deformation reaches a certain level, the organization appears stacking faults and twins crossing fracture or serious distortion and crystal division.
With the increase of deformation, a large number of high density deformation twins appear.
(3) After asynchronous rolling, a large number of high-density twins appear in the organization of the high manganese steel, which not only decrease gas holes and other casting defects, but also greatly improved the hardening performance.