Search results

In the present work, the effects of reinforcement type, reinforcement surface treatment, alloying additions, remelting time and remelting number upon the chemical and property degradations of discontinuously reinforced Al matrix composites, are investigated by means of Differential Scanning calorimeter (DSC), Transmission Electron Microscopy (TEM) and thermodynamic calculations.
Understanding the factors that influence the physical and mechanical properties of these materials presents quite a challenge, because these are sensitive to the type of reinforcement, the mode of manufacture, the recycling history and the detailed remelt-recycling parameters of the composite such as remelting temperature, holding time and number of times of recycling.
Otherwise, the control of remelt-processing parameters of the SiCp/Al composites with a certain mount of silicon content in master alloy, using the kinetics expressions, can be suitably achieved. 2.1.4 Effect of Remelting Tempaerature and Remelting Run Numbers Fig.4 and Fig.5 show the DSC heating trace of SiCp/pure Al composites remelted at 750 oC and SiCp/Al-8Si composites remelted at 1050 oC, respectively [11].
Later these crystals coalesced and formed aggregates of minute Al4C3 that precipitated near the interfacial zone, or were pushed to the grain boundary by the solidification front [11]. 2.3 Mechanical Property Evolution The particular microstructure in remelted SiCp/pure Al composites has two important consequences due to the formation of the reaction product Al4C3, it not only decreases the resistance of the material to the erosion process, but also reduces the material' s mechanical propertie.
It should be also noted that, unlike SiC, which is stable below the solidus, this is not the case for Al2O3, and reaction can continue in the solid state. 3.2 Mechanical Property Evolution The former results indicated that the tensile and fracture toughness behavior of the subsequently extruded and heat treated Al2O3/Al MMC is essentially unaffected by the number of times the material is recycled [1,2]. 4.

Microstructures of Ti-29Nb-13Ta-4.6Zr (TNTZ) aged at temperatures between 573 and 723 K after solution treatment at 1063 K have super fine omega phase, or� both super fine alpha and omega phases, respectively in beta phase with an average grain diameter of 20 µm.
Stress-fatigue life (the number of cycles to failure) curves, that is, S-N curves, obtained from plain fatigue tests on cold-rolled and forged Ti-29Nb-13Ta-4.6Zr (TNTZ), and forged Ti-15Mo-5Zr-3Al (Ti1553) S-N curves of cold-rolled and forged Ti-29Nb-13Ta-4.6Zr, and forged Ti15Mo-5Zr-3Al conducted with various heat treatments obtained from plain fatigue tests.
Maximum cyclic stress㧘�max / MPa Number of cycles to failure㧘Nf 105 106 107 104 300 400 500 600 700 800 900 300 400 500 600 700 800 900 : ST (CRP) and ST (FB) : ST (CRP) + 673K, 259.2ks : ST (CRP) + 573K, 259.2ks : ST (CRP) + 598K, 259.2ks : ST (FB) + 723K, 172.8 ks : Annealing (FB) Ti-29Nb-13Ta-4.6Zr Ti-15Mo-5Zr-3Al : ST (CRP) and ST (FB) : ST (CRP) + 673K, 259.2ks : ST (CRP) + 573K, 259.2ks : ST (CRP) + 598K, 259.2ks : ST (FB) + 723K, 172.8 ks : Annealing (FB) Ti-29Nb-13Ta-4.6Zr Ti-15Mo-5Zr-3Al Fig. 1 Low cycle fatigue life region High cycle fatigue life region Journal Title and Volume Number (to be inserted by the publisher) conducted with various heat treatments in air are shown in Fig. 1.
Hasegawa, Tensile Properties and Cyto-toxicity of New Biomedical � Type Titanium alloys, Tetsu-to-Hgane, 86(2000), p40 0 100 200 300 400 500 600 104 Maximum cyclic stress, �max / MPa S-N curve of forged Ti-29Nb-13Ta4.6Zr conducted with ST obtained from plain and fretting fatigue tests in air and Ringer’s solution. 105 106 107 Number of cycles to failure, Nf Ti-29Nb-13Ta-4.6Zr: ST (FB) Solid symbol: in air Open symbol: in Ringer’ solution Fig. 4 : Fretting fatigue : Plain fatigue Low cycle fatigue life region High cycle fatigue life region 0 100 200 300 400 500 600 104 Maximum cyclic stress, �max / MPa S-N curve of forged Ti-29Nb-13Ta4.6Zr conducted with ST obtained from plain and fretting fatigue tests in air and Ringer’s solution. 105 106 107 Number of cycles to failure, Nf Ti-29Nb-13Ta-4.6Zr: ST (FB) Solid symbol: in air Open symbol: in Ringer’ solution Fig. 4 : Fretting fatigue : Plain fatigue Low cycle fatigue life region
High cycle fatigue life region Journal Title and Volume Number (to be inserted by the publisher) [5] M.

Use of statistical methods is intrinsic characteristics of the random process, the various kinds of statistical method orthogonal design is a kind of very effective, because the orthogonal design with the overall dispersion, comparability and equilibrium in a balanced match between experiment factors at the same time, and greatly reduced the number of test process, at the same time to maximize access to information.
Table2-2 The tested factors and levels of L9(34) Level Factor Aggregate Polystyrene fiber mixing amount [%] PNF expanding agent mixing amount [%] Water reducing agent mixing amount [%] 1 Clastic rock 0 0 0.2 2 Recycled aggregate 0.4 6 0 3 Cobblestone 0.7 9 0.4 Table 2-3 Design of orthogonal test Number Column Number Aggregate Polystyrene fiber mixing amount [%] PNF expanding agent mixing amount [%] Water reducing agent mixing amount [%] 1 1 [Clastic rock] 1（0.7%） 1（0%） 1（0.2%） 2 1 [Clastic rock] 2（0.4%） 2（6%） 2（0%） 3 1 [Clastic rock] 3（0%） 3（9%） 3（0.4%） 4 2[Recycled aggregate] 1（0.7%） 2（6%） 3（0.4%） 5 2[Recycled aggregate] 2（0.4%） 3（9%） 1（0.2%） 6 2[Recycled aggregate] 3（0%） 1（0%） 2（0%） 7 3[Cobblestone] 1（0.7%） 3（9%） 2（0%） 8 3[Cobblestone] 2（0.4%） 1（0%） 3（0.4%） 9 3[Cobblestone] 3（0%） 2（6%） 1（0.2%） Experiment of raw materials.
Namely the first j column factor level for b, the test times for a (rows), if the number of repeat each level for r, then a = br.
The analysis results of the compressive strength range Table 2-10 L9（34） The result of Compressive strength Sequence number Factor Compressive strength A B C D Compressive strength actual measurement X2 1 1 1 1 1 26.80 718.2400 2 1 2 2 2 25.00 625.0000 3 1 3 3 3 27.50 756.2500 4 2 1 2 3 30.90 954.8100 5 2 2 3 1 31.20 973.4400 6 2 3 1 2 29.60 876.1600 7 3 1 3 2 25.00 625.0000 8 3 2 1 3 22.00 484.0000 9 3 3 2 1 23.20 538.2400 yj1 26.43 27.57 26.13 27.07 ∑y2i=6551.14 yj2 30.57 26.07 26.37 26.53 yj3 23.40 26.77 27.90 26.80 RJ 12.4 4.5 5.3 1.6 Optimal level A2 B1 C3 D1 Primary and secondary factor Optimal combination A2 C3 B1D1 By the poor analysis available: recycled concrete compressive strength was slightly better than those of normal concrete; Same ratio under the condition of same grain size distribution in strength of recycled aggregate concrete, gravel, pebbles; Fiber strength when the dosage is 0.7%; Factors in primary and secondary analysis of four
Conclusion In this paper, through experimental analysis in the same mixture ratio under the condition of compressive strength of recycled concrete is slightly higher than that of natural aggregate strength; Same ratio under the condition of same grain size distribution in strength of recycled aggregate concrete, gravel, pebbles; Fiber strength when the dosage Is 0.7%.

Use a plate colony counting technique, the influence of ipt rice plants on bacteria number of rhizospheric soil was investigated.
Introduction Rice is the second most important cereal grain next to wheat in the world.
The numbers of bacterial were determined as colony-forming units (CFU) on a beef-extract-peptone medium containing 10 g NaCl, 3 g beef extract, and 10 g peptone per liter.
But the non-ipt control had a higher CFU number (91.33) than ipt rice from T8 transgenic progeny in filling stage (57.67) (Figure 2).
Bacterial colonies were presented by the means of soil bacterial number on the plates.

It was figured out that Central Composite Design (CCD) was suitable to be used to save the number of experimental runs.
Generally, the number of sand types and resin types in each formulae is up to 3 types.
Sand Type %Si Brightness (Lux) pH Roundness AFS Grain Size Cost per kg. ($) Phenolic Resin Type Flow Length (mm.)
DOE requires necessary number of experimental runs, thus helps reduce experimental cost and time.
Thus, the number of independent variables was 5 instead of 7.

It was established that a decrease in the coefficient of friction from 0.9 to 0.6 leads to a decrease in the number of foci and areas of contact stresses, as well as temperature analysis showed that a decrease in the friction forces reduces heat transfer in the cutting zone by about 40 ° C.
The parameters of dividing the workpiece model into finite elements were chosen so as to ensure sufficient mesh accuracy and, therefore, the accuracy of calculations in the deformation zone with a minimum number of elements (to ensure an acceptable calculation speed).
The total number of elements is relatively small, about 80,000.
For this, the program has a choice of several sets of material properties data that can be modeled and analyzed: • Plastic properties of materials • Elastic properties of materials • Thermal processing data • Diffusion data • Grain growth or recrystallization model • Data on the hardness of materials • Material fragility data These parameters make it possible to specify the required output values ​​of the simulation, which increases the accuracy of the obtained data and reduces the time of their calculation.
Radial and axial deformations were determined directly in the sections with the marked numbers in Figure 12, by the controlled nodal points in each section, circumferential deformations were calculated by the change in the radii of the points [6].

The resulting product is angular in nature, lending itself to cold pressing, where the irregular morphology promotes interlocking between individual grains to limit voidage.
It is reported the retained hydrogen aids densification [11], whilst refining and generating an ultrafine grain (UFG) microstructure, leading to improved mechanical properties [11].
A considerable number of these are devoted to transforming Kroll/Hunter into a continuous process, i.e.
A number of techniques are under consideration by various parties, being reviewed in (Table 3).
Following the success of this preliminary proof of concept, a number of demonstration parts were fabricated, applicable to a range of industrial sectors.

The conditions for obtaining highly mobile self-compacting concrete mixtures, in addition to the use of chemical additives, is a combination of such parameters as: • granulometric composition of the filler, providing a uniform volumetric distribution of particles by fractions; • the volume of cement paste, providing the necessary extension of the filler grains; • water content ensuring the fluidity of the system while maintaining sedimentation stability.
The sand should be round, the presence of needle grains is not allowed, as in their presence there may be problems with the mobility of the concrete mixture and its accelerated thickening.
When selecting the composition of the self-compacting concrete mixture, it should be borne in mind that the volume of the cement paste should be greater than the volume of voids, so that the grains of the large aggregate are completely surrounded by a layer of cement paste.
During the construction of the metro using self-compacting concrete, it was possible to reduce the number of concreters by 12 people, improve the quality of work and reduce the construction time.
Discussion and Conclusion Experience concreting of tunnels under the pre-routed tunnels proved very effective, greatly reduce the turnaround time and ensure high quality, reduce the number of concrete during concrete placement.

Since the waste was disposed of directly onto the alluvial sediments, a number of contaminants were shown to penetrate efficiently through the soil strata and eventually reach the groundwater system.
In the other words, Atterberg limits are important to describe the consistency of fine-grained soils or help to identify the state of soil [20].
The result of grain-size analysis showed that the soil consisted of 47.71% sand, 31.3% silt and 6.13% clay with the rest to be classified as gravel of 14.87%.
From the analysis, it clearly illustrated that the grain size of the local soil was silty sand which was closely with the result from previous study [25].
Basic properties of local soil at landfill Properties Results Moisture content 18.7 pH 4.45 Organic content (%) 0.41 Carbon content (%) 0.14 Atterberg limits (%) - Liquid limit 67.5 - Plastic limit 16.93 - Plasticity index 50.57 Specific gravity (N/m3) 2.33 Specific surface area (m2/g) 22.8 Cation exchange capacity (meq/100g) 3.15-3.19 Particle size distribution (%) - Sand ( > 0.063 mm) 47.7 - Silt (0.063 – 0.002 mm) 31.3 - Clay ( < 0.002 mm) 6.13 Heavy metal content mg/L (Background data) - As 0.43 - Cd 0.08 - Cr 0.23 - Cu 0.05 - Fe 14.7 - Mn 0.66 - Ni 0.03 - Pb 0.57 - Zn 2.56 Figure 6 present the percentage transmission (%T) in y-axis for various wave numbers in x-axis, cm-1 given by the FTIR spectrum of the soil.

The carbon appears to take shape of disordered amorphous or graphite-like layers surrounding the Ni3C or the evolving fcc nickel grains, respectively [4,5].
Right side: Prepared plug targets, number of plugs and the Ni:C surface ratios, which were achieved.
In case of XRD for example the signals overlap with that of the hexagonal nickel, if the Ni3C-grains are too small [17].
This is most probably caused by the decreasing grain size coming along with the expansion of the nickel lattice due to the incorporation of carbon (Fig. 5).
In the spectral range from 150 to 1150 cm1 a number of peaks can be observed.