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Table 1 Dimensions and initial temperatures of the workpiece and extrusion tooling Billet length [mm] 812 Reduction ratio 19.6 Billet diameter [mm] 202 Billet temperature [°C] 450 Container insider diameter [mm] 203 Tooling temperature [°C] 400 Container outside diameter [mm] 360 (a) (b) Fig. 1 (a) Cross section of the rectangular hollow profile with the shaded area selected for FE simulation and (b) porthole die used to produce the profile.
The flow stress-strain data of the AA7020 alloy determined from hot compression tests at temperatures from 250 to 575 °C and strain rates from 0.01 to 100 s -1 and then corrected for deformational heating [4] were used as the input data of the workpiece material.
At this stage, the reduction ratio is quite low, only 2.25.

The same trend of roughness reduction was noticed with specimen ´s3´ where, Ra 3=0.74 µm and Rz 3= 4.73 µm were obtained.
(b) Specimen ´s0 ´, 1. scan, after cutting -15 -10 -5 0 5 0 1000 2000 3000 4000 5000 6000 7000 8000 X axis (µm) Y axis (µm) Specimen ´s4´, 1. scan, after LSP -20 -10 0 10 20 0 1000 2000 3000 4000 5000 6000 7000 8000 X axis (µm) Y axis (µm) (a) pQ Psw ⋅≅ 02.1 (1) The optimum pressure Psw in LSP is determined by the Hugoniot Elastic Limit (HEL), which is calculated from dynamic yield strenght σy dyn and Poisson number ν, using the equation [7]: MPa MPa HEL dyn y 6.630 )66.01( 320)33.01( )21( )1( = − ⋅− = − ⋅− = ν σν (2) From the data above it can be inferred that the Hugoniot elastic limit with shock stresses is much higher than the yield strenght of the precipitation-hardened aluminium alloy (σy dyn =320 MPa).
On the basis of the data on strains with individual drilling increments the principal residual stresses were calculated
The excessive pulse power density resulted in a reduction of the maximum value of the compressive residual stress in the material although they were increasing with depth. 4.

Two type-S thermocouples are placed at the middle section of the specimen, providing thermal data of the solidification process and allowing the estimation of the thermal coherency temperature [18].
The modulus of primary austenite, Mγ, describes the reduction of surface area to volume ratio of the austenite phase.
This suggests that not only the distance between the centre of gravity of austenite particles is increasing (Dγ) as a direct result of the reduction of surface area to volume ratio, but also the space between the austenite particles (DIPhyd).
In the b), c) and d) figures, the circles represent the values from the current investigation, related to CGI material, while the triangles represent the literature data for a similar investigation performed in LGI [14].

Introduction Since 2000, Taiwan has continued to improve its efforts in workplace accident reduction, and workplace safety has reached a certain level.
Andi [8] concluded that good workers’ safety cognition build good safety culture, which initiates the reduction of construction accidents.
Data collected from the questionnaire was subjected to SPSS 17.0 statistical analysis.
Summary of the background of survey respondents Managers Laborers Position Sample size % Position Sample size % Worksite director 19 5.8 Steel worker 121 36.1 Industrial safety personnel 11 3.3 Formwork worker 103 30.7 Superintender 31 9.3 Scaffolding / concrete worker 22 6.6 Director of field operations 10 3.0 Misc. manual labor 11 3.3 Other management position 3 0.9 Other labor position 4 1.2 Data Analysis Reliability analysis Reliability refers to the consistency and stability of test results.

Because the total reduction was constant, the rolling schedule with the higher strain below TNR ("Old 1.0") had less reduction in the roughing stage than the schedule with lower strain below TNR ("Old 0.5").
The calculated values are plotted in Fig. 5, and show very good agreement with the experimental data. 0 20 40 60 80 100 120950 1050 1150 1250 1350 Temperature (o C) Mean Grain Diameter (micron) Measured Calculated 0 20 40 60 80 100 120950 1050 1150 1250 1350 Temperature (oC) Mean Grain Diameter (micron) Measured Calculated Figure 5.
The values of recrystallized grain diameter predicted by the models of Bai et al. [5] and Sellars [6] both fit the measured data well (Fig. 8).

QDs sizes and distribution data based on the images were assessed using Transmission Electron Microscopy Tecnai G2-20-FEI microscope at an accelerating voltage of 200 kV coupled to Energy-dispersive X-ray spectroscopy (EDS, EDX).
This optical bandgap is the lowest excitation energy of the QDs and it was estimated from absorption coefficient data as a function of wavelength using the “Tauc relation” as showed in Eq. 7: αhν = B(hν-EQD)n (7) Where α is the absorption coefficient, hn is the photon energy, B is the band form parameter, and n = 1/2 for direct bandgap and 2 for indirect bandgap.
Apparently, the most likely mechanism acting on the system stabilization is the reduction of the surface energy by the interactions with the hydroxyl and carboxylate groups from PVA-COOH chains, as schematically represented in Fig.1B.
However, at higher coverage, after the growth of a second layer (thicker shell), the efficiency has decreased with a relevant reduction of the PL intensity.

The blocks were then homogeneized at 1050 °C for 36 h in order to insure chemical homogeneity and hot-rolled at 1050 °C using 5% reduction steps until a total reduction of 65%.
The EBSD data were acquired with an Oxford® HKL Channel 5 software package.
The data analyses were carried out by means of the Oxford® AZTEC software package.

Introduction Recent years have seen a significant putsch toward the development of cost reduction technologies for the production of engineering components with titanium alloys [1, 2], particularly via the so called ‘near net shape’ forming routes.
These low level variations are considered to be signal noise associated with the raw voltage data and so are not considered to be indicative of any arc stability characteristics.
The data presented below shows that the hardness levels in the HAZ of PS samples differ significantly from that of both RHP and wrought materials.
Kraft, Summary of Emerging Titanium Cost Reduction Technologies, (EHK Technologies-for ORNL, Vancouver, WA, 2004), 1-59

Thus, optimal selection of cutting conditions still requires the expertise and experience of a skilled machinist or the information from a machining data handbook.
Considering our case, a reduction factor of 0.75 was implied, and we set the reference cutting force for our test to 525 N.
Similarly, NC codes were generated for 40 and 120 segments (data not presented here due to lack of space).
Table 2 Comparison of machining time before and after applying feed rate scheduling Machine time (s) Reduction (%) Without feed rate scheduling 20.5 Feed rate scheduling (20 segments) 15.8 22.9 Feed rate scheduling (30 segments) 14.3 30.2 Feed rate scheduling (40 segments) 10.7 47.8 Feed rate scheduling (60 segments) 10.0 51.2 Feed rate scheduling (120 segments) 9.2 55.1 (a) (b) Fig. 7 Machine time before and after implementing feed rate scheduling.

This technique provides data on the viscosity response of the semisolid slurry under a rapid share change (i.e. a transient condition).
The normalized height reduction (h/h0, h = instantaneous height of billet and h0 = initial height of billet) as function of compression time is shown in Figure 5.
(a) (b) Fig. 5 Normalized height reductions (h/h0) of SEED processed 7075 slurries as a function of time under rapid compression for different temperatures.
The data are plotted in the transient state (less than 1 second) as the deformation was completed around 0.7 second.