title: Gaining understanding of the effect of alloy composition on the properties of Ti–Cu–Mn–Al alloys

authors: Al-Hajiri, M

abstract: High performance cheaper Ti alloys can be developed based on the addition of several alloying elements, amongst which are Cu, Mn and Al. Studies are available in literature about binary and some ternary alloys based on the addition of these elements; however, no quaternary Ti–Cu–Mn–Al alloys were developed. Therefore, in this study quaternary Ti–Cu–Mn–Al alloys were manufactured via powder metallurgy to gain a better understanding of the effect of the alloy composition and the achievable mechanical performance. It is found that the selected quaternary Ti–Cu–Mn–Al alloys are characterised by a lamellar structure, which is progressively refined as the amount of alloying elements increases, and precipitation of the Ti2Cu intermetallic occurs if the Cu content is high enough. The amount of residual porosity increases and changes morphology as more thermal energy is invested in the diffusion of the alloying elements. In terms of mechanical behaviour, the quaternary Ti–Cu–Mn–Al alloys undergo both elastic and plastic deformation upon tensile loading. Strength and hardness linearly increase and the ductility monotonically decreases, which is the result of the compromise between the amount of residual porosity and the several strengthening mechanisms brought about by the actual total amount of alloying elements added.

text: Gaining understanding of the effect of alloy composition on the properties of Ti–Cu–Mn–Al alloys High performance cheaper Ti alloys can be developed based on the addition of several alloying elements, amongst which are Cu, Mn and Al. Studies are available in literature about binary and some ternary alloys based on the addition of these elements; however, no quaternary Ti–Cu–Mn–Al alloys were developed. Therefore, in this study quaternary Ti–Cu–Mn–Al alloys were manufactured via powder metallurgy to gain a better understanding of the effect of the alloy composition and the achievable mechanical performance. It is found that the selected quaternary Ti–Cu–Mn–Al alloys are characterised by a lamellar structure, which is progressively refined as the amount of alloying elements increases, and precipitation of the Ti2Cu intermetallic occurs if the Cu content is high enough. The amount of residual porosity increases and changes morphology as more thermal energy is invested in the diffusion of the alloying elements. In terms of mechanical behaviour, the quaternary Ti–Cu–Mn–Al alloys undergo both elastic and plastic deformation upon tensile loading. Strength and hardness linearly increase and the ductility monotonically decreases, which is the result of the compromise between the amount of residual porosity and the several strengthening mechanisms brought about by the actual total amount of alloying elements added.

year: 2024-08-01

title: Improved linearity using harmonic error rejection in a full-field range imaging system

authors: Payne, Andrew D.

subjects: phase detection

abstract: Full field range imaging cameras are used to simultaneously measure the distance for every pixel in a given scene using an intensity modulated illumination source and a gain modulated receiver array. The light is reflected from an object in the scene, and the modulation envelope experiences a phase shift proportional to the target distance. Ideally the waveforms are sinusoidal, allowing the phase, and hence object range, to be determined from four measurements using an arctangent function. In practice these waveforms are often not perfectly sinusoidal, and in some cases square waveforms are instead used to simplify the electronic drive requirements. The waveforms therefore commonly contain odd harmonics which contribute a nonlinear error to the phase determination, and therefore an error in the range measurement. We have developed a unique sampling method to cancel the effect of these harmonics, with the results showing an order of magnitude improvement in the measurement linearity without the need for calibration or lookup tables, while the acquisition time remains unchanged. The technique can be applied to existing range imaging systems without having to change or modify the complex illumination or sensor systems, instead only requiring a change to the signal generation and timing electronics.

text: Improved linearity using harmonic error rejection in a full-field range imaging system Full field range imaging cameras are used to simultaneously measure the distance for every pixel in a given scene using an intensity modulated illumination source and a gain modulated receiver array. The light is reflected from an object in the scene, and the modulation envelope experiences a phase shift proportional to the target distance. Ideally the waveforms are sinusoidal, allowing the phase, and hence object range, to be determined from four measurements using an arctangent function. In practice these waveforms are often not perfectly sinusoidal, and in some cases square waveforms are instead used to simplify the electronic drive requirements. The waveforms therefore commonly contain odd harmonics which contribute a nonlinear error to the phase determination, and therefore an error in the range measurement. We have developed a unique sampling method to cancel the effect of these harmonics, with the results showing an order of magnitude improvement in the measurement linearity without the need for calibration or lookup tables, while the acquisition time remains unchanged. The technique can be applied to existing range imaging systems without having to change or modify the complex illumination or sensor systems, instead only requiring a change to the signal generation and timing electronics.

year: 2008

title: The Google Translator Toolkit and minority languages case study: Translating Moodle 2.0 into te reo Māori

authors: Manuirirangi, Hōri

abstract: This paper describes a case study where the Google Translator Toolkit (GTT) was used to undertake a large translation task involving a minority language. The task involved the translation of 50,000 interface terms of the Moodle learning management system into te reo Māori (the Māori language).  

The paper begins by describing how some minority languages are not in an environment where technology can be easily used for translations. It then suggests that te reo Māori however, is in a position to use technology and suggests some technologies that are suitable. The paper then briefly describes the GTT and the translation task that this tool was used for. The translators' feedback on the use of this technology in this environment is summarised and it appears that the GTT is suitable to be used by minority language translators.

text: The Google Translator Toolkit and minority languages case study: Translating Moodle 2.0 into te reo Māori This paper describes a case study where the Google Translator Toolkit (GTT) was used to undertake a large translation task involving a minority language. The task involved the translation of 50,000 interface terms of the Moodle learning management system into te reo Māori (the Māori language).  

The paper begins by describing how some minority languages are not in an environment where technology can be easily used for translations. It then suggests that te reo Māori however, is in a position to use technology and suggests some technologies that are suitable. The paper then briefly describes the GTT and the translation task that this tool was used for. The translators' feedback on the use of this technology in this environment is summarised and it appears that the GTT is suitable to be used by minority language translators.

year: 2011