title: Modification of sintered titanium alloys by hot isostatic pressing

authors: Bolzoni, Leandro

subjects: HIP

abstract: Powder metallurgy (PM) permits to obtain titanium alloys with properties and microstructures close to ingot metallurgy products. However, residual porosity is normally present in the products produced by the PM route of powder pressing and sintering (P&S)\, and this needs to be reduced by using post-sintering process step such as hot isostatic pressing (HIP) and forging. In this study, the microstructural and mechanical property changes caused by HIP of samples of two alloys, near-α Ti-3Al-2.5V alloy and α+β Ti-6Al-4V, produced by P&S route were investigated. Two types of powders were utilised: prealloyed powders and blend of elemental titanium powder and master alloy powder. Four conditions defined by HIP temperature, pressure and time were used to HIP the sintered samples with two geometries. The results show that, independent of the HIP conditions used, HIP increased the relative density of the samples to approximately 97.5% and their hardness by 30-50 HV depending on the HIP condition. However, HIP at 1000°C changes the fracture mode of the sintered samples from ductile to brittle.

text: Modification of sintered titanium alloys by hot isostatic pressing Powder metallurgy (PM) permits to obtain titanium alloys with properties and microstructures close to ingot metallurgy products. However, residual porosity is normally present in the products produced by the PM route of powder pressing and sintering (P&S)\, and this needs to be reduced by using post-sintering process step such as hot isostatic pressing (HIP) and forging. In this study, the microstructural and mechanical property changes caused by HIP of samples of two alloys, near-α Ti-3Al-2.5V alloy and α+β Ti-6Al-4V, produced by P&S route were investigated. Two types of powders were utilised: prealloyed powders and blend of elemental titanium powder and master alloy powder. Four conditions defined by HIP temperature, pressure and time were used to HIP the sintered samples with two geometries. The results show that, independent of the HIP conditions used, HIP increased the relative density of the samples to approximately 97.5% and their hardness by 30-50 HV depending on the HIP condition. However, HIP at 1000°C changes the fracture mode of the sintered samples from ductile to brittle.

year: 2012

title: Automated Technology Based Behavioural Intervention to Promote Exercise Adherence: A Pilot Study to Ascertain Efficacy

authors: Allen, Vincent Thor

subjects: Exercise adherence

abstract: Exercise has been shown to be an effective treatment for a range of physical and mental health problems. Development of automated exercise therapy options will result in greater accessibility of treatment for those who would be otherwise unable to access it. The purpose of this study was to design and evaluate an automated technology based behavioural intervention for the purpose of increasing the participant’s physical exercise adherence.
The study was run as a non-concurrent multiple baseline across participants design over a 12 week period. Nine participants (2 male, 7 female) aged 18 to 34 (M = 23.11) took part in the study. They completed a baseline phase of three to six weeks during which exercise data were recorded. The intervention phase lasted seven to eight weeks, during which an intervention was delivered via email and online survey in an attempt to increase physical exercise, and promote long term exercise adherence. Effectiveness of the intervention was evaluated using measures of duration and intensity of exercise activity, and an 18 item Exercise Self-Efficacy Scale.
For most participants there was a significant increase in exercise activity and exercise self-efficacy score as a result of the intervention. Component analysis of the intervention provided information as to which aspects were effective, and which may need to be modified for subsequent iterations. These results show that an automated technology based behavioural intervention can increase exercise behaviour in such a way that promotes long term adherence. Future studies could focus on using a smartphone app as the delivery method for similar interventions as this would allow for additional features to be added, and more effective delivery of the aspects of the intervention that have been shown to work.

text: Automated Technology Based Behavioural Intervention to Promote Exercise Adherence: A Pilot Study to Ascertain Efficacy Exercise has been shown to be an effective treatment for a range of physical and mental health problems. Development of automated exercise therapy options will result in greater accessibility of treatment for those who would be otherwise unable to access it. The purpose of this study was to design and evaluate an automated technology based behavioural intervention for the purpose of increasing the participant’s physical exercise adherence.
The study was run as a non-concurrent multiple baseline across participants design over a 12 week period. Nine participants (2 male, 7 female) aged 18 to 34 (M = 23.11) took part in the study. They completed a baseline phase of three to six weeks during which exercise data were recorded. The intervention phase lasted seven to eight weeks, during which an intervention was delivered via email and online survey in an attempt to increase physical exercise, and promote long term exercise adherence. Effectiveness of the intervention was evaluated using measures of duration and intensity of exercise activity, and an 18 item Exercise Self-Efficacy Scale.
For most participants there was a significant increase in exercise activity and exercise self-efficacy score as a result of the intervention. Component analysis of the intervention provided information as to which aspects were effective, and which may need to be modified for subsequent iterations. These results show that an automated technology based behavioural intervention can increase exercise behaviour in such a way that promotes long term adherence. Future studies could focus on using a smartphone app as the delivery method for similar interventions as this would allow for additional features to be added, and more effective delivery of the aspects of the intervention that have been shown to work.

year: 2015

title: Rejoinder

authors: Kelly, Martin

abstract: Our paper (Kelly et al., 1999) set out to have points recognized as ‘needing to be addressed’ on the agendas of institutions currently providing accounting education. We believe that many institutions are continuing to fail to respond to recognized problems. We are grateful to the Commentators for recognizing our purpose. They note that our paper:
1. raises some important issues which need to be urgently addressed (Commentator 1);
2. illuminates why it is dif  cult to implement change even when there is a consensus to do so (Commentator 2);
3. provides a very important theme which has been neglected by many accounting educators (Commentator 3).

text: Rejoinder Our paper (Kelly et al., 1999) set out to have points recognized as ‘needing to be addressed’ on the agendas of institutions currently providing accounting education. We believe that many institutions are continuing to fail to respond to recognized problems. We are grateful to the Commentators for recognizing our purpose. They note that our paper:
1. raises some important issues which need to be urgently addressed (Commentator 1);
2. illuminates why it is dif  cult to implement change even when there is a consensus to do so (Commentator 2);
3. provides a very important theme which has been neglected by many accounting educators (Commentator 3).

year: 2000