Effect of offset on the blade stress in tube roll-cutting process
The main objective of this study is to obtain the reasonable range of offset in tube roll-cutting process by analyzing the effect of the process kinematics. For this aim, the roll-cutting processes are simulated. Due to the existence of the offset, the relative feed speed of blade is not constant. In this paper, the relationship between the radial feed speed shock of a blade relative to the tube and the offset is introduced. The effects of offset on the roll-cutting force and the blade stress have been analyzed. Regarding the stress of the blade, the offset should be less than 0.15mm for Φ76×3.5mm tube with the blade radial displacement per cycle as 1.0 mm.
Simulation Based Process Parameters Study of the Tube Roll-cutting
In the large-diameter tube product line, the tube roll-cutting induces the tube shrinkage. The dashing blade is vulnerable part in the cutting machine. To decrease the tube shrinkage and increase the blade working life, the cutting processes with various process parameters are simulated by using the FEM. This paper is concerned with the quantitative effect of process parameters on the tube rollcutting. The considered parameters are the initial feed speed and the maximum cutting force. A comparison between the numerical and experimental results proves the validity of simulation. The relationship between the tube shrinkage and the process parameters is obtained by studying the cut dimension. The result of the stress analysis shows the influence of process parameters on the stress value. The appropriate process parameters are recommended through comparison among the simulated results for cutting Φ76×3.5mm tube.
Extent of East-African Nurse Leaders' Participation in Health Policy Development
This paper reports part of a bigger study whose aim was to develop an empowerment model that could be used to enhance nurse leaders' participation in health policy development. A Delphi survey was applied which included the following criteria: expert panelists, iterative rounds, statistical analysis, and consensus building. The expert panelists were purposively selected and included national nurse leaders in leadership positions at the nursing professional associations, nursing regulatory bodies, ministries of health, and universities in East Africa. The study was conducted in three iterative rounds. The results reported here were gathered as part of the first round of the study and that examined the extent of nurse leaders' participation in health policy development. Seventy-eight (78) expert panelists were invited to participate in the study, and the response rate was 47%. Data collection was done with the use of a self-report questionnaire. Data analysis was done by use of SPSS and descriptive statistics were examined. The findings indicated that nurse leaders participate in health policy development though participation is limited and not consistent across all the stages of health policy development. The recommendations from the findings are that health policy development process needs to be pluralistic and inclusive of all nurse leaders practicing in positions related to policy development and the process must be open to their ideas and suggestions.