Parametric Study on the Residual Tensile Strength of Flax Natural Fibre Composites after Drilling Operation

AbstractThe need for hole making on synthetic and natural fibre composites is inevitable due to further requirement of assembly process of different composite parts. However, regardless of the fibre types, the damage cause by drilling operation, namely delamination and matrix cracking around the hole, often deteriorated the long-term mechanical performance of these composites. In this study, the parametric effects of drilling conditions, namely feed rate, spindle speed and drill point angle on residual tensile strength have been investigated. Taguchi technique with statistical analyses was employed as to analyze the residual tensile strength of woven flax epoxy composite after drilling process. A three-axis CNC machine was used to create a hole on the composite specimens based on two levels of drilling parameters and drill bit geometries. Subsequently, static loading tests were performed as specified in the ASTM Standard D3039 (Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials). From the analysis, it is evident that feed rate is the most important parameter that influence the aforementioned output

Effectiveness of the EMPOWER-PAR Intervention in Improving Clinical Outcomes of Type 2 Diabetes Mellitus in Primary Care: A Pragmatic Cluster Randomised Controlled Trial

10.1186/s12875-016-0557-1BMC Family Practice1711-1

Exploring the cost-effectiveness of high versus low perioperative fraction of inspired oxygen in the prevention of surgical site infections among abdominal surgery patients in three low- and middle-income countries

Background: This study assessed the potential cost-effectiveness of high (80–100%) vs low (21–35%) fraction of inspired oxygen (FiO2) at preventing surgical site infections (SSIs) after abdominal surgery in Nigeria, India, and South Africa. Methods: Decision-analytic models were constructed using best available evidence sourced from unbundled data of an ongoing pilot trial assessing the effectiveness of high FiO2, published literature, and a cost survey in Nigeria, India, and South Africa. Effectiveness was measured as percentage of SSIs at 30 days after surgery, a healthcare perspective was adopted, and costs were reported in US dollars ($). Results: High FiO2 may be cost-effective (cheaper and effective). In Nigeria, the average cost for high FiO2 was$216 compared with $222 for low FiO2 leading to a −$6 (95% confidence interval [CI]: −$13 to −$1) difference in costs. In India, the average cost for high FiO2 was $184 compared with$195 for low FiO2 leading to a −$11 (95$15 to −$6) difference in costs. In South Africa, the average cost for high FiO2 was$1164 compared with $1257 for low FiO2 leading to a −$93 (95% CI: −$132 to −$65) difference in costs. The high FiO2 arm had few SSIs, 7.33% compared with 8.38% for low FiO2, leading to a −1.05 (95% CI: −1.14 to −0.90) percentage point reduction in SSIs. Conclusion: High FiO2 could be cost-effective at preventing SSIs in the three countries but further data from large clinical trials are required to confirm this