Effect of synthetic graphite and activated charcoal addition on the mechanical, microstructure and wear properties of AZ 81 Mg alloys

AbstractIn the present study, the grain refinement effects of carbon on AZ 81 (Mg–8%Al) alloys were investigated through the addition of synthetic graphite and activated charcoal inoculants. The mechanical and dry sliding wear properties of AZ 81 (Mg–8%Al) alloys with and without grain refiners were studied. The composition, microstructure and wear surface of the cast alloys were analyzed with the aid of atomic absorption spectroscopy, optical and scanning electron microscopes. The wear test was conducted at a speed of 5.37m/s and two loading (20N and 30N) conditions in a pin on disc wear apparatus. The mean grain size of the alloy is significantly reduced from about 185 to 32μm when the carbon content is increased to 0.98% C. Both tensile strength and ductility increase with increasing carbon content. Also, the wear rate decreases with the increase of carbon content in the alloy. The activated charcoal with 0.98wt% C is found to be a better grain refiner in improving the properties of tensile behaviour and wear resistance. The fracture surface morphology shows the brittle intergranular fracture. Analyses of wear surface morphology show that abrasive and delamination wear mechanisms are responsible for the wear loss in the AZ 81 alloy

Transaction Processing Monitor Support for Scalable Data Warehouses

An often overlooked criteria in a data warehousing implementation plan and in research is the volume of concurrent user requests accessing the system. A transaction processing monitor control can help a data warehouse meet the strict response requirements of these user requests. TP monitors also bring several other characteristics such as heterogeneous database integration support, a path for incremental growth, good performance tuning support, automatic failure recovery, load balancing, and transactional semantics, all of which are assets to a data warehous

Effect Of Non-Ballistic Active Knee Extension In Neural Slump Position On Hamstring Flexibility

PURPOSE :- To assess how neural slump mobilization affects hamstring flexibility BACKGROUND :- Thirty adult individuals in good health with restricted right hamstring flexibility (minimum of 15 degrees less active knee extension assessed with femur held at 90 degrees of hip flexion) were divided into two groups at random. METHOD:- Subjects in Group A will engage in non-ballistic static stretching for 30 seconds, which will be followed by static stretching for 30 seconds after a 5-minute rest period for two weeks. Group-B: Over the course of two weeks, the subject will complete static stretches maintained for 30 seconds, repeated five times, with a 1-second break in between each stretch. STATICAL ANALYSIS :- To compare the mean value for pre-treatment and post-treatment ROM across groups as well as the comparison of the mean values for pre-treatment and post-treatment ROM within the group, independent sample t-test and paired t-test were employed, respectively. A value of p was chosen.05 RESULT:- According to a within-group analysis, group A's mean range of motion was larger after therapy than it was before treatment (53.83 2.43), and this difference was determined to be statistically significant (p=0.00). The difference between the mean post-treatment range of motion value for group B (51.44 2.63) and the mean pre-treatment range of motion value (38.49 3.26) was determined to be statistically significant (p=0.00). The results of the between-group analysis showed that group A's mean post-treatment range of motion value was greater than group B's (53.83 2.43 vs. 51.44 2.63), and this difference was judged to be statistically significant (p=0.016). CONCLUSION :- The results of the current study showed that static stretching combined with the neural slump posture improved hamstring flexibility in adults more than static stretching alone, resulting in changes in the accuracy of the active knee extension measuremen