Energy consumption analysis in turning Ti-6Al-4V alloy.

One of the major concerns in manufacturing industries include the amount of energy consumed during machining processes. Therefore, the study of the specific energy during machining must be analyzed in relation to the process parameters (feed rate, speed and depth of cut). This work demonstrates the analysis of specific cutting energy (SCE) and cutting power during titanium alloys machining under dry conditions. Turning experiments with uncoated carbide inserts were performed applying Taguchi Design of Experiments technique and analyzed the effect of speed, feed and depth of cut during turning Ti-6Al-4V titanium alloys. ANOVA was done to find out the influence of the machining parameters on energy consumption. The outcome of this analysis indicates that feed rate is the highly dominant factor responsible for the SCE of a machine tool, whereas, cutting speed was found as the influential factor affecting the power during the machining process. The environmental and economic performance for a machining process may be significantly improved by reducing energy consumption using appropriate machining conditions

Numerical simulation of a low aspect ratio wing at low Reynolds number

In this work the numerical simulation of aerodynamic performance of low aspect ratio wings at low Reynolds numbers applicable to micro aerial vehicle is carried out. Commercial software STAR-CCM+ was used to simulate the flow and predict the aerodynamics performances of the low aspect ratio wing. Results were presented in terms of pressure coefficient distribution, flow visualization, lift and drag coefficients for angle of attacks ranging from 0˚ to 18˚ and Reynolds numbers ranging from 104 to 105 Keywords: Rectangular planform wing; Tip vortices; Flow separation . The results showed that, for rectangular planform wing, the distribution of the pressure is dominated by vortices. The results also showed the formation of tip vortices at lower Reynolds number for rectangular wing configuration. It is evident from the results that the type of wing configurations plays a very important role in delaying or preventing the flow separation

Growth Differentiation Factor 5 Regulates Cardiac Repair After Myocardial Infarction

ObjectivesThe aim of this study was to examine the function of the bone morphogenic protein growth differentiation factor 5 (Gdf5) in a mouse model of myocardial infarction (MI).BackgroundThe Gdf5 has been implicated in skeletal development, but a potential role in the heart had not been studied.MethodsThe Gdf5-knockout (KO) and wild-type (WT) mice were subjected to permanent left anterior descending coronary artery (LAD) ligation. Cardiac pathology, function, gene expression levels, and signaling pathways downstream of Gdf5 were examined. Effects of recombinant Gdf5 (rGdf5) were tested in primary cardiac cell cultures.ResultsThe WT mice showed increased cardiac Gdf5 levels after MI, with increased expression in peri-infarct cardiomyocytes and myofibroblasts. At 1 and 7 days after MI, no differences were observed in ischemic or infarct areas between WT and Gdf5-KO mice. However, by 28 days after MI, Gdf5-KO mice exhibited increased infarct scar expansion and thinning with decreased arteriolar density compared with WT. The Gdf5-KO hearts also displayed increased left ventricular dilation, with decreased contractility after MI. At 4 days after MI, Gdf5-KO mice exhibited increased cardiomyocyte apoptosis and decreased expression of anti-apoptotic genes Bcl2 and Bcl-xL compared with WT. Unexpectedly, Gdf5-KO hearts displayed increased Smad 1/5/8 phosphorylation but decreased p38-mitogen-activated protein kinase (MAPK) phosphorylation versus WT. The latter was associated with increased collagen gene (Col1a1, Col3a1) expression and fibrosis. In cultures, rGdf5 induced p38-MAPK phosphorylation in cardiac fibroblasts and Smad-dependent increases in Bcl2 and Bcl-xL in cardiomyocytes.ConclusionsIncreased expression of Gdf5 after MI limits infarct scar expansion in vivo. These effects might be mediated by Gdf5-induced p38-MAPK signaling in fibroblasts and Gdf5-driven Smad-dependent pro-survival signaling in cardiomyocytes

Gender Differences in Twitter Complaints

This study aimed to identify and compare the different strategies used by males and females in making complaints. Both genders adopt different strategies when making complaints.  In this qualitative study, the content analysis method was adopted, and based on Trosborg's Theory of Complaint, complaints messages posted by 23 Twitter users were analyzed. The results showed that males perform dissatisfaction more frequently than females. However, females use blame strategy at a higher frequency than males. This research revealed a new perspective on gender differences and valuable insights influencing complaint-making strategies. Keywords: Complaints, Code-switching, Language Choice, Strategies eISSN: 2398-4287 © 2022. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open-access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under the responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians), and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. DOI: https://doi.org/10.21834/ebpj.v7iSI7.376

Multi-objective optimization for sustainable turning Ti6Al4V alloy using grey relational analysis (GRA) based on analytic hierarchy process (AHP).

Sustainable machining necessitates energy-efficient processes, longer tool lifespan, and greater surface integrity of the products in modern manufacturing. However, when considering Ti6Al4V alloy, these objectives turn out to be difficult to achieve as titanium alloys pose serious machinability challenges, especially at elevated temperatures. In this research, we investigate the optimal machining parameters required for turning of Ti6Al4V alloy. Turning experiments were performed to optimize four response parameters, i.e., specific cutting energy (SCE), wear rate (R), surface roughness (Ra), and material removal rate (MRR) with uncoated H13 carbide inserts in the dry cutting environment. Grey relational analysis (GRA) combined with the analytic hierarchy process (AHP) was performed to develop a multi-objective function. Response surface optimization was used to optimize the developed multi-objective function and determine the optimal cutting condition. As per the ANOVA, the interaction of feed rate and cutting speed (f × V) was found to be the most significant factor influencing the grey relational grade (GRG) of the multi-objective function. The optimized machining conditions increased the MRR and tool life by 34% and 7%, whereas, reducing the specific cutting energy and surface roughness by 6% and 2% respectively. Using Taguchi-based GRA by analytic hierarchy process (AHP) weights method, the benefits of high-speed machining Ti6Al4V through multi-response optimization were achieved

Tool wear progression and its effect on energy consumption in turning of titanium alloy (Ti-6Al-4V).

To achieve greater productivity, titanium alloy requires cutting at higher speeds (above 100 m min−1) that affects the tool life and energy consumption during the machining process. This research work correlates the wear progression and Specific Cutting Energy (SCE) in turning Ti-6Al-4V alloy using H13 tools (uncoated carbide) in dry conditions from low to high cutting speeds. Cutting condition employed in this study were selected from published wear map developed for titanium (Ti-6Al-4V alloy) with the same tool. Flank wear growth of the tool has been investigated at different length of cuts in correlation with the SCE under different cutting conditions. The useful tool life was found to be shorter at high-speed machining conditions, thus the end of useful tool life criteria (ISO 3685) was reached at a much shorter length of cuts as compared to low-speed machining conditions. The cutting conditions corresponding to high wear rate also resulted in high SCE. Finally, SCE and wear have been related by a linear relationship that can be used to monitor wear and/or SCE utilization during machining. The results help in the selection of appropriate cutting conditions that will enhance the tool life and minimize SCE consumption during machining titanium alloy