Milling of Inconel 718: an experimental and integrated modeling approach for surface roughness

Inconel 718, a hard-to-cut superalloy is reputed for having poor machining performance due to its low thermal conductivity. Consequently, the surface quality of the machined parts suffers. The surface roughness value must fall within the stringent limits to ensure the functional performance of the components used in aerospace and bioimplant applications. One doable way to enhance its machinability is the adequate dissipation of heat from the machining zone through efficient and ecofriendly cooling environment. With this perspective, an experimental and integrated green-response surface machiningbased- evolutionary optimization (G-RSM-EO) approach is presented during this investigation. The results are compared with two base-line techniques: the traditional flooded approach with Hocut WS 8065 mineral oil, and the dry green approach. A Box-Behnken response surface methodology (RSM) is employed to design the milling tests considering three control parameters, i.e., cutting speed (vs), feed/flute (fz), and axial depth of cut (ap). These control parameters are used in the various experiments conducted during this research work. The parametric analysis is then accomplished through surface plots, and the analysis of variance (ANOVA) is presented to assess the effects of these control parameters. Afterwards, a multiple regression model is developed to identify the parametric relevance of vs, fz, and ap, with surface roughness (SR) as the response attribute. A residual analysis is performed to validate the statistical adequacy of the predicted model. Lastly, the surface roughness regression model is considered as the objective function of the particle swarm optimization (PSO) model to minimize the surface roughness of the machined parts. The optimized SR results are compared to the widely employed genetic algorithm (GA) and RSM-based desirability function approach (DF). The confirmatory machining tests proved that the integrated optimization approach with PSO being an evolutionary technique is more effective compared to GA and DF with respect to accuracy (0.05% error), adequacy, and processing time (3.19 min). Furthermore, the study reveals that the Mecagreen 450 biodegradable oil-enriched flooded strategy has significantly improved the milling of Inconel 718 in terms of eco-sustainability and productivity, i.e., 42.9% cost reduction in cutting fluid consumption and 73.5% improvement in surface quality compared to the traditional flooded approach and the dry green approach. Moreover, the G-RSM-EO approach presents a sustainable alternative by achieving a Ra of 0.3942 μm that is finer than a post-finishing operation used to produce close tolerance reliable components for aerospace industry

Environmentally Conscious Machining of Inconel 718: Surface Roughness, Tool Wear and Material Removal Rate Assessment

Flood cooling is a typical strategy used in the machining of difficult-to-cut materials where high temperatures are produced.Several environmental and health concerns are associated with the cutting fluids employed during this technique. Vegetable oil-based fluids appear to be the best substitute to conventional mineral/synthetic oils due to their environmentally friendly, biode-gradable, renewable, and less toxic properties. Therefore, this paper attempts to establish an environmentally conscious, flood-cooling alternative through replacing conventional fluids with a synthetic vegetable ester-based (Mecagreen 450) biodegradableoil to investigate the machinability aspects of Inconel 718. In addition to the cooling environment, cutting speed (vs), feed pertooth (fz), and axial depth of cut (ap) have been used as control variables. ATaguchi L9array has been selected for the design ofexperiments (DOE). Parametric effects and microscopic analyses have been carried out to investigate the three response param-eters, i.e., surface roughness (Ra), tool wear, and material removal rate (MRR). Tool wear analysis is further supplemented withscanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS)

Experimental investigation of surface roughness for different thickness of aluminium in abrasive waterjet machining

Abrasive waterjet machining is a novel method of machining complex shapes and profiles. Surface roughness is a widely used machining characteristic to define the quality of the machined components. This present study reports the effects of workpiece material thickness, abrasive mass flow rate and standoff distance on surface roughness while performing abrasive waterjet machining. A L9 Taguchi array is used for the design of experimentation signal to noise ratio and analysis of variance is carried out. The experimental results show that the most influential parameter affecting surface roughness is workpiece thickness

An approach to PLC in fast moving consumer goods: A case study from Pakistan

Fast moving consumer goods (FMCGs) is possibly the toughest and most disciplined of all industries. The survival, market share and profitability of a FMGC organization rely on number of factors including innovative thoughts, focused consumer, competitor analysis and deep marketing knowledge. These factors are necessary considerations throughout the Product Life Cycle (PLC). PLC analysis is considered to be a valuable tool for strategic planning for organizations and was first introduced to track the product's progress in all phases from introduction to disposal. FMCG organizations gain a competitive edge by using a product life cycle approach over those who do not use it. This paper presents a case study of a local FMGC organization and its approach to PLC. The study revealed that the PLC approach has significant effects on the success of the product in the market

Implementation of TPM in a process industry: a case study from Pakistan

Quality of any manufactured product is closely associated with to maintenance of manufacturing systems of any organization. To achieve a world class manufacturing system, two new manufacturing paradigm Total Productive Maintenance (TPM) and Total Quality Management (TQM) have emerged over the period along with other widely used concepts. In this paper, a case study related to implementation of Total Productive Maintenance is shared for a packaging material manufacturing organization. TPM Concept is implemented in the business flexible unit equipped with various flexographic printing machines. Overall Equipment Effectiveness (OEE) is used as the key performance measure of success of TPM implementation. The losses associated with equipment effectiveness are identified and all the pillars of TPM are implemented in a phased manner eliminating the losses and thus improving the utilization of flexographic printing machines

Application of value stream mapping (VSM) in gear manufacturing process: A case study

Since the end of 20th century, Lean Manufacturing has been recognized as an important approach in competitive industrial environments to improving productivity by reducing process cycle time. To remain competitive in the market, organizations are compelled to find new domains for improvements in order to reduce production lead time and to smooth the flow of processes. The current research aims at designing efficient future VSM to improve productivity by reducing process cycle time and waste in a gear manufacturing process in an automotive industry. The approach was based on mapping the current state of the process to identify the non-value-added activities and also for opportunities for improvement in value added activities. Kaizen events are the main metrics for improvement in the current process by integrating it with the future value stream map. This study concluded that the designed future value stream map helps effectively in identifying the wasteful activities i.e. distance travelled and inventory at different workstations. VSM integrated with Kaizen proves itself a useful approach in achieving continuous process improvement

Antidiabetic potential of Nigella sativa L seed oil in alloxaninduced diabetic rabbits

Purpose: To evaluate the antidiabetic, hypolipidemic and antioxidant potential of seed oil of Nigella sativa L (NSO). Methods: Nigella sativa seed oil (NSO) was extracted with Soxhlet apparatus using petroleum ether, and was given orally at a dose of 2.5 ml/kg body weight to alloxan-induced diabetic rabbits daily for 24 days. Biochemical parameters including total cholesterol (TC), triglycerides (TGs), low density lipoprotein cholesterol (LDL), very low lipoprotein cholesterol (VLDL), high density lipoprotein (HDL) and plasma glucose were determined in the treatment and control groups. Furthermore, bilirubin, vitamin C, catalase and mean body weight were assessed. Results: NSO treatment significantly lowered serum blood glucose levels and lipid contents, but increased the mean body weight, HDL-C and vitamin C levels of diabetic rabbits (p < 0.001). Moreover, NSO significantly decreased catalase activity, TC, TGs, LDL-C and VLDL-C levels, but normalized bilirubin levels in diabetic rabbits. Conclusion: These results indicate that NSO possesses significant antidiabetic potential. Thus, it may be useful as an adjunct with antidiabetic medication but further studies are required to ascertain this. Keywords: Black cumin, Diabetes, Hypoglycemic, Hypolipidemic, Antioxidant

Effect of L-type calcium channel blocker (amlodipine) on myocardial iron deposition in patients with thalassaemia with moderate-to-severe myocardial iron deposition: protocol for a randomised, controlled trial

Introduction: Sideroblastic cardiomyopathy secondary to repeated blood transfusions is a feared complication in thalassaemia. Control of myocardial iron is thus becoming the cornerstone of thalassaemia management. Recent evidence suggests a role for L-type Ca2+ channels in mediating iron uptake by the heart. Blocking the cellular iron uptake through these channels may add to the benefit of therapy to standard chelation in reducing myocardial iron. We aim to determine the efficacy of amlodipine (a calcium channel blocker) as an adjunct to standard aggressive chelation in retarding myocardial iron deposition in thalassaemics with or without cardiomyopathy.Outcomes: The primary outcome is to compare the efficacy of amlodipine+chelation (intervention) versus standard chelation (control) in retarding myocardial iron deposition. Secondary outcomes include the effect of amlodipine therapy on systolic and diastolic function, strain and strain rate and liver iron content.Methods and analysis: This is a single-centre, parallel-group, prospective randomised control trial. Twenty patients will be randomised in a 1:1 allocation ratio into the intervention and control arms. In addition to conventional echocardiography, MRI T2* values for assessment of cardiac and liver iron load will be obtained at baseline and at 6 and 12 months. Cardiac T2* will be reported as the geometric mean and per cent coefficient of variation, and an increase in cardiac T2* values from baseline will be used as an end point to compare the efficacy of therapy. A p Value of Study setting: Department of Pediatric and Child Health, Aga Khan University Hospital, Karachi, Pakistan.Ethics and dissemination: This study has been approved by the Ethics Review Committee and Clinical Trials Unit at The Aga Khan University with respect to scientific content and compliance with applicable research and human subjects regulations. Findings will be reported through scientific publications and research conferences and project summary papers for participants

Variations in physico-chemical and antioxidant attributes of grape seed oil as function of extraction techniques

The aim of the current research work was to assess and compare the impact of two extraction techniques on the physico-chemical, and antioxidant parameters of grape seed oil (GSO). The GSO extracted by Soxhlet and Folch methods indicated a notable variation in the oil yield (8.58 % and 10.19%) and saponification value (196.35 and 189.33 mg of KOH g-1), respectively. However, no significant (p<0.05) variation was detected for density, acid value, refractive index, iodine no, unsaponifiable matter, and free fatty acids between the tested two oils. Meanwhile, the oil produced by Soxhlet method exhibited relatively a higher extent of unsaturated dienes, trienes, peroxide value, p-anisidine value, and thus poor oxidation state. A notable variation in the content of principal fatty acid (linoleic acid) was recorded between Folch extracted oil (70.11%) and Soxhlet extracted oil (66.57%). The contents of total tocopherols were noted to be considerably higher for Folch extracted oil (105.55 mg kg-1) than the Soxhlet extracted oil (73.70 mg kg-1). Among the individual phenolics analyzed by HPLC, gallic acid (14.02 mg kg-1) and caffeic acid (5.20 mg kg-1) were detected as major component in Folch extracted oil and Soxhlet extracted oil, respectively. The results of the present comparative study support that Folch method is relatively a good choice for the extraction of GSO with promising nutritive quality in terms of oxidation parameters, contents of linoleic acid and antioxidant phenolics

Discovery of novel 1,2,4-triazole tethered β-hydroxy sulfides as bacterial tyrosinase inhibitors: synthesis and biophysical evaluation through in vitro and in silico approaches

In this study, a series of 1,2,4-triazole-tethered β-hydroxy sulfide scaffolds 11a–h was synthesized in good to remarkable yields (69–90%) through the thiolysis of oxiranes by the thiols in aqueous basic catalytic conditions. The synthesized 1,2,4-triazole-tethered β-hydroxy sulfides were screened against bacterial tyrosinase enzyme, and Gram-positive and Gram-negative bacterial cultures i.e., (S. aureus) Staphylococcus aureus & (E. coli) Escherichia coli. Among the synthesized derivatives, the molecules 11a (IC50 = 7.67 ± 1.00 μM), 11c (IC50 = 4.52 ± 0.09 μM), 11d (IC50 = 6.60 ± 1.25 μM), and 11f (IC50 = 5.93 ± 0.50 μM) displayed the better tyrosinase inhibitory activity in comparison to reference drugs ascorbic acid (IC50 = 11.5 ± 1.00 μM) and kojic acid (IC50 = 30.34 ± 0.75 μM). The molecule benzofuran-triazol-propan-2-ol 11c proved to be the most potent bacterial tyrosinase inhibitory agent with a minimum IC50 of 4.52 ± 0.09 μM, as compared to other synthesized counterparts and both standards (kojic acid and ascorbic acid). The compound diphenyl-triazol-propan-2-ol 11a and benzofuran-triazole-propan-2-ol 11c showed comparable anti-bacterial chemotherapeutic efficacy with minimum inhibitory concentrations (MIC = 2.0 ± 2.25 mg mL−1 and 2.5 ± 0.00 mg mL−1, respectively) against S. aureus bacterial strain in comparison with standard antibiotic penicillin (MIC = 2.2 ± 1.15 mg mL−1). Furthermore, among the synthesized derivatives, only compound 11c demonstrated better anti-bacterial activity (MIC = 10 ± 0.40 mg mL−1) against E. coli, which was slightly less than the standard antibiotic i.e., penicillin (MIC = 2.4 ± 1.00 mg mL−1). The compound 11c demonstrated a better binding score (−7.08 kcal mol−1) than ascorbic acid (−5.59 kcal mol−1) and kojic acid (−5.78 kcal mol−1). Molecular docking studies also validate the in vitro anti-tyrosinase assay results; therefore, the molecule 11c can be the lead bacterial tyrosinase inhibitor as well as the antibacterial agent against both types of bacterial strains after suitable structural modifications