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

Adult laryngeal haemangioma; a rare entity

Laryngeal haemangioma is commonly seen in children. Adult laryngeal haemangiomas are rare and usually involve the supraglottic region. Most common symptom includes dysphagia, dysphonia and shortness of breath. Detailed history, fiberoptic laryngoscopy and computerized scanning may suggest benign nature of the lesion but diagnosis is only confirmed by a biopsy. In comparison to infantile haemangiomas which usually respond to propronolol, the treatment of adult laryngeal haemangiomas is always surgical removal. We present a case report of a supraglottic haemangioma in an adult male, who was treated surgically without any complications

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

Adaptation of the Recent Life Changes Questionnaire (RLCQ) to measure stressful life events in adults residing in an urban megapolis in Pakistan

Background: Contextually relevant stressful life events are integral to the quantification of stress. None such measures have been adapted for the Pakistani population. Methods: The RLCQ developed by Richard Rahe measures stress of an individual through recording the experience of life changing events. We used qualitative methodology in order to identify contextually relevant stressors in an open ended format, using serial in-depth interviews until thematic saturation of reported stressful life events was achieved. In our next phase of adaptation, our objective was to scale each item on the questionnaire, so as to weigh each of these identified events, in terms of severity of stress. This scaling exercise was performed on 200 random participants residing in the four communities of Karachi namely Kharadar, Dhorajee, Gulshan and Garden. For analysis of the scaled tool, exploratory factor analysis was used to inform structuring. Finally, to complete the process of adaption, content and face validity exercises were performed. Content validity by subject expert review and face validity was performed by translation and back translation of the adapted RLCQ. This yielded our final adapted tool. Results: Stressful life events emerging from the qualitative phase of the study reflect daily life stressors arising from the unstable socio-political environment. Some such events were public harassment, robbery/theft, missed life opportunities due to nepotism, extortion and threats, being a victim of state sponsored brutality, lack of electricity, water, sanitation, fuel, destruction due to natural disasters and direct or media based exposure to suicide bombing in the city. Personal or societal based relevant stressors included male child preference, having an unmarried middle aged daughter, lack of empowerment and respect reported by females. The finally adapted RLCQ incorporated Environmental Stress as a new category. Conclusion: The processes of qualitative methodology, in depth interview, community based scaling and face and content validity yielded an adapted RLCQ that represents contextually relevant life stress for adults residing in urban Pakistan

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

Determining the potential scalability of transport interventions for improving maternal, child, and newborn health in Pakistan

Background: Pakistan is far behind in achieving the Millennium Development Goals regarding the reduction of child and maternal mortality. Amongst other factors, transport barriers make the requisite obstetric care inaccessible for women during pregnancy and at birth, when complications may become life threatening for mother and child. The significance of efficient transport in maternal and neonatal health calls for identifying which currently implemented transport interventions have potential for scalability. Methods: A qualitative appraisal of data and information about selected transport interventions generated primarily by beneficiaries, coordinators, and heads of organizations working with maternal, child, and newborn health programs was conducted against the CORRECT criteria of Credibility, Observability, Relevance, Relative Advantage, Easy-Transferability, Compatibility and Testability. Qualitative comparative analysis (QCA) techniques were used to analyse seven interventions against operational indicators. Logical inference was drawn to assess the implications of each intervention. QCA was used to determine simplifying and complicating factors to measure potential for scaling up of the selected transport intervention. Results: Despite challenges like deficient in-journey care and need for greater community involvement, community-based ambulance services were managed with the support of the community and had a relatively simple model, and therefore had high scalability potential. Other interventions, including facility-based services, public-sector emergency services, and transport voucher schemes, had limitations of governance, long-term sustainability, large capital expenditures, and need for management agencies that adversely affected their scalability potential. Conclusion: To reduce maternal and child morbidity and mortality and increase accessibility of health facilities, it is important to build effective referral linkages through efficient transport systems. Effective linkages between community-based models, facility-based models, and public sector emergency services should be established to provide comprehensive coverage. Voucher scheme integrated with community-based services may bring improvements in service utilization

Thermal-aware resource allocation in earliest deadline first using fluid scheduling

Thermal issues in microprocessors have become a major design constraint because of their adverse effects on the reliability, performance and cost of the system. This article proposes an improvement in earliest deadline first, a uni-processor scheduling algorithm, without compromising its optimality in order to reduce the thermal peaks and variations. This is done by introducing a factor of fairness to earliest deadline first algorithm, which introduces idle intervals during execution and allows uniform distribution of workload over the time. The technique notably lowers the number of context switches when compare with the previous thermal-aware scheduling algorithm based on the same amount of fairness. Although, the algorithm is proposed for uni-processor environment, it is also applicable to partitioned scheduling in multi-processor environment, which primarily converts the multi-processor scheduling problem to a set of uni-processor scheduling problem and thereafter uses a uni-processor scheduling technique for scheduling. The simulation results show that the proposed approach reduces up to 5% of the temperature peaks and variations in a uni-processor environment while reduces up to 7% and 6% of the temperature spatial gradient and the average temperature in multi-processor environment, respectively