Optimisation of grinding parameters for wheel loading and dressing
Grinding is a finishing process often used to produce desired surface roughness with required precision and quality. The performance of grinding wheel significantly depends on the nature of the wheel, morphology of the abrasive grits and the grinding parameters namely speed, feed and depth of cut. As the wheel is performing its grinding operation, its cutting surface is being loaded with metal particles of the workpiece. This wheel loading also affects the surface finish of the workpiece. Hence monitoring the grinding wheel loading and dressing at proper time intervals becomes mandatory to get the desired surface finish. In the quest of developing a low cost monitoring system, it is good enough to analyse the wheel loading on widely used metal specimens such as mild steel, HCHCr steel and aluminium under optimised cutting conditions using the conventional silicon carbide and aluminium oxide wheels for better evaluation of the results. In this work the grinding parameters are optimised by using ANOVA technique. A full factorial experiment was carried out at 5% level of significance, i.e. at 95% confidence level.
Optimisation of Micro Injection Moulding Process through Design of Experiments
Abstract The paper presents the optimisation of Micro Injection Moulding (MIM) process through Design of Experiments (DoE). MIM is a relatively new technology which is used for the rapid manufacture of micro components. In order to meet the quality and reliability constraints it is important to reduce variability during its operation due to changes in process parameters. In this study, an understanding of the MIM process and consequently its optimisation is carried out by DoE based on six parameters which influence the surface quality, flow length and the aspect ratio. Significant single process parameters and interactions between them were determined through statistical analysis. For the 2-level test, an aspect ratio of 20, 21, and 20 were achieved respectively for Polypropylene (PP), Acrylonitrile-Butadiene-Styrene (ABS) and Polyoxymethylene (POM).
Law as Palimpsest: Conceptualizing Contingency in Judicial Opinions (forthcoming 2009)
Metaphors create conceptualizations, and for decades legal academics have employed metaphors to shape understandings of legal problems. But no metaphor in current use successfully conceptualizes the contingency of judicial opinions and the complexity of the relationship between opinions and precedent. This Article seeks to fill this void by introducing a new metaphor, the palimpsest, into the realm of legal analysis. A palimpsest is a writing surface that can be cleared away for reuse, like a personal blackboard. What distinguishes a palimpsest from other writing surfaces is that its removed contents do not disappear, but remain, obscured yet recoverable: A writing on a palimpsest never goes away. This Article argues that thinking of judicial opinions as being part of a shared, ever-evolving palimpsest underscores the fact that they are ultimately contingent and serves as a reminder of the multiple levels of interconnectedness between them and the cases they cite. Precedents—like the underlayers of a palimpsest—never go away, and they inform and shape the application of opinions in ways far more significant than simply serving as points of reference. A palimpsestic approach to understanding judicial decisionmaking also helps to explain why even the oldest, most reviled cases remain part of our national psyche—like underlayers of a palimpsest, they can never truly disappear, and their continued presence forces us to grapple with their existence. Finally, considering judicial opinions as part of a shared palimpsest reminds us that even the most troubling opinion is ultimately contingent, its application subject to reexamination and revision by future courts and future generations. Just as such an opinion replaces its precedents, it too will one day be replaced, like each of a palimpsest’s layers. 2 Law as Palimpsest [Vol. __:__ Law as Palimpsest: Conceptualizing Contingency in Judicial Opinions