Multi-response optimisation of sintering parameters of Al–Si alloy/fly ash composite using Taguchi method and grey relational analysis

In this paper, an attempt has been made to optimise the sintering process parameters of Al–Si (12%) alloy/fly ash composite using grey relational analysis. Al–Si alloy/fly ash composite was produced using powder metallurgy technique. Al–Si alloy powder was homogenously mixed with various weight percentages of fly ash (5–15 wt.%) and compacted at a pressure ranging from 307 to 512 MPa. The green compacts were sintered at temperatures between 575 and 625°C. Experiments have been performed under different conditions of temperature, fly ash content, and compacting pressure. Taguchi’s L₉ orthogonal array was used to investigate the sintering process parameters. Optimal levels of parameters were identified using grey relational analysis, and significant parameter was determined by analysis of variance. Experimental results indicate that multi-response characteristics such as density and hardness can be improved effectively through grey relational analysis.     

Degradation of polyester waste by aliphatic and aromatic alcohols

Polyester waste was degraded with ethanol, n-propanol, and benzyl alcohol in an autoclave at 280°C under pressure to give seven unknown compounds. The products of each reaction were isolated by using column chromatography and were identified on the basis of elemental analysis and spectral data.     

Enhancing Wear Resistance of Cryo Treated Cu-Be2 Alloy

Silicon - In this investigation, the influence of cryogenic treatment on the tribological properties of Cu-Be2 alloy was investigated. Deep cryogenic treatment and shallow cryogenic treatment were...     

Evolution of PVA gels prepared without crosslinking agents as a cell adhesive surface

Physical parameters (such as crosslinking density, crystallinity and mechanical properties) have been found to largely affect cellular behavior on polymer scaffolds. This study demonstrated that transparent pure Poly (vinyl alcohol) hydrogels prepared via a freeze–thaw method can be made to support cell adhesion by controlling physical parameters such as concentration and the number of freeze–thaw cycles. For a given number of freeze–thaw cycles, (specifically 45), polymer concentration dependent structural and mechanical properties (such as tensile strength and stiffness) were correlated with cell adhesion. The maximum cell attachment occurred on the hydrogels with the greatest mechanical properties, crystallinity and crosslinking density. The hydrogel surfaces were more favorable to human dermal fibroblasts than human lens epithelial cells and retained their transparency as well as dimensional stability with only a small degree of swelling. Fibroblast laden hydrogels showed extensive alkaline phosphatase activity which confirmed their healthy proliferation and function. In this manner, this study suggests that transparent Poly (vinyl alcohol) hydrogels prepared by the freeze thaw method described here should be further studied for numerous tissue engineering applications.     

Comparison of temperature rise within pulp chamber during light curing of composite restoration

In this study, total of 60 extracted human teeth were divided into four groups. Group I and II were subjected to LCU A (2550 mW/cm²) and Group III and IV to LCU B (700 mW/cm²), respectively. The increase in temperature level from baseline was recorded using K type thermocouple while curing of dentin bonding agent and composite resins. The temperature rise was significantly higher for Light Curing Unit A which had higher intensity light than Light Curing Unit B. Remaining dentin thickness of the prepared tooth also has significant role in the temperature rise. Hence, light curing units should be used with caution to avoid over-exposure of teeth. Dental practitioners need to prepare teeth with silicone indices and pre-assessment of radiographs to avoid over-preparation. Regular check of intensity of light curing unit using commercially available intensity meter is advocated.     

Quality assessment of polyester chips and yarn by TMS-2

Penetration in polyester chips of different manufacturers and yarn (undrawn and drawn) was studied between 323 and 423 K on a thermomechanical system (TMS-2) using a penetration kit. It was observed that the penetration of the probe varied in the case of chips from manufacturer to manufacturer. The undrawn and drawn yarns from different batches and also within the same batch showed a clear variation in penetration curve, which may be attributed to the degree of crystallization. The same technique can be utilized for an assessment of the quality of yarn in continuous production and for differentiating the manufacturing process of polyester chips.     

Proteomic profiling of cancer of the gingivo-buccal complex: Identification of new differentially expressed markers

Tobacco-related oral cancer is the most common cancer among Indian males, gingivo-buccal complex (GBC) being the most affected subsite due to the habit of chewing tobacco. Proteins from the lysates of microdissected normal and transformed epithelium from clinically well-characterized tissue samples of the GBC were separated by two-dimensional gel electrophoresis to identify differentially expressed proteins. Eleven protein spots showed differential expression, which could withstand the stringency of statistical evaluation. The observations were confirmed with additional tissues. Nine of these differentiators were identified by MS as lactate dehydrogenase B, α-enolase, prohibitin, cathepsin D, apolipoprotein A-I, tumor protein translationally controlled-1, an SFN family protein, 14-3-3σ and tropomyosin. Cluster analysis indicated that these proteins, as a coexpressed set, could distinguish normal and transformed epithelium. Functionally, these differentiator molecules are relevant to the pathways and processes that have been previously implicated in oral carcinogenesis and could therefore be investigated further as a panel of markers for management of cancer of the GBC.