Experimental investigation on porosity and flexural strength of polymer parts fabricated by fused deposition modeling

Nowadays, polymer parts are fabricated by fused deposition modeling (FDM) techniques of additive manufacturing for biomedical, sports, and automotive applications. But, functional use of these parts in high-strength applications is limited due to anisotropic nature of the FDM process. Various researchers have proved that those process variables of FDM affect the mechanical properties of polymer parts. The present paper describes an experimental investigation of porosity and flexural strength of thermoplastic polymer (poly-lactic acid) parts fabricated by FDM. Influence of three process variables namely nozzle temperature, print speed, and raster width on porosity and flexural strength of parts is studied. Experiments are planned using a central composite design. Specimens are first weighed for density measurements and then tested using three-point flexural loading on a tensometer. It is found that all three process variables have a significant effect on porosity and flexural strength. Print speed is the most influential parameter for porosity, while raster width is the most significant parameter for flexural strength. Further, regressive models are developed to predict the responses. Also, microstructure of fractured specimens is studied using a scanning electron microscope. Optimization of process variables is performed to minimize porosity and maximize flexural strength using the desirability function approach.     

A SiGe-Source Doping-Less Double-Gate Tunnel FET: Design and Analysis Based on Charge Plasma Technique with Enhanced Performance

Silicon - In this article, a distinctive charge plasma (CP) technique is employed to design two doping-less dual gate tunnel field effect transistors (DL-DG-TFETs) with Si0.5Ge0.5 and Si as source...     

Crystallization Kinetics on Melt Spun and HPT-Processed Zr62Cu22Al10Fe5Dy1 Metallic Glass

Metallurgical and Materials Transactions A - The influence of conventional and accumulative HPT (Acc. HPT) process on structural properties of Zr62Cu22Al10Fe5Dy1 metallic glass (MG) phase is...     

Recent Advances in Small Molecule-Based Intracellular pH Probes

Intracellular pH plays an important role in many biological and pathological processes. Small-molecule based pH probes are found to be the most effective for pH sensing because of ease of preparation, high sensitivity, and quick response. They have many advantages such as small perturbation to the functions of the target, functional adaptability, cellular component-specific localization, etc. The present review highlights the flurry of recent activity in the development of such probes. The probes are categorized based on the type of fluorophore used like quinoline, coumarin, BODIPY, rhodamine, indolium, naphthalimide, etc., and their analytical performance is discussed.