CAD Based Predictive Models of the Undeformed Chip Geometry in Drilling
Twist drills are geometrical complex tools and thus various researchers have adopted different mathematical and experimental approaches for their simulation. The present paper acknowledges the increasing use of modern CAD systems and using the API (Application Programming Interface) of a CAD system, drilling simulations are carried out. The developed DRILL3D software routine, creates parametrically controlled tool geometries and using different cutting conditions, achieves the generation of solid models for all the relevant data involved (drilling tool, cut workpiece, undeformed chip). The final data derived, consist a platform for further direct simulations regarding the determination of cutting forces, tool wear, drilling optimizations etc. Keywords—Drilling, CAD based simulation, 3D-modelling.
GEOMETRIC MODELING OF TWIST DRILLS
Accurate geometric models of twist drills are needed to determine the required grinding wheel profile for generating a given drill flute profile design, as well as, for finite element simulations of the drilling process. This paper presents a method to create accurate models of two-flute conical twist drills using analytical equations to generate drill flute profile needed for production of twist drills with straight lips and solidmodelling techniques to generate geometric models of twist drills. Boolean operations are used to mimic the drill manufacturing steps and generate the fully designed drill.
Amphotericin B microspheres: A therapeutic approach to minimize toxicity while maintaining antifungal efficacy
Amphotericin B microsphere formulations with and without addition of polyethylene glycol 2000 in cross-linked bovine serum albumin were prepared. Amphotericin B microspheres were characterized for particle size (<5 µm), zeta potential (∼30 mV) and drug interaction by DSC and FTIR and were found to be stable formulations. Drug release profiles for these microspheres revealed that the release was primarily by diffusion. In vitro toxicity as assessed by release of haemoglobin and potassium demonstrated no toxic effect as compared with conventional solution formulation. Antifungal activity in vitro was comparable to solution formulation when tested by broth dilution method.