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.
Cutting Tool Technology: Industrial Handbook
Cutting Tool Materials Turning and Chip-breaking Technology Drilling and Associated Technologies Milling Cutters and Associated Technologies Threading Technologies Modular Tooling and Tool Management Machinability and Surface Integrity Cutting Fluids Machining and Monitoring Strategies
l-Phenylalanine dehydrogenase from Brevibacterium sp. for production of l-phenylalanine by reductive amination of phenylpyruvate
SummaryFor production of l-phenylalanine the reductive amination of phenylpyruvate, catalyzed by phenylalanine-dehydrogenase was examined. To reach high levels and a sufficient stability of the inducible intracellular enzyme, growth conditions of Brevibacterium sp. are optimized. For continuous production of l-phenylalanine in an enzyme membrane reactor, the kinetic parameters of the partially purified enzyme are determined.In continuous production a space time yield of 37.4 g l-Phe l-1 d-1 can be reached.By means of the measured kinetic parameters and simultaneous calculation of the mass balances of all reaction components the behaviour of the reactor can be simulated. For certain conditions the multi-enzyme-system shows multiple steady-states.