Background: Mesenchymal stem cells (MSCs) have been recently received increasing attention for cell-based therapy, especially in regenerative medicine. However, the low survival rate of these cells restricts their therapeutic applications. It is hypothesized that autophagy might play an important role in cellular homeostasis and survival. This study aims to investigate the regenerative potentia...

Magnetic bearings are used in several applications, but they didn’t succeed in the machine tool industry, due basically to their low damping, with its associated low chatter free cutting capacity. This work shows the development of a high speed milling spindle supported on magnetic bearings with high chatter resistance. That is achieved by using control strategies which add damping to the beari...

This paper describes a combined mathematicalgraphical approach for optimum tool path planning in order to improve machining efficiency. A methodology has been used that stabilizes machining operations by adjusting material removal rate in pocket milling operations while keeping cutting forces within limits. This increases the life of cutting tool and reduces the risk of tool breakage, machining...

Chatter vibrations result in reduced productivity, poor surface finish and decreased cutting tool life. Milling cutters with nonconstant pitch angles can be very effective in improving stability against chatter. In this paper, an analytical stability model and a design method are presented for nonconstant pitch cutters. An explicit relation is obtained between the stability limit and the pitch ...

Most qualitative simulation techniques perform simulation at a single level of detail highlighting a fixed set of distinctions . This can lead to intractable branching within the behavioral description . The complexity of the simulation can be reduced by eliminating uninteresting distinctions . Behavior abstraction provides a hierarchy of behavioral descriptions allowing the modeler to select t...

Recently, use of parallel turning operations has been increasing due to the potential they offer for improved material removal rate using multiple cutting tools. However, chatter vibrations resulting from process instability may limit the productivity in these operations. In order to determine favourable conditions for increased stability, dynamics of parallel turning operations must be modelle...

An end milling process is widely used in fabrication of complex contours and shape parts at high spindle speeds. Many researchers try to investigate one of important aspect, which come across during machining is the self exited chatter vibration which causes severe damage of the tool and quality of the machined surface. The present work is focused on the Magneto-Rheological Damping effect on st...

This article provides a comprehensive account of the application of the main theorems from the theory of non-linear dynamics to experimental data of chatter vibrations. The description of the complex oscillations are based on experimental investigations from interior diameter turning experiments. The theory of nonlinear dynamics and stochastic analysis have been considered to explain such pheno...

background: mesenchymal stem cells (mscs) have been recently received increasing attention for cell-based therapy, especially in regenerative medicine. however, the low survival rate of these cells restricts their therapeutic applications. it is hypothesized that autophagy might play an important role in cellular homeostasis and survival. this study aims to investigate the regenerative potentia...