First, the dynamics of LC-circuits are formulated as a Hamiltonian system defined with respect to a Poisson bracket which may be degenerate, i.e., nonsymplectic. This Poisson bracket is deduced from the network graph of the circuit and captures the dynamic invariants due to KirchhoWs laws. Second, the antisymmetric relations defining the Poisson bracket are realized as a physical network using ...

OBJECTIVE The aim of this study was to assess whether repetitive opening and closure of self-ligating bracket clips can cause plastic deformation of the clip. METHODS Three types of active/interactive ceramic self-ligating brackets (n = 20) were tested: In-Ovation C, Quicklear and WOW. A standardized controlled device performed 500 cycles of opening and closure movements of the bracket clip w...

The aim of this study was to compare the static and kinetic frictional forces generated by various contemporary designs of self-ligating brackets (SLBs) and different wire alloys. In total, six different brackets (four passive type SLB, one active SLB, and one conventional bracket) were investigated using stainless steel, nickel-titanium, and titanium-molybdenum alloy archwires of several sizes...

A bracket has been designed to allow a Kowa RC II fundus camera to be mounted firmly on a Haag-Streit goo slit lamp. The bracket provides a steady support which is of particular importance in fluorescein fundus angiography. The bracket consists oftwo parts. The upper part of mild steel and finished in satin chrome fits into the camera shoe and can be locked into place. The lower part is black a...

Content A physical and concrete context for the theory .................................................................................. 1 Entering in the domain of validity of the theory of the (E) question .................................................. 2 Definition 01: extended Lie’s product (or bracket) ......................................................................... 2 A statem...

There is every indication that classical friction controls sliding mechanics below some critical contact angle, theta c. Once that angle is exceeded, however, binding and notching phenomena increasingly restrict sliding mechanics. Using geometric archwire and bracket parameters, the theta c is calculated as the boundary between classical frictional behaviour and binding-related phenomena. What ...

We explain a general approximation technique for nonholonomic systems by discussing in detail a special example, chosen so as to illustrate some of the technical aspects of the general construction. The example considered is that of an extension of a two-input system obtained by adding a single bracket of degree ve. This bracket is suuciently complicated to exhibit some phenomena, such as multi...

In this paper we consider the optimal structure of double bracket flows and generalisations of these flows to more complex gradient flows. We discuss different notions of optimality and the relationship of the flows to the structure of convex polytopes.