Magnetically operated limit switch has improved reliability, minimizes arcing

Limit switch for reliable, low-travel, snap action with negligible arcing uses an electrically nonconductive permanent magnet consisting of a ferrimagnetic ceramic and ferromagnetic pole shoes which form a magnetic and electrically conductive circuit with a ferrous-metal armature

Complicial structures in the nerves of omega-categories

It is known that strict omega-categories are equivalent through the nerve functor to complicial sets and to sets with complicial identities. It follows that complicial sets are equivalent to sets with complicial identities. We discuss these equivalences. In particular we give a conceptual proof that the nerves of omega-categories are complicial sets, and a direct proof that complicial sets are sets with complicial identities

Modular divisor functions and quadratic reciprocity

It is a well-known result by B. Riemann that the terms of a conditionally convergent series of real numbers can be rearranged in a permutation such that the resulting series converges to any prescribed sum s: add p1 consecutive positive terms until their sum is greater than s; then subtract q1 consecutive negative terms until the sum drops below s, and so on. For the alternating harmonic series, with the aid of a computer program, it can be noticed that there are some fascinating patterns in the sequences pn and qn. For example, if s = log 2 + (1/2) log (38/5) the sequence pn is 5, 7, 8, 7, 8, 7, 8, 8, 7, 8, 7, 8, . . . in which we notice the repetition of the pattern 8, 7, 8, 7, 8, while if s = log 2+ (1/2) log (37/5) the sequence pn is 5, 7, 7, 7, 8, 7, 8, 7, 7, 8, 7, 8, . . . in which the pattern is 7, 7, 8, 7, 8. Where do these patterns come from? Let us observe that 38/5 = 7 + 3/5 and 37/5 = 7 + 2/5. The length of the repeating pattern is the denominator 5, the values of pn, at least from some n on, are 7 and 8, and the number 8 appears 3 times in the pattern of the first example, and 2 times in that of the second one. These are not coincidences: we explain them in this paper

The algebra of the nerves of omega-categories

We show that the nerve of a strict omega-category can be described algebraically as a simplicial set with additional operations subject to certain identities. The resulting structures are called sets with complicial identities. We also construct an equivalence between the categories of strict omega-categories and of sets with complical identities

Electromagnetic Mach principle

We will introduce a gauge model which an electromagnetic coupling constant and local mass are related to all the charge in the universe. we will use the standard Dirac action, but where the mass and the electromagnetic coupling constant are a function of the sum of all the charge in the universe, which represent Mach principle for electromagnetic coupling constant. The formalisation is not manifestly Lorentz invariant, however Lorentz invariance can be restored by performing a phase transformation of the Dirac field.Comment: 3 page

Confining Boundary conditions from dynamical Coupling Constants

It is shown that it is possible to consistently and gauge invariantly formulate models where the coupling constant is a non trivial function of a scalar field . In the $U(1)$ case the coupling to the gauge field contains a term of the form $g(\phi)j_\mu (A^{\mu} +\partial^{\mu}B)$ where $B$ is an auxiliary field and $j_\mu$ is the Dirac current. The scalar field $\phi$ determines the local value of the coupling of the gauge field to the Dirac particle. The consistency of the equations determine the condition $\partial^{\mu}\phi j_\mu = 0$ which implies that the Dirac current cannot have a component in the direction of the gradient of the scalar field. As a consequence, if $\phi$ has a soliton behaviour, like defining a bubble that connects two vacuua, we obtain that the Dirac current cannot have a flux through the wall of the bubble, defining a confinement mechanism where the fermions are kept inside those bags. Consistent models with time dependent fine structure constant can be also constructedComment: 4 pages, 3 figures. A new reference added and discussion expande

Power spectral measurement of atmospheric turbulence in severe storms and cumulus clouds

Power spectrum measurements of atmospheric turbulence in severe storms and cumulus cloud