This paper addresses the design and commutation of a novel kind of spherical stepper motor in which the poles of the stator are electromagnets and the poles of the rotor (rotating ball) are permanent magnets. Due to the fact that points on a sphere can only be arranged with equal spacing in a limited number of cases (corresponding to the Platonic solids), design of spherical stepper motors with...

Orbiting EDM has the advantages of superior machining quality over static EDM due to advanced flushing. However, improper tool correction to the relative motion in orbiting EDM will result in dimension errors of the product. As features vary in morphology, tool design for orbiting EDM is a challenging task, particularly for mould comprises assorted features. A strategy for correcting the orbita...

a brass vortex tube (vt) with interchangeable parts is used to determine the optimum cold end orifice diameter, main tube length and diameter. experiments were carried out to study the effects of operating pressure as well. it is shown that there is an optimum value for cold end orifice diameter, which is equal to 4mm and there is an optimum value for cold and hot exit temperature difference at...

the binary and ternary codes spanned by the rows of the point by block incidence matrices of some 2-designs and their complementary and orthogonal designs are studied. a new method is also introduced to study optimal codes.

We present a new optical system design for a projector with a single digital micromirror device (Texas Instruments Digital Micromirror Device) that improves on previous designs in terms of optical efficiency, uniformity, and contrast while yielding a low-profile and compact system. A rod integrator is incorporated with a compact relay system to maximize light efficiency and to increase illumina...

Recently, many optimal designs for axial flux permanent magnet (AFPM) motors were performed based on finiteelement (FE) analysis. Most of the models are based on reduction of 3D problem to 2D problem which is not accurate for design aspects. This paper describes an accurate electromagnetic analysis of a surface mounted, 28 pole AFPM with concentrated stator winding. The AFPM is modeled with thr...

The advent of Transformation Optics established the link between geometry and material properties, and has resulted in a degree of control over electromagnetic fields that was previously impossible. For waves confined to a surface it is known that there is a simpler, but related, geometrical equivalence between the surface shape and the refractive index, and here we demonstrate that conventiona...

The road and railway infrastructure in Poland has been intensively developed and modernized for the last years. Around 300 new bridges are built annually. Among the new structures, there is a group of modern extradosed bridges. This paper presents examples of short-, medium-, and long-span extradosed bridges designed and built in recent years in Poland. The following structures are described in...