Abstract: An optical fiber comprises a core having an elliptical cross section and a cladding having a circular cross section. The core has an aspect ratio between 2 and 40. The core and the cladding have a common central axis with the core being enclosed by the cladding. The difference of a refractive index of the cladding to a refractive index of the core is between 1×10?2 and 1.5×10?1. A trench is located between the core and the cladding. The trench has a uniform width and encircles the core. The refractive index of the trench is lower than the refractive index of the cladding.

Abstract: An inverter for a photovoltaic apparatus, which includes a DC section, a DC/AC conversion section, an AC section and a control section. The DC section includes a plurality of DC input channels each including a DC/DC converter electrically connected between input terminals and the output terminals of the DC input channels. The inverter includes a measuring circuit arrangement adapted to measure an isolation resistance of the photovoltaic strings electrically connected with the DC input channels, when the inverter operates in predefined test conditions.

Abstract: An optical fiber comprises a core having an elliptical cross section and a cladding having a circular cross section. The core has an ellipticity between 2 and 40. The core and the cladding have a common central axis with the core being enclosed by the cladding. The difference of a refractive index of the cladding to a refractive index of the core is between 1×10?2 and 1.5×10?1. A trench is located between the core and the cladding. The trench has a uniform width and encircles the core. The refractive index of the trench is lower than the refractive index of the cladding.

Abstract: An inverter for a photovoltaic apparatus, which comprises a DC section, a DC/AC conversion section, an AC section and a control section. Said DC section includes a plurality of DC input channels each comprising a DC/DC converter electrically connected between input terminals and said output terminals of said DC input channels. The inverter comprises a measuring circuit arrangement adapted to measure an isolation resistance of the photovoltaic strings electrically connected with said DC input channels, when said inverter operates in predefined test conditions.

Abstract: An ultrasonic measuring device and method for determining bone density and structure includes an electronic control unit, a positioning unit housing at least a transducer pair and carrying a receiving unit, the unit being adapted to be coupled to a bone segment of the human body and carrying a locating device for ascertaining the position of the bone segment with respect to the unit, and an electronic unit for determining a first waveform representing an ultrasonic signal transmitted through the metaphysis portion of the bony segment and a second waveform representing an ultrasonic signal transmitted through the diaphysis portion, and an electronic processor and display for displaying the first and second waveforms as a measured output.

Abstract: An extrusion device (1) the extrusion head (2) of which features a number of superimposed shaped plates (9, 10, 11, 12) clamped together by a clamping device (3) located and operating externally of the extrusion head (2) about which it defines a releasable ring device; the extrusion device (1) having an automatic release device (4) for separating the shaped plates (9, 10, 11, 12) when the ring device is released.