Abstract: A hose with high flexibility and heat resistance, and low permeability to greenhouse gases, particularly for climate control, conditioning and refrigeration systems, for vehicles and fixed installations, comprising at least one outer layer made of rubber, and at least one layer of flexible thermoplastic material coupled to at least one layer of impermeable thermoplastic material, the latter layers constituting an inner core of the hose.

Abstract: An operational method is disclosed for the display of images by an electro-optical device comprising a liquid-crystal cell inserted between two polarizing devices, means being provided for impressing on the liquid crystal electric pulses, the improved method comprising the step of applying a pulsed energization, each pulse being any voltage waveform having a duration and an RMS amplitude such as to originate, at each pulse, a cell luminous response and not exceeding 1.3 times those which are required to produce a flash of light with a peak amplitude which cannot be further increased without causing more than one peak to appear. In the case of repetitive energization, the pulse repetition period, under steady conditions, shall be such that at the end of the period, the luminous response of the cell falls irreversibly to a value which is not more than one half of that peak value corresponding to "white level".