Abstract: A system and method for determining noise power levels across a range of frequencies of the optical signal output from a device operating at a specified optical power and drive current and, in particular, for determining relative intensity noise values (RIN). The system may comprise a reference laser for generating an optical reference signal and a photodetector for converting the optical signal output from the reference laser and the device under test into equivalent electrical signals. The system also comprises means for measuring ac and dc components of the electrical signals output from the photodetector. The system may be used to measure RIN levels to an accuracy of less than 1 dB. Such measurements are of particular importance in the field of fiber optic telecommunications. The reference laser is shot noise limited in the frequency range of interest, typically between 20 MHz and 20 GHz, and has a narrow linewidth, typically less than 5 kHz.

Abstract: A method of fabricating a micro-mechanical sensor (101) comprising the steps for forming an insulating layer (6) onto the surface of a first wafer (4) bonding a second wafer (2) to the insulating layer (6), patterning and subsequently etching either the first (4) or second wafer (6) such that channels (18, 20) are created in either the first (2) or second (4) wafer terminating adjacent the insulating layer (6) and etching the insulating layer (6) to remove portions of the insulating layer (6) below the etched wafer such that those portions of the etched wafer below a predetermined cross section, suspended portions (22), become substantially freely suspended above the un-etched wafer. This method uses Silicon on Insulator technology. Also disclosed is a micro-mechanical gyroscope structure (101) allowing an anisotropic silicon to be used to fabricate a sensor functioning as if fabricated from isotropic silicon.

Abstract: A method of protecting a human or animal body from the effects of infection with Y. pestis is provided comprising administering to the body a vaccine including Yersinia pestis V antigen and Yersinia pestis F1 antigens or a protective epitopic part of each of these in a form other than whole Y. Pestis organisms. Preferably the antigens are administered in the form of a live vaccine or as recombinantly produced isolated and/or purified proteins. DNA encoding the whole or part of the F1 antigen and DNA encoding the whole or part of the V antigen may be used directly as a agnetic vaccine.

Abstract: A ceramic plate capable of luminescing under electron X-ray or other ionizing radiation comprises a fine powder bound in water glass such as sodium or potassium hydroxy silicates, or sodium or potassium borates. The powder is typically less than 50 .mu.m mean particle size e.g. 10 .mu.m size. Powder material includes: calcium borate, yttrium aluminate, zinc yttrium silicate, calcium silicate, germanate, Magnesium borate, Barium borate, strontium borate. Dopant materials may be Tb, Tm, Ce, Eu, Pr, Yb, Mn, Cu, Ag, Pb added in amounts up to 15% weight or more. The plate is formed by mixing powder and water glass into a dough. The dough is pressed in a mould to remove excess water glass and fired at about 950.degree. C. for about 8 hours. Alternatively excess water is used when mixing powder and water glass. This excess water is allowed to evaporate while the plate is in a mould prior to pressing and firing.

Abstract: A projectile component is provided with a thermally ablative coating capable of giving complete protection against the erosive effects of in-bore and in-flight heating, with minimal impairment of aerodynamic performance.

Abstract: A material suitable for a guest-host liquid crystal device comprises a soion of a liquid crystal material and a pleochroic dye where in the pleochroic dye comprises at least one anthrquinone compound free from water solubilizing and ionic substituents and having the formula: ##STR1## wherein Q is NH.sub.2, OH, alkyl, aryl, NO.sub.2 or halo;n is 0 to 4;each X independently is H, --SR, --NZ.sub.1 Z.sub.2 or Q;each R independently is alkyl, aryl or cycloalkyl;Z.sub.1 and Z.sub.2 are independently H, alkyl, cycloalkyl or aryl; provided that there are at least two groups X which are different --SR groups.

Abstract: The disclosure of this invention pertains to a system for optimizing fuel consumption in an aircraft having two engines, wherein a computer is programmed to increase the fuel flow to the engine which, consequent upon a fuel flow perturbation, shows itself to be responsible for the greater acceleration of the aircraft. Direction changes resulting from unequal fuel flows to the engines are compensated for by automatic rudder control, and speed changes resulting from the fuel flow changes are compensated for by automatic speed control also acting on fuel flow, all whereby direction and speed of flight are maintained while fuel consumption is minimized.