Abstract: A heater diverter valve (20) is provided in an engine cooling system having a radiator and a circulating pump, The valve has a first inlet (31) connected to a heater so that coolant flowing through the engine and then through the heater is returned to the pump return line through the valve via the first inlet and an outlet (33). A second inlet (32) is connected to engine and transmission oil coolers so that coolant which flows from the engine supply line through the coolers is returned to the pump return line via the second inlet and the outlet. The valve includes a shuttle (24) which at lower coolant temperatures closes off the second inlet (32) to prevent coolant flow. The second inlet (32) is opened at higher temperatures when a wax type thermal actuator pushes the shuttle towards the first inlet (31).

Abstract: A birefringent spectral filter comprises a first birefringent stage and a polarizing beam splitter optically coupled to the first birefringent stage. The first birefringent stage is adapted to generate an optical path difference between light propagating along each of two orthogonal axes. This configuration is most advantageous when light incident on the first birefringent stage is polarized at 45° relative to the extraordinary axis of the birefringent material. The first birefringent stage may advantageously include a first and second layers of birefringent material and a half-wave plate disposed therebetween. Preferably, the first and second layers of birefringent material have orthogonally aligned extraordinary axes.

Abstract: A wavefront tilt measurement system for measuring the wavefront tilt of light passing through transmitting or receiving optical systems, the optical systems including a primary aperture and internal optical elements defining an optical system focal plane. A light source emits light at the optical system focal plane towards the internal optical elements such that light from the light source emerges from the primary aperture. A plurality of tilt sensors are disposed adjacent to the primary aperture to receive light emerging from the primary aperture. Each tilt sensor includes a sensor focal plane and a plurality of detector elements. Each tilt sensor generates at the focal plane a plurality of overlapping regions of zero and first order images of light emerging from the primary aperture. The measured intensity of light in the overlapping regions is used to determine the wavefront tilt of light emerging from the primary aperture.

Abstract: Methods and compositions are disclosed for controlled addition of components that decrease the viscosity of the viscoelastic surfactant fluids or for controlled changes in the electrolyte concentration or composition of the viscoelastic surfactant fluids. One aspect of the invention relates to the use of internal breakers with a delayed activation. Another aspect of the invention relates to the use of precursors that release a breaking system such as alcohol by a process such as melting, slow dissolution, reaction with a compound present in the fluid or added to the fluid during or after the step of injecting, rupture of an encapsulating coating and de-adsorption of a breaking agent absorbed into solid particles. In another aspect of the invention, alcohols are included in a pad to reduce the low-shear viscosity and reduce the resistance to flow of the treatment fluids during a desired phase of the treatment.

Abstract: A dispersive spectrometer comprising a primary lens that images a scene onto a slit through which light from a thin portion of the scene passes to a collimating lens. A grism is optically coupled to the collimating lens. The grism includes a diffractive element and is disposed such that light from the thin portion of the scene has an angle of incidence upon the diffractive element that is greater than one-third of the critical angle at the surface of the grism. The diffractive element disperses light from the thin portion of the scene in a direction that is perpendicular to the major dimension of the thin portion of the scene. A focusing lens is optically coupled to the grism to receive dispersed light from the thin portion of the scene. The focusing lens defines a focal plane onto which light from the thin slice of the scene is imaged.

Abstract: A vehicle (10) is disclosed which includes a thermostat (22) in a bottom hose (24) of a radiator (16). An onboard diagnostic arrangement is provided to monitor the efficiency of the thermostat (22). Temperature sensors (S1, S2) are provided to monitor the temperature of the coolant across the radiator (16) so that a controller (40) can derive from those measurements the temperature differential across the thermostat (22). If the temperature Teng of the coolant at the thermostat inlet is below the thermostat opening temperature Topen and the differential temperature between the thermostat inlet temperature Teng and the thermostat outlet temperature Trad is below a fault threshold Dtstat, the thermostat (22) is evaluated as being stuck open or leaking, which results in a fault being recorded and a malfunction indicator lamp (MIL) being illuminated.

Abstract: A wavefront tilt measurement system for measuring the wavefront tilt of light passing through transmitting or receiving optical systems, the optical systems including a primary aperture and internal optical elements defining an optical system focal plane. A light source emits light at the optical system focal plane towards the internal optical elements such that light from the light source emerges from the primary aperture. A plurality of tilt sensors are disposed adjacent to the primary aperture to receive light emerging from the primary aperture. Each tilt sensor includes a sensor focal plane and a plurality of detector elements. Each tilt sensor generates at the focal plane a plurality of overlapping regions of zero and first order images of light emerging from the primary aperture. The measured intensity of light in the overlapping regions is used to determine the wavefront tilt of light emerging from the primary aperture.

Abstract: A dispersive spectrometer comprising a primary lens that images a scene onto a slit through which light from a thin portion of the scene passes to a collimating lens. A grism is optically coupled to the collimating lens. The grism includes a diffractive element and is disposed such that light from the thin portion of the scene has an angle of incidence upon the diffractive element that is greater than one-third of the critical angle at the surface of the grism. The diffractive element disperses light from the thin portion of the scene in a direction that is perpendicular to the major dimension of the thin portion of the scene. A focusing lens is optically coupled to the grism to receive dispersed light from the thin portion of the scene. The focusing lens defines a focal plane onto which light from the thin slice of the scene is imaged.

Abstract: A high speed high resolution spectral sensor is formed by placing a cascade of chained wide field-of-view Mach-Zender interferometers inside a dispersive sensor between the sensor's grating and the focusing lens. Also is disclosed an optical filter with wide field-of-view capabilities. Such a filter is formed by inserting a plurality of gap plates of certain thicknesses and refractive indices. The invention provides formulas for calculation of optimal dimensions for such gap plates.

Abstract: Methods and compositions are disclosed for controlled addition of components that decrease the viscosity of the viscoelastic surfactant fluids or for controlled changes in the electrolyte concentration or composition of the viscoelastic surfactant fluids. One aspect of the invention relates to the use of internal breakers with a delayed activation. Another aspect of the invention relates to the use of precursors that release a breaking system such as alcohol by a process such as melting, slow dissolution, reaction with a compound present in the fluid or added to the fluid during or after the step of injecting, rupture of an encapsulating coating and de-adsorption of a breaking agent absorbed into solid particles. In another aspect of the invention, alcohols are included in a pad to reduce the low-shear viscosity and reduce the resistance to flow of the treatment fluids during a desired phase of the treatment.

Abstract: An improved lateral shearing interferometer system for use with an original optical wavefront and a displaced optical wavefront having a phase difference from the original optical wavefront is disclosed. It comprises a lateral shearing interferometer that responds to the original optical wavefront and the displaced optical wavefront and develops an optical interference pattern representative of the optical phase differences. An optical detector located at the focal plane of the optical interference pattern provides a selective array of electrical signals representative of separated portions of the interference pattern. A data processor is programmed to indicate the separated portions of said interference pattern, which has pixels in non-adjacent locations in odd rows and no pixels in even rows. The pixels correspond to locations of actuators for correcting the phase difference.

Abstract: A dual sensor wavefront correction system is adaptable to correcting wavefronts including wavefronts that are severely scintillated. The system includes a Hartmann wavefront sensor as well as a unit shear lateral shearing interferometer (LSI) wavefront sensor. The optical output signals from the Hartmann wavefront sensor are applied to a real reconstructor which provides an estimation of the distortion in the wavefront during most conditions except for conditions of severe turbulence. In order to provide compensation for the phase discontinuities in a scintillated wavefront, a unit shear lateral shearing interferometer (LSI) wavefront sensor is provided. The optical output signals from the unit shear LSI wavefront sensor are processed by a complex reconstructor in order to provide relatively accurate estimates of the tilt signals at the discontinuities.

Abstract: An array of a large number of low quality light collectors measure light generated by arrays of coherent light illuminators and rebounded from a target. The resulting data is utilized to derive the resulting speckle pattern which in turn is Fourier transformed to reconstruct the target image.

Abstract: A separator (8) for separating liquid from gas is disclosed in which two or part cylindrical chambers (12, 12', 14, 14', 16) are arranged to produce contra-rotating vortices therein when a liquid and gas mixture is passed therethrough. The change in direction of the flow when passing from one chamber to the next and the centifugal effect of the vortex flow separates the denser fluid from the less dense gas.

Abstract: An optical wavefront sensor for measuring phase tilt in two dimensions across the cross section of a beam (14), using only a single lenslet array (26) and a single camera sensor array (28). The rectangular lenslet array (26) is oriented at 45 degrees to first and second orthogonal sets of axes defining multiple points of interest (22') in the beam cross section, such that each lenslet subaperture is centered (at 40) between adjacent points of interest on the first and second axes. The points of interest (22') are locations corresponding to the positions of actuators (22) in an adaptive optics system. The camera sensor array (28) has more cells per unit area than there are subapertures per unit area. Only selected cells are activated, to provide for measurements at the approximate mid-points of lines between adjacent points of interest (22') on the first and second orthogonal axes.

Abstract: To ensure an adequate supply of hot engine coolant to a heater circuit at low engine speeds, a combined thermostat and bypass valve 10 is arranged to restrict bypass flow by means of a spring-loaded bypass valve 38 operating at a bypass delivery port 16. At low engine speeds the bypass flow pressure is insufficient to lift the bypass valve 38 from its seating and the flow through a heat exchanger "H" in the heater circuit is thereby enhanced.

Abstract: A cooling circuit for an internal combustion engine is disclosed in which the bypass and thermostat assembly includes means to prevent relatively cold coolant entering the thermostat assembly from a bottom hose to impinge upon a temperature sensitive valve actuating means. The bypass and thermostat assembly is therefore unaffected by relatively colder coolant entering the assembly as the temperature sensitive part of the thermostat remains immersed in relatively warm coolant entering the assembly through a bypass hose even when the bypass is closed.

Abstract: An internal combustion engine comprises an iron block 2 and an aluminium head 3 held together by bolts 6. The bolts 6 extend through oil drainage passages 8 in the head and through bores 9 in the block and engage with the block at a point substantially spaced from the head/block interface. The increased length of the bolts 6 allows them to stretch to accommodate the relatively large expansion of the head as the engine warms up. Good thermal contact is provided between the bolts and the water jacket of the engine so that the bolts warm up quickly.

Abstract: An internal combustion engine has a cylinder head assembly with a camshaft 28 mounted therein and breather passages 70 through it. A guard member 38 is mounted on the head casting 12 and includes guards 40 over the cams 42 side walls 39 and a bearing ladder for the camshaft. A gasket 46 between the guard member 38 and a cover 44 forms, with the guard member 38, a separation region 50 having an inlet 72 fed by the breather passages and outlets 51 in the form of holes through the gasket 46. The gas can flow from the breather passages to the outlets 51 is slow and substantially horizontal so oil can separate out of the gas. The guards 40 prevent oil from the cams 42 from mixing with the breather gases.

Abstract: An internal combustion engine 20 comprises a cylinder block 22, a cylinder head 24, and a plurality of fasteners 47 holding the head onto the block. The block comprises a single structure having walls 34 defining four cylinder bores 36 arranged in a line for receiving pistons, longitudinal support sections 60, 61 extending along the block one on either side of the line of bores and transverse support sections 74 joined to the longitudinal support sections and extending substantially tangentially to the bores. The fasteners 47 are arranged to engage with the block 22 such that a substantial part of the load exerted on the top of the walls 36 of the bores is transmitted to the fasteners via the support sections. This prevents forces from being transmitted radially into the cylinder walls 36 and thereby reduces bore distortion.