Abstract: A method and apparatus for the photo-acoustic identification and quantification of one or more analyte species present in a gaseous or liquid medium in low concentration utilizing a laser and a resonant optical cavity containing the medium and having within the cavity at least two partially transparent mirrors, one of which is a cavity coupling mirror and one of which is moveably mounted on an assembly responsive to an input signal.

Abstract: A method for concentrating a particulate matter, comprising at least two constituents of different densities, in which a slurry of particulate matter is subjected to centrifugation and to centripetal pulses in a centrifugation chamber. A dense fraction of the slurry and a light fraction of the slurry are drawn off separately from the centrifugation chamber. In order to produce the centripetal pulses, a fluid is injected into the slurry, in a direction oblique or tangential to the direction of centrifugation. The fluid is injected substantially continuously into the slurry.

Abstract: Optical mirror elements having a diffusive backing, methods for making such optical mirror elements, and devices incorporating such optical mirror elements. The optical mirror element typically includes a first, reflective surface, and a second surface having uneven or granular features, wherein light passing through the first surface is diffusely reflected by the uneven or granular features of the second surface. The optical mirror elements are particularly well suited for use in Herriott Cell arrangements in gas analyzers.

Abstract: Methods and apparatus to perform wavefront analysis, including phase and amplitude information, and 3D measurements in optical systems, and in particular those based on analyzing the output of an intermediate plane, such as an image plane, of an optical system. Measurement of surface topography in the presence of thin film coatings, or of the individual layers of a multilayered structure is described. Multi-wavelength analysis in combination with phase and amplitude mapping is utilized. Methods of improving phase and surface topography measurements by wavefront propagation and refocusing, using virtual wavefront propagation based on solutions of Maxwell's equations are described. Reduction of coherence noise in optical imaging systems is achieved by such phase manipulation methods, or by methods utilizing a combination of wideband and coherent sources.

Abstract: A flow meter includes a heater for heating a fluid flow along a membrane. A temperature difference is measured between and upstream point and a downstream point. There are additionally provided one or more strips of material having a relatively high heat conductivity. Strips that are substantially perpendicular to the flow direction direct heat from the heater to the sides of the membrane, causing a large proportion of the heat that would otherwise drive heat flows to be dispersed and decreases inaccuracies or bias in the measured flow rate. Strips of material that are provided parallel to the flow direction act to direct heat from the heater along the direction of flow. This increases the proportion of heat that flows along this axis and guides the flow and hence reduces the proportion of heat available to drive heat flows that cause inaccuracies and bias in the measured flow rates.

Abstract: Gas analyzer systems and methods for measuring concentrations of gasses and in particular dry mole fraction of components of a gas. The systems and method allow for rapid measurement of the gas density and/or dry mole fraction of gases for a number of environmental monitoring applications, including high speed flux measurements. A novel coupling design allows for tool-free removal of a cell enclosing a flow path to enable in field cleaning of optical components.

Abstract: An imaging system that allows for unhindered access to a sample to be imaged. A housing structure is configured with a drawer having a platform. The platform may be configured to hold a sample, such as an animal, and/or the platform may be configured to mate with a sample holding member, such as a removable carrying tray for holding the sample. The drawer presents the platform to an imaging device or system internal to the housing when in a closed, or imaging, state. When in an extended state, the drawer presents the platform external to the housing to allow unobstructed manipulation of a sample on the drawer platform (or on the sample holding member on the platform). When used, a sample holding member such as a removable carrying tray may be docked with the drawer platform, and various interconnects, such as gas ports and electrical connectors, on the sample holding member engage with corresponding elements on the platform when docked.

Abstract: In a three phase BLDC motor the rotor position is monitored by detecting the zero crossing points of the induced back EMF signals BEMF_U, BEMF_V, BEMF_W in the phase windings U, V, W. As they are illustrated, the back EMF signals are substantially sinusoidal but they may in other situations be substantially trapezoidal. The three back EMF signals are 120° out of phase with each other. In order to accurately monitor the back EMF in a phase winding, the driving waveform for each phase U, V, W includes an undriven period P close to the expected zero crossing point. The period P can be a preset part of the driving waveform or can be an interruption of the normal driving waveform in response to suitable interrupt signals. In order to determine the zero crossing points of each back EMF signal, two (or more) samples of the back EMF are taken during the undriven period P and used to interpolate the back EMF signal to determine the zero crossing point.

Abstract: A 2-phase BLDC motor is driven by a trapezoidal waveform. For one-half of the motor rotation period T, the phase is driven by the trapezoidal waveform and for the other half-period, the coil remains undriven. An up down counter is operable to increment at a first frequency f1 and to decrement at a second frequency f2. Incrementing operation is initiated at the start of the driven period of the waveform and stopped at the start of the down slope of the waveform. Decrementing operation is initiated at the start of the down slope of the waveform and stopped at the end of the down slope. The ratio of frequencies f1:f2 is used to measure the relative duration of the slope to the driven period and is selected to mirror the desired ratio of slope duration:driven period duration.

Abstract: Bulletproof vests, body armor, and other tactical vests with quick release buckle mechanisms are described along with methods of their use. The multi-point buckle mechanisms release upon rotating a shaft, allowing the vest panels and straps to fall cleanly to the ground without knocking the wearer off balance. Waist belt clips allow a wearer to put the vest on over his or her head without engaging the emergency release, or the multi-point buckle mechanism can release only the waist straps upon rotating the shaft in the opposite direction. A flap protects the rotatable quick release mechanism from inadvertent activation.

Abstract: The invention relates to a metal matrix ceramic composite (MMCC) wear-parts comprising a wearing portion formed by a ceramic cake and is impregnated by metal. The ceramic cake comprises ceramic grains and carbide grains. The invention also relates to a method for manufacturing the wear-parts. The invention further describes a grinding roll and a table liner for a vertical mill each comprising a metal matrix ceramic composite wear part(s) of the invention.