Abstract: A heat-loss pressure microsensor for measuring a gas pressure is disclosed that includes a plurality of pressure gauges arranged proximate to one another on a substrate. The gauges may include a pair of gauges, each gauge including a thermistor having an electrical resistance that varies with its temperature, the thermistor's temperature being responsive to the gas pressure, a platform to receive the thermistor, and a support structure to hold the platform above the substrate. Each gauge may be configured to produce a gauge output signal related to the electrical resistance of its thermistor. The two gauges are configured with their platforms having equal nominal perimeters and different nominal surface areas, and their support structures having the same nominal geometry. A differential signal may be obtained from the two gauge output signals. The differential signal conveys information about the gas pressure and exhibits reduced sensitivity to fabrication-related dimensional variations.

Abstract: A heat-loss pressure microsensor for measuring a gas pressure is disclosed that includes a plurality of pressure gauges arranged proximate to one another on a substrate. The gauges may include a pair of gauges, each gauge including a thermistor having an electrical resistance that varies with its temperature, the thermistor's temperature being responsive to the gas pressure, a platform to receive the thermistor, and a support structure to hold the platform above the substrate. Each gauge may be configured to produce a gauge output signal related to the electrical resistance of its thermistor. The two gauges are configured with their platforms having equal nominal perimeters and different nominal surface areas, and their support structures having the same nominal geometry. A differential signal may be obtained from the two gauge output signals. The differential signal conveys information about the gas pressure and exhibits reduced sensitivity to fabrication-related dimensional variations.

Abstract: A method and system for imaging a target scene using a microbolometer array having multiple lines of microbolometer pixels are disclosed. Each line is switchable between an exposed state and a shielded state, where the line is exposed to the target scene and a reference scene, respectively. The method may include alternating between generating a target frame of the target scene and generating a reference frame of the reference scene, each of which in a rolling shutter mode. The method may also include, concurrently with the generating steps, alternating between sequentially shielding each line after its readout in the exposed state for its next readout in the shielded state, and sequentially exposing each line after its readout in the shielded state for its next readout in the exposed state. The method may also include adjusting the target frames using the reference frames to generate thermal images of the target scene.

Abstract: The invention relates to a method of transferring a tissue web with residual moisture to a Yankee cylinder and final removal of the dried tissue web from the Yankee cylinder using a doctor blade and collecting the dried web on a reel-up machine forming a tissue reel. The invention also relates to the Yankee adhesive composition per se. The method involves preparation of a water solution of a Yankee adhesive composition with less than 10% final solids content to be applied on the surface of the Yankee cylinder ahead of transferring the tissue web with residual moisture to the Yankee cylinder. The inventive method applies an aqueous PVOH solution with a very high molecular weight polyvinyl alcohol as a part of the solid content of the Yankee adhesive in an amount ranging from 20-65% of the final solids content of the Yankee adhesive. The aqueous PVOH solution with the very high molecular weight polyvinyl alcohol establish a viscosity ranging from 90 cP to 300 cP.

Abstract: The invention relates to a method of transferring a tissue web with residual moisture to a Yankee cylinder and final removal of the dried tissue web from the Yankee cylinder using a doctor blade and collecting the dried web on a reel-up machine forming a tissue reel. The invention also relates to the Yankee adhesive composition per se. The method involves preparation of a water solution of a Yankee adhesive composition with less than 10% final solids content to be applied on the surface of the Yankee cylinder ahead of transferring the tissue web with residual moisture to the Yankee cylinder. The inventive method applies an aqueous PVOH solution with a very high molecular weight polyvinyl alcohol as a part of the solid content of the Yankee adhesive in an amount ranging from 20-65% of the final solids content of the Yankee adhesive. The aqueous PVOH solution with the very high molecular weight polyvinyl alcohol establish a viscosity ranging from 90 cP to 300 cP.

Abstract: The infrared scene projector has a support structure having an airtight chamber; an image projector secured to the support structure; a conversion chip having a substrate secured to the support structure, and an array of conversion units received on a face of the substrate, the array of conversion units being enclosed inside the airtight chamber and being optically coupled to the image projector, each one of the conversion units having at least one supporting post secured to the face of the substrate and a suspended platform held spaced apart from the face of the substrate by the at least one supporting post, the conversion chip being adapted to convert at least one of visible and near-infrared light received from the image projector into infrared radiation; and an infrared beam path extending away from the array of conversion units.

Abstract: The infrared scene projector has a support structure having an airtight chamber; an image projector secured to the support structure; a conversion chip having a substrate secured to the support structure, and an array of conversion units received on a face of the substrate, the array of conversion units being enclosed inside the airtight chamber and being optically coupled to the image projector, each one of the conversion units having at least one supporting post secured to the face of the substrate and a suspended platform held spaced apart from the face of the substrate by the at least one supporting post, the conversion chip being adapted to convert at least one of visible and near-infrared light received from the image projector into infrared radiation; and an infrared beam path extending away from the array of conversion units.

Abstract: A method for controlling condensation of hydrogen peroxide at a preselected temperature within a sealed sterilization chamber including an article to be sterilized includes the steps of applying to the sealed chamber a vacuum of a first pressure sufficient to evaporate, at the preselected temperature, an aqueous solution of hydrogen peroxide of a first concentration. The hydrogen peroxide solution is then evaporated into a water vapor component and a hydrogen peroxide vapor component. The evaporated solution is injected into the sealed chamber in repeated pulses. The injecting is terminated once a preselected second pressure, higher than the first pressure, is reached in the chamber. The pulse volume is selected to allow selective control of the condensation of the hydrogen peroxide vapor component to achieve a layer of micro-condensation of hydrogen peroxide on the article, which layer has a second hydrogen peroxide concentration higher than the first hydrogen peroxide concentration.

Abstract: A method of metering of hydrogen peroxide gas into an evacuated sterilization chamber is disclosed. The method includes the steps of continuously monitoring a pressure in the sterilization chamber; connecting a passage of known volume to the evacuated chamber for evacuating the passage; sealing the passage; connecting the evacuated passage to a supply of hydrogen peroxide solution for a time sufficient to draw the hydrogen peroxide solution into and fill the passage; sealing the passage; and repeating those steps until a preselected pressure increase in the sterilization chamber is detected. The pressure increase is preferably 19 Torr. The known volume of the metering passage is preferably between 75 ?L and 15 ?L to control unwanted condensation of hydrogen peroxide in the sterilization chamber. Expensive peroxide concentration measurement systems are replaced with an economical low cost pressure sensor for control of the hydrogen peroxide concentration.

Abstract: A method of controlling unwanted condensation of hydrogen peroxide in a sterilization chamber at a preselected temperature is disclosed. The method includes the steps of maintaining the sterilization chamber at a vacuum pressure below the pressure at which hydrogen peroxide will boil at the preselected temperature, evaporating successive pulses of hydrogen peroxide, and injecting the evaporated hydrogen peroxide into the chamber, whereby the volume of each pulse of hydrogen peroxide is less than 75 ?L, preferably less than 35 ?L, most preferably less than 20 ?L. Sterilization results are improved by controlling unwanted condensation of hydrogen peroxide.

Abstract: A hydrogen peroxide delivery system for a sterilizer having a hydrogen peroxide injection unit and a housing is disclosed. The system includes a cradle for supporting a hydrogen peroxide solution container, a drainage arrangement for aspirating the hydrogen peroxide solution from the container, and a delivery arrangement for supplying the aspirated hydrogen peroxide solution to the hydrogen peroxide injection unit. The drainage arrangement includes a needle for penetrating a seal on the container and extending into the hydrogen peroxide solution in the container. A needle drive moves the needle from an at rest position, wherein the needle is retracted to allow insertion of a new hydrogen peroxide container into the cradle, to a penetrating position wherein the needle penetrates the seal of the container and extends all the way to the bottom of the container to ensure complete drainage of the hydrogen peroxide solution from the container.

Abstract: A metering unit is provided for metering hydrogen peroxide into an evacuated vessel, for controlling the concentration of hydrogen peroxide in the vessel. The metering unit includes a body defining a metering passage having a fixed volume and upstream and downstream ends, an upstream connection for connecting the upstream end to a hydrogen peroxide supply, a downstream connection for connecting the downstream end to a hydrogen peroxide vaporizer, an upstream valve for selectively closing the upstream end and a downstream valve for selectively closing the downstream end, and a controller for operating the valves in a non-overlapping and opposite manner for selectively preventing opening of both valves at the same time. With the metering unit of this disclosure, expensive peroxide concentration measurement systems are replaced with an economical monitoring of the number of injection cycles using a passage of fixed volume.

Abstract: A method of metering a preselected volume of hydrogen peroxide into a vessel under vacuum is disclosed. The method comprises the steps of connecting a passage of known volume to the vessel under vacuum to evacuate the passage; sealing the passage; connecting the passage to a supply of hydrogen peroxide solution for a time sufficient to draw the hydrogen peroxide solution into the evacuated passage and fill the passage with the hydrogen peroxide solution; sealing the passage; and repeating steps a) to d) until a cumulative volume of fills of the passage is equal to the preselected volume. The volume of the passage is preferably 15 ?L to 75 ?L. Sterilization is controlled in an economic manner by obviating the need for a means to measure the hydrogen peroxide concentration in the chamber.

Abstract: A method for controlling condensation of hydrogen peroxide at a preselected temperature within a sealed sterilization chamber including an article to be sterilized includes the steps of applying to the sealed chamber a vacuum of a first pressure sufficient to evaporate, at the preselected temperature, an aqueous solution of hydrogen peroxide of a first concentration. The hydrogen peroxide solution is then evaporated into a water vapor component and a hydrogen peroxide vapor component. The evaporated solution is injected into the sealed chamber in repeated pulses. The injecting is terminated once a preselected second pressure, higher than the first pressure, is reached in the chamber. The pulse volume is selected to allow selective control of the condensation of the hydrogen peroxide vapor component to achieve a layer of micro-condensation of hydrogen peroxide on the article, which layer has a second hydrogen peroxide concentration higher than the first hydrogen peroxide concentration.

Abstract: A method of sterilizing an article by sequentially exposing the article to hydrogen peroxide and ozone is disclosed. The article is exposed under vacuum first to an evaporated aqueous solution of hydrogen peroxide and subsequently to an ozone containing gas. The exposure is carried out without reducing the water vapor content of the sterilization atmosphere, the water vapor content being derived from the aqueous solvent of the hydrogen peroxide solution and from the decomposition of the hydrogen peroxide into water and oxygen. The complete sterilization process is carried out while the chamber remains sealed and without removal of any component of the sterilization atmosphere. For this purpose, the chamber is initially evacuated to a first vacuum pressure sufficient to cause evaporation of the aqueous hydrogen peroxide at the temperature of the chamber atmosphere. The chamber is then sealed for the remainder of the sterilization process and during all sterilant injection cycles.

Abstract: A microbolometer detector has an improved support structure. The microbolometer detector includes a substrate and a support structure including at least one post connected to and projecting substantially vertically from the substrate. The microbolometer detector also includes a platform held above the substrate and including a central region substantially vertically aligned with the at least one post of the support structure and a peripheral region surrounding the central region, the platform being supported by the support structure from the central region thereof. The microbolometer further includes at least one thermistor located in the peripheral region of the platform. A microbolometer focal plane array may also include multiple microbolometer detectors arranged in a two-dimensional array. The support structures are particularly well suited for supporting relatively large platforms of microbolometer detectors, particularly for far-infrared and terahertz detection and spectroscopy applications.

Abstract: A method detects a loss of calibration of a thermal imaging radiometer including an array of imaging microbolometers and a gauge microbolometer. The detection method includes applying a first and a second electrical stimulation to the gauge microbolometer to bring it to a first and a second predetermined temperature, followed by measuring an ohmic responsivity of the gauge microbolometer that is representative of a difference between the first and second electrical stimulations. The measured ohmic responsivity is compared with a reference ohmic responsivity, such that a loss of calibration is signaled whenever the measured and reference ohmic responsivities differ by more than a predetermined threshold. A correction method includes steps of the detection method, to yield a corrected voltage response function for each imaging microbolometer. Advantageously, the methods involve probing the electrical response of the gauge microbolometer without requiring thermoregulated blackbody calibrations sources.

Abstract: A microbolometer detector has an improved support structure. The microbolometer detector includes a substrate and a support structure including at least one post connected to and projecting substantially vertically from the substrate. The microbolometer detector also includes a platform held above the substrate and including a central region substantially vertically aligned with the at least one post of the support structure and a peripheral region surrounding the central region, the platform being supported by the support structure from the central region thereof. The microbolometer further includes at least one thermistor located in the peripheral region of the platform. A microbolometer focal plane array may also include multiple microbolometer detectors arranged in a two-dimensional array. The support structures are particularly well suited for supporting relatively large platforms of microbolometer detectors, particularly for far-infrared and terahertz detection and spectroscopy applications.

Abstract: A method detects a loss of calibration of a thermal imaging radiometer including an array of imaging microbolometers and a gauge microbolometer. The detection method includes applying a first and a second electrical stimulation to the gauge microbolometer to bring it to a first and a second predetermined temperature, followed by measuring an ohmic responsivity of the gauge microbolometer that is representative of a difference between the first and second electrical stimulations. The measured ohmic responsivity is compared with a reference ohmic responsivity, such that a loss of calibration is signaled whenever the measured and reference ohmic responsivities differ by more than a predetermined threshold. A correction method includes steps of the detection method, to yield a corrected voltage response function for each imaging microbolometer. Advantageously, the methods involve probing the electrical response of the gauge microbolometer without requiring thermoregulated blackbody calibrations sources.

Abstract: A method of controlling unwanted condensation of hydrogen peroxide in a sterilization chamber at a preselected temperature is disclosed. The method includes the steps of maintaining the sterilization chamber at a vacuum pressure below the pressure at which hydrogen peroxide will boil at the preselected temperature, evaporating successive pulses of hydrogen peroxide, and injecting the evaporated hydrogen peroxide into the chamber, whereby the volume of each pulse of hydrogen peroxide is less than 75 ?L, preferably less than 35 ?L, most preferably less than 20 ?L. Sterilization results are improved by controlling unwanted condensation of hydrogen peroxide.