Abstract: A terahertz time-domain spectrometer scanning sensor system includes a transmitter and a receiver that are secured to a mobile scanner head. Optical pump light, in the form of short pulses launched from a stationary laser located remotely from the scanner head, is delivered to the transmitter and receiver through a controlled fiber optic cable arrangement so that variations in temporal pulse relays that are associated fiber optic transmission are minimized. In this fashion, the movement of the fiber optic cable is maneuvered along a defined path so as to control the bends in the cable and thus minimize variations in temporal delays that can otherwise arise as the pulses of light are transmitted through the fiber. Pulses of laser light launched from the laser into the optical fiber will exit the cable with consistent (i) time of arrival, (ii) phase duration, and (iii) polarization state and energy.

Abstract: An optical, non-contact sensor for measuring the thickness or weight of layered products and particularly those that contain a light-reflective substrate incorporates a reflective surface to cause incident radiation from a light source to plurality of time within the layered products before being detected in a receiver. A diffusing element can be incorporated as a diffuse source of illumination. The Lambertian-type light scattering generated by the diffuse element causes the incident light to interact multiple times with the layered product resulting in enhanced sensor sensitivity to selected components in the layered product and measurement error induced by specular reflection of the light from the reflective substrate is minimized.

Abstract: Alignment is a critical component for modeling a cross-directional (CD) papermaking process. It specifies the spatial relationship between individual CD actuators to paper quality measurements. Misalignment can occur unexpectedly due to sheet wander or CD shrinkage variation. In certain applications and circumstances, a misalignment of one third (?) actuator zone width can result in significant paper quality degradation. Detecting a misalignment and identifying CD alignment in closed loop are highly demanded in paper mills but these are nontrivial problems. A technique for maintaining proper CD alignment in sheetmaking systems entails monitoring the alignment online, triggering closed loop identification if misalignment is detected, and then deploying the new alignment. No personnel intervention is required.

Abstract: A sensor head-transporting roller carriage has four pairs of wheels acting around pivot points at the four corners of the carriage, which is advanced along tracks that are supported by vertical structures. The lateral wheel spacing is chosen in correlation with the track support interval distances such that the vertical travel of all the wheels together is averaged, to be zero. As a result, variations in displacement alignment of the sensor are minimized. In addition, the pivot mechanism results in a fifty percent reduction in the effect of random vertical deflections caused by track debris or wheel concentricity etc. versus standard non-pivoting wheel sets. The roller carriage moves the sensor head along the cross direction to monitoring physical characteristics of a web of material that is moving in the machine direction.

Abstract: Ash composition measurements of calcium carbonate and gypsum in paper is accomplished with a dual X-ray sensor system with one X-ray source that is powered at about 5.9 KV and a second X-ray source that is powered at about 4.2 KV. Corresponding detectors measure radiation from the respective X-ray sources that is emitted from the paper. Data derived from the measurements yields the gypsum and crystal water content in the paper. The dual X-ray sensor system can be employed in conjunction with infrared total moisture measurements of paper products being manufactured on a papermaking making machine, which contain gypsum and calcium carbonate, in order to correct for the gypsum crystal water effect.

Abstract: An air stabilization system employing two substantially parallel, codirectional Coanda nozzles, that are positioned adjacent a flexible moving web, with each nozzle exhausting gas at the same downstream machine direction, subjects the moving web to shear forces effective to stabilize the web. Each nozzle includes an elongated slot that is substantially perpendicular to the path of the moving web and a backstep located downstream of the direction of airflow extending from the Coanda slot. The two Coanda nozzles serve as separate points along the machine direction for controlling the height of the moving web. By modulating the velocities or other parameters of gases exiting the Coanda nozzles, the shape of the moving web between the nozzles can be manipulated to present a planar contour for measurements. The air stabilization system can be incorporated into a scanner head to measure the caliper of paper, plastic, and other flexible web products.

Abstract: An air stabilization system employing two parallel, opposite-facing Coanda nozzles, with each nozzle exhausting gas at opposite directions, subjects a moving flexible web to opposing forces effective to create local tension within the web. Each nozzle includes an elongated slot that is perpendicular to the path of the moving web. The nozzles serve as separate points along the machine direction for controlling the height of the web. The operative surface with the nozzles can exhibit a flush surface. The nozzles can be formed on elevated structures on the operative surface. The operative surface can be covered with a transparent substrate to minimize shape distortions on the moving web and to prevent debris from collecting around the sensor. An internal baffle is employed to channel air flow within each nozzle. The baffle equalizes the gas pressure across the nozzle and directs air flow towards it.

Abstract: Fiber optic sensors employ a high brightness light source such as a fiber optic supercontinuum source, multiplexed superluminescent light emitting diodes, or a broadband tunable laser diode. Light is delivered to the measurement location via fiber optics and sensor optics directs infrared radiation onto material the being monitored that is located in a hostile environment. A disperse element is positioned in the detection beam path in order to separate the wavelengths and to perform spectral analysis. A spectral analysis of the radiation that emerges from the sheet yields information on a plurality of parameters for the material. For papermaking applications, the moisture level, temperature and cellulose content in the paper can be obtained.

Abstract: An air stabilization system employing two parallel, opposite facing Coanda nozzles, that are positioned adjacent a flexible moving web, with each nozzle exhausting gas at opposite directions, subjects the moving web to opposing forces effective to stabilize the web. Each nozzle includes an elongated slot that is parallel to the path of the moving web. The two Coanda nozzles serve as separate points along the machine direction for controlling the height of the moving web. By modulating the flow, pressure and other parameters of gases exiting the Coanda nozzles, the shape of the moving web between the nozzles can be manipulated to present a planar contour for measurements. The air stabilization system can be incorporated into a scanner head to measure the caliper of paper, plastic, and other flexible web products.

Abstract: A rail system made of one or more flexible guide rods, each consisting of a tension rod, is used to support lightweight, mobile devices such as carriages, scanning heads or optical sensors. The rail is configured to permit movement of the mobile device, when driven by an external drive mechanism, along a main scanning direction but prohibits rotational movement of the mobile device. In this fashion, the mobile device remains substantially at the same measured distance from the flat surface of an object, e.g., moving sheet or web, being analyzed.

Abstract: Devices, systems and methods for controlling the coating of a sample are disclosed. The exemplary system may have a manufacturing device for providing a sample with one or more sample characteristics associated with one or more coating characteristics. The exemplary system may have a sample sensor for determining the one or more sample characteristics and a manufacturing controller for controlling the manufacturing device and controlling the one or more characteristics of the sample provided by the manufacturing device based on the determined one or more sample characteristics. The exemplary system may also have a coating device for providing coating to the sample with the one or more coating characteristics; a coating sensor for determining the one or more coating characteristics; and a coating controller for controlling the coating device and controlling the one or more characteristics of the coating provided by the coating device based on the determined one or more coating characteristics.

Abstract: Optical delay line system that includes a retro-reflection mirror which is displaced along a circular path while being maintained in angular alignment with launch and return sources of light subject the components of the system to minimum levels of unbalanced linear acceleration. A retroreflector is pivotally mounted on a rotating element such that the optical axis of the retroreflector's motion is mobile such that its angle or position changes relative to a fixed observer. There is no linear stopping and starting of the retroreflector and all acceleration of the retroreflector is rotational acceleration with small angles so the required forces in the optical delay line are greatly reduced. Both large displacement and high repetition rates are achieved. The system can be configured so that optical fibers serve as launch and return optics. Alternatively, free space beam paths deliver light to the optical delay and return the reflected light from the retroreflector.

Abstract: An air stabilization system employing two parallel, opposite-facing Coanda nozzles, with each nozzle exhausting gas at opposite directions, subjects a moving flexible web to opposing forces effective to create local tension within the web. Each nozzle includes an elongated slot that is perpendicular to the path of the moving web. The nozzles serve as separate points along the machine direction for controlling the height of the web. The operative surface with the nozzles can exhibit a flush surface. The nozzles can be formed on elevated structures on the operative surface. The operative surface can be covered with a transparent substrate to minimize shape distortions on the moving web and to prevent debris from collecting around the sensor. By modulating the velocities of gases exiting the nozzles, the shape of the web can be manipulated to present a planar contour. The air stabilization system can be incorporated into a caliper scanner.

Abstract: A steam distributor for applying steam to a continuously moving paper sheet employs one or more drop-out steam profiling cartridges. Each cartridge is connected to a steam distribution apparatus and includes a number of profiling zones that are covered by a contoured, smooth profiling screen from which steam is applied. The profiling screens are welded to baffles which enhances the structural integrity of the cartridge. No external clamps or other devices are employed that would otherwise disrupt the smooth, curved exterior surface of the profiling screens. The spaced-apart baffles also eliminate the spilling over of steam from one profiling zone to the next which has the effect of minimizing the response width for steam profiling control. The use of the drop-out cartridges permits quick and easy removal of the profiling screens for change-out or cleaning.

Abstract: Fluorescent nanoparticles such as quantum dots are incorporated into plastic, paper and other web layered products to achieve cross-direction and machine direction on-line analysis of the individual layers therein. Fluorescent nanoparticles markers are added in known proportions into product formulations. By detecting the fluorescence from the nanoparticles, the thickness and other physical characteristics of the web can be traced at various stages of production. In addition, by using different populations of fluorescent nanoparticles that emit radiation at different wavelengths, data from individual layers in a composite structure can be ascertained simultaneously with a single sensor. The technique is particularly suited for monitoring difficult-to-measure polymers in complex multilayer structures.

Abstract: The performance of scanning systems can be significantly enhanced by replacing the traditional power track with preferably just two wires or transmission channels for effecting communication between (i) the sensors on the mobile carriage of the scanning system and (ii) the controls, power sources, and related devices that are typically located in a compartment or module which is a significant distance away. This can be implemented by employing selected multiplexer and complementary de-multiplexer combinations in the scanner head and in the module. This technique reduces EMI noise, power loss, drag on the moving scanner heads carrying the sensors, and cost of construction.

Abstract: A reverse bump test, for identifying the alignment of a sheetmaking system while the system remains in closed-loop control, includes the following steps: (a) leaving the control system in closed-loop, (b) artificially inserting a step signal on top of the measurement (or setpoint) profile from the scanner, (c) recording the data as the control system moves the actuators to remove the perceived disturbance (or setpoint change), and (d) refining or developing a model from the artificial measurement disturbance (or setpoint change) to the actuator profile. The technique supplies the probing/perturbation signal to the scanner measurement, which is equivalent to supplying the probing/perturbation signal to the setpoint target) rather than inserting bumps via the actuator set points as has been practiced traditionally.

Abstract: An integrated, continuous process for transforming feedstock, e.g., reformate, which contains high levels of benzene into a low-benzene content feedstock that is suitable for gasoline blending initially removes benzene from the reformate by extractive distillation, then partially hydrogenating the high purity benzene into cyclohexane under mild conditions in a one-stage hydrogenation reactor, and thereafter recovering a cyclohexane product with high purity from the hydrogenation reactor effluent in a back-end purification step using extractive distillation. The initial or front-end separation step yields a low-benzene content reformate.

Abstract: A highly effective liquid-liquid extraction process to remove nitrogen compounds and especially basic nitrogen compounds from aromatic light petroleum oils with excellent recovery employs de-ionized water, which can be acidified, as the extractive solvent. The product is an aromatic hydrocarbon with ultra-low amounts of nitrogen poisons that can deactivate acidic catalysts. The extracted oils are suitable feedstock for the subsequent catalytic processes that are promoted with the high performance solid catalysts, which are extremely sensitive to nitrogen poison.

Abstract: A high voltage power supply for use in a system such as a microfluidics system, uses a DC-DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC-DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.