Measurement Of Critical Parameters Research Articles

An average photon number measurement scheme based on balanced homodyne detection

<sec>Quantum key distribution (QKD) has become an alternative technology defensing the security threat resulting from quantum computing. Owing to its superiority in coexistence with optical infrastructures and cost-effective, continuous variable QKD (CV-QKD) is widely studied and developed towards the practical application stage. The standardized measurement of critical parameters of the system should be studied urgently.</sec><sec>In this work we propose a scheme based on balanced homodyne detection with phase-randomized local oscillator to realize the average photon number measurement. By controlling local oscillator phase positively, which obeys <inline-formula><tex-math id="M2">\begin{document}$ [0,\mathrm{ }2\mathrm{\pi }] $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="24-20211216_M2.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="24-20211216_M2.png"/></alternatives></inline-formula> uniform distribution, a linear relationship between average photon numbers and the variance of detector output can be obtained in simulation and experiment. With high-accuracy (～0.1) photons/pulse and large range ～23 dB, this average photon number measurement scheme provides a great reference to evaluating the critical parameters of CV-QKD system in the practical process.</sec>

Octopus – Application test of a simple and effective tool for polishing slurry monitoring

In the digital age it has become a fundamental issue to monitor and control process parameters continuously and automatically. The monitoring of critical process parameters enables better quality at lower production costs and higher yields. In order to investigate the interactions between production quality and polishing parameters, we have developed a solution for automatic and reliable measurement of critical parameters. With this paper we first document the resolution and accuracy of the system compared to manual measuring methods currently in use.

A new laboratory for the students of the Faculty of Engineering at the University of Sherbrooke to support the characterization and the validation of their prototypes

In order to help the students of the Faculty of Engineering at the Université de Sherbrooke within the field of product design in engineering, the Laboratory for the Characterization and the Validation of Prototypes (LCVP) has been created. The facilities feature most of the resources needed to conduct experiments toward the estimation and measurement of critical parameters and specifications along the design process but also toward the final validation of a product design. To that end the support of a professional researcher is provided to advise the students toward the proper implementation of their test benches. Overall, the LCVP provides state-of-the-art equipment and competent resources to the students from various departments at both undergraduate and graduate levels therefore improving their product design experience, while enhancing their competencies. This is indeed a unique feature of the LCVP, setting it apart from other initiatives targeted at supporting capstone and student projects.

Testing of Coiled Nylon Actuators for Use in Spastic Hand Exoskeletons.

Natural muscles have many favorable characteristics including their high power-to-weight ratio, efficient energy conversion and fast actuation times. These factors become important criteria for judging artificial actuation methods. Unfortunately, traditional systems such as pneumatic and electromagnetic motors have yet to attain similar characteristics. In recent years, a new category of actuators has been developed from highly twisted and coiled low-cost nylon fibers. These muscles are capable of providing a powerful stroke per cycle with a reversible contraction. In this paper, twisted and coiled polymer (TCP) actuators with two different commercially available nylon fibers: Shieldex conductive yarn 117/17 and 235/34 are fabricated and tested, then implemented into a low profile, hand exoskeleton. Maintaining quality control on muscle fabrication proved to be challenging and the use of nylon as muscle actuators for exoskeletons would require much more research and better measurements of critical parameters before providing a consistent solution.

Nanometrología: Impacto en los sistemas de producción

<p>El presente trabajo es el resultado de una revisión bibliográfica sobre: la aplicación de la nanometrología en diferentes sectores industriales y cómo esta contribuye a alcanzar los estándares de calidad de los productos a través de la medición de parámetros críticos en los procesos productivos; así como una descripción de los retos a los que se enfrenta esta ciencia en diferentes sectores. Se reportan los avances y el desarrollo de nuevas técnicas que permiten medir las características de los nanodispositivos, nanomateriales y equipos, lo que ha permitido potenciar el desarrollo de industrias, una disminución de los costos y la automatización de los procesos. Dentro del texto se hace referencia a industrias en progreso y el efecto que tiene el control de parámetros para la optimización de los procesos, el diseño de nanodispositivos y la creciente necesidad de la reglamentación en el uso de nanocompuestos, el diseño de técnica confiables y de protocolos para el uso de nanopartículas. El adelanto de la nanometrología ha contribuido al desarrollo de materiales de referencia, herramientas que aumenten la exactitud y precisión de las medidas, así como técnicas para la calibración de las herramientas y equipos apropiados para las medidas a nanoescala, lo que se traduce en un proceso productivo controlado que garantiza la calidad de los productos. Finalmente, se incluye el estado de la nanometrología en Colombia, enfocada en procesos industriales, como: el sector de alimentos, textil, salud y producción de nanomateriales, así como el trabajo desarrollado por grupos de investigación.</p>

Design and Development of a Specially Modified Positive Displacement Rotary Screw Pump and Relevant Hydraulic Circuit to Enhance “Entrained Air Handling” Capability in a Closed Loop Lube Oil System

Rotary screw type positive displacement (RSPD) pumps are commonly used in oil and gas industry for pumping of mineral lube oil in services where they can be mechanically driven by gears coupled to a train driver. Installation of these pumps is critical and should be designed jointly by vendors and users according to project specific restrictions (i.e., the arrangement of the entire oil circulation system). This paper describes a real case in which restrictions due to lube oil system arrangement have produced low pump suction head and have amplified the influence of air bubbles that remained entrained in oil despite lube oil tank degassing. The investigations have been directed toward the mathematical modeling of the aeration phenomenon coupled with experimental measurements of critical parameters taken on the shop plant. Among corrective actions identified and considered there are reduction of quantity of air entering the lube oil system and revamping of the entire lube oil system with changes in piping, tank and also in pump model together with special modifications of internal path to enhance air handling capabilities. In order to validate pump behavior with reference to resistance to aeration (monitoring noise and vibration) a special simulation setup was jointly developed by end user and manufacturer on a pilot test bench to carry out the various performance tests. The numerical data collected during shop aeration test have confirmed that the pump was able to handle the expected amount of entrained air with noise and vibrations within industrial limits. The pumps tested in the pilot bench were installed at user's site and the effectiveness of the synergic corrective actions listed above was successfully verified. The study concludes that an early estimation of entrained air in the lube oil system is critical for design and development of either the RSPD pump or the entire lube oil circuit of a motor compressor train. When a critical quantity of entrained air is likely to be reached at pump suction (near 10% in volume), pump manufacturers and end users should apply some basic rules related to “design for aeration” of the pump and agree on a nonroutine test to be performed at manufacturer's shop before pump installation at site. This will serve as a reliable prediction of pump air handling capabilities, without which effective operation, reliability and durability of the pump could be jeopardized.

Design and validation of an angle-resolved low-coherence interferometry fiber probe for in vivo clinical measurements of depth-resolved nuclear morphology

We present a novel Fourier-domain angle-resolved low-coherence interferometry (a /LCI) fiber probe designed for in vivo clinical application in gastrointestinal endoscopy. The a/LCI technique measures the depth-resolved angular scattering distribution to determine the size distribution and optical density of cell nuclei for assessing the health of epithelial tissues. Clinical application is enabled by an endoscopic fiber-optic probe that employs a 2.3-m-long coherent fiber bundle and is compatible with the standard 2.8-mm-diam biopsy channel of a gastroscope. The probe allows for real-time data acquisition by collecting the scattering from multiple angles in parallel, enabled by the Fourier domain approach. The performance of the probe is characterized through measurement of critical parameters. The depth-resolved sizing capability of the system is demonstrated using single- and double-layer microsphere phantoms with subwavelength sizing precision and accuracy achieved. Initial results from a clinical feasibility test are also presented to show in vivo application in the human esophagus.

A Fixed Robotic Profiler System to Sense Real-Time Episodic Pulses in Corpus Christi Bay

Real-time observations of coastal environments are needed to capture episodic events that control aquatic ecosystem dynamics. The National Science Foundation established the Water and Environmental Research Systems Network to test various aspects of real-time observatory design and operation, and Corpus Christi Bay (TX) was selected as one of the Water and Environmental Research Systems test beds. Implementation of a real-time observation system faces challenges such as use of heterogeneous monitoring instrumentation, measurement of critical parameters at greater spatial and temporal resolution, reduction of sensor biofouling, reliable data acquisition and delivery, and data management. We developed a robotic profiler system that moves a suite of water quality sensors in the water column, collecting data at multiple depths. This system significantly reduces biofouling of the sensors and accommodates a diverse array of sensors that measure various environmental parameters. In addition, the associated cyberinfrastructure provides sensor data to stakeholders in real time and allows remote access to the fixed robotic platforms, which supports instrument management, data quality assurance and quality control, implementation of event-based sampling schemes, sensor troubleshooting, and so on. Moreover, it can process diverse data streams and reliably transfer measured data to the users. Two snapshots of observational data are presented in this article to illustrate the system capability in measuring parameters that can shed light on important processes controlling episodic events in the bay.

Spatially resolved measurements of critical parameters in superconducting filaments by laser scanning technique

We present an experimental study of local transport properties of superconducting filaments by means of low temperature scanning laser microscopy (LTSLM). A novel theoretical model that treats the laser-beam-induced voltage response is proposed and applied to analyze the measured data. The method of LTSLM allows to visualize the local inhomogeneities in individual filaments extracted from (Bi,Pb)/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10+x//Ag tapes. Using the proposed theoretical analysis we extract the spatial distributions of the critical currents and critical temperatures over the sample. Tile data obtained by LTLSM show good agreement with standard non-local transport measurements. Using autocorrelation analysis of the voltage response, the characteristic length of the critical current variation is retrieved for filaments that belong to different parts of the tape.

Thermodynamic properties of R410B

The thermal properties of the refrigerant R410B have been investigated by the constant volume piezometer method at temperatures 279-385K and pressures 0.9-6MPA. Results of the measurement of critical parameters and the capillary constant are presented. The Martin-Hou equation of state was proposed for the calculation of thermodynamic properties. Data on thermophysical properties on the saturation line are presented

Precise measurements of critical parameters of sulfur hexafluoride by laser interferometry

A laser interferometry has been applied, in the present study, for determination of the critical temperature and critical exponents of sulfur hexafluoride (SF6). By means of laser holographic technique by real-time method, a series of Fraunhofer diffraction patterns due to the density fluctuation of the sample fluid in the very vicinity of the critical point has been successively photographed and analyzed. A dual-thermostat system which was designed and constructed for the present purpose has made the sample temperature constant within 15 μK for several days. We have obtained 107 data for (ρ L−ρ v)/ρ c along the vapor-liquid coexistence curve in the reduced temperature range 10−6≦¦ΔT *¦≦7×10−5 and additional 34 data for the isothermal compressibility in the single phase region. By analyzing these measurements with the aid of the simple power law, the critical temperature and the critical exponents of SF6 have been determined as T c=318.708±0.001 K, β=0.350±0.004, and γ=1.24±0.02, respectively.