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At least 73 records · Page 4

Sap flow data, Jan 2022-Dec 2022, Panama: PNM,BCI, and SLZ

Sap flow was monitored at three Panamanian sites: Parque Natural Metropolitano (PNM), Barro Colorado Island (BCI), and Bosque Protector San Lorenzo (SLZ), using a total of 54 G-20mm sap flow sensors. Raw output from the data logger connected to 54 sap flow sensors are converted from xxx.dat. to xxx.csv. files. The metadata file (E-field log_v1-1_PNM_BCI_SLZ_sapflow_2022.xls) has information on locations where the sensors were installed, and other installation/maintenance details. No data processing or QA/QC was done on the raw datasets except conversion of dat. files to csv. files. Processed datasets have been uploaded separately. Contact mizanur.rahman@pnnl.gov or nate.mcdowell@pnnl.gov if you need to use this dataset for additional information.

54 ENVIRONMENTAL SCIENCES↗

Analyzing Mechanical integrity of Microwave resonant Cavity flowmeter

The microwave resonant cavity flow sensor has been proposed to address the difficulties of measuring high-temperature molten salt flow in reactor vessels. The flow sensor consists of a metallic cylindrical cavity coupled to a microwave waveguide. The cylindrical cavity has one of the flat surfaces thin enough to undergo microscopic deflection due to dynamic pressure of the exerted by the flowing fluid. Deflection of the membrane causes a shift in the microwave resonant frequency. Fluid velocity can be estimated from the calibration curve. The objective of this report is to investigate mechanical integrity of the flowmeter’s membrane. The membrane is a thin stainless-steel circular plate with a clamped edge, subjected to uniform load. By calculating the stress on the plate due to deflection and, comparing the stress to the material ultimate tensile strength and yield strength, it can be estimated if the plate will fail. If the maximum stress is greater than the yield strength, the plate will undergo plastic deformation, and the sensor will be disabled. A stress greater than the ultimate tensile strength will cause the plate to fracture. The stress on the plate was calculated with an analytic closed form solution model, and with COMSOL Structural Mechanics Module which does not involve any approximations. Stresses in both the analytic model and COMSOL numerical model were calculated for stainless steel 316 thin circular plates under room temperature conditions, where the fluid is water. The diameter of the circular plate is approximately one inch, and thickness is 10mil. Fluid flow velocity is in the range from 0.5m/s to 1m/s. The results from the two models are similar. Both the analytic model and COMSOL model showed that maximum stresses on the plate, which are at the radial boundary of the plate, are three orders of magnitude smaller than the yield strength and ultimate tensile strength. This indicates that the sensor is at a low risk of mechanical failure.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Determination of corrections to flow direction sensor measurements over an angle-of-attack range from 0 degree to 85 degrees

An investigation was conducted into the nature of corrections for angle-of-attack and angle-of-sideslip measurements obtained with sensors mounted in front of each wingtip of a general aviation airplane. These flow corrections have been obtained from both wind-tunnel and flight tests over an angle-of-attack range from 0 to 85 deg. Both the angle-of-attack and angle-of-sideslip flow corrections were found to be substantial. The corrections were a function of the angle of attack and angle of sideslip and were fairly insensitive to configuration changes and rotational effects. The angle-of-attack flow correction determined from the static wind-tunnel tests agreed reasonably well with the correction determined from flight tests.

Moul, T. M.↗

Integrated Liquid Bismuth Propellant Feed System

A prototype bismuth propellant feed and control system was constructed and tested. An electromagnetic pump was used in this system to provide fine control of the hydrostatic pressure, and a new type of in-line flow sensor was developed to provide an accurate, real-time measurement of the mass flow rate. High-temperature material compatibility was a driving design requirement for the pump and flow sensor, leading to the selection of macor for the main body of both components. Post-test inspections of both components revealed no cracks or leaking in either. In separate proof-of-concept experiments, the pump produced a linear pressure rise as a function of current that compared favorably with theoretical pump pressure predictions, with a pressure of 10 kPa at 30 A. Flow sensing was successfully demonstrated in a bench-top test using gallium as a substitute liquid metal. A real-time controller was successfully used to control the entire system, simultaneously monitoring all power supplies and performing data acquisition duties.

Polzin, Kurt A.↗

Microencapsulation system and method

A microencapsulation apparatus is provided which is configured to form co-axial multi-lamellar microcapsules from materials discharged from first and second microsphere dispensers of the apparatus. A method of fabricating and processing microcapsules is also provided which includes forming distinct droplets comprising one or more materials and introducing the droplets directly into a solution bath to form a membrane around the droplets such that a plurality of microcapsules are formed. A microencapsulation system is provided which includes a microcapsule production unit, a fluidized passage for washing and harvesting microcapsules dispensed from the microcapsule production unit and a flow sensor for sizing and counting the microcapsules. In some embodiments, the microencapsulation system may further include a controller configured to simultaneously operate the microcapsule production unit, fluidized passage and flow sensor to process the microcapsules in a continuous manner.

Morrison, Dennis R.↗

Microencapsulation system and method

A microencapsulation apparatus is provided which is configured to form co-axial multi-lamellar microcapsules from materials discharged from first and second microsphere dispensers of the apparatus. A method of fabricating and processing microcapsules is also provided which includes forming distinct droplets comprising one or more materials and introducing the droplets directly into a solution bath to form a membrane around the droplets such that a plurality of microcapsules are formed. A microencapsulation system is provided which includes a microcapsule production unit, a fluidized passage for washing and harvesting microcapsules dispensed from the microcapsule production unit and a flow sensor for sizing and counting the microcapsules. In some embodiments, the microencapsulation system may further include a controller configured to simultaneously operate the microcapsule production unit, fluidized passage and flow sensor to process the microcapsules in a continuous manner.

Morrison, Dennis R.↗

ISS Payload Racks Automated Flow Control Calibration Method

Payload Racks utilize MTL and/or LTL station water for cooling of payloads and avionics. Flow control range from valves of fully closed, to up to 300 Ibmhr. Instrument accuracies are as high as f 7.5 Ibm/hr for flow sensors and f 3 Ibm/hr for valve controller, for a total system accuracy of f 10.5 Ibm/hr. Improved methodology was developed, tested and proven that reduces accuracy of the commanded flows to less than f 1 Ibmhr. Uethodology could be packed in a "calibration kit" for on- orbit flow sensor checkout and recalibration, extending the rack operations before return to earth. -

Simmonds, Boris G.↗

NASA Tech Briefs, January 2010

Topics covered include: Cryogenic Flow Sensor; Multi-Sensor Mud Detection; Gas Flow Detection System; Mapping Capacitive Coupling Among Pixels in a Sensor Array; Fiber-Based Laser Transmitter for Oxygen A-Band Spectroscopy and Remote Sensing; Low-Profile, Dual-Wavelength, Dual-Polarized Antenna; Time-Separating Heating and Sensor Functions of Thermistors in Precision Thermal Control Applications; Cellular Reflectarray Antenna; A One-Dimensional Synthetic-Aperture Microwave Radiometer; Electrical Switching of Perovskite Thin-Film Resistors; Two-Dimensional Synthetic-Aperture Radiometer; Ethernet-Enabled Power and Communication Module for Embedded Processors; Electrically Variable Resistive Memory Devices; Improved Attachment in a Hybrid Inflatable Pressure Vessel; Electrostatic Separator for Beneficiation of Lunar Soil; Amorphous Rover; Space-Frame Antenna; Gear-Driven Turnbuckle Actuator; In-Situ Focusing Inside a Thermal Vacuum Chamber; Space-Frame Lunar Lander; Wider-Opening Dewar Flasks for Cryogenic Storage; Silicon Oxycarbide Aerogels for High-Temperature Thermal Insulation; Supercapacitor Electrolyte Solvents with Liquid Range Below -80 C; Designs and Materials for Better Coronagraph Occulting Masks; Fuel-Cell-Powered Vehicle with Hybrid Power Management; Fine-Water-Mist Multiple-Orientation-Discharge Fire Extinguisher; Fuel-Cell Water Separator; Turbulence and the Stabilization Principle; Improved Cloud Condensation Nucleus Spectrometer; Better Modeling of Electrostatic Discharge in an Insulator; Sub-Aperture Interferometers; Terahertz Mapping of Microstructure and Thickness Variations; Multiparallel Three-Dimensional Optical Microscopy; Stabilization of Phase of a Sinusoidal Signal Transmitted Over Optical Fiber; Vacuum-Compatible Wideband White Light and Laser Combiner Source System; Optical Tapers as White-Light WGM Resonators; EPR Imaging at a Few Megahertz Using SQUID Detectors; Reducing Field Distortion in Magnetic Resonance Imaging; Fluorogenic Cell-Based Biosensors for Monitoring Microbes; A Constant-Force Resistive Exercise Unit; GUI to Facilitate Research on Biological Damage from Radiation; On-Demand Urine Analyzer; More-Realistic Digital Modeling of a Human Body; and Advanced Liquid-Cooling Garment Using Highly Thermally Conductive Sheets.

Source record↗

Compact and Integrated Liquid Bismuth Propellant Feed System

Operation of Hall thrusters with bismuth propellant has been shown to be a promising path toward high-power, high-performance, long-lifetime electric propulsion for spaceflight missions [1]. There has been considerable effort in the past three years aimed at resuscitating this promising technology and validating earlier experimental results indicating the advantages of a bismuth-fed Hall thruster. A critical element of the present effort is the precise metering of propellant to the thruster, since performance cannot be accurately assessed without an accurate accounting of mass flow rate. Earlier work used a pre./post-test propellant weighing scheme that did not provide any real-time measurement of mass flow rate while the thruster was firing, and makes subsequent performance calculations difficult. The motivation of the present work is to develop a precision liquid bismuth Propellant Management System (PMS) that provides hot, molten bismuth to the thruster while simultaneously monitoring in real-time the propellant mass flow rate. The system is a derivative of our previous propellant feed system [2], but the present system represents a more compact design. In addition, all control electronics are integrated into a single unit and designed to reside on a thrust stand and operate in the relevant vacuum environment where the thruster is operating, significantly increasing the present technology readiness level of liquid metal propellant feed systems. The design of various critical components in a bismuth PMS are described. These include the bismuth reservoir and pressurization system, 'hotspot' flow sensor, power system and integrated control system. Particular emphasis is given to selection of the electronics employed in this system and the methods that were used to isolate the power and control systems from the high-temperature portions of the feed system and thruster. Open loop calibration test results from the 'hotspot' flow sensor are reported, and results of integrated thruster/PMS tests demonstrate operation of the feed system in the relevant environment.

Polzin, Kurt A.↗

Terrestrial laser scanning data (Levels 0 and 1) from Urban Biogeochemistry Pilot Project sites, Knoxville, Tennessee, Jul 2024 - Jul 2025

This data package contains data from terrestrial laser scanning (TLS) at five urban park sites in Knoxville, Tennessee, USA. All parks include open-grown and/or closed-canopy trees and mixed nearby land use. These study sites were established as part of the Urban Biogeochemistry Pilot Project, which has an overall goal of better understanding how hydrobiogeochemical cycling is altered within the human environment. These five sites represent a gradient of urbanization, and were instrumented to understand hydrological and biogeochemical cycling (e.g., soil moisture, soil physical properties and biogeochemistry, tree transpiration, species type). The TLS data archived here were collected to provide detailed, three-dimensional information about forest structure. Specifically, data were collected to allow tree- and stand-level characterization of woody structure and leaf area. TLS scans were placed to capture the area around trees with sap flow sensors, and as much of a 50 m radius area around the meteorological station as possible given site property limits. Derived products will allow upscaling of water content and transpiration data. This data package contains the following data: - High-level files document further details of the campaign and data package: 1_CampaignSummary.csv provides details about the campaign and study site, 2_ScanAreasDetail.csv provides details about each separate scan area (groups of scans post-processed into a single point cloud), 3_TerrestrialLidarSensor.csv provides further technical details about the Riegl VZ-400i TLS sensor, TLS_CSV_dd.csv is a CSV Data Dictionary providing information about the fields in CSV files following the ESS-DIVE CSV File Formatting Guidelines Reporting Format, TLS_flmd.csv is a File Level Metadata file providing information about each file in the data package following the ESS-DIVE File Level Metadata Reporting Format, and README.txt is a text file describing the overall project and file structure. - Level 0 data are the raw data (.PROJ folders) as recorded by the Riegl VZ-400i TLS instrument before scan co-registration and post-processing with the Riegl's proprietary RiSCAN PRO software, which requires a license. - Level 1 data contain post-processed, co-registered data from each scan area. The "PointClouds" folder for each scan area contains a .las file with 1 cm resolution point cloud data exported from RiSCAN PRO. These are the main files likely to be of interest to most users and can be further processed with any software capable of manipulating .las files (e.g. Python, R CloudCompare). The "Project Information" folder contains log files from post-processing in RiSCAN PRO that may be of interest to users who want to see detailed records of post-processing, including all PDF reports generated by RiSCAN PRO. The "ScanPositions" folder contains information about the final position of all TLS scans, after post-processing, in multiple formats. The file ScanPositions_*.csv provides final geo-referenced scan positions, and the file SOP_backup_*.csv can be used in RiSCAN PRO to restore the co-registered scan positions if users wish to re-process raw data (Level 0 .PROJ folders) with RiSCAN PRO software (e.g., subsample to a different resolution, exclude a certain scan position, or apply different filters on reflectance or deviation values) without redoing time-consuming co-registration steps.

54 ENVIRONMENTAL SCIENCES↗

Aerodynamic characteristics of a vane flow angularity sensor system capable of measuring flight path accelerations for the Mach number range from 0.40 to 2.54

The aerodynamic characteristics of the angle of attack vane and the angle of sideslip vane are summarized. The test conditions ranged in free stream Mach number from 0.40 to 2.54, in angle of attack from -2 deg to 22 deg, in angle of sideslip from -2 deg to 12 deg, and in Reynolds number from 590,000 per meter to 1.8 million per meter. The results of the wind tunnel investigation are compared with results obtained with similar vane configurations. Comparisons with a NACA vane configuration are also made. In addition, wind tunnel-derived upwash for the test installation is compared with analytical predictions.

Sakamoto, G. M.↗

Status of high-range and flow-direction sensor

This paper describes the two systems used to provide certain research measurements for the X-15 aircraft. These systems are: (1) a probe and associated system that will be capable of operating throughout the extreme temperature environment encountered on reentry to provide a measure of the angle of attack and sideslip to the pilot and (2) an instrumented ground range capable of monitoring the flight of the airplane throughout its entire trajectory.

Truszynski, G M↗

Noise reducing screen devices for in-flow pressure sensors

An acoustic sensor assembly is provided for sensing acoustic signals in a moving fluid such as high speed fluid stream. The assembly includes one or more acoustic sensors and a porous, acoustically transparent screen supported between the moving fluid stream and the sensor and having a major surface disposed so as to be tangent to the moving fluid. A layer of reduced velocity fluid separating the sensor from the porous screen. This reduced velocity fluid can comprise substantially still air. A foam filler material attenuates acoustic signals arriving at the assembly from other than a predetermined range of incident angles.

Schmitz, Fredric↗

Sensor chip and apparatus for tactile and/or flow sensing

A sensor chip, comprising a flexible, polymer-based substrate, and at least one microfabricated sensor disposed on the substrate and including a conductive element. The at least one sensor comprises at least one of a tactile sensor and a flow sensor. Other embodiments of the present invention include sensors and/or multi-modal sensor nodes.

Liu, Chang↗

Sensor chip and apparatus for tactile and/or flow sensing

A sensor chip, comprising a flexible, polymer-based substrate, and at least one microfabricated sensor disposed on the substrate and including a conductive element. The at least one sensor comprises at least one of a tactile sensor and a flow sensor. Other embodiments of the present invention include sensors and/or multi-modal sensor nodes.

Liu, Chang↗

Assessment of Flow-Enhanced Electrochemical Sensor Testing and Deployments for MSRs

This report serves as the deliverable for Milestone M3RS-23AN0401061 that is part of Work Package RS-23AN040106 (Flow Enhanced Sensors for MSRs – ANL). The goal of this milestone was to determine performance of the flow enhanced electrochemical sensor (FEES) and modular flow instrumentation testbed (MFIT) in safeguards relevant scenarios. Flow enhanced electrochemical sensors are a type of electroanalytical sensor that has been developed at Argonne National Laboratory to be installed directly into MSR flow conduits to make measurements of the salt composition. These sensors represent a significant improvement in capabilities compared to earlier electroanalytical sensors that instead can only be operated in quiescent conditions. Previous work has focused on testing of the FEES in flowing conditions provided by the MFIT to assess the accuracy and precision of the sensor measurements. To further improve this capability, in FY23 we undertook a campaign of safeguards relevant scenarios in molten salt containing a range of uranium chloride concentrations (0 to 3 wt%). All the testing carried out in FY23 was aided by a control system designed to automatically actuate flow conditions and collect data. This new automation system is estimated to have increased experimental throughput by a factor of four and enabled testing in a variety of complex conditions. The advancements in throughput and repeatability led to improved quantification of actinide concentrations using the in-flow sensors, with a reduction of the mean absolute relative error from 5.6% in FY22 to 3.1% in FY23. In addition to safeguards scenarios run in the MFIT, FY23 work included deployment of a FEES at a partner institution where it will be tested in a flowing salt loop. The FEES was successfully integrated into that loop and is being tested prior to loop startup. In FY23, work also continued on the smaller flow system that we have named the mini-MFIT. This smaller system is capable of rapid prototyping of new sensor designs prior to installation in the larger MFIT radiological flow system. Work was carried out to test this new system in non-radiological molten salts in a separate glovebox. This work is helping us to enhance the accuracy of our salt monitoring capabilities through the integration of multiple types of sensors. The high degree of accuracy required by 10 CFR 74 represents a significant challenge, and further design evolution and integration of the sensors into multimodal sensing frameworks will be needed to further push the measurement accuracy to the needed level.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗