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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 145 records · Page 8

Predicting Instability and the Effect of Wind Loading on Single-Axis Trackers

As PV modules continue to trend toward larger, thinner, and more flexible forms they grow more susceptible to damage from dynamic wind loading. As a result, understanding the impact of wind on PV systems, particularly when mounted on solar-tracking hardware, and identifying robust, stable array layouts and stow strategies is becoming increasingly important for the PV community. In our ongoing DuraMAT project, we are developing an open-source software package, PVade (PV aerodynamic design engineering), to simulate the cascading fluid-structure interaction that occurs within solar-tracking arrays to enable researchers to test hardware, layout, and tracker control changes, leading to enhanced stability and a reduction in wind-driven damage. We will give an overview of the PVade software, highlighting recent user-interface and algorithm developments, before presenting the latest outcomes from our ongoing validation campaign in which we analyze and compare with experimental data obtained from a DuraMAT 1 project. From there, we will present simulated results from a larger, multi-row array and highlight relationships between varying tracker angles and stability as measured by different experimentally validated metrics.

fluid structure interaction↗

Characterization of the GEM chambers for the SBS/BB Front Tracker at JLAB HallA

The present thesis discusses the main aspects and results of the ongoing SBS-GEM development, production and test, according to the following structure: - In chapter 1 the theoretical and experimental importance of nucleon electromagnetic form factors is described. Furthermore, the discrepancy of ep scattering data obtained about the FFs ratio between the Rosenbluth separation method and the polarization transfer method is highlighted and, therefore, the Super Bigbite Program at JLab is introduced. - In chapter 2 the experimental apparatus of the SBS project is described, focusing on the main components of the spectrometers involved; the Super Bigbite Spectrometer for the hadron arm and the BigBite spectrometer for the electron arm. - Chapter 3 describes the SBS/BB front tracker and the motivation on the GEM technology choice. In addition, the main features and advantages of the technology used are also described. - Chapter 4 describes the commissioning of the GEM trackers at JLab. The whole iter of the GEM modules is presented, from the assembly in clean-room to the characterization tests with cosmic rays performed at JLab. - In chapter 5 a new method of analyzing the signals extracted from the strips of GEM modules is introduced. This study goal is the real-time suppression of noisy data by mean of innovative A.I. techniques.

Re, Leonard Giuseppe↗

The CMS Phase 2 Outer Tracker Analyzer of Test Outputs - POTATO!

The Phase-2 upgrade of the Large Hadron Collider (LHC), also known as the High-Luminosity LHC (HL-LHC) is designed to achieve peak instantaneous luminosities which is about an order of magnitude higher than the nominal design value of $10^{34}~cm^{-2}s^{-1}$ delivering a total of atleast $3000 fb^{-1}$ data over 10 years of operation at $\sqrt{s}~=~14~TeV$. One crucial aspect of the CMS Phase-2 detector upgrade is the replacement of the existing tracking detector in order to deal with the extreme HL-LHC conditions, retaining and further expanding the physics performances achieved in the previous years. The outer part of the upgraded tracker (OT), will be equipped with over 13,000 macro Pixel-Strip (PS) and Strip-Strip (2S) modules! Module production is distributed across centers worldwide and necessitates coordinated efforts and standardized procedures. Along with production and assembly of the modules, Fermilab OT group is also working on a tool, Phase 2 Outer Tracker Analyzer of Test Outputs (POTATO) that will analyze, grade, upload and manage the large quantity of files to be stored in the centralized Database (DB). In this contribution a brief overview of the module testing and the power and dire need of POTATO to handle this large number of test outputs will be presented.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

MRT (Medical Reporting Tracker)

Medical Report Tracker (MRT) was created to respond to COVID19 data, process and analytic needs of our clinic staff. The report tracker captures data around symptoms and contacts, test results, and last work date and location. The MRT is built using Nintex Online, SharePoint Online and Power BI/Excel.

Devitt, Carrie↗

Machine learning for photovoltaic single axis tracker fault detection and classification

More than 81% of the annual capacity of utility-scale photovoltaic (PV) power plants in the U.S. use single-axis trackers (SATs) due to SATs delivering 4% in capacity factor on average over fixed-array systems. However, SATs are subject to faults, such as software misconfigurations and mechanical failures, resulting in suboptimal tracking. If left undetected, the overall power yield of the PV power plant is reduced significantly. Minimizing downtime and ensuring efficient operation of SATs requires robust detection and diagnosis mechanisms for SAT faults. We present a machine learning framework for implementing real-time SAT fault detection and classification. Our implementation of the proposed framework reliably identifies measurements taken from a test PV system undergoing emulated SAT faults relative to state-of-the-art algorithms and produces nearly zero false positives on our testing days. Code and data are available at https://pvpmc.sandia.gov/tools.

Fault classification↗

Star Tracker Based ATP System Conceptual Design and Pointing Accuracy Estimation

A star tracker based beaconless (a.k.a. non-cooperative beacon) acquisition, tracking and pointing concept for precisely pointing an optical communication beam is presented as an innovative approach to extend the range of high bandwidth (> 100 Mbps) deep space optical communication links throughout the solar system and to remove the need for a ground based high power laser as a beacon source. The basic approach for executing the ATP functions involves the use of stars as the reference sources from which the attitude knowledge is obtained and combined with high bandwidth gyroscopes for propagating the pointing knowledge to the beam pointing mechanism. Details of the conceptual design are presented including selection of an orthogonal telescope configuration and the introduction of an optical metering scheme to reduce misalignment error. Also, estimates are presented that demonstrate that aiming of the communications beam to the Earth based receive terminal can be achieved with a total system pointing accuracy of better than 850 nanoradians (3 sigma) from anywhere in the solar system.

star tracker↗

Celestial Attitude Reference and Determination System (CARDS) Daytime Star Tracker

The Wallops Star Tracker system provides a means of attitude knowledge during balloon missions based on stars detected in the systems field of view. It was developed as an attitude reference source for the Wallops Arc-Second Pointer (WASP) system, but can be utilized as a stand-alone system to support other requirements. The system, known as the Celestial Attitude Reference and Determination System (CARDS), will be described, and the results of the CARDS test flights and the current development status will be presented.

Balloonborne Instruments↗

Realization of a Faster, Cheaper, Better Star Tracker for the New Millennium

The first Danish satellite, إrsted, will be launched in August of 1997. The scientific objective of إrsted is to perform a precision mapping of the Earth's magnetic field. Attitude data for the payload and the satellite are provided by the Advanced Stellar Compass (ASC) star tracker. The ASC consists of a CCD star camera and a capable microprocessor which operates by comparing the star image frames taken by the camera to its internal star catalogs.

star↗

CCD Star Tracker Experience -- Key Results from Astro 1 flight

Charge-coupled devices (CCDs) have now flown successfully in a number of space scientific and engineering instruments, and have rapidly become the preferred technology for most imaging applications. One of their earliest planned applications in space was in the precision (subarcsecond) star tracker for the Astro series of UV missions.

Astro↗

Flight Performance of TOPEX/POSEIDON Star Tracker

The TOPEX/POSEIDON spacecraft was launched on August 10, 1992. This paper will present data on the measured performance of the ASTRA Star Trackers supplied by Hughes Danbury Optical Systems (HDOS) for this satellite.

Topex/Poseidon↗