Index to 1986 NASA Tech Briefs, volume 11, numbers 1-4

Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1986 Tech Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Improving the mechanistic study of neuromuscular diseases through the development of a fully wireless and implantable recording device

Neuromuscular diseases manifest by a handful of known phenotypes affecting the peripheral nerves, skeletal muscle fibers, and neuromuscular junction. Common signs of these diseases include demyelination, myasthenia, atrophy, and aberrant muscle activity—all of which may be tracked over time using one or more electrophysiological markers. Mice, which are the predominant mammalian model for most human diseases, have been used to study congenital neuromuscular diseases for decades. However, our understanding of the mechanisms underlying these pathologies is still incomplete. This is in part due to the lack of instrumentation available to easily collect longitudinal, in vivo electrophysiological activity from mice. There remains a need for a fully wireless, batteryless, and implantable recording system that can be adapted for a variety of electrophysiological measurements and also enable long-term, continuous data collection in very small animals. To meet this need a miniature, chronically implantable device has been developed that is capable of wirelessly coupling energy from electromagnetic fields while implanted within a body. This device can both record and trigger bioelectric events and may be chronically implanted in rodents as small as mice. This grants investigators the ability to continuously observe electrophysiological changes corresponding to disease progression in a single, freely behaving, untethered animal. The fully wireless closed-loop system is an adaptable solution for a range of long-term mechanistic and diagnostic studies in rodent disease models. Its high level of functionality, adjustable parameters, accessible building blocks, reprogrammable firmware, and modular electrode interface offer flexibility that is distinctive among fully implantable recording or stimulating devices. The key significance of this work is that it has generated novel instrumentation in the form of a fully implantable bioelectric recording device having a much higher level of functionality than any other fully wireless system available for mouse work. This has incidentally led to contributions in the areas of wireless power transfer and neural interfaces for upper-limb prosthesis control. Herein the solution space for wireless power transfer is examined including a close inspection of far-field power transfer to implanted bioelectric sensors. Methods of design and characterization for the iterative development of the device are detailed. Furthermore, its performance and utility in remote bioelectric sensing applications is demonstrated with humans, rats, healthy mice, and mouse models for degenerative neuromuscular and motoneuron diseases

MULTI‐PHYSICAL MODELLING AND PROTOTYPING OF AN ENERGY HARVESTING SYSTEM INTEGRATED IN A RAILWAY PNEUMATIC SUSPENSION

The aim of this PhD thesis is the investigation of an energy harvesting system to be integrated in a railway pneumatic spring to recovery otherwise wasted energy source from suspension vibration. Exploiting the piezoelectric effect to convert the mechanical energy into an electrical one, the final scope consists on the use of this system to power supply one or more sensors that can give useful information for the monitoring and the diagnostics of vehicle or its subsystems. Starting from the analysis of the energy sources, a multi‐physical approach to the study of an energy harvesting system is proposed to take into account all physics involved in the phenomenon, to make the most of the otherwise wasted energy and to develop a suitable and affordable tool for the design. The project of the energy harvesting device embedded in a railway pneumatic spring has been carried out by means of using a finite element technique and multi‐physics modelling activity. The possibility to combine two energy extraction processes was investigated with the purpose of making the most of the characteristics of the system and maximize the energy recovering. Exploiting commercial piezoelectric transducers, an experimental activity was conducted in two steps. A first mock‐up was built and tested on a shaker to develop the device and to tune the numerical model against experimental evidence. In the second step a fullscale prototype of an air spring for metro application with the EH system was realized. In order to test the full‐scale component, the design of a new test bench was carried out. Finally, the Air spring integrated with the EH device was tested and models validated

Semi-active six degree of freedom vibration control

This body of work develops a modular, semi-active isolation suspension for 6-DOF vibration control of ground support equipment near a rocket launch. The objective is to provide vibration and shock attenuation for a broad disturbance spectrum with semi-actively controlled magnetorheological (MR) dampers. MR dampers have adaptable rheological properties that can be quickly altered by the application of an external magnetic field, allowing the device to be tailored to the source disturbance. These changes are large, reversible, and rapid (10 -3 s), which make MR fluid an excellent medium for mechanical vibration damping. This work addresses several practical issues the MR suspension may face, including perturbations in operating temperature, payload mass, and center of gravity. A model of a single, linear-stroke MR damper is developed to capture the force behavior for practical operating temperatures between 0°C and 100°C. The impact of temperature and payload mass on the attenuation performance is evaluated through a simplified 1-DOF system. The analysis is extended to a multi-damper suspension for 6-DOF vibration control and a mathematical model is derived to describe the system dynamics. Several control laws are formulated in the 6-DOF framework, considering both centralized and decentralized algorithms. The mathematical model is validated experimentally with a full-scale, deliverable system tested at George Washington University's Earthquake Engineering Laboratory shake table in response to simulated disturbances from NASA's Space Shuttle Mobile Launch Platform during the STS-31 launch. The model is used to analyze the attenuation ability of the suspension considering MR damper orientation, control strategy, and perturbations in payload mass, center of gravity location, and operating temperature. The semi-active suspension is shown to be a robust, adaptable solution with low power consumption requirements compared to the state of the art

Cumulative index to NASA Tech Briefs, 1986-1990, volumes 10-14

Tech Briefs are short announcements of new technology derived from the R&D activities of the National Aeronautics and Space Administration. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This cumulative index of Tech Briefs contains abstracts and four indexes (subject, personal author, originating center, and Tech Brief number) and covers the period 1986 to 1990. The abstract section is organized by the following subject categories: electronic components and circuits, electronic systems, physical sciences, materials, computer programs, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Energy harvesting technologies for structural health monitoring of airplane components - a review

With the aim of increasing the efficiency of maintenance and fuel usage in airplanes, structural health monitoring (SHM) of critical composite structures is increasingly expected and required. The optimized usage of this concept is subject of intensive work in the framework of the EU COST Action CA18203 "Optimising Design for Inspection" (ODIN). In this context, a thorough review of a broad range of energy harvesting (EH) technologies to be potentially used as power sources for the acoustic emission and guided wave propagation sensors of the considered SHM systems, as well as for the respective data elaboration and wireless communication modules, is provided in this work. EH devices based on the usage of kinetic energy, thermal gradients, solar radiation, airflow, and other viable energy sources, proposed so far in the literature, are thus described with a critical review of the respective specific power levels, of their potential placement on airplanes, as well as the consequently necessary power management architectures. The guidelines provided for the selection of the most appropriate EH and power management technologies create the preconditions to develop a new class of autonomous sensor nodes for the in-process, non-destructive SHM of airplane components.The work of S. Zelenika, P. Gljušcic, E. Kamenar and Ž. Vrcan is partly enabled by using the equipment funded via the EU European Regional Development Fund (ERDF) project no. RC.2.2.06-0001: “Research Infrastructure for Campus-based Laboratories at the University of Rijeka (RISK)” and partly supported by the University of Rijeka, Croatia, project uniri-tehnic-18-32 „Advanced mechatronics devices for smart technological solutions“. Z. Hadas, P. Tofel and O. Ševecek acknowledge the support provided via the Czech Science Foundation project GA19-17457S „Manufacturing and analysis of flexible piezoelectric layers for smart engineering”. J. Hlinka, F. Ksica and O. Rubes gratefully acknowledge the financial support provided by the ESIF, EU Operational Programme Research, Development and Education within the research project Center of Advanced Aerospace Technology (Reg. No.: CZ.02.1.01/0.0/0.0/16_019/0000826) at the Faculty of Mechanical Engineering, Brno University of Technology. V. Pakrashi would like to acknowledge UCD Energy Institute, Marine and Renewable Energy Ireland (MaREI) centre Ireland, Strengthening Infrastructure Risk Assessment in the Atlantic Area (SIRMA) Grant No. EAPA\826/2018, EU INTERREG Atlantic Area and Aquaculture Operations with Reliable Flexible Shielding Technologies for Prevention of Infestation in Offshore and Coastal Areas (FLEXAQUA), MarTera Era-Net cofund PBA/BIO/18/02 projects. The work of J.P.B. Silva is partially supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UIDB/FIS/04650/2020. M. Mrlik gratefully acknowledges the support of the Ministry of Education, Youth and Sports of the Czech Republic-DKRVO (RP/CPS/2020/003

Aeronautical engineering: A special bibliography with indexes, supplement 38, December 1973

This special bibliography lists 473 reports, articles, and other documents introduced into the NASA scientific and technical information system in November 1973

Acoustic and Elastic Waves: Recent Trends in Science and Engineering

The present Special Issue intends to explore new directions in the field of acoustics and ultrasonics. The interest includes, but is not limited to, the use of acoustic technology for condition monitoring of materials and structures. Topics of interest (among others): • Acoustic emission in materials and structures (without material limitation) • Innovative cases of ultrasonic inspection • Wave dispersion and waveguides • Monitoring of innovative materials • Seismic waves • Vibrations, damping and noise control • Combination of mechanical wave techniques with other types for structural health monitoring purposes. Experimental and numerical studies are welcome

12th International Conference on Vibrations in Rotating Machinery

Since 1976, the Vibrations in Rotating Machinery conferences have successfully brought industry and academia together to advance state-of-the-art research in dynamics of rotating machinery. 12th International Conference on Vibrations in Rotating Machinery contains contributions presented at the 12th edition of the conference, from industrial and academic experts from different countries. The book discusses the challenges in rotor-dynamics, rub, whirl, instability and more. The topics addressed include: - Active, smart vibration control - Rotor balancing, dynamics, and smart rotors - Bearings and seals - Noise vibration and harshness - Active and passive damping - Applications: wind turbines, steam turbines, gas turbines, compressors - Joints and couplings - Challenging performance boundaries of rotating machines - High power density machines - Electrical machines for aerospace - Management of extreme events - Active machines - Electric supercharging - Blades and bladed assemblies (forced response, flutter, mistuning) - Fault detection and condition monitoring - Rub, whirl and instability - Torsional vibration Providing the latest research and useful guidance, 12th International Conference on Vibrations in Rotating Machinery aims at those from industry or academia that are involved in transport, power, process, medical engineering, manufacturing or construction