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Sample records for acoustic power required

  1. Powered-Lift Aerodynamics and Acoustics. [conferences

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Powered lift technology is reviewed. Topics covered include: (1) high lift aerodynamics; (2) high speed and cruise aerodynamics; (3) acoustics; (4) propulsion aerodynamics and acoustics; (5) aerodynamic and acoustic loads; and (6) full-scale and flight research.

  2. Low power acoustic harvesting of aerosols

    SciTech Connect

    Kaduchak, G.; Sinha, D. N.

    2001-01-01

    A new acoustic device for levitation and/or concentration of aerosols and sniall liquid/solid samples (up to several millimeters in diameter) in air has been developed. The device is inexpensive, low-power, and, in its simplest embodiment, does not require accurate alignmen1 of a resonant cavity. It is constructed from a cylindrical PZT tube of outside diameter D = 19.0 mm and thickness-to-radius ratio h/a - 0.03. The lowest-order breathing mode of the tube is tuned to match a resonant mode of the interior air-filled cylindrical cavity. A high Q cavity results that can be driven efficiently. An acoustic standing wave is created in the inteirior cavity of the cylindrical shell where particle concrmtration takes place at the nodal planes of the field. It is shown that drops of water in excess of 1 mm in diameter may be levitated against the force of gravity for approxirnately 100 mW of input electrical power. The main objective of the research is to implement this lowpower device to concentrate and harvest aerosols in a flowing system. Several different cavity geonietries iwe presented for efficient collection of 1 he conaartratetl aerosols. Concentraiion factors greater than 40 iue demonstrated for particles of size 0.7 1.1 in a flow volume of 50 L/minute.

  3. Power absorption in acoustically driven ferromagnetic resonance

    NASA Astrophysics Data System (ADS)

    Labanowski, D.; Jung, A.; Salahuddin, S.

    2016-01-01

    Surface acoustic waves (SAWs) have recently been used to drive ferromagnetic resonance by exploiting the coupling between strain and magnetization in magnetostrictive materials in a technique called acoustically driven ferromagnetic resonance (ADFMR). In this work, we quantitatively examine the power absorbed by the magnetic elements in such systems. We find that power absorption scales exponentially with the length of the magnetic element in the direction of SAW propagation, with the rate of scaling set by the thickness of magnetic material. In addition, we find that ADFMR behaves consistently across a wide range of input power values (>65 dB). Our results indicate that devices such as filters, oscillators, and sensors can be designed that operate with very low power, yet provide high tunability.

  4. Selectively manipulable acoustic-powered microswimmers

    PubMed Central

    Ahmed, Daniel; Lu, Mengqian; Nourhani, Amir; Lammert, Paul E.; Stratton, Zak; Muddana, Hari S.; Crespi, Vincent H.; Huang, Tony Jun

    2015-01-01

    Selective actuation of a single microswimmer from within a diverse group would be a first step toward collaborative guided action by a group of swimmers. Here we describe a new class of microswimmer that accomplishes this goal. Our swimmer design overcomes the commonly-held design paradigm that microswimmers must use non-reciprocal motion to achieve propulsion; instead, the swimmer is propelled by oscillatory motion of an air bubble trapped within the swimmer's polymer body. This oscillatory motion is driven by the application of a low-power acoustic field, which is biocompatible with biological samples and with the ambient liquid. This acoustically-powered microswimmer accomplishes controllable and rapid translational and rotational motion, even in highly viscous liquids (with viscosity 6,000 times higher than that of water). And by using a group of swimmers each with a unique bubble size (and resulting unique resonance frequencies), selective actuation of a single swimmer from among the group can be readily achieved. PMID:25993314

  5. Acoustic attenuation design requirements established through EPNL parametric trades

    NASA Technical Reports Server (NTRS)

    Veldman, H. F.

    1972-01-01

    An optimization procedure for the provision of an acoustic lining configuration that is balanced with respect to engine performance losses and lining attenuation characteristics was established using a method which determined acoustic attenuation design requirements through parametric trade studies using the subjective noise unit of effective perceived noise level (EPNL).

  6. Historical and projected power requirements

    NASA Technical Reports Server (NTRS)

    Wolfe, M. G.

    1978-01-01

    Policy planning for projected space power requirements is discussed. Topics of discussion cover: (1) historical space power trends (prime power requirements and power system costs); and (2) two approaches to future space power requirements (mission/traffic model approach and advanced system scenario approach). Graphs, tables, and flow charts are presented.

  7. Optimizing thermoacoustic regenerators for maximum amplification of acoustic power.

    PubMed

    Holzinger, Tobias; Emmert, Thomas; Polifke, Wolfgang

    2014-11-01

    Identifying optimum design parameters and operating conditions of thermoacoustic engines or refrigerators is crucial for the further development of such devices. This publication proposes an optimization criterion for the stack of a thermoacoustic device with the objective of maximizing the amplification of acoustic energy by the stack. For this purpose, the stack is described as an acoustic multi-port, represented mathematically by its scattering matrix. It is shown how the scattering matrix may be deduced from the standard thermo-acoustic governing equations. Then an acoustic power balance is deduced from the scattering matrix. The spectral norm and the eigenvectors of the scattering matrix identify optimal acoustic states. Stack design operating parameters and frequencies with maximum amplification of acoustic power are identified for various stack configurations. The corresponding acoustic states are interpreted physically. PMID:25373945

  8. 76 FR 52734 - Underwater Locating Devices (Acoustic) (Self-Powered)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-23

    ...This notice announces the planned revocation of all Technical Standard Order authorizations (TSOA) issued for the production of Underwater Locating Devices (Acoustic) (Self-Powered) manufactured to the TSO-C121 and TSO-C121a specifications. These actions are necessary because the planned issuance of TSO-C121b, Underwater Locating Devices (Acoustic) (Self-Powered), with a minimum performance......

  9. 77 FR 13174 - Underwater Locating Devices (Acoustic) (Self-Powered)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-05

    ...This is a confirmation notice for the planned revocation of all Technical Standard Order authorizations issued for the production of Underwater Locating Devices (Acoustic) (Self-Powered) manufactured to the TSO-C121 and TSO-C121a specifications. These actions are necessary because the planned issuance of TSO-C121b, Underwater Locating Devices (Acoustic) (Self-Powered), minimum performance......

  10. Klamath Falls: High-Power Acoustic Well Stimulation Technology

    SciTech Connect

    Black, Brian

    2006-07-24

    Acoustic well stimulation (AWS) technology uses high-power sonic waves from specific frequency spectra in an attempt to stimulate production in a damaged or low-production wellbore. AWS technology is one of the most promising technologies in the oil and gas industry, but it has proven difficult for the industry to develop an effective downhole prototype. This collaboration between Klamath Falls Inc. and the Rocky Mountain Oilfield Testing Center (RMOTC) included a series of tests using high-power ultrasonic tools to stimulate oil and gas production. Phase I testing was designed and implemented to verify tool functionality, power requirements, and capacity of high-power AWS tools. The purpose of Phase II testing was to validate the production response of wells with marginal production rates to AWS stimulation and to capture and identify any changes in the downhole environment after tool deployment. This final report presents methodology and results.

  11. Power cepstrum technique with application to model helicopter acoustic data

    NASA Technical Reports Server (NTRS)

    Martin, R. M.; Burley, C. L.

    1986-01-01

    The application of the power cepstrum to measured helicopter-rotor acoustic data is investigated. A previously applied correction to the reconstructed spectrum is shown to be incorrect. For an exact echoed signal, the amplitude of the cepstrum echo spike at the delay time is linearly related to the echo relative amplitude in the time domain. If the measured spectrum is not entirely from the source signal, the cepstrum will not yield the desired echo characteristics and a cepstral aliasing may occur because of the effective sample rate in the frequency domain. The spectral analysis bandwidth must be less than one-half the echo ripple frequency or cepstral aliasing can occur. The power cepstrum editing technique is a useful tool for removing some of the contamination because of acoustic reflections from measured rotor acoustic spectra. The cepstrum editing yields an improved estimate of the free field spectrum, but the correction process is limited by the lack of accurate knowledge of the echo transfer function. An alternate procedure, which does not require cepstral editing, is proposed which allows the complete correction of a contaminated spectrum through use of both the transfer function and delay time of the echo process.

  12. Acoustic environmental accuracy requirements for response determination

    NASA Technical Reports Server (NTRS)

    Pettitt, M. R.

    1983-01-01

    A general purpose computer program was developed for the prediction of vehicle interior noise. This program, named VIN, has both modal and statistical energy analysis capabilities for structural/acoustic interaction analysis. The analytic models and their computer implementation were verified through simple test cases with well-defined experimental results. The model was also applied in a space shuttle payload bay launch acoustics prediction study. The computer program processes large and small problems with equal efficiency because all arrays are dynamically sized by program input variables at run time. A data base is built and easily accessed for design studies. The data base significantly reduces the computational costs of such studies by allowing the reuse of the still-valid calculated parameters of previous iterations.

  13. An Evaluation of the Additional Acoustic Power Needed to Overcome the Effects of a Test-Article's Absorption During Reverberant Chamber Acoustic Testing of Spaceflight Hardware

    NASA Technical Reports Server (NTRS)

    Hozman, Aron D.; Hughes, William O.

    2014-01-01

    The exposure of a customer's aerospace test-article to a simulated acoustic launch environment is typically performed in a reverberant acoustic test chamber. The acoustic pre-test runs that will ensure that the sound pressure levels of this environment can indeed be met by a test facility are normally performed without a test-article dynamic simulator of representative acoustic absorption and size. If an acoustic test facility's available acoustic power capability becomes maximized with the test-article installed during the actual test then the customer's environment requirement may become compromised. In order to understand the risk of not achieving the customer's in-tolerance spectrum requirement with the test-article installed, an acoustic power margin evaluation as a function of frequency may be performed by the test facility. The method for this evaluation of acoustic power will be discussed in this paper. This method was recently applied at the NASA Glenn Research Center Plum Brook Station's Reverberant Acoustic Test Facility for the SpaceX Falcon 9 Payload Fairing acoustic test program.

  14. An Evaluation of the Additional Acoustic Power Needed to Overcome the Effects of a Test-Article's Absorption during Reverberant Chamber Acoustic Testing of Spaceflight Hardware

    NASA Technical Reports Server (NTRS)

    Hozman, Aron D.; Hughes, William O.

    2014-01-01

    The exposure of a customers aerospace test-article to a simulated acoustic launch environment is typically performed in a reverberant acoustic test chamber. The acoustic pre-test runs that will ensure that the sound pressure levels of this environment can indeed be met by a test facility are normally performed without a test-article dynamic simulator of representative acoustic absorption and size. If an acoustic test facilitys available acoustic power capability becomes maximized with the test-article installed during the actual test then the customers environment requirement may become compromised. In order to understand the risk of not achieving the customers in-tolerance spectrum requirement with the test-article installed, an acoustic power margin evaluation as a function of frequency may be performed by the test facility. The method for this evaluation of acoustic power will be discussed in this paper. This method was recently applied at the NASA Glenn Research Center Plum Brook Stations Reverberant Acoustic Test Facility for the SpaceX Falcon 9 Payload Fairing acoustic test program.

  15. Distribution of Acoustic Power Spectra for an Isolated Helicopter Fuselage

    NASA Astrophysics Data System (ADS)

    Kusyumov, A. N.; Mikhailov, S. A.; Garipova, L. I.; Batrakov, A. S.; Barakos, G.

    2016-03-01

    The broadband aerodynamic noise can be studied, assuming isotropic flow, turbulence and decay. Proudman's approach allows practical calculations of noise based on CFD solutions of RANS or URANS equations at the stage of post processing and analysis of the solution. Another aspect is the broadband acoustic spectrum and the distribution of acoustic power over a range of frequencies. The acoustic energy spectrum distribution in isotropic turbulence is non monotonic and has a maximum at a certain value of Strouhal number. In the present work the value of acoustic power peak frequency is determined using a prescribed form of acoustic energy spectrum distribution presented in papers by S. Sarkar and M. Y. Hussaini and by G. M. Lilley. CFD modelling of the flow around isolated helicopter fuselage model was considered using the HMB CFD code and the RANS equations.

  16. Innovative Approach for Developing Spacecraft Interior Acoustic Requirement Allocation

    NASA Technical Reports Server (NTRS)

    Chu, S. Reynold; Dandaroy, Indranil; Allen, Christopher S.

    2016-01-01

    The Orion Multi-Purpose Crew Vehicle (MPCV) is an American spacecraft for carrying four astronauts during deep space missions. This paper describes an innovative application of Power Injection Method (PIM) for allocating Orion cabin continuous noise Sound Pressure Level (SPL) limits to the sound power level (PWL) limits of major noise sources in the Environmental Control and Life Support System (ECLSS) during all mission phases. PIM is simulated using both Statistical Energy Analysis (SEA) and Hybrid Statistical Energy Analysis-Finite Element (SEA-FE) models of the Orion MPCV to obtain the transfer matrix from the PWL of the noise sources to the acoustic energies of the receivers, i.e., the cavities associated with the cabin habitable volume. The goal of the allocation strategy is to control the total energy of cabin habitable volume for maintaining the required SPL limits. Simulations are used to demonstrate that applying the allocated PWLs to the noise sources in the models indeed reproduces the SPL limits in the habitable volume. The effects of Noise Control Treatment (NCT) on allocated noise source PWLs are investigated. The measurement of source PWLs of involved fan and pump development units are also discussed as it is related to some case-specific details of the allocation strategy discussed here.

  17. High-Power Piezoelectric Acoustic-Electric Power Feedthru for Metal Walls

    NASA Technical Reports Server (NTRS)

    Bao, Xiaoqi; Biederman, Will; Sherrit, Stewart; Badescu, Mircea; Bar-Cohen, Yoseph; Jones, Christopher; Aldrich, Jack; Chang, Zensheu

    2008-01-01

    Piezoelectric acoustic-electric power feed-through devices transfer electric power wirelessly through a solid wall by using acoustic waves. This approach allows for the removal of holes through structures. The technology is applicable to power supply for electric equipment inside sealed containers, vacuum or pressure vessels, etc where the holes on the wall are prohibitive or result in significant performance degrade or complex designs. In the author's previous work, 100-W electric power was transferred through a metal wall by a small, simple-structure piezoelectric device. To meet requirements of higher power applications, the feasibility to transfer kilowatts level power was investigated. Pre-stressed longitudinal piezoelectric feedthru devices were analyzed by finite element model. An equivalent circuit model was developed to predict the power transfer characteristics to different electric loads. Based on the analysis results, a prototype device was designed, fabricated and a demonstration of the transmission of electric power up to 1-kW was successfully conducted. The methods to minimize the plate wave excitation on the wall were also analyzed. Both model analysis and experimental results are presented in detail in this presentation.

  18. Acoustic Requirements for a Multi-Purpose Hall.

    ERIC Educational Resources Information Center

    Schulte, W. Allen

    2002-01-01

    This case study examines the proposed design of a new lecture/recital hall in Centennial Hall at Lynchburg College that will be used for lectures, public events, a film studies course, and musical recitals. It explores the audio-visual challenges presented by the differing acoustical requirements for the building. (EV)

  19. Acoustical power amplification and damping by temperature gradients.

    PubMed

    Biwa, Tetsushi; Komatsu, Ryo; Yazaki, Taichi

    2011-01-01

    Ceperley proposed a concept of a traveling wave heat engine ["A pistonless Stirling engine-The traveling wave heat engine," J. Acoust. Soc. Am. 66, 1508-1513 (1979).] that provided a starting point of thermoacoustics today. This paper verifies experimentally his idea through observation of amplification and strong damping of a plane acoustic traveling wave as it passes through axial temperature gradients. The acoustic power gain is shown to obey a universal curve specified by a dimensionless parameter ωτα; ω is the angular frequency and τα is the relaxation time for the gas to thermally equilibrate with channel walls. As an application of his idea, a three-stage acoustic power amplifier is developed, which attains the gain up to 10 with a moderate temperature ratio of 2.3. PMID:21302995

  20. High-frequency multi-wavelength acoustic power maps

    NASA Astrophysics Data System (ADS)

    Hill, Frank; Ladenkov, Oleg; Ehgamberdiev, Shuhrat; Chou, Dean-Yi

    2001-01-01

    Acoustic power maps have been constructed using SOHO/MDI velocity and intensity data in Ni I 6768; NSO High-L Helioseismometer (HLH) Ca K intensity; and Taiwan Oscillation Network (TON) intensity in Ca K. The HLH data provides maps up to a frequency of 11.9 mHz, substantially higher than the usual 8.33 mHz. The Ca K observations show a surprising strong enhancement of power within a sunspot at all temporal frequencies, while the Ni I data show the well-known suppression of power. Tests suggest that this apparent acoustic enhancement is the result of strong intensity gradients observed through terrestrial seeing.

  1. Military power requirements and backup power considerations

    SciTech Connect

    Botts, T.E.

    1986-01-01

    All US Air Force (USAF) facilities have certain critical power requirements that must be met in order to carry out their mission successfully. Internal USAF studies have shown that the mission can degrade precipitously as the available power decreases below the mission critical level. Now, more than ever before, the military and private industry are finding that certain functions, such as automated data processing and automated process control, respond catastrophically to power reductions. Furthermore, increased reliance on electrical power means, in the case of the Air Force, that critical power requirements are anticipated to increase by half over the next 15 yr. For these reasons and others, the USAF is investigating several means of improving the availability of electric power under adverse conditions above that which can be provided by an off-base supplier. Among the approaches to this problem being pursued at this time are a program to improve all sorts of generator sets on a service-wide basis and the Multimegawatt Terrestrial Power (MTP) Program, which is pursuing the design and testing of a small dedicated nuclear power source to provide critical mission power. The purpose of this paper is to provide some insight into some of the issues associated with USAF power programs.

  2. Acoustical criteria for hospital patient rooms: Resolving competing requirements

    NASA Astrophysics Data System (ADS)

    Brooks, Bennett M.

    2003-10-01

    The acoustical criteria for patient rooms in hospitals, nursing homes, and rehabilitation facilities may be based on several needs. One important requirement is that noise levels in the room be conducive to restful sleep. Also, caregivers must have easy auditory and visual access to the patients, and be able to hear vital sign monitor alarms. This often means that patient rooms are located near central nurse stations and that patient room doors are left open. Further, the recently published federal privacy standards developed by the U.S. Department of Health and Human Services (HSS) under the Health Insurance Portability and Accountability Act (HIPAA) require that ``appropriate physical safeguards'' be put in place to protect the confidentiality of patient health information. The simultaneous and competing requirements for speech privacy, caregiver access, and good sleeping conditions present a serious acoustical challenge to health care facility designers. Specific facility design issues and potential solution strategies are presented.

  3. Aeroacoustics of volcanic jets: Acoustic power estimation and jet velocity dependence

    NASA Astrophysics Data System (ADS)

    Matoza, Robin S.; Fee, David; Neilsen, Tracianne B.; Gee, Kent L.; Ogden, Darcy E.

    2013-12-01

    A fundamental goal of volcano acoustics is to relate observed infrasonic signals to the eruptive processes generating them. A link between acoustic power Πacoustic analogy theory). We reexamine this approach in the context of the current understanding of jet noise, using data from a laboratory jet, a full-scale military jet aircraft, and a full-scale rocket motor. Accurate estimates of Πrequire good spatial sampling of jet noise directionality; this is not usually possible in volcano acoustic field experiments. Typical volcano acoustic data better represent point measurements of acoustic intensity Iacoustic intensity differ from those for acoustic power and are of the form Iacoustic data and thus requires modification. Quantitative integration of field, numerical, and laboratory studies within a modern aeroacoustics framework will lead to a more accurate relationship between volcanic infrasound and eruption parameters.

  4. Measurement of the total acoustic output power of HITU transducers

    NASA Astrophysics Data System (ADS)

    Jenderka, Klaus-V.; Beissner, Klaus

    2010-03-01

    The majority of High Intensity Therapeutic Ultrasound (HITU) applications use strongly focused ultrasound fields generating very high local intensities in the focal region. The metrology of these high-power ultrasound fields is a challenge for the established measurement procedures and devices. This paper describes the results of measurements by means of the radiation force for a total acoustic output power up to 400 W at 1.5 MHz and up to 200 W at 2.45 MHz. For this purpose, a radiation force balance set-up was adapted for the determination of large acoustic output powers. For two types of HITU transducers, the relationship between the total acoustic output power and the applied net electrical power was determined at close transducer-target distance. Further, dependence of the measured electro-acoustic radiation conductance on the transducer-target distance was investigated at reduced power levels, considering the appearance of focal anomalies. Concluding, a list of the main uncertainty contributions, and an estimate of the uncertainty for the used radiation force balance set-up is given for measurements at high power levels.

  5. Power requirements for PHERB powertrain

    NASA Astrophysics Data System (ADS)

    Norbakyah, J. S.; Atiq, W. H.; Salisa, A. R.

    2015-12-01

    Boats are considered as favourite maritime transportation designed for recreation activities, fishing and surveillance purposes. However, in tropical developed countries, boats are employed for different applications such as passenger and goods transportation. In this paper, the power requirements for a proposed plug-in hybrid electric recreational boat (PHERB) powertrain is determined using a steady state velocity and the Kuala Terengganu river driving cycle according to the boat parameters, specifications and performance requirements. The boat power requirements can be used to size the main components for PHERB powertrain. The results obtained from this analysis are within reasonable range and satisfactory.

  6. Ultrasonic waveguide sensor for acoustic monitoring of nuclear power plants

    SciTech Connect

    Mel'nikov, V.I.; Khokhlov, V.N.; Duntsev, A.V.

    1988-02-01

    Waveguide sensors are being increasingly used for acoustic emission monitoring of equipment in nuclear power plants and in systems for acoustic diagnostics of the coolant. In this paper we examine the construction of a waveguide sensor for acoustic monitoring for the example of an impedance sensor for the steam content of water coolant, intended for use in the active emission-reception mode. The dynamic properties of the sensor are determined by the construction and the dimensions of the transducer, and are usually represented by its amplitude-frequency characteristic, which, as a rule, is of the resonance type. The longitudinal-wave waveguide, made from steel wire 0.8-1.2 mm in diameter, can transmit signals in the band 50-1000 kHz. To increase the reliability and the ease of maintenance of the monitoring system the transducer and the waveguide are connected in a detachable manner.

  7. Acoustics

    NASA Technical Reports Server (NTRS)

    Goodman, Jerry R.; Grosveld, Ferdinand

    2007-01-01

    The acoustics environment in space operations is important to maintain at manageable levels so that the crewperson can remain safe, functional, effective, and reasonably comfortable. High acoustic levels can produce temporary or permanent hearing loss, or cause other physiological symptoms such as auditory pain, headaches, discomfort, strain in the vocal cords, or fatigue. Noise is defined as undesirable sound. Excessive noise may result in psychological effects such as irritability, inability to concentrate, decrease in productivity, annoyance, errors in judgment, and distraction. A noisy environment can also result in the inability to sleep, or sleep well. Elevated noise levels can affect the ability to communicate, understand what is being said, hear what is going on in the environment, degrade crew performance and operations, and create habitability concerns. Superfluous noise emissions can also create the inability to hear alarms or other important auditory cues such as an equipment malfunctioning. Recent space flight experience, evaluations of the requirements in crew habitable areas, and lessons learned (Goodman 2003; Allen and Goodman 2003; Pilkinton 2003; Grosveld et al. 2003) show the importance of maintaining an acceptable acoustics environment. This is best accomplished by having a high-quality set of limits/requirements early in the program, the "designing in" of acoustics in the development of hardware and systems, and by monitoring, testing and verifying the levels to ensure that they are acceptable.

  8. Enhanced output power by eigenfrequency shift in acoustic energy harvester

    NASA Astrophysics Data System (ADS)

    Li, Bin; You, Jeong Ho

    2014-04-01

    In our previous studies, multiple piezoelectric cantilever plates were placed inside a quarter-wavelength straight tube resonator to harvest low frequency acoustic energy. To investigate the modification of eigenmodes in the tube resonator due to the presence of piezoelectric plates, the eigenfrequency shift properties by introducing single and multiple rectangular blockages in open-closed ducts are studied by using 1D segmented Helmholtz equations, Webster horn equation, and finite element simulations. The first-mode eigenfrequency of the duct is reduced when the blockage is placed near the open inlet. The decrease of eigenfrequency leads to the enhancement of absorbed acoustic power in the duct. Furthermore, the first half of the tube resonator possesses high pressure gradient resulting in larger driving forces for the vibration motion of piezoelectric plates. Therefore, in our harvesters, it is better to place the piezoelectric plates in the first half of the tube resonator to obtain high output voltage and power.

  9. Method of measuring reactive acoustic power density in a fluid

    DOEpatents

    Wheatley, John C.; Swift, Gregory W.; Migliori, Albert

    1985-01-01

    A method for determining reactive acoustic power density level and its direction in a fluid using a single sensor is disclosed. In the preferred embodiment, an apparatus for conducting the method, which is termed a thermoacoustic couple, consists of a stack of thin, spaced apart polymeric plates, selected ones of which include multiple bimetallic thermocouple junctions positioned along opposite end edges thereof. The thermocouple junctions are connected in series in the nature of a thermopile, and are arranged so as to be responsive to small temperature differences between the opposite edges of the plates. The magnitude of the temperature difference, as represented by the magnitude of the electrical potential difference generated by the thermopile, is found to be directly related to the level of acoustic power density in the gas.

  10. Method of measuring reactive acoustic power density in a fluid

    DOEpatents

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1985-09-03

    A method for determining reactive acoustic power density level and its direction in a fluid using a single sensor is disclosed. In the preferred embodiment, an apparatus for conducting the method, which is termed a thermoacoustic couple, consists of a stack of thin, spaced apart polymeric plates, selected ones of which include multiple bimetallic thermocouple junctions positioned along opposite end edges thereof. The thermocouple junctions are connected in series in the nature of a thermopile, and are arranged so as to be responsive to small temperature differences between the opposite edges of the plates. The magnitude of the temperature difference, as represented by the magnitude of the electrical potential difference generated by the thermopile, is found to be directly related to the level of acoustic power density in the gas. 5 figs.

  11. Evaluation of human middle ear function via an acoustic power assessment.

    PubMed

    Allen, Jont B; Jeng, Patricia S; Levitt, Harry

    2005-01-01

    Measurements of middle ear (ME) acoustic power flow (power reflectance, power absorption, and transmittance) and normalized impedance (acoustic resistance, acoustic reactance, and impedance magnitude) were compared for their utility in clinical applications. Transmittance, a measure of the acoustic power absorbed by the ME, was found to have several important advantages over other measures of acoustic power flow. In addition to its simple and audiologically relevant physical interpretation (absorbed power), the normal transmittance curve has a simple shape that is visually similar to the ME transfer function. The acoustic impedance measures (resistance and reactance) provided important additional information about ME status and supplemented transmittance measurements. Together these measurements can help identify unusual conditions such as eardrum perforations. While this article is largely a review of the development of a commercial power reflectance measurement system, previously unpublished experimental results are presented. PMID:16470465

  12. Acoustic power of a moving point source in a moving medium

    NASA Technical Reports Server (NTRS)

    Cole, J. E., III; Sarris, I. I.

    1976-01-01

    The acoustic power output of a moving point-mass source in an acoustic medium which is in uniform motion and infinite in extent is examined. The acoustic medium is considered to be a homogeneous fluid having both zero viscosity and zero thermal conductivity. Two expressions for the acoustic power output are obtained based on a different definition cited in the literature for the average energy-flux vector in an acoustic medium in uniform motion. The acoustic power output of the source is found by integrating the component of acoustic intensity vector in the radial direction over the surface of an infinitely long cylinder which is within the medium and encloses the line of motion of the source. One of the power expressions is found to give unreasonable results even though the flow is uniform.

  13. A radioisotope-powered surface acoustic wave transponder

    NASA Astrophysics Data System (ADS)

    Tin, S.; Lal, A.

    2009-09-01

    We demonstrate a 63Ni radioisotope-powered pulse transponder that has a SAW (surface acoustic wave) device as the frequency transmission frequency selector. Because the frequency is determined by a SAW device, narrowband detection with an identical SAW device enables the possibility for a long-distance RF-link. The SAW transponders can be buried deep into structural constructs such as steel and concrete, where changing batteries or harvesting vibration or EM energy is not a reliable option. RF-released power to radioisotope- released power amplification is 108, even when regulatory safe amounts of 63Ni are used. Here we have achieved an 800 µW pulse (315 MHz, 10 µs pause) across a 50 Ω load every 3 min, using a 1.5 milli-Ci 63Ni source.

  14. Estimation of the detection range of a hydroacoustic system based on the acoustic power flux receiver

    NASA Astrophysics Data System (ADS)

    Gordienko, V. A.; Krasnopistsev, N. V.; Nasedkin, A. V.; Nekrasov, V. N.

    2007-11-01

    Approaches to estimating the detection range of systems based on vector receivers are considered. The approaches rely on a detailed analysis of the process of signal’s acoustic power flux formation in the presence of ambient sea noise and uncover the signal information parameters at the receiver output that provide the required statistically confident range of weak signal detection under these conditions. Based on the sonar equations and the known fundamental relationships between the outputs of a pressure receiver and a vector receiver for signal and noise, estimates of the maximum possible gain in the detection range of an acoustic power flux receiver are considered as a function of anisotropy of the ambient noise field in the area.

  15. Reversing pathologically increased EEG power by acoustic coordinated reset neuromodulation

    PubMed Central

    Adamchic, Ilya; Toth, Timea; Hauptmann, Christian; Tass, Peter Alexander

    2014-01-01

    Acoustic Coordinated Reset (CR) neuromodulation is a patterned stimulation with tones adjusted to the patient's dominant tinnitus frequency, which aims at desynchronizing pathological neuronal synchronization. In a recent proof-of-concept study, CR therapy, delivered 4–6 h/day more than 12 weeks, induced a significant clinical improvement along with a significant long-lasting decrease of pathological oscillatory power in the low frequency as well as γ band and an increase of the α power in a network of tinnitus-related brain areas. As yet, it remains unclear whether CR shifts the brain activity toward physiological levels or whether it induces clinically beneficial, but nonetheless abnormal electroencephalographic (EEG) patterns, for example excessively decreased δ and/or γ. Here, we compared the patients' spontaneous EEG data at baseline as well as after 12 weeks of CR therapy with the spontaneous EEG of healthy controls by means of Brain Electrical Source Analysis source montage and standardized low-resolution brain electromagnetic tomography techniques. The relationship between changes in EEG power and clinical scores was investigated using a partial least squares approach. In this way, we show that acoustic CR neuromodulation leads to a normalization of the oscillatory power in the tinnitus-related network of brain areas, most prominently in temporal regions. A positive association was found between the changes in tinnitus severity and the normalization of δ and γ power in the temporal, parietal, and cingulate cortical regions. Our findings demonstrate a widespread CR-induced normalization of EEG power, significantly associated with a reduction of tinnitus severity. PMID:23907785

  16. American National Standard Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools.

    ERIC Educational Resources Information Center

    Acoustical Society of America, Melville, New York.

    This standards publication provides acoustical performance criteria, design requirements, and design guidelines for new school classrooms and other learning spaces. The standards may be applied when practicable to the major renovation of existing classrooms. These criteria, requirements, and guidelines are keyed to the acoustical qualities needed…

  17. Space power development impact on technology requirements

    NASA Technical Reports Server (NTRS)

    Cassidy, J. F.; Fitzgerald, T. J.; Gilje, R. I.; Gordon, J. D.

    1986-01-01

    The paper is concerned with the selection of a specific spacecraft power technology and the identification of technology development to meet system requirements. Requirements which influence the selection of a given technology include the power level required, whether the load is constant or transient in nature, and in the case of transient loads, the time required to recover the power, and overall system safety. Various power technologies, such as solar voltaic power, solar dynamic power, nuclear power systems, and electrochemical energy storage, are briefly described.

  18. 1KW Power Transmission Using Wireless Acoustic-Electric Feed-Through (WAEF)

    NASA Technical Reports Server (NTRS)

    Sherrit, S.; Bao, X.; Badescu, M.; Aldrich, J.; Bar-Cohen, Y.; Biederman, W.

    2008-01-01

    A variety of space applications require the delivery of power into sealed structures. Since the structural integrity can be degraded by holes for cabling we present an alternative method of delivering power and information using stress waves to the internal space of a sealed structure. One particular application of this technology is in sample return missions where it is critical to preserve the sample integrity and to prevent earth contamination. Therefore, the container has to be hermetically sealed and the integrity of the seal must be monitored in order to insure to a high degree of reliability the integrity of the sample return vessel. In this study we investigated the use of piezoelectric acoustic-electric power feed-through devices to transfer electric power wirelessly through a solid wall by using elastic or acoustic waves. The technology is applicable to a range of space and terrestrial applications where power is required by electronic equipment inside sealed containers, vacuum or pressure vessels, etc., where holes in the wall are prohibitive or may result in significant structural performance degradation or unnecessarily complex designs. To meet requirements of higher power applications, the feasibility to transfer kilowatts level power was investigated. Pre-stressed longitudinal piezoelectric feed-through devices were analyzed by finite element models and an equivalent circuit model was developed to predict the power transfer characteristics to different electric loads. Based on the results of the analysis a prototype device was designed, fabricated and a demonstration of the transmission of electric power up to 1.068-kW was successfully conducted. Efficiencies in the 80-90% range were also demonstrated and methods to increase the efficiency further are currently being considered.

  19. An integrated modular power-aware microsensor architecture and application to unattended acoustic vehicle tracking

    NASA Astrophysics Data System (ADS)

    Bajura, Michael; Schott, Brian; Flidr, Jaroslav; Czarnaski, Joe; Worth, Carl; Tho, Tam; Wang, Li

    2005-05-01

    We introduce a truly modular, power-aware, distributed microsensor architecture, capable of seamlessly spanning performance metrics from point-optimized low-power to point-optimized high-power applications. This type of performance is often needed in unattended ground sensor applications such as acoustic sensing and tracking, where long periods of minimal sensing activity are intermixed with short periods of intense sensor processing. The system design and implementation of a microsensor platform based on this architecture are described with experimental results. We show that although building a modular power-aware system requires additional hardware components, it results in system capable of rapid physical hardware and software reconfiguration with module reuse for new applications, while achieving a significant decrease in overall system power.

  20. Acoustic intensity near a high-powered military jet aircraft.

    PubMed

    Stout, Trevor A; Gee, Kent L; Neilsen, Tracianne B; Wall, Alan T; James, Michael M

    2015-07-01

    The spatial variation in vector acoustic intensity has been calculated between 100 and 3000 Hz near a high-performance military aircraft. With one engine of a tethered F-22A Raptor operating at military power, a tetrahedral intensity probe was moved to 27 locations in the geometric near and mid-fields to obtain the frequency-dependent intensity vector field. The angles of the maximum intensity region rotate from aft to sideline with increasing frequency, becoming less directional above 800 Hz. Between 100 and 400 Hz, which are principal radiation frequencies, the ray-traced dominant source region rapidly contracts and moves upstream, approaching nearly constant behavior by 1000 Hz. PMID:26233049

  1. Relationship between acoustic power and acoustic radiation force on absorbing and reflecting targets for spherically focusing radiators.

    PubMed

    Gélat, Pierre; Shaw, Adam

    2015-03-01

    Total acoustic output power is an important parameter required by standards for most ultrasonic medical equipment including high-intensity focused ultrasound (HIFU) systems. Radiation force balances are routinely used; however, radiation force is not strictly dependent on the ultrasound power but, rather, on the wave momentum resolved in one direction. Consequently, measurements based on radiation force become progressively less accurate as the ultrasound wave deviates further from a true plane wave. HIFU transducers can be very strongly focused with F-numbers less than one: under these conditions, the uncertainty associated with use of the radiation force method becomes very significant. International Standards IEC 61161 and IEC 62555 suggest plane-wave correction factors for unfocused transducers radiating onto an ideal absorbing target and focusing corrections for focused transducers radiating onto ideal absorbing targets and onto conical reflecting targets (IEC 61161). Previous models have relied on calculations based on the Rayleigh integral, which is not strictly correct for curved sources. In the work described here, an approach combining finite element methods with a discretization of the Helmholtz equation was developed, making it possible to model the boundary condition at the structure/fluid interface more correctly. This has been used to calculate the relationship between radiation force and total power for both absorbing and conical reflecting targets for transducers ranging from planar to an F-number of 0.5 (hemispherical) and to compare with the recommendations of IEC 61161 and IEC 62555. PMID:25683223

  2. Progress in Acoustic Transmission of Power through Walls

    NASA Technical Reports Server (NTRS)

    Sherrit,Stewart; Coty, Benjamin; Bao, Xiaoqi; Bar-Cohen, Yoseph; Badescu, Mircea; Chang, Zensheu

    2008-01-01

    A document presents updated information on implementation of the wireless acoustic-electric feed-through (WAEF) concept, which was reported in Using Piezoelectric Devices To Transmit Power Through Walls (NPO-41157), NASA Tech Briefs, Vol. 32, No. 6 (June 2008), page 70. To recapitulate: In a basic WAEF setup, a transmitting piezoelectric transducer on one side of a wall is driven at resonance to excite ultrasonic vibrations in the wall. A receiving piezoelectric transducer on the opposite side of the wall converts the vibrations back to an ultrasonic AC electric signal, which is then detected and otherwise processed in a manner that depends on the modulation (if any) applied to the signal and whether the signal is used to transmit power, data, or both. The present document expands upon the previous information concerning underlying physical principles, advantages, and potential applications of WAEF. It discusses the design and construction of breadboard prototype piezoelectric transducers for WAEF. It goes on to present results of computational simulations of performance and results of laboratory tests of the prototypes. In one notable test, a 100-W light bulb was lit by WAEF to demonstrate the feasibility of powering a realistic load.

  3. Sympathetic Tone Induced by High Acoustic Tempo Requires Fast Respiration.

    PubMed

    Watanabe, Ken; Ooishi, Yuuki; Kashino, Makio

    2015-01-01

    Many studies have revealed the influences of music, and particularly its tempo, on the autonomic nervous system (ANS) and respiration patterns. Since there is the interaction between the ANS and the respiratory system, namely sympatho-respiratory coupling, it is possible that the effect of musical tempo on the ANS is modulated by the respiratory system. Therefore, we investigated the effects of the relationship between musical tempo and respiratory rate on the ANS. Fifty-two healthy people aged 18-35 years participated in this study. Their respiratory rates were controlled by using a silent electronic metronome and they listened to simple drum sounds with a constant tempo. We varied the respiratory rate-acoustic tempo combination. The respiratory rate was controlled at 15 or 20 cycles per minute (CPM) and the acoustic tempo was 60 or 80 beats per minute (BPM) or the environment was silent. Electrocardiograms and an elastic chest band were used to measure the heart rate and respiratory rate, respectively. The mean heart rate and heart rate variability (HRV) were regarded as indices of ANS activity. We observed a significant increase in the mean heart rate and the low (0.04-0.15 Hz) to high (0.15-0.40 Hz) frequency ratio of HRV, only when the respiratory rate was controlled at 20 CPM and the acoustic tempo was 80 BPM. We suggest that the effect of acoustic tempo on the sympathetic tone is modulated by the respiratory system. PMID:26284521

  4. Sympathetic Tone Induced by High Acoustic Tempo Requires Fast Respiration

    PubMed Central

    Watanabe, Ken; Ooishi, Yuuki; Kashino, Makio

    2015-01-01

    Many studies have revealed the influences of music, and particularly its tempo, on the autonomic nervous system (ANS) and respiration patterns. Since there is the interaction between the ANS and the respiratory system, namely sympatho-respiratory coupling, it is possible that the effect of musical tempo on the ANS is modulated by the respiratory system. Therefore, we investigated the effects of the relationship between musical tempo and respiratory rate on the ANS. Fifty-two healthy people aged 18–35 years participated in this study. Their respiratory rates were controlled by using a silent electronic metronome and they listened to simple drum sounds with a constant tempo. We varied the respiratory rate—acoustic tempo combination. The respiratory rate was controlled at 15 or 20 cycles per minute (CPM) and the acoustic tempo was 60 or 80 beats per minute (BPM) or the environment was silent. Electrocardiograms and an elastic chest band were used to measure the heart rate and respiratory rate, respectively. The mean heart rate and heart rate variability (HRV) were regarded as indices of ANS activity. We observed a significant increase in the mean heart rate and the low (0.04–0.15 Hz) to high (0.15–0.40 Hz) frequency ratio of HRV, only when the respiratory rate was controlled at 20 CPM and the acoustic tempo was 80 BPM. We suggest that the effect of acoustic tempo on the sympathetic tone is modulated by the respiratory system. PMID:26284521

  5. A power semiconductor test circuit with reduced power requirements

    NASA Technical Reports Server (NTRS)

    Been, J. F.

    1970-01-01

    Switching circuit utilizing silicon controlled rectifier reduces input power requirements normally associated with testing power semiconductors in an operational type mode. Circuit alleviates problems of inaccessibility, lack of large amounts of power, physical size of power resistors, wiring, and heat generation.

  6. Acoustic agglomeration of power plant fly ash. Final report

    SciTech Connect

    Reethof, G.; McDaniel, O.H.

    1982-01-01

    The work has shown that acoustic agglomeration at practical acoustic intensities and frequencies is technically and most likely economically viable. The following studies were performed with the listed results: The physics of acoustic agglomeration is complex particularly at the needed high acoustic intensities in the range of 150 to 160 dB and frequencies in the 2500 Hz range. The analytical model which we developed, although not including nonlinear acoustic efforts, agreed with the trends observed. We concentrated our efforts on clarifying the impact of high acoustic intensities on the generation of turbulence. Results from a special set of tests show that although some acoustically generated turbulence of sorts exists in the 150 to 170 dB range with acoustic streaming present, such turbulence will not be a significant factor in acoustic agglomeration compared to the dominant effect of the acoustic velocities at the fundamental frequency and its harmonics. Studies of the robustness of the agglomerated particles using the Anderson Mark III impactor as the source of the shear stresses on the particles show that the agglomerates should be able to withstand the rigors of flow through commercial cyclones without significant break-up. We designed and developed a 700/sup 0/F tubular agglomerator of 8'' internal diameter. The electrically heated system functioned well and provided very encouraging agglomeration results at acoustic levels in the 150 to 160 dB and 2000 to 3000 Hz ranges. We confirmed earlier results that an optimum frequency exists at about 2500 Hz and that larger dust loadings will give better results. Studies of the absorption of acoustic energy by various common gases as a function of temperature and humidity showed the need to pursue such an investigation for flue gas constituents in order to provide necessary data for the design of agglomerators. 65 references, 56 figures, 4 tables.

  7. Benthic microbial fuel cell as direct power source for an acoustic modem and seawater oxygen/temperature sensor system.

    PubMed

    Gong, Yanming; Radachowsky, Sage E; Wolf, Michael; Nielsen, Mark E; Girguis, Peter R; Reimers, Clare E

    2011-06-01

    Supported by the natural potential difference between anoxic sediment and oxic seawater, benthic microbial fuel cells (BMFCs) promise to be ideal power sources for certain low-power marine sensors and communication devices. In this study a chambered BMFC with a 0.25 m(2) footprint was used to power an acoustic modem interfaced with an oceanographic sensor that measures dissolved oxygen and temperature. The experiment was conducted in Yaquina Bay, Oregon over 50 days. Several improvements were made in the BMFC design and power management system based on lessons learned from earlier prototypes. The energy was harvested by a dynamic gain charge pump circuit that maintains a desired point on the BMFC's power curve and stores the energy in a 200 F supercapacitor. The system also used an ultralow power microcontroller and quartz clock to read the oxygen/temperature sensor hourly, store data with a time stamp, and perform daily polarizations. Data records were transmitted to the surface by the acoustic modem every 1-5 days after receiving an acoustic prompt from a surface hydrophone. After jump-starting energy production with supplemental macroalgae placed in the BMFC's anode chamber, the average power density of the BMFC adjusted to 44 mW/m(2) of seafloor area which is better than past demonstrations at this site. The highest power density was 158 mW/m(2), and the useful energy produced and stored was ≥ 1.7 times the energy required to operate the system. PMID:21545151

  8. Acoustics

    NASA Astrophysics Data System (ADS)

    The acoustics research activities of the DLR fluid-mechanics department (Forschungsbereich Stroemungsmechanik) during 1988 are surveyed and illustrated with extensive diagrams, drawings, graphs, and photographs. Particular attention is given to studies of helicopter rotor noise (high-speed impulsive noise, blade/vortex interaction noise, and main/tail-rotor interaction noise), propeller noise (temperature, angle-of-attack, and nonuniform-flow effects), noise certification, and industrial acoustics (road-vehicle flow noise and airport noise-control installations).

  9. Mobility power flow analysis of coupled plate structure subjected to mechanical and acoustic excitation

    NASA Technical Reports Server (NTRS)

    Cuschieri, J. M.

    1992-01-01

    The mobility power flow approach that was previously applied in the derivation of expressions for the vibrational power flow between coupled plate substructures forming an L configuration and subjected to mechanical loading is generalized. Using the generalized expressions, both point and distributed mechanical loads on one or both of the plates can be considered. The generalized approach is extended to deal with acoustic excitation of one of the plate substructures. In this case, the forces (acoustic pressures) acting on the structure are dependent on the response of the structure because of the scattered pressure component. The interaction between the plate structure and the acoustic fluid leads to the derivation of a corrected mode shape for the plates' normal surface velocity and also for the structure mobility functions. The determination of the scattered pressure components in the expressions for the power flow represents an additional component in the power flow balance for the source plate and the receiver plate. This component represents the radiated acoustical power from the plate structure. For a number of coupled plate substrates, the acoustic pressure generated by one substructure will interact with the motion of another substructure. That is, in the case of the L-shaped plate, acoustic interaction exists between the two plate substructures due to the generation of the acoustic waves by each of the substructures. An approach to deal with this phenomena is described.

  10. Power and energy requirements for electromagnetic launchers

    NASA Astrophysics Data System (ADS)

    Lottes, P. A.; Holtz, R. E.; Uherka, K. L.

    A large data base exists covering almost all aspects of the requirements for the successful development of electromagnetic launchers. To extend the use of electromagnetic launchers to the limits of technology for such exotic applications as hypervelocity weaponry or space launch systems, it is useful to examine the energy and power requirements for such uses. One way to do this is to purposely neglect all system losses in order to determine minimum power and energy requirements. Actual power requirements will most likely be higher by at least a factor of three. Calculations are presented for minimum power requirements, launch acceleration time, projectile kinetic energy, and projectile inertial force as a function of projectile mass, projectile terminal velocity, and the length of the launch tube. Results of these calculations are presented.

  11. Acoustic-loads research for powered-lift configurations

    NASA Technical Reports Server (NTRS)

    Schoenster, J. A.; Willis, C. M.; Schroeder, J. C.; Mixson, J. S.

    1976-01-01

    Data presented from large-scale model tests with jet engines having thrusts of 9 kN (2000 lb) and 36 kN (8000 lb) include acoustic loads for an externally blown wing and flap induced by a TF34 jet engine, an upper surface blown (USB) aircraft model in a wind tunnel, and two USB models in static tests. Comparisons of these results with results from acoustic loads studies on configurations of other sizes are made and the implications of these results on interior noise and acoustic fatigue are discussed.

  12. Propulsion element requirements using electrical power system unscheduled power

    NASA Technical Reports Server (NTRS)

    Zimmermann, Frank; Hodge, Kathy

    1989-01-01

    The suitability of using the electrical energy from the Space Station's Electrical Power System (EPS) during the periods of peak solar insolation which is currently not specifically allocated (unscheduled power) to produce propulsion propellants, gaseous hydrogen, and oxygen by electrolyzing water is investigated. Reboost propellant requirements are emphasized, but the results are more generally relevant because the balance of recurring propellant requirements are an order of magnitude smaller and the nonrecurring requirements are not significant on an average basis.

  13. Monitoring Thermal Fatigue Damage In Nuclear Power Plant Materials Using Acoustic Emission

    SciTech Connect

    Meyer, Ryan M.; Ramuhalli, Pradeep; Watson, Bruce E.; Pitman, Stan G.; Roosendaal, Timothy J.; Bond, Leonard J.

    2012-04-26

    Proactive aging management of nuclear power plant passive components requires technologies to enable monitoring and accurate quantification of material condition at early stages of degradation (i.e., pre-macrocrack). Acoustic emission (AE) is well-suited to continuous monitoring of component degradation and is proposed as a method to monitor degradation during accelerated thermal fatigue tests. A key consideration is the ability to separate degradation responses from external sources such as water spray induced during thermal fatigue testing. Water spray provides a significant background of acoustic signals, which can overwhelm AE signals caused by degradation. Analysis of AE signal frequency and energy is proposed in this work as a means for separating degradation signals from background sources. Encouraging results were obtained by applying both frequency and energy filters to preliminary data. The analysis of signals filtered using frequency and energy provides signatures exhibiting several characteristics that are consistent with degradation accumulation in materials. Future work is planned to enable verification of the efficacy of AE for thermal fatigue crack initiation detection. While the emphasis has been placed on the use of AE for crack initiation detection during accelerated aging tests, this work also has implications with respect to the use of AE as a primary tool for early degradation monitoring in nuclear power plant materials. The development of NDE tools for characterization of aging in materials can also benefit from the use of a technology such as AE which can continuously monitor and detect crack initiation during accelerated aging tests.

  14. Space Station Freedom primary power wiring requirements

    NASA Technical Reports Server (NTRS)

    Hill, Thomas J.

    1994-01-01

    The Space Station Freedom (SSF) Program requirements are a 30 year reliable service life in low Earth orbit in hard vacuum or pressurized module service without detrimental degradation. Specific requirements are outlined in this presentation for SSF primary power and cable insulation. The primary power cable status and the WP-4 planned cable test program are also reviewed along with Rocketdyne-WP04 prime insulation candidates.

  15. Pulsed power requirements for electromagnetic launchers

    SciTech Connect

    Weldon, W.F.; Woodson, H.H.

    1984-03-01

    Both linear (railgun) and coaxial (mass driver, etc.) electromagnetic launchers (EMLs) are treated as time-varying impedances to determine the relationships between acceleration force, payload velocity, and power supply voltage and current. These relationships are then examined in the light of electromagnetic parameters associated with each EML type to establish a basis for determining and comparing power supply requirements for various EMLs.

  16. Pulsed power requirements for electromagnetic launches

    NASA Astrophysics Data System (ADS)

    Weldon, W. F.; Woodson, H. H.

    1986-02-01

    Both linear (railgun) and coaxial (mass driver, etc.) electromagnetic launchers (EMLS) are treated as time-varying impedances to determine the relationships between acceleration force, payload velocity, and power supply voltage and current. These relationships are then examined in the light of electromagnetic parameters associated with each EML type ot establish a basis for determining and comparing power supply requirements for various EMLs.

  17. Design and implementation of an omni-directional underwater acoustic micro-modem based on a low-power micro-controller unit.

    PubMed

    Won, Tae-Hee; Park, Sung-Joon

    2012-01-01

    For decades, underwater acoustic communication has been restricted to the point-to-point long distance applications such as deep sea probes and offshore oil fields. For this reason, previous acoustic modems were typically characterized by high data rates and long working ranges at the expense of large size and high power consumption. Recently, as the need for underwater wireless sensor networks (UWSNs) has increased, the research and development of compact and low-power consuming communication devices has become the focus. From the consideration that the requisites of acoustic modems for UWSNs are low power consumption, omni-directional beam pattern, low cost and so on, in this paper, we design and implement an omni-directional underwater acoustic micro-modem satisfying these requirements. In order to execute fast digital domain signal processing and support flexible interfaces with other peripherals, an ARM Cortex-M3 is embedded in the micro-modem. Also, for the realization of small and omni-directional properties, a spherical transducer having a resonant frequency of 70 kHz and a diameter of 34 mm is utilized for the implementation. Physical layer frame format and symbol structure for efficient packet-based underwater communication systems are also investigated. The developed acoustic micro-modem is verified analytically and experimentally in indoor and outdoor environments in terms of functionality and performance. Since the modem satisfies the requirements for use in UWSNs, it could be deployed in a wide range of applications requiring underwater acoustic communication. PMID:22438765

  18. A Requirements-Driven Optimization Method for Acoustic Treatment Design

    NASA Technical Reports Server (NTRS)

    Berton, Jeffrey J.

    2016-01-01

    Acoustic treatment designers have long been able to target specific noise sources inside turbofan engines. Facesheet porosity and cavity depth are key design variables of perforate-over-honeycomb liners that determine levels of noise suppression as well as the frequencies at which suppression occurs. Layers of these structures can be combined to create a robust attenuation spectrum that covers a wide range of frequencies. Looking to the future, rapidly-emerging additive manufacturing technologies are enabling new liners with multiple degrees of freedom, and new adaptive liners with variable impedance are showing promise. More than ever, there is greater flexibility and freedom in liner design. Subject to practical considerations, liner design variables may be manipulated to achieve a target attenuation spectrum. But characteristics of the ideal attenuation spectrum can be difficult to know. Many multidisciplinary system effects govern how engine noise sources contribute to community noise. Given a hardwall fan noise source to be suppressed, and using an analytical certification noise model to compute a community noise measure of merit, the optimal attenuation spectrum can be derived using multidisciplinary systems analysis methods. The subject of this paper is an analytical method that derives the ideal target attenuation spectrum that minimizes noise perceived by observers on the ground.

  19. High-power acoustic insult to living cultured cells as studied by high-frequency scanning acoustic microscopy

    NASA Astrophysics Data System (ADS)

    Miyasaka, Chiaki; Tittmann, Bernhard R.

    2002-06-01

    A plurality of articles discussing combined effects of acoustic high-pressure (mechanical factor) and heat (thermal factor) caused by acoustic vibration on biological tissues and cells has been published. Herein, we contribute the preliminary results describing the behavior of living human skin cells when separately applying shock waves and thermal insult to them. First, we gradually increased temperature of a culturing medium from 37.5 to 52 degree(s)C using the heat plate with temperature controller, and carried out in-situ observation of the cells grown on a substrate via the medium using a scanning acoustic microscope. Second, we provided the pressure using high power ultrasonic pulses generated by a laser induced ultrasonic shock wave system to the cells, wherein the pressure caused by the pulses was measured by a hydrophone, and wherein temperature was monitored by thermocouples. The cells were observed just after giving the impact. The difference between phenomena indicating cellular insult and injury (e.g., shrinkage or lift-off) were clearly visualized by the scanning acoustic microscope with frequency at 1.0 GHz.

  20. Nuclear Space Power Systems Materials Requirements

    SciTech Connect

    Buckman, R.W. Jr.

    2004-02-04

    High specific energy is required for space nuclear power systems. This generally means high operating temperatures and the only alloy class of materials available for construction of such systems are the refractory metals niobium, tantalum, molybdenum and tungsten. The refractory metals in the past have been the construction materials selected for nuclear space power systems. The objective of this paper will be to review the past history and requirements for space nuclear power systems from the early 1960's through the SP-100 program. Also presented will be the past and present status of refractory metal alloy technology and what will be needed to support the next advanced nuclear space power system. The next generation of advanced nuclear space power systems can benefit from the review of this past experience. Because of a decline in the refractory metal industry in the United States, ready availability of specific refractory metal alloys is limited.

  1. Nuclear Space Power Systems Materials Requirements

    NASA Astrophysics Data System (ADS)

    Buckman, R. W.

    2004-02-01

    High specific energy is required for space nuclear power systems. This generally means high operating temperatures and the only alloy class of materials available for construction of such systems are the refractory metals niobium, tantalum, molybdenum and tungsten. The refractory metals in the past have been the construction materials selected for nuclear space power systems. The objective of this paper will be to review the past history and requirements for space nuclear power systems from the early 1960's through the SP-100 program. Also presented will be the past and present status of refractory metal alloy technology and what will be needed to support the next advanced nuclear space power system. The next generation of advanced nuclear space power systems can benefit from the review of this past experience. Because of a decline in the refractory metal industry in the United States, ready availability of specific refractory metal alloys is limited.

  2. Power processing requirements for solar electric propulsion.

    NASA Technical Reports Server (NTRS)

    Macie, T. W.; Costogue, E. N.

    1971-01-01

    The successful integration of a light-weight, high-efficiency power conditioning (PC) unit with an electron bombardment ion thruster using a hollow cathode at JPL has been reported recently. This paper summarizes the presently conceived requirements by which the next generation of PCs should be judged and evaluated. The requirements are formulated in terms of a deep space mission, which implies that the characteristics of the solar source will vary in terms of output power and output voltage. The requirements identified by practical experience during long-term evaluation between 1968-1970 are described and explained.

  3. Acoustic spectroscopy: A powerful analytical method for the pharmaceutical field?

    PubMed

    Bonacucina, Giulia; Perinelli, Diego R; Cespi, Marco; Casettari, Luca; Cossi, Riccardo; Blasi, Paolo; Palmieri, Giovanni F

    2016-04-30

    Acoustics is one of the emerging technologies developed to minimize processing, maximize quality and ensure the safety of pharmaceutical, food and chemical products. The operating principle of acoustic spectroscopy is the measurement of the ultrasound pulse intensity and phase after its propagation through a sample. The main goal of this technique is to characterise concentrated colloidal dispersions without dilution, in such a way as to be able to analyse non-transparent and even highly structured systems. This review presents the state of the art of ultrasound-based techniques in pharmaceutical pre-formulation and formulation steps, showing their potential, applicability and limits. It reports in a simplified version the theory behind acoustic spectroscopy, describes the most common equipment on the market, and finally overviews different studies performed on systems and materials used in the pharmaceutical or related fields. PMID:26976503

  4. Stabilized Acoustic Levitation of Dense Materials Using a High-Powered Siren

    NASA Technical Reports Server (NTRS)

    Gammell, P. M.; Croonquist, A.; Wang, T. G.

    1982-01-01

    Stabilized acoustic levitation and manipulation of dense (e.g., steel) objects of 1 cm diameter, using a high powered siren, was demonstrated in trials that investigated the harmonic content and spatial distribution of the acoustic field, as well as the effect of sample position and reflector geometries on the acoustic field. Although further optimization is possible, the most stable operation achieved is expected to be adequate for most containerless processing applications. Best stability was obtained with an open reflector system, using a flat lower reflector and a slightly concave upper one. Operation slightly below resonance enhances stability as this minimizes the second harmonic, which is suspected of being a particularly destabilizing influence.

  5. Piezoelectric Power Requirements for Active Vibration Control

    NASA Technical Reports Server (NTRS)

    Brennan, Matthew C.; McGowan, Anna-Maria Rivas

    1997-01-01

    This paper presents a method for predicting the power consumption of piezoelectric actuators utilized for active vibration control. Analytical developments and experimental tests show that the maximum power required to control a structure using surface-bonded piezoelectric actuators is independent of the dynamics between the piezoelectric actuator and the host structure. The results demonstrate that for a perfectly-controlled system, the power consumption is a function of the quantity and type of piezoelectric actuators and the voltage and frequency of the control law output signal. Furthermore, as control effectiveness decreases, the power consumption of the piezoelectric actuators decreases. In addition, experimental results revealed a non-linear behavior in the material properties of piezoelectric actuators. The material non- linearity displayed a significant increase in capacitance with an increase in excitation voltage. Tests show that if the non-linearity of the capacitance was accounted for, a conservative estimate of the power can easily be determined.

  6. Mobility power flow analysis of an L-shaped plate structure subjected to acoustic excitation

    NASA Technical Reports Server (NTRS)

    Cuschieri, J. M.

    1989-01-01

    An analytical investigation based on the Mobility Power Flow method is presented for the determination of the vibrational response and power flow for two coupled flat plate structures in an L-shaped configuration, subjected to acoustical excitation. The principle of the mobility power flow method consists of dividing the global structure into a series of subsystems coupled together using mobility functions. Each separate subsystem is analyzed independently to determine the structural mobility functions for the junction and excitation locations. The mobility functions, together with the characteristics of the junction between the subsystems, are then used to determine the response of the global structure and the power flow. In the coupled plate structure considered here, mobility power flow expressions are derived for excitation by an incident acoustic plane wave. In this case, the forces (acoustic pressures) acting on the structure are dependent on the response of the structure because of the scattered pressure component. The interaction between the structure and the fluid leads to the derivation of a corrected mode shape for the plates' normal surface velocity and also for the structure mobility functions. The determination of the scattered pressure components in the expressions for the power flow represents an additional component in the power flow balance for the source plate and the receiver plate. This component represents the radiated acoustical power from the plate structure.

  7. Future Orbital Power Systems Technology Requirements

    NASA Technical Reports Server (NTRS)

    1978-01-01

    NASA is actively involved in program planning for missions requiring several orders of magnitude, more energy than in the past. Therefore, a two-day symposium was held to review the technology requirements for future orbital power systems. The purpose of the meeting was to give leaders from government and industry a broad view of current government supported technology efforts and future program plans in space power. It provided a forum for discussion, through workshops, to comment on current and planned programs and to identify opportunities for technology investment. Several papers are presented to review the technology status and the planned programs.

  8. Space Station Freedom secondary power wiring requirements

    NASA Technical Reports Server (NTRS)

    Sawyer, C. R.

    1994-01-01

    Secondary power is produced by DDCU's (direct current to direct current converter units) and routed to and through secondary power distribution assemblies (SPDA's) to loads or tertiary distribution assemblies. This presentation outlines requirements of Space Station Freedom (SSF) EEE (electrical, electronic, and electromechanical) parts wire and the approved electrical wire and cable. The SSF PDRD (Program Definition and Requirements Document) language problems and resolution are reviewed. The cable routing to and from the SPDA's is presented as diagrams and the wire recommendations and characteristics are given.

  9. Space Station Freedom growth power requirements

    NASA Technical Reports Server (NTRS)

    Meredith, B. D.; Ahlf, P. R.; Saucillo, R. J.

    1990-01-01

    Options and scenarios for the evolution of Space Station Freedom beyond the current baseline have been established and analyzed at NASA Langley Research Center to identify growth requirements for the program's Preliminary Requirements Review (PRR). Time-phase requirements for electrical power and other critical resources were determined based upon the future needs of the science, technology and commercial users. In addition, impacts and resource growth were determined for the utilization of station as a transportation node in support of human exploration initiatives to the moon and/or Mars. The set of requirements chosen for the PRR were selected on the basis of their adequacy in accommodating each of the evolution options and scenarios within each option, thereby maximizing future flexibility. In the case of electrical power, growth to 275 kW (average) was determined to be adequate for evolutionary missions and station housekeeping growth, given projections of future earth-to-orbit transportation capabilities.

  10. Standby battery requirements for telecommunications power

    NASA Astrophysics Data System (ADS)

    May, G. J.

    The requirements for standby power for telecommunications are changing as the network moves from conventional systems to Internet Protocol (IP) telephony. These new systems require higher power levels closer to the user but the level of availability and reliability cannot be compromised if the network is to provide service in the event of a failure of the public utility. Many parts of these new networks are ac rather than dc powered with UPS systems for back-up power. These generally have lower levels of reliability than dc systems and the network needs to be designed such that overall reliability is not reduced through appropriate levels of redundancy. Mobile networks have different power requirements. Where there is a high density of nodes, continuity of service can be reasonably assured with short autonomy times. Furthermore, there is generally no requirement that these networks are the provider of last resort and therefore, specifications for continuity of power are directed towards revenue protection and overall reliability targets. As a result of these changes, battery requirements for reserve power are evolving. Shorter autonomy times are specified for parts of the network although a large part will continue to need support for hours rather minutes. Operational temperatures are increasing and battery solutions that provide longer life in extreme conditions are becoming important. Different battery technologies will be discussed in the context of these requirements. Conventional large flooded lead/acid cells both with pasted and tubular plates are used in larger central office applications but the majority of requirements are met with valve-regulated lead/acid (VRLA) batteries. The different types of VRLA battery will be described and their suitability for various applications outlined. New developments in battery construction and battery materials have improved both performance and reliability in recent years. Alternative technologies are also being proposed

  11. MONITORING POWER PLANT EFFICIENCY USING THE MICROWAVE-EXCITED THERMAL-ACOUSTIC EFFECT TO MEASURE UNBURNED CARBON

    SciTech Connect

    Robert C. Brown; Robert J. Weber; Jeffrey J. Swetelitsch

    2005-01-01

    The objective of this project is to explore microwave-excited thermal-acoustic (META) phenomena for quantitative analysis of granular and powdered materials, with the culmination of the research to be an on-line carbon-in-ash monitor for coal-fired power plants. This technique of analyzing unburned carbon in fly ash could be a less tedious and time consuming method as compared to the traditional LOI manual procedure. Phase 1 of the research focused on off-line single-frequency thermal-acoustic measurements where an off-line fly ash monitor was constructed that could operate as analytical tool to explore instrument and methodology parameters for quantifying the microwave-excited thermal-acoustic effect of carbon in fly ash, and it was determined that the off-line thermal-acoustic technique could predict the carbon content of a random collection of fly ashes with a linear correlation constant of R{sup 2} = 0.778. Much higher correlations are expected for fly ashes generated from a single boiler. Phase 2 of the research developing a methodology to generate microwave spectra of various powders, including fly ash, coal, and inorganic minerals, and to determine if these microwave spectra could be used for chemical analyses. Although different minerals produced different responses, higher resolution microwave spectra would be required to be able to distinguish among minerals. Phase 3 of the research focused on the development of an on-line fly ash monitor that could be adapted to measure either a thermal-acoustic or thermal-elastic response to due microwave excitation of fly ash. The thermal-acoustic response was successfully employed for this purpose but the thermal-elastic response was too weak to yield a useful on-line device.

  12. Space Station power requirements and issues

    SciTech Connect

    Huckins, E.; Ahlf, P.

    1994-12-01

    This paper provides an overview of the space station configuration and summarizes the requirements, architecture, and significant challenges associated with the Electrical Power System (EPS). The space station configuration was baselined during the Systems Design Review (SDR) process in March, 1994. The current configuration includes the addition of Russia as an international partner, resulting in major changes to the assembly sequence, pressurized module complement, and overall power architecture. The Russian contributions to the power system architecture, as well as an overview and development status of the US provided elements is presented. Finally, a planned flight demonstration of solar dynamic power system on the Mir as part of the first phase of US/Russian cooperation in human space flight is described.

  13. Ultrasonic acoustic health monitoring of ball bearings using neural network pattern classification of power spectral density

    NASA Astrophysics Data System (ADS)

    Kirchner, William; Southward, Steve; Ahmadian, Mehdi

    2010-03-01

    This paper presents a generic passive non-contact based approach using ultrasonic acoustic emissions (UAE) to facilitate the neural network classification of bearing health, and more specifically the bearing operating condition. The acoustic emission signals used in this study are in the ultrasonic range (20-120 kHz). A direct benefit of microphones capable of measurements in this frequency range is their inherent directionality. Using selected bands from the UAE power spectrum signature, it is possible to pose the health monitoring problem as a multi-class classification problem, and make use of a single neural network to classify the ultrasonic acoustic emission signatures. Artificial training data, based on statistical properties of a significantly smaller experimental data set is used to train the neural network. This specific approach is generic enough to suggest that it is applicable to a variety of systems and components where periodic acoustic emissions exist.

  14. An Evaluation of the Additional Acoustic Power Needed to Overcome the Effects of a Test-Articles Absorption During Reverberant Chamber Acoustic Testing of Spaceflight Hardware

    NASA Technical Reports Server (NTRS)

    Hozman, Aron D.; Hughes, William O.

    2014-01-01

    It is important to realize that some test-articles may have significant sound absorption that may challenge the acoustic power capabilities of a test facility. Therefore, to mitigate this risk of not being able to meet the customers target spectrum, it is prudent to demonstrate early-on an increased acoustic power capability which compensates for this test-article absorption. This paper describes a concise method to reduce this risk when testing aerospace test-articles which have significant absorption. This method was successfully applied during the SpaceX Falcon 9 Payload Fairing acoustic test program at the NASA Glenn Research Center Plum Brook Stations RATF.

  15. Studies of acoustic-electric feed-throughs for power transmission through structures

    NASA Technical Reports Server (NTRS)

    Sherrit, Stewart; Doty, Benjamin; Badescu, Mircea; Bao, Xiaoqi; Bar-Cohen, Yoseph; Aldrich, Jack; Chang, Zensheu

    2006-01-01

    There are numerous engineering design problems where the use of wires to transfer power and communicate data thru the walls of a structure is prohibitive or significantly difficult that it may require a complex design. Using physical feedthroughs in such systems may make them susceptible to leakage of chemicals or gasses, loss of pressure or vacuum, as well as difficulties in providing adequate thermal or electrical insulation. Moreover, feeding wires thru a wall of a structure reduces the strength of the structure and makes the structure prone to cracking due to fatigue that can result from cyclic loading and stress concentrations. One area that has already been identified to require a wireless alternative to electrical feedthroughs is the container of the Mars Sample Return Mission, which will need wireless sensors to sense a pressure leak and to avoid potential contamination. The idea of using elastic or acoustic waves to transfer power was suggested recently by [Y. Hu, et al., July 2003]. This system allows for the avoidance of cabling or wiring. The technology is applicable to the transfer of power for actuation, sensing and other tasks inside any sealed container or vacuum/pressure vessel. An alternative approach to the modeling presented previously [Sherrit et a., 2005] used network analysis to solve the same problem in a clear and expandable manner. Experimental tests on three different designs of these devices were performed. The three designs used different methods of coupling the piezoelectric element to the wall. In the first test the piezoelectric material was bolted using a backing structure. In the second test the piezoelectric was clamped after the application of grease and finally the piezoelectric element was attached using a conductive epoxy. The mechanical clamp with grease produced the highest measured efficiency of 53% however this design was the least practical from a fabrication viewpoint. The power transfer efficiency of conductive epoxy

  16. Actuator requirements for laser power beaming

    SciTech Connect

    Zeiders, G.W.

    1994-12-31

    Design considerations and working formulas and graphs are presented for estimating the actuator requirements for adaptive optics correction of global tilt and residual piston error arising from atmospheric turbulence along a ground-to-space path. Frequency characteristics are calculated for several important crosswind conditions for the case where the active segments are very small compared to the full aperture; it is shown that the velocity profile has a strong effect on the power spectra and that high slew rates significantly increase the required high-frequency response and accentuate the effects of high-attitude turbulence. Predictions are given for the SELENE laser power beaming system which uses active control of a segmented primary telescope mirror.

  17. Research on power-law acoustic transient signal detection based on wavelet transform

    NASA Astrophysics Data System (ADS)

    Han, Jian-hui; Yang, Ri-jie; Wang, Wei

    2007-11-01

    Aiming at the characteristics of acoustic transient signal emitted from antisubmarine weapon which is being dropped into water (torpedo, aerial sonobuoy and rocket assisted depth charge etc.), such as short duration, low SNR, abruptness and instability, based on traditional power-law detector, a new method to detect acoustic transient signal is proposed. Firstly wavelet transform is used to de-noise signal, removes random spectrum components and improves SNR. Then Power- Law detector is adopted to detect transient signal. The simulation results show the method can effectively extract envelop characteristic of transient signal on the condition of low SNR. The performance of WT-Power-Law markedly outgoes that of traditional Power-Law detection method.

  18. High-power LED package requirements

    NASA Astrophysics Data System (ADS)

    Wall, Frank; Martin, Paul S.; Harbers, Gerard

    2004-01-01

    Power LEDs have evolved from simple indicators into illumination devices. For general lighting applications, where the objective is to light up an area, white LED arrays have been utilized to serve that function. Cost constraints will soon drive the industry to provide a discrete lighting solution. Early on, that will mean increasing the power densities while quantum efficiencies are addressed. For applications such as automotive headlamps & projection, where light needs to be tightly collimated, or controlled, arrays of die or LEDs will not be able to satisfy the requirements & limitations defined by etendue. Ultimately, whether a luminaire requires a small source with high luminance, or light spread over a general area, economics will force the evolution of the illumination LED into a compact discrete high power package. How the customer interfaces with this new package should be an important element considered early on in the design cycle. If an LED footprint of adequate size is not provided, it may prove impossible for the customer, or end user, to get rid of the heat in a manner sufficient to prevent premature LED light output degradation. Therefore it is critical, for maintaining expected LED lifetime & light output, that thermal performance parameters be defined, by design, at the system level, which includes heat sinking methods & interface materials or methdology.

  19. High frequency formulation for the acoustic power spectrum due to cascade-turbulence interaction.

    PubMed

    Cheong, Cheolung; Joseph, Phillip; Lee, Soogab

    2006-01-01

    This paper investigates the noise radiated by a cascade of flat-plate airfoils interacting with homogeneous, isotropic turbulence. An analytic formulation for the spectrum of acoustic power of a two-dimensional flat-plate is derived. The main finding of this paper is that the acoustic power spectrum from the cascade of flat airfoils may be split into two distinct frequency regions of low frequency and high frequency, separated by a critical frequency. Below this frequency, cascade effects due to the interaction between neighboring airfoils are shown to be important. At frequencies above the critical frequency, cascade effects are shown to be relatively weak. In this frequency range, acoustic power is shown to be approximately proportional to the number of blades. Based on this finding at high frequencies, an approximate expression is derived for the power spectrum that is valid above the critical frequency and which is in excellent agreement with the exact expression for the broadband power spectrum. The formulation is used to perform a parametric study on the effects on the power spectrum of the blade number, stagger angle, gap-chord ratio, and Mach number. The theory is also shown to provide a close fit to the measured spectrum of rotor-stator interaction. PMID:16454269

  20. Comparison of Comet Enflow and VA One Acoustic-to-Structure Power Flow Predictions

    NASA Technical Reports Server (NTRS)

    Grosveld, Ferdinand W.; Schiller, Noah H.; Cabell, Randolph H.

    2010-01-01

    Comet Enflow is a commercially available, high frequency vibroacoustic analysis software based on the Energy Finite Element Analysis (EFEA). In this method the same finite element mesh used for structural and acoustic analysis can be employed for the high frequency solutions. Comet Enflow is being validated for a floor-equipped composite cylinder by comparing the EFEA vibroacoustic response predictions with Statistical Energy Analysis (SEA) results from the commercial software program VA One from ESI Group. Early in this program a number of discrepancies became apparent in the Enflow predicted response for the power flow from an acoustic space to a structural subsystem. The power flow anomalies were studied for a simple cubic, a rectangular and a cylindrical structural model connected to an acoustic cavity. The current investigation focuses on three specific discrepancies between the Comet Enflow and the VA One predictions: the Enflow power transmission coefficient relative to the VA One coupling loss factor; the importance of the accuracy of the acoustic modal density formulation used within Enflow; and the recommended use of fast solvers in Comet Enflow. The frequency region of interest for this study covers the one-third octave bands with center frequencies from 16 Hz to 4000 Hz.

  1. Frequency-Preserved Acoustic Diode Model with High Forward-Power-Transmission Rate

    NASA Astrophysics Data System (ADS)

    Liu, Chang; Du, Zongliang; Sun, Zhi; Gao, Huajian; Guo, Xu

    2015-06-01

    The acoustic diode (AD) can provide brighter and clearer ultrasound images by eliminating acoustic disturbances caused by sound waves traveling in two directions at the same time and interfering with each other. Such an AD could give designers new flexibility in making ultrasonic sources like those used in medical imaging or nondestructive testing. However, current AD designs, based on nonlinear effects, only partially fill this role by converting sound to a new frequency and blocking any backward flow of the original frequency. In this work, an AD model that preserves the frequencies of acoustic waves and has a relatively high forward-power-transmission rate is proposed. Theoretical analysis indicates that the proposed AD has forward, reverse, and breakdown characteristics very similar to electrical diodes. The significant rectifying effect of the proposed AD is verified numerically through a one-dimensional example. Possible schemes for experimental realization of this model as well as more complex and efficient AD designs are also discussed.

  2. Requirements for a transformerless power conditioning system

    NASA Technical Reports Server (NTRS)

    Klein, J.; Koerner, T.; Rippel, W.; Kalbach, J.

    1984-01-01

    Requirements for development of a Transformerless Power Conditioning Subsystem (TPCS) that will meet utility, manufacturer, and customer needs are detailed. Issues analyzed include current utility guidelines, safety and grounding issues that appear as local codes, various kinds of TPCS connections that can be developed, dc injection, and a brief survey of TPCS circuit topologies that will meet requirements. The major result is that a finite time exists for control operation before dc injection into the distribution transformer causes customer outage (on the order of seconds). This time permits the control system to sense a dc injection condition and remove the TPCS from the utility system. Requirements for such a control system are specified. A three wire connection will ensure balanced operation for customer loads and two wire connections caused average value dc to be injected into single phase loads. This type of connection also allows for the lowest array voltage. The conclusion is that requirements for a TPCS can be determined and that there are not showstopping issues preventing implementation. The actual design and topology of the TPCS was left for further study.

  3. Power method for calculating the far acoustic field of the helicopter lift rotor

    NASA Astrophysics Data System (ADS)

    Samokhin, V. F.

    2011-05-01

    A semiempirical method for calculating the far acoustic field of the lift rotor of a helicopter operating in the regime of oblique flow over it is described. The basic parametric relations for the acoustic radiation power of rotor noise components have been obtained on the basis of the Lamb idea that vortex-free motion arises under the action of a periodic force on an infinitely small volume of the medium. All sources of lift rotor noise are subdivided into two groups pertaining, respectively, to the inductive and profile parts of the total power supplied to the rotor. A comparison has been made between the results of calculation of the harmonic components of lift rotor noise made on the basis of the power method and the experimental data for the Mi-28 helicopter.

  4. Power system scheduling with fuzzy reserve requirements

    SciTech Connect

    Guan, X.; Luh, P.B.; Prasannan, B.

    1996-05-01

    The modeling of constraints is an important issue in power system scheduling. Constraints can be generally classified into two categories: (1) physical limits and (2) operating limits. A schedule violating physical limit or constraint would not be acceptable. An operating limit, however, is often imposed to enhance system security but does not represent a physical bound. This kind of soft limits can be temporarily violated a little bit if necessary, but not too much. These constraints are therefore fuzzy in nature, and crisp treatment of them may lead to over conservative solutions. In this paper, a fuzzy optimization-based method is developed to solve power system scheduling problem with fuzzy reserve requirements. The problem is first converted to a crisp and separable optimization problem. Lagrange multipliers are then used to relax system-wide constraints and decompose the problem into a number of unit-wise subproblems and a membership subproblem. These subproblems can be efficiently solved, and the multipliers are updated by using a subgradient method. Heuristics are then used to construct a feasible schedule based on subproblem solutions. Numerical testing results show that near optimal schedules are obtained, and the method can provide a good balance between reducing costs and satisfying reserve requirements.

  5. Self-heating study of bulk acoustic wave resonators under high RF power.

    PubMed

    Ivira, Brice; Fillit, René-Yves; Ndagijimana, Fabien; Benech, Philippe; Parat, Guy; Ancey, Pascal

    2008-01-01

    The present work first provides an experimental technique to study self-heating of bulk acoustic wave (BAW) resonators under high RF power in the gigahertz range. This study is specially focused on film bulk acoustic wave resonators and solidly mounted resonators processed onto silicon wafers and designed for wireless systems. Precisely, the reflection coefficient of a one-port device is measured while up to several watts are applied and power leads to electrical drifts of impedances. In the following, we describe how absorbed power can be determined from the incident one in real time. Therefore, an infrared camera held over the radio frequency micro electromechanical system (RF-MEMS) surface with an exceptional spatial resolution reaching up to 2 microm/pixels gives accurate temperature mapping of resonators after emissivity correction. From theoretical point of view, accurate three-dimensional (3-D) structures for finite-element modeling analyses are carried out to know the best materials and architectures to use for enhancing power handling. In both experimental and theoretical investigations, comparison is made between film bulk acoustic wave resonators and solidly mounted resonators. Thus, the trend in term of material, architecture, and size of device for power application such as in transmission path of a transceiver is clearly identified. PMID:18334320

  6. Problems in Assessment of Wind Energy Potential and Acoustic Noise Distribution when Designing Wind Power Plants

    NASA Astrophysics Data System (ADS)

    Bezrukovs, Valerijs; Bezrukovs, Vladislavs; Levins, Nikolajs

    2011-01-01

    Interest in the use of renewable energy in Latvia is increasing every year. Government support and availability of large unpopulated areas on the coast makes the use of these lands for the placement of large wind power plants (WPP) attractive. The key factors that determine the choice of the location of WPP are reliable information about distribution of the resource of wind energy in this area and the influence of wind turbines on the environment. The paper presents the results of years-long observations on the density fluctuations of wind energy at heights of 10 to 60 m in the area in the Baltic Sea coast in Ventspils and Ainaži. The velocity observations since 2007 have been gathered by measurements complex of the LOGGER 9200 Symphonie type. The results are presented in the form of tables, bar charts and graphs. Extrapolation results of wind velocity and density mean values on heights up to 150 m for the two areas with different terrain types were shown. The distribution of acoustic noise in the vicinity of the WPP was studied and an assessment of its impact on the environment in accordance with the Latvian government requirements was conducted.

  7. Design of Low-power Wake-up Circuits in Underwater Acoustic Communication

    NASA Astrophysics Data System (ADS)

    Cuixia, Zhang; Jiaxin, Wu; Yuanxuan, Li

    In underwater acoustic communication, the power consumption of the underwater communication equipments at harsh conditions of marine environment is an important problem. Under that scenario, we propose a design of low-power wake-up circuits based on SCM C8051F020 system. Compare to traditional wake-up circuits which directly judge the energy of received signals, our approach can greatly reduce the misjudgment caused by the environmental disturbance, and the performance of energy conservation is effective. The low-power wake-up circuits possess a promising application prospect in the long-distance wireless underwater communication.

  8. 2-D steering and propelling of acoustic bubble-powered microswimmers.

    PubMed

    Feng, Jian; Yuan, Junqi; Cho, Sung Kwon

    2016-06-21

    This paper describes bi-directional (linear and rotational) propelling and 2-D steering of acoustic bubble-powered microswimmers that are achieved in a centimeter-scale pool (beyond chip level scale). The core structure of a microswimmer is a microtube with one end open in which a gaseous bubble is trapped. The swimmer is propelled by microstreaming flows that are generated when the trapped bubble is oscillated by an external acoustic wave. The bubble oscillation and thus propelling force are highly dependent on the frequency of the acoustic wave and the bubble length. This dependence is experimentally studied by measuring the resonance behaviors of the testing pool and bubble using a laser Doppler vibrometer (LDV) and by evaluating the generated streaming flows. The key idea in the present 2-D steering is to utilize this dependence. Multiple bubbles with different lengths are mounted on a single microswimmer with a variety of arrangements. By controlling the frequency of the acoustic wave, only frequency-matched bubbles can strongly oscillate and generate strong propulsion. By arranging multiple bubbles of different lengths in parallel but with their openings opposite and switching the frequency of the acoustic wave, bi-directionally linear propelling motions are successfully achieved. The propelling forces are calculated by a CFD analysis using the Ansys Fluent® package. For bi-directional rotations, a similar method but with diagonal arrangement of bubbles on a rectangular swimmer is also applied. The rotation can be easily reversed when the frequency of the acoustic wave is switched. For 2-D steering, short bubbles are aligned perpendicular to long bubbles. It is successfully demonstrated that the microswimmer navigates through a T-junction channel under full control with and without carrying a payload. During the navigation, the frequency is the main control input to select and resonate targeted bubbles. All of these operations are achieved by a single

  9. Power law statistics of force and acoustic emission from a slowly penetrated granular bed

    NASA Astrophysics Data System (ADS)

    Matsuyama, K.; Katsuragi, H.

    2014-01-01

    Penetration-resistant force and acoustic emission (AE) from a plunged granular bed are experimentally investigated through their power law distribution forms. An AE sensor is buried in a glass bead bed. Then, the bed is slowly penetrated by a solid sphere. During the penetration, the resistant force exerted on the sphere and the AE signal are measured. The resistant force shows power law relation to the penetration depth. The power law exponent is independent of the penetration speed, while it seems to depend on the container's size. For the AE signal, we find that the size distribution of AE events obeys power laws. The power law exponent depends on grain size. Using the energy scaling, the experimentally observed power law exponents are discussed and compared to the Gutenberg-Richter (GR) law.

  10. Safeguard Requirements for Fusion Power Plants

    SciTech Connect

    Robert J. Goldston and Alexander Glaser

    2012-08-10

    Nuclear proliferation risks from magnetic fusion energy associated with access to fissile materials can be divided into three main categories: 1) clandestine production of fissile material in an undeclared facility, 2) covert production and diversion of such material in a declared and safeguarded facility, and 3) use of a declared facility in a breakout scenario, in which a state openly produces fissile material in violation of international agreements. The degree of risk in each of these categories is assessed, taking into account both state and non-state actors, and it is found that safeguards are required for fusion energy to be highly attractive from a non-proliferation standpoint. Specific safeguard requirements and R&D needs are outlined for each category of risk, and the technical capability of the ITER experiment, under construction, to contribute to this R&D is noted. A preliminary analysis indicates a potential legal pathway for fusion power systems to be brought under the Treaty for the Non-Proliferation of Nuclear Weapons. "Vertical" proliferation risks associated with tritium and with the knowledge that can be gained from inertial fusion energy R&D are outlined.

  11. An investigation of acoustic noise requirements for the Space Station centrifuge facility

    NASA Technical Reports Server (NTRS)

    Castellano, Timothy

    1994-01-01

    Acoustic noise emissions from the Space Station Freedom (SSF) centrifuge facility hardware represent a potential technical and programmatic risk to the project. The SSF program requires that no payload exceed a Noise Criterion 40 (NC-40) noise contour in any octave band between 63 Hz and 8 kHz as measured 2 feet from the equipment item. Past experience with life science experiment hardware indicates that this requirement will be difficult to meet. The crew has found noise levels on Spacelab flights to be unacceptably high. Many past Ames Spacelab life science payloads have required waivers because of excessive noise. The objectives of this study were (1) to develop an understanding of acoustic measurement theory, instruments, and technique, and (2) to characterize the noise emission of analogous Facility components and previously flown flight hardware. Test results from existing hardware were reviewed and analyzed. Measurements of the spectral and intensity characteristics of fans and other rotating machinery were performed. The literature was reviewed and contacts were made with NASA and industry organizations concerned with or performing research on noise control.

  12. Determining the nominal power transfer coefficient for passive surface acoustic wave devices

    NASA Astrophysics Data System (ADS)

    Timoshenko, A. N.; Palamarchuk, A. A.; Semenko, A. I.

    1982-05-01

    A method for calculating the nominal power transfer coefficient of passive SAW devices operating in a linear mode is described. Relations of practical importance are obtained, making it possible, on the basis of known characteristics of acousto-electric transducers and acoustic lines, to determine the losses incurred by devices when they are connected to radioelectronic equipment. The relations also permit an assessment of the uniformity of the amplitude-frequency characteristics of the devices.

  13. Correlation of combustor acoustic power levels inferred from internal fluctuating pressure measurements

    NASA Technical Reports Server (NTRS)

    Vonglahn, U. H.

    1978-01-01

    Combustion chamber acoustic power levels inferred from internal fluctuating pressure measurements are correlated with operating conditions and chamber geometries over a wide range. The variables include considerations of chamber design (can, annular, and reverse-flow annular) and size, number of fuel nozzles, burner staging and fuel split, airflow and heat release rates, and chamber inlet pressure and temperature levels. The correlated data include those obtained with combustion component development rigs as well as engines.

  14. Thermometric- and Acoustic-Based Beam Power Monitor for Ultra-Bright X-Rays

    SciTech Connect

    Bentsen, Gregory; /Rochester U. /SLAC

    2010-08-25

    A design for an average beam power monitor for ultra-bright X-ray sources is proposed that makes simultaneous use of calorimetry and radiation acoustics. Radiation incident on a solid target will induce heating and ultrasonic vibrations, both of which may be measured to give a fairly precise value of the beam power. The monitor is intended for measuring ultra-bright Free-Electron Laser (FEL) X-ray beams, for which traditional monitoring technologies such as photo-diodes or scintillators are unsuitable. The monitor consists of a Boron Carbide (B{sub 4}C) target designed to absorb most of the incident beam's energy. Resistance temperature detectors (RTD) and piezoelectric actuators are mounted on the outward faces of the target to measure the temperature changes and ultrasonic vibrations induced by the incident beam. The design was tested using an optical pulsed beam (780 nm, 120 and 360 Hz) from a Ti:sapphire oscillator at several energies between 0.8 and 2.6 mJ. The RTDs measured an increase in temperature of about 10 K over a period of several minutes. The piezoelectric sensors recorded ringing acoustic oscillations at 580 {+-} 40 kHz. Most importantly, the amplitude of the acoustic signals was observed to scale linearly with beam power up to 2 mJ of pulse energy. Above this pulse energy, the vibrational signals became nonlinear. Several causes for this nonlinearity are discussed, including amplifier saturation and piezoelectric saturation. Despite this nonlinearity, these measurements demonstrate the feasibility of such a beam power measurement device. The advantage of two distinct measurements (acoustic and thermometric) provides a useful method of calibration that is unavailable to current LCLS diagnostics tools.

  15. Power feature required for PEFC powered electric propulsion ship

    SciTech Connect

    Yoshida, Isao; Oka, Masaru

    1996-12-31

    This report covers part of a joint study on a PEFC system for ship propulsion, summarized in a presentation to this Seminar, entitled {open_quote}Study on a Polymer Electrolyte Fuel Cell (PEFC) Propulsion System for Surface Ships{close_quotes}, and which envisages application to a 1,500 DWT cargo vessel. The aspect treated here concerns an analysis of the load-following performance required and estimated of a PEFC system to power the envisaged ship. The analysis proved that difficulty should be expected of the fuel supply circuit in following with adequate rapidity the sharp changes of load on fuel cell under certain conditions. Further integrated experiments and simulation exercises are currently in progress to further analyze the response characteristics of the fuel supply circuit-particularly of the methanol reformer and gas reservoir-to determine the best measure to be adopted for overcoming the expected difficulty.

  16. 18 CFR 35.37 - Market power analysis required.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Market power analysis... power analysis required. (a) (1) In addition to other requirements in subparts A and B, a Seller must submit a market power analysis in the following circumstances: when seeking market-based rate...

  17. Evaluation of a novel solid-state method for determining the acoustic power generated by physiotherapy ultrasound transducers.

    PubMed

    Zeqiri, Bajram; Barrie, Jill

    2008-09-01

    A new secondary method of determining ultrasound power is presented based on the pyroelectricity of a thin membrane of the piezoelectric polymer, polyvinylidene fluoride (PVDF). In operation, the membrane is backed by a polyurethane-based rubber material that is extremely attenuating to ultrasound, resulting in the majority of the acoustic power applied to the PVDF being absorbed within a short distance of the membrane-backing interface. The resulting rapid heating leads to a pyroelectric voltage being generated across the electrodes of the sensor that, under appropriate conditions, is related to the rate of change of temperature with respect to time. For times immediately after changes in transducer excitation (switching either ON or OFF), the change in the pyroelectric voltage is proportional to the delivered ultrasound power level. This paper describes a systematic evaluation of the measurement concept applied at physiotherapy frequencies and power levels, investigating key aspects such as repeatability, linearity and sensitivity. The research demonstrates the way that heating of the backing material affects the sensor performance, but outlines the potential of the method as a reproducible, rapid, solid-state method of determining power, requiring calibration using a known ultrasound power source. PMID:18440695

  18. Moisture estimation in power transformer oil using acoustic signals and spectral kurtosis

    NASA Astrophysics Data System (ADS)

    Leite, Valéria C. M. N.; Veloso, Giscard F. C.; Borges da Silva, Luiz Eduardo; Lambert-Torres, Germano; Borges da Silva, Jonas G.; Onofre Pereira Pinto, João

    2016-03-01

    The aim of this paper is to present a new technique for estimating the contamination by moisture in power transformer insulating oil based on the spectral kurtosis analysis of the acoustic signals of partial discharges (PDs). Basically, in this approach, the spectral kurtosis of the PD acoustic signal is calculated and the correlation between its maximum value and the moisture percentage is explored to find a function that calculates the moisture percentage. The function can be easily implemented in DSP, FPGA, or any other type of embedded system for online moisture monitoring. To evaluate the proposed approach, an experiment is assembled with a piezoelectric sensor attached to a tank, which is filled with insulating oil samples contaminated by different levels of moisture. A device generating electrical discharges is submerged into the oil to simulate the occurrence of PDs. Detected acoustic signals are processed using fast kurtogram algorithm to extract spectral kurtosis values. The obtained data are used to find the fitting function that relates the water contamination to the maximum value of the spectral kurtosis. Experimental results show that the proposed method is suitable for online monitoring system of power transformers.

  19. Incident signal power comparison for localization of concurrent multiple acoustic sources.

    PubMed

    Salvati, Daniele; Canazza, Sergio

    2014-01-01

    In this paper, a method to solve the localization of concurrent multiple acoustic sources in large open spaces is presented. The problem of the multisource localization in far-field conditions is to correctly associate the direction of arrival (DOA) estimated by a network array system to the same source. The use of systems implementing a Bayesian filter is a traditional approach to address the problem of localization in multisource acoustic scenario. However, in a real noisy open space the acoustic sources are often discontinuous with numerous short-duration events and thus the filtering methods may have difficulty to track the multiple sources. Incident signal power comparison (ISPC) is proposed to compute DOAs association. ISPC is based on identifying the incident signal power (ISP) of the sources on a microphone array using beamforming methods and comparing the ISP between different arrays using spectral distance (SD) measurement techniques. This method solves the ambiguities, due to the presence of simultaneous sources, by identifying sounds through a minimization of an error criterion on SD measures of DOA combinations. The experimental results were conducted in an outdoor real noisy environment and the ISPC performance is reported using different beamforming techniques and SD functions. PMID:24701179

  20. Incident Signal Power Comparison for Localization of Concurrent Multiple Acoustic Sources

    PubMed Central

    2014-01-01

    In this paper, a method to solve the localization of concurrent multiple acoustic sources in large open spaces is presented. The problem of the multisource localization in far-field conditions is to correctly associate the direction of arrival (DOA) estimated by a network array system to the same source. The use of systems implementing a Bayesian filter is a traditional approach to address the problem of localization in multisource acoustic scenario. However, in a real noisy open space the acoustic sources are often discontinuous with numerous short-duration events and thus the filtering methods may have difficulty to track the multiple sources. Incident signal power comparison (ISPC) is proposed to compute DOAs association. ISPC is based on identifying the incident signal power (ISP) of the sources on a microphone array using beamforming methods and comparing the ISP between different arrays using spectral distance (SD) measurement techniques. This method solves the ambiguities, due to the presence of simultaneous sources, by identifying sounds through a minimization of an error criterion on SD measures of DOA combinations. The experimental results were conducted in an outdoor real noisy environment and the ISPC performance is reported using different beamforming techniques and SD functions. PMID:24701179

  1. Aircraft IR/acoustic detection evaluation. Volume 2: Development of a ground-based acoustic sensor system for the detection of subsonic jet-powered aircraft

    NASA Technical Reports Server (NTRS)

    Kraft, Robert E.

    1992-01-01

    The design and performance of a ground-based acoustic sensor system for the detection of subsonic jet-powered aircraft is described and specified. The acoustic detection system performance criteria will subsequently be used to determine target detection ranges for the subject contract. Although the defined system has never been built and demonstrated in the field, the design parameters were chosen on the basis of achievable technology and overall system practicality. Areas where additional information is needed to substantiate the design are identified.

  2. Biosonar resolving power: echo-acoustic perception of surface structures in the submillimeter range

    PubMed Central

    Simon, Ralph; Knörnschild, Mirjam; Tschapka, Marco; Schneider, Annkathrin; Passauer, Nadine; Kalko, Elisabeth K. V.; von Helversen, Otto

    2014-01-01

    The minimum distance for which two points still can be separated from each other defines the resolving power of a visual system. In an echo-acoustic context, the resolving power is usually measured as the smallest perceivable distance of two reflecting surfaces on the range axis and is found to be around half a millimeter for bats employing frequency modulated (FM) echolocation calls. Only few studies measured such thresholds with physical objects, most often bats were trained on virtual echoes i.e., echoes generated and played back by a computer; moreover, bats were sitting while they received the stimuli. In these studies differences in structure depth between 200 and 340 μm were found. However, these low thresholds were never verified for free-flying bats and real physical objects. Here, we show behavioral evidence that the echo-acoustic resolving power for surface structures in fact can be as low as measured for computer generated echoes and even lower, sometimes below 100 μm. We found this exceptional fine discrimination ability only when one of the targets showed spectral interferences in the frequency range of the bats′ echolocation call while the other target did not. This result indicates that surface structure is likely to be perceived as a spectral quality rather than being perceived strictly in the time domain. Further, it points out that sonar resolving power directly depends on the highest frequency/shortest wavelength of the signal employed. PMID:24616703

  3. 47 CFR 2.1046 - Measurements required: RF power output.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Measurements required: RF power output. 2.1046... Measurements required: RF power output. (a) For transmitters other than single sideband, independent sideband and controlled carrier radiotelephone, power output shall be measured at the RF output terminals...

  4. 49 CFR 236.551 - Power supply voltage; requirement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Power supply voltage; requirement. 236.551 Section... Train Stop, Train Control and Cab Signal Systems Rules and Instructions; Locomotives § 236.551 Power supply voltage; requirement. The voltage of power supply shall be maintained within 10 percent of...

  5. 47 CFR 73.614 - Power and antenna height requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Power and antenna height requirements. 73.614... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.614 Power and antenna height requirements.... No minimum antenna height above average terrain is specified. (b) Maximum power. Applications...

  6. 47 CFR 73.614 - Power and antenna height requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Power and antenna height requirements. 73.614... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.614 Power and antenna height requirements.... No minimum antenna height above average terrain is specified. (b) Maximum power. Applications...

  7. 47 CFR 73.614 - Power and antenna height requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Power and antenna height requirements. 73.614... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.614 Power and antenna height requirements.... No minimum antenna height above average terrain is specified. (b) Maximum power. Applications...

  8. 47 CFR 73.614 - Power and antenna height requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Power and antenna height requirements. 73.614... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.614 Power and antenna height requirements.... No minimum antenna height above average terrain is specified. (b) Maximum power. Applications...

  9. 47 CFR 73.614 - Power and antenna height requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Power and antenna height requirements. 73.614... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.614 Power and antenna height requirements.... No minimum antenna height above average terrain is specified. (b) Maximum power. Applications...

  10. Features of Propagation of the Acoustic-Gravity Waves Generated by High-Power Periodic Radiation

    NASA Astrophysics Data System (ADS)

    Chernogor, L. F.; Frolov, V. L.

    2013-09-01

    We present the results of the bandpass filtering of temporal variations of the Doppler frequency shift of radio signals from a vertical-sounding Doppler radar located near the city of Kharkov when the ionosphere was heated by high-power periodic (with 10 and 15-min periods) radiation from the Sura facility. The filtering was done in the ranges of periods that are close to the acoustic cutoff period and the Brunt—Väisälä period (4-6, 8-12, and 13-17 min). Oscillations with periods of 4-6 min and amplitudes of 50-100 mHz were not recorded in fact. Oscillations with periods of 8-12 and 13-17 min and amplitudes of 60-100 mHz were detected in almost all the sessions. In the former and the latter oscillations, the time of delay with respect to the heater switch-on was close to 100 min and about 40-50 min, respectively. These values correspond to group propagation velocities of about 160 and 320-400 m/s. The Doppler shift oscillations were caused by the acoustic-gravity waves which led to periodic variations in the electron number density with a relative amplitude of about 0.1-1.0%. It was demonstrated that the acoustic-gravity waves were not recorded when the effective power of the Sura facility was equal to 50 MW and they were confidently observed when the effective power was increased up to 130 MW. It is shown that the period of the wave processes was determined by the period of the heating-pause cycles, and the duration of the wave trains did not depend on the duration of the series of heating-pause cycles. The data suggest that the generation mechanism of recorded wave disturbances is different from the mechanism proposed in 1970-1990.

  11. 18 CFR 35.37 - Market power analysis required.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Market power analysis required. 35.37 Section 35.37 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT FILING OF RATE SCHEDULES AND...

  12. 18 CFR 35.37 - Market power analysis required.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Market power analysis required. 35.37 Section 35.37 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT FILING OF RATE SCHEDULES AND...

  13. 18 CFR 35.37 - Market power analysis required.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Market power analysis required. 35.37 Section 35.37 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT FILING OF RATE SCHEDULES AND...

  14. 18 CFR 35.37 - Market power analysis required.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Market power analysis required. 35.37 Section 35.37 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT FILING OF RATE SCHEDULES AND...

  15. Dust-acoustic waves and stability in the permeating dusty plasma. II. Power-law distributions

    SciTech Connect

    Gong Jingyu; Du Jiulin; Liu Zhipeng

    2012-08-15

    The dust-acoustic waves and the stability theory for the permeating dusty plasma with power-law distributions are studied by using nonextensive q-statistics. In two limiting physical cases, when the thermal velocity of the flowing dusty plasma is much larger than, and much smaller than the phase velocity of the waves, we derived the dust-acoustic wave frequency, the instability growth rate, and the instability critical flowing velocity. As compared with the formulae obtained in part I [Gong et al., Phys. Plasmas 19, 043704 (2012)], all formulae of the present cases and the resulting plasma characteristics are q-dependent, and the power-law distribution of each plasma component of the permeating dusty plasma has a different q-parameter and thus has a different nonextensive effect. Further, we make numerical analyses of an example that a cometary plasma tail is passing through the interplanetary space dusty plasma and we show that these power-law distributions have significant effects on the plasma characteristics of this kind of plasma environment.

  16. Ultrasonic power transfer from a spherical acoustic wave source to a free-free piezoelectric receiver: Modeling and experiment

    NASA Astrophysics Data System (ADS)

    Shahab, S.; Gray, M.; Erturk, A.

    2015-03-01

    Contactless powering of small electronic components has lately received growing attention for wireless applications in which battery replacement or tethered charging is undesired or simply impossible, and ambient energy harvesting is not a viable solution. As an alternative to well-studied methods of contactless energy transfer, such as the inductive coupling method, the use of ultrasonic waves transmitted and received by piezoelectric devices enables larger power transmission distances, which is critical especially for deep-implanted electronic devices. Moreover, energy transfer by means of acoustic waves is well suited in situations where no electromagnetic fields are allowed. The limited literature of ultrasonic acoustic energy transfer is mainly centered on proof-of-concept experiments demonstrating the feasibility of this method, lacking experimentally validated modeling efforts for the resulting multiphysics problem that couples the source and receiver dynamics with domain acoustics. In this work, we present fully coupled analytical, numerical, and experimental multiphysics investigations for ultrasonic acoustic energy transfer from a spherical wave source to a piezoelectric receiver bar that operates in the 33-mode of piezoelectricity. The fluid-loaded piezoelectric receiver under free-free mechanical boundary conditions is shunted to an electrical load for quantifying the electrical power output for a given acoustic source strength of the transmitter. The analytical acoustic-piezoelectric structure interaction modeling framework is validated experimentally, and the effects of system parameters are reported along with optimal electrical loading and frequency conditions of the receiver.

  17. Ultrasonic power transfer from a spherical acoustic wave source to a free-free piezoelectric receiver: Modeling and experiment

    SciTech Connect

    Shahab, S.; Gray, M.; Erturk, A.

    2015-03-14

    Contactless powering of small electronic components has lately received growing attention for wireless applications in which battery replacement or tethered charging is undesired or simply impossible, and ambient energy harvesting is not a viable solution. As an alternative to well-studied methods of contactless energy transfer, such as the inductive coupling method, the use of ultrasonic waves transmitted and received by piezoelectric devices enables larger power transmission distances, which is critical especially for deep-implanted electronic devices. Moreover, energy transfer by means of acoustic waves is well suited in situations where no electromagnetic fields are allowed. The limited literature of ultrasonic acoustic energy transfer is mainly centered on proof-of-concept experiments demonstrating the feasibility of this method, lacking experimentally validated modeling efforts for the resulting multiphysics problem that couples the source and receiver dynamics with domain acoustics. In this work, we present fully coupled analytical, numerical, and experimental multiphysics investigations for ultrasonic acoustic energy transfer from a spherical wave source to a piezoelectric receiver bar that operates in the 33-mode of piezoelectricity. The fluid-loaded piezoelectric receiver under free-free mechanical boundary conditions is shunted to an electrical load for quantifying the electrical power output for a given acoustic source strength of the transmitter. The analytical acoustic-piezoelectric structure interaction modeling framework is validated experimentally, and the effects of system parameters are reported along with optimal electrical loading and frequency conditions of the receiver.

  18. Space station electric power system requirements and design

    NASA Technical Reports Server (NTRS)

    Teren, Fred

    1987-01-01

    An overview of the conceptual definition and design of the space station Electric Power System (EPS) is given. Responsibilities for the design and development of the EPS are defined. The EPS requirements are listed and discussed, including average and peak power requirements, contingency requirements, and fault tolerance. The most significant Phase B trade study results are summarized, and the design selections and rationale are given. Finally, the power management and distribution system architecture is presented.

  19. Environmental requirements at hydroelectric power plants

    SciTech Connect

    Cada, G.F.; Francfort, J.E.

    1993-12-31

    Hydroelectric power is the most mature and widely implemented of the renewable energy technologies. The energy of flowing water has been used to perform work directly since ancient times, and the use of hydropower turbines to generate electricity traces back to the 19th century. Two commonly used turbine types, the Francis and Kaplan turbines, are essentially refinements of the simple reaction turbine of Hero of Alexandria, dating from about 100 B.C. (NAS 1976). Hydroelectric power production provides over 10% of the net electrical generation in the US, more than petroleum or natural gas and far more than the other renewable energy technologies combined. On a regional basis, hydroelectric power represents 14% of the net electrical power generation in the Rocky Mountain states and nearly 63% along the Pacific Coast. Those states that have the largest percentages of their electricity generated by hydropower (e.g., Idaho, Oregon, Montana, and Washington) also tend to have the lowest average cost of electricity per kilowatt-hour.

  20. Shear-horizontal surface acoustic wave phononic device with high density filling material for ultra-low power sensing applications

    SciTech Connect

    Richardson, M.; Bhethanabotla, V. R.; Sankaranarayanan, S. K. R. S.

    2014-06-23

    Finite element simulations of a phononic shear-horizontal surface acoustic wave (SAW) sensor based on ST 90°-X Quartz reveal a dramatic reduction in power consumption. The phononic sensor is realized by artificially structuring the delay path to form an acoustic meta-material comprised of a periodic microcavity array incorporating high-density materials such as tantalum or tungsten. Constructive interference of the scattered and secondary reflected waves at every microcavity interface leads to acoustic energy confinement in the high-density regions translating into reduced power loss. Tantalum filled cavities show the best performance while tungsten inclusions create a phononic bandgap. Based on our simulation results, SAW devices with tantalum filled microcavities were fabricated and shown to significantly decrease insertion loss. Our findings offer encouraging prospects for designing low power, highly sensitive portable biosensors.

  1. Design and Modeling of High Power Density Acoustic Transducer Materials for Autonomous Undersea Vehicles

    NASA Astrophysics Data System (ADS)

    Heitmann, Adam Arthur

    Advances in piezocrystal transducer materials technology has opened new avenues to impact the size, weight, and power consumption of sonar systems for deployment in autonomous undersea vehicles (AUVs). Although piezocrystals exhibit exceptional electromechanical properties, they have low ferroelectric Curie temperatures, small electrical coercivities, and exhibit temperature, electrical field, and/or stress induced phase transitions between ferroelectric phases with differing electromechanical properties. New piezocrystal materials are required that can provide the compositional tailoring capability needed to increase the Curie temperature and coercive field, ameliorate the deleterious effects of ferroelectric-ferroelectric phase transitions, and enable property optimization for specific transducer applications. Currently, new piezocrystal systems and compositions are selected almost exclusively by empirical 'make and measure' approaches guided by past experiences. These empirical processes can be time and labor intensive and as a result there exists only limited predictive capability for finding new piezocrystal compositions even in known piezocrystal systems. In this study we seek to develop a comprehensive phenomenological theory and a unified parameterization scheme applicable to binary and ternary ferroelectric solid solution systems in order to enable the accelerated development and characterization of new piezocrystal systems for optimized transducer performance. A modified form of the classical Ginzburg-Landau-Devonshire theory of weak first-order transitions is applied to perovskite-structured ferroelectric systems based on the ternary oxide compounds, barium titanate and lead titanate, which places special emphasis on the role played by the crystallographic anisotropy of polarization. It is shown that the theory produces excellent qualitative agreement with the experimentally measured phase diagram topologies, crystal lattice parameters, and

  2. Evaluation of Acoustic Doppler Current Profiler to Measure Discharge at New York Power Authority's Niagara Power Project, Niagara Falls, New York

    USGS Publications Warehouse

    Zajd, Henry J., Jr.

    2007-01-01

    The need for accurate real-time discharge in the International Niagara River hydro power system requires reliable, accurate and reproducible data. The U.S. Geological Survey has been widely using Acoustic Doppler Current Profilers (ADCP) to accurately measure discharge in riverine channels since the mid-1990s. The use of the ADCP to measure discharge has remained largely untested at hydroelectric-generation facilities such as the New York Power Authority's (NYPA) Niagara Power Project in Niagara Falls, N.Y. This facility has a large, engineered diversion channel with the capacity of high volume discharges in excess of 100,000 cubic feet per second (ft3/s). Facilities such as this could benefit from the use of an ADCP, if the ADCP discharge measurements prove to be more time effective and accurate than those obtained from the flow-calculation techniques that are currently used. Measurements of diversion flow by an ADCP in the 'Pant Leg' diversion channel at the Niagara Power Project were made on November 6, 7, and 8, 2006, and compared favorably (within 1 percent) with those obtained concurrently by a conventional Price-AA current-meter measurement during one of the ADCP measurement sessions. The mean discharge recorded during each 2-hour individual ADCP measurement session compared favorably with (3.5 to 6.8 percent greater than) the discharge values computed by the flow-calculation method presently in use by NYPA. The use of ADCP technology to measure discharge could ultimately permit increased power-generation efficiency at the NYPA Niagara Falls Power Project by providing improved predictions of the amount of water (and thus the power output) available.

  3. Capabilities, Design, Construction and Commissioning of New Vibration, Acoustic, and Electromagnetic Capabilities Added to the World's Largest Thermal Vacuum Chamber at NASA's Space Power Facility

    NASA Technical Reports Server (NTRS)

    Motil, Susan M.; Ludwiczak, Damian R.; Carek, Gerald A.; Sorge, Richard N.; Free, James M.; Cikanek, Harry A., III

    2011-01-01

    NASA s human space exploration plans developed under the Exploration System Architecture Studies in 2005 included a Crew Exploration Vehicle launched on an Ares I launch vehicle. The mass of the Crew Exploration Vehicle and trajectory of the Ares I coupled with the need to be able to abort across a large percentage of the trajectory generated unprecedented testing requirements. A future lunar lander added to projected test requirements. In 2006, the basic test plan for Orion was developed. It included several types of environment tests typical of spacecraft development programs. These included thermal-vacuum, electromagnetic interference, mechanical vibration, and acoustic tests. Because of the size of the vehicle and unprecedented acoustics, NASA conducted an extensive assessment of options for testing, and as result, chose to augment the Space Power Facility at NASA Plum Brook Station, of the John H. Glenn Research Center to provide the needed test capabilities. The augmentation included designing and building the World s highest mass capable vibration table, the highest power large acoustic chamber, and adaptation of the existing World s largest thermal vacuum chamber as a reverberant electromagnetic interference test chamber. These augmentations were accomplished from 2007 through early 2011. Acceptance testing began in Spring 2011 and will be completed in the Fall of 2011. This paper provides an overview of the capabilities, design, construction and acceptance of this extraordinary facility.

  4. 47 CFR 73.211 - Power and antenna height requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Power and antenna height requirements. 73.211... RADIO BROADCAST SERVICES FM Broadcast Stations § 73.211 Power and antenna height requirements. (a... Class C and C0 stations is 100 kW. (2) Class C0 stations must have an antenna height above...

  5. 47 CFR 73.211 - Power and antenna height requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Power and antenna height requirements. 73.211... RADIO BROADCAST SERVICES FM Broadcast Stations § 73.211 Power and antenna height requirements. (a... Class C and C0 stations is 100 kW. (2) Class C0 stations must have an antenna height above...

  6. 47 CFR 73.211 - Power and antenna height requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Power and antenna height requirements. 73.211... RADIO BROADCAST SERVICES FM Broadcast Stations § 73.211 Power and antenna height requirements. (a... Class C and C0 stations is 100 kW. (2) Class C0 stations must have an antenna height above...

  7. 47 CFR 73.211 - Power and antenna height requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Power and antenna height requirements. 73.211... RADIO BROADCAST SERVICES FM Broadcast Stations § 73.211 Power and antenna height requirements. (a... Class C and C0 stations is 100 kW. (2) Class C0 stations must have an antenna height above...

  8. 47 CFR 73.211 - Power and antenna height requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Power and antenna height requirements. 73.211... RADIO BROADCAST SERVICES FM Broadcast Stations § 73.211 Power and antenna height requirements. (a... Class C and C0 stations is 100 kW. (2) Class C0 stations must have an antenna height above...

  9. 46 CFR 45.193 - Towboat power requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Towboat power requirements. 45.193 Section 45.193 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Unmanned River Barges on Lake Michigan Routes § 45.193 Towboat power requirements. The towing vessel...

  10. 46 CFR 45.193 - Towboat power requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Towboat power requirements. 45.193 Section 45.193 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Unmanned River Barges on Lake Michigan Routes § 45.193 Towboat power requirements. The towing vessel...

  11. 46 CFR 45.193 - Towboat power requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Towboat power requirements. 45.193 Section 45.193 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Unmanned River Barges on Lake Michigan Routes § 45.193 Towboat power requirements. The towing vessel...

  12. 46 CFR 45.193 - Towboat power requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Towboat power requirements. 45.193 Section 45.193 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Unmanned River Barges on Lake Michigan Routes § 45.193 Towboat power requirements. The towing vessel...

  13. 46 CFR 45.193 - Towboat power requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Towboat power requirements. 45.193 Section 45.193 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Unmanned River Barges on Lake Michigan Routes § 45.193 Towboat power requirements. The towing vessel...

  14. Acoustic tooth cleaner

    NASA Technical Reports Server (NTRS)

    Heyman, J. S. (Inventor)

    1982-01-01

    An acoustic oral hygiene unit is described that uses acoustic energy to oscillate mild abrasive particles in a water suspension which is then directed in a low pressure stream onto the teeth. The oscillating abrasives scrub the teeth clean removing food particles, plaque, calculous, and other foreign material from tooth surfaces, interproximal areas, and tooth-gingiva interface more effectively than any previous technique. The relatively low power output and the basic design makes the invention safe and convenient for everyday use in the home without special training. This invention replaces all former means of home dental prophylaxis, and requires no augmentation to fulfill all requirements for daily oral hygienic care.

  15. Acoustic waveguide technique for sensing incipient faults in underground power-transmission cables: including acousto-optic techniques. Final report

    SciTech Connect

    Harrold, R.T.

    1981-09-01

    The feasibility of using acoustic waveguide techniques for sensing incipient faults in underground power transmission cables was determined. Theoretical and practical studies were made of both the acoustic emission spectrum signatures associated with cable incipient faults, and the attenuation of acoustic waves in waterfilled metal tubes used as waveguides. Based on critical data, it can be estimated that in favorable circumstances, the acoustic waveguide system would only be useful for sensing incipient faults in underground cables of approx. 800 meters (approx. 0.5 miles) or less in length. As underground power transmission cables are often several kilometers in length, it was clear at this stage of the study, that simple acoustic waveguide sensing techniques would not be adequate, and some modification would be needed. With DOE approval it was decided to investigate acousto-optic sensing techniques in order to extend the detection range. In particular, a system in which acoustic emissions from cable incipient faults impinge on a fiber-optic lightguide and locally change its refractive indes, and as a consequence, modulate laser light transmitted along the light guide. Experiments based on this concept were successful, and it has been demonstrated that it is possible to sense acoustic emissions with energy levels below one micro-joule. A practical test of this system in the laboratory using a section of compressed gas-insulated cable with an internal flashover was successfully carried out. Long distance fault sensing with this technique should be feasible as laser light can be transmitted several kilometers in fiber optic lightguides. It is believed that laser-acousto-optic fault sensing is a viable technique which, with development, could be applied for fault sensing in power cables and other apparatus.

  16. Integrated optical, acoustically tunable wavelength filter

    NASA Astrophysics Data System (ADS)

    Frangen, J.; Herrmann, H.; Ricken, R.; Seibert, H.; Sohler, W.

    1989-11-01

    A TM/TE convertor is combined with a TE-pass polarizer on a common LiNbO3 chip to obtain an integrated optical, acoustically tunable wavelength filter. Its tuning range is 1.45-1.57 micron wavelength with a filter half-width of 2.8 nm. Due to the combined acoustical/optical strip guide structure used in the mode convertor, a very low acoustic drive power of only 9 mW is required.

  17. Baryon acoustic oscillations in 2D: Modeling redshift-space power spectrum from perturbation theory

    SciTech Connect

    Taruya, Atsushi; Nishimichi, Takahiro; Saito, Shun

    2010-09-15

    We present an improved prescription for the matter power spectrum in redshift space taking proper account of both nonlinear gravitational clustering and redshift distortion, which are of particular importance for accurately modeling baryon acoustic oscillations (BAOs). Contrary to the models of redshift distortion phenomenologically introduced but frequently used in the literature, the new model includes the corrections arising from the nonlinear coupling between the density and velocity fields associated with two competitive effects of redshift distortion, i.e., Kaiser and Finger-of-God effects. Based on the improved treatment of perturbation theory for gravitational clustering, we compare our model predictions with the monopole and quadrupole power spectra of N-body simulations, and an excellent agreement is achieved over the scales of BAOs. Potential impacts on constraining dark energy and modified gravity from the redshift-space power spectrum are also investigated based on the Fisher-matrix formalism, particularly focusing on the measurements of the Hubble parameter, angular diameter distance, and growth rate for structure formation. We find that the existing phenomenological models of redshift distortion produce a systematic error on measurements of the angular diameter distance and Hubble parameter by 1%-2%, and the growth-rate parameter by {approx}5%, which would become non-negligible for future galaxy surveys. Correctly modeling redshift distortion is thus essential, and the new prescription for the redshift-space power spectrum including the nonlinear corrections can be used as an accurate theoretical template for anisotropic BAOs.

  18. 2007 Wholesale Power Rate Case Initial Proposal : Revenue Requirement Study.

    SciTech Connect

    United States. Bonneville Power Administration.

    2005-11-01

    The purpose of this Study is to establish the level of revenues from wholesale power rates necessary to recover, in accordance with sound business principles, the Federal Columbia River Power System (FCRPS) costs associated with the production, acquisition, marketing, and conservation of electric power. The generation revenue requirement includes: recovery of the Federal investment in hydro generation, fish and wildlife and conservation costs; Federal agencies' operations and maintenance (O&M) expenses allocated to power; capitalized contract expenses associated with non-Federal power suppliers such as Energy Northwest (EN); other power purchase expenses, such as short-term power purchases; power marketing expenses; cost of transmission services necessary for the sale and delivery of FCRPS power; and all other generation-related costs incurred by the Administrator pursuant to law.

  19. Simulation of Acoustic Noise Generated by an Airbreathing, Beam-Powered Launch Vehicle

    NASA Astrophysics Data System (ADS)

    Kennedy, W. C.; Van Laak, P.; Scarton, H. A.; Myrabo, L. N.

    2005-04-01

    A simple acoustic model is developed for predicting the noise signature vs. power level for advanced laser-propelled lightcraft — capable of single-stage flights into low Earth orbit. This model predicts the noise levels generated by a pulsed detonation engine (PDE) during the initial lift-off and acceleration phase, for two representative `tractor-beam' lightcraft designs: a 1-place `Mercury' vehicle (2.5-m diameter, 900-kg); and a larger 5-place `Apollo' vehicle (5-m diameter, 5555-kg) — both the subject of an earlier study. The use of digital techniques to simulate the expected PDE noise signature is discussed, and three examples of fly-by noise signatures are presented. The reduction, or complete elimination of perceptible noise from such engines, can be accomplished by shifting the pulse frequency into the supra-audible or sub-audible range.

  20. Structural Dynamic Assessment of the GN2 Piping System for NASA's New and Powerful Reverberant Acoustic Test Facility

    NASA Technical Reports Server (NTRS)

    McNelis, Mark E.; Staab, Lucas D.; Akers, James C.; Hughes, WIlliam O.; Chang, Li, C.; Hozman, Aron D.; Henry, Michael W.

    2012-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) has led the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC's Plum Brook Station in Sandusky, Ohio, USA from 2007-2011. SAIC-Benham has completed construction of a new reverberant acoustic test facility to support the future testing needs of NASA's space exploration program and commercial customers. The large Reverberant Acoustic Test Facility (RATF) is approximately 101,000 cu ft in volume and was designed to operate at a maximum empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world's known active reverberant acoustic test facilities. Initial checkout acoustic testing was performed on March 2011 by SAIC-Benham at test levels up to 161 dB OASPL. During testing, several branches of the gaseous nitrogen (GN2) piping system, which supply the fluid to the noise generating acoustic modulators, failed at their "t-junctions" connecting the 12 inch supply line to their respective 4 inch branch lines. The problem was initially detected when the oxygen sensors in the horn room indicated a lower than expected oxygen level from which was inferred GN2 leaks in the piping system. In subsequent follow up inspections, cracks were identified in the failed "t-junction" connections through non-destructive evaluation testing . Through structural dynamic modeling of the piping system, the root cause of the "t-junction" connection failures was determined. The structural dynamic assessment identified several possible corrective design improvements to the horn room piping system. The effectiveness of the chosen design repairs were subsequently evaluated in September 2011 during acoustic verification testing to 161 dB OASPL.

  1. Structural Dynamic Assessment of the GN2 Piping System for NASA's New and Powerful Reverberant Acoustic Test Facility

    NASA Technical Reports Server (NTRS)

    McNelis, Mark E.; Staab, Lucas D.; Akers, James C.; Hughes, William O.; Chang, Li C.; Hozman, Aron D.; Henry, Michael W.

    2012-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) has led the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC's Plum Brook Station in Sandusky, Ohio, USA from 2007 to 2011. SAIC-Benham has completed construction of a new reverberant acoustic test facility to support the future testing needs of NASA's space exploration program and commercial customers. The large Reverberant Acoustic Test Facility (RATF) is approximately 101,000 cubic feet in volume and was designed to operate at a maximum empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world s known active reverberant acoustic test facilities. Initial checkout acoustic testing was performed on March 2011 by SAIC-Benham at test levels up to 161 dB OASPL. During testing, several branches of the gaseous nitrogen (GN2) piping system, which supply the fluid to the noise generating acoustic modulators, failed at their T-junctions connecting the 12 in. supply line to their respective 4 in. branch lines. The problem was initially detected when the oxygen sensors in the horn room indicated a lower than expected oxygen level from which was inferred GN2 leaks in the piping system. In subsequent follow up inspections, cracks were identified in the failed T-junction connections through non-destructive evaluation testing. Through structural dynamic modeling of the piping system, the root cause of the T-junction connection failures was determined. The structural dynamic assessment identified several possible corrective design improvements to the horn room piping system. The effectiveness of the chosen design repairs were subsequently evaluated in September 2011 during acoustic verification testing to 161 dB OASPL.

  2. A Novel Device for Total Acoustic Output Measurement of High Power Transducers

    NASA Astrophysics Data System (ADS)

    Howard, S.; Twomey, R.; Morris, H.; Zanelli, C. I.

    2010-03-01

    The objective of this work was to develop a device for ultrasound power measurement applicable over a broad range of medical transducer types, orientations and powers, and which supports automatic measurements to simplify use and minimize errors. Considering all the recommendations from standards such as IEC 61161, an accurate electromagnetic null-balance has been designed for ultrasound power measurements. The sensing element is placed in the water to eliminate errors due to surface tension and water evaporation, and the motion and detection of force is constrained to one axis, to increase immunity to vibration from the floor, water sloshing and water surface waves. A transparent tank was designed so it could easily be submerged in a larger tank to accommodate large transducers or side-firing geometries, and can also be turned upside-down for upward-firing transducers. A vacuum lid allows degassing the water and target in situ. An external control module was designed to operate the sensing/driving loop and to communicate to a local computer for data logging. The sensing algorithm, which incorporates temperature compensation, compares the feedback force needed to cancel the motion for sources in the "on" and "off" states. These two states can be controlled by the control unit or manually by the user, under guidance by a graphical user interface (the system presents measured power live during collection). Software allows calibration to standard weights, or to independently calibrated acoustic sources. The design accommodates a variety of targets, including cone, rubber, brush targets and an oil-filled target for power measurement via buoyancy changes. Measurement examples are presented, including HIFU sources operating at powers from 1 to 100.

  3. Small scale aspects of warm dark matter: Power spectra and acoustic oscillations

    SciTech Connect

    Boyanovsky, Daniel; Wu Jun

    2011-02-15

    We provide a semianalytic derivation of approximate evolution equations for density perturbations of warm dark matter candidates that decoupled while relativistic with arbitrary distribution functions, their solutions at small scales, and a simple numerical implementation that yields their transfer functions and power spectra. Density perturbations evolve through three stages: radiation domination when the particle is relativistic and nonrelativistic and matter domination. An early integrated Sachs-Wolfe effect during the first stage leads to an enhancement of density perturbations and a plateau in the transfer function for k < or approx. k{sub fs}, the free-streaming wave vector. An effective fluid description emerges at small scales which includes the effects of free streaming in initial conditions and inhomogeneities. The transfer function features warm dark matter acoustic oscillations at scales k > or approx. 2k{sub fs}. A simple analytic interpolation of the power spectra between large and small scales and a numerical implementation valid for arbitrary distribution functions is provided. As an application we study the power spectra for two models of sterile neutrinos with m{approx}keV produced nonresonantly and compare our results to those obtained from Boltzmann codes.

  4. Solar cycle variations in the powers and damping rates of low-degree solar acoustic oscillations

    NASA Astrophysics Data System (ADS)

    Broomhall, A.-M.; Pugh, C. E.; Nakariakov, V. M.

    2015-12-01

    Helioseismology uses the Sun's natural resonant oscillations to study the solar interior. The properties of the solar oscillations are sensitive to the Sun'2019;s magnetic activity cycle. Here we examine variations in the powers, damping rates, and energy supply rates of the most prominent acoustic oscillations in unresolved, Sun-as-a-star data, obtained by the Birmingham Solar Oscillations Network (BiSON) during solar cycles 22, 23, and the first half of 24. The variations in the helioseismic parameters are compared to the 10.7 cm flux, a well-known global proxy of solar activity. As expected the oscillations are most heavily damped and the mode powers are at a minimum at solar activity maximum. The 10.7 cm flux was linearly regressed using the fractional variations of damping rates and powers observed during cycle 23. In general, good agreement is found between the damping rates and the 10.7 cm flux. However, the linearly regressed 10.7 cm flux and fractional variation in powers diverge in cycles 22 and 24, indicating that the relationship between the mode powers and the 10.7 cm flux is not consistent from one cycle to the next. The energy supply rate of the oscillations, which is usually approximately constant, also decreases at this time. We have determined that this discrepancy is not because of the first-order bias introduced by an increase in the level of background noise or gaps in the data. Although we cannot categorically rule out an instrumental origin, the divergence observed in cycle 24, when the data were of high quality and the data coverage was over 80%, raises the possibility that the effect may be solar in origin.

  5. A high-temperature acoustic-electric system for power delivery and data communication through thick metallic barriers

    NASA Astrophysics Data System (ADS)

    Lawry, T. J.; Wilt, K. R.; Roa-Prada, S.; Ashdown, J. D.; Saulnier, G. J.; Scarton, H. A.; Das, P. K.; Gavens, A. J.

    2011-06-01

    In many sensing applications that monitor extreme environmental conditions within sealed metallic vessels, penetrating vessel walls in order to feed through power and data cables is impractical, as this may compromise a vessels structural integrity and its environmental isolation. Frequent servicing of sensing equipment within these environments is costly, so the use of batteries is strongly undesired and power harvesting techniques are preferred. Traditional electromagnetic power delivery and communication techniques, however, are highly ineffective in these applications, due to Faraday shielding effects from the metallic vessel walls. A viable, non-destructive alternative is to use piezoelectric materials to transmit power through thick metallic barriers acoustically. We present critical elements of a high-temperature battery-less sensor system prototype, including power harvesting, voltage regulation, and data communication circuitry able to operate up to 260°C. Power transmission is achieved by coaxially aligning a pair of high-temperature piezoelectric transducers on opposite sides of a thick steel barrier. Continuous-wave excitation of the outside transducer creates an acoustic beam that is captured by the opposite transducer, forming an acoustic-electric link for power harvesting circuitry. Simultaneously, sensor data can be transmitted out of the high-temperature environment by switching the electrical impedance placed across the leads of the inside transducer, creating a reflection-based amplitude modulated signal on the outside transducer. Transducer housing, loading, and alternatives for acoustic couplants are discussed. Measurement results are presented, and it was found that the system can harvest up to 1 watt of power and communicate sensor data up to 50 kbps, while operating at 260°C.

  6. 49 CFR 236.551 - Power supply voltage; requirement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Rules and Instructions; Locomotives § 236.551 Power... 49 Transportation 4 2011-10-01 2011-10-01 false Power supply voltage; requirement. 236.551...

  7. 47 CFR 73.511 - Power and antenna height requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Power and antenna height requirements. 73.511 Section 73.511 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Noncommercial Educational FM Broadcast Stations § 73.511 Power and...

  8. 47 CFR 73.511 - Power and antenna height requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Power and antenna height requirements. 73.511 Section 73.511 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Noncommercial Educational FM Broadcast Stations § 73.511 Power and...

  9. 47 CFR 73.511 - Power and antenna height requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Power and antenna height requirements. 73.511 Section 73.511 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Noncommercial Educational FM Broadcast Stations § 73.511 Power and...

  10. 47 CFR 73.511 - Power and antenna height requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Power and antenna height requirements. 73.511 Section 73.511 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Noncommercial Educational FM Broadcast Stations § 73.511 Power and...

  11. 47 CFR 73.511 - Power and antenna height requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Power and antenna height requirements. 73.511 Section 73.511 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Noncommercial Educational FM Broadcast Stations § 73.511 Power and...

  12. National Maglev initiative: California line electric utility power system requirements

    NASA Technical Reports Server (NTRS)

    Save, Phil

    1994-01-01

    The electrical utility power system requirements were determined for a Maglev line from San Diego to San Francisco and Sacramento with a maximum capacity of 12,000 passengers an hour in each direction at a speed of 300 miles per hour, or one train every 30 seconds in each direction. Basically the Maglev line requires one 50-MVA substation every 12.5 miles. The need for new power lines to serve these substations and their voltage levels are based not only on equipment loading criteria but also on limitations due to voltage flicker and harmonics created by the Maglev system. The resulting power system requirements and their costs depend mostly on the geographical area, urban or suburban with 'strong' power systems, or mountains and rural areas with 'weak' power systems. A reliability evaluation indicated that emergency power sources, such as a 10-MW battery at each substation, were not justified if sufficient redundancy is provided in the design of the substations and the power lines serving them. With a cost of $5.6 M per mile, the power system requirements, including the 12-kV DC cables and the inverters along the Maglev line, were found to be the second largest cost component of the Maglev system, after the cost of the guideway system ($9.1 M per mile), out of a total cost of $23 M per mile.

  13. Acoustic/Magnetic Stress Sensor

    NASA Technical Reports Server (NTRS)

    Heyman, J. S.; Namkung, M.

    1986-01-01

    High-resolution sensor fast, portable, does not require permanent bonding to structure. Sensor measures nondestructively type (compressive or tensile) and magnitude of stresses and stress gradients present in class of materials. Includes precise high-resolution acoustic interferometer, sending acoustic transducer, receiving acoustic transducer, electromagnet coil and core, power supply, and magnetic-field-measuring device such as Hall probe. This measurement especially important for construction and applications where steel is widely used. Sensor useful especially for nondestructive evaluation of stress in steel members because of portability, rapid testing, and nonpermanent installation.

  14. Lift and Power Requirements in Flight in a Dragonfly

    NASA Astrophysics Data System (ADS)

    Sun, Mao; Wang, Ji Kang

    The lift and power requirements of a model dragonfly in forward flight are studied, using the method of numerically solving the Navier-Stokes equations. The graph of power against flight speed is U-shaped, suggesting that a dragonfly might have a preferred cruising speed. Considerable variation in the relative phase between fore- and hindwings results in only very small change in power requirement. This suggests theat the forewing-hingwing interaction is weak and furthermore, might explain why phase angles ranging from to are employed by dragonflies in hovering and forward flight.

  15. 40 CFR 256.21 - Requirements for State regulatory powers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Requirements for State regulatory powers. 256.21 Section 256.21 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR DEVELOPMENT AND IMPLEMENTATION OF STATE SOLID WASTE MANAGEMENT PLANS Solid Waste Disposal Programs § 256.21 Requirements...

  16. Power system requirements and selection for the space exploration initiative

    SciTech Connect

    Biringer, K.L. ); Bartine, D.E. ); Buden, D. ); Foreman, J. ); Harrison, S. )

    1991-01-01

    The Space Exploration Initiative (SEI) seeks to reestablish a US program of manned and unmanned space exploration. The President has called for a program which includes a space station element, a manned habitation of the moon, and a human exploration of Mars. The NASA Synthesis Group has developed four significantly different architectures for the SEI program. One key element of a space exploration effort is the power required to support the missions. The Power Speciality Team of the Synthesis Group was tasked with assessing and evaluating the power requirements and candidate power technologies for such missions. Inputs to the effort came from existing NASA studies as well as other governments agency inputs such as those from DOD and DOE. In addition, there were industry and university briefings and results of solicitations from the AIAA and the general public as part of the NASA outreach effort. Because of the variety of power needs in the SEI program, there will be a need for multiple power system technologies including solar, nuclear and electrochemical. Due to the high rocket masses required to propel payloads to the moon and beyond to Mars, there is great emphasis placed on the need for high power density and high energy density systems. Power system technology development work is needed results will determine the ultimate technology selections. 23 refs., 10 figs.

  17. System requirements for laser power beaming to geosynchronous satellites

    SciTech Connect

    Neal, R.D.; McKechnie, T.S.; Neal, D.R.

    1994-03-01

    Geosynchronous satellites use solar arrays as their primary source of electrical power. During earth eclipse, which occurs 90 times each year, the satellites are powered by batteries, but the heavy charge-discharge cycle decreases their life expectancy. By beaming laser power to satellites during the eclipses, satellite life expectancy can be significantly increased. In this paper, the authors investigate the basic system parameters and trade-offs of using reactor pumped laser technology to beam power from the Nevada Test Site. A first order argument is used to develop a consistent set of requirements for such a system.

  18. NASA low power DIPS [Dynamic Isotope Power System] conceptual design requirements document

    SciTech Connect

    Johnson, G.; Determan, W.; Otting, W.

    1990-01-01

    This document describes the requirements for a low power (0.5--1.0 kwe) Dynamic Isotope Power System (DIPS) for interplanetary and space exploration missions using the Mariner Mark II spacecraft. The reference mission used to establish these requirements was the Cassini orbiter mission to Saturn. Requirements specific to two other missions (Outer Planet Orbiter/Probe and Comet Nucleus Sample Return) are also included. A list of references used to develop these requirements is provided. 17 refs., 2 figs., 2 tabs.

  19. Electrofishing power requirements in relation to duty cycle

    USGS Publications Warehouse

    Miranda, L.E.; Dolan, C.R.

    2004-01-01

    Under controlled laboratory conditions we measured the electrical peak power required to immobilize (i.e., narcotize or tetanize) fish of various species and sizes with duty cycles (i.e., percentage of time a field is energized) ranging from 1.5% to 100%. Electrofishing effectiveness was closely associated with duty cycle. Duty cycles of 10-50% required the least peak power to immobilize fish; peak power requirements increased gradually above 50% duty cycle and sharply below 10%. Small duty cycles can increase field strength by making possible higher instantaneous peak voltages that allow the threshold power needed to immobilize fish to radiate farther away from the electrodes. Therefore, operating within the 10-50% range of duty cycles would allow a larger radius of immobilization action than operating with higher duty cycles. This 10-50% range of duty cycles also coincided with some of the highest margins of difference between the electrical power required to narcotize and that required to tetanize fish. This observation is worthy of note because proper use of duty cycle could help reduce the mortality associated with tetany documented by some authors. Although electrofishing with intermediate duty cycles can potentially increase effectiveness of electrofishing, our results suggest that immobilization response is not fully accounted for by duty cycle because of a potential interaction between pulse frequency and duration that requires further investigation.

  20. Digital stroboscopic holographic interferometry for power flow measurements in acoustically driven membranes

    NASA Astrophysics Data System (ADS)

    Keustermans, William; Pires, Felipe; De Greef, Daniël; Vanlanduit, Steve J. A.; Dirckx, Joris J. J.

    2016-06-01

    Despite the importance of the eardrum and the ossicles in the hearing chain, it remains an open question how acoustical energy is transmitted between them. Identifying the transmission path at different frequencies could lead to valuable information for the domain of middle ear surgery. In this work a setup for stroboscopic holography is combined with an algorithm for power flow calculations. With our method we were able to accurately locate the power sources and sinks in a membrane. The setup enabled us to make amplitude maps of the out-of-plane displacement of a vibrating rubber membrane at subsequent instances of time within the vibration period. From these, the amplitude maps of the moments of force and velocities are calculated. The magnitude and phase maps are extracted from this amplitude data, and form the input for the power flow calculations. We present the algorithm used for the measurements and for the power flow calculations. Finite element models of a circular plate with a local energy source and sink allowed us to test and optimize this algorithm in a controlled way and without the present of noise, but will not be discussed below. At the setup an earphone was connected with a thin tube which was placed very close to the membrane so that sound impinges locally on the membrane, hereby acting as a local energy source. The energy sink was a little piece of foam carefully placed against the membrane. The laser pulses are fired at selected instants within the vibration period using a 30 mW HeNe continuous wave laser (red light, 632.8 nm) in combination with an acousto-optic modulator. A function generator controls the phase of these illumination pulses and the holograms are recorded using a CCD camera. We present the magnitude and phase maps as well as the power flow measurements on the rubber membrane. Calculation of the divergence of this power flow map provides a simple and fast way of identifying and locating an energy source or sink. In conclusion

  1. An Ultra-Low Power and Flexible Acoustic Modem Design to Develop Energy-Efficient Underwater Sensor Networks

    PubMed Central

    Sánchez, Antonio; Blanc, Sara; Yuste, Pedro; Perles, Angel; Serrano, Juan José

    2012-01-01

    This paper is focused on the description of the physical layer of a new acoustic modem called ITACA. The modem architecture includes as a major novelty an ultra-low power asynchronous wake-up system implementation for underwater acoustic transmission that is based on a low-cost off-the-shelf RFID peripheral integrated circuit. This feature enables a reduced power dissipation of 10 μW in stand-by mode and registers very low power values during reception and transmission. The modem also incorporates clear channel assessment (CCA) to support CSMA-based medium access control (MAC) layer protocols. The design is part of a compact platform for a long-life short/medium range underwater wireless sensor network. PMID:22969324

  2. Integrated Optical, Acoustically Tunable Wavelength Filter

    NASA Astrophysics Data System (ADS)

    Frangen, J.; Herrmann, Harald; Ricken, Raimund; Seibert, Holger; Sohler, Wolfgang; Strake, E.

    1989-12-01

    An integrated optical, acoustically tunable wavelength filter, consisting of a combination of TM-TE converter and integrated polarizer in LiNbO3, is demonstrated. The filter bandwidth is 2.8 nm; the center wavelength can be tuned from λ = 1.45 pm to λ = 1.57 pm by adjusting the driving acoustic frequency. Due to the combined acoustical/optical strip guide structure, used in the mode converter, a very low acoustic drive power of only 9 mW is required.

  3. Power Requirement for Nonequilibrium MHD-Bypass Scramjet

    NASA Technical Reports Server (NTRS)

    Park, Chul; Bogdanoff, David W.; Mehta, Unmeel

    2000-01-01

    It has been suggested previously that the performance of scramjet propulsion system may be improved by the use of magnetohydrodynamic (MHD) energy bypass: an MHD generator could be made to decelerate the flow entering the combustor, thereby improving combustion efficiency, and the electrical power generated could be made to accelerate the flow exiting from the combustor prior to expanding through the nozzle. In one of such proposed schemes, the MHD generator is proposed to be operated at a low temperature and ionization is to be achieved under nonequilibrium by the application of an external power. In the present work, the required power of such an external source is calculated assuming a 100%-efficient nonequilibrium ionization scheme. The power required is that needed to prevent the degree of ionization from reaching equilibrium with the low gas temperature. The flow is seeded with potassium or cesium. Specific impulse is calculated with and without turbulent friction. The results show that, for typical intended flight conditions, the specific impulse obtained is substantially higher than that of a typical scramjet, but the required external-power is several times that of the power generated in the MHD generator.

  4. International environmental issues and requirements for new power projects

    SciTech Connect

    Newman, J.R.; Maltby, J.H.

    1997-12-31

    The purpose of this presentation was to discuss the emerging role of financial entities in determining environmental requirements for international power projects. The paper outlines the following: emerging conditions; examples of announced privatization energy projects by country; types of government and international financial entity sources; problems for IPPs; similarity and differences between the World Bank and the USEPA; comparison of the international standards and regulations for power plants; recent trends/issues involving international power project approval; and recommendations for understanding/expediting the financial entities` environmental approval process and how to expedite this process.

  5. Temperature Measurements on Hot Spots of Power Substations Utilizing Surface Acoustic Wave Sensors

    NASA Astrophysics Data System (ADS)

    Cavaco, M. A. M.; Benedet, M. E.; Neto, L. R.

    2011-12-01

    In several applications in the field of metrology, the direct connection of the sensor element with the respective signal-processing unit of the measurement system is not trivial. It can be mentioned, as an example, the measurement of hot points in electric power substations because of the high electrical potential. To solve that problem, two alternatives were studied, one using active surface acoustic wave (SAW) sensors and other using passive SAW tags. For the passive sensor, a SAW radio-frequency identification (RFID) temperature detector was used. That technology is widely applied for typical transport identification (grain transportation, road traffic control), but its application in the field of metrology is innovative. The variation in temperature makes an alteration in the characteristics of the piezoelectric material of the SAW matrix, changing mostly the resonance frequency. Using SAW-RFID, the problem of measuring temperature basically is directed to the identification of the frequency of resonance of the SAW. The use of active SAW sensors has been demonstrated to be much more satisfactory for the solution of such a problem because of the limitation in the range of the passive sensors.

  6. Space radioisotope power source requirements update and technology status

    SciTech Connect

    Mondt, J.F.

    1998-07-01

    The requirements for a space advanced radioisotope power source are based on potential deep space missions being investigated for the NASA Advanced Space Systems Development Program. Since deep space missions have not been approved, updating requirements is a continuos parallel process of designing the spacecraft and the science instruments to accomplish the potential missions and developing the power source technology to meet changing requirements. There are at least two potential missions, Pluto/Kuiper Express and Europa Orbiter, which may require space advanced radioisotope power sources. The Europa Orbiter has been selected as the preferred first potential mission. However the final decision will depend on the technology readiness of all the subsystems and the project must be able to switch to Pluto Kuiper Express as the first mission as late as the beginning of fiscal year 2000. Therefore the requirements for the power source will cover both potential missions. As the deep space spacecraft design evolves to meet the science requirements and the Alkali Metal Thermal to Electric (AMTEC) technology matures the advanced radioisotope power source design requirements are updated The AMTEC technology developed to date uses stainless steel for the sodium containment material. The higher efficiency required for the space power system dictates that the AMTEC technology must operate at a higher temperature than possible with stainless steel. Therefore refractory materials have been selected as the baseline material for the AMTEC cell. These refractory materials are Nb1Zr for the hot side and Nb1Zr or Nb10Hf1Ti for the cold side. These materials were selected so the AMTEC cell can operate at 1150K to 1350K hot side temperature and 600K to 700K cold side temperature and meet the present power and mass requirements using four to six general purpose heat source modules as the heat source. The new containment materials and brazes will be evaluated as to lifetime

  7. Simultaneous backward data transmission and power harvesting in an ultrasonic transcutaneous energy transfer link employing acoustically dependent electric impedance modulation.

    PubMed

    Ozeri, Shaul; Shmilovitz, Doron

    2014-09-01

    The advancement and miniaturization of body implanted medical devices pose several challenges to Ultrasonic Transcutaneous Energy Transfer (UTET), such as the need to reduce the size of the piezoelectric resonator, and the need to maximize the UTET link power-transfer efficiency. Accordingly, the same piezoelectric resonator that is used for energy harvesting at the body implant, may also be used for ultrasonic backward data transfer, for instance, through impedance modulation. This paper presents physical considerations and design guidelines of the body implanted transducer of a UTET link with impedance modulation for a backward data transfer. The acoustic matching design procedure was based on the 2×2 transfer matrix chain analysis, in addition to the Krimholtz Leedom and Matthaei KLM transmission line model. The UTET power transfer was carried out at a frequency of 765 kHz, continuous wave (CW) mode. The backward data transfer was attained by inserting a 9% load resistance variation around its matched value (550 Ohm), resulting in a 12% increase in the acoustic reflection coefficient. A backward data transmission rate of 1200 bits/s was experimentally demonstrated using amplitude shift keying, simultaneously with an acoustic power transfer of 20 mW to the implant. PMID:24861424

  8. Heat engine requirements for advanced solar thermal power systems

    NASA Technical Reports Server (NTRS)

    Jaffe, L. D.; Pham, H. Q.

    1981-01-01

    Requirements and constraints are established for power conversion subsystems, including heat engine, alternator and auxiliaries, of dish concentrator solar thermal power systems. In order to be competitive with conventional power systems, it is argued that the heat engine should be of less than 40 kW rated output, in a subsystem with an efficiency of at least 40% at rated output and at least 37% at half power. An interval between major overhauls of 50,000 hours is also desirable, along with minor maintenance and lubrication not more than four times a year requiring no more than one man-hour each time, and optimal reliability. Also found to be important are the capability for hybrid operation using heat from a solar receiver, fuel-fired combustor or both simultaneously, operation at any attitude, stability to transients in input power and output loading, operation at ambient temperatures from -30 to 50 C, and compatibility with environmental and safety requirements. Cost targets include a price of $180/kWe, and operation, maintenance and replacement costs averaging $0.001/kWh for 30 years of operation.

  9. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Power requirements, generating sources. 111.10-4 Section 111.10-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING... services include cooking, heating, air conditioning (where installed), domestic refrigeration,...

  10. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Power requirements, generating sources. 111.10-4 Section 111.10-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING... services include cooking, heating, air conditioning (where installed), domestic refrigeration,...

  11. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Power requirements, generating sources. 111.10-4 Section 111.10-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING... services include cooking, heating, air conditioning (where installed), domestic refrigeration,...

  12. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Power requirements, generating sources. 111.10-4 Section 111.10-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING... services include cooking, heating, air conditioning (where installed), domestic refrigeration,...

  13. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Power requirements, generating sources. 111.10-4 Section 111.10-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING... services include cooking, heating, air conditioning (where installed), domestic refrigeration,...

  14. Results from Symposium on Future Orbital power systems technology requirements

    NASA Technical Reports Server (NTRS)

    Gorland, S.

    1979-01-01

    The technology requirements for future orbital power systems were reviewed. Workshops were held in 10 technology disciplines to discuss technology deficiencies, adequacy of current programs to resolve those deficiencies and recommendations for tasks that might reduce the testing and risks involved in future orbital energy systems. Those recommendations are summarized.

  15. Nuclear power technology requirements for NASA exploration missions

    NASA Technical Reports Server (NTRS)

    Bloomfield, Harvey S.

    1990-01-01

    It is pointed out that future exploration of the moon and Mars will mandate developments in many areas of technology. In particular, major advances will be required in planet surface power systems. Critical nuclear technology challenges that can enable strategic self-sufficiency, acceptable operational costs, and cost-effective space transportation goals for NASA exploration missions have been identified. Critical technologies for surface power systems include stationary and mobile nuclear reactor and radioisotope heat sources coupled to static and dynamic power conversion devices. These technologies can provide dramatic reductions in mass, leading to operational and transportation cost savings. Critical technologies for space transportation systems include nuclear thermal rocket and nuclear electric propulsion options, which present compelling concepts for significantly reducing mass, cost, or travel time required for Earth-Mars transport.

  16. System Modeling of Lunar Oxygen Production: Mass and Power Requirements

    NASA Technical Reports Server (NTRS)

    Steffen, Christopher J.; Freeh, Joshua E.; Linne, Diane L.; Faykus, Eric W.; Gallo, Christopher A.; Green, Robert D.

    2007-01-01

    A systems analysis tool for estimating the mass and power requirements for a lunar oxygen production facility is introduced. The individual modeling components involve the chemical processing and cryogenic storage subsystems needed to process a beneficiated regolith stream into liquid oxygen via ilmenite reduction. The power can be supplied from one of six different fission reactor-converter systems. A baseline system analysis, capable of producing 15 metric tons of oxygen per annum, is presented. The influence of reactor-converter choice was seen to have a small but measurable impact on the system configuration and performance. Finally, the mission concept of operations can have a substantial impact upon individual component size and power requirements.

  17. Structure- and fluid-borne acoustic power sources induced by turbulent flow in 90° piping elbows

    NASA Astrophysics Data System (ADS)

    Hambric, S. A.; Boger, D. A.; Fahnline, J. B.; Campbell, R. L.

    2010-01-01

    The structure- and fluid-borne vibro-acoustic power spectra induced by turbulent fluid flow over the walls of a continuous 90° piping elbow are computed. Although the actual power input to the piping by the wall pressure fluctuations is distributed throughout the elbow, equivalent total power inputs to various structural wavetypes (bending, torsion, axial) and fluid (plane-waves) at the inlet and discharge of the elbow are computed. The powers at the elbow “ports” are suitable inputs to wave- and statistically-based models of larger piping systems that include the elbow. Calculations for several flow and structural parameters, including pipe wall thickness, flow speed, and flow Reynolds number are shown. The power spectra are scaled on flow and structural-acoustic parameters so that levels for conditions other than those considered in the paper may be estimated, subject to geometric similarity constraints (elbow radius/pipe diameter). The approach for computing the powers (called CHAMP - combined hydroacoustic modeling programs), which links computational fluid dynamics, finite element and boundary element modeling, and efficient random analysis techniques, is general, and may be applied to other piping system components excited by turbulent fluid flow, such as U-bends and T-sections.

  18. Conductor requirements for high-temperature superconducting utility power transformers

    SciTech Connect

    Pleva, E. F.; Mehrotra, V.; Schwenterly, S W

    2010-01-01

    High-temperature superconducting (HTS) coated conductors in utility power transformers must satisfy a set of operating requirements that are driven by two major considerations-HTS transformers must be economically competitive with conventional units, and the conductor must be robust enough to be used in a commercial manufacturing environment. The transformer design and manufacturing process will be described in order to highlight the various requirements that it imposes on the HTS conductor. Spreadsheet estimates of HTS transformer costs allow estimates of the conductor cost required for an HTS transformer to be competitive with a similarly performing conventional unit.

  19. Micro acoustic spectrum analyzer

    DOEpatents

    Schubert, W. Kent; Butler, Michael A.; Adkins, Douglas R.; Anderson, Larry F.

    2004-11-23

    A micro acoustic spectrum analyzer for determining the frequency components of a fluctuating sound signal comprises a microphone to pick up the fluctuating sound signal and produce an alternating current electrical signal; at least one microfabricated resonator, each resonator having a different resonant frequency, that vibrate in response to the alternating current electrical signal; and at least one detector to detect the vibration of the microfabricated resonators. The micro acoustic spectrum analyzer can further comprise a mixer to mix a reference signal with the alternating current electrical signal from the microphone to shift the frequency spectrum to a frequency range that is a better matched to the resonant frequencies of the microfabricated resonators. The micro acoustic spectrum analyzer can be designed specifically for portability, size, cost, accuracy, speed, power requirements, and use in a harsh environment. The micro acoustic spectrum analyzer is particularly suited for applications where size, accessibility, and power requirements are limited, such as the monitoring of industrial equipment and processes, detection of security intrusions, or evaluation of military threats.

  20. Reversible swarming and separation of self-propelled chemically powered nanomotors under acoustic fields.

    PubMed

    Xu, Tailin; Soto, Fernando; Gao, Wei; Dong, Renfeng; Garcia-Gradilla, Victor; Magaña, Ernesto; Zhang, Xueji; Wang, Joseph

    2015-02-18

    The collective behavior of biological systems has inspired efforts toward the controlled assembly of synthetic nanomotors. Here we demonstrate the use of acoustic fields to induce reversible assembly of catalytic nanomotors, controlled swarm movement, and separation of different nanomotors. The swarming mechanism relies on the interaction between individual nanomotors and the acoustic field, which triggers rapid migration and assembly around the nearest pressure node. Such on-demand assembly of catalytic nanomotors is extremely fast and reversible. Controlled movement of the resulting swarm is illustrated by changing the frequency of the acoustic field. Efficient separation of different types of nanomotors, which assemble in distinct swarming regions, is illustrated. The ability of acoustic fields to regulate the collective behavior of catalytic nanomotors holds considerable promise for a wide range of practical applications. PMID:25634724

  1. Wireless acoustic-electric feed-through for power and signal transmission

    NASA Technical Reports Server (NTRS)

    Sherrit, Stewart (Inventor); Bar-Cohen, Yoseph (Inventor); Bao, Xiaoqi (Inventor); Doty, Benjamin (Inventor); Badescu, Mircea (Inventor); Chang, Zensheu (Inventor)

    2011-01-01

    An embodiment provides electrical energy from a source on one side of a medium to a load on the other side of the medium, the embodiment including a first piezoelectric to generate acoustic energy in response to electrical energy from the source, and a second piezoelectric to convert the received acoustic energy to electrical energy used by the load. Other embodiments are described and claimed.

  2. Applications of adaptive focused acoustics to compound management.

    PubMed

    Nixon, Elizabeth; Holland-Crimmin, Sue; Lupotsky, Brian; Chan, James; Curtis, Jon; Dobbs, Karen; Blaxill, Zoe

    2009-06-01

    Since the introduction of lithotripsy kidney stone therapy, Focused Acoustics and its properties have been thoroughly utilized in medicine and exploration. More recently, Compound Management is exploring its applications and benefits to sample integrity. There are 2 forms of Focused Acoustics: Acoustic Droplet Ejection and Adaptive Focused Acoustics, which work by emitting high-powered acoustic waves through water toward a focused point. This focused power results in noncontact plate-to-plate sample transfer or sample dissolution, respectively. For the purposes of this article, only Adaptive Focused Acoustics will be addressed. Adaptive Focused Acoustics uses high-powered acoustic waves to mix, homogenize, dissolve, and thaw samples. It facilitates transferable samples through noncontact, closed-container, isothermal mixing. Experimental results show significantly reduced mixing times, limited degradation, and ideal use for heat-sensitive compounds. Upon implementation, acoustic dissolution has reduced the number of samples requiring longer mixing times as well as reducing the number impacted by incomplete compound dissolution. It has also helped in increasing the overall sample concentration from 6 to 8 mM to 8 to 10 mM by ensuring complete compound solubilization. The application of Adaptive Focused Acoustics, however, cannot be applied to all Compound Management processes, such as sample thawing and low-volume sample reconstitution. This article will go on to describe the areas where Adaptive Focused Acoustics adds value as well as areas in which it has shown no clear benefit. PMID:19487768

  3. Thermal storage requirements for parabolic dish solar power plants

    NASA Technical Reports Server (NTRS)

    Wen, L.; Steele, H.

    1980-01-01

    The cost effectiveness of a high temperature thermal storage system is investigated for a representative parabolic dish solar power plant. The plant supplies electrical power in accordance with a specific, seasonally varying demand profile. The solar power received by the plant is supplemented by power from fuel combustion. The cost of electricity generated by the solar power plant is calculated, using the cost of mass-producible subsystems (specifically, parabolic dishes, receivers, and power conversion units) now being designed for this type of solar plant. The trade-off between fuel and thermal storage is derived in terms of storage effectiveness, the cost of storage devices, and the cost of fuel. Thermal storage requirements, such as storage capacity, storage effectiveness, and storage cost are established based on the cost of fuel and the overall objective of minimizing the cost of the electricity produced by the system. As the cost of fuel increases at a rate faster than general inflation, thermal storage systems in the $40 to $70/kWthr range could become cost effective in the near future.

  4. Acoustic transmitters for underwater neutrino telescopes.

    PubMed

    Ardid, Miguel; Martínez-Mora, Juan A; Bou-Cabo, Manuel; Larosa, Giuseppina; Adrián-Martínez, Silvia; Llorens, Carlos D

    2012-01-01

    In this paper acoustic transmitters that were developed for use in underwater neutrino telescopes are presented. Firstly, an acoustic transceiver has been developed as part of the acoustic positioning system of neutrino telescopes. These infrastructures are not completely rigid and require a positioning system in order to monitor the position of the optical sensors which move due to sea currents. To guarantee a reliable and versatile system, the transceiver has the requirements of reduced cost, low power consumption, high pressure withstanding (up to 500 bars), high intensity for emission, low intrinsic noise, arbitrary signals for emission and the capacity of acquiring and processing received signals. Secondly, a compact acoustic transmitter array has been developed for the calibration of acoustic neutrino detection systems. The array is able to mimic the signature of ultra-high-energy neutrino interaction in emission directivity and signal shape. The technique of parametric acoustic sources has been used to achieve the proposed aim. The developed compact array has practical features such as easy manageability and operation. The prototype designs and the results of different tests are described. The techniques applied for these two acoustic systems are so powerful and versatile that may be of interest in other marine applications using acoustic transmitters. PMID:22666022

  5. Acoustic Transmitters for Underwater Neutrino Telescopes

    PubMed Central

    Ardid, Miguel; Martínez-Mora, Juan A.; Bou-Cabo, Manuel; Larosa, Giuseppina; Adrián-Martínez, Silvia; Llorens, Carlos D.

    2012-01-01

    In this paper acoustic transmitters that were developed for use in underwater neutrino telescopes are presented. Firstly, an acoustic transceiver has been developed as part of the acoustic positioning system of neutrino telescopes. These infrastructures are not completely rigid and require a positioning system in order to monitor the position of the optical sensors which move due to sea currents. To guarantee a reliable and versatile system, the transceiver has the requirements of reduced cost, low power consumption, high pressure withstanding (up to 500 bars), high intensity for emission, low intrinsic noise, arbitrary signals for emission and the capacity of acquiring and processing received signals. Secondly, a compact acoustic transmitter array has been developed for the calibration of acoustic neutrino detection systems. The array is able to mimic the signature of ultra-high-energy neutrino interaction in emission directivity and signal shape. The technique of parametric acoustic sources has been used to achieve the proposed aim. The developed compact array has practical features such as easy manageability and operation. The prototype designs and the results of different tests are described. The techniques applied for these two acoustic systems are so powerful and versatile that may be of interest in other marine applications using acoustic transmitters. PMID:22666022

  6. Electrical power requirements analysis. Single failure tolerant entry

    NASA Technical Reports Server (NTRS)

    Pipher, M. D.; Green, P. A.; Wolfgram, D. F.

    1977-01-01

    The results of an analysis of the orbiter electrical power system for the case of a single failure tolerant (SFT) entry are presented. The analysis was performed using the shuttle electrical power system analysis computer program. It was performed to permit assessment of the capability of the orbiter systems to support the proposed entry configuration and to provide the data necessary to identify potential constraints and limitations. Three contingency modes have been identified which would require an SFT entry. This analysis addresses an SFT entry resulting from the loss of two fuel cell powerplants, while on orbit. The results of the analysis indicate that, even under near optimum conditions, the fuel cell power demand will exceed the tested operating capacity of 16 kw, and that various electrical components may experience voltages below 24 VDC.

  7. Enhancement of NRC station blackout requirements for nuclear power plants

    SciTech Connect

    McConnell, M. W.

    2012-07-01

    The U.S. Nuclear Regulatory Commission (NRC) established a Near-Term Task Force (NTTF) in response to Commission direction to conduct a systematic and methodical review of NRC processes and regulations to determine whether the agency should make additional improvements to its regulatory system and to make recommendations to the Commission for its policy direction, in light of the accident at the Fukushima Dai-ichi Nuclear Power Plant. The NTTF's review resulted in a set of recommendations that took a balanced approach to defense-in-depth as applied to low-likelihood, high-consequence events such as prolonged station blackout (SBO) resulting from severe natural phenomena. Part 50, Section 63, of Title 10 of the Code of Federal Regulations (CFR), 'Loss of All Alternating Current Power,' currently requires that each nuclear power plant must be able to cool the reactor core and maintain containment integrity for a specified duration of an SBO. The SBO duration and mitigation strategy for each nuclear power plant is site specific and is based on the robustness of the local transmission system and the transmission system operator's capability to restore offsite power to the nuclear power plant. With regard to SBO, the NTTF recommended that the NRC strengthen SBO mitigation capability at all operating and new reactors for design-basis and beyond-design-basis external events. The NTTF also recommended strengthening emergency preparedness for prolonged SBO and multi-unit events. These recommendations, taken together, are intended to clarify and strengthen US nuclear reactor safety regarding protection against and mitigation of the consequences of natural disasters and emergency preparedness during SBO. The focus of this paper is on the existing SBO requirements and NRC initiatives to strengthen SBO capability at all operating and new reactors to address prolonged SBO stemming from design-basis and beyond-design-basis external events. The NRC initiatives are intended to

  8. NASA requirements and applications environments for electrical power wiring

    NASA Technical Reports Server (NTRS)

    Stavnes, Mark W.; Hammond, Ahmad N.

    1992-01-01

    While a large data base for electrical arc track-resistant wire insulation exists for aircraft electrical power systems, comparable spacecraft-pertinent data are in limited supply. Existing insulation systems have been found to arc-track at potentials as low as 28 V dc. An account is presently given of the electrical, thermal, mechanical, and operational requirements for specification and testing of candidate wiring systems for spacecraft applications.

  9. Lift and power requirements of hovering insect flight

    NASA Astrophysics Data System (ADS)

    Mao, Sun; Gang, Du

    2003-10-01

    Lift and power requirements for hovering flight of eight species of insects are studied by solving the Navier-Stokes equation numerically. The solution provides velocity and pressure fields, from which unsteady aerodynamic forces and moments are obtained. The inertial torque of wing mass are computed analytically. The wing length of the insects ranges from 2 mm (fruit fly) to 52mm (hawkmoth); Reynolds numbers Re (based on mean flapping speed and mean chord length) ranges from 75 to 3 850. The primary findings are shown in the following: (1) Either small ( R=2mm, Re=75), medium ( R≈10mm, Re≈500) or large ( R≈50 mm, Re≈4000) insects mainly employ the same high-lift mechanism, delayed stall, to produce lift in hovering flight. The midstroke angle of attack needed to produce a mean lift equal to the insect weight is approximately in the range of 25° to 45°, which is approximately in agreement with observation. (2) For the small insect (fruit fly) and for the medium and large insects with relatively small wingbeat frequency (cranefly, ladybird and hawkmoth), the specific power ranges from 18 to 39 W·kg-1, the major part of the power is due to aerodynamic force, and the elastic storage of negatige work does not change the specific power greatly. However for medium and large insects with relatively large wingbeat frequency (hoverfly, dronefly, honey bee and bumble bee), the specific power ranges from 39 to 61 W·kg-1, the major part of the power is due to wing inertia, and the elastic storage of negative work can decrease the specific power by approximately 33%. (3) For the case of power being mainly contributed by aerodynamic force (fruit fly, cranefly, ladybird and hawkmoth), the specific power is proportional to the product of the wingbeat frequency, the stroke amplitude, the wing length and the drag-to-lift ratio. For the case of power being mainly contributed by wing inertia (hoverfly, dronefly, honey bee and bumble bee), the specific power (without

  10. Challenging Pneumatic Requirements for Acoustic Testing of the Cryogenic Second Stage for the New Delta 3 Rocket

    NASA Technical Reports Server (NTRS)

    Webb, Andrew T.

    1998-01-01

    The paper describes the unique pneumatic test requirements for the acoustic and shock separation testing of the Second Stage for the new Delta III Rocket at the Goddard Space Flight Center in Greenbelt, Maryland. The testing was conducted in the 45,000 cu ft (25-feet wide by 30-feet deep by 50-foot high) Acoustic Facility. The acoustic testing required that the liquid oxygen (LOX) and liquid hydrogen (LH2) tanks be filled with enough liquid nitrogen (LN2) to simulate launch fuel masses during testing. The challenge for this test dealt with designing, procuring, and fabricating the pneumatic supply systems for quick assembly while maintaining the purity requirements and minimizing costs. The pneumatic systems were designed to fill and drain the both LOX and LH2 tanks as well as to operate the fill/drain and vent valves for each of the tanks. The test criteria for the pneumatic sub-systems consisted of function, cleanliness, availability, and cost. The first criteria, function, required the tanks to be filled and drained in an efficient manner while preventing them from seeing pressures greater than 9 psig which would add a pressure cycle to the tank. An LN2 tanker, borrowed from another NASA facility, served as the pre-cool and drain tanker. Pre-cooling the tanks allowed for more efficient and cost effective transfer from the LN2 delivery tankers. Helium gas, supplied from a high purity tube trailer, was used to pressurize the vapor space above the LN2 pushing it into the drain tanker. The tube trailer also supplied high pressure helium to the vehicle for valve control and component purges. Cleanliness was maintained by proper component selection, end-use particle filtration, and any on-site cleaning determined necessary by testing. In order to meet the availability/cost juggling act, products designed for LOX delivery systems were procured to ensure system compatibility while off the shelf valves and tubing designed for the semiconductor industry were procured for

  11. Perception of power modulation of light in conjunction with acoustic stimulation

    NASA Astrophysics Data System (ADS)

    Hahlweg, Cornelius F.; Weyer, Cornelia; Gercke-Hahn, Harald; Gutzmann, Holger L.; Brahmann, Andre; Rothe, Hendrik

    2013-09-01

    The present paper is derived from an ongoing study on the human perception of combined optical and acoustical periodical stimuli. Originating from problems of occupational medicine concerning artificial illumination and certain machinery with coherent optical and acoustical emissions there are effects which are interesting in the context of Optics and Music. Because of the difficulties in evaluation of physical and psychological effects of such coherent stimuli in a first step we questioned if such coherence is perceivable at all. Concept, experimental set-up and first results are discussed in short.

  12. A high-powered siren for stable acoustic levitation of dense materials in the earth's gravity

    NASA Technical Reports Server (NTRS)

    Gammel, Paul M.; Croonquist, Arvid P.; Wang, Taylor G.

    1988-01-01

    Levitation of large dense samples (e.g., 1-cm diameter steel balls) has been performed in a 1-g environment. A siren was used to study the effects of reflector geometry and variable-frequency operation in order to attain stable acoustic positioning. The harmonic content and spatial distribution of the acoustic field have been investigated. The best stability was obtained with an open reflector system, using a flat lower reflector and a slightly concave upper reflector while operating at a frequency slightly below resonance.

  13. Advanced Distributed Measurements and Data Processing at the Vibro-Acoustic Test Facility, GRC Space Power Facility, Sandusky, Ohio - an Architecture and an Example

    NASA Technical Reports Server (NTRS)

    Hill, Gerald M.; Evans, Richard K.

    2009-01-01

    A large-scale, distributed, high-speed data acquisition system (HSDAS) is currently being installed at the Space Power Facility (SPF) at NASA Glenn Research Center s Plum Brook Station in Sandusky, OH. This installation is being done as part of a facility construction project to add Vibro-acoustic Test Capabilities (VTC) to the current thermal-vacuum testing capability of SPF in support of the Orion Project s requirement for Space Environments Testing (SET). The HSDAS architecture is a modular design, which utilizes fully-remotely managed components, enables the system to support multiple test locations with a wide-range of measurement types and a very large system channel count. The architecture of the system is presented along with details on system scalability and measurement verification. In addition, the ability of the system to automate many of its processes such as measurement verification and measurement system analysis is also discussed.

  14. Estimates of power requirements for a Manned Mars Rover powered by a nuclear reactor

    NASA Technical Reports Server (NTRS)

    Morley, Nicholas J.; El-Genk, Mohamed S.; Cataldo, Robert; Bloomfield, Harvey

    1991-01-01

    This paper assesses the power requirement for a Manned Mars Rover vehicle. Auxiliary power needs are fulfilled using a hybrid solar photovoltaic/regenerative fuel cell system, while the primary power needs are meet using an SP-100 type reactor. The primary electric power needs, which include 30-kW(e) net user power, depend on the reactor thermal power and the efficiency of the power conversion system. Results show that an SP-100 type reactor coupled to a Free Piston Stirling Engine yields the lowest total vehicle mass and lowest specific mass for the power system. The second lowest mass was for a SP-100 reactor coupled to a Closed Brayton Cycle using He/Xe as the working fluid. The specific mass of the nuclear reactor power system, including a man-rated radiation shield, ranged from 150-kg/kW(e) to 190-kg/KW(e) and the total mass of the Rover vehicle varied depend upon the cruising speed.

  15. Estimates of power requirements for a Manned Mars Rover powered by a nuclear reactor

    NASA Astrophysics Data System (ADS)

    Morley, Nicholas J.; El-Genk, Mohamed S.; Cataldo, Robert; Bloomfield, Harvey

    This paper assesses the power requirement for a Manned Mars Rover vehicle. Auxiliary power needs are fulfilled using a hybrid solar photovoltaic/regenerative fuel cell system, while the primary power needs are meet using an SP-100 type reactor. The primary electric power needs, which include 30-kW(e) net user power, depend on the reactor thermal power and the efficiency of the power conversion system. Results show that an SP-100 type reactor coupled to a Free Piston Stirling Engine yields the lowest total vehicle mass and lowest specific mass for the power system. The second lowest mass was for a SP-100 reactor coupled to a Closed Brayton Cycle using He/Xe as the working fluid. The specific mass of the nuclear reactor power system, including a man-rated radiation shield, ranged from 150-kg/kW(e) to 190-kg/KW(e) and the total mass of the Rover vehicle varied depend upon the cruising speed.

  16. Estimates of power requirements for a manned Mars rover powered by a nuclear reactor

    NASA Astrophysics Data System (ADS)

    Morley, Nicholas J.; El-Genk, Mohamed S.; Cataldo, Robert; Bloomfield, Harvey

    1991-01-01

    This paper assesses the power requirement for a Manned Mars Rover vehicle. Auxiliary power needs are fulfilled using a hybrid solar photovoltaic/regenerative fuel cell system, while the primary power needs are met using an SP-100 type reactor. The primary electric power needs, which include 30-kWe net user power, depend on the reactor thermal power and the efficiency of the power conversion system. Results show that an SP-100 type reactor coupled to a Free Piston Stirling Engine (FPSE) yields the lowest total vehicle mass and lowest specific mass for the power system. The second lowest mass was for a SP-100 reactor coupled to a Closed Brayton Cycle (CBC) using He/Xe as the working fluid. The specific mass of the nuclear reactor power systrem, including a man-rated radiation shield, ranged from 150-kg/kWe to 190-kg/kWe and the total mass of the Rover vehicle varied depend upon the cruising speed.

  17. Advanced space power requirements and techniques. Task 1: Mission projections and requirements. Volume 1: Technical report

    NASA Technical Reports Server (NTRS)

    Wolfe, M. G.

    1978-01-01

    The objectives of this study were to: (1) develop projections of the NASA, DoD, and civil space power requirements for the 1980-1995 time period; (2) identify specific areas of application and space power subsystem type needs for each prospective user; (3) document the supporting and historical base, including relevant cost related measures of performance; and (4) quantify the benefits of specific technology projection advancements. The initial scope of the study included: (1) construction of likely models for NASA, DoD, and civil space systems; (2) generation of a number of future scenarios; (3) extraction of time phased technology requirements based on the scenarios; and (4) cost/benefit analyses of some of the technologies identified.

  18. The effect of the size of the opening on the acoustic power radiated by a reed woodwind instrument

    NASA Astrophysics Data System (ADS)

    Guilloteau, Alexis; Guillemain, Philippe; Kergomard, Jean; Jousserand, Michael

    2015-05-01

    For a given note, the maker of woodwind instruments can choose between different sizes for the toneholes under the condition that the location is appropriate. The present paper aims at analyzing the consequences of this choice on the power radiated by a hole, which depends on the coupling between the acoustic resonator and the excitation mechanism of the self-sustained oscillation, thus on the blowing pressure. For that purpose a simplified reed instrument is investigated, with a cylindrical pipe and a unique orifice at the pipe termination. The orifice diameter was varied between the pipe diameter and a size such that the instrument did not play. The pipe length was in each case adjusted to keep the resonance frequency constant. A simple analytical model predicts that, for a given mouth pressure of the instrumentalist, the radiated power does not depend on the size of the hole if it is wide enough and if resonator losses are ignored. Numerical solution of a model including losses confirms this result: the difference in radiated power between two diaphragm sizes remains smaller than the difference obtained if the radiated power would be proportional to the orifice cross section area. This is confirmed by experiments using an artificial mouth, but the results show that the linear losses are underestimated, and that significant nonlinear losses occur. The measurements are limited to the acoustic pressure at a given distance of the orifice. Experiments also show that rounding edges of the orifice reduces nonlinear losses resulting in an increase of the power radiated and of the extinction threshold, and resulting in a larger dynamical range.

  19. Unveiling acoustic physics of the CMB using nonparametric estimation of the temperature angular power spectrum for Planck

    SciTech Connect

    Aghamousa, Amir; Shafieloo, Arman; Arjunwadkar, Mihir; Souradeep, Tarun E-mail: shafieloo@kasi.re.kr E-mail: tarun@iucaa.ernet.in

    2015-02-01

    Estimation of the angular power spectrum is one of the important steps in Cosmic Microwave Background (CMB) data analysis. Here, we present a nonparametric estimate of the temperature angular power spectrum for the Planck 2013 CMB data. The method implemented in this work is model-independent, and allows the data, rather than the model, to dictate the fit. Since one of the main targets of our analysis is to test the consistency of the ΛCDM model with Planck 2013 data, we use the nuisance parameters associated with the best-fit ΛCDM angular power spectrum to remove foreground contributions from the data at multipoles ℓ ≥50. We thus obtain a combined angular power spectrum data set together with the full covariance matrix, appropriately weighted over frequency channels. Our subsequent nonparametric analysis resolves six peaks (and five dips) up to ℓ ∼1850 in the temperature angular power spectrum. We present uncertainties in the peak/dip locations and heights at the 95% confidence level. We further show how these reflect the harmonicity of acoustic peaks, and can be used for acoustic scale estimation. Based on this nonparametric formalism, we found the best-fit ΛCDM model to be at 36% confidence distance from the center of the nonparametric confidence set—this is considerably larger than the confidence distance (9%) derived earlier from a similar analysis of the WMAP 7-year data. Another interesting result of our analysis is that at low multipoles, the Planck data do not suggest any upturn, contrary to the expectation based on the integrated Sachs-Wolfe contribution in the best-fit ΛCDM cosmology.

  20. Solid Rocket Motor Acoustic Testing

    SciTech Connect

    Rogers, J.D.

    1999-03-31

    Acoustic data are often required for the determination of launch and powered flight loads for rocket systems and payloads. Such data are usually acquired during test firings of the solid rocket motors. In the current work, these data were obtained for two tests at a remote test facility where we were visitors. This paper describes the data acquisition and the requirements for working at a remote site, interfacing with the test hosts.

  1. An experimental device for investigating the force and power requirements of a powered gait orthosis.

    PubMed

    Ruthenberg, B J; Wasylewski, N A; Beard, J E

    1997-04-01

    The Powered Gait Orthosis (PGO) is a powered exoskeleton developed as an experimental device to provide bipedal locomotion to individuals with physical impairment. The current prototype consists of a single degree of freedom (DOF) system for each leg, providing power and proper displacement required for bipedal locomotion. It is the goal of this research to obtain the forces that are present in the device while it is in normal operation. In addition, the time ratio of the hip function generator has been varied to determine the effect that different time ratios have on system forces and required user energy. The time ratio is the relationship between the time period that the thigh is in swing phase and when it is in support phase. Knowing the forces in the system and the optimal time ratio will allow for the design and construction of a feasible device for the rehabilitation and assistance of individuals who have lost the ability to walk. PMID:9108347

  2. Microgravity fluid management requirements of advanced solar dynamic power systems

    NASA Technical Reports Server (NTRS)

    Migra, Robert P.

    1987-01-01

    The advanced solar dynamic system (ASDS) program is aimed at developing the technology for highly efficient, lightweight space power systems. The approach is to evaluate Stirling, Brayton and liquid metal Rankine power conversion systems (PCS) over the temperature range of 1025 to 1400K, identify the critical technologies and develop these technologies. Microgravity fluid management technology is required in several areas of this program, namely, thermal energy storage (TES), heat pipe applications and liquid metal, two phase flow Rankine systems. Utilization of the heat of fusion of phase change materials offers potential for smaller, lighter TES systems. The candidate TES materials exhibit large volume change with the phase change. The heat pipe is an energy dense heat transfer device. A high temperature application may transfer heat from the solar receiver to the PCS working fluid and/or TES. A low temperature application may transfer waste heat from the PCS to the radiator. The liquid metal Rankine PCS requires management of the boiling/condensing process typical of two phase flow systems.

  3. Informatics requirements for a restructured competitive electric power industry

    SciTech Connect

    Pickle, S.; Marnay, C.; Olken, F.

    1996-08-01

    The electric power industry in the United States is undergoing a slow but nonetheless dramatic transformation. It is a transformation driven by technology, economics, and politics; one that will move the industry from its traditional mode of centralized system operations and regulated rates guaranteeing long-run cost recovery, to decentralized investment and operational decisionmaking and to customer access to true spot market prices. This transformation will revolutionize the technical, procedural, and informational requirements of the industry. A major milestone in this process occurred on December 20, 1995, when the California Public Utilities Commission (CPUC) approved its long-awaited electric utility industry restructuring decision. The decision directed the three major California investor-owned utilities to reorganize themselves by the beginning of 1998 into a supply pool, at the same time selling up to a half of their thermal generating plants. Generation will be bid into this pool and will be dispatched by an independent system operator. The dispatch could potentially involve bidders not only from California but from throughout western North America and include every conceivable generating technology and scale of operation. At the same time, large customers and aggregated customer groups will be able to contract independently for their supply and the utilities will be required to offer a real-time pricing tariff based on the pool price to all their customers, including residential. In related proceedings concerning competitive wholesale power markets, the Federal Energy Regulatory Commission (FERC) has recognized that real-time information flows between buyers and sellers are essential to efficient equitable market operation. The purpose of this meeting was to hold discussions on the information technologies that will be needed in the new, deregulated electric power industry.

  4. Supplying the power requirements to a sensor network using radio frequency power transfer.

    PubMed

    Percy, Steven; Knight, Chris; Cooray, Francis; Smart, Ken

    2012-01-01

    Wireless power transmission is a method of supplying power to small electronic devices when there is no wired connection. One way to increase the range of these systems is to use a directional transmitting antenna, the problem with this approach is that power can only be transmitted through a narrow beam and directly forward, requiring the transmitter to always be aligned with the sensor node position. The work outlined in this article describes the design and testing of an autonomous radio frequency power transfer system that is capable of rotating the base transmitter to track the position of sensor nodes and transferring power to that sensor node. The system's base station monitors the node's energy levels and forms a charge queue to plan charging order and maintain energy levels of the nodes. Results show a radio frequency harvesting circuit with a measured S11 value of -31.5 dB and a conversion efficiency of 39.1%. Simulation and experimentation verified the level of power transfer and efficiency. The results of this work show a small network of three nodes with different storage types powered by a central base node. PMID:23012506

  5. Generation of Acoustic Gravity Waves by Periodic Radio Transmissions from a High-Power Ionospheric Heater

    NASA Astrophysics Data System (ADS)

    Frolov, Vladimir; Chernogor, Leonid; Rozumenko, Victor

    The Radiophysical Research Institute (Nizhny Novgorod, Russia) and Kharkiv V. N. Karazin National University (Kharkiv, Ukraine) have studied opportunities for the effective generation of acoustic gravity waves (AGWs) in 3 - 180-min period range. The excitation of such waves was conducted for the last several years using the SURA heating facility (Nizhny Novgorod). The detection of the HF-induced AGWs was carried out in the Radiophysical Observatory located near Kharkiv City at a distance of about 960 km from the SURA. A coherent radar for vertical sounding, an ionosonde, and magnetometer chains were used in our measurements. The main results are the following (see [1-5]): 1. Infrasound oscillation trains with a period of 6 min are detected during periodic SURA heater turn-on and -off. Similar oscillation trains are detected after long time pumping, during periodic transmissions with a period of 20 s, as well as after pumping turn-off. The train recordings begin 28 - 54 min after the heater turn-on or -off, and the train propagation speeds are about 300 - 570 m/s, the value of which is close to the sound speed at upper atmospheric altitudes. The amplitude of the Doppler shift frequency is of 10 - 40 mHz, which fits to the 0.1 - 0.3% electron density disturbances at ionospheric altitudes. The amplitude of the infrasound oscillations depends on the SURA mode of operation and the state of the upper atmosphere and ionosphere. 2. High-power radio transmissions stimulate the generation (or enhancement) of waves at ionospheric altitudes in the range of internal gravity wave periods. The HF-induced waves propagate with speeds of 360 - 460 m/s and produce changes in electron density with amplitudes of 2 - 3%. The generation of such periodic perturbations is more preferable with periods of 10 - 60 minutes. Their features depend significantly on the heater mode of operation. It should be stressed that perturbation intensity increases when a pumping wave frequency approaches

  6. Review of power requirements for satellite remote sensing systems

    NASA Technical Reports Server (NTRS)

    Morain, Stanley A.

    1988-01-01

    The space environment offers a multitude of attributes and opportunities to be used to enhance human life styles and qualities of life for all future generations, worldwide. Among the prospects having immense social as well as economic benefits are earth-observing systems capable of providing near real-time data in such areas as food and fiber production, marine fisheries, ecosystem monitoring, disaster assessment, and global environmental exchanges. The era of Space Station, the Shuttle program, the planned unmanned satellites in both high and low Earth orbit will transfer to operational status what, until now, has been largely research and development proof of concept for remotely sensing Earth's natural and cultural resources. An important aspect of this operational status focuses on the orbital designs and power requirements needed to optimally sense any of these important areas.

  7. 26 CFR 601.503 - Requirements of power of attorney, signatures, fiduciaries and Commissioner's authority to...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 20 2011-04-01 2011-04-01 false Requirements of power of attorney, signatures... STATEMENT OF PROCEDURAL RULES Conference and Practice Requirements § 601.503 Requirements of power of...) Requirements. A power of attorney must contain the following information— (1) Name and mailing address of...

  8. 26 CFR 601.503 - Requirements of power of attorney, signatures, fiduciaries and Commissioner's authority to...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 20 2014-04-01 2014-04-01 false Requirements of power of attorney, signatures... STATEMENT OF PROCEDURAL RULES Conference and Practice Requirements § 601.503 Requirements of power of...) Requirements. A power of attorney must contain the following information— (1) Name and mailing address of...

  9. 26 CFR 601.503 - Requirements of power of attorney, signatures, fiduciaries and Commissioner's authority to...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 20 2012-04-01 2012-04-01 false Requirements of power of attorney, signatures... STATEMENT OF PROCEDURAL RULES Conference and Practice Requirements § 601.503 Requirements of power of...) Requirements. A power of attorney must contain the following information— (1) Name and mailing address of...

  10. 26 CFR 601.503 - Requirements of power of attorney, signatures, fiduciaries and Commissioner's authority to...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 20 2013-04-01 2013-04-01 false Requirements of power of attorney, signatures... STATEMENT OF PROCEDURAL RULES Conference and Practice Requirements § 601.503 Requirements of power of...) Requirements. A power of attorney must contain the following information— (1) Name and mailing address of...

  11. 26 CFR 601.503 - Requirements of power of attorney, signatures, fiduciaries and Commissioner's authority to...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 20 2010-04-01 2010-04-01 false Requirements of power of attorney, signatures... STATEMENT OF PROCEDURAL RULES Conference and Practice Requirements § 601.503 Requirements of power of...) Requirements. A power of attorney must contain the following information— (1) Name and mailing address of...

  12. Air Force space power and thermal management technology - Requirements for the early 21st century

    NASA Astrophysics Data System (ADS)

    Herrera, Ernest D.; Kuck, Inara

    Typical projections for military space power and thermal management technologies have posited requirements for high powered and highly survivable systems. Recent changes in defense needs, however, will require spacecraft that are smaller, lower powered, less survivable, and highly proliferated. Technologies will be developed to provide low cost, ultra-light, high power density, 'smart' conventional power systems. Compact nuclear power systems will also be developed to meet higher power needs.

  13. Acoustic neuroma

    MedlinePlus

    Vestibular schwannoma; Tumor - acoustic; Cerebellopontine angle tumor; Angle tumor ... Acoustic neuromas have been linked with the genetic disorder neurofibromatosis type 2 (NF2). Acoustic neuromas are uncommon.

  14. Electromagnetic Launch Vehicle Fairing and Acoustic Blanket Model of Received Power Using FEKO

    NASA Technical Reports Server (NTRS)

    Trout, Dawn H.; Stanley, James E.; Wahid, Parveen F.

    2011-01-01

    Evaluating the impact of radio frequency transmission in vehicle fairings is important to sensitive spacecraft. This paper employees the Multilevel Fast Multipole Method (MLFMM) feature of a commercial electromagnetic tool to model the fairing electromagnetic environment in the presence of an internal transmitter. This work is an extension of the perfect electric conductor model that was used to represent the bare aluminum internal fairing cavity. This fairing model includes typical acoustic blanketing commonly used in vehicle fairings. Representative material models within FEKO were successfully used to simulate the test case.

  15. Some Problems of modern acoustics

    NASA Technical Reports Server (NTRS)

    Stan, A.

    1974-01-01

    The multidisciplinary and interdisciplinary character of acoustics is considered and its scientific, technological, economical and social implications, as well as the role of acoustics in creating new machines and equipment and improving the quality of products are outlined. Research beyond audible frequencies, as well as to extremely high acoustic intensities, which requires the development of a nonlinear acoustics is elaborated.

  16. Acoustic impedance microscopy for biological tissue characterization.

    PubMed

    Kobayashi, Kazuto; Yoshida, Sachiko; Saijo, Yoshifumi; Hozumi, Naohiro

    2014-09-01

    A new method for two-dimensional acoustic impedance imaging for biological tissue characterization with micro-scale resolution was proposed. A biological tissue was placed on a plastic substrate with a thickness of 0.5mm. A focused acoustic pulse with a wide frequency band was irradiated from the "rear side" of the substrate. In order to generate the acoustic wave, an electric pulse with two nanoseconds in width was applied to a PVDF-TrFE type transducer. The component of echo intensity at an appropriate frequency was extracted from the signal received at the same transducer, by performing a time-frequency domain analysis. The spectrum intensity was interpreted into local acoustic impedance of the target tissue. The acoustic impedance of the substrate was carefully assessed prior to the measurement, since it strongly affects the echo intensity. In addition, a calibration was performed using a reference material of which acoustic impedance was known. The reference material was attached on the same substrate at different position in the field of view. An acoustic impedance microscopy with 200×200 pixels, its typical field of view being 2×2 mm, was obtained by scanning the transducer. The development of parallel fiber in cerebella cultures was clearly observed as the contrast in acoustic impedance, without staining the specimen. The technique is believed to be a powerful tool for biological tissue characterization, as no staining nor slicing is required. PMID:24852259

  17. Near-Field Acoustic Power Level Analysis of F31/A31 Open Rotor Model at Simulated Cruise Conditions, Technical Report II

    NASA Technical Reports Server (NTRS)

    Sree, Dave

    2015-01-01

    Near-field acoustic power level analysis of F31A31 open rotor model has been performed to determine its noise characteristics at simulated cruise flight conditions. The non-proprietary parts of the test data obtained from experiments in the 8x6 supersonic wind tunnel were provided by NASA-Glenn Research Center. The tone and broadband components of total noise have been separated from raw test data by using a new data analysis tool. Results in terms of sound pressure levels, acoustic power levels, and their variations with rotor speed, freestream Mach number, and input shaft power, with different blade-pitch setting angles at simulated cruise flight conditions, are presented and discussed. Empirical equations relating models acoustic power level and input shaft power have been developed. The near-field acoustic efficiency of the model at simulated cruise conditions is also determined. It is hoped that the results presented in this work will serve as a database for comparison and improvement of other open rotor blade designs and also for validating open rotor noise prediction codes.

  18. The Acoustic Analogy: A Powerful Tool in Aeroacoustics with Emphasis on Jet Noise Prediction

    NASA Technical Reports Server (NTRS)

    Farassat, F.; Doty, Michael J.; Hunter, Craig A.

    2004-01-01

    The acoustic analogy introduced by Lighthill to study jet noise is now over 50 years old. In the present paper, Lighthill s Acoustic Analogy is revisited together with a brief evaluation of the state-of-the-art of the subject and an exploration of the possibility of further improvements in jet noise prediction from analytical methods, computational fluid dynamics (CFD) predictions, and measurement techniques. Experimental Particle Image Velocimetry (PIV) data is used both to evaluate turbulent statistics from Reynolds-averaged Navier-Stokes (RANS) CFD and to propose correlation models for the Lighthill stress tensor. The NASA Langley Jet3D code is used to study the effect of these models on jet noise prediction. From the analytical investigation, a retarded time correction is shown that improves, by approximately 8 dB, the over-prediction of aft-arc jet noise by Jet3D. In experimental investigation, the PIV data agree well with the CFD mean flow predictions, with room for improvement in Reynolds stress predictions. Initial modifications, suggested by the PIV data, to the form of the Jet3D correlation model showed no noticeable improvements in jet noise prediction.

  19. Acoustic methods of remote probing of the lower atmosphere

    NASA Technical Reports Server (NTRS)

    Little, C. G.

    1969-01-01

    The potential usefulness of acoustic methods for the remote probing of the lower atmosphere is reviewed. Starting with a comparison of the effects of temperature, wind, and humidity fluctuations upon the refractive index of air to electromagnetic and acoustic waves, it is shown that the fluctuations in acoustic refractive index may be expected to be about one thousand times stronger than in the radio case. Since the scattered power is proportional to the square of the refractive index fluctuations, the scatter of acoustic waves may be expected to be roughly one million times stronger than for radio waves. In addition, the million-fold ratio between the velocities of electromagnetic and acoustic waves results in an acoustic system requiring one million times less bandwidth to interrogate a given atmospheric volume.

  20. 18 CFR 284.504 - Standard requirements for market-power authorizations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Standard requirements for market-power authorizations. 284.504 Section 284.504 Conservation of Power and Water Resources....504 Standard requirements for market-power authorizations. (a) Applicants granted the authority...

  1. 18 CFR 284.504 - Standard requirements for market-power authorizations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Standard requirements for market-power authorizations. 284.504 Section 284.504 Conservation of Power and Water Resources....504 Standard requirements for market-power authorizations. (a) Applicants granted the authority...

  2. 46 CFR 58.30-50 - Requirements for miscellaneous fluid power and control systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Requirements for miscellaneous fluid power and control...) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-50 Requirements for miscellaneous fluid power and control systems. (a) All fluid power and...

  3. 46 CFR 58.30-50 - Requirements for miscellaneous fluid power and control systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Requirements for miscellaneous fluid power and control...) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-50 Requirements for miscellaneous fluid power and control systems. (a) All fluid power and...

  4. 46 CFR 58.30-50 - Requirements for miscellaneous fluid power and control systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Requirements for miscellaneous fluid power and control...) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-50 Requirements for miscellaneous fluid power and control systems. (a) All fluid power and...

  5. 46 CFR 58.30-50 - Requirements for miscellaneous fluid power and control systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Requirements for miscellaneous fluid power and control...) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-50 Requirements for miscellaneous fluid power and control systems. (a) All fluid power and...

  6. 46 CFR 58.30-50 - Requirements for miscellaneous fluid power and control systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Requirements for miscellaneous fluid power and control...) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-50 Requirements for miscellaneous fluid power and control systems. (a) All fluid power and...

  7. Acoustic agglomeration of power-plant fly ash. A comprehensive semi-annual progress report

    SciTech Connect

    Reethof, G.

    1980-02-01

    Results obtained during the reporting period are presented. The agglomeration of submicron fly ash particles has been studied as a function of sound pressure level, sound frequency, loading, and exposure time. A second generation model of the agglomeration process is being developed. A high-frequency, high-intensity variable speed siren delivering at least 600 W at frequencies up to 4000 Hz has been developed and tested. Details on the design and operation are presented. The agglomeration chamber has been completely cleaned and the aerosol generating system has been rebuilt. A mathematical model of the acoustics of agglomeration is being developed. Preliminary results of computerized electron microscopic scanning of fly ash particles during agglomeration are presented. (DMC)

  8. Acoustic emission monitoring for inspection of seam-welded hot reheat piping in fossil power plants

    NASA Astrophysics Data System (ADS)

    Rodgers, John M.; Morgan, Bryan C.; Tilley, Richard M.

    1996-11-01

    Although failure of the seam weld on reheat steam piping has been an infrequent occurrence, such failure is still a major safety concern for fossil plant operations. EPRI has provided guidelines for a piping management program base don periodic inspection. More recently, EPRI has also sponsored research to develop inspection techniques to both improve the quality and reduce the cost of piping inspections. Foremost in this research has been the use of acoustic emission (AE) techniques to detect crack damage in seam welds. AE has the substantial cost advantages of both allowing inspection without full removal of the thermal insulation on the reheat piping and making short-re- inspection intervals practical. This paper reviews the EPRI guidelines for performing an AE inspection on seam-welded hot reheat piping.

  9. Electromagnetic Launch Vehicle Fairing and Acoustic Blanket Model of Received Power Using FEKO

    NASA Technical Reports Server (NTRS)

    Trout, Dawn H.; Stanley, James E.; Wahid, Parveen F.

    2011-01-01

    Evaluating the impact of radio frequency transmission in vehicle fairings is important to electromagnetically sensitive spacecraft. This study employs the multilevel fast multipole method (MLFMM) from a commercial electromagnetic tool, FEKO, to model the fairing electromagnetic environment in the presence of an internal transmitter with improved accuracy over industry applied techniques. This fairing model includes material properties representative of acoustic blanketing commonly used in vehicles. Equivalent surface material models within FEKO were successfully applied to simulate the test case. Finally, a simplified model is presented using Nicholson Ross Weir derived blanket material properties. These properties are implemented with the coated metal option to reduce the model to one layer within the accuracy of the original three layer simulation.

  10. Time-domain simulation of constitutive relations for nonlinear acoustics including relaxation for frequency power law attenuation media modeling

    NASA Astrophysics Data System (ADS)

    Jiménez, Noé; Camarena, Francisco; Redondo, Javier; Sánchez-Morcillo, Víctor; Konofagou, Elisa E.

    2015-10-01

    We report a numerical method for solving the constitutive relations of nonlinear acoustics, where multiple relaxation processes are included in a generalized formulation that allows the time-domain numerical solution by an explicit finite differences scheme. Thus, the proposed physical model overcomes the limitations of the one-way Khokhlov-Zabolotskaya-Kuznetsov (KZK) type models and, due to the Lagrangian density is implicitly included in the calculation, the proposed method also overcomes the limitations of Westervelt equation in complex configurations for medical ultrasound. In order to model frequency power law attenuation and dispersion, such as observed in biological media, the relaxation parameters are fitted to both exact frequency power law attenuation/dispersion media and also empirically measured attenuation of a variety of tissues that does not fit an exact power law. Finally, a computational technique based on artificial relaxation is included to correct the non-negligible numerical dispersion of the finite difference scheme, and, on the other hand, improve stability trough artificial attenuation when shock waves are present. This technique avoids the use of high-order finite-differences schemes leading to fast calculations. The present algorithm is especially suited for practical configuration where spatial discontinuities are present in the domain (e.g. axisymmetric domains or zero normal velocity boundary conditions in general). The accuracy of the method is discussed by comparing the proposed simulation solutions to one dimensional analytical and k-space numerical solutions.

  11. An Overview of Power Capability Requirements for Exploration Missions

    NASA Technical Reports Server (NTRS)

    Davis, Jose M.; Cataldo, Robert L.; Soeder, James F.; Manzo, Michelle A.; Hakimzadeh, Roshanak

    2005-01-01

    Advanced power is one of the key capabilities that will be needed to achieve NASA's missions of exploration and scientific advancement. Significant gaps exist in advanced power capabilities that are on the critical path to enabling human exploration beyond Earth orbit and advanced robotic exploration of the solar system. Focused studies and investment are needed to answer key development issues for all candidate technologies before down-selection. The viability of candidate power technology alternatives will be a major factor in determining what exploration mission architectures are possible. Achieving the capabilities needed to enable the CEV, Moon, and Mars missions is dependent on adequate funding. Focused investment in advanced power technologies for human and robotic exploration missions is imperative now to reduce risk and to make informed decisions on potential exploration mission decisions beginning in 2008. This investment would begin the long lead-time needed to develop capabilities for human exploration missions in the 2015 to 2030 timeframe. This paper identifies some of the key technologies that will be needed to fill these power capability gaps. Recommendations are offered to address capability gaps in advanced power for Crew Exploration Vehicle (CEV) power, surface nuclear power systems, surface mobile power systems, high efficiency power systems, and space transportation power systems. These capabilities fill gaps that are on the critical path to enabling robotic and human exploration missions. The recommendations address the following critical technology areas: Energy Conversion, Energy Storage, and Power Management and Distribution.

  12. Pseudopotential approach for dust acoustic solitary waves in dusty plasmas with kappa-distributed ions and electrons and dust grains having power law size distribution

    SciTech Connect

    Banerjee, Gadadhar; Maitra, Sarit

    2015-04-15

    Sagdeev's pseudopotential method is used to study small as well as arbitrary amplitude dust acoustic solitons in a dusty plasma with kappa distributed electrons and ions with dust grains having power law size distribution. The existence of potential well solitons has been shown for suitable parametric region. The criterion for existence of soliton is derived in terms of upper and lower limit for Mach numbers. The numerical results show that the size distribution can affect the existence as well as the propagation characteristics of the dust acoustic solitons. The effect of kappa distribution is also highlighted.

  13. Improved Hard Lower Bounds on the Geodynamo Power Requirements

    NASA Astrophysics Data System (ADS)

    Livermore, P. W.; Ierley, G.

    2007-12-01

    The Earth's thermal history is currently undergoing renewed scrutiny, the age of the inner core taking center stage of the debate. A key element of the controversy is estimates of the power required to drive the geodynamo or, equivalently, the power lost to Ohmic dissipation in the core. A recent prominent estimate of 1-2 TW (Roberts et al. 2003) presents substantial difficulty in forming a consistent Earth model, as the associated high heat flux leaking out of the core- mantle boundary would cool the core too fast, leading to an inner core far younger than expected. A current high- profile theory that sidesteps this difficulty suggests the existence of radiogenic heating in the core, reducing the solidification rate for a prescribed heat flux. Other lower estimates of 0.1-0.5 TW (Christensen & Tilgner, 2004) on the Ohmic dissipation do not require such a source of energy to explain an old inner core, of age comparable to that of the geomagnetic field. The current estimates of Ohmic dissipation are based on numerical geodynamo simulations, computations currently performed with parameter values far from those that are geophysically realistic. Despite the resulting magnetic and velocity fields being arguably at least Earth-like, the extrapolation of such models to the real Earth is nonetheless no more than suggestive. We present results concerning rigorous lower bounds on the Ohmic dissipation associated with the present day field. A lower bound exceeding any existing estimate would immediately rule that estimate as invalid; a sufficiently high value would lead to the inescapable inference of radiogenic heating in order to explain an old inner core. We build on previous work (Jackson and Livermore, 2007), where we considered the minimum Ohmic dissipation subject to various constraints: the field structure on the core-mantle boundary derived from observations of the present day geomagnetic field, and Earth-nutation models (Buffett et al. 2002) that predict rms field

  14. Low power underwater acoustic DPSK detection: Theoretical prediction and experimental results

    NASA Astrophysics Data System (ADS)

    Dunne, Andrew

    This thesis presents two methods of analyzing the effectiveness of a prototype differential phase-shift keying (DPSK) detection circuit. The first method is to make modifications to the existing hardware to reliably output and record the cross-correlation values of the DPSK detection process. The second method is to write a MATLAB detection algorithm which accurately simulates the detection results of the hardware system without the need of any electronics. These two systems were tested and verified with a bench test using computer generated DPSK signals. The hardware system was tested using real acoustic data from shallow and deep water at-sea tests to determine the effectiveness of the DPSK detection circuit in different ocean environments. The hydrophone signals from the tests were recorded so that the cross-correlation values could be verified using the MATLAB detector. As a result of this study, these two systems provided more insight into how well the DPSK detection prototype works and helped to identify ways of improving the detection reliability and overall performance of the prototype DPSK detection circuit.

  15. Manpower Requirements in the Nuclear Power Industry, 1982-1991.

    ERIC Educational Resources Information Center

    Johnson, Ruth C.

    A study projected employment needs created by growth and employee turnover for the nuclear power industry over the next decade. Only employment by electric utilities in the commercial generation of nuclear power was investigated. Employment data for 1981 were collected in a survey of 60 member utilities of the Institute of Nuclear Power…

  16. The Development of the Acoustic Design of NASA Glenn Research Center's New Reverberant Acoustic Test Facility

    NASA Technical Reports Server (NTRS)

    Hughes, William O.; McNelis, Mark E.; Hozman, Aron D.; McNelis, Anne M.

    2011-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is leading the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC's Plum Brook Station in Sandusky, Ohio, USA. Benham Companies, LLC is currently constructing modal, base-shake sine and reverberant acoustic test facilities to support the future testing needs of NASA s space exploration program. The large Reverberant Acoustic Test Facility (RATF) will be approximately 101,000 ft3 in volume and capable of achieving an empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world s known active reverberant acoustic test facilities. The key to achieving the expected acoustic test spectra for a range of many NASA space flight environments in the RATF is the knowledge gained from a series of ground acoustic tests. Data was obtained from several NASA-sponsored test programs, including testing performed at the National Research Council of Canada s acoustic test facility in Ottawa, Ontario, Canada, and at the Redstone Technical Test Center acoustic test facility in Huntsville, Alabama, USA. The majority of these tests were performed to characterize the acoustic performance of the modulators (noise generators) and representative horns that would be required to meet the desired spectra, as well as to evaluate possible supplemental gas jet noise sources. The knowledge obtained in each of these test programs enabled the design of the RATF sound generation system to confidently advance to its final acoustic design and subsequent on-going construction.

  17. The Development of the Acoustic Design of NASA Glenn Research Center's New Reverberant Acoustic Test Facility

    NASA Technical Reports Server (NTRS)

    Hughes, William O.; McNelis, Mark E.; Hozman, Aron D.; McNelis, Anne M.

    2011-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is leading the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC s Plum Brook Station in Sandusky, Ohio. Benham Companies, LLC is currently constructing modal, base-shake sine and reverberant acoustic test facilities to support the future testing needs of NASA s space exploration program. The large Reverberant Acoustic Test Facility (RATF) will be approximately 101,000 ft3 in volume and capable of achieving an empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world s known active reverberant acoustic test facilities. The key to achieving the expected acoustic test spectra for a range of many NASA space flight environments in the RATF is the knowledge gained from a series of ground acoustic tests. Data was obtained from several NASA-sponsored test programs, including testing performed at the National Research Council of Canada s acoustic test facility in Ottawa, Ontario, Canada, and at the Redstone Technical Test Center acoustic test facility in Huntsville, Alabama. The majority of these tests were performed to characterize the acoustic performance of the modulators (noise generators) and representative horns that would be required to meet the desired spectra, as well as to evaluate possible supplemental gas jet noise sources. The knowledge obtained in each of these test programs enabled the design of the RATF sound generation system to confidently advance to its final acoustic design and subsequent on-going construction.

  18. Acoustical Environment of School Buildings.

    ERIC Educational Resources Information Center

    Fitzroy, Dariel; Reid, John L.

    A field study was made of the acoustical environment of schools designed for increased flexibility to meet the spatial requirements of new teaching methods. The object of the study was to define all the criteria for the acoustical design of this type of classroom including the determination of--(1) minimum acoustical separation required for…

  19. ACOUSTICAL ENVIRONMENT OF SCHOOL BUILDINGS.

    ERIC Educational Resources Information Center

    FITZROY, DARIEL; REID, JOHN L.

    A FIELD STUDY WAS MADE OF THE ACOUSTICAL ENVIRONMENT OF SCHOOLS DESIGNED FOR INCREASED FLEXIBILITY TO MEET THE SPATIAL REQUIREMENTS OF NEW TEACHING METHODS. THE OBJECT OF THE STUDY WAS TO DEFINE ALL THE CRITERIA FOR THE ACOUSTICAL DESIGN OF THIS TYPE OF CLASSROOM INCLUDING THE DETERMINATION OF--(1) MINIMUM ACOUSTICAL SEPARATION REQUIRED FOR…

  20. 10 CFR 73.58 - Safety/security interface requirements for nuclear power reactors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Safety/security interface requirements for nuclear power reactors. 73.58 Section 73.58 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PHYSICAL PROTECTION OF... requirements for nuclear power reactors. (a) Each operating nuclear power reactor licensee with a...

  1. 10 CFR 73.58 - Safety/security interface requirements for nuclear power reactors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Safety/security interface requirements for nuclear power reactors. 73.58 Section 73.58 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PHYSICAL PROTECTION OF... requirements for nuclear power reactors. (a) Each operating nuclear power reactor licensee with a...

  2. 42 CFR 84.146 - Method of measuring the power and torque required to operate blowers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...—Apparatus for measuring power required to operate blower. (42 CFR part 84, subpart J, § 84.146) EC01FE91.050 ... 42 Public Health 1 2010-10-01 2010-10-01 false Method of measuring the power and torque required... RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.146 Method of measuring the power and...

  3. 42 CFR 84.146 - Method of measuring the power and torque required to operate blowers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...—Apparatus for measuring power required to operate blower. (42 CFR part 84, subpart J, § 84.146) EC01FE91.050 ... 42 Public Health 1 2013-10-01 2013-10-01 false Method of measuring the power and torque required... RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.146 Method of measuring the power and...

  4. 42 CFR 84.146 - Method of measuring the power and torque required to operate blowers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...—Apparatus for measuring power required to operate blower. (42 CFR part 84, subpart J, § 84.146) EC01FE91.050 ... 42 Public Health 1 2014-10-01 2014-10-01 false Method of measuring the power and torque required... RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.146 Method of measuring the power and...

  5. 42 CFR 84.146 - Method of measuring the power and torque required to operate blowers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...—Apparatus for measuring power required to operate blower. (42 CFR part 84, subpart J, § 84.146) EC01FE91.050 ... 42 Public Health 1 2011-10-01 2011-10-01 false Method of measuring the power and torque required... RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.146 Method of measuring the power and...

  6. 29 CFR 1919.22 - Requirements governing braking devices and power sources.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... winch, or electric cranes shall be equipped so that a failure of the electric power shall stop the... 29 Labor 7 2010-07-01 2010-07-01 false Requirements governing braking devices and power sources... Requirements governing braking devices and power sources. All types of winches and cranes shall be...

  7. The 25 kW power module evolution study. Part 1: Payload requirements and growth scenarios

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Payload power level requirements and their general impact on the baseline and growth versions of the 25 kW power module during the 1983 to 1990 period are discussed. Extended duration Orbiter sortie flight, supported by a power module, with increased payload power requirements per flight, and free-flyer payload missions are included. Other payload disciplines considered, but not emphasized for the 1983 to 1986 period include astrophysics/astronomy, earth observations, solar power satellite, and life sciences. Of these, only the solar power satellite is a prime driver for the power module.

  8. Manpower requirements in the nuclear power industry, 1982-1991

    SciTech Connect

    Johnson, R.C.

    1982-09-01

    The objective of this study is to project occupational employment needs, created by growth and employee turnover, for the nuclear power industry over the next decade. Employment data for 1981 were collected in a survey conducted by the Institute of Nuclear Power Operations of its 60 member utilities. The data were analyzed statistically to identify factors that account for variations in power plant staffing and the number of off-site nuclear support personnel employed by a utility. Total employment in the nuclear power industry is predicted to increase from 54,400 in 1981 to 73,600 in 1991. Nuclear generating capacity will increase from 58 to 124 gigawatts, based on the midline forecast of the Energy Information Administration. The projections assume that current regulations will remain in effect and no new plans for additional generating facilities will be initiated.

  9. Interface requirements for electric propulsion power processing equipment

    NASA Technical Reports Server (NTRS)

    Biess, J. J.; Schoenfeld, A. D.; Goldin, D. S.; Shank, J. H.

    1973-01-01

    Power processor interfaces, internal functions, and design techniques established for the 30-cm ion engine power processor are discussed. The interfaces include the ion engine interface, the spacecraft interface, source/load interactions, protection, and optimization criteria. In the analysis, particular attention is given to the interaction and protection aspects. A breadbord system designed and built for the 30-cm ion engine is discussed which will be used as an engineering tool to establish guidelines for electric propulsion systems.

  10. Cylindrical acoustic levitator/concentrator

    DOEpatents

    Kaduchak, Gregory; Sinha, Dipen N.

    2002-01-01

    A low-power, inexpensive acoustic apparatus for levitation and/or concentration of aerosols and small liquid/solid samples having particulates up to several millimeters in diameter in air or other fluids is described. It is constructed from a commercially available, hollow cylindrical piezoelectric crystal which has been modified to tune the resonance frequency of the breathing mode resonance of the crystal to that of the interior cavity of the cylinder. When the resonance frequency of the interior cylindrical cavity is matched to the breathing mode resonance of the cylindrical piezoelectric transducer, the acoustic efficiency for establishing a standing wave pattern in the cavity is high. The cylinder does not require accurate alignment of a resonant cavity. Water droplets having diameters greater than 1 mm have been levitated against the force of gravity using; less than 1 W of input electrical power. Concentration of aerosol particles in air is also demonstrated.

  11. 47 CFR 73.811 - LPFM power and antenna height requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false LPFM power and antenna height requirements. 73... SERVICES RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.811 LPFM power and antenna... operate with maximum facilities of 100 watts effective radiated power (ERP) at 30 meters antenna...

  12. 47 CFR 73.811 - LPFM power and antenna height requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false LPFM power and antenna height requirements. 73... SERVICES RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.811 LPFM power and antenna... operate with maximum facilities of 100 watts effective radiated power (ERP) at 30 meters antenna...

  13. 47 CFR 73.811 - LPFM power and antenna height requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false LPFM power and antenna height requirements. 73... SERVICES RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.811 LPFM power and antenna... operate with maximum facilities of 100 watts effective radiated power (ERP) at 30 meters antenna...

  14. 30 CFR 75.1909 - Nonpermissible diesel-powered equipment; design and performance requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Nonpermissible diesel-powered equipment; design... Diesel-Powered Equipment § 75.1909 Nonpermissible diesel-powered equipment; design and performance requirements. (a) Nonpermissible diesel-powered equipment, except for the special category of equipment...

  15. 33 CFR 150.519 - What are the requirements for emergency lighting and power systems?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... emergency lighting and power systems? 150.519 Section 150.519 Navigation and Navigable Waters COAST GUARD... Specialty Equipment Emergency Lighting and Power Systems § 150.519 What are the requirements for emergency lighting and power systems? (a) The operator must test and inspect the emergency lighting and power...

  16. 33 CFR 150.519 - What are the requirements for emergency lighting and power systems?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... emergency lighting and power systems? 150.519 Section 150.519 Navigation and Navigable Waters COAST GUARD... Specialty Equipment Emergency Lighting and Power Systems § 150.519 What are the requirements for emergency lighting and power systems? (a) The operator must test and inspect the emergency lighting and power...

  17. 33 CFR 150.519 - What are the requirements for emergency lighting and power systems?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... emergency lighting and power systems? 150.519 Section 150.519 Navigation and Navigable Waters COAST GUARD... Specialty Equipment Emergency Lighting and Power Systems § 150.519 What are the requirements for emergency lighting and power systems? (a) The operator must test and inspect the emergency lighting and power...

  18. 33 CFR 150.519 - What are the requirements for emergency lighting and power systems?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... emergency lighting and power systems? 150.519 Section 150.519 Navigation and Navigable Waters COAST GUARD... Specialty Equipment Emergency Lighting and Power Systems § 150.519 What are the requirements for emergency lighting and power systems? (a) The operator must test and inspect the emergency lighting and power...

  19. 33 CFR 150.519 - What are the requirements for emergency lighting and power systems?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... emergency lighting and power systems? 150.519 Section 150.519 Navigation and Navigable Waters COAST GUARD... Specialty Equipment Emergency Lighting and Power Systems § 150.519 What are the requirements for emergency lighting and power systems? (a) The operator must test and inspect the emergency lighting and power...

  20. Acoustic Mechanical Feedthroughs

    NASA Technical Reports Server (NTRS)

    Sherrit, Stewart; Walkemeyer, Phillip; Bao, Xiaoqi; Bar-Cohen, Yoseph; Badescu, Mircea

    2013-01-01

    Electromagnetic motors can have problems when operating in extreme environments. In addition, if one needs to do mechanical work outside a structure, electrical feedthroughs are required to transport the electric power to drive the motor. In this paper, we present designs for driving rotary and linear motors by pumping stress waves across a structure or barrier. We accomplish this by designing a piezoelectric actuator on one side of the structure and a resonance structure that is matched to the piezoelectric resonance of the actuator on the other side. Typically, piezoelectric motors can be designed with high torques and lower speeds without the need for gears. One can also use other actuation materials such as electrostrictive, or magnetostrictive materials in a benign environment and transmit the power in acoustic form as a stress wave and actuate mechanisms that are external to the benign environment. This technology removes the need to perforate a structure and allows work to be done directly on the other side of a structure without the use of electrical feedthroughs, which can weaken the structure, pipe, or vessel. Acoustic energy is pumped as a stress wave at a set frequency or range of frequencies to produce rotary or linear motion in a structure. This method of transferring useful mechanical work across solid barriers by pumping acoustic energy through a resonant structure features the ability to transfer work (rotary or linear motion) across pressure or thermal barriers, or in a sterile environment, without generating contaminants. Reflectors in the wall of barriers can be designed to enhance the efficiency of the energy/power transmission. The method features the ability to produce a bi-directional driving mechanism using higher-mode resonances. There are a variety of applications where the presence of a motor is complicated by thermal or chemical environments that would be hostile to the motor components and reduce life and, in some instances, not be

  1. 26 CFR 601.504 - Requirements for filing power of attorney.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 20 2014-04-01 2014-04-01 false Requirements for filing power of attorney. 601.504 Section 601.504 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INTERNAL REVENUE PRACTICE STATEMENT OF PROCEDURAL RULES Conference and Practice Requirements § 601.504 Requirements for filing power of attorney....

  2. 26 CFR 601.504 - Requirements for filing power of attorney.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 20 2013-04-01 2013-04-01 false Requirements for filing power of attorney. 601.504 Section 601.504 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INTERNAL REVENUE PRACTICE STATEMENT OF PROCEDURAL RULES Conference and Practice Requirements § 601.504 Requirements for filing power of attorney....

  3. Reliability program requirements for Space and Terrestrial Nuclear Power Systems

    SciTech Connect

    Not Available

    1982-10-01

    The objectives of the reliability program requirements described in this report are (1) to provide contractors with an outline of the reliability requirements established by the Department of Energy (DOE) in the areas of design, development, production, testing, and acceptance of space and terrestrial nuclear systems hardware, and (2) to guide the contractor in meeting these requirements. This publication or particular portions of it is applicable as specified in the contract. Whether the contractors/subcontractors are subject to all the requirements or only to part of them will be specified by contract, program letter, or by the contract statement-of-work.

  4. Harnessing the Power or Narratives to Understand User Requirements

    ERIC Educational Resources Information Center

    Hvalshagen, Merete

    2011-01-01

    It is estimated that $150 billion is wasted yearly on information and communications technology failures in the US. The most common reason for failure is deficiencies in the specified requirements. IS researchers and IS practitioners are therefore continuously exploring methods for effectively analyzing and capturing the user requirements. One…

  5. Acoustic waveguide technique for sensing incipient faults in underground power-transmission cables: Including acousto-optic techniques

    NASA Astrophysics Data System (ADS)

    Harrold, R. T.

    1981-09-01

    Theoretical and practical studies were made of both the acoustic emission, spectrum signatures associated with underground cable incipient faults, and the attenuation of acoustic waves in waterfilled metal tubes used as waveguided. Based on critical data, it can be estimated that in favorable circumstances, the acoustic waveguide system would only be useful for sensing incipient faults in underground cables of approx. 800 meters of less in length. A system were investigated which acoustic emissions from cable incipient faults impinge on a fiber-optic lightguide and locally change its refractive index and modulate laser light transmitted along the light guide. Experiments based on this concept show that is is possible t sense acoustic emissions with energy levels below on micro-joule. A test of this system using a section of compressed gas-insulated cable with an internal flashover was successfully carried out.

  6. Requirements for a Hydrogen Powered All-Electric Manned Helicopter

    NASA Technical Reports Server (NTRS)

    Datta, Anubhav

    2012-01-01

    The objective of this paper is to set propulsion system targets for an all-electric manned helicopter of ultra-light utility class to achieve performance comparable to combustion engines. The approach is to begin with a current two-seat helicopter (Robinson R 22 Beta II-like), design an all-electric power plant as replacement for its existing piston engine, and study performance of the new all-electric aircraft. The new power plant consists of high-pressure Proton Exchange Membrane fuel cells, hydrogen stored in 700 bar type-4 tanks, lithium-ion batteries, and an AC synchronous permanent magnet motor. The aircraft and the transmission are assumed to remain the same. The paper surveys the state of the art in each of these areas, synthesizes a power plant using best available technologies in each, examines the performance achievable by such a power plant, identifies key barriers, and sets future technology targets to achieve performance at par with current internal combustion engines.

  7. 40 CFR 256.21 - Requirements for State regulatory powers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the criteria for classification of solid waste disposal facilities (40 CFR part 257). Such authority... powers. 256.21 Section 256.21 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR DEVELOPMENT AND IMPLEMENTATION OF STATE SOLID WASTE MANAGEMENT PLANS Solid...

  8. 40 CFR 256.21 - Requirements for State regulatory powers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the criteria for classification of solid waste disposal facilities (40 CFR part 257). Such authority... powers. 256.21 Section 256.21 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR DEVELOPMENT AND IMPLEMENTATION OF STATE SOLID WASTE MANAGEMENT PLANS Solid...

  9. 40 CFR 256.21 - Requirements for State regulatory powers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the criteria for classification of solid waste disposal facilities (40 CFR part 257). Such authority... powers. 256.21 Section 256.21 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR DEVELOPMENT AND IMPLEMENTATION OF STATE SOLID WASTE MANAGEMENT PLANS Solid...

  10. Ocean acoustic hurricane classification.

    PubMed

    Wilson, Joshua D; Makris, Nicholas C

    2006-01-01

    Theoretical and empirical evidence are combined to show that underwater acoustic sensing techniques may be valuable for measuring the wind speed and determining the destructive power of a hurricane. This is done by first developing a model for the acoustic intensity and mutual intensity in an ocean waveguide due to a hurricane and then determining the relationship between local wind speed and underwater acoustic intensity. From this it is shown that it should be feasible to accurately measure the local wind speed and classify the destructive power of a hurricane if its eye wall passes directly over a single underwater acoustic sensor. The potential advantages and disadvantages of the proposed acoustic method are weighed against those of currently employed techniques. PMID:16454274

  11. Research requirements for emergency power to permit hover-one-engine-inoperative helicopter operation

    NASA Technical Reports Server (NTRS)

    Yost, J. H.

    1976-01-01

    The research and technology demonstration requirements to achieve emergency-power capability for a civil helicopter are documented. The goal for emergency power is the ability to hover with one engine inoperative, transition to minimum-power forward flight, and continue to a safe landing where emergency power may or may not be required. The best method to obtain emergency power is to augment the basic engine power by increasing the engine's speed and turbine-inlet temperature, combined with water-alcohol injection at the engine inlet. Other methods, including turbine boost power and flywheel energy, offer potential for obtaining emergency power for minimum time durations. Costs and schedules are estimated for a research and development program to bring emergency power through a hardware-demonstration test. Interaction of engine emergency-power capability with other helicopter systems is examined.

  12. AST Launch Vehicle Acoustics

    NASA Technical Reports Server (NTRS)

    Houston, Janice; Counter, D.; Giacomoni, D.

    2015-01-01

    The liftoff phase induces acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are then used in the prediction of internal vibration responses of the vehicle and components which result in the qualification levels. Thus, predicting these liftoff acoustic (LOA) environments is critical to the design requirements of any launch vehicle. If there is a significant amount of uncertainty in the predictions or if acoustic mitigation options must be implemented, a subscale acoustic test is a feasible pre-launch test option to verify the LOA environments. The NASA Space Launch System (SLS) program initiated the Scale Model Acoustic Test (SMAT) to verify the predicted SLS LOA environments and to determine the acoustic reduction with an above deck water sound suppression system. The SMAT was conducted at Marshall Space Flight Center and the test article included a 5% scale SLS vehicle model, tower and Mobile Launcher. Acoustic and pressure data were measured by approximately 250 instruments. The SMAT liftoff acoustic results are presented, findings are discussed and a comparison is shown to the Ares I Scale Model Acoustic Test (ASMAT) results.

  13. Space nuclear reactor power-perception, requirements, and mission integration

    NASA Astrophysics Data System (ADS)

    Isenberg, Lon; Martin, C. R.

    The authors describe the opportunities for the military and the civil sector given a successful development of a space reactor power system. The centerpiece is the SP-100 program. Numerous studies have identified serious design limitations for military missions. These same studies suggest that thermionic technology has great promise for military missions. By way of highlighting some of the concerns over the current SP-100 program, the authors focus on some of the technology issues. Recently, as a result of two military studies, the military and the Department of Energy (DOE) have proposed a memorandum of understanding to cosponsor a second reactor development program based on thermionic technology. The authors believe the DOE should strongly endorse joint development of thermionics with the military. Additionally, the reactor power source should be closely integrated with a particular mission.

  14. Economic requirements for competitive laser fusion power production

    SciTech Connect

    Hogan, W.J.; Meier, W.R.

    1985-11-15

    An economic model of a laser fusion commercial power plant is used to identify the design and operating regimes of the driver, target and reaction chamber that will result in economic competitiveness with future fission and coal plants. We find that, for a plant with a net power of 1 GW/sub e/, the cost of the driver must be less than $0.4 to 0.6 B, and the recirculating power fraction must be less than 25%. Target gain improvements at low driver energy are the most beneficial but also the most difficult to achieve. The optimal driver energy decreases with increasing target technology. The sensitivity of the cost of electricity to variations in cost and performance parameters decreases with increasing target technology. If chamber pulse rates of a few Hz can be achieved, then gains of 80 to 100 will be sufficient, and higher pulse rates do not help much. Economic competitiveness becomes more difficult with decreasing plant size. Finally, decreasing the cost of the balance of plant has the greatest beneficial effect on economic competitiveness. 6 refs., 5 figs., 2 tabs.

  15. Advanced solar dynamic space power systems perspectives, requirements and technology needs

    NASA Technical Reports Server (NTRS)

    Dustin, M. O.; Savino, J. M.; Lacy, D. E.; Migra, R. P.; Juhasz, A. J.; Coles, C. E.

    1986-01-01

    Projected NASA, Civil, Commercial, and Military missions will require space power systems of increased versatility and power levels. The Advanced Solar Dynamic (ASD) Power systems offer the potential for efficient, lightweight, survivable, relatively compact, long-lived space power systems applicable to a wide range of power levels (3 to 300 kWe), and a wide variety of orbits. The successful development of these systems could satisfy the power needs for a wide variety of these projected missions. Thus, the NASA Lewis Research Center has embarked upon an aggressive ASD reserach project under the direction of NASA's Office of Aeronautics and Space Technology (DAST). The project is being implemented through a combination of in-house and contracted efforts. Key elements of this project are missions analysis to determine the power systems requirements, systems analysis to identify the most attractive ASD power systems to meet these requirements, and to guide the technology development efforts, and technology development of key components.

  16. Preliminary assessment of the power requirements of a manned rover for Mars missions

    NASA Technical Reports Server (NTRS)

    El-Genk, Mohamed S.; Morley, Nicholas J.; Cataldo, Robert; Bloomfield, Harvey

    1990-01-01

    A preliminary study to determine the total mass and power requirements of a manned Mars rover is presented. Estimates of the power requirements for the nuclear reactor power system are determined as functions of the number of crew members, the emergency return trip scenario in case of a total malfunction of the reactor system, the cruising speed and range of the vehicle, and the specific mass of the power system. It is shown that the cruising speed of the vehicle and the soil traction factor significantly affect the traversing power requirement and therefore the mass of the nuclear power system. The cruising speed of the vehicle must be limited to 14.5 and 24 km/hr for power system specific masses of 150 kg/kWe and 50 kg/kWe, respectively, for the nuclear power system mass not to exceed 50 percent of the total mass of the rover.

  17. NASA powered lift facility internally generated noise and its transmission to the acoustic far field

    NASA Technical Reports Server (NTRS)

    Huff, Ronald G.

    1988-01-01

    Noise tests of NASA Lewis Research Center's Powered Lift Facility (PLF) were performed to determine the frequency content of the internally generated noise that reaches the far field. The sources of the internally generated noise are the burner, elbows, valves, and flow turbulence. Tests over a range of nozzle pressure ratios from 1.2 to 3.5 using coherence analysis revealed that low frequency noise below 1200 Hz is transmitted through the nozzle. Broad banded peaks at 240 and 640 Hz were found in the transmitted noise. Aeroacoustic excitation effects are possible in this frequency range. The internal noise creates a noise floor that limits the amount of jet noise suppression that can be measured on the PLF and similar facilities.

  18. NASA requirements and applications environments for electrical power wiring

    NASA Technical Reports Server (NTRS)

    Stavnes, Mark W.; Hammoud, Ahmad N.

    1992-01-01

    Serious problems can occur from insulation failures in the wiring harnesses of aerospace vehicles. In most recorded incidents, the failures have been identified to be the result of arc tracking, the propagation of an arc along wiring bundles through degradation of insulation. Propagation of the arc can lead to the loss of the entire wiring harness and the functions which it supports. While an extensive database of testing for arc track resistant wire insulations has been developed for aircraft applications, the counterpart requirements for spacecraft are very limited. The electrical, thermal, mechanical, chemical, and operational requirements for specification and testing of candidate wiring systems for spacecraft applications is presented.

  19. An evaluation of the land and material requirements for the satellite power system

    NASA Technical Reports Server (NTRS)

    Ankerbrandt, S. D.

    1980-01-01

    Current research and evaluation of the physical resources requirements for the Satellite Power System (SPS) concentrates on three topics: land requirements and the siting of rectennas; the environmental impacts of the rectenna siting; and the materials requirements. The first two focus exclusively on the Earth based element of the SPS while the materials assessment considered requirements for both the space and Earth systems.

  20. Nanowave devices for terahertz acoustic phonons

    NASA Astrophysics Data System (ADS)

    Lanzillotti-Kimura, N. D.; Fainstein, A.; Lemaître, A.; Jusserand, B.

    2006-02-01

    The emergence of the area of nanophononics requires the development of terahertz (THz) acoustic devices with tailored properties. We describe nonperiodic planar nanostructures with specific THz phononic response and superior performance. We show that improved devices based on GaAs and AlAs layers can be designed using an optimization Nelder-Mead simplex method, and grown with state-of-the-art molecular beam epitaxy. We also demonstrate that high-resolution Raman scattering provides a powerful tool to characterize these devices. We illustrate the concept with results on acoustic THz edge and color filters.

  1. Partial discharge localization in power transformers based on the sequential quadratic programming-genetic algorithm adopting acoustic emission techniques

    NASA Astrophysics Data System (ADS)

    Liu, Hua-Long; Liu, Hua-Dong

    2014-10-01

    Partial discharge (PD) in power transformers is one of the prime reasons resulting in insulation degradation and power faults. Hence, it is of great importance to study the techniques of the detection and localization of PD in theory and practice. The detection and localization of PD employing acoustic emission (AE) techniques, as a kind of non-destructive testing, plus due to the advantages of powerful capability of locating and high precision, have been paid more and more attention. The localization algorithm is the key factor to decide the localization accuracy in AE localization of PD. Many kinds of localization algorithms exist for the PD source localization adopting AE techniques including intelligent and non-intelligent algorithms. However, the existed algorithms possess some defects such as the premature convergence phenomenon, poor local optimization ability and unsuitability for the field applications. To overcome the poor local optimization ability and easily caused premature convergence phenomenon of the fundamental genetic algorithm (GA), a new kind of improved GA is proposed, namely the sequence quadratic programming-genetic algorithm (SQP-GA). For the hybrid optimization algorithm, SQP-GA, the sequence quadratic programming (SQP) algorithm which is used as a basic operator is integrated into the fundamental GA, so the local searching ability of the fundamental GA is improved effectively and the premature convergence phenomenon is overcome. Experimental results of the numerical simulations of benchmark functions show that the hybrid optimization algorithm, SQP-GA, is better than the fundamental GA in the convergence speed and optimization precision, and the proposed algorithm in this paper has outstanding optimization effect. At the same time, the presented SQP-GA in the paper is applied to solve the ultrasonic localization problem of PD in transformers, then the ultrasonic localization method of PD in transformers based on the SQP-GA is proposed. And

  2. 33 CFR 150.710 - What are the requirements for supplying power to aids to navigation?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... supplying power to aids to navigation? 150.710 Section 150.710 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: OPERATIONS Aids to Navigation § 150.710 What are the requirements for supplying power to aids to navigation? The power of...

  3. 33 CFR 150.710 - What are the requirements for supplying power to aids to navigation?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... supplying power to aids to navigation? 150.710 Section 150.710 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: OPERATIONS Aids to Navigation § 150.710 What are the requirements for supplying power to aids to navigation? The power of...

  4. 33 CFR 150.710 - What are the requirements for supplying power to aids to navigation?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... supplying power to aids to navigation? 150.710 Section 150.710 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: OPERATIONS Aids to Navigation § 150.710 What are the requirements for supplying power to aids to navigation? The power of...

  5. 33 CFR 150.710 - What are the requirements for supplying power to aids to navigation?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... supplying power to aids to navigation? 150.710 Section 150.710 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: OPERATIONS Aids to Navigation § 150.710 What are the requirements for supplying power to aids to navigation? The power of...

  6. 33 CFR 150.710 - What are the requirements for supplying power to aids to navigation?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... supplying power to aids to navigation? 150.710 Section 150.710 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: OPERATIONS Aids to Navigation § 150.710 What are the requirements for supplying power to aids to navigation? The power of...

  7. Reduced power processor requirements for the 30-cm diameter Hg ion thruster

    NASA Technical Reports Server (NTRS)

    Rawlin, V. K.

    1979-01-01

    An evaluation of simplifications for the thruster power processor interface for a 30 cm Hg ion thruster is presented. Tests on the engine, thruster control, and the power supplies are performed. Reduced power processors requirements are defined and the impact on thruster design, performance, and lifetime are assessed.

  8. 47 CFR 73.811 - LPFM power and antenna height requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false LPFM power and antenna height requirements. 73.811 Section 73.811 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.811 LPFM power and...

  9. 47 CFR 73.811 - LPFM power and antenna height requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false LPFM power and antenna height requirements. 73.811 Section 73.811 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.811 LPFM power and...

  10. 33 CFR 149.660 - What are the requirements for emergency power?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... or natural gas transfer pumping equipment) in accordance with 46 CFR 112.05. General Alarm System ... emergency power? 149.660 Section 149.660 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND... Equipment Emergency Power § 149.660 What are the requirements for emergency power? (a) Each pumping...

  11. 33 CFR 149.660 - What are the requirements for emergency power?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... or natural gas transfer pumping equipment) in accordance with 46 CFR 112.05. General Alarm System ... emergency power? 149.660 Section 149.660 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND... Equipment Emergency Power § 149.660 What are the requirements for emergency power? (a) Each pumping...

  12. 10 CFR 50.65 - Requirements for monitoring the effectiveness of maintenance at nuclear power plants.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... maintenance at nuclear power plants. 50.65 Section 50.65 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC... Construction Permits § 50.65 Requirements for monitoring the effectiveness of maintenance at nuclear power..., including normal shutdown operations. (a)(1) Each holder of an operating license for a nuclear power...

  13. 10 CFR 50.65 - Requirements for monitoring the effectiveness of maintenance at nuclear power plants.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... maintenance at nuclear power plants. 50.65 Section 50.65 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC... Construction Permits § 50.65 Requirements for monitoring the effectiveness of maintenance at nuclear power..., including normal shutdown operations. (a)(1) Each holder of an operating license for a nuclear power...

  14. 10 CFR 50.65 - Requirements for monitoring the effectiveness of maintenance at nuclear power plants.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... maintenance at nuclear power plants. 50.65 Section 50.65 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC... Construction Permits § 50.65 Requirements for monitoring the effectiveness of maintenance at nuclear power..., including normal shutdown operations. (a)(1) Each holder of an operating license for a nuclear power...

  15. 10 CFR 50.65 - Requirements for monitoring the effectiveness of maintenance at nuclear power plants.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... maintenance at nuclear power plants. 50.65 Section 50.65 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC... Construction Permits § 50.65 Requirements for monitoring the effectiveness of maintenance at nuclear power..., including normal shutdown operations. (a)(1) Each holder of an operating license for a nuclear power...

  16. Unique Features of Dynamic Isotope Power Systems for High-Requirements Spacecraft

    SciTech Connect

    Raab, Bernard

    1980-08-01

    The Dynamic Isotope Power System, designed for spacecraft requiring prime power in the 500-to-2000 watt range, has been successfully built and ground tested. A number of studies, summarized herein, have demonstrated the advantages of using such a power system instead of the conventional solar system, for a variety of earth-orbit missions. These advantages stem from the unique nature of the dynamic isotope system, different in kind from solar power systems. As a result, in many cases, the spacecraft design can be significantly simplified and more closely harmonized with mission requirements. This overall advantage can be crucial in missions which have stringent pointing, stability, viewing and/or positioning requirements.

  17. The effect of the coupling between the top plate and the fingerboard on the acoustic power radiated by a classical guitar (L).

    PubMed

    García-Mayén, Héctor; Santillán, Arturo

    2011-03-01

    An experimental investigation on the coupling between the fingerboard and the top plate of a classical guitar at low frequencies is presented. The study was carried out using a finished top plate under fixed boundary conditions and a commercial guitar. Radiated sound power was determined in one-third octave bands up to the band of 1 kHz based on measurements of sound intensity. The results provide evidence that the way in which the fingerboard and top plate are coupled is not a relevant factor in the radiated acoustic power of the classical guitar in the studied frequency range. PMID:21428477

  18. Spacecraft Internal Acoustic Environment Modeling

    NASA Technical Reports Server (NTRS)

    Allen, Christopher; Chu, S. Reynold

    2008-01-01

    The objective of the project is to develop an acoustic modeling capability, based on commercial off-the-shelf software, to be used as a tool for oversight of the future manned Constellation vehicles to ensure compliance with acoustic requirements and thus provide a safe and habitable acoustic environment for the crews, and to validate developed models via building physical mockups and conducting acoustic measurements.

  19. Power requirements for batteries in hybrid electric vehicles

    NASA Astrophysics Data System (ADS)

    Nelson, Robert F.

    The operation of batteries in hybrid electric vehicles (HEVs) involves unusual constraints not seen in other applications. This paper reviews the specifications and operational requirements imposed on batteries due to the projected architectures for HEVs as defined by the DOE/PNGV Program. It also reviews the performance issues involved in battery HEV operation and surveys the strengths and weaknesses of the candidate electrochemical technologies. Finally, battery designs are recommended for the two major projected HEV applications, namely the so-called "fast-response" and "slow-response" systems identified in the DOE/PNGV Programme.

  20. POWER (power optimization for wireless energy requirements): A MATLAB based algorithm for design of hybrid energy systems

    NASA Astrophysics Data System (ADS)

    Cook, K. A.; Albano, F.; Nevius, P. E.; Sastry, A. M.

    We have expanded and implemented an algorithm for selecting power supplies into a turnkey MATLAB code, "POWER" (power optimization for wireless energy requirements). Our algorithm uses three approaches to system design, specifying either: (1) a single, aggregate power profile; (2) a power system designed to satisfy several power ranges (micro-, milli- and Watt); or (3) a power system designed to be housed within specified spaces within the system. POWER was verified by conducting two case studies on hearing prosthetics: the TICA (LZ 3001) (Baumann group at the Tübingen University) and Amadeus cochlear implant (CI) (WIMS-ERC at the University of Michigan) based on a volume constraint of 2 cm 3. The most suitable solution identified by POWER for the TICA device came from Approach 1, wherein one secondary cell provided 26,000 cycles of 16 h operation. POWER identified Approach 2 as the solution for the WIMS-ERC Amadeus CI, which consisted of 1 cell for the microWatt power range and 1 cell for the milliWatt range (4.43 cm 3, ∼55% higher than the target volume), and provided 3280 cycles of 16 h operation (including re-charge of the batteries). Future work will be focused on continuously improving our present tool.

  1. Plug and Process Loads Capacity and Power Requirements Analysis

    SciTech Connect

    Sheppy, M.; Gentile-Polese, L.

    2014-09-01

    This report addresses gaps in actionable knowledge that would help reduce the plug load capacities designed into buildings. Prospective building occupants and real estate brokers lack accurate references for plug and process load (PPL) capacity requirements, so they often request 5-10 W/ft2 in their lease agreements. Limited initial data, however, suggest that actual PPL densities in leased buildings are substantially lower. Overestimating PPL capacity leads designers to oversize electrical infrastructure and cooling systems. Better guidance will enable improved sizing and design of these systems, decrease upfront capital costs, and allow systems to operate more energy efficiently. The main focus of this report is to provide industry with reliable, objective third-party guidance to address the information gap in typical PPL densities for commercial building tenants. This could drive changes in negotiations about PPL energy demands.

  2. Highly directional acoustic receivers.

    PubMed

    Cray, Benjamin A; Evora, Victor M; Nuttall, Albert H

    2003-03-01

    The theoretical directivity of a single combined acoustic receiver, a device that can measure many quantities of an acoustic field at a collocated point, is presented here. The formulation is developed using a Taylor series expansion of acoustic pressure about the origin of a Cartesian coordinate system. For example, the quantities measured by a second-order combined receiver, denoted a dyadic sensor, are acoustic pressure, the three orthogonal components of acoustic particle velocity, and the nine spatial gradients of the velocity vector. The power series expansion, which can be of any order, is cast into an expression that defines the directivity of a single receiving element. It is shown that a single highly directional dyadic sensor can have a directivity index of up to 9.5 dB. However, there is a price to pay with highly directive sensors; these sensors can be significantly more sensitive to nonacoustic noise sources. PMID:12656387

  3. Solar powered biohydrogen production requires specific localization of the hydrogenase

    SciTech Connect

    Burroughs, Nigel J.; Boehm, Marko; Eckert, Carrie; Mastroianni, Giulia; Spence, Edward M.; Yu, Jianfeng; Nixon, Peter J.; Appel, Jens; Mullineaux, Conrad W.; Bryan, Samantha J.

    2014-09-04

    Cyanobacteria contain a bidirectional [NiFe] hydrogenase which transiently produces hydrogen upon exposure of anoxic cells to light, potentially acting as a “valve” releasing excess electrons from the electron transport chain. However, its interaction with the photosynthetic electron transport chain remains unclear. By GFP-tagging the HoxF diaphorase subunit we show that the hydrogenase is thylakoid associated, comprising a population dispersed uniformly through the thylakoids and a subpopulation localized to discrete puncta in the distal thylakoid. Thylakoid localisation of both the HoxH and HoxY hydrogenase subunits is confirmed by immunogold electron microscopy. The diaphorase HoxE subunit is essential for recruitment to the dispersed thylakoid population, potentially anchoring the hydrogenase to the membrane, but aggregation to puncta occurs through a distinct HoxE-independent mechanism. Membrane association does not require NDH-1. Localization is dynamic on a scale of minutes, with anoxia and high light inducing a significant redistribution between these populations in favour of puncta. Lastly, since HoxE is essential for access to its electron donor, electron supply to the hydrogenase depends on a physiologically controlled localization, potentially offering a new avenue to enhance photosynthetic hydrogen production by exploiting localization/aggregation signals.

  4. Solar powered biohydrogen production requires specific localization of the hydrogenase

    DOE PAGESBeta

    Burroughs, Nigel J.; Boehm, Marko; Eckert, Carrie; Mastroianni, Giulia; Spence, Edward M.; Yu, Jianfeng; Nixon, Peter J.; Appel, Jens; Mullineaux, Conrad W.; Bryan, Samantha J.

    2014-09-04

    Cyanobacteria contain a bidirectional [NiFe] hydrogenase which transiently produces hydrogen upon exposure of anoxic cells to light, potentially acting as a “valve” releasing excess electrons from the electron transport chain. However, its interaction with the photosynthetic electron transport chain remains unclear. By GFP-tagging the HoxF diaphorase subunit we show that the hydrogenase is thylakoid associated, comprising a population dispersed uniformly through the thylakoids and a subpopulation localized to discrete puncta in the distal thylakoid. Thylakoid localisation of both the HoxH and HoxY hydrogenase subunits is confirmed by immunogold electron microscopy. The diaphorase HoxE subunit is essential for recruitment to themore » dispersed thylakoid population, potentially anchoring the hydrogenase to the membrane, but aggregation to puncta occurs through a distinct HoxE-independent mechanism. Membrane association does not require NDH-1. Localization is dynamic on a scale of minutes, with anoxia and high light inducing a significant redistribution between these populations in favour of puncta. Lastly, since HoxE is essential for access to its electron donor, electron supply to the hydrogenase depends on a physiologically controlled localization, potentially offering a new avenue to enhance photosynthetic hydrogen production by exploiting localization/aggregation signals.« less

  5. EVALUATION OF ACOUSTIC FORCES ON A PARTICLE IN AEROSOL MEDIUM

    SciTech Connect

    Lee, S; Richard Dimenna, R

    2007-09-27

    The acoustic force exerted on a solid particle was evaluated to develop a fundamental understanding of the critical physical parameters or constraints affecting particle motion and capture in a collecting device. The application of an acoustic force to the collection of a range of submicron-to-micron particles in a highly turbulent airflow stream laden with solid particles was evaluated in the presence of other assisting and competing forces. This scoping estimate was based on the primary acoustic force acting directly on particles in a dilute aerosol system, neglecting secondary interparticle effects such as agglomeration of the sub-micron particles. A simplified analysis assuming a stable acoustic equilibrium with an infinite sound speed in the solid shows that for a solid-laden air flow in the presence of a standing wave, particles will move toward the nearest node. The results also show that the turbulent drag force on a 1-{micro}m particle resulting from eddy motion is dominant when compared with the electrostatic force or the ultrasonic acoustic force. At least 180 dB acoustic pressure level at 1 MHz is required for the acoustic force to be comparable to the electrostatic or turbulent drag forces in a high-speed air stream. It is noted that particle size and pressure amplitude are dominant parameters for the acoustic force. When acoustic pressure level becomes very large, the acoustic energy will heat up the surrounding air medium, which may cause air to expand. With an acoustic power of about 600 watts applied to a 2000-lpm air flow, the air temperature can increase by as much as 15 C at the exit of the collector.

  6. Powering the Space Exploration Initiative - NASA future space power requirements and issues

    NASA Technical Reports Server (NTRS)

    Bennett, Gary L.

    1991-01-01

    The Space Exploration Initiative (SEI) establishes the long-term goal of returning to the moon and then exploring Mars. One of the prerequisites for SEI is the exploration technology program which includes program elements on space nuclear power and surface solar power. These program elements in turn build upon the ongoing NASA research and technology base program in space energy conversion. NASA's future space mission planning encompasses both robotic and piloted missions spanning a range of power levels and operational conditions. In response to the breadth of future candidate missions, NASAs current research and technology program in space energy conversion spans a number of technologies so that spacecraft designers can be make intelligent decisions about future power system options. These technologies are discussed.

  7. A new, simple electrostatic-acoustic hybrid levitator

    NASA Technical Reports Server (NTRS)

    Lierke, E. G.; Loeb, H.; Gross, D.

    1990-01-01

    Battelle has developed a hybrid levitator by combining the known single-axis acoustic standing wave levitator with a coaxial DC electric field. The resulting Coulomb forces on the charged liquid or solid sample support its weight and, together with the acoustic force, center the sample. Liquid samples with volumes approximately less than 100 micro-liters are deployed from a syringe reservoir into the acoustic pressure node. The sample is charged using a miniature high voltage power supply (approximately less than 20 kV) connected to the syringe needle. As the electric field, generated by a second miniature power supply, is increased, the acoustic intensity is reduced. The combination of both fields allows stable levitation of samples larger than either single technique could position on the ground. Decreasing the acoustic intensity reduces acoustic convection and sample deformation. Neither the electrostatic nor the acoustic field requires sample position sensing or active control. The levitator, now used for static and dynamic fluid physics investigations on the ground, can be easily modified for space operations.

  8. Power Requirements Determined for High-Power-Density Electric Motors for Electric Aircraft Propulsion

    NASA Technical Reports Server (NTRS)

    Johnson, Dexter; Brown, Gerald V.

    2005-01-01

    Future advanced aircraft fueled by hydrogen are being developed to use electric drive systems instead of gas turbine engines for propulsion. Current conventional electric motor power densities cannot match those of today s gas turbine aircraft engines. However, if significant technological advances could be made in high-power-density motor development, the benefits of an electric propulsion system, such as the reduction of harmful emissions, could be realized.

  9. Acoustic well cleaner

    DOEpatents

    Maki, Jr., Voldi E.; Sharma, Mukul M.

    1997-01-21

    A method and apparatus are disclosed for cleaning the wellbore and the near wellbore region. A sonde is provided which is adapted to be lowered into a borehole and which includes a plurality of acoustic transducers arranged around the sonde. Electrical power provided by a cable is converted to acoustic energy. The high intensity acoustic energy directed to the borehole wall and into the near wellbore region, redissolves or resuspends the material which is reducing the permeability of the formation and/or restricting flow in the wellbore.

  10. High intensity focused ultrasound sonothrombolysis: the use of perfluorocarbon droplets to achieve clot lysis at reduced acoustic powers

    PubMed Central

    Pajek, Daniel; Burgess, Alison; Huang, Yuexi; Hynynen, Kullervo

    2014-01-01

    The purpose of this study was to evaluate use of intravascular perfluorocarbon (PFC) droplets to reduce the sonication powers required to achieve clot lysis using high intensity focused ultrasound (HIFU). HIFU with droplets was initially applied to blood clots in an in vitro flow apparatus and inertial cavitation thresholds were determined. An embolic model for ischemic stroke was used to demonstrate the feasibility of this technique in vivo. Recanalization with intravascular droplets was achieved in vivo at 24±5% of the sonication power without droplets. Rabbits receiving 1 ms pulsed sonication during continuous intravascular droplet infusion recanalized in 71% of cases (p=0.041 vs controls). Preliminary experiments showed that damage was contained to the ultrasonic focus, suggesting that safe treatments would be possible with a more tightly focused hemispherical array that allows the whole focus to be placed inside of the main arteries in the human brain. PMID:25023095

  11. Acoustic transducer

    DOEpatents

    Drumheller, D.S.

    1997-12-30

    An acoustic transducer is described comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2,000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers. 4 figs.

  12. Acoustic transducer

    DOEpatents

    Drumheller, Douglas S.

    1997-01-01

    An acoustic transducer comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers.

  13. Extended operating range of the 30-cm ion thruster with simplified power processor requirements

    NASA Technical Reports Server (NTRS)

    Rawlin, V. K.

    1981-01-01

    A two grid 30 cm diameter mercury ion thruster was operated with only six power supplies over the baseline J series thruster power throttle range with negligible impact on thruster performance. An analysis of the functional model power processor showed that the component mass and parts count could be reduced considerably and the electrical efficiency increased slightly by only replacing power supplies with relays. The input power, output thrust, and specific impulse of the thruster were then extended, still using six supplies, from 2660 watts, 0.13 newtons, and 2980 seconds to 9130 watts, 0.37 newtons, and 3820 seconds, respectively. Increases in thrust and power density enable reductions in the number of thrusters and power processors required for most missions. Preliminary assessments of the impact of thruster operation at increased thrust and power density on the discharge characteristics, performance, and lifetime of the thruster were also made.

  14. A modular Space Station/Base electrical power system - Requirements and design study.

    NASA Technical Reports Server (NTRS)

    Eliason, J. T.; Adkisson, W. B.

    1972-01-01

    The requirements and procedures necessary for definition and specification of an electrical power system (EPS) for the future space station are discussed herein. The considered space station EPS consists of a replaceable main power module with self-contained auxiliary power, guidance, control, and communication subsystems. This independent power source may 'plug into' a space station module which has its own electrical distribution, control, power conditioning, and auxiliary power subsystems. Integration problems are discussed, and a transmission system selected with local floor-by-floor power conditioning and distribution in the station module. This technique eliminates the need for an immediate long range decision on the ultimate space base power sources by providing capability for almost any currently considered option.

  15. Study of power management technology for orbital multi-100KWe applications. Volume 3: Requirements

    NASA Technical Reports Server (NTRS)

    Mildice, J. W.

    1980-01-01

    Mid to late 1980's power management technology needs to support development of a general purpose space platform, capable of suplying 100 to 250 KWe to a variety of users in low Earth orbit are examined. A typical, shuttle assembled and supplied space platform is illustred, along with a group of payloads which might reasonably be expected to use such a facility. Examination of platform and user power needs yields a set of power requirements used to evaluate power management options for life cycle cost effectivness. The most cost effective ac/dc and dc systems are evaluated, specifically to develop system details which lead to technology goals, including: array and transmission voltages, best frequency for ac power transmission, and advantages and disadvantages of ac and dc systems for this application. System and component requirements are compared with the state-of-the-art to identify areas where technological development is required.

  16. Satellite Power Systems (SPS) concept definition study (Exhibit D). Volume 7: System/subsystems requirements databook

    NASA Technical Reports Server (NTRS)

    Hanley, G. M.

    1981-01-01

    This volume summarizes the basic requirements used as a guide to systems analysis, and is a basis for the selection of candidate Satellite Power Systems (SPS) point designs. Initially, these collected data reflected the level of definition resulting from the evaluation of a broad spectrum of SPS concepts. As the various concepts matured, these requirements were updated to reflect the requirements identified for the projected satellite system/subsystem point designs. Included is an updated version of earlier Rockwell concepts using klystrons as the specific microwave power amplification approach, as well as a more in-depth definition, analysis and preliminary point design on two concepts based on the use of advanced solid state technology to accomplish the task of high power amplification of the 2.45 GHz transmitted power beam to the Earth receiver. Finally, a preliminary definition of a concept using magnetrons as the microwave power amplifiers is presented.

  17. Acoustic Neuroma

    MedlinePlus

    An acoustic neuroma is a benign tumor that develops on the nerve that connects the ear to the brain. ... can press against the brain, becoming life-threatening. Acoustic neuroma can be difficult to diagnose, because the ...

  18. Acoustic energy harvesting based on a planar acoustic metamaterial

    NASA Astrophysics Data System (ADS)

    Qi, Shuibao; Oudich, Mourad; Li, Yong; Assouar, Badreddine

    2016-06-01

    We theoretically report on an innovative and practical acoustic energy harvester based on a defected acoustic metamaterial (AMM) with piezoelectric material. The idea is to create suitable resonant defects in an AMM to confine the strain energy originating from an acoustic incidence. This scavenged energy is converted into electrical energy by attaching a structured piezoelectric material into the defect area of the AMM. We show an acoustic energy harvester based on a meta-structure capable of producing electrical power from an acoustic pressure. Numerical simulations are provided to analyze and elucidate the principles and the performances of the proposed system. A maximum output voltage of 1.3 V and a power density of 0.54 μW/cm3 are obtained at a frequency of 2257.5 Hz. The proposed concept should have broad applications on energy harvesting as well as on low-frequency sound isolation, since this system acts as both acoustic insulator and energy harvester.

  19. Power Output and Air Requirements of a Two-stroke Cycle Engine for Aeronautical Use

    NASA Technical Reports Server (NTRS)

    Paton, C R; Kemper, Carlton

    1927-01-01

    This investigation was undertaken to determine the pressure and amount of air necessary for satisfactory high-speed, two-stroke cycle operation and thus permit the power requirements of the air pump or blower to be determined. Based on power output and air requirement here obtained the two-stroke cycle engine would seem to be favorable for aeronautical use. No attempts were made to secure satisfactory operation at idling speeds.

  20. SP-100 Dynamic Power and Lithium-Propellant MPD Nuclear Electric Propulsion Technology Requirements

    NASA Astrophysics Data System (ADS)

    Frisbee, Robert H.; Hoffman, Nathan J.; Murray, Kathy H.

    1994-07-01

    The objective of this study was to evaluate the requirements (including system integration, design, test requirements, and schedule) for the propulsion and power conversion systems of a nuclear electric propulsion (NEP) vehicle using an SP-100 reactor with a dynamic power conversion system, Li-propellant magnetoplasmadynamic (MPD) thrusters, Li-propellant storage and feed systems, and the power conditioning electronics required to convert the power output from the power system to the form (voltage, current) needed by the thrusters. Potassium-Rankine power conversion systems have the potential for the greatest mission benefit in terms of minimum mass and volume (as compared to Brayton or Stirling power conversion systems), but they require the most development. High-current, low-voltage turboalternators are needed for the MPD thruster system envisioned here, although one alternative would be to use more near-term high-voltage alternators at the potential cost of higher rectifier losses or added transformer mass. Power processing is not expected to be a major technology driver, but development of high-current, low-voltage space- and radiation-qualified components is needed. Finally, increases in MPD thruster life would reduce mass, system complexity, and packaging constraints; similarly, higher thruster efficiencies are desirable to reduce trip time.

  1. 7 CFR 1710.202 - Requirement to prepare a load forecast-power supply borrowers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... and provide an approved load forecast in support of any request for RUS financial assistance. The... provide an approved load forecast in support of any request for RUS financial assistance. The member power... 7 Agriculture 11 2010-01-01 2010-01-01 false Requirement to prepare a load forecast-power...

  2. Auxiliary payload power system study for space processing applications payloads. Preliminary requirements study

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The preliminary designs, specifications, and programmatic data for the auxiliary payload power system (APPS) are presented. The APPS concept is an independent system to be carried in the Orbiter's cargo bay having the capability of housing and supporting space processing applications (SPA) experiment payloads and augmenting Spacelab power and heat rejection capabilities as required in the performance of these experiments.

  3. 29 CFR 1919.22 - Requirements governing braking devices and power sources.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Requirements governing braking devices and power sources. All types of winches and cranes shall be provided... winch, or electric cranes shall be equipped so that a failure of the electric power shall stop the... electric winches and cranes during the tests shall be taken from the vessel's circuits. Shore current...

  4. 29 CFR 1919.22 - Requirements governing braking devices and power sources.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Requirements governing braking devices and power sources. All types of winches and cranes shall be provided... winch, or electric cranes shall be equipped so that a failure of the electric power shall stop the... electric winches and cranes during the tests shall be taken from the vessel's circuits. Shore current...

  5. 29 CFR 1919.22 - Requirements governing braking devices and power sources.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Requirements governing braking devices and power sources. All types of winches and cranes shall be provided... winch, or electric cranes shall be equipped so that a failure of the electric power shall stop the... electric winches and cranes during the tests shall be taken from the vessel's circuits. Shore current...

  6. 29 CFR 1919.22 - Requirements governing braking devices and power sources.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Requirements governing braking devices and power sources. All types of winches and cranes shall be provided... winch, or electric cranes shall be equipped so that a failure of the electric power shall stop the... electric winches and cranes during the tests shall be taken from the vessel's circuits. Shore current...

  7. Acoustic Seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor)

    2006-01-01

    The invention relates to a sealing device having an acoustic resonator. The acoustic resonator is adapted to create acoustic waveforms to generate a sealing pressure barrier blocking fluid flow from a high pressure area to a lower pressure area. The sealing device permits noncontacting sealing operation. The sealing device may include a resonant-macrosonic-synthesis (RMS) resonator.

  8. Acoustic seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor)

    2006-01-01

    The invention relates to a sealing device having an acoustic resonator. The acoustic resonator is adapted to create acoustic waveforms to generate a sealing pressure barrier blocking fluid flow from a high pressure area to a lower pressure area. The sealing device permits noncontacting sealing operation. The sealing device may include a resonant-macrosonic-synthesis (RMS) resonator.

  9. Investigation of correlation of LF power modulation of light in natural and artificial illumination situations and acoustic emission

    NASA Astrophysics Data System (ADS)

    Kleeberg, Florian P.; Gutzmann, Holger L.; Weyer, Cornelia; Weiß, Jürgen; Dörfler, Joachim; Hahlweg, Cornelius F.

    2014-09-01

    The present paper is a follow up of a paper presented in 2013 at the Novel Optical Systems conference in the session on Optics and Music. It is derived from an ongoing study on the human perception of combined optical and acoustical periodical stimuli. Originating from problems concerning artificial illumination and certain machinery with coherent optical and acoustical emissions there are effects to be observed which are interesting in the context of occupational medicine. It seems, that acoustic stimuli in the frequency range of the flicker fusion and below might lead to unexpected perceptible effects beyond those of the single stimuli. The effect of infrasound stimuli as a whole body perception seems to be boosted. Because of the difficulties in evaluation of physical and psychological effects of such coherent stimuli in a first step we question if such coherence is perceivable at all. Further, the problem of modulation of optical signals by acoustical signal is concerned. A catalogue of scenarios and 'effects to look for' including measurement concepts is presented and discussed.

  10. Acoustic, piezoelectric, and dielectric nonlinearities of AlN in coupled resonator filters for high RF power levels.

    PubMed

    Sahyoun, Walaa; Duchamp, Jean-Marc; Benech, Philippe

    2011-10-01

    Coupled resonator filters (CRFs) are the new generation of BAW filters recently designed for the front-end modules of mobile transmission systems. Looking for designers' requirements, CRF devices have been characterized and modeled. The model based on equivalent circuits relies on material constants such as stiffness and electro-coupling coefficients, and works only for linear-mode propagation. Because of their positions between antennas and power amplifiers, they often work under high RF power, inducing nonlinear response in the AlN piezoelectric layer. In this work, we analyze for the first time the nonlinear behavior of AlN material particularly for coupled BAW resonators. To characterize the nonlinear effects in CRFs, we measure the 1-dB gain compression point (P1dB) and the intercept point (IP(3)). Then, we develop a nonlinear model of CRFs using harmonic balance (HB) simulation in commercially available software. The HB environment allows fitting simulations to measurements in terms of P(1dB) and IP(3). We find that a high RF power induces nonlinear changes in the material constants' real parts: elastic stiffness c(33) (4.9%), piezoelectric e(33) (17.4%), and permittivity ϵ(33) (5.2%). These nonlinear variations of material constants describe the nonlinear behavior of CRF devices using the same deposit process for AlN material. PMID:21989879

  11. Proceedings: Workshop on Prospects and Requirements for Geographic Expansion of Wind Power Usage

    NASA Astrophysics Data System (ADS)

    Steitz, P.

    1986-11-01

    The proceedings of a workshop on the Prospects and Requirements for Geographic Expansion of Wind Power Usage held March 5-6, 1986, in Dallas, Texas are reported. The workshop was sponsored by the Electric Power Research Institute (EPRI) in cooperation with the Solar Energy Research Institute (SERI). SERI is operated by Midwest Research Institute for the US Department of Energy. The workshop participants concluded that there are a number of areas in the United States with substantial wind resources. Determining the potential for development of these resources for wind power will require local, detailed wind measurements. The participants saw no technology barriers to more widespread usage of wind power. They considered the greatest potential for advancement of wind power technology to be in the application of power electronics to enable variable speed wind turbine operation and to integrate and improve wind power station control and protection. Although wind power stations were seen as posing no health hazards, public and utility acceptance of the technology, the participants agreed, will require strong educational activities in all aspects of wind power. The implications of these conclusions for the research programs of EPRI and other sectors are discussed.

  12. Performance and production requirements for the optical components in a high-average-power laser system

    SciTech Connect

    Chow, R.; Doss, F.W.; Taylor, J.R.; Wong, J.N.

    1999-07-02

    Optical components needed for high-average-power lasers, such as those developed for Atomic Vapor Laser Isotope Separation (AVLIS), require high levels of performance and reliability. Over the past two decades, optical component requirements for this purpose have been optimized and performance and reliability have been demonstrated. Many of the optical components that are exposed to the high power laser light affect the quality of the beam as it is transported through the system. The specifications for these optics are described including a few parameters not previously reported and some component manufacturing and testing experience. Key words: High-average-power laser, coating efficiency, absorption, optical components

  13. PRSEUS Acoustic Panel Fabrication

    NASA Technical Reports Server (NTRS)

    Nicolette, Velicki; Yovanof, Nicolette P.; Baraja, Jaime; Mathur, Gopal; Thrash, Patrick; Pickell, Robert

    2011-01-01

    This report describes the development of a novel structural concept, Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS), that addresses the demanding fuselage loading requirements for the Hybrid Wing or Blended Wing Body (BWB) airplane configuration with regards to acoustic response. A PRSEUS panel was designed and fabricated and provided to NASA-LaRC for acoustic response testing in the Structural Acoustics Loads and Transmission (SALT) facility). Preliminary assessments of the sound transmission characteristics of a PRSEUS panel subjected to a representative Hybrid Wing Body (HWB) operating environment were completed for the NASA Environmentally Responsible Aviation (ERA) Program.

  14. Effect of power system technology and mission requirements on high altitude long endurance aircraft

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony J.

    1994-01-01

    An analysis was performed to determine how various power system components and mission requirements affect the sizing of a solar powered long endurance aircraft. The aircraft power system consists of photovoltaic cells and a regenerative fuel cell. Various characteristics of these components, such as PV cell type, PV cell mass, PV cell efficiency, fuel cell efficiency, and fuel cell specific mass, were varied to determine what effect they had on the aircraft sizing for a given mission. Mission parameters, such as time of year, flight altitude, flight latitude, and payload mass and power, were also altered to determine how mission constraints affect the aircraft sizing. An aircraft analysis method which determines the aircraft configuration, aspect ratio, wing area, and total mass, for maximum endurance or minimum required power based on the stated power system and mission parameters is presented. The results indicate that, for the power system, the greatest benefit can be gained by increasing the fuel cell specific energy. Mission requirements also substantially affect the aircraft size. By limiting the time of year the aircraft is required to fly at high northern or southern latitudes, a significant reduction in aircraft size or increase in payload capacity can be achieved.

  15. 10 CFR 73.58 - Safety/security interface requirements for nuclear power reactors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Safety/security interface requirements for nuclear power reactors. 73.58 Section 73.58 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PHYSICAL PROTECTION OF PLANTS AND MATERIALS Physical Protection Requirements at Fixed Sites § 73.58 Safety/security...

  16. 36 CFR 3.6 - What are the requirements to operate a power driven vessel?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false What are the requirements to operate a power driven vessel? 3.6 Section 3.6 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR BOATING AND WATER USE ACTIVITIES § 3.6 What are the requirements to operate...

  17. 36 CFR 3.6 - What are the requirements to operate a power driven vessel?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false What are the requirements to operate a power driven vessel? 3.6 Section 3.6 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR BOATING AND WATER USE ACTIVITIES § 3.6 What are the requirements to operate...

  18. 10 CFR 50.72 - Immediate notification requirements for operating nuclear power reactors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Immediate notification requirements for operating nuclear power reactors. 50.72 Section 50.72 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Inspections, Records, Reports, Notifications § 50.72 Immediate notification requirements for operating nuclear...

  19. 10 CFR 73.58 - Safety/security interface requirements for nuclear power reactors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Safety/security interface requirements for nuclear power reactors. 73.58 Section 73.58 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PHYSICAL PROTECTION OF PLANTS AND MATERIALS Physical Protection Requirements at Fixed Sites § 73.58 Safety/security...

  20. 10 CFR 73.58 - Safety/security interface requirements for nuclear power reactors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Safety/security interface requirements for nuclear power reactors. 73.58 Section 73.58 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PHYSICAL PROTECTION OF PLANTS AND MATERIALS Physical Protection Requirements at Fixed Sites § 73.58 Safety/security...

  1. Design and Characterization of a High-power Laser-induced Acoustic Desorption (LIAD) Probe Coupled with a Fourier-transform Ion Cyclotron Resonance Mass Spectrometer

    PubMed Central

    Shea, Ryan C.; Habicht, Steven C.; Vaughn, Weldon E.; Kenttämaa, Hilkka I.

    2008-01-01

    We report here the construction and characterization of a high-power laser-induced acoustic desorption (LIAD) probe designed for Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometers to facilitate analysis of non-volatile, thermally labile compounds. This “next generation” LIAD probe offers significant improvements in sensitivity and desorption efficiency for analytes with larger molecular weights via the use of higher laser irradiances. Unlike the previous probes which utilized a power limiting optical fiber to transmit the laser pulses through the probe, this probe employs a set of mirrors and a focusing lens. At the end of the probe, the energy from the laser pulses propagates through a thin metal foil as an acoustic wave, resulting in desorption of neutral molecules from the opposite side of the foil. Following desorption, the molecules can be ionized by electron impact or chemical ionization. Almost an order of magnitude greater power density (up to 5.0 × 109 W/cm2) is achievable on the backside of the foil with the high-power LIAD probe compared to the earlier LIAD probes (maximum power density ~9.0 × 108 W/cm2). The use of higher laser irradiances is demonstrated not to cause fragmentation of the analyte. The use of higher laser irradiances increases sensitivity since it results in the evaporation of a greater number of molecules per laser pulse. Measurement of the average velocities of LIAD evaporated molecules demonstrates that higher laser irradiances do not correlate with higher velocities of the gaseous analyte molecules. PMID:17319645

  2. Requirements for a common nuclear propulsion and power reactor for human exploration missions to Mars

    NASA Astrophysics Data System (ADS)

    Cataldo, Robert L.; Borowski, Stanley K.

    1998-01-01

    Requirements for propulsion and power systems capable of achieving a safe, reliable, robust and affordable human Mars exploration mission have been identified. Nuclear systems have been identified that can meet the challenges of short trip times, reduced number of launch vehicles, potential for ``all propulsive'' maneuvers, abundant in-space power and low mass, volume and deployed area, and energy rich surface power. Reduced total systems cost will also be mandatory to achieve affordable human exploration of Mars. Hence, it is desirable to design a space propulsion and surface power reactor with the greatest degree of commonality as possible with the goal of reducing total system costs.

  3. Requirements for a common nuclear propulsion and power reactor for human exploration missions to Mars

    SciTech Connect

    Cataldo, Robert L.; Borowski, Stanley K.

    1998-01-15

    Requirements for propulsion and power systems capable of achieving a safe, reliable, robust and affordable human Mars exploration mission have been identified. Nuclear systems have been identified that can meet the challenges of short trip times, reduced number of launch vehicles, potential for 'all propulsive' maneuvers, abundant in-space power and low mass, volume and deployed area, and energy rich surface power. Reduced total systems cost will also be mandatory to achieve affordable human exploration of Mars. Hence, it is desirable to design a space propulsion and surface power reactor with the greatest degree of commonality as possible with the goal of reducing total system costs.

  4. Acoustic cryocooler

    DOEpatents

    Swift, Gregory W.; Martin, Richard A.; Radenbaugh, Ray

    1990-01-01

    An acoustic cryocooler with no moving parts is formed from a thermoacoustic driver (TAD) driving a pulse tube refrigerator (PTR) through a standing wave tube. Thermoacoustic elements in the TAD are spaced apart a distance effective to accommodate the increased thermal penetration length arising from the relatively low TAD operating frequency in the range of 15-60 Hz. At these low operating frequencies, a long tube is required to support the standing wave. The tube may be coiled to reduce the overall length of the cryocooler. One or two PTR's are located on the standing wave tube adjacent antinodes in the standing wave to be driven by the standing wave pressure oscillations. It is predicted that a heat input of 1000 W at 1000 K will maintian a cooling load of 5 W at 80 K.

  5. Design of an implantable power supply for an intraocular sensor, using POWER (power optimization for wireless energy requirements)

    NASA Astrophysics Data System (ADS)

    Albano, F.; Chung, M. D.; Blaauw, D.; Sylvester, D. M.; Wise, K. D.; Sastry, A. M.

    The reduction in size and power usage of MEMS (microelectromechanical systems) devices has enabled development of fully implantable medical devices [K.D. Wise, IEEE Eng. Med. Biol. Magaz. 24(5) (2005) 22-29], though major obstacles remain in developing devices of very small scale (<1 mm) [T. Simunic, L. Benini, G. De Micheli, IEEE Trans. Very Large Scale Integr. (VLSI) Syst. 9 (2001) 15-28]. One of the most challenging applications; an intraocular sensor (IOS) developed by the Wireless Integrated Micro-Systems-Engineering Research Center (WIMS-ERC) at The University of Michigan; is the subject of the present study. Our specific objectives are fourfold: (1) to model the power usage of an intraocular sensor (IOS); (2) to develop a methodology for optimization of Hybrid Implantable Power Systems (HIPS); (3) to apply the selection tool to identify candidate power systems; and (4) to establish a methodology to fabricate and test the performance of an optimized power supply. In the present study we fabricated and tested three different cells. For one of these, 10 complete discharge and recharge cycles were successfully obtained. The experimental capacity was 7.70 mAh (15% of theoretical) for a discharge rate of C/5. As part of future work, a microbattery will be built for the WIMS-ERC IOS and tested in a fully integrated testbed.

  6. Magnetohydrodynamics (MHD) Engineering Test Facility (ETF) 200 MWe power plant. Design Requirements Document (DRD)

    NASA Technical Reports Server (NTRS)

    Rigo, H. S.; Bercaw, R. W.; Burkhart, J. A.; Mroz, T. S.; Bents, D. J.; Hatch, A. M.

    1981-01-01

    A description and the design requirements for the 200 MWe (nominal) net output MHD Engineering Test Facility (ETF) Conceptual Design, are presented. Performance requirements for the plant are identified and process conditions are indicated at interface stations between the major systems comprising the plant. Also included are the description, functions, interfaces and requirements for each of these major systems. The lastest information (1980-1981) from the MHD technology program are integrated with elements of a conventional steam electric power generating plant.

  7. Scaling and dimensional analysis of acoustic streaming jets

    SciTech Connect

    Moudjed, B.; Botton, V.; Henry, D.; Ben Hadid, H.

    2014-09-15

    This paper focuses on acoustic streaming free jets. This is to say that progressive acoustic waves are used to generate a steady flow far from any wall. The derivation of the governing equations under the form of a nonlinear hydrodynamics problem coupled with an acoustic propagation problem is made on the basis of a time scale discrimination approach. This approach is preferred to the usually invoked amplitude perturbations expansion since it is consistent with experimental observations of acoustic streaming flows featuring hydrodynamic nonlinearities and turbulence. Experimental results obtained with a plane transducer in water are also presented together with a review of the former experimental investigations using similar configurations. A comparison of the shape of the acoustic field with the shape of the velocity field shows that diffraction is a key ingredient in the problem though it is rarely accounted for in the literature. A scaling analysis is made and leads to two scaling laws for the typical velocity level in acoustic streaming free jets; these are both observed in our setup and in former studies by other teams. We also perform a dimensional analysis of this problem: a set of seven dimensionless groups is required to describe a typical acoustic experiment. We find that a full similarity is usually not possible between two acoustic streaming experiments featuring different fluids. We then choose to relax the similarity with respect to sound attenuation and to focus on the case of a scaled water experiment representing an acoustic streaming application in liquid metals, in particular, in liquid silicon and in liquid sodium. We show that small acoustic powers can yield relatively high Reynolds numbers and velocity levels; this could be a virtue for heat and mass transfer applications, but a drawback for ultrasonic velocimetry.

  8. Drive Rig Mufflers for Model Scale Engine Acoustic Testing

    NASA Technical Reports Server (NTRS)

    Stephens, David

    2010-01-01

    Testing of air breathing propulsion systems in the 9x15 foot wind tunnel at NASA Glenn Research Center depends on compressed air turbines for power. The drive rig turbines exhaust directly to the wind tunnel test section, and have been found to produce significant unwanted noise that reduces the quality of the acoustic measurements of the model being tested. In order to mitigate this acoustic contamination, a muffler can be attached downstream of the drive rig turbine. The modern engine designs currently being tested produce much less noise than traditional engines, and consequently a lower noise floor is required of the facility. An acoustic test of a muffler designed to mitigate this extraneous noise is presented, and a noise reduction of 8 dB between 700 Hz and 20 kHz was documented, significantly improving the quality of acoustic measurements in the facility.

  9. Nonlinear acoustics experimental characterization of microstructure evolution in Inconel 617

    SciTech Connect

    Yao, Xiaochu; Liu, Yang; Lissenden, Cliff J.

    2014-02-18

    Inconel 617 is a candidate material for the intermediate heat exchanger in a very high temperature reactor for the next generation nuclear power plant. This application will require the material to withstand fatigue-ratcheting interaction at temperatures up to 950°C. Therefore nondestructive evaluation and structural health monitoring are important capabilities. Acoustic nonlinearity (which is quantified in terms of a material parameter, the acoustic nonlinearity parameter, β) has been proven to be sensitive to microstructural changes in material. This research develops a robust experimental procedure to track the evolution of damage precursors in laboratory tested Inconel 617 specimens using ultrasonic bulk waves. The results from the acoustic non-linear tests are compared with stereoscope surface damage results. Therefore, the relationship between acoustic nonlinearity and microstructural evaluation can be clearly demonstrated for the specimens tested.

  10. SP-100 dynamic power and lithium-propellant MPD nuclear electric propulsion technology requirements

    SciTech Connect

    Frisbee, R.H.; Hoffman, N.J.; Murray, K.H.

    1994-12-31

    The objective of this study was to evaluate the requirements for the propulsion and power conversion systems of a nuclear electric propulsion (NEP) vehicle using an SP-100 reactor with a dynamic power conversion system, Li-propellant magnetoplasmadynamic (MPD) thrusters, Li-propellant storage and feed systems, and power conditioning electronics required to convert the power output from the power system to the form needed by the thrusters. Potassium-Rankine power conversion systems have the potential for the greatest mission benefit in terms of minimum mass and volume, but they require the most development. High-current, low-voltage turboalternators are needed for the MPD thruster system envisioned here. Power processing is not expected to be a major technology driver, but development of high-current, low-voltage space- and radiation-qualified components is needed. Finally, increases in MPD thruster life would reduce mass, system complexity, and packaging constraints; similarly, higher thruster efficiencies are desirable to reduce trip time.

  11. System Design Techniques for Reducing the Power Requirements of Advanced life Support Systems

    NASA Technical Reports Server (NTRS)

    Finn, Cory; Levri, Julie; Pawlowski, Chris; Crawford, Sekou; Luna, Bernadette (Technical Monitor)

    2000-01-01

    The high power requirement associated with overall operation of regenerative life support systems is a critical Z:p technological challenge. Optimization of individual processors alone will not be sufficient to produce an optimized system. System studies must be used in order to improve the overall efficiency of life support systems. Current research efforts at NASA Ames Research Center are aimed at developing approaches for reducing system power and energy usage in advanced life support systems. System energy integration and energy reuse techniques are being applied to advanced life support, in addition to advanced control methods for efficient distribution of power and thermal resources. An overview of current results of this work will be presented. The development of integrated system designs that reuse waste heat from sources such as crop lighting and solid waste processing systems will reduce overall power and cooling requirements. Using an energy integration technique known as Pinch analysis, system heat exchange designs are being developed that match hot and cold streams according to specific design principles. For various designs, the potential savings for power, heating and cooling are being identified and quantified. The use of state-of-the-art control methods for distribution of resources, such as system cooling water or electrical power, will also reduce overall power and cooling requirements. Control algorithms are being developed which dynamically adjust the use of system resources by the various subsystems and components in order to achieve an overall goal, such as smoothing of power usage and/or heat rejection profiles, while maintaining adequate reserves of food, water, oxygen, and other consumables, and preventing excessive build-up of waste materials. Reductions in the peak loading of the power and thermal systems will lead to lower overall requirements. Computer simulation models are being used to test various control system designs.

  12. Insulation Requirements of High-Voltage Power Systems in Future Spacecraft

    NASA Technical Reports Server (NTRS)

    Qureshi, A. Haq; Dayton, James A., Jr.

    1995-01-01

    The scope, size, and capability of the nation's space-based activities are limited by the level of electrical power available. Long-term projections show that there will be an increasing demand for electrical power in future spacecraft programs. The level of power that can be generated, conditioned, transmitted, and used will have to be considerably increased to satisfy these needs, and increased power levels will require that transmission voltages also be increased to minimize weight and resistive losses. At these projected voltages, power systems will not operate satisfactorily without the proper electrical insulation. Open or encapsulated power supplies are currently used to keep the volume and weight of space power systems low and to protect them from natural and induced environmental hazards. Circuits with open packaging are free to attain the pressure of the outer environment, whereas encapsulated circuits are imbedded in insulating materials, which are usually solids, but could be liquids or gases. Up to now, solid insulation has usually been chosen for space power systems. If the use of solid insulation is continued, when voltages increase, the amount of insulation for encapsulation also will have to increase. This increased insulation will increase weight and reduce system reliability. Therefore, non-solid insulation media must be examined to satisfy future spacecraft power and voltage demands. In this report, we assess the suitability of liquid, space vacuum, and gas insulation for space power systems.

  13. Digital Controller For Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Tarver, D. Kent

    1989-01-01

    Acoustic driver digitally controls sound fields along three axes. Allows computerized acoustic levitation and manipulation of small objects for such purposes as containerless processing and nuclear-fusion power experiments. Also used for controlling motion of vibration-testing tables in three dimensions.

  14. Topological Acoustics

    NASA Astrophysics Data System (ADS)

    Yang, Zhaoju; Gao, Fei; Shi, Xihang; Lin, Xiao; Gao, Zhen; Chong, Yidong; Zhang, Baile

    2015-03-01

    The manipulation of acoustic wave propagation in fluids has numerous applications, including some in everyday life. Acoustic technologies frequently develop in tandem with optics, using shared concepts such as waveguiding and metamedia. It is thus noteworthy that an entirely novel class of electromagnetic waves, known as "topological edge states," has recently been demonstrated. These are inspired by the electronic edge states occurring in topological insulators, and possess a striking and technologically promising property: the ability to travel in a single direction along a surface without backscattering, regardless of the existence of defects or disorder. Here, we develop an analogous theory of topological fluid acoustics, and propose a scheme for realizing topological edge states in an acoustic structure containing circulating fluids. The phenomenon of disorder-free one-way sound propagation, which does not occur in ordinary acoustic devices, may have novel applications for acoustic isolators, modulators, and transducers.

  15. Topological acoustics.

    PubMed

    Yang, Zhaoju; Gao, Fei; Shi, Xihang; Lin, Xiao; Gao, Zhen; Chong, Yidong; Zhang, Baile

    2015-03-20

    The manipulation of acoustic wave propagation in fluids has numerous applications, including some in everyday life. Acoustic technologies frequently develop in tandem with optics, using shared concepts such as waveguiding and metamedia. It is thus noteworthy that an entirely novel class of electromagnetic waves, known as "topological edge states," has recently been demonstrated. These are inspired by the electronic edge states occurring in topological insulators, and possess a striking and technologically promising property: the ability to travel in a single direction along a surface without backscattering, regardless of the existence of defects or disorder. Here, we develop an analogous theory of topological fluid acoustics, and propose a scheme for realizing topological edge states in an acoustic structure containing circulating fluids. The phenomenon of disorder-free one-way sound propagation, which does not occur in ordinary acoustic devices, may have novel applications for acoustic isolators, modulators, and transducers. PMID:25839273

  16. Scanning tomographic acoustic microscopy: principles and recent developments (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Wade, G.; Meyyappan, A.

    1987-09-01

    Acoustic Microscopy is an important branch of non-destructive evaluation which provides high resolution for imaging the detailed structure of a small object. When an acoustic microscope operates in the transmission mode, the micrograph is simply a shadowgraph of all the structures encountered by the acoustic wave passing through the object. Because of diffraction and overlapping, the resultant images are difficult to comprehend in the case of specimens of substantial thickness and structural complexity. We used the principles of diffraction tomography and acoustical holography along with digital calcuations of wavefield propagation to overcome this problem. We have described in previously-published work how a scanning laser acoustic microscope (SLAM) can be modified to obtain data for subsurface tomographic imaging. In this paper, we review the principles of scanning tomographic acoustic microscopy (STAM). The required modification of SLAM to obtain STAM and the reconstruction process are described. We show how we are able to accurately acquire the complex-amplitude information necessary for image reconstruction. We demonstrate the power of this technique by comparing digitally-computed images thus obtained with analogue images of a conventional SLAM. The results show that high-quality, high-resolution subsurface images can be obtained from experimentally acquired data. We also describe techniques to obtain projection data from different angles of wave incidence enabling us to tomographically reconstruct different planes of a complex specimen in microscopic detail. With these modifications in place, STAM should shortly become a powerful tool in non-destructive evaluation.

  17. Flight validation of ground-based assessment for control power requirements at high angles of attack

    NASA Technical Reports Server (NTRS)

    Ogburn, Marilyn E.; Ross, Holly M.; Foster, John V.; Pahle, Joseph W.; Sternberg, Charles A.; Traven, Ricardo; Lackey, James B.; Abbott, Troy D.

    1994-01-01

    A review is presented in viewgraph format of an ongoing NASA/U.S. Navy study to determine control power requirements at high angles of attack for the next generation high-performance aircraft. This paper focuses on recent flight test activities using the NASA High Alpha Research Vehicle (HARV), which are intended to validate results of previous ground-based simulation studies. The purpose of this study is discussed, and the overall program structure, approach, and objectives are described. Results from two areas of investigation are presented: (1) nose-down control power requirements and (2) lateral-directional control power requirements. Selected results which illustrate issues and challenges that are being addressed in the study are discussed including test methodology, comparisons between simulation and flight, and general lessons learned.

  18. Theoretical requirements for broadband perfect absorption of acoustic waves by ultra-thin elastic meta-films

    PubMed Central

    Duan, Yuetao; Luo, Jie; Wang, Guanghao; Hang, Zhi Hong; Hou, Bo; Li, Jensen; Sheng, Ping; Lai, Yun

    2015-01-01

    We derive and numerically demonstrate that perfect absorption of elastic waves can be achieved in two types of ultra-thin elastic meta-films: one requires a large value of almost pure imaginary effective mass density and a free space boundary, while the other requires a small value of almost pure imaginary effective modulus and a hard wall boundary. When the pure imaginary density or modulus exhibits certain frequency dispersions, the perfect absorption effect becomes broadband, even in the low frequency regime. Through a model analysis, we find that such almost pure imaginary effective mass density with required dispersion for perfect absorption can be achieved by elastic metamaterials with large damping. Our work provides a feasible approach to realize broadband perfect absorption of elastic waves in ultra-thin films. PMID:26184117

  19. Acoustic neuroma

    MedlinePlus

    Vestibular schwannoma; Tumor - acoustic; Cerebellopontine angle tumor; Angle tumor ... 177. Battista RA. Gamma knife radiosurgery for vestibular schwannoma. Otolaryngol Clin North Am . 2009;42:635-654. ...

  20. General requirements on matter power spectrum predictions for cosmology with weak lensing tomography

    SciTech Connect

    Hearin, Andrew P.; Zentner, Andrew R.; Ma, Zhaoming E-mail: zentner@pitt.edu

    2012-04-01

    Forthcoming projects such as DES, LSST, WFIRST, and Euclid aim to measure weak lensing shear correlations with unprecedented precision, constraining the dark energy equation of state at the percent level. Reliance on photometrically-determined redshifts constitutes a major source of uncertainty for these surveys. Additionally, interpreting the weak lensing signal requires a detailed understanding of the nonlinear physics of gravitational collapse. We present a new analysis of the stringent calibration requirements for weak lensing analyses of future imaging surveys that addresses both photo-z uncertainty and errors in the calibration of the matter power spectrum. We find that when photo-z uncertainty is taken into account the requirements on the level of precision in the prediction for the matter power spectrum are more stringent than previously thought. Including degree-scale galaxy clustering statistics in a joint analysis with weak lensing not only strengthens the survey's constraining power by ∼ 20%, but can also have a profound impact on the calibration demands, decreasing the degradation in dark energy constraints with matter power spectrum uncertainty by a factor of 2-5. Similarly, using galaxy clustering information significantly relaxes the demands on photo-z calibration. We compare these calibration requirements to the contemporary state-of-the-art in photometric redshift estimation and predictions of the power spectrum and suggest strategies to utilize forthcoming data optimally.

  1. Compact acoustic refrigerator

    DOEpatents

    Bennett, Gloria A.

    1992-01-01

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits (22), in a borehole environment. An acoustic engine (12, 14) includes first thermodynamic elements (12) for generating a standing acoustic wave in a selected medium. An acoustic refrigerator (16, 26, 28) includes second thermodynamic elements (16) located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements (16) and a relatively hot temperature at a second end of the second thermodynamic elements (16). A resonator volume (18) cooperates with the first and second thermodynamic elements (12, 16) to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements (12, 16), first heat pipes (24, 26) transfer heat from the heat load (22) to the second thermodynamic elements (16) and second heat pipes (28, 32) transfer heat from first and second thermodynamic elements (12, 16) to the borehole environment.

  2. Compact acoustic refrigerator

    SciTech Connect

    Bennett, G.A.

    1991-12-31

    This invention is comprised of a compact acoustic refrigeration system that actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment.

  3. Compact acoustic refrigerator

    DOEpatents

    Bennett, G.A.

    1992-11-24

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment. 18 figs.

  4. Online Identification of Power Required for Self-Sustainability of the Battery in Hybrid Electric Vehicles

    SciTech Connect

    Malikopoulos, Andreas

    2014-01-01

    Hybrid electric vehicles have shown great potential for enhancing fuel economy and reducing emissions. Deriving a power management control policy to distribute the power demanded by the driver optimally to the available subsystems (e.g., the internal combustion engine, motor, generator, and battery) has been a challenging control problem. One of the main aspects of the power management control algorithms is concerned with the self-sustainability of the electrical path, which must be guaranteed for the entire driving cycle. This paper considers the problem of identifying online the power required by the battery to maintain the state of charge within a range of the target value. An algorithm is presented that realizes how much power the engine needs to provide to the battery so that self-sustainability of the electrical path is maintained.

  5. Spacecraft Internal Acoustic Environment Modeling

    NASA Technical Reports Server (NTRS)

    Chu, S. Reynold; Allen, Chris

    2009-01-01

    The objective of the project is to develop an acoustic modeling capability, based on commercial off-the-shelf software, to be used as a tool for oversight of the future manned Constellation vehicles. The use of such a model will help ensure compliance with acoustic requirements. Also, this project includes modeling validation and development feedback via building physical mockups and conducting acoustic measurements to compare with the predictions.

  6. Effect of acoustic frequency and power density on the aqueous ultrasonic-assisted extraction of grape pomace (Vitis vinifera L.) - a response surface approach.

    PubMed

    González-Centeno, María Reyes; Knoerzer, Kai; Sabarez, Henry; Simal, Susana; Rosselló, Carmen; Femenia, Antoni

    2014-11-01

    Aqueous ultrasound-assisted extraction (UAE) of grape pomace was investigated by Response Surface Methodology (RSM) to evaluate the effect of acoustic frequency (40, 80, 120kHz), ultrasonic power density (50, 100, 150W/L) and extraction time (5, 15, 25min) on total phenolics, total flavonols and antioxidant capacity. All the process variables showed a significant effect on the aqueous UAE of grape pomace (p<0.05). The Box-Behnken Design (BBD) generated satisfactory mathematical models which accurately explain the behavior of the system; allowing to predict both the extraction yield of phenolic and flavonol compounds, and also the antioxidant capacity of the grape pomace extracts. The optimal UAE conditions for all response factors were a frequency of 40kHz, a power density of 150W/L and 25min of extraction time. Under these conditions, the aqueous UAE would achieve a maximum of 32.31mg GA/100g fw for total phenolics and 2.04mg quercetin/100g fw for total flavonols. Regarding the antioxidant capacity, the maximum predicted values were 53.47 and 43.66mg Trolox/100g fw for CUPRAC and FRAP assays, respectively. When comparing with organic UAE, in the present research, from 12% to 38% of total phenolic bibliographic values were obtained, but using only water as the extraction solvent, and applying lower temperatures and shorter extraction times. To the best of the authors' knowledge, no studies specifically addressing the optimization of both acoustic frequency and power density during aqueous-UAE of plant materials have been previously published. PMID:24548543

  7. How wing kinematics affect power requirements and aerodynamic force production in a robotic bat wing.

    PubMed

    Bahlman, Joseph W; Swartz, Sharon M; Breuer, Kenneth S

    2014-06-01

    Bats display a wide variety of behaviors that require different amounts of aerodynamic force. To control and modulate aerodynamic force, bats change wing kinematics, which, in turn, may change the power required for wing motion. There are many kinematic mechanisms that bats, and other flapping animals, can use to increase aerodynamic force, e.g. increasing wingbeat frequency or amplitude. However, we do not know if there is a difference in energetic cost between these different kinematic mechanisms. To assess the relationship between mechanical power input and aerodynamic force output across different isolated kinematic parameters, we programmed a robotic bat wing to flap over a range of kinematic parameters and measured aerodynamic force and mechanical power. We systematically varied five kinematic parameters: wingbeat frequency, wingbeat amplitude, stroke plane angle, downstroke ratio, and wing folding. Kinematic values were based on observed values from free flying Cynopterus brachyotis, the species on which the robot was based. We describe how lift, thrust, and power change with increases in each kinematic variable. We compare the power costs associated with generating additional force through the four kinematic mechanisms controlled at the shoulder, and show that all four mechanisms require approximately the same power to generate a given force. This result suggests that no single parameter offers an energetic advantage over the others. Finally, we show that retracting the wing during upstroke reduces power requirements for flapping and increases net lift production, but decreases net thrust production. These results compare well with studies performed on C. brachyotis, offering insight into natural flight kinematics. PMID:24851830

  8. Far-Field Acoustic Power Level and Performance Analyses of F31/A31 Open Rotor Model at Simulated Scaled Takeoff, Nominal Takeoff, and Approach Conditions: Technical Report I

    NASA Technical Reports Server (NTRS)

    Sree, Dave

    2015-01-01

    Far-field acoustic power level and performance analyses of open rotor model F31/A31 have been performed to determine its noise characteristics at simulated scaled takeoff, nominal takeoff, and approach flight conditions. The nonproprietary parts of the data obtained from experiments in 9- by 15-Foot Low-Speed Wind Tunnel (9?15 LSWT) tests were provided by NASA Glenn Research Center to perform the analyses. The tone and broadband noise components have been separated from raw test data by using a new data analysis tool. Results in terms of sound pressure levels, acoustic power levels, and their variations with rotor speed, angle of attack, thrust, and input shaft power have been presented and discussed. The effect of an upstream pylon on the noise levels of the model has been addressed. Empirical equations relating model's acoustic power level, thrust, and input shaft power have been developed. The far-field acoustic efficiency of the model is also determined for various simulated flight conditions. It is intended that the results presented in this work will serve as a database for comparison and improvement of other open rotor blade designs and also for validating open rotor noise prediction codes.

  9. Acoustic noise from volcanoes - Theory and experiment

    NASA Technical Reports Server (NTRS)

    Woulff, G.; Mcgetchin, T. R.

    1976-01-01

    The paper discusses some theoretical aspects of acoustic investigation of volcanoes and describes a field experiment involving the recording, analysis, and interpretation of acoustic radiation from energetic fumaroles at Volcan Acatenango, Guatemala, during mid-January 1973. Particular attention is given to deriving information about the flow velocity of the erupting medium from acoustics as a means to study eruption dynamics. Theoretical considerations suggest that acoustic power radiated during gaseous volcanic eruptions may be related to gas exit velocity according to appropriate power laws. Eruption acoustics proves useful as a means of quantitative monitoring of volcanic activity.

  10. Development and testing of cabin sidewall acoustic resonators for the reduction of cabin tone levels in propfan-powered aircraft

    NASA Technical Reports Server (NTRS)

    Kuntz, H. L.; Gatineau, R. J.; Prydz, R. A.; Balena, F. J.

    1991-01-01

    The use of Helmholtz resonators to increase the sidewall transmission loss (TL) in aircraft cabin sidewalls is evaluated. Development, construction, and test of an aircraft cabin acoustic enclosure, built in support of the Propfan Test Assessment (PTA) program, is described. Laboratory and flight test results are discussed. Resonators (448) were located between the enclosure trim panels and the fuselage shell. In addition, 152 resonators were placed between the enclosure and aircraft floors. The 600 resonators were each tuned to a propfan fundamental blade passage frequency (235 Hz). After flight testing on the PTA aircraft, noise reduction (NR) tests were performed with the enclosure in the Kelly Johnson Research and Development Center Acoustics Laboratory. Broadband and tonal excitations were used in the laboratory. Tonal excitation simulated the propfan flight test excitation. The resonators increase the NR of the cabin walls around the resonance frequency of the resonator array. Increases in NR of up to 11 dB were measured. The effects of flanking, sidewall absorption, cabin absorption, resonator loading of trim panels, and panel vibrations are presented. Resonator and sidewall panel design and test are discussed.

  11. Application of enhanced modern structured analysis techniques to Space Station Freedom electric power system requirements

    NASA Technical Reports Server (NTRS)

    Biernacki, John; Juhasz, John; Sadler, Gerald

    1991-01-01

    A team of Space Station Freedom (SSF) system engineers are in the process of extensive analysis of the SSF requirements, particularly those pertaining to the electrical power system (EPS). The objective of this analysis is the development of a comprehensive, computer-based requirements model, using an enhanced modern structured analysis methodology (EMSA). Such a model provides a detailed and consistent representation of the system's requirements. The process outlined in the EMSA methodology is unique in that it allows the graphical modeling of real-time system state transitions, as well as functional requirements and data relationships, to be implemented using modern computer-based tools. These tools permit flexible updating and continuous maintenance of the models. Initial findings resulting from the application of EMSA to the EPS have benefited the space station program by linking requirements to design, providing traceability of requirements, identifying discrepancies, and fostering an understanding of the EPS.

  12. Musical Acoustics

    NASA Astrophysics Data System (ADS)

    Gough, Colin

    This chapter provides an introduction to the physical and psycho-acoustic principles underlying the production and perception of the sounds of musical instruments. The first section introduces generic aspects of musical acoustics and the perception of musical sounds, followed by separate sections on string, wind and percussion instruments.

  13. Satellite Power System (SPS) resource requirements (critical materials, energy and land)

    NASA Technical Reports Server (NTRS)

    Kotin, A. D.

    1978-01-01

    The resource impacts of the proposed satellite power system are evaluated. Three classes of resource impacts are considered separately: critical materials, energy, and land use. The analysis focuses on the requirements associated with the annual development of two five-gigawatt satellites and the associated receiving facilities.

  14. 26 CFR 601.504 - Requirements for filing power of attorney.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Treasury Department Circular No. 21, as amended, 31 CFR part 240. Endorsement and payment of such check by... prescribed by Circular No. 21, 31 CFR part 240. For restrictions on the assignment of claims, see Revised... 26 Internal Revenue 20 2010-04-01 2010-04-01 false Requirements for filing power of attorney....

  15. 26 CFR 601.504 - Requirements for filing power of attorney.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Treasury Department Circular No. 21, as amended, 31 CFR part 240. Endorsement and payment of such check by... prescribed by Circular No. 21, 31 CFR part 240. For restrictions on the assignment of claims, see Revised... 26 Internal Revenue 20 2011-04-01 2011-04-01 false Requirements for filing power of attorney....

  16. 26 CFR 601.504 - Requirements for filing power of attorney.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Treasury Department Circular No. 21, as amended, 31 CFR part 240. Endorsement and payment of such check by... prescribed by Circular No. 21, 31 CFR part 240. For restrictions on the assignment of claims, see Revised... 26 Internal Revenue 20 2012-04-01 2012-04-01 false Requirements for filing power of attorney....

  17. 14 CFR 121.331 - Supplemental oxygen requirements for pressurized cabin airplanes: Reciprocating engine powered...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Supplemental oxygen requirements for pressurized cabin airplanes: Reciprocating engine powered airplanes. 121.331 Section 121.331 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE:...

  18. 42 CFR 84.146 - Method of measuring the power and torque required to operate blowers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Method of measuring the power and torque required to operate blowers. 84.146 Section 84.146 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators...

  19. 10 CFR 50.65 - Requirements for monitoring the effectiveness of maintenance at nuclear power plants.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Issuance, Limitations, and Conditions of Licenses and... plants. The requirements of this section are applicable during all conditions of plant operation, including normal shutdown operations. (a)(1) Each holder of an operating license for a nuclear power...

  20. Ideal MHD Stability Prediction and Required Power for EAST Advanced Scenario

    NASA Astrophysics Data System (ADS)

    Chen, Junjie; Li, Guoqiang; Qian, Jinping; Liu, Zixi

    2012-11-01

    The Experimental Advanced Superconducting Tokamak (EAST) is the first fully superconducting tokamak with a D-shaped cross-sectional plasma presently in operation. The ideal magnetohydrodynamic (MHD) stability and required power for the EAST advanced tokamak (AT) scenario with negative central shear and double transport barrier (DTB) are investigated. With the equilibrium code TOQ and stability code GATO, the ideal MHD stability is analyzed. It is shown that a moderate ratio of edge transport barriers' (ETB) height to internal transport barriers' (ITBs) height is beneficial to ideal MHD stability. The normalized beta βN limit is about 2.20 (without wall) and 3.70 (with ideal wall). With the scaling law of energy confinement time, the required heating power for EAST AT scenario is calculated. The total heating power Pt increases as the toroidal magnetic field BT or the normalized beta βN is increased.

  1. Satellite Power Systems (SPS) concept definition study. Volume 2: SPS system requirements

    NASA Technical Reports Server (NTRS)

    Hanley, G.

    1978-01-01

    Collected data reflected the level of definition resulting from the evaluation of a broad spectrum of SPS (satellite power systems) concepts. As the various concepts matured, these requirements were updated to reflect the requirements identified for the projected satellite system/subsystem point design(s). The study established several candidate concepts which were presented to provide a basis for the selection of one or two approaches that would be given a more comprehensive examination. The two selected concepts were expanded and constitute the selected system point designs. The identified system/subsystem requirements was emphasized and information on the selected point design was provided.

  2. Power Control and Monitoring Requirements for Thermal Vacuum/Thermal Balance Testing of the MAP Observatory

    NASA Technical Reports Server (NTRS)

    Johnson, Chris; Hinkle, R. Kenneth (Technical Monitor)

    2002-01-01

    The specific heater control requirements for the thermal vacuum and thermal balance testing of the Microwave Anisotropy Probe (MAP) Observatory at the Goddard Space Flight Center (GSFC) in Greenbelt, Maryland are described. The testing was conducted in the 10m wide x 18.3m high Space Environment Simulator (SES) Thermal Vacuum Facility. The MAP thermal testing required accurate quantification of spacecraft and fixture power levels while minimizing heater electrical emissions. The special requirements of the MAP test necessitated construction of five (5) new heater racks.

  3. Tandem concentrator photovoltaic array applied to Space Station Freedom evolutionary power requirements

    NASA Technical Reports Server (NTRS)

    Fisher, Edward M., Jr.

    1991-01-01

    Additional power is required to support Space Station Freedom (SSF) evolution. Boeing Defense and Space Group, LeRC, and Entech Corporation have participated in the development of efficiency gallium arsenide and gallium antimonide solar cells make up the solar array tandem cell stacks. Entech's Mini-Dome Fresnel Lens Concentrators focus solar energy onto the active area of the solar cells at 50 times one solar energy flux. Development testing for a flight array, to be launched in Nov. 1992 is under way with support from LeRC. The tandem cells, interconnect wiring, concentrator lenses, and structure were integrated into arrays subjected to environmental testing. A tandem concentrator array can provide high mass and area specific power and can provide equal power with significantly less array area and weight than the baseline array design. Alternatively, for SSF growth, an array of twice the baseline power can be designed which still has a smaller drag area than the baseline.

  4. Rechargeable lithium battery for use in applications requiring a low to high power output

    DOEpatents

    Bates, John B.

    1997-01-01

    Rechargeable lithium batteries which employ characteristics of thin-film batteries can be used to satisfy power requirements within a relatively broad range. Thin-film battery cells utilizing a film of anode material, a film of cathode material and an electrolyte of an amorphous lithium phosphorus oxynitride can be connected in series or parallel relationship for the purpose of withdrawing electrical power simultaneously from the cells. In addition, such battery cells which employ a lithium intercalation compound as its cathode material can be connected in a manner suitable for supplying power for the operation of an electric vehicle. Still further, by incorporating within the battery cell a relatively thick cathode of a lithium intercalation compound, a relatively thick anode of lithium and an electrolyte film of lithium phosphorus oxynitride, the battery cell is rendered capable of supplying power for any of a number of consumer products, such as a laptop computer or a cellular telephone.

  5. Rechargeable lithium battery for use in applications requiring a low to high power output

    DOEpatents

    Bates, John B.

    1996-01-01

    Rechargeable lithium batteries which employ characteristics of thin-film batteries can be used to satisfy power requirements within a relatively broad range. Thin-film battery cells utilizing a film of anode material, a film of cathode material and an electrolyte of an amorphorus lithium phosphorus oxynitride can be connected in series or parallel relationship for the purpose of withdrawing electrical power simultaneously from the cells. In addition, such battery cells which employ a lithium intercalation compound as its cathode material can be connected in a manner suitable for supplying power for the operation of an electric vehicle. Still further, by incorporating within the battery cell a relatively thick cathode of a lithium intercalation compound, a relatively thick anode of lithium and an electrolyte film of lithium phosphorus oxynitride, the battery cell is rendered capable of supplying power for any of a number of consumer products, such as a laptop computer or a cellular telephone.

  6. Power processing and control requirements of dispersed solar thermal electric generation systems

    NASA Technical Reports Server (NTRS)

    Das, R. L.

    1980-01-01

    Power Processing and Control requirements of Dispersed Receiver Solar Thermal Electric Generation Systems are presented. Kinematic Stirling Engines, Brayton Engines and Rankine Engines are considered as prime movers. Various types of generators are considered for ac and dc link generations. It is found that ac-ac Power Conversion is not suitable for implementation at this time. It is also found that ac-dc-ac Power Conversion with a large central inverter is more efficient than ac-dc-ac Power Conversion using small dispersed inverters. Ac-link solar thermal electric plants face potential stability and synchronization problems. Research and development efforts are needed in improving component performance characteristics and generation efficiency to make Solar Thermal Electric Generation economically attractive.

  7. Surface acoustic wave stabilized oscillators

    NASA Technical Reports Server (NTRS)

    Parker, T. E.

    1978-01-01

    A number of 401.2 MHz surface acoustic wave (SAW) controlled oscillators were built and tested. The performance of these oscillators was evaluated for possible use as stable oscillators in communication systems. A short term frequency stability of better than 1 x 10 to the minus 9th power for one second was measured for the SAW oscillators. Long term frequency drift was measured and was found to be dependent on SAW design and packaging. Drift rates ranging from 15 ppm in twenty weeks to 2.5 ppm in twenty weeks were observed. Some further improvement was required. The temperature dependence of the saw oscillators was evaluated and it was concluded that some form of temperature compensation will be necessary to meet the requirements of some communication systems.

  8. Power systems and requirements for the integration of smart structures into aircraft

    NASA Astrophysics Data System (ADS)

    Lockyer, Allen J.; Martin, Christopher A.; Lindner, Douglas K.; Walia, Paramjit S.

    2002-07-01

    Electrical power distribution for recently developed smart actuators becomes an important air-vehicle challenge if projected smart actuation benefits are to be met. Among the items under development are variable shape inlets and control surfaces that utilize shape memory alloys (SMA); full span, chord-wise and span-wise contouring trailing control surfaces that use SMA or piezoelectric materials for actuation; and other strain-based actuators for buffet load alleviation, flutter suppression and flow control. At first glance, such technologies afford overall vehicle performance improvement, however, integration system impacts have yet to be determined or quantified. Power systems to support smart structures initiatives are the focus of the current paper. The paper has been organized into five main topics for further discussion: (1) air-vehicle power system architectures - standard and advanced distribution concepts for actuators, (2) smart wing actuator power requirements and results - highlighting wind tunnel power measurements from shape memory alloy and piezoelectric ultrasonic motor actuated control surfaces and different dynamic pressure and angle of attack; (3) vehicle electromagnetic effects (EME) issues, (4) power supply design considerations for smart actuators - featuring the aircraft power and actuator interface, and (5) summary and conclusions.

  9. Power and length requirements for all-optical switching in semiconductor-doped glass waveguides

    NASA Astrophysics Data System (ADS)

    Mayweather, Derek T.; Digonnet, Michel J. F.; Pantell, Richard H.; Shaw, H. J.

    1994-10-01

    We present a theoretical model that computes the nonlinear index (n2) of semiconductor- doped glasses (SDG), based on the material's properties, and predicts the power and length requirements, as well as the optimum operating wavelengths, for an all-optical SDG waveguide switch. The main conclusions are that (1) n2 depends strongly on pump intensity, which partly explains the large disparity in reported values of n2, (2) the pump and signal wavelengths should be in specific and different ranges to minimize switching power and signal loss, (3) for CdSSe- and CdTe-doped glasses, n2 is relatively small, and the switching power requirement for these two SDGs is consequently quite high (2 - 16 W). We provide evidence that this weak nonlinearity, compared to that of similar semiconductors in bulk, is due to the strong nonradiative recombination of carriers arising from the small size of the semiconductor microcrystallites. Projections indicate that the switching power would be reduced by up to three orders of magnitude by increasing the microcrystallite size, thus producing a slower (ns) but more power-efficient switch.

  10. The Testing Behind the Test Facility: the Acoustic Design of the NASA Glenn Research Center's World-Class Reverberant Acoustic Test Facility

    NASA Technical Reports Server (NTRS)

    Hughes, William O.; McNelis, Mark E.; Hozman, Aron D.; McNelis, Anne M.

    2010-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is leading the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC s Plum Brook Station in Sandusky, Ohio, U.S.A. Benham Companies, LLC is currently constructing modal, base-shake sine and reverberant acoustic test facilities to support the future testing needs of NASA s space exploration program. The large Reverberant Acoustic Test Facility (RATF) will be approximately 101,000 ft3 in volume and capable of achieving an empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world s known active reverberant acoustic test facilities. The key to achieving the expected acoustic test spectra for a range of many NASA space flight environments in the RATF is the knowledge gained from a series of ground acoustic tests. Data was obtained from several NASA-sponsored test programs, including testing performed at the National Research Council of Canada s acoustic test facility in Ottawa, Ontario, Canada, and at the Redstone Technical Test Center acoustic test facility in Huntsville, Alabama, U.S.A. The majority of these tests were performed to characterize the acoustic performance of the modulators (noise generators) and representative horns that would be required to meet the desired spectra, as well as to evaluate possible supplemental gas jet noise sources. The knowledge obtained in each of these test programs enabled the design of the RATF sound generation system to confidently advance to its final acoustic design and subsequent ongoing construction.

  11. The Testing Behind The Test Facility: The Acoustic Design of the NASA Glenn Research Center's World-Class Reverberant Acoustic Test Facility

    NASA Technical Reports Server (NTRS)

    Hughes, William O.; McNelis, Mark E.; McNelis, Anne M.

    2011-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is leading the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC?s Plum Brook Station in Sandusky, Ohio, USA. Benham Companies, LLC is currently constructing modal, base-shake sine and reverberant acoustic test facilities to support the future testing needs of NASA?s space exploration program. T he large Reverberant Acoustic Test Facility (RATF) will be approximately 101,000 ft3 in volume and capable of achieving an empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world?s known active reverberant acoustic test facilities. The key to achieving the expected acoustic test spectra for a range of many NASA space flight environments in the RATF is the knowledge gained from a series of ground acoustic tests. Data was obtained from several NASA-sponsored test programs, including testing performed at the National Research Council of Canada?s acoustic test facility in Ottawa, Ontario, Canada, and at the Redstone Technical Test Center acoustic test facility in Huntsville, Alabama, USA. The majority of these tests were performed to characterize the acoustic performance of the modulators (noise generators) and representative horns that would be required to meet the desired spectra, as well as to evaluate possible supplemental gas jet noise sources. The knowledge obtained in each of these test programs enabled the design of the RATF sound generation system to confidently advance to its final acoustic de-sign and subsequent on-going construction.

  12. The Testing Behind The Test Facility: The Acoustic Design of the NASA Glenn Research Center's World-Class Reverberant Acoustic Test Facility

    NASA Technical Reports Server (NTRS)

    Hozman, Aron D.; Hughes, William O.; McNelis, Mark E.; McNelis, Anne M.

    2011-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is leading the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC's Plum Brook Station in Sandusky, Ohio, USA. Benham Companies, LLC is currently constructing modal, base-shake sine and reverberant acoustic test facilities to support the future testing needs of NASA's space exploration program. The large Reverberant Acoustic Test Facility (RATF) will be approximately 101,000 cu ft in volume and capable of achieving an empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world's known active reverberant acoustic test facilities. The key to achieving the expected acoustic test spectra for a range of many NASA space flight environments in the RATF is the knowledge gained from a series of ground acoustic tests. Data was obtained from several NASA-sponsored test programs, including testing performed at the National Research Council of Canada's acoustic test facility in Ottawa, Ontario, Canada, and at the Redstone Technical Test Center acoustic test facility in Huntsville, Alabama, USA. The majority of these tests were performed to characterize the acoustic performance of the modulators (noise generators) and representative horns that would be required to meet the desired spectra, as well as to evaluate possible supplemental gas jet noise sources. The knowledge obtained in each of these test programs enabled the design of the RATF sound generation system to confidently advance to its final acoustic design and subsequent on-going construction.

  13. Surface Acoustic Wave Microfluidics

    NASA Astrophysics Data System (ADS)

    Yeo, Leslie Y.; Friend, James R.

    2014-01-01

    Fluid manipulations at the microscale and beyond are powerfully enabled through the use of 10-1,000-MHz acoustic waves. A superior alternative in many cases to other microfluidic actuation techniques, such high-frequency acoustics is almost universally produced by surface acoustic wave devices that employ electromechanical transduction in wafer-scale or thin-film piezoelectric media to generate the kinetic energy needed to transport and manipulate fluids placed in adjacent microfluidic structures. These waves are responsible for a diverse range of complex fluid transport phenomena - from interfacial fluid vibration and drop and confined fluid transport to jetting and atomization - underlying a flourishing research literature spanning fundamental fluid physics to chip-scale engineering applications. We highlight some of this literature to provide the reader with a historical basis, routes for more detailed study, and an impression of the field's future directions.

  14. Design requirements document for the phase 1 privatization electrical power system

    SciTech Connect

    Singh, G.

    1997-10-31

    The electrical system for the Phase 1 privatization facilities will support the TWRS mission by providing the electrical power to the Phase 1 privatized facilities. This system will receive power from the Department of Energy-Richland Operations (RL) A4-8 230 kV transmission system powered from Bonneville Power Administration (BPA) Ashe and Midway 230 kV Substations. The existing RL 230 kV transmission line will be modified and looped 1021 into the new 230 kV substation bus. The new substation will be located in the vicinity of the privatized facilities, approximately 3.2 km (2 mi) south of the existing RL A4-8 230 kV transmission line. The substation will be capable of providing up to 40 MW of electrical power to support the Phase 1 privatization facilities and has space for accommodating future expansions. The substation will require at least two 230-13.8 kV transformers, 13.8 kV split bus switchgear, switchgear building, grounding transformers, instrument transformers, control and monitoring equipment, associated protection and isolation devices, lightning protection, yard lighting, cable and raceways, and infrastructure needed to provide desired availability and reliability. The power from the 13.8 kV switchgear located in the switchgear building will be delivered at the privatization facilities site boundaries. The 13.8 kV distribution system inside the privatization facilities site boundaries is the responsibility of the privatization contract.

  15. Biomimetic smart sensors for autonomous robotic behavior I: acoustic processing

    NASA Astrophysics Data System (ADS)

    Deligeorges, Socrates; Xue, Shuwan; Soloway, Aaron; Lichtenstein, Lee; Gore, Tyler; Hubbard, Allyn

    2009-05-01

    Robotics are rapidly becoming an integral tool on the battlefield and in homeland security, replacing humans in hazardous conditions. To enhance the effectiveness of robotic assets and their interaction with human operators, smart sensors are required to give more autonomous function to robotic platforms. Biologically inspired sensors are an essential part of this development of autonomous behavior and can increase both capability and performance of robotic systems. Smart, biologically inspired acoustic sensors have the potential to extend autonomous capabilities of robotic platforms to include sniper detection, vehicle tracking, personnel detection, and general acoustic monitoring. The key to enabling these capabilities is biomimetic acoustic processing using a time domain processing method based on the neural structures of the mammalian auditory system. These biologically inspired algorithms replicate the extremely adaptive processing of the auditory system yielding high sensitivity over broad dynamic range. The algorithms provide tremendous robustness in noisy and echoic spaces; properties necessary for autonomous function in real world acoustic environments. These biomimetic acoustic algorithms also provide highly accurate localization of both persistent and transient sounds over a wide frequency range, using baselines on the order of only inches. A specialized smart sensor has been developed to interface with an iRobot Packbot® platform specifically to enhance its autonomous behaviors in response to personnel and gunfire. The low power, highly parallel biomimetic processor, in conjunction with a biomimetic vestibular system (discussed in the companion paper), has shown the system's autonomous response to gunfire in complicated acoustic environments to be highly effective.

  16. Room Acoustics

    NASA Astrophysics Data System (ADS)

    Kuttruff, Heinrich; Mommertz, Eckard

    The traditional task of room acoustics is to create or formulate conditions which ensure the best possible propagation of sound in a room from a sound source to a listener. Thus, objects of room acoustics are in particular assembly halls of all kinds, such as auditoria and lecture halls, conference rooms, theaters, concert halls or churches. Already at this point, it has to be pointed out that these conditions essentially depend on the question if speech or music should be transmitted; in the first case, the criterion for transmission quality is good speech intelligibility, in the other case, however, the success of room-acoustical efforts depends on other factors that cannot be quantified that easily, not least it also depends on the hearing habits of the listeners. In any case, absolutely "good acoustics" of a room do not exist.

  17. Acoustic Neuroma

    MedlinePlus

    ... slow growing tumor which arise primarily from the vestibular portion of the VIII cranial nerve and lie ... you have a "brain tumor" called acoustic neuroma (vestibular schwannoma). You think you are the only one ...

  18. Underwater Acoustics

    NASA Astrophysics Data System (ADS)

    Kuperman, William A.; Roux, Philippe

    It is well underwater established that sound waves, compared to electromagnetic waves, propagate long distances in the ocean. Hence, in the ocean as opposed to air or a vacuum, one uses sound navigation and ranging (SONAR) instead navigation and ranging (SONAR) of radar, acoustic communication instead of radio, and acoustic imaging and tomography instead of microwave or optical imaging or X-ray tomography. Underwater acoustics is the science of sound in water (most commonly in the ocean) and encompasses not only the study of sound propagation, but also the masking of sound signals by interfering phenomenon and signal processing for extracting these signals from interference. This chapter we will present the basics physics of ocean acoustics and then discuss applications.

  19. Earth Observing System (EOS) Terra Spacecraft 120 Volt Power Subsystem: Requirements, Development and Implementation

    NASA Technical Reports Server (NTRS)

    Keys, Denney J.

    2000-01-01

    Built by the Lockheed-Martin Corporation, the Earth Observing System (EOS) TERRA spacecraft represents the first orbiting application of a 120 Vdc high voltage spacecraft electrical power system implemented by the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC). The EOS TERRA spacecraft's launch provided a major contribution to the NASA Mission to Planet Earth program while incorporating many state of the art electrical power system technologies to achieve its mission goals. The EOS TERRA spacecraft was designed around five state-of-the-art scientific instrument packages designed to monitor key parameters associated with the earth's climate. The development focus of the TERRA electrical power system (EPS) resulted from a need for high power distribution to the EOS TERRA spacecraft subsystems and instruments and minimizing mass and parasitic losses. Also important as a design goal of the EPS was maintaining tight regulation on voltage and achieving low conducted bus noise characteristics. This paper outlines the major requirements for the EPS as well as the resulting hardware implementation approach adopted to meet the demands of the EOS TERRA low earth orbit mission. The selected orbit, based on scientific needs, to achieve the EOS TERRA mission goals is a sun-synchronous circular 98.2degree inclination Low Earth Orbit (LEO) with a near circular average altitude of 705 kilometers. The nominal spacecraft orbit is approximately 99 minutes with an average eclipse period of about 34 minutes. The scientific goal of the selected orbit is to maintain a repeated 10:30 a.m. +/- 15 minute descending equatorial crossing which provides a fairly clear view of the earth's surface and relatively low cloud interference for the instrument observation measurements. The major EOS TERRA EPS design requirements are single fault tolerant, average orbit power delivery of 2, 530 watts with a defined minimum lifetime of five years (EOL). To meet

  20. Power spectra of geoid undulations. [definition of altimeter design requirements for geoid recovery

    NASA Technical Reports Server (NTRS)

    Brown, R. D.

    1975-01-01

    Data from spacecraft altimeters are expected to contribute to an improved determination of the marine geoid. To better define altimeter system design requirements for geoid recovery, amplitudes of geoid undulations at short wavelengths were examined. Models of detailed geoids in selected areas around the earth, developed from a combination of satellite derived spherical harmonics and 1 deg-by-1 deg area mean free-air gravity anomalies, were subjected to a spectral analysis. The resulting undulation power spectra were compared to existing estimates for the magnitude of geoid undulations at short wavelengths. The undulation spectra were found to be consistent with Kaula's rule of thumb, following an inverse third power relationship with spatial frequency for wavelengths at least as small as 300 km. The requirements imposed by this relationship on altimeter accuracy, data rate, and horizontal resolution to meet the goal of a detailed geoid description are discussed.

  1. COMBUSTION ACOUSTICS DIAGNOSTICS

    EPA Science Inventory

    This is an Exploratory Research Project that was awarded by APPCD for research on developing an acoustic flame condition monitor. It will involve a bench scale experiment of 4-6 weeks duration to record adjacent audible energy of a Bunsen burner. The experiment will require a d...

  2. Reactive power interconnection requirements for PV and wind plants : recommendations to NERC.

    SciTech Connect

    McDowell, Jason; Walling, Reigh; Peter, William; Von Engeln, Edi; Seymour, Eric; Nelson, Robert; Casey, Leo; Ellis, Abraham; Barker, Chris.

    2012-02-01

    Voltage on the North American bulk system is normally regulated by synchronous generators, which typically are provided with voltage schedules by transmission system operators. In the past, variable generation plants were considered very small relative to conventional generating units, and were characteristically either induction generator (wind) or line-commutated inverters (photovoltaic) that have no inherent voltage regulation capability. However, the growing level of penetration of non-traditional renewable generation - especially wind and solar - has led to the need for renewable generation to contribute more significantly to power system voltage control and reactive power capacity. Modern wind-turbine generators, and increasingly PV inverters as well, have considerable dynamic reactive power capability, which can be further enhanced with other reactive support equipment at the plant level to meet interconnection requirements. This report contains a set of recommendations to the North-America Electricity Reliability Corporation (NERC) as part of Task 1-3 (interconnection requirements) of the Integration of Variable Generation Task Force (IVGTF) work plan. The report discusses reactive capability of different generator technologies, reviews existing reactive power standards, and provides specific recommendations to improve existing interconnection standards.

  3. How Many Model Evaluations Are Required To Predict The AEP Of A Wind Power Plant?

    NASA Astrophysics Data System (ADS)

    Murcia, J. P.; Réthoré, P. E.; Natarajan, A.; Sørensen, J. D.

    2015-06-01

    Wind farm flow models have advanced considerably with the use of large eddy simulations (LES) and Reynolds averaged Navier-Stokes (RANS) computations. The main limitation of these techniques is their high computational time requirements; which makes their use for wind farm annual energy production (AEP) predictions expensive. The objective of the present paper is to minimize the number of model evaluations required to capture the wind power plant's AEP using stationary wind farm flow models. Polynomial chaos techniques are proposed based on arbitrary Weibull distributed wind speed and Von Misses distributed wind direction. The correlation between wind direction and wind speed are captured by defining Weibull-parameters as functions of wind direction. In order to evaluate the accuracy of these methods the expectation and variance of the wind farm power distributions are compared against the traditional binning method with trapezoidal and Simpson's integration rules. The wind farm flow model used in this study is the semi-empirical wake model developed by Larsen [1]. Three test cases are studied: a single turbine, a simple and a real offshore wind power plant. A reduced number of model evaluations for a general wind power plant is proposed based on the convergence of the present method for each case.

  4. Power Requirements for The NASA Mars Design Reference Architecture (DRA) 5.0

    NASA Technical Reports Server (NTRS)

    Cataldo, Robert L.

    2009-01-01

    This paper summarizes the power systems analysis results from NASA s recent Mars DRA 5.0 study which examined three architecture options and resulting mission requirements for a human Mars landing mission in the post-2030 timeframe. DRA 5.0 features a long approximately 500 day surface stay split mission using separate cargo and crewed Mars transfer vehicles. Two cargo flights, utilizing minimum energy trajectories, pre-deploy a cargo lander to the surface and a habitat lander into a 24-hour elliptical Mars parking orbit where it remains until the arrival of the crew during the next mission opportunity approximately 26 months later. The pre-deployment of cargo poses unique challenges for set-up and emplacement of surface assets that results in the need for self or robotically deployed designs. Three surface architecture options were evaluated for breadth of science content, extent of exploration range/capability and variations in system concepts and technology. This paper describes the power requirements for the surface operations of the three mission options, power system analyses including discussion of the nuclear fission, solar photovoltaic and radioisotope concepts for main base power and long range mobility.

  5. Material Requirements, Selection And Development for the Proposed JIMO SpacePower System

    NASA Astrophysics Data System (ADS)

    Ring, P. J.; Sayre, E. D.

    2004-02-01

    NASA is proposing a major new nuclear Space initiative-The Jupiter Icy Moons Orbiter (JIMO). A mission such as this inevitably requires a significant power source both for propulsion and for on-board power. Three reactor concepts, liquid metal cooled, heat pipe cooled and gas cooled are being considered together with three power conversion systems Brayton (cycle), Thermoelectric and Stirling cycles, and possibly Photo voltaics for future systems. Regardless of the reactor system selected it is almost certain that high temperature (materials), refractory alloys, will be required. This paper revisits the material selection options, reviewing the rationale behind the SP-100 selection of Nb-1Zr as the major cladding and structural material and considers the alternatives and developments needed for the longer duty cycle of the JIMO power supply. A side glance is also taken at the basis behind the selection of Uranium nitride fuel over UO2 or UC and a brief discussion of the reason for the selection of Lithium as the liquid metal coolant for SP-100 over other liquid metals.

  6. SNR characterization in distributed acoustic sensing

    NASA Astrophysics Data System (ADS)

    Gabai, Haniel; Eyal, Avishay

    2016-05-01

    In this paper we study the SNR associated with acoustic detection in Rayleigh-based Distributed Acoustic Sensing (DAS) systems. The study is focused on phase sensitive DAS due to its superiority in terms of linearity and sensitivity. Since DAS is based on coherent interference of backscattered light from multiple scatterers it is prone to signal fading. When left unresolved, the issue of signal fading renders the associated SNR randomly dependent on position and time. Hence, its proper measurement and characterization requires statistical tools. Here such tools are introduced and a methodology for finding the mean SNR and its distribution is implemented in both experiment and simulation. It is shown that the distribution of the DAS-SNR can be obtained from the distribution of backscattered power in OTDR and the mean DAS-SNR is proportional to the energy of the interrogation pulse.

  7. Acoustic field positioning for containerless processing

    NASA Technical Reports Server (NTRS)

    Whymark, R. R.

    1975-01-01

    The noncontact positioning of materials in a space processing chamber is accomplished using a new type of acoustic levitator. Liquid and solid materials are positioned using a single source of sound. Fine control of position may be obtained by motion of an acoustical reflector. The electrical power required is usually less than 100 watts. The system operates satisfactorily at high and low temperatures and is adaptable as an 'add-on' feature to existing space experiments. Containerless melting and solidification can be performed and a freely suspended liquid can be shaped to the contour of the sound field. Experiments are described in which aluminum, glass and plastic materials are melted and solidified in the containerless state. The system has applications to containerless crystal growth, melting and related processes.

  8. Risk-informed assessment of regulatory and design requirements for future nuclear power plants. Annual report

    SciTech Connect

    2000-08-01

    OAK B188 Risk-informed assessment of regulatory and design requirements for future nuclear power plants. Annual report. The overall goal of this research project is to support innovation in new nuclear power plant designs. This project is examining the implications, for future reactors and future safety regulation, of utilizing a new risk-informed regulatory system as a replacement for the current system. This innovation will be made possible through development of a scientific, highly risk-formed approach for the design and regulation of nuclear power plants. This approach will include the development and/or confirmation of corresponding regulatory requirements and industry standards. The major impediment to long term competitiveness of new nuclear plants in the U.S. is the capital cost component--which may need to be reduced on the order of 35% to 40% for Advanced Light Water Reactors (ALWRS) such as System 80+ and Advanced Boiling Water Reactor (ABWR). The required cost reduction for an ALWR such as AP600 or AP1000 would be expected to be less. Such reductions in capital cost will require a fundamental reevaluation of the industry standards and regulatory bases under which nuclear plants are designed and licensed. Fortunately, there is now an increasing awareness that many of the existing regulatory requirements and industry standards are not significantly contributing to safety and reliability and, therefore, are unnecessarily adding to nuclear plant costs. Not only does this degrade the economic competitiveness of nuclear energy, it results in unnecessary costs to the American electricity consumer. While addressing these concerns, this research project will be coordinated with current efforts of industry and NRC to develop risk-informed, performance-based regulations that affect the operation of the existing nuclear plants; however, this project will go further by focusing on the design of new plants.

  9. Acoustic and electromagnetic waves

    NASA Astrophysics Data System (ADS)

    Jones, Douglas Samuel

    Theoretical models of EM and acoustic wave propagation are presented in an introductory text intended for intermediate-level science and engineering students. Chapters are devoted to the mathematical representation of acoustic and EM fields, the special theory of relativity, radiation, resonators, waveguide theory, refraction, surface waves, scattering by smooth objects, diffraction by edges, and transient waves. The mathematical tools required for the analysis (Bessel, Legendre, Mathieu, parabolic-cylinder, and spheroidal functions; tensor calculus; and the asymptotic evaluation of integrals) are covered in appendices.

  10. Analysis of OSNR requirements for higher modulation schemes for various local oscillator powers

    NASA Astrophysics Data System (ADS)

    Sahu, Amaresh Kumar

    2015-06-01

    To meet the growing demands of data traffic in long haul communication, it is necessary to efficiently use the low-loss region(C-band) of the optical spectrum, by increasing the no. of optical channels and increasing the bit rate on each channel .But narrow pulses occupy higher spectral bandwidth. To circumvent this problem, higher order modulation schemes such as QPSK and QAM can be used to modulate the bits, which increases the spectral efficiency without demanding any extra spectral bandwidth. On the receiver side, to meet a satisfy, a given BER, the received optical signal requires to have minimum OSNR. In our study in this paper, we analyses for different modulation schemes, the OSNR required with and without preamplifier. The theoretical limit of OSNR requirement for a modulation scheme is compared for a given link length by varying the local oscillator (LO) power. Our analysis shows that as we increase the local oscillator (LO) power, the OSNR requirement decreases for a given BER. Also a combination of preamplifier and local oscillator (LO) gives the OSNR closest to theoretical limit.

  11. Enhancement of acoustic tomography using spatial and frequency diversities

    NASA Astrophysics Data System (ADS)

    Mansour, Ali

    2012-12-01

    This article introduces several contributions to enhance an important application such as acoustic tomography (AT), using mainly the spatial and spectral diversities of underwater acoustic signals. Due to their inherited properties, (i.e. spareness, non-stationarity or cyclostationarity, wide-band frequency range, wide range of power, etc.), the process of underwater acoustic signals becomes a real challenge for many scientists and engineers who are involved in studies related to the ocean. For various applications, these studies require huge and daily information. AT techniques remain fast and cheap ways to obtain such data. Nowadays, active acoustic tomography (AAT), is communally used to generate powerful and repetitive acoustic sources. Recently, researchers have been attracted by an alternative way, called passive acoustic tomography (PAT), which uses acoustic opportune signals of their environment. PAT techniques are mainly used for ecological, economical and other reasons such as military applications. With PAT, no signal is emitted; therefore, problems become more challenging. The number and positions of existent sources are unknown, and sensors measure mixtures of available sources. Algorithms based on time or frequency domains are widely deployed to classify, identify, and study received signals in AAT applications. For PAT, researchers employ multiple sensors in order to add an extra dimension, (such as space). This article focuses on approaches used in space along with time or frequency to extract information, improve performances, and simplify the overall architecture. This article explains the use of signal processing and statistical approaches to solve problems raised using PAT and discusses the experimental results. The review of the literature offers a big variety of algorithms to deal with classic AAT problems. Therefore, only problems related to PAT have been considered herein.

  12. Sample Size Requirements for Structural Equation Models: An Evaluation of Power, Bias, and Solution Propriety

    PubMed Central

    Wolf, Erika J.; Harrington, Kelly M.; Clark, Shaunna L.; Miller, Mark W.

    2015-01-01

    Determining sample size requirements for structural equation modeling (SEM) is a challenge often faced by investigators, peer reviewers, and grant writers. Recent years have seen a large increase in SEMs in the behavioral science literature, but consideration of sample size requirements for applied SEMs often relies on outdated rules-of-thumb. This study used Monte Carlo data simulation techniques to evaluate sample size requirements for common applied SEMs. Across a series of simulations, we systematically varied key model properties, including number of indicators and factors, magnitude of factor loadings and path coefficients, and amount of missing data. We investigated how changes in these parameters affected sample size requirements with respect to statistical power, bias in the parameter estimates, and overall solution propriety. Results revealed a range of sample size requirements (i.e., from 30 to 460 cases), meaningful patterns of association between parameters and sample size, and highlight the limitations of commonly cited rules-of-thumb. The broad “lessons learned” for determining SEM sample size requirements are discussed. PMID:25705052

  13. 18 CFR 292.208 - Special requirements for hydroelectric small power production facilities located at a new dam or...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... for hydroelectric small power production facilities located at a new dam or diversion. 292.208 Section... requirements for hydroelectric small power production facilities located at a new dam or diversion. (a) A hydroelectric small power production facility that impounds or diverts the water of a natural watercourse...

  14. 18 CFR 292.208 - Special requirements for hydroelectric small power production facilities located at a new dam or...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Special requirements for hydroelectric small power production facilities located at a new dam or diversion. 292.208 Section 292.208 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE PUBLIC...

  15. 10 CFR 73.55 - Requirements for physical protection of licensed activities in nuclear power reactors against...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Requirements for physical protection of licensed activities in nuclear power reactors against radiological sabotage. 73.55 Section 73.55 Energy NUCLEAR... power reactor licensee, licensed under 10 CFR part 50, shall implement the requirements of this...

  16. 10 CFR 73.55 - Requirements for physical protection of licensed activities in nuclear power reactors against...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Requirements for physical protection of licensed activities in nuclear power reactors against radiological sabotage. 73.55 Section 73.55 Energy NUCLEAR... power reactor licensee, licensed under 10 CFR part 50, shall implement the requirements of this...

  17. 18 CFR 292.209 - Exceptions from requirements for hydroelectric small power production facilities located at a new...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... requirements for hydroelectric small power production facilities located at a new dam or diversion. 292.209... Exceptions from requirements for hydroelectric small power production facilities located at a new dam or... license or exemption is filed for a project located at a Government dam, as defined in section 3(10)...

  18. 18 CFR 292.209 - Exceptions from requirements for hydroelectric small power production facilities located at a new...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... requirements for hydroelectric small power production facilities located at a new dam or diversion. 292.209... Exceptions from requirements for hydroelectric small power production facilities located at a new dam or... license or exemption is filed for a project located at a Government dam, as defined in section 3(10)...

  19. 18 CFR 292.209 - Exceptions from requirements for hydroelectric small power production facilities located at a new...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... requirements for hydroelectric small power production facilities located at a new dam or diversion. 292.209... Exceptions from requirements for hydroelectric small power production facilities located at a new dam or... license or exemption is filed for a project located at a Government dam, as defined in section 3(10)...

  20. 10 CFR 503.8 - No alternate power supply-general requirement for certain exemptions for new powerplants.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false No alternate power supply-general requirement for certain exemptions for new powerplants. 503.8 Section 503.8 Energy DEPARTMENT OF ENERGY (CONTINUED) ALTERNATE FUELS NEW FACILITIES General Requirements for Exemptions § 503.8 No alternate power...

  1. 10 CFR 503.8 - No alternate power supply-general requirement for certain exemptions for new powerplants.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false No alternate power supply-general requirement for certain exemptions for new powerplants. 503.8 Section 503.8 Energy DEPARTMENT OF ENERGY (CONTINUED) ALTERNATE FUELS NEW FACILITIES General Requirements for Exemptions § 503.8 No alternate power...

  2. 10 CFR 503.8 - No alternate power supply-general requirement for certain exemptions for new powerplants.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false No alternate power supply-general requirement for certain exemptions for new powerplants. 503.8 Section 503.8 Energy DEPARTMENT OF ENERGY (CONTINUED) ALTERNATE FUELS NEW FACILITIES General Requirements for Exemptions § 503.8 No alternate power...

  3. 10 CFR 503.8 - No alternate power supply-general requirement for certain exemptions for new powerplants.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false No alternate power supply-general requirement for certain exemptions for new powerplants. 503.8 Section 503.8 Energy DEPARTMENT OF ENERGY (CONTINUED) ALTERNATE FUELS NEW FACILITIES General Requirements for Exemptions § 503.8 No alternate power...

  4. 10 CFR 503.8 - No alternate power supply-general requirement for certain exemptions for new powerplants.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false No alternate power supply-general requirement for certain exemptions for new powerplants. 503.8 Section 503.8 Energy DEPARTMENT OF ENERGY (CONTINUED) ALTERNATE FUELS NEW FACILITIES General Requirements for Exemptions § 503.8 No alternate power...

  5. Acoustic biosensors

    PubMed Central

    Fogel, Ronen; Seshia, Ashwin A.

    2016-01-01

    Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors. PMID:27365040

  6. Acoustic biosensors.

    PubMed

    Fogel, Ronen; Limson, Janice; Seshia, Ashwin A

    2016-06-30

    Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors. PMID:27365040

  7. Acoustic fluidization and the scale dependence of impact crater morphology

    NASA Technical Reports Server (NTRS)

    Melosh, H. J.; Gaffney, E. S.

    1983-01-01

    A phenomenological Bingham plastic model has previously been shown to provide an adequate description of the collapse of impact craters. This paper demonstrates that the Bingham parameters may be derived from a model in which acoustic energy generated during excavation fluidizes the rock debris surrounding the crater. Experimental support for the theoretical flow law is presented. Although the Bingham yield stress cannot be computed without detailed knowledge of the initial acoustic field, the Bingham viscosity is derived from a simple argument which shows that it increases as the 3/2 power of crater diameter, consistent with observation. Crater collapse may occur in material with internal dissipation Q as low as 100, comparable to laboratory observations of dissipation in granular materials. Crater collapse thus does not require that the acoustic field be regenerated during flow.

  8. Calculations and Experimental Investigations on the Feed-Power Requirement of Airplanes with Boundary-Layer Control

    NASA Technical Reports Server (NTRS)

    Krueger, W.

    1947-01-01

    Calculations and test results are given about the feed-power requirement of airplanes with boundary-layer control. Curves and formulas for the rough estimate of pressure-loss and feed-power requirement are set up for the investigated arrangements which differ structurally and aerodynamically. According to these results the feed power for three different designs is calculated at the end of the report.

  9. Fly-By-Light/Power-By-Wire Requirements and Technology Workshop

    NASA Technical Reports Server (NTRS)

    Baker, Robert L. (Editor); Pitts, Felix L. (Editor)

    1992-01-01

    The results of the Fly-By-Light/Power-By-Wire (FBL/PBW) Workshop held on March 17-19, 1992, at the NASA Langley Research Center are presented. The FBL/PBW program is a joint NASA LeRC/LaRC effort to develop the technology base for confident application of integrated FBL/PBW systems to transport aircraft. The objectives of the workshop were to ascertain the FBL/PBW program technical requirements and satisfy the requirements and needs from the industry viewpoint, provide a forum for presenting and documenting alternative technical approaches which satisfy the requirements, and assess the plan adequacy in accomplishing plan objectives, aims, and technology transfer. Areas addressed were: optical sensor systems, power-by-wire systems, FBL/PBW fault-tolerant architectures, electromagnetic environment assessment, and system integration and demonstration. The workshop consisted of an introductory meeting, a 'keynote' presentation, a series of individual panel sessions covering the above areas, with midway presentations by the panel chairpersons, followed by a final summarizing/integrating session by the individual panels, and a closing plenary session summarizing the results of the workshop.

  10. LLNL`s acoustic spectrometer

    SciTech Connect

    Baker, J.

    1997-03-17

    This paper describes the development of a frequency sensitive acoustic transducer that operates in the 10 Hz to 10 kHz regime. This device uses modem silicon microfabrication techniques to form mechanical tines that resonate at specified frequencies. This high-sensitivity device is intended for low-power battery powered applications.

  11. Transportation and Power Requirements for He3 Mining of the Jovian Planets

    NASA Astrophysics Data System (ADS)

    Kammash, Terry; Tang, Ricky

    2008-01-01

    A bi-modal fusion propulsion system that can be used for transportation to and the mining of He3 from the Jovian planets is proposed. It consists of the Gasdynamic Mirror (GDM) fusion reactor which is analyzed for utilization as a propulsion device, as well as for use as a surface power system. The fusion reactions in the device are initiated by the heating provided by the fission fragments and the annihilation products produced by the ``at rest'' annihilation of antiprotons in uranium U238 target nuclei. The energetic pions and muons of the antiproton-proton (or neutron) annihilation in the U238 nucleus can heat a suitable fusion fuel to several keV temperature during their short lifetime, while the remaining heating to ignition is provided by the fission fragments. We examine the use of such a system to travel to Jupiter, for instance, to mine the He3 which is known to exist to the tune of 350 trillion tons in its atmosphere. Such a rich source of this isotope can readily meet the needs of a fusion-powered global industrial energy consumption estimated at 5400 tons annually, for an indefinite length of time. Although He3 exists to a much lesser degree in the lunar regolith, the power requirements for its extraction, estimated at 270 GJ per kg, may render its economic viability very much in question. It is suggested that mining the planets at a power requirement 30 times less than its lunar counterpart may be more desirable in spite of the distances involved, if a reasonably rapid transportation system can be devised. In its propulsive mode, the GDM device is shown to be capable of traveling to Jupiter and bringing back the annual world need of He3 in about six months. Based on such performance, it is quite reasonable to envision a space tanker employing the proposed propulsion system to fly from Earth to the outer planet of choice, spend a period of time in the planet's atmosphere extracting He3, or loading it from an extractor plant already in place, and then

  12. Transportation and Power Requirements for He{sup 3} Mining of the Jovian Planets

    SciTech Connect

    Kammash, Terry; Tang, Ricky

    2008-01-21

    A bi-modal fusion propulsion system that can be used for transportation to and the mining of He{sup 3} from the Jovian planets is proposed. It consists of the Gasdynamic Mirror (GDM) fusion reactor which is analyzed for utilization as a propulsion device, as well as for use as a surface power system. The fusion reactions in the device are initiated by the heating provided by the fission fragments and the annihilation products produced by the 'at rest' annihilation of antiprotons in uranium U{sup 238} target nuclei. The energetic pions and muons of the antiproton-proton (or neutron) annihilation in the U{sup 238} nucleus can heat a suitable fusion fuel to several keV temperature during their short lifetime, while the remaining heating to ignition is provided by the fission fragments. We examine the use of such a system to travel to Jupiter, for instance, to mine the He{sup 3} which is known to exist to the tune of 350 trillion tons in its atmosphere. Such a rich source of this isotope can readily meet the needs of a fusion-powered global industrial energy consumption estimated at 5400 tons annually, for an indefinite length of time. Although He{sup 3} exists to a much lesser degree in the lunar regolith, the power requirements for its extraction, estimated at 270 GJ per kg, may render its economic viability very much in question. It is suggested that mining the planets at a power requirement 30 times less than its lunar counterpart may be more desirable in spite of the distances involved, if a reasonably rapid transportation system can be devised. In its propulsive mode, the GDM device is shown to be capable of traveling to Jupiter and bringing back the annual world need of He{sup 3} in about six months. Based on such performance, it is quite reasonable to envision a space tanker employing the proposed propulsion system to fly from Earth to the outer planet of choice, spend a period of time in the planet's atmosphere extracting He{sup 3}, or loading it from an

  13. Interpreting Space-Mission LET Requirements for SEGR in Power MOSFETs

    NASA Technical Reports Server (NTRS)

    Lauenstein, J. M.; Ladbury, R. L.; Batchelor, D. A.; Goldsman, N.; Kim, H. S.; Phan, A. M.

    2010-01-01

    A Technology Computer Aided Design (TCAD) simulation-based method is developed to evaluate whether derating of high-energy heavy-ion accelerator test data bounds the risk for single-event gate rupture (SEGR) from much higher energy on-orbit ions for a mission linear energy transfer (LET) requirement. It is shown that a typical derating factor of 0.75 applied to a single-event effect (SEE) response curve defined by high-energy accelerator SEGR test data provides reasonable on-orbit hardness assurance, although in a high-voltage power MOSFET, it did not bound the risk of failure.

  14. Analysis of Plug Load Capacities and Power Requirements in Commercial Buildings: Preprint

    SciTech Connect

    Sheppy, M.; Torcellini, P.; Gentile-Polese, L.

    2014-08-01

    Plug and process load power requirements are frequently overestimated because designers often use estimates based on 'nameplate' data, or design assumptions are high because information is not available. This generally results in oversized heating, ventilation, and air-conditioning systems; increased initial construction costs; and increased energy use caused by inefficiencies at low, part-load operation. Rightsizing of chillers in two buildings reduced whole-building energy use by 3%-4%. If an integrated design approach could enable 3% whole-building energy savings in all U.S. office buildings stock, it could save 34 TBtu of site energy per year.

  15. Investigation of High-alpha Lateral-directional Control Power Requirements for High-performance Aircraft

    NASA Technical Reports Server (NTRS)

    Foster, John V.; Ross, Holly M.; Ashley, Patrick A.

    1993-01-01

    Designers of the next-generation fighter and attack airplanes are faced with the requirements of good high-angle-of-attack maneuverability as well as efficient high speed cruise capability with low radar cross section (RCS) characteristics. As a result, they are challenged with the task of making critical design trades to achieve the desired levels of maneuverability and performance. This task has highlighted the need for comprehensive, flight-validated lateral-directional control power design guidelines for high angles of attack. A joint NASA/U.S. Navy study has been initiated to address this need and to investigate the complex flight dynamics characteristics and controls requirements for high-angle-of-attack lateral-directional maneuvering. A multi-year research program is underway which includes ground-based piloted simulation and flight validation. This paper will give a status update of this program that will include a program overview, description of test methodology and preliminary results.

  16. Dispersion of interface waves in sediments with power-law shear speed profiles. II. Experimental observations and seismo-acoustic inversions.

    PubMed

    Chapman, D M; Godin, O A

    2001-10-01

    The propagation of seismic interface waves is investigated in soft marine sediments in which the density is constant, the shear modulus is small, and the profile of shear speed c(s) versus depth z is of the power-law form c(s) (z) = c0z(v), in which c0 and v are constants (0< v < 1). Both the phase speed V and the group speed U of interface waves scale with frequency as f(v/(v -1)) and they obey the simple relation U= (1 - v) V. These relations are derived in a simple way using ray theory and the WKB method; a companion paper [O. A. Godin and D. M. F. Chapman, J. Acoust. Soc. Am. 110, 1890 (2001)] rigorously derives the same result from the solutions to the equations of motion. The frequency scaling is shown to exist in experimental data sets of interface wave phase speed and group speed. Approximate analytical formulas for the dispersion relations (phase and group speed versus frequency) enable direct inversion of the profile parameters c0 and v from the experimental data. In cases for which there is multi-mode dispersion data, the water-sediment density ratio can be determined as well. The theory applies to vertically polarized (P-SV) modes as well as to horizontally polarized (SH) modes (that is, Love waves). PMID:11681371

  17. Using Electric Vehicles to Meet Balancing Requirements Associated with Wind Power

    SciTech Connect

    Tuffner, Francis K.; Kintner-Meyer, Michael CW

    2011-07-31

    Many states are deploying renewable generation sources at a significant rate to meet renewable portfolio standards. As part of this drive to meet renewable generation levels, significant additions of wind generation are planned. Due to the highly variable nature of wind generation, significant energy imbalances on the power system can be created and need to be handled. This report examines the impact on the Northwest Power Pool (NWPP) region for a 2019 expected wind scenario. One method for mitigating these imbalances is to utilize plug-in hybrid electric vehicles (PHEVs) or battery electric vehicles (BEVs) as assets to the grid. PHEVs and BEVs have the potential to meet this demand through both charging and discharging strategies. This report explores the usage of two different charging schemes: V2GHalf and V2GFull. In V2GHalf, PHEV/BEV charging is varied to absorb the additional imbalance from the wind generation, but never feeds power back into the grid. This scenario is highly desirable to automotive manufacturers, who harbor great concerns about battery warranty if vehicle-to-grid discharging is allowed. The second strategy, V2GFull, varies not only the charging of the vehicle battery, but also can vary the discharging of the battery back into the power grid. This scenario is currently less desirable to automotive manufacturers, but provides an additional resource benefit to PHEV/BEVs in meeting the additional imbalance imposed by wind. Key findings in the report relate to the PHEV/BEV population required to meet the additional imbalance when comparing V2GHalf to V2GFull populations, and when comparing home-only-charging and work-and-home-charging scenarios. Utilizing V2GFull strategies over V2GHalf resulted in a nearly 33% reduction in the number of vehicles required. This reduction indicates fewer vehicles are needed to meet the unhandled energy, but they would utilize discharging of the vehicle battery into the grid. This practice currently results in the

  18. Virtual acoustic displays

    NASA Technical Reports Server (NTRS)

    Wenzel, Elizabeth M.

    1991-01-01

    A 3D auditory display can potentially enhance information transfer by combining directional and iconic information in a quite naturalistic representation of dynamic objects in the interface. Another aspect of auditory spatial clues is that, in conjunction with other modalities, it can act as a potentiator of information in the display. For example, visual and auditory cues together can reinforce the information content of the display and provide a greater sense of presence or realism in a manner not readily achievable by either modality alone. This phenomenon will be particularly useful in telepresence applications, such as advanced teleconferencing environments, shared electronic workspaces, and monitoring telerobotic activities in remote or hazardous situations. Thus, the combination of direct spatial cues with good principles of iconic design could provide an extremely powerful and information-rich display which is also quite easy to use. An alternative approach, recently developed at ARC, generates externalized, 3D sound cues over headphones in realtime using digital signal processing. Here, the synthesis technique involves the digital generation of stimuli using Head-Related Transfer Functions (HRTF's) measured in the two ear-canals of individual subjects. Other similar approaches include an analog system developed by Loomis, et. al., (1990) and digital systems which make use of transforms derived from normative mannikins and simulations of room acoustics. Such an interface also requires the careful psychophysical evaluation of listener's ability to accurately localize the virtual or synthetic sound sources. From an applied standpoint, measurement of each potential listener's HRTF's may not be possible in practice. For experienced listeners, localization performance was only slightly degraded compared to a subject's inherent ability. Alternatively, even inexperienced listeners may be able to adapt to a particular set of HRTF's as long as they provide adequate

  19. Acoustic asymmetric transmission based on time-dependent dynamical scattering

    PubMed Central

    Wang, Qing; Yang, Yang; Ni, Xu; Xu, Ye-Long; Sun, Xiao-Chen; Chen, Ze-Guo; Feng, Liang; Liu, Xiao-ping; Lu, Ming-Hui; Chen, Yan-Feng

    2015-01-01

    An acoustic asymmetric transmission device exhibiting unidirectional transmission property for acoustic waves is extremely desirable in many practical scenarios. Such a unique property may be realized in various configurations utilizing acoustic Zeeman effects in moving media as well as frequency-conversion in passive nonlinear acoustic systems and in active acoustic systems. Here we demonstrate a new acoustic frequency conversion process in a time-varying system, consisting of a rotating blade and the surrounding air. The scattered acoustic waves from this time-varying system experience frequency shifts, which are linearly dependent on the blade’s rotating frequency. Such scattering mechanism can be well described theoretically by an acoustic linear time-varying perturbation theory. Combining such time-varying scattering effects with highly efficient acoustic filtering, we successfully develop a tunable acoustic unidirectional device with 20 dB power transmission contrast ratio between two counter propagation directions at audible frequencies. PMID:26038886

  20. On the power required to control the circular cylinder wake by rotary oscillations

    NASA Astrophysics Data System (ADS)

    Bergmann, Michel; Cordier, Laurent; Brancher, Jean-Pierre

    2006-08-01

    In this Brief Communication, we determine an approximate relation that gives the mean time power required to control the wake flow downstream from a circular cylinder. The control law is the sinusoidal tangential velocity imposed on whole or part of the cylinder surface. The mean control power thus depends on four parameters: the amplitude and the Strouhal number of forcing, the control angle that defines the controlled upstream part of the cylinder, and the Reynolds number. This relation indicates that the control power grows like the square of the forcing amplitude, like the square root of the forcing Strouhal number, linearly with the control angle and varies like the inverse of the square root of the Reynolds number. We show that the values obtained with this approximate relation are in very good agreement with the corresponding values given numerically. Finally, the energetic efficiency of the control is discussed. We claimed that the most energetically efficient control law corresponds a priori to low forcing amplitudes applied to a restricted upstream part of the cylinder for relatively high values of the Reynolds number.

  1. The role of elastic energy in activities with high force and power requirements: a brief review.

    PubMed

    Wilson, Jacob M; Flanagan, Eamonn P

    2008-09-01

    The purpose of this article is to provide strength and conditioning practitioners with an understanding of the role of elastic energy in activities with high force and power requirements. Specifically, the article covers 1) the nature of elasticity and its application to human participants, 2) the role of elastic energy in activities requiring a stretch-shorten cycle such as the vertical jump, 3) the role of muscular stiffness in athletic performance, 4) the control of muscular stiffness through feedforward and feedback mechanisms, and 5) factors affecting muscular stiffness. Finally, practical applications are provided. In this section, it is suggested that the storage and reuse of elastic energy is optimized at relatively higher levels of stiffness. Because stiffness decreases as fatigue ensues as well as with stretching before an event, the article emphasizes the need for proper preparation phases in a periodized cycle and the avoidance of long static stretches before high-force activities. The importance of teaching athletes to transition from eccentric to concentric movements with minimal time delays is also proposed due to the finding that time delays appear to decrease the reuse of elastic energy. In addition to teaching within the criterion tasks, evidence is provided that minimizing transitions in plyometric training, a technique demonstrated to increase musculotendinous stiffness, can optimize power output in explosive movements. Finally, evidence is provided that training and teaching programs designed to optimize muscular stiffness may protect athletes against sports-related injuries. PMID:18714212

  2. Effect of NLTE emissivity models on NIF ignition hohlraum power requirements

    NASA Astrophysics Data System (ADS)

    Suter, L.; Hansen, S.; Rosen, M.; Springer, P.; Callahan, D.

    2008-11-01

    It's well known that the NLTE atomic physics model can significantly affect the power requirements and plasma conditions in ignition hohlraums. This is because the emissivity(Te,ne) is a significant factor in determining the time dependent coronal temperature of the hot blow-off plasma filling ignition hohlraums which, in turn, determines the total energy stored in that coronal plasma at any instant. In this talk we present best estimates of NLTE emissivity using the SCRAM model, including the range of uncertainty, and compare them with the emissivity of the model used to design NIF ignition hohlraums and set the NIF pulse shape. We then present pulse shapes derived from hohlraum simulations using an atomic physics model that approximates the SCRAM emissivities. We discuss the differences in coronal energetics and show how this affects the pulse shape and decreases the peak power requirement. Finally, we present design simulations of potential NIF-commissioning scaling experiments that could distinguish among emissivity models. Prepared by LLNL under Contract DE-AC52-07NA27344.

  3. The metabolic power requirements of flight and estimations of flight muscle efficiency in the cockatiel (Nymphicus hollandicus).

    PubMed

    Morris, Charlotte R; Nelson, Frank E; Askew, Graham N

    2010-08-15

    Little is known about how in vivo muscle efficiency, that is the ratio of mechanical and metabolic power, is affected by changes in locomotory tasks. One of the main problems with determining in vivo muscle efficiency is the large number of muscles generally used to produce mechanical power. Animal flight provides a unique model for determining muscle efficiency because only one muscle, the pectoralis muscle, produces nearly all of the mechanical power required for flight. In order to estimate in vivo flight muscle efficiency, we measured the metabolic cost of flight across a range of flight speeds (6-13 m s(-1)) using masked respirometry in the cockatiel (Nymphicus hollandicus) and compared it with measurements of mechanical power determined in the same wind tunnel. Similar to measurements of the mechanical power-speed relationship, the metabolic power-speed relationship had a U-shape, with a minimum at 10 m s(-1). Although the mechanical and metabolic power-speed relationships had similar minimum power speeds, the metabolic power requirements are not a simple multiple of the mechanical power requirements across a range of flight speeds. The pectoralis muscle efficiency (estimated from mechanical and metabolic power, basal metabolism and an assumed value for the 'postural costs' of flight) increased with flight speed and ranged from 6.9% to 11.2%. However, it is probable that previous estimates of the postural costs of flight have been too low and that the pectoralis muscle efficiency is higher. PMID:20675549

  4. Turbofan Acoustic Propagation and Radiation

    NASA Technical Reports Server (NTRS)

    Eversman, Walter

    2000-01-01

    This document describes progress in the development of finite element codes for the prediction of near and far field acoustic radiation from the inlet and aft fan ducts of turbofan engines. The report consists of nine papers which have appeared in archival journals and conference proceedings, or are presently in review for publication. Topics included are: 1. Aft Fan Duct Acoustic Radiation; 2. Mapped Infinite Wave Envelope Elements for Acoustic Radiation in a Uniformly Moving Medium; 3. A Reflection Free Boundary Condition for Propagation in Uniform Flow Using Mapped Infinite Wave Envelope Elements; 4. A Numerical Comparison Between Multiple-Scales and FEM Solution for Sound Propagation in Lined Flow Ducts; 5. Acoustic Propagation at High Frequencies in Ducts; 6. The Boundary Condition at an Impedance Wall in a Nonuniform Duct with Potential Flow; 7. A Reverse Flow Theorem and Acoustic Reciprocity in Compressible Potential Flows; 8. Reciprocity and Acoustics Power in One Dimensional Compressible Potential Flows; and 9. Numerical Experiments on Acoustic Reciprocity in Compressible Potential Flows.

  5. Acoustic 3D imaging of dental structures

    SciTech Connect

    Lewis, D.K.; Hume, W.R.; Douglass, G.D.

    1997-02-01

    Our goals for the first year of this three dimensional electodynamic imaging project was to determine how to combine flexible, individual addressable; preprocessing of array source signals; spectral extrapolation or received signals; acoustic tomography codes; and acoustic propagation modeling code. We investigated flexible, individually addressable acoustic array material to find the best match in power, sensitivity and cost and settled on PVDF sheet arrays and 3-1 composite material.

  6. Acoustic energy transmission in cast iron pipelines

    NASA Astrophysics Data System (ADS)

    Kiziroglou, Michail E.; Boyle, David E.; Wright, Steven W.; Yeatman, Eric M.

    2015-12-01

    In this paper we propose acoustic power transfer as a method for the remote powering of pipeline sensor nodes. A theoretical framework of acoustic power propagation in the ceramic transducers and the metal structures is drawn, based on the Mason equivalent circuit. The effect of mounting on the electrical response of piezoelectric transducers is studied experimentally. Using two identical transducer structures, power transmission of 0.33 mW through a 1 m long, 118 mm diameter cast iron pipe, with 8 mm wall thickness is demonstrated, at 1 V received voltage amplitude. A near-linear relationship between input and output voltage is observed. These results show that it is possible to deliver significant power to sensor nodes through acoustic waves in solid structures. The proposed method may enable the implementation of acoustic - powered wireless sensor nodes for structural and operation monitoring of pipeline infrastructure.

  7. Dynamic considerations for composite metal-rubber laminate acoustic power coupling bellows with application to thermoacoustic refrigeration

    NASA Astrophysics Data System (ADS)

    Smith, Robert William

    Many electrically driven thermoacoustic refrigerators have employed corrugated metal bellows to couple work from an electro-mechanical transducer to the working fluid typically. An alternative bellows structure to mediate this power transfer is proposed: a laminated hollow cylinder comprised of alternating layers of rubber and metal 'hoop-stack'. Fatigue and visoelastic power dissipation in the rubber are critical considerations; strain energy density plays a role in both. Optimal aspect ratios for a rectangle corss-section in the rubber, for given values of bellows axial strain and oscillatory pressure loads are discussed. Comparisons of tearing energies estimated from known load cases and those obtained by finite element analysis for candidate dimensions are presented. The metal layers of bellows are subject to an out-of-plane buckling instability for the case of external pressure loading; failure of this type was experimentally observed. The proposed structure also exhibits column instability when subject to internal pressure, as do metal bellows. For hoop-stack bellows, shear deflection cannot be ignored and this leads to column instability for both internal and external pressures, the latter being analogous to the case of tension buckling of a beam. During prototype bellows testing, transverse modes of vibration are believed to have been excited parametrically as a consequence of the oscillatory pressures. Some operating frequencies of interest in this study lie above the cut-on frequency at which Timoshenko beam theory (TBT) predicts multiple phase speeds; it is shown that TBT fails to accurately predict both mode shapes and resonance frequencies in this regime. TBT is also shown to predict multiple phase speeds in the presence of axial tension, or external pressures, at magnitudes of interest in this study, over the entire frequency spectrum. For modes below cut-on absent a pressure differential (or equivalently, axial load) TBT predicts decreasing resonance

  8. Simplified Rotation In Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Gaspar, M. S.; Trinh, E. H.

    1989-01-01

    New technique based on old discovery used to control orientation of object levitated acoustically in axisymmetric chamber. Method does not require expensive equipment like additional acoustic drivers of precisely adjustable amplitude, phase, and frequency. Reflecting object acts as second source of sound. If reflecting object large enough, close enough to levitated object, or focuses reflected sound sufficiently, Rayleigh torque exerted on levitated object by reflected sound controls orientation of object.

  9. Acoustic transducer for acoustic microscopy

    DOEpatents

    Khuri-Yakub, Butrus T.; Chou, Ching H.

    1990-01-01

    A shear acoustic transducer-lens system in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens.

  10. Acoustic transducer for acoustic microscopy

    DOEpatents

    Khuri-Yakub, B.T.; Chou, C.H.

    1990-03-20

    A shear acoustic transducer-lens system is described in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens. 9 figs.

  11. Acoustic positioning using a tetrahedral ultrashort baseline array of an acoustic modem source transmitting frequency-hopped sequences.

    PubMed

    Beaujean, Pierre-Philippe J; Mohamed, Asif I; Warin, Raphael

    2007-01-01

    Acoustic communications and positioning are vital aspects of unmanned underwater vehicle operations. The usage of separate units on each vehicle has become an issue in terms of frequency bandwidth, space, power, and cost. Most vehicles rely on acoustic modems transmitting frequency-hopped multiple frequency-shift keyed sequences for command-and-control operations, which can be used to locate the vehicle with a good level of accuracy without requiring extra signal transmission. In this paper, an ultrashort baseline acoustic positioning technique has been designed, simulated, and tested to locate an acoustic modem source in three dimensions using a tetrahedral, half-wavelength acoustic antenna. The position estimation is performed using the detection sequence contained in each message, which is a series of frequency-hopped pulses. Maximum likelihood estimation of azimuth and elevation estimation is performed using a varying number of pulse and various signal-to-noise ratios. Simulated and measured position estimation error match closely, and indicate that the accuracy of this system improves dramatically as the number of pulses processed increases, given a fixed signal-to-noise ratio. PMID:17297770

  12. X33 cut quartz for temperature compensated SAW (Surface Acoustic Wave) devices

    NASA Astrophysics Data System (ADS)

    Webster, Richard T.

    1986-07-01

    An X-cut, 33.44 degree quartz crystal for propagating surface acoustic waves with a temperature stability in the order of - 0.0209 ppm/sq.cm. is described. The crystal orientation requires only a single rotation (33.44 degrees) from the crystal axes. This orientation is substantially simpler than previously reported cuts with comparable temperature stability which typically require three rotations. The X-cut orientation has a surface acoustic wave (SAW) velocity of 3175 m/sec, an electromechanical coupling of 0.0004, and a power flow angle of 2.7 degrees.

  13. Vehicular sources in acoustic propagation experiments

    NASA Technical Reports Server (NTRS)

    Prado, Gervasio; Fitzgerald, James; Arruda, Anthony; Parides, George

    1990-01-01

    One of the most important uses of acoustic propagation models lies in the area of detection and tracking of vehicles. Propagation models are used to compute transmission losses in performance prediction models and to analyze the results of past experiments. Vehicles can also provide the means for cost effective experiments to measure acoustic propagation conditions over significant ranges. In order to properly correlate the information provided by the experimental data and the propagation models, the following issues must be taken into consideration: the phenomenology of the vehicle noise sources must be understood and characterized; the vehicle's location or 'ground truth' must be accurately reproduced and synchronized with the acoustic data; and sufficient meteorological data must be collected to support the requirements of the propagation models. The experimental procedures and instrumentation needed to carry out propagation experiments are discussed. Illustrative results are presented for two cases. First, a helicopter was used to measure propagation losses at a range of 1 to 10 Km. Second, a heavy diesel-powered vehicle was used to measure propagation losses in the 300 to 2200 m range.

  14. Survey of future requirements for large space structures. [space platforms, large antennas, and power surfaces

    NASA Technical Reports Server (NTRS)

    Hedgepeth, J. M.

    1976-01-01

    The future requirements for large space structures were examined and the foundation for long range planning of technology development for such structures is provided. Attention is concentrated on a period after 1985 for actual use. Basic ground rule of the study was that applications be of significant importance and have promise of direct economic benefit to mankind. The inputs to the study came from visits to a large number of government and industrial organizations, written studies in current literature, and approximate analyses of potential applications. The paper identifies diverse space applications for large area structures in three general categories: (1) large surfaces for power, (2) large antenna to receive and transmit energy over the radio frequency bandwidth, and (3) space platforms to provide area for general utilizations.

  15. Medical Acoustics

    NASA Astrophysics Data System (ADS)

    Beach, Kirk; Dunmire, Barbrina

    Medical acoustics can be subdivided into diagnostics and therapy. Diagnostics are further separated into auditory and ultrasonic methods, and both employ low amplitudes. Therapy (excluding medical advice) uses ultrasound for heating, cooking, permeablizing, activating and fracturing tissues and structures within the body, usually at much higher amplitudes than in diagnostics. Because ultrasound is a wave, linear wave physics are generally applicable, but recently nonlinear effects have become more important, even in low-intensity diagnostic applications.

  16. Acoustic chaos

    SciTech Connect

    Lauterborn, W.; Parlitz, U.; Holzfuss, J.; Billo, A.; Akhatov, I.

    1996-06-01

    Acoustic cavitation, a complex, spatio-temporal dynamical system, is investigated with respect to its chaotic properties. The sound output, the {open_quote}{open_quote}noise{close_quote}{close_quote}, is subjected to time series analysis. The spatial dynamics of the bubble filaments is captured by high speed holographic cinematography and subsequent digital picture processing from the holograms. Theoretical models are put forward for describing the pattern formation. {copyright} {ital 1996 American Institute of Physics.}

  17. 42 CFR 84.1145 - Silica dust test; non-powered single-use dust respirators; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Silica dust test; non-powered single-use dust respirators; minimum requirements. 84.1145 Section 84.1145 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... Efficiency Respirators and Combination Gas Masks § 84.1145 Silica dust test; non-powered single-use...

  18. 42 CFR 84.1145 - Silica dust test; non-powered single-use dust respirators; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Silica dust test; non-powered single-use dust respirators; minimum requirements. 84.1145 Section 84.1145 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... Efficiency Respirators and Combination Gas Masks § 84.1145 Silica dust test; non-powered single-use...

  19. 42 CFR 84.1145 - Silica dust test; non-powered single-use dust respirators; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Silica dust test; non-powered single-use dust respirators; minimum requirements. 84.1145 Section 84.1145 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... Efficiency Respirators and Combination Gas Masks § 84.1145 Silica dust test; non-powered single-use...

  20. 18 CFR 292.209 - Exceptions from requirements for hydroelectric small power production facilities located at a new...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... requirements for hydroelectric small power production facilities located at a new dam or diversion. 292.209 Section 292.209 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE PUBLIC UTILITY REGULATORY POLICIES ACT OF 1978 REGULATIONS...

  1. 18 CFR 292.209 - Exceptions from requirements for hydroelectric small power production facilities located at a new...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... requirements for hydroelectric small power production facilities located at a new dam or diversion. 292.209 Section 292.209 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE PUBLIC UTILITY REGULATORY POLICIES ACT OF 1978 REGULATIONS...

  2. 10 CFR 73.55 - Requirements for physical protection of licensed activities in nuclear power reactors against...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... power reactor licensee, licensed under 10 CFR part 50, shall implement the requirements of this section... applicants for an operating license under 10 CFR part 50, or combined license under 10 CFR part 52 who have... nuclear power reactors licensed under 10 CFR parts 50 or 52 and authorized to use special nuclear...

  3. 10 CFR 73.55 - Requirements for physical protection of licensed activities in nuclear power reactors against...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... power reactor licensee, licensed under 10 CFR part 50, shall implement the requirements of this section... applicants for an operating license under 10 CFR part 50, or combined license under 10 CFR part 52 who have... nuclear power reactors licensed under 10 CFR parts 50 or 52 and authorized to use special nuclear...

  4. 10 CFR 73.55 - Requirements for physical protection of licensed activities in nuclear power reactors against...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... power reactor licensee, licensed under 10 CFR part 50, shall implement the requirements of this section... applicants for an operating license under 10 CFR part 50, or combined license under 10 CFR part 52 who have... nuclear power reactors licensed under 10 CFR parts 50 or 52 and authorized to use special nuclear...

  5. Effect of Blade Cutout on Power Required by Helicopters Operating at High Tip-Speed Ratios

    NASA Technical Reports Server (NTRS)

    Gessow, Alfred; Gustafson, F. B.

    1960-01-01

    A numerical study was made of the effects of blade cutout on the power required by a sample helicopter rotor traveling at tip-speed ratios of 0.3, 0.4, and 0.5. The amount of cutout varied from 0 to 0.5 of the rotor radius and the calculations were carried out for a thrust coefficient-solidity ratio of 0.04. In these calculations the blade within the cutout radius was assumed to have zero chord. The effect of such cutout on profile-drag power ranged from almost no effect at a tip-speed ratio of 0.3 to as much as a 60 percent reduction at a tip-speed ratio of 0.5. Optimum cutout was about 0.3 of the rotor radius. Part of the large power reduction at a tip-speed ratio of 0.5 resulted from a reduction in tip-region stall, brought about by cutout. For tip-speed ratios greater than 0.3, cutout also effected a significant increase in the ability of the rotor to overcome helicopter parasite drag. It is thus seen that the adverse trends (at high tip-speed ratios) indicated by the uniform-chord theoretical charts are caused in large measure by the center portion of the rotor. The extent to which a modified-design rotor can actually be made more efficient at high speeds than a uniform-chord rotor will depend in practice on the degree of success in minimizing the blade plan form near the center and on special modifications in center-section profiles. A few suggestions and estimates in regard to such modifications are included herein.

  6. A Symmetrical, Planar SOFC Design for NASA's High Specific Power Density Requirements

    NASA Technical Reports Server (NTRS)

    Cable, Thomas L.; Sofie, Stephen W.

    2007-01-01

    Solid oxide fuel cell (SOFC) systems for aircraft applications require an order of magnitude increase in specific power density (1.0 kW/kg) and long life. While significant research is underway to develop anode supported cells which operate at temperatures in the range of 650-800 C, concerns about Cr-contamination from the metal interconnect may drive the operating temperature down further, to 750 C and lower. Higher temperatures, 900-1000 C, are more favorable for SOFC stacks to achieve specific power densities of 1.0 kW/kg. Since metal interconnects are not practical at these high temperatures and can account for up to 75% of the weight of the stack, NASA is pursuing a design that uses a thin, LaCrO3-based ceramic interconnect that incorporates gas channels into the electrodes. The bi-electrode supported cell (BSC) uses porous YSZ scaffolds, on either side of a 10-20 microns electrolyte. The porous support regions are fabricated with graded porosity using the freeze-tape casting process which can be tailored for fuel and air flow. Removing gas channels from the interconnect simplifies the stack design and allows the ceramic interconnect to be kept thin, on the order of 50 -100 microns. The YSZ electrode scaffolds are infiltrated with active electrode materials following the high temperature sintering step. The NASA-BSC is symmetrical and CTE matched, providing balanced stresses and favorable mechanical properties for vibration and thermal cycling.

  7. Requirements and interfaces to cryogenic and power supply plants for the ITER magnet system

    SciTech Connect

    Yoshida, K.; Kalinin, V.; Stoner, S.

    1996-12-31

    This paper describes the requirements and interfaces of cryogenic and power supply plants for the ITER magnet system. The heat loads and mass flow rates of the magnet system is evaluated to keep coil temperature within 6.5 K during the plasma operation of 2200 s. The helium consumption in the current leads is estimated for a current feed of 4.5 MA from 4 K to 300 K. The location of the electrical insulation breaks is compared near winding and outside of cryostat. The terminal box is designed for interfacing the cryogenic and power supply systems. Separate vacuums for the cryostat and the cryolines facilitate maintenance of all cryogenic components without warm-up of the whole system. A superconducting busbar is used to supply current from a current connector at the coil to the vapor-cooled lead in the coil terminal box. The layout of cryogenic lines and equipment is designed to consider space limitations and routing restrictions in the tokamak hall and the electrical termination building. The main parameters of the cryogenic plant (cryoplant) are discussed.

  8. Acoustic detection of electron spin resonance

    NASA Astrophysics Data System (ADS)

    Coufal, H.

    1981-07-01

    The ESR-signal of DPPH was recorded by detecting the modulation of the absorbed microwave power with a gas-coupled microphone. This photo-acoustic detection scheme is compared with conventional ESR-detection. Applications of the acoustical detection method to other modulation spectroscopic techniques, particularly NMR, are discussed.

  9. 12 CFR 714.6 - Are you required to retain salvage powers over the leased property?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... property? You must retain salvage powers over the leased property. Salvage powers protect you from a loss and provide you with the power to take action if there is an unanticipated change in conditions...

  10. Eliminating Nonlinear Acoustical Effects From Thermoacoustic Refrigeration Systems

    NASA Astrophysics Data System (ADS)

    Garrett, Steven L.; Smith, Robert W. M.; Poese, Matthew E.

    2006-05-01

    Nonlinear acoustical effects dissipate energy that degrades thermoacoustic refrigerator performance. The largest of these effects occur in acoustic resonators and include shock formation; turbulence and boundary layer disruption; and entry/exit (minor) losses induced by changes in resonator cross-sectional area. Effects such as these also make the creation of accurate performance models more complicated. Suppression of shock formation by intentional introduction of resonator anharmonicity has been common practice for the past two decades. Recent attempts to increase cooling power density by increasing pressure amplitudes has required reduction of turbulence and minor loss by using an new acousto-mechanical resonator topology. The hybrid resonator still stores potential energy in the compressibility of the gaseous working fluid, but stores kinetic energy in the moving (solid) mass of the motor and piston. This talk will first present nonlinear acoustical loss measurements obtained in a "conventional" double-Helmholtz resonator geometry (TRITON) that dissipated four kilowatts of acoustic power. We will then describe the performance of the new "bellows bounce" resonator configuration and "vibromechanical multiplier" used in the first successful implementation of this approach that created an ice cream freezer produced at Penn State for Ben & Jerry's.

  11. On-chip manipulation of single microparticles, cells, and organisms using surface acoustic waves

    PubMed Central

    Ding, Xiaoyun; Lin, Sz-Chin Steven; Kiraly, Brian; Yue, Hongjun; Li, Sixing; Chiang, I-Kao; Shi, Jinjie; Benkovic, Stephen J.; Huang, Tony Jun

    2012-01-01

    Techniques that can dexterously manipulate single particles, cells, and organisms are invaluable for many applications in biology, chemistry, engineering, and physics. Here, we demonstrate standing surface acoustic wave based “acoustic tweezers” that can trap and manipulate single microparticles, cells, and entire organisms (i.e., Caenorhabditis elegans) in a single-layer microfluidic chip. Our acoustic tweezers utilize the wide resonance band of chirped interdigital transducers to achieve real-time control of a standing surface acoustic wave field, which enables flexible manipulation of most known microparticles. The power density required by our acoustic device is significantly lower than its optical counterparts (10,000,000 times less than optical tweezers and 100 times less than optoelectronic tweezers), which renders the technique more biocompatible and amenable to miniaturization. Cell-viability tests were conducted to verify the tweezers’ compatibility with biological objects. With its advantages in biocompatibility, miniaturization, and versatility, the acoustic tweezers presented here will become a powerful tool for many disciplines of science and engineering. PMID:22733731

  12. Acoustic fault injection tool (AFIT)

    NASA Astrophysics Data System (ADS)

    Schoess, Jeffrey N.

    1999-05-01

    On September 18, 1997, Honeywell Technology Center (HTC) successfully completed a three-week flight test of its rotor acoustic monitoring system (RAMS) at Patuxent River Flight Test Center. This flight test was the culmination of an ambitious 38-month proof-of-concept effort directed at demonstrating the feasibility of detecting crack propagation in helicopter rotor components. The program was funded as part of the U.S. Navy's Air Vehicle Diagnostic Systems (AVDS) program. Reductions in Navy maintenance budgets and available personnel have dictated the need to transition from time-based to 'condition-based' maintenance. Achieving this will require new enabling diagnostic technologies. The application of acoustic emission for the early detection of helicopter rotor head dynamic component faults has proven the feasibility of the technology. The flight-test results demonstrated that stress-wave acoustic emission technology can detect signals equivalent to small fatigue cracks in rotor head components and can do so across the rotating articulated rotor head joints and in the presence of other background acoustic noise generated during flight operation. During the RAMS flight test, 12 test flights were flown from which 25 Gbyte of digital acoustic data and about 15 hours of analog flight data recorder (FDR) data were collected from the eight on-rotor acoustic sensors. The focus of this paper is to describe the CH-46 flight-test configuration and present design details about a new innovative machinery diagnostic technology called acoustic fault injection. This technology involves the injection of acoustic sound into machinery to assess health and characterize operational status. The paper will also address the development of the Acoustic Fault Injection Tool (AFIT), which was successfully demonstrated during the CH-46 flight tests.

  13. Compressive acoustic sound speed profile estimation.

    PubMed

    Bianco, Michael; Gerstoft, Peter

    2016-03-01

    Ocean acoustic sound speed profile (SSP) estimation requires the inversion of acoustic fields using limited observations. Compressive sensing (CS) asserts that certain underdetermined problems can be solved in high resolution, provided their solutions are sparse. Here, CS is used to estimate SSPs in a range-independent shallow ocean by inverting a non-linear acoustic propagation model. It is shown that SSPs can be estimated using CS to resolve fine-scale structure. PMID:27036293

  14. 21 CFR 1311.45 - Requirements for registrants that allow powers of attorney to obtain CSOS digital certificates...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE REQUIREMENTS FOR ELECTRONIC ORDERS AND PRESCRIPTIONS Obtaining and Using Digital Certificates for Electronic Orders § 1311.45 Requirements for...) A registrant that grants power of attorney must report to the DEA Certification Authority within...

  15. 21 CFR 1311.45 - Requirements for registrants that allow powers of attorney to obtain CSOS digital certificates...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE REQUIREMENTS FOR ELECTRONIC ORDERS AND PRESCRIPTIONS Obtaining and Using Digital Certificates for Electronic Orders § 1311.45 Requirements for...) A registrant that grants power of attorney must report to the DEA Certification Authority within...

  16. 21 CFR 1311.45 - Requirements for registrants that allow powers of attorney to obtain CSOS digital certificates...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE REQUIREMENTS FOR ELECTRONIC ORDERS AND PRESCRIPTIONS Obtaining and Using Digital Certificates for Electronic Orders § 1311.45 Requirements for...) A registrant that grants power of attorney must report to the DEA Certification Authority within...

  17. 21 CFR 1311.45 - Requirements for registrants that allow powers of attorney to obtain CSOS digital certificates...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE REQUIREMENTS FOR ELECTRONIC ORDERS AND PRESCRIPTIONS Obtaining and Using Digital Certificates for Electronic Orders § 1311.45 Requirements for...) A registrant that grants power of attorney must report to the DEA Certification Authority within...

  18. Power System Concepts for the Lunar Outpost: A Review of the Power Generation, Energy Storage, Power Management and Distribution (PMAD) System Requirements and Potential Technologies for Development of the Lunar Outpost

    NASA Technical Reports Server (NTRS)

    Khan, Z.; Vranis, A.; Zavoico, A.; Freid, S.; Manners, B.

    2006-01-01

    This paper will review potential power system concepts for the development of the lunar outpost including power generation, energy storage, and power management and distribution (PMAD). In particular, the requirements of the initial robotic missions will be discussed and the technologies considered will include cryogenics and regenerative fuel cells (RFC), AC and DC transmission line technology, high voltage and low voltage power transmission, conductor materials of construction and power beaming concepts for transmitting power to difficult to access locations such as at the bottom of craters. Operating conditions, component characteristics, reliability, maintainability, constructability, system safety, technology gaps/risk and adaptability for future lunar missions will be discussed for the technologies considered.

  19. A NEW STATISTIC FOR ANALYZING BARYON ACOUSTIC OSCILLATIONS

    SciTech Connect

    Xu, X.; Eisenstein, D. J.; Eckel, J.; Mehta, K.; Metchnik, M.; Pinto, P.; White, M.; Padmanabhan, N.; Seo, H.-J.

    2010-08-01

    We introduce a new statistic {omega}{sub l}(r{sub s}) for measuring and analyzing large-scale structure and particularly the baryon acoustic oscillations. {omega}{sub l}(r{sub s}) is a band-filtered, configuration space statistic that is easily implemented and has advantages over the traditional power spectrum and correlation function estimators. Unlike these estimators, {omega}{sub l}(r{sub s}) can localize most of the acoustic information into a single dip at the acoustic scale while avoiding sensitivity to the poorly constrained large-scale power (i.e., the integral constraint) through the use of a localized and compensated filter. It is also sensitive to anisotropic clustering through pair counting and does not require any binning of data. We measure the shift in the acoustic peak due to nonlinear effects using the monopole {omega}{sub 0}(r{sub s}) derived from subsampled dark matter (DM) catalogs as well as from mock galaxy catalogs created via halo occupation distribution modeling. All of these are drawn from 44 realizations of 1024{sup 3} particle DM simulations in a 1 h {sup -1} Gpc box at z = 1. We compare these shifts with those obtained from the power spectrum and conclude that the results agree. We therefore expect that distance measurements obtained from {omega}{sub 0}(r{sub s}) and P(k) will be consistent with each other. We also show that it is possible to extract the same amount of acoustic information by fitting over a finite range using either {omega}{sub 0}(r{sub s}) or P(k) derived from equal volume surveys.

  20. Acoustic Tooth Cleaner

    NASA Technical Reports Server (NTRS)

    Heyman, J. S.

    1984-01-01

    Acoustically-energized water jet aids in plaque breakdown. Acoustic Wand includes acoustic transducer 1/4 wave plate, and tapered cone. Together elements energize solution of water containing mild abrasive injected into mouth to help prevent calculous buildup.

  1. Spacecraft Internal Acoustic Environment Modeling

    NASA Technical Reports Server (NTRS)

    Chu, SShao-sheng R.; Allen, Christopher S.

    2009-01-01

    Acoustic modeling can be used to identify key noise sources, determine/analyze sub-allocated requirements, keep track of the accumulation of minor noise sources, and to predict vehicle noise levels at various stages in vehicle development, first with estimates of noise sources, later with experimental data. In FY09, the physical mockup developed in FY08, with interior geometric shape similar to Orion CM (Crew Module) IML (Interior Mode Line), was used to validate SEA (Statistical Energy Analysis) acoustic model development with realistic ventilation fan sources. The sound power levels of these sources were unknown a priori, as opposed to previous studies that RSS (Reference Sound Source) with known sound power level was used. The modeling results were evaluated based on comparisons to measurements of sound pressure levels over a wide frequency range, including the frequency range where SEA gives good results. Sound intensity measurement was performed over a rectangular-shaped grid system enclosing the ventilation fan source. Sound intensities were measured at the top, front, back, right, and left surfaces of the and system. Sound intensity at the bottom surface was not measured, but sound blocking material was placed tinder the bottom surface to reflect most of the incident sound energy back to the remaining measured surfaces. Integrating measured sound intensities over measured surfaces renders estimated sound power of the source. The reverberation time T6o of the mockup interior had been modified to match reverberation levels of ISS US Lab interior for speech frequency bands, i.e., 0.5k, 1k, 2k, 4 kHz, by attaching appropriately sized Thinsulate sound absorption material to the interior wall of the mockup. Sound absorption of Thinsulate was modeled in three methods: Sabine equation with measured mockup interior reverberation time T60, layup model based on past impedance tube testing, and layup model plus air absorption correction. The evaluation/validation was

  2. Contributed Review: Recent developments in acoustic energy harvesting for autonomous wireless sensor nodes applications

    NASA Astrophysics Data System (ADS)

    Khan, Farid Ullah; Khattak, Muhammad Umair

    2016-02-01

    Rapid developments in micro electronics, micro fabrication, ultra-large scale of integration, ultra-low power sensors, and wireless technology have greatly reduced the power consumption requirements of wireless sensor nodes (WSNs) and make it possible to operate these devices with energy harvesters. Likewise, other energy harvesters, acoustic energy harvesters (AEHs), have been developed and are gaining swift interest in last few years. This paper presents a review of AEHs reported in the literature for the applications of WSNs. Based on transduction mechanism, there are two types of AEHs: piezoelectric acoustic energy harvesters (PEAEHs) and electromagnetic acoustic energy harvesters (EMAEHs). The reported AEHs are mostly characterized under the sound pressure level (SPL) that ranges from 45 to 161 dB. The range for resonant frequency of the produced AEHs is from 146 Hz to 24 kHz and these produced 0.68 × 10-6 μW to 30 mW power. The maximum power (30 mW) is produced by a PEAEH, when the harvester is subjected to a SPL of 161 dB and 2.64 kHz frequency. However, for EMAEHs, the maximum power reported is about 1.96 mW (at 125 dB and 143 Hz). Under the comparable SPLs, the power production by the reported EMAEHs is relatively better than that of PEAEHs, moreover, due to lower resonant frequency, the EMAEHs are more feasible for the low frequency band acoustical environment.

  3. Contributed Review: Recent developments in acoustic energy harvesting for autonomous wireless sensor nodes applications.

    PubMed

    Khan, Farid Ullah; Khattak, Muhammad Umair

    2016-02-01

    Rapid developments in micro electronics, micro fabrication, ultra-large scale of integration, ultra-low power sensors, and wireless technology have greatly reduced the power consumption requirements of wireless sensor nodes (WSNs) and make it possible to operate these devices with energy harvesters. Likewise, other energy harvesters, acoustic energy harvesters (AEHs), have been developed and are gaining swift interest in last few years. This paper presents a review of AEHs reported in the literature for the applications of WSNs. Based on transduction mechanism, there are two types of AEHs: piezoelectric acoustic energy harvesters (PEAEHs) and electromagnetic acoustic energy harvesters (EMAEHs). The reported AEHs are mostly characterized under the sound pressure level (SPL) that ranges from 45 to 161 dB. The range for resonant frequency of the produced AEHs is from 146 Hz to 24 kHz and these produced 0.68 × 10(-6) μW to 30 mW power. The maximum power (30 mW) is produced by a PEAEH, when the harvester is subjected to a SPL of 161 dB and 2.64 kHz frequency. However, for EMAEHs, the maximum power reported is about 1.96 mW (at 125 dB and 143 Hz). Under the comparable SPLs, the power production by the reported EMAEHs is relatively better than that of PEAEHs, moreover, due to lower resonant frequency, the EMAEHs are more feasible for the low frequency band acoustical environment. PMID:26931827

  4. ACOUSTIC LINERS FOR TURBOFAN ENGINES

    NASA Technical Reports Server (NTRS)

    Minner, G. L.

    1994-01-01

    This program was developed to design acoustic liners for turbofan engines. This program combines results from theoretical models of wave alternation in acoustically treated passages with experimental data from full-scale fan noise suppressors. By including experimentally obtained information, the program accounts for real effects such as wall boundary layers, duct terminations, and sound modal structure. The program has its greatest use in generating a number of design specifications to be used for evaluation of trade-offs. The program combines theoretical and empirical data in designing annular acoustic liners. First an estimate of the noise output of the fan is made based on basic fan aerodynamic design variables. Then, using a target noise spectrum after alternation and the estimated fan noise spectrum, a design spectrum is calculated as their difference. Next, the design spectrum is combined with knowledge of acoustic liner performance and the liner design variables to specify the acoustic design. Details of the liner design are calculated by combining the required acoustic impedance with a mathematical model relating acoustic impedance to the physical structure of the liner. Input to the noise prediction part of the program consists of basic fan operating parameters, distance that the target spectrum is to be measured and the target spectrum. The liner design portion of the program requires the required alternation spectrum, desired values of length to height and several option selection parameters. Output from the noise prediction portion is a noise spectrum consisting of discrete tones and broadband noise. This may be used as input to the liner design portion of the program. The liner design portion of the program produces backing depths, open area ratios, and face plate thicknesses. This program is written in FORTRAN V and has been implemented in batch mode on a UNIVAC 1100 series computer with a central memory requirement of 12K (decimal) of 36 bit words.

  5. NRC review of Electric Power Research Institute's Advanced Light Reactor Utility Requirements Document - Program summary, Project No. 669

    SciTech Connect

    Not Available

    1992-08-01

    The staff of the US Nuclear Regulatory Commission has prepared Volume 1 of a safety evaluation report (SER), NRC Review of Electric Power Research Institute's Advanced Light Water Reactor Utility Requirements Document -- Program Summary,'' to document the results of its review of the Electric Power Research Institute's Advanced Light Water Reactor Utility Requirements Document.'' This SER provides a discussion of the overall purpose and scope of the Requirements Document, the background of the staff's review, the review approach used by the staff, and a summary of the policy and technical issues raised by the staff during its review.

  6. Spatiotemporally resolved granular acoustics

    NASA Astrophysics Data System (ADS)

    Owens, Eli; Daniels, Karen

    2011-03-01

    Acoustic techniques provide a non-invasive method of characterizing granular material properties; however, there are many challenges in formulating accurate models of sound propagation due to the inherently heterogeneous nature of granular materials. In order to quantify acoustic responses in space and time, we perform experiments in a photoelastic granular material in which the internal stress pattern (in the form of force chains) is visible. We utilize two complementary methods, high-speed imaging and piezoelectric transduction, to provide particle-scale measurements of the amplitude of the acoustic wave. We observe that the average wave amplitude is largest within particles experiencing the largest forces. The force-dependence of this amplitude is in qualitative agreement with a simple Hertzian-like model for contact area. In addition, we investigate the power spectrum of the propagating signal using the piezoelectric sensors. For a Gaussian wave packet input, we observe a broad spectrum of transmitted frequencies below the driving frequency, and we quantify the characteristic frequencies and corresponding length scales of our material as the system pressure is varied.

  7. Effects of subsampling of passive acoustic recordings on acoustic metrics.

    PubMed

    Thomisch, Karolin; Boebel, Olaf; Zitterbart, Daniel P; Samaran, Flore; Van Parijs, Sofie; Van Opzeeland, Ilse

    2015-07-01

    Passive acoustic monitoring is an important tool in marine mammal studies. However, logistics and finances frequently constrain the number and servicing schedules of acoustic recorders, requiring a trade-off between deployment periods and sampling continuity, i.e., the implementation of a subsampling scheme. Optimizing such schemes to each project's specific research questions is desirable. This study investigates the impact of subsampling on the accuracy of two common metrics, acoustic presence and call rate, for different vocalization patterns (regimes) of baleen whales: (1) variable vocal activity, (2) vocalizations organized in song bouts, and (3) vocal activity with diel patterns. To this end, above metrics are compared for continuous and subsampled data subject to different sampling strategies, covering duty cycles between 50% and 2%. The results show that a reduction of the duty cycle impacts negatively on the accuracy of both acoustic presence and call rate estimates. For a given duty cycle, frequent short listening periods improve accuracy of daily acoustic presence estimates over few long listening periods. Overall, subsampling effects are most pronounced for low and/or temporally clustered vocal activity. These findings illustrate the importance of informed decisions when applying subsampling strategies to passive acoustic recordings or analyses for a given target species. PMID:26233026

  8. Fdtd Calculation of Linear Acoustic Phenomena and Its Application to Architectural Acoustics and Environmental Noise Prediction

    NASA Astrophysics Data System (ADS)

    Sakamoto, S.

    The finite difference time domain (FDTD) method is widely used as an effective and powerful tool for analyzing acoustic problems. In architectural acoustics, impulse response is the most important quantity and therefore the FDTD method, by which the physical quantities are obtained in time domain, is more advantageous than other wave-based analysis methods, by many of which the calculation is performed in frequency domain. This paper reports application of the FDTD method to room acoustics and outdoor noise assessment.

  9. Pulse power requirements for large aperture optical switches based on plasma electrode Pockels cells

    SciTech Connect

    Rhodes, M.A.; Taylor, J.

    1992-06-01

    We discuss very large-aperture optical switches (greater than 30 [times] 30 cm) as an enabling technology for inertial confinement fusion drivers based on multipass laser amplifiers. Large-scale laser fusion drivers such as the Nova laser have been based on single-pass amplifier designs in part because of the unavailability of a suitable large-aperture switch. We are developing an optical switch based on a Pockels cell employing plasma-electrodes. A plasma-electrode Pockels cell (PEPC) is a longitudinal-mode Pockels cell in which a plasma discharge is formed on each side of an electro-optic crystal (typically KDP or deuterated KDP, often designated KD*P). The plasmas formed on either side of the crystal act as transparent electrodes for a switching-pulse and are intended to allow uniform charging of the entire crystal. The switching-pulse is a nominally rectangular high-voltage pulse equal to the half-wave voltage V[sub x] ( 8 kV for KD*P or 17 kV for KDP) and is applied across the crystal via the plasma-electrodes. When the crystal is charged to V[sub x], the polarization of an incoming, linearly polarized, laser beam is rotated by 90[degree]. When used in conjunction with an appropriate, passive polarizer, an optical switch is thus realized. A switch with a clear aperture of 37 [times] 37 cm is now in construction for the Beamlet laser which will serve as a test bed for this switch as well as other technologies required for an advanced NOVA laser design. In this paper, we discuss the unique power electronics requirements of PEPC optical switches.

  10. Pulse power requirements for large aperture optical switches based on plasma electrode Pockels cells

    SciTech Connect

    Rhodes, M.A.; Taylor, J.

    1992-06-01

    We discuss very large-aperture optical switches (greater than 30 {times} 30 cm) as an enabling technology for inertial confinement fusion drivers based on multipass laser amplifiers. Large-scale laser fusion drivers such as the Nova laser have been based on single-pass amplifier designs in part because of the unavailability of a suitable large-aperture switch. We are developing an optical switch based on a Pockels cell employing plasma-electrodes. A plasma-electrode Pockels cell (PEPC) is a longitudinal-mode Pockels cell in which a plasma discharge is formed on each side of an electro-optic crystal (typically KDP or deuterated KDP, often designated KD*P). The plasmas formed on either side of the crystal act as transparent electrodes for a switching-pulse and are intended to allow uniform charging of the entire crystal. The switching-pulse is a nominally rectangular high-voltage pulse equal to the half-wave voltage V{sub x} ( 8 kV for KD*P or 17 kV for KDP) and is applied across the crystal via the plasma-electrodes. When the crystal is charged to V{sub x}, the polarization of an incoming, linearly polarized, laser beam is rotated by 90{degree}. When used in conjunction with an appropriate, passive polarizer, an optical switch is thus realized. A switch with a clear aperture of 37 {times} 37 cm is now in construction for the Beamlet laser which will serve as a test bed for this switch as well as other technologies required for an advanced NOVA laser design. In this paper, we discuss the unique power electronics requirements of PEPC optical switches.

  11. Wireless Acoustic Measurement System

    NASA Technical Reports Server (NTRS)

    Anderson, Paul D.; Dorland, Wade D.; Jolly, Ronald L.

    2007-01-01

    A prototype wireless acoustic measurement system (WAMS) is one of two main subsystems of the Acoustic Prediction/ Measurement Tool, which comprises software, acoustic instrumentation, and electronic hardware combined to afford integrated capabilities for predicting and measuring noise emitted by rocket and jet engines. The other main subsystem is described in the article on page 8. The WAMS includes analog acoustic measurement instrumentation and analog and digital electronic circuitry combined with computer wireless local-area networking to enable (1) measurement of sound-pressure levels at multiple locations in the sound field of an engine under test and (2) recording and processing of the measurement data. At each field location, the measurements are taken by a portable unit, denoted a field station. There are ten field stations, each of which can take two channels of measurements. Each field station is equipped with two instrumentation microphones, a micro- ATX computer, a wireless network adapter, an environmental enclosure, a directional radio antenna, and a battery power supply. The environmental enclosure shields the computer from weather and from extreme acoustically induced vibrations. The power supply is based on a marine-service lead-acid storage battery that has enough capacity to support operation for as long as 10 hours. A desktop computer serves as a control server for the WAMS. The server is connected to a wireless router for communication with the field stations via a wireless local-area network that complies with wireless-network standard 802.11b of the Institute of Electrical and Electronics Engineers. The router and the wireless network adapters are controlled by use of Linux-compatible driver software. The server runs custom Linux software for synchronizing the recording of measurement data in the field stations. The software includes a module that provides an intuitive graphical user interface through which an operator at the control server

  12. Wireless Acoustic Measurement System

    NASA Technical Reports Server (NTRS)

    Anderson, Paul D.; Dorland, Wade D.

    2005-01-01

    A prototype wireless acoustic measurement system (WAMS) is one of two main subsystems of the Acoustic Prediction/Measurement Tool, which comprises software, acoustic instrumentation, and electronic hardware combined to afford integrated capabilities for predicting and measuring noise emitted by rocket and jet engines. The other main subsystem is described in "Predicting Rocket or Jet Noise in Real Time" (SSC-00215-1), which appears elsewhere in this issue of NASA Tech Briefs. The WAMS includes analog acoustic measurement instrumentation and analog and digital electronic circuitry combined with computer wireless local-area networking to enable (1) measurement of sound-pressure levels at multiple locations in the sound field of an engine under test and (2) recording and processing of the measurement data. At each field location, the measurements are taken by a portable unit, denoted a field station. There are ten field stations, each of which can take two channels of measurements. Each field station is equipped with two instrumentation microphones, a micro-ATX computer, a wireless network adapter, an environmental enclosure, a directional radio antenna, and a battery power supply. The environmental enclosure shields the computer from weather and from extreme acoustically induced vibrations. The power supply is based on a marine-service lead-acid storage battery that has enough capacity to support operation for as long as 10 hours. A desktop computer serves as a control server for the WAMS. The server is connected to a wireless router for communication with the field stations via a wireless local-area network that complies with wireless-network standard 802.11b of the Institute of Electrical and Electronics Engineers. The router and the wireless network adapters are controlled by use of Linux-compatible driver software. The server runs custom Linux software for synchronizing the recording of measurement data in the field stations. The software includes a module that

  13. Detachable acoustic electric feedthrough

    NASA Astrophysics Data System (ADS)

    Moss, Scott; Skippen, Jeremy; Konak, Michael; Powlesland, Ian; Galea, Steve

    2010-04-01

    This paper outlines the development and characterisation of a detachable acoustic electric feedthrough (DAEF) to transfer power and data across a metal (or composite) plate. The DAEF approach is being explored as a potential means of wirelessly powering in-situ structural health monitoring systems embedded within aircraft and other high value engineering assets. The DAEF technique operates via two axially aligned piezoelectric-magnet structures mounted on opposite sides of a plate. Magnetic force is used to align the two piezoelectric-magnet structures, to create an acoustic path across a plate. The piezoelectric-magnet structures consisted of Pz26 piezoelectric disk elements bonded to NdFeB magnets, with a standard ultrasonic couplant (High-Z) used between the magnet and plate to facilitate the passage of ultrasound. Measured impedance curves are matched to modeled curves using the Comsol multi-physics software coupled with a particle-swarm approach, allowing optimised Pz26 material parameters to be found (i.e. stiffness, coupling and permittivity matrices). The optimised Pz26 parameters are then used in an axi-symmetric Comsol model to make predictions about the DAEF power transfer, which is then experimentally confirmed. With an apparent input power of 1 VA and 4.2 MHz drive frequency, the measured power transfer efficiency across a 1.6 mm Al plate is ~34%. The effect of various system parameters on power transfer is explored, including bondline thickness and plate thickness. DAEF data communication is modelled using LTspice with three-port one-dimensional piezoelectric models, indicating that data rates of 115 kBit/s are feasible.

  14. Investigation of Power Requirements for Ice Prevention and Cyclical De-Icing of Inlet Guide Vanes with Internal Electric Heaters

    NASA Technical Reports Server (NTRS)

    VonGlahn, Uwe; Blatz, Robert E.

    1950-01-01

    An investigation was conducted to determine the electric power requirements necessary for ice protection of inlet guide vanes by continuous heating and by cyclical de-icing. Data are presented to show the effect of ambient-air temperature, liquid-water content, air velocity, heat-on period, and cycle times on the power requirements for these two methods of ice protection. The results showed that for a hypothetical engine using 28 inlet guide vanes under similar icing conditions, cyclical de-icing can provide a total power saving as high as 79 percent over that required for continuous heating. Heat-on periods in the order of 10 seconds with a cycle ratio of about 1:7 resulted in the best over-all performance with respect to total power requirements and aerodynamic losses during the heat-off period. Power requirements reported herein may be reduced by as much as 25 percent by achieving a more uniform surface-temperature distribution. A parameter in terms of engine mass flow, vane size, vane surface temperature, and the icing conditions ahead of the inlet guide vanes.was developed by which an extension of the experimental data to icing conditions and inlet guide vanes, other than those investigated was possible.

  15. The historical trend in float zone crystal diameters and power requirements for float zoned silicon crystals

    NASA Technical Reports Server (NTRS)

    Kramer, H. G.

    1981-01-01

    The power needed to zone silicon crystals by radio frequency heating was analyzed. The heat loss mechanisms are examined. Curves are presented for power as a function of crystal diameter for commercial silicon zoning.

  16. Requirements for Large Eddy Simulation Computations of Variable-Speed Power Turbine Flows

    NASA Technical Reports Server (NTRS)

    Ameri, Ali A.

    2016-01-01

    Variable-speed power turbines (VSPTs) operate at low Reynolds numbers and with a wide range of incidence angles. Transition, separation, and the relevant physics leading to them are important to VSPT flow. Higher fidelity tools such as large eddy simulation (LES) may be needed to resolve the flow features necessary for accurate predictive capability and design of such turbines. A survey conducted for this report explores the requirements for such computations. The survey is limited to the simulation of two-dimensional flow cases and endwalls are not included. It suggests that a grid resolution necessary for this type of simulation to accurately represent the physics may be of the order of Delta(x)+=45, Delta(x)+ =2 and Delta(z)+=17. Various subgrid-scale (SGS) models have been used and except for the Smagorinsky model, all seem to perform well and in some instances the simulations worked well without SGS modeling. A method of specifying the inlet conditions such as synthetic eddy modeling (SEM) is necessary to correctly represent the inlet conditions.

  17. The Knotted Sky II: does BICEP2 require a nontrivial primordial power spectrum?

    SciTech Connect

    Abazajian, Kevork N.; Aslanyan, Grigor; Easther, Richard; Price, Layne C. E-mail: g.aslanyan@auckland.ac.nz E-mail: lpri691@aucklanduni.ac.nz

    2014-08-01

    An inflationary gravitational wave background consistent with BICEP2 is difficult to reconcile with a simple power-law spectrum of primordial scalar perturbations. Tensor modes contribute to the temperature anisotropies at multipoles with l∼< 100, and this effect — together with a prior on the form of the scalar perturbations — was the source of previous bounds on the tensor-to-scalar ratio. We compute Bayesian evidence for combined fits to BICEP2 and Planck for three nontrivial primordial spectra: a) a running spectral index, b) a cutoff at fixed wavenumber, and c) a spectrum described by a linear spline with a single internal knot. We find no evidence for a cutoff, weak evidence for a running index, and significant evidence for a ''broken'' spectrum. Taken at face-value, the BICEP2 results require two new inflationary parameters in order to describe both the broken scale invariance in the perturbation spectrum and the observed tensor-to-scalar ratio. Alternatively, this tension may be resolved by additional data and more detailed analyses.

  18. Minimum data requirement for neural networks based on power spectral density analysis.

    PubMed

    Deng, Jiamei; Maass, Bastian; Stobart, Richard

    2012-04-01

    One of the most critical challenges ahead for diesel engines is to identify new techniques for fuel economy improvement without compromising emissions regulations. One technique is the precise control of air/fuel ratio, which requires the measurement of instantaneous fuel consumption. Measurement accuracy and repeatability for fuel rate is the key to successfully controlling the air/fuel ratio and real-time measurement of fuel consumption. The volumetric and gravimetric measurement principles are well-known methods for measurement of fuel consumption in internal combustion engines. However, the fuel flow rate measured by these methods is not suitable for either real-time control or real-time measurement purposes because of the intermittent nature of the measurements. This paper describes a technique that can be used to find the minimum data [consisting of data from just 2.5% of the non-road transient cycle (NRTC)] to solve the problem concerning discontinuous data of fuel flow rate measured using an AVL 733S fuel meter for a medium or heavy-duty diesel engine using neural networks. Only torque and speed are used as the input parameters for the fuel flow rate prediction. Power density analysis is used to find the minimum amount of the data. The results show that the nonlinear autoregressive model with exogenous inputs could predict the particulate matter successfully with R(2) above 0.96 using 2.5% NRTC data with only torque and speed as inputs. PMID:24805042

  19. Imaging marine geophysical environments with vector acoustics.

    PubMed

    Lindwall, Dennis

    2006-09-01

    Using vector acoustic sensors for marine geoacoustic surveys instead of the usual scalar hydrophones enables one to acquire three-dimensional (3D) survey data with instrumentation and logistics similar to current 2D surveys. Vector acoustic sensors measure the sound wave direction directly without the cumbersome arrays that hydrophones require. This concept was tested by a scaled experiment in an acoustic water tank that had a well-controlled environment with a few targets. Using vector acoustic data from a single line of sources, the three-dimensional tank environment was imaged by directly locating the source and all reflectors. PMID:17004497

  20. Bird population density estimated from acoustic signals

    USGS Publications Warehouse

    Dawson, D.K.; Efford, M.G.

    2009-01-01

    Many animal species are detected primarily by sound. Although songs, calls and other sounds are often used for population assessment, as in bird point counts and hydrophone surveys of cetaceans, there are few rigorous methods for estimating population density from acoustic data. 2. The problem has several parts - distinguishing individuals, adjusting for individuals that are missed, and adjusting for the area sampled. Spatially explicit capture-recapture (SECR) is a statistical methodology that addresses jointly the second and third parts of the problem. We have extended SECR to use uncalibrated information from acoustic signals on the distance to each source. 3. We applied this extension of SECR to data from an acoustic survey of ovenbird Seiurus aurocapilla density in an eastern US deciduous forest with multiple four-microphone arrays. We modelled average power from spectrograms of ovenbird songs measured within a window of 0??7 s duration and frequencies between 4200 and 5200 Hz. 4. The resulting estimates of the density of singing males (0??19 ha -1 SE 0??03 ha-1) were consistent with estimates of the adult male population density from mist-netting (0??36 ha-1 SE 0??12 ha-1). The fitted model predicts sound attenuation of 0??11 dB m-1 (SE 0??01 dB m-1) in excess of losses from spherical spreading. 5.Synthesis and applications. Our method for estimating animal population density from acoustic signals fills a gap in the census methods available for visually cryptic but vocal taxa, including many species of bird and cetacean. The necessary equipment is simple and readily available; as few as two microphones may provide adequate estimates, given spatial replication. The method requires that individuals detected at the same place are acoustically distinguishable and all individuals vocalize during the recording interval, or that the per capita rate of vocalization is known. We believe these requirements can be met, with suitable field methods, for a significant