WorldWideScience

Sample records for underway vibration survey

  1. Dynamic survey of wind turbine vibrations

    Science.gov (United States)

    Chiang, Chih-Hung; Hsu, Keng-Tsang; Cheng, Chia-Chi; Pan, Chieh-Chen; Huang, Chi-Luen; Cheng, Tao-Ming

    2016-04-01

    Six wind turbines were blown to the ground by the wind gust during the attack of Typhoon Soudelor in August 2015. Survey using unmanned aerial vehicle, UAV, found the collapsed wind turbines had been broken at the lower section of the supporting towers. The dynamic behavior of wind turbine systems is thus in need of attention. The vibration of rotor blades and supporting towers of two wind turbine systems have been measured remotely using IBIS, a microwave interferometer. However the frequency of the rotor blade can be analyzed only if the microwave measurements are taken as the wind turbine is parked and secured. Time-frequency analyses such as continuous wavelet transform and reassigned spectrograms are applied to the displacement signals obtained. A frequency of 0.44Hz exists in both turbines B and C at various operating conditions. Possible links between dynamic characteristics and structural integrity of wind turbine -tower systems is discussed.

  2. Literature survey on anti-vibration gloves

    CSIR Research Space (South Africa)

    Sampson, E

    2003-08-01

    Full Text Available -arm vibration. (ISO 5349) 7 Figure 2: Test handle with placement of sensors (from ISO 10819, 1996) 10 Figure 3: Operators posture and handle direction (ISO 10819, 1996). 11 1. Introduction Prolonged exposure to vibration affects the human body in many... handle and the suggested position of the sensors. Figure 2: Test handle with placement of sensors (ISO 10819, 1996) The posture of the operator could affect the level of vibration transmitted to the hand since a change in the posture may cause...

  3. Surface water and atmospheric underway carbon data obtained during the World Ocean Circulation Experiment Indian Ocean survey cruises (R/V Knorr, December 1998--January 1996)

    Energy Technology Data Exchange (ETDEWEB)

    Kozyr, A. [Univ. of Tennessee, Knoxville, TN (United States). Energy, Environment, and Resources Center; Allison, L. [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center

    1997-11-01

    This data documentation presents the results of the surface water and atmospheric underway measurements of mole fraction of carbon dioxide (xCO{sub 2}), sea surface salinity, and sea surface temperature, obtained during the World Ocean Circulation Experiment (WOCE) Indian Ocean survey cruises (December 1994--January 1996). Discrete and underway carbon measurements were made by members of the CO{sub 2} survey team. The survey team is a part of the Joint Global Ocean Flux Study supported by the US Department of Energy to make carbon-related measurements on the WOCE global survey cruises. Approximately 200,000 surface seawater and 50,000 marine air xCO{sub 2} measurements were recorded.

  4. A Survey of Floor Vibration Noise at All Sectors in the APS Experiment Hall

    Energy Technology Data Exchange (ETDEWEB)

    Kearney, Steven [Argonne National Lab. (ANL), Argonne, IL (United States); Shu, Deming [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-01-01

    A vibration survey of the APS experiment hall floor was conducted. It was found that beamlines 10-20 have particularly low levels of vibration when compared to the rest of the facility. The vibration spectrum for each beamline floor can be found in the appendix. Throughout the majority of the 5-100 Hz vibration spectrum beamlines at the APS fall below the most stringent NEST vibration criteria. Lastly, it was concluded that the magnitude of vibrations at a particular beamline is largely dependent upon the magnitude of vibrations present at the nearby mezzanine support column.

  5. Vibration survey of topsides piping on a producing FPSO in the Gulf of Guinea

    NARCIS (Netherlands)

    Ochonogor, C.; Madawaki, I.; Anaturk, A.; Eijk, A.; Slis, E.J.P.; Schoonewille, H.

    2012-01-01

    Visible mechanical vibrations were noticed on two topsides piping systems on a producing FPSO, in the Gulf of Guinea following increased production in 2008 and 2009. A field survey was undertaken on the piping of the FPSO to investigate the actual pulsation and vibration levels followed by a

  6. An International Survey of Shock and Vibration Technology

    Science.gov (United States)

    1979-03-01

    and certain musical instruments. The human eardrum is a membrane. Membranes are also extensively used in machine design for such items as pumps...Film Bearings", J. Sound Vib., 35 (3), pp 361-377, (Aug. 8, 1974). 434. Parkinson , A.G., "The Modal Interpretation of the Vibration of a Damped...D.L. and Swallow, J.C., "Annoying Floor Vibrations--Diagnosis and Therapy ", Sound Vib. 9 (3), pp 12-17 (Mar. 1975). 496. Leipholz, H.H.E., "Aspects

  7. Hot Ground Vibration Tests

    Data.gov (United States)

    National Aeronautics and Space Administration — Ground vibration tests or modal surveys are routinely conducted to support flutter analysis for subsonic and supersonic vehicles. However, vibration testing...

  8. 49-FT Boat Utility Stern Loading (BUSL) (49403 Underway Testing)

    National Research Council Canada - National Science Library

    Macesker, Bert

    1997-01-01

    .... The trials consisted of speed/power, tactical measurements. spiral maneuver, zig zag maneuvers, bollard pull, noise and vibration survey, endurance test, emergency stop, scale weighing, and an initial corrosion survey...

  9. Carbon dioxide, temperature, and salinity collected via surface underway survey in the East Coast of the United States (northwestern Atlantic Ocean) during the Ocean Margins Program cruises (NODC Accession 0083626)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0083626 includes underway chemical and physical data collected from COLUMBUS ISELIN, ENDEAVOR, GYRE, OCEANUS, and SEWARD JOHNSON in the North Atlantic...

  10. A meta-analysis of surveys into vibration annoyance from railway

    NARCIS (Netherlands)

    Janssen, S.A.; Vos, H.; Koopman, A.

    2013-01-01

    The EU-project CargoVibes aims to describe the expected annoyance due to vibration among residents living near (freight) railway lines. Compared to the state of knowledge on the annoyance response to noise, relatively little is known about the relationship between vibration exposure and annoyance.

  11. Survey of Technical Preventative Measures to Reduce Whole-Body Vibration Effects when Designing Mobile Machinery

    Science.gov (United States)

    DONATI, P.

    2002-05-01

    Engineering solutions to minimize the effects on operators of vibrating mobile machinery can be conveniently grouped into three areas: Reduction of vibration at source by improvement of the quality of terrain, careful selection of vehicle or machine, correct loading, proper maintenance, etc.Reduction of vibration transmission by incorporating suspension systems (tyres, vehicle suspensions, suspension cab and seat) between the operator and the source of vibration.Improvement of cab ergonomics and seat profiles to optimize operator posture. These paper reviews the different techniques and problems linked to categories (2) and (3). According to epidemiological studies, the main health risk with whole-body vibration exposure would appear to be lower back pain. When designing new mobile machinery, all factors which may contribute to back injury should be considered in order to reduce risk. For example, optimized seat suspension is useless if the suspension seat cannot be correctly and easily adjusted to the driver's weight or if the driver is forced to drive in a bent position to avoid his head striking the ceiling due to the spatial requirement of the suspension seat.

  12. Vibration survey of internal combustion engines for use on unmanned air vehicles

    International Nuclear Information System (INIS)

    Duanis, B.

    1998-01-01

    This paper describes the method, the procedure and data results of engine vibration test which is carried out on engines for use on unmanned air vehicles. The paper focuses on the testing of rotating propulsion systems powered by an internal combustion engine which is composed of main rotating components such as the alternator, gearbox, propeller , dampers and couplings. Three measurement methods for measuring torsional and lateral vibrations are presented: a. Gear tooth pulse signal. b. Shaft Strain Gage. c. Laser Displacement Sensors The paper also presents data from tests which were performed using each method and discusses the applications, the advantages and disadvantages of each method

  13. Vibration Feature Extraction and Analysis for Fault Diagnosis of Rotating Machinery-A Literature Survey

    Directory of Open Access Journals (Sweden)

    Saleem Riaz

    2017-02-01

    Full Text Available Safety, reliability, efficiency and performance of rotating machinery in all industrial applications are the main concerns. Rotating machines are widely used in various industrial applications. Condition monitoring and fault diagnosis of rotating machinery faults are very important and often complex and labor-intensive. Feature extraction techniques play a vital role for a reliable, effective and efficient feature extraction for the diagnosis of rotating machinery. Therefore, developing effective bearing fault diagnostic method using different fault features at different steps becomes more attractive. Bearings are widely used in medical applications, food processing industries, semi-conductor industries, paper making industries and aircraft components. This paper review has demonstrated that the latest reviews applied to rotating machinery on the available a variety of vibration feature extraction. Generally literature is classified into two main groups: frequency domain, time frequency analysis. However, fault detection and diagnosis of rotating machine vibration signal processing methods to present their own limitations. In practice, most healthy ingredients faulty vibration signal from background noise and mechanical vibration signals are buried. This paper also reviews that how the advanced signal processing methods, empirical mode decomposition and interference cancellation algorithm has been investigated and developed. The condition for rotating machines based rehabilitation, prevent failures increase the availability and reduce the cost of maintenance is becoming necessary too. Rotating machine fault detection and diagnostics in developing algorithms signal processing based on a key problem is the fault feature extraction or quantification. Currently, vibration signal, fault detection and diagnosis of rotating machinery based techniques most widely used techniques. Furthermore, the researchers are widely interested to make automatic

  14. Integral Analysis of Seismic Refraction and Ambient Vibration Survey for Subsurface Profile Evaluation

    Science.gov (United States)

    Hazreek, Z. A. M.; Kamarudin, A. F.; Rosli, S.; Fauziah, A.; Akmal, M. A. K.; Aziman, M.; Azhar, A. T. S.; Ashraf, M. I. M.; Shaylinda, M. Z. N.; Rais, Y.; Ishak, M. F.; Alel, M. N. A.

    2018-04-01

    Geotechnical site investigation as known as subsurface profile evaluation is the process of subsurface layer characteristics determination which finally used for design and construction phase. Traditionally, site investigation was performed using drilling technique thus suffers from several limitation due to cost, time, data coverage and sustainability. In order to overcome those problems, this study adopted surface techniques using seismic refraction and ambient vibration method for subsurface profile depth evaluation. Seismic refraction data acquisition and processing was performed using ABEM Terraloc and OPTIM software respectively. Meanwhile ambient vibration data acquisition and processing was performed using CityShark II, Lennartz and GEOPSY software respectively. It was found that studied area consist of two layers representing overburden and bedrock geomaterials based on p-wave velocity value (vp = 300 – 2500 m/s and vp > 2500 m/s) and natural frequency value (Fo = 3.37 – 3.90 Hz) analyzed. Further analysis found that both methods show some good similarity in term of depth and thickness with percentage accuracy at 60 – 97%. Consequently, this study has demonstrated that the application of seismic refractin and ambient vibration method was applicable in subsurface profile depth and thickness estimation. Moreover, surface technique which consider as non-destructive method adopted in this study was able to compliment conventional drilling method in term of cost, time, data coverage and environmental sustainaibility.

  15. The relationship between occupational noise and vibration exposure and headache/eyestrain, based on the fourth Korean Working Condition Survey (KWCS.

    Directory of Open Access Journals (Sweden)

    Jihyun Kim

    Full Text Available The individual and combined effect of occupational noise and vibration exposures, on workers' health has not been thoroughly investigated. In order to find better ways to prevent and manage workers' headache, this study aimed to investigate the effects of occupational noise and vibration exposure on headache/eyestrain.We used data from the fourth Korean Working Condition Survey (2014. After applying inclusion and exclusion criteria, 25,751 workers were included. Occupational noise and vibration exposure and the prevalence of headache/eyestrain were investigated by self-reported survey. Chi-square tests were used to compare differences in baseline characteristics between the group with headache/eyestrain and the group without. Odds ratios and 95% confidence intervals were estimated using a logistic regression model adjusted for several covariates. Area under the receiver operating characteristics curve (AUROC analysis was used to evaluate the effect of occupational noise and/or vibration exposure.Among the 25,751 study subjects, 4,903 had experienced headache/eyestrain in the preceding year. There were significant differences in age, education level, household income, occupational classification, shift work, occupational vibration exposure, and occupational noise exposure between the two groups (all p<0.05. The odds ratios between each exposure and headache/eyestrain increased proportionally with the level of exposure, increasing from 1.08 to 1.26 with increasing vibration exposure, and from 1.25 to 1.41 with increasing noise exposure. According to the AUROC analysis, the predictive power of each exposure was significant, and increased when the two exposures were considered in combination.The findings of this study show that both occupational noise and vibration exposures are associated with headache/eyestrain; noise exposure more strongly so. However, when the two exposures are considered in combination, the explanatory power for headache

  16. The relationship between occupational noise and vibration exposure and headache/eyestrain, based on the fourth Korean Working Condition Survey (KWCS).

    Science.gov (United States)

    Kim, Jihyun; Lee, Wanhyung; Won, Jong-Uk; Yoon, Jin-Ha; Seok, Hongdeok; Kim, Yeong-Kwang; Lee, Seunghyun; Roh, Jaehoon

    2017-01-01

    The individual and combined effect of occupational noise and vibration exposures, on workers' health has not been thoroughly investigated. In order to find better ways to prevent and manage workers' headache, this study aimed to investigate the effects of occupational noise and vibration exposure on headache/eyestrain. We used data from the fourth Korean Working Condition Survey (2014). After applying inclusion and exclusion criteria, 25,751 workers were included. Occupational noise and vibration exposure and the prevalence of headache/eyestrain were investigated by self-reported survey. Chi-square tests were used to compare differences in baseline characteristics between the group with headache/eyestrain and the group without. Odds ratios and 95% confidence intervals were estimated using a logistic regression model adjusted for several covariates. Area under the receiver operating characteristics curve (AUROC) analysis was used to evaluate the effect of occupational noise and/or vibration exposure. Among the 25,751 study subjects, 4,903 had experienced headache/eyestrain in the preceding year. There were significant differences in age, education level, household income, occupational classification, shift work, occupational vibration exposure, and occupational noise exposure between the two groups (all pheadache/eyestrain increased proportionally with the level of exposure, increasing from 1.08 to 1.26 with increasing vibration exposure, and from 1.25 to 1.41 with increasing noise exposure. According to the AUROC analysis, the predictive power of each exposure was significant, and increased when the two exposures were considered in combination. The findings of this study show that both occupational noise and vibration exposures are associated with headache/eyestrain; noise exposure more strongly so. However, when the two exposures are considered in combination, the explanatory power for headache/eyestrain is increased. Therefore, efforts aimed at reducing and

  17. Risk of hand-arm vibration syndrome according to occupation and sources of exposure to hand-transmitted vibration: A national survey.

    Science.gov (United States)

    Palmer, K T; Griffin, M J; Syddall, H; Pannett, B; Cooper, C; Coggon, D

    2001-04-01

    Although some occupational sources of hand-transmitted vibration (HTV) have been extensively investigated, the risks associated with others are poorly characterized. A questionnaire was mailed to a community sample of 12,240 men aged 16- 64 years and 906 men from the armed forces. Questions covered current occupation, sources of HTV, numbness or tingling in the fingers in the past week, and finger blanching. In the 5,364 respondents who had been at work in the past week, associations between symptoms and exposures were examined by logistic regression, with odds ratios converted into prevalence ratios (PRs). Altogether, 513 men (10%) reported cold-induced finger blanching and 769 (14%) sensory symptoms in the fingers. The risk of blanching was increased in builders (PR 2.4, 95% CI 1.0-5.2), carpenters and joiners (PR 1.9, 95% CI 1.0-3.4), motor mechanics (PR 2.3, 95% CI 1.1-4.6), and laborers (PR 2.8, 95% CI 1.3-6.0); while the risk of sensory symptoms was elevated in laborers (PR 4.0, 95% CI 2.3-6.6) and plant operatives (PR 3.5, 95% CI 1.9-5.9). Use of hand-guided mowers, concrete breakers, chain saws, and jig saws was significantly associated with symptoms. Little attention has been paid to the risks of vibration injury in construction workers, woodworkers, motor mechanics, and laborers, or to the risks from mowers, jig saws and several other common vibratory tools. These should be a focus for further investigation and preventive measures.

  18. Heart disease attributed to occupational noise, vibration and other co-exposure: Self-reported population-based survey among Bulgarian workers

    Directory of Open Access Journals (Sweden)

    Angel M. Dzhambov

    2016-08-01

    Full Text Available Background: Cardiovascular disease (CVD is the main mortality cause worldwide. Noise and vibration are considered to be occupational risk factors, but little is known about their cardiovascular effects in Bulgaria in terms of gender and various professional groups. The aim of this study has been to investigate the risk of prevalent CVD, associated with occupational noise and vibration exposure. Material and Methods: We conducted a secondary analysis of the data from 3 waves of the European Working Conditions Survey (EWCS 2001–2010 – a nationally-representative cross-sectional questionnaire survey covering 3149 workers aged ≥ 15 years in Bulgaria. Data on self-reported heart disease were linked to self-reported occupational noise and vibration, adjusting for other factors. Results from the 3 waves were pooled together using the inverse variance heterogeneity (IVhet meta-analysis. Results: For noise, the risk was elevated among women (relative risk (RR = 1.26, 95% confidence interval (CI: 0.53–3.01, but not men (RR = 0.49, 95% CI: 0.14–1.65. Long-term workers had RR = 1.01, 95% CI: 0.60–1.69. For vibration, the risk was increased in all participants. It was higher among men (RR = 2.56, 95% CI: 1.60–4.09 than it was among women (RR = 1.32, 95% CI: 0.77–2.27. Among long-term, industrial, and service workers it was RR = 1.56, 95% CI: 1.02–2.40; RR = 1.10, 95% CI: 0.61–1.98, and RR = 1.18, 95% CI: 0.57–2.46, respectively. Conclusions: Occupational vibration was a risk factor for prevalent heart disease in Bulgaria. Noise was an alleged risk factor only among long-term workers and women. Med Pr 2016;67(4:435–445

  19. In Portugal, the energy revolution is underway

    International Nuclear Information System (INIS)

    Mary, Olivier

    2015-01-01

    As at the beginning of 2013, 70 per cent of the electricity consumed in Portugal had a renewable origin, this article outlines that this result is based on a strong-willed policy. In fact, Portugal entered the energy transition in 2001 with its '4E program' (energy efficiency and endogenous energies) which aimed at reaching 60 per cent of renewable energies in electricity consumption by 2020. This program was based on a strong development of wind and hydraulic energy. Moreover, the country developed its own capacities for the manufacturing of wind turbines. On another hand, other renewable energies (notably solar energy) seem a bit late although several projects are underway. As far as hydraulic energy, a dam project is a matter of controversy

  20. Vibration mixer

    Energy Technology Data Exchange (ETDEWEB)

    Alekhin, S.A.; Chernov, V.S.; Denisenko, V.V.; Gorodnyanskiy, I.F.; Prokopov, L.I.; Tikhonov, Yu.P.

    1983-01-01

    The vibration mixer is proposed which contains a housing, vibration drive with rod installed in the upper part of the mixing mechanism made in the form of a hollow shaft with blades. In order to improve intensity of mixing and dispersion of the mud, the shaft with the blades is arranged on the rod of the vibrator and is equipped with a cam coupling whose drive disc is attached to the vibration rod. The rod is made helical, while the drive disc of the cam coupling is attached to the helical surface of the rod. In addition, the vibration mixer is equipped with perforated discs installed on the ends of the rods.

  1. Man-Induced Vibrations

    DEFF Research Database (Denmark)

    Jönsson, Jeppe; Hansen, Lars Pilegaard

    1994-01-01

    work has been done on the measurement of the exact load functions and related reponse analysis. A recent work using a spectral description has been performed by Per-Erik Erikson and includes a good literature survey. Bachmann and Ammann give a good overview of vibrations caused by human activity. Other...

  2. NOAA Ship Nancy Foster Underway Meteorological Data, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Nancy Foster Underway Meteorological Data (Near Real Time, updated daily) are from the Shipboard Automated Meteorological and Oceanographic System (SAMOS)...

  3. NOAA Ship Delaware II Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Delaware II Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  4. NOAA Ship Pisces Underway Meteorological Data, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Pisces Underway Meteorological Data (Near Real Time, updated daily) are from the Shipboard Automated Meteorological and Oceanographic System (SAMOS)...

  5. Research Ship Southern Surveyor Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship Southern Surveyor Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic...

  6. NOAA Ship Miller Freeman Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Miller Freeman Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  7. NOAA Ship Okeanos Explorer Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Okeanos Explorer Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic...

  8. NOAA Ship Gordon Gunter Underway Meteorological Data, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Gordon Gunter Underway Meteorological Data (Near Real Time, updated daily) are from the Shipboard Automated Meteorological and Oceanographic System (SAMOS)...

  9. NOAA Ship Hi'ialakai Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Hi'ialakai Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  10. Research Ship Healy Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship Healy Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  11. Research Ship Nathaniel B. Palmer Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship Nathaniel B. Palmer Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and...

  12. NOAA Ship Pisces Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Pisces Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System (SAMOS)...

  13. Research Ship New Horizon Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship New Horizon Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic...

  14. NOAA Ship Oregon II Underway Meteorological Data, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Oregon II Underway Meteorological Data (Near Real Time, updated daily) are from the Shipboard Automated Meteorological and Oceanographic System (SAMOS)...

  15. Research Ship Knorr Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship Knorr Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  16. Research Ship Oceanus Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship Oceanus Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  17. Research Ship Laurence M. Gould Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship Laurence M. Gould Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic...

  18. NOAA Ship Ronald Brown Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Ronald Brown Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  19. NOAA Ship Oscar Dyson Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Oscar Dyson Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  20. Research Ship Melville Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship Melville Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  1. Research Ship Kilo Moana Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship Kilo Moana Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  2. Research Ship Tangaroa Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship Tangaroa Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  3. Research Ship Robert Gordon Sproul Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship Robert Gordon Sproul Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and...

  4. NOAA Ship David Starr Jordan Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship David Starr Jordan Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic...

  5. NOAA Ship Bell M. Shimada Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Bell M. Shimada Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic...

  6. Research Ship T. G. Thompson Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship T. G. Thompson Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic...

  7. NOAA Ship Ronald Brown Underway Meteorological Data, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Ronald Brown Underway Meteorological Data (Near Real Time, updated daily) are from the Shipboard Automated Meteorological and Oceanographic System (SAMOS)...

  8. NOAA Ship Okeanos Explorer Underway Meteorological Data, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Okeanos Explorer Underway Meteorological Data (Near Real Time, updated daily) are from the Shipboard Automated Meteorological and Oceanographic System...

  9. NOAA Ship Oscar Elton Sette Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Oscar Elton Sette Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic...

  10. Research Ship Atlantic Explorer Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship Atlantic Explorer Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic...

  11. NOAA Ship Ka'imimoana Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Ka'imimoana Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  12. NOAA Ship Oscar Dyson Underway Meteorological Data, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Oscar Dyson Underway Meteorological Data (Near Real Time, updated daily) are from the Shipboard Automated Meteorological and Oceanographic System (SAMOS)...

  13. Research Ship Aurora Australis Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship Aurora Australis Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic...

  14. NOAA Ship Oregon II Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Oregon II Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  15. NOAA Ship Fairweather Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Fairweather Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  16. Research Ship Atlantis Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship Atlantis Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  17. NOAA Ship Rainier Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Rainier Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  18. NOAA Ship Gordon Gunter Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Gordon Gunter Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  19. NOAA Ship Rainier Underway Meteorological Data, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Rainier Underway Meteorological Data (Near Real Time, updated daily) are from the Shipboard Automated Meteorological and Oceanographic System (SAMOS)...

  20. NOAA Ship Fairweather Underway Meteorological Data, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Fairweather Underway Meteorological Data (Near Real Time, updated daily) are from the Shipboard Automated Meteorological and Oceanographic System (SAMOS)...

  1. Research Ship Roger Revelle Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship Roger Revelle Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic...

  2. NOAA Ship Nancy Foster Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Nancy Foster Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  3. NOAA Ship Henry B. Bigelow Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Henry B. Bigelow Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic...

  4. Evaluation of vibration limits and mitigation techniques for urban construction.

    Science.gov (United States)

    2013-10-01

    The overriding purpose of this research was to develop a comprehensive framework to address : vibration issues prior to and during construction, including calculation of anticipated ground : vibrations during project design, condition surveys of stru...

  5. Vibrating minds

    CERN Multimedia

    2009-01-01

    Ed Witten is one of the leading scientists in the field of string theory, the theory that describes elementary particles as vibrating strings. This week he leaves CERN after having spent a few months here on sabbatical. His wish is that the LHC will unveil supersymmetry.

  6. Vibrational spectroscopy

    Science.gov (United States)

    Umesh P. Agarwal; Rajai Atalla

    2010-01-01

    Vibrational spectroscopy is an important tool in modern chemistry. In the past two decades, thanks to significant improvements in instrumentation and the development of new interpretive tools, it has become increasingly important for studies of lignin. This chapter presents the three important instrumental methods-Raman spectroscopy, infrared (IR) spectroscopy, and...

  7. Vibrational spectroscopy

    International Nuclear Information System (INIS)

    Fadini, A.

    1980-01-01

    We present 13 programs for the calculation of vibrational spectroscopic problems applied to small molecules with high symmetry. The programs are compiled for the well known programmable pocket calculator Texas Instruments SR-52. To the special problems, the mathematical formulas, input and output instructions, several numerical examples, literature and the programs with comments are given. Order n = 1: The force constants, isotopic vibrational frequencies and the vibrational amplitudes are calculated for the two mass system XY(Csub(infinitely v)). For the three mass system XY 2 (Dsub(infinitely h)) only the force constants and isotopic frequencies are calculated. Order n = 2: For the three mass systems XYZ(Csub(infinitely v)) and XY 2 (Csub(infinitely 2v)) the inverse matrices G of the kinetic energy are presented. For complete sets of data (with isotopic frequencies, Coriolis coupling constants etc.) the complete force constant matrices are calculated. For non complete sets of data one starts in most cases with diagonal force constant matrices. The complete force constant matrix F is calculated with a minimalisation approximation. The eigenvector matrices L result from the G - F - and N-matrices. The N-matrices are calculated from the G- and F-matrices or from the F- and L-matrices respectively. Order n = 3: The matrix G of the system XYZ(Csub(S)) is calculated. For higher orders n, the 'isotopic reduction method' for the calculation of single force constants of proper systems is described. (orig.) [de

  8. Urban vibrations

    DEFF Research Database (Denmark)

    Morrison, Ann; Knudsen, L.; Andersen, Hans Jørgen

    2012-01-01

      lab   studies   in   that   we   found   a   decreased   detection   rate   in   busy   environments.   Here   we   test   with   a   much   larger   sample   and   age   range,   and   contribute   with   the   first   vibration  sensitivity  testing  outside  the  lab  in  an  urban   public...

  9. Sea experiments of the Underway Conductivity-Temperature-Depth prototype made in China

    Science.gov (United States)

    Song, Xiangzhou; Li, Hui; Lin, Xiaopei; Chen, Xueen; Guo, Xinshun; Tian, Jiwei

    2009-12-01

    A new instrument for upper ocean survey, namely the UCTD (Underway Conductivity-Temperature-Depth), which combines some of the advantages of other underway instruments, is introduced in this paper. The Introduction section presents a description of the construction and function of the UCTD, and the experiments conducted in the South China Sea on board the R/V Dong Fang Hong 2 in July 2007 and August 2008. The UCTD system, with pressure and temperature sensors in the probe, is conveniently portable, cost-effective and environment-friendly. It is hopefully suitable for future cruises. An intercomparison based on regressing with the experiment temperature data from both SeaBird plus911 CTD and the UCTD showed that the standard deviation is 0.88°C and the correlation coefficient is 0.96, achieving the goals set for the current oceanography uses. In the hydrodynamic experiments, the descending velocities and depths were calculated for different ship speeds. A pulling test was designed with a tensiometer to measure the magnitude of the pull. The maximal tension of the line was found to be 66.2 kg, which is far lower than the bearing limit of the Hollow Spectra line. Finally, some improvement suggestions are put forward for future experiments and production.

  10. Theory of vibration protection

    CERN Document Server

    Karnovsky, Igor A

    2016-01-01

    This text is an advancement of the theory of vibration protection of mechanical systems with lumped and distributed parameters. The book offers various concepts and methods of solving vibration protection problems, discusses the advantages and disadvantages of different methods, and the fields of their effective applications. Fundamental approaches of vibration protection, which are considered in this book, are the passive, parametric and optimal active vibration protection. The passive vibration protection is based on vibration isolation, vibration damping and dynamic absorbers. Parametric vibration protection theory is based on the Shchipanov-Luzin invariance principle. Optimal active vibration protection theory is based on the Pontryagin principle and the Krein moment method. The book also contains special topics such as suppression of vibrations at the source of their occurrence and the harmful influence of vibrations on humans. Numerous examples, which illustrate the theoretical ideas of each chapter, ar...

  11. Human response to vibration in residential environments.

    Science.gov (United States)

    Waddington, David C; Woodcock, James; Peris, Eulalia; Condie, Jenna; Sica, Gennaro; Moorhouse, Andrew T; Steele, Andy

    2014-01-01

    This paper presents the main findings of a field survey conducted in the United Kingdom into the human response to vibration in residential environments. The main aim of this study was to derive exposure-response relationships for annoyance due to vibration from environmental sources. The sources of vibration considered in this paper are railway and construction activity. Annoyance data were collected using questionnaires conducted face-to-face with residents in their own homes. Questionnaires were completed with residents exposed to railway induced vibration (N = 931) and vibration from the construction of a light rail system (N = 350). Measurements of vibration were conducted at internal and external positions from which estimates of 24-h vibration exposure were derived for 1073 of the case studies. Sixty different vibration exposure descriptors along with 6 different frequency weightings were assessed as potential predictors of annoyance. Of the exposure descriptors considered, none were found to be a better predictor of annoyance than any other. However, use of relevant frequency weightings was found to improve correlation between vibration exposure and annoyance. A unified exposure-response relationship could not be derived due to differences in response to the two sources so separate relationships are presented for each source.

  12. Experimental chaos in nonlinear vibration isolation system

    International Nuclear Information System (INIS)

    Lou Jingjun; Zhu Shijian; He Lin; He Qiwei

    2009-01-01

    The chaotic vibration isolation method was studied thoroughly from an experimental perspective. The nonlinear load-deflection characteristic of the conical coil spring used in the experiment was surveyed. Chaos and subharmonic responses including period-2 and period-6 motions were observed. The line spectrum reduction and the drop of the acceleration vibration level in chaotic state and that in non-chaotic state were compared, respectively. It was concluded from the experiment that the nonlinear vibration isolation system in chaotic state has strong ability in line spectrum reduction.

  13. SURVEY

    DEFF Research Database (Denmark)

    SURVEY er en udbredt metode og benyttes inden for bl.a. samfundsvidenskab, humaniora, psykologi og sundhedsforskning. Også uden for forskningsverdenen er der mange organisationer som f.eks. konsulentfirmaer og offentlige institutioner samt marketingsafdelinger i private virksomheder, der arbejder...... med surveys. Denne bog gennemgår alle surveyarbejdets faser og giver en praktisk indføring i: • design af undersøgelsen og udvælgelse af stikprøver, • formulering af spørgeskemaer samt indsamling og kodning af data, • metoder til at analysere resultaterne...

  14. Vibrations and Stability

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    About this textbook An ideal text for students that ties together classical and modern topics of advanced vibration analysis in an interesting and lucid manner. It provides students with a background in elementary vibrations with the tools necessary for understanding and analyzing more complex...... dynamical phenomena that can be encountered in engineering and scientific practice. It progresses steadily from linear vibration theory over various levels of nonlinearity to bifurcation analysis, global dynamics and chaotic vibrations. It trains the student to analyze simple models, recognize nonlinear...... and physics. This edition includes a new chapter on the useful effects of fast vibrations and many new exercise problems. Written for: Students in mechanical or structural engineering. Keywords: Nonlinear Vibrations, Bifurcations, Chaotic Vibrations, Vibrations and Stability....

  15. Human response to vibration

    National Research Council Canada - National Science Library

    Mansfield, Neil J

    2005-01-01

    .... Vibration measurements and standards are also addressed. This book meets the needs of those requiring knowledge of human response to vibration in order to make practical improvements to physical working environments...

  16. Vibrations and Stability

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    dynamical phenomena that can be encountered in engineering and scientific practice. It progresses steadily from linear vibration theory over various levels of nonlinearity to bifurcation analysis, global dynamics and chaotic vibrations. It trains the student to analyze simple models, recognize nonlinear...... and physics. This edition includes a new chapter on the useful effects of fast vibrations and many new exercise problems. Written for: Students in mechanical or structural engineering. Keywords: Nonlinear Vibrations, Bifurcations, Chaotic Vibrations, Vibrations and Stability.......About this textbook An ideal text for students that ties together classical and modern topics of advanced vibration analysis in an interesting and lucid manner. It provides students with a background in elementary vibrations with the tools necessary for understanding and analyzing more complex...

  17. Tunable Passive Vibration Suppressor

    Science.gov (United States)

    Boechler, Nicholas (Inventor); Dillon, Robert Peter (Inventor); Daraio, Chiara (Inventor); Davis, Gregory L. (Inventor); Shapiro, Andrew A. (Inventor); Borgonia, John Paul C. (Inventor); Kahn, Daniel Louis (Inventor)

    2016-01-01

    An apparatus and method for vibration suppression using a granular particle chain. The granular particle chain is statically compressed and the end particles of the chain are attached to a payload and vibration source. The properties of the granular particles along with the amount of static compression are chosen to provide desired filtering of vibrations.

  18. Vibration of plates

    CERN Document Server

    Chakraverty, Snehashish

    2008-01-01

    Plates are integral parts of most engineering structures and their vibration analysis is required for safe design. This work provides a comprehensive introduction to vibration theory and analysis of two-dimensional plates. It offers information on vibration problems along with a discussion of various plate geometries and boundary conditions.

  19. Vibrations and Eigenvalues

    Indian Academy of Sciences (India)

    We make music by causing strings, membranes, or air columns to vibrate. Engineers design safe structures by control- ling vibrations. I will describe to you a very simple vibrating system and the mathematics needed to analyse it. The ideas were born in the work of Joseph-Louis Lagrange (1736–1813), and I begin by quot-.

  20. Comparative studies of perceived vibration strength for commercial mobile phones.

    Science.gov (United States)

    Lee, Heow Pueh; Lim, Siak Piang

    2014-05-01

    A mobile phone, also known as cell phone or hand phone, is among the most popular electrical devices used by people all over the world. The present study examines the vibration perception of mobile phones by co-relating the relevant design parameters such as excitation frequency, and size and mass of mobile phones to the vibration perception survey by volunteers. Five popular commercially available mobile phone models were tested. The main findings for the perception surveys were that higher vibration frequency and amplitude of the peak acceleration would result in stronger vibration perception of the mobile phones. A larger contact surface area with the palms and figures, higher peak acceleration and the associated larger peak inertia force may be the main factors for the relatively higher vibration perception. The future design for the vibration alert of the mobile phones is likely to follow this trend. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  1. Visualized Characterization for Cerebral Response of Acupuncture Deqi: Paradox Underway

    Directory of Open Access Journals (Sweden)

    Jie Yang

    2013-01-01

    Full Text Available Acupuncture as an oriental natural healing therapy with prolonged history has been extensively utilized in the management of great numbers of disorders. Deqi, a renowned acupuncture needling sensation, is profoundly regarded as the predictor and also the prerequisite of a preferable acupuncture treatment efficacy. Till now, there is still no consistency being reached towards the mechanism of acupuncture Deqi as a result of the discrepancy for publicly acknowledged evidence. Recent visualized research on Deqi using modern technologies has demonstrated possible central mechanism towards it. However, there is a conspicuous paradox underway in the research of cerebral response to acupuncture Deqi. This paper provided a view of up-to-date studies using visualized tools to characterize the brain response to acupuncture Deqi, such as functional magnetic resonance imaging (fMRI and positron emission tomography/computed tomography (PET/CT. The paradox was extruded to highlight certain reasons from a TCM view. It is hypothesized that acupoints located at different dermal sites, state of participant, and needling manipulation can all contribute to the current paradox. Hence, further studies on acupuncture Deqi should pay more attention to the strategy of experiment design with generalized measurement, valid sham control methods, and more to subjects in diseased condition.

  2. Anti-vibration gloves?

    Science.gov (United States)

    Hewitt, Sue; Dong, Ren G; Welcome, Daniel E; McDowell, Thomas W

    2015-03-01

    For exposure to hand-transmitted vibration (HTV), personal protective equipment is sold in the form of anti-vibration (AV) gloves, but it remains unclear how much these gloves actually reduce vibration exposure or prevent the development of hand-arm vibration syndrome in the workplace. This commentary describes some of the issues that surround the classification of AV gloves, the assessment of their effectiveness and their applicability in the workplace. The available information shows that AV gloves are unreliable as devices for controlling HTV exposures. Other means of vibration control, such as using alternative production techniques, low-vibration machinery, routine preventative maintenance regimes, and controlling exposure durations are far more likely to deliver effective vibration reductions and should be implemented. Furthermore, AV gloves may introduce some adverse effects such as increasing grip force and reducing manual dexterity. Therefore, one should balance the benefits of AV gloves and their potential adverse effects if their use is considered. © Crown copyright 2014.

  3. Vibration of hydraulic machinery

    CERN Document Server

    Wu, Yulin; Liu, Shuhong; Dou, Hua-Shu; Qian, Zhongdong

    2013-01-01

    Vibration of Hydraulic Machinery deals with the vibration problem which has significant influence on the safety and reliable operation of hydraulic machinery. It provides new achievements and the latest developments in these areas, even in the basic areas of this subject. The present book covers the fundamentals of mechanical vibration and rotordynamics as well as their main numerical models and analysis methods for the vibration prediction. The mechanical and hydraulic excitations to the vibration are analyzed, and the pressure fluctuations induced by the unsteady turbulent flow is predicted in order to obtain the unsteady loads. This book also discusses the loads, constraint conditions and the elastic and damping characters of the mechanical system, the structure dynamic analysis, the rotor dynamic analysis and the system instability of hydraulic machines, including the illustration of monitoring system for the instability and the vibration in hydraulic units. All the problems are necessary for vibration pr...

  4. Vibrating fuel grapple. [LMFBR

    Science.gov (United States)

    Chertock, A.J.; Fox, J.N.; Weissinger, R.B.

    A reactor refueling method is described which utilizes a vibrating fuel grapple for removing spent fuel assemblies from a reactor core. It incorporates a pneumatic vibrator in the grapple head which allows additional withdrawal capability without exceeding the allowable axial force limit. The only moving part in the vibrator is a steel ball, pneumatically driven by a gas, such as argon, around a track, with centrifugal force created by the ball being transmitted through the grapple to the assembly handling socket.

  5. Geometry and evolution of a fault-controlled Quaternary basin by means of TDEM and single-station ambient vibration surveys: The example of the 2009 L'Aquila earthquake area, central Italy

    Science.gov (United States)

    Civico, R.; Sapia, V.; Di Giulio, G.; Villani, F.; Pucci, S.; Baccheschi, P.; Amoroso, S.; Cantore, L.; Di Naccio, D.; Hailemikael, S.; Smedile, A.; Vassallo, M.; Marchetti, M.; Pantosti, D.

    2017-03-01

    We applied a joint survey approach integrating time domain electromagnetic soundings and single-station ambient vibration surveys in the Middle Aterno Valley (MAV), an intermontane basin in central Italy and the locus of the 2009 L'Aquila earthquake. By imaging the buried interface between the infilling deposits and the top of the pre-Quaternary bedrock, we reveal the 3-D basin geometry and gain insights into the long-term basin evolution. We reconstruct a complex subsurface architecture, characterized by three main depocenters separated by thresholds. Basin infill thickness varies from 200-300 m in the north to more than 450 m to the southeast. Our subsurface model indicates a strong structural control on the architecture of the basin and highlights that the MAV experienced considerable modifications in its configuration over time. The buried shape of the MAV suggests a recent and still ongoing predominant tectonic control by the NW-SE trending Paganica-San Demetrio Fault System (PSDFS), which crosscuts older ENE and NNE trending extensional faults. Furthermore, we postulate that the present-day arrangement of the PSDFS is the result of the linkage of two previously isolated fault segments. We provide constraints on the location of the southeastern boundary of the PSDFS, defining an overall 19 km long fault system characterized by a considerable seismogenetic potential and a maximum expected magnitude larger than M 6.5. This study emphasizes the benefit of combining two easily deployable geophysical methods for reconstructing the 3-D geometry of a tectonically controlled basin. Our joint approach provided us with a consistent match between these two independent estimations of the basin substratum depth within 15%.

  6. NOAA Ship Hi'ialakai Underway Meteorological Data, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Hi'ialakai Underway Meteorological Data (Near Real Time, updated daily) are from the Shipboard Automated Meteorological and Oceanographic System (SAMOS)...

  7. NOAA Ship Oscar Elton Sette Underway Meteorological Data, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Oscar Elton Sette Underway Meteorological Data (Near Real Time, updated daily) are from the Shipboard Automated Meteorological and Oceanographic System...

  8. NOAA Ship McArthurII Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship McArthur II Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  9. NOAA Ship Ka'imimoana Underway Meteorological Data, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Ka'imimoana Underway Meteorological Data (Near Real Time, updated daily) are from the Shipboard Automated Meteorological and Oceanographic System (SAMOS)...

  10. NOAA Ship Bell M. Shimada Underway Meteorological Data, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Bell M. Shimada Underway Meteorological Data (Near Real Time, updated daily) are from the Shipboard Automated Meteorological and Oceanographic System...

  11. NOAA Ship Henry B. Bigelow Underway Meteorological Data, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Henry B. Bigelow Underway Meteorological Data (Near Real Time, updated daily) are from the Shipboard Automated Meteorological and Oceanographic System...

  12. A Task Analysis of Underway Replenishment for Virtual Environment Ship-Handling Simulator Scenario Development

    National Research Council Canada - National Science Library

    Norris, Steven

    1998-01-01

    ...) in Newport, RI, researchers at the Naval Air Warfare Center Training Systems Division (NAWCTSD) in Orlando, FL discovered a need for a task analysis of a Conning Officer during an Underway Replenishment...

  13. Mechanical vibration and shock analysis, sinusoidal vibration

    CERN Document Server

    Lalanne, Christian

    2014-01-01

    Everything engineers need to know about mechanical vibration and shock...in one authoritative reference work! This fully updated and revised 3rd edition addresses the entire field of mechanical vibration and shock as one of the most important types of load and stress applied to structures, machines and components in the real world. Examples include everything from the regular and predictable loads applied to turbines, motors or helicopters by the spinning of their constituent parts to the ability of buildings to withstand damage from wind loads or explosions, and the need for cars to m

  14. Model Indepedent Vibration Control

    OpenAIRE

    Yuan, Jing

    2010-01-01

    A NMIFC system is proposed for broadband vibration control. It has two important features. Feature F1 is that the NMIFC is stable without introducing any invasive effects, such as probing signals or controller perturbations, into the vibration system; feature F2 is

  15. Vibration Theory, Vol. 3

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.

    The present textbook has been written based on previous lecture notes for a course on stochastic vibration theory that is being given on the 9th semester at Aalborg University for M. Sc. students in structural engineering. The present 4th edition of this textbook on linear stochastic vibration...

  16. Handbook Of Noise And Vibration

    International Nuclear Information System (INIS)

    1995-12-01

    This book is about noise and vibration. The first chapter has explanations of noise such as basic of sound, influence of noise, assessment of noise, measurement of prevention of noise and technology, case of noise measurement and soundproof. The second chapter describes vibration with outline, theory of vibration, interpretation of vibration, measurement for reduction of vibration, case of design of protection against vibration. It deals with related regulation and method of measurement.

  17. Vibrations of rotating machinery

    CERN Document Server

    Matsushita, Osami; Kanki, Hiroshi; Kobayashi, Masao; Keogh, Patrick

    2017-01-01

    This book opens with an explanation of the vibrations of a single degree-of-freedom (dof) system for all beginners. Subsequently, vibration analysis of multi-dof systems is explained by modal analysis. Mode synthesis modeling is then introduced for system reduction, which aids understanding in a simplified manner of how complicated rotors behave. Rotor balancing techniques are offered for rigid and flexible rotors through several examples. Consideration of gyroscopic influences on the rotordynamics is then provided and vibration evaluation of a rotor-bearing system is emphasized in terms of forward and backward whirl rotor motions through eigenvalue (natural frequency and damping ratio) analysis. In addition to these rotordynamics concerning rotating shaft vibration measured in a stationary reference frame, blade vibrations are analyzed with Coriolis forces expressed in a rotating reference frame. Other phenomena that may be assessed in stationary and rotating reference frames include stability characteristic...

  18. Vibrations in deformed nuclei

    International Nuclear Information System (INIS)

    Aprahamian, A.

    1992-01-01

    Quadrupole oscillations around a deformed shape give rise to vibrations in deformed nuclei. Single phonon vibrations of K = 0 (β) and K = 2 (γ) are a systematic feature in deformed nuclei, but the existence of multi-phonon vibrations had remained an open question until the recently reported results in 168 Er. In this nucleus, a two-phonon K = 4(γγ) band was observed at approximately 2.5 times the energy of the single γ vibration. The authors have studied several deformed rare-earth nuclei using the ( 4 He,2n) reaction in order to map out the systematic behavior of these multi-phonon vibrations. Recently, they have identified a similar K = 4 band in 154 Gd

  19. Structural Stability and Vibration

    DEFF Research Database (Denmark)

    Wiggers, Sine Leergaard; Pedersen, Pauli

    This book offers an integrated introduction to the topic of stability and vibration. Strikingly, it describes stability as a function of boundary conditions and eigenfrequency as a function of both boundary conditions and column force. Based on a post graduate course held by the author at the Uni......This book offers an integrated introduction to the topic of stability and vibration. Strikingly, it describes stability as a function of boundary conditions and eigenfrequency as a function of both boundary conditions and column force. Based on a post graduate course held by the author...... and their derivation, thus stimulating them to write interactive and dynamic programs to analyze instability and vibrational modes....

  20. Coherent vibrational dynamics

    CERN Document Server

    Lanzani, Guglielmo; De Silvestri, Sandro

    2007-01-01

    Vibrational spectroscopy is a powerful investigation tool for a wide class of materials covering diverse areas in physics, chemistry and biology. The continuous development in the laser field regarding ultrashort pulse generation has led to the possibility of producing light pulses that can follow vibrational motion coupled to the electronic transitions in molecules and solids in real time. Aimed at researchers and graduate students using vibrational spectroscopy, this book provides both introductory chapters as well as more advanced contents reporting on recent progress. It also provides a good starting point for scientists seeking a sound introduction to ultrafast optics and spectroscopic techniques.

  1. Vibration Analysis and the Accelerometer

    Science.gov (United States)

    Hammer, Paul

    2011-01-01

    Have you ever put your hand on an electric motor or motor-driven electric appliance and felt it vibrate? Ever wonder why it vibrates? What is there about the operation of the motor, or the object to which it is attached, that causes the vibrations? Is there anything "regular" about the vibrations, or are they the result of random causes? In this…

  2. PREFACE: Vibrations at surfaces Vibrations at surfaces

    Science.gov (United States)

    Rahman, Talat S.

    2011-12-01

    This special issue is dedicated to the phenomenon of vibrations at surfaces—a topic that was indispensible a couple of decades ago, since it was one of the few phenomena capable of revealing the nature of binding at solid surfaces. For clean surfaces, the frequencies of modes with characteristic displacement patterns revealed how surface geometry, as well as the nature of binding between atoms in the surface layers, could be different from that in the bulk solid. Dispersion of the surface phonons provided further measures of interatomic interactions. For chemisorbed molecules on surfaces, frequencies and dispersion of the vibrational modes were also critical for determining adsorption sites. In other words, vibrations at surfaces served as a reliable means of extracting information about surface structure, chemisorption and overlayer formation. Experimental techniques, such as electron energy loss spectroscopy and helium-atom-surface scattering, coupled with infra-red spectroscopy, were continually refined and their resolutions enhanced to capture subtleties in the dynamics of atoms and molecules at surfaces. Theoretical methods, whether based on empirical and semi-empirical interatomic potential or on ab initio electronic structure calculations, helped decipher experimental observations and provide deeper insights into the nature of the bond between atoms and molecules in regions of reduced symmetry, as encountered on solid surfaces. Vibrations at surfaces were thus an integral part of the set of phenomena that characterized surface science. Dedicated workshops and conferences were held to explore the variety of interesting and puzzling features revealed in experimental and theoretical investigations of surface vibrational modes and their dispersion. One such conference, Vibrations at Surfaces, first organized by Harald Ibach in Juelich in 1980, continues to this day. The 13th International Conference on Vibrations at Surfaces was held at the University of

  3. A vibration sieve

    Energy Technology Data Exchange (ETDEWEB)

    Alekhin, S.A.; Denisenko, V.V.; Dzhalalov, M.G.; Kirichek, F.P.; Pitatel, Yu.A.; Prokopov, L.I.; Tikhonov, Yu.P.

    1982-01-01

    A vibration sieve is proposed which includes a vibration drive, a body and a screen installed on shock absorbers, a device for washing out the screen, and a subassembly for loading the material. To increase the operational reliability and effectiveness of the vibration sieve by improving the cleaning of the screen, the loading subassembly is equipped with a baffle with a lever which is hinged to it. The device for washing out the screen is made in the form of an electromagnet with a connecting rod, a switch and an eccentric, a friction ratchet mechanism and sprinkling systems. Here, the latter are interconnected, using a connecting rod, while the sprinkling system is installed on rollers under the screen. The electromagnetic switch is installed under the lever. The body is made with grooves for installing the sprinkling system. The vibration sieve is equipped with a switch which interacts with the connecting rod. The friction ratchet mechanism is equipped with a lug.

  4. 2008 Vibrational Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Philip J. Reid

    2009-09-21

    The conference focuses on using vibrational spectroscopy to probe structure and dynamics of molecules in gases, liquids, and interfaces. The goal is to bring together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of systems.

  5. Zero-determinant strategy: An underway revolution in game theory

    International Nuclear Information System (INIS)

    Hao Dong; Rong Zhi-Hai; Zhou Tao

    2014-01-01

    Repeated games describe situations where players interact with each other in a dynamic pattern and make decisions according to outcomes of previous stage games. Very recently, Press and Dyson have revealed a new class of zero-determinant (ZD) strategies for the repeated games, which can enforce a fixed linear relationship between expected payoffs of two players, indicating that a smart player can control her unwitting co-player's payoff in a unilateral way [Proc. Acad. Natl. Sci. USA 109, 10409 (2012)]. The theory of ZD strategies provides a novel viewpoint to depict interactions among players, and fundamentally changes the research paradigm of game theory. In this brief survey, we first introduce the mathematical framework of ZD strategies, and review the properties and constrains of two specifications of ZD strategies, called pinning strategies and extortion strategies. Then we review some representative research progresses, including robustness analysis, cooperative ZD strategy analysis, and evolutionary stability analysis. Finally, we discuss some significant extensions to ZD strategies, including the multi-player ZD strategies, and ZD strategies under noise. Challenges in related research fields are also listed. (topical review - statistical physics and complex systems)

  6. AVM branch vibration test equipment

    International Nuclear Information System (INIS)

    Anne, J.P.

    1995-01-01

    An inventory of the test equipment of the AVM Branch ''Acoustic and Vibratory Mechanics Analysis Methods'' group has been undertaken. The purpose of this inventory is to enable better acquaintance with the technical characteristics of the equipment, providing an accurate definition of their functionalities, ad to inform potential users of the possibilities and equipment available in this field. The report first summarizes the various experimental surveys conduced. Then, using the AVM equipment database to draw up an exhaustive list of available equipment, it provides a full-scope picture of the vibration measurement systems (sensors, conditioners and exciters) and data processing resources commonly used on industrial sites and in laboratories. A definition is also given of a mobile test unit, called 'shelter', and a test bench used for the testing and performance rating of the experimental analysis methods developed by the group. The report concludes with a description of two fixed installations: - the calibration bench ensuring the requisite quality level for the vibration measurement systems ; - the training bench, whereby know-how acquired in the field in the field of measurement and experimental analysis processes is made available to others. (author). 27 refs., 15 figs., 2 appends

  7. Vibration transducer calibration techniques

    Science.gov (United States)

    Brinkley, D. J.

    1980-09-01

    Techniques for the calibration of vibration transducers used in the Aeronautical Quality Assurance Directorate of the British Ministry of Defence are presented. Following a review of the types of measurements necessary in the calibration of vibration transducers, the performance requirements of vibration transducers, which can be used to measure acceleration, velocity or vibration amplitude, are discussed, with particular attention given to the piezoelectric accelerometer. Techniques for the accurate measurement of sinusoidal vibration amplitude in reference-grade transducers are then considered, including the use of a position sensitive photocell and the use of a Michelson laser interferometer. Means of comparing the output of working-grade accelerometers with that of previously calibrated reference-grade devices are then outlined, with attention given to a method employing a capacitance bridge technique and a method to be used at temperatures between -50 and 200 C. Automatic calibration procedures developed to speed up the calibration process are outlined, and future possible extensions of system software are indicated.

  8. Vibrations in orthopedics.

    Science.gov (United States)

    Nokes, L D; Thorne, G C

    1988-01-01

    Measurements of various mechanical properties of skeletal material using vibration techniques have been reported. The purposes of such investigations include the monitoring of pathogenic disorders such as osteoporosis, the rate and extent of fracture healing, and the status of internal fixations. Early investigations pioneered the application of conventional vibration measurement equipment to biological systems. The more recent advent of the microcomputer has made available to research groups more sophisticated techniques for data acquisition and analysis. The economical advantages of such equipment has led to the development of portable research instrumentation which lends itself to use in a clinical environment. This review article reports on the developments and progression of the various vibrational techniques and theories as applied to musculoskeletal systems.

  9. From Knowledge-Inquiry to Wisdom-Inquiry: Is the Revolution Underway?

    Science.gov (United States)

    Iredale, Mathew

    2007-01-01

    In the final paragraph of his 1984 book "From knowledge to wisdom, a revolution in the aims and methods of science," the philosopher Nicholas Maxwell boldly declared that an intellectual revolution was underway in the aims and methods of science, and academic inquiry in general, from what he termed knowledge-inquiry to wisdom-inquiry.…

  10. Vibrations and waves

    CERN Document Server

    Kaliski, S

    2013-01-01

    This book gives a comprehensive overview of wave phenomena in different media with interacting mechanical, electromagnetic and other fields. Equations describing wave propagation in linear and non-linear elastic media are followed by equations of rheological models, models with internal rotational degrees of freedom and non-local interactions. Equations for coupled fields: thermal, elastic, electromagnetic, piezoelectric, and magneto-spin with adequate boundary conditions are also included. Together with its companion volume Vibrations and Waves. Part A: Vibrations this work provides a wealth

  11. Vibration Theory, Vol. 3

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.

    The present textbook has been written based on previous lecture notes for a course on stochastic vibration theory that is being given on the 9th semester at Aalborg University for M. Sc. students in structural engineering. The present 2nd edition of this textbook on linear stochastic vibration th...... theory is basically unchanged in comparison to the 1st edition. Only section 4.2 on single input - single output systems and chapter 6 on offshore structures have been modified in order to enhance the clearness....

  12. Heterogeneous Dynamics of Coupled Vibrations

    NARCIS (Netherlands)

    Cringus, Dan; Jansen, Thomas I. C.; Pshenichnikov, Maxim S.; Schoenlein, RW; Corkum, P; DeSilvestri, S; Nelson, KA; Riedle, E

    2009-01-01

    Frequency-dependent dynamics of coupled stretch vibrations of a water molecule are revealed by 2D IR correlation spectroscopy. These are caused by non-Gaussian fluctuations of the environment around the individual OH stretch vibrations.

  13. Composite Struts Would Damp Vibrations

    Science.gov (United States)

    Dolgin, Benjamin P.

    1991-01-01

    New design of composite-material (fiber/matrix laminate) struts increases damping of longitudinal vibrations without decreasing longitudinal stiffness or increasing weight significantly. Plies with opposing chevron patterns of fibers convert longitudinal vibrational stresses into shear stresses in intermediate viscoelastic layer, which dissipate vibrational energy. Composite strut stronger than aluminum strut of same weight and stiffness.

  14. Development of vibrating insoles

    NARCIS (Netherlands)

    Hijmans, J.M.; Geertzen, J.H.B.; Schokker, B.; Postema, K.

    2007-01-01

    The objective of this study was to describe the development of vibrating insoles. Insoles, providing a subsensory mechanical noise signal to the plantar side of the feet, may improve balance in healthy young and older people and in patients with stroke or diabetic neuropathy. This study describes

  15. Vibrational Spectroscopy and Astrobiology

    Science.gov (United States)

    Chaban, Galina M.; Kwak, D. (Technical Monitor)

    2001-01-01

    Role of vibrational spectroscopy in solving problems related to astrobiology will be discussed. Vibrational (infrared) spectroscopy is a very sensitive tool for identifying molecules. Theoretical approach used in this work is based on direct computation of anharmonic vibrational frequencies and intensities from electronic structure codes. One of the applications of this computational technique is possible identification of biological building blocks (amino acids, small peptides, DNA bases) in the interstellar medium (ISM). Identifying small biological molecules in the ISM is very important from the point of view of origin of life. Hybrid (quantum mechanics/molecular mechanics) theoretical techniques will be discussed that may allow to obtain accurate vibrational spectra of biomolecular building blocks and to create a database of spectroscopic signatures that can assist observations of these molecules in space. Another application of the direct computational spectroscopy technique is to help to design and analyze experimental observations of ice surfaces of one of the Jupiter's moons, Europa, that possibly contains hydrated salts. The presence of hydrated salts on the surface can be an indication of a subsurface ocean and the possible existence of life forms inhabiting such an ocean.

  16. Structural Stability and Vibration

    DEFF Research Database (Denmark)

    Wiggers, Sine Leergaard; Pedersen, Pauli

    This book offers an integrated introduction to the topic of stability and vibration. Strikingly, it describes stability as a function of boundary conditions and eigenfrequency as a function of both boundary conditions and column force. Based on a post graduate course held by the author...

  17. Vibrations and Eigenvalues

    Indian Academy of Sciences (India)

    rical or mechanical reasonings, but solely algebraic [analytic] operations subjected to a uniform and regular procedure. Those. Keywords. Vibrations, eigenvalues .... Suggested Reading. [1] R Bhatia, Fourier Series, Hindustan Book Agency, Second Edition, 2003. [2] G Strang, Essays in Linear Algebra, SIAM, 2012. 872.

  18. Compact Vibration Damper

    Science.gov (United States)

    Ivanco, Thomas G. (Inventor)

    2014-01-01

    A vibration damper includes a rigid base with a mass coupled thereto for linear movement thereon. Springs coupled to the mass compress in response to the linear movement along either of two opposing directions. A converter coupled to the mass converts the linear movement to a corresponding rotational movement. A rotary damper coupled to the converter damps the rotational movement.

  19. Blade Vibration Measurement System

    Science.gov (United States)

    Platt, Michael J.

    2014-01-01

    The Phase I project successfully demonstrated that an advanced noncontacting stress measurement system (NSMS) could improve classification of blade vibration response in terms of mistuning and closely spaced modes. The Phase II work confirmed the microwave sensor design process, modified the sensor so it is compatible as an upgrade to existing NSMS, and improved and finalized the NSMS software. The result will be stand-alone radar/tip timing radar signal conditioning for current conventional NSMS users (as an upgrade) and new users. The hybrid system will use frequency data and relative mode vibration levels from the radar sensor to provide substantially superior capabilities over current blade-vibration measurement technology. This frequency data, coupled with a reduced number of tip timing probes, will result in a system capable of detecting complex blade vibrations that would confound traditional NSMS systems. The hardware and software package was validated on a compressor rig at Mechanical Solutions, Inc. (MSI). Finally, the hybrid radar/tip timing NSMS software package and associated sensor hardware will be installed for use in the NASA Glenn spin pit test facility.

  20. Vibration characteristics of ultrasonic complex vibration for hole machining

    Science.gov (United States)

    Asami, Takuya; Miura, Hikaru

    2012-05-01

    Complex vibration sources that use diagonal slits as a longitudinal-torsional vibration converter have been applied to ultrasonic motors, ultrasonic rock drilling, and ultrasonic welding. However, there are few examples of the application of these sources to ultrasonic machining in combination with an abrasive. Accordingly, a new method has been developed for machining of holes in brittle materials by using the ultrasonic longitudinal and torsional vibration of a hollow-type stepped horn with a diagonal slit vibration converter. In this paper, we compared vibration of a uniform rod and a hollow-type stepped horn, both with diagonal slits, when the conditions of the diagonal slits are constant.

  1. The effects of vibration-reducing gloves on finger vibration

    Science.gov (United States)

    Welcome, Daniel E.; Dong, Ren G.; Xu, Xueyan S.; Warren, Christopher; McDowell, Thomas W.

    2015-01-01

    Vibration-reducing (VR) gloves have been used to reduce the hand-transmitted vibration exposures from machines and powered hand tools but their effectiveness remains unclear, especially for finger protection. The objectives of this study are to determine whether VR gloves can attenuate the vibration transmitted to the fingers and to enhance the understanding of the mechanisms of how these gloves work. Seven adult male subjects participated in the experiment. The fixed factors evaluated include hand force (four levels), glove condition (gel-filled, air bladder, no gloves), and location of the finger vibration measurement. A 3-D laser vibrometer was used to measure the vibrations on the fingers with and without wearing a glove on a 3-D hand-arm vibration test system. This study finds that the effect of VR gloves on the finger vibration depends on not only the gloves but also their influence on the distribution of the finger contact stiffness and the grip effort. As a result, the gloves increase the vibration in the fingertip area but marginally reduce the vibration in the proximal area at some frequencies below 100 Hz. On average, the gloves reduce the vibration of the entire fingers by less than 3% at frequencies below 80 Hz but increase at frequencies from 80 to 400 Hz. At higher frequencies, the gel-filled glove is more effective at reducing the finger vibration than the air bladder-filled glove. The implications of these findings are discussed. Relevance to industry Prolonged, intensive exposure to hand-transmitted vibration can cause hand-arm vibration syndrome. Vibration-reducing gloves have been used as an alternative approach to reduce the vibration exposure. However, their effectiveness for reducing finger-transmitted vibrations remains unclear. This study enhanced the understanding of the glove effects on finger vibration and provided useful information on the effectiveness of typical VR gloves at reducing the vibration transmitted to the fingers. The new

  2. Vibration Attenuation of Plate Using Multiple Vibration Absorbers

    Directory of Open Access Journals (Sweden)

    Zaman Izzuddin

    2014-07-01

    Full Text Available Vibrations are undesired phenomenon and it can cause harm, distress and unsettling influence to the systems or structures, for example, aircraft, automobile, machinery and building. One of the approach to limit this vibration by introducing passive vibration absorber attached to the structure. In this paper, the adequacy of utilizing passive vibration absorbers are investigated. The vibration absorber system is designed to minimize the vibration of a thin plate fixed along edges. The plate’s vibration characteristics, such as, natural frequency and mode shape are determined using three techniques: theoretical equations, finite element (FE analysis and experiment. The results demonstrate that the first four natural frequencies of fixed-fixed ends plate are 48, 121, 193 and 242 Hz, and these results are corroborated well with theoretical, FE simulation and experiment. The experiment work is further carried out with attached single and multiple vibration absorbers onto plate by tuning the absorber’s frequency to match with the excitation frequency. The outcomes depict that multiple vibration absorbers are more viable in lessening the global structural vibration.

  3. Magnetic circuit modifications in resonant vibration harvesters

    Science.gov (United States)

    Szabo, Zoltan; Fiala, Pavel; Dohnal, Premysl

    2018-01-01

    The paper discusses the conclusions obtained from a research centered on a vibration-powered milli- or micro generator (MG) operating as a harvester to yield the maximum amount of energy transferred by the vibration of an independent system. The investigation expands on the results proposed within papers that theoretically define the properties characterizing the basic configurations of a generator based on applied Faraday's law of induction. We compared two basic principles of circuit closing in a magnetic circuit that, fully or partially, utilizes a ferromagnetic material, and a large number of generator design solutions were examined and tested. In the given context, the article brings a compact survey of the rules facilitating energy transformation and the designing of harvesters.

  4. Acquisition of an Underway CTD System for the Flow Encountering Abrupt Topography DRI

    Science.gov (United States)

    2015-09-30

    Acquisition of an Underway CTD System for the Flow Encountering Abrupt Topography DRI T. M. Shaun Johnston Scripps Institution of Oceanography...westward flow in the North Equatorial Current (NEC) encounters tall, steep, submarine topography and islands. During the Flow Encountering Abrupt... Topography (FLEAT) DRI, investigators will determine: • Whether appreciable energy/momentum is lost from the large-scale NEC flow to smaller scales and

  5. Aspect-dependent radiated noise analysis of an underway autonomous underwater vehicle.

    Science.gov (United States)

    Gebbie, John; Siderius, Martin; Allen, John S

    2012-11-01

    This paper presents an analysis of the acoustic emissions emitted by an underway REMUS-100 autonomous underwater vehicle (AUV) that were obtained near Honolulu Harbor, HI using a fixed, bottom-mounted horizontal line array (HLA). Spectral analysis, beamforming, and cross-correlation facilitate identification of independent sources of noise originating from the AUV. Fusion of navigational records from the AUV with acoustic data from the HLA allows for an aspect-dependent presentation of calculated source levels of the strongest propulsion tone.

  6. Improved Submariner Eyewear for Routine Wear and Emergency Equipment Use Underway

    Science.gov (United States)

    2010-01-15

    regulations governing the protection of human subjects. Approved for Public Release; Distribution Unlimited. ii [THIS PAGE...participants’ eyeglass prescription. The new test eyewear was delivered to the subjects just prior to underway. Participants received two pairs of...to wear, but my own eyeglasses work better for me. • I felt that overall the wired frames were well suited to boat use, though I would change a

  7. Vibrational stability of graphene

    Directory of Open Access Journals (Sweden)

    Yangfan Hu

    2013-05-01

    Full Text Available The mechanical stability of graphene as temperature rises is analyzed based on three different self-consistent phonon (SCP models. Compared with three-dimensional (3-D materials, the critical temperature Ti at which instability occurs for graphene is much closer to its melting temperature Tm obtained from Monte Carlo simulation (Ti ≃ 2Tm, K. V. Zakharchenko, A. Fasolino, J. H. Los, and M. I. Katsnelson, J. Phys. Condens. Matter 23, 202202. This suggests that thermal vibration plays a significant role in melting of graphene while melting for 3-D materials is often dominated by topologic defects. This peculiar property of graphene derives from its high structural anisotropy, which is characterized by the vibrational anisotropic coefficient (VAC, defined upon its Lindermann ratios in different directions. For any carbon based material with a graphene-like structure, the VAC value must be smaller than 5.4 to maintain its stability. It is also found that the high VAC value of graphene is responsible for its negative thermal expansion coefficient at low temperature range. We believe that the VAC can be regarded as a new criterion concerning the vibrational stability of any low-dimensional (low-D materials.

  8. Pickin’ up good vibrations

    CERN Multimedia

    Katarina Anthony

    2015-01-01

    In preparation for the civil engineering work on the HL-LHC, vibration measurements were carried out at the LHC’s Point 1 last month. These measurements will help evaluate how civil engineering work could impact the beam, and will provide crucial details about the site’s geological make-up before construction begins.   A seismic truck at Point 1 generated wave-like vibrations measured by EN/MME. From carrying out R&D to produce state-of-the-art magnets to developing innovative, robust materials capable of withstanding beam impact, the HL-LHC is a multi-faceted project involving many groups and teams across CERN’s departments. It was in this framework that the project management mandated CERN's Mechanical and Materials Engineering (EN/MME) group to measure the propagation of vibrations around Point 1. Their question: can civil engineering work for the HL-LHC – the bulk of which is scheduled for LS2 – begin while the LHC is running? Alth...

  9. Quantification of the effects of audible rattle and source type on the human response to environmental vibration.

    Science.gov (United States)

    Woodcock, J; Sica, G; Peris, E; Sharp, C; Moorhouse, A T; Waddington, D C

    2016-03-01

    The present research quantifies the influence of source type and the presence of audible vibration-induced rattle on annoyance caused by vibration in residential environments. The sources of vibration considered are railway and the construction of a light rail system. Data were measured in the United Kingdom using a socio-vibration survey (N = 1281). These data are analyzed using ordinal logit models to produce exposure-response relationships describing community annoyance as a function of vibration exposure. The influence of source type and the presence of audible vibration-induced rattle on annoyance are investigated using dummy variable analysis, and quantified using odds-ratios and community tolerance levels. It is concluded that the sample population is more likely to express higher levels of annoyance if the vibration source is construction compared to railway, and if vibration-induced rattle is audible.

  10. Random vibrations theory and practice

    CERN Document Server

    Wirsching, Paul H; Ortiz, Keith

    1995-01-01

    Random Vibrations: Theory and Practice covers the theory and analysis of mechanical and structural systems undergoing random oscillations due to any number of phenomena— from engine noise, turbulent flow, and acoustic noise to wind, ocean waves, earthquakes, and rough pavement. For systems operating in such environments, a random vibration analysis is essential to the safety and reliability of the system. By far the most comprehensive text available on random vibrations, Random Vibrations: Theory and Practice is designed for readers who are new to the subject as well as those who are familiar with the fundamentals and wish to study a particular topic or use the text as an authoritative reference. It is divided into three major sections: fundamental background, random vibration development and applications to design, and random signal analysis. Introductory chapters cover topics in probability, statistics, and random processes that prepare the reader for the development of the theory of random vibrations a...

  11. Tutorial: Novel properties of defects in semiconductors revealed by their vibrational spectra

    Science.gov (United States)

    Stavola, Michael; Fowler, W. Beall

    2018-04-01

    This is an introductory survey of the vibrational spectroscopy of defects in semiconductors that contain light-mass elements. The capabilities of vibrational spectroscopy for the identification of defects, the determination of their microscopic structures, and their dynamics are illustrated by a few examples. Several additional examples are discussed, with a focus on defects with properties not obviously accessible by vibrational spectroscopy, such as the diffusivity of an impurity, the negative U ordering of electronic levels, and the time constant for a nuclear-spin flip. These novel properties have, nonetheless, been revealed by vibrational spectra and their interpretation by theory.

  12. Sea surface temperature and salinity from the Global Ocean Surface Underway Data (GOSUD) from 1980-01-03 to present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This collection contains the Global Ocean Surface Underway Data (GOSUD) from 1980-01-03 to present as submitted to NOAA/NCEI. The data includes information about sea...

  13. Lattice Vibrations in Chlorobenzenes:

    DEFF Research Database (Denmark)

    Reynolds, P. A.; Kjems, Jørgen; White, J. W.

    1974-01-01

    Lattice vibrational dispersion curves for the ``intermolecular'' modes in the triclinic, one molecule per unit cell β phase of p‐C6D4Cl2 and p‐C6H4Cl2 have been obtained by inelastic neutron scattering. The deuterated sample was investigated at 295 and at 90°K and a linear extrapolation to 0°K...... was applied in order to correct for anharmonic effects. Calculations based on the atom‐atom model for van der Waals' interaction and on general potential parameters for the aromatic compounds agree reasonably well with the experimental observations. There is no substantial improvement in fit obtained either...

  14. Digital analysis of vibrations

    International Nuclear Information System (INIS)

    Bohnstedt, H.J.; Walter, G.

    1982-01-01

    Vibrational measurements, e.g. on turbomachinery, can be evaluated rapidly and economically with the aid of a combination of the following instruments: a desk-top computer, a two-channel vector filter and a FFT spectral analyzer. This equipment combination is available within the Allianz Centre for Technology and has also been used for mobile, on-site investigations during the last year. It enables calculation and display of time functions, kinetic shaft orbits, displacement diagrams. Bode plots, polar-coordinate plots, cascade diagrams and histograms. (orig.) [de

  15. Quantum dynamics of vibrational excitations and vibrational charge ...

    Indian Academy of Sciences (India)

    Administrator

    Dedicated to the memory of the late Professor S K Rangarajan. *For correspondence. Quantum dynamics of vibrational excitations and vibrational charge transfer processes in H. +. + O2 collisions at collision energy 23 eV. †. SAIESWARI AMARAN# and SANJAY KUMAR*. Department of Chemistry, Indian Institute of ...

  16. Off-axis Modal Active Vibration Control Of Rotational Vibrations

    NARCIS (Netherlands)

    Babakhani, B.; de Vries, Theodorus J.A.; van Amerongen, J.

    Collocated active vibration control is an effective and robustly stable way of adding damping to the performance limiting vibrations of a plant. Besides the physical parameters of the Active Damping Unit (ADU) containing the collocated actuator and sensor, its location with respect to the

  17. Blasting vibrations control: The shortcomings of traditional methods

    Energy Technology Data Exchange (ETDEWEB)

    Vuillaume, P.M.; Kiszlo, M. [Institut National de l`Environnement Industriel et des Risques, Verneuil en Halatte (France); Bernard, T. [Compagnie Nouvelle de Scientifiques, Nice (France)

    1996-12-31

    In the context of its studies for the French ministry of the environment and for the French national coal board, INERIS (the French institute for the industrial environment and hazards, formerly CERCHAR) has made a complete critical survey of the methods generally used to reduce the levels of blasting vibrations. It is generally acknowledged that the main parameter to control vibrations is the so-called instantaneous charge, or charge per delay. This should be reduced as much as possible in order to diminish vibration levels. On account of this, the use of a new generation of blasting devices, such as non-electric detonators or electronic sequential timers has been developed since the seventies. INERIS has collected data from about 900 blasts in 2 quarries and 3 open pit mines. These data include input parameters such as borehole diameter, burden, spacing, charge per hole, charge per delay, total fired charge, etc ... They also include output measurements, such as vibration peak particle velocities, and main frequencies. These data have been analyzed with the help of multi variable statistical tools. Blasting tests were undertaken to evaluate new methods of vibrations control, such as the superposition of vibration signals. These methods appear to be accurate in many critical cases, but certainly would be highly improved with a better accuracy of firing delays. The development of electronic detonators seems to be the way of the future for a better blasting control.

  18. 14 CFR 33.33 - Vibration.

    Science.gov (United States)

    2010-01-01

    ... and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Reciprocating Aircraft Engines § 33.33 Vibration. The... vibration and without imparting excessive vibration forces to the aircraft structure. ...

  19. Melt Stirring by Horizontal Crucible Vibration

    Science.gov (United States)

    Wolf, M. F.; Elwell, D.; Feigelson, R. S.

    1985-01-01

    Horizontal vibration suggested as technique for more effective stirring of melts in crystal-growth apparatus. Vibrational technique may replace accelerated crucible rotation. Potential superiority of vibrational technique shown by preliminary experiments in which ink stirred into water.

  20. Reduction of personnel vibration hazards in underground coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Oh, X.; Middlin, A. (Vipac Engineers and Scientists Ltd. (Australia))

    1991-03-01

    Whole-Body Vibration (WBV) due to the 'rough ride' in vehicles is a major source of back and neck injury in underground coal mines. Hand-Arm Vibration (HAV) from hand held equipment can also cause long term health damage. Surveys in three collieries in NSW have been conducted to measure the vibration levels to which miners are being exposed and to assess them according to the two relevant Australian Standards namely AS2670 and AS2763. WBV results indicated that shock loadings must be the source of back and neck injuries that are occurring due to 'rough ride'. Existing off-the-shelf seat suspensions were demonstrated to be inadequate for providing effective shock isolation, due to them being prone to bottoming out under rough conditions, and due their scissor action mechanism becoming rapidly jammed by dirt to the point where they become rigid. Commercially available seats were evaluated and tested on a hydraulic shaker, but none proved able to provide the required vibration isolation. A prototype seat suspension was developed by Vipac. This suspension was shaker tested and trialled in low loaders at two collieries. The seat proved capable of cushioning shock loads without bottoming out, as well as attenuating the dominant vibration at 2.5 Hz and higher. This suspension with encapsulated mechanism could be readily adapted to suit a wide range of underground vehicles. The HAV survey results identified the Wombat roof-bolter as the major item requiring vibration level reductions. Extensive investigations resulted in the design of a prototype vibration isolated handle. During field tests this prototype handle reduced the HAV level such that the Exposure Time (10th percentile) was increased from 7 to 11.5 years. Guidelines are presented for additional developments which would further improve this performance and result in a handle design suitable for retrofitting to existing roof bolters.

  1. Vibration response of misaligned rotors

    Science.gov (United States)

    Patel, Tejas H.; Darpe, Ashish K.

    2009-08-01

    Misalignment is one of the common faults observed in rotors. Effect of misalignment on vibration response of coupled rotors is investigated in the present study. The coupled rotor system is modelled using Timoshenko beam elements with all six dof. An experimental approach is proposed for the first time for determination of magnitude and harmonic nature of the misalignment excitation. Misalignment effect at coupling location of rotor FE model is simulated using nodal force vector. The force vector is found using misalignment coupling stiffness matrix, derived from experimental data and applied misalignment between the two rotors. Steady-state vibration response is studied for sub-critical speeds. Effect of the types of misalignment (parallel and angular) on the vibration behaviour of the coupled rotor is examined. Along with lateral vibrations, axial and torsional vibrations are also investigated and nature of the vibration response is also examined. It has been found that the misalignment couples vibrations in bending, longitudinal and torsional modes. Some diagnostic features in the fast Fourier transform (FFT) of torsional and longitudinal response related to parallel and angular misalignment have been revealed. Full spectra and orbit plots are effectively used to reveal the unique nature of misalignment fault leading to reliable misalignment diagnostic information, not clearly brought out by earlier studies.

  2. Molecular vibrations the theory of infrared and Raman vibrational spectra

    CERN Document Server

    Wilson, E Bright; Cross, Paul C

    1980-01-01

    Pedagogical classic and essential reference focuses on mathematics of detailed vibrational analyses of polyatomic molecules, advancing from application of wave mechanics to potential functions and methods of solving secular determinant.

  3. 49 CFR 178.819 - Vibration test.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Vibration test. 178.819 Section 178.819... Testing of IBCs § 178.819 Vibration test. (a) General. The vibration test must be conducted for the... vibration test. (b) Test method. (1) A sample IBC, selected at random, must be filled and closed as for...

  4. Flexural vibrations of finite composite poroelastic cylinders

    Indian Academy of Sciences (India)

    If the wavelength is infinite, frequency equations are degenerated as product of two determinants pertaining to extensional vibrations and shear vibrations. In this case, it is seen that the nature of the surface does not have any influence over shear vibrations unlike in the case of extensional vibrations. For illustration purpose ...

  5. Vibration Theory, Vol. 1B

    DEFF Research Database (Denmark)

    Asmussen, J. C.; Nielsen, Søren R. K.

    The present collection of MATLAB exercises has been published as a supplement to the textbook, Svingningsteori, Bind 1 and the collection of exercises in Vibration theory, Vol. 1A, Solved Problems. Throughout the exercise references are made to these books. The purpose of the MATLAB exercises...... is to give a better understanding of the physical problems in linear vibration theory and to surpress the mathematical analysis used to solve the problems. For this purpose the MATLAB environment is excellent....

  6. Carbon dioxide, temperature, and salinity collected from surface underway survey from May 1986 to April 1989 (NODC Accession 9400164)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains chemical and physical profile data containing measuremnts of depth, salinity and temperature collected between May 1986 and April 1989. Data...

  7. Cause elucidation of sodium leakage incident at `Monju` reactor. Vibration of thermometer due to fluid force

    Energy Technology Data Exchange (ETDEWEB)

    Iwata, Koji; Wada, Yusaku; Morishita, Masaki; Yamaguchi, Akira; Ichimiya, Masakazu [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1997-01-01

    This is a report of summarized results of investigation and analysis on fracture of thermometer which is direct reason of sodium leakage incident at the second main cooling system of fast breeder reactor `Monju`. Various surveys such as on various damage factors, on flowing power vibrational features containing flowing power vibrational test of thermometer, on evaluation of high cycle fatigue due to flowing power vibration and details on propagation of and fracture due to fatigue crack, on why only said thermometer damaged, and so forth were executed. As results of these examinations, a decision was arrived that high cycle fatigue due to vibration formed by fluid force (fluid force vibration) was a direct cause of the thermometer damage. (G.K.)

  8. Vibrational spectroscopy of proteins

    International Nuclear Information System (INIS)

    Schwaighofer, A.

    2013-01-01

    Two important steps for the development of a biosensor are the immobilization of the biological component (e.g. protein) on a surface and the enhancement of the signal to improve the sensitivity of detection. To address these subjects, the present work describes Fourier transform infrared (FTIR) investigations of several proteins bound to the surface of an attenuated total reflection (ATR) crystal. Furthermore, new nanostructured surfaces for signal enhancement were developed for use in FTIR microscopy. The mitochondrial redox-protein cytochrome c oxidase (CcO) was incorporated into a protein-tethered bilayer lipid membrane (ptBLM) on an ATR crystal featuring a roughened two-layer gold surface for signal enhancement. Electrochemical excitation by periodic potential pulses at different modulation frequencies was followed by time-resolved FTIR spectroscopy. Phase sensitive detection was used for deconvolution of the IR spectra into vibrational components. A model based on protonation-dependent chemical reaction kinetics could be fitted to the time evolution of IR bands attributed to several different redox centers of the CcO. Further investigations involved the odorant binding protein 14 (OBP14) of the honey bee (Apis mellifera), which was studied using ATR-FTIR spectroscopy and circular dichroism. OBP14 was found to be thermally stable up to 45 °C, thus permitting the potential application of this protein for the fabrication of biosensors. Thermal denaturation measurements showed that odorant binding increases the thermal stability of the OBP-odorant complex. In another project, plasmonic nanostructures were fabricated that enhance the absorbance in FTIR microscopy measurements. The nanostructures are composed of an array of round-shaped insulator and gold discs on top of a continuous gold layer. Enhancement factors of up to ⁓125 could be observed with self-assembled monolayers of dodecanethiol molecules immobilized on the gold surface (author) [de

  9. Evaluation of hand-arm vibration reducing effect of anti-vibration glove

    OpenAIRE

    樹野, 淳也; 前田, 節雄; 横田, 和樹; 平, 雄一郎

    2015-01-01

    Many kinds of the anti-vibration glove have been developed for reducing hand-arm vibration during the operation with vibration tools. International standard ISO 10819 evaluates the physical effect of gloves' vibration transmissibility but not evaluates the physiological effect of human hands. Thus, in this paper, we proposed the evaluation using the temporary threshold shift of vibrotactile perception threshold to evaluate the hand-arm vibration reducing effect of anti-vibration glove. We per...

  10. Primary pump vibration under accident conditions

    International Nuclear Information System (INIS)

    Guthrie, B.M.; Currie, T.C.

    1984-06-01

    This report presents the results of an international survey on the subject of vibration in nuclear primary coolant pumps due to two-phase flow, accident conditions. The literature search also revealed few Canadian references other than those of Ontario Hydro. Ontario Hydro's work has been extensive. Confidence in the mechanical integrity of the pumpsets is good, given the extent of the testing. However, conclusions with respect to piping integrity and thermal-hydraulic performance are difficult to determine due to the inexact geometry of the piping and the difficulties in estimating fluid conditions at the pump. The tests help to understand the phenomena and provide background information for analysis, but should be applied with caution to plant analyses. Much of the discussion in the report relates to pump head instability. This is perceived to be the most important flow regime causing vibration, as attested by the emphasis of the reviewed literature. A method for quantitative assessment of the forcing functions acting on the pump-piping system due to void generation and collapse is recommended. A relatively fundamental analytical approach is proposed, supplemented by reduced scale testing in the latter stages. 151 refs

  11. PC based vibration monitoring system

    International Nuclear Information System (INIS)

    Jain, Sanjay K.; Roy, D.A.; Pithawa, C.K.; Patil, R.K.

    2004-01-01

    Health of large rotating machinery gets reflected in the vibration signature of the rotor and supporting structures and proper recording of these signals and their analysis can give a clear picture of the health of the machine. Using these data and their trending, it is possible to predict an impending trouble in the machine so that preventive action can be taken in time and catastrophic failure can be avoided. Continuous monitoring and analysis can give quick warning and enable operator to take preventive measures. Reactor Control Division, BARC is developing a PC based Vibration monitoring system for turbo generator machinery. The System can acquire 20 vibration signals at a rate of 5000 samples per second and also 15 process signals at a rate of 100 samples/ sec. The software for vibration monitoring system includes acquisition modules, analysis modules and Graphical User Interface module. The acquisition module involves initialization, setting of required parameters and acquiring the data from PC-based data acquisition cards. The acquired raw vibration data is then stored for analysis using various software packages. The display and analysis of acquired data is done in LabVIEW 7.0 where the data is displayed in time as well as frequency domain along with the RMS value of the signal. (author)

  12. Hand-arm vibration syndrome

    Science.gov (United States)

    Shen, Shixin (Cindy); House, Ronald A.

    2017-01-01

    Abstract Objective To provide family physicians with an understanding of the epidemiology, pathogenesis, symptoms, diagnosis, and management of hand-arm vibration syndrome (HAVS), an important and common occupational disease in Canada. Sources of information A MEDLINE search was conducted for research and review articles on HAVS. A Google search was conducted to obtain gray literature relevant to the Canadian context. Additional references were obtained from the articles identified. Main message Hand-arm vibration syndrome is a prevalent occupational disease affecting workers in multiple industries in which vibrating tools are used. However, it is underdiagnosed in Canada. It has 3 components—vascular, in the form of secondary Raynaud phenomenon; sensorineural; and musculoskeletal. Hand-arm vibration syndrome in its more advanced stages contributes to substantial disability and poor quality of life. Its diagnosis requires careful history taking, in particular occupational history, physical examination, laboratory tests to rule out alternative diagnoses, and referral to an occupational medicine specialist for additional investigations. Management involves reduction of vibration exposure, avoidance of cold conditions, smoking cessation, and medication. Conclusion To ensure timely diagnosis of HAVS and improve prognosis and quality of life, family physicians should be aware of this common occupational disease and be able to elicit the relevant occupational history, refer patients to occupational medicine clinics, and appropriately initiate compensation claims. PMID:28292796

  13. g-boson degree of freedom in vibrational regions

    International Nuclear Information System (INIS)

    Di Yaomin

    1991-01-01

    The g-boson degree of freedom in the vibrational regions is discussed in term of the energies and the electromagnetic transitions. Several closed expressions for the rates of M1, E2 transitions and the E2, M1 mixing ratios are obtained. Some survey is made and it reveals it is meaningful to investigate the g-boson degree of freedom in those regions

  14. Combined Effects of High-Speed Railway Noise and Ground Vibrations on Annoyance.

    Science.gov (United States)

    Yokoshima, Shigenori; Morihara, Takashi; Sato, Tetsumi; Yano, Takashi

    2017-07-27

    The Shinkansen super-express railway system in Japan has greatly increased its capacity and has expanded nationwide. However, many inhabitants in areas along the railways have been disturbed by noise and ground vibration from the trains. Additionally, the Shinkansen railway emits a higher level of ground vibration than conventional railways at the same noise level. These findings imply that building vibrations affect living environments as significantly as the associated noise. Therefore, it is imperative to quantify the effects of noise and vibration exposures on each annoyance under simultaneous exposure. We performed a secondary analysis using individual datasets of exposure and community response associated with Shinkansen railway noise and vibration. The data consisted of six socio-acoustic surveys, which were conducted separately over the last 20 years in Japan. Applying a logistic regression analysis to the datasets, we confirmed the combined effects of vibration/noise exposure on noise/vibration annoyance. Moreover, we proposed a representative relationship between noise and vibration exposures, and the prevalence of each annoyance associated with the Shinkansen railway.

  15. Rolling Deck to Repository (R2R): Fleetwide Standard Underway Data Products

    Science.gov (United States)

    Sweeney, A. D.; Clark, P. D.; Miller, S. P.; Stocks, K.; Arko, R. A.; Ferrini, V.

    2009-12-01

    The Rolling Deck to Repository (R2R) project was recently launched with the ambitious goal of documenting “routine underway data” from the US academic research fleet and delivering those data to established national archives. Data distributions will be submitted by 18 operating institutions for 30 vessels, from hundreds of cruises per year. R2R will be responsible for digital data collected with instruments that are part of the ship’s permanent equipment and are routinely operated and recorded by the ship’s technicians. Examples include navigation, multibeam, subbottom, gravimeter, magnetics, ADCP, CTD, meteorology, etc. It is anticipated that most underway data will be promptly and publicly released. However R2R will have the ability to securely embargo any specific datasets identified in advance by the chief scientist, for a proprietary hold period of up to two years as mandated by the NSF 04-004 Division of Ocean Sciences Data and Sample Policy. It is important to note that there are data types that R2R will not address. For example, the chief scientist will continue to be responsible for the documentation and archiving of data from specific instruments brought on board by the scientific party, not part of the ship’s standard equipment. Similarly, data collected with National Facility assets including the National Deep Submergence Facility (NDSF), Ocean Bottom Seismograph Instrument Pool (OBSIP) and the National Marine Seismic Facility (NMSF) will continue to be submitted to the appropriate archiving facility directly by those facilities, rather than through R2R. Soon after the shipboard data is received by R2R, the entire original distribution will be safely stored in a deep archive for long-term preservation, and a cataloging process will be undertaken to assemble data sets for delivery to National Data Centers, as described more fully in the invited presentation by Robert Arko, “Rolling Deck to Repository: Technical Design - Experiences and

  16. Ultrasonic metal welding with a vibration source using longitudinal and torsional vibration transducers

    Science.gov (United States)

    Asami, Takuya; Tamada, Yosuke; Higuchi, Yusuke; Miura, Hikaru

    2017-07-01

    Conventional ultrasonic metal welding for joining dissimilar metals uses a linear vibration locus, although this method suffers from problems such as low overall weld strength. Our previous studies have shown that ultrasonic welding with a planar vibration locus improves the weld strength. However, the vibration source in our previous studies had problems in longitudinal-torsional vibration controllability and small welding tip. Therefore, the study of the optimal shape of the vibration locus was difficult. Furthermore, improvement of weld strength cannot be expected. We have developed a new ultrasonic vibration source that can control the longitudinal-torsional vibration and can connect to a large welding tip. In this study, we clarified the longitudinal-torsional vibration controllability of the developed ultrasonic vibration source. Moreover, we clarified that using the planar locus of the developed vibration source produced a higher weld strength than our previous studies, and clarified the optimal shape of the vibration locus.

  17. Ground Vibration Testing Options for Space Launch Vehicles

    Science.gov (United States)

    Patterson, Alan; Smith, Robert K.; Goggin, David; Newsom, Jerry

    2011-01-01

    New NASA launch vehicles will require development of robust systems in a fiscally-constrained environment. NASA, Department of Defense (DoD), and commercial space companies routinely conduct ground vibration tests as an essential part of math model validation and launch vehicle certification. Although ground vibration testing must be a part of the integrated test planning process, more affordable approaches must also be considered. A study evaluated several ground vibration test options for the NASA Constellation Program flight test vehicles, Orion-1 and Orion-2, which concluded that more affordable ground vibration test options are available. The motivation for ground vibration testing is supported by historical examples from NASA and DoD. The approach used in the present study employed surveys of ground vibration test subject-matter experts that provided data to qualitatively rank six test options. Twenty-five experts from NASA, DoD, and industry provided scoring and comments for this study. The current study determined that both element-level modal tests and integrated vehicle modal tests have technical merits. Both have been successful in validating structural dynamic math models of launch vehicles. However, element-level testing has less overall cost and schedule risk as compared to integrated vehicle testing. Future NASA launch vehicle development programs should anticipate that some structural dynamics testing will be necessary. Analysis alone will be inadequate to certify a crew-capable launch vehicle. At a minimum, component and element structural dynamic tests are recommended for new vehicle elements. Three viable structural dynamic test options were identified. Modal testing of the new vehicle elements and an integrated vehicle test on the mobile launcher provided the optimal trade between technical, cost, and schedule.

  18. Design and application of an electromagnetic vibrator seismic source

    Science.gov (United States)

    Haines, S.S.

    2006-01-01

    Vibrational seismic sources frequently provide a higher-frequency seismic wavelet (and therefore better resolution) than other sources, and can provide a superior signal-to-noise ratio in many settings. However, they are often prohibitively expensive for lower-budget shallow surveys. In order to address this problem, I designed and built a simple but effective vibrator source for about one thousand dollars. The "EMvibe" is an inexpensive electromagnetic vibrator that can be built with easy-to-machine parts and off-the-shelf electronics. It can repeatably produce pulse and frequency-sweep signals in the range of 5 to 650 Hz, and provides sufficient energy for recording at offsets up to 20 m. Analysis of frequency spectra show that the EMvibe provides a broader frequency range than the sledgehammer at offsets up to ??? 10 m in data collected at a site with soft sediments in the upper several meters. The EMvibe offers a high-resolution alternative to the sledgehammer for shallow surveys. It is well-suited to teaching applications, and to surveys requiring a precisely-repeatable source signature.

  19. DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Martin E. Cobern

    2004-08-31

    The deep hard rock drilling environment induces severe vibrations into the drillstring, which can cause reduced rates of penetration (ROP) and premature failure of the equipment. The only current means of controlling vibration under varying conditions is to change either the rotary speed or the weight-on-bit (WOB). These changes often reduce drilling efficiency. Conventional shock subs are useful in some situations, but often exacerbate the problems. The objective of this project is development of a unique system to monitor and control drilling vibrations in a ''smart'' drilling system. This system has two primary elements: (1) The first is an active vibration damper (AVD) to minimize harmful axial, lateral and torsional vibrations. The hardness of this damper will be continuously adjusted using a robust, fast-acting and reliable unique technology. (2) The second is a real-time system to monitor drillstring vibration, and related parameters. This monitor adjusts the damper according to local conditions. In some configurations, it may also send diagnostic information to the surface via real-time telemetry. The AVD is implemented in a configuration using magnetorheological (MR) fluid. By applying a current to the magnetic coils in the damper, the viscosity of the fluid can be changed rapidly, thereby altering the damping coefficient in response to the measured motion of the tool. Phase I of this program entailed modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype. Phase I of the project was completed by the revised end date of May 31, 2004. The objectives of this phase were met, and all prerequisites for Phase II have been completed.

  20. Innovative Techniques Simplify Vibration Analysis

    Science.gov (United States)

    2010-01-01

    In the early years of development, Marshall Space Flight Center engineers encountered challenges related to components in the space shuttle main engine. To assess the problems, they evaluated the effects of vibration and oscillation. To enhance the method of vibration signal analysis, Marshall awarded Small Business Innovation Research (SBIR) contracts to AI Signal Research, Inc. (ASRI), in Huntsville, Alabama. ASRI developed a software package called PC-SIGNAL that NASA now employs on a daily basis, and in 2009, the PKP-Module won Marshall s Software of the Year award. The technology is also used in many industries: aircraft and helicopter, rocket engine manufacturing, transportation, and nuclear power."

  1. Quantum dynamics of vibrational excitations and vibrational charge ...

    Indian Academy of Sciences (India)

    Quantum mechanical study of vibrational state-resolved differential cross sections and transition probabilities for both the elastic/inelastic and the charge transfer processes have been carried out in the H+ + O2 collisions at the experimental collision energy of 23 eV. The quantum dynamics has been performed within the ...

  2. Quantum dynamics of vibrational excitations and vibrational charge ...

    Indian Academy of Sciences (India)

    Administrator

    + O2 collisions at the experimental collision energy of 23 eV. The quantum dynamics has been performed within the vibrational close-coupling rotational infinite-order sudden approximation frame- work employing our newly obtained quasi-diabatic potential energy surfaces corresponding to the ground and the first excited ...

  3. Determination of the absorption coefficient of chromophoric dissolved organic matter from underway spectrophotometry.

    Science.gov (United States)

    Dall'Olmo, Giorgio; Brewin, Robert J W; Nencioli, Francesco; Organelli, Emanuele; Lefering, Ina; McKee, David; Röttgers, Rüdiger; Mitchell, Catherine; Boss, Emmanuel; Bricaud, Annick; Tilstone, Gavin

    2017-11-27

    Measurements of the absorption coefficient of chromophoric dissolved organic matter (ay) are needed to validate existing ocean-color algorithms. In the surface open ocean, these measurements are challenging because of low ay values. Yet, existing global datasets demonstrate that ay could contribute between 30% to 50% of the total absorption budget in the 400-450 nm spectral range, thus making accurate measurement of ay essential to constrain these uncertainties. In this study, we present a simple way of determining ay using a commercially-available in-situ spectrophotometer operated in underway mode. The obtained ay values were validated using independent collocated measurements. The method is simple to implement, can provide measurements with very high spatio-temporal resolution, and has an accuracy of about 0.0004 m -1 and a precision of about 0.0025 m -1 when compared to independent data (at 440 nm). The only limitation for using this method at sea is that it relies on the availability of relatively large volumes of ultrapure water. Despite this limitation, the method can deliver the ay data needed for validating and assessing uncertainties in ocean-colour algorithms.

  4. Predicting Statistical Distributions of Footbridge Vibrations

    DEFF Research Database (Denmark)

    Pedersen, Lars; Frier, Christian

    2009-01-01

    The paper considers vibration response of footbridges to pedestrian loading. Employing Newmark and Monte Carlo simulation methods, a statistical distribution of bridge vibration levels is calculated modelling walking parameters such as step frequency and stride length as random variables...

  5. Isotope separation using vibrationally excited molecules

    International Nuclear Information System (INIS)

    1979-01-01

    This invention relates to isotope separation employing isotopically selective vibrational excitation and vibration-translation reactions of the excited particles. Uranium enrichment, using uranium hexafluoride, is a particular embodiment. (U.K.)

  6. Application of eigenfunction orthogonalities to vibration problems

    CSIR Research Space (South Africa)

    Fedotov, I

    2009-07-01

    Full Text Available The modelling of vibration problems is of great importance in engineering. A popular method of analysing such problems is the variational method. The simplest vibration model is represented using the example of a long rod. Two kinds...

  7. Shock and Vibration. Volume 1, Issue 1

    National Research Council Canada - National Science Library

    Pilkey, Walter D

    1994-01-01

    ..., and earthquake engineering. Among the specific areas to be covered are vibration testing and control, vibration condition monitoring and diagnostics, shock hardenings, modal technology, shock testing, data acquisition, fluid...

  8. Ultrasonic vibration for structural health monitoring

    Science.gov (United States)

    Liang, Y.; Yan, F.; Borigo, C.; Rose, J. L.

    2013-01-01

    Guided waves and vibration analysis are two useful techniques in Nondestructive Evaluation and Structural Health Monitoring. Bridging the gap between guided waves and vibration, a novel testing method ultrasonic vibration is demonstrated here. Ultrasonic vibration is capable to achieve defect detection sensitivity as ultrasonic guided waves, while maintaining the efficiency of traditional vibration in the way of adopting several sensors to cover the whole structure. In this new method, continuous guided wave energy will impinge into the structure to make the structure vibrate steadily. The steady state vibration is achieved after multiple boundary reflections of the continuous guided wave. In ultrasonic vibration experiments, annual array transducer is used as the actuator. The loading functions are tuned by the frequencies and phase delays among each transducer element. Experiments demonstrate good defect detection ability of by optimally selecting guided wave loadings.

  9. Vibrations on board and health effects

    DEFF Research Database (Denmark)

    Jensen, Anker; Jepsen, Jørgen Riis

    2014-01-01

    There is only limited knowledge of the exposure to vibrations of ships’ crews and their risk of vibration-induced health effects. Exposure to hand-arm vibrations from the use of vibrating tools at sea does not differ from that in the land-based trades. However, in contrast to most other work places......, seafarers are also exposed to vibrations to the feet when standing on vibrating surfaces onboard. Anecdotal reports have related the development of “white feet” to local exposure to vibration, e.g. in mining, but this connection has not been investigated in the maritime setting. As known from studies...... for such relation among seafarers except for fishermen, who, however, are also exposed to additional recognised physical risk factors at work. The assessment and reduction of vibrations by naval architects relates to technical implications of this impact for the ships’ construction, but has limited value...

  10. Resonant vibration control of rotating beams

    DEFF Research Database (Denmark)

    Svendsen, Martin Nymann; Krenk, Steen; Høgsberg, Jan Becker

    2011-01-01

    Rotatingstructures,like e.g.wind turbine blades, may be prone to vibrations associated with particular modes of vibration. It is demonstrated, how this type of vibrations can be reduced by using a collocated sensor–actuator system, governed by a resonant controller. The theory is here demonstrated...... modal connectivity, only very limited modal spill-over is generated. The controller acts by resonance and therefore has only a moderate energy consumption, and successfully reduces modal vibrations at the resonance frequency....

  11. Simultaneous Vibration Suppression and Energy Harvesting

    Science.gov (United States)

    2013-08-15

    and clear sky condition (the condition of vibration induced during normal flight) are simulated using the Dryden PSD signal for both clear sky and...a cc ele ra tio n [ g ] Cumulus Cloud Wind Gust Clear Sky Normal Vibration Figure 4 Vibration response due to flow simulated using Dryden ... John Wiley & Sons, Ltd., Chichester, West Sussex, UK, 416 pp. (ISBN 978-0-470-68254-8) Inman, Daniel J., 2009. Engineering (ME 3504 Vibrations

  12. Flow induced vibrations in liquid metal fast breeder reactors

    International Nuclear Information System (INIS)

    1989-01-01

    Flow induced vibrations are well known phenomena in industry. Engineers have to estimate their destructive effects on structures. In the nuclear industry, flow induced vibrations are assessed early in the design process, and the results are incorporated in the design procedures. In many cases, model testing is used to supplement the design process to ensure that detrimental behaviour due to flow induced vibrations will not occur in the component in question. While these procedures attempt to minimize the probability of adverse performance of the various components, there is a problem in the extrapolation of analytical design techniques and/or model testing to actual plant operation. Therefore, sodium tests or vibrational measurements of components in the reactor system are used to provide additional assurance. This report is a general survey of experimental and calculational methods in this area of structural mechanics. The report is addressed to specialists and institutions in industrialized and developing countries who are responsible for the design and operation of liquid metal fast breeder reactors. 92 refs, 90 figs, 8 tabs

  13. 33 CFR 159.103 - Vibration test.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Vibration test. 159.103 Section...) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing § 159.103 Vibration test. The device... subjected to a sinusoidal vibration for a period of 12 hours, 4 hours in each of the x, y, and z planes, at...

  14. 14 CFR 27.907 - Engine vibration.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine vibration. 27.907 Section 27.907... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant General § 27.907 Engine vibration. (a) Each engine must be installed to prevent the harmful vibration of any part of the engine or rotorcraft. (b) The addition of the...

  15. 14 CFR 29.251 - Vibration.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Vibration. 29.251 Section 29.251... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Miscellaneous Flight Requirements § 29.251 Vibration. Each part of the rotorcraft must be free from excessive vibration under each appropriate speed and power...

  16. 14 CFR 29.907 - Engine vibration.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine vibration. 29.907 Section 29.907... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant General § 29.907 Engine vibration. (a) Each engine must be installed to prevent the harmful vibration of any part of the engine or rotorcraft. (b) The...

  17. 14 CFR 27.251 - Vibration.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Vibration. 27.251 Section 27.251... STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Miscellaneous Flight Requirements § 27.251 Vibration. Each part of the rotorcraft must be free from excessive vibration under each appropriate speed and power...

  18. 49 CFR 178.608 - Vibration standard.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Vibration standard. 178.608 Section 178.608... Testing of Non-bulk Packagings and Packages § 178.608 Vibration standard. (a) Each packaging must be capable of withstanding, without rupture or leakage, the vibration test procedure outlined in this section...

  19. 14 CFR 33.63 - Vibration.

    Science.gov (United States)

    2010-01-01

    ... and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.63 Vibration. Each engine... because of vibration and without imparting excessive vibration forces to the aircraft structure. [Doc. No...

  20. Fourier Analysis Of Vibrations Of Round Structures

    Science.gov (United States)

    Davis, Gary A.

    1990-01-01

    Fourier-series representation developed for analysis of vibrations in complicated, round structures like turbopump impellers. Method eliminates guesswork involved in characterization of shapes of vibrational modes. Easy way to characterize complicated modes, leading to determination of responsiveness of given mode to various forcing functions. Used in conjunction with finite-element numerical simulation of vibrational modes of structure.

  1. Vibration and Sound Damping in Polymers

    Indian Academy of Sciences (India)

    IAS Admin

    Excessive vibrations or loud sounds cause deafness or reduced efficiency of people, wastage of energy and fatigue failure of machines/structures. Hence, unwanted vibrations need to be dampened. This article describes the transmis- sion of vibrations/sound through different materials such as metals and polymers.

  2. Vibration Theory, Vol. 1A

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.

    The present collection of solved problems has been published as a supplement to the textbook Svingningsteori. Bind 1. Lineær svingningsteori,Aalborg tekniske Universitetsforlag, 1991, whicj is used in the introductory course on linear vibration theory that is being given on th e8th semester...

  3. Vibration Damping Circuit Card Assembly

    Science.gov (United States)

    Hunt, Ronald Allen (Inventor)

    2016-01-01

    A vibration damping circuit card assembly includes a populated circuit card having a mass M. A closed metal container is coupled to a surface of the populated circuit card at approximately a geometric center of the populated circuit card. Tungsten balls fill approximately 90% of the metal container with a collective mass of the tungsten balls being approximately (0.07) M.

  4. Vibrational properties of amorphous semiconductors

    International Nuclear Information System (INIS)

    Schulz, P.A.B.

    1985-01-01

    A model for the lattice dynamics of a-Si 1-X N X is introduced. This model is based on a Born hamiltonian, solved in the Bethe lattice approximation. Starting from the local density of vibrational states, we analize the infrared absoption spectra of this material. (author) [pt

  5. Low-Vibration Oscillating Compressor

    Science.gov (United States)

    Studer, P. A.

    1984-01-01

    Oscillating compressor momentum compensated: produces little vibration in its supporting structure. Compressure requires no lubrication and virtually free of wear. Compresses working fluids such as helium, nitrogen or chlorfluorocarbons for Stirling-cycle refrigeration or other purposes. Compressor includes two mutually opposed ferromagnetic pistons of same shape and mass. Electromagnetic flux links both pistons, causing magnetic attraction between them.

  6. Ultrafast vibrations of gold nanorings

    DEFF Research Database (Denmark)

    Kelf, T; Tanaka, Y; Matsuda, O

    2011-01-01

    We investigate the vibrational modes of gold nanorings on a silica substrate with an ultrafast optical technique. By comparison with numerical simulations, we identify several resonances in the gigahertz range associated with axially symmetric deformations of the nanoring and substrate. We...

  7. Harmonic vibrations of multispan beams

    DEFF Research Database (Denmark)

    Dyrbye, Claes

    1996-01-01

    Free and forced harmonic vibrations of multispan beams are determined by a method which implies 1 equation regardless of the configuration. The necessary formulas are given in the paper. For beams with simple supports and the same length of all (n) spans, there is a rather big difference between...

  8. Vibrational entropies in metallic alloys

    Science.gov (United States)

    Ozolins, Vidvuds; Asta, Mark; Wolverton, Christopher

    2000-03-01

    Recently, it has been recognized that vibrational entropy can have significant effects on the phase stability of metallic alloys. Using density functional linear response calculations and molecular dynamics simulations we study three representative cases: (i) phase diagram of Al-rich Al-Sc alloys, (ii) stability of precipitate phases in CuAl_2, and (iii) phonon dynamics in bcc Zr. We find large vibrational entropy effects in all cases. In the Al-Sc system, vibrations increase the solid solubility of Sc in Al by decreasing the stability of the L12 (Al_3Sc) phase. This leads to a nearly ten-fold increase in the solid solubility of Sc in Al at T=800 K. In the Cu-Al system, our calculations predict that the tetragonal Laves phase of CuAl2 has 0.35 kB/atom higher vibrational entropy than the cubic CaF_2-type phase (the latter is predicted to be the T=0 K ground state of CuAl_2). This entropy difference causes a structural transformation in CuAl2 precipitates from the fluorite to the tetragonal Laves phase around T=500 K. Finally, we analyze the highly unusual dynamics of anharmonically stabilized bcc Zr, finding large diffuse-scattering intensity streaks between the bcc Bragg peaks.

  9. Effect of shelf aging on vibration transmissibility of anti-vibration gloves

    Science.gov (United States)

    SHIBATA, Nobuyuki

    2017-01-01

    Anti-vibration gloves have been used in real workplaces to reduce vibration transmitted through hand-held power tools to the hand. Generally materials used for vibration attenuation in gloves are resilient materials composed of certain synthetic and/or composite polymers. The mechanical characteristics of the resilient materials used in anti-vibration gloves are prone to be influenced by environmental conditions such as temperature, humidity, and photo-irradiation, which cause material degradation and aging. This study focused on the influence of shelf aging on the vibration attenuation performance of air-packaged anti-vibration gloves following 2 yr of shelf aging. Effects of shelf aging on the vibration attenuation performance of anti-vibration gloves were examined according to the Japan industrial standard JIS T8114 test protocol. The findings indicate that shelf aging induces the reduction of vibration attenuation performance in air-packaged anti-vibration gloves. PMID:28978817

  10. Spectrophotometric high-precision seawater pH determination for use in underway measuring systems

    Directory of Open Access Journals (Sweden)

    S. Aßmann

    2011-10-01

    Full Text Available Autonomous sensors are required for a comprehensive documentation of the changes in the marine carbon system and thus to differentiate between its natural variability and anthropogenic impacts. Spectrophotometric determination of pH – a key variable of the seawater carbon system – is particularly suited to achieve precise and drift-free measurements. However, available spectrophotometric instruments are not suitable for integration into automated measurement systems (e.g. FerryBox since they do not meet the major requirements of reliability, stability, robustness and moderate cost. Here we report on the development and testing of a~new indicator-based pH sensor that meets all of these requirements. This sensor can withstand the rough conditions during long-term deployments on ships of opportunity and is applicable to the open ocean as well as to coastal waters with a complex matrix and highly variable conditions. The sensor uses a high resolution CCD spectrometer as detector connected via optical fibers to a custom-made cuvette designed to reduce the impact of air bubbles. The sample temperature can be precisely adjusted (25 °C ± 0.006 °C using computer-controlled power supplies and Peltier elements thus avoiding the widely used water bath. The overall setup achieves a measurement frequency of 1 min−1 with a precision of ±0.0007 pH units, an average offset of +0.0005 pH units to a reference system, and an offset of +0.0081 pH units to a certified standard buffer. Application of this sensor allows monitoring of seawater pH in autonomous underway systems, providing a key variable for characterization and understanding of the marine carbon system.

  11. Experience in WWER fuel assemblies vibration analysis

    International Nuclear Information System (INIS)

    Ovtcharov, O.; Pavelko, V.; Usanov, A.; Arkadov, G.; Dolgov, A.; Molchanov, V.

    2003-01-01

    It is stated that the vibration studies of internals and the fuel assemblies should be conducted during the reactor designing, commissioning and commercial operation stages and the analysis methods being used should complement each other. The present paper describes the methods and main results of the vibration noise studies of internals and the fuel assemblies of the operating NPPs with WWER reactors, as an example of the implementation of the comprehensive approach to the analysis on equipment flow-induced vibration. At that, the characteristics of internals and fuel assemblies vibration loading were dealt jointly as they are elements of the same compound oscillating system and their vibrations have the interrelated nature

  12. Multiple Rabi Splittings under Ultrastrong Vibrational Coupling.

    Science.gov (United States)

    George, Jino; Chervy, Thibault; Shalabney, Atef; Devaux, Eloïse; Hiura, Hidefumi; Genet, Cyriaque; Ebbesen, Thomas W

    2016-10-07

    From the high vibrational dipolar strength offered by molecular liquids, we demonstrate that a molecular vibration can be ultrastrongly coupled to multiple IR cavity modes, with Rabi splittings reaching 24% of the vibration frequencies. As a proof of the ultrastrong coupling regime, our experimental data unambiguously reveal the contributions to the polaritonic dynamics coming from the antiresonant terms in the interaction energy and from the dipolar self-energy of the molecular vibrations themselves. In particular, we measure the opening of a genuine vibrational polaritonic band gap of ca. 60 meV. We also demonstrate that the multimode splitting effect defines a whole vibrational ladder of heavy polaritonic states perfectly resolved. These findings reveal the broad possibilities in the vibrational ultrastrong coupling regime which impact both the optical and the molecular properties of such coupled systems, in particular, in the context of mode-selective chemistry.

  13. Human annoyance, acceptability and concern as responses to vibration from the construction of Light Rapid Transit lines in residential environments

    Energy Technology Data Exchange (ETDEWEB)

    Wong-McSweeney, D., E-mail: D.B.C.WongMcSweeney@salford.ac.uk [Acoustics Research Centre, University of Salford, Salford M5 4TW (United Kingdom); Woodcock, J.S.; Peris, E.; Waddington, D.C.; Moorhouse, A.T. [Acoustics Research Centre, University of Salford, Salford M5 4TW (United Kingdom); Redel-Macías, M.D. [Dep. Rural Engineering Campus de Rabanales, University of Córdoba, Córdoba (Spain)

    2016-10-15

    The aim of this paper is to investigate the use of different self-reported measures for assessing the human response to environmental vibration from the construction of an urban LRT (Light Rapid Transit) system. The human response to environmental stressors such as vibration and noise is often expressed in terms of exposure–response relationships that describe annoyance as a function of the magnitude of the vibration. These relationships are often the basis of noise and vibration policy and the setting of limit values. This paper examines measures other than annoyance by expressing exposure–response relationships for vibration in terms of self-reported concern about property damage and acceptability. The exposure–response relationships for concern about property damage and for acceptability are then compared with those for annoyance. It is shown that concern about property damage occurs at vibration levels well below those where there is any risk of damage. Earlier research indicated that concern for damage is an important moderator of the annoyance induced. Acceptability, on the other hand, might be influenced by both annoyance and concern, as well as by other considerations. It is concluded that exposure–response relationships expressing acceptability as a function of vibration exposure could usefully complement existing relationships for annoyance in future policy decisions regarding environmental vibration. The results presented in this paper are derived from data collected through a socio-vibration survey (N = 321) conducted for the construction of an urban LRT in the United Kingdom. - Highlights: • The human response to construction vibration is assessed in residential environments. • Exposure–response relationships are generated based on survey and semi-empirical vibration estimation. • Annoyance, concern and acceptability are compared as response measures. • Concern and acceptability are viable measures complementing annoyance.

  14. Design of external vibration absorber for vibration suppression of milling cutter in processing

    Science.gov (United States)

    Zhang, Ya-hui; Zhang, Nian-song; Wang, Ai-min

    2018-01-01

    A new type of external dynamic vibration absorber is designed to control the vibration at a specific frequency of the milling cutter during the milling process. The structural design of the dynamic vibration absorber and the selection of the corresponding parameters are conducted. The finite element model of the cutter is established and connected with the vibration absorber. The results of the harmonic response analysis of milling cutter before and after the installation of the vibration absorber are compared and show that the vibration absorber can reduce the vibration of the cutter at the resonant frequency, which means it has a good vibration damping performance. The vibration absorber has the advantages of simple structure, convenient frequency modulation and easy installation. This context lay the foundation of further application for damping cutter.

  15. Ultrasonic vibration machining of Inconel

    International Nuclear Information System (INIS)

    Park, Myung Ho

    2003-01-01

    Recently, the demand for advanced technology of high precision and high efficiency processing of hard materials such as Inconel is increasing with progress of industrial goods. However, the machinability of Inconel is very inferior to the other conventional industrial materials and the machining technology for Inconel involves many problems to be solved in machining accuracy, machining efficiency, etc. Therefore it is needs to establish the machining technology. The purpose of this study is to develop an advanced ultrasonic vibration machining technology for Inconel, using the 60kHz and 75kHz high frequency, amplitude about 8μm and 4μm, respectively. As the result, this new ultrasonic vibration machining is reasonable and suitable for the high efficient, accuracy machining method of Inconel

  16. A night with good vibrations

    CERN Multimedia

    2002-01-01

    Next week-end, the Geneva Science History Museum invites you to a Science Night under the banner of waves and vibrations. Scientists, artists and storytellers from more than forty institutes and local or regional associations will show that waves and vibrations form an integral part of our environment. You will be able to get in contact with the nature of waves through interactive exhibitions on sound and light and through hands-on demonstrations arranged in the Park of the Perle du Lac. On the CERN stand, you will be able to measure the speed of light with a bar of chocolate, and understand the scattering of waves with plastic ducks. Amazing, no? In addition to the stands, the Night will offer many other activities: reconstructions of experiments, a play, a concert of crystal glasses, an illuminated fountain, a house of spirits. More information Science Night, 6 and 7 July, Park of the Perle du Lac, Geneva

  17. Vibration Analysis via Wireless Network

    Science.gov (United States)

    2007-09-01

    C. RELATED WORK The thesis builds upon the research foundation established by several students at the Naval Postgraduate School. Chimi Zacot [4...reading of a MEMS device in only one coordinate axis, one degree of freedom. To fully understand the vibration of the machinery would require an...the signals between the coordinate axis. Figure 15. Spectral Distance Results for 115V DC Motor with Load Applied. 30 Measured

  18. Optical vibrating-sample magnetometer

    CERN Document Server

    Diaz-Michelena, M; López, E; Sanchez, M C; Aroca, C

    2000-01-01

    A highly sensitive method of detecting vibrations of a cantilever in atomic-force microscopy has been introduced as a detector in an alternating-gradient field magnetometer. Use of light is the success of this system as it is compatible with vacuum systems and closed-flux cryostats. The optical signal is electronically conditioned easily. Experimental results show that highly sensitive measurements can be achieved.

  19. Tool-specific performance of vibration-reducing gloves for attenuating fingers-transmitted vibration

    Science.gov (United States)

    Welcome, Daniel E.; Dong, Ren G.; Xu, Xueyan S.; Warren, Christopher; McDowell, Thomas W.

    2016-01-01

    BACKGROUND Fingers-transmitted vibration can cause vibration-induced white finger. The effectiveness of vibration-reducing (VR) gloves for reducing hand transmitted vibration to the fingers has not been sufficiently examined. OBJECTIVE The objective of this study is to examine tool-specific performance of VR gloves for reducing finger-transmitted vibrations in three orthogonal directions (3D) from powered hand tools. METHODS A transfer function method was used to estimate the tool-specific effectiveness of four typical VR gloves. The transfer functions of the VR glove fingers in three directions were either measured in this study or during a previous study using a 3D laser vibrometer. More than seventy vibration spectra of various tools or machines were used in the estimations. RESULTS When assessed based on frequency-weighted acceleration, the gloves provided little vibration reduction. In some cases, the gloves amplified the vibration by more than 10%, especially the neoprene glove. However, the neoprene glove did the best when the assessment was based on unweighted acceleration. The neoprene glove was able to reduce the vibration by 10% or more of the unweighted vibration for 27 out of the 79 tools. If the dominant vibration of a tool handle or workpiece was in the shear direction relative to the fingers, as observed in the operation of needle scalers, hammer chisels, and bucking bars, the gloves did not reduce the vibration but increased it. CONCLUSIONS This study confirmed that the effectiveness for reducing vibration varied with the gloves and the vibration reduction of each glove depended on tool, vibration direction to the fingers, and finger location. VR gloves, including certified anti-vibration gloves do not provide much vibration reduction when judged based on frequency-weighted acceleration. However, some of the VR gloves can provide more than 10% reduction of the unweighted vibration for some tools or workpieces. Tools and gloves can be matched for

  20. Surveillance of vibrations in PWR

    International Nuclear Information System (INIS)

    Espefaelt, R.; Lorenzen, J.; Aakerhielm, F.

    1980-07-01

    The core of a PWR - including fuel elements, internal structure, control rods and core support structure inside the pressure vessel - is subjected to forces which can cause vibrations. One sensitive means to detect and analyse such vibrations is by means of the noise from incore and excore neutron detector signals. In this project noise recordings have been made on two occasions in the Ringhals 2 plant and the obtained data been analysed using the Studsvik Noise Analysis Program System (SNAPS). The results have been intepreted and a detailed description of the vibrational status of the core and pressure vessel internals has been produced. On the basis of the obtained results it is proposed that neutron signal noise analysis should be performed at each PWR plant in the beginning, middle and end of each fuel cycle and an analysis be made using the methods developed in the project. It would also provide a contribution to a higher degree of preparedness for diagnostic tasks in case of unexpected and abnormal events. (author)

  1. On-line vibration and loose parts monitoring of nuclear power stations as a preventive maintenance tool

    International Nuclear Information System (INIS)

    An equipment for on-line monitoring of vibrations and loose parts of nuclear power plants is described. The unit consists of piezoelectric transducers, preamplifiers, a data processor, and peripherals. It secures on-line measurement without interfering with the operation of the power plant. A diagram is given showing the monitor of vibrations and loose parts for pressurized water reactors and the Spectra-Scan equipment for the automatic recording and computer processing of noise signals is described. A survey is given of diagnostic methods for internal vibrations, noise and oscillations and procedures for the analysis of recordings are described. The experiences of Atomica International with the observation of vibrations in nuclear power plants are described and an economic assessment is presented of the efficiency of on-line monitoring of these vibrations. A cost-benefit analysis is made of such equipment which justifies their introduction. (B.S.)

  2. Underway physical and meteorological data collected aboard NOAA Ship ALBATROSS IV in the Northwest Atlantic from 2007-05-08 to 2007-06-11 (NODC Accession 0020395)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Underway physical and meteorological data were collected using thermosalinograph and meteorological sensors from NOAA Ship ALBATROSS IV in the NW Atlantic Ocean from...

  3. Underway meteorological, navigational, optical, physical and time series data collected aboard NOAA Ship Gordon Gunter in the Gulf of Mexico on 2016-10-01 (NCEI Accession 0164087)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0164087 contains raw underway meteorological, navigational, optical, physical and time series data logged by the Scientific Computer System (SCS)...

  4. Historical underway surface temperature data collected aboard the ship Skelton Castle on a voyage from England to India, 28 February 1800 to 3 June 1800 (NODC Accession 0095925)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Underway surface air temperature and sea water temperature were collected aboard the Skelton Castle while in route from England to Bombay India as part of the East...

  5. Underway meteorological, navigational, physical and time series data collected aboard NOAA Ship Henry B. Bigelow in the North Atlantic Ocean on 2016-08-26 (NCEI Accession 0162238)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0162238 contains raw underway meteorological, navigational, physical and time series data logged by the Scientific Computer System (SCS) aboard NOAA...

  6. Underway pCO2 and other measurements aboard NOAA Ship Ronald H. Brown during the 2007 cruises (NODC Accession 0081023)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0081023 includes Surface underway, chemical, meteorological, optical and physical data collected from NOAA Ship RONALD H. BROWN in the Caribbean Sea,...

  7. Underway meteorological, navigational, physical and time series data collected aboard NOAA Ship Oscar Elton Sette in the North Pacific Ocean on 2016-06-22 (NCEI Accession 0155170)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0155170 contains raw underway meteorological, navigational, physical and time series data logged by the Scientific Computer System (SCS) aboard NOAA...

  8. Underway pCO2 Measurements in Surface Waters and the Atmosphere During the R/V Nathaniel B. Palmer 2016 Expeditions (NCEI Accession 0166630)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0166630 includes Surface underway data collected from R/V Nathaniel B. Palmer in the South Pacific Ocean, South Atlantic Ocean, Southern Oceans from...

  9. Vibration-type particle separation device with piezoceramic vibrator

    Science.gov (United States)

    Ooe, Katsutoshi; Doi, Akihiro

    2008-12-01

    During hemanalysis, it is necessary to separate blood cells from whole blood. Many blood separation methods, for example, centrifugation and filtering, are in practical use. However, the use of these methods involves problems from the perspectives of processing speed and processing volume. We develop new types of blood separation devices that use piezo-ceramic vibrators. The first device uses a capillary. One end of the capillary is fixed to the device frame, and the other is fixed to a piezo-ceramic vibrator. The vibrator transmits bending waves to the capillary. This device can process only a small amount of solution; therefore, it is not suitable for hemanalysis. In order to solve this problem, we developed a second device; this device has a pair of thin glass plates with a small gap as a substitute for the capillary used in the first device. These devices are based on the fact that particles heavier than water move toward transverse velocity antinodes while those lighter than water move toward velocity nodes. In this report, we demonstrate the highspeed separation of silica microbeads and 50-vol% glycerol water by using these devices. The first device can separate the abovementioned solution within 3 min while the second can separate it within 1 min. Both devices are driven by a rectangular wave of 15 to 20 Vpp. Furthermore, it has been confirmed that red blood cells are separated from diluted whole blood using the first device within approximately 1 min. These devices have transparency, so they can compose as the analysis system with the chemical analyzer easily.

  10. Actively controlled vibration welding system and method

    Science.gov (United States)

    Cai, Wayne W.; Kang, Bongsu; Tan, Chin-An

    2013-04-02

    A vibration welding system includes a controller, welding horn, an active material element, and anvil assembly. The assembly may include an anvil body connected to a back plate and support member. The element, e.g., a piezoelectric stack or shape memory alloy, is positioned with respect to the assembly. The horn vibrates in a desirable first direction to form a weld on a work piece. The element controls any vibrations in a second direction by applying calibrated response to the anvil body in the second direction. A method for controlling undesirable vibrations in the system includes positioning the element with respect to the anvil assembly, connecting the anvil body to the support member through the back plate, vibrating the horn in a desirable first direction, and transmitting an input signal to the element to control vibration in an undesirable second direction.

  11. Theory And Working Of Noise And Vibration

    International Nuclear Information System (INIS)

    Jeong, Il Rok

    1988-09-01

    This book deals with theory of noise including physical property of noise like term and characteristic of sound, occurrence of sound, characteristic of noise pollution and main cause of occurrence of noise, technique of prevention of noise with noise reduction, construction guide for prevention of noise, and measure of interior noise. It also has the theory of vibration such as an introduction of vibration, and technology of prevention of vibration, official test method of environmental pollution, and summary of protection of the environment.

  12. Active Noise and Vibration Control Literature Survey: Sensors and Actuators

    Science.gov (United States)

    1999-08-01

    changes the simple monopole source to a less efficient dipole . The use of a second control source at the duct exit has been investigated by Trinder...noise attenuator. J. Sound Vib., 110, 471-481. 7.8 Electromagnetic Actuators Lecoufle, J.C. (1987): Actionneurs electriques industriels : technologie et

  13. High force vibration testing with wide frequency range

    Science.gov (United States)

    Romero, Edward F.; Jepsen, Richard A.; Gregory, Danny Lynn

    2013-04-02

    A shaker assembly for vibration testing includes first and second shakers, where the first shaker includes a piezo-electric material for generating vibration. A support structure permits a test object to be supported for vibration of the test object by both shakers. An input permits an external vibration controller to control vibration of the shakers.

  14. Axisymmetric vibrations of thick shells of revolution

    International Nuclear Information System (INIS)

    Suzuki, Katsuyoshi; Kosawada, Tadashi; Takahashi, Shin

    1983-01-01

    Axisymmetric shells of revolution are used for chemical plants, nuclear power plants, aircrafts, structures and so on, and the elucidation of their free vibration is important for the design. In this study, the axisymmetric vibration of a barrel-shaped shell was analyzed by the modified thick shell theory. The Lagrangian during one period of the vibration of a shell of revolution was determined, and from its stopping condition, the vibration equations and the boundary conditions were derived. The vibration equations were analyzed strictly by using the series solution. Moreover, the basic equations for the strain of a shell and others were based on those of Love. As the examples of numerical calculation, the natural frequency and vibration mode of the symmetrical shells of revolution fixed at both ends and supported at both ends were determined, and their characteristics were clarified. By comparing the results of this study with the results by thin shell theory, the effects of shearing deformation and rotary inertia on the natural frequency and vibration mode were clarified. The theoretical analysis and the numerical calculation are described. The effects of shearing deformation and rotary inertia on the natural frequency became larger in the higher order vibration. The vibration mode did not much change in both theories. (Kako, I.)

  15. Developed vibration waveform monitoring unit for CBM

    International Nuclear Information System (INIS)

    Hamada, T.; Hotsuta, K.; Hirose, I.; Morita, E.

    2007-01-01

    In nuclear power plants, many rotating machines such as pumps and fans are in use. Shikoku Research Institute Inc. has recently developed easy-to-use tools to facilitate the maintenance of such equipment. They include a battery-operated vibration waveform monitoring unit which allows unmanned vibration monitoring on a regular basis and data collection even from intermittently operating equipment, a waveform data collector which can be used for easy collection, storage, control, and analysis of raw vibration waveform data during normal operation, and vibration analysis and evaluation tools. A combination of these tools has a high potential for optimization of rotating equipment maintenance. (author)

  16. Vibrational dynamics of crystalline L-alanine

    Energy Technology Data Exchange (ETDEWEB)

    Bordallo, H.N.; Eckert, J. [Los Alamos National Lab., NM (United States); Barthes, M. [Univ. Montpellier II (France)

    1997-11-01

    The authors report a new, complete vibrational analysis of L-alanine and L-alanine-d{sub 4} which utilizes IINS intensities in addition to frequency information. The use of both isotopomers resulted in a self-consistent force field for and assignment of the molecular vibrations in L-alanine. Some details of the calculation as well as a comparison of calculated and observed IINS spectra are presented. The study clarifies a number of important issues on the vibrational dynamics of this molecule and presents a self-consistent force field for the molecular vibrations in crystalline L-alanine.

  17. Surface Acoustic Wave (SAW Vibration Sensors

    Directory of Open Access Journals (Sweden)

    Jerzy Filipiak

    2011-12-01

    Full Text Available In the paper a feasibility study on the use of surface acoustic wave (SAW vibration sensors for electronic warning systems is presented. The system is assembled from concatenated SAW vibration sensors based on a SAW delay line manufactured on a surface of a piezoelectric plate. Vibrations of the plate are transformed into electric signals that allow identification of the sensor and localization of a threat. The theoretical study of sensor vibrations leads us to the simple isotropic model with one degree of freedom. This model allowed an explicit description of the sensor plate movement and identification of the vibrating sensor. Analysis of frequency response of the ST-cut quartz sensor plate and a damping speed of its impulse response has been conducted. The analysis above was the basis to determine the ranges of parameters for vibrating plates to be useful in electronic warning systems. Generally, operation of electronic warning systems with SAW vibration sensors is based on the analysis of signal phase changes at the working frequency of delay line after being transmitted via two circuits of concatenated four-terminal networks. Frequencies of phase changes are equal to resonance frequencies of vibrating plates of sensors. The amplitude of these phase changes is proportional to the amplitude of vibrations of a sensor plate. Both pieces of information may be sent and recorded jointly by a simple electrical unit.

  18. Electromagnetic Vibration Energy Harvesting for Railway Applications

    Directory of Open Access Journals (Sweden)

    Bradai S.

    2018-01-01

    Full Text Available Safe localization of trains via GPS and wireless sensors is essential for railway traffic supervision. Especially for freight trains and because normally no power source is available on the wagons, special solutions for energy supply have to be developed based on energy harvesting techniques. Since vibration is available in this case, it provides an interesting source of energy. Nevertheless, in order to have an efficient design of the harvesting system, the existing vibration needs to be investigated. In this paper, we focus on the characterization of vibration parameters in railway application. We propose an electromagnetic vibration converter especially developed to this application. Vibration profiles from a train traveling between two German cities were measured using a data acquisition system installed on the train’s wagon. Results show that the measured profiles present multiple frequency signals in the range of 10 to 50 Hz and an acceleration of up to 2 g. A prototype for a vibration converter is designed taking into account the real vibration parameters, robustness and integrability requirements. It is based on a moving coil attached to a mechanical spring. For the experimental emulation of the train vibrations, a shaker is used as an external artificial vibration source controlled by a laser sensor in feedback. A maximum voltage of 1.7 V peak to peak which corresponds to a maximum of 10 mW output power where the applied excitation frequency is close to the resonant frequency of the converter which corresponds to 27 Hz.

  19. Vibration fatigue using modal decomposition

    Science.gov (United States)

    Mršnik, Matjaž; Slavič, Janko; Boltežar, Miha

    2018-01-01

    Vibration-fatigue analysis deals with the material fatigue of flexible structures operating close to natural frequencies. Based on the uniaxial stress response, calculated in the frequency domain, the high-cycle fatigue model using the S-N curve material data and the Palmgren-Miner hypothesis of damage accumulation is applied. The multiaxial criterion is used to obtain the equivalent uniaxial stress response followed by the spectral moment approach to the cycle-amplitude probability density estimation. The vibration-fatigue analysis relates the fatigue analysis in the frequency domain to the structural dynamics. However, once the stress response within a node is obtained, the physical model of the structure dictating that response is discarded and does not propagate through the fatigue-analysis procedure. The structural model can be used to evaluate how specific dynamic properties (e.g., damping, modal shapes) affect the damage intensity. A new approach based on modal decomposition is presented in this research that directly links the fatigue-damage intensity with the dynamic properties of the system. It thus offers a valuable insight into how different modes of vibration contribute to the total damage to the material. A numerical study was performed showing good agreement between results obtained using the newly presented approach with those obtained using the classical method, especially with regards to the distribution of damage intensity and critical point location. The presented approach also offers orders of magnitude faster calculation in comparison with the conventional procedure. Furthermore, it can be applied in a straightforward way to strain experimental modal analysis results, taking advantage of experimentally measured strains.

  20. Vibrational spectroscopy of Cm–C/Cb–Cb stretching vibrations of ...

    Indian Academy of Sciences (India)

    operator which conveniently describes stretching vibrations of biomolecules. For a copper tetramesityl porphyrin molecule, the higher excited vibrational levels are calculated by applying the U(2) algebraic approach. Keywords. Lie algebraic techniques; vibrational spectra; copper tetramesityl porphyrin. PACS Nos 31.65.

  1. Adaptive photodetectors for vibration monitoring

    International Nuclear Information System (INIS)

    Sokolov, I.A.

    2003-01-01

    We present characteristics of laser vibrometer using semiconductor GaAs and molecular SnS 2 adaptive photodetectors (AP) based on the effect of the non-steady-state photoelectromotive force. AP enable efficient direct conversion of high-frequency phase modulation of speckle-like optical wave reflected from the vibrating object into an output electrical signal with concomitant setting of optimal operation point of the interferometer and suppression of amplitude laser noise. The sensitivity of the setup is analyzed and further improvements in operation of AP are discussed

  2. EMBEDDED SYSTEMS FOR VIBRATION MONITORING

    Directory of Open Access Journals (Sweden)

    Miloš Milovančević

    2014-08-01

    Full Text Available The purpose of the research presented in this paper is the development of the optimal micro configuration for vibration monitoring of pumping aggregate, based on Microchip’s microcontroller (MC. Hardware used is 10-bit MC, upgraded with 12/bit A/D converter. Software for acquisition and data analysis is optimized for testing turbo pumps with rotation speed up to 2000 rpm. This software limitation is set for automatic diagnostics and for individual and manual vibro-diagnostic; the only limitation is set by accelerometer performance. The authors have performed numerous measurements on a wide range of turbo aggregates for establishing the operational condition of pumping aggregates.

  3. Multivariate Analysis of Ladle Vibration

    Science.gov (United States)

    Yenus, Jaefer; Brooks, Geoffrey; Dunn, Michelle

    2016-08-01

    The homogeneity of composition and uniformity of temperature of the steel melt before it is transferred to the tundish are crucial in making high-quality steel product. The homogenization process is performed by stirring the melt using inert gas in ladles. Continuous monitoring of this process is important to make sure the action of stirring is constant throughout the ladle. Currently, the stirring process is monitored by process operators who largely rely on visual and acoustic phenomena from the ladle. However, due to lack of measurable signals, the accuracy and suitability of this manual monitoring are problematic. The actual flow of argon gas to the ladle may not be same as the flow gage reading due to leakage along the gas line components. As a result, the actual degree of stirring may not be correctly known. Various researchers have used one-dimensional vibration, and sound and image signals measured from the ladle to predict the degree of stirring inside. They developed online sensors which are indeed to monitor the online stirring phenomena. In this investigation, triaxial vibration signals have been measured from a cold water model which is a model of an industrial ladle. Three flow rate ranges and varying bath heights were used to collect vibration signals. The Fast Fourier Transform was applied to the dataset before it has been analyzed using principal component analysis (PCA) and partial least squares (PLS). PCA was used to unveil the structure in the experimental data. PLS was mainly applied to predict the stirring from the vibration response. It was found that for each flow rate range considered in this study, the informative signals reside in different frequency ranges. The first latent variables in these frequency ranges explain more than 95 pct of the variation in the stirring process for the entire single layer and the double layer data collected from the cold model. PLS analysis in these identified frequency ranges demonstrated that the latent

  4. Vibration diagnostics instrumentation for ILC

    Energy Technology Data Exchange (ETDEWEB)

    Bertolini, A.

    2007-06-15

    The future e{sup -}e{sup +} 500 GeV International Linear Collider will rely on unprecedented nanometer scale particle beam size at the interaction point, in order to achieve the design luminosity. Tight tolerances on static and dynamic alignment of the accelerator cavities and optical components are demanded to transport and focus the high energy electron and positron beams with reasonable position jitter and low emittance. A brief review of techniques and devices evaluated and developed so far for the vibration diagnostics of the machine is presented in this paper. (orig.)

  5. Vibration diagnostics instrumentation for ILC

    International Nuclear Information System (INIS)

    Bertolini, A.

    2007-06-01

    The future e - e + 500 GeV International Linear Collider will rely on unprecedented nanometer scale particle beam size at the interaction point, in order to achieve the design luminosity. Tight tolerances on static and dynamic alignment of the accelerator cavities and optical components are demanded to transport and focus the high energy electron and positron beams with reasonable position jitter and low emittance. A brief review of techniques and devices evaluated and developed so far for the vibration diagnostics of the machine is presented in this paper. (orig.)

  6. Vibrational Spectroscopy of Chromatographic Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Jeanne E. Pemberton

    2011-03-10

    Chromatographic separations play a central role in DOE-supported fundamental research related to energy, biological systems, the environment, and nuclear science. The overall portfolio of research activities in the Separations and Analysis Program within the DOE Office of Basic Energy Sciences includes support for activities designed to develop a molecular-level understanding of the chemical processes that underlie separations for both large-scale and analytical-scale purposes. The research effort funded by this grant award was a continuation of DOE-supported research to develop vibrational spectroscopic methods to characterize the interfacial details of separations processes at a molecular level.

  7. Monothiodibenzoylmethane: Structural and vibrational assignments

    DEFF Research Database (Denmark)

    Hansen, Bjarke Knud Vilster; Gorski, Alexander; Posokhov, Yevgen

    2007-01-01

    The vibrational structure of the title compound (1,3-diphenyl-3-thioxopropane-1-one, TDBM) was studied by a variety of experimental and theoretical methods. The stable ground state configuration of TDBM was investigated by IR absorption measurements in different media, by LD polarization spectros...... to an “open”, non-chelated enethiol form (t-TCC), thereby supporting the previous conclusions by Posokhov et al. No obvious indications of the contribution of other forms to the observed spectra could be found....

  8. Introduction to vibrations and waves

    CERN Document Server

    Pain, H John

    2015-01-01

    Based on the successful multi-edition book "The Physics ofVibrations and Waves" by John Pain, the authors carry overthe simplicity and logic of the approach taken in the originalfirst edition with its focus on the patterns underlying andconnecting so many aspects of physical behavior, whilst bringingthe subject up-to-date so it is relevant to teaching in the21st century.The transmission of energy by wave propagation is a key conceptthat has applications in almost every branch of physics withtransmitting mediums essentially acting as a continuum of coupledoscillators. The characterization of t

  9. Force Limited Random Vibration Test of TESS Camera Mass Model

    Science.gov (United States)

    Karlicek, Alexandra; Hwang, James Ho-Jin; Rey, Justin J.

    2015-01-01

    The Transiting Exoplanet Survey Satellite (TESS) is a spaceborne instrument consisting of four wide field-of-view-CCD cameras dedicated to the discovery of exoplanets around the brightest stars. As part of the environmental testing campaign, force limiting was used to simulate a realistic random vibration launch environment. While the force limit vibration test method is a standard approach used at multiple institutions including Jet Propulsion Laboratory (JPL), NASA Goddard Space Flight Center (GSFC), European Space Research and Technology Center (ESTEC), and Japan Aerospace Exploration Agency (JAXA), it is still difficult to find an actual implementation process in the literature. This paper describes the step-by-step process on how the force limit method was developed and applied on the TESS camera mass model. The process description includes the design of special fixtures to mount the test article for properly installing force transducers, development of the force spectral density using the semi-empirical method, estimation of the fuzzy factor (C2) based on the mass ratio between the supporting structure and the test article, subsequent validating of the C2 factor during the vibration test, and calculation of the C.G. accelerations using the Root Mean Square (RMS) reaction force in the spectral domain and the peak reaction force in the time domain.

  10. Hand-arm vibration syndrome among travertine workers: a follow up study.

    Science.gov (United States)

    Bovenzi, M; Franzinelli, A; Scattoni, L; Vannuccini, L

    1994-06-01

    In a six year follow up study of the handarm vibration syndrome, 62 stoneworkers operating hand held vibrating tools in 10 travertine quarries and mills were first investigated in 1985 and then in 1991. The frequency weighted acceleration of vibration from the rock drills and stone hammers used by the travertine workers exceeded 20 m/s2, indicating a hazardous work activity according to the proposal of the EC directive for physical agents. A clinical examination and a cold provocation test were repeated with the same procedures as those adopted at the time of the first survey. The stoneworkers were divided into groups according to current work state: active stoneworkers who continued to use powered tools during the follow up (n = 21, median exposure time 22 years), and ex-stoneworkers with retirement vibration free intervals of three years (n = 22, median exposure time 27.5 years) and of six years (n = 19, median exposure time 20 years). In the group of active stoneworkers, a 38% onset a new cases of vibration-induced white finger (VWF) was found during the follow up (p stone workers after a few extra years of vibrating tool usage argues for an urgent implementation of preventive measures in the stone industry.

  11. Research into hand-arm vibration syndrome and its prevention in Japan.

    Science.gov (United States)

    Yamada, S; Sakakibara, H

    1994-05-01

    Research on vibration syndrome in Japan began in the 1930s with studies of the disorder among railway, mining and shipyard workers. In 1947, the Ministry of Labor decided vibration syndrome among operators of rock drills and riveters etc. was an occupational disease. Industrial developments in the 1950s and 1960s promoted the survey of vibration syndrome in mining, stone quarrying and forestry. The Ministry of Labor (1965) and the National Personnel Agency (1966) legally recognized vibration syndrome among chain saw operators as an occupational disease. Guidelines for prevention and early therapy were issued in the 1970s and 80s. From the late 1970s into the 1980s, research focused on the clinical picture, diagnostic methods and therapy. In pathophysiology, advances were made in research into the autonomic nervous system during the 1980s. The 1970s and 80s saw a steady reduction in risk from technological change and working conditions, and advances in medical care, education and meteorological forecasting. A comprehensive prevention system established in the 1980s in the Japanese forest industry involved: 1) work restrictions, 2) an improved health care system, 3) advances in the design of vibrating tools, handle-warming devices, and 4) improved worker education. This comprehensive preventive system was legally introduced into other industries, resulting in a rapid decrease in the incidence of vibration syndrome in Japan.

  12. Noise and vibration analysis system

    International Nuclear Information System (INIS)

    Johnsen, J.R.; Williams, R.L.

    1985-01-01

    The analysis of noise and vibration data from an operating nuclear plant can provide valuable information that can identify and characterize abnormal conditions. Existing plant monitoring equipment, such as loose parts monitoring systems (LPMS) and neutron flux detectors, may be capable of gathering noise data, but may lack the analytical capability to extract useful meanings hidden in the noise. By analyzing neutron noise signals, the structural motion and integrity of core components can be assessed. Computer analysis makes trending of frequency spectra within a fuel cycle and from one cycle to another a practical means of core internals monitoring. The Babcock and Wilcox Noise and Vibration Analysis System (NVAS) is a powerful, compact system that can automatically perform complex data analysis. The system can acquire, process, and store data, then produce report-quality plots of the important parameter. Software to perform neutron noise analysis and loose parts analysis operates on the same hardware package. Since the system is compact, inexpensive, and easy to operate, it allows utilities to perform more frequency analyses without incurring high costs and provides immediate results

  13. Flow induced vibrations of piping

    International Nuclear Information System (INIS)

    Gibert, R.J.; Axisa, F.

    1977-01-01

    In order to design the supports of piping systems, estimations of the vibrations induced by the fluid conveyed through the pipes are generally needed. For that purpose it is necessary to calculate the model parameters of liquid containing pipes. In most computer codes, fluid effects are accounted for just by adding the fuid mass to the structure. This may lead to serious errors.- Inertial effects from the fluid are not correctly evaluated especially in the case of bended or of non-uniform section pipes. Fluid boundary conditions are simply ignored. - In many practical problems fluid compressibility cannot be negelcted, even in the low frequencies domain which corresponds to efficient excitation by turbulent sources of the flow. This paper presents a method to take into account these efects, by solving a coupled mechanical acoustical problem: the computer code TEDEL of the C.E.A./D.E.M.T. System, based on the finite-elements method, has been extended to calculate simultaneously the pressure fluctuations in the fluid and the vibrations of the pipe. (Auth.)

  14. Time-resolved vibrational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tokmakoff, Andrei [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Champion, Paul [Northeastern Univ., Boston, MA (United States); Heilweil, Edwin J. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Nelson, Keith A. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Ziegler, Larry [Boston Univ., MA (United States)

    2009-05-14

    This document contains the Proceedings from the 14th International Conference on Time-Resolved Vibrational Spectroscopy, which was held in Meredith, NH from May 9-14, 2009. The study of molecular dynamics in chemical reaction and biological processes using time-resolved spectroscopy plays an important role in our understanding of energy conversion, storage, and utilization problems. Fundamental studies of chemical reactivity, molecular rearrangements, and charge transport are broadly supported by the DOE's Office of Science because of their role in the development of alternative energy sources, the understanding of biological energy conversion processes, the efficient utilization of existing energy resources, and the mitigation of reactive intermediates in radiation chemistry. In addition, time-resolved spectroscopy is central to all fiveof DOE's grand challenges for fundamental energy science. The Time-Resolved Vibrational Spectroscopy conference is organized biennially to bring the leaders in this field from around the globe together with young scientists to discuss the most recent scientific and technological advances. The latest technology in ultrafast infrared, Raman, and terahertz spectroscopy and the scientific advances that these methods enable were covered. Particular emphasis was placed on new experimental methods used to probe molecular dynamics in liquids, solids, interfaces, nanostructured materials, and biomolecules.

  15. Flow induced vibrations of piping

    International Nuclear Information System (INIS)

    Gibert, R.J.; Axisa, F.

    1977-01-01

    This paper presents a method to take into account the inertial effects and the fluid compressibility by solving a coupled mechanical-acoustical problem: the computer code TEDEL of the C.E.A./D.E.M.T. System, based on the finite-element method, has been extended to calculate simultaneously the pressure fluctuations in the fluid and the vibrations of the pipe. By this way the mechanical-acoustical coupled eigenmodes of any piping system can be obtained. These eigenmodes are used to determine the response of the system to various sources (acoustical sources or forces exciting directly the structure). Equations have been written in the hypothesis that acoustical wave lengths remain large compared to the diameter of the pipe. Indeed this is largely verified in almost practical cases. The method has been checked by an experiment performed on the GASCOGNE loop at D.E.M.T. The piping system under test consist of a tube with four elbows. The circuit is ended at each extremity by a large vessel which performs acoustical isolation by generating modes for the pressure. Excitation of the circuit is caused by a valve located near the downstream vessel. This provide an efficient localised broad band acoustical source. The comparison between the test results and the calculations has shown that the low frequency resonant characteristics of the pipe and the vibrational amplitude at various flow-rates can be correctly predicted [fr

  16. Vibrational Locomotion Enabling Subsurface Exploration of Unconsolidated Regolith Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The idea of vibrational locomotion is based on vibrational-fluidization in ISRU reactor systems, which has proven very effective for regolith mixing. The vibrating...

  17. Onset of positional vertigo during exposure to combined G loading and chest-to-spine vibration.

    Science.gov (United States)

    Liston, Dorion B; Adelstein, Bernard D; Stone, Leland S

    2014-02-01

    Aerospace environments commonly expose pilots to vibration and sustained acceleration, alone and in combination. Of 16 experimental research participants, 3 reported symptoms of vertigo and signs of torsional nystagmus during or shortly following exposure to sustained chest-to-spine (+3.8 Gx) acceleration (G loading) and chest-to-spine (0.5 g(x)) vibration in the 8-16 Hz band. Two of the participants reported intermittent vertigo for up to 2 wk, were diagnosed with benign paroxysmal positional vertigo (BPPV), and were treated successfully with the Epley Maneuver. On a follow-up survey, a third participant reported transient BPPV-like vertigo, which resolved spontaneously. The follow-up survey also prompted participants to self-report other effects following research protocol exposure to vibration and G loading, revealing details about other minor and transient, but more common, effects that resolved within 3 h. Our studies indicated a significantly elevated incidence of BPPV following exposure to vibration plus G loading compared to vibration alone that was positively correlated with participant age. One mechanism for the rolling sensation in BPPV involves broken or dislodged otoconia floating within one of the posterior semicircular canals, making the canal gravity-sensitive. Our observations highlight a heretofore unforeseen risk of otolith damage sustained during launch, undetectable in space, potentially contributing to vertigo and perceived tumbling upon re-entry from microgravity.

  18. [Complaints of low back pain among private farmers exposed to whole body vibration].

    Science.gov (United States)

    Solecki, Leszek

    2014-01-01

    Work-related lower back disorders, which involve the lumbo-sacral region, as well as injuries of the lumbar section of the spine, are a serious and constantly growing problem in Europe. Whole body vibration is one of the major hazardous factors suspected of the development of back pain. The study covered a selected group of males, 98 farmers (aged 55.3 +/- 10.1) from the area of 7 communes in the Lublin Region, engaged in the mixed agricultural production (plant-animal). The control group consisted of 40 academic workers (university and research institute employees) aged 48.9 +/- 9.6 years. A questionnaire concerning low back pain (in the lumbar region) designed by the researchers of the Institute of Rural Health in Lublin was used as a major research tool. The degree of farmers' exposure to whole body vibration was evaluated based on the parameter known as a cumulative vibration dose (d) (years x m2 x s(-1)). The measurements showed that the cumulative vibration dose for the selected group of farmers (98) remained within the range of 2.90-9.68 (years x m2 x s(-1)), in the time interval between 15-50 years of work in conditions of exposure to vibration. The survey confirmed that private farmers exposed to whole body vibration considerably more frequently complained of back pain (92 farmers, 94% of the total number of respondents), than academic workers (control group not exposed to whole body vibration (25 researchers, 63%); p farmers than in the control group (p farmers during the entire period of occupational activity increases with a growing dose of whole body vibration (p = 0.005). In the incidence of chronic pain an upward tendency was observed (statistically insignificant).

  19. 14 CFR 33.43 - Vibration test.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Vibration test. 33.43 Section 33.43... STANDARDS: AIRCRAFT ENGINES Block Tests; Reciprocating Aircraft Engines § 33.43 Vibration test. (a) Each... configuration of the propeller type which is used for the endurance test, and using, for other engines, the same...

  20. Flexural vibrations of finite composite poroelastic cylinders

    Indian Academy of Sciences (India)

    infinite hollow poroelastic cylinders. Axially symmetric vibrations of finite composite poroe- lastic cylinders that are bonded end to end are investigated by Shah & Tajuddin (2009). The analysis of the flexural vibrations in cylindrical structures has wide applications in the field of acoustics structural design and Biomechanics, ...

  1. General vibration monitoring: Utility Building, August 1992

    International Nuclear Information System (INIS)

    Jendrzejczyk, J.A.; Wambsganss, M.W.; Smith, R.K.

    1993-01-01

    This vibration data was generated from measurements made on 8/12/92. The contents are self explanatory. They are baseline measurements and no exceptionally large vibration amplitude or response was observed. These measurements represent baseline measurements, i.e., measurements with no driving forces active, made on the utility building, a service building for the Advanced Photon Source at Argonne National Laboratory

  2. Optimal control of vibrational transitions of HCl

    Indian Academy of Sciences (India)

    2016-09-07

    Sep 7, 2016 ... Many H-abstraction reactions in chemistry involve halides like HCl, HBr and HI. And they often need to undergo coherent vibrational excitation to promote the reaction (for instance, the late-barrier reactions in chemistry require vibrationally hot reactant molecules to have the reaction promoted) efficiently.

  3. Noncontact Ultrasonic Vibration Of Weld Puddles

    Science.gov (United States)

    Gilbert, Jeffrey L.

    1990-01-01

    Proposed ultrasonic stimulator vibrates weld puddle without making contact. Vibration breaks up large grain clumps in solidifying puddle, creating more uniform, fine-grain microstructure. Resulting weld joint less susceptible to hot cracking and other stress-related forms of degradation.

  4. 49 CFR 178.985 - Vibration test.

    Science.gov (United States)

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR PACKAGINGS Testing of Large Packagings § 178.985 Vibration test. (a) General. All rigid Large Packaging and flexible Large Packaging design types must be capable of withstanding the vibration test. (b) Test method. (1) A...

  5. Dissimilar Dynamics of Coupled Water Vibrations

    NARCIS (Netherlands)

    Jansen, Thomas L. C.; Cringus, Dan; Pshenichnikov, Maxim S.

    2009-01-01

    Dissimilar dynamics of coupled stretch vibrations of a water molecule are revealed by two-dimensional, IR correlation spectroscopy. These are caused by essentially non-Gaussian fluctuations of the electric field exerted by the environment on the individual OH stretch vibrations. Non-Gaussian

  6. Vibration and Sound Damping in Polymers

    Indian Academy of Sciences (India)

    IAS Admin

    The damping property of rubbers is utilized in products like vibration damper ... engineering rubber products used for vibration isolation. In Greek, .... Natural rubber. – 73. Poly(methyl methacrylate) 105. Butadiene rubber. – 100. Polycarbonate. 145. Silicone rubber. – 127. Polynorbornene. 215. Table 1. Comparing the Tg of.

  7. Benefits of Spacecraft Level Vibration Testing

    Science.gov (United States)

    Gordon, Scott; Kern, Dennis L.

    2015-01-01

    NASA-HDBK-7008 Spacecraft Level Dynamic Environments Testing discusses the approaches, benefits, dangers, and recommended practices for spacecraft level dynamic environments testing, including vibration testing. This paper discusses in additional detail the benefits and actual experiences of vibration testing spacecraft for NASA Goddard Space Flight Center (GSFC) and Jet Propulsion Laboratory (JPL) flight projects. JPL and GSFC have both similarities and differences in their spacecraft level vibration test approach: JPL uses a random vibration input and a frequency range usually starting at 5 Hz and extending to as high as 250 Hz. GSFC uses a sine sweep vibration input and a frequency range usually starting at 5 Hz and extending only to the limits of the coupled loads analysis (typically 50 to 60 Hz). However, both JPL and GSFC use force limiting to realistically notch spacecraft resonances and response (acceleration) limiting as necessary to protect spacecraft structure and hardware from exceeding design strength capabilities. Despite GSFC and JPL differences in spacecraft level vibration test approaches, both have uncovered a significant number of spacecraft design and workmanship anomalies in vibration tests. This paper will give an overview of JPL and GSFC spacecraft vibration testing approaches and provide a detailed description of spacecraft anomalies revealed.

  8. Enriched vibrational resonance in certain discrete systems

    Indian Academy of Sciences (India)

    We wish to report the occurrence of vibrational resonance in certain discrete systems like sine square map and sine circle map, in a unique fashion, comprising of multiple resonant peaks which pave the way for enrichment. As the systems of our choice are capable of exhibiting vibrational resonance behaviour unlike the ...

  9. Experimental evaluation of vibrations in heat exchangers

    International Nuclear Information System (INIS)

    Martin Ghiselli, A.

    1997-01-01

    Flow induced vibrations may produce damage of heat exchangers, condensers and steam generators tubes. To evaluate this problem a set of tests were developed to know the real support state of the tubes, which have great influence on the vibration response. This paper include a description of the tests and the results obtained applying them on a heat exchanger equipment. (author) [es

  10. Vibrations in pipelines of nuclear power plants

    International Nuclear Information System (INIS)

    Leal, M.R.L.V.; Bevilacqua, L.

    1984-01-01

    It is presented the main causes of vibrations in nuclear power plants pipelines to allow the identification of critical areas and correct the errors during the specification design. The methods of vibration analysis to give subsidies in the determination of the corrective providences when the problem appears during the commissioning or the generation energy, are also presented. (M.C.K.) [pt

  11. Modified Composite Struts Would Damp Vibrations

    Science.gov (United States)

    Chen, Gun-Shing; Dolgin, Benjamin P.

    1993-01-01

    Composite-material (fiber/matrix laminate) struts damping longitudinal vibrations fabricated more easily in proposed new design. Prior design described in "Composite Struts Would Damp Vibrations" (NPO-17914). New design similar except pattern of fibers includes rounded bends (instead of sharp bends) in fibers.

  12. Optical fiber grating vibration sensor for vibration monitoring of hydraulic pump

    Science.gov (United States)

    Zhang, Zhengyi; Liu, Chuntong; Li, Hongcai; He, Zhenxin; Zhao, Xiaofeng

    2017-06-01

    In view of the existing electrical vibration monitoring traditional hydraulic pump vibration sensor, the high false alarm rate is susceptible to electromagnetic interference and is not easy to achieve long-term reliable monitoring, based on the design of a beam of the uniform strength structure of the fiber Bragg grating (FBG) vibration sensor. In this paper, based on the analysis of the vibration theory of the equal strength beam, the principle of FBG vibration tuning based on the equal intensity beam is derived. According to the practical application of the project, the structural dimensions of the equal strength beam are determined, and the optimization design of the vibrator is carried out. The finite element analysis of the sensor is carried out by ANSYS, and the first order resonant frequency is 94.739 Hz. The vibration test of the sensor is carried out by using the vibration frequency of 35 Hz and the vibration source of 50 Hz. The time domain and frequency domain analysis results of test data show that the sensor has good dynamic response characteristics, which can realize the accurate monitoring of the vibration frequency and meet the special requirements of vibration monitoring of hydraulic pump under specific environment.

  13. Passively damped vibration welding system and method

    Science.gov (United States)

    Tan, Chin-An; Kang, Bongsu; Cai, Wayne W.; Wu, Tao

    2013-04-02

    A vibration welding system includes a controller, welding horn, an anvil, and a passive damping mechanism (PDM). The controller generates an input signal having a calibrated frequency. The horn vibrates in a desirable first direction at the calibrated frequency in response to the input signal to form a weld in a work piece. The PDM is positioned with respect to the system, and substantially damps or attenuates vibration in an undesirable second direction. A method includes connecting the PDM having calibrated properties and a natural frequency to an anvil of an ultrasonic welding system. Then, an input signal is generated using a weld controller. The method includes vibrating a welding horn in a desirable direction in response to the input signal, and passively damping vibration in an undesirable direction using the PDM.

  14. Modeling Displacement Measurement using Vibration Transducers

    Directory of Open Access Journals (Sweden)

    AGOSTON Katalin

    2014-05-01

    Full Text Available This paper presents some aspects regarding to small displacement measurement using vibration transducers. Mechanical faults, usages, slackness’s, cause different noises and vibrations with different amplitude and frequency against the normal sound and movement of the equipment. The vibration transducers, accelerometers and microphone are used for noise and/or sound and vibration detection with fault detection purpose. The output signal of the vibration transducers or accelerometers is an acceleration signal and can be converted to either velocity or displacement, depending on the preferred measurement parameter. Displacement characteristics are used to indicate when the machine condition has changed. There are many problems using accelerometers to measure position or displacement. It is important to determine displacement over time. To determinate the movement from acceleration a double integration is needed. A transfer function and Simulink model was determinate for accelerometers with capacitive sensing element. Using these models the displacement was reproduced by low frequency input.

  15. Systematic vibration thermodynamic properties of bromine

    Science.gov (United States)

    Liu, G. Y.; Sun, W. G.; Liao, B. T.

    2015-11-01

    Based on the analysis of the maturity and finiteness of vibrational levels of bromine molecule in ground state and evaluating the effect on statistical computation, according to the elementary principles of quantum statistical theorem, using the full set of bromine molecular vibrational levels determined with algebra method, the statistical contribution for bromine systematical macroscopic thermodynamic properties is discussed. Thermodynamic state functions Helmholtz free energy, entropy and observable vibration heat capacity are calculated. The results show that the determination of full set of vibrational levels and maximum vibrational quantum number is the key in the correct statistical analysis of bromine systematical thermodynamic property. Algebra method results are clearly different from data of simple harmonic oscillator and the related algebra method results are no longer analytical but numerical and are superior to simple harmonic oscillator results. Compared with simple harmonic oscillator's heat capacities, the algebra method's heat capacities are more consistent with the experimental data in the given temperature range of 600-2100 K.

  16. Phosphate vibrations as reporters of DNA hydration

    Science.gov (United States)

    Corcelli, Steven

    The asymmetric phosphate stretch vibrational frequency is extraordinarily sensitive to its local solvent environment. Using density functional theory calculations on the model compound dimethyl phosphate, the asymmetric phosphate stretch vibrational frequency was found to shift linearly with the magnitude of an electric field along the symmetry axis of the PO2 moiety (i.e. the asymmetric phosphate stretch is an excellent linear vibrational Stark effect probe). With this linear relationship established, asymmetric phosphate stretch vibrational frequencies were computed during the course of a molecular dynamics simulation of fully hydrated DNA. Moreover, contributions to shifts in the frequencies from subpopulations of water molecules (e.g. backbone, minor groove, major groove, etc.) were calculated to reveal how phosphate vibrations report the onset of DNA hydration in experiments that vary the relative humidity of non-condensing (dry) DNA samples.

  17. Energy scavenging from environmental vibration.

    Energy Technology Data Exchange (ETDEWEB)

    Galchev, Tzeno (University of Michigan); Apblett, Christopher Alan; Najafi, Khalil (University of Michigan)

    2009-10-01

    The goal of this project is to develop an efficient energy scavenger for converting ambient low-frequency vibrations into electrical power. In order to achieve this a novel inertial micro power generator architecture has been developed that utilizes the bi-stable motion of a mechanical mass to convert a broad range of low-frequency (< 30Hz), and large-deflection (>250 {micro}m) ambient vibrations into high-frequency electrical output energy. The generator incorporates a bi-stable mechanical structure to initiate high-frequency mechanical oscillations in an electromagnetic scavenger. This frequency up-conversion technique enhances the electromechanical coupling and increases the generated power. This architecture is called the Parametric Frequency Increased Generator (PFIG). Three generations of the device have been fabricated. It was first demonstrated using a larger bench-top prototype that had a functional volume of 3.7cm3. It generated a peak power of 558{micro}W and an average power of 39.5{micro}W at an input acceleration of 1g applied at 10 Hz. The performance of this device has still not been matched by any other reported work. It yielded the best power density and efficiency for any scavenger operating from low-frequency (<10Hz) vibrations. A second-generation device was then fabricated. It generated a peak power of 288{micro}W and an average power of 5.8{micro}W from an input acceleration of 9.8m/s{sup 2} at 10Hz. The device operates over a frequency range of 20Hz. The internal volume of the generator is 2.1cm{sup 3} (3.7cm{sup 3} including casing), half of a standard AA battery. Lastly, a piezoelectric version of the PFIG is currently being developed. This device clearly demonstrates one of the key features of the PFIG architecture, namely that it is suitable for MEMS integration, more so than resonant generators, by incorporating a brittle bulk piezoelectric ceramic. This is the first micro-scale piezoelectric generator capable of <10Hz operation. The

  18. Vibration Control in Periodic Structures

    DEFF Research Database (Denmark)

    Høgsberg, Jan Becker

    2017-01-01

    Within the framework of periodic structures, the calibration of RL shunted piezoelectric inclusions is investigated with respect to maximum damping of a particular wave form. A finite element setting is assumed, with local shunted inclusions inside the unit cell. The effect of the shunts is repre......Within the framework of periodic structures, the calibration of RL shunted piezoelectric inclusions is investigated with respect to maximum damping of a particular wave form. A finite element setting is assumed, with local shunted inclusions inside the unit cell. The effect of the shunts....... The presentation contains dispersion diagrams and vibration amplitude curves for the optimally calibrated RL shunt system in a 1-D periodic structure with local piezoelectric inclusions....

  19. Carbon Nanotube Tape Vibrating Gyroscope

    Science.gov (United States)

    Tucker, Dennis Stephen (Inventor)

    2016-01-01

    A vibrating gyroscope includes a piezoelectric strip having length and width dimensions. The piezoelectric strip includes a piezoelectric material and carbon nanotubes (CNTs) substantially aligned and polled along the strip's length dimension. A spindle having an axis of rotation is coupled to the piezoelectric strip. The axis of rotation is parallel to the strip's width dimension. A first capacitance sensor is mechanically coupled to the spindle for rotation therewith. The first capacitance sensor is positioned at one of the strip's opposing ends and is spaced apart from one of the strip's opposing faces. A second capacitance sensor is mechanically coupled to the spindle for rotation therewith. The second capacitance sensor is positioned at another of the strip's opposing ends and is spaced apart from another of the strip's opposing faces. A voltage source applies an AC voltage to the piezoelectric strip.

  20. Steam generator tube vibration study

    International Nuclear Information System (INIS)

    Enderlin, W.I.

    1986-01-01

    Chemical cleaning has been proposed to remove magnetite buildup in some pressurized water reactor steam generators. The US Nuclear Regulatory Commission (NRC) has expressed concern that such cleaning would combine with the tube denting caused by magnetite formation to enlarge tube/tube support plate clearances, increasing the level of flow-induced vibrations that could lead to unacceptably high tube wear and failure rates. In support of NRC, the Pacific Northwest Laboratory investigated whether such increased clearances would exacerbate tube fretting wear. Using a full-length scale model of a steam generator tube bundle, flow tests were conducted at an instrumented location through clearances representing as-built and post-cleaned tube conditions. Test results indicated little potential for increased tube wear as a result of chemical cleaning, under normal operating conditions at tube support locations similar to that tested

  1. Isospin effects in nuclear vibrations

    International Nuclear Information System (INIS)

    Madsen, V.A.; Brown, V.R.

    1984-09-01

    A review of the evidence that the ratio of neutron and proton multipole matrix elements for collective vibrations in single-closed-shell nuclei differ systematically from N/Z is presented. A theoretical framework is given for understanding the data on the basis of the ideas of core polarization. It follows that nuclear deformation parameters are probe dependent and that analysis of excitations by two different probes such as (p,p') and (n,n') can, in principle, give the ratio M/sub n//M/sub p/. Application is made to first 2 + states of open shell nuclei. Trends of M/sub n//M/sub p/ for higher 2 + states are presented. Expected systematics of M/sub n//M/sub p/ ratios for giant isoscalar quadrupole transitions are presented. 22 references

  2. Super-multiplex vibrational imaging

    Science.gov (United States)

    Wei, Lu; Chen, Zhixing; Shi, Lixue; Long, Rong; Anzalone, Andrew V.; Zhang, Luyuan; Hu, Fanghao; Yuste, Rafael; Cornish, Virginia W.; Min, Wei

    2017-04-01

    The ability to visualize directly a large number of distinct molecular species inside cells is increasingly essential for understanding complex systems and processes. Even though existing methods have successfully been used to explore structure-function relationships in nervous systems, to profile RNA in situ, to reveal the heterogeneity of tumour microenvironments and to study dynamic macromolecular assembly, it remains challenging to image many species with high selectivity and sensitivity under biological conditions. For instance, fluorescence microscopy faces a ‘colour barrier’, owing to the intrinsically broad (about 1,500 inverse centimetres) and featureless nature of fluorescence spectra that limits the number of resolvable colours to two to five (or seven to nine if using complicated instrumentation and analysis). Spontaneous Raman microscopy probes vibrational transitions with much narrower resonances (peak width of about 10 inverse centimetres) and so does not suffer from this problem, but weak signals make many bio-imaging applications impossible. Although surface-enhanced Raman scattering offers high sensitivity and multiplicity, it cannot be readily used to image specific molecular targets quantitatively inside live cells. Here we use stimulated Raman scattering under electronic pre-resonance conditions to image target molecules inside living cells with very high vibrational selectivity and sensitivity (down to 250 nanomolar with a time constant of 1 millisecond). We create a palette of triple-bond-conjugated near-infrared dyes that each displays a single peak in the cell-silent Raman spectral window; when combined with available fluorescent probes, this palette provides 24 resolvable colours, with the potential for further expansion. Proof-of-principle experiments on neuronal co-cultures and brain tissues reveal cell-type-dependent heterogeneities in DNA and protein metabolism under physiological and pathological conditions, underscoring the

  3. Review of Energy Harvesters Utilizing Bridge Vibrations

    Directory of Open Access Journals (Sweden)

    Farid Ullah Khan

    2016-01-01

    Full Text Available For health monitoring of bridges, wireless acceleration sensor nodes (WASNs are normally used. In bridge environment, several forms of energy are available for operating WASNs that include wind, solar, acoustic, and vibration energy. However, only bridge vibration has the tendency to be utilized for embedded WASNs application in bridge structures. This paper reports on the recent advancements in the area of vibration energy harvesters (VEHs utilizing bridge oscillations. The bridge vibration is narrowband (1 to 40 Hz with low acceleration levels (0.01 to 3.8 g. For utilization of bridge vibration, electromagnetic based vibration energy harvesters (EM-VEHs and piezoelectric based vibration energy harvesters (PE-VEHs have been developed. The power generation of the reported EM-VEHs is in the range from 0.7 to 1450000 μW. However, the power production by the developed PE-VEHs ranges from 0.6 to 7700 μW. The overall size of most of the bridge VEHs is quite comparable and is in mesoscale. The resonant frequencies of EM-VEHs are on the lower side (0.13 to 27 Hz in comparison to PE-VEHs (1 to 120 Hz. The power densities reported for these bridge VEHs range from 0.01 to 9539.5 μW/cm3 and are quite enough to operate most of the commercial WASNs.

  4. Systematic analyses of vibration noise of a vibration isolation system for high-resolution scanning tunneling microscopes.

    Science.gov (United States)

    Iwaya, Katsuya; Shimizu, Ryota; Hashizume, Tomihiro; Hitosugi, Taro

    2011-08-01

    We designed and constructed an effective vibration isolation system for stable scanning tunneling microscopy measurements using a separate foundation and two vibration isolation stages (i.e., a combination of passive and active vibration isolation dampers). Systematic analyses of vibration data along the horizontal and vertical directions are present, including the vibration transfer functions of each stage and the overall vibration isolation system. To demonstrate the performance of the system, tunneling current noise measurements are conducted with and without the vibration isolation. Combining passive and active vibration isolation dampers successfully removes most of the vibration noise in the tunneling current up to 100 Hz. These comprehensive vibration noise data, along with details of the entire system, can be used to establish a clear guideline for building an effective vibration isolation system for various scanning probe microscopes and electron microscopes.

  5. Vibration Measurement with PULSE and DSPACE Equipment

    Directory of Open Access Journals (Sweden)

    Radim KLEČKA

    2009-06-01

    Full Text Available This contribution describes techniques and results of measurement with TIRA vibration generator. A method of experimental modal analysis allows next restore of vibration data. The goal is check validity of head expanders and screw connection. This process is based to using ME’scope environment. Another goal is check possibilities of dSPACE platform to vibration measurement. This task includes design of connection between dSPACE system and power amplifier, creating of graphical user interface and analyzing main configuration parameters to improve quality of drive signal.

  6. Vibrational and Thermal Properties of Oxyanionic Crystals

    Science.gov (United States)

    Korabel'nikov, D. V.

    2018-03-01

    The vibrational and thermal properties of dolomite and alkali chlorates and perchlorates were studied in the gradient approximation of density functional theory using the method of a linear combination of atomic orbitals (LCAO). Long-wave vibration frequencies, IR and Raman spectra, and mode Gruneisen parameters were calculated. Equation-of-state parameters, thermodynamic potentials, entropy, heat capacity, and thermal expansion coefficient were also determined. The thermal expansion coefficient of dolomite was established to be much lower than for chlorates and perchlorates. The temperature dependence of the heat capacity at T > 200 K was shown to be generally governed by intramolecular vibrations.

  7. Applications of Fault Detection in Vibrating Structures

    Science.gov (United States)

    Eure, Kenneth W.; Hogge, Edward; Quach, Cuong C.; Vazquez, Sixto L.; Russell, Andrew; Hill, Boyd L.

    2012-01-01

    Structural fault detection and identification remains an area of active research. Solutions to fault detection and identification may be based on subtle changes in the time series history of vibration signals originating from various sensor locations throughout the structure. The purpose of this paper is to document the application of vibration based fault detection methods applied to several structures. Overall, this paper demonstrates the utility of vibration based methods for fault detection in a controlled laboratory setting and limitations of applying the same methods to a similar structure during flight on an experimental subscale aircraft.

  8. Vibration-Induced Climbing of Drops

    Science.gov (United States)

    Brunet, P.; Eggers, J.; Deegan, R. D.

    2007-10-01

    We report an experimental study of liquid drops moving against gravity, when placed on a vertically vibrating inclined plate, which is partially wetted by the drop. The frequency of vibrations ranges from 30 to 200 Hz, and, above a threshold in vibration acceleration, drops experience an upward motion. We attribute this surprising motion to the deformations of the drop, as a consequence of an up or down symmetry breaking induced by the presence of the substrate. We relate the direction of motion to contact angle measurements. This phenomenon can be used to move a drop along an arbitrary path in a plane, without special surface treatments or localized forcing.

  9. Elaboration of an implementation approach of a condition-based maintenance through vibration analysis

    Directory of Open Access Journals (Sweden)

    Semma El Mehdi

    2015-01-01

    Full Text Available Vibration analysis is a powerful and widely used tool in industry for monitoring rotating machinery. Despite the possibilities offered by the measuring equipment of vibration through technological progress, companies which practice Vibration Based Analysis (VBM show performance below expectations in terms of machine availability. Our duty then is to develop an approach for the implementation of the VBM taking into consideration the keys to success and avoiding the causes of failure. We carried out an analysis of 30 years of practice of the VBM within a large Moroccan company in the chemical industry, through a collective approach called DCA (in French applied short diagnosis and a survey among national and international experts in the field of the VBM. The synthesis of these studies has led us to propose a comprehensive and structured approach that comes in 5 phases: inventory, feasibility studies, preparation phase, implementation phase, evaluation and improvement phase.

  10. Vibrational Cooling in A Cold Ion Trap: Vibrationally Resolved Photoelectron Spectroscopy of Cold C60- Anions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xue B.; Woo, Hin-koon; Wang, Lai S.

    2005-08-01

    We demonstrate vibrational cooling of anions via collisions with a background gas in an ion trap attached to a cryogenically controlled cold head (10 ? 400 K). Photoelectron spectra of vibrationally cold C60- anions, produced by electrospray ionization and cooled in the cold ion trap, have been obtained. Relative to spectra taken at room temperature, vibrational hot bands are completely eliminated, yielding well resolved vibrational structures and a more accurate electron affinity for neutral C60. The electron affinity of C60 is measured to be 2.683 ? 0.008 eV. The cold spectra reveal complicated vibrational structures for the transition to the C60 ground state due to the Jahn-Teller effect in the ground state of C60-. Vibrational excitations in the two Ag modes and eight Hg modes are observed, providing ideal data to assess the vibronic couplings in C60-.

  11. Model Predictive Vibration Control Efficient Constrained MPC Vibration Control for Lightly Damped Mechanical Structures

    CERN Document Server

    Takács, Gergely

    2012-01-01

    Real-time model predictive controller (MPC) implementation in active vibration control (AVC) is often rendered difficult by fast sampling speeds and extensive actuator-deformation asymmetry. If the control of lightly damped mechanical structures is assumed, the region of attraction containing the set of allowable initial conditions requires a large prediction horizon, making the already computationally demanding on-line process even more complex. Model Predictive Vibration Control provides insight into the predictive control of lightly damped vibrating structures by exploring computationally efficient algorithms which are capable of low frequency vibration control with guaranteed stability and constraint feasibility. In addition to a theoretical primer on active vibration damping and model predictive control, Model Predictive Vibration Control provides a guide through the necessary steps in understanding the founding ideas of predictive control applied in AVC such as: ·         the implementation of ...

  12. Rolling the dice on the ice; New modes for underway data acquisition in the Arctic Ocean

    Science.gov (United States)

    Coakley, B.; Dove, D.

    2012-12-01

    Exploration of the Arctic Ocean has always depended on the sea ice. It has been a platform supporting drifting ice stations and an obstacle to be over come by force (icebreakers) or finesse (US Navy fast attack submarines). Reduced seasonal sea ice cover has made it possible to work more freely in the peripheral Arctic Ocean, opening relatively unknown regions to scientific exploration and study. In September 2011, the RV Marcus G. Langseth set sail from Dutch Harbor, Alaska bound through Bering Strait for the Arctic Ocean. This was the first Arctic Ocean trip for MGG data acquisition by a US academic research vessel since 1994, when the RV Maurice Ewing collected a 2-D MCS profile across the Bering Shelf, through the Strait and along the Beaufort Shelf, stopping near Barrow, Alaska. RV Langseth arrived on the mid-Chukchi shelf and streamed gear just south of the "Crackerjack" well, drilled by Shell Exploration in the late eighties. The ship sailed north, crossing the "Popcorn" well and then set a course to the NW, setting the baseline for the survey parallel to the Beaufort Shelf edge. Sailing through almost entirely ice-free waters, approximately 5300 km of multi-channel seismic reflection data were acquired on a NW-SE oriented grid, which straddled the transition from Chukchi Shelf to the Chukchi Borderland. It would not have been possible for Langseth, which is not ice reinforced, to acquire these data prior to 2007. The dramatic expansion of late Summer open water in the western Arctic Ocean made it possible to use this ship effectively across a broad swath of the shelf and the periphery of the deep central basin. While the survey region was almost entirely ice free during this cruise, which straddled the ice minimum for 2011, it was not possible to predict this a priori, despite expectations set by the previous five years of ice edge retreat. For this reason, the Canadian Ice Service was engaged to provide interpreted ice imagery, multiple times per day

  13. Biomonitoring of physiological status and cognitive performance of underway submariners undergoing a novel watch-standing schedule

    Science.gov (United States)

    Duplessis, C. A.; Cullum, M. E.; Crepeau, L. J.

    2005-05-01

    Submarine watch-standers adhere to a 6 hour-on, 12 hour-off (6/12) watch-standing schedule, yoking them to an 18-hr day, engendering circadian desynchronization and chronic sleep deprivation. Moreover, the chronic social crowding, shift work, and confinement of submarine life provide additional stressors known to correlate with elevated secretory immunoglobulin A (sIgA) and cortisol levels, reduced performance, immunologic dysfunction, malignancies, infections, gastrointestinal illness, coronary disease, anxiety, and depression. We evaluated an alternative, compressed, fixed work schedule designed to enhance circadian rhythm entrainment, sleep hygiene, performance, and health on 10 underway submariners, who followed the alternative and 6/12 schedules for approximately 2 weeks each. We measured subjects" sleep, cognitive performance, and salivary biomarker levels. Pilot analysis of the salivary data on one subject utilizing ELISA suggests elevated biomarker levels of stress. Average PM cortisol levels were 0.2 μg/L (normal range: nondetectable - 0.15 μg/L), and mean sIgA levels were 562 μg/ml (normal range: 100-500 μg/ml). Future research exploiting real-time salivary bioassays, via fluorescent polarimetry technology, identified by the Office of Naval Research (ONR) as a future Naval requirement, allows researchers to address correlations between stress-induced elaboration of salivary biomarkers with physiological and performance decrements, thereby fostering insight into the underway submariner"s psychoimmunological status. This may help identify strategies that enhance resilience to stressors. Specifically, empirically-based modeling can identify optimal watch-standing schedules and stress-mitigating procedures -- within the operational constraints of the submarine milieu and the mission --that foster improved circadian entrainment and reduced stress reactivity, enhancing physiological health, operational performance, safety, and job satisfaction.

  14. 14 CFR 23.251 - Vibration and buffeting.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Vibration and buffeting. 23.251 Section 23... Requirements § 23.251 Vibration and buffeting. There must be no vibration or buffeting severe enough to result in structural damage, and each part of the airplane must be free from excessive vibration, under any...

  15. Whole-body vibration dosage alters leg blood flow

    NARCIS (Netherlands)

    Lythgo, Noel; Eser, Prisca; de Groot, Patricia; Galea, Mary

    The effect of whole-body vibration dosage on leg blood flow was investigated. Nine healthy young adult males completed a set of 14 random vibration and non-vibration exercise bouts whilst squatting on a Galileo 900 plate. Six vibration frequencies ranging from 5 to 30 Hz (5 Hz increments) were used

  16. 14 CFR 25.251 - Vibration and buffeting.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Vibration and buffeting. 25.251 Section 25... Vibration and buffeting. (a) The airplane must be demonstrated in flight to be free from any vibration and... airplane must be demonstrated in flight to be free from excessive vibration under any appropriate speed and...

  17. Putting a damper on drilling's bad vibrations

    Energy Technology Data Exchange (ETDEWEB)

    Jardine, S. (Sedco forex, Montrouge (France)); Malone, D. (Anadrill, Sugar Land, TX (United States)); Sheppard, M. (Schlumberger Cambridge Research, Cambridge (United Kingdom))

    1994-01-01

    Harmful drilling vibrations are costing the industry dearly. Three main vibration types (axial, torsional and transverse) are explained and its causes discussed. Technology exists to eliminate most vibrations, but requires more systematic deployment than is usual. Hardware that eliminates vibrations is reviewed, including downhole shock measurement, torque feedback shock guards and antiwhirl bits. 9 figs., 11 refs.

  18. The immediate effect of vibration therapy on flexibility in female ...

    African Journals Online (AJOL)

    The immediate effect of vibration therapy on flexibility in female junior elite gymnasts. ... Therefore, the aim of this study was to investigate the acute effects of vibration therapy on the flexibility of female gymnasts. A pre-test ... Keywords: Static stretching, vibration training, vibration therapy, acute effect, artistic gymnastics.

  19. Calculation of vibrational excitation cross-sections in resonant ...

    Indian Academy of Sciences (India)

    WINTEC

    tron is re-emitted after the anion has completed at least one vibration, the nuclear wave function for A– exhibits a reflection from the right turning point, and there is vibrational structure in the resonant scattering cross-sections even for the lowest vibrational excita- tion of the target.1–5 The pronounced vibrational struc-.

  20. Human responses to wave slamming vibration on a polar supply and research vessel.

    Science.gov (United States)

    Omer, H; Bekker, A

    2018-02-01

    A polar supply and research vessel is pre-disposed to wave slamming which has caused complaints among crew and researchers regarding interference with sleep, equipment use and research activities. The present work undertook to survey passenger claims of sleep interference, disturbed motor tasks and equipment damage as a result of wave slamming during normal operations of this vessel. The hypothesis was investigated that whole-body vibration metrics from ISO 2631-1 are potentially suitable for the prediction of human slamming complaints. Full-scale acceleration measurements were performed and wave slamming events were subsequently identified from the human weighted acceleration time histories. A daily diary survey was also conducted to gather the human response. The vibration caused by wave slamming was found to be strongly correlated with sleep disturbances and activity interference. Sleep and equipment use were found to be the most affected parameters by slamming. Daily vibration dose values were determined by accumulating the vibration as a result of slamming over 24 h periods. This metric accounted for increased magnitudes and frequency of slamming incidents and proved to be the best metric to represent human responses to slamming vibration. The greatest percentage of activities affected by slamming related to sleep regardless of daily cumulative VDV magnitude. More than 50% of the recorded responses related to sleep when the daily cumulative VDV ranged between 8.0 m/s 1.75 -10.0 m/s 1.75 . The peak vertical vibration levels recorded on the vessel reach magnitudes which are associated with sleep disturbance in environments where acoustic noise is present. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Whole-body vibration and ergonomic study of US railroad locomotives

    Science.gov (United States)

    Johanning, Eckardt; Landsbergis, Paul; Fischer, Siegfried; Christ, Eberhard; Göres, Benno; Luhrman, Raymond

    2006-12-01

    US locomotive operators have exposure to multi-axis whole-body vibration (WBV) and shocks while seated. This study assessed operator-related and ergonomic seating design factors that may have confounding or mitigating influence on WBV exposure and its effects. Vibration exposure was measured according to international guidelines (ISO 2631-1; 1997); ergonomic work place factors and vibration effects were studied with a cross-sectional survey instrument distributed to a randomly selected group of railroad engineers ( n=2546) and a control group; and during vehicle inspections. The survey response rate was 47% for the RR engineers ( n=1195) and 41% for the controls ( n=323). Results of the mean basic vibration measurements were for the x, y, z-direction and vector sum 0.14, 0.22, 0.28 and 0.49 m/s 2 respectively; almost all crest factors (CF), MTVV and VDV values were above the critical ratios given in ISO 2631-1. The prevalence of serious neck and lower back disorders among locomotive engineers was found to be nearly double that of the sedentary control group without such exposure. Railroad engineers rated their seats mostly unacceptable regarding different adjustment and comfort aspects (3.02-3.51; scale 1=excellent to 4=unacceptable), while the control group rated their chairs more favorably (1.96-3.44). Existing cab and seat design in locomotives can result in prolonged forced awkward spinal posture of the operator combined with WBV exposure. In a logistic regression analysis, time at work being bothered by vibration (h/day) was significantly associated with an increased risk of low back pain, shoulder and neck pain, and sciatic pain among railroad engineers. Customized vibration attenuation seats and improved cab design of the locomotive controls should be further investigated.

  2. The modelling of industrial robot manipulator vibration

    Energy Technology Data Exchange (ETDEWEB)

    Marcham, L.J.; Rao, B.K.N.; Noroozi, S.; Penson, R.P. [Southampton Inst. (United Kingdom). Systems Engineering Research Centre

    1996-11-01

    The work reported in this paper addresses the modelling of robot manipulator vibration, with the specific aim of producing a model suitable to be employed within an active compensation controller. An overview of existing work on the modelling of robot dynamics, both mathematically and empirically, is reported. A model of the dynamics of an industrial manipulator, inclusive of vibration, derived using Lagrangian mechanics is presented and further developed through the application of experimental modal analysis, by which the position dependent modal parameters of an industrial robot manipulator are determined. The model results are compared with experimental vibration data taken from the end-effector of a PUMA562C industrial manipulator using laser interferometry. Control of an end-effector located, active compensator for vibration suppression, based upon the derived model is discussed and recommendations which form the basis of further investigations, currently being undertaken, are presented.

  3. Vibrational and electronic spectroscopic studies of melatonin

    Science.gov (United States)

    Singh, Gurpreet; Abbas, J. M.; Dogra, Sukh Dev; Sachdeva, Ritika; Rai, Bimal; Tripathi, S. K.; Prakash, Satya; Sathe, Vasant; Saini, G. S. S.

    2014-01-01

    We report the infrared absorption and Raman spectra of melatonin recorded with 488 and 632.8 nm excitations in 3600-2700 and 1700-70 cm-1 regions. Further, we optimized molecular structure of the three conformers of melatonin within density functional theory calculations. Vibrational frequencies of all three conformers have also been calculated. Observed vibrational bands have been assigned to different vibrational motions of the molecules on the basis of potential energy distribution calculations and calculated vibrational frequencies. Observed band positions match well with the calculated values after scaling except Nsbnd H stretching mode frequencies. It is found that the observed and calculated frequencies mismatch of Nsbnd H stretching is due to intermolecular interactions between melatonin molecules.

  4. International Conference on Acoustics and Vibration

    CERN Document Server

    Chaari, Fakher; Walha, Lasaad; Abdennadher, Moez; Abbes, Mohamed; Haddar, Mohamed

    2017-01-01

    The book provides readers with a snapshot of recent research and industrial trends in field of industrial acoustics and vibration. Each chapter, accepted after a rigorous peer-review process, reports on a selected, original piece of work presented and discussed at International Conference on Acoustics and Vibration (ICAV2016), which was organized by the Tunisian Association of Industrial Acoustics and Vibration (ATAVI) and held March 21-23, in Hammamet, Tunisia. The contributions, mainly written by north African authors, covers advances in both theory and practice in a variety of subfields, such as: smart materials and structures; fluid-structure interaction; structural acoustics as well as computational vibro-acoustics and numerical methods. Further topics include: engines control, noise identification, robust design, flow-induced vibration and many others.This book provides a valuable resource for both academics and professionals dealing with diverse issues in applied mechanics. By combining advanced theori...

  5. A Miniature Coupled Bistable Vibration Energy Harvester

    International Nuclear Information System (INIS)

    Zhu, D; Arthur, D C; Beeby, S P

    2014-01-01

    This paper reports the design and test of a miniature coupled bistable vibration energy harvester. Operation of a bistable structure largely depends on vibration amplitude rather than frequency, which makes it very promising for wideband vibration energy harvesting applications. A coupled bistable structure consists of a pair of mobile magnets that create two potential wells and thus the bistable phenomenon. It requires lower excitation to trigger bistable operation compared to conventional bistable structures. Based on previous research, this work focused on miniaturisation of the coupled bistable structure for energy harvesting application. The proposed bistable energy harvester is a combination of a Duffing's nonlinear structure and a linear assisting resonator. Experimental results show that the output spectrum of the miniature coupled bistable vibration energy harvester was the superposition of several spectra. It had a higher maximum output power and a much greater bandwidth compared to simply the Duffing's structure without the assisting resonator

  6. Rheumatic effects of vibration at work

    Science.gov (United States)

    Palmer, Keith T; Bovenzi, Massimo

    2016-01-01

    Occupational exposures to vibration come in many guises and are very common at a population level. It follows that an important minority of working-aged patients seen by medical services will have been exposed to this hazard of employment. Vibration can cause human health effects which may manifest in the patients that rheumatologists see. In this chapter we identify the health effects of relevance to them, and review their epidemiology, pathophysiology, clinical presentation, differential diagnosis, and vocational and clinical management. On either side of this, we describe the nature and assessment of the hazard, the scale and common patterns of exposure to vibration in the community, and the legal basis for controlling health risks, and comment on the role of health surveillance in detecting early adverse effects and what can be done to prevent the rheumatic effects of vibration at work. PMID:26612239

  7. Chronic subdural hematomas caused by vibrating Chinese ...

    African Journals Online (AJOL)

    Abstract. We present two middle aged Nigerian patients who developed significant chronic subdural hematomas weeks after going on vibrating Chinese massage chairs. This complication of using the chairs has not been previously reported.

  8. Anharmonic Theoretical Vibrational Spectroscopy of Polypeptides.

    Science.gov (United States)

    Panek, Paweł T; Jacob, Christoph R

    2016-08-18

    Because of the size of polypeptides and proteins, the quantum-chemical prediction of their vibrational spectra presents an exceptionally challenging task. Here, we address one of these challenges, namely, the inclusion of anharmonicities. By performing the expansion of the potential energy surface in localized-mode coordinates instead of the normal-mode coordinates, it becomes possible to calculate anharmonic vibrational spectra of polypeptides efficiently and reliably. We apply this approach to calculate the infrared, Raman, and Raman optical activity spectra of helical alanine polypeptides consisting of up to 20 amino acids. We find that while anharmonicities do not alter the band shapes, simple scaling procedures cannot account for the different shifts found for the individual bands. This closes an important gap in theoretical vibrational spectroscopy by making it possible to quantify the anharmonic contributions and opens the door to a first-principles calculation of multidimensional vibrational spectra.

  9. Theory of Arched Structures Strength, Stability, Vibration

    CERN Document Server

    Karnovsky, Igor A

    2012-01-01

    Theory of Arched Structures: Strength, Stability, Vibration presents detailed procedures for analytical analysis of the strength, stability, and vibration of arched structures of different types, using exact analytical methods of classical structural analysis. The material discussed is divided into four parts. Part I covers stress and strain with a particular emphasis on analysis; Part II discusses stability and gives an in-depth analysis of elastic stability of arches and the role that matrix methods play in the stability of the arches; Part III presents a comprehensive tutorial on dynamics and free vibration of arches, and forced vibration of arches; and Part IV offers a section on special topics which contains a unique discussion of plastic analysis of arches and the optimal design of arches.

  10. Monitoring Engine Vibrations And Spectrum Of Exhaust

    Science.gov (United States)

    Martinez, Carol L.; Randall, Michael R.; Reinert, John W.

    1991-01-01

    Real-time computation of intensities of peaks in visible-light emission spectrum of exhaust combined with real-time spectrum analysis of vibrations into developmental monitoring technique providing up-to-the-second information on conditions of critical bearings in engine. Conceived to monitor conditions of bearings in turbopump suppling oxygen to Space Shuttle main engine, based on observations that both vibrations in bearings and intensities of visible light emitted at specific wavelengths by exhaust plume of engine indicate wear and incipient failure of bearings. Applicable to monitoring "health" of other machinery via spectra of vibrations and electromagnetic emissions from exhausts. Concept related to one described in "Monitoring Bearing Vibrations For Signs Of Damage", (MFS-29734).

  11. Vibrations and stability of complex beam systems

    CERN Document Server

    Stojanović, Vladimir

    2015-01-01

     This book reports on solved problems concerning vibrations and stability of complex beam systems. The complexity of a system is considered from two points of view: the complexity originating from the nature of the structure, in the case of two or more elastically connected beams; and the complexity derived from the dynamic behavior of the system, in the case of a damaged single beam, resulting from the harm done to its simple structure. Furthermore, the book describes the analytical derivation of equations of two or more elastically connected beams, using four different theories (Euler, Rayleigh, Timoshenko and Reddy-Bickford). It also reports on a new, improved p-version of the finite element method for geometrically nonlinear vibrations. The new method provides more accurate approximations of solutions, while also allowing us to analyze geometrically nonlinear vibrations. The book describes the appearance of longitudinal vibrations of damaged clamped-clamped beams as a result of discontinuity (damage). It...

  12. Signatures of vibronic coupling in two-dimensional electronic-vibrational and vibrational-electronic spectroscopies

    Science.gov (United States)

    Gaynor, James D.; Khalil, Munira

    2017-09-01

    Two-Dimensional Electronic-Vibrational (2D EV) spectroscopy and Two-Dimensional Vibrational-Electronic (2D VE) spectroscopy are new coherent four-wave mixing spectroscopies that utilize both electronically resonant and vibrationally resonant field-matter interactions to elucidate couplings between electronic and vibrational degrees of freedom. A system Hamiltonian is developed here to lay a foundation for interpreting the 2D EV and 2D VE signals that arise from a vibronically coupled molecular system in the condensed phase. A molecular system consisting of one anharmonic vibration and two electronic states is modeled. Equilibrium displacement of the vibrational coordinate and vibrational frequency shifts upon excitation to the first electronic excited state are included in our Hamiltonian through linear and quadratic vibronic coupling terms. We explicitly consider the nuclear dependence of the electronic transition dipole moment and demonstrate that these spectroscopies are sensitive to non-Condon effects. A series of simulations of 2D EV and 2D VE spectra obtained by varying parameters of the system, system-bath, and interaction Hamiltonians demonstrate that one of the following conditions must be met to observe signals: (1) non-zero linear and/or quadratic vibronic coupling in the electronic excited state, (2) vibrational-coordinate dependence of the electronic transition dipole moment, or (3) electronic-state-dependent vibrational dephasing dynamics. We explore how these vibronic interactions are manifested in the positions, amplitudes, and line shapes of the peaks in 2D EV and 2D VE spectroscopies.

  13. Vibration analysis and vibration damage assessment in nuclear and process equipment

    International Nuclear Information System (INIS)

    Pettigrew, M.J.; Taylor, C.E.; Fisher, N.J.; Yetisir, M.; Smith, B.A.W.

    1997-01-01

    Component failures due to excessive flow-induced vibration are still affecting the performance and reliability of process and nuclear components. The purpose of this paper is to discuss flow-induced vibration analysis and vibration damage prediction. Vibration excitation mechanisms are described with particular emphasis on fluid elastic instability. The dynamic characteristics of process and power equipment are explained. The statistical nature of some parameters, in particular support conditions, is discussed. The prediction of fretting-wear damage is approached from several points-of-view. An energy approach to formulate fretting-wear damage is proposed. (author)

  14. Vibrational excitation and vibrationally resolved electronic excitation cross sections of positron-H2 scattering

    Science.gov (United States)

    Zammit, Mark; Fursa, Dmitry; Savage, Jeremy; Bray, Igor

    2016-09-01

    Vibrational excitation and vibrationally resolved electronic excitation cross sections of positron-H2 scattering have been calculated using the single-centre molecular convergent close-coupling (CCC) method. The adiabatic-nuclei approximation was utilized to model the above scattering processes and obtain the vibrationally resolved positron-H2 scattering length. As previously demonstrated, the CCC results are converged and accurately account for virtual and physical positronium formation by coupling basis functions with large orbital angular momentum. Here vibrationally resolved integrated and differential cross sections are presented over a wide energy range and compared with previous calculations and available experiments. Los Alamos National Laboratory and Curtin University.

  15. Data of piezoelectric vibration energy harvesting of a bridge undergoing vibration testing and train passage.

    Science.gov (United States)

    Cahill, Paul; Hazra, Budhaditya; Karoumi, Raid; Mathewson, Alan; Pakrashi, Vikram

    2018-04-01

    The data presented in this article is in relation to the research article "Vibration energy harvesting based monitoring of an operational bridge undergoing forced vibration and train passage" Cahill et al. (2018) [1]. The article provides data on the full-scale bridge testing using piezoelectric vibration energy harvesters on Pershagen Bridge, Sweden. The bridge is actively excited via a swept sinusoidal input. During the testing, the bridge remains operational and train passages continue. The test recordings include the voltage responses obtained from the vibration energy harvesters during these tests and train passages. The original dataset is made available to encourage the use of energy harvesting for Structural Health Monitoring.

  16. Actual behaviour of a ball vibration absorber

    Czech Academy of Sciences Publication Activity Database

    Pirner, Miroš

    2002-01-01

    Roč. 90, č. 8 (2002), s. 987-1005 ISSN 0167-6105 R&D Projects: GA ČR(CZ) GV103/96/K034 Institutional support: RVO:68378297 Keywords : TV towers * wind-excited vibrations * vibration absorbers * pendulum absorber Subject RIV: JM - Building Engineering Impact factor: 0.513, year: 2002 http://www.sciencedirect.com/science/article/pii/S0167610502002155#

  17. Optical vibration measurement of mechatronics devices

    Science.gov (United States)

    Yanabe, Shigeo

    1993-09-01

    An optical vibration measuring system which enables to detect both linear and angular displacement of 25 nm and 5 prad was developed. The system is mainly composed of a He-Ne laser, a displacement detecting photo-diode and lenses, and has linear and angular displacement magnification mechanism using two different principles of optical lever. The system was applied to measure vibrational characteristics of magnetic head slider of hard disk drives and to measure stator teeth driving velocities of ultrasonic motor.

  18. Space shuttle main engine vibration data base

    Science.gov (United States)

    Lewallen, Pat

    1986-01-01

    The Space Shuttle Main Engine Vibration Data Base is described. Included is a detailed description of the data base components, the data acquisition process, the more sophisticated software routines, and the future data acquisition methods. Several figures and plots are provided to illustrate the various output formats accessible to the user. The numerous vibration data recall and analysis capabilities available through automated data base techniques are revealed.

  19. Studies of interstellar vibrationally-excited molecules

    International Nuclear Information System (INIS)

    Ziurys, L.M.; Snell, R.L.; Erickson, N.R.

    1986-01-01

    Several molecules thus far have been detected in the ISM in vibrationally-excited states, including H 2 , SiO, HC 3 N, and CH 3 CN. In order for vibrational-excitation to occur, these species must be present in unusually hot and dense gas and/or where strong infrared radiation is present. In order to do a more thorough investigation of vibrational excitation in the interstellar medium (ISM), studies were done of several mm-wave transitions originating in excited vibrational modes of HCN, an abundant interstellar molecule. Vibrationally-excited HCN was recently detected toward Orion-KL and IRC+10216, using a 12 meter antenna. The J=3-2 rotational transitions were detected in the molecule's lowest vibrational state, the bending mode, which is split into two separate levels, due to l-type doubling. This bending mode lies 1025K above ground state, with an Einstein A coefficient of 3.6/s. The J=3-2 line mode of HCN, which lies 2050K above ground state, was also observed toward IRC+10216, and subsequently in Orion-KL. Further measurements of vibrationally-excited HCN were done using a 14 meter telescope, which include the observations of the (0,1,0) and (0,2,0) modes towards Orion-KL, via their J=3-2 transitions at 265-267 GHz. The spectrum of the J=3-2 line in Orion taken with the 14 meter telescope, is shown, along with a map, which indicates that emission from vibrationally-excited HCN arises from a region probably smaller than the 14 meter telescope's 20 arcsec beam

  20. Active and passive vibration control of structures

    CERN Document Server

    Spelsberg-Korspeter, Gottfried

    2014-01-01

    Active and Passive Vibration Control of Structures form an issue of very actual interest in many different fields of engineering, for example in the automotive and aerospace industry, in precision engineering (e.g. in large telescopes), and also in civil engineering. The papers in this volume bring together engineers of different background, and it fill gaps between structural mechanics, vibrations and modern control theory.  Also links between the different applications in structural control are shown.

  1. RESEARCH OF BRIDGE STRUCTURE VIBRATION CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    V.P. Babak

    2005-02-01

    Full Text Available  Bridge structure test results with using different types of dynamic force have been considered. It has been shown, that the developed technique of registering and processing vibration signals allows obtaining thin spectrum structure. The analysis of its change that is defined by the type of structure loading applied has been carried out. Key parameters of the vibration signals registered have been defined.

  2. Mechanical vibration where do we stand?

    CERN Document Server

    Schneider, Wilhelm; Elishakoff, Isaac

    2007-01-01

    Written by the world’s leading researchers on various topics of linear, nonlinear, and stochastic mechanical vibrations, this work gives an authoritative overview of the classic yet still very modern subject of mechanical vibrations. It poses the question: What are the most important contributions made in the past decade The reader will be able to gain a critical and authoritative overview of the subject from various complementary perspectives.

  3. Prediction of induced vibrations in stall

    Energy Technology Data Exchange (ETDEWEB)

    Thirstrup Petersen, J.; Thomsen, K.; Aagaard Madsen, H. [Risoe National Lab., Wind Energy and Atmospheric Physics Dept., Roskilde (Denmark)

    1999-03-01

    The main results from recent research in stall induced vibrations are presented. The focus is on the edgewise blade vibrations, which during the last decade have turned out to be a potential threat against the stable operation of stall regulated wind turbines and a fact, which must be dealt with by the designer. The basic physical explanation for the phenomenon and examples of design precaution, which can be taken, are presented. (au)

  4. Modelling chaotic vibrations using NASTRAN

    Science.gov (United States)

    Sheerer, T. J.

    1993-01-01

    Due to the unavailability and, later, prohibitive cost of the computational power required, many phenomena in nonlinear dynamic systems have in the past been addressed in terms of linear systems. Linear systems respond to periodic inputs with periodic outputs, and may be characterized in the time domain or in the frequency domain as convenient. Reduction to the frequency domain is frequently desireable to reduce the amount of computation required for solution. Nonlinear systems are only soluble in the time domain, and may exhibit a time history which is extremely sensitive to initial conditions. Such systems are termed chaotic. Dynamic buckling, aeroelasticity, fatigue analysis, control systems and electromechanical actuators are among the areas where chaotic vibrations have been observed. Direct transient analysis over a long time period presents a ready means of simulating the behavior of self-excited or externally excited nonlinear systems for a range of experimental parameters, either to characterize chaotic behavior for development of load spectra, or to define its envelope and preclude its occurrence.

  5. Dancing drops over vibrating substrates

    Science.gov (United States)

    Borcia, Rodica; Borcia, Ion Dan; Helbig, Markus; Meier, Martin; Egbers, Christoph; Bestehorn, Michael

    2017-04-01

    We study the motion of a liquid drop on a solid plate simultaneously submitted to horizontal and vertical harmonic vibrations. The investigation is done via a phase field model earlier developed for describing static and dynamic contact angles. The density field is nearly constant in every bulk region (ρ = 1 in the liquid phase, ρ ≈ 0 in the vapor phase) and varies continuously from one phase to the other with a rapid but smooth variation across the interfaces. Complicated explicit boundary conditions along the interface are avoided and captured implicitly by gradient terms of ρ in the hydrodynamic basic equations. The contact angle θ is controlled through the density at the solid substrate ρ S , a free parameter varying between 0 and 1 [R. Borcia, I.D. Borcia, M. Bestehorn, Phys. Rev. E 78, 066307 (2008)]. We emphasize the swaying and the spreading modes, earlier theoretically identified by Benilov and Billingham via a shallow-water model for drops climbing uphill along an inclined plane oscillating vertically [E.S. Benilov, J. Billingham, J. Fluid Mech. 674, 93 (2011)]. The numerical phase field simulations will be completed by experiments. Some ways to prevent the release of the dancing drops along a hydrophobic surface into the gas atmosphere are also discussed in this paper.

  6. Heat and mass transfer enforcement of vibrating fluidized bed

    Science.gov (United States)

    Chu, Zhide; Yang, Junhong; Li, Xuhui; Song, Yang

    1994-12-01

    This paper briefly introduces the development of vibrating fluidized bed at home and abroad, elaborates the vibration properties of vibrating fluidized bed, the fluidizing velocity and pressure drop of the bed layer. It also deduces the non-steady state drying dynamic equations of vibrating fluidized bed, analyzes main factors which influence the drying rate and inquires into drying rules of fixed bed and vibrating fluidized bed.

  7. Using piezo-electric material to simulate a vibration environment

    Science.gov (United States)

    Jepsen, Richard A.; Davie, Neil T.; Vangoethem, Douglas J.; Romero, Edward F.

    2010-12-14

    A target object can be vibrated using actuation that exploits the piezo-electric ("PE") property. Under combined conditions of vibration and centrifugal acceleration, a centrifugal load of the target object on PE vibration actuators can be reduced by using a counterweight that offsets the centrifugal loading. Target objects are also subjected to combinations of: spin, vibration, and acceleration; spin and vibration; and spin and acceleration.

  8. Method and apparatus for vibrating a substrate during material formation

    Science.gov (United States)

    Bailey, Jeffrey A [Richland, WA; Roger, Johnson N [Richland, WA; John, Munley T [Benton City, WA; Walter, Park R [Benton City, WA

    2008-10-21

    A method and apparatus for affecting the properties of a material include vibrating the material during its formation (i.e., "surface sifting"). The method includes the steps of providing a material formation device and applying a plurality of vibrations to the material during formation, which vibrations are oscillations having dissimilar, non-harmonic frequencies and at least two different directions. The apparatus includes a plurality of vibration sources that impart vibrations to the material.

  9. Zero-Annihilation Periodic Control For Damping Vibrations

    Science.gov (United States)

    Bayard, David S.; Boussalis, Dhemetrios

    1995-01-01

    Report presents study on use of recently developed zero-annihilation periodic (ZAP) controller for active suppression of vibrations in flexible structures characterized by non-minimum-phase transfer functions. Non-minimum-phase situation occurs if certain kinds of vibration-sensor/vibration-actuator pairs (e.g., piezoelectric) used, and/or if vibration sensor(s) not colocated with vibration actuator(s).

  10. Frequency adjustable MEMS vibration energy harvester

    Science.gov (United States)

    Podder, P.; Constantinou, P.; Amann, A.; Roy, S.

    2016-10-01

    Ambient mechanical vibrations offer an attractive solution for powering the wireless sensor nodes of the emerging “Internet-of-Things”. However, the wide-ranging variability of the ambient vibration frequencies pose a significant challenge to the efficient transduction of vibration into usable electrical energy. This work reports the development of a MEMS electromagnetic vibration energy harvester where the resonance frequency of the oscillator can be adjusted or tuned to adapt to the ambient vibrational frequency. Micro-fabricated silicon spring and double layer planar micro-coils along with sintered NdFeB micro-magnets are used to construct the electromagnetic transduction mechanism. Furthermore, another NdFeB magnet is adjustably assembled to induce variable magnetic interaction with the transducing magnet, leading to significant change in the spring stiffness and resonance frequency. Finite element analysis and numerical simulations exhibit substantial frequency tuning range (25% of natural resonance frequency) by appropriate adjustment of the repulsive magnetic interaction between the tuning and transducing magnet pair. This demonstrated method of frequency adjustment or tuning have potential applications in other MEMS vibration energy harvesters and micromechanical oscillators.

  11. Frequency adjustable MEMS vibration energy harvester

    International Nuclear Information System (INIS)

    Podder, P; Constantinou, P; Roy, S; Amann, A

    2016-01-01

    Ambient mechanical vibrations offer an attractive solution for powering the wireless sensor nodes of the emerging “Internet-of-Things”. However, the wide-ranging variability of the ambient vibration frequencies pose a significant challenge to the efficient transduction of vibration into usable electrical energy. This work reports the development of a MEMS electromagnetic vibration energy harvester where the resonance frequency of the oscillator can be adjusted or tuned to adapt to the ambient vibrational frequency. Micro-fabricated silicon spring and double layer planar micro-coils along with sintered NdFeB micro-magnets are used to construct the electromagnetic transduction mechanism. Furthermore, another NdFeB magnet is adjustably assembled to induce variable magnetic interaction with the transducing magnet, leading to significant change in the spring stiffness and resonance frequency. Finite element analysis and numerical simulations exhibit substantial frequency tuning range (25% of natural resonance frequency) by appropriate adjustment of the repulsive magnetic interaction between the tuning and transducing magnet pair. This demonstrated method of frequency adjustment or tuning have potential applications in other MEMS vibration energy harvesters and micromechanical oscillators. (paper)

  12. Vibration monitoring with artificial neural networks

    International Nuclear Information System (INIS)

    Alguindigue, I.

    1991-01-01

    Vibration monitoring of components in nuclear power plants has been used for a number of years. This technique involves the analysis of vibration data coming from vital components of the plant to detect features which reflect the operational state of machinery. The analysis leads to the identification of potential failures and their causes, and makes it possible to perform efficient preventive maintenance. Earlydetection is important because it can decrease the probability of catastrophic failures, reduce forced outgage, maximize utilization of available assets, increase the life of the plant, and reduce maintenance costs. This paper documents our work on the design of a vibration monitoring methodology based on neural network technology. This technology provides an attractive complement to traditional vibration analysis because of the potential of neural network to operate in real-time mode and to handle data which may be distorted or noisy. Our efforts have been concentrated on the analysis and classification of vibration signatures collected from operating machinery. Two neural networks algorithms were used in our project: the Recirculation algorithm for data compression and the Backpropagation algorithm to perform the actual classification of the patterns. Although this project is in the early stages of development it indicates that neural networks may provide a viable methodology for monitoring and diagnostics of vibrating components. Our results to date are very encouraging

  13. Broadband Vibration Attenuation Using Hybrid Periodic Rods

    Directory of Open Access Journals (Sweden)

    S. Asiri

    2008-12-01

    Full Text Available This paper presents both theoretically and experimentally a new kind of a broadband vibration isolator. It is a table-like system formed by four parallel hybrid periodic rods connected between two plates. The rods consist of an assembly of periodic cells, each cell being composed of a short rod and piezoelectric inserts. By actively controlling the piezoelectric elements, it is shown that the periodic rods can efficiently attenuate the propagation of vibration from the upper plate to the lower one within critical frequency bands and consequently minimize the effects of transmission of undesirable vibration and sound radiation. In such a system, longitudinal waves can propagate from the vibration source in the upper plate to the lower one along the rods only within specific frequency bands called the "Pass Bands" and wave propagation is efficiently attenuated within other frequency bands called the "Stop Bands". The spectral width of these bands can be tuned according to the nature of the external excitation. The theory governing the operation of this class of vibration isolator is presented and their tunable filtering characteristics are demonstrated experimentally as functions of their design parameters. This concept can be employed in many applications to control the wave propagation and the force transmission of longitudinal vibrations both in the spectral and spatial domains in an attempt to stop/attenuate the propagation of undesirable disturbances.

  14. Tunable Mechanical Filter for Longitudinal Vibrations

    Directory of Open Access Journals (Sweden)

    S. Asiri

    2007-01-01

    Full Text Available This paper presents both theoretically and experimentally a new kind of vibration isolator called tunable mechanical filter which consists of four parallel hybrid periodic rods connected between two plates. The rods consist of an assembly of periodic cells, each cell being composed of a short rod and piezoelectric inserts. By actively controlling the piezoelectric elements, it is shown that the periodic rods can efficiently attenuate the propagation of vibration from the upper plate to the lower one within critical frequency bands and consequently minimize the effects of transmission of undesirable vibration and sound radiation. In such a filter, longitudinal waves can propagate from the vibration source in the upper plate to the lower one along the rods only within specific frequency bands called the “Pass Bands” and wave propagation is efficiently attenuated within other frequency bands called the “Stop Bands”. The spectral width of these bands can be tuned according to the nature of the external excitation. The theory governing the operation of this class of vibration isolator is presented and their tunable filtering characteristics are demonstrated experimentally as functions of their design parameters. The concept of this mechanical filter as presented can be employed in many applications to control the wave propagation and the force transmission of longitudinal vibrations both in the spectral and spatial domains in an attempt to stop/attenuate the propagation of undesirable disturbances.

  15. On Kinetics Modeling of Vibrational Energy Transfer

    Science.gov (United States)

    Gilmore, John O.; Sharma, Surendra P.; Cavolowsky, John A. (Technical Monitor)

    1996-01-01

    Two models of vibrational energy exchange are compared at equilibrium to the elementary vibrational exchange reaction for a binary mixture. The first model, non-linear in the species vibrational energies, was derived by Schwartz, Slawsky, and Herzfeld (SSH) by considering the detailed kinetics of vibrational energy levels. This model recovers the result demanded at equilibrium by the elementary reaction. The second model is more recent, and is gaining use in certain areas of computational fluid dynamics. This model, linear in the species vibrational energies, is shown not to recover the required equilibrium result. Further, this more recent model is inconsistent with its suggested rate constants in that those rate constants were inferred from measurements by using the SSH model to reduce the data. The non-linear versus linear nature of these two models can lead to significant differences in vibrational energy coupling. Use of the contemporary model may lead to significant misconceptions, especially when integrated in computer codes considering multiple energy coupling mechanisms.

  16. No Telescoping Effect with Dual Tendon Vibration.

    Directory of Open Access Journals (Sweden)

    Valeria Bellan

    Full Text Available The tendon vibration illusion has been extensively used to manipulate the perceived position of one's own body part. However, findings from previous research do not seem conclusive sregarding the perceptual effect of the concurrent stimulation of both agonist and antagonist tendons over one joint. On the basis of recent data, it has been suggested that this paired stimulation generates an inconsistent signal about the limb position, which leads to a perceived shrinkage of the limb. However, this interesting effect has never been replicated. The aim of the present study was to clarify the effect of a simultaneous and equal vibration of the biceps and triceps tendons on the perceived location of the hand. Experiment 1 replicated and extended the previous findings. We compared a dual tendon stimulation condition with single tendon stimulation conditions and with a control condition (no vibration on both 'upward-downward' and 'towards-away from the elbow' planes. Our results show a mislocalisation towards the elbow of the position of the vibrated arm during dual vibration, in line with previous results; however, this did not clarify whether the effect was due to arm representation contraction (i.e., a 'telescoping' effect. Therefore, in Experiment 2 we investigated explicitly and implicitly the perceived arm length during the same conditions. Our results clearly suggest that in all the vibration conditions there was a mislocalisation of the entire arm (including the elbow, but no evidence of a contraction of the perceived arm length.

  17. Monitoring Vibration of A Model of Rotating Machine

    Directory of Open Access Journals (Sweden)

    Arko Djajadi

    2012-03-01

    Full Text Available Mechanical movement or motion of a rotating machine normally causes additional vibration. A vibration sensing device must be added to constantly monitor vibration level of the system having a rotating machine, since the vibration frequency and amplitude cannot be measured quantitatively by only sight or touch. If the vibration signals from the machine have a lot of noise, there are possibilities that the rotating machine has defects that can lead to failure. In this experimental research project, a vibration structure is constructed in a scaled model to simulate vibration and to monitor system performance in term of vibration level in case of rotation with balanced and unbalanced condition. In this scaled model, the output signal of the vibration sensor is processed in a microcontroller and then transferred to a computer via a serial communication medium, and plotted on the screen with data plotter software developed using C language. The signal waveform of the vibration is displayed to allow further analysis of the vibration. Vibration level monitor can be set in the microcontroller to allow shutdown of the rotating machine in case of excessive vibration to protect the rotating machine from further damage. Experiment results show the agreement with theory that unbalance condition on a rotating machine can lead to larger vibration amplitude compared to balance condition. Adding and reducing the mass for balancing can be performed to obtain lower vibration level. 

  18. Two-dimensional vibrational-electronic spectroscopy

    Science.gov (United States)

    Courtney, Trevor L.; Fox, Zachary W.; Slenkamp, Karla M.; Khalil, Munira

    2015-10-01

    Two-dimensional vibrational-electronic (2D VE) spectroscopy is a femtosecond Fourier transform (FT) third-order nonlinear technique that creates a link between existing 2D FT spectroscopies in the vibrational and electronic regions of the spectrum. 2D VE spectroscopy enables a direct measurement of infrared (IR) and electronic dipole moment cross terms by utilizing mid-IR pump and optical probe fields that are resonant with vibrational and electronic transitions, respectively, in a sample of interest. We detail this newly developed 2D VE spectroscopy experiment and outline the information contained in a 2D VE spectrum. We then use this technique and its single-pump counterpart (1D VE) to probe the vibrational-electronic couplings between high frequency cyanide stretching vibrations (νCN) and either a ligand-to-metal charge transfer transition ([FeIII(CN)6]3- dissolved in formamide) or a metal-to-metal charge transfer (MMCT) transition ([(CN)5FeIICNRuIII(NH3)5]- dissolved in formamide). The 2D VE spectra of both molecules reveal peaks resulting from coupled high- and low-frequency vibrational modes to the charge transfer transition. The time-evolving amplitudes and positions of the peaks in the 2D VE spectra report on coherent and incoherent vibrational energy transfer dynamics among the coupled vibrational modes and the charge transfer transition. The selectivity of 2D VE spectroscopy to vibronic processes is evidenced from the selective coupling of specific νCN modes to the MMCT transition in the mixed valence complex. The lineshapes in 2D VE spectra report on the correlation of the frequency fluctuations between the coupled vibrational and electronic frequencies in the mixed valence complex which has a time scale of 1 ps. The details and results of this study confirm the versatility of 2D VE spectroscopy and its applicability to probe how vibrations modulate charge and energy transfer in a wide range of complex molecular, material, and biological systems.

  19. Impulsiveness of vibration as an additional factor in the hazards associated with hand-arm vibration.

    Science.gov (United States)

    Starck, J; Pyykkö, I

    1986-08-01

    Impulsiveness is defined as the difference between peak and root-mean-square signals. As the difference varies in time, the cumulative distribution function has been used to describe the probability of achieving a certain value of impulsiveness. To make numerical comparison of different vibration signals possible, an impulse index has been selected from the cumulative distribution function. Symptoms of vibration-induced white finger were observed and compared to those expected on the basis of measurements taken according to guidelines of the International Organization for Standardization (ISO). Agreement was found for chain-saw vibration. In the case of pedestal grinding, the ISO draft underestimated the hazardous effects of vibration. Stone workers using pneumatic hammers were exposed to highly impulsive but asymmetrical vibration. The corresponding asymmetry was not, however, observed between the symptoms of the left and right hands, a finding which indicates that coupling between the tool and the hand is important for impulse vibration. The results suggest that the impulse character of vibration increases the risk of vibration-induced pathology. The analysis of high-impulse acceleration peaks obtained by the method presented in this study could provide additional data necessary to improve risk assessment.

  20. Vibrations and alternated stresses in turbomachineries; Vibrations et contraintes alternees dans les turbomachines

    Energy Technology Data Exchange (ETDEWEB)

    Naudin, M. [Conservatoire National des Arts et Metiers (CNAM), 75 - Paris (France)]|[FRAMATOME, 92 - Paris-La-Defense (France); Pugnet, J.M. [Conservatoire National des Arts et Metiers (CNAM), Grenoble-1 Univ., 38 (France)]|[FRAMATOME, 92 - Paris-La-Defense (France)

    1999-07-01

    Vibration phenomena are sources of mechanical incidents in turbomachineries. A calculation of the Eigenmodes of machine parts and a knowledge of their possible excitation during the machine operation can greatly improve the reliability and availability of the equipments. The development of computer tools and in particular the use of finite-element codes has allowed a more and more precise calculation of Eigenmodes and Eigenfrequencies. However, the analysis of excitation sources remains sometimes insufficient to explain and anticipate some complex vibrational phenomena encountered in rotative machines. The aim of this paper is to present, using two different examples, the methodology to be used in order to perform a complete vibrational analysis of mechanical components. The following aspects are reviewed successively: 1 - the damped vibrational system: study of the free motion, study of the response to an harmonic forced excitation; 2 - vibrational analysis of turbine blades: steam turbine blades, Eigenmodes of mobile blades, excitation sources, Campbell diagram, calculation of static and dynamical stresses, Haigh diagram, acceptance criteria and safety coefficient, influence of corrosion; 3 - dynamical analysis of the bending of a lineshaft: different flexion Eigenmodes, stiffness and damping of bearings, calculation of flexion Eigenmodes, excitation sources, vibrational stability of the lineshaft and vibration level; 3 - generalization: vibration of blades, shaft dynamics, alternative machines. (J.S.) 10 refs.

  1. Vibration transfers to measure the performance of vibration isolated platforms on site using background noise excitation

    NARCIS (Netherlands)

    Segerink, Franciscus B.; Korterik, Jeroen P.; Offerhaus, Herman L.

    2011-01-01

    This article demonstrates a quick and easy way of quantifying the performance of a vibration-isolated platform. We measure the vibration transfer from floor to table using background noise excitation from the floor. As no excitation device is needed, our setup only requires two identical sensors (in

  2. Implausibility of the vibrational theory of olfaction.

    Science.gov (United States)

    Block, Eric; Jang, Seogjoo; Matsunami, Hiroaki; Sekharan, Sivakumar; Dethier, Bérénice; Ertem, Mehmed Z; Gundala, Sivaji; Pan, Yi; Li, Shengju; Li, Zhen; Lodge, Stephene N; Ozbil, Mehmet; Jiang, Huihong; Penalba, Sonia F; Batista, Victor S; Zhuang, Hanyi

    2015-05-26

    The vibrational theory of olfaction assumes that electron transfer occurs across odorants at the active sites of odorant receptors (ORs), serving as a sensitive measure of odorant vibrational frequencies, ultimately leading to olfactory perception. A previous study reported that human subjects differentiated hydrogen/deuterium isotopomers (isomers with isotopic atoms) of the musk compound cyclopentadecanone as evidence supporting the theory. Here, we find no evidence for such differentiation at the molecular level. In fact, we find that the human musk-recognizing receptor, OR5AN1, identified using a heterologous OR expression system and robustly responding to cyclopentadecanone and muscone, fails to distinguish isotopomers of these compounds in vitro. Furthermore, the mouse (methylthio)methanethiol-recognizing receptor, MOR244-3, as well as other selected human and mouse ORs, responded similarly to normal, deuterated, and (13)C isotopomers of their respective ligands, paralleling our results with the musk receptor OR5AN1. These findings suggest that the proposed vibration theory does not apply to the human musk receptor OR5AN1, mouse thiol receptor MOR244-3, or other ORs examined. Also, contrary to the vibration theory predictions, muscone-d30 lacks the 1,380- to 1,550-cm(-1) IR bands claimed to be essential for musk odor. Furthermore, our theoretical analysis shows that the proposed electron transfer mechanism of the vibrational frequencies of odorants could be easily suppressed by quantum effects of nonodorant molecular vibrational modes. These and other concerns about electron transfer at ORs, together with our extensive experimental data, argue against the plausibility of the vibration theory.

  3. The Astrophysical Weeds: Rotational Transitions in Excited Vibrational States

    Science.gov (United States)

    Alonso, José L.; Kolesniková, Lucie; Alonso, Elena R.; Mata, Santiago

    2017-06-01

    The number of unidentified lines in the millimeter and submillimeter wave surveys of the interstellar medium has grown rapidly. The major contributions are due to rotational transitions in excited vibrational states of a relatively few molecules that are called the astrophysical weeds. necessary data to deal with spectral lines from astrophysical weeds species can be obtained from detailed laboratory rotational measurements in the microwave and millimeter wave region. A general procedure is being used at Valladolid combining different time and/or frequency domain spectroscopic tools of varying importance for providing the precise set of spectroscopic constants that could be used to search for this species in the ISM. This is illustrated in the present contribution through its application to several significant examples. Fortman, S. M., Medvedev, I. R., Neese, C.F., & De Lucia, F.C. 2010, ApJ,725, 1682 Rotational Spectra in 29 Vibrationally Excited States of Interstellar Aminoacetonitrile, L. Kolesniková, E. R. Alonso, S. Mata, and J. L. Alonso, The Astrophysical Journal Supplement Series 2017, (in press).

  4. Driving an Active Vibration Balancer to Minimize Vibrations at the Fundamental and Harmonic Frequencies

    Science.gov (United States)

    Holliday, Ezekiel S. (Inventor)

    2014-01-01

    Vibrations of a principal machine are reduced at the fundamental and harmonic frequencies by driving the drive motor of an active balancer with balancing signals at the fundamental and selected harmonics. Vibrations are sensed to provide a signal representing the mechanical vibrations. A balancing signal generator for the fundamental and for each selected harmonic processes the sensed vibration signal with adaptive filter algorithms of adaptive filters for each frequency to generate a balancing signal for each frequency. Reference inputs for each frequency are applied to the adaptive filter algorithms of each balancing signal generator at the frequency assigned to the generator. The harmonic balancing signals for all of the frequencies are summed and applied to drive the drive motor. The harmonic balancing signals drive the drive motor with a drive voltage component in opposition to the vibration at each frequency.

  5. Construction of a Vibration Monitoring System for HANARO's Rotating Machinery and Analysis of Pump Vibration Signals

    International Nuclear Information System (INIS)

    Ryu, Jeong Soo; Yoon, Doo Byung

    2005-01-01

    HANARO is an open-tank-in-pool type research reactor with a thermal power of 30MW. In order to remove the heat generated by the reactor core and the reflector vessel, primary cooling pumps and reflector cooling pumps circulate coolant. These pumps are installed at the RCI(Reactor Concrete Island) which is covered by heavy concrete hatches. For the prevention of an abnormal operation of these pumps in the RCI, it is necessary to construct a vibration monitoring system that provides an alarm signal to the reactor control room when the rotating speed or the vibration level exceeds the allowable limit. The first objective of this work is to construct a vibration monitoring system for HANARO's rotating machinery. The second objective is to verify the possibility of condition monitoring of the rotating machinery. To construct a vibration monitoring system, as a first step, the standards and references related to the vibration monitoring system were investigated. In addition, to determine the number and the location of sensors that can effectively characterize the overall vibration of a pump, the vibration of the primary cooling pumps and the reflector cooling pumps were measured. Based on these results, detailed construction plans for the vibration monitoring system for HANARO were established. Then, in accordance with the construction plans, the vibration monitoring system for HANARO's rotating machinery was manufactured and installed at HANARO. To achieve the second objective, FFT analysis and bearing fault detection of the measured vibration signals were performed. The analysis results demonstrate that the accelerometers mounted at the bearing locations of the pumps can effectively monitor the pump condition

  6. Frequency weightings of hand-transmitted vibration for predicting vibration-induced white finger.

    Science.gov (United States)

    Bovenzi, Massimo; Pinto, Iole; Picciolo, Francesco; Mauro, Marcella; Ronchese, Federico

    2011-05-01

    The aim of this study was to investigate the performance of four frequency weightings for hand-transmitted vibration to predict the incidence of vibration-induced white finger (VWF). In a longitudinal study of vibration-exposed forestry and stone workers (N=206), the incidence of VWF was related to measures of vibration exposure expressed in terms of 8-hour frequency-weighted energy-equivalent root-mean-square (rms) acceleration magnitude [A(8)] and years of follow-up. To calculate A(8), the rms acceleration magnitudes of vibration were weighted by means of four frequency weightings: (i) W(h) (the frequency weighting specified in ISO 5349-1:2001); (ii) W(h-bl) (the band-limiting component of W(h)); (iii) W(hf) (a frequency weighting based on finger vibration power absorption); and (iv) W(hT) (a frequency weighting based on a Japanese study of VWF prevalence). The relations of VWF to alternative measures of vibration exposure were assessed by the generalized estimating equations (GEE) method to account for the within-subject dependency of the observations over time. Data analysis with a GEE logistic model and a measure of statistical fit suggested that calculating A(8) by weighting the tool rms accelerations with W(h-bl)gave better predictions of the cumulative incidence of VWF than the other alternative measures of daily vibration exposure. Values of A(8) derived from the currently recommended ISO frequency weighting Wh produced poorer predictions of the incidence of VWF than those obtained with frequency weightings W(hf)or W(hT). This prospective cohort study suggests that measures of daily vibration exposure which give relatively more weight to intermediate and high frequency vibration are more appropriate for assessing the probability of VWF.

  7. Distributed Absorber for Noise and Vibration Control

    Directory of Open Access Journals (Sweden)

    Michel Azoulay

    2011-01-01

    Full Text Available An approach to a wide-band frequency passive vibration attenuation is introduced in this paper. This aims to suppress noise and vibration of extended multimode objects like plates, panels and shells. The absorber is arranged in the form of a single-layer assembly of small inertial bodies (balls being distributed and moulded within the light visco-elastic media (e.g. silicone resin. The absorber as a whole is embedded into object face covering the critical patches of the system surface. For the purpose of characterization, the authors introduced the complex frequency response function relating the volume velocity produced by the vibrating object surface (response stimulated by a point-wise force (stimulus applied to a particular point. The simulation and optimization of the main frequency characteristics has been performed using a full scale 3-dimensional Finite Element model. These revealed some new dynamic features of absorber's structures, which can contribute to vibration attenuation. A full-scale physical experimentation with synthesised absorber's structures confirmed the main results of simulation and has shown significant noise reduction over a staggering 0–20 kHz frequency band. This was achieved with a negligible weight and volume penalty due to the addition of the absorber. The results can find multiple applications in noise and vibration control of different structures. Some examples of such applications are presented.

  8. Vibrational characteristics and wear of fuel rods

    International Nuclear Information System (INIS)

    Schmugar, K.L.

    1977-01-01

    Fuel rod wear, due to vibration, is a continuing concern in the design of liquid-cooled reactors. In my report, the methodology and models that are used to predict fuel rod vibrational response and vibratory wear, in a light water reactor environment, are discussed. This methodology is being followed at present in the design of Westinghouse Nuclear Fuel. Fuel rod vibrations are expressed as the normal bending modes, and sources of rod vibration are examined with special emphasis on flow-induced mechanisms in the stable flow region. In a typical Westinghouse PWR fuel assembly design, each fuel rod is supported at multiple locations along the rod axis by a square-shaped 'grid cell'. For a fuel rod /grid support system, the development of small oscillatory motions, due to fluid flow at the rod/grid interface, results in material wear. A theoretical wear mode is developed using the Archard Theory of Adhesive Wear as the basis. Without question certainty, fretting wear becomes a serious problem if it progresses to the stage where the fuel cladding is penetrated and fuel is exposed to the coolant. Westinghouse fuel is designed to minimize fretting wear by limiting the relative motion between the fuel rod and its supports. The wear producing motion between the fuel rod and its supports occurs when the vibration amplitude exceeds the slippage threshold amplitude

  9. Vibration-proof FBR type reactor

    International Nuclear Information System (INIS)

    Kawamura, Yutaka.

    1992-01-01

    In a reactor container in an FBR type reactor, an outer building and upper and lower portions of a reactor container are connected by a load transmission device made of a laminated material of rubber and steel plates. Each of the reactor container and the outer building is disposed on a lower raft disposed on a rock by way of a vibration-proof device made of a laminated material of rubber and steel plates. Vibration-proof elements for providing vertical eigen frequency of the vibration-proof system comprising the reactor building and the vibration-proof device within a range of 3Hz to 5Hz are used. That is, the peak of designed acceleration for response spectrum in the horizontal direction of the reactor structural portions is shifted to side of shorter period from the main frequency region of the reactor structure. Alternatively, rigidity of the vibration-proof elements is decreased to shift the peak to the side of long period from the main frequency region. Designed seismic force can be greatly reduced both horizontally and vertically, to reduce the wall thickness of the structural members, improve the plant economy and to ensure the safety against earthquakes. (N.H.)

  10. Structural Design Optimization On Thermally Induced Vibration

    International Nuclear Information System (INIS)

    Gu, Yuanxian; Chen, Biaosong; Zhang, Hongwu; Zhao, Guozhong

    2002-01-01

    The numerical method of design optimization for structural thermally induced vibration is originally studied in this paper and implemented in application software JIFEX. The direct and adjoint methods of sensitivity analysis for thermal induced vibration coupled with both linear and nonlinear transient heat conduction is firstly proposed. Based on the finite element method, the structural linear dynamics is treated simultaneously with coupled linear and nonlinear transient heat structural linear dynamics is treated simultaneously with coupled linear and nonlinear transient heat conduction. In the thermal analysis model, the nonlinear heat conduction considered is result from the radiation and temperature-dependent materials. The sensitivity analysis of transient linear and nonlinear heat conduction is performed with the precise time integration method. And then, the sensitivity analysis of structural transient dynamics is performed by the Newmark method. Both the direct method and the adjoint method are employed to derive the sensitivity equations of thermal vibration, and there are two adjoint vectors of structure and heat conduction respectively. The coupling effect of heat conduction on thermal vibration in the sensitivity analysis is particularly investigated. With coupling sensitivity analysis, the optimization model is constructed and solved by the sequential linear programming or sequential quadratic programming algorithm. The methods proposed have been implemented in the application software JIFEX of structural design optimization, and numerical examples are given to illustrate the methods and usage of structural design optimization on thermally induced vibration

  11. Mechanical vibration of viscoelastic liquid droplets

    Science.gov (United States)

    Sharp, James; Harrold, Victoria

    2014-03-01

    The resonant vibrations of viscoelastic sessile droplets supported on different substrates were monitored using a simple laser light scattering technique. In these experiments, laser light was reflected from the surfaces of droplets of high Mw poly acrylamide-co-acrylic acid (PAA) dissolved in water. The scattered light was allowed to fall on the surface of a photodiode detector and a mechanical impulse was applied to the drops using a vibration motor mounted beneath the substrates. The mechanical impulse caused the droplets to vibrate and the scattered light moved across the surface of the photodiode. The resulting time dependent photodiode signal was then Fourier transformed to obtain the mechanical vibrational spectra of the droplets. The frequencies and widths of the resonant peaks were extracted for droplets containing different concentrations of PAA and with a range of sizes. This was repeated for PAA loaded water drops on surfaces which displayed different values of the three phase contact angle. The results were compared to a simple model of droplet vibration which considers the formation of standing wave states on the surface of a viscoelastic droplet. We gratefully acknowledge the support of the Leverhulme trust under grant number RPG-2012-702.

  12. Nanoscale piezoelectric vibration energy harvester design

    Science.gov (United States)

    Foruzande, Hamid Reza; Hajnayeb, Ali; Yaghootian, Amin

    2017-09-01

    Development of new nanoscale devices has increased the demand for new types of small-scale energy resources such as ambient vibrations energy harvesters. Among the vibration energy harvesters, piezoelectric energy harvesters (PEHs) can be easily miniaturized and fabricated in micro and nano scales. This change in the dimensions of a PEH leads to a change in its governing equations of motion, and consequently, the predicted harvested energy comparing to a macroscale PEH. In this research, effects of small scale dimensions on the nonlinear vibration and harvested voltage of a nanoscale PEH is studied. The PEH is modeled as a cantilever piezoelectric bimorph nanobeam with a tip mass, using the Euler-Bernoulli beam theory in conjunction with Hamilton's principle. A harmonic base excitation is applied as a model of the ambient vibrations. The nonlocal elasticity theory is used to consider the size effects in the developed model. The derived equations of motion are discretized using the assumed-modes method and solved using the method of multiple scales. Sensitivity analysis for the effect of different parameters of the system in addition to size effects is conducted. The results show the significance of nonlocal elasticity theory in the prediction of system dynamic nonlinear behavior. It is also observed that neglecting the size effects results in lower estimates of the PEH vibration amplitudes. The results pave the way for designing new nanoscale sensors in addition to PEHs.

  13. Vibration Isolation for Parallel Hydraulic Hybrid Vehicles

    Directory of Open Access Journals (Sweden)

    The M. Nguyen

    2008-01-01

    Full Text Available In recent decades, several types of hybrid vehicles have been developed in order to improve the fuel economy and to reduce the pollution. Hybrid electric vehicles (HEV have shown a significant improvement in fuel efficiency for small and medium-sized passenger vehicles and SUVs. HEV has several limitations when applied to heavy vehicles; one is that larger vehicles demand more power, which requires significantly larger battery capacities. As an alternative solution, hydraulic hybrid technology has been found effective for heavy duty vehicle because of its high power density. The mechanical batteries used in hydraulic hybrid vehicles (HHV can be charged and discharged remarkably faster than chemical batteries. This feature is essential for heavy vehicle hybridization. One of the main problems that should be solved for the successful commercialization of HHV is the excessive noise and vibration involving with the hydraulic systems. This study focuses on using magnetorheological (MR technology to reduce the noise and vibration transmissibility from the hydraulic system to the vehicle body. In order to study the noise and vibration of HHV, a hydraulic hybrid subsystem in parallel design is analyzed. This research shows that the MR elements play an important role in reducing the transmitted noise and vibration to the vehicle body. Additionally, locations and orientations of the isolation system also affect the efficiency of the noise and vibration mitigation. In simulations, a skyhook control algorithm is used to achieve the highest possible effectiveness of the MR isolation system.

  14. Vibration behavior of the artificial barrier system

    Energy Technology Data Exchange (ETDEWEB)

    Mikoshiba, Tadashi; Ogawa, Nobuyuki; Nakamura, Izuru [National Research Inst. for Earth sceince and Disaster Prevention (Japan)

    2000-02-01

    This study aims at production of a mimic specimen of artificial barrier, experimental elucidation of influence of seismic motion due to a vibration experiment on the artificial barrier system, and establishment of an evaluating method on its long-term behavior. The study has been carried out under a cooperative study of the National Research Institute for Earth Science and Disaster Prevention and the Japan Nuclear Cycle Development Institute. In 1998 fiscal year, an artificial barrier specimen initiated by crosscut road was produced, and their random wave and actual seismic wave vibrations were carried out to acquire their fundamental data. As a result of the both vibrations, it was found that in a Case 2 specimen of which buffer material was swelled by poured water, the material was integrated with a mimic over-pack to vibrate under judgement of eigen-frequency, maximum acceleration ratio, and so forth on the test results. And, in a Case 1 specimen, it was thought that the mimic over-pack showed an extreme non-linear performance (soft spring) because of reducing eigen-frequency with increase of its vibration level. (G.K.)

  15. Isotope separation using vibrationally excited molecules

    International Nuclear Information System (INIS)

    Woodroffe, J.A.; Keck, J.C.

    1977-01-01

    A system for isotope separation or enrichment wherein molecules of a selected isotope type in a flow of molecules of plural isotope types are vibrationally excited and collided with a background gas to provide enhanced diffusivity for the molecules of the selected isotope type permitting their separate collection. The system typically is for the enrichment of uranium using a uranium hexafluoride gas in combination with a noble gas such as argon. The uranium hexafluoride molecules having a specific isotope of uranium are vibrationally excited by laser radiation. The vibrational energy is converted to a translation energy upon collision with a particle of the background gas and the added translation energy enhances the diffusivity of the selected hexafluoride molecules facilitating its condensation on collection surfaces provided for that purpose. This process is periodically interrupted and the cryogenic flow halted to permit evaporation of the collected molecules to provide a distinct, enriched flow

  16. Mechanical vibration to electrical energy converter

    Science.gov (United States)

    Kellogg, Rick Allen [Tijeras, NM; Brotz, Jay Kristoffer [Albuquerque, NM

    2009-03-03

    Electromechanical devices that generate an electrical signal in response to an external source of mechanical vibrations can operate as a sensor of vibrations and as an energy harvester for converting mechanical vibration to electrical energy. The devices incorporate a magnet that is movable through a gap in a ferromagnetic circuit, wherein a coil is wound around a portion of the ferromagnetic circuit. A flexible coupling is used to attach the magnet to a frame for providing alignment of the magnet as it moves or oscillates through the gap in the ferromagnetic circuit. The motion of the magnet can be constrained to occur within a substantially linear range of magnetostatic force that develops due to the motion of the magnet. The devices can have ferromagnetic circuits with multiple arms, an array of magnets having alternating polarity and, encompass micro-electromechanical (MEM) devices.

  17. Surface Vibration Reconstruction using Inverse Numerical Acoustics

    Directory of Open Access Journals (Sweden)

    F. Martinus

    2003-05-01

    Full Text Available This paper explores the use of inverse numerical acoustics to reconstruct the surface vibration of a noise source. Inverse numerical acoustics is mainly used for source identification. This approach uses the measured sound pressure at a set of field points and the Helmholtz integral equation to reconstruct the normal surface velocity. The number of sound pressure measurements is considerably less than the number of surface vibration nodes. An overview of inverse numerical acoustics is presented and compared with other holography techniques such as nearfield acoustical holography and the Helmholtz equation least squares method. In order to obtain an acceptable reproduction of the surface vibration, several critical factors such as the field point selection and the effect of experimental errors have to be handled properly. Other practical considerations such as the use of few measured velocities and regularization techniques will also be presented. Examples will include a diesel engine, a transmission housing and an engine cover.

  18. Status of the Vibrational Theory of Olfaction

    Science.gov (United States)

    Hoehn, Ross D.; Nichols, David E.; Neven, Hartmut; Kais, Sabre

    2018-03-01

    The vibrational theory of olfaction is an attempt to describe a possible mechanism for olfaction which is explanatory and provides researchers with a set of principles which permit predictions allowing for structure-odor relations. Similar theories have occurred several times throughout olfactory science; this theory has again recently come to prominence by Luca Turin who suggested that inelastic electron tunneling is the method by which vibrations are detected by the olfactory receptors within the hose. This work is intended to convey to the reader the an up-to-date account of the vibrational theory of olfaction, both the historical iterations as well as the present iteration. This text is designed to give a chronological account of both theoretical and experimental studies on the topic, while providing context, comments and background where they were found to be needed.

  19. Vibration dynamics of single atomic nanocontacts

    International Nuclear Information System (INIS)

    Khater, A; Bourahla, B; Tigrine, R

    2007-01-01

    The motivation for this work is to introduce a model for an atomic nanocontact, whereby its mechanical properties can be analysed via the local spectra. The model system consists of two sets of triple parallel semi-infinite atomic chains joined by a single atom in between. We calculate the vibration spectra and the local densities of vibration states, in the harmonic approximation, for the irreducible set of sites that constitute the nanocontact domain. The nanocontact observables are numerically calculated for different cases of elastic hardening and softening, to investigate how the local dynamics can respond to changes in the microscopic environment on the domain. We have also calculated the phonon scattering and coherent conductance at the nanocontact, derived in a Landauer-Buettiker matrix approach. The analysis of the spectra, of the densities of vibration states, and of the phonon conductance, identifies characteristic features and demonstrates the central role of a core subset of sites in the nanocontact domain

  20. Effects of Cutting Tool Parameters on Vibration

    Directory of Open Access Journals (Sweden)

    Ince Mehmet Alper

    2016-01-01

    Full Text Available This paper presents of the influence on vibration of Co28Cr6Mo medical alloy machined on a CNC lathe based on cutting parameters (rotational speed, feed rate, depth of cut and tool tip radius. The influences of cutting parameters have been presented in graphical form for understanding. To achieve the minimum vibration, the optimum values obtained for rpm, feed rate, depth of cut and tool tip radius were respectively, 318 rpm, 0.25 mm/rev, 0.9 mm and 0.8 mm. Maximum vibration has been revealed the values obtained for rpm, feed rate, depth of cut and tool tip radius were respectively, 636 rpm, 0.1 mm/rev, 0,5 mm and 0.8 mm.

  1. Vibration Based Sun Gear Damage Detection

    Science.gov (United States)

    Hood, Adrian; LaBerge, Kelsen; Lewicki, David; Pines, Darryll

    2013-01-01

    Seeded fault experiments were conducted on the planetary stage of an OH-58C helicopter transmission. Two vibration based methods are discussed that isolate the dynamics of the sun gear from that of the planet gears, bearings, input spiral bevel stage, and other components in and around the gearbox. Three damaged sun gears: two spalled and one cracked, serve as the focus of this current work. A non-sequential vibration separation algorithm was developed and the resulting signals analyzed. The second method uses only the time synchronously averaged data but takes advantage of the signal/source mapping required for vibration separation. Both algorithms were successful in identifying the spall damage. Sun gear damage was confirmed by the presence of sun mesh groups. The sun tooth crack condition was inconclusive.

  2. Vibration-damping structure for reactor building

    International Nuclear Information System (INIS)

    Kuno, Toshio; Iba, Chikara; Tanaka, Hideki; Kageyama, Mitsuru

    1998-01-01

    In a damping structure of a reactor building, an inner concrete body and a reactor container are connected by way of a vibration absorbing member. As the vibration absorbing member, springs or dampers are used. The inner concrete body and the reactor container each having weight and inherent frequency different from each other are opposed displaceably by way of the vibration absorbing member thereby enabling to reduce seismic input and reduce shearing force at least at leg portions. Accordingly, seismic loads are reduced to increase the grounding rate of the base thereby enabling to satisfy an allowable value. Therefore, it is not necessary to strengthen the inner concrete body and the reactor container excessively, the amount of reinforcing rods can be reduced, and the amount of a portion of the base buried to the ground can be reduced thereby enabling to constitute the reactor building easily. (N.H.)

  3. Desert ants learn vibration and magnetic landmarks.

    Directory of Open Access Journals (Sweden)

    Cornelia Buehlmann

    Full Text Available The desert ants Cataglyphis navigate not only by path integration but also by using visual and olfactory landmarks to pinpoint the nest entrance. Here we show that Cataglyphis noda can additionally use magnetic and vibrational landmarks as nest-defining cues. The magnetic field may typically provide directional rather than positional information, and vibrational signals so far have been shown to be involved in social behavior. Thus it remains questionable if magnetic and vibration landmarks are usually provided by the ants' habitat as nest-defining cues. However, our results point to the flexibility of the ants' navigational system, which even makes use of cues that are probably most often sensed in a different context.

  4. Control aid for xenon vibration in reactor

    International Nuclear Information System (INIS)

    Kanekawa, Takashi.

    1990-01-01

    In the present invention, the control operation for suppressing xenon vibrations in a reactor is aided for saving forecasting analysis and operator's skills. That is, parameters to be controlled for the suppression of xenon vibrations are power distribution, iodine distribution and xenon distribution. But what can be observed by operaters by the conventional fast overtone method is only the output distribution. In the present invention, the output level of the reactor core is always observed. Then, mathematical processings are conducted for the iodine distribution, the xenon distribution and the power distribution in the reactor core based on the histeresis of the parameters obtained by the measurement using physical constants and reactor design data. The xenon vibration control is aided by displaying the change with time of the distortion in axial direction. Accordingly, operators can always recognize the axial distortion of the power distribution, the iodine distribution and the xenon distribution. (I.S.)

  5. Status of the Vibrational Theory of Olfaction

    Directory of Open Access Journals (Sweden)

    Ross D. Hoehn

    2018-03-01

    Full Text Available The vibrational theory of olfaction is an attempt to describe a possible mechanism for olfaction which is explanatory and provides researchers with a set of principles which permit predictions allowing for structure-odor relations. Similar theories have occurred several times throughout olfactory science; this theory has again recently come to prominence by Luca Turin, who suggested that inelastic electron tunneling is the method by which vibrations are detected by the olfactory receptors within the hose. This work is intended to convey to the reader an up-to-date account of the vibrational theory of olfaction, both the historical iterations as well as the present iteration. This text is designed to give a chronological account of both theoretical and experimental studies on the topic, while providing context, comments, and background where they were found to be needed.

  6. Torsion - Vibration Couplings in the CH{_3}OO{\\cdot} Radical

    Science.gov (United States)

    Huang, Meng; Miller, Terry A.; McCoy, Anne B.; Hsu, Kuo-Hsiang; Huang, Yu-Hsuan; Lee, Yuan-Pern

    2016-06-01

    A partially rotationally resolved infrared spectrum of CH{_3}OO{\\cdot} in the CH stretch region has been reported. The rotational contour of the {ν_2} CH stretch band in the experimental spectrum can be simulated with an asymmetric rotor model. The simulation shows good agreement with the experimental spectrum except that the broadening of the Q-branch in the experimental spectrum remains unexplained. This broadening is likely due to the sequence band transitions from the torsionally excited levels populated at room temperature to combination levels involving the CH stretch and the same number of torsional quanta. A four dimension model involving three CH stretches and the CH{_3} torsion is applied to the CH{_3}OO{\\cdot} radical to obtain the frequencies and intensities of the vibrational transitions in the CH stretch region. Based on these calculations, the torsional sequence bands are calculated to be slightly shifted from the origin band, because of the couplings between the CH stretches and CH{_3} torsion, thereby causing the apparent broadening observed for the {ν_2} fundamental. Due to the accidental degeneracy of two different CH stretch and CH{_3} torsion combination levels which differ by one quantum in the torsional excitation, the frequencies of the torsional sequence bands will be very sensitive to details of the potential, which makes the shifts difficult to precisely predict with electronic structure calculations. Complementary analyses are now underway for the other two CH stretch vibrational bands, {ν_1} and {ν_9}. K.-H. Hsu, Y.-H. Huang, Y.-P. Lee, M. Huang, T. A. Miller and A. B. McCoy J. Phys. Chem. A, in press, DOI: 10.1021/acs.jpca.5b12334

  7. Optical Measurement of Cable and String Vibration

    Directory of Open Access Journals (Sweden)

    Y. Achkire

    1998-01-01

    Full Text Available This paper describes a non contacting measurement technique for the transverse vibration of small cables and strings using an analog position sensing detector. On the one hand, the sensor is used to monitor the cable vibrations of a small scale mock-up of a cable structure in order to validate the nonlinear cable dynamics model. On the other hand, the optical sensor is used to evaluate the performance of an active tendon control algorithm with guaranteed stability properties. It is demonstrated experimentally, that a force feedback control law based on a collocated force sensor measuring the tension in the cable is feasible and provides active damping in the cable.

  8. Lambda-matrices and vibrating systems

    CERN Document Server

    Lancaster, Peter; Stark, M; Kahane, J P

    1966-01-01

    Lambda-Matrices and Vibrating Systems presents aspects and solutions to problems concerned with linear vibrating systems with a finite degrees of freedom and the theory of matrices. The book discusses some parts of the theory of matrices that will account for the solutions of the problems. The text starts with an outline of matrix theory, and some theorems are proved. The Jordan canonical form is also applied to understand the structure of square matrices. Classical theorems are discussed further by applying the Jordan canonical form, the Rayleigh quotient, and simple matrix pencils with late

  9. Noise and vibration in friction systems

    CERN Document Server

    Sergienko, Vladimir P

    2015-01-01

    The book analyzes the basic problems of oscillation processes and theoretical aspects of noise and vibration in friction systems. It presents generalized information available in literature data and results of the authors in vibroacoustics of friction joints, including car brakes and transmissions. The authors consider the main approaches to abatement of noise and vibration in non-stationary friction processes. Special attention is paid to materials science aspects, in particular to advanced composite materials used to improve the vibroacoustic characteristics of tribopairs The book is intended for researchers and technicians, students and post-graduates specializing in mechanical engineering, maintenance of machines and transport means, production certification, problems of friction and vibroacoustics.

  10. Skull Vibration Induced Nystagmus in Otorhinolaryngology

    Directory of Open Access Journals (Sweden)

    Carmen Sánchez Blanco

    2018-01-01

    Full Text Available Introduction and objective: The Vibration Induced Nystagmus (VIN is a useful, easy, non-invasive examination that involves an asymmetry of the vestibular function. Applying a 100Hz vibration over the mastoid process induces a horizontal nystagmus beating towards the normal side in patients with unilateral vestibular loss. In this paper we show the physiological foundations, practical conditions and the interpretation of the results. Methods: Narrative review. Discussion and conclusions: VIN starts with stimulation onset and it stops at stimulation offset. It has the same direction when you stimulate both mastoids. It shows a little or no habituation and it is permanent even in well compensated patients.

  11. Multiaxis Rainflow Fatigue Methods for Nonstationary Vibration

    Science.gov (United States)

    Irvine, T.

    2016-01-01

    Mechanical structures and components may be subjected to cyclical loading conditions, including sine and random vibration. Such systems must be designed and tested accordingly. Rainflow cycle counting is the standard method for reducing a stress time history to a table of amplitude-cycle pairings prior to the Palmgren-Miner cumulative damage calculation. The damage calculation is straightforward for sinusoidal stress but very complicated for random stress, particularly for nonstationary vibration. This paper evaluates candidate methods and makes a recommendation for further study of a hybrid technique.

  12. Forced vibrations of rotating circular cylindrical shells

    International Nuclear Information System (INIS)

    Igawa, Hirotaka; Maruyama, Yoshiyuki; Endo, Mitsuru

    1995-01-01

    Forced vibrations of rotating circular cylindrical shells are investigated. Basic equations, including the effect of initial stress due to rotation, are formulated by the finite-element method. The characteristic relations for finite elements are derived from the energy principle by considering the finite strain. The equations of motion can be separated into quasi-static and dynamic ones, i.e., the equations in the steady rotating state and those in the vibration state. Radial concentrated impulses are considered as the external dynamic force. The transient responses of circular cylindrical shells are numerically calculated under various boundary conditions and rotating speeds. (author)

  13. Localized Surface Plasmons in Vibrating Graphene Nanodisks

    DEFF Research Database (Denmark)

    Wang, Weihua; Li, Bo-Hong; Stassen, Erik

    2016-01-01

    in graphene disks have the additional benefit to be highly tunable via electrical stimulation. Mechanical vibrations create structural deformations in ways where the excitation of localized surface plasmons can be strongly modulated. We show that the spectral shift in such a scenario is determined...... by a complex interplay between the symmetry and shape of the modal vibrations and the plasmonic mode pattern. Tuning confined modes of light in graphene via acoustic excitations, paves new avenues in shaping the sensitivity of plasmonic detectors, and in the enhancement of the interaction with optical emitters...

  14. Design of Wind Turbine Vibration Monitoring System

    Directory of Open Access Journals (Sweden)

    Shoubin Wang

    2013-04-01

    Full Text Available In order to ensure safety of wind turbine operation and to reduce the occurrence of faults as well as to improve the reliability of wind turbine operation, a vibration monitoring for wind turbine is developed. In this paper, it analyses the enlargement of all the parts of the structure and the working mechanism, the research method of wind turbine operation vibration is introduced, with the focus being the use of the sensor principle. Finally the hardware design and software of this system is introduced and the main function of this system is described, which realizes condition monitoring of the work state of wind turbines.

  15. Vibration Energy Harvesting Potential for Turbomachinery Applications

    Directory of Open Access Journals (Sweden)

    Adrian STOICESCU

    2018-03-01

    Full Text Available The vibration energy harvesting process represents one of the research directions for increasing power efficiency of electric systems, increasing instrumentation nodes autonomy in hard to reach locations and decreasing total system mass by eliminating cables and higher-power adapters. Research based on the possibility of converting vibration energy into useful electric energy is used to evaluate the potential of its use on turbomachinery applications. Aspects such as the structure and characteristics of piezoelectric generators, harvesting networks, their setup and optimization, are considered. Finally, performance test results are shown using piezoelectric systems on a turbine engine.

  16. Active vibration control by robust control techniques

    International Nuclear Information System (INIS)

    Lohar, F.A.

    2001-01-01

    This paper studies active vibration control of multi-degree-of-freedom system. The control techniques considered are LTR, H/sup 2/ and H/sup infinite/. The results show that LTR controls the vibration but its respective settling time is higher than that of the other techniques. The control performance of H/sup infinite/ control is similar to that of H/sup 2/ control in the case of it weighting functions. However, H/sup infinite/ control is superior to H/sup 2/ control with respect to robustness, steady state error and settling time. (author)

  17. Multimode vibrational couplings in resonant positron annihilation.

    Science.gov (United States)

    d'A Sanchez, Sergio; Lima, Marco A P; Varella, Márcio T do N

    2011-09-02

    The mechanisms for multimode vibrational couplings in resonant positron annihilation are not well understood. We show that these resonances can arise from positron-induced distortions of the potential energy surface (target response to the positron field). Though these distortions can transfer energy into single- and multiquantum vibrations, they have so far been disregarded as a pathway to resonant annihilation. We also compare the existing annihilation theories and show that the currently accepted model can be cast as a special case of the Feshbach annihilation theory.

  18. Integrated predictive maintenance program vibration and lube oil analysis: Part I - history and the vibration program

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, H.

    1996-12-01

    This paper is the first of two papers which describe the Predictive Maintenance Program for rotating machines at the Palo Verde Nuclear Generating Station. The organization has recently been restructured and significant benefits have been realized by the interaction, or {open_quotes}synergy{close_quotes} between the Vibration Program and the Lube Oil Analysis Program. This paper starts with the oldest part of the program - the Vibration Program and discusses the evolution of the program to its current state. The {open_quotes}Vibration{close_quotes} view of the combined program is then presented.

  19. The Shock Vibration Bulletin. Part 3. Isolation and Damping, Vibration Test Criteria, and Vibration Analysis and Test

    Science.gov (United States)

    1987-01-01

    fatigae equivalent test time of 45-mimates. 1. BACKGROUND subjected to both vibration and loose cargo testing as well an the type and amount of...Environmental Test the track laying environment. Nethods, 10 March 1975. 8. FUTURE EFFORTS 11. Soci, Darrell F., Fatigae Life Estimation Techniques, Technical

  20. Alleviation of Buffet-Induced Vibration Using Piezoelectric Actuators

    National Research Council Canada - National Science Library

    Morgenstern, Shawn D

    2006-01-01

    .... The objective of this research was to determine the most critical natural modes of vibration for the F-16 ventral fin and design piezoelectric actuators capable of reducing buffet-induced ventral fin vibration...

  1. Coupled electromechanical model of an imperfect piezoelectric vibrating cylinder gyroscope

    CSIR Research Space (South Africa)

    Loveday, PW

    1996-01-01

    Full Text Available Coupled electromechanical equations of motion, describing the dynamics of a vibrating cylinder gyroscope, are derived using Hamilton's principle and the Rayleigh-Ritz method. The vibrating cylinder gyroscope comprises a thin walled steel cylinder...

  2. Update LADOTD policy on pile driving vibration management.

    Science.gov (United States)

    2012-02-01

    The main objective of this project was to update the current Louisiana Department of Transportation and Development (LADOTD) policy on pile driving vibration risk management with a focus on how to determine an appropriate vibration monitoring area. T...

  3. Active vibration isolation of a rigidly mounted turbo pump

    NARCIS (Netherlands)

    Basten, T.G.H.; Doppenberg, E.J.J.

    2006-01-01

    Manufacturers of precision equipment are constantly aiming at increased accuracy. Elimination of disturbing vibrations is therefore getting more and more important. The technical limitations of passive isolation methods require alternative strategies for vibration reduction, such as active

  4. Wireless Inductive Power Device Suppresses Blade Vibrations

    Science.gov (United States)

    Morrison, Carlos R.; Provenza, Andrew J.; Choi, Benjamin B.; Bakhle, Milind A.; Min, James B.; Stefko, George L.; Duffy, Kirsten P.; Fougers, Alan J.

    2011-01-01

    Vibration in turbomachinery can cause blade failures and leads to the use of heavier, thicker blades that result in lower aerodynamic efficiency and increased noise. Metal and/or composite fatigue in the blades of jet engines has resulted in blade destruction and loss of lives. Techniques for suppressing low-frequency blade vibration, such as gtuned circuit resistive dissipation of vibratory energy, h or simply "passive damping," can require electronics incorporating coils of unwieldy dimensions and adding unwanted weight to the rotor. Other approaches, using vibration-dampening devices or damping material, could add undesirable weight to the blades or hub, making them less efficient. A wireless inductive power device (WIPD) was designed, fabricated, and developed for use in the NASA Glenn's "Dynamic Spin Rig" (DSR) facility. The DSR is used to simulate the functionality of turbomachinery. The relatively small and lightweight device [10 lb (approx.=4.5 kg)] replaces the existing venerable and bulky slip-ring. The goal is the eventual integration of this technology into actual turbomachinery such as jet engines or electric power generators, wherein the device will facilitate the suppression of potentially destructive vibrations in fan blades. This technology obviates slip rings, which require cooling and can prove unreliable or be problematic over time. The WIPD consists of two parts: a remote element, which is positioned on the rotor and provides up to 100 W of electrical power to thin, lightweight piezoelectric patches strategically placed on/in fan blades; and a stationary base unit that wirelessly communicates with the remote unit. The base unit supplies inductive power, and also acts as an input and output corridor for wireless measurement, and active control command to the remote unit. Efficient engine operation necessitates minimal disturbance to the gas flow across the turbine blades in any effort to moderate blade vibration. This innovation makes it

  5. Gran Sasso: Gallex underway

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Although the experiment actually started collecting its solar neutrino data last Summer, November 30 saw the official inauguration of the Gallex experiment. A collaboration between Heidelberg, Karlsruhe and Munich in Germany, Saclay and Nice in France, Milan and Rome in Italy, Rehovot in Israel and Brookhaven in the US, Gallex uses 30 tonnes of gallium (as gallium chloride solution) to intercept neutrinos from the sun

  6. Space physics exhibits underway

    Science.gov (United States)

    DeVito, M. Catherine

    AGU is planning a new space science exhibit for the Smithsonian Institution's National Air and Space Museum in Washington that will help visitors come to an understanding of space science as a comprehensive, interdisciplinary, and exciting field. The title of the exhibit is “Electric Space: Our Earth-Sun Environment.” The exhibit's five modules will include demonstrations of the effects of particle and field radiation on humans and satellites in space and on human technology on the ground. The project also includes a larger traveling version that will visit science and technology centers throughout the United States. The first exhibit is planned to open at the Air and Space Museum in late summer or early fall 1992, in time for International Space Year activities; the traveling exhibit will begin touring in early 1993.

  7. Adjustable Nonlinear Springs to Improve Efficiency of Vibration Energy Harvesters

    OpenAIRE

    Boisseau, S.; Despesse, G.; Seddik, B. Ahmed

    2012-01-01

    Vibration Energy Harvesting is an emerging technology aimed at turning mechanical energy from vibrations into electricity to power microsystems of the future. Most of present vibration energy harvesters are based on a mass spring structure introducing a resonance phenomenon that allows to increase the output power compared to non-resonant systems, but limits the working frequency bandwidth. Therefore, they are not able to harvest energy when ambient vibrations' frequencies shift. To follow sh...

  8. Pacinian channel mediated vasoconstriction in the fingers during vibration exposure

    OpenAIRE

    Ye, Ying

    2013-01-01

    A review of the literature showed that acute vascular responses to hand-transmitted vibration depend on the magnitude, the frequency, and the duration of the vibration but the mechanisms involved in the immediate vasoconstriction on exposure to vibration are not clear. This research was designed to advance understanding of the relation between the characteristics of vibration and changes in vascular circulation on exposed hands, and to develop a model of the mechanoreceptor channel involved i...

  9. Structural Characteristics of Rotate Vector Reducer Free Vibration

    OpenAIRE

    Chen, Chuan; Yang, Yuhu

    2017-01-01

    For RV reducer widely used in robots, vibration significantly affects its performance. A lumped parameter model is developed to investigate free vibration characteristics without and with gyroscopic effects. The dynamic model considers key factors affecting vibration such as involute and cycloid gear mesh stiffness, crankshaft bending stiffness, and bearing stiffness. For both nongyroscopic and gyroscopic systems, free vibrations are examined and compared with each other. Results reveal the s...

  10. Optical Remote Sensing Algorithm Validation using High-Frequency Underway Biogeochemical Measurements in Three Large Global River Systems

    Science.gov (United States)

    Kuhn, C.; Richey, J. E.; Striegl, R. G.; Ward, N.; Sawakuchi, H. O.; Crawford, J.; Loken, L. C.; Stadler, P.; Dornblaser, M.; Butman, D. E.

    2017-12-01

    More than 93% of the world's river-water volume occurs in basins impacted by large dams and about 43% of river water discharge is impacted by flow regulation. Human land use also alters nutrient and carbon cycling and the emission of carbon dioxide from inland reservoirs. Increased water residence times and warmer temperatures in reservoirs fundamentally alter the physical settings for biogeochemical processing in large rivers, yet river biogeochemistry for many large systems remains undersampled. Satellite remote sensing holds promise as a methodology for responsive regional and global water resources management. Decades of ocean optics research has laid the foundation for the use of remote sensing reflectance in optical wavelengths (400 - 700 nm) to produce satellite-derived, near-surface estimates of phytoplankton chlorophyll concentration. Significant improvements between successive generations of ocean color sensors have enabled the scientific community to document changes in global ocean productivity (NPP) and estimate ocean biomass with increasing accuracy. Despite large advances in ocean optics, application of optical methods to inland waters has been limited to date due to their optical complexity and small spatial scale. To test this frontier, we present a study evaluating the accuracy and suitability of empirical inversion approaches for estimating chlorophyll-a, turbidity and temperature for the Amazon, Columbia and Mississippi rivers using satellite remote sensing. We demonstrate how riverine biogeochemical measurements collected at high frequencies from underway vessels can be used as in situ matchups to evaluate remotely-sensed, near-surface temperature, turbidity, chlorophyll-a derived from the Landsat 8 (NASA) and Sentinel 2 (ESA) satellites. We investigate the use of remote sensing water reflectance to infer trophic status as well as tributary influences on the optical characteristics of the Amazon, Mississippi and Columbia rivers.

  11. Complaints of low back pain among private farmers exposed to whole body vibration

    Directory of Open Access Journals (Sweden)

    Leszek Solecki

    2014-02-01

    Full Text Available Introduction: Work-related lower back disorders , which involve the lumbo-sacral region, as well as injuries of the lumbar section of the spine, are a serious and constantly growing problem in Europe. Whole body vibration is one of the major hazardous factors suspected of the development of back pain. Material and Methods: The study covered a selected group of males, 98 farmers (aged 55.3±10.1 from the area of 7 communes in the Lublin Region, engaged in the mixed agricultural production (plant-animal. The control group consisted of 40 academic workers (university and research institute employees aged 48.9±9.6 years. A questionnaire concerning low back pain (in the lumbar region designed by the researchers of the Institute of Rural Health in Lublin was used as a major research tool. The degree of farmers' exposure to whole body vibration was evaluated based on the parameter known as a cumulative vibration dose (d (years×m2×s-4. Results: The measurements showed that the cumulative vibration dose for the selected group of farmers (98 remained within the range of 2.90-9.68 (years×m2×s-4, in the time interval between 15-50 years of work in conditions of exposure to vibration. The survey confirmed that private farmers exposed to whole body vibration considerably more frequently complained of back pain (92 farmers, 94% of the total number of respondents, than academic workers (control group not exposed to whole body vibration (25 researchers, 63%; p < 0.0001. Also the frequency of back pain in all the three time intervals of employment (15-25, 26-35, 36-50 years is significantly higher in the group of farmers than in the control group (p < 0.05. Conclusions: The frequency of back pains experienced by farmers during the entire period of occupational activity increases with a growing dose of whole body vibration (p = 0.005. In the incidence of chronic pain an upward tendency was observed (statistically insignificant. Med Pr 2014;65(1:55–64

  12. Estimation of spinal loading in vertical vibrations by numerical simulation

    NARCIS (Netherlands)

    Verver, M.M.; Hoof, J.F.A.M. van; Oomens, C.W.J.; Wouw, N. van de; Wismans, J.S.H.M.

    2003-01-01

    Objective. This paper describes the prediction of spinal forces in car occupants during vertical vibrations using a numerical multi-body occupant model. Background. An increasing part of the population is exposed to whole body vibrations in vehicles. In literature, vertical vibrations and low back

  13. Free asymmetric transverse vibration of polar orthotropic annular ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Houmat A 2001 A sector Fourier p-element applied to free vibration analysis of sectorial plates. J. Sound Vibr. 243: 269–282. Irie T, Yamada G, Ito F 1979 Free vibration of polar orthotropic sector plates. J. Sound Vibr 67: 89–100. Irie T, Tanaka K, Yamada G 1988 Free vibration of a cantilever annular sector plate with curved ...

  14. Numerical analysis using state space method for vibration control of ...

    African Journals Online (AJOL)

    In passenger cars the vibrations developed at the ground are transmitted to the passengers through seats. Due to vibrations discomfort is experienced by the passengers. Dampers are being successfully utilized to reduce the vibrations in civil engineering structures. Few dampers are used in passenger cars as well.

  15. Vibrational Relaxation in Neat Crystals of Naphthalene by Picosecond CARS

    NARCIS (Netherlands)

    Hesp, Ben H.; Wiersma, Douwe A.

    1980-01-01

    Picosecond delayed CARS experiments on totally symmetric modes in naphthalene at 1.5 K are reported. The Raman lineshape of the vibrational excitons is lorentzian and vibrational relaxation can be surprisingly slow. The Raman lineshape of the Ag exciton level of the 766 cm-1 vibrational mode reveals

  16. Catalytic synthesis of ammonia using vibrationally excited nitrogen

    DEFF Research Database (Denmark)

    Henriksen, Niels Engholm; Billing, Gert D.; Hansen, Flemming Yssing

    1992-01-01

    to that from conventional synthesis. In the present study the nitrogen molecules are only excited at the inlet of a plug flow reactor, and the importance of vibrational relaxation is investigated. We show that vibrational excitation can give an enhanced yield of ammonia also in the situation where vibrational...

  17. 47 CFR 10.530 - Common vibration cadence.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Common vibration cadence. 10.530 Section 10.530... § 10.530 Common vibration cadence. A Participating CMS Provider and equipment manufacturers may only market devices for public use under part 10 that include a vibration cadence capability that meets the...

  18. A seismic vertical vibrator driven by linear motors

    NARCIS (Netherlands)

    Noorlandt, R.P.; Drijkoningen, G.G.; Schneider, R.M.

    2012-01-01

    In this paper we present a newly developed vertical seismic vibrator driven by linear motors. We explain the different components the vibrator consists of. We show that the harmonic distortion of the linear-motor vibrator signal is very small. We also show that, without applying a feedback loop on

  19. Mitigating ground vibration by periodic inclusions and surface structures

    DEFF Research Database (Denmark)

    Andersen, Lars Vabbersgaard; Bucinskas, Paulius; Persson, Peter

    2016-01-01

    Ground vibration from traffic is a source of nuisance in urbanized areas. Trenches and wave barriers can provide mitigation of vibrations, but single barriers need to have a large depth to be effective-especially in the low-frequency range relevant to traffic-induced vibration. Alternatively...

  20. Vibration control of an elastic strip by a singular force

    Indian Academy of Sciences (India)

    J. Sound and Vibration 315: 1–21. Han J H, Tani J, Qui J 2006 Active flutter suppression of a lifting surface using piezoelectric actuation and modern control theory. J. Sound and Vibration 291: 706–722. Han J H, Lee I 1999 Optimal placement of piezoelectric sensors and actuators for vibration control of a composite plate ...

  1. Whole body vibration improves attention and motor performance in ...

    African Journals Online (AJOL)

    Background: Whole body vibration (WBV) is a form of physical stimulation via mechanical vibrations transmitted to a subject. It is assumed that WBV induces sensory stimulation in cortical brain regions through the activation of skin and muscle receptors responding to the vibration. The effects of WBV on muscle strength are ...

  2. A novel technique for active vibration control, based on optimal

    Indian Academy of Sciences (India)

    In the last few decades, researchers have proposed many control techniques to suppress unwanted vibrations in a structure. In this work, a novel and simple technique is proposed for the active vibration control. In this technique, an optimal tracking control is employed to suppress vibrations in a structure by simultaneously ...

  3. Purification of drilling fluids by vibration-settling tanks

    Energy Technology Data Exchange (ETDEWEB)

    Bulatov, A.I.; Prokopov, L.I.; Proselkov, Yu.M.; Reznichenko, I.N.; Skvortsov, D.S.; Volkov, A.P.

    1982-01-01

    Results are presented of studies done by the authors of a prototype of a new tool for cleaning a drilling fluid, a vibration settling tank. It is indicated that the vibration settling tank has many advantages over the most advanced vibration screens VS-1. This makes it possible to recommend development and broad industrial testing of this apparatus.

  4. Numerical Modelling of Rubber Vibration Isolators: identification of material parameters

    NARCIS (Netherlands)

    Beijers, C.A.J.; Noordman, Bram; de Boer, Andries; Ivanov, N.I.; Crocker, M.J.

    2004-01-01

    Rubber vibration isolators are used for vibration isolation of engines at high frequencies. To make a good prediction regarding the characteristics of a vibration isolator in the design process, numerical models can be used. However, for a reliable prediction of the dynamic behavior of the isolator,

  5. Lambda-matrices and vibrating systems

    CERN Document Server

    Lancaster, Peter

    2002-01-01

    Features aspects and solutions of problems of linear vibrating systems with a finite number of degrees of freedom. Starts with development of necessary tools in matrix theory, followed by numerical procedures for relevant matrix formulations and relevant theory of differential equations. Minimum of mathematical abstraction; assumes a familiarity with matrix theory, elementary calculus. 1966 edition.

  6. Hydromonochord: Visualizing String Vibration by Water Swirls

    Science.gov (United States)

    Sommer, Wilfried; Meier-Boke, Ralf; Meinzer, Nicholas

    2010-01-01

    The hydromonochord is a horizontal vibrating string that just makes contact with the surface of a water bath. The motion of the string sets up a pattern of swirls on the surface of the water, thus complementing the usual pattern of nodes and antinodes. The device is based on the traditional monochord. A water basin (Fig. 1) has two slits in the…

  7. [Raynaud's phenomenon in occupational vibration exposure].

    Science.gov (United States)

    Letzel, S; Muttray, A

    2013-03-01

    A 34-year-old female stonemason was referred for expert opinion. The question at issue was, whether she suffered from vibration-induced white finger disease. She was exposed to high-frequency hand-arm vibrations for many years. She reported white finger attacks at the long fingers, which were associated with cold weather. Until this point, physical findings were normal. The cold water provocation test showed a slight delay of the rewarming for the long fingers of the right hand. The nailfold capillary microscopy was normal. The slight Raynaud's phenomenon was recognized as an occupational disease with a diagnosis of vibration-induced white finger disease. About three years later, the symptoms of the Raynaud's phenomenon had deteriorated, although the patient had finished working with vibrating tools. The cold water provocation test confirmed the deterioration. At this time, the patient had inflamed swellings of some joints caused by rheumatoid arthritis. The differential diagnosis of a Raynaud's phenomenon should include occupational causes. Occupational history is diagnostically indicative. If an occupational disease is assumed, a report must be filed. With respect to German social law, the deterioration of the Raynaud's phenomenon was caused by the rheumatoid arthritis, which is regarded as independent from the job. © Georg Thieme Verlag KG Stuttgart · New York.

  8. Vibrations of a pipe on elastic foundations

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    MARKOVA and D S LOLOV. Department of Technical Mechanics, Faculty of Hydro-technics, University of ... rotational springs at the length of the pipe. A new term appears in the equation of the transverse vibrations. This new term is opposed to the ...

  9. On the particle-vibration multiplets

    International Nuclear Information System (INIS)

    Khodel, V.A.; Platonov, A.P.; Saperstein, E.E.

    1980-01-01

    The particle-vibration multiplet spectra in the lead region are calculated in the framework of the self-consistent theory of finite Fermi systems. The calculated results are compared with the experimental data and with the results of other authors. (author)

  10. Structural, intramolecular hydrogen bonding and vibrational studies ...

    Indian Academy of Sciences (India)

    The harmonic oscillator model of aromaticity (HOMA) index elucidated the impact of hydrogen bond- ing in the ring. Intramolecular hydrogen bonding energy has been calculated from topological study. The low wavenumber vibrational modes obtained from experimental FT-Raman spectrum also supported the presence.

  11. Measuring vibrations in fuel channels CNE

    International Nuclear Information System (INIS)

    Martín Ghiselli, A.; Fiori, J.; Sacchi, M.; Villabrille, G.

    2013-01-01

    This paper present a description of implementation and execution of vibration measurements made at the request of NUCLEOELECTRICA ARGENTINA S.A. on the ends of the reactor fuel channels of Embalse Nuclear Power Plant to explore possible differences between the dynamic behavior of empty fuel channel and with full charge of fuel elements inside. (author)

  12. Composite materials inspection. [ultrasonic vibration holographic NDT

    Science.gov (United States)

    Erf, R. K.

    1974-01-01

    Investigation of the application requirements, advantages, and limitations of nondestructive testing by a technique of ultrasonic-vibration holographic-interferometry readout used in a production control facility for the inspection of a single product such as composite compressor blades. It is shown that, for the detection and characterization of disbonds in composite material structures, this technique may represent the most inclusive test method.

  13. Microgyroscope with Vibrating Post as Rotation Transducer

    Science.gov (United States)

    Tang, Tony K.; Gutierrez, Roman

    2003-01-01

    The figure depicts a micromachined silicon vibratory gyroscope that senses rotation about its z axis. The rotation-sensitive vibratory element is a post oriented (when at equilibrium) along the z axis and suspended at its base by thin, flexible silicon bands oriented along the x and y axes, respectively. Unlike in the vibratory microgyroscopes described in the immediately preceding article ["Cloverleaf Vibratory Microgyroscope With Integrated Post" (NPO-20688)] and other previous articles in NASA Tech Briefs, the rotation-sensitive vibratory element does not include a cloverleaf-shaped structure that lies (when at equilibrium) in the x-y plane. As in the cases of the previously reported vibratory microgyroscopes, vibrations of the rotation-sensitive vibratory element are excited electrostatically, the vibrations are measured by use of capacitive proximity sensors, and the rate of rotation along the axis of sensitivity is deduced from the effect of the Coriolis force upon the vibrations. To create electrodes for electrostatic excitation and capacitive sensing of vibrations, portions of the facing surfaces of the post and of the four stationary members that surround the post are rendered electrically conductive; this can be accomplished by either depositing metal films or else doping the silicon in the affected areas.

  14. Vibration of Elastic Functionally Graded Thick Rings

    Directory of Open Access Journals (Sweden)

    Guang-Hui Xu

    2017-01-01

    Full Text Available The free vibration behaviors of functionally graded rings were investigated theoretically. The material graded in the thickness direction according to the power law rule and the rings were assumed to be in plane stress and plane strain states. Based on the first-order shear deformation theory and the kinetic relation of von Kárman type, the frequency equation for free vibration of functionally graded ring was derived. The derived results were verified by those in literatures which reveals that the present theory can be appropriate to predict the free vibration characteristics for quite thick rings with the radius-to-thickness ratio from 60 down to 2.09. Comparison between the plane stress case and the plane strain case indicates a slight difference. Meanwhile, the effects of the structural dimensional parameters and the material inhomogeneous parameter are examined. It is interesting that the value of the logarithmic form of vibration frequency is inversely proportional to the logarithmic form of the radius-to-thickness ratio or the mean radius.

  15. Vibrational dynamics of ice in reverse micelles

    NARCIS (Netherlands)

    Dokter, A.M.; Petersen, C.; Woutersen, S.; Bakker, H.J.

    2008-01-01

    he ultrafast vibrational dynamics of HDO:D2O ice at 180 K in anionic reverse micelles is studied by midinfrared femtosecond pump-probe spectroscopy. Solutions containing reverse micelles are cooled to low temperatures by a fast-freezing procedure. The heating dynamics of the micellar solutions is

  16. Toward yrast spectroscopy in soft vibrational nuclei

    International Nuclear Information System (INIS)

    Marumori, Toshio; Kuriyama, Atsushi; Sakata, Fumihiko.

    1979-10-01

    In a formally parallel way with that exciting progress has been recently achieved in understanding the yrast spectra of the rotational nuclei in terms of the quasi-particle motion in the rotating frame, an attempt to understand the yrast spectra of the vibrational nuclei in terms of the quasi-particle motion is proposed. The essential idea is to introduce the quasi-particle motion in a generalized vibrating frame, which can be regarded as a rotating frame in the gauge space of ''physical'' phonons where the number of the physical phonons plays the role of the angular momentum. On the basis of a simple fundamental principle called as the ''invariance principle of the Schroedinger equation'', which leads us to the ''maximal decoupling'' between the physical phonon and the intrinsic modes, it is shown that the vibrational frame as well as the physical-phonon-number operator represented by the quasi-particles can be self-consistently determined. A new scope toward the yrast spectroscopy of the vibrational nuclei in terms of the quasi-particle motion is discussed. (author)

  17. Vibration Measurements on the Frejlev Mast

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Hansen, Lars Pilegaard

    The present report presents full-scale measurements on the Frejlev-mast which is a 200 meter hight guyed steel mast located 10 km. from Aalborg. The goal of the research was to investigate various techniques which could be used to estimate cable forces from vibration measurements. The cables...

  18. Nonlinear Vibration of a Magnetic Spring

    Science.gov (United States)

    Zhong, Juhua; Cheng, Zhongqi; Ge, Ziming; Zhang, Yuelan; Lu, Wenqiang; Song, Feng; Li, Chuanyong

    2012-01-01

    To demonstrate the different vibration characteristics of a magnetic spring compared with those of a metal one, a magnetic spring apparatus was constructed from a pair of circular magnets of the same size with an inside diameter of 2.07 cm and an outside diameter of 4.50 cm. To keep the upper magnet in a suspension state, the two magnets were…

  19. Internal Temperature Control For Vibration Testers

    Science.gov (United States)

    Dean, Richard J.

    1996-01-01

    Vibration test fixtures with internal thermal-transfer capabilities developed. Made of aluminum for rapid thermal transfer. Small size gives rapid response to changing temperatures, with better thermal control. Setup quicker and internal ducting facilitates access to parts being tested. In addition, internal flows smaller, so less energy consumed in maintaining desired temperature settings.

  20. Structural, intramolecular hydrogen bonding and vibrational studies ...

    Indian Academy of Sciences (India)

    An extensive theoretical study on the molecular structure and vibrational analysis of 3-amino-4- methoxy benzamide (3A4MBA) was undertaken using density functional theoretical (DFT) method. The possibility of formation of intramolecular hydrogen bonding was identified from structural parameter analysis and confirmed ...

  1. Structural, intramolecular hydrogen bonding and vibrational studies

    Indian Academy of Sciences (India)

    An extensive theoretical study on the molecular structure and vibrational analysis of 3-amino-4- methoxy benzamide (3A4MBA) was undertaken using density functional theoretical (DFT) method. The possibility of formation of intramolecular hydrogen bonding was identified from structural parameter analysis and confirmed ...

  2. Smart paint sensor for monitoring structural vibrations

    International Nuclear Information System (INIS)

    Al-Saffar, Y; Baz, A; Aldraihem, O

    2012-01-01

    A class of smart paint sensors is proposed for monitoring the structural vibration of beams. The sensor is manufactured from an epoxy resin which is mixed with carbon black nano-particles to make it electrically conducting and sensitive to mechanical vibrations. A comprehensive theoretical and experimental investigation is presented to understand the underlying phenomena governing the operation of this class of paint sensors and evaluate its performance characteristics. A theoretical model is presented to model the electromechanical behavior of the sensor system using molecular theory. The model is integrated with an amplifier circuit in order to predict the current and voltage developed by the paint sensor when subjected to loading. Furthermore, the sensor/amplifier circuit models are coupled with a finite element model of a base beam to which the sensor is bonded. The resulting multi-field model is utilized to predict the behavior of both the sensor and the beam when subjected to a wide variety of vibration excitations. The predictions of the multi-field finite element model are validated experimentally and the behavior of the sensor is evaluated both in the time and the frequency domains. The performance of the sensor is compared with the performance of conventional strain gages to emphasize its potential and merits. The presented techniques are currently being extended to sensors that can monitor the vibration and structural power flow of two-dimensional structures. (paper)

  3. Cable Vibration due to Ice Accretions

    DEFF Research Database (Denmark)

    Gjelstrup, Henrik; Georgakis, Christos; Larsen, Allan

    investigation behind the causes of this relatively isolated hanger vibration event on the Great Belt East Bridge is presented. Furthermore a stability criterion for a 3DOF bluff body is proposed. One of the main assumptions of the investigation is that icy conditions may have contributed in some way to large...

  4. Laserlike Vibrational Instability in Rectifying Molecular Conductors

    DEFF Research Database (Denmark)

    Lu, Jing Tao; Hedegård, Per; Brandbyge, Mads

    2011-01-01

    We study the damping of molecular vibrations due to electron-hole pair excitations in donor-acceptor (D-A) type molecular rectifiers. At finite voltage additional nonequilibrium electron-hole pair excitations involving both electrodes become possible, and contribute to the stimulated emission....... We investigate the effect in realistic molecular rectifier structures using first-principles calculations....

  5. Vibrational resonance in the Morse oscillator

    Indian Academy of Sciences (India)

    Abstract. The occurrence of vibrational resonance is investigated in both classical and quantum mechanical Morse oscillators driven by a biharmonic force. The biharmonic force consists of two forces of widely different frequencies ω and with. ≫ ω. In the damped and biharmoni- cally driven classical Morse oscillator, ...

  6. Optimal control of vibrational transitions of HCl

    Indian Academy of Sciences (India)

    Control of fundamental and overtone transitions of a vibration are studied for the diatomic molecule, HCl. Specifically, the results of the effect of variation of the penalty factor on the physical attributes of the system (i.e., probabilities) and pulse (i.e., amplitudes) considering three different pulse durations for each value of the ...

  7. Succesful teaching of experimental vibration research

    NARCIS (Netherlands)

    Wolbert, Bert; van der Hoogt, Peter; Lok, Zacharias A.J.; de Boer, Andries

    For more than 20 years, master students have been offered a practical training on experimental vibration research by the Structural Dynamics & Acoustics Section of the University of Twente. The basic theoretical knowledge, necessary to attend this practical training, is provided for the Master part

  8. Forced Vibrations of a Cantilever Beam

    Science.gov (United States)

    Repetto, C. E.; Roatta, A.; Welti, R. J.

    2012-01-01

    The theoretical and experimental solutions for vibrations of a vertical-oriented, prismatic, thin cantilever beam are studied. The beam orientation is "downwards", i.e. the clamped end is above the free end, and it is subjected to a transverse movement at a selected frequency. Both the behaviour of the device driver and the beam's weak-damping…

  9. Probability of Failure in Random Vibration

    DEFF Research Database (Denmark)

    Nielsen, Søren R.K.; Sørensen, John Dalsgaard

    1988-01-01

    Close approximations to the first-passage probability of failure in random vibration can be obtained by integral equation methods. A simple relation exists between the first-passage probability density function and the distribution function for the time interval spent below a barrier before out...

  10. Enriched vibrational resonance in certain discrete systems

    Indian Academy of Sciences (India)

    Corresponding author. E-mail: philominathan@gmail.com ... vibrational resonance behaviour unlike the earlier reports, they are taken for investigation and the necessary numerical and analytical results are ..... quasiperiodic route to chaos instead of period-doubling route. The effect of perturbation in the destruction of ...

  11. Experimental study of acoustic vibration in BWRs

    International Nuclear Information System (INIS)

    Kumagai, Kosuke; Someya, Satoshi; Okamoto, Koji

    2009-01-01

    In recent years, the power uprate of Boiling Water Reactors have been conducted at several existing power plants as a way to improve plant economy. In one of the power uprated plants (117.8% uprates) in the United States, the steam dryer breakages due to fatigue fracture occurred. It is conceivable that the increased steam flow passing through the branches caused a self-induced vibration with the propagation of sound wave into the steam-dome. The resonance among the structure, flow and the pressure fluctuation resulted in the breakages. To understand the basic mechanism of the resonance, previous researches were done by a point measurement of the pressure and by a phase averaged measurement of the flow, while it was difficult to detect the interaction among them by the conventional method. In this study, Dynamic Particle Image Velocimetry (PIV) System was applied to investigate the effect of sound on natural convection and forced convection. Dynamic PIV system is the newest entrant to the field of fluid flow measurement. Its paramount advantage is the instantaneous global evaluation of conditions over plane extended across the whole velocity field. Also, to evaluate the coupling between the acoustic wave and structure (simulated as tuning fork vibrator in this experiment), in the resonance frequency of tuning fork vibrator, fluid behavior and the motion of tuning fork vibrator are measured simultaneously. (author)

  12. Longitudinal shear vibrations of composite poroelastic cylinders ...

    African Journals Online (AJOL)

    Employing Biot's theory of wave propagation in liquid saturated porous media, longitudinal shear vibrations of composite poroelastic cylinders of infinite extent are investigated. The composite poroelastic cylinder is made of two different poroelastic materials. The dilatations of liquid and solid media are zero, hence liquid ...

  13. Simulation of fuel rods vibration in power reactors by vibration of tape coated with cadmium

    International Nuclear Information System (INIS)

    Holland, L.

    1982-01-01

    The circulation of cooling water in light water power reactor makes a vibration in internal components. The monitoring of those vibrations is necessary aiming to the safety use of reactors. Aiming at study those vibrations a neutron absorber, type vibratory tape was introduced in the core of a research reactor type Pulstar, operating at 80 W of power. The induced power variations were measured with an ionization chamber put besides the reactor core. The detector signal was recorded and analysed in a PDP-11 computer. The analysis of the results show that the power density of the detector signal, and thus, the power reactor, increase in the O-25 Hz range with an increase in the pulse height vibration. (E.G.) [pt

  14. Experimental Study on Piezoelectric Energy Harvesting from Vortex-Induced Vibrations and Wake-Induced Vibrations

    Directory of Open Access Journals (Sweden)

    Min Zhang

    2016-01-01

    Full Text Available A rigid circular cylinder with two piezoelectric beams attached on has been tested through vortex-induced vibrations (VIV and wake-induced vibrations (WIV by installing a big cylinder fixed upstream, in order to study the influence of the different flow-induced vibrations (FIV types. The VIV test shows that the output voltage increases with the increases of load resistance; an optimal load resistance exists for the maximum output power. The WIV test shows that the vibration of the small cylinder is controlled by the vortex frequency of the large one. There is an optimal gap of the cylinders that can obtain the maximum output voltage and power. For a same energy harvesting device, WIV has higher power generation capacity; then the piezoelectric output characteristics can be effectively improved.

  15. Data of piezoelectric vibration energy harvesting of a bridge undergoing vibration testing and train passage

    Directory of Open Access Journals (Sweden)

    Paul Cahill

    2018-04-01

    Full Text Available The data presented in this article is in relation to the research article “Vibration energy harvesting based monitoring of an operational bridge undergoing forced vibration and train passage” Cahill et al. (2018 [1]. The article provides data on the full-scale bridge testing using piezoelectric vibration energy harvesters on Pershagen Bridge, Sweden. The bridge is actively excited via a swept sinusoidal input. During the testing, the bridge remains operational and train passages continue. The test recordings include the voltage responses obtained from the vibration energy harvesters during these tests and train passages. The original dataset is made available to encourage the use of energy harvesting for Structural Health Monitoring.

  16. Structure and vibrations of glutathione studied by vibrational spectroscopy and density functional theory.

    Science.gov (United States)

    Singh, Gurpreet; Dogra, Sukh Dev; Kaur, Sarvpreet; Tripathi, S K; Prakash, Satya; Rai, Bimal; Saini, G S S

    2015-01-01

    The vibrational properties of glutathione have been investigated by infrared absorption and Raman spectroscopic techniques, and density functional theory calculations at the B3LYP/6-31+G(d,p) level. Assignments of all the experimentally observed vibrational bands have been done with the help of simulated vibrational spectra and potential energy distribution calculations of glutathione water cluster, which includes the effect of hydrogen bonding. Optimized molecular parameters of energy minimized structure have been compared with the available experimental values. Calculated molecular parameters of glutathione-water cluster match well with the experimental values. Some of the calculated molecular parameters and vibrational frequencies of vapor phase glutathione-water cluster suggest participation of some atoms of glutathione in hydrogen bonding. Experimentally observed UV-Visible absorption spectrum of glutathione has also been reported. Observed band at 203 nm has been assigned to electronic transitions calculated with time dependent density functional theory. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Vibration Analysis of a Residential Building

    Directory of Open Access Journals (Sweden)

    Sampaio Regina Augusta

    2015-01-01

    Full Text Available The aim of this paper is to present the results of a study regarding vibration problems in a 17 storey residential building during pile driving in its vicinity. The structural design of the building was checked according to the Brazilian standards NBR6118 and NBR6123, and using commercial finite element software. An experimental analysis was also carried out using low frequency piezo-accelerometers attached to the building structure. Structure vibrations were recorded under ambient conditions. Four monitoring tests were performed on different days. The objective of the first monitoring test was an experimental modal analysis. To obtain de modal parameters, data was processed in the commercial software ARTEMIS employing two methods: the Stochastic Subspace Identification and the Frequency Domain Decomposition. Human comfort was investigated considering the International Standard ISO 2631. The Portuguese standard, NP2074, was also used as a reference, since it aims to limit the adverse effects of vibrations in structures caused by pile driving in the vicinity of the structure. The carried out experimental tests have shown that, according to ISO2301, the measure vibration levels are above the acceptance limits. However, velocity peaks are below the limits established by NP2074. It was concluded that, although the structure has adequate capacity to resist internal forces according to normative criteria, it has low horizontal stiffness, which could be verified by observing the vibration frequencies and mode shapes obtained with the finite element models, and its similarity with the experimental results. Thus, the analyses indicate the occurrence of discomfort by the residents.

  18. Effect of Vibrations on Transportation System

    Science.gov (United States)

    Birlik, Gülin; Sezgin, Önder Cem

    In overly populated cities people living in suburban areas have to endure long journeys in order to reach their job sites. Whether they go by train, bus or by car they are inevitably exposed to vibrations, of considerable magnitude, in vertical (z) and lateral (x, y) directions. The immediate effect of vibration exposure is the fatigue of ones' muscles. This is verified by the blood and saliva analysis of the volunteers travelling in a train. Their lactic acid levels were increased by 34% at the end of a 5 hr journey. The most affected people by vibration were, without doubt, the train operators and bus drivers. 42% of the suburban train operators had pain complaints at their waists. az(floor) in the machinist cabin of a suburban train was measured to be, on the average, 0.23 m/s2. Max peak was 1.34 m/s2. The bus and car drivers were exposed to lower vibrations but they were exposed to multiple shocks originating from the non-standardized humps placed on the roads. Peak az(seat) = 0.054 m/s2 (f = 5.25 Hz) (vcar = 30 km/hr) on an asphalt road increased considerably while crossing over a hump. This value was 1.27 m/s2 (f = 4.5 Hz) in case of bus drivers (vbus = 20 km/hr). Studies have been done to provide practical measures for the reduction of the vibrations transmitted to the drivers. The waist belts filled with fluids of different viscosities prepared for this purpose seemed to be promising. The cushions filled with glycerin and gel were observed to be the best alternatives.

  19. Transient vibration analytical modeling and suppressing for vibration absorber system under impulse excitation

    Science.gov (United States)

    Wang, Xi; Yang, Bintang; Yu, Hu; Gao, Yulong

    2017-04-01

    The impulse excitation of mechanism causes transient vibration. In order to achieve adaptive transient vibration control, a method which can exactly model the response need to be proposed. This paper presents an analytical model to obtain the response of the primary system attached with dynamic vibration absorber (DVA) under impulse excitation. The impulse excitation which can be divided into single-impulse excitation and multi-impulse excitation is simplified as sinusoidal wave to establish the analytical model. To decouple the differential governing equations, a transform matrix is applied to convert the response from the physical coordinate to model coordinate. Therefore, the analytical response in the physical coordinate can be obtained by inverse transformation. The numerical Runge-Kutta method and experimental tests have demonstrated the effectiveness of the analytical model proposed. The wavelet of the response indicates that the transient vibration consists of components with multiple frequencies, and it shows that the modeling results coincide with the experiments. The optimizing simulations based on genetic algorithm and experimental tests demonstrate that the transient vibration of the primary system can be decreased by changing the stiffness of the DVA. The results presented in this paper are the foundations for us to develop the adaptive transient vibration absorber in the future.

  20. Vibration immission forecast by means of train equivalent synthetic vibration experiments

    Directory of Open Access Journals (Sweden)

    Steinhauser Peter

    2015-01-01

    Full Text Available Vibration abatement measures at a railway track require forecasts before the rails are put into place. Due to the multiple feedback system between train, track, geodynamics of the local underground and the dynamic behavior of the neighbourhood buildings these prognoses become very elaborate. All the parameters of the dynamic system scatter extremely as the results from numerous investigations prove. This concerns vibration emission spectra, tunnel mobility, geodynamic vibration loss along the transfer through the underground as well as the natural frequencies from buildings and ceilings. Therefore experimental in-situ investigations are indispensable for trustworthy forecasts. In this paper the VibroScan method is presented, whose basic idea is to implement the principle of equivalence between the synthetic vibrations used for the experiments and train vibration emissions at the highest possible degree. This is focused on emission spectra, force of excitation, unsprung wheelset mass and axle load. The necessary experimental provisions are discussed and some examples of results are given like the protection of the Musikverein building in Vienna or the Sagrada Familia basilica in Barcelona against vibrations from tunnels in the immediate neighbourhood.

  1. Low-frequency vibration control of floating slab tracks using dynamic vibration absorbers

    Science.gov (United States)

    Zhu, Shengyang; Yang, Jizhong; Yan, Hua; Zhang, Longqing; Cai, Chengbiao

    2015-09-01

    This study aims to effectively and robustly suppress the low-frequency vibrations of floating slab tracks (FSTs) using dynamic vibration absorbers (DVAs). First, the optimal locations where the DVAs are attached are determined by modal analysis with a finite element model of the FST. Further, by identifying the equivalent mass of the concerned modes, the optimal stiffness and damping coefficient of each DVA are obtained to minimise the resonant vibration amplitudes based on fixed-point theory. Finally, a three-dimensional coupled dynamic model of a metro vehicle and the FST with the DVAs is developed based on the nonlinear Hertzian contact theory and the modified Kalker linear creep theory. The track irregularities are included and generated by means of a time-frequency transformation technique. The effect of the DVAs on the vibration absorption of the FST subjected to the vehicle dynamic loads is evaluated with the help of the insertion loss in one-third octave frequency bands. The sensitivities of the mass ratio of DVAs and the damping ratio of steel-springs under the floating slab are discussed as well, which provided engineers with the DVA's adjustable room for vibration mitigation. The numerical results show that the proposed DVAs could effectively suppress low-frequency vibrations of the FST when tuned correctly and attached properly. The insertion loss due to the attachment of DVAs increases as the mass ratio increases, whereas it decreases with the increase in the damping ratio of steel-springs.

  2. Development of S-wave portable vibrator; S ha potable vibrator shingen no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Kaida, Y.; Matsubara, Y. [OYO Corp., Tokyo (Japan); Nijhof, V.; Brouwer, J.

    1996-05-01

    An S-wave portable vibrator to serve as a seismic source has been developed for the purpose of applying the shallow-layer reflection method to the study of the soil ground. The author, et al., who previously developed a P-wave portable vibrator has now developed an S-wave version, considering the advantage of the S-wave over the P-wave in that, for example, the S-wave velocity may be directly compared with the N-value representing ground strength and that the S-wave travels more slowly than the P-wave through sticky soil promising a higher-resolution exploration. The experimentally constructed S-wave vibrator consists of a conventional P-wave vibrator and an L-type wooden base plate combined therewith. Serving as the monitor for vibration is a conventional accelerometer without any modification. The applicability test was carried out at a location where a plank hammering test was once conducted for reflection aided exploration, and the result was compared with that of the plank hammering test. As the result, it was found that after some preliminary treatment the results of the two tests were roughly the same but that both reflected waves were a little sharper in the S-wave vibrator test than in the plank hammering test. 4 refs., 9 figs., 1 tab.

  3. The influence of flywheel micro vibration on space camera and vibration suppression

    Science.gov (United States)

    Li, Lin; Tan, Luyang; Kong, Lin; Wang, Dong; Yang, Hongbo

    2018-02-01

    Studied the impact of flywheel micro vibration on a high resolution optical satellite that space-borne integrated. By testing the flywheel micro vibration with six-component test bench, the flywheel disturbance data is acquired. The finite element model of the satellite was established and the unit force/torque were applied at the flywheel mounting position to obtain the micro vibration data of the camera. Integrated analysis of the data of the two parts showed that the influence of flywheel micro vibration on the camera is mainly concentrated around 60-80 Hz and 170-230 Hz, the largest angular displacement of the secondary mirror along the optical axis direction is 0.04″ and the maximum angular displacement vertical to optical axis is 0.032″. After the design and installation of vibration isolator, the maximum angular displacement of the secondary mirror is 0.011″, the decay rate of root mean square value of the angular displacement is more than 50% and the maximum is 96.78%. The whole satellite was suspended to simulate the boundary condition on orbit; the imaging experiment results show that the image motion caused by the flywheel micro vibrationis less than 0.1 pixel after installing the vibration isolator.

  4. Vibration transfers to measure the performance of vibration isolated platforms on site using background noise excitation

    Science.gov (United States)

    Segerink, F. B.; Korterik, J. P.; Offerhaus, H. L.

    2011-06-01

    This article demonstrates a quick and easy way of quantifying the performance of a vibration-isolated platform. We measure the vibration transfer from floor to table using background noise excitation from the floor. As no excitation device is needed, our setup only requires two identical sensors (in our case, low noise accelerometers), a data acquisition system, and processing software. Background noise excitation from the floor has the additional advantage that any non-linearity in the suspension system relevant to the actual vibration amplitudes will be taken into account. Measurement time is typically a few minutes, depending on the amount of background noise. The (coherent) transfer of the vibrations in the floor to the platform, as well as the (non-coherent) acoustical noise pick-up by the platform are measured. Since we use calibrated sensors, the absolute value of the vibration levels is established and can be expressed in vibration criterion curves. Transfer measurements are shown and discussed for two pneumatic isolated optical tables, a spring suspension system, and a simple foam suspension system.

  5. VIBRATION SENSORS AND MICROELECTROMECHANICAL SYSTEM FOR MOBILE DEVICES SUCH AS ANALOGS, FOR EVALUATION OF VIBRATION OF ROTARY MACHINES

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available The paper carried out a comparison of vibration sensors used to measure the vibration condition units with gas turbine engines, with motion sensors, microelectromechanical systems used in modern mobile devices (for example, devices on the platform "Android". It provides opinions on the possibility of assessment of vibration, using sensors of mobile devices.

  6. Apparatus and method for vibrating a casing string during cementing

    International Nuclear Information System (INIS)

    Rankin, R.E.; Rankin, K.T.

    1992-01-01

    This patent describes a method of cementing a string of casing in a well. It comprises: securing a vibrating device into the string of casing near the lower end of the string of casing; lowering the string of casing into the well to the desired depth; pumping a cement slurry down the string of casing; causing a portion of the cement slurry being pumped down the string of casing to vibrate the vibrating device; and wherein the vibrating device is secured in the string of casing by cementing the vibrating device within a sub, then securing the sub into the string of casing prior to lowering the string of casing into the well

  7. Vibrational mechanics nonlinear dynamic effects, general approach, applications

    CERN Document Server

    Blekhman, Iliya I

    2000-01-01

    This important book deals with vibrational mechanics - the new, intensively developing section of nonlinear dynamics and the theory of nonlinear oscillations. It offers a general approach to the study of the effect of vibration on nonlinear mechanical systems.The book presents the mathematical apparatus of vibrational mechanics which is used to describe such nonlinear effects as the disappearance and appearance under vibration of stable positions of equilibrium and motions (i.e. attractors), the change of the rheological properties of the media, self-synchronization, self-balancing, the vibrat

  8. Production, Delivery and Application of Vibration Energy in Healthcare

    International Nuclear Information System (INIS)

    Abundo, Paolo; Trombetta, Chiara; Foti, Calogero; Rosato, Nicola

    2011-01-01

    In Rehabilitation Medicine therapeutic application of vibration energy in specific clinical treatments and in sport rehabilitation is being affirmed more and more.Vibration exposure can have positive or negative effects on the human body depending on the features and time of the characterizing wave. The human body is constantly subjected to different kinds of vibrations, inducing bones and muscles to actively modify their structure and metabolism in order to fulfill the required functions. Like every other machine, the body supports only certain vibration energy levels over which long term impairments can be recognized. As shown in literature anyway, short periods of vibration exposure and specific frequency values can determine positive adjustments.

  9. Production, Delivery and Application of Vibration Energy in Healthcare

    Science.gov (United States)

    Abundo, Paolo; Trombetta, Chiara; Foti, Calogero; Rosato, Nicola

    2011-02-01

    In Rehabilitation Medicine therapeutic application of vibration energy in specific clinical treatments and in sport rehabilitation is being affirmed more and more.Vibration exposure can have positive or negative effects on the human body depending on the features and time of the characterizing wave. The human body is constantly subjected to different kinds of vibrations, inducing bones and muscles to actively modify their structure and metabolism in order to fulfill the required functions. Like every other machine, the body supports only certain vibration energy levels over which long term impairments can be recognized. As shown in literature anyway, short periods of vibration exposure and specific frequency values can determine positive adjustments.

  10. The photodissociation and reaction dynamics of vibrationally excited molecules

    Energy Technology Data Exchange (ETDEWEB)

    Crim, F.F. [Univ. of Wisconsin, Madison (United States)

    1993-12-01

    This research determines the nature of highly vibrationally excited molecules, their unimolecular reactions, and their photodissociation dynamics. The goal is to characterize vibrationally excited molecules and to exploit that understanding to discover and control their chemical pathways. Most recently the author has used a combination of vibrational overtone excitation and laser induced fluorescence both to characterize vibrationally excited molecules and to study their photodissociation dynamics. The author has also begun laser induced grating spectroscopy experiments designed to obtain the electronic absorption spectra of highly vibrationally excited molecules.

  11. Analysis of different vibration patterns to guide blind people.

    Science.gov (United States)

    Durá-Gil, Juan V; Bazuelo-Ruiz, Bruno; Moro-Pérez, David; Mollà-Domenech, Fernando

    2017-01-01

    The literature indicates the best vibration positions and frequencies on the human body where tactile information is transmitted. However, there is a lack of knowledge about how to combine tactile stimuli for navigation. The aim of this study is to compare different vibration patterns outputted to blind people and to determine the most intuitive vibration patterns to indicate direction for navigation purposes through a tactile belt. The vibration patterns that stimulate the front side of the waist are preferred for indicating direction. Vibration patterns applied on the back side of the waist could be suitable for sending messages such as stop.

  12. Analysis of different vibration patterns to guide blind people

    Directory of Open Access Journals (Sweden)

    Juan V. Durá-Gil

    2017-03-01

    Full Text Available The literature indicates the best vibration positions and frequencies on the human body where tactile information is transmitted. However, there is a lack of knowledge about how to combine tactile stimuli for navigation. The aim of this study is to compare different vibration patterns outputted to blind people and to determine the most intuitive vibration patterns to indicate direction for navigation purposes through a tactile belt. The vibration patterns that stimulate the front side of the waist are preferred for indicating direction. Vibration patterns applied on the back side of the waist could be suitable for sending messages such as stop.

  13. Catalytic synthesis of ammonia using vibrationally excited nitrogen

    DEFF Research Database (Denmark)

    Henriksen, Niels Engholm; Billing, Gert D.; Hansen, Flemming Yssing

    1992-01-01

    In a previous study we have considered the catalytic synthesis of ammonia in the presence of vibrationally excited nitrogen. The distribution over vibrational states was assumed to be maintained during the reaction, and it was shown that the yield of ammonia increased considerably compared...... to that from conventional synthesis. In the present study the nitrogen molecules are only excited at the inlet of a plug flow reactor, and the importance of vibrational relaxation is investigated. We show that vibrational excitation can give an enhanced yield of ammonia also in the situation where vibrational...

  14. Smart Sensor for Analyzing Train Vibration in WCR Zone

    Directory of Open Access Journals (Sweden)

    Alka DUBEY

    2009-09-01

    Full Text Available In the present paper a smart vibration sensor is developed for railway electric engine WAP-7. Which is a self-sensation device equipped with recording and wireless communication interface. One programmed microcontroller 89C52 is used, which record vibration of trains with real time into memory. There is certain limit of vibrations, which is acceptable by track. Beyond this limit track can be damaged and may result major casualty. Smart sensor indicate the level of current vibration with its ideal value for prevention of excessive vibration it starts buzz ring. The work is highly applicable to the high speed trains. The high level vibration cause serious accidents due to the vibration.

  15. Application of system concept in vibration and noise reduction

    Directory of Open Access Journals (Sweden)

    SHENG Meiping

    2017-08-01

    Full Text Available Although certain vibration and noise control technologies are maturing, such as vibration absorption, vibration isolation, sound absorption and sound insulation, and new methods for specific frequency bands or special environments have been proposed unceasingly, there is still no guarantee that practical effective vibration and noise reduction can be obtained. An important constraint for vibration and noise reduction is the lack of a system concept, and the integrity and relevance of such practical systems as ship structure have not obtained enough attention. We have tried to use the system engineering theory in guiding vibration and noise reduction, and have already achieved certain effects. Based on the system concept, the noise control of a petroleum pipeline production workshop has been completed satisfactorily, and the abnormal noise source identification of an airplane has been accomplished successfully. We want to share our experience and suggestions to promote the popularization of the system engineering theory in vibration and noise control.

  16. Vibrational population distributions in nonequilibrium nozzle expansion flows

    Science.gov (United States)

    Watt, W. S.; Rich, J. W.

    1971-01-01

    Experimental measurements and theoretical calculations of the vibrational population distribution in nonequilibrium nozzle expansion flows of gas mixtures are reported. These studies were directed toward determining whether vibrational energy exchange pumping could lead to laser action on the vibrational bands of a diatomic molecule. Three different types of experiments were conducted. These showed (1) that vibrational energy was preferentially transferred from N2 to CO in supersonic nozzle flows containing these gases; (2) that under some conditions this vibrational energy exchange pumping mechanism created population inversions in the vibrational levels of CO; and (3) that at large expansion ratios the magnitude of these population inversions was sufficient to sustain lasing in the nozzle. A theoretical model was developed to calculate vibrational state population distributions in gas dynamic expansions of a mixture of diatomic gases. Although only isothermal calculations have been completed, these data indicate that population inversions are predicted for conditions similar to those obtained in the nozzle expansion flows.

  17. "Suntelligence" Survey

    Science.gov (United States)

    ... to the American Academy of Dermatology's "Suntelligence" sun-smart survey. Please answer the following questions to measure ... be able to view a ranking of major cities suntelligence based on residents' responses to this survey. ...

  18. Vibration reduction in a tilting rotor using centrifugal pendulum vibration absorbers

    Science.gov (United States)

    Shi, Chengzhi; Shaw, Steven W.; Parker, Robert G.

    2016-12-01

    This paper investigates vibration reduction in a rigid rotor with tilting, rotational, and translational motions using centrifugal pendulum vibration absorbers (CPVAs). A linearized vibration model is derived for the system consisting of the rotor and multiple sets of absorbers tuned to different orders. Each group of absorbers lies in a given plane perpendicular to the rotor rotation axis. Gyroscopic system modal analysis is applied to derive the steady-state response of the absorbers and the rotor to external, rotor-order, periodic forces and torques with frequency mΩ, where Ω is the mean rotor speed and m is the engine order (rotor-order). It is found that an absorber group with tuning order m is effective at reducing the rotor translational, tilting, and rotational vibrations, provided certain conditions are met. When the periodic force and torque are caused by N substructures that are equally spaced around the rotor, the rotor translational and tilting vibrations at order j are addressed by two absorber groups with tuning orders jN±1. In this case, the rotor rotational vibration at order j can be attenuated by an absorber group with tuning order jN. The results show how the response depends on the load amplitudes and order, the rotor speed, and design parameters associated with the sets of absorbers, most importantly, their tuning, mass, and plane of placement. In the ideal case with zero damping and exact tuning of the absorber sets, the vibrations can be eliminated for a range of loads over which the linearized model holds. The response for systems with detuned absorbers is also determined, which is relevant to applications where small detuning is employed due to robustness issues, and to allow for a larger range of operating loads over which the absorbers are effective. The system also exhibits undesirable resonances very close to these tuning conditions, an issue that is difficult to resolve and deserves further investigation.

  19. Adaptations of mouse skeletal muscle to low intensity vibration training

    Science.gov (United States)

    McKeehen, James N.; Novotny, Susan A.; Baltgalvis, Kristen A.; Call, Jarrod A.; Nuckley, David J.; Lowe, Dawn A.

    2013-01-01

    Purpose We tested the hypothesis that low intensity vibration training in mice improves contractile function of hindlimb skeletal muscles and promotes exercise-related cellular adaptations. Methods We subjected C57BL/6J mice to 6 wk, 5 d·wk−1, 15 min·d−1 of sham or low intensity vibration (45 Hz, 1.0 g) while housed in traditional cages (Sham-Active, n=8; Vibrated-Active, n=10) or in small cages to restrict physical activity (Sham-Restricted, n=8; Vibrated-Restricted, n=8). Contractile function and resistance to fatigue were tested in vivo (anterior and posterior crural muscles) and ex vivo on the soleus muscle. Tibialis anterior and soleus muscles were evaluated histologically for alterations in oxidative metabolism, capillarity, and fiber types. Epididymal fat pad and hindlimb muscle masses were measured. Two-way ANOVAs were used to determine effects of vibration and physical inactivity. Results Vibration training resulted in a 10% increase in maximal isometric torque (P=0.038) and 16% faster maximal rate of relaxation (P=0.030) of the anterior crural muscles. Posterior crural muscles were unaffected by vibration, with the exception of greater rates of contraction in Vibrated-Restricted mice compared to Vibrated-Active and Sham-Restricted mice (P=0.022). Soleus muscle maximal isometric tetanic force tended to be greater (P=0.057) and maximal relaxation was 20% faster (P=0.005) in Vibrated compared to Sham mice. Restriction of physical activity induced muscle weakness but was not required for vibration to be effective in improving strength or relaxation. Vibration training did not impact muscle fatigability or any indicator of cellular adaptation investigated (P≥0.431). Fat pad but not hindlimb muscle masses were affected by vibration training. Conclusion Vibration training in mice improved muscle contractility, specifically strength and relaxation rates, with no indication of adverse effects to muscle function or cellular adaptations. PMID:23274599

  20. Control of Drop Motion by Mechanical Vibrations

    Science.gov (United States)

    Bestehorn, Michael

    2014-11-01

    Since the first experimental observations of Michael Faraday in 1831 it is known that a vibrating liquid may show an instability of its flat free surface with respect to oscillating regular surface patterns. We study thin liquid films on a horizontal substrate in the long wave approximation. The films are parametrically excited by mechanical horizontal or inclined oscillations. Inertia effects are taken into account and the standard thin film formulation is extended by a second equation for the vertically averaged mass flux. The films can be additionally unstable by Van der Waals forces on a partially wetting substrate, leading to the formation of drops. These drops can be manipulated by the vibrations to move in a desired direction. Linear results based on a damped complex valued Mathieu equation as well as fully nonlinear results using a reduced model will be presented, for more details see.

  1. Automatic monitoring of vibration welding equipment

    Energy Technology Data Exchange (ETDEWEB)

    Spicer, John Patrick; Chakraborty, Debejyo; Wincek, Michael Anthony; Wang, Hui; Abell, Jeffrey A; Bracey, Jennifer; Cai, Wayne W

    2014-10-14

    A vibration welding system includes vibration welding equipment having a welding horn and anvil, a host device, a check station, and a robot. The robot moves the horn and anvil via an arm to the check station. Sensors, e.g., temperature sensors, are positioned with respect to the welding equipment. Additional sensors are positioned with respect to the check station, including a pressure-sensitive array. The host device, which monitors a condition of the welding equipment, measures signals via the sensors positioned with respect to the welding equipment when the horn is actively forming a weld. The robot moves the horn and anvil to the check station, activates the check station sensors at the check station, and determines a condition of the welding equipment by processing the received signals. Acoustic, force, temperature, displacement, amplitude, and/or attitude/gyroscopic sensors may be used.

  2. Acoustical analysis of gear housing vibration

    Science.gov (United States)

    Seybert, A. F.; Wu, T. W.; Wu, X. F.; Oswald, Fred B.

    1991-01-01

    The modal and acoustical analysis of the NASA gear-noise rig is described. Experimental modal analysis techniques were used to determine the modes of vibration of the transmission housing. The resulting modal data were then used in a boundary element method (BEM) analysis to calculate the sound pressure and sound intensity on the surface of the housing as well as the radiation efficiency of each mode. The radiation efficiencies of the transmission housing modes are compared with theoretical results for finite, baffled plates. A method that uses the measured mode shapes and the BEM to predict the effect of simple structural changes on the sound radiation efficiency of the modes of vibration is also described.

  3. Dynamics and vibrations progress in nonlinear analysis

    CERN Document Server

    Kachapi, Seyed Habibollah Hashemi

    2014-01-01

    Dynamical and vibratory systems are basically an application of mathematics and applied sciences to the solution of real world problems. Before being able to solve real world problems, it is necessary to carefully study dynamical and vibratory systems and solve all available problems in case of linear and nonlinear equations using analytical and numerical methods. It is of great importance to study nonlinearity in dynamics and vibration; because almost all applied processes act nonlinearly, and on the other hand, nonlinear analysis of complex systems is one of the most important and complicated tasks, especially in engineering and applied sciences problems. There are probably a handful of books on nonlinear dynamics and vibrations analysis. Some of these books are written at a fundamental level that may not meet ambitious engineering program requirements. Others are specialized in certain fields of oscillatory systems, including modeling and simulations. In this book, we attempt to strike a balance between th...

  4. Vibrational Raman optical activity of ketose monosaccharides

    Science.gov (United States)

    Bell, Alasdair F.; Hecht, Lutz; Barron, Laurence D.

    1995-07-01

    The vibrational Raman optical activity (ROA) spectra of the four ketose sugars D-fructose, L-sorbose, D-tagatose and D-psicose in aqueous solution, which have been measured in backscattering in the range ≈250-1500 cm -1, are reported. These results are combined with those from a previous ROA study of aldose and pentose sugars in an attempt to establish new vibrational assignments and to verify old ones. The high information content of these spectra provides a new perspective on all the central features of monosaccharide stereochemistry including dominant anomeric configuration, ring conformation, exocyclic CH 2OH group conformation and relative disposition of the hydroxyl groups around the ring.

  5. Optomechanical proposal for monitoring microtubule mechanical vibrations

    Science.gov (United States)

    Barzanjeh, Sh.; Salari, V.; Tuszynski, J. A.; Cifra, M.; Simon, C.

    2017-07-01

    Microtubules provide the mechanical force required for chromosome separation during mitosis. However, little is known about the dynamic (high-frequency) mechanical properties of microtubules. Here, we theoretically propose to control the vibrations of a doubly clamped microtubule by tip electrodes and to detect its motion via the optomechanical coupling between the vibrational modes of the microtubule and an optical cavity. In the presence of a red-detuned strong pump laser, this coupling leads to optomechanical-induced transparency of an optical probe field, which can be detected with state-of-the art technology. The center frequency and line width of the transparency peak give the resonance frequency and damping rate of the microtubule, respectively, while the height of the peak reveals information about the microtubule-cavity field coupling. Our method opens the new possibilities to gain information about the physical properties of microtubules, which will enhance our capability to design physical cancer treatment protocols as alternatives to chemotherapeutic drugs.

  6. HOLOGRAPHIC VISUALIZATION OF CYLINDRICAL PIEZOCERAMIC TRANSDUCERS VIBRATIONS

    Directory of Open Access Journals (Sweden)

    R. Vasiliauskas

    2013-01-01

    Full Text Available The piezomaterial used in cylindrical piezoceramic transducers vibrations requiring high precision displacements indicates that accuracy depends on design and technological factors. The analyzed criteria have made possible to choose the piezomaterial for optimal mechatronic system having a maximal displacement. The experimental investigation of precision vibrosystems by means of 3D holographic visualization enables one to obtain appreciably larger amount of information about the vibrating surface in comparison with traditional methods. On the basis of the developed methodology of analyzing the experimental data derived from 3D holographic visualization and by using the experimental holography stand, we have obtained results making it possible to optimize the design of operation of the piezoceramic mechatronic system or its separate elements.

  7. 10th International Conference on Vibration Problems

    CERN Document Server

    Horáček, Jaromír; Okrouhlík, Miloslav; Marvalová, Bohdana; Verhulst, Ferdinand; Sawicki, Jerzy; Vibration Problems ICOVP 2011

    2011-01-01

    This volume presents the Proceedings of the 10th International Conference on Vibration Problems, September 5-8, 2011, Prague, Czech Republic. Since they started in 1990 the ICOVP conferences have matured into a reference platform reflecting the state-of-the-art of dynamics in the broadest sense, bringing together scientists from different backgrounds who are actively working on vibration-related problems in theoretical, experimental and applied dynamics, thus facilitating a lively exchange of ideas, methods and results. Dynamics as a scientific discipline draws inspiration from a large variety of engineering areas, such as Mechanical and Civil Engineering, Aero and Space Technology, Wind and Earthquake Engineering and Transport and Building Machinery. Moreover, the basic research in dynamics nowadays includes many fields of theoretical physics and various interdisciplinary subject areas. ICOVP 2011 covers all branches of dynamics and offers the most up-to-date results and developments in a high-quality select...

  8. Vibration Detection Using Optical Fiber Sensors

    Directory of Open Access Journals (Sweden)

    Yoany Rodríguez García

    2010-01-01

    Full Text Available Condition monitoring of heavy electromechanical equipment is commonly accomplished in the industry using vibration analysis. Several techniques, mainly based on capacitive and piezoelectric accelerometers, have been applied for predictive maintenance. However, the negative influence of the electromagnetic interference (EMI can be a real problem when electrical signals are used to detect and transmit physical parameters in noisy environments such as electric power generator plants with high levels of EMI. Optical fiber sensors are increasingly used because of the nonelectrical nature of signals. In this paper, the most frequently used vibration optical fiber sensors will be reviewed, classifying them by the sensing techniques and measurement principles. The main techniques, intensity modulation, fiber bragg gratings and Fabry-Pérot Interferometry, will be reviewed here.

  9. Transportation Shock and Vibration Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Maheras, Steven J.; Lahti, Erik A.; Ross, Steven B.

    2013-06-06

    This report fulfills the M4 milestone M4FT-13OR08220112, "Report Documenting Experimental Activities." The purpose of this report is to document the results of a literature review conducted of studies related to the vibration and shock associated with the normal conditions of transport for rail shipments of used nuclear fuel from commercial light-water reactors. As discussed in Adkins (2013), the objective of this report is to determine if adequate data exist that would enable the impacts of the shock and vibration associated with the normal conditions of transport on commercial light-water reactor used nuclear fuel shipped in current generation rail transportation casks to be realistically modeled.

  10. Suppression of friction by mechanical vibrations.

    Science.gov (United States)

    Capozza, Rosario; Vanossi, Andrea; Vezzani, Alessandro; Zapperi, Stefano

    2009-08-21

    Mechanical vibrations are known to affect frictional sliding and the associated stick-slip patterns causing sometimes a drastic reduction of the friction force. This issue is relevant for applications in nanotribology and to understand earthquake triggering by small dynamic perturbations. We study the dynamics of repulsive particles confined between a horizontally driven top plate and a vertically oscillating bottom plate. Our numerical results show a suppression of the high dissipative stick-slip regime in a well-defined range of frequencies that depends on the vibrating amplitude, the normal applied load, the system inertia and the damping constant. We propose a theoretical explanation of the numerical results and derive a phase diagram indicating the region of parameter space where friction is suppressed. Our results allow to define better strategies for the mechanical control of friction.

  11. Vibration of Piezoelectric Nanowires Including Surface Effects

    Directory of Open Access Journals (Sweden)

    R. Ansari

    2014-04-01

    Full Text Available In this paper, surface and piezoelectric effects on the vibration behavior of nanowires (NWs are investigated by using a Timoshenko beam model. The electric field equations and the governing equations of motion for the piezoelectric NWs are derived with the consideration of surface effects. By the exact solution of the governing equations, an expression for the natural frequencies of NWs with simply-supported boundary conditions is obtained. The effects of piezoelectricity and surface effects on the vibrational behavior of Timoshenko NWs are graphically illustrated. A comparison is also made between the predictions of Timoshenko beam model and those of its Euler-Bernoulli counterpart. Additionally, the present results are validated through comparison with the available data in the literature.

  12. Hydrodynamics induced vibration to trash-racks

    International Nuclear Information System (INIS)

    Sadrnejad, A.

    2002-01-01

    In conventional power plants trash-racks are provided at the intakes to protect the turbines. In pumped storage plants, the draft tube or tailrace must also have trash-racks to protect the units while pumping. Because the loads believed to cause many failures of trash-racks are dynamic in nature, it is important to understand the dynamic characteristics of trash-racks structures in general and a single rack in particular. The classical added-mass solution structure-fluid dynamic interaction is known as an approximate solution procedure. An accurate added-mass approach mixed with implementation in finite element framework is proposed. In this proposal, experimental conclusions, supported by theory, led to presentation of more accurate results in vibration of trash-racks. This numerical solution as a powerful method to solve such a complex problem can be employed to carry out dynamic characteristics of these structures while vibrating in water

  13. Gas Bubble Dynamics under Mechanical Vibrations

    Science.gov (United States)

    Mohagheghian, Shahrouz; Elbing, Brian

    2017-11-01

    The scientific community has a limited understanding of the bubble dynamics under mechanical oscillations due to over simplification of Navier-Stockes equation by neglecting the shear stress tensor and not accounting for body forces when calculating the acoustic radiation force. The current work experimental investigates bubble dynamics under mechanical vibration and resulting acoustic field by measuring the bubble size and velocity using high-speed imaging. The experimental setup consists of a custom-designed shaker table, cast acrylic bubble column, compressed air injection manifold and an optical imaging system. The mechanical vibrations resulted in accelerations between 0.25 to 10 times gravitational acceleration corresponding to frequency and amplitude range of 8 - 22Hz and 1 - 10mm respectively. Throughout testing the void fraction was limited to definition of Bjerknes force in combination with Rayleigh-Plesset equation. Physical behavior of the system was capture and classified. Bubble size, velocity as well as size and spatial distribution will be presented.

  14. Vibration welding system with thin film sensor

    Science.gov (United States)

    Cai, Wayne W; Abell, Jeffrey A; Li, Xiaochun; Choi, Hongseok; Zhao, Jingzhou

    2014-03-18

    A vibration welding system includes an anvil, a welding horn, a thin film sensor, and a process controller. The anvil and horn include working surfaces that contact a work piece during the welding process. The sensor measures a control value at the working surface. The measured control value is transmitted to the controller, which controls the system in part using the measured control value. The thin film sensor may include a plurality of thermopiles and thermocouples which collectively measure temperature and heat flux at the working surface. A method includes providing a welder device with a slot adjacent to a working surface of the welder device, inserting the thin film sensor into the slot, and using the sensor to measure a control value at the working surface. A process controller then controls the vibration welding system in part using the measured control value.

  15. Rotors fault detection using vibration methods

    Directory of Open Access Journals (Sweden)

    Andrzej GRZADZIELA

    2009-01-01

    Full Text Available Ships’ propulsion plant usually works in a hard environment caused by static forces and permanent dynamic loads. Basic elements of propulsion systems are rotation machines like gas turbine engines, gear boxes, propulsion shafts etc. Another loads coming from technological faults of rotation machines like misalignment, unbalancing or resonance. Exciding of tolerated values of shaft alignments or unbalancing can cause a damage of radial and thrust bearings in relative short time. Similar situation is occurred when the mode or modes of rotors natural resonances are in the range of operational speed. The paper compares three methods of calculating and recognizing modes of rotors’ natural frequencies using laboratory model of rotational machine. Results of FEM modeling, modal hammers measurements and synchronous vibration measurement show that free stop-down process is an interesting area for the vibration diagnosing of rotational machines.

  16. Vibrational Based Inspection Of A Steel Mast

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Rytter, A.

    1994-01-01

    The aim of this paper is to present the results from a research project concerning vibrational based inspection of a 20 meter high steel mast containing well defined damages. Introductory analyses dealing with among other things evaluation of potential damage indicators and determination of accep...... of acceptable damage levels are described. The modal parameters of the mast are determined by using ARMA-models on signals from wind induced response of the mast. Two different damage detection methods are tested, evaluated and compared....

  17. Vibrations Reduction of Industrial Sewing Machines

    Science.gov (United States)

    Šidlof, P.; Votrubec, V.

    This paper deals with balancing of industrial sewing machines. We have proposed an eccentric balancing mechanism that balances crank mechanism of the needle bar. It significantly reduces vibrations. Big advantage is that the variation of drive shaft angular velocity only slightly raises. To create a new computational apparatus we began to use and supplement new simulating software MathModelica. Optimization, some calculations and evaluations are then executed in software Mathematica.

  18. The high level vibration test program

    International Nuclear Information System (INIS)

    Hofmayer, C.H.; Curreri, J.R.; Park, Y.J.; Kato, W.Y.; Kawakami, S.

    1989-01-01

    As part of cooperative agreements between the US and Japan, tests have been performed on the seismic vibration table at the Tadotsu Engineering Laboratory of Nuclear Power Engineering Test Center (NUPEC) in Japan. The objective of the test program was to use the NUPEC vibration table to drive large diameter nuclear power piping to substantial plastic strain with an earthquake excitation and to compare the results with state-of-the-art analysis of the problem. The test model was subjected to a maximum acceleration well beyond what nuclear power plants are designed to withstand. A modified earthquake excitation was applied and the excitation level was increased carefully to minimize the cumulative fatigue damage due to the intermediate level excitations. Since the piping was pressurized, and the high level earthquake excitation was repeated several times, it was possible to investigate the effects of ratchetting and fatigue as well. Elastic and inelastic seismic response behavior of the test model was measured in a number of test runs with an increasing excitation input level up to the limit of the vibration table. In the maximum input condition, large dynamic plastic strains were obtained in the piping. Crack initiation was detected following the second maximum excitation run. Crack growth was carefully monitored during the next two additional maximum excitation runs. The final test resulted in a maximum crack depth of approximately 94% of the wall thickness. The HLVT (high level vibration test) program has enhanced understanding of the behavior of piping systems under severe earthquake loading. As in other tests to failure of piping components, it has demonstrated significant seismic margin in nuclear power plant piping

  19. Acoustic vibration effects in classical nucleation theory

    Science.gov (United States)

    Baird, James K.; Su, C.-H.

    2018-04-01

    Acoustic vibration is often used to improve the yield of crystals and nanoparticles growing from solutions and melts. As there is still a debate on how acoustic vibration actually works, we have examined the possibility that acoustic pressure can affect the rate of nucleation. Our method is based on an expansion of the free energy of the nucleus in powers of the acoustic pressure. With the assumption that the period of the sound wave is short as compared to the time scale for nucleation, we replace the powers of the acoustic pressure by their time averages, retaining the average of the square of the acoustic pressure as the leading term. By assuming a nucleus having spherical shape, we use the Young-Laplace equation to relate the pressure inside the nucleus to the ambient pressure. Without making further approximations not already standard in classical nucleation theory, we find that the proximate effect of acoustic pressure is to reduce both the size of the critical nucleus as well as the work required to form it from monomers. As the work serves as the activation energy, the ultimate effect of acoustic pressure is to increase the rate of nucleation. If we assume that the atomic structure of the nucleus is the same as that of an ordinary solid, however, we find the compressibility is too small for acoustic vibration effects to be noticeable. If on the other hand, we assume that the structure is similar to that of a loosely bound colloidal particle, then the effects of acoustic vibration become potentially observable.

  20. Development of Vibrating Disc Piezoelectric Gyroscope

    OpenAIRE

    A.K. Singh; U.K. Gorain

    2004-01-01

    The paper presents an indigenously developed vibrating disc piezoelectric gyroscope, in which both excitation and detection have been done through piezoelectric, using PZT-5H material. The gyroscope has been driven to resonant state by direct piezoelectric effect, using 20 V ac signal at 93 kHz, and the output has been detected by the reverse piezoelectric effect.The performance of this gyroscope has been tested with 3 microprocessor-controlled turntable, and the output of the gyroscope has b...

  1. Vibration of circular bladed disk with imperfections

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav; Pešek, Luděk

    2011-01-01

    Roč. 21, č. 10 (2011), s. 2893-2904 ISSN 0218-1274 R&D Projects: GA ČR GA101/09/1166 Institutional research plan: CEZ:AV0Z20760514 Keywords : circular bladed disk * vibration * imperfection * nonlinear damping Subject RIV: BI - Acoustics Impact factor: 0.755, year: 2011 http://www.worldscinet.com/ijbc/21/2110/S0218127411030210.html

  2. Vortex induced vibrations in gapped restrainted pipes

    International Nuclear Information System (INIS)

    Veloso, P. de A.A.; Loula, A.F.D.

    1984-01-01

    The vortex induced vibration problem of gapped restrained piping is solved numerically. The model proposed by Skop-Griffin is used to describe the pipe-fluid interaction. The variational formulation is obtained modeling the gapped restraints as non-linear elastic springs. The regularized problem is solved using a finite element discretization for the spatial domain. In the time domain a finite difference discretization is used for the lift coefficient equatin and a Newmark discretization for the equation of motion. (Author) [pt

  3. Investigation of Vibration Reduction through Structural Optimization.

    Science.gov (United States)

    1980-07-01

    energy calculations (Equation 13) were beyond the scope of this study. However, by using the Direct Mctrix Abstraction Program ( DMAP ) capability in NASTRAN ...Fuselage vertical bending 26.96 29.47 6th Skid mode 29.04 - 25 The AH-lG elastic-line NASTRAN model (including the DMAP ALTER procedure developed for...energy method for reducing vibration response, primarily via structural stiffness changes, using NASTRAN beam-element repre- sentation of the WI-G with

  4. Isogeometric Shape Optimization of Vibrating Membranes

    DEFF Research Database (Denmark)

    Nguyen, Dang Manh; Evgrafov, Anton; Gersborg, Allan Roulund

    2011-01-01

    We consider a model problem of isogeometric shape optimization of vibrating membranes whose shapes are allowed to vary freely. The main obstacle we face is the need for robust and inexpensive extension of a B-spline parametrization from the boundary of a domain onto its interior, a task which has...... perform a number of numerical experiments with our isogeometric shape optimization algorithm and present smooth, optimized membrane shapes. Our conclusion is that isogeometric analysis fits well with shape optimization....

  5. Horizontal vibrations of piles in a centrifuge

    International Nuclear Information System (INIS)

    Bourdin, B.

    1987-01-01

    The aim of the thesis is the study of soil dynamics for important structures like nuclear power plants, offshore platforms, dams etc. Experimental results of horizontal vibrations on a pile partially anchored in a soil scale model put into a centrifuge are presented. Mechanical similitude conditions from equilibrium equations or rheologic laws are described. After a description of testing equipment (centrifuge, electrodynamic excitator) experimental results are interpreted with a model. Non-linearities on frequency response curves are characterized [fr

  6. Tuneable vibration absorber design to suppress vibrations: An application in boring manufacturing process

    Science.gov (United States)

    Moradi, H.; Bakhtiari-Nejad, F.; Movahhedy, M. R.

    2008-11-01

    Dynamic vibration absorbers are used to reduce the undesirable vibrations in many applications such as electrical transmission lines, helicopters, gas turbines, engines, bridges, etc. Tuneable vibration absorbers (TVA) are also used as semi-active controllers. In this paper, the application of a TVA for suppression of chatter vibrations in the boring manufacturing process is presented. The boring bar is modeled as a cantilever Euler-Bernoulli beam and the TVA is composed of mass, spring and dashpot elements. In addition, the effect of spring mass is considered in this analysis. After formulation of the problem, the optimum specifications of the absorber such as spring stiffness, absorber mass and its position are determined using an algorithm based on the mode summation method. The analog-simulated block diagram of the system is developed and the effects of various excitations such as step, ramp, etc. on the absorbed system are simulated. In addition, chatter stability is analyzed in dominant modes of boring bar. Results show that at higher modes, larger critical widths of cut and consequently more material removal rate (MRR) can be achieved. In the case of self-excited vibration, which is associated with a delay differential equation, the optimum absorber suppresses the chatter and increases the limit of stability.

  7. A smart dynamic vibration absorber for suppressing the vibration of a string supported by flexible beams

    Science.gov (United States)

    Nambu, Yohsuke; Yamamoto, Shota; Chiba, Masakatsu

    2014-02-01

    This study aims to effectively and robustly suppress the vibration of tension-stabilized structures (TSSs) using a smart dynamic vibration absorber (DVA). In recent years, a strong need has emerged for high-precision and high-functionality space structural systems for realizing advanced space missions. TSSs have attracted attention in this regard as large yet lightweight structural systems with high storage efficiency. A fundamental issue in the application of TSSs is vibration control of strings, of which TSSs are predominantly composed. In particular, the suppression of microvibrations is difficult because the deformation is almost perpendicular to the direction of vibration. A DVA is an effective device for suppressing microvibrations. However, the damping performance is sensitive to changes in dynamic properties. Furthermore, aging degradation and temperature dependence negatively affect DVA performance. This study aimed to develop a smart, active DVA with self-sensing actuation to improve robustness. A small cantilever with a piezoelectric transducer was utilized as a smart DVA. Numerical simulations and experiments showed that a passive DVA and the smart DVA suppressed vibrations but that the smart DVA showed improved effectiveness and robustness.

  8. The vibration discomfort of standing people: evaluation of multi-axis vibration.

    Science.gov (United States)

    Thuong, Olivier; Griffin, Michael J

    2015-01-01

    Few studies have investigated discomfort caused by multi-axis vibration and none has explored methods of predicting the discomfort of standing people from simultaneous fore-and-aft, lateral and vertical vibration of a floor. Using the method of magnitude estimation, 16 subjects estimated their discomfort caused by dual-axis and tri-axial motions (octave-bands centred on either 1 or 4 Hz with various magnitudes in the fore-and-aft, lateral and vertical directions) and the discomfort caused by single-axis motions. The method of predicting discomfort assumed in current standards (square-root of the sums of squares of the three components weighted according to their individual contributions to discomfort) provided reasonable predictions of the discomfort caused by multi-axis vibration. Improved predictions can be obtained for specific stimuli, but no single simple method will provide accurate predictions for all stimuli because the rate of growth of discomfort with increasing magnitude of vibration depends on the frequency and direction of vibration.

  9. Time-varying output performances of piezoelectric vibration energy harvesting under nonstationary random vibrations

    Science.gov (United States)

    Yoon, Heonjun; Kim, Miso; Park, Choon-Su; Youn, Byeng D.

    2018-01-01

    Piezoelectric vibration energy harvesting (PVEH) has received much attention as a potential solution that could ultimately realize self-powered wireless sensor networks. Since most ambient vibrations in nature are inherently random and nonstationary, the output performances of PVEH devices also randomly change with time. However, little attention has been paid to investigating the randomly time-varying electroelastic behaviors of PVEH systems both analytically and experimentally. The objective of this study is thus to make a step forward towards a deep understanding of the time-varying performances of PVEH devices under nonstationary random vibrations. Two typical cases of nonstationary random vibration signals are considered: (1) randomly-varying amplitude (amplitude modulation; AM) and (2) randomly-varying amplitude with randomly-varying instantaneous frequency (amplitude and frequency modulation; AM-FM). In both cases, this study pursues well-balanced correlations of analytical predictions and experimental observations to deduce the relationships between the time-varying output performances of the PVEH device and two primary input parameters, such as a central frequency and an external electrical resistance. We introduce three correlation metrics to quantitatively compare analytical prediction and experimental observation, including the normalized root mean square error, the correlation coefficient, and the weighted integrated factor. Analytical predictions are in an excellent agreement with experimental observations both mechanically and electrically. This study provides insightful guidelines for designing PVEH devices to reliably generate electric power under nonstationary random vibrations.

  10. Vibration Suppression of Electronic Box by a Dual Function Piezoelectric Energy Harvester-Tuned Vibration Absorber

    Directory of Open Access Journals (Sweden)

    Sajid Rafique

    2014-04-01

    Full Text Available Over the past few years, remarkable developments in piezoelectric materials have motivated many researchers to work in the field of vibration energy harvesting by using piezoelectric beam like smart structures. This paper aimed to present the most recent application of a dual function piezoelectric device which can suppress vibration and harvest vibration energy simultaneously and a brief illustration of conventional mechanical and electrical TVAs (Tuned Vibration Absorber. It is shown that the proposed dual function device combines the benefits of conventional mechanical and electrical TVAs and reduces their relative disadvantages. Conversion of mechanical energy into electrical energy introduces damping and, hence, the optimal damping required by this TVA is generated by the energy harvesting effects. This paper presents the methodology of implementing the theory of 'electromechanical' TVAs to suppress the response of any real world structure. The work also illustrates the prospect of extensive applications of such novel "electromechanical" TVAs in defence and industry. The results show that the optimum degree of vibration suppression of an electronic box is achieved by this dual function TVA through suitable tuning of the attached electrical circuitry

  11. Electronic and vibrational spectroscopy and vibrationally mediated photodissociation of V+(OCO).

    Science.gov (United States)

    Citir, Murat; Altinay, Gokhan; Metz, Ricardo B

    2006-04-20

    Electronic spectra of gas-phase V+(OCO) are measured in the near-infrared from 6050 to 7420 cm(-1) and in the visible from 15,500 to 16,560 cm(-1), using photofragment spectroscopy. The near-IR band is complex, with a 107 cm(-1) progression in the metal-ligand stretch. The visible band shows clearly resolved vibrational progressions in the metal-ligand stretch and rock, and in the OCO bend, as observed by Brucat and co-workers. A vibrational hot band gives the metal-ligand stretch frequency in the ground electronic state nu3'' = 210 cm(-1). The OCO antisymmetric stretch frequency in the ground electronic state (nu1'') is measured by using vibrationally mediated photodissociation. An IR laser vibrationally excites ions to nu1'' = 1. Vibrationally excited ions selectively dissociate following absorption of a second, visible photon at the nu1' = 1 CO2, due to interaction with the metal. Larger blue shifts observed for complexes with fewer ligands agree with trends seen for larger V+(OCO)n clusters.

  12. Underway meteorological, navigational, optical, physical and time series data collected aboard NOAA Ship Oscar Elton Sette in the North Pacific Ocean and South Pacific Ocean from 2016-02-21 to 2016-03-25 (NCEI Accession 0155172)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0155172 contains raw underway meteorological, navigational, optical, physical and time series data logged by the Scientific Computer System (SCS)...

  13. Underway meteorological, navigational, optical, physical and time series data collected aboard NOAA Ship Pisces in the North Atlantic Ocean from 2016-10-18 to 2016-10-20 (NCEI Accession 0164092)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0164092 contains raw underway meteorological, navigational, optical, physical and time series data logged by the Scientific Computer System (SCS)...

  14. Underway meteorological, navigational, optical, physical, profile and time series data collected aboard NOAA Ship Pisces in the North Atlantic Ocean from 2016-06-08 to 2016-06-25 (NCEI Accession 0155294)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0155294 contains raw underway meteorological, navigational, optical, physical, profile and time series data logged by the Scientific Computer System...

  15. Underway meteorological, navigational, optical, physical, profile and time series data collected aboard NOAA Ship Pisces in the North Atlantic Ocean from 2016-07-03 to 2016-08-03 (NCEI Accession 0155990)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0155990 contains raw underway meteorological, navigational, optical, physical, profile and time series data logged by the Scientific Computer System...

  16. Underway meteorological, navigational, optical, physical, profile and time series data collected aboard NOAA Ship Oregon II in the Gulf of Mexico and North Atlantic Ocean from 2017-07-26 to 2017-08-10 (NCEI Accession 0164961)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0164961 contains raw underway meteorological, navigational, optical, physical, profile and time series data logged by the Scientific Computer System...

  17. Underway meteorological, navigational, optical, physical and time series data collected aboard NOAA Ship Oscar Dyson in the Bering Sea from 2016-05-03 to 2016-05-04 (NCEI Accession 0165030)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0165030 contains raw underway meteorological, navigational, optical, physical and time series data logged by the Scientific Computer System (SCS)...

  18. Underway meteorological, navigational, optical, physical, profile and time series data collected aboard NOAA Ship Oregon II in the Gulf of Mexico and North Atlantic Ocean from 2014-05-04 to 2014-05-31 (NODC Accession 0118842)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0118842 contains raw underway meteorological, navigational, optical, physical, profile and time series data logged by the Scientific Computer System...

  19. Underway meteorological, navigational, physical, profile and time series data collected aboard NOAA Ship Henry B. Bigelow in the North Atlantic Ocean from 2015-08-12 to 2015-08-21 (NCEI Accession 0131861)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0131861 contains raw underway meteorological, navigational, physical, profile and time series data logged by the Scientific Computer System (SCS)...

  20. Underway meteorological, navigational, physical and time series data collected aboard NOAA Ship Fairweather in the Gulf of Alaska from 2014-04-28 to 2014-07-28 (NODC Accession 0126498)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0126498 contains raw underway meteorological, navigational, physical and time series data logged by the Scientific Computer System (SCS) aboard NOAA...

  1. Underway meteorological, navigational, physical and time series data collected aboard NOAA Ship Rainier in the Gulf of Alaska from 2014-05-19 to 2014-09-04 (NODC Accession 0123694)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0123694 contains raw underway meteorological, navigational, physical and time series data logged by the Scientific Computer System (SCS) aboard NOAA...

  2. Underway meteorological, navigational, optical, physical and time series data collected aboard NOAA Ship Oscar Dyson in the Gulf of Alaska from 2013-03-14 to 2013-03-28 (NODC Accession 0124186)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0124186 contains raw underway meteorological, navigational, optical, physical and time series data logged by the Scientific Computer System (SCS)...

  3. Underway meteorological, navigational, optical, physical and time series data collected aboard NOAA Ship Oscar Dyson in the Gulf of Alaska from 2015-03-14 to 2015-03-31 (NCEI Accession 0130691)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0130691 contains raw underway meteorological, navigational, optical, physical and time series data logged by the Scientific Computer System (SCS)...

  4. Underway meteorological, navigational, optical, physical and time series data collected aboard NOAA Ship Oscar Dyson in the Gulf of Alaska and North Pacific Ocean from 2016-02-11 to 2016-02-20 (NCEI Accession 0150731)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0150731 contains raw underway meteorological, navigational, optical, physical and time series data logged by the Scientific Computer System (SCS)...

  5. Underway meteorological, navigational, optical, physical and time series data collected aboard NOAA Ship Bell M. Shimada in the North Pacific Ocean from 2016-05-27 to 2016-05-28 (NCEI Accession 0164091)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0164091 contains raw underway meteorological, navigational, optical, physical and time series data logged by the Scientific Computer System (SCS)...

  6. Underway meteorological, navigational, optical, physical, profile and time series data collected aboard NOAA Ship Bell M. Shimada in the North Pacific Ocean from 2017-05-15 to 2017-05-24 (NCEI Accession 0164430)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0164430 contains raw underway meteorological, navigational, optical, physical, profile and time series data logged by the Scientific Computer System...

  7. Underway meteorological, navigational, optical, physical, profile and time series data collected aboard NOAA Ship Gordon Gunter in the Gulf of Mexico and North Atlantic Ocean from 2015-08-07 to 2015-09-28 (NCEI Accession 0131988)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0131988 contains raw underway meteorological, navigational, optical, physical, profile and time series data logged by the Scientific Computer System...

  8. Underway meteorological, navigational, physical and time series data collected aboard NOAA Ship Hi'ialakai in the North Pacific Ocean from 2015-11-01 to 2015-11-14 (NCEI Accession 0150693)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0150693 contains raw underway meteorological, navigational, physical and time series data logged by the Scientific Computer System (SCS) aboard NOAA...

  9. Underway meteorological, navigational, optical, physical and time series data collected aboard NOAA Ship Gordon Gunter in the Gulf of Mexico and North Atlantic Ocean from 2015-04-14 to 2015-06-13 (NCEI Accession 0128347)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0128347 contains raw underway meteorological, navigational, optical, physical and time series data logged by the Scientific Computer System (SCS)...

  10. Underway meteorological, navigational, optical, physical, profile and time series data collected aboard NOAA Ship Gordon Gunter in the Gulf of Mexico from 2012-10-19 to 2012-10-29 (NODC Accession 0113519)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113519 contains raw underway meteorological, navigational, optical, physical, profile and time series data logged by the Scientific Computer System...

  11. Underway meteorological, navigational, optical, physical and time series data collected aboard NOAA Ship Nancy Foster in the Gulf of Mexico and North Atlantic Ocean from 2013-04-26 to 2013-06-01 (NODC Accession 0113336)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113336 contains raw underway meteorological, navigational, optical, physical and time series data logged by the Scientific Computer System (SCS)...

  12. Underway meteorological, navigational, physical and time series data collected aboard NOAA Ship Thomas Jefferson in the North Atlantic Ocean from 2017-07-22 to 2017-07-26 (NCEI Accession 0164960)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0164960 contains raw underway meteorological, navigational, physical and time series data logged by the Scientific Computer System (SCS) aboard NOAA...

  13. Underway meteorological, navigational, physical and time series data collected aboard NOAA Ship Rainier in the Gulf of Alaska from 2015-09-16 to 2015-09-25 (NCEI Accession 0138191)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0138191 contains raw underway meteorological, navigational, physical and time series data logged by the Scientific Computer System (SCS) aboard NOAA...

  14. Underway meteorological, navigational, optical, physical, profile and time series data collected aboard NOAA Ship Oregon II in the Gulf of Mexico and North Atlantic Ocean from 2014-07-26 to 2014-09-29 (NODC Accession 0122397)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0122397 contains raw underway meteorological, navigational, optical, physical, profile and time series data logged by the Scientific Computer System...

  15. Underway meteorological, navigational, optical, physical, profile and time series data collected aboard NOAA Ship Pisces in the Gulf of Mexico from 2014-05-27 to 2014-09-30 (NODC Accession 0119414)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0119414 contains raw underway meteorological, navigational, optical, physical, profile and time series data logged by the Scientific Computer System...

  16. Underway meteorological, navigational, optical, physical and time series data collected aboard NOAA Ship Oscar Dyson in the Bering Sea from 2014-05-20 to 2014-06-08 (NODC Accession 0125267)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0125267 contains raw underway meteorological, navigational, optical, physical and time series data logged by the Scientific Computer System (SCS)...

  17. Underway meteorological, navigational, optical, physical and time series data collected aboard NOAA Ship Oscar Elton Sette in the North Pacific Ocean and Philippine Sea from 2014-06-19 to 2014-07-19 (NODC Accession 0123094)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0123094 contains raw underway meteorological, navigational, optical, physical and time series data logged by the Scientific Computer System (SCS)...

  18. Underway meteorological, navigational, physical and time series data collected aboard NOAA Ship Thomas Jefferson in the North Atlantic Ocean from 2013-03-11 to 2013-03-13 (NODC Accession 0123054)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0123054 contains raw underway meteorological, navigational, physical and time series data logged by the Scientific Computer System (SCS) aboard NOAA...

  19. Underway navigational, physical and time series data collected aboard NOAA Ship Thomas Jefferson in the North Atlantic Ocean from 2013-06-17 to 2013-10-02 (NODC Accession 0123055)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0123055 contains raw underway navigational, physical and time series data logged by the Scientific Computer System (SCS) aboard NOAA Ship Thomas...

  20. Underway meteorological, navigational, physical and time series data collected aboard NOAA Ship Hi'ialakai in the North Pacific Ocean from 2014-09-06 to 2014-09-30 (NODC Accession 0122499)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0122499 contains raw underway meteorological, navigational, physical and time series data logged by the Scientific Computer System (SCS) aboard NOAA...