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Sample records for core damage frequency

  1. Core damage frequency (reactor design) perspectives based on IPE results

    SciTech Connect

    Camp, A.L.; Dingman, S.E.; Forester, J.A.

    1996-12-31

    This paper provides perspectives gained from reviewing 75 Individual Plant Examination (IPE) submittals covering 108 nuclear power plant units. Variability both within and among reactor types is examined to provide perspectives regarding plant-specific design and operational features, and C, modeling assumptions that play a significant role in the estimates of core damage frequencies in the IPEs. Human actions found to be important in boiling water reactors (BWRs) and in pressurized water reactors (PWRs) are presented and the events most frequently found important are discussed.

  2. Summary of core damage frequency from internal initiators: Peach Bottom

    SciTech Connect

    Kolaczkowski, A.M.; Lambright, J.A.; Cathey, N.

    1986-01-01

    Probabilistic risk assessments (PRAs) based on internal initiators are being conducted on a number of reference plants to provide the US Nuclear Regulatory Commission (NRC) with updated information about light-water reactor risk. The results of these analyses will be used by the NRC to prepare NUREG-1150 which will examine the NRC's current perception of risk. Peach Bottom has been chosen as one of the reference plants. The Peach Bottom Atomic Power Station has two boiling water reactor (BWR) units, each with a capacity of 1150 MW(e). The reactors are each housed in a Mark I containment. Peach Bottom Unit 2 analyzed here, was studied before as part of WASH-1400. A number of plant features tend to be important in determining the nature and frequency of the core melt scenarios for Peach Bottom. These features include the recent above-average diesel generator performance history, the single emergency service water system for both units, the numerous emergency core cooling systems, recent procedure modifications and the low volume containment.

  3. Analysis of core damage frequency from internal events: Peach Bottom, Unit 2

    SciTech Connect

    Kolaczkowski, A.M.; Lambright, J.A.; Ferrell, W.L.; Cathey, N.G.; Najafi, B.; Harper, F.T.

    1986-10-01

    This document contains the internal event initiated accident sequence analyses for Peach Bottom, Unit 2; one of the reference plants being examined as part of the NUREG-1150 effort by the Nuclear Regulatory Commission. NUREG-1150 will document the risk of a selected group of nuclear power plants. As part of that work, this report contains the overall core damage frequency estimate for Peach Bottom, Unit 2, and the accompanying plant damage state frequencies. Sensitivity and uncertainty analyses provided additional insights regarding the dominant contributors to the Peach Bottom core damage frequency estimate. The mean core damage frequency at Peach Bottom was calculated to be 8.2E-6. Station blackout type accidents (loss of all ac power) were found to dominate the overall results. Anticipated Transient Without Scram accidents were also found to be non-negligible contributors. The numerical results are largely driven by common mode failure probability estimates and to some extent, human error. Because of significant data and analysis uncertainties in these two areas (important, for instance, to the most dominant scenario in this study), it is recommended that the results of the uncertainty and sensitivity analyses be considered before any actions are taken based on this analysis.

  4. Core damage frequency observations and insights of LWRs based on the IPEs

    SciTech Connect

    Dingman, S.E.; Camp, A.L.; Drouin, M.T.

    1995-04-01

    Seventy-eight plants are expected to submit Individual Plant Examinations (IPEs) for severe accident vulnerabilities to the US Nuclear Regulatory Commission (NRC). The majority of the plants have elected to perform full Level 1 probabilistic risk assessments (PRAs) to meet the intent of the IPEs. Because of this, it is possible to compare the results from the IPE submittals to determine general observations and {open_quotes}lessons learned{close_quotes} from the IPEs. The IPE Insights Program is performing this evaluation, and preliminary results are presented in this paper. The core damage frequency and core damage sequences are identified and compared for pressurized water reactors and boiling water reactors. Examination of the results indicates that variations among plant results are due to a combination of actual plant design/operational features and analysis approaches. The findings are consistent with previous NRC studies, such as WASH-1400 and NUREG-1150.

  5. Analysis of core damage frequency: Peach Bottom, Unit 2 internal events appendices

    SciTech Connect

    Kolaczkowski, A.M.; Cramond, W.R.; Sype, T.T.; Maloney, K.J.; Wheeler, T.A.; Daniel, S.L.; Sandia National Labs., Albuquerque, NM )

    1989-08-01

    This document contains the appendices for the accident sequence analysis of internally initiated events for the Peach Bottom, Unit 2 Nuclear Power Plant. This is one of the five plant analyses conducted as part of the NUREG-1150 effort for the Nuclear Regulatory Commission. The work performed and described here is an extensive reanalysis of that published in October 1986 as NUREG/CR-4550, Volume 4. It addresses comments from numerous reviewers and significant changes to the plant systems and procedures made since the first report. The uncertainty analysis and presentation of results are also much improved, and considerable effort was expended on an improved analysis of loss of offsite power. The content and detail of this report is directed toward PRA practitioners who need to know how the work was done and the details for use in further studies. The mean core damage frequency is 4.5E-6 with 5% and 95% uncertainty bounds of 3.5E-7 and 1.3E-5, respectively. Station blackout type accidents (loss of all ac power) contributed about 46% of the core damage frequency with Anticipated Transient Without Scram (ATWS) accidents contributing another 42%. The numerical results are driven by loss of offsite power, transients with the power conversion system initially available operator errors, and mechanical failure to scram. 13 refs., 345 figs., 171 tabs.

  6. Analysis of core damage frequency due to external events at the DOE (Department of Energy) N-Reactor

    SciTech Connect

    Lambright, J.A.; Bohn, M.P.; Daniel, S.L. ); Baxter, J.T. ); Johnson, J.J.; Ravindra, M.K.; Hashimoto, P.O.; Mraz, M.J.; Tong, W.H.; Conoscente, J.P. ); Brosseau, D.A. )

    1990-11-01

    A complete external events probabilistic risk assessment has been performed for the N-Reactor power plant, making full use of all insights gained during the past ten years' developments in risk assessment methodologies. A detailed screening analysis was performed which showed that all external events had negligible contribution to core damage frequency except fires, seismic events, and external flooding. A limited scope analysis of the external flooding risk indicated that it is not a major risk contributor. Detailed analyses of the fire and seismic risks resulted in total (mean) core damage frequencies of 1.96E-5 and 4.60E-05 per reactor year, respectively. Detailed uncertainty analyses were performed for both fire and seismic risks. These results show that the core damage frequency profile for these events is comparable to that found for existing commercial power plants if proposed fixes are completed as part of the restart program. 108 refs., 85 figs., 80 tabs.

  7. Efficiency of Analytical Methodologies in Uncertainty Analysis of Seismic Core Damage Frequency

    NASA Astrophysics Data System (ADS)

    Kawaguchi, Kenji; Uchiyama, Tomoaki; Muramatsu, Ken

    Fault Tree and Event Tree analysis is almost exclusively relied upon in the assessments of seismic Core Damage Frequency (CDF). In this approach, Direct Quantification of Fault tree using Monte Carlo simulation (DQFM) method, or simply called Monte Carlo (MC) method, and Binary Decision Diagram (BDD) method were introduced as alternatives for a traditional approximation method, namely Minimal Cut Set (MCS) method. However, there is still no agreement as to which method should be used in a risk assessment of seismic CDF, especially for uncertainty analysis. The purpose of this study is to examine the efficiencies of the three methods in uncertainty analysis as well as in point estimation so that the decision of selecting a proper method can be made effectively. The results show that the most efficient method would be BDD method in terms of accuracy and computational time. However, it will be discussed that BDD method is not always applicable to PSA models while MC method is so in theory. In turn, MC method was confirmed to agree with the exact solution obtained by BDD method, but it took a large amount of time, in particular for uncertainty analysis. On the other hand, it was shown that the approximation error of MCS method may not be as bad in uncertainty analysis as it is in point estimation. Based on these results and previous works, this paper will propose a scheme to select an appropriate analytical method for a seismic PSA study. Throughout this study, SECOM2-DQFM code was expanded to be able to utilize BDD method and to conduct uncertainty analysis with both MC and BDD method.

  8. Review of the Oconee-3 probabilistic risk assessment: external events, core damage frequency. Volume 2

    SciTech Connect

    Hanan, N.A.; Ilberg, D.; Xue, D.; Youngblood, R.; Reed, J.W.; McCann, M.; Talwani, T.; Wreathall, J.; Kurth, P.D.; Bandyopadhyay, K.

    1986-03-01

    A review of the Oconee-3 Probabilistic Risk Assessment (OPRA) was conducted with the broad objective of evaluating qualitatively and quantitatively (as much as possible) the OPRA assessment of the important sequences that are ''externally'' generated and lead to core damage. The review included a technical assessment of the assumptions and methods used in the OPRA within its stated objective and with the limited information available. Within this scope, BNL performed a detailed reevaluation of the accident sequences generated by internal floods and earthquakes and a less detailed review (in some cases a scoping review) for the accident sequences generated by fires, tornadoes, external floods, and aircraft impact. 12 refs., 24 figs., 31 tabs.

  9. Core damage frequency prespectives for BWR 3/4 and Westinghouse 4-loop plants based on IPE results

    SciTech Connect

    Dingman, S.; Camp, S.; LaChance, J.; Mary Drouin

    1995-12-31

    This paper discusses the core damage frequency (CDF) insights gained by analyzing the results of the Individual Plant Examinations (IPES) for two groups of plants: boiling water reactor (BWR) 3/4 plants with Reactor Core Isolation Cooling systems, and Westinghouse 4-loop plants. Wide variability was observed for the plant CDFs and for the CDFs of the contributing accident classes. On average, transients-with loss of injection, station blackout sequences, and transients with loss of decay heat removal are important contributors for the BWR 3/4 plants, while transients, station blackout sequences, and loss-of-coolant accidents are important for the Westinghouse 4-loop plants. The key factors that contribute to the variability in the results are discussed. The results are often driven by plant-specific design and operational characteristics, but differences in modeling approaches are also important for some accident classes.

  10. Procedures for the external event core damage frequency analyses for NUREG-1150

    SciTech Connect

    Bohn, M.P.; Lambright, J.A. )

    1990-11-01

    This report presents methods which can be used to perform the assessment of risk due to external events at nuclear power plants. These methods were used to perform the external events risk assessments for the Surry and Peach Bottom nuclear power plants as part of the NRC-sponsored NUREG-1150 risk assessments. These methods apply to the full range of hazards such as earthquakes, fires, floods, etc. which are collectively known as external events. The methods described in this report have been developed under NRC sponsorship and represent, in many cases, both advancements and simplifications over techniques that have been used in past years. They also include the most up-to-date data bases on equipment seismic fragilities, fire occurrence frequencies and fire damageability thresholds. The methods described here are based on making full utilization of the power plant systems logic models developed in the internal events analyses. By making full use of the internal events models one obtains an external event analysis that is consistent both in nomenclature and in level of detail with the internal events analyses, and in addition, automatically includes all the appropriate random and tests/maintenance unavailabilities as appropriate. 50 refs., 9 figs., 11 tabs.

  11. Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1: Analysis of core damage frequency from internal floods during mid-loop operations. Volume 4

    SciTech Connect

    Kohut, P.

    1994-07-01

    The major objective of the Surry internal flood analysis was to provide an improved understanding of the core damage scenarios arising from internal flood-related events. The mean core damage frequency of the Surry plant due to internal flood events during mid-loop operations is 4.8E-06 per year, and the 5th and 95th percentiles are 2.2E-07 and 1.8E-05 per year, respectively. Some limited sensitivity calculations were performed on three plant improvement options. The most significant result involves modifications of intake-level structure on the canal, which reduced core damage frequency contribution from floods in mid-loop by about 75%.

  12. Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1. Volume 5: Analysis of core damage frequency from seismic events during mid-loop operations

    SciTech Connect

    Budnitz, R.J.; Davis, P.R.; Ravindra, M.K.; Tong, W.H.

    1994-08-01

    In 1989 the US Nuclear Regulatory Commission (NRC) initiated an extensive program to examine carefully the potential risks during low-power and shutdown operations. The program included two parallel projects, one at Brookhaven National Laboratory studying a pressurized water reactor (Surry Unit 1) and the other at Sandia National Laboratories studying a boiling water reactor (Grand Gulf). Both the Brookhaven and Sandia projects have examined only accidents initiated by internal plant faults--so-called ``internal initiators.`` This project, which has explored the likelihood of seismic-initiated core damage accidents during refueling shutdown conditions, is complementary to the internal-initiator analyses at Brookhaven and Sandia. This report covers the seismic analysis at Surry Unit 1. All of the many systems modeling assumptions, component non-seismic failure rates, and human error rates that were used in the internal-initiator study at Surry have been adopted here, so that the results of the two studies can be as comparable as possible. Both the Brookhaven study and this study examine only two shutdown plant operating states (POSs) during refueling outages at Surry, called POS 6 and POS 10, which represent mid-loop operation before and after refueling, respectively. This analysis has been limited to work analogous to a level-1 seismic PRA, in which estimates have been developed for the core-damage frequency from seismic events during POSs 6 and 10. The results of the analysis are that the core-damage frequency of earthquake-initiated accidents during refueling outages in POS 6 and POS 10 is found to be low in absolute terms, less than 10{sup {minus}6}/year.

  13. Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1. Volume 5: Analysis of core damage frequency from seismic events for plant operational state 5 during a refueling outage

    SciTech Connect

    Budnitz, R.J.; Davis, P.R.; Ravindra, M.K.; Tong, W.H.

    1994-08-01

    In 1989 the US Nuclear Regulatory Commission (NRC) initiated an extensive program to examine carefully the potential risks during low-power and shutdown operations. The program included two parallel projects, one at Sandia National Laboratories studying a boiling water reactor (Grand Gulf), and the other at Brookhaven National Laboratory studying a pressurized water reactor (Surry Unit 1). Both the Sandia and Brookhaven projects have examined only accidents initiated by internal plant faults---so-called ``internal initiators.`` This project, which has explored the likelihood of seismic-initiated core damage accidents during refueling outage conditions, is complementary to the internal-initiator analyses at Brookhaven and Sandia. This report covers the seismic analysis at Grand Gulf. All of the many systems modeling assumptions, component non-seismic failure rates, and human effort rates that were used in the internal-initiator study at Grand Gulf have been adopted here, so that the results of the study can be as comparable as possible. Both the Sandia study and this study examine only one shutdown plant operating state (POS) at Grand Gulf, namely POS 5 representing cold shutdown during a refueling outage. This analysis has been limited to work analogous to a level-1 seismic PRA, in which estimates have been developed for the core-damage frequency from seismic events during POS 5. The results of the analysis are that the core-damage frequency for earthquake-initiated accidents during refueling outages in POS 5 is found to be quite low in absolute terms, less than 10{sup {minus}7}/year.

  14. Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1: Analysis of core damage frequency from internal events during mid-loop operations, Appendices E (Sections E.1--E.8). Volume 2, Part 3A

    SciTech Connect

    Chu, T.L.; Musicki, Z.; Kohut, P.

    1994-06-01

    During 1989, the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. The program includes two parallel projects being performed by Brookhaven National Laboratory (BNL) and Sandia National Laboratories (SNL). Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The objective of this report is to document the approach utilized in the Surry plant and discuss the results obtained. A parallel report for the Grand Gulf plant is prepared by SNL. This study shows that the core-damage frequency during mid-loop operation at the Surry plant is comparable to that of power operation. The authors recognize that there is very large uncertainty in the human error probabilities in this study. This study identified that only a few procedures are available for mitigating accidents that may occur during shutdown. Procedures written specifically for shutdown accidents would be useful.

  15. Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1: Analysis of core damage frequency from internal events during mid-loop operations, Appendices A--D. Volume 2, Part 2

    SciTech Connect

    Chu, T.L.; Musicki, Z.; Kohut, P.

    1994-06-01

    During 1989, the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the Potential risks during low Power and shutdown operations. The program includes two parallel projects being performed by Brookhaven National Laboratory (BNL) and Sandia National Laboratories (SNL). Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the Plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The objective of this report is to document the approach utilized in the Surry plant and discuss the results obtained. A parallel report for the Grand Gulf plant is prepared by SNL. This study shows that the core-damage frequency during mid-loop operation at the Surry plant is comparable to that of power operation. We recognize that there is very large uncertainty in the human error probabilities in this study. This study identified that only a few procedures are available for mitigating accidents that may occur during shutdown. Procedures written specifically for shutdown accidents would be useful. This document, Volume 2, Pt. 2 provides appendices A through D of this report.

  16. Permeability recovery of damaged water sensitive core using ultrasonic waves.

    PubMed

    Khan, Nasir; Pu, Chunsheng; Li, Xu; He, Yanlong; Zhang, Lei; Jing, Cheng

    2017-09-01

    It is imperative to recover the well productivity lose due to formation damage nearby wellbore during variant well operations. Some indispensable issues in conventional techniques make ultrasonic technology more attractive due to simple, reliable, favorable, cost-effective, and environment friendly nature. This study proposes the independent and combined use of ultrasonic waves and chemical agents for the treatment of already damaged core samples caused by exposure to distilled water. Results elucidate that ultrasonic waves with optimum (20kHz, 1000W) instead of maximum frequency and power worked well in the recovery owing to peristaltic transport caused by matching of natural frequency with acoustic waves frequency. In addition, hundred minutes was investigated as optimum irradiation time which provided ample time span to detach fine loosely suspended particles. However, further irradiation adversely affected the damaged permeability recovery. Moreover, permeability improvement attributes to cavitation due to ultrasonic waves propagation through fluid contained in porous medium and thermal energy generated by three different ways. Eventually, experimental outcomes indicated that maximum (25.3%) damaged permeability recovery was witnessed by applying ultrasonic waves with transducer #2 (20kHz and 1000W) and optimum irradiation timeframe (100min). This recovery was further increased to 45.8% by applying chemical agent and optimum ultrasonic waves simultaneously. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Damage detection using frequency shift path

    NASA Astrophysics Data System (ADS)

    Wang, Longqi; Lie, Seng Tjhen; Zhang, Yao

    2016-01-01

    This paper introduces a novel concept called FREquency Shift (FRESH) path to describe the dynamic behavior of structures with auxiliary mass. FRESH path combines the effects of frequency shifting and amplitude changing into one space curve, providing a tool for analyzing structure health status and properties. A damage index called FRESH curvature is then proposed to detect local stiffness reduction. FRESH curvature can be easily adapted for a particular problem since the sensitivity of the index can be adjusted by changing auxiliary mass or excitation power. An algorithm is proposed to adjust automatically the contribution from frequency and amplitude in the method. Because the extraction of FRESH path requires highly accurate frequency and amplitude estimators; therefore, a procedure based on discrete time Fourier transform is introduced to extract accurate frequency and amplitude with the time complexity of O (n log n), which is verified by simulation signals. Moreover, numerical examples with different damage sizes, severities and damping are presented to demonstrate the validity of the proposed damage index. In addition, applications of FRESH path on two steel beams with different damages are presented and the results show that the proposed method is valid and computational efficient.

  18. Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit-1: Analysis of core damage frequency from internal events during mid-loop operations. Appendix I, Volume 2, Part 5

    SciTech Connect

    Chu, T.L.; Musicki, Z.; Kohut, P.; Yang, J.; Bozoki, G.; Hsu, C.J.; Diamond, D.J.; Bley, D.; Johnson, D.; Holmes, B.

    1994-06-01

    Traditionally, probabilistic risk assessments (PRA) of severe accidents in nuclear power plants have considered initiating events potentially occurring only during full power operation. Some previous screening analyses that were performed for other modes of operation suggested that risks during those modes were small relative to full power operation. However, more recent studies and operational experience have implied that accidents during low power and shutdown could be significant contributors to risk. During 1989, the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. The program includes two parallel projects being performed by Brookhaven National Lab. (BNL) and Sandia National Labs. (SNL). Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The objective of this volume of the report is to document the approach utilized in the level-1 internal events PRA for the Surry plant, and discuss the results obtained. A phased approach was used in the level-1 program. In phase 1, which was completed in Fall 1991, a coarse screening analysis examining accidents initiated by internal events (including internal fire and flood) was performed for all plant operational states (POSs). The objective of the phase 1 study was to identify potential vulnerable plant configurations, to characterize (on a high, medium, or low basis) the potential core damage accident scenarios, and to provide a foundation for a detailed phase 2 analysis.

  19. Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit-1: Analysis of core damage frequency from internal events during mid-loop operations. Appendices F-H, Volume 2, Part 4

    SciTech Connect

    Chu, T.L.; Musicki, Z.; Kohut, P.; Yang, J.; Bozoki, G.; Hsu, C.J.; Diamond, D.J.; Bley, D.; Johnson, D.; Holmes, B.

    1994-06-01

    Traditionally, probabilistic risk assessments (PRA) of severe accidents in nuclear power plants have considered initiating events potentially occurring only during full power operation. Some previous screening analyses that were performed for other modes of operation suggested that risks during those modes were small relative to full power operation. However, more recent studies and operational experience have implied that accidents during low power and shutdown could be significant contributors to risk. Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The scope of the program includes that of a level-3 PRA. In phase 2, mid-loop operation was selected as the plant configuration to be analyzed based on the results of the phase 1 study. The objective of the phase 2 study is to perform a detailed analysis of the potential accident scenarios that may occur during mid-loop operation, and compare the results with those of NUREG-1150. The scope of the level-1 study includes plant damage state analysis, and uncertainty analysis. Volume 1 summarizes the results of the study. Internal events analysis is documented in Volume 2. It also contains an appendix that documents the part of the phase 1 study that has to do with POSs other than mid-loop operation. Internal fire and internal flood analyses are documented in Volumes 3 and 4. A separate study on seismic analysis, documented in Volume 5, was performed for the NRC by Future Resources Associates, Inc. Volume 6 documents the accident progression, source terms, and consequence analysis.

  20. Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1: Analysis of core damage frequency from internal events during mid-loop operations. Appendix E (Sections E.9-E.16), Volume 2, Part 3B

    SciTech Connect

    Chu, T.L.; Musicki, Z.; Kohut, P.; Yang, J.; Bozoki, G.; Hsu, C.J.; Diamond, D.J.; Wong, S.M.; Bley, D.; Johnson, D.

    1994-06-01

    Traditionally, probabilistic risk assessments (PRA) of severe accidents in nuclear power plants have considered initiating events potentially occurring only during full power operation. Some previous screening analyses that were performed for other modes of operation suggested that risks during those modes were small relative to full power operation. However, more recent studies and operational experience have implied that accidents during low power and shutdown could be significant contributors to risk. Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The scope of the program includes that of a level-3 PRA. In phase 2, mid-loop operation was selected as the plant configuration to be analyzed based on the results of the phase 1 study. The objective of the phase 2 study is to perform a detailed analysis of the potential accident scenarios that may occur during mid-loop operation, and compare the results with those of NUREG-1150. The scope of the level-1 study includes plant damage state analysis, and uncertainty analysis. Volume 1 summarizes the results of the study. Internal events analysis is documented in Volume 2. It also contains an appendix that documents the part of the phase 1 study that has to do with POSs other than mid-loop operation. Internal fire and internal flood analyses are documented in Volumes 3 and 4. A separate study on seismic analysis, documented in Volume 5, was performed for the NRC by Future Resources Associates, Inc. Volume 6 documents the accident progression, source terms, and consequence analysis.

  1. TMI-2 core damage: a summary of present knowledge

    SciTech Connect

    Owen, D.E.; Mason, R.E.; Meininger, R.D.; Franz, W.A.

    1983-01-01

    Extensive fuel damage (oxidation and fragmentation) has occurred and the top approx. 1.5 m of the center portion of the TMI-2 core has relocated. The fuel fragmentation extends outward to slightly beyond one-half the core radius in the direction examined by the CCTV camera. While the radial extent of core fragmentation in other directions was not directly observed, control and spider drop data and in-core instrument data suggest that the core void is roughly symmetrical, although there are a few indications of severe fuel damage extending to the core periphery. The core material fragmented into a broad range of particle sizes, extending down to a few microns. APSR movement data, the observation of damaged fuel assemblies hanging unsupported from the bottom of the reactor upper plenum structure, and the observation of once-molten stainless steel immediately above the active core indicate high temperatures (up to at least 1720 K) extended to the very top of the core. The relative lack of damage to the underside of the plenum structure implies a sharp temperature demarcation at the core/plenum interface. Filter debris and leadscrew deposit analyses indicate extensive high temperature core materials interaction, melting of the Ag-In-Cd control material, and transport of particulate control material to the plenum and out of the vessel.

  2. Interim prediction method for low frequency core engine noise

    NASA Technical Reports Server (NTRS)

    Huff, R. G.; Clark, B. J.; Dorsch, R. G.

    1974-01-01

    A literature survey on low-frequency core engine noise is presented. Possible sources of low frequency internally generated noise in core engines are discussed with emphasis on combustion and component scrubbing noise. An interim method is recommended for predicting low frequency core engine noise that is dominant when jet velocities are low. Suggestions are made for future research on low frequency core engine noise that will aid in improving the prediction method and help define possible additional internal noise sources.

  3. Damage tolerance of a composite sandwich with interleaved foam core

    NASA Technical Reports Server (NTRS)

    Ishai, Ori; Hiel, Clement

    1992-01-01

    A composite sandwich panel consisting of carbon fiber-reinforced plastic (CFRP) skins and a syntactic foam core was selected as an appropriate structural concept for the design of wind tunnel compressor blades. Interleaving of the core with tough interlayers was done to prevent core cracking and to improve damage tolerance of the sandwich. Simply supported sandwich beam specimens were subjected to low-velocity drop-weight impacts as well as high velocity ballistic impacts. The performance of the interleaved core sandwich panels was characterized by localized skin damage and minor cracking of the core. Residual compressive strength (RCS) of the skin, which was derived from flexural test, shows the expected trend of decreasing with increasing size of the damage, impact energy, and velocity. In the case of skin damage, RCS values of around 50 percent of the virgin interleaved reference were obtained at the upper impact energy range. Based on the similarity between low-velocity and ballistic-impact effects, it was concluded that impact energy is the main variable controlling damage and residual strength, where as velocity plays a minor role.

  4. Damage tolerance of a composite sandwich with interleaved foam core

    NASA Technical Reports Server (NTRS)

    Ishai, Ori; Hiel, Clement

    1992-01-01

    A composite sandwich panel consisting of carbon fiber-reinforced plastic (CFRP) skins and a syntactic foam core was selected as an appropriate structural concept for the design of wind tunnel compressor blades. Interleaving of the core with tough interlayers was done to prevent core cracking and to improve damage tolerance of the sandwich. Simply supported sandwich beam specimens were subjected to low-velocity drop-weight impacts as well as high velocity ballistic impacts. The performance of the interleaved core sandwich panels was characterized by localized skin damage and minor cracking of the core. Residual compressive strength (RCS) of the skin, which was derived from flexural test, shows the expected trend of decreasing with increasing size of the damage, impact energy, and velocity. In the case of skin damage, RCS values of around 50 percent of the virgin interleaved reference were obtained at the upper impact energy range. Based on the similarity between low-velocity and ballistic-impact effects, it was concluded that impact energy is the main variable controlling damage and residual strength, where as velocity plays a minor role.

  5. Astrometric "Core-shifts" at the Highest Frequencies

    NASA Technical Reports Server (NTRS)

    Rioja, Maria; Dodson, Richard

    2010-01-01

    We discuss the application of a new VLBI astrometric method named "Source/Frequency Phase Referencing" to measurements of "core-shifts" in radio sources used for geodetic observations. We detail the reasons that astrometrical observations of 'core-shifts' have become critical in the era of VLBI2010. We detail how this new method allows the problem to be addressed at the highest frequencies and outline its superior compensation of tropospheric errors.

  6. An examination of impact damage in glass-phenolic and aluminum honeycomb core composite panels

    NASA Technical Reports Server (NTRS)

    Nettles, A. T.; Lance, D. G.; Hodge, A. J.

    1990-01-01

    An examination of low velocity impact damage to glass-phenolic and aluminum core honeycomb sandwich panels with carbon-epoxy facesheets is presented. An instrumented drop weight impact test apparatus was utilized to inflict damage at energy ranges between 0.7 and 4.2 joules. Specimens were checked for extent of damage by cross sectional examination. The effect of core damage was assessed by subjecting impact-damaged beams to four-point bend tests. Skin-only specimens (facings not bonded to honeycomb) were also tested for comparison purposes. Results show that core buckling is the first damage mode, followed by delaminations in the facings, matrix cracking, and finally fiber breakage. The aluminum honeycomb panels exhibited a larger core damage zone and more facing delaminations than the glass-phenolic core, but could withstand more shear stress when damaged than the glass-phenolic core specimens.

  7. Damage detection using modal frequency curve and squared residual wavelet coefficients-based damage indicator

    NASA Astrophysics Data System (ADS)

    Yang, Chen; Oyadiji, S. Olutunde

    2017-01-01

    A theoretical and experimental study of the frequency-based damage detection method has been presented in this paper. Based on the eigenvalue problem and perturbation assumption of defect in modal response, the theoretical basis of the modal frequency curve method is established. The extraction of defect characteristics from the modal frequency curve via discrete wavelet transform is illustrated. The above background leads to the development of a new multiple-mode damage indicator for damage localisation and a damage estimator for size prediction. Then, the proposed method has been applied to aluminium samples with pre-defined damage sections. Finite element modelling and experimental testing results are presented to demonstrate the performance of the method. Additionally, detectability with respect to the various mass ratios is investigated to support the ability of the method in real applications. The numerical and experimental results suggest that the use of the damage indicator provides a more robust and unambiguous damage identification than the sole use of the wavelet coefficients of the modes investigated. In addition, the damage estimator predicts the defect size to a satisfactory level.

  8. Frequency-dependent core shifts and parameter estimation in Blazars

    NASA Astrophysics Data System (ADS)

    Agarwal, Aditi

    2016-07-01

    We study the core shift effect in the parsec-scale jet of blazars using the 4.8-36.8 GHz radio light curves obtained from four decades of continuous monitoring. From a piecewise Gaussian fit to each flare, time lags between the observation frequencies and spectral indices (α) based on peak amplitudes (A) are determined. Index k is calculated and found to be ˜1, indicating equipartition between the magnetic field energy density and the particle energy density. A mean magnetic field strength at 1 pc (B1) and at the core (Bcore) are inferred which are found to be consistent with previous estimates. The measure of core position offset is also performed by averaging over all frequency pairs. Based on the statistical trend shown by the measured core radius as a function of frequency, we infer that the synchrotron opacity model may not be valid for all cases. A Fourier periodogram analysis yields power-law slopes in the range -1.6 to -3.5 describing the power spectral density shape and gives bend timescales. This result, and both positive and negative spectral indices, indicate that the flares originate from multiple shocks in a small region. Important objectives met in our study include: the demonstration of the computational efficiency and statistical basis of the piecewise Gaussian fit; consistency with previously reported results; evidence for the core shift dependence on observation frequency and its utility in jet diagnostics in the region close to the resolving limit of very long baseline interferometry observations.

  9. Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1. Analysis of core damage frequency from internal events for plant operational state 5 during a refueling outage. Internal events appendices K to M

    SciTech Connect

    Forester, J.; Yakle, J.; Walsh, B.; Darby, J.; Whitehead, D.; Staple, B.; Brown, T.

    1994-07-01

    This report provides supporting documentation for various tasks associated with the performance of the probabilistic risk assessment for Plant Operational State 5 (approximately Cold Shutdown as defined by Grand Gulf Technical Specifications) during a refueling outage at Grand Gulf, Unit 1 as documented in Volume 2, Part 1 of NUREG/CR-6143. The report contains the following appendices: K - HEP Locator Files; L - Supporting Information for the Plant Damage State Analysis; M - Summary of Results from the Coarse Screening Analysis - Phase 1A.

  10. Damage analysis in Al thin films fatigued at ultrahigh frequencies

    NASA Astrophysics Data System (ADS)

    Eberl, Christoph; Spolenak, Ralph; Kraft, Oliver; Kubat, Franz; Ruile, Werner; Arzt, Eduard

    2006-06-01

    A quantitative damage analysis provides insight into the damage mechanisms and lifetimes of aluminum thin films fatigued at ultrahigh frequencies. Surface acoustic wave test devices were used to test continuous and patterned Al thin films up to more than 1014 cycles. The analysis revealed increasing extrusion and void formation concentrated at grain boundaries. This finding and the observed grain growth indicate a high material flux at the grain boundaries induced by the cyclic load. A correlation between device degradation and defect density is established which is explained by a theoretical model. For stress amplitudes as low as 14 MPa lifetime measurements showed no fatigue limit for 420 nm Al thin films.

  11. Permeability and of the San Andreas Fault core and damage zone from SAFOD drill core

    NASA Astrophysics Data System (ADS)

    Rathbun, A. P.; Fry, M.; Kitajima, H.; Song, I.; Carpenter, B. M.; Marone, C.; Saffer, D. M.

    2012-12-01

    Quantifying fault-rock permeability is important toward understanding both the regional hydrologic behavior of fault zones, and poro-elastic processes that may affect faulting and earthquake mechanics by mediating effective stress. These include persistent fluid overpressures hypothesized to reduce fault strength, as well as dynamic processes that may occur during earthquake slip, including thermal pressurization and dilatancy hardening. To date, studies of permeability on fault rocks and gouge from plate-boundary strike-slip faults have mainly focused on samples from surface outcrops. We report on permeability tests conducted on the host rock, damage zone, and a major actively creeping fault strand (Central Deformation Zone, CDZ) of the San Andreas Fault (SAF), obtained from coring across the active SAF at ~2.7 km depth as part of SAFOD Phase III. We quantify permeability on subsamples oriented both perpendicular and parallel to the coring axis, which is nearly perpendicular to the SAF plane, to evaluate permeability anisotropy. The fault strand samples were obtained from the CDZ, which accommodates significant creep, and hosts ~90% of the observed casing deformation measured between drilling phases. The CDZ is 2.6 m thick with a matrix grain size < 10 μm and ~5% vol. clasts, and contains ~80% clay, of which ~90% is smectite. We also tested damage zone samples taken from adjacent core sections within a few m on either side of the CDZ. Permeability experiments were conducted in a triaxial vessel, on samples 25.4 mm in diameter and ~20-35 mm in length. We conducted measurements under isotropic stress conditions, at effective stress (Pc') of ~5-70 MPa. We measure permeability using a constant head flow-through technique. At the highest Pc', low permeability of the CDZ and damage zone necessitates using a step loading transient method and is in good agreement with permeabilities obtained from flow-through experiments. We quantify compression behavior by monitoring

  12. Frequency Response of an Aircraft Wing with Discrete Source Damage Using Equivalent Plate Analysis

    NASA Technical Reports Server (NTRS)

    Krishnamurthy, T.; Eldred, Lloyd B.

    2007-01-01

    An equivalent plate procedure is developed to provide a computationally efficient means of matching the stiffness and frequencies of flight vehicle wing structures for prescribed loading conditions. Several new approaches are proposed and studied to match the stiffness and first five natural frequencies of the two reference models with and without damage. One approach divides the candidate reference plate into multiple zones in which stiffness and mass can be varied using a variety of materials including aluminum, graphite-epoxy, and foam-core graphite-epoxy sandwiches. Another approach places point masses along the edge of the stiffness-matched plate to tune the natural frequencies. Both approaches are successful at matching the stiffness and natural frequencies of the reference plates and provide useful insight into determination of crucial features in equivalent plate models of aircraft wing structures.

  13. Status of the TMI-2 core: a review of damage assessments

    SciTech Connect

    Croucher, D.W.

    1981-01-01

    Assessments of the damage within the core of the Three Mile Island Unit 2 reactor, performed by reconstructing the transient thermal-hydraulic sequence of events, estimating the amount of hydrogen generation, and evaluating the amount of fission products released, are reviewed and summarized. Minimum and maximum bounds of damage to the core are identified.

  14. Summary of core damage frequency from internal initiators: Peach Bottom

    SciTech Connect

    Kolaczkowski, A.M.; Lambright, J.A.; Cathey, N.

    1986-01-01

    Probabilistic risk assessments (PRA) based on internal initiators are being conducted on a number of reference plants in order to provide the Nuclear Regulatory Commission (NRC) with updated information about light water reactor risk. The results of these analyses will be used by the NRC to prepare NUREG-1150 which will examine the NRC's current perception of risk. Peach Bottom has been chosen as one of the reference plants.

  15. The BWR lower head response during a large-break LOCA with core damage

    SciTech Connect

    Alammar, M.A.

    1996-12-31

    Some of the important issues in severe accident management guidelines development deal with estimating the time to lower head vessel failure after core damage and the time window available for water injection that would prevent vessel failure. These issues are obviously scenario dependent, but bounding estimates are needed. The scenario chosen for this purpose was a design-basis accident (DBA) loss-of-coolant accident (LOCA) because it was one of the contributors to the Oyster Creek containment failure frequency. Oyster Creek is a 1930-MW(thermal) boiling water reactor (BWR)-2. The lower head response models have improved since the Three Mile Island unit 2 (TMI-2) vessel investigation project (VIP) results became known, specifically the addition of rapid- and slow-cooling models. These mechanisms were found to have taken place in the TMI-2 lower head during debris cooldown and were important contributors in preventing vessel failure.

  16. Combining nutation and surface gravity observations to estimate the Earth's core and inner core resonant frequencies

    NASA Astrophysics Data System (ADS)

    Ziegler, Yann; Lambert, Sébastien; Rosat, Séverine; Nurul Huda, Ibnu; Bizouard, Christian

    2017-04-01

    Nutation time series derived from very long baseline interferometry (VLBI) and time varying surface gravity data recorded by superconducting gravimeters (SG) have long been used separately to assess the Earth's interior via the estimation of the free core and inner core resonance effects on nutation or tidal gravity. The results obtained from these two techniques have been shown recently to be consistent, making relevant the combination of VLBI and SG observables and the estimation of Earth's interior parameters in a single inversion. We present here the intermediate results of the ongoing project of combining nutation and surface gravity time series to improve estimates of the Earth's core and inner core resonant frequencies. We use VLBI nutation time series spanning 1984-2016 derived by the International VLBI Service for geodesy and astrometry (IVS) as the result of a combination of inputs from various IVS analysis centers, and surface gravity data from about 15 SG stations. We address here the resonance model used for describing the Earth's interior response to tidal excitation, the data preparation consisting of the error recalibration and amplitude fitting for nutation data, and processing of SG time-varying gravity to remove any gaps, spikes, steps and other disturbances, followed by the tidal analysis with the ETERNA 3.4 software package, the preliminary estimates of the resonant periods, and the correlations between parameters.

  17. Precursors to potential severe core damage accidents. A status report, 1982--1983

    SciTech Connect

    Forester, J.A.; Mitchell, D.B.; Whitehead, D.W.

    1997-04-01

    This study is a continuation of earlier work that evaluated 1969-1981 and 1984-1994 events affecting commercial light-water reactors. One-hundred nine operational events that affected 51 reactors during 1982 and 1983 and that are considered to be precursors to potential severe core damage are described. All these events had conditional probabilities of subsequent severe core damage greater than or equal to 1.0 x 10{sup {minus}6}. These events were identified by first computer screening the 1982-83 licensee event reports from commercial light-water reactors to select events that could be precursors to core damage. Candidates underwent engineering evaluation that identified, analyzed, and documented the precursors. This report discusses the general rationale for the study, the selection and documentation of events as precursors, and the estimation of conditional probabilities of subsequent severe core damage for the events.

  18. Parameters affecting of Akkuyu's safety assessment for severe core damages

    NASA Astrophysics Data System (ADS)

    Kavun, Yusuf; Karasulu, Muzaffer

    2015-07-01

    We have looked at all past core meltdowns (Three Mile Island, Chernobyl and Fukushima incidents) and postulated the fourth one might be taking place in the future most probably in a newly built reactors anywhere of the earth in any type of NPP. The probability of this observation is high considering the nature of the machine and human interaction. Operation experience is a very significant parameter as well as the safety culture of the host nation. The concerns is not just a lack of experience with industry with the new comers, but also the infrastructure and established institutions who will be dealing with the Emergencies. Lack of trained and educated Emergency Response Organizations (ERO) is a major concern. The culture on simple fire drills even makes the difference when a severe condition occurs in the industry. The study assumes the fourth event will be taking place at the Akkuyu NGS and works backwards as required by the "what went wrong " scenarios and comes up with interesting results. The differences studied in depth to determine the impact to the severe accidents. The all four design have now core catchers. We have looked at the operator errors'like in TMI); Operator errors combined with design deficiencies(like in Chernobyl) and natural disasters( like in Fukushima) and found operator errors to be more probable event on the Akkuyu's postulated next incident. With respect to experiences of the operators we do not have any data except for long and successful operating history of the Soviet design reactors up until the Chernobyl incident. Since the Akkuyu will be built, own and operated by the Russians we have found no alarming concerns at the moment. At the moment, there is no body be able to operate those units in Turkey. Turkey is planning to build the required manpower during the transition period. The resolution of the observed parameters lies to work and educate, train of the host nation and exercise together.

  19. Microwave damage susceptibility trend of a bipolar transistor as a function of frequency

    NASA Astrophysics Data System (ADS)

    Ma, Zhen-Yang; Chai, Chang-Chun; Ren, Xing-Rong; Yang, Yin-Tang; Chen, Bin; Song, Kun; Zhao, Ying-Bo

    2012-09-01

    We conduct a theoretical study of the damage susceptibility trend of a typical bipolar transistor induced by a high-power microwave (HPM) as a function of frequency. The dependences of the burnout time and the damage power on the signal frequency are obtained. Studies of the internal damage process and the mechanism of the device are carried out from the variation analysis of the distribution of the electric field, current density, and temperature. The investigation shows that the burnout time linearly depends on the signal frequency. The current density and the electric field at the damage position decrease with increasing frequency. Meanwhile, the temperature elevation occurs in the area between the p-n junction and the n-n+ interface due to the increase of the electric field. Adopting the data analysis software, the relationship between the damage power and frequency is obtained. Moreover, the thickness of the substrate has a significant effect on the burnout time.

  20. Core damage severity evaluation for pressurized water reactors by artificial intelligence methods

    NASA Astrophysics Data System (ADS)

    Mironidis, Anastasios Pantelis

    1998-12-01

    During the course of nuclear power evolution, accidents have occurred. However, in the western world, none of them had a severe impact on the public because of the design features of nuclear plants. In nuclear reactors, barriers constitute physical obstacles to uncontrolled fission product releases. These barriers are an important factor in safety analysis. During an accident, reactor safety systems become actuated to prevent the barriers from been breached. In addition, operators are required to take specified actions, meticulously depicted in emergency response procedures. In an accident, on-the-spot knowledge regarding the condition of the core is necessary. In order to make the right decisions toward mitigating the accident severity and its consequences, we need to know the status of the core [1, 3]. However, power plant instrumentation that can provide a direct indication of the status of the core during the time when core damage is a potential outcome, does not exist. Moreover, the information from instruments may have large uncertainty of various types. Thus, a very strong potential for misinterpreting incoming information exists. This research endeavor addresses the problem of evaluating the core damage severity of a Pressurized Water Reactor during a transient or an accident. An expert system has been constructed, that incorporates knowledge and reasoning of human experts. The expert system's inference engine receives incoming plant data that originate in the plethora of core-related instruments. Its knowledge base relies on several massive, multivariate fuzzy logic rule-sets, coupled with several artificial neural networks. These mathematical models have encoded information that defines possible core states, based on correlations of parameter values. The inference process classifies the core as intact, or as experiencing clad damage and/or core melting. If the system detects a form of core damage, a quantification procedure will provide a numerical

  1. Performance of High-frequency High-flux Magnetic Cores at Cryogenic Temperatures

    NASA Technical Reports Server (NTRS)

    Gerber, Scott S.; Hammoud, Ahmad; Elbuluk, Malik E.; Patterson, Richard L.

    2002-01-01

    Three magnetic powder cores and one ferrite core, which are commonly used in inductor and transformer design for switch mode power supplies, were selected for investigation at cryogenic temperatures. The powder cores are Molypermalloy Core (MPC), High Flux Core (HFC), and Kool Mu Core (KMC). The performance of four inductors utilizing these cores has been evaluated as a function of temperature from 20 C to -180 C. All cores were wound with the same wire type and gauge to obtain equal values of inductance at room temperature. Each inductor was evaluated in terms of its inductance, quality (Q) factor, resistance, and dynamic hysteresis characteristics (B-H loop) as a function of temperature and frequency. Both sinusoidal and square wave excitations were used in these investigations. Measured data obtained on the inductance showed that both the MPC and the HFC cores maintain a constant inductance value, whereas with the KMC and ferrite core hold a steady value in inductance with frequency but decrease as temperature is decreased. All cores exhibited dependency, with varying degrees, in their quality factor and resistance on test frequency and temperature. Except for the ferrite, all cores exhibited good stability in the investigated properties with temperature as well as frequency. Details of the experimental procedures and test results are presented and discussed in the paper.

  2. Cosmic ray radiography of the damaged cores of the Fukushima reactors.

    PubMed

    Borozdin, Konstantin; Greene, Steven; Lukić, Zarija; Milner, Edward; Miyadera, Haruo; Morris, Christopher; Perry, John

    2012-10-12

    The passage of muons through matter is dominated by the Coulomb interaction with electrons and nuclei. The interaction with the electrons leads to continuous energy loss and stopping of the muons. The interaction with nuclei leads to angle "diffusion." Two muon-imaging methods that use flux attenuation and multiple Coulomb scattering of cosmic-ray muons are being studied as tools for diagnosing the damaged cores of the Fukushima reactors. Here, we compare these two methods. We conclude that the scattering method can provide detailed information about the core. Attenuation has low contrast and little sensitivity to the core.

  3. Cosmic ray radiography of the damaged cores of the Fukushima reactors

    DOE PAGES

    Borozdin, Konstantin; Greene, Steven; Lukić, Zarija; ...

    2012-10-11

    The passage of muons through matter is dominated by the Coulomb interaction with electrons and nuclei. The interaction with the electrons leads to continuous energy loss and stopping of the muons. The interaction with nuclei leads to angle “diffusion.” Two muon-imaging methods that use flux attenuation and multiple Coulomb scattering of cosmic-ray muons are being studied as tools for diagnosing the damaged cores of the Fukushima reactors. Here, we compare these two methods. We conclude that the scattering method can provide detailed information about the core. Lastly, attenuation has low contrast and little sensitivity to the core.

  4. High Frequency Magneto Dielectric Effects In Self Assembled Ferrite Ferroelectric Core Shell Nanoparticles

    DTIC Science & Technology

    2014-09-10

    SECURITY CLASSIFICATION OF: Magneto-dielectric effects in self-assembled core -shell nanoparticles of nickel ferrite (NFO) and barium titanate (BTO) have...been investigated in the millimeter wave frequencies. The core -shell nano-composites were synthesized by coating 100 nm nickel ferrite and 50 nm...distribution is unlimited. High frequency magneto-dielectric effects in self-assembled ferrite -ferroelectric core -shell nanoparticles The views, opinions

  5. On the classification of normalized natural frequencies for damage detection in cantilever beam

    NASA Astrophysics Data System (ADS)

    Dahak, Mustapha; Touat, Noureddine; Benseddiq, Noureddine

    2017-08-01

    The presence of a damage on a beam causes changes in the physical properties, which introduce flexibility, and reduce the natural frequencies of the beam. Based on this, a new method is proposed to locate the damage zone in a cantilever beam. In this paper, the cantilever beam is discretized into a number of zones, where each zone has a specific classification of the first four normalized natural frequencies. The damaged zone is distinguished by only the classification of the normalized frequencies of the structure. In the case when the damage is symmetric to the vibration node, we use the unchanged natural frequency as a second information to obtain a more accurate location. The effectiveness of the proposed method is shown by a numerical simulation with ANSYS software and experimental investigation of a cantilever beam with different damage.

  6. Brain temperature, body core temperature, and intracranial pressure in acute cerebral damage

    PubMed Central

    Rossi, S; Zanier, E; Mauri, I; Columbo, A; Stocchetti, N

    2001-01-01

    OBJECTIVES—To assess the frequency of hyperthermia in a population of acute neurosurgical patients; to assess the relation between brain temperature (ICT) and core temperature (Tc); to investigate the effect of changes in brain temperature on intracranial pressure (ICP).
METHODS—The study involved 20 patients (10 severe head injury, eight subarachnoid haemorrhage, two neoplasms) with median Glasgow coma score (GCS) 6. ICP and ICT were monitored by an intraventricular catheter coupled with a thermistor. Internal Tc was measured in the pulmonary artery by a Swan-Ganz catheter.
RESULTS—Mean ICT was 38.4 (SD 0.8) and mean Tc 38.1 (SD 0.8)°C; 73% of ICT and 57.5% of Tc measurements were ⩾38°C. The mean difference between ICT and Tc was 0.3 (SD 0.3)°C (range −0.7 to 2.3°C) (p=0. 0001). Only in 12% of patients was Tc higher than ICT. The main reason for the differences between ICT and Tc was body core temperature: the difference between ICT and Tc increased significantly with body core temperature and fell significantly when this was lowered. The mean gradient between ICT and Tc was 0.16 (SD 0.31)°C before febrile episodes (ICT being higher than Tc), and 0.41 (SD 0.38)°C at the febrile peak (p<0.05). When changes in temperature were considered, ICT had a profound influence on ICP. Increases in ICT were associated with a significant rise in ICP, from 14.9(SD 7.9) to 22 (SD 10.4) mm Hg (p<0.05). As the fever ebbed there was a significant decrease in ICP, from 17.5 (SD 8.62) to 16 (SD 7.76) mm Hg (p=0.02).
CONCLUSIONS—Fever is extremely frequent during acute cerebral damage and ICT is significantly higher than Tc. Moreover, Tc may underestimate ICT during the phases when temperature has the most impact on the intracranial system because of the close association between increases in ICT and ICP.

 PMID:11561026

  7. Spatial resolution improvement for Lamb wave-based damage detection using frequency dependency compensation

    NASA Astrophysics Data System (ADS)

    Zeng, Liang; Lin, Jing; Bao, Jingjing; Joseph, Roshan Prakash; Huang, Liping

    2017-04-01

    In Lamb wave inspection systems, the transfer functions of the transmitter and receiver, and the attenuation as Lamb wave propagates through the structure, result in frequency dependency in the amplitude of Lamb modes. This frequency dependency in amplitude also influences the testing resolution and complicates the damage evaluation. With the goal of spatial resolution improving, a frequency dependency compensation method is proposed. In this method, an accurate estimation of the frequency-dependent amplitude is firstly obtained, then a refined inverse filter is designed and applied to the raw Lamb mode signals to compensate the frequency dependency. An experimental example is introduced to illustrate the process of the proposed method. Besides, its sensitivity to the propagation distance and Taylor expansion order is thoroughly investigated. Finally, the proposed method is employed for damage detection. Its effectiveness in testing resolution improvement and damage identification could be obviously demonstrated by the imaging result of the damage.

  8. Towards ultimate low frequency air-core magnetometer sensitivity.

    PubMed

    Pellicer-Guridi, Ruben; Vogel, Michael W; Reutens, David C; Vegh, Viktor

    2017-05-23

    Air-core magnetometers are amongst the most commonly used magnetic field detectors in biomedical instruments. They offer excellent sensitivity, low fabrication complexity and a robust, cost-effective solution. However, air-core magnetometers must be tailored to the specific application to achieve high sensitivity, which can be decisive in the accuracy of the diagnoses and the time required for the examination. Existing methods proposed for the design of air-core magnetometers are based on simplified models and simulations using a reduced number of variables, potentially leading to sensitivity that is suboptimal. To circumvent this we chose a method with fewer assumptions and a larger number of decision variables which employed a genetic algorithm, a global optimisation method. Experimental validation shows that the model is appropriate for the design of highly sensitive air-core magnetometers. Moreover, our results support the suitability of a genetic algorithm for optimization in this context. The new method described herein will be made publicly available via our website to facilitate the development of less costly biomedical instruments using air-core magnetometers with unprecedented sensitivity.

  9. Multi-frequency local wavenumber analysis and ply correlation of delamination damage.

    PubMed

    Juarez, Peter D; Leckey, Cara A C

    2015-09-01

    Wavenumber domain analysis through use of scanning laser Doppler vibrometry has been shown to be effective for non-contact inspection of damage in composites. Qualitative and semi-quantitative local wavenumber analysis of realistic delamination damage and quantitative analysis of idealized damage scenarios (Teflon inserts) have been performed previously in the literature. This paper presents a new methodology based on multi-frequency local wavenumber analysis for quantitative assessment of multi-ply delamination damage in carbon fiber reinforced polymer (CFRP) composite specimens. The methodology is presented and applied to a real world damage scenario (impact damage in an aerospace CFRP composite). The methodology yields delamination size and also correlates local wavenumber results from multiple excitation frequencies to theoretical dispersion curves in order to robustly determine the delamination ply depth. Results from the wavenumber based technique are validated against a traditional nondestructive evaluation method.

  10. Selection of optimal artificial boundary condition (ABC) frequencies for structural damage identification

    NASA Astrophysics Data System (ADS)

    Mao, Lei; Lu, Yong

    2016-07-01

    In this paper, the sensitivities of artificial boundary condition (ABC) frequencies to the damages are investigated, and the optimal sensors are selected to provide the reliable structural damage identification. The sensitivity expressions for one-pin and two-pin ABC frequencies, which are the natural frequencies from structures with one and two additional constraints to its original boundary condition, respectively, are proposed. Based on the expressions, the contributions of the underlying mode shapes in the ABC frequencies can be calculated and used to select more sensitive ABC frequencies. Selection criteria are then defined for different conditions, and their performance in structural damage identification is examined with numerical studies. From the findings, conclusions are given.

  11. Survival of extensively damaged endodontically treated incisors restored with different types of posts-and-core foundation restoration material.

    PubMed

    Lazari, Priscilla Cardoso; de Carvalho, Marco Aurélio; Del Bel Cury, Altair A; Magne, Pascal

    2017-09-16

    Which post-and-core combination will best improve the performance of extensively damaged endodontically treated incisors without a ferrule is still unclear. The purpose of this in vitro study was to investigate the restoration of extensively damaged endodontically treated incisors without a ferrule using glass-ceramic crowns bonded to various composite resin foundation restorations and 2 types of posts. Sixty decoronated endodontically treated bovine incisors without a ferrule were divided into 4 groups and restored with various post-and-core foundation restorations. NfPfB=no-ferrule (Nf) with glass-fiber post (Pf) and bulk-fill resin foundation restoration (B); NfPfP=no-ferrule (Nf) with glass-fiber post (Pf) and dual-polymerized composite resin core foundation restoration (P); NfPt=no-ferrule (Nf) with titanium post (Pt) and resin core foundation restoration; and NfPtB=no-ferrule (Nf) with titanium post (Pt) and bulk-fill resin core foundation restoration (B). Two additional groups from previously published data from the same authors (FPf=2mm of ferrule (F) and glass-fiber post (Pf) and composite resin core foundation restoration; and NfPf=no-ferrule (Nf) with glass-fiber post (Pf) and composite resin core foundation restoration), which were tested concomitantly and using the same experimental arrangement, were included for comparison. All teeth were prepared to receive bonded glass-ceramic crowns luted with dual-polymerized resin cement and were subjected to accelerated fatigue testing under submerged conditions at room temperature. Cyclic isometric loading was applied to the incisal edge at an angle of 30 degrees with a frequency of 5 Hz, beginning with a load of 100 N (5000 cycles). A 100-N load increase was applied every 15000 cycles. The specimens were loaded until failure or to a maximum of 1000 N (140000 cycles). The 6 groups (4 groups from the present study and 2 groups from the previously published study) were compared using the Kaplan-Meier survival

  12. New creep-fatigue damage model based on the frequency modified strain range method

    SciTech Connect

    Kim, Y.J.; Seok, C.S.; Park, J.J.

    1996-12-01

    For mechanical systems operating at high temperature, damage due to the interaction effect of creep and fatigue plays an important role. The objective of this paper is to propose a modified creep-fatigue damage model which separately analyzes the pure creep damage due to the hold time and the creep-fatigue interaction damage during the startup and the shutdown period. The creep damage was calculated by the general creep damage equation and the creep-fatigue interaction damage was calculated by the modified equation which is based on the frequency modified strain range method with strain rate term. In order to verify the proposed model, a series of high temperature low cycle fatigue tests were performed. The test specimens were made from Inconel-718 superalloy and the test parameters were wave form and hold time. A good agreement between the predicted lives based on the proposed model and experimentally obtained ones was obtained.

  13. Detection of damaged supports under railway track based on frequency shift

    NASA Astrophysics Data System (ADS)

    Wang, Longqi; Zhang, Yao; Lie, Seng Tjhen

    2017-03-01

    In railway transportation systems, the tracks are usually fastened on sleepers which are supported by the ballast. A lot of research has been conducted to guarantee the safety of railway track because of its importance, and more concern is expressed about monitoring of track itself such as railway level and alignment. The ballast and fasteners which provide strong support to the railway track are important as well whereas the detection of loose or missing fasteners and damaged ballast mainly relies on visual inspection. Although it is reliable when the fastener is missing and the damaged ballast is on the surface, it provides less help if the fastener is only loose and the damaged ballast is under the sleepers, which are however frequently observed in practice. This paper proposes an approach based on frequency shift to identify the damaged supports including the loose or missing fasteners and damaged ballast. In this study, the rail-sleeper-ballast system is modeled as an Euler beam evenly supported by a series of springs, the stiffness of which are reduced when the fastener is loose or missing and the ballast under the sleepers is damaged. An auxiliary mass is utilized herein and when it is mounted on the beam, the natural frequencies of the whole system will change with respect to the location of the auxiliary mass. The auxiliary mass induced frequency shift is analyzed and it is found the natural frequencies change periodically when the supports are undamaged, whereas the periodicity will be broken due to damaged supports. In fact, the natural frequencies drop clearly when the auxiliary mass moves over the damaged support. A special damage index only using the information of the damaged states is proposed and both numerical and experimental examples are carried out to validate the proposed method.

  14. Steady flows in rotating spherical cavity excited by multi-frequency oscillations of free inner core

    NASA Astrophysics Data System (ADS)

    Kozlov, Victor G.; Kozlov, Nikolai V.; Subbotin, Stanislav V.

    2017-01-01

    Fluid motion in a rotating spherical cavity in the conditions of resonant oscillations of free inner core is experimentally investigated. The centrifugal force retains a solid core with density less than the fluid density near the center of the cavity. In the absence of external force field the system "solid core - liquid" performs solid body rotation. The oscillations of the core are excited by an external oscillating force field and this results in differential rotation of the core with respect to the cavity. The direction of rotation is determined by the ratio of the oscillation frequency to the cavity angular velocity. The core oscillations with the radian frequency, which exceeds the cavity angular velocity, are investigated. It is found that a steady flow in the form of a system of nested fluid columns of circular cross section, which rotate at different angular velocities, is generated in the cavity as a result of oscillations of the core and the fluid. It is shown that at simultaneous influence of several oscillating fields the resulting steady flow is determined by a linear superposition of the flows, which are excited by the oscillations of the inner core with different frequencies. At a certain ratio of the vibration frequency to the rotation one the transformation of the circular shape of the column into the elliptical one is observed.

  15. Precursors to potential severe core damage accidents: 1995 A status report

    SciTech Connect

    Belles, R.J.; Cletcher, J.W.; Copinger, D.A.

    1997-04-01

    Ten operational events that affected 10 commercial light-water reactors during 1995 and that are considered to be precursors to potential severe core damage are described. All these events had conditional probabilities of subsequent severe core damage greater than or equal to 1.0 x 10{sup {minus}6}. These events were identified by first computer-screening the 1995 licensee event reports from commercial light-water reactors to identify those events that could potentially be precursors. Candidate precursors were selected and evaluated in a process similar to that used in previous assessments. Selected events underwent engineering evaluation that identified, analyzed, and documented the precursors. Other events designated by the Nuclear Regulatory Commission (NRC) also underwent a similar evaluation. Finally, documented precursors were submitted for review by licensees and NRC headquarters and regional offices to ensure the plant design and its response to the precursor were correctly characterized. This study is a continuation of earlier work, which evaluated 1969-1981 and 1984-1994 events. The report discusses the general rationale for this study, the selection and documentation of events as precursors, and the estimation of conditional probabilities of subsequent severe core damage for the events.

  16. Precursors to potential severe core damage accidents: 1997 -- A status report. Volume 26

    SciTech Connect

    Belles, R.J.; Cletcher, J.W.; Copinger, D.A.; Muhlheim, M.D.; Dolan, B.W.; Minarick, J.W.

    1998-11-01

    This report describes the five operational events in 1997 that affected five commercial light-water reactors (LWRs) and that are considered to be precursors to potential severe core damage accidents. All these events had conditional probabilities of subsequent severe core damage greater than or equal to 1.0 {times} 10{sup {minus}6}. These events were identified by first computer-screening the 1997 licensee event reports from commercial LWRs to identify those events that could be precursors. Candidate precursors were selected and evaluated in a process similar to that used in previous assessments. Selected events underwent engineering evaluation that identified, analyzed, and documented the precursors. Other events designated by the Nuclear Regulatory Commission (NRC) also underwent a similar evaluation. Finally, documented precursors were submitted for review by licensees and NRC headquarters to ensure that the plant design and its response to the precursor were correctly characterized. This study is a continuation of earlier work, which evaluated 1969--1996 events. The report discusses the general rationale for this study, the selection and documentation of events as precursors, and the estimation of conditional probabilities of subsequent severe core damage for the events.

  17. Precursors to potential severe core damage accidents: 1994, a status report. Volume 22: Appendix I

    SciTech Connect

    Belles, R.J.; Cletcher, J.W.; Copinger, D.A.; Vanden Heuvel, L.N.; Dolan, B.W.; Minarick, J.W. |

    1995-12-01

    Nine operational events that affected eleven commercial light-water reactors (LWRs) during 1994 and that are considered to be precursors to potential severe core damage are described. All these events had conditional probabilities of subsequent severe core damage greater than or equal to 1.0 {times} 10{sup {minus}6}. These events were identified by computer-screening the 1994 licensee event reports from commercial LWRs to identify those that could be potential precursors. Candidate precursors were then selected and evaluated in a process similar to that used in previous assessments. Selected events underwent engineering evaluation that identified, analyzed, and documented the precursors. Other events designated by the Nuclear Regulatory Commission (NRC) also underwent a similar evaluation. Finally, documented precursors were submitted for review by licensees and NRC headquarters and regional offices to ensure that the plant design and its response to the precursor were correctly characterized. This study is a continuation of earlier work, which evaluated 1969--1981 and 1984--1993 events. The report discusses the general rationale for this study, the selection and documentation of events as precursors, and the estimation of conditional probabilities of subsequent severe core damage for events. This document is bound in two volumes: Vol. 21 contains the main report and Appendices A--H; Vol. 22 contains Appendix 1.

  18. Robust structural damage detection and localization based on joint approximate diagonalization technique in frequency domain

    NASA Astrophysics Data System (ADS)

    Cao, Shancheng; Ouyang, Huajiang

    2017-01-01

    The structural characteristic deflection shapes (CDS’s) such as mode shapes and operational deflection shapes are highly sensitive to structural damage in beam- or plate-type structures. Nevertheless, they are vulnerable to measurement noise and could result in unacceptable identification errors. In order to increase the accuracy and noise robustness of damage identification based on CDS’s using vibration responses of random excitation, joint approximate diagonalization (JAD) technique and gapped smoothing method (GSM) are combined to form a sensitive and robust damage index (DI), which can simultaneously detect the existence of damage and localize its position. In addition, it is possible to apply this approach to damage identification of structures under ambient excitation. First, JAD method which is an essential technique of blind source separation is investigated to simultaneously diagonalize a set of power spectral density matrices corresponding to frequencies near a certain natural frequency to estimate a joint unitary diagonalizer. The columns of this joint diagonalizer contain dominant CDS’s. With the identified dominant CDS’s around different natural frequencies, GSM is used to extract damage features and a robust damage identification index is then proposed. Numerical and experimental examples of beams with cracks are used to verify the validity and noise robustness of JAD based CDS estimation and the proposed DI. Furthermore, damage identification using dominant CDS’s estimated by JAD method is demonstrated to be more accurate and noise robust than by the commonly used singular value decomposition method.

  19. Effect of Correlations of Component Failures and Cross-Connections of EDGs on Seismically Induced Core Damages of a Multi-Unit Site

    NASA Astrophysics Data System (ADS)

    Muramatsu, Ken; Liu, Qiao; Uchiyama, Tomoaki

    Aiming at proposing effective applications of seismic probabilistic safety assessment (PSA) for design and risk management of nuclear facilities, we conducted a preliminary seismic PSA study for a multi-unit site to examine core damage frequency (CDF) and core damage sequences with consideration of the effect of correlations of component failures. In addition, we also examined the effectiveness of an accident management measure, namely, cross-connections of emergency diesel generators (EDGs) between adjacent units in this study. Twin BWR-5 units of the same design were hypothesized to be located at the same site in this study and the CDF as well as the accident sequences of this two-unit site were analyzed by using SECOM2, a system reliability analysis code for seismic PSA. The results showed that the calculated CDF was dependent on the assumptions on the correlations of component failures. When the rules for assigning correlation coefficients of component responses defined in the NUREG-1150 program were adopted, the CDF of a single unit, the CDF of this two-unit site (the frequency of core damages of at least one unit at this site) and the frequency of simultaneous core damages of both units increased by factors of about 1.3, 1.2 and 2.3, respectively. In addition, it might be possible that the simultaneous core damages of both units are caused by different accident sequence pairs as well as the same sequence pairs. When cross-connections of EDGs between two units were available, the CDF of a single unit, the CDF of this two-unit site as well as the frequency of simultaneous core damages of both units decreased. In addition, the CDF of this two-unit site was smaller than the CDF of a single unit site. These results show that cross-connections of EDGs might be beneficial for a multi-unit site if the rules for assigning correlation coefficients defined in NUREG-1150 program are reasonable.

  20. Field and laboratory investigations of coring-induced damage in core recovered from Marker Bed 139 at the waste isolation pilot plant underground facility

    SciTech Connect

    Holcomb, D.J.; Zeuch, D.H.; Morin, K.; Hardy, R.; Tormey, T.V.

    1995-09-01

    A combined laboratory and field investigation was carried out to determine the extent of coring-induced damage done to samples cored from Marker Bed 139 at the WIPP site. Coring-induced damage, if present, has the potential to significantly change the properties of the material used for laboratory testing relative to the in situ material properties, resulting in misleading conclusions. In particular, connected, crack-like damage could make the permeability of cored samples orders of magnitude greater than the in situ permeabilities. Our approach compared in situ velocity and resistivity measurements with laboratory measurements of the same properties. Differences between in situ and laboratory results could be attributed to differences in the porosity due to cracks. The question of the origin of the changes could not be answered directly from the results of the measurements. Pre-existing cracks, held closed by the in situ stress, could open when the core was cut free, or new cracks could be generated by coring-induced damage. We used core from closely spaced boreholes at three orientations (0{degree}, {plus_minus}45{degrees} relative to vertical) to address the origin of cracks. The absolute orientation of pre-existing cracks would be constant, independent of the borehole orientation. In contrast, cracks induced by coring were expected to show an orientation dependent on that of the source borehole.

  1. Application of frequency domain ARX features for linear and nonlinear structural damage identification

    NASA Astrophysics Data System (ADS)

    Adams, Douglas E.; Farrar, Charles R.

    2002-06-01

    Many different vibration-based dynamic input-output and output only data features have been used to identify structural damage and assess structural integrity. Since structural damage introduces linear or nonlinear variations into all of these features, all of them might give positive indications of damage but may not distinguish between linear or nonlinear types of damage. This information can sometimes be used to more reliably diagnose damage by first, helping to distinguish between damage, which is inherently nonlinear, and healthy nonlinearities in a baseline structure; and second, serving as an absolute damage prognosis indicator which, together with prior information about the structural mechanics, determined the degree to which a structure is damaged. A set of potential features that distinguish between linear and nonlinear damage are discussed here. These features are auto-regressive exogenous dynamic transmissiblity model coefficients in the frequency domain. The auto-regressive coefficients are used to characterize the nonlinear nature of damage states and the exogenous coefficients are used to characterize the linear nature of such states. After reviewing the theoretical development of this data model, experimental measurements from a three-story test structure are analyzed using these model coefficients and statistical features are extracted from the coefficients. By using two complementary features, a better indication of the severity of damage is obtained.

  2. Precursors to potential severe core damage accidents, 1986: A status report: Main report and Appendixes A,B, and C

    SciTech Connect

    Minarick, J W; Harris, J D; Austin, P N; Cletcher, J W; Hagen, E W

    1988-05-01

    The Accident Sequence Precursor Program reviews licensee event reports of operational events that have occurred at LWRs to identify and categorize precursors to potential severe core-damage accidents. Accident sequences considered in the study are those associated with inadequate core cooling. Accident sequence precursors are events that are important elements in such sequences. Such precursors could be infrequent initiating events or equipment failures that, when coupled with one or more postulated events, could result in a plant condition with inadequate core cooling. Originally proposed in the Risk Assessment Review Group Report (Lewis Committee report) in 1978, the study - subsequently named the Accident Sequence Precursor Program - was initiated at the Nuclear Operations Analysis Center in 1979. Earlier reports by the program involved assessment of events that occurred in 1969-1981 and 1984-1985. The present report involves the assessment of events that occurred during 1986. A nuclear plant has safety systems for mitigating the consequences of accidents or off-normal initiating events that may occur during the course of plant operation. These systems are built to high-quality standards and are redundant; nonetheless, they have a nonzero probability of failing or being in a failed state when required to operate. This report uses LERs and other plant data, estimated system unavailabilities, the expected average frequency of initiating events (LOFWs, LOOPs, LOCAs), and event details to evaluate the potential impact of the following two situations.

  3. Surface Profiling and Core Evaluation of Aluminum Honeycomb Sandwich Aircraft Panels Using Multi-Frequency Eddy Current Testing.

    PubMed

    Reyno, Tyler; Underhill, P Ross; Krause, Thomas W; Marsden, Catharine; Wowk, Diane

    2017-09-14

    Surface damage on honeycomb aircraft panels is often measured manually, and is therefore subject to variation based on inspection personnel. Eddy current testing (ECT) is sensitive to variations in probe-to-specimen spacing, or lift-off, and is thus promising for high-resolution profiling of surface damage on aluminum panels. Lower frequency testing also allows inspection through the face sheet, an advantage over optical 3D scanning methods. This paper presents results from the ECT inspection of surface damage on an approximately flat aluminum honeycomb aircraft panel, and compares the measurements to those taken using optical 3D scanning technology. An ECT C-Scan of the dented panel surface was obtained by attaching the probe to a robotic scanning apparatus. Data was taken simultaneously at four frequencies of 25, 100, 400 and 1600 kHz. A reference surface was then defined that approximated the original, undamaged panel surface, which also compensated for the effects of specimen tilt and thermal drift within the ECT instrument. Data was converted to lift-off using height calibration curves developed for each probe frequency. A damage region of 22,550 mm² area with dents ranging in depth from 0.13-1.01 mm was analyzed. The method was accurate at 1600 kHz to within 0.05 mm (2σ) when compared with 231 measurements taken via optical 3D scanning. Testing at 25 kHz revealed a 3.2 mm cell size within the honeycomb core, which was confirmed via destructive evaluation. As a result, ECT demonstrates potential for implementation as a method for rapid in-field aircraft panel surface damage assessment.

  4. Precursors to potential severe core damage accidents: 1992, A status report. Volume 17, Main report and Appendix A

    SciTech Connect

    Cox, D.F.; Cletcher, J.W.; Copinger, D.A.; Cross-Dial, A.E.; Morris, R.H.; Vanden Heuvel, L.N.; Dolan, B.W.; Jansen, J.M.; Minarick, J.W.; Lau, W.; Salyer, W.D.

    1993-12-01

    Twenty-seven operational events with conditional probabilities of subsequent severe core damage of 1.0 {times} 10E-06 or higher occurring at commercial light-water reactors during 1992 are considered to be precursors to potential core damage. These are described along with associated significance estimates, categorization, and subsequent analyses. The report discusses (1) the general rationale for this study, (2) the selection and documentation of events as precursors, (3) the estimation and use of conditional probabilities of subsequent severe core damage to rank precursor events, and (4) the plant models used in the analysis process.

  5. Nonlinear ultrasonics for in situ damage detection during high frequency fatigue

    NASA Astrophysics Data System (ADS)

    Kumar, Anish; Torbet, Christopher J.; Jones, J. Wayne; Pollock, Tresa M.

    2009-07-01

    In this paper, we report the use of the feedback signal of an ultrasonic fatigue system to dynamically deduce fatigue damage accumulation via changes in the nonlinear ultrasonic parameter. The applicability of this parameter in comparison to the resonant frequency for assessment of fatigue damage accumulation in a wrought aluminum alloy has been demonstrated, without the need for coupling fluids or independent generation of incident ultrasonic waves. The ultrasonic nonlinearity increased and the resonant frequency of the system decreased with initiation and propagation of the major crack. The nonlinear ultrasonic parameter shows greater sensitivity to damage accumulation than the resonant frequency. The number of cycles for crack propagation, estimated based on the changes in the nonlinear ultrasonic parameter, is in very good agreement with calculated crack growth rates based on the fractography studies.

  6. Frequency response of laminated composite plates and shells with matrix cracks type of damage mode

    NASA Astrophysics Data System (ADS)

    Emam, Aly A.

    The present study has been designed to tackle a new set of problems for structural composites, as these materials are finding new applications in civil engineering field. An attempt has been made to study the frequency response of laminated polymer composite plates and shallow shells containing matrix cracks type of damage with arbitrary support conditions and free vibratory motions. The shell governing equations are derived using a simplified shallow shell theory based on a first order shear deformation field. The continuum damage mechanics approach has been used to model the matrix cracks in a damaged region within the plates and shallow shells. In such approach, the damage is accounted for in the laminate constitutive equations by using a set of second order tensor internal state variables which are strain-like quantities. The simplified damage model was then used to study the changes in frequency response of laminated composite plates and shallow cylindrical shells. The Ritz method and a finite element method have been proposed and developed as approximate solution procedures to quantify the change in the free vibration frequencies due to matrix cracks type of damage under both material as well as geometrical variables such as size, shape and extent of damage, degree of curvature, ratio of orthotropy, thickness ratio as well as support conditions. The analysis of various plates and shells with a centrally located damaged-zone depicts a typical trend of reduction in the vibration frequencies. This reduction is more pronounced for higher frequency modes and it shows greater sensitivity toward the size of the damaged region and density of cracks. The results also show that the changes in the frequency, especially for the fundamental mode, appear to be less sensitive to the shell boundary conditions as well as small values of curvature. The investigation of various undamaged plates and shallow shells demonstrates the importance of a first-order shear deformation

  7. Effects of intensity and frequency of crown damage on resprouting of Erica arborea L. (Ericaceae)

    NASA Astrophysics Data System (ADS)

    Riba, Miquel

    1998-02-01

    A clipping experiment was conducted to analyse the effects of intensity and frequency of crown damage on compensatory responses by resprouting in the shrub species Erica arborea. Increased sprout removal (crown damage intensity) promoted recruitment and increased the total dry weight of new sprout cohorts. Mean size (diameter) of new sprout cohorts was greater under increased intensity of crown damage, although no differences in size variability (CV) were obtained. Increased crown damage events stimulated recruitment of new sprouts, but had no effect on their total dry weight and reduced their mean size. Increased intensity and frequency of crown damage also promoted growth (RGR) of uncut sprouts according to local position on the lignotuber. The results show that qualitatively different compensatory responses can be obtained depending on the modular structure of the genet and the frequency and intensity of crown damage. They also suggest that competition for underground resources might be important for explaining the interactions among sprouts within the genet. Modular behavior in resprouting species under extreme disturbance regimes (e.g. heavy grazing after fire) is also expected to have a negative effect on overall genet growth and reproduction.

  8. Pulse Frequency Effect on Neutron Damage in -Iron: A KMC Analysis

    SciTech Connect

    Perlado, J M; Lodi, D; Dominguez, E; Ogando, F; Prieto, J; Diaz de la Rubia, T; Caturla, J

    2001-05-01

    The pulsed nature of the irradiation and the high neutron dose are the critical factors in an Inertial Fusion Energy reactor (IFE). The damage that structural materials suffer under these extremes conditions require a careful study and assessment. The goal of our work is to simulate, trough the multiscale modeling approach, the damage accumulation in {alpha}-Fe under conditions relevant to a IFE Reactor. We discuss how the pulse frequency, 1 Hz, 10 Hz, and the dose rate of 10{_} and 10{_}dpa/s affect the damage production and accumulation. Results of the damage that this demanding environment can produce on a protected first structural exposed to 150 keV average recoil ion will be presented. A further comparison it has been made with the damage produced by a continuous irradiation at similar average dose.

  9. Time-frequency characterization of lamb waves for material evaluation and damage inspection of plates

    NASA Astrophysics Data System (ADS)

    Frank Pai, P.; Deng, Haoguang; Sundaresan, Mannur J.

    2015-10-01

    Guided wave-based technique is one major approach for damage inspection of structures. To detect a small damage, an elastic wave's wavelength needs to be in the order of the damage size and hence the frequency needs to be high. Unfortunately, high-frequency wave dynamics always involves complicated wave reflection, refraction and diffraction, and it is difficult to separate them in order to perform detailed examination and system identification. This paper investigates dynamic characteristics of Lamb waves in plates in order to be used for material evaluation and damage inspection of thin-walled structures. A one-dimensional finite-element modeling and analysis technique is developed for computing dispersion curves and all symmetric and antisymmetric modes of Lamb waves in isotropic and multi-layer plates. Moreover, the conjugate-pair decomposition (CPD) method is introduced for time-frequency analysis of propagating Lamb waves. Results show that, under a k-cycle sine-burst excitation at a plate's edge, the time-varying frequency of a surface point's response can reveal the Lamb wave propagating inside the plate being a symmetric or an antisymmetric mode. The frequency of the measured wave packet increases from the wave front to the trailing edge if it is a symmetric mode, and the frequency decreases from the wave front to the trailing edge if it is an antisymmetric mode. Moreover, interaction of two different wave packets results in a peak in the time-frequency curve. These characteristics can be used for accurate separation of wave packets and identification of different wave speeds to enable fast and accurate material evaluation and damage inspection. Transient finite-element analysis of Lamb waves in finite plates with crack/delamination show that k-cycle sine-burst probing waves are good agents for guided wave-based damage inspection of structures. Although crack and delamination introduce different waves into and complicate the probing wave packet, time-frequency

  10. A comparative assessment of different frequency based damage detection in unidirectional composite plates using MFC sensors

    NASA Astrophysics Data System (ADS)

    de Medeiros, Ricardo; Sartorato, Murilo; Vandepitte, Dirk; Tita, Volnei

    2016-11-01

    The basic concept of the vibration based damage identification methods is that the dynamic behaviour of a structure can change if damage occurs. Damage in a structure can alter the structural integrity, and therefore, the physical properties like stiffness, mass and/or damping may change. The dynamic behaviour of a structure is a function of these physical properties and will, therefore, directly be affected by the damage. The dynamic behaviour can be described in terms of time, frequency and modal domain parameters. The changes in these parameters (or properties derived from these parameters) are used as indicators of damage. Hence, this work has two main objectives. The first one is to provide an overview of the structural vibration based damage identification methods. For this purpose, a fundamental description of the structural vibration based damage identification problem is given, followed by a short literature overview of the damage features, which are commonly addressed. The second objective is to create a damage identification method for detection of the damage in composite structures. To aid in this process, two basic principles are discussed, namely the effect of the potential damage case on the dynamic behaviour, and the consequences involved with the information reduction in the signal processing. Modal properties from the structural dynamic output response are obtained. In addition, experimental and computational results are presented for the application of modal analysis techniques applied to composite specimens with and without damage. The excitation of the structures is performed using an impact hammer and, for measuring the output data, accelerometers as well as piezoelectric sensors. Finite element models are developed by shell elements, and numerical results are compared to experimental data, showing good correlation for the response of the specimens in some specific frequency range. Finally, FRFs are analysed using suitable metrics, including a

  11. Nonlinear frequency conversion in bismuth-doped tellurite suspended core fiber

    NASA Astrophysics Data System (ADS)

    Ryasnyanskiy, Aleksandr; Lin, Aoxiang; Belwalkar, Amit; Guintrand, Cyril; Biaggio, Ivan; Toulouse, Jean

    2011-08-01

    We have developed a new kind of tellurite glass with composition 70.5TeO 2-12ZnO-10Na 2O-7.5Bi 2O 3 by conventional melting-quenching techniques. A suspended-core fiber (SCF) with a triangular-shaped core (~ 2.9 μm) has been drawn from an extruded perform. Several nonlinear frequency conversion processes are being demonstrated, which point to the potential of such a fiber.

  12. Exfoliated BN shell-based high-frequency magnetic core-shell materials.

    PubMed

    Zhang, Wei; Patel, Ketan; Ren, Shenqiang

    2017-09-14

    The miniaturization of electric machines demands high frequency magnetic materials with large magnetic-flux density and low energy loss to achieve a decreased dimension of high rotational speed motors. Herein, we report a solution-processed high frequency magnetic composite (containing a nanometal FeCo core and a boron nitride (BN) shell) that simultaneously exhibits high electrical resistivity and magnetic permeability. The frequency dependent complex initial permeability and the mechanical robustness of nanocomposites are intensely dependent on the content of BN insulating phase. The results shown here suggest that insulating magnetic nanocomposites have potential for application in next-generation high-frequency electric machines with large electrical resistivity and permeability.

  13. Nanolaminated Permalloy Core for High-Flux, High-Frequency Ultracompact Power Conversion

    SciTech Connect

    Kim, J; Kim, M; Galle, P; Herrault, F; Shafer, R; Park, JY; Allen, MG

    2013-09-01

    Metallic magnetic materials have desirable magnetic properties, including high permeability, and high saturation flux density, when compared with their ferrite counterparts. However, eddy-current losses preclude their use in many switching converter applications, due to the challenge of simultaneously achieving sufficiently thin laminations such that eddy currents are suppressed (e.g., 500 nm-1 mu m for megahertz frequencies), while simultaneously achieving overall core thicknesses such that substantial power can be handled. A CMOS-compatible fabrication process based on robot-assisted sequential electrodeposition followed by selective chemical etching has been developed for the realization of a core of substantial overall thickness (tens to hundreds of micrometers) comprised of multiple, stacked permalloy (Ni80Fe20) nanolaminations. Tests of toroidal inductors with nanolaminated cores showed negligible eddy-current loss relative to total core loss even at a peak flux density of 0.5 T in the megahertz frequency range. To illustrate the use of these cores, a buck power converter topology is implemented with switching frequencies of 1-2 MHz. Power conversion efficiency greater than 85% with peak operating flux density of 0.3-0.5 T in the core and converter output power level exceeding 5 W was achieved.

  14. Application of frequency domain ARX models and extreme value statistics to damage detection

    NASA Astrophysics Data System (ADS)

    Fasel, Timothy R.; Sohn, Hoon; Farrar, Charles R.

    2003-08-01

    In this study, the applicability of an auto-regressive model with exogenous inputs (ARX) in the frequency domain to structural health monitoring (SHM) is explored. Damage sensitive features that explicitly consider the nonlinear system input/output relationships produced by damage are extracted from the ARX model. Furthermore, because of the non-Gaussian nature of the extracted features, Extreme Value Statistics (EVS) is employed to develop a robust damage classifier. EVS is useful in this case because the data of interest are in the tails (extremes) of the damage sensitive feature distribution. The suitability of the ARX model, combined with EVS, to nonlinear damage detection is demonstrated using vibration data obtained from a laboratory experiment of a three-story building model. It is found that the current method, while able to discern when damage is present in the structure, is unable to localize the damage to a particular joint. An impedance-based method using piezoelectric (PZT) material as both an actuator and a sensor is then proposed as a possible solution to the problem of damage localization.

  15. Failure Predictions for VHTR Core Components using a Probabilistic Contiuum Damage Mechanics Model

    SciTech Connect

    Fok, Alex

    2013-10-30

    The proposed work addresses the key research need for the development of constitutive models and overall failure models for graphite and high temperature structural materials, with the long-term goal being to maximize the design life of the Next Generation Nuclear Plant (NGNP). To this end, the capability of a Continuum Damage Mechanics (CDM) model, which has been used successfully for modeling fracture of virgin graphite, will be extended as a predictive and design tool for the core components of the very high- temperature reactor (VHTR). Specifically, irradiation and environmental effects pertinent to the VHTR will be incorporated into the model to allow fracture of graphite and ceramic components under in-reactor conditions to be modeled explicitly using the finite element method. The model uses a combined stress-based and fracture mechanics-based failure criterion, so it can simulate both the initiation and propagation of cracks. Modern imaging techniques, such as x-ray computed tomography and digital image correlation, will be used during material testing to help define the baseline material damage parameters. Monte Carlo analysis will be performed to address inherent variations in material properties, the aim being to reduce the arbitrariness and uncertainties associated with the current statistical approach. The results can potentially contribute to the current development of American Society of Mechanical Engineers (ASME) codes for the design and construction of VHTR core components.

  16. Adenovirus core protein VII down-regulates the DNA damage response on the host genome.

    PubMed

    Avgousti, Daphne C; Della Fera, Ashley N; Otter, Clayton J; Herrmann, Christin; Pancholi, Neha J; Weitzman, Matthew D

    2017-08-09

    Viral manipulation of cellular proteins allows viruses to suppress host defenses and generate infectious progeny. Due to the linear double-stranded DNA nature of the adenovirus genome, the cellular DNA damage response (DDR) is considered a barrier for successful infection. The adenovirus genome is packaged with protein VII, a viral-encoded histone-like core protein that is suggested to protect incoming viral genomes from detection by cellular DNA damage machinery. We showed that protein VII localizes to host chromatin during infection, leading us to hypothesize that protein VII may affect DNA damage responses on the cellular genome. Here, we show that protein VII at cellular chromatin results in a significant decrease in accumulation of phosphorylated H2AX (γH2AX) following irradiation, indicating that protein VII inhibits DDR signaling. The oncoprotein SET was recently suggested to modulate the DDR by affecting access of repair proteins to chromatin. Since protein VII binds SET, we investigated a role for SET in DDR inhibition by protein VII. We show that knockdown of SET partially rescues the protein VII-induced decrease in γH2AX accumulation on the host genome, suggesting that SET is required for inhibition. Finally, we show that knockdown of SET also allows ATM to localize to incoming viral genomes bound by protein VII during infection with a mutant lacking early region E4. Together, our data suggest that the protein VII-SET interaction contributes to DDR evasion by adenovirus. Our results provide an additional example of a strategy used by adenovirus to manipulate the host DDR and show how viruses can modify cellular processes through manipulation of host chromatin.IMPORTANCE The DNA damage response (DDR) is a cellular network crucial for maintaining genome integrity. DNA viruses replicating in the nucleus challenge the resident genome and must overcome cellular responses, including the DDR. Adenoviruses are prevalent human pathogens that can cause a

  17. Metal-core piezoelectric fiber-based smart layer for damage detection using sparse virtual element boundary measurement

    NASA Astrophysics Data System (ADS)

    Zhang, Chao; Cheng, Li; Qiu, Jinhao; Wang, Hongyuan

    2016-04-01

    Metal-core Piezoelectric Fiber (MPF) was shown to have great potential to be a structurally integrated sensor for structural health monitoring (SHM) applications. Compared with the typical foil strain gauge, MPF is more suitable for high frequency strain measurement and can create direct conversion of mechanical energy into electric energy without the need for complex signal conditioners or gauge bridges. In this paper, a MPF-based smart layer is developed as an embedded network of distributed strain sensors that can be surface-mounted on a thin-walled structure. Each pair of the adjacent MPFs divides the entire structure into several "virtual elements (VEs)". By exciting the structure at the natural frequency of the VE, a "weak" formulation of the previously developed Pseudo-excitation (PE) approach based on sparse virtual element boundary measurement (VEBM) is proposed to detect the damage. To validate the effectiveness of the VEBM based approach, experiments are conducted to locate a small crack in a cantilever beam by using a MPF- based smart layer and a Laser Doppler Vibrometer (LDV). Results demonstrate that the proposed VEBM approach not only inherits the enhanced noise immunity capability of the "weak" formulation of the PE approach, but also allows a significant reduction in the number of measurement points as compared to the original version of the PE approach.

  18. Structural Damage Detection Using Changes in Natural Frequencies: Theory and Applications

    NASA Astrophysics Data System (ADS)

    He, K.; Zhu, W. D.

    2011-07-01

    A vibration-based method that uses changes in natural frequencies of a structure to detect damage has advantages over conventional nondestructive tests in detecting various types of damage, including loosening of bolted joints, using minimum measurement data. Two major challenges associated with applications of the vibration-based damage detection method to engineering structures are addressed: accurate modeling of structures and the development of a robust inverse algorithm to detect damage, which are defined as the forward and inverse problems, respectively. To resolve the forward problem, new physics-based finite element modeling techniques are developed for fillets in thin-walled beams and for bolted joints, so that complex structures can be accurately modeled with a reasonable model size. To resolve the inverse problem, a logistical function transformation is introduced to convert the constrained optimization problem to an unconstrained one, and a robust iterative algorithm using a trust-region method, called the Levenberg-Marquardt method, is developed to accurately detect the locations and extent of damage. The new methodology can ensure global convergence of the iterative algorithm in solving under-determined system equations and deal with damage detection problems with relatively large modeling error and measurement noise. The vibration-based damage detection method is applied to various structures including lightning masts, a space frame structure and one of its components, and a pipeline. The exact locations and extent of damage can be detected in the numerical simulation where there is no modeling error and measurement noise. The locations and extent of damage can be successfully detected in experimental damage detection.

  19. Estimating the Radius of the Convective Core of Main-sequence Stars from Observed Oscillation Frequencies

    NASA Astrophysics Data System (ADS)

    Yang, Wuming

    2016-10-01

    The determination of the size of the convective core of main-sequence stars is usually dependent on the construction of models of stars. Here we introduce a method to estimate the radius of the convective core of main-sequence stars with masses between about 1.1 and 1.5 M ⊙ from observed frequencies of low-degree p-modes. A formula is proposed to achieve the estimation. The values of the radius of the convective core of four known stars are successfully estimated by the formula. The radius of the convective core of KIC 9812850 estimated by the formula is 0.140 ± 0.028 R ⊙. In order to confirm this prediction, a grid of evolutionary models was computed. The value of the convective-core radius of the best-fit model of KIC 9812850 is 0.149 R ⊙, which is in good agreement with that estimated by the formula from observed frequencies. The formula aids in understanding the interior structure of stars directly from observed frequencies. The understanding is not dependent on the construction of models.

  20. Identification of characteristic frequencies of damaged railway tracks using field hammer test measurements

    NASA Astrophysics Data System (ADS)

    Oregui, M.; Li, Z.; Dollevoet, R.

    2015-03-01

    In this paper, the feasibility of the Frequency Response Function (FRF)-based statistical method to identify the characteristic frequencies of railway track defects is studied. The method compares a damaged track state to a healthy state based on non-destructive field hammer test measurements. First, a study is carried out to investigate the repeatability of hammer tests in railway tracks. By changing the excitation and measurement locations it is shown that the variability introduced by the test process is negligible. Second, following the concepts of control charts employed in process monitoring, a method to define an approximate healthy state is introduced by using hammer test measurements at locations without visual damage. Then, the feasibility study includes an investigation into squats (i.e. a major type of rail surface defect) of varying severity. The identified frequency ranges related to squats agree with those found in an extensively validated vehicle-borne detection system. Therefore, the FRF-based statistical method in combination with the non-destructive hammer test measurements has the potential to be employed to identify the characteristic frequencies of damaged conditions in railway tracks in the frequency range of 300-3000 Hz.

  1. Frequencies and Flutter Speed Estimation for Damaged Aircraft Wing Using Scaled Equivalent Plate Analysis

    NASA Technical Reports Server (NTRS)

    Krishnamurthy, Thiagarajan

    2010-01-01

    Equivalent plate analysis is often used to replace the computationally expensive finite element analysis in initial design stages or in conceptual design of aircraft wing structures. The equivalent plate model can also be used to design a wind tunnel model to match the stiffness characteristics of the wing box of a full-scale aircraft wing model while satisfying strength-based requirements An equivalent plate analysis technique is presented to predict the static and dynamic response of an aircraft wing with or without damage. First, a geometric scale factor and a dynamic pressure scale factor are defined to relate the stiffness, load and deformation of the equivalent plate to the aircraft wing. A procedure using an optimization technique is presented to create scaled equivalent plate models from the full scale aircraft wing using geometric and dynamic pressure scale factors. The scaled models are constructed by matching the stiffness of the scaled equivalent plate with the scaled aircraft wing stiffness. It is demonstrated that the scaled equivalent plate model can be used to predict the deformation of the aircraft wing accurately. Once the full equivalent plate geometry is obtained, any other scaled equivalent plate geometry can be obtained using the geometric scale factor. Next, an average frequency scale factor is defined as the average ratio of the frequencies of the aircraft wing to the frequencies of the full-scaled equivalent plate. The average frequency scale factor combined with the geometric scale factor is used to predict the frequency response of the aircraft wing from the scaled equivalent plate analysis. A procedure is outlined to estimate the frequency response and the flutter speed of an aircraft wing from the equivalent plate analysis using the frequency scale factor and geometric scale factor. The equivalent plate analysis is demonstrated using an aircraft wing without damage and another with damage. Both of the problems show that the scaled

  2. Damage Location and Quantification Indices of Shear Structures Based on Changes in the First Two or Three Natural Frequencies

    PubMed Central

    2014-01-01

    This study proposes damage detection algorithms for multistory shear structures that only need the first two or three natural frequencies. The methods are able to determine the location and severity of damage on the basis of damage location indices (DLI) and damage quantification indices (DQI) consisting of the changes in the first few squared natural frequencies of the undamaged and damaged states. The damage is assumed to be represented by a reduction in stiffness. This stiffness reduction causes a shift in the natural frequencies of the structure. The uncertainty associated with system identification methods for obtaining natural frequencies is also carefully considered. The methods are accurate and cost-effective means only requiring the changes in the natural frequencies. PMID:27471745

  3. Composite sandwich construction with syntactic foam core - A practical assessment of post-impact damage and residual strength

    NASA Technical Reports Server (NTRS)

    Hiel, C.; Dittman, D.; Ishai, O.

    1993-01-01

    An account is given of an inspection method that has been successfully used to assess the postimpact damage and residual strength of syntactic (glass microspheres in epoxy matrix) foam-core sandwich panels with hybrid (carbon and glass fiber-reinforced) composite skins, which inherently possess high damage tolerance. SEM establishes that the crushing of the microspheres is responsible for the absorption of most of the impact energy. Damage tolerance is a function of the localization of damage by that high impact energy absorption.

  4. Internal Damage Detection and Assessment in Beams Using Experimental Natural Frequencies

    DTIC Science & Technology

    2005-06-13

    damage size increased. Doyle10 (1995) used the spectral element method to estimate crack size and location in an aluminum beam containing a transverse...T3 and 2024 O aluminum beams were used to determine whether natural frequency response measurement in beam structures is a usable method of damage...6948 4.40% 9.12% 12.60% 15.23% 17.28% 12-cm 1445 2124 2913 3812 4821 23.42% 31.04% 36.16% 39.84% 42.60% 16-cm 938.0 1473 2122 2885 3762 50.29% 52.18

  5. Direct comparison of statistical damage frequency method and raster scan procedure

    NASA Astrophysics Data System (ADS)

    Batavičiūtė, G.; Ščiuka, M.; Plerpaitė, V.; Melninkaitis, A.

    2015-11-01

    Presented study addresses the nano-size defects acting as damage precursors in nanosecond laser pulse irradiation regime. Defects embedded within the surface of glass are investigated in terms of defect ensembles. Damage frequency method and raster scan procedure are directly compared on the set of two samples: uncoated fused silica substrates and SiO2 monolayer films. The extracted defect ensembles appear to be different from each other. The limitations of compared methods such as pulse-to-pulse variation of laser intensity and sample contamination induced by laser ablation were identified as the main causes of observed differences.

  6. Monitoring of corrosion damage using high-frequency guided ultrasonic waves

    NASA Astrophysics Data System (ADS)

    Chew, D.; Fromme, P.

    2014-03-01

    Due to adverse environmental conditions corrosion can develop during the life cycle of industrial structures, e.g., offshore oil platforms, ships, and desalination plants. Both pitting corrosion and generalized corrosion leading to wall thickness loss can cause the degradation of the integrity and load bearing capacity of the structure. Structural health monitoring of corrosion damage in difficult to access areas can in principle be achieved using high frequency guided waves propagating along the structure from accessible areas. Using standard ultrasonic transducers with single sided access to the structure, high frequency guided wave modes were generated that penetrate through the complete thickness of the structure. Wall thickness reduction was induced using accelerated corrosion in a salt water bath. The corrosion damage was monitored based on the effect on the wave propagation and interference of the different modes. The change in the wave interference was quantified based on an analysis in the frequency domain (Fourier transform) and was found to match well with theoretical predictions for the wall thickness loss. High frequency guided waves have the potential for corrosion damage monitoring at critical and difficult to access locations from a stand-off distance.

  7. Monitoring of corrosion damage using high-frequency guided ultrasonic waves

    NASA Astrophysics Data System (ADS)

    Chew, D.; Fromme, P.

    2015-03-01

    Due to adverse environmental conditions corrosion can develop during the life cycle of industrial structures, e.g., offshore oil platforms, ships, and desalination plants. Both pitting corrosion and generalized corrosion leading to wall thickness loss can cause the degradation of the integrity and load bearing capacity of the structure. Structural health monitoring of corrosion damage in difficult to access areas can in principle be achieved using high frequency guided waves propagating along the structure from accessible areas. Using standard ultrasonic transducers with single sided access to the structure, high frequency guided wave modes were generated that penetrate through the complete thickness of the structure. Wall thickness reduction was induced using accelerated corrosion in a salt water bath. The corrosion damage was monitored based on the effect on the wave propagation and interference of the different modes. The change in the wave interference was quantified based on an analysis in the frequency domain (Fourier transform) and was found to match well with theoretical predictions for the wall thickness loss. High frequency guided waves have the potential for corrosion damage monitoring at critical and difficult to access locations from a stand-off distance.

  8. Energy-Deposition and Damage Calculations in Core-Vessel Inserts at the Spallation Neutron Source

    SciTech Connect

    Murphy, B.D.

    2002-06-25

    Heat-deposition and damage calculations are described for core-vessel inserts in the target area of the Spallation Neutron Source. Two separate designs for these inserts (or neutron beam tubes) were studied; a single-unit insert and a multi-unit insert. The single unit contains a neutron guide; the multi unit does not. Both units are constructed of stainless steel. For the single unit, separate studies were carried out with the guide composed of stainless steel, glass, and aluminum. Results are also reported for an aluminum window on the front of the insert, a layer of nickel on the guide, a cadmium shield surrounding the guide, and a stainless steel plug in the beam-tube opening. The locations of both inserts were the most forward positions to be occupied by each design respectively thus ensuring that the calculations are conservative.

  9. Wide Temperature Core Loss Characteristics of Transverse Magnetically Annealed Amorphous Tapes for High Frequency Aerospace Magnetics

    NASA Technical Reports Server (NTRS)

    Niedra, Janis M.; Schwarze, Gene E.

    1999-01-01

    100 kHz core loss properties of sample transverse magnetically annealed, cobalt-based amorphous and iron-based nanocrystalline tape wound magnetic cores are presented over the temperature range of -150 C to 150 C, at selected values of B(sub peak). For B-fields not close to saturation, the core loss is not sensitive to temperature in this range and is as low as seen in the best MnZn power ferrites at their optimum temperatures. Frequency resolved characteristics are given over the range of 50 kHz to 1 MHz, but at B(sub peak) = 0.1 T and 50 C only. For example, the 100 kHz specific core loss ranged from 50 - 70 mW/cubic cm for the 3 materials, when measured at 0.1 T and 50 C. This very low high frequency core loss, together with near zero saturation magnetostriction and insensitivity to rough handling, makes these amorphous ribbons strong candidates for power magnetics applications in wide temperature aerospace environments.

  10. Dating a tropical ice core by time-frequency analysis of ion concentration depth profiles

    NASA Astrophysics Data System (ADS)

    Gay, M.; De Angelis, M.; Lacoume, J.-L.

    2014-09-01

    Ice core dating is a key parameter for the interpretation of the ice archives. However, the relationship between ice depth and ice age generally cannot be easily established and requires the combination of numerous investigations and/or modelling efforts. This paper presents a new approach to ice core dating based on time-frequency analysis of chemical profiles at a site where seasonal patterns may be significantly distorted by sporadic events of regional importance, specifically at the summit area of Nevado Illimani (6350 m a.s.l.), located in the eastern Bolivian Andes (16°37' S, 67°46' W). We used ion concentration depth profiles collected along a 100 m deep ice core. The results of Fourier time-frequency and wavelet transforms were first compared. Both methods were applied to a nitrate concentration depth profile. The resulting chronologies were checked by comparison with the multi-proxy year-by-year dating published by de Angelis et al. (2003) and with volcanic tie points. With this first experiment, we demonstrated the efficiency of Fourier time-frequency analysis when tracking the nitrate natural variability. In addition, we were able to show spectrum aliasing due to under-sampling below 70 m. In this article, we propose a method of de-aliasing which significantly improves the core dating in comparison with annual layer manual counting. Fourier time-frequency analysis was applied to concentration depth profiles of seven other ions, providing information on the suitability of each of them for the dating of tropical Andean ice cores.

  11. Structural damage identification with multi-objective DIRECT algorithm using natural frequencies and single mode shape

    NASA Astrophysics Data System (ADS)

    Cao, Pei; Yoo, David; Shuai, Qi; Tang, J.

    2017-04-01

    Structural damage identification has been continuously pursued in engineering practices to facilitate diagnosis and prognosis in structural health monitoring (SHM) systems. In SHM, the changes of modal parameters are frequently used as inputs. In this research, we employ the multiple damage location assurance criterion (MDLAC) to characterize the correlation between predictions of both frequency changes and single mode shape change with the measured data. The damage locations and severities can be obtained by maximizing the MDLAC values. Thereafter, a multi-objective optimization problem based on their MDLAC values can be formulated and optimized by applying a newly devised multi-objective DIRECT approach. The proposed approach offers practical attractions of only requiring a short amount of computational time, and the results are conclusive and repeatable.

  12. [Frequency characteristics of the semicicular canals damage in patients with Meniere disease].

    PubMed

    Xu, K X; Chen, T S; Wang, W; Li, S S; Liu, Q; Wen, C; Han, X; Lin, P

    2017-03-07

    Objective: To evaluate semicircular canal damage and its frequency characteristics in Meniere disease patients. Methods: Sixty-seven Meniere disease patients accepted the video-head impulse test(vHIT)which responses to semicircular canal function of high frequency area, head shaking test(HST) which responses to semicircular canal function of middle frequency area, and caloric test(CT) which responses to semicircular canal function of low frequency area.Preferences were recorded including the video head impulse test gain (vHIT-G), head shaking nystagmus (HSN) and parameters of the unilateral weakness (UW) as observation index, and results of all the three tests were analyzed according to Meniere disease patients. SPSS 17.0 software was used to analyzed the data. Results: The positive rate of CT, HSN and vHIT were 70.1%(47/67), 41.8%(28/67) and 23.9%(16/67) respectively. Comparation of the positive rate among CT, HST and vHIT showed statistically significant difference (χ(2)=10.93, P=0.001; χ(2)=28.79, P=0.000). Comparation of the positive rate between HST and vHIT showed statistically significant difference(χ(2)=4.87, P=0.027). Conclusions: Semicircular canal function damage in Meniere disease patients mainly presents in the low frequency area, which indicates a characteristic phenomenon that low-frequency function area (caloric test results) is more predisposed to be involved than that of middle-frequency function area (head shaking testing)and high-frequency function area (video head impulse testing) in Meniere disease patients.

  13. Resolution and Dynamical Core Dependence of Atmospheric River Frequency in Global Model Simulations

    SciTech Connect

    Hagos, Samson M.; Leung, Lai-Yung R.; Yang, Qing; Zhao, Chun; Lu, Jian

    2015-04-01

    This study examines the sensitivity of atmospheric river (AR) frequency simulated by a global model with different grid resolutions and dynamical cores. Analysis is performed on aquaplanet simulations using version 4 of Community Atmosphere Model (CAM4) at 240, 120, 60 and 30 km model resolutions each with the Model for Prediction Across Scales (MPAS) and High-Order Methods Modeling Environment (HOMME) dynamical cores. The frequency of AR events decreases with model resolution and the HOMME dynamical core produces more AR events than MPAS. Comparing the frequencies determined using absolute and percentile thresholds of large-scale conditions used to define an AR, model sensitivity is found to be related to the overall sensitivity of sub-tropical westerlies, atmospheric precipitable water content and profile and to a lesser extent on extra-tropical Rossby wave activity to model resolution and dynamical core. Real world simulations using MPAS at 120 km and 30 km grid resolutions also exhibit a decrease of AR frequency with increasing resolution over southern East Pacific, but there difference is smaller over northern East Pacific. This inter-hemispheric difference is related to the enhancement of convection in over the tropics with increased resolution. This anomalous convection sets off Rossby wave patterns that weaken the subtropical westerlies over southern East Pacific but have relatively little effect on those over northern East Pacific. In comparison to NCEP2 reanalysis, MPAS real world simulations are found to underestimate AR frequencies at both resolutions likely because of their climatologically drier sub-tropics and poleward shifted jets. This study highlights the important links between model climatology of large-scale conditions and extremes.

  14. Detection of sudden structural damage using blind source separation and time-frequency approaches

    NASA Astrophysics Data System (ADS)

    Morovati, V.; Kazemi, M. T.

    2016-05-01

    Seismic signal processing is one of the most reliable methods of detecting the structural damage during earthquakes. In this paper, the use of the hybrid method of blind source separation (BSS) and time-frequency analysis (TFA) is explored to detect the changes in the structural response data. The combination of the BSS and TFA is applied to the seismic signals due to the non-stationary nature of them. Firstly, the second-order blind identification technique is used to decompose the response signal of structural vibration into modal coordinate signals which will be mono-components for TFA. Then each mono-component signal is analyzed to extract instantaneous frequency of structure. Numerical simulations and a real-world seismic-excited structure with time-varying frequencies show the accuracy and robustness of the developed algorithm. TFA of extracted sources shows that used method can be successfully applied to structural damage detection. The results also demonstrate that the combined method can be used to identify the time instant of structural damage occurrence more sharply and effectively than by the use of TFA alone.

  15. High-frequency microwave ablation method for enhanced cancer treatment with minimized collateral damage.

    PubMed

    Yoon, Jeonghoon; Cho, Jeiwon; Kim, Namgon; Kim, Dae-Duk; Lee, Eunsook; Cheon, Changyul; Kwon, Youngwoo

    2011-10-15

    To overcome the limits of conventional microwave ablation, a new frequency spectrum above 6 GHz has been explored for low-power and low collateral damage ablation procedure. A planar coaxial probe-based applicator, suitable for easy insertion into the human body, was developed for our study to cover a wideband frequency up to 30 GHz. Thermal ablations with small input power (1-3 W) at various microwave frequencies were performed on nude mice xenografted with human breast cancer. Comparative study of ablation efficiencies revealed that 18-GHz microwave results in the largest difference in the temperature rise between cancer and normal tissues as well as the highest ablation efficiency, reaching 20 times that of 2 GHz. Thermal profile study on the composite region of cancer and fat also showed significantly reduced collateral damage using 18 GHz. Application of low-power (1 W) 18-GHz microwave on the nude mice xenografted with human breast cancer cells resulted in recurrence-free treatment. The proposed microwave ablation method can be a very effective process to treat small-sized tumor with minimized invasiveness and collateral damages. Copyright © 2010 UICC.

  16. Off-resonance frequency operation for power transfer in a loosely coupled air core transformer

    DOEpatents

    Scudiere, Matthew B

    2012-11-13

    A power transmission system includes a loosely coupled air core transformer having a resonance frequency determined by a product of inductance and capacitance of a primary circuit including a primary coil. A secondary circuit is configured to have a substantially same product of inductance and capacitance. A back EMF generating device (e.g., a battery), which generates a back EMF with power transfer, is attached to the secondary circuit. Once the load power of the back EMF generating device exceeds a certain threshold level, which depends on the system parameters, the power transfer can be achieved at higher transfer efficiency if performed at an operating frequency less than the resonance frequency, which can be from 50% to 95% of the resonance frequency.

  17. Ultrasonic guided wave based damage imaging by time-reversal method in frequency-wavenumber domain

    NASA Astrophysics Data System (ADS)

    Xu, C. G.; Xu, B. Q.; Luo, Y.; Xu, G. D.; Lu, L. Z.

    2017-05-01

    More attention has been drawn to ultrasonic guided waves (UGW) based damage detection method for its advantages of wide range inspection of large scale structures. However, complex propagation characteristics of guided waves as well as traditional contact ultrasonic transducers limit its application for the practical damage detection. By combining Scanning Laser Doppler vibrometer (SLDV) technology, Time-Reversal method in frequency-wavenumber domain (f-k RTM) can compensate for the dispersive nature of Lamb waves, localize multiple damage sites and identify their sizes without time consuming numerical calculation. In this work, we adopt f-k RTM for damage detection in plate-like structure. Instead of SLDV in experiment, 3D finite element numerical method is adopted to obtain scattered ultrasonic guided wavefield data with high spatial resolution. The direct path waves were extracted to obtain the incident wavefield while the scattered signals were used to calculate the scattering wave field. Damage imaging can also be achieved by introducing crosscorrelation imaging condition. Imaging results show that the method is very effective for crack localization and boundary shape-recognition. Numerical simulation results and imaging algorithm laid the foundation for the method applied in experiment and practice.

  18. On the effect of core correlation on the geometry and harmonic frequencies of small polyatomic molecules

    NASA Astrophysics Data System (ADS)

    Martin, Jan M. L.

    1995-08-01

    The effect of core correlation on computed properties of a set of experimentally well studied first-row compounds has been investigated using augmented coupled cluster (CCSD(T)) methods and specially tailored one-particle basis sets. Core correlation accounts for virtually all the remaining error in bond lengths, but simple additivity corrections based on the bond order absorb essentially all such effects starting from [4s3p2d1f] basis sets. There are nontrivial effects on harmonic frequencies, but these do not lead to improved agreement with experiment due to an error compensation between neglect of core correlation and residual n-particle space inadequacies. Finally, while significant (up to 2.5 kcal/mol) effects on total atomization energies are seen, these are essentially completely absorbed in the three-term basis set incompleteness correction proposed by the author.

  19. Computing ferrite core losses at high frequency by finite elements method including temperature influence

    SciTech Connect

    Ahmed, B.; Ahmad, J.; Guy, G.

    1994-09-01

    A finite elements method coupled with the Preisach model of hysteresis is used to compute-the ferrite losses in medium power transformers (10--60 kVA) working at relatively high frequencies (20--60 kHz) and with an excitation level of about 0.3 Tesla. The dynamic evolution of the permeability is taken into account. The simple and doubly cubic spline functions are used to account for temperature effects respectively on electric and on magnetic parameters of the ferrite cores. The results are compared with test data obtained with 3C8 and B50 ferrites at different frequencies.

  20. Low frequency of target organ damage in Taiwanese with white coat hypertension.

    PubMed

    Tseng, Yung-Zu; Chiang, Fu-Tien; Hsu, Kwan-Lih; Lo, Huey-Ming; Tseng, Chuen-Den; Lin, Jiunn-Lee; Hwang, Juey-Jen; Lai, Ling-Ping

    2005-05-01

    The clinical importance of white coat hypertension (WCH) remains to be clarified. This study investigated the target organ damage in Taiwanese with WCH. A total of 188 consecutive Taiwanese (88 men and 100 women), aged 26 to 75 years who had an abnormal office casual blood pressure (systolic blood pressure >/= 140 mm Hg or diastolic blood pressure >/= 90 mm Hg or both) and a normal ambulatory blood pressure (ABP) average (systolic ABP average < 140 mm Hg and diastolic ABP average < 90 mm Hg) at the outpatient clinic or from a mass survey were enrolled. Office casual blood pressure measurements were obtained by standard sphygmomanometric methods. Twenty-four-hour blood pressures were recorded by a commercial ambulatory pressure recorder (Del Mar Avionics, Model 1990 Pressurometer IV System). Hypertension-related target organ complications were assessed by electrocardiogram, chest X-ray, urinalysis and eye fundus examinations. Target organ damage was found in 6.4% of subjects with WCH. Roentgenographic left ventricular hypertrophy (LVH) was found in 1.1% of subjects and electrocardiographic LVH in 2.7%. Proteinuria was found in 1.6% of subjects and retinopathy in 1.1%. The frequencies of various target organ damage were not significantly associated with age, gender and the definition of normal ABP average as 135/85 mm Hg or 140/90 mm Hg. WCH represents a low-risk stratum for target organ damage in Taiwanese. These subjects should be identified and followed up regularly. The factors responsible for the low frequency of target organ damage in Taiwanese with WCH need further study.

  1. [Damage to implants due to high-frequency electrocautery : analysis of four fractured hip endoprostheses shafts].

    PubMed

    Konrads, C; Wente, M N; Plitz, W; Rudert, M; Hoberg, M

    2014-12-01

    In revision surgery of joints, high-frequency electrocauterization instruments are used for homeostasis and dissection of soft tissue. If there is contact of these instruments with the metal implants, flashover can occur. This can lead to thermal microstructural changes in the material and as a consequence may reduce the fatigue strength of the implant. Four cases of hip revision surgeries were analysed. In all cases flashovers occurred and secondarily, the titanium hip endoprosthesis stem broke in the neck section of the prosthesis. The conducted investigations showed that contact between the high-frequency instrument and the anterolateral aspect of the endoprosthesis neck had occurred. Electrothermal implant damage was found in the broken area. If in hip revision surgery the stem is not to be replaced, contact between high-frequency instruments and the metal implant should be avoided.

  2. Finite Frequency Measurements of Conventional and Core-diffracted P-waves (P and Pdiff)

    NASA Astrophysics Data System (ADS)

    Hosseini, K.; Sigloch, K.; Stähler, S. C.

    2014-12-01

    Core-diffracted waves are body waves that dive deep enough to sense the core, and by interaction with this wave guide become dispersive. They sample the core-mantle boundary and the lower third of the mantle extensively. In ray theoretical modeling, the deepest part of the ray starts to graze the core at around 97 degrees distance, but ray theory is a very poor approximation to propagation of core-diffracted waves. In reality, finite-frequency waves with their spatially extend sensitivity regions start to sense the core at significantly smaller distances already. The actual, non-ray-like sensitivities have been difficult to model, as have been the associated synthetic seismograms. Core-diffracted waves have therefore not been used in tomography, despite abundant observations of these phases on modern broadband seismograms. Hence current global body-wave tomographies illuminate the lower third of the mantle much less well than the upper and especially the middle third. This study aims for broadband, global waveform tomography that seamlessly incorporates core-diffracted phases alongside conventional, teleseismic waves as well as regional body-waves. Here, we investigate the properties of P-diffracted waves in terms of waveform characteristics and travel-time measurements as compared to teleseismic P-wave measured by the same methods. Travel time anomalies, the primary data for tomography, are measured by waveform cross-correlation of data with synthetics, where the synthetics are calculated from fully numerical wave propagation in a spherically symmetric background model. These same numerical tools will be used to calculate the associated sensitivity kernels for tomography (figure, top). Demonstrating the extent to which waveform modeling can fit real data, we assemble and discuss a global data set of 851,905 Pdiff and 2,368,452 P-wave multi-frequency cross-correlation travel times. Findings are summarized in the Pdiff travel time map (figure, bottom) in which most

  3. Limited damage of tissue mimic caused by a collapsing bubble under low-frequency ultrasound exposure.

    PubMed

    Yoshida, Kenji; Obata, Kazuya; Tsukamoto, Akira; Ushida, Takashi; Watanabe, Yoshiaki

    2014-08-01

    In this study, we investigated the bubble induced serious damage to tissue mimic exposed to 27-kHz ultrasound. The initial bubble radius ranged from 80 to 100 μm, which corresponded approximately to the experimentally-evaluated resonant radius of the given ultrasound frequency. The tissue mimic consisted of 10 wt% gelatine gel covered with cultured canine kidney epithelial cells. The collapsing bubble behaviour during the ultrasound exposure with negative peak pressures of several hundred kPa was captured by a high-speed camera system. After ultrasound exposure, a cell viability test was conducted based on microscopic bright-field images and fluorescence images for living and dead cells. In the viability test, cells played a role in indicating the damaged area. The bubble oscillations killed the cells, and on occasion detached layers of cultured cells from the gel. The damaged area was comparable or slightly larger than the initial bubble size, and smaller than the maximum bubble size. We concluded that only a small area in close proximity to the bubble could be damaged even above transient cavitation threshold.

  4. Safety apparatus for nuclear reactor to prevent structural damage from overheating by core debris

    DOEpatents

    Gabor, J.D.; Cassulo, J.C.; Pedersen, D.R.; Baker, L. Jr.

    The invention teaches safety apparatus that can be included in a nuclear reactor, either when newly fabricated or as a retrofit add-on, that will minimize proliferation of structural damage to the reactor in the event the reactor is experiencing an overheating malfunction whereby radioactive nuclear debris might break away from and can be discharged from the reactor core. The invention provides a porous bed of sublayer on the lower surface of the reactor containment vessel so that the debris falls on and piles up on the bed. Vapor release elements upstand from the bed in some laterally spaced array. Thus should the high heat flux of the debris interior vaporize the coolant at that location, the vaporized coolant can be vented downwardly to and laterally through the bed to the vapor release elements and in turn via the release elements upwardly through the debris. This minimizes the pressure buildup in the debris and allows for continuing infiltration of the liquid coolant into the debris interior.

  5. Safety apparatus for nuclear reactor to prevent structural damage from overheating by core debris

    DOEpatents

    Gabor, John D.; Cassulo, John C.; Pedersen, Dean R.; Baker Jr., Louis

    1986-07-01

    The invention teaches safety apparatus that can be included in a nuclear reactor, either when newly fabricated or as a retrofit add-on, that will minimize proliferation of structural damage to the reactor in the event the reactor is experiencing an overheating malfunction whereby radioactive nuclear debris might break away from and be discharged from the reactor core. The invention provides a porous bed or sublayer on the lower surface of the reactor containment vessel so that the debris falls on and piles up on the bed. Vapor release elements upstand from the bed in some laterally spaced array. Thus should the high heat flux of the debris interior vaporize the coolant at that location, the vaporized coolant can be vented downwardly to and laterally through the bed to the vapor release elements and in turn via the release elements upwardly through the debris. This minimizes the pressure buildup in the debris and allows for continuing infiltration of the liquid coolant into the debris interior.

  6. Safety apparatus for nuclear reactor to prevent structural damage from overheating by core debris

    DOEpatents

    Gabor, John D.; Cassulo, John C.; Pedersen, Dean R.; Baker, Jr., Louis

    1986-01-01

    The invention teaches safety apparatus that can be included in a nuclear reactor, either when newly fabricated or as a retrofit add-on, that will minimize proliferation of structural damage to the reactor in the event the reactor is experiencing an overheating malfunction whereby radioactive nuclear debris might break away from and be discharged from the reactor core. The invention provides a porous bed or sublayer on the lower surface of the reactor containment vessel so that the debris falls on and piles up on the bed. Vapor release elements upstand from the bed in some laterally spaced array. Thus should the high heat flux of the debris interior vaporize the coolant at that location, the vaporized coolant can be vented downwardly to and laterally through the bed to the vapor release elements and in turn via the release elements upwardly through the debris. This minimizes the pressure buildup in the debris and allows for continuing infiltration of the liquid coolant into the debris interior.

  7. Time-frequency vibration analysis for the detection of motor damages caused by bearing currents

    NASA Astrophysics Data System (ADS)

    Prudhom, Aurelien; Antonino-Daviu, Jose; Razik, Hubert; Climente-Alarcon, Vicente

    2017-02-01

    Motor failure due to bearing currents is an issue that has drawn an increasing industrial interest over recent years. Bearing currents usually appear in motors operated by variable frequency drives (VFD); these drives may lead to common voltage modes which cause currents induced in the motor shaft that are discharged through the bearings. The presence of these currents may lead to the motor bearing failure only few months after system startup. Vibration monitoring is one of the most common ways for detecting bearing damages caused by circulating currents; the evaluation of the amplitudes of well-known characteristic components in the vibration Fourier spectrum that are associated with race, ball or cage defects enables to evaluate the bearing condition and, hence, to identify an eventual damage due to bearing currents. However, the inherent constraints of the Fourier transform may complicate the detection of the progressive bearing degradation; for instance, in some cases, other frequency components may mask or be confused with bearing defect-related while, in other cases, the analysis may not be suitable due to the eventual non-stationary nature of the captured vibration signals. Moreover, the fact that this analysis implies to lose the time-dimension limits the amount of information obtained from this technique. This work proposes the use of time-frequency (T-F) transforms to analyse vibration data in motors affected by bearing currents. The experimental results obtained in real machines show that the vibration analysis via T-F tools may provide significant advantages for the detection of bearing current damages; among other, these techniques enable to visualise the progressive degradation of the bearing while providing an effective discrimination versus other components that are not related with the fault. Moreover, their application is valid regardless of the operation regime of the machine. Both factors confirm the robustness and reliability of these tools

  8. FANCI Regulates Recruitment of the FA Core Complex at Sites of DNA Damage Independently of FANCD2.

    PubMed

    Castella, Maria; Jacquemont, Celine; Thompson, Elizabeth L; Yeo, Jung Eun; Cheung, Ronald S; Huang, Jen-Wei; Sobeck, Alexandra; Hendrickson, Eric A; Taniguchi, Toshiyasu

    2015-10-01

    The Fanconi anemia (FA)-BRCA pathway mediates repair of DNA interstrand crosslinks. The FA core complex, a multi-subunit ubiquitin ligase, participates in the detection of DNA lesions and monoubiquitinates two downstream FA proteins, FANCD2 and FANCI (or the ID complex). However, the regulation of the FA core complex itself is poorly understood. Here we show that the FA core complex proteins are recruited to sites of DNA damage and form nuclear foci in S and G2 phases of the cell cycle. ATR kinase activity, an intact FA core complex and FANCM-FAAP24 were crucial for this recruitment. Surprisingly, FANCI, but not its partner FANCD2, was needed for efficient FA core complex foci formation. Monoubiquitination or ATR-dependent phosphorylation of FANCI were not required for the FA core complex recruitment, but FANCI deubiquitination by USP1 was. Additionally, BRCA1 was required for efficient FA core complex foci formation. These findings indicate that FANCI functions upstream of FA core complex recruitment independently of FANCD2, and alter the current view of the FA-BRCA pathway.

  9. FANCI Regulates Recruitment of the FA Core Complex at Sites of DNA Damage Independently of FANCD2

    PubMed Central

    Castella, Maria; Jacquemont, Celine; Thompson, Elizabeth L.; Yeo, Jung Eun; Cheung, Ronald S.; Huang, Jen-Wei; Sobeck, Alexandra; Hendrickson, Eric A.; Taniguchi, Toshiyasu

    2015-01-01

    The Fanconi anemia (FA)-BRCA pathway mediates repair of DNA interstrand crosslinks. The FA core complex, a multi-subunit ubiquitin ligase, participates in the detection of DNA lesions and monoubiquitinates two downstream FA proteins, FANCD2 and FANCI (or the ID complex). However, the regulation of the FA core complex itself is poorly understood. Here we show that the FA core complex proteins are recruited to sites of DNA damage and form nuclear foci in S and G2 phases of the cell cycle. ATR kinase activity, an intact FA core complex and FANCM-FAAP24 were crucial for this recruitment. Surprisingly, FANCI, but not its partner FANCD2, was needed for efficient FA core complex foci formation. Monoubiquitination or ATR-dependent phosphorylation of FANCI were not required for the FA core complex recruitment, but FANCI deubiquitination by USP1 was. Additionally, BRCA1 was required for efficient FA core complex foci formation. These findings indicate that FANCI functions upstream of FA core complex recruitment independently of FANCD2, and alter the current view of the FA-BRCA pathway. PMID:26430909

  10. High frequency, high temperature specific core loss and dynamic B-H hysteresis loop characteristics of soft magnetic alloys

    NASA Technical Reports Server (NTRS)

    Wieserman, W. R.; Schwarze, G. E.; Niedra, J. M.

    1990-01-01

    Limited experimental data exists for the specific core loss and dynamic B-H loops for soft magnetic materials for the combined conditions of high frequency and high temperature. This experimental study investigates the specific core loss and dynamic B-H loop characteristics of Supermalloy and Metglas 2605SC over the frequency range of 1 to 50 kHz and temperature range of 23 to 300 C under sinusoidal voltage excitation. The experimental setup used to conduct the investigation is described. The effects of the maximum magnetic flux density, frequency, and temperature on the specific core loss and on the size and shape of the B-H loops are examined.

  11. High frequency, high temperature specific core loss and dynamic B-H hysteresis loop characteristics of soft magnetic alloys

    NASA Technical Reports Server (NTRS)

    Wieserman, W. R.; Schwarze, G. E.; Niedra, J. M.

    1990-01-01

    Limited experimental data exists for the specific core loss and dynamic B-H loop for soft magnetic materials for the combined conditions of high frequency and high temperature. This experimental study investigates the specific core loss and dynamic B-H loop characteristics of Supermalloy and Metglas 2605SC over the frequency range of 1 to 50 kHz and temperature range of 23 to 300 C under sinusoidal voltage excitation. The experimental setup used to conduct the investigation is described. The effects of the maximum magnetic flux density, frequency, and temperature on the specific core loss and on the size and shape of the B-H loops are examined.

  12. Damage detection and gain-scheduled control of CFRP smart board mounting the metal core assisted piezoelectric fiber

    NASA Astrophysics Data System (ADS)

    Takagi, Kiyoshi; Sato, Hiroshi; Saigo, Muneharu

    2005-05-01

    This paper reports damage detection and vibration control of a new smart board designed by mounting piezoelectric fibers with metal cores on the surface of a CFRP composite. Damage to the board is identified on the assumption that the piezoelectric fibers used as sensors and actuators are broken simultaneously at the damaged location. When such damage-induced breakage occurs, the piezoelectric fibers expand and contract between the root and the damaged position on the cantilever beam. Damaged positions are detected by focusing attention on this property. Furthermore, this deterioration of sensors and actuators caused by breaks in the piezoelectric fibers is a consideration in the design of the gain-scheduled controller. First, the length of the piezoelectric fibers is measured to derive a finite-element method (FEM) model of the cantilever beam. If the fiber length is shortened due to a break, there is a decrease not only in actuator performance but also in the sensor output. Thus, peak gain of the FEM model is calculated for the length of every piezoelectric fiber. Damage detection is based on the computed relation between peak gain and the damage position. Furthermore, a reduced-order model that considers only the first mode is derived for the controller design and transformed into a linear fractional transformation (LFT) representation for the gain-scheduled controller design. The position of the damage is the contributing parameter in the variation. Next, the gain-scheduled controller is designed using LFT representation. Finally, the simulation and experimental results of the damage detection and the gain-scheduled control are presented. These results show that our gain-scheduled controller can improve control performance when damage cause a break in the piezoelectric fiber.

  13. Spin torque resonant vortex core expulsion for an efficient radio-frequency detection scheme

    NASA Astrophysics Data System (ADS)

    Cros, V.; Jenkins, A. S.; Lebrun, R.; Bortolotti, P.; Grimaldi, E.; Tsunegi, S.; Kubota, H.; Yakushiji, K.; Fukushima, A.; Yuasa, S.

    It has been proposed by Tulaparkur et al.[1ref] that a high frequency detector based on the so called spin-diode effect in spin transfer oscillators could eventually replace conventional Schottky diodes, due to their nanoscale size, frequency tunability, and large output sensitivity. Although a promising candidate for ICT applications, the output voltage generated from this effect is consistently low. Here we present a scheme for a new type of spintronics-based high frequency detector based on the expulsion of the vortex core of a magnetic tunnel junction. The resonant expulsion of the core leads to a large and sharp change in resistance associated with the difference in magnetoresistance between the vortex ground state and the final C-state, which is predominantly in either the parallel or anti-parallel direction relative to the polariser layer. Interestingly, this reversible effect is independent of the incoming rf current amplitude, offering a compelling perspective for a fast real-time rf threshold detector. REF : EU FP7 Grant (MOSAIC No. ICT-FP7-317950 is acknowledged.

  14. New CODIS core loci allele frequencies for 96,400 Brazilian individuals.

    PubMed

    Aguiar, Vitor R C; de Castro, Amanda M; Almeida, Vanessa C O; Malta, Frederico S V; Ferreira, Alessandro C S; Louro, Iúri D

    2014-11-01

    We have reported the allele frequencies of 15 STR loci, including the original 13 CODIS core loci, in over 100,000 Brazilian individuals. A new CODIS core loci has been proposed, but the recently established Brazilian Integrated Network of DNA Databases made a decision in 2010 to postpone the implementation of this new set of loci due to the lack of allele frequency data for the Brazilian population. We aimed to report allele frequencies of 20 loci, estimated from 96,400 Brazilian individuals undergoing paternity testing during 2011-2013. The percentage of missing data was less than 0.6% for all loci, except for CSF1PO (3.15%) and D7S820 (2.5%). The dropout rates estimated by the MicroDrop software were 0.013 for CSF1PO, 0.000037 for D7S820 and less than 0.000001 for other loci. Small missing data percentages and dropout rates reflect the high quality of the data.

  15. Role of Macronutrients and Micronutrients in DNA Damage: Results From a Food Frequency Questionnaire

    PubMed Central

    Ladeira, Carina; Carolino, Elisabete; Gomes, Manuel C; Brito, Miguel

    2017-01-01

    The links between diet and genomic instability have been under investigation for several decades, and evidence suggests a significant causal or preventive role for various dietary factors. This study investigates the influence of macronutrients (calories, protein, and glucides) and micronutrients, such as vitamins and minerals, as assessed by a food frequency questionnaire, on genotoxicity biomarkers measured by cytokinesis-blocked micronucleus assay and comet assay. The results found significant positive and negative correlations. Micronucleus frequency tends to increase with higher intake of caffeine, calcium, magnesium, zinc, and protein (P < .05, Spearman correlation). Calorie and omega-6 intakes are negatively correlated with DNA damage measured by the comet assay. These results are somewhat controversial because some of the correlations found are contrary to dominant views in the literature; however, we suggest that unraveling the association between diet and genetic instability requires a much better understanding of the modulating role of macronutrients and micronutrients. PMID:28469462

  16. Role of Macronutrients and Micronutrients in DNA Damage: Results From a Food Frequency Questionnaire.

    PubMed

    Ladeira, Carina; Carolino, Elisabete; Gomes, Manuel C; Brito, Miguel

    2017-01-01

    The links between diet and genomic instability have been under investigation for several decades, and evidence suggests a significant causal or preventive role for various dietary factors. This study investigates the influence of macronutrients (calories, protein, and glucides) and micronutrients, such as vitamins and minerals, as assessed by a food frequency questionnaire, on genotoxicity biomarkers measured by cytokinesis-blocked micronucleus assay and comet assay. The results found significant positive and negative correlations. Micronucleus frequency tends to increase with higher intake of caffeine, calcium, magnesium, zinc, and protein (P < .05, Spearman correlation). Calorie and omega-6 intakes are negatively correlated with DNA damage measured by the comet assay. These results are somewhat controversial because some of the correlations found are contrary to dominant views in the literature; however, we suggest that unraveling the association between diet and genetic instability requires a much better understanding of the modulating role of macronutrients and micronutrients.

  17. Designing high frequency ac inductors using ferrite and Molypermalloy Powder Cores (MPP)

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.; Wagner, A. P.

    1985-01-01

    The major considerations in the design of high frequency ac inductors are reviewed. Two methods for designing the inductor: the area product method and the core geometry method, are presented. The two major effects of the inductor air gap, fringing flux power loss and increase of inductance, are discussed. Equations for the inductor design and a step-by-step design procedure are given. The use of a lumped air gap or a distributed air gap are discussed and a comparison of the losses resulting from these gaps, together with experimental results are presented.

  18. Designing high frequency ac inductors using ferrite and Molypermalloy Powder Cores (MPP)

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.; Wagner, A. P.

    1985-01-01

    The major considerations in the design of high frequency ac inductors are reviewed. Two methods for designing the inductor: the area product method and the core geometry method, are presented. The two major effects of the inductor air gap, fringing flux power loss and increase of inductance, are discussed. Equations for the inductor design and a step-by-step design procedure are given. The use of a lumped air gap or a distributed air gap are discussed and a comparison of the losses resulting from these gaps, together with experimental results are presented.

  19. Damage detection and quantification in a structural model under seismic excitation using time-frequency analysis

    NASA Astrophysics Data System (ADS)

    Chan, Chun-Kai; Loh, Chin-Hsiung; Wu, Tzu-Hsiu

    2015-04-01

    In civil engineering, health monitoring and damage detection are typically carry out by using a large amount of sensors. Typically, most methods require global measurements to extract the properties of the structure. However, some sensors, like LVDT, cannot be used due to in situ limitation so that the global deformation remains unknown. An experiment is used to demonstrate the proposed algorithms: a one-story 2-bay reinforce concrete frame under weak and strong seismic excitation. In this paper signal processing techniques and nonlinear identification are used and applied to the response measurements of seismic response of reinforced concrete structures subject to different level of earthquake excitations. Both modal-based and signal-based system identification and feature extraction techniques are used to study the nonlinear inelastic response of RC frame using both input and output response data or output only measurement. From the signal-based damage identification method, which include the enhancement of time-frequency analysis of acceleration responses and the estimation of permanent deformation using directly from acceleration response data. Finally, local deformation measurement from dense optical tractor is also use to quantify the damage of the RC frame structure.

  20. Dexamethasone loaded core-shell SF/PEO nanofibers via green electrospinning reduced endothelial cells inflammatory damage.

    PubMed

    Chen, Weiming; Li, Dawei; Ei-Shanshory, Ahmed; El-Newehy, Mohamed; Ei-Hamshary, Hany A; Al-Deyab, Salem S; He, Chuanglong; Mo, Xiumei

    2015-02-01

    Silk fibroin (SF)/PEO nanofibers prepared by green electrospinning is safe, non-toxic and environment friendly, it is a potential drug delivery carrier for tissue engineering. In this study, a core-shell nanofibers named as Dex@SF/PEO were obtained by green electrospinning with SF/PEO as the shell and dexamethasone (Dex) in the core. The nanofiber morphology and core-shell structure were studied by Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). The Dex release behavior from the nanofibers was tested by High Performance liquid (HPLC) method. The protective effect of drug loaded nanofibers mats on Porcine hip artery endothelial cells (PIECs) against LPS-induced inflammatory damage were determined by MTT assay. TEM result showed the distinct core-shell structure of nanofibers. In vitro drug release studies demonstrated that dexamethasone can sustain release over 192 h and core-shell nanofibers showed more slow release of Dex compared with the blending electrospinning nanofibers. Anti-inflammatory activity in vitro showed that released Dex can reduce the PIECs inflammatory damage and apoptosis which induced by lipopolysaccharide (LPS). Dex@SF/PEO nanofibers are safe and non-toxic because of no harmful organic solvents used in the preparation, it is a promising environment friendly drug carrier for tissue engineering. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Study of laser-induced damage to large core silica fiber by Nd:YAG and Alexandrite lasers

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoguang; Li, Jie; Hokansson, Adam; Whelan, Dan; Clancy, Michael

    2009-02-01

    As a continuation of our earlier study at 2.1 μm wavelength, we have investigated the laser damage to several types of step-index, large core (1500 μm) silica fibers at two new wavelengths by high power long pulsed Nd:YAG (1064 nm) and Alexandrite (755 nm) lasers. It was observed that fibers with different designs showed a significant difference in performance at these wavelengths. We will also report a correlation of damage to the fibers between the two laser wavelengths. The performance analyses of different fiber types under the given test conditions will enable optimization of fiber design for specific applications.

  2. Performance of the Dual-frequency Precipitation Radar on the GPM core satellite

    NASA Astrophysics Data System (ADS)

    Iguchi, Toshio; Seto, Shinta; Awaka, Jun; Meneghini, Robert; Kubota, Takuji; Oki, Riko; Chandra, Venkatchalam; Kawamoto, Nozomi

    2016-04-01

    The GPM core satellite was launched on February 28, 2014. This paper describes some of the results of precipitation measurements with the Dual-Frequency Precipitation Radar (DPR) on the GPM core satellite. The DPR, which was developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT), consists of two radars: Ku-band precipitation radar (KuPR) and Ka-band radar (KaPR). The performance of the DPR is evaluated by comparing the level 2 products with the corresponding TRMM/PR data and surface rain measurements. The scanning geometry and footprint size of KuPR and those of PR are nearly identical. The major differences between them are the sensitivity, visiting frequency, and the rain retrieval algorithm. KuPR's sensitivity is twice as good as PR. The increase of sensitivity reduces the cases of missing light rain. Since relatively light rain prevails in Japan, the difference in sensitivity may cause a few percentage points in the bias. Comparisons of the rain estimates by GPM/DPR with AMeDAS rain gauge data over Japan show that annual KuPR's estimates over Japan agree quite well with the rain gauge estimates although the monthly or local statistics of these two kinds of data scatter substantially. KuPR's esimates are closer to the gauge estimates than the TRMM/PR. Possible sources of the differences that include sampling errors, sensitivity, and the algorithm are examined.

  3. Hollow-core photonic-crystal-fiber-based optical frequency references

    NASA Astrophysics Data System (ADS)

    Holá, Miroslava; Hrabina, Jan; Mikel, Břetislav; Lazar, Josef; Číp, Ondřej

    2016-12-01

    This research deals with preparation of an optical frequency references based on hollow-core photonic crystal fibers (HC-PCF). This fiber-based type of absorption cells represents a effiecient way how to replace classic bulky and fragile glass made tubes references with low-weight and low-volume optical fibers. This approach allows not only to increase possible interaction length between incident light and absorption media but it also carries a possibility of manufacturing of easy-operable reference which is set up just by plugging-in of optical connectors into the optical setup. We present the results of preparation, manufacturing and filling of a set of fiber-based cells intended for lasers frequency stabilization. The work deals with setting and optimalization of HC-PCF splicing processes, minimalization of optical losses between HC-PCF and SMF fiber transitions and finishing of HC-PCF spliced ends with special care for optimal closing of hollow-core structure needed for avoiding of absorption media leakage.

  4. Pure odd-frequency superconductivity at the cores of proximity vortices

    NASA Astrophysics Data System (ADS)

    Alidoust, Mohammad; Zyuzin, Alexander; Halterman, Klaus

    2017-01-01

    After more than a decade, direct observation of the odd frequency triplet pairing state in superconducting hybrid structures remains elusive. We propose an experimentally feasible setup that can unambiguously reveal the zero energy peak due to proximity-induced equal spin superconducting triplet correlations. We theoretically investigate a two-dimensional Josephson junction in the diffusive regime. The nanostructure consists of a normal metal sandwiched between two ferromagnetic layers with spiral magnetization patterns. By applying an external magnetic field perpendicular to the junction plane, vortices nucleate in the normal metal. The calculated energy and spatially resolved density of states, along with the pair potential, reveal that remarkably, only triplet Cooper pairs survive in the vortex cores. These isolated odd frequency triplet correlations result in well defined zero energy peaks in the local density of states that can be identified through tunneling spectroscopy experiments. Moreover, the diffusive regime considered here rules out the possibility of Andreev bound states in the vortex core as contributors to the zero energy peaks.

  5. Monitoring of hidden damage in multi-layered aerospace structures using high-frequency guided waves

    NASA Astrophysics Data System (ADS)

    Semoroz, A.; Masserey, B.; Fromme, P.

    2011-04-01

    Aerospace structures contain multi-layered components connected by fasteners, where fatigue cracks and disbonds or localized lack of sealant can develop due to cyclic loading conditions and stress concentration. High frequency guided waves propagating along such a structure allow for the efficient non-destructive testing of large components, such as aircraft wings. The type of multi-layered model structure investigated in this contribution consists of two aluminium plates adhesively bonded with an epoxy based sealant layer. Using commercially available transducer equipment, specific high frequency guided ultrasonic wave modes that penetrate through the complete thickness of the structure were excited. The wave propagation along the structure was measured experimentally using a laser interferometer. Two types of hidden damage were considered: a localized lack of sealant and small surface defects in the metallic layer facing the sealant. The detection sensitivity using standard pulse-echo measurement equipment has been quantified and the detection of small hidden defects from significant stand-off distances has been shown. Fatigue experiments were carried out and the potential of high frequency guided waves for the monitoring of fatigue crack growth at a fastener hole during cyclic loading was discussed.

  6. Precursors to potential severe core damage accidents: 1994, a status report. Volume 21: Main report and appendices A--H

    SciTech Connect

    Belles, R.J.; Cletcher, J.W.; Copinger, D.A.; Vanden Heuvel, L.N.; Dolan, B.W.; Minarick, J.W. |

    1995-12-01

    Nine operational events that affected eleven commercial light-water reactors (LWRs) during 1994 and that are considered to be precursors to potential severe core damage are described. All these events had conditional probabilities of subsequent severe core damage greater than or equal to 1.0 {times} 10{sup {minus}6}. These events were identified by computer-screening the 1994 licensee event reports from commercial LWRs to identify those that could be potential precursors. Candidate precursors were then selected and evaluated in a process similar to that used in previous assessments. Selected events underwent engineering evaluation that identified, analyzed, and documented the precursors. Other events designated by the Nuclear Regulatory Commission (NRC) also underwent a similar evaluation. Finally, documented precursors were submitted for review by licensees and NRC headquarters and regional offices to ensure that the plant design and its response to the precursor were correctly characterized. This study is a continuation of earlier work, which evaluated 1969--1981 and 1984--1993 events. The report discusses the general rationale for this study, the selection and documentation of events as precursors, and the estimation of conditional probabilities of subsequent severe core damage for events. This document is bound in two volumes: Vol. 21 contains the main report and Appendices A--H; Vol. 22 contains Appendix 1.

  7. Laboratory simulation of high-frequency GPR responses of damaged tunnel liners

    NASA Astrophysics Data System (ADS)

    Siggins, A. F.; Whiteley, Robert J.

    2000-04-01

    Concrete lined tunnels and pipelines commonly suffer from damage due to subsidence or poor drainage in the surrounding soils, corrosion of reinforcement if present, and acid vapor leaching of the lining. There is a need to conduct tunnel condition monitoring using non-destructive testing methods (NDT) on a regular basis in many buried installations, for example sewers and storm water drains. A wide variety of NDT methods have been employed in the past to monitor these linings including closed circuit TV (CCTV) inspection, magnetic and various electromagnetic and seismic methods. Ground penetrating radar, GPR, is a promising technique for this application, however there are few systems currently available that can provide the high resolution imaging needed to test the lining. A recently developed Australian GPR system operating at 1400 MHz offers the potential to overcome many of these limitations while maintaining adequate resolution to the rear of the linings which are typically less than 0.5 meters thick. The new high frequency GPR has a nominal resolution of 0.03 m at the center of the pulse band-width. This is a significant improvement over existing radars with the possible exception of some horn based systems. This paper describes the results of a laboratory study on a model tunnel lining using the new 1.4 GHz radar. The model simulated a concrete lining with various degrees of damage including, heavily leached sections, voids and corroded reinforcing. The test results established that the new GPR was capable of imaging subtle variations in the concrete structure and that simulated damage could be detected throughout the liner depth. Furthermore, resolution was found to exceed 0.02 m which was significantly better than expected.

  8. Genetic damage in humans exposed to extremely low-frequency electromagnetic fields.

    PubMed

    Maes, A; Verschaeve, L

    2016-10-01

    The classification of extremely low-frequency magnetic fields by the International Agency for Research on Cancer in the group of 'possible human carcinogens' (group 2B) is essentially based on epidemiologic evidence showing an association between MF exposures and childhood leukaemia. Despite many in vitro and in vivo investigations, there is no established causal relationship yet. However, human cytogenetic biomonitoring studies that were conducted in the past show predominantly positive results, i.e. increased cytogenetic damage in peripheral blood lymphocytes or buccal cells of ELF-MF-exposed subjects. This is important given the established link between observed cytogenetic damage in cells of people and an increased cancer risk. We here conducted an evaluation of the published investigations and found that many of the studies clearly have shortcomings, which often prevent any firm conclusion. As a matter of fact, there are reasons to believe that effects are not that impressive. However, the totality of the studies cannot simply be disregarded warranting further caution and the application, to a certain extent, of the precautionary principle.

  9. The effects of frequency-dependent amplitude on the time-reversed Lamb wave based baseline-free damage detection

    NASA Astrophysics Data System (ADS)

    Zeng, Liang; Lin, Jing; Luo, Zhi; Gao, Fei

    2017-02-01

    Time reversal is the process that a response signal recorded at a receiver location is reversed in time and emitted back to the original source transducer. In the absence of any damage, theoretically the main wave packet of the reconstructed signal could exactly resemble the original input wave form. However, since the amplitude response of Lamb wave mode is generally frequency dependent, the reconstruction is not perfect. In this study, the influences of the frequency-dependent amplitude to the spectrum of the reconstructed signal is investigated. The results show that the peak frequency shifts and the bandwidth varies due to the frequency dependency of amplitude. This spectrum distortion affects the wave form of the main wave packet of the reconstructed signal significantly. Since the baseline-free damage detection is accomplished by comparing the wave form of the TR reconstructed signal with that of the original input signal, these effects would be captured by the damage index and be attributed to the presence of damage. Thus a false alarm may arise. To mitigate these effects, an amplitude modification strategy is established. With the application of this strategy, the modified baseline-free damage detection method is then employed for monitoring the growth of damage.

  10. Geometry of the Nojima fault at Nojima-Hirabayashi, Japan - I. A simple damage structure inferred from borehole core permeability

    USGS Publications Warehouse

    Lockner, David A.; Tanaka, Hidemi; Ito, Hisao; Ikeda, Ryuji; Omura, Kentaro; Naka, Hisanobu

    2009-01-01

    The 1995 Kobe (Hyogo-ken Nanbu) earthquake, M = 7.2, ruptured the Nojima fault in southwest Japan. We have studied core samples taken from two scientific drillholes that crossed the fault zone SW of the epicentral region on Awaji Island. The shallower hole, drilled by the Geological Survey of Japan (GSJ), was started 75 m to the SE of the surface trace of the Nojima fault and crossed the fault at a depth of 624 m. A deeper hole, drilled by the National Research Institute for Earth Science and Disaster Prevention (NIED) was started 302 m to the SE of the fault and crossed fault strands below a depth of 1140 m. We have measured strength and matrix permeability of core samples taken from these two drillholes. We find a strong correlation between permeability and proximity to the fault zone shear axes. The half-width of the high permeability zone (approximately 15 to 25 m) is in good agreement with the fault zone width inferred from trapped seismic wave analysis and other evidence. The fault zone core or shear axis contains clays with permeabilities of approximately 0.1 to 1 microdarcy at 50 MPa effective confining pressure (10 to 30 microdarcy at in situ pressures). Within a few meters of the fault zone core, the rock is highly fractured but has sustained little net shear. Matrix permeability of this zone is approximately 30 to 60 microdarcy at 50 MPa effective confining pressure (300 to 1000 microdarcy at in situ pressures). Outside this damage zone, matrix permeability drops below 0.01 microdarcy. The clay-rich core material has the lowest strength with a coefficient of friction of approximately 0.55. Shear strength increases with distance from the shear axis. These permeability and strength observations reveal a simple fault zone structure with a relatively weak fine-grained core surrounded by a damage zone of fractured rock. In this case, the damage zone will act as a high-permeability conduit for vertical and horizontal flow in the plane of the

  11. Detection of g modes in the asymptotic frequency range: evidence for a rapidly rotating core

    NASA Astrophysics Data System (ADS)

    Ulrich, Roger K.; Fossat, Eric; Boumier, Patrick; Corbard, Thierry; Provost, Janine; Salabert, David; Schmider, François-Xavier; Gabriel, Alan; Grec, Gerard; Renaud, Catherine; Robillot, Jean-Maurice; Roca Cortés, Teodoro; Turck-Chièze, Sylvaine

    2017-08-01

    We present the identification of very low frequency g modes, in the asymptotic regime, and two important parameters: the core rotation rate and the asymptotic equidistant period spacing of these g modes. The GOLF instrument on the SOHO space observatory has provided two decades of full disk helioseismic data. The search for g modes in GOLF measurements has been extremely difficult, due to solar and instrumental noise. In the present study, the p modes of the GOLF signal are analyzed differently, searching for possible collective frequency modulations produced by periodic changes in the deep solar structure. Such modulations provide access to only very low frequency g modes, thus allowing statistical methods to take advantage of their asymptotic properties. For oscillatory periods in the range between 9 and nearly 48 hours, almost 100 g modes of spherical harmonic degree 1 and more than 100 g modes of degree 2 are predicted. They are not observed individually, but when combined, they unambiguously provide their asymptotic period equidistance and rotational splittings, in excellent agreement with the requirements of the asymptotic approximations. P0, the g-mode period equidistance parameter, is measured to be 34 min 01 s, with a 1 s uncertainty. The previously unknown g-mode splittings have now been measured from a non synodic reference with a very high accuracy, and they imply a mean weighted rotation of 1277 ± 10 nHz (9-day period) of their kernels, resulting in a rapid rotation frequency of 1644 ± 23 nHz (period of one week) of the solar core itself, which is a factor 3:8 ± 0:1 faster than the rotation of the radiative envelope.Acknowledgements. Ulrich is first author on this abstract due to AAS rules, Fossat is the actual first author. SOHO is a project of international collaboration between ESA and NASA. We would like to acknowledge the support received continuously during more than 3 decades from CNES. DS acknowledges the financial support from the CNES GOLF

  12. Chromosomal damage in human diploid fibroblasts by intermittent exposure to extremely low-frequency electromagnetic fields.

    PubMed

    Winker, Robert; Ivancsits, Sabine; Pilger, Alexander; Adlkofer, Franz; Rüdiger, H W

    2005-08-01

    Environmental exposure to extremely low-frequency electromagnetic fields (ELF-EMFs) has been implicated in the development of cancer in humans. An important basis for assessing a potential cancer risk due to ELF-EMF exposure is knowledge of biological effects on human cells at the chromosomal level. Therefore, we investigated in the present study the effect of intermittent ELF electromagnetic fields (50 Hz, sinusoidal, 5'field-on/10'field-off, 2-24 h, 1 mT) on the induction of micronuclei (MN) and chromosomal aberrations in cultured human fibroblasts. ELF-EMF radiation resulted in a time-dependent increase of micronuclei, which became significant after 10 h of intermittent exposure at a flux density of 1 mT. After approximately 15 h a constant level of micronuclei of about three times the basal level was reached. In addition, chromosomal aberrations were increased up to 10-fold above basal levels. Our data strongly indicate a clastogenic potential of intermittent low-frequency electromagnetic fields, which may lead to considerable chromosomal damage in dividing cells.

  13. Finite element analysis of the dynamic behavior of a laminated windscreen with frequency dependent viscoelastic core.

    PubMed

    Bouayed, Kaïss; Hamdi, Mohamed-Ali

    2012-08-01

    This paper presents numerical and experimental validation of results obtained by a shell finite element, which has been developed for modeling of the dynamic behavior of sandwich multilayered structures with a viscoelastic core. The proposed shell finite element is very easy to implement in existing finite element solvers, since it uses only the displacements as degrees of freedom at external faces and at inter-layer interfaces. The displacement field is linearly interpolated in the thickness direction of each layer, and analytical integration is made in the thickness direction in order to avoid meshing of each sandwich layer by solid elements. Only the two dimensional mid-surface of reference is meshed, facilitating the mesh generation task. A simplified modal approach using a real modal basis is also proposed to efficiently calculate the dynamic response of the sandwich structure. The proposed method reduces the memory size and computing time and takes into account the frequency-dependence of the polymer core mechanical properties. Results obtained by the proposed element in conjunction with the simplified modal method have been numerically and experimentally validated by comparison to results obtained by commercial software codes (MSC/NASTRAN and ESI/RAYON-VTM), and to measurements done on automobile windscreens.

  14. Quanty for core level spectroscopy - excitons, resonances and band excitations in time and frequency domain

    NASA Astrophysics Data System (ADS)

    Haverkort, Maurits W.

    2016-05-01

    Depending on the material and edge under consideration, core level spectra manifest themselves as local excitons with multiplets, edge singularities, resonances, or the local projected density of states. Both extremes, i.e., local excitons and non-interacting delocalized excitations are theoretically well under control. Describing the intermediate regime, where local many body interactions and band-formation are equally important is a challenge. Here we discuss how Quanty, a versatile quantum many body script language, can be used to calculate a variety of different core level spectroscopy types on solids and molecules, both in the frequency as well as the time domain. The flexible nature of Quanty allows one to choose different approximations for different edges and materials. For example, using a newly developed method merging ideas from density renormalization group and quantum chemistry [1-3], Quanty can calculate excitons, resonances and band-excitations in x-ray absorption, photoemission, x-ray emission, fluorescence yield, non-resonant inelastic x-ray scattering, resonant inelastic x-ray scattering and many more spectroscopy types. Quanty can be obtained from: http://www.quanty.org.

  15. Analysis of core damage frequency: Peach Bottom, Unit 2 internal events

    SciTech Connect

    Kolaczkowski, A.M.; Cramond, W.R.; Sype, T.T.; Maloney, K.J.; Wheeler, T.A.; Daniel, S.L.; Sandia National Labs., Albuquerque, NM )

    1989-08-01

    This document contains the appendices for the accident sequence analysis of internally initiated events for the Peach Bottom, Unit 2 Nuclear Power Plant. This is one of the five plant analyses conducted as part of the NUREG-1150 effort for the Nuclear Regulatory Commission. The work performed and described here is an extensive reanalysis of that published in October 1986 as NUREG/CR-4550, Volume 4. It addresses comments from numerous reviewers and significant changes to the plant systems and procedures made since the first report. The uncertainty analysis and presentation of results are also much improved, and considerable effort was expended on an improved analysis of loss of offsite power. The content and detail of this report is directed toward PRA practitioners who need to know how the work was done and the details for use in further studies. 58 refs., 58 figs., 52 tabs.

  16. [Core principles of treatment of corneal damage in patients with thyroid eye disease].

    PubMed

    Grusha, Y O; Ismailova, D S; Sherstneva, L V

    To develop a therapeutic approach and to estimate the efficiency of complex treatment of corneal damage in patients with thyroid eye disease (TED). The study enrolled 44 patients (52 eyes) divided into 2 groups depending on the severity of corneal damage. Treatment of those with severe involvement included pathogenetic measures (pulse steroid therapy and/or radiation therapy) and surgery (orbital decompression, eyelid and corneal surgery). As the result of the treatment, orbital inflammation decreased and the state of the cornea improved in all patients. The treatment of corneal damage in patients with TED may differ depending on numerous factors, such as the severity of corneal damage and activity of orbital inflammation. Taking into account the potential danger of corneal involvement, one should make efforts to early detection and management of the risk factors.

  17. Contribution to modeling of the reflooding of a severely damaged reactor core using PRELUDE experimental results

    SciTech Connect

    Bachrata, A.; Fichot, F.; Repetto, G.; Quintard, M.; Fleurot, J.

    2012-07-01

    In case of accident at a nuclear power plant, water sources may not be available for a long period of time and the core heats up due to the residual power. The reflooding (injection of water into core) may be applied if the availability of safety injection is recovered during accident. If the injection becomes available only in the late phase of accident, water will enter a core configuration that will differ significantly from original rod-bundle geometry. Any attempt to inject water after significant core degradation can lead to further fragmentation of core material. The fragmentation of fuel rods may result in the formation of a 'debris bed'. The typical particle size in a debris bed might reach few millimeters (characteristic length-scale: 1 to 5 mm), i.e., a high permeability porous medium. The French 'Institut de Radioprotection et de Surete Nucleaire' is developing experimental programs (PEARL and PRELUDE) and simulation tools (ICARE-CATHARE and ASTEC) to study and optimize the severe accident management strategy and to assess the probabilities to stop the progress of in-vessel core degradation. It is shown that the quench front exhibits either a ID behaviour or a 2D one, depending on injection rate or bed characteristics. The PRELUDE experiment covers a rather large range of variation of parameters, for which the developed model appears to be quite predictive. (authors)

  18. Current status of the dual-frequency precipitation radar on the global precipitation measurement core spacecraft

    NASA Astrophysics Data System (ADS)

    Furukawa, K.; Nio, T.; Konishi, T.; Oki, R.; Masaki, T.; Kubota, T.; Iguchi, T.; Hanado, H.

    2015-10-01

    The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core satellite was developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT). The GPM is a follow-on mission of the Tropical Rainfall Measuring Mission (TRMM). The objectives of the GPM mission are to observe global precipitation more frequently and accurately than TRMM. The frequent precipitation measurement about every three hours will be achieved by some constellation satellites with microwave radiometers (MWRs) or microwave sounders (MWSs), which will be developed by various countries. The accurate measurement of precipitation in mid-high latitudes will be achieved by the DPR. The GPM core satellite is a joint product of National Aeronautics and Space Administration (NASA), JAXA and NICT. NASA developed the satellite bus and the GPM Microwave Imager (GMI), and JAXA and NICT developed the DPR. JAXA and NICT developed the DPR through procurement. The configuration of precipitation measurement using active radar and a passive radiometer is similar to TRMM. The major difference is that DPR is used in GPM instead of the precipitation radar (PR) in TRMM. The inclination of the core satellite is 65 degrees, and the nominal flight altitude is 407 km. The non-sun-synchronous circular orbit is necessary for measuring the diurnal change of rainfall similarly to TRMM. The DPR consists of two radars, which are Ku-band (13.6 GHz) precipitation radar (KuPR) and Ka-band (35.5 GHz) precipitation radar (KaPR). Both KuPR and KaPR have almost the same design as TRMM PR. The DPR system design and performance were verified through the ground test. GPM core observatory was launched at 18:37:00 (UT) on February 27, 2014 successfully. DPR orbital check out was completed in May 2014. The results of orbital checkout show that DPR meets its specification on orbit. After completion of initial checkout, DPR started Normal

  19. Predicting the width and average fracture frequency of damage zones using a partial least squares statistical analysis: Implications for fault zone development

    NASA Astrophysics Data System (ADS)

    O'Hara, Alex P.; Jacobi, Robert D.; Sheets, H. David

    2017-05-01

    reducing fracture frequency is due to the progressive development of a fault core at the expense of the adjacent damage zone and the consumption of the highest-frequency fractures adjacent to the fault surface.

  20. Accumulation of p21 proteins at DNA damage sites independent of p53 and core NHEJ factors following irradiation

    SciTech Connect

    Koike, Manabu; Yutoku, Yasutomo; Koike, Aki

    2011-08-19

    Highlights: {yields} p21 accumulated rapidly at laser-irradiated sites via its C-terminal region. {yields} p21 colocalized with the DSB marker {gamma}-H2AX and the DSB sensor Ku80. {yields} Accumulation of p21 is dependent on PCNA, but not p53 and the NHEJ core factors. {yields} Accumulation activity of p21 was conserved among human and animal cells. {yields} p21 is a useful tool as a detection marker of DNA damaged sites. -- Abstract: The cyclin-dependent kinase (CDK) inhibitor p21 plays key roles in p53-dependent DNA-damage responses, i.e., cell cycle checkpoints, senescence, or apoptosis. p21 might also play a role in DNA repair. p21 foci arise at heavy-ion-irradiated DNA-double-strand break (DSB) sites, which are mainly repaired by nonhomologous DNA-end-joining (NHEJ). However, no mechanisms of p21 accumulation at double-strand break (DSB) sites have been clarified in detail. Recent works indicate that Ku70 and Ku80 are essential for the accumulation of other NHEJ core factors, e.g., DNA-PKcs, XRCC4 and XLF, and other DNA damage response factors, e.g., BRCA1. Here, we show that p21 foci arise at laser-irradiated sites in cells from various tissues from various species. The accumulation of EGFP-p21 was detected in not only normal cells, but also transformed or cancer cells. Our results also showed that EGFP-p21 accumulated rapidly at irradiated sites, and colocalized with the DSB marker {gamma}-H2AX and with the DSB sensor protein Ku80. On the other hand, the accumulation occurred in Ku70-, Ku80-, or DNA-PKcs-deficient cell lines and in human papillomavirus 18-positive cells, whereas the p21 mutant without the PCNA-binding region (EGFP-p21(1-146)) failed to accumulate at the irradiated sites. These findings suggest that the accumulation of p21, but not functional p53 and the NHEJ core factors, is dependent on PCNA. These findings also suggest that the accumulation activity of p21 at DNA damaged sites is conserved among human and animal cells, and p21 is a useful

  1. Frequency stabilization of a 2.05 μm laser using hollow-core fiber CO2 frequency reference cell

    NASA Astrophysics Data System (ADS)

    Meras, Patrick; Poberezhskiy, Ilya Y.; Chang, Daniel H.; Spiers, Gary D.

    2010-04-01

    We have designed and built a hollow-core fiber frequency reference cell, filled it with CO2, and used it to demonstrate frequency stabilization of a 2.05 μm Tm:Ho:YLF laser using frequency modulation (FM) spectroscopy technique. The frequency reference cell is housed in a compact and robust hermetic package that contains a several meter long hollow-core photonic crystal fiber optically coupled to index-guiding fibers with a fusion splice on one end and a mechanical splice on the other end. The package has connectorized fiber pigtails and a valve used to evacuate, refill it, or adjust the gas pressure. We have demonstrated laser frequency standard deviation decreasing from >450MHz (free-running) to <2.4MHz (stabilized). The 2.05 μm laser wavelength is of particular interest for spectroscopic instruments due to the presence of many CO2 and H20 absorption lines in its vicinity. To our knowledge, this is the first reported demonstration of laser frequency stabilization at this wavelength using a hollow-core fiber reference cell. This approach enables all-fiber implementation of the optical portion of laser frequency stabilization system, thus making it dramatically more lightweight, compact, and robust than the traditional free-space version that utilizes glass or metal gas cells. It can also provide much longer interaction length of light with gas and does not require any alignment. The demonstrated frequency reference cell is particularly attractive for use in aircraft and space coherent lidar instruments for measuring atmospheric CO2 profile.

  2. An investigation on low frequency fatigue damage of mooring lines applied in a semi-submersible platform

    NASA Astrophysics Data System (ADS)

    Du, Junfeng; Wang, Shuqing; Chang, Anteng; Li, Huajun

    2016-06-01

    Assessing the fatigue life of mooring systems is important for deep water structures. In this paper, a comprehensive fatigue analysis is conducted on the mooring lines applied in a semi-submersible platform with special focus on the low frequency (LF) fatigue damage. Several influential factors, including water depth, wave spectral parameters, and riser system, are considered. Numerical simulation of a semi-submersible platform with the mooring/riser system is executed under different conditions, and the fatigue damage of mooring lines is assessed by using the time domain analysis method as a benchmark. The effects of these factors on the mooring line tension and the fatigue damage are investigated and discussed in detail. Research results indicate that the LF fatigue damage only accounts for a very small portion of the total damage, although the LF components dominate the global motion response and the mooring line tension of the semi-submersible platform. However, it is demonstrated that the LF fatigue damage is clearly affected by the influential factors. The increase in water depth and spectral peak periods, and the existence of risers can weaken the contribution of the LF components to the mooring line fatigue damage, while the fatigue damage due to the LF components increases with the increase of significant wave height.

  3. Time-frequency analysis of GPR data to investigate the damage of monumental buildings

    NASA Astrophysics Data System (ADS)

    Leucci, Giovanni; Masini, Nicola; Persico, Raffaele

    2012-08-01

    The presence of particular microclimatic conditions inside monumental buildings is responsible for bio-deterioration processes. In many cases, efflorescence and moulds are visible on the facades of several monuments of historical importance. In many other cases, the effects of decay processes are not visible, thus making difficult the diagnosis and the consequent setup of effective rehabilitation and preservation interventions, especially in the presence of a complex geometry and/or a large variability of construction materials. In such cases, a valuable contribution could be provided by geophysical methods (such as electrical resistivity, electromagnetic conductivity, ground-penetrating radar (GPR), etc), which have been proved to be successful tools for sub-surface investigation and characterization of historical buildings. In old monumental buildings, the masonry structures frequently exhibit cracks, voids, detachments and high moisture contrasts that can give rise to reflection events in radar signals. However, the complexity of the geometry and the structural heterogeneity that characterize these old structures often make the GPR results difficult to analyse and interpret. In particular, the spatial variation in GPR signal attenuation can provide important information about the electrical properties of the investigated materials that, in turn, can be used to assess the physical parameters associated with damage. In this paper, we propose an approach that analyses the data in the form of ‘frequency maps’ to evidence absorption losses probably linked to higher moisture content. Two real case histories back up the proposed method.

  4. Feasibility study of structural damage detection using NARMAX modelling and Nonlinear Output Frequency Response Function based analysis

    NASA Astrophysics Data System (ADS)

    Peng, Z. K.; Lang, Z. Q.; Wolters, C.; Billings, S. A.; Worden, K.

    2011-04-01

    Nonlinear Output Frequency Response Functions (NOFRFs) are a series of one-dimensional functions of frequency recently proposed by the authors to facilitate the analysis of nonlinear systems in the frequency domain. The present study is concerned with a feasibility study of the application of the well-known Nonlinear Auto-Regressive Moving Average with eXogenous Inputs (NARMAX) modelling method and the NOFRFs-based analyses to the detection of damage in engineering structures. The new technique includes three steps. First, a NARX model is established by applying the NARMAX modelling method to input and output data collected from a test on an inspected structure. Then, the NOFRFs and an associated index for the inspected structure are determined from the established NARX model. Finally, structural damage detection is conducted by comparing the values of the NOFRF index of the inspected structure with the values of the index for a damage-free structure. An experimental application to the detection of damage in aluminium plates demonstrates the potential and effectiveness of the new damage detection technique.

  5. The frequency of pre-core gene mutations in chronic hepatitis B infection: a study of Malaysian subjects.

    PubMed

    Yap, S F; Wong, P W; Chen, Y C; Rosmawati, M

    2002-03-01

    A retrospective study was carried out to determine the frequency of the pre-core stop codon mutant virus in a group of chronic hepatitis B carriers: 81 cases were considered [33 hepatits B e antigen (HBe) positive and 48 HBe negative]. All of the HBe positive cases had detectable viral DNA by hybridization analysis; in the case of the HBe negative cases, one third had detectable viral DNA by hybridization analysis and two thirds had HBV DNA detectable by polymerase chain reaction (PCR) amplification. Pre-core stop codon mutant detection was carried out on all specimens using allele-specific oligonucleotide hybridization following PCR amplification of the target sequence. The pre-core mutant was detected in 13/33 (39.4%) of HBe positive cases and in 32/48 (66.7%) of HBe negative cases. Sequence analysis was carried out on 8 of the 16 HBe negative specimens that did not carry the pre-core mutant virus to determine the molecular basis for the HBe minus phenotype in these cases: the 1762/1764 TA paired mutation in the second AT rich region of the core promoter was detected in five cases; a start codon mutation was detected in one case. The predominant mutation resulting in the HBe minus phenotype in our isolates was the 1896A pre-core ("pre-core stop codon") mutation; other mutations responsible for the phenotype included the core promoter paired mutation and pre-core start codon mutation. In view of the high frequency of the pre-core mutant virus, sequence analysis was performed to determine the virus genotype on the basis of the nucleotide sequence of codon 15. The sequences of 21 wild type virus (14 HBe positive and 7 HBe negative cases) were examined: 15 were found to be codon 15 CCT variants (71.4%); the frequency in the HBe positive group was 12/14 (85.7%), while that in the HBe negative group was 3/7 (42.9%). The high frequency of the codon 15 CCT variant in association with the frequent occurrence of the pre-core mutant in our isolates concurs with the results

  6. Identification of Damaged Wheat Kernels and Cracked-Shell Hazelnuts with Impact Acoustics Time-Frequency Patterns

    USDA-ARS?s Scientific Manuscript database

    A new adaptive time-frequency (t-f) analysis and classification procedure is applied to impact acoustic signals for detecting hazelnuts with cracked shells and three types of damaged wheat kernels. Kernels were dropped onto a steel plate, and the resulting impact acoustic signals were recorded with ...

  7. Continuous and short fiber reinforced composite in root post-core system of severely damaged incisors.

    PubMed

    Garoushi, Sufyan; Vallittu, Pekka K; Lassila, Lippo V J

    2009-03-18

    The aim of this study was to determine the static load-bearing capacity of endodontically treated maxillary incisors restored with post-core complex made of experimental fiber composite resin (FC) and complete crown made of particulate filler composite (PFC). Further aim was to evaluate the effect of FC resin on the failure mode of the restoration. The experimental composite resin (FC) was prepared by mixing 22.5 wt% of short E-glass fibers (3 mm in length) and 22.5 wt% of semi-interpenetrating polymer network (IPN) resin with 55 wt% of silane treated silica fillers. Thirty extracted sound upper central incisors were used. Twenty teeth were prepared by cutting the clinical crown 2 mm above the cemento-enamel junction horizontally. Restorations were made by two techniques (n=10). Group A (control group) contained samples of sound incisor teeth. Group B had teeth restored using glass fiber post (everStick, Stick- Teck) and PFC (Filtek Z250, 3M-ESPE) to build up core and complete crown. In Group C, the teeth were restored with FC as post-core and complete crown of PFC. The root canals were prepared and posts were cemented with a dual cure resin cement. The restorations were polymerized with a hand-light curing unit. All restored teeth were stored in water at room temperature for 24 h before they were statically loaded with speed of 1.0 mm/min until fracture. Data were analyzed using ANOVA (p=0.05). Failure modes were visually examined. ANOVA revealed that restored incisors (Group B and C) had a statistically significantly lower load-bearing capacity (p<0.05) than the control group. Restorations made from FC post-core and PFC coverage (Group C) gave force value of 363 N (112 SD), which was higher than the value of Group B (211 N, 50 SD). Within the limitations of this study, the teeth restored with experimental fiber composite post-core demonstrated higher load bearing capacity than those with fiber post and PFC core.

  8. High frequency core localized modes in neutral beam heated plasmas on TFTR

    SciTech Connect

    Nazikian, R.; Chang, Z.; Fredrickson, E.D.

    1995-11-01

    A band of high frequency modes in the range 50--150 kHz with intermediate toroidal mode numbers 4 < n < 10 are commonly observed in the core of supershot plasmas on TFTR. Two distinct varieties of MHD modes are identified corresponding to a flute-like mode predominantly appearing around the q = 1 surface and an outward ballooning mode for q > 1. The flute-like modes have nearly equal amplitude on the high field and low field side of the magnetic axis and are mostly observed in moderate performance supershot plasmas with {tau}{sub E} < 2{tau}{sub L} while the ballooning-like modes have enhanced amplitude on the low field side of the magnetic axis and tend to appear in higher performance supershot plasmas with {tau}{sub E} > 2{tau}{sub L}, where {tau}{sub L} is the equivalent L-mode confinement time. The modes propagate in the ion diamagnetic drift direction and are highly localized with radial widths {Delta}r {approximately} 5--10 cm, fluctuation levels {tilde n}/n, {tilde T}{sub e}/T{sub e} < 0.01, and radial displacements {zeta}{sub r} {approximately} 0.1 cm. Unlike the toroidally localized high-n activity observed just prior to major and minor disruptions on TFTR, these modes are typically much weaker, more benign, and may be indicative of kinetic ballooning modes destabilized by resonant circulating neutral beam ions.

  9. Design criteria for a self-actuated shutdown system to ensure limitation of core damage. [LMFBR

    SciTech Connect

    Deane, N.A.; Atcheson, D.B.

    1981-09-01

    Safety-based functional requirements and design criteria for a self-actuated shutdown system (SASS) are derived in accordance with LOA-2 success criteria and reliability goals. The design basis transients have been defined and evaluated for the CDS Phase II design, which is a 2550 MWt mixed oxide heterogeneous core reactor. A partial set of reactor responses for selected transients is provided as a function of SASS characteristics such as reactivity worth, trip points, and insertion times.

  10. Effects of core position of locally resonant scatterers on low-frequency acoustic absorption in viscoelastic panel

    NASA Astrophysics Data System (ADS)

    Zhong, Jie; Wen, Ji-Hong; Zhao, Hong-Gang; Yin, Jian-Fei; Yang, Hai-Bin

    2015-08-01

    Locally resonant sonic materials, due to their ability to control the propagation of low-frequency elastic waves, have become a promising option for underwater sound absorption materials. In this paper, the finite element method is used to investigate the absorption characteristics of a viscoelastic panel periodically embedded with a type of infinite-long non-coaxially cylindrical locally resonant scatterers (LRSs). The effect of the core position in the coating layer of the LRS on the low-frequency (500 Hz-3000 Hz) sound absorption property is investigated. With increasing the longitudinal core eccentricity e, there occur few changes in the absorptance at the frequencies below 1500 Hz, however, the absorptance above 1500 Hz becomes gradually better and the valid absorption (with absorptance above 0.8) frequency band (VAFB) of the viscoelastic panel becomes accordingly broader. The absorption mechanism is revealed by using the displacement field maps of the viscoelastic panel and the steel slab. The results show two typical resonance modes. One is the overall resonance mode (ORM) caused by steel backing, and the other is the core resonance mode (CRM) caused by LRS. The absorptance of the viscoelastic panel by ORM is induced mainly by the vibration of the steel slab and affected little by core position. On the contrary, with increasing the core eccentricity, the CRM shifts toward high frequency band and decouples with the ORM, leading to two separate absorption peaks and the broadened VAFB of the panel. Project supported by the National Natural Science Foundation of China (Grant No. 51275519).

  11. Modeling and analysis framework for core damage propagation during flow-blockage-initiated accidents in the Advanced Neutron Source Reactor at Oak Ridge National Laboratory

    SciTech Connect

    Kim, S.H.; Taleyarkhan, R.P.; Navarro-Valenti, S.; Georgevich, V.

    1995-09-01

    This paper describes modeling and analysis to evaluate the extent of core damage during flow blockage events in the Advanced Neutron Source (ANS) reactor planned to be built at the Oak Ridge National Laboratory (ORNL). Damage propagation is postulated to occur from thermal conduction between damaged and undamaged plates due to direct thermal contact. Such direct thermal contact may occur because of fuel plate swelling during fission product vapor release or plate buckling. Complex phenomena of damage propagation were modeled using a one-dimensional heat transfer model. A scoping study was conducted to learn what parameters are important for core damage propagation, and to obtain initial estimates of core melt mass for addressing recriticality and steam explosion events. The study included investigating the effects of the plate contact area, the convective heat transfer coefficient, thermal conductivity upon fuel swelling, and the initial temperature of the plate being contacted by the damaged plate. Also, the side support plates were modeled to account for their effects on damage propagation. The results provide useful insights into how various uncertain parameters affect damage propagation.

  12. Modeling and analysis framework for core damage propagation during flow-blockage-initiated accidents in the advanced neutron source reactor at Oak Ridge National Laboratory

    SciTech Connect

    Kim, S.H.; Taleyarkhan, R.P.; Navarro-Valenti, S.; Georgevich, V.

    1995-09-01

    This paper describes modeling and analysis to evaluate the extent of core damage during flow blockage events in the Advanced Neutron Source (ANS) reactor planned to be built at the Oak Ridge National Laboratory (ORNL). Damage propagation is postulated to occur from thermal conduction between damaged and undamaged plates due to direct thermal contact. Such direct thermal contact may occur because of fuel plate swelling during fission product vapor release or plate buckling. Complex phenomena of damage propagation were modeled using a one-dimensional heat transfer model. A scoping study was conducted to learn what parameters are important for core damage propagation, and to obtain initial estimates of core melt mass for addressing recriticality and steam explosion events. The study included investigating the effect of the plate contact area, the convective heat transfer coefficient, thermal conductivity upon fuel swelling, and the initial temperature of the plate being contacted by the damaged plate. Also, the side support plates were modeled to account for their effects on damage propagation. The results provide useful insights into how various uncertain parameters affect damage propagation.

  13. High permeability and low loss of Ni-Zn-Fe ferrite/metal composite cores in high frequency region

    NASA Astrophysics Data System (ADS)

    Mori, Satoshi; Mitsuoka, Takeshi; Sonehara, Makoto; Sato, Toshiro; Matsushita, Nobuhiro

    2017-05-01

    A Ni-Zn-Fe ferrite was deposited on the surface of Fe-Si and three kinds of Fe-Si-Cr powders as an insulating material using an ultrasonic-enhanced ferrite plating method. All ferrite-coated powders exhibited a high magnetization of about 180 emu/g derived from their soft magnetic metal and ferrite composition. The three different ferrite-coated Fe-Si-Cr cores annealed at 973 K exhibited a constant permeability μ' of 55-60 in the frequency range up to 50 MHz owing to the insulating effect of the ferrite layer. In contrast, the permeability μ' of the ferrite-coated Fe-3.5Si mass % core decreased in the MHz range. The Cr component acted as a passive layer that made it possible to maintain the Ni-Zn-Fe ferrite layer after annealing. The core loss of the ferrite-coated Fe-3.5Si-4.5Cr mass % core was 448 kW/m3 at 100 kHz and 50 mT, which was half of that observed for the Fe-3.5Si-4.5Cr core without ferrite layer. Additionally, the eddy-current loss of the ferrite-coated Fe-3.5Si-4.5Cr core was strongly decreased compared with the non-coated Fe-3.5Si-4.5Cr core owing to the insulating properties of the ferrite layer.

  14. Finite-frequency measurements of conventional and core-diffracted P-waves (P and Pdiff) for waveform tomography

    NASA Astrophysics Data System (ADS)

    Hosseini, Kasra; Sigloch, Karin; Staehler, Simon C.

    2014-05-01

    In its lowermost 200-300 km, the mantle has a complex structure resulting from accumulations of downwellings (subducted slabs), upwellings (LLSVPs and plumes), and probably phase transitions; seismic velocities and density show large variations but are not tightly constrained. Core-diffracted body waves are the seismic phases that sample the lowermost mantle extensively and are prime candidates to be used in tomography for enhancing resolution in this depth range. Since they are diffracted along the core-mantle boundary, their behavior is highly dispersive and cannot be modeled satisfactory using ray theory, nor early versions of finite-frequency modeling. Hence they have rarely been used for tomography so far, and where they have been, large imaging blur can be expected. We present a processing scheme to measure finite-frequency travel-time anomalies of arbitrary seismic body-wave phases in a fully automated way, with an initial focus on core-diffracted P waves. The aim is to extract a maximum of information from observed broadband seismograms using multi-frequency techniques. Using a matched-filtering approach, predicted and observed waveforms are compared in a cross-correlation sense in eight overlapping frequency passbands, with dominant periods ranging between 30 and 2.7sec. This method was applied to a global data set of ≡2000 teleseismic events in our waveform archive, which resulted in 1,616,184 P and 536,190 Pdiff usable multi-frequency measurements of high cross-correlation coefficient (≥ 0.8). The measurements are analyzed statistically in terms of goodness of fit, effects of epicentral distance, and frequency-dependent behavior of P and Pdiff phases. The results for Pdiff waves are displayed by projecting the measured travel time anomalies onto the phase's nominal grazing segments along the core-mantle boundary.

  15. Recriticality in a BWR (boiling water reactor) following a core damage event

    SciTech Connect

    Scott, W.B.; Harrison, D.G.; Libby, R.A.; Tokarz, R.D. ); Wooton, R.D.; Denning, R.S.; Tayloe, R.W. Jr. )

    1990-12-01

    This report describes the results of a study conducted by Pacific Northwest Laboratory to assist the US Nuclear Regulatory Commission in evaluating the potential for recriticality in boiling water reactors (BWRs) during certain low probability severe accidents. Based on a conservative bounding analysis, this report concludes that there is a potential for recriticality in BWRs if core reflood occurs after control blade melting has begun but prior to significant fuel rod melting. However, a recriticality event will most likely not generate a pressure pulse significant enough to fail the vessel. Instead, a quasi-steady power level would result and the containment pressure and temperature would increase until the containment failure pressure is reached, unless actions are taken to terminate the event. Two strategies are identified that would aid in regaining control of the reactor and terminate the recriticality event before containment failure pressures are reached. The first strategy involves initiating boration injection at or before the time of core reflood if the potential for control blade melting exists. The second strategy involves initiating residual heat removal suppression pool cooling to remove the heat load generated by the recriticality event and thus extend the time available for boration. 31 figs., 17 tabs.

  16. Modeling of Viscoelastic Properties of Porous Rocks Saturated with Viscous Fluid at Seismic Frequencies at the Core Scale

    NASA Astrophysics Data System (ADS)

    Schmitt, D. R.; Wang, Z.; Wang, F.; Wang, R.

    2015-12-01

    Currently the moduli and velocities of rocks at seismic frequencies are usually measured by the strain-stress method in lab. However, such measurements require well-designed equipment and skilled technicians, which greatly hinders the experimental investigation on the elastic and visco-elastic properties of rocks at seismic frequencies. We attempt to model the dynamic moduli of porous rocks saturated with viscous fluid at seismic frequencies on core scale using the strain-stress method, aiming to provide a complement to real core measurements in lab. First, we build 2D geometrical models containing the pore structure information of porous rocks based on the digital images (such as thin section, SEM, CT, etc.) of real rocks. Then we assume the rock frames are linearly elastic, and use the standard Maxwell spring-dash pot model to describe the visco-elastic properties of pore fluids. Boundary conditions are set according to the strain-stress method; and the displacement field is calculated using the finite element method (FEM). We numerically test the effects of fluid viscosity, frequency, and pore structure on the visco-elastic properties based on the calculation results. In our modeling, the viscosity of the pore fluid ranges from 103mPas to 109mPas; and the frequency varies from 5Hz to 500Hz. The preliminary results indicate that the saturated rock behaves stiffer and shows larger phase lag between stress and strain when the viscosity of the pore fluid and (or) the frequency increase.

  17. Model for vortex-core tunneling spectroscopy of chiral p-wave superconductors via odd-frequency pairing states.

    PubMed

    Tanuma, Yasunari; Hayashi, Nobuhiko; Tanaka, Yukio; Golubov, Alexander A

    2009-03-20

    The local density of states is studied theoretically in terms of the odd-frequency (odd-omega) Cooper pairing induced around a vortex core. We find that a zero energy peak in the density of states at the vortex center is robust against nonmagnetic impurities in a chiral p-wave superconductor owing to an odd-omega s-wave pair amplitude. We suggest how to discriminate a spin-triplet pairing symmetry and spatial chiral-domain structure by scanning tunneling spectroscopy via odd-omega pair amplitudes inside vortex cores.

  18. The Orbital Checkout Status of the Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core observatory

    NASA Astrophysics Data System (ADS)

    Miura, Takeshi; Kojima, Masahiro; Furukawa, Kinji; Hyakusoku, Yasutoshi; Ishikiri, Takayuki; Kai, Hiroki; Iguchi, Toshio; Hanado, Hiroshi; Nakagawa, Katsuhiro

    2014-05-01

    The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core observatory is developed by Japan Aerospace Exploration Agency (JAXA) with National Institute of Information and Communications Technology (NICT). GPM objective is to observe global precipitation more frequently and accurately. GPM contributes to climate and water cycle change studies, flood prediction and numerical weather forecast. GPM consists of the GPM core observatory and constellation satellites carrying microwave radiometers (MWRs) and/or sounders (MWSs). The frequent measurement will be achieved by constellation satellites, and the accurate measurement will be achieved by the DPR with high sensitivity and dual frequency capability. The GPM core observatory is jointly developed by National Aeronautics and Space Administration (NASA) and JAXA. NASA is developing the satellite bus and GPM microwave radiometer (GMI), and JAXA is developing the DPR. The DPR consists of Ku-band (13.6 GHz) radar suitable for heavy rainfall in the tropical region, and Ka-band (35.55 GHz) radar suitable for light rainfall in higher latitude region. Drop size distribution information will be derived which contributes to the improvement of rainfall estimate accuracy. DPR will also play a key role to improve rainfall estimation accuracy of constellation satellites. DPR proto-flight test at JAXA Tsukuba space center has been completed in February 2012. The DPR has handed over to NASA and integrated to the core observatory in May 2012. The system test of the core observatory has completed in November 2013 and DPR test results satisfied its system requirements. The core observatory was shipped to launch site of JAXA Tanegashima space center in Japan. Launch site activities have started on November 2013 and GPM core observatory will be launched in early 2014. DPR orbital check out will be started in March 2014 and it will be completed in April 2014. In this presentation, the orbital check out

  19. The effect of age, gender, diet and lifestyle on DNA damage measured using micronucleus frequency in human peripheral blood lymphocytes.

    PubMed

    Fenech, Michael; Bonassi, Stefano

    2011-01-01

    Micronucleus (MN) frequency in cytokinesis-blocked peripheral blood lymphocytes (PBL) has become one of the best-established biomarkers for studying DNA damage occurring in vivo in humans. The application of this method in population biomonitoring studies requires a deep understanding of how lifestyle and common host variables may influence MN frequency in PBL. In this mini-review, an update is provided on results from studies reporting on the impact of age, gender, diet and lifestyle factors (e.g. exercise, alcohol, smoking and recreational drugs) on this biomarker. Evidence from these studies shows that each of these factors, either in isolation or in combination, can significantly influence MN frequency. Proper control for these factors is required to enable better measurement of the impact of other conditions, such as environmental exposure to genotoxins or a susceptible genetic background, on MN frequency in PBL.

  20. Extremely low-frequency electromagnetic fields do not affect DNA damage and gene expression profiles of yeast and human lymphocytes.

    PubMed

    Luceri, Cristina; De Filippo, Carlotta; Giovannelli, Lisa; Blangiardo, Marta; Cavalieri, Duccio; Aglietti, Filippo; Pampaloni, Monica; Andreuccetti, Daniele; Pieri, Lapo; Bambi, Franco; Biggeri, Annibale; Dolara, Piero

    2005-09-01

    We studied the effects of extremely low-frequency (50 Hz) electromagnetic fields (EMFs) on peripheral human blood lymphocytes and DBY747 Saccharomyces cerevisiae. Graded exposure to 50 Hz magnetic flux density was obtained with a Helmholtz coil system set at 1, 10 or 100 microT for 18 h. The effects of EMFs on DNA damage were studied with the single-cell gel electrophoresis assay (comet assay) in lymphocytes. Gene expression profiles of EMF-exposed human and yeast cells were evaluated with DNA microarrays containing 13,971 and 6,212 oligonucleotides, respectively. After exposure to the EMF, we did not observe an increase in the amount of strand breaks or oxidated DNA bases relative to controls or a variation in gene expression profiles. The results suggest that extremely low-frequency EMFs do not induce DNA damage or affect gene expression in these two different eukaryotic cell systems.

  1. Using CdTe/ZnSe core/shell quantum dots to detect DNA and damage to DNA.

    PubMed

    Moulick, Amitava; Milosavljevic, Vedran; Vlachova, Jana; Podgajny, Robert; Hynek, David; Kopel, Pavel; Adam, Vojtech

    2017-01-01

    CdTe/ZnSe core/shell quantum dot (QD), one of the strongest and most highly luminescent nanoparticles, was directly synthesized in an aqueous medium to study its individual interactions with important nucleobases (adenine, guanine, cytosine, and thymine) in detail. The results obtained from the optical analyses indicated that the interactions of the QDs with different nucleobases were different, which reflected in different fluorescent emission maxima and intensities. The difference in the interaction was found due to the different chemical behavior and different sizes of the formed nanoconjugates. An electrochemical study also confirmed that the purines and pyrimidines show different interactions with the core/shell QDs. Based on these phenomena, a novel QD-based method is developed to detect the presence of the DNA, damage to DNA, and mutation. The QDs were successfully applied very easily to detect any change in the sequence (mutation) of DNA. The QDs also showed their ability to detect DNAs directly from the extracts of human cancer (PC3) and normal (PNT1A) cells (detection limit of 500 pM of DNA), which indicates the possibilities to use this easy assay technique to confirm the presence of living organisms in extreme environments.

  2. Using CdTe/ZnSe core/shell quantum dots to detect DNA and damage to DNA

    PubMed Central

    Moulick, Amitava; Milosavljevic, Vedran; Vlachova, Jana; Podgajny, Robert; Hynek, David; Kopel, Pavel; Adam, Vojtech

    2017-01-01

    CdTe/ZnSe core/shell quantum dot (QD), one of the strongest and most highly luminescent nanoparticles, was directly synthesized in an aqueous medium to study its individual interactions with important nucleobases (adenine, guanine, cytosine, and thymine) in detail. The results obtained from the optical analyses indicated that the interactions of the QDs with different nucleobases were different, which reflected in different fluorescent emission maxima and intensities. The difference in the interaction was found due to the different chemical behavior and different sizes of the formed nanoconjugates. An electrochemical study also confirmed that the purines and pyrimidines show different interactions with the core/shell QDs. Based on these phenomena, a novel QD-based method is developed to detect the presence of the DNA, damage to DNA, and mutation. The QDs were successfully applied very easily to detect any change in the sequence (mutation) of DNA. The QDs also showed their ability to detect DNAs directly from the extracts of human cancer (PC3) and normal (PNT1A) cells (detection limit of 500 pM of DNA), which indicates the possibilities to use this easy assay technique to confirm the presence of living organisms in extreme environments. PMID:28243089

  3. Modeling and analysis framework for core damage propagation during flow-blockage-initiated accidents in the Advanced Neutron Source reactor at Oak Ridge National Laboratory

    SciTech Connect

    Kim, S.H.; Taleyarkhan, R.P.; Navarro-Valenti, S.; Georgevich, V.

    1995-12-31

    This paper describes modeling and analysis to evaluate the extent of core damage during flow blockage events in the Advanced Neutron Source (ANS) reactor planned to be built at ORNL. Damage propagation is postulated to occur from thermal conduction between dmaged and undamaged plates due to direct thermal contact. Such direct thermal contact may occur beause of fuel plate swelling during fission product vapor release or plate buckling. Complex phenomena of damage propagation were modeled using a one-dimensional heat transfer model. A parametric study was done for several uncertain variables. The study included investigating effects of plate contact area, convective heat transfer coefficient, thermal conductivity on fuel swelling, and initial temperature of the plate being contacted by the damaged plate. Also, the side support plates were modeled to account for their effects of damage propagation. Results provide useful insights into how variouss uncertain parameters affect damage propagation.

  4. Locating small structural damages in pipes using space-frequency DORT processing

    NASA Astrophysics Data System (ADS)

    Deng, Fei; Teixeira, Fernando L.

    A new imaging algorithm is introduced and applied for inspection of damages in pipes employing ultrasonic guided waves. The algorithm is based on the decomposition of the time-reversal operator (DORT, in its French acronym) and is demonstrated using both simulations and experiments. Its performance is compared against more traditional time-reversal imaging algorithms. The proposed algorithm is shown to be effective to determine the number and relative location of multiple small damages in pipes with good resolution.

  5. Systemic air embolism during percutaneous core needle biopsy of the lung: frequency and risk factors

    PubMed Central

    2012-01-01

    Background Detection of risk factors for an air embolism in the left atrium, left ventricle, or systemic circulation (systemic air embolism, SAE) during a percutaneous core needle biopsy (PCNB) of the thorax. Methods In a retrospective observational study, all PCNBs of the thorax in 610 patients between 2007 and 2009 were analyzed. The SmartStep™ technique (General Electric) was used for the biopsy, with which the examiner can prepare a batch of three 1.25-mm or 2.5-mm collimated slices within a second using a foot switch in the CT room to check the needle position. The image data thus generated and the control CT scans that followed were examined retrospectively for the presence of intravascular air. Intravascular air was defined as two or more adjacent voxels with absorption values of < -200 HU in the left atrium, left ventricle, aorta, or arteries during or after the procedure. The univariate statistical analysis of categorical variables was made using 2 by 2 tables and the Fisher test. The groups were compared using the Mann-Whitney test. Finally, a multivariate logistic regression analysis was used to identify independent risk factors for the occurrence of an SAE. Results The radiological incidence of an SAE during a PCNB was 3.8% (23/610 patients), whereas the clinically apparent incidence was 0.49%. Two patients developed clinical symptoms consisting of transient hemiplegia or transient amaurosis; one died due to a fatal SAE of the coronary arteries. The mortality was thus 0.16%. The depth of the needle in the lesion (Wald: 6.859), endotracheal anesthesia (Wald: 5.721), location of the lesion above the level of the left atrium (Wald: 5.159), and prone position of the patients (Wald: 4.317) were independent risk factors for the incidence of an SAE (p < 0.05 each). Using explorative criteria, the acute angle of the needle to the tumor surface, and the transition of ventilated lung were independent factors. The frequency of biopsies, needle penetration depth

  6. DERIVATION OF THE MAGNETIC FIELD IN A CORONAL MASS EJECTION CORE VIA MULTI-FREQUENCY RADIO IMAGING

    SciTech Connect

    Tun, Samuel D.; Vourlidas, A.

    2013-04-01

    The magnetic field within the core of a coronal mass ejection (CME) on 2010 August 14 is derived from analysis of multi-wavelength radio imaging data. This CME's core was found to be the source of a moving type IV radio burst, whose emission is here determined to arise from the gyrosynchrotron process. The CME core's true trajectory, electron density, and line-of-sight depth are derived from stereoscopic observations, constraining these parameters in the radio emission models. We find that the CME carries a substantial amount of mildly relativistic electrons (E < 100 keV) in a strong magnetic field (B < 15 G), and that the spectra at lower heights are preferentially suppressed at lower frequencies through absorption from thermal electrons. We discuss the results in light of previous moving type IV burst studies, and outline a plan for the eventual use of radio methods for CME magnetic field diagnostics.

  7. Frequency and Type of Situational Awareness Errors Contributing to Death and Brain Damage: A Closed Claims Analysis.

    PubMed

    Schulz, Christian M; Burden, Amanda; Posner, Karen L; Mincer, Shawn L; Steadman, Randolph; Wagner, Klaus J; Domino, Karen B

    2017-08-01

    Situational awareness errors may play an important role in the genesis of patient harm. The authors examined closed anesthesia malpractice claims for death or brain damage to determine the frequency and type of situational awareness errors. Surgical and procedural anesthesia death and brain damage claims in the Anesthesia Closed Claims Project database were analyzed. Situational awareness error was defined as failure to perceive relevant clinical information, failure to comprehend the meaning of available information, or failure to project, anticipate, or plan. Patient and case characteristics, primary damaging events, and anesthesia payments in claims with situational awareness errors were compared to other death and brain damage claims from 2002 to 2013. Anesthesiologist situational awareness errors contributed to death or brain damage in 198 of 266 claims (74%). Respiratory system damaging events were more common in claims with situational awareness errors (56%) than other claims (21%, P < 0.001). The most common specific respiratory events in error claims were inadequate oxygenation or ventilation (24%), difficult intubation (11%), and aspiration (10%). Payments were made in 85% of situational awareness error claims compared to 46% in other claims (P = 0.001), with no significant difference in payment size. Among 198 claims with anesthesia situational awareness error, perception errors were most common (42%), whereas comprehension errors (29%) and projection errors (29%) were relatively less common. Situational awareness error definitions were operationalized for reliable application to real-world anesthesia cases. Situational awareness errors may have contributed to catastrophic outcomes in three quarters of recent anesthesia malpractice claims.Situational awareness errors resulting in death or brain damage remain prevalent causes of malpractice claims in the 21st century.

  8. Soft Magnetic Films Made of Iron-Iron Oxide Core-Shell Nanocluster Impact for High Frequency Applications

    NASA Astrophysics Data System (ADS)

    Yao, Qi; Singh, M. Kaur T.; Souza, Ryan; Qiang, You

    2009-05-01

    High-frequency soft magnetic thin films, are increasingly in demand with rapid improvement and miniaturization in electromagnetic devices. To achieve high permeability in high frequency up to GHz, high resistivity, saturation magnetization and uniaxial anisotropy field are required. Accordingly, Fe/Ferrite core-shell nanocluster thin films are prepared at room temperature directly on the top of CMOS by novel energetic cluster impact. To avoid high-temperature field deposition or post-annealing, bias voltage up to 20 kV is applied to the oblique substrate to induce in-plane shape anisotropy. The high magnetic moment of Fe cores and the insulated Fe oxide shells jointly cause the combination of high saturation magnetization and high resistivity of the nanocluster thin films. Consequently, the thin films exhibit high permeabilities in up to 1.5 GHz, which are measured by a shorted transmission-line perturbation method. Moreover, the core fraction and the surface density are adjusted, which shows remarkable effects on the thin films' high-frequency permeabilities.

  9. [Characteristics, frequency and factors present in nipples damage occurence in lactating women].

    PubMed

    Shimoda, Gilcéria Tochika; Silva, Isilia Aparecida; Santos, Jair Lício Ferreira

    2005-01-01

    Our objectives were to verify the occurrence of nipple damage, according to the newborn and mother characteristics; to characterize the suction pattern of newborn, whose mothers present nipple damage. The sample was of 1020 lactating women and their infants, and of them, 84 were followed up by the researcher. It was verified that the gestational age of the newborn, the skin color, parity and the type of anesthesia received by the mothers during the labor were statistically significant for the occurrence of nipple damage. Only 5.95% of the newborn revealed appropriate grasp and dynamic suction, increasing to 43.33% at the first appointment after hospital discharge. The most of women presented complete healing of lesion from 5 to 6 days postpartum, this indicate that this period of a week is critical, when the mother needs stimulation and follow-up to the maintainance of lactation.

  10. Tornado risk analysis at Savannah River Plant using windspeed damage thresholds and single building strike frequencies

    SciTech Connect

    Taylor, D.H.; McDonald, J.R.; Twisdale, L.A.

    1985-01-01

    In order to evaluate the safety of existing structures and properly design new structures, an analysis of tornado resistance was conducted on each process building at SRP and other buildings by type. Damage estimates were cataloged for each Fujita class windspeed interval and windspeeds were cataloged as a function of increased levels of damage. The probability, for any structure, of a tornado exceeding each windspeed threshold was calculated using the TORRISK computer code which was developed for calculating the probability of a tornado strike on nuclear power generating plants.

  11. Sub-frequency range stress wave factor NDE technique for assessing damage in fiber-epoxy composites

    NASA Astrophysics Data System (ADS)

    Hong, Gang

    This research aims at modifying, improving and calibrating the Stress Wave Factor Nondestructive Evaluation (SWF NDE) technique and applying it to a fiber epoxy composite material and other composite structures. In order to access the composite's integrity the Energy of SWF within a selected Sub Frequency Range (SFR) instead of the whole measured frequency range as of conventional SWF is used. This technique, introduced and examined herein and is termed the Sub Frequency Range Stress Wave Factors (SFR-SWF) and is tailored to improve the conventional SWF technique with respect to sensibility and accuracy. A series of controlled damage tests were performed, and relevant acousto-ultrasonic observations were conducted. The overall property of the composites subjected to hygrothermal degradation, the localized defects such as the surface crack and the historical damage were assessed with conventional SWF and SFR-SWF. The two methods are compared in detail. The hygrothermal degradation and surface crack experiments were also simulated using the finite element method. Dynamic numerical analysis was conducted to simulate the wave propagation process, both in time domain and frequency domain using the commercial finite element code ABAQUS. The numerical results were also evaluated via both SWF and SFR-SWF, and were compared with the results of experiments. Thus, the potential of SFR-SWF was evaluated. A general conclusion from this research is that the SFR-SWF has the better capability than that of the conventional SWF in assessing the composite's overall condition, localized defects and historical damage. Since there are still open questions regarding the physical understanding of the SWF and SFR-SWF, the finite element analysis provides confirmation for certain observed behaviors of the Acousto-Ultrasonic and SFR-SWF technique.

  12. Frequency-dependent tidal dissipation in a viscoelastic Saturnian core and expansion of Mimas' semi-major axis

    NASA Astrophysics Data System (ADS)

    Shoji, D.; Hussmann, H.

    2017-03-01

    Context. Regarding tidal dissipation in Saturn, usually parameterized by Saturn's quality factor Q, there remains a discrepancy between conventional estimates and the latest determination that has been derived from astrometric observations of Saturn's inner satellites. If dissipation in Saturn is as large as the astrometric observations suggest, and is independent of time and tidal frequency, conventional models predict that Mimas' initial orbit should be located inside Saturn's synchronous orbit or even inside its Roche limit, in contradiction to formation models. Aims: Using simple structure models and assuming Saturn's core to be viscoelastic, we look for dissipation models which are consistent with both the latest astrometric observations and with Mimas' orbital migration. Methods: Firstly, using a two-layer model of Saturn's interior structure, we constrain the ranges of rigidity and viscosity of Saturn's core which are consistent with Saturn's dissipation derived from astrometric observations at the tidal frequencies of Enceladus, Tethys, and Dione. Next, within the constrained viscosity and rigidity ranges, we calculate Mimas' semi-major axis considering the frequency dependence of viscoelastic dissipation in Saturn's core. By the two calculations, we evaluate (1) Saturnian models which can explain the astrometrically determined Saturnian dissipation, and (2) whether Mimas' initial semi-major axis is larger than the synchronous orbit. Results: We show that if the core is assumed to be solid with a viscosity of 1013-1014 Pa s (depending on its size), the lower boundary of the observed Saturnian dissipation at tidal frequencies of Enceladus, Tethys, and Dione (k2s/Qs 4 × 10-5 where k2s is Saturn's second degree Love number and Qs its quality factor) can be explained by our model. In this viscosity range, Mimas can stay outside the synchronous orbit and the Roche limit for 4.5 billion years of evolution. Conclusions: In the case of a frequency dependent

  13. Decreased Pulmonary Damage in Primates With Inhalation Injury Treated with High-Frequency Ventilation.

    DTIC Science & Technology

    1993-09-01

    these events? A couple of practical questions: How did you control the DR. JOSEPH M. CIVETTA (Miami, Florida): I wish to com- central core temperature...this ventilatory mode. meet conventional requirements for ventilatory support. Pa- Dr. Civetta asked about the inspired oxygen concentration tients

  14. Lobular neoplasia diagnosed on breast Core biopsy: frequency of carcinoma on excision and implications for management.

    PubMed

    Calhoun, Benjamin C; Collie, Angela M B; Lott-Limbach, Abberly A; Udoji, Esther N; Sieck, Leah R; Booth, Christine N; Downs-Kelly, Erinn

    2016-12-01

    The appropriate follow-up and treatment for patients with a core biopsy diagnosis of lobular neoplasia (atypical lobular hyperplasia or lobular carcinoma in situ) remains controversial. Several studies have attempted to address this issue, with recommendations ranging from close clinical follow-up or surveillance to mandatory surgical excision in all cases. We report the findings at our institution, where virtually every core needle biopsy diagnosis of lobular neoplasia results in follow-up excision. The goal of the study was to identify potential predictors of upgrade to a more significant lesion. We identified 76 patients over a 15-year period with a core biopsy diagnosis of pure lobular neoplasia and no other high-risk lesions. Subsequent surgical excision identified 10 cases (13%) that were upgraded to carcinoma. Upgrade diagnoses included invasive ductal carcinoma (n=1), invasive lobular carcinoma (n=4), ductal carcinoma in situ (n=3), and pleomorphic lobular carcinoma in situ (n=2). All 10 upgraded cases had imaging findings suspicious for malignancy including irregular masses, asymmetric densities, or pleomorphic calcifications. Of the 10 upgraded cases, 7 were diagnosed as lobular carcinoma in situ on core biopsy. The data support a role for radiologic-pathologic correlation in the evaluation of suspicious breast lesions and suggest that the extent of lobular neoplasia in core biopsy specimens may be an indicator of the likelihood of upgrade to carcinoma.

  15. Extremely low-frequency magnetic fields can impair spermatogenesis recovery after reversible testicular damage induced by heat.

    PubMed

    Tenorio, Bruno Mendes; Ferreira Filho, Moisés Bonifacio Alves; Jimenez, George Chaves; de Morais, Rosana Nogueira; Peixoto, Christina Alves; Nogueira, Romildo de Albuquerque; da Silva Junior, Valdemiro Amaro

    2014-06-01

    Male infertility is often related to reproductive age couples experiencing fertility-related issues. Men may have fertility problems associated with reversible testicular damage. Considering that men have been increasingly exposed to extremely low-frequency magnetic fields generated by the production, distribution and use of electricity, this study analyzed whether 60 Hz and 1 mT magnetic field exposure may impair spermatogenesis recovery after reversible testicular damage induced by heat shock using rats as an experimental model. Adult male rats were subjected to a single testicular heat shock (HS, 43 °C for 12 min) and then exposed to the magnetic field for 15, 30 and 60 d after HS. Magnetic field exposure during the spermatogenesis recovery induced changes in testis components volume, cell ultrastructure and histomorphometrical parameters. Control animals had a reestablished and active spermatogenesis at 60 d after heat shock, while animals exposed to magnetic field still showed extensive testicular degeneration. Magnetic field exposure did not change the plasma testosterone. In conclusion, extremely low-frequency magnetic field may be harmful to fertility recovery in males affected by reversible testicular damage.

  16. A new generation of CMOS-compatible high frequency micro-inductors with ferromagnetic cores: Theory, fabrication and characterisation

    NASA Astrophysics Data System (ADS)

    Seemann, K.; Leiste, H.; Bekker, V.

    2006-07-01

    A new generation of CMOS-compatible micro-inductor prototypes with magnetic cores were realized, characterised as well as theoretically modelled in a frequency range up to 4 GHz, a frequency range where, e.g., mobile communication and global positioning systems (GPS) are operated. The micro-inductor's electrical magnitudes like inductance ( L) and quality factor ( Q) were theoretically described by means of an equivalent circuit model taking the frequency behaviour of the magnetic film core, expressed by the Landau-Lifschitz and Maxwell equations, into account. Six inch targets were used to deposit metallic layers (Al 99Si 0.5Cu 0.5), diffusion barriers (Si 3N 4), insulating layers (SiO 2) and magnetic films (Fe 39Co 30Ta 8N 23) by DC or reactive r.-f.-magnetron sputtering. All film materials were patterned by NUV-lithography (Near Ultra Violet), plasma beam milling and reactive ion etching to form the micro-inductors on 4-inch silicon wafers. The inductor windings are arranged in a way that they possess a low resistance and generate a quasi closed flux at the end of the cores to minimise eddy current losses in the silicon substrate. In order to diminish demagnetising effects in an efficient working core the magnetic films were patterned into micro squares with lateral dimensions of 20 and 100 μm with 100 nm in thickness. More magnetic volume and a higher micro-inductor cross-section was achieved by producing 100 nm magnetic double layers separated by a 800 nm thick Si 3N 4 inter-layer. To guarantee a sufficiently high cut-off frequency of the magnetic films, they were annealed in a static magnetic field at a temperature of 400 °C for uniaxial anisotropy induction. This represents a temperature treatment where aluminium CMOS processes take place. As a result of patterning, the magnetic film material exhibited a remarkable increase of the cut-off frequency from 2 GHz in laterally extended films up to 3.2 GHz which could be also observed in the measured frequency

  17. [Damage to a hip endoprosthesis caused by high-frequency electrocautery].

    PubMed

    Huber, G; Weik, T; Morlock, M M

    2009-07-01

    Contact between high-frequency cauterising instruments and metal endoprostheses can cause visible flashovers. The resulting local heating might partially transform the microstructure of the prostheses. In the present case a flashover to the in situ titanium hip endoprosthesis during the revision of a fractured ceramic head decreased the fatigue strength of the prosthesis and ultimately caused its failure. During revision surgery it is essential to prevent contact between in situ metal components and high-frequency cauterising instruments.

  18. The frequency of poly(G) tracts in the human genome and their use as a sensor of DNA damage.

    PubMed

    Murray, Vincent

    2015-02-01

    Tandem repeats of short DNA sequences are commonly found in human DNA. These simple sequence repeats or microsatellites are highly polymorphic in the human genome. Since the anti-tumour agent cisplatin preferentially forms DNA adducts at runs of consecutive guanine nucleotides (poly(G)), the position and frequency of occurrence of poly(G) sequences in the updated human genome was investigated. There are more runs of consecutive guanines than would be expected by random chance. This especially true for poly(G) sequences longer than approximately n=9. A plot of poly(G) length against log(observed/expected) frequency produced a straight line for n>9. A similar observation was also found for poly(A) DNA sequence repeats. This data implied that the increase in observed/expected frequency is directly related to length of DNA repeat. It was proposed that long runs of consecutive guanine nucleotides could be a sensitive sensor of cellular DNA damage since a number of DNA damaging agents cause lesions at poly(G) sequences.

  19. Development of a multi-frequency diffuse photon density wave device for the characterization of tissue damage at multiple depths

    NASA Astrophysics Data System (ADS)

    Diaz, David; Weingarten, Michael S.; Neidrauer, Michael T.; Samuels, Joshua A.; Huneke, Richard B.; Kuzmin, Vladimir L.; Lewin, Peter A.; Zubkov, Leonid A.

    2014-02-01

    The ability to determine the depth and degree of cutaneous and subcutaneous tissue damage is critical for medical applications such as burns and pressure ulcers. The Diffuse Photon Density Wave (DPDW) methodology at near infrared wavelengths can be used to non-invasively measure the optical absorption and reduced scattering coefficients of tissue at depths of several millimeters. A multi-frequency DPDW system with one light source and one detector was constructed so that light is focused onto the tissue surface using an optical fiber and lens mounted to a digitally-controlled actuator which changes the distance between light source and detector. A variable RF generator enables the modulation frequency to be selected between 50 to 400MHz. The ability to digitally control both source-detector separation distance and modulation frequency allows for virtually unlimited number of data points, enabling precise selection of the volume and depth of tissue that will be characterized. Suspensions of Intralipid and india ink with known absorption and reduced scattering coefficients were used as optical phantoms to assess device accuracy. Solid silicon phantoms were formulated for stability testing. Standard deviations for amplitude and phase shift readings were found to be 0.9% and 0.2 degrees respectively, over a one hour period. The ability of the system to quantify tissue damage in vivo at multiple depths was tested in a porcine burn model.

  20. Damage detection in multi-span beams based on the analysis of frequency changes

    NASA Astrophysics Data System (ADS)

    Gillich, G. R.; Ntakpe, J. L.; Abdel Wahab, M.; Praisach, Z. I.; Mimis, M. C.

    2017-05-01

    Crack identification in multi-span beams is performed to determine whether the structure is healthy or not. Among all crack identification methods, these based on measured natural frequency changes present the advantage of simplicity and easy to use in practical engineering. To accurately identify the cracks characteristics for multi-span beam structure, a mathematical model is established, which can predict frequency changes for any boundary conditions, the intermediate supports being hinges. This relation is based on the modal strain energy concept. Since frequency changes are relative small, to obtain natural frequencies with high resolution, a signal processing algorithm based on superposing of numerous spectra is also proposed, which overcomes the disadvantage of Fast Fourier Transform in the aspect of frequency resolution. Based on above-mentioned mathematical model and signal processing algorithm, the method of identifying cracks on multi-span beams is presented. To verify the accuracy of this identification method, experimental examples are conducted on a two-span structure. The results demonstrate that the method proposed in this paper can accurately identify the crack position and depth.

  1. Monte Carlo simulation of dynamic phase transitions and frequency dispersions of hysteresis curves in core/shell ferrimagnetic cubic nanoparticle

    NASA Astrophysics Data System (ADS)

    Vatansever, Erol

    2017-05-01

    By means of Monte Carlo simulation method with Metropolis algorithm, we elucidate the thermal and magnetic phase transition behaviors of a ferrimagnetic core/shell nanocubic system driven by a time dependent magnetic field. The particle core is composed of ferromagnetic spins, and it is surrounded by an antiferromagnetic shell. At the interface of the core/shell particle, we use antiferromagnetic spin-spin coupling. We simulate the nanoparticle using classical Heisenberg spins. After a detailed analysis, our Monte Carlo simulation results suggest that present system exhibits unusual and interesting magnetic behaviors. For example, at the relatively lower temperature regions, an increment in the amplitude of the external field destroys the antiferromagnetism in the shell part of the nanoparticle, leading to a ground state with ferromagnetic character. Moreover, particular attention has been dedicated to the hysteresis behaviors of the system. For the first time, we show that frequency dispersions can be categorized into three groups for a fixed temperature for finite core/shell systems, as in the case of the conventional bulk systems under the influence of an oscillating magnetic field.

  2. A three-phase three-winding core-type transformer model for low-frequency transient studies

    SciTech Connect

    Chen, X.; Venkata, S.S.

    1997-04-01

    A topology-based and duality-derived three-phase, three-winding, core-type transformer model is presented. The model treats the leakage inductances and the coupling effects of the core in a straightforward and integrated way. The long-established positive- and zero-sequence star equivalent circuits of a three-phase three-winding transformer are derived from the original equivalent magnetic circuit of the transformer by applying duality. Formulations for determining the values of the leakage inductances and the core loss resistances from transformer open- and short-circuit test data are presented. A supporting routine is written to generate the {lambda}-i curves for each segment of the core and the other input data for EMTP. Since the duality-derived model consists of only RLC elements, no device-specific code to EMTP time-step code is needed. Winding capacitances are lumped to the terminals. The model is suitable for simulation of power system low-frequency transients such as inrush currents and ferroresonance, short circuits, and abnormalities including transformer winding faults.

  3. Extremely Low Frequency Magnetic Fields Do Not Induce DNA Damage in Human Lens Epithelial Cells In Vitro.

    PubMed

    Zhu, Kan; Lv, Ye; Cheng, Qian; Hua, Jianing; Zeng, Qunli

    2016-05-01

    Non-ionizing radiations, e.g., radiofrequency electromagnetic fields, could induce DNA damage and oxidative stress in human lens epithelial cells (LECs) which can be early events in cataractogenesis. Extremely low frequency magnetic fields (ELF MF) as another common form of man-made electromagnetic fields has been considered as suspected human carcinogen by International Agency for Research on Cancer (IARC) and become a focus that people play more and more attentions to. This study aimed to determine whether ELF MF can induce DNA damage in cultured human LECs at a relatively low intensity. Human LECs were exposed or sham-exposed to a 50 Hz ELF MF which produced by a well-designed exposure system at the intensity of 0.4 mT. DNA damage in human LECs was examined by the phosphorylated form of histone variant H2AX (γH2AX) foci formation assay and further explored with western blot, flow cytometry, and alkaline comet assay. Immunofluorescence analysis showed that 0.4 mT ELF MF did not significantly increase γH2AX foci formation in human LECs after 2, 6, 12, 24, or 48 hr exposure. No significant differences had been detected in γH2AX expression level between the ELF MF- and sham-exposure groups, while no obvious chromosomal DNA fragmentation was detected by alkaline comet assay after ELF MF exposure. The results indicate an absence of genotoxicity in ELF MF-exposed human epithelial cells and do not support the hypothesis that environmental ELF MF might be causally led to genomic instability via chromosomal damage response processes. Neither short nor long term continuous exposure to 50 Hz ELF MF at 0.4 mT could induce DNA damage in human lens epithelial cells in vitro.

  4. 50-Hz extremely low frequency electromagnetic fields enhance cell proliferation and DNA damage: possible involvement of a redox mechanism.

    PubMed

    Wolf, Federica I; Torsello, Angela; Tedesco, Beatrice; Fasanella, Silvia; Boninsegna, Alma; D'Ascenzo, Marcello; Grassi, Claudio; Azzena, Gian Battista; Cittadini, Achille

    2005-03-22

    HL-60 leukemia cells, Rat-1 fibroblasts and WI-38 diploid fibroblasts were exposed for 24-72 h to 0.5-1.0-mT 50-Hz extremely low frequency electromagnetic field (ELF-EMF). This treatment induced a dose-dependent increase in the proliferation rate of all cell types, namely about 30% increase of cell proliferation after 72-h exposure to 1.0 mT. This was accompanied by increased percentage of cells in the S-phase after 12- and 48-h exposure. The ability of ELF-EMF to induce DNA damage was also investigated by measuring DNA strand breaks. A dose-dependent increase in DNA damage was observed in all cell lines, with two peaks occurring at 24 and 72 h. A similar pattern of DNA damage was observed by measuring formation of 8-OHdG adducts. The effects of ELF-EMF on cell proliferation and DNA damage were prevented by pretreatment of cells with an antioxidant like alpha-tocopherol, suggesting that redox reactions were involved. Accordingly, Rat-1 fibroblasts that had been exposed to ELF-EMF for 3 or 24 h exhibited a significant increase in dichlorofluorescein-detectable reactive oxygen species, which was blunted by alpha-tocopherol pretreatment. Cells exposed to ELF-EMF and examined as early as 6 h after treatment initiation also exhibited modifications of NF kappa B-related proteins (p65-p50 and I kappa B alpha), which were suggestive of increased formation of p65-p50 or p65-p65 active forms, a process usually attributed to redox reactions. These results suggest that ELF-EMF influence proliferation and DNA damage in both normal and tumor cells through the action of free radical species. This information may be of value for appraising the pathophysiologic consequences of an exposure to ELF-EMF.

  5. Loss of High Frequency Upon Propagation through Shock-Damaged Rock,

    DTIC Science & Technology

    1995-08-14

    which are pre-damaged by shock waves. EXPERIMENTAL TECHNIOUE: Sample Preparation The rock studied was San Marcos gabbro which has been studied previously...Ahrens and Rubin, 1993; Rubin and Ahrens, 1991] The density of San Marcos gabbro is 2.87 g/cm 3, and there is very low initial crack density...Initially a large gabbro target with dimensions 200x200x150 mm was impacted by a lead projectile at a velocity of 1.2 km/s, the projectile had a diameter of

  6. Geochemical characteristics of fault core and damage zones of the Hong-Che Fault Zone of the Junggar Basin (NW China) with implications for the fault sealing process

    NASA Astrophysics Data System (ADS)

    Liu, Yin; Wu, Kongyou; Wang, Xi; Pei, Yangwen; Liu, Bo; Guo, Jianxun

    2017-08-01

    Faults may have a complex internal structure, including fault core and damage zone, and can act as major conduits for fluid migration. The migration of fluids along faults is generally associated with strong fluid-rock interaction, forming large amounts of cement that fill in the fractures. The cementation of the fault fractures is considered to be one of the important parameters of fault sealing. The different components of faults have diverse geochemical features because of varying physical characteristics. The investigation of the geochemical characteristics of the fault and damage zones could provide important information about the fault sealing process, which is very important in oil and gas exploration. To understand the fault-cemented sealing process, detailed geochemical studies were conducted on the fault and damage zones of the Hong-Che Fault of the northwestern Junggar Basin in China. The major and trace element data of our study suggest that the fault core is characterized by higher loss on ignition (LOI), potassium loss, Chemical Index of Alteration (CIA), and Plagioclase Index of Alteration (PIA) values and lower high field strength element (HFSE), large-ion lithosphile element (LILE), and rare earth element (REE) concentrations compared with the damage zone, implying more serious elemental loss and weathering of the fault core compared with the damage zone during faulting. The carbon and oxygen isotope data reveal that the cement of the Hong-Che Fault Zone formed due to multiple sources of fluids. The fault core was mainly affected by deep sources of hydrothermal fluids. In combination with previous studies, we suggest a potential fault-cemented sealing process during the period of fault movement. The fault core acts as the fluid conduit during faulting. After faulting, the fault core is cemented and the damage zone becomes the major conduit for fluid migration. The cementation firstly occurs on two sides of the damage zone in the upper part of the

  7. Evaluation of early hearing damage in personal listening device users using extended high-frequency audiometry and otoacoustic emissions.

    PubMed

    Sulaiman, A H; Husain, R; Seluakumaran, K

    2014-06-01

    Although sound exposure from personal listening devices (PLDs) could potentially lead to noise-induced hearing loss (NIHL), the actual hearing risk associated with the use of these devices is still unclear. In this study, early hearing effects related to PLD usage were evaluated in 35 young adult PLD users (listening for >1 h/day, at >50% of the maximum volume setting of their devices) and their age- and sex-matched controls using a combination of conventional and extended high-frequency audiometry as well as transient-evoked otoacoustic emission (TEOAE) and distortion product of otoacoustic emission (DPOAE) measurements. The mean listening duration of the PLD users was 2.7 ± 1.0 h/day while their estimated average listening volume was 81.3 ± 9.0 dBA (free-field corrected). Typical signs of NIHL were not detected in the audiogram of PLD users and their audiometric thresholds at most of the conventional test frequencies (0.25-8 kHz) were comparable with those obtained from controls. However, compared with the controls, mean hearing thresholds of PLD users at many of the extended high-frequencies (9-16 kHz) were significantly higher. In addition, TEOAE and DPOAE amplitudes in users were reduced compared with controls. The deterioration of extended high-frequency thresholds and the decrease in DPOAE amplitudes were more evident in the users' right ears. These results indicate the presence of an early stage of hearing damage in the PLD user group. Preventive steps should be taken as the initial hearing damage in these users could eventually progress into permanent NIHL after many years of PLD use.

  8. Laser-induced breakdown and damage generation by nonlinear frequency conversion in ferroelectric crystals: Experiment and theory

    SciTech Connect

    Louchev, Oleg A.; Saito, Norihito; Wada, Satoshi; Hatano, Hideki; Kitamura, Kenji

    2013-11-28

    Using our experimental data for ns pulsed second harmonic generation (SHG) by periodically poled stoichiometric LiTaO{sub 3} (PPSLT) crystals, we consider in detail the mechanism underlying laser-induced damage in ferroelectric crystals. This mechanism involves generation and heating of free electrons, providing an effective kinetic pathway for electric breakdown and crystal damage in ns pulsed operation via combined two-photon absorption (TPA) and induced pyroelectric field. In particular, a temperature increase in the lattice of ≈1 K induced initially by ns SHG and TPA at the rear of operating PPSLT crystal is found to induce a gradient of spontaneous polarization generating a pyroelectric field of ≈10 kV/cm, accelerating free electrons generated by TPA to an energy of ≈10 eV, followed by impact ionization and crystal damage. Under the damage threshold for ns operation, the impact ionization does not lead to the avalanche-like increase of free electron density, in contrast to the case of shorter ps and fs pulses. However, the total number of collisions by free electrons, ≈10{sup 18} cm{sup −3} (generated during the pulse and accelerated to the energy of ≈10 eV), can produce widespread structural defects, which by entrapping electrons dramatically increase linear absorption for both harmonics in subsequent pulses, creating a positive feedback for crystal lattice heating, pyroelectric field and crystal damage. Under pulse repetition, defect generation starting from the rear of the crystal can propagate towards its center and front side producing damage tracks along the laser beam and stopping SHG. Theoretical analysis leads to numerical estimates and analytical approximation for the threshold laser fluence for onset of this damage mechanism, which agree well with our (i) experiments for the input 1064 nm radiation in 6.8 kHz pulsed SHG by PPSLT crystal, (ii) pulsed low frequency 532 nm radiation transmission experiments, and also (iii) with the data

  9. Radio frequency-mediated local thermotherapy for destruction of pancreatic tumors using Ni-Au core-shell nanowires

    NASA Astrophysics Data System (ADS)

    Hopkins, Xiaoping; Gill, Waqas Amin; Kringel, Rosemarie; Wang, Guankui; Hass, Jamie; Acharya, Suresh; Park, Jungrae; Tak Jeon, In; An, Boo Hyun; Lee, Ji Sung; Ryu, Jong Eun; Hill, Rod; McIlroy, David; Kim, Young Keun; Choi, Daniel S.

    2017-01-01

    We present a novel method of radio frequency (RF)-mediated thermotherapy in tumors by remotely heating nickel (Ni)-gold (Au) core-shell nanowires (CSNWs). Ectopic pancreatic tumors were developed in nude mice to evaluate the thermotherapeutic effects on tumor progression. Tumor ablation was produced by RF-mediated thermotherapy via activation of the paramagnetic properties of the Ni-Au CSNWs. Histopathology demonstrated that heat generated by RF irradiation caused significant cellular death with pyknotic nuclei and nuclear fragmentation dispersed throughout the tumors. These preliminary results suggest that thermotherapy ablation induced via RF activation of nanowires provides a potential alternative therapy for cancer treatment.

  10. Time-frequency analysis of electro-mechanical impedance (EMI) signature for physics-based damage detections using piezoelectric wafer active sensor (PWAS)

    NASA Astrophysics Data System (ADS)

    Zahedi, F.; Huang, H.

    2017-05-01

    This paper investigates the physical connections between the electromechanical impedance (EMI) signature and the time-domain pulse-echo signal. The EMI signature, acquired from a piezoelectric wafer transducer bonded on a structure, is frequently used for damage detections. Although the EMI signature is very sensitive to damage, it cannot provide any physical insight about the details of the damage, e.g. its type, location, etc. Moreover, legitimate condition changes such as thermal fluctuations may be mistaken as damage. In this paper, we demonstrate that the EMI signature is essentially a pulse-echo signal represented in the frequency domain. Therefore, analyzing the EMI signature in both the time and frequency domains enables us to perform physical-based damage detection and characterization. A digital signal processing algorithm was introduced to convert the frequency-domain EMI signature to a time-domain pulse-echo signal at any given excitation frequency. Analyzing the ‘resonant phase’ and the ‘echo phase’ of the time domain signal separately revealed that the resonance signal is more sensitive to the bonding conditions while the time-of-flight of the echo signal can be correlated to the damage location. In addition, the damage detection sensitivity is significantly enhanced when the damage indices are calculated from the spectra of the resonance and echo signals instead of the as-acquired raw EMI signature.

  11. Frequency tunability of solid-core photonic crystal fibers filled with nanoparticle-doped liquid crystals.

    PubMed

    Scolari, Lara; Gauza, Sebastian; Xianyu, Haiqing; Zhai, Lei; Eskildsen, Lars; Alkeskjold, Thomas T; Wu, Shin-Tson; Bjarklev, Anders

    2009-03-02

    We infiltrate liquid crystals doped with BaTiO3 nanoparticles in a photonic crystal fiber and compare the measured transmission spectrum with the one achieved without dopant. New interesting features, such as frequency modulation response of the device and a transmission spectrum with tunable attenuation on the short wavelength side of the widest bandgap, suggest a potential application of this device as a tunable all-in-fiber gain equalization filter with an adjustable slope. The tunability of the device is achieved by varying the amplitude and the frequency of the applied external electric field. The threshold voltage for doped and undoped liquid crystals in a silica capillary and in a glass cell are also measured as a function of the frequency of the external electric field and the achieved results are compared.

  12. Radio-Frequency Driven Dielectric Heaters for Non-Nuclear Testing in Nuclear Core Development

    NASA Technical Reports Server (NTRS)

    Sims, William Herbert, III (Inventor); Godfroy, Thomas J. (Inventor); Bitteker, Leo (Inventor)

    2004-01-01

    Apparatus and methods are provided through which a radio-frequency dielectric heater has a cylindrical form factor, a variable thermal energy deposition through variations in geometry and composition of a dielectric, and/or has a thermally isolated power input.

  13. Quantitative Characterisation of Fracturing Around the Damage Zone Surrounding New Zealand's Alpine Fault Using X-ray CT Scans of DFDP-1 Core

    NASA Astrophysics Data System (ADS)

    Williams, J. N.; Toy, V.; Massiot, C.; Mcnamara, D. D.; Wang, T.

    2015-12-01

    X-ray computer tomography (CT) scans of core recovered from the first phase of the Deep Fault Drilling Project (DFDP-1) through the Alpine Fault provide an excellent opportunity to analyse brittle deformation around the fault. In particular, assessment can be made of the heavily fractured protolith constituting the damage zone. Damage zone structures are divided into two types that result from two distinct processes: (1) "off fault damage" formed by stress changes induced by the passage of a seismic rupture and (2) "off fault deformation" that represent structures, which accommodate strain around the fault that was not localised on the principal slip zone (PSZ). The distribution of these damage zones structures within CT scans of the recovered core was measured along a scanline parallel to the core axis and assessed using a weighted moving average technique to account for orientation bias. The results of this analysis reveal that within the part of the fault rocks sampled by DFDP-1 there is no increase in density of these structures towards the PSZ. This is in agreement with independent analysis using Borehole Televiewer Data of the DFDP-1B borehole. Instead, we consider the density of these structures to be controlled to the first order by lithology, which modulates the mechanical properties of the fault rocks such as its frictional strength and cohesion. Comparisons of fracture density to p-wave velocities obtained from wireline logs indicate they are independent of each other, therefore, for the cores sampled in this study fractures impart no influence on the elastic properties of the rock. This is consistent with the observation from core that the majority of fractures are cemented. We consider how this might influence future rupture dynamics.

  14. Orbital checkout result of the dual-frequency precipitation radar on the global precipitation measurement core spacecraft

    NASA Astrophysics Data System (ADS)

    Furukawa, K.; Kojima, M.; Miura, T.; Hyakusoku, Y.; Kai, H.; Ishikiri, T.; Iguchi, T.; Hanado, H.; Nakagawa, K.; Okumura, M.

    2014-10-01

    The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core satellite was developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT). The GPM is a follow-on mission of the Tropical Rainfall Measuring Mission (TRMM). The objectives of the GPM mission are to observe global precipitation more frequently and accurately than TRMM. The frequent precipitation measurement about every three hours will be achieved by some constellation satellites with microwave radiometers (MWRs) or microwave sounders (MWSs), which will be developed by various countries. The accurate measurement of precipitation in mid-high latitudes will be achieved by the DPR. The GPM core satellite is a joint product of National Aeronautics and Space Administration (NASA), JAXA and NICT. NASA developed the satellite bus and the GPM Microwave Imager (GMI), and JAXA and NICT developed the DPR. JAXA and NICT developed the DPR through procurement. The contract for DPR was awarded to NEC TOSHIBA Space Systems, Ltd. The configuration of precipitation measurement using active radar and a passive radiometer is similar to TRMM. The major difference is that DPR is used in GPM instead of the precipitation radar (PR) in TRMM. The inclination of the core satellite is 65 degrees, and the flight altitude is about 407 km. The non-sun-synchronous circular orbit is necessary for measuring the diurnal change of rainfall similarly to TRMM. The DPR consists of two radars, which are Ku-band (13.6 GHz) precipitation radar (KuPR) and Ka-band (35.5 GHz) precipitation radar (KaPR). Both KuPR and KaPR have almost the same design as TRMM PR. The DPR system design and performance were verified through the development test and the proto flight test. DPR had handed over to NASA and integration of the DPR to the GPM core spacecraft had completed in May 2012. GPM core spacecraft satellite system test had completed in November 2013

  15. Facile Hydrothermal Synthesis of Fe3O4/C Core-Shell Nanorings for Efficient Low-Frequency Microwave Absorption.

    PubMed

    Wu, Tong; Liu, Yun; Zeng, Xiang; Cui, Tingting; Zhao, Yanting; Li, Yana; Tong, Guoxiu

    2016-03-23

    Using elliptical iron glycolate nanosheets as precursors, elliptical Fe3O4/C core-shell nanorings (NRs) [25 ± 10 nm in wall thickness, 150 ± 40 nm in length, and 1.6 ± 0.3 in long/short axis ratio] are synthesized via a one-pot hydrothermal route. The surface-poly(vinylpyrrolidone) (PVP)-protected-glucose reduction/carbonization/Ostwald ripening mechanism is responsible for Fe3O4/C NR formation. Increasing the glucose/precursor molar ratio can enhance carbon contents, causing a linear decrease in saturation magnetization (Ms) and coercivity (Hc). The Fe3O4/C NRs reveal enhanced low-frequency microwave absorption because of improvements to their permittivity and impedance matching. A maximum RL value of -55.68 dB at 3.44 GHz is achieved by Fe3O4/C NRs with 11.95 wt % C content at a volume fraction of 17 vol %. Reflection loss (RL) values (≤-20 dB) are observed at 2.11-10.99 and 16.5-17.26 GHz. Our research provides insights into the microwave absorption mechanism of elliptical Fe3O4/C core-shell NRs. Findings indicate that ring-like and core-shell nanostructures are promising structures for devising new and effective microwave absorbers.

  16. [Investigation of core Y-haplogroups frequency occuring in Moscow and Saint-Petersburg citizens].

    PubMed

    Fesenko, D O; Kalennik, O V; Grigor'eva, O O; Zasedatelev, A S; Nasedkina, T V

    2013-01-01

    A DNA collection of 239 Moscow and 62 SPB citizens has been investigated by means of a biochip for genotyping of Y-chromosome haplogroup markers: M130 (C), M145 (DE), P257 (G), M69 (H), U179 (I), M304 (J), M185 (L), M231 (N), M175 (0), P224 (R), L146 (R1a) and M343 (R1b). Haplogroup frequency distribution in populations native to Moscow and Saint-Petersburg has been obtained. Three subsamples varying in duration of residence (one, two or three generations) were compared. Increasing of J, G, R1b frequencies may be related to immigration from Caucasia and other regions.

  17. Frequency-domain assessment of gear-tooth bending-fatigue damage-progression using the average-log-ratio, ALR, algorithm

    NASA Astrophysics Data System (ADS)

    Mark, William D.; Hines, Jason A.

    2014-04-01

    Frequency-domain (rotational-harmonic) behavior of the average-log-ratio, ALR, gear-damage detection algorithm [MSSP 24 (2010) 2807-2823] [18] is utilized to explain behavior caused by tooth-bending-fatigue damage progression. For spur and helical gears, the strongest bending-fatigue damage contributions are typically found in the rotational-harmonic region below the tooth-meshing fundamental harmonic, where ALR increases almost monotonically with increasing damage. However, when the combined elastic/plastic deformation of a damaged tooth or teeth exceeds tooth tip/root/end relief magnitude, at tooth-contact initiation and/or termination, the lowest-order transmission-error discontinuity is changed from slope discontinuity to step discontinuity, resulting in transmission-error high-frequency (rotational-harmonic n) behavior changing from proportional to 1/n2 to proportional to 1/n, therefore indicating progression to severe damage. Decomposition of the ALR damage-detection metric into rotational-harmonic frequency bands using accelerometer recordings from a notched-tooth spiral-bevel gear test illustrates the above-described behavior, thereby showing increasing stages of damage progression prior to complete gear failure.

  18. Wide range tuning of resonant frequency for a vortex core in a regular triangle magnet

    PubMed Central

    Yakata, Satoshi; Tanaka, Terumitsu; Kiseki, Kohei; Matsuyama, Kimihide; Kimura, Takashi

    2013-01-01

    A magnetic vortex structure stabilized in a micron or nano-sized ferromagnetic disk has a strong potential as a unit cell for spin-based nano-electronic devices because of negligible magnetostatic interaction and superior thermal stability. Moreover, various intriguing fundamental physics such as bloch point reversal and symmetry breaking can be induced in the dynamical behaviors in the magnetic vortex. The static and dynamic properties of the magnetic vortex can be tuned by the disk dimension and/or the separation distance between the disks. However, to realize these modifications, the preparations of other devices with different sample geometries are required. Here, we experimentally demonstrate that, in a regular-triangle Permalloy dot, the dynamic properties of a magnetic vortex are greatly modified by the application of the in-plane magnetic field. The obtained wide range tunability based on the asymmetric position dependence of the core potential provides attractive performances in the microwave spintronic devices. PMID:24356511

  19. Wide range tuning of resonant frequency for a vortex core in a regular triangle magnet.

    PubMed

    Yakata, Satoshi; Tanaka, Terumitsu; Kiseki, Kohei; Matsuyama, Kimihide; Kimura, Takashi

    2013-12-20

    A magnetic vortex structure stabilized in a micron or nano-sized ferromagnetic disk has a strong potential as a unit cell for spin-based nano-electronic devices because of negligible magnetostatic interaction and superior thermal stability. Moreover, various intriguing fundamental physics such as bloch point reversal and symmetry breaking can be induced in the dynamical behaviors in the magnetic vortex. The static and dynamic properties of the magnetic vortex can be tuned by the disk dimension and/or the separation distance between the disks. However, to realize these modifications, the preparations of other devices with different sample geometries are required. Here, we experimentally demonstrate that, in a regular-triangle Permalloy dot, the dynamic properties of a magnetic vortex are greatly modified by the application of the in-plane magnetic field. The obtained wide range tunability based on the asymmetric position dependence of the core potential provides attractive performances in the microwave spintronic devices.

  20. Wide range tuning of resonant frequency for a vortex core in a regular triangle magnet

    NASA Astrophysics Data System (ADS)

    Yakata, Satoshi; Tanaka, Terumitsu; Kiseki, Kohei; Matsuyama, Kimihide; Kimura, Takashi

    2013-12-01

    A magnetic vortex structure stabilized in a micron or nano-sized ferromagnetic disk has a strong potential as a unit cell for spin-based nano-electronic devices because of negligible magnetostatic interaction and superior thermal stability. Moreover, various intriguing fundamental physics such as bloch point reversal and symmetry breaking can be induced in the dynamical behaviors in the magnetic vortex. The static and dynamic properties of the magnetic vortex can be tuned by the disk dimension and/or the separation distance between the disks. However, to realize these modifications, the preparations of other devices with different sample geometries are required. Here, we experimentally demonstrate that, in a regular-triangle Permalloy dot, the dynamic properties of a magnetic vortex are greatly modified by the application of the in-plane magnetic field. The obtained wide range tunability based on the asymmetric position dependence of the core potential provides attractive performances in the microwave spintronic devices.

  1. Radial scars diagnosed on breast core biopsy: Frequency of atypia and carcinoma on excision and implications for management.

    PubMed

    Donaldson, Alana R; Sieck, Leah; Booth, Christine N; Calhoun, Benjamin C

    2016-12-01

    The risk of finding carcinoma in excisions following a core needle biopsy diagnosis of radial scar is not well defined and clinical management is variable. The aim of this study is to determine the frequency of high-risk lesions, ductal carcinoma in situ, and invasive carcinoma in excisions following a core biopsy diagnosis of radial scar. Dedicated breast pathologists and radiologists correlated the histologic and radiologic findings and categorized radial scars as the target lesion or an incidental finding. High-risk lesions were defined as atypical hyperplasia or classical lobular carcinoma in situ. Of the 79 radial scars identified over a 14-year period, 22 were associated with atypia or carcinoma in the core biopsy. Thirty-seven (37) of the 57 benign radial scars underwent excision with benign findings in 30 (81%), high-risk lesions in six (16%), and flat epithelial atypia in one (3%). There were no upgrades to carcinoma. One patient with a benign radial scar developed a 3-mm focus of intermediate-grade estrogen receptor-positive ductal carcinoma in situ in the same quadrant of the ipsilateral breast 72 months after excision. One patient with an incidental un-excised benign radial scar was diagnosed with ductal carcinoma in situ at a separate site of suspicious calcifications. In this series, none of the benign radial scars was upgraded to carcinoma. Radial scar was the targeted lesion in all cases with high-risk lesions on excision. Surgical excision may not be mandatory for patients with benign incidental radial scars on core biopsy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Potential damage to DC superconducting magnets due to the high frequency electromagnetic waves

    NASA Technical Reports Server (NTRS)

    Gabriel, G. J.

    1977-01-01

    Experimental data are presented in support of the hypothesis that a dc superconducting magnet coil does not behave strictly as an inductor, but as a complicated electrodynamic device capable of supporting electromagnetic waves. Travel times of nanosecond pulses and evidence of sinusoidal standing waves were observed on a prototype four-layer solenoidal coil at room temperature. Ringing observed during switching transients appears as a sequence of multiple reflected square pulses whose durations are related to the layer lengths. With sinusoidal excitation of the coil, the voltage amplitude between a pair of points on the coil exhibits maxima at those frequencies such that the distance between these points is an odd multiple of half wavelength in free space. Evidence indicates that any disturbance, such as that resulting from switching or sudden fault, initiates multiple reflections between layers, thus raising the possibility for sufficiently high voltages to cause breakdown.

  3. Initial performance of the rain retrieval algorithm for the Dual-frequency Precipitation Radar on the GPM core satellite

    NASA Astrophysics Data System (ADS)

    Iguchi, Toshio; Seto, Shinta; Awaka, Jun; Meneghini, Robert; Kubota, Takuji; Chandra, V. Chandra; Yoshida, Naofumi; Urita, Shinji; Kwiatkowski, John; Hanado, Hiroshi

    2014-05-01

    The GPM core satellite is scheduled to be launched on February 28, 2014. This paper will report results of the early performance test of the Dual-Frequency Precipitation Radar (DPR) on the GPM core satellite in orbit. The DPR, which was developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT), consists of two radars: Ku-band precipitation radar (KuPR, 13.6 GHz) and Ka-band radar (KaPR, 35.5 GHz). KuPR is very similar to TRMM/PR, but its sensitivity is better than PR. The higher sensitivity is realized by the increase of the transmitting power and the increase of the independent samples. A technique of variable pulse repetition frequency (PRF) is used to optimize the sampling window for precipitation echoes and the number of independent samples. KaPR has a high sensitivity mode in order to detect light rain and some snow, which are predominant in high latitudes. The beams of KuPR and KaPR can be matched by adjusting the phase offset to each element of the phased array antenna in the across-track direction and the transmitting time offset between the two radars in the along-track direction. Beam matching is essential for the use of the dual-frequency algorithm to retrieve accurate rainfall rates. The hardware performance of DPR will be checked immediately after the launch. In addition to the basic characteristics of the radar such as the transmitting power, sensitivity, and resolutions, other characteristics peculiar to the DPR such as beam matching will be tested. The performance of the DPR algorithm will be evaluated by comparing the level 2 products with the corresponding TRMM/PR data in statistical ways. Such statistics include not only the radar reflectivity and rain rate histograms, but also precipitation detectability and rain classification.

  4. Fault core and damage zone fracture attributes vary along strike owing to interaction of fracture growth, quartz accumulation, and differing sandstone composition

    NASA Astrophysics Data System (ADS)

    Laubach, S. E.; Eichhubl, P.; Hargrove, P.; Ellis, M. A.; Hooker, J. N.

    2014-11-01

    Small, meter-to decimeter-displacement oblique-slip faults cut latest Precambrian lithic arkose to feldspathic litharenite and Cambrian quartz arenite sandstones in NW Scotland. Despite common slip and thermal histories during faulting, the two sandstone units have different fault-core and damage-zone attributes, including fracture length and aperture distributions, and location of quartz deposits. Fault cores are narrow (less than 1 m), low-porosity cataclasite in lithic arkose/feldspathic litharenites. Damage zone-parallel opening-mode fractures are long (meters or more) with narrow ranges of lengths and apertures, are mostly isolated, have sparse quartz cement, and are open. In contrast, quartz arenites, despite abundant quartz cement, have fault cores that contain porous breccia and dense, striated slip zones. Damage-zone fractures have lengths ranging from meters to centimeters or less, but with distributions skewed to short fractures, and have power-law aperture distributions. Owing to extensive quartz cement, they tend to be sealed. These attributes reflect inhibited authigenic quartz accumulation on feldspar and lithic grains, which are unfavorable precipitation substrates, and favored accumulation on detrital quartz. In quartz breccia, macropores >0.04 mm wide persist where surrounded by slow-growing euhedral quartz. Differences in quartz occurrence and size distributions are compatible with the hypothesis that cement deposits modify the probability of fracture reactivation. Existing fractures readily reactivate in focused growth where quartz accumulation is low and porosity high. Only some existing, partly cemented fractures reactivate and some deformation is manifest in new fracture formation in partitioned growth where quartz accumulation is high. Consequences include along-strike differences in permeability and locus of fluid flow between cores and damage zones and fault strength.

  5. An Ultrasonic Multiple-Access Ranging Core Based on Frequency Shift Keying Towards Indoor Localization.

    PubMed

    Segers, Laurent; Van Bavegem, David; De Winne, Sam; Braeken, An; Touhafi, Abdellah; Steenhaut, Kris

    2015-07-30

    This paper describes a new approach and implementation methodology for indoor ranging based on the time difference of arrival using code division multiple access with ultrasound signals. A novel implementation based on a field programmable gate array using finite impulse response filters and an optimized correlation demodulator implementation for ultrasound orthogonal signals is developed. Orthogonal codes are modulated onto ultrasound signals using frequency shift keying with carrier frequencies of 24.5 kHz and 26 kHz. This implementation enhances the possibilities for real-time, embedded and low-power tracking of several simultaneous transmitters. Due to the high degree of parallelism offered by field programmable gate arrays, up to four transmitters can be tracked simultaneously. The implementation requires at most 30% of the available logic gates of a Spartan-6 XC6SLX45 device and is evaluated on accuracy and precision through several ranging topologies. In the first topology, the distance between one transmitter and one receiver is evaluated. Afterwards, ranging analyses are applied between two simultaneous transmitters and one receiver. Ultimately, the position of the receiver against four transmitters using trilateration is also demonstrated. Results show enhanced distance measurements with distances ranging from a few centimeters up to 17 m, while keeping a centimeter-level accuracy.

  6. An Ultrasonic Multiple-Access Ranging Core Based on Frequency Shift Keying Towards Indoor Localization

    PubMed Central

    Segers, Laurent; Van Bavegem, David; De Winne, Sam; Braeken, An; Touhafi, Abdellah; Steenhaut, Kris

    2015-01-01

    This paper describes a new approach and implementation methodology for indoor ranging based on the time difference of arrival using code division multiple access with ultrasound signals. A novel implementation based on a field programmable gate array using finite impulse response filters and an optimized correlation demodulator implementation for ultrasound orthogonal signals is developed. Orthogonal codes are modulated onto ultrasound signals using frequency shift keying with carrier frequencies of 24.5 kHz and 26 kHz. This implementation enhances the possibilities for real-time, embedded and low-power tracking of several simultaneous transmitters. Due to the high degree of parallelism offered by field programmable gate arrays, up to four transmitters can be tracked simultaneously. The implementation requires at most 30% of the available logic gates of a Spartan-6 XC6SLX45 device and is evaluated on accuracy and precision through several ranging topologies. In the first topology, the distance between one transmitter and one receiver is evaluated. Afterwards, ranging analyses are applied between two simultaneous transmitters and one receiver. Ultimately, the position of the receiver against four transmitters using trilateration is also demonstrated. Results show enhanced distance measurements with distances ranging from a few centimeters up to 17 m, while keeping a centimeter-level accuracy. PMID:26263986

  7. Interpretation Of Multifrequency Crosswell Electromagnetic Data With Frequency Dependent Core Data

    SciTech Connect

    Kirkendall, B; Roberts, J

    2005-06-07

    Interpretation of cross-borehole electromagnetic (EM) images acquired at enhanced oil recovery (EOR) sites has proven to be difficult due to the typically complex subsurface geology. Significant problems in image interpretation include correlation of specific electrical conductivity values with oil saturations, the time-dependent electrical variation of the subsurface during EOR, and the non-unique electrical conductivity relationship with subsurface conditions. In this study we perform laboratory electrical properties measurements of core samples from the EOR site to develop an interpretation approach that combines field images and petrophysical results. Cross-borehole EM images from the field indicate resistivity increases in EOR areas--behavior contrary to the intended waterflooding design. Laboratory measurements clearly show a decrease in resistivity with increasing effective pressure and are attributed to increased grain-to-grain contact enhancing a strong surface conductance. We also observe a resistivity increase for some samples during brine injection. These observations possibly explain the contrary behavior observed in the field images. Possible mechanisms for increasing the resistivity in the region include (1) increased oil content as injectate sweeps oil toward the plane of the observation wells; (2) lower conductance pore fluid displacing the high-conductivity brine; (3) degradation of grain-to-grain contacts of the initially conductive matrix; and (4) artifacts of the complicated resistivity/time history similar to that observed in the laboratory experiments.

  8. Using ParaPost Tenax fiberglass and ParaCore build-up material to restore severely damaged teeth.

    PubMed

    Caicedo, Ricardo; Castellon, Paulino

    2005-01-01

    This article describes a technique using ParaPost Tenax Fiber White, ParaPost Cement, and ParaPost ParaCore build-up material to restore a tooth with a significant loss of tooth structure. After successful root canal therapy, the posts were bonded in the canals and the core was built using ParaPost ParaCore build-up material. At that point, the tooth was prepared to receive a conventional porcelain-fused-to-metal crown.

  9. Modeling of viscoelastic properties of nonpermeable porous rocks saturated with highly viscous fluid at seismic frequencies at the core scale

    NASA Astrophysics Data System (ADS)

    Wang, Zizhen; Schmitt, Douglas R.; Wang, Ruihe

    2017-08-01

    A core scale modeling method for viscoelastic properties of rocks saturated with viscous fluid at low frequencies is developed based on the stress-strain method. The elastic moduli dispersion of viscous fluid is described by the Maxwell's spring-dash pot model. Based on this modeling method, we numerically test the effects of frequency, fluid viscosity, porosity, pore size, and pore aspect ratio on the storage moduli and the stress-strain phase lag of saturated rocks. And we also compared the modeling results to the Hashin-Shtrikman bounds and the coherent potential approximation (CPA). The dynamic moduli calculated from the modeling are lower than the predictions of CPA, and both of these fall between the Hashin-Shtrikman bounds. The modeling results indicate that the frequency and the fluid viscosity have similar effects on the dynamic moduli dispersion of fully saturated rocks. We observed the Debye peak in the phase lag variation with the change of frequency and viscosity. The pore structure parameters, such as porosity, pore size, and aspect ratio affect the rock frame stiffness and result in different viscoelastic behaviors of the saturated rocks. The stress-strain phase lags are larger with smaller stiffness contrasts between the rock frame and the pore fluid. The viscoelastic properties of saturated rocks are more sensitive to aspect ratio compared to other pore structure parameters. The results suggest that significant seismic dispersion (at about 50-200 Hz) might be expected for both compressional and shear waves passing through rocks saturated with highly viscous fluids.Plain Language SummaryWe develop a <span class="hlt">core</span> scale modeling method to simulate the viscoelastic properties of rocks saturated with viscous fluid at low <span class="hlt">frequencies</span> based on the stress-strain method. The elastic moduli dispersion of viscous fluid is described by the Maxwell's spring-dash pot model. By using this modeling method, we numerically test</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4214743','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4214743"><span>Identifying the <span class="hlt">Core</span> Components of Emotional Intelligence: Evidence from Amplitude of Low-<span class="hlt">Frequency</span> Fluctuations during Resting State</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, Xiangpeng; Hitchman, Glenn; Wang, Lijun; Chen, Antao</p> <p>2014-01-01</p> <p>Emotional intelligence (EI) is a multi-faceted construct consisting of our ability to perceive, monitor, regulate and use emotions. Despite much attention being paid to the neural substrates of EI, little is known of the spontaneous brain activity associated with EI during resting state. We used resting-state fMRI to investigate the association between the amplitude of low-<span class="hlt">frequency</span> fluctuations (ALFFs) and EI in a large sample of young, healthy adults. We found that EI was significantly associated with ALFFs in key nodes of two networks: the social emotional processing network (the fusiform gyrus, right superior orbital frontal gyrus, left inferior frontal gyrus and left inferior parietal lobule) and the cognitive control network (the bilateral pre-SMA, cerebellum and right precuneus). These findings suggest that the neural correlates of EI involve several brain regions in two crucial networks, which reflect the <span class="hlt">core</span> components of EI: emotion perception and emotional control. PMID:25356830</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9061E..08C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9061E..08C"><span>A preliminary study on the prediction of <span class="hlt">damaged</span> areas on ordinary concrete and lightweight concrete using electromechanical impedance technique with different <span class="hlt">frequency</span> ranges</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cho, K. J.; Na, S.; Jang, J. G.; Lee, H. K.</p> <p>2014-03-01</p> <p>The electromechanical impedance (EMI) method for NDE uses a single piezoelectric material to act as an actuator and a sensor simultaneously, and the EMI method is suitable for structures with complex surfaces. However, this technique still has wide range of problems which needs to be investigated. For one, locating <span class="hlt">damaged</span> areas on a host structure precisely is known to be extremely difficult as this non-model based technique heavily relies on the variations in the impedance signatures. In this study, an attempt to locate the <span class="hlt">damaged</span> areas on an ordinary concrete panel and a lightweight concrete panel using bottom ash is carried out by using different <span class="hlt">frequency</span> ranges. Since the sensing range decreases as the excitation <span class="hlt">frequency</span> of piezoelectric material increases, one can possibly predict the <span class="hlt">damaged</span> areas by analyzing the impedance signatures from different <span class="hlt">frequency</span> ranges. Statistical analysis method such as root mean square deviation (RMSD) is applied to determine the changes of the experimental structures, and the RMSD values of low <span class="hlt">frequency</span> range and high <span class="hlt">frequency</span> range are compared to verify the relationship between the <span class="hlt">frequency</span> range and sensing range. Furthermore, the applicability of this method to locating the <span class="hlt">damaged</span> areas is investigated on various materials including the lightweight concrete.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApCM..tmp..104L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApCM..tmp..104L"><span>Synergistic Effects of <span class="hlt">Frequency</span> and Temperature on <span class="hlt">Damage</span> Evolution and Life Prediction of Cross-Ply Ceramic Matrix Composites under Tension-Tension Fatigue Loading</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Longbiao, Li</p> <p>2016-12-01</p> <p>In this paper, the synergistic effects of loading <span class="hlt">frequency</span> and testing temperature on the fatigue <span class="hlt">damage</span> evolution and life prediction of cross-ply SiC/MAS ceramic-matrix composite have been investigated. The <span class="hlt">damage</span> parameters of the fatigue hysteresis modulus, fatigue hysteresis dissipated energy and the interface shear stress were used to monitor the <span class="hlt">damage</span> evolution inside of SiC/MAS composite. The evolution of fatigue hysteresis dissipated energy, the interface shear stress and broken fibers fraction versus cycle number, and the fatigue life S-N curves of SiC/MAS composite under the loading <span class="hlt">frequency</span> of 1 and 10 Hz at 566 °C and 1093 °C in air condition have been predicted. The synergistic effects of the loading <span class="hlt">frequency</span> and testing temperature on the degradation rate of fatigue hysteresis dissipated energy and the interface shear stress have been analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18795035','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18795035"><span>Stabilized soliton self-<span class="hlt">frequency</span> shift and 0.1- PHz sideband generation in a photonic-crystal fiber with an air-hole-modified <span class="hlt">core</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Bo-Wen; Hu, Ming-Lie; Fang, Xiao-Hui; Li, Yan-Feng; Chai, Lu; Wang, Ching-Yue; Tong, Weijun; Luo, Jie; Voronin, Aleksandr A; Zheltikov, Aleksei M</p> <p>2008-09-15</p> <p>Fiber dispersion and nonlinearity management strategy based on a modification of a photonic-crystal fiber (PCF) <span class="hlt">core</span> with an air hole is shown to facilitate optimization of PCF components for a stable soliton <span class="hlt">frequency</span> shift and subpetahertz sideband generation through four-wave mixing. Spectral recoil of an optical soliton by a red-shifted dispersive wave, generated through a soliton instability induced by high-order fiber dispersion, is shown to stabilize the soliton self-<span class="hlt">frequency</span> shift in a highly nonlinear PCF with an air-hole-modified <span class="hlt">core</span> relative to pump power variations. A fiber with a 2.3-microm-diameter <span class="hlt">core</span> modified with a 0.9-microm-diameter air hole is used to demonstrate a robust soliton self-<span class="hlt">frequency</span> shift of unamplified 50-fs Ti: sapphire laser pulses to a central wavelength of about 960 nm, which remains insensitive to variations in the pump pulse energy within the range from 60 to at least 100 pJ. In this regime of <span class="hlt">frequency</span> shifting, intense high- and low-<span class="hlt">frequency</span> branches of dispersive wave radiation are simultaneously observed in the spectrum of PCF output. An air-hole-modified-<span class="hlt">core</span> PCF with appropriate dispersion and nonlinearity parameters is shown to provide efficient four-wave mixing, giving rise to Stokes and anti-Stokes sidebands whose <span class="hlt">frequency</span> shift relative to the pump wavelength falls within the subpetahertz range, thus offering an attractive source for nonlinear Raman microspectroscopy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SPIE.8190E..23W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SPIE.8190E..23W"><span>On the cooperativeness of nanosecond-laser induced <span class="hlt">damage</span> during <span class="hlt">frequency</span> doubling of 1064 nm light in KTiOPO4</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wagner, Frank; Duchateau, Guillaume; Hildenbrand, Anne; Natoli, Jean-Yves; Commandre, Mireille</p> <p>2011-12-01</p> <p>Due to its high nonlinear coefficients, KTP (KTiOPO4) is one of the most important nonlinear optical materials for <span class="hlt">frequency</span> doubling of Nd:YAG lasers. Former studies suggest a certain cooperativeness of the laser induced <span class="hlt">damage</span> mechanism between the 1064 nm and the 532 nm wavelengths present during second harmonic generation. We report on experiments that allow confirming and quantifying the cooperativeness of the laser <span class="hlt">damage</span> mechanism in this material and compare it to known data from KDP. A <span class="hlt">damage</span> scenario based on the formation of color centers, which are also responsible for the gray tracking effect, will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790023328','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790023328"><span>Analytical <span class="hlt">core</span> loss calculations for magnetic materials used in high <span class="hlt">frequency</span> high power converter applications. Ph.D. Thesis - Toledo Univ.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Triner, J. E.</p> <p>1979-01-01</p> <p>The basic magnetic properties under various operating conditions encountered in the state-of-the-art DC-AC/DC converters are examined. Using a novel <span class="hlt">core</span> excitation circuit, the basic B-H and loss characteristics of various <span class="hlt">core</span> materials may be observed as a function of circuit configuration, <span class="hlt">frequency</span> of operation, input voltage, and pulse-width modulation conditions. From this empirical data, a mathematical loss characteristics equation is developed to analytically predict the specific <span class="hlt">core</span> loss of several magnetic materials under various waveform excitation conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H12C..07T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H12C..07T"><span>Impacts of Light Precipitation Detection with Dual <span class="hlt">Frequency</span> Radar on Global Precipitation Measurement <span class="hlt">Core</span> Observatory (GPM/DPR)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takayabu, Y. N.; Hamada, A.; Oki, R.; Kachi, M.; Kubota, T.; Iguchi, T.; Shige, S.; Nakamura, K.</p> <p>2014-12-01</p> <p>The Dual-<span class="hlt">frequency</span> Precipitation Radar (DPR) on board the GPM <span class="hlt">Core</span> Observatory consists of Ku-band (13.6 GHz) and Ka-band (35.5 GHz) radars, with an improved minimum detection sensitivity of precipitation compared to the Tropical Rainfall Measuring Mission Precipitation Radar (TRMM PR). We have studied impacts of improved detection sensitivity with the GPM DPR compared with the TRMM PR. One example of light precipitation is, a scattered rainfall around a trough over the subtropical South Pacific Ocean, which consists of weak but erect precipitation reaching over the melting level of ~2.5 km and trailing precipitation above, which reaches as high as 5km. Another example is a light anvil precipitation spreading from convective <span class="hlt">cores</span> of a storm in the upper troposphere, overcasting shallow convective precipitation below. The ability of globally detecting such light precipitation will improve our knowledge of precipitation processes. Utilizing an early version of the DPR product, a quick evaluation on statistical impacts of increasing the detection sensitivity from 17dBZ to 12dBZ has been performed. Here, 17dBZ is the value which is mostly accepted as the performed detection sensitivity of the TRMM PR, and 12dBZ is the guaranteed sensitivity for GPM Ka-band radar. For the near surface precipitation, impacts are significant in terms of numbers, but limited to several regions in terms of the rainfall volume. Volume impacts are much larger at the upper troposphere, which is indicated by the detection of the anvil precipitation, for example. The upper level improvements are mostly found where the deep precipitation systems exist. Quantitative discussions utilizing the latest version of the DPR data, which is scheduled to be released to the public in September, will be presented at the session.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26152512','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26152512"><span>Enhanced cell-wall <span class="hlt">damage</span> mediated, antibacterial activity of <span class="hlt">core</span>-shell ZnO@Ag heterojunction nanorods against Staphylococcus aureus and Pseudomonas aeruginosa.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ponnuvelu, Dinesh Veeran; Suriyaraj, Shanmugam Prema; Vijayaraghavan, Thiruvenkatam; Selvakumar, Rajendran; Pullithadathail, Biji</p> <p>2015-07-01</p> <p>Hybrid ZnO@Ag <span class="hlt">core</span>-shell nanorods have been synthesized by a synthetic strategy based on seed mediated growth. Formation of <span class="hlt">core</span>-shell nanostructures was confirmed by UV- diffused reflectance spectroscopy (UV-DRS), X-ray diffraction studies, field emission scanning electron microscopy and high resolution transmission electron microscopy. UV-DRS analysis of hybrid <span class="hlt">core</span>-shell nanorods suggests the possibility of interfacial electron transfer between surface anchored Ag nanoclusters and ZnO nanorods. Successful decoration of Ag nanoclusters with an average diameter of ~7 ± 0.5 nm was observed forming the heterojunctions on the surface of the ZnO nanorods. An enhanced antibacterial property was observed for the ZnO@Ag <span class="hlt">core</span>-shell nanorods against both Staphylococcus aureus and Pseudomonas aeruginosa lbacteria. The synergetic antibacterial activity of ZnO@Ag nanorods was found to be more prominent against Gram-positive bacteria than Gram-negative bacteria. The plausible reason for this enhanced antibacterial activity of the <span class="hlt">core</span>-shell nanorods can be attributed to the physical <span class="hlt">damage</span> caused by the interaction of the material with outer cell wall layer due to the production of reactive oxygen species by interfacial electron transfer between ZnO nanorods and plasmonic Ag nanoclusters. Overall, the ZnO@Ag <span class="hlt">core</span>-shell nanorods were found to be promising materials that could be developed further as an effective antibacterial agent against wide range of microorganisms to control spreading and persistence of bacterial infections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/8643678','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/8643678"><span>Overexpression of a Rrp1 transgene reduces the somatic mutation and recombination <span class="hlt">frequency</span> induced by oxidative DNA <span class="hlt">damage</span> in Drosophila melanogaster.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Szakmary, A; Huang, S M; Chang, D T; Beachy, P A; Sander, M</p> <p>1996-02-20</p> <p>Recombination repair protein 1 (Rrp1) includes a C-terminal region homologous to several DNA repair proteins, including Escherichia coli exonuclease III and human APE, that repair oxidative and alkylation <span class="hlt">damage</span> to DNA. The nuclease activities of Rrp1 include apurinic/apyrimidinic endonuclease, 3'-phosphodiesterase, 3'-phosphatase, and 3'-exonuclease. As shown previously, the C-terminal nuclease region of Rrp1 is sufficient to repair oxidative- and alkylation-induced DNA <span class="hlt">damage</span> in repair-deficient E. coli mutants. DNA strand-transfer and single-stranded DNA renaturation activities are associated with the unique N-terminal region of Rrp1, which suggests possible additional functions that include recombinational repair or homologous recombination. By using the Drosophila w/w+ mosaic eye system, which detects loss of heterozygosity as changes in eye pigmentation, somatic mutation and recombination <span class="hlt">frequencies</span> were determined in transgenic flies overexpressing wild-type Rrp1 protein from a heat-shock-inducible transgene. A large decrease in mosaic clone <span class="hlt">frequency</span> is observed when Rrp1 overexpression precedes treatment with gamma-rays, bleomycin, or paraquat. In contrast, Rrp1 overexpression does not alter the spot <span class="hlt">frequency</span> after treatment with the alkylating agents methyl methanesulfonate or methyl nitrosourea. A reduction in mosaic clone <span class="hlt">frequency</span> depends on the expression of the Rrp1 transgene and on the nature of the induced DNA <span class="hlt">damage</span>. These data suggest a lesion-specific involvement of Rrp1 in the repair of oxidative DNA <span class="hlt">damage</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26591599','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26591599"><span>[Pulse-modulated Electromagnetic Radiation of Extremely High <span class="hlt">Frequencies</span> Protects Cellular DNA against <span class="hlt">Damaging</span> Effect of Physico-Chemical Factors in vitro].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gapeyev, A B; Lukyanova, N A</p> <p>2015-01-01</p> <p>Using a comet assay technique, we investigated protective effects of. extremely high <span class="hlt">frequency</span> electromagnetic radiation in combination with the <span class="hlt">damaging</span> effect of X-ray irradiation, the effect of <span class="hlt">damaging</span> agents hydrogen peroxide and methyl methanesulfonate on DNA in mouse whole blood leukocytes. It was shown that the preliminary exposure of the cells to low intensity pulse-modulated electromagnetic radiation (42.2 GHz, 0.1 mW/cm2, 20-min exposure, modulation <span class="hlt">frequencies</span> of 1 and 16 Hz) caused protective effects decreasing the DNA <span class="hlt">damage</span> by 20-45%. The efficacy of pulse-modulated electromagnetic radiation depended on the type of genotoxic agent and increased in a row methyl methanesulfonate--X-rays--hydrogen peroxide. Continuous electromagnetic radiation was ineffective. The mechanisms of protective effects may be connected with an induction of the adaptive response by nanomolar concentrations of reactive oxygen species formed by pulse-modulated electromagnetic radiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JNR....17..199R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JNR....17..199R"><span>Haloperidol-loaded lipid-<span class="hlt">core</span> polymeric nanocapsules reduce DNA <span class="hlt">damage</span> in blood and oxidative stress in liver and kidneys of rats</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roversi, Katiane; Benvegnú, Dalila M.; Roversi, Karine; Trevizol, Fabíola; Vey, Luciana T.; Elias, Fabiana; Fracasso, Rafael; Motta, Mariana H.; Ribeiro, Roseane F.; dos S. Hausen, Bruna; Moresco, Rafael N.; Garcia, Solange C.; da Silva, Cristiane B.; Burger, Marilise E.</p> <p>2015-04-01</p> <p>Haloperidol (HP) nanoencapsulation improves therapeutic efficacy, prolongs the drug action time, and reduces its motor side effects. However, in a view of HP toxicity in organs like liver and kidneys in addition to the lack of knowledge regarding the toxicity of polymeric nanocapsules, our aim was to verify the influence of HP-nanoformulation on toxicity and oxidative stress markers in the liver and kidneys of rats, also observing the <span class="hlt">damage</span> caused in the blood. For such, 28 adult male Wistar rats were designated in four experimental groups ( n = 7) and treated with vehicle (C group), free haloperidol suspension (FH group), blank nanocapsules suspension (B-Nc group), and haloperidol-loaded lipid-<span class="hlt">core</span> nanocapsules suspension (H-Nc group). The nanocapsules formulation presented the size of approximately 250 nm. All suspensions were administered to the animals (0.5 mg/kg/day-i.p.) for a period of 28 days. Our results showed that FH caused <span class="hlt">damage</span> in the liver, evidenced by increased lipid peroxidation, plasma levels of aspartate aminotransferase, and alanine aminotransferase, as well as decreased cellular integrity and vitamin C levels. In kidneys, FH treatment caused <span class="hlt">damage</span> to a lesser extent, observed by decreased activity of δ-aminolevulinate dehydratase (ALA-D) and levels of VIT C. In addition, FH treatment was also related to a higher DNA <span class="hlt">damage</span> index in blood. On the other hand, animals treated with H-Nc and B-Nc did not show <span class="hlt">damage</span> in liver, kidneys, and DNA. Our study indicates that the nanoencapsulation of haloperidol was able to prevent the sub-chronic toxicity commonly observed in liver, kidneys, and DNA, thus reflecting a pharmacological superiority in relation to free drug.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S34A..03N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S34A..03N"><span>Laboratory Mid-<span class="hlt">frequency</span> (Kilohertz) Range Seismic Property Measurements and X-ray CT Imaging of Fractured Sandstone <span class="hlt">Cores</span> During Supercritical CO2 Injection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakagawa, S.; Kneafsey, T. J.; Chang, C.; Harper, E.</p> <p>2014-12-01</p> <p>During geological sequestration of CO2, fractures are expected to play a critical role in controlling the migration of the injected fluid in reservoir rock. To detect the invasion of supercritical (sc-) CO2 and to determine its saturation, velocity and attenuation of seismic waves can be monitored. When both fractures and matrix porosity connected to the fractures are present, wave-induced dynamic poroelastic interactions between these two different types of rock porosity—high-permeability, high-compliance fractures and low-permeability, low-compliance matrix porosity—result in complex velocity and attenuation changes of compressional waves as scCO2 invades the rock. We conducted <span class="hlt">core</span>-scale laboratory scCO2 injection experiments on small (diameter 1.5 inches, length 3.5-4 inches), medium-porosity/permeability (porosity 15%, matrix permeability 35 md) sandstone <span class="hlt">cores</span>. During the injection, the compressional and shear (torsion) wave velocities and attenuations of the entire <span class="hlt">core</span> were determined using our Split Hopkinson Resonant Bar (short-<span class="hlt">core</span> resonant bar) technique in the <span class="hlt">frequency</span> range of 1-2 kHz, and the distribution and saturation of the scCO2 determined via X-ray CT imaging using a medical CT scanner. A series of tests were conducted on (1) intact rock <span class="hlt">cores</span>, (2) a <span class="hlt">core</span> containing a mated, <span class="hlt">core</span>-parallel fracture, (3) a <span class="hlt">core</span> containing a sheared <span class="hlt">core</span>-parallel fracture, and (4) a <span class="hlt">core</span> containing a sheared, <span class="hlt">core</span>-normal fracture. For intact <span class="hlt">cores</span> and a <span class="hlt">core</span> containing a mated sheared fracture, injections of scCO2 into an initially water-saturated sample resulted in large and continuous decreases in the compressional velocity as well as temporary increases in the attenuation. For a sheared <span class="hlt">core</span>-parallel fracture, large attenuation was also observed, but almost no changes in the velocity occurred. In contrast, a sample containing a <span class="hlt">core</span>-normal fracture exhibited complex behavior of compressional wave attenuation: the attenuation peaked as the leading edge of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23206529','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23206529"><span>Are <span class="hlt">core</span> component processes of executive function dissociable within the frontal lobes? Evidence from humans with focal prefrontal <span class="hlt">damage</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tsuchida, Ami; Fellows, Lesley K</p> <p>2013-01-01</p> <p>Executive function encompasses a range of control processes supporting flexible, goal-directed behaviour. Attentional set-shifting, updating of information in working memory, and inhibitory control have been proposed as key components of executive function, but debate continues as to the validity of this conceptual framework, and the neural substrates of these putative components. Here we examined prefrontal structure-function relationships for each of these component processes in a large cohort of patients with focal prefrontal <span class="hlt">damage</span>. Forty-five patients with focal <span class="hlt">damage</span> to various sectors of prefrontal cortex (PFC), and 50 demographically matched healthy control subjects performed an attention shifting task, the Stroop colour naming task, and a spatial search task. Voxel-based lesion-symptom mapping revealed that <span class="hlt">damage</span> to left ventrolateral PFC led to impaired performance on both the Stroop and attention shifting tasks. In contrast, performance of the spatial search task depended on several regions within PFC, but notably not left ventrolateral PFC. These observations were confirmed with direct comparison of performance between patients grouped according to lesion location. This dissociation partly supports the component process view of executive function, distinguishing the goal-directed regulation of attention (perhaps specifically in the verbal domain) from the requirements of the spatial search task, including the updating of information in spatial working memory. These findings are easier to reconcile with modular, material-specific accounts than with more unitary models of executive function.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10164710','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10164710"><span>Assessment of <span class="hlt">core</span> <span class="hlt">damage</span> models in SCDAP/RELAP5 during OECD LOFT LP-FP-2</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Coryell, E.W.</p> <p>1991-12-31</p> <p>The US Nuclear Regulatory Commission has sponsored a program to apply the SCDAP/RELAP5 code to analysis of the transient and reflood phases of the OECD LOFT LP-FP-2 Experiment. The principal objectives of the LP-FP-2 experiment were to determine the fission product release from the fuel during the early phases of a severe fuel <span class="hlt">damage</span> scenario and to examine the phenomena controlling fission product transport in a vapor/aerosol environment. Calculations with the SCDAP/RELAP5 code, developed at the INEL with NRC support, have been performed to (1) examine the phenomena controlling the progression of both transient and reflood phases of the experiment, (2) enhance our understanding of the phenomena occurring during reflood and add credence to the postulated phenomenological sequence, (3) assess the ability of SCDAP/RELAP5 to examine severe fuel <span class="hlt">damage</span> issues and phenomena, and (4) identify code strengths and deficiencies with the intent of prioritizing code improvements. Results indicate that the code is able to analyze the early phases of severe fuel <span class="hlt">damage</span> reasonably well, with potential deficiencies in modelling interaction between molten control rod material and intact fuel.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RMRE...50.2495M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RMRE...50.2495M"><span>A Variable-Parameter Creep <span class="hlt">Damage</span> Model Incorporating the Effects of Loading <span class="hlt">Frequency</span> for Rock Salt and Its Application in a Bedded Storage Cavern</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ma, Linjian; Wang, Mingyang; Zhang, Ning; Fan, Pengxian; Li, Jie</p> <p>2017-09-01</p> <p>Laboratory tests were conducted to assess the effects of the loading <span class="hlt">frequency</span> on the time-dependent behavior and <span class="hlt">damage</span> properties of rock salt under confining stress states. Axial two-stage irreversible deformation based on the loci of the minimum load of each cycle was observed, and this observation was similar to the result of conventional creep tests under static loads. The unloading modulus decreased exponentially with respect to time, and the <span class="hlt">damage</span> variable was represented in terms of the decay of the material stiffness. To account for the effects of the loading <span class="hlt">frequency</span> on the time-dependent degradation of rock salt, a unified <span class="hlt">damage</span> evolution equation was formulated based on the experimental results. A creep <span class="hlt">damage</span> model of rock salt was proposed by introducing non-stationary modular components into the Burgers viscoelastic model. Numerical simulation was performed using the newly developed model to evaluate the stability and serviceability of a storage cavern in a bedded salt formation under various loading scenarios. The simulated results indicate that a lower injection-withdrawal <span class="hlt">frequency</span> results in a greater volume convergence rate and a wider dilatancy region of the storage cavern. Additionally, the stress concentration and dilatancy of the surrounding rock mass extend much deeper into the mudstone interbeds than into other regions of the cavern.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23228337','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23228337"><span>Effect of <span class="hlt">core</span> design and veneering technique on <span class="hlt">damage</span> and reliability of Y-TZP-supported crowns.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guess, Petra C; Bonfante, Estevam A; Silva, Nelson R F A; Coelho, Paulo G; Thompson, Van P</p> <p>2013-03-01</p> <p>To evaluate the effect of framework design modification and veneering techniques in fatigue reliability and failure modes of veneered Yttria-Stabilized Tetragonal Zirconia Polycrystals (Y-TZP) crowns. A CAD-based mandibular molar crown preparation served as a master die. Y-TZP crown <span class="hlt">cores</span> (VITA-In-Ceram-YZ, Vita-Zahnfabrik, Bad Säckingen, Germany) in conventional (0.5mm uniform thickness) or anatomically designed fashion (cusp support) were porcelain veneered with either hand-layer (VM9) or pressed (PM9) techniques. Crowns (n=84) were cemented on 30 days aged dentin-like composite dies with resin cement. Crowns were subjected to single load to fracture (n=3 each group) and mouth-motion step-stress fatigue (n=18) by sliding a WC indenter (r=3.18 mm) 0.7 mm buccally on the inner incline surface of the mesio-lingual cusp. Stress-level curves (use level probability lognormal) and reliability (with 2-sided 90% confidence bounds, CB) for completion of a mission of 50.000 cycles at 200 N load were calculated. Fractographic analyses were performed under light-polarized and scanning electron microscopes. Higher reliability for hand-layer veneered conventional <span class="hlt">core</span> (0.99, CB 0.98-1) was found compared to its counterpart press-veneered (0.50 CB 0.33-65). Framework design modification significantly increased reliability for both veneering techniques (PM9 [0.98 CB 0.87-0.99], VM9 [1.00 CB 0.99-1]) and resulted in reduced veneer porcelain fracture sizes. Main fracture mode observed was veneer porcelain chipping, regardless of framework design and veneering technique. Hand-layer porcelain veneered on conventional <span class="hlt">core</span> designs presented higher reliability than press-veneered with similar <span class="hlt">core</span> designs. Anatomic <span class="hlt">core</span> design modification significantly increased the reliability and resulted in reduced chip size of either veneering techniques. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2897548','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2897548"><span>Novel Functional Residues in the <span class="hlt">Core</span> Domain of Histone H2B Regulate Yeast Gene Expression and Silencing and Affect the Response to DNA <span class="hlt">Damage</span> ▿</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kyriss, McKenna N. M.; Jin, Yi; Gallegos, Isaura J.; Sanford, James A.; Wyrick, John J.</p> <p>2010-01-01</p> <p>Previous studies have identified novel modifications in the <span class="hlt">core</span> fold domain of histone H2B, but relatively little is known about the function of these putative histone modification sites. We have mutated <span class="hlt">core</span> modifiable residues that are conserved in Saccharomyces cerevisiae histone H2B and characterized the effects of the mutants on yeast silencing, gene expression, and the DNA <span class="hlt">damage</span> response. We identified three histone H2B <span class="hlt">core</span> modifiable residues as functionally important. We find that mutating H2B K49 in yeast confers a UV sensitivity phenotype, and we confirm that the homologous residue in human histone H2B is acetylated and methylated in human cells. Our results also indicate that mutating H2B K111 impairs the response to methyl methanesulfonate (MMS)-induced DNA lesions and disrupts telomeric silencing and Sir4 binding. In contrast, mutating H2B R102 enhances silencing at yeast telomeres and the HML silent mating loci and increases Sir4 binding to these regions. The H2B R102A mutant also represses the expression of endogenous genes adjacent to yeast telomeres, which is likely due to the ectopic spreading of the Sir complex in this mutant strain. We propose a structural model by which H2B R102 and K111 regulate the binding of the Sir complex to the nucleosome. PMID:20479120</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3911009','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3911009"><span>Resistance of Bacillus subtilis Spore DNA to Lethal Ionizing Radiation <span class="hlt">Damage</span> Relies Primarily on Spore <span class="hlt">Core</span> Components and DNA Repair, with Minor Effects of Oxygen Radical Detoxification</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Raguse, Marina; Reitz, Günther; Okayasu, Ryuichi; Li, Zuofeng; Klein, Stuart; Setlow, Peter; Nicholson, Wayne L.</p> <p>2014-01-01</p> <p>The roles of various <span class="hlt">core</span> components, including α/β/γ-type small acid-soluble spore proteins (SASP), dipicolinic acid (DPA), <span class="hlt">core</span> water content, and DNA repair by apurinic/apyrimidinic (AP) endonucleases or nonhomologous end joining (NHEJ), in Bacillus subtilis spore resistance to different types of ionizing radiation including X rays, protons, and high-energy charged iron ions have been studied. Spores deficient in DNA repair by NHEJ or AP endonucleases, the oxidative stress response, or protection by major α/β-type SASP, DPA, and decreased <span class="hlt">core</span> water content were significantly more sensitive to ionizing radiation than wild-type spores, with highest sensitivity to high-energy-charged iron ions. DNA repair via NHEJ and AP endonucleases appears to be the most important mechanism for spore resistance to ionizing radiation, whereas oxygen radical detoxification via the MrgA-mediated oxidative stress response or KatX catalase activity plays only a very minor role. Synergistic radioprotective effects of α/β-type but not γ-type SASP were also identified, indicating that α/β-type SASP's binding to spore DNA is important in preventing DNA <span class="hlt">damage</span> due to reactive oxygen species generated by ionizing radiation. PMID:24123749</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MSSP...93..241Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MSSP...93..241Z"><span>Quasi-optical coherence vibration tomography technique for <span class="hlt">damage</span> detection in beam-like structures based on auxiliary mass induced <span class="hlt">frequency</span> shift</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhong, Shuncong; Zhong, Jianfeng; Zhang, Qiukun; Maia, Nuno</p> <p>2017-09-01</p> <p>A novel quasi-optical coherence vibration tomography (Quasi-OCVT) measurement system suitable for structural <span class="hlt">damage</span> detection is proposed by taking the concept of two-dimensional optical coherence vibration tomography (2D-OCVT) technique. An artificial quasi-interferogram fringe pattern (QIFP) similar to the interferogram of 2D-OCVT system, as a sensor, was pasted on the surface of a vibrating structure. Image sequences of QIFP were captured by a high-speed camera that worked as a detector. The period density of the imaged QIFP changed due to the structural vibration, from which the vibration information of the structure could be obtained. Noise influence on the measurement accuracy, torsional sensitivity and optical distortion effect of the Quasi-OCVT system were investigated. The efficiency and reliability of the proposed method were demonstrated by applying the system to <span class="hlt">damage</span> detection of a cracked beam-like structure with a roving auxiliary mass. The roving of the mass along the cracked beam brings about the change of natural <span class="hlt">frequencies</span> that could be obtained by the Quasi-OCVT technique. Therefore, <span class="hlt">frequency</span>-shift curves can be achieved and these curves provide additional spatial information for structural <span class="hlt">damage</span> detection. Same cases were also analyzed by the finite element method (FEM) and conventional accelerometer-based measurement method. Comparisons were carried out among these results. Results obtained by the proposed Quasi-OCVT method had a good agreement with the ones obtained by FEM, from which the <span class="hlt">damage</span> could be directly detected. However, the results obtained by conventional accelerometer showed misleading ambiguous peaks at <span class="hlt">damage</span> position owing to the mass effect on the structure, where the <span class="hlt">damage</span> location cannot be identified confidently without further confirmation. The good performance of the cost-effective Quasi-OCVT method makes it attractive for vibration measurement and <span class="hlt">damage</span> detection of beam-like structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23112505','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23112505"><span>Increase in DNA <span class="hlt">damage</span> in lymphocytes and micronucleus <span class="hlt">frequency</span> in buccal cells in silica-exposed workers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Halder, Ajanta; De, Madhusnata</p> <p>2012-01-01</p> <p>The alkaline single cell gel electrophoresis (comet assay) was applied to study the genotoxic properties of silica in human peripheral blood lymphocytes (PBL). The study was designed to evaluate the DNA <span class="hlt">damage</span> of lymphocytes and the end points like micronuclei from buccal smears in a group of 45 workers, occupationally exposed to silica, from small mines and stone quarries. The results were compared to 20 sex and age matched normal individuals. There was a statistically significant difference in the <span class="hlt">damage</span> levels between the exposed group and the control groups. The types of <span class="hlt">damages</span> (type I -type 1V) were used to measure the DNA <span class="hlt">damage</span>. The numbers of micronuclei were higher in the silica-exposed population. The present study suggests that the silica exposure can induce lymphocyte DNA <span class="hlt">damage</span> and produces significant variation of micronuclei in buccal smear.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19547058','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19547058"><span>Insight to UV-induced formation of laser <span class="hlt">damage</span> on LiB(3)O(5) optical surfaces during long-term sum-<span class="hlt">frequency</span> generation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Möller, S; Andresen, A; Merschjann, C; Zimmermann, B; Prinz, M; Imlau, M</p> <p>2007-06-11</p> <p>Microscopic investigations of UV-induced formation of laser <span class="hlt">damage</span> on LiB(3)O(5) optical surfaces during long-term sum-<span class="hlt">frequency</span> generation (SFG) uncovers a significant growth of a SiO(2)-amorphous layer spatially limited to the illuminated area. The layer gives rise to a catastrophic break-down of the LiB(3)O(5)-output surface upon long-term laser operation even at intensities far below the laser-induced <span class="hlt">damage</span> threshold. The interaction of UV laser light, LiB(3)O(5) surface and foreign atoms in the ambient atmosphere is discussed in the frame of a two-step process for surface-<span class="hlt">damage</span> formation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006SPIE.6176..131P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006SPIE.6176..131P"><span>Time reversal method for <span class="hlt">damage</span> detection of cracked plates in the medium <span class="hlt">frequency</span> range: the case of wavelength-size cracks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pasco, Yann; Pinsonnault, Jérôme; Berry, Alain; Masson, Patrice; Micheau, Philippe</p> <p>2006-03-01</p> <p>The use of time reversal methods for localization and characterization of <span class="hlt">damages</span> in plates is usually combined with high <span class="hlt">frequency</span> guided waves in a local elastic wave propagation formulation. In such a situation, pulses and echos may be clearly separated in time. As a consequence, the diffracted field on a <span class="hlt">damage</span> with large geometrical dimensions compared to the wavelength used for wave propagation allows to consider the structure itself as "near infinite" because the modal behavior is not apparent. However, those high requencies may not be required and in the presented approach, medium <span class="hlt">frequencies</span> are used and boundary conditions need to be considered. The interest of this <span class="hlt">frequency</span> range is in using lightweight signal processing devices limited to low data transfer rates as expected for in flight fuselage skin inspections. It also allows to filter artifacts like very small <span class="hlt">damages</span> in the structure. This study focuses on the case of wavelengths which are in the order of the largest geometrical dimension of the cracks. In the paper, a modelling tool is first extended to describe the vibration behavior of pristine and <span class="hlt">damaged</span> finite thin plates in the low and medium <span class="hlt">frequency</span> range below 50 kHz. The proposed analytical model employs a Hierarchical Trigonometric Functions Set (HTFS) to characterize homogeneous plates with through cracks. To approximate the effect of a small crack in a plate for all combinations of classical boundary conditions, high order approximation functions are required. The proposed approach takes the advantage of the stability of the HTFS for these high orders. A notable advantage of this model is that it does not require a dense uniform meshing of the plate, with a minimum of 10 nodes per wavelength, as most finite element models require. The time reversal concept introduced before is thus validated with this model for a finite plate with known boundary conditions. Experimental validation of the model is conducted in the time domain for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060044248&hterms=purpose&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dpurpose','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060044248&hterms=purpose&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dpurpose"><span>Foam <span class="hlt">core</span> shield (FCS) systems : a new dual - purpose technology for shielding against meteoroid strike <span class="hlt">damage</span> and for thermal control of spacecrafts/satellite components</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Adams, Marc A.; Zwissler, James G.; Hayes, Charles; Fabensky, Beth; Cornelison, Charles; Alexander, Lesley; Bishop, Karen</p> <p>2005-01-01</p> <p>A new technology is being developed that can protect spacecraft and satellite components against <span class="hlt">damage</span> from meteoroid strikes and control the thermal environment of the protected components. This technology, called Foam <span class="hlt">Core</span> Shield (FCS) systems, has the potential to replace the multi-layer insulation blankets (MLI) that have been used on spacecraft for decades. In order to be an attractive candidate for replacing MLI, FCS systems should not only provide superior protection against meteoroid strikes but also provide an equal or superior ability to control the temperature of the protected component. Properly designed FCS systems can provide these principal functions, meteoroid strike protection and thermal control, with lower system mass and a smaller system envelope than ML.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060044248&hterms=purposes+right&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dpurposes%2Bright','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060044248&hterms=purposes+right&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dpurposes%2Bright"><span>Foam <span class="hlt">core</span> shield (FCS) systems : a new dual - purpose technology for shielding against meteoroid strike <span class="hlt">damage</span> and for thermal control of spacecrafts/satellite components</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Adams, Marc A.; Zwissler, James G.; Hayes, Charles; Fabensky, Beth; Cornelison, Charles; Alexander, Lesley; Bishop, Karen</p> <p>2005-01-01</p> <p>A new technology is being developed that can protect spacecraft and satellite components against <span class="hlt">damage</span> from meteoroid strikes and control the thermal environment of the protected components. This technology, called Foam <span class="hlt">Core</span> Shield (FCS) systems, has the potential to replace the multi-layer insulation blankets (MLI) that have been used on spacecraft for decades. In order to be an attractive candidate for replacing MLI, FCS systems should not only provide superior protection against meteoroid strikes but also provide an equal or superior ability to control the temperature of the protected component. Properly designed FCS systems can provide these principal functions, meteoroid strike protection and thermal control, with lower system mass and a smaller system envelope than ML.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22204736','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22204736"><span>Repair pathways independent of the Fanconi anemia nuclear <span class="hlt">core</span> complex play a predominant role in mitigating formaldehyde-induced DNA <span class="hlt">damage</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Noda, Taichi; Takahashi, Akihisa; Kondo, Natsuko; Mori, Eiichiro; Okamoto, Noritomo; Nakagawa, Yosuke; Ohnishi, Ken; Zdzienicka, Malgorzata Z.; Thompson, Larry H.; Helleday, Thomas; Asada, Hideo; and others</p> <p>2011-01-07</p> <p>The role of the Fanconi anemia (FA) repair pathway for DNA <span class="hlt">damage</span> induced by formaldehyde was examined in the work described here. The following cell types were used: mouse embryonic fibroblast cell lines FANCA{sup -/-}, FANCC{sup -/-}, FANCA{sup -/-}C{sup -/-}, FANCD2{sup -/-} and their parental cells, the Chinese hamster cell lines FANCD1 mutant (mt), FANCGmt, their revertant cells, and the corresponding wild-type (wt) cells. Cell survival rates were determined with colony formation assays after formaldehyde treatment. DNA double strand breaks (DSBs) were detected with an immunocytochemical {gamma}H2AX-staining assay. Although the sensitivity of FANCA{sup -/-}, FANCC{sup -/-} and FANCA{sup -/-}C{sup -/-} cells to formaldehyde was comparable to that of proficient cells, FANCD1mt, FANCGmt and FANCD2{sup -/-} cells were more sensitive to formaldehyde than the corresponding proficient cells. It was found that homologous recombination (HR) repair was induced by formaldehyde. In addition, {gamma}H2AX foci in FANCD1mt cells persisted for longer times than in FANCD1wt cells. These findings suggest that formaldehyde-induced DSBs are repaired by HR through the FA repair pathway which is independent of the FA nuclear <span class="hlt">core</span> complex. -- Research highlights: {yields} We examined to clarify the repair pathways of formaldehyde-induced DNA <span class="hlt">damage</span>. Formaldehyde induces DNA double strand breaks (DSBs). {yields} DSBs are repaired through the Fanconi anemia (FA) repair pathway. {yields} This pathway is independent of the FA nuclear <span class="hlt">core</span> complex. {yields} We also found that homologous recombination repair was induced by formaldehyde.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18846465','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18846465"><span>Confocal dual-<span class="hlt">frequency</span> enhances the <span class="hlt">damaging</span> effect of high-intensity focused ultrasound in tissue-mimicking phantom.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kuang, Sheng-Li; Hu, Bing; Jiang, Li-Xin; He, Pei-Zhong; Xia, Rong-Min; Shou, Wen-De</p> <p>2008-01-01</p> <p>The volume of the lesions created by conventional single-<span class="hlt">frequency</span> high-intensity focused ultrasound (HIFU) is small, which leads to long treatment duration in patients who are undergoing tumor ablation. In this study, the lesions induced by confocal dual-<span class="hlt">frequency</span> HIFU in an optically transparent tissue-mimicking phantom were investigated and compared with the lesions created by conventional single-<span class="hlt">frequency</span> HIFU. The results show that using different exposure times resulted in lesions of different sizes in both dual-<span class="hlt">frequency</span> and single-<span class="hlt">frequency</span> HIFU modes at the same spatially averaged intensity level (ISAL = 4900 W cm(-2)), but the lesion dimensions made in dual-<span class="hlt">frequency</span> mode were significantly larger than those made in single-<span class="hlt">frequency</span> mode. Difference <span class="hlt">frequency</span> acoustic fields that exist in the confocal region of dual-<span class="hlt">frequency</span> HIFU may be the reason for the enlargement of the lesions' dimensions. The dual-<span class="hlt">frequency</span> HIFU mode may represent a new technique to improve the ablation efficiency of HIFU. The total time for the ablation of a tumor can be reduced, thus requiring less therapy time and reducing possible patient complications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9399708','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9399708"><span>Measurement of DNA <span class="hlt">damage</span> after exposure to electromagnetic radiation in the cellular phone communication <span class="hlt">frequency</span> band (835.62 and 847.74 MHz).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Malyapa, R S; Ahern, E W; Straube, W L; Moros, E G; Pickard, W F; Roti Roti, J L</p> <p>1997-12-01</p> <p>Mouse C3H 10T1/2 fibroblasts and human glioblastoma U87MG cells were exposed to cellular phone communication <span class="hlt">frequency</span> radiations to investigate whether such exposure produces DNA <span class="hlt">damage</span> in in vitro cultures. Two types of <span class="hlt">frequency</span> modulations were studied: <span class="hlt">frequency</span>-modulated continuous-wave (FMCW), with a carrier <span class="hlt">frequency</span> of 835.62 MHz, and code-division multiple-access (CDMA) centered on 847.74 MHz. Exponentially growing (U87MG and C3H 10T1/2 cells) and plateau-phase (C3H 10T1/2 cells) cultures were exposed to either FMCW or CDMA radiation for varying periods up to 24 h in specially designed radial transmission lines (RTLs) that provided relatively uniform exposure with a specific absorption rate (SAR) of 0.6 W/kg. Temperatures in the RTLs were monitored continuously and maintained at 37 +/- 0.3 degrees C. Sham exposure of cultures in an RTL (negative control) and 137Cs gamma-irradiated samples (positive control) were included with every experiment. The alkaline comet assay as described by Olive et al. (Exp. Cell Res. 198, 259-269, 1992) was used to measure DNA <span class="hlt">damage</span>. No significant differences were observed between the test group exposed to FMCW or CDMA radiation and the sham-treated negative controls. Our results indicate that exposure of cultured mammalian cells to cellular phone communication <span class="hlt">frequencies</span> under these conditions at an SAR of 0.6 W/kg does not cause DNA <span class="hlt">damage</span> as measured by the alkaline comet assay.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23571976','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23571976"><span>Fully-elastic multi-granular network with space/<span class="hlt">frequency</span>/time switching using multi-<span class="hlt">core</span> fibres and programmable optical nodes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Amaya, N; Irfan, M; Zervas, G; Nejabati, R; Simeonidou, D; Sakaguchi, J; Klaus, W; Puttnam, B J; Miyazawa, T; Awaji, Y; Wada, N; Henning, I</p> <p>2013-04-08</p> <p>We present the first elastic, space division multiplexing, and multi-granular network based on two 7-<span class="hlt">core</span> MCF links and four programmable optical nodes able to switch traffic utilising the space, <span class="hlt">frequency</span> and time dimensions with over 6000-fold bandwidth granularity. Results show good end-to-end performance on all channels with power penalties between 0.75 dB and 3.7 dB.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950025786','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950025786"><span>Effects of temperature, <span class="hlt">frequency</span>, flux density, and excitation waveform on the <span class="hlt">core</span> loss and dynamic B-H loops of supermalloy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schwarze, Gene E.; Wieserman, William R.; Niedra, Janis M.</p> <p>1995-01-01</p> <p>The availability of experimental data which characterize the performance of soft magnetic materials for the combined conditions of temperature and <span class="hlt">frequency</span> over a wide flux density range for different types of excitation is almost nonexistent. An experimental investigation of an 80-20 Ni-Fe alloy (Supermalloy) was conducted over the temperature (T) range of 23 to 300 C, <span class="hlt">frequency</span> (f) range of 1 to 50 kHz, and maximum flux densities (B(sub M)) from 0.1 T up to 0.7 T for both sine and square wave voltage excitation. The investigation focused on the effects of (B(sub M)), f, T, and excitation waveform on the specific <span class="hlt">core</span> loss (SCL) and dynamic B-H loops. The results show that the ratio (R) of sine to square wave excitation specific <span class="hlt">core</span> loss was always greater than unity for a given f and T and identical values of B(sub M). The values of R ranged from 1.07 to 1.34. The classical theory of <span class="hlt">core</span> loss separation into a hysteresis and eddy current loss component was used to theoretically determine the lower and upper bounds on R, against which the experimental R-values were compared. The experimental R-values were also used to make a comparison of the <span class="hlt">core</span> loss of a sine and square wave voltage driven transformer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24727058','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24727058"><span>Penetration of normal, <span class="hlt">damaged</span> and diseased skin--an in vitro study on dendritic <span class="hlt">core</span>-multishell nanotransporters.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Alnasif, Nesrin; Zoschke, Christian; Fleige, Emanuel; Brodwolf, Robert; Boreham, Alexander; Rühl, Eckart; Eckl, Katja-Martina; Merk, Hans-Friedrich; Hennies, Hans Christian; Alexiev, Ulrike; Haag, Rainer; Küchler, Sarah; Schäfer-Korting, Monika</p> <p>2014-07-10</p> <p>A growing intended or accidental exposure to nanoparticles asks for the elucidation of potential toxicity linked to the penetration of normal and lesional skin. We studied the skin penetration of dye-tagged dendritic <span class="hlt">core</span>-multishell (CMS) nanotransporters and of Nile red loaded CMS nanotransporters using fluorescence microscopy. Normal and stripped human skin ex vivo as well as normal reconstructed human skin and in vitro skin disease models served as test platforms. Nile red was delivered rapidly into the viable epidermis and dermis of normal skin, whereas the highly flexible CMS nanotransporters remained solely in the stratum corneum after 6h but penetrated into deeper skin layers after 24h exposure. Fluorescence lifetime imaging microscopy proved a stable dye-tag and revealed striking nanotransporter-skin interactions. The viable layers of stripped skin were penetrated more efficiently by dye-tagged CMS nanotransporters and the cargo compared to normal skin. Normal reconstructed human skin reflected the penetration of Nile red and CMS nanotransporters in human skin and both, the non-hyperkeratotic non-melanoma skin cancer and hyperkeratotic peeling skin disease models come along with altered absorption in the skin diseases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23827365','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23827365"><span><span class="hlt">Frequency</span> of polymorphism -262 c/t in catalase gene and oxidative <span class="hlt">damage</span> in Slovak children with bronchial asthma.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Babusikova, Eva; Jesenak, Milos; Evinova, Andrea; Banovcin, Peter; Dobrota, Dusan</p> <p>2013-12-01</p> <p>Bronchial asthma is a complex disease in which genetic factors, environmental factors and oxidative <span class="hlt">damage</span> are responsible for the initiation and modulation of disease progression. If antioxidant mechanisms fail, reactive oxygen species <span class="hlt">damage</span> the biomolecules followed by progression of the disease. Catalase is one of the most important endogenous enzymatic antioxidants. In the present study, we examined the hypothesis that increased oxidative <span class="hlt">damage</span> and polymorphism in the CAT gene (-262 promoter region, C/T) are associated with childhood bronchial asthma. Genotyping of the polymorphisms in the CAT gene in healthy (249) and asthmatic children (248) was performed using polymerase chain reaction-restriction fragment length polymorphism. Markers of oxidative <span class="hlt">damage</span>: content of sulfhydryl groups and thiobarbituric acid-reactive substances were determined by spectrophotometry in children. The TT genotype of catalase was more frequent among the asthmatic patients (22.6%) than in healthy children (4.8%) (odds ratio=5.63; 95% confidence interval=2.93-10.81, P<.001). The amount of sulfhydryl groups decreased significantly and conversely, the content of thiobarbituric acid-reactive substances increased significantly in bronchial asthma and in catalase TT genotype compared to other catalase genotypes of this gene. These results suggest that catalase polymorphism might participate in development of bronchial asthma and in enhanced oxidative <span class="hlt">damage</span> in asthmatic children. Genetic variation of enzymatic antioxidants may modulate disease risk. Copyright © 2013 SEPAR. Published by Elsevier Espana. All rights reserved.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26720589','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26720589"><span>Increased micronucleus, nucleoplasmic bridge, nuclear bud <span class="hlt">frequency</span> and oxidative DNA <span class="hlt">damage</span> associated with prolactin levels and pituitary adenoma diameters in patients with prolactinoma.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bitgen, N; Donmez-Altuntas, H; Bayram, F; Cakir, I; Hamurcu, Z; Diri, H; Baskol, G; Senol, S; Durak, A C</p> <p>2016-01-01</p> <p>Prolactinoma is the most common pituitary tumor. Most pituitary tumors are benign, but they often are clinically significant. We investigated cytokinesis-block micronucleus cytome (CBMN cyt) assay parameters and oxidative DNA <span class="hlt">damage</span> in patients with prolactinoma to assess the relations among age, prolactin level, pituitary adenoma diameter and 8-hydroxy-2'-deoxyguanosine (8-OHdG) level in patients with prolactinoma. We investigated 27 patients diagnosed with prolactinoma and 20 age- and sex-matched healthy controls. We measured CBMN cyt parameters and plasma 8-OHdG levels in peripheral blood lymphocytes of patients with prolactinoma and controls. The <span class="hlt">frequencies</span> of micronucleus (MN), nucleoplasmic bridge, nuclear bud, apoptotic and necrotic cells, and plasma 8-OHdG levels in patients with prolactinoma were significantly greater than controls. MN <span class="hlt">frequency</span> was correlated positively with age, prolactin levels and pituitary adenoma diameters in patients with prolactinoma. The increased chromosomal and oxidative DNA <span class="hlt">damage</span>, and the positive correlation between MN <span class="hlt">frequency</span>, prolactin levels and pituitary adenoma diameters may be associated with increased risk of cancer in patients with prolactinoma, because increased MN <span class="hlt">frequency</span> is a predictor of cancer risk.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017LaPhy..27d5102C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017LaPhy..27d5102C"><span>A <span class="hlt">frequency</span>-stabilized laser based on a hollow-<span class="hlt">core</span> photonic crystal fiber CO2 gas cell and its application scheme</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Ze-Heng; Yang, Fei; Chen, Di-Jun; Cai, Hai-Wen</p> <p>2017-04-01</p> <p>A <span class="hlt">frequency</span>-stabilized laser system based on a hollow-<span class="hlt">core</span> photonic crystal fiber (HC-PCF) CO2 gas cell for the space-borne CO2 light detection and ranging (LIDAR) is proposed. This system will help realize precise measurement of the global atmospheric CO2 concentrations. The relation between the <span class="hlt">frequency</span> stability and the temperature of the HC-PCF cell was studied in detail. It is proved that accurate control of the temperature of the HC-PCF cell is very important to realize high stability of the proposed system. The laser is locked to CO2 gas R18 absorption line at 1572.0179 nm, and its peak-to-peak <span class="hlt">frequency</span> stability is approximately 485 kHz, satisfying the requirements for the integrated path differential absorption system for CO2 measurement with an accuracy of  <1 ppm over 5 h.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20569191','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20569191"><span>Brain DNA <span class="hlt">damage</span> and 70-kDa heat shock protein expression in CD1 mice exposed to extremely low <span class="hlt">frequency</span> magnetic fields.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mariucci, Giuseppina; Villarini, Milena; Moretti, Massimo; Taha, Elena; Conte, Carmela; Minelli, Alba; Aristei, Cynthia; Ambrosini, Maria Vittoria</p> <p>2010-08-01</p> <p>The question of whether exposure to extremely low <span class="hlt">frequency</span> magnetic fields (ELF-MF), may contribute to cerebral cancer and neurodegeneration is of current interest. In this study we investigated whether exposure to ELF-MF (50 Hz-1 mT) harms cerebral DNA and induces expression of 70-kDa heat shock protein (hsp70). CD1 mice were exposed to a MF (50 Hz-1 mT) for 1 or 7 days (15 h/day) and sacrificed either at the end of exposure or after 24 h. Unexposed and sham-exposed mice were used as controls. Mouse brains were dissected into cerebral cortex-striatum, hippocampus and cerebellum to evaluate primary DNA <span class="hlt">damage</span> and hsp70 gene expression. Food intake, weight gain, and motor activity were also evaluated. An increase in primary DNA <span class="hlt">damage</span> was detected in all cerebral areas of the exposed mice sacrificed at the end of exposure, as compared to controls. DNA <span class="hlt">damage</span>, as can be evaluated by the comet assay, appeared to be repaired in mice sacrificed 24 h after a 7-day exposure. Neither a short (15 h) nor long (7 days) MF-exposure induced hsp70 expression, metabolic and behavioural changes. These results indicate that in vivo ELF-MF induce reversible brain DNA <span class="hlt">damage</span> while they do not elicit the stress response.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3501591','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3501591"><span>Lack of CAK complex accumulation at DNA <span class="hlt">damage</span> sites in XP-B and XP-B/CS fibroblasts reveals differential regulation of CAK anchoring to <span class="hlt">core</span> TFIIH by XPB and XPD helicases during nucleotide excision repair</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhu, Qianzheng; Wani, Gulzar; Sharma, Nidhi; Wani, Altaf</p> <p>2012-01-01</p> <p>Transcription factor II H (TFIIH) is composed of <span class="hlt">core</span> TFIIH and Cdk-activating kinase (CAK) complexes. Besides transcription, TFIIH also participates in nucleotide excision repair (NER), verifying DNA lesions through its helicase components XPB and XPD. The assembly state of TFIIH is known to be affected by truncation mutations in Xeroderma pigmentosum group G/Cockayne syndrome (XP-G/CS). Here, we showed that CAK component MAT1 was rapidly recruited to UV-induced DNA <span class="hlt">damage</span> sites, co-localizing with <span class="hlt">core</span> TFIIH component p62, and dispersed from the <span class="hlt">damage</span> sites upon completion of DNA repair. While the <span class="hlt">core</span> TFIIH-CAK association remained intact, MAT1 failed to accumulate at DNA <span class="hlt">damage</span> sites in fibroblasts harboring XP-B or XP-B/CS mutations. Nevertheless, MAT1, XPD and XPC as well as XPG were able to accumulate at <span class="hlt">damage</span> sites in XP-D fibroblasts, in which the <span class="hlt">core</span> TFIIH-CAK association also remained intact. Interestingly, XPG recruitment was impaired in XP-B/CS fibroblasts derived from patients with mild phenotype, but persisted in XP-B/CS fibroblasts from severely affected patients resulting in a nonfunctional preincision complex. An examination of steady-state levels of RNA polymerase II (RNAPII) indicated that UV-induced RNAPII phosphorylation was dramatically reduced in XP-B/CS fibroblasts. These results demonstrated that the CAK rapidly disassociates from the <span class="hlt">core</span> TFIIH upon assembly of nonfunctional preincision complex in XP-B and XP-B/CS cells. The persistency of nonfunctional preincision complex correlates with the severity exhibited by XP-B patients. The results suggest that XPB and XPD helicases differentially regulate the anchoring of CAK to <span class="hlt">core</span> TFIIH during <span class="hlt">damage</span> verification step of NER. PMID:23083890</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JGRB..118.4975C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRB..118.4975C"><span>Polar motion excitations for an Earth model with <span class="hlt">frequency</span>-dependent responses: 1. A refined theory with insight into the Earth's rheology and <span class="hlt">core</span>-mantle coupling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Wei; Ray, Jim; Li, JianCheng; Huang, ChengLi; Shen, WenBin</p> <p>2013-09-01</p> <p>study aims to improve the polar motion theory by developing refined <span class="hlt">frequency</span>-dependent transfer functions with the most current models for ocean tides, the Earth's rheology, and <span class="hlt">core</span>-mantle coupling. First, we present a power law for mantle anelasticity constrained by the Chandler period TCW and quality factor QCW and an empirical quasi-fluid rheology model with a linear dependence on <span class="hlt">frequency</span>, which is suitable for a period as long as ~18.6 years. Then we adopt the diurnal ocean tides from the International Earth Rotation and Reference Systems Service Conventions (2010), the long-period ocean model of Dickman and Gross (2010), and the equilibrium ocean pole tide model of Desai (2002) to calculate the oceanic corrections to the Love numbers. Further, we present discussions on the geophysical and observational aspects of the Chandler period TCW and quality factor QCW, and provide preferred values and intervals for TCW and QCW, which allow us to place some constraints on the mantle anelasticity and <span class="hlt">core</span>-mantle coupling ratio ηCW. Although ηCW is affected by uncertainties in TCW and QCW, we find its real part should be around 2%-3% while its imaginary part might be only a few thousandths. Finally, the <span class="hlt">frequency</span>-dependent polar motion transfer functions T L and T NL are determined based on the models of <span class="hlt">frequency</span>-dependent Love numbers and <span class="hlt">core</span>-mantle coupling discussed above. Our transfer functions are related to the values of TCW and QCW, however, our analyses demonstrate that our transfer functions are rather stable and not sensitive to perturbations in TCW and QCW.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4698035','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4698035"><span>Type I interferon transcriptional signature in neutrophils and high <span class="hlt">frequency</span> of low-density granulocytes are associated with tissue <span class="hlt">damage</span> in malaria</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rocha, Bruno Coelho; Marques, Pedro Elias; Leoratti, Fabiana Maria de Souza; Junqueira, Caroline; Pereira, Dhelio Batista; Antonelli, Lis Ribeiro do Valle; Menezes, Gustavo Batista</p> <p>2015-01-01</p> <p>SUMMARY Neutrophils are the most abundant leukocyte population in the bloodstream, the primary compartment of Plasmodium sp. infection. Yet, the role of these polymorphonuclear cells in mediating either resistance or pathogenesis of malaria is poorly understood. We report that circulating neutrophils from malaria patients are highly activated, as indicated by a strong type I interferon transcriptional signature, increased expression of surface activation markers, the enhanced release of reactive oxygen species and myeloperoxidase, as well as the high <span class="hlt">frequency</span> of low-density granulocytes. The activation of neutrophils was associated with increased levels of serum alanine and aspartate aminotransferases, indicating liver <span class="hlt">damage</span>. In a rodent malaria model, we observed an intense recruitment of neutrophils to liver sinusoids. Neutrophil migration, IL-1β and chemokine expression as well as liver <span class="hlt">damage</span> were all dependent on type I interferon signaling. The data suggests that type I interferon signaling have a central role in neutrophil activation and malaria pathogenesis. PMID:26711347</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3243236','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3243236"><span>Comparative Analysis of the VA/Kaiser and NLM <span class="hlt">CORE</span> Problem Subsets: An Empirical Study Based on Problem <span class="hlt">Frequency</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wright, Adam; Feblowitz, Joshua; McCoy, Allison B.; Sittig, Dean F.</p> <p>2011-01-01</p> <p>The problem list is a critical component of the electronic medical record, with implications for clinical care, provider communication, clinical decision support, quality measurement and research. However, many of its benefits depend on the use of coded terminologies. Two standard terminologies (ICD-9 and SNOMED-CT) are available for problem documentation, and two SNOMED-CT subsets (VA/KP and <span class="hlt">CORE</span>) are available for SNOMED-CT users. We set out to examine these subsets, characterize their overlap and measure their coverage. We applied the subsets to a random sample of 100,000 records from Brigham and Women’s Hospital to determine the proportion of problems covered. Though <span class="hlt">CORE</span> is smaller (5,814 terms vs. 17,761 terms for VA/KP), 94.8% of coded problem entries from BWH were in the <span class="hlt">CORE</span> subset, while only 84.0% of entries had matches in VA/KP (p<0.001). Though both subsets had reasonable coverage, <span class="hlt">CORE</span> was superior in our sample, and had fewer clinically significant gaps. PMID:22195218</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvA..95e3814F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvA..95e3814F"><span>Characterization and shaping of the time-<span class="hlt">frequency</span> Schmidt mode spectrum of bright twin beams generated in gas-filled hollow-<span class="hlt">core</span> photonic crystal fibers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Finger, M. A.; Joly, N. Y.; Russell, P. St. J.; Chekhova, M. V.</p> <p>2017-05-01</p> <p>We vary the time-<span class="hlt">frequency</span> mode structure of ultrafast pulse-pumped modulational instability (MI) twin beams in an argon-filled hollow-<span class="hlt">core</span> kagome-style photonic crystal fiber by adjusting the pressure, pump pulse chirp, fiber length, and parametric gain. Compared to solid-<span class="hlt">core</span> systems, the pressure-dependent dispersion landscape brings increased flexibility to the tailoring of <span class="hlt">frequency</span> correlations, and we demonstrate that the pump pulse chirp can be used to tune the joint spectrum of femtosecond-pumped χ(3 ) sources. We also characterize the resulting mode content, not only by measuring the multimode second-order correlation function g(2 ), but also by directly reconstructing the shapes and weights of time-<span class="hlt">frequency</span> Schmidt (TFS) modes. We show that the number of modes directly influences the shot-to-shot pulse-energy and spectral-shape fluctuations in MI. Using this approach we control and monitor the number of TFS modes within the range from 1.3 to 4 using only a single fiber.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15162036','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15162036"><span>The repair of gamma-ray-induced chromosomal <span class="hlt">damage</span> in human lymphocytes after exposure to extremely low <span class="hlt">frequency</span> electromagnetic fields.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lloyd, D; Hone, P; Edwards, A; Cox, R; Halls, J</p> <p>2004-01-01</p> <p>G(0) human blood lymphocytes were irradiated with 2.0 Gy gamma-rays and cultured to metaphase whilst held in a 50-Hz power <span class="hlt">frequency</span> magnetic field of 0.23, 0.47 or 0.7 mT. No differences were found in the <span class="hlt">frequencies</span> of gamma-induced chromosome aberrations observed in cells held in the EM fields compared with replicates held in a sham coil. Similar field conditions have been reported to increase the <span class="hlt">frequency</span> of gamma-induced HPRT mutations, leading to a suggestion that the EM fields alter the fidelity of repair of genomic lesions. This was not confirmed by the chromosome aberration assay described here.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MSSP...46..389O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MSSP...46..389O"><span>The local maxima method for enhancement of time-<span class="hlt">frequency</span> map and its application to local <span class="hlt">damage</span> detection in rotating machines</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Obuchowski, Jakub; Wyłomańska, Agnieszka; Zimroz, Radosław</p> <p>2014-06-01</p> <p>In this paper a new method of fault detection in rotating machinery is presented. It is based on a vibration time series analysis in time-<span class="hlt">frequency</span> domain. A raw vibration signal is decomposed via the short-time Fourier transform (STFT). The time-<span class="hlt">frequency</span> map is considered as matrix (M×N) with N sub-signals with length M. Each sub-signal is considered as a time series and might be interpreted as energy variation for narrow <span class="hlt">frequency</span> bins. Each sub-signal is processed using a novel approach called the local maxima method. Basically, we search for local maxima because they should appear in the signal if local <span class="hlt">damage</span> in bearings or gearbox exists. Finally, information for all sub-signals is combined in order to validate impulsive behavior of energy. Due to random character of the obtained time series, each maximum occurrence has to be checked for its significance. If there are time points for which the average number of local maxima for all sub-signals is significantly higher than for the other time instances, then location of these maxima is “weighted” as more important (at this time instance local maxima create for a set of Δf a pattern on the time-<span class="hlt">frequency</span> map). This information, called vector of weights, is used for enhancement of spectrogram. When vector of weights is applied for spectrogram, non-informative energy is suppressed while informative features on spectrogram are enhanced. If the distribution of local maxima on spectrogram creates a pattern of wide-band cyclic energy growth, the machine is suspected of being <span class="hlt">damaged</span>. For healthy condition, the vector of the average number of maxima for each time point should not have outliers, aggregation of information from all sub-signals is rather random and does not create any pattern. The method is illustrated by analysis of very noisy both real and simulated signals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23078776','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23078776"><span><span class="hlt">Core</span>-shell magnetite-silica composite nanoparticles enhancing DNA <span class="hlt">damage</span> induced by a photoactive platinum-diimine complex in red light.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Zhigang; Chai, Aiyun</p> <p>2012-12-01</p> <p>Lack of solubility under physiological conditions poses an additional risk for toxicity and side effects for intravenous delivery of the photodynamic therapeutic agent in vivo. Employing magnetite-silica composite nanoparticles as carriers of the photodynamic therapeutic agents may be a promising way to solve the problem. In this study, <span class="hlt">core</span>-shell magnetite-silica composite nanoparticles were prepared by a sol-gel method, and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering, then they were used as carriers of a photoactive platinum diimine complex. The interactions of the photosensitizer-loaded magnetic composite nanoparticles with DNA in red light were monitored by agarose-gel electrophoresis. The results suggest that high doses of magnetite-silica composite nanoparticles might facilitate the transformation of covalently closed circular (ccc)-DNA band to open circular (oc)-DNA band though they are harmless to DNA at their low concentrations, therefore enhancing the extent of DNA <span class="hlt">damage</span> caused by the metal complex in red light.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15466591','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15466591"><span>Camptothecin enhances the <span class="hlt">frequency</span> of oligonucleotide-directed gene repair in mammalian cells by inducing DNA <span class="hlt">damage</span> and activating homologous recombination.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ferrara, Luciana; Kmiec, Eric B</p> <p>2004-01-01</p> <p>Camptothecin (CPT) is an anticancer drug that promotes DNA breakage at replication forks and the formation of lesions that activate the processes of homologous recombination (HR) and nonhomologous end joining. We have taken advantage of the CPT-induced <span class="hlt">damage</span> response by coupling it to gene repair directed by synthetic oligonucleotides, a process in which a mutant base pair is converted into a wild-type one. Here, we show that pretreating DLD-1 cells with CPT leads to a significant stimulation in the <span class="hlt">frequency</span> of correction of an integrated mutant enhanced green fluorescent protein gene. The stimulation is dose-dependent and coincident with the formation of double-strand DNA breaks. Caffeine, but not vanillin, blocks the enhancement of gene repair suggesting that, in this system, HR is the pathway most responsible for elevating the <span class="hlt">frequency</span> of correction. The involvement of HR is further proven by studies in which wortmannin was seen to inhibit gene repair at high concentrations but not at lower levels that are known to inhibit DNA-PK activity. Taken together, our results suggest that DNA <span class="hlt">damage</span> induced by CPT activates a cellular response that stimulates gene repair in mammalian cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12194305','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12194305"><span>Observation of radiation-specific <span class="hlt">damage</span> in human cells exposed to depleted uranium: dicentric <span class="hlt">frequency</span> and neoplastic transformation as endpoints.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Miller, A C; Xu, J; Stewart, M; Brooks, K; Hodge, S; Shi, L; Page, N; McClain, D</p> <p>2002-01-01</p> <p>Depleted uranium (DU) is a dense heavy metal used primarily in military applications. Published data from our laboratory have demonstrated that DU exposure in vitro to immortalised human osteoblast cells (HOS) is both neoplastically transforming and genotoxic. DU possesses both a radiological (alpha-particle) and chemical (metal) component. Since DU has a low specific activity in comparison to natural uranium, it is not considered to be a significant radiological hazard. The potential contribution of radiation to DU-induced biological effects is unknown and the involvement of radiation in DU-induced biological effects could have significant implications for current risk estimates for internalised DU exposure. Two approaches were used to address this question. The <span class="hlt">frequency</span> of dicentrics was measured in HOS cells following DU exposure in vitro. Data demonstrated that DU exposure (50 microM, 24 h) induced a significant elevation in dicentric <span class="hlt">frequency</span> in vitro in contrast to incubation with the heavy metals, nickel and tungsten which did not increase dicentric <span class="hlt">frequency</span> above background levels. Using the same concentration (50 microM) of three uranyl nitrate compounds that have different uranium isotopic concentrations and therefore, different specific activities, the effect on neoplastic transformation in vitro was examined. HOS cells were exposed to one of three-uranyl nitrate compounds (238U-uranyl nitrate, specific activity 0.33 microCi.g-1; DU-uranyl nitrate, specific activity 0.44 microCi.g-1; and 235U-uranyl nitrate, specific activity 2.2 microCi.g-1) delivered at a concentration of 50 microM for 24 h. Results showed, at equal uranium concentration, there was a specific activity dependent increase in neoplastic transformation <span class="hlt">frequency</span>. Taken together these data suggest that radiation can play a role in DU-induced biological effects in vitro.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PEPS....2...34T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PEPS....2...34T"><span>Complex inner <span class="hlt">core</span> boundary from <span class="hlt">frequency</span> characteristics of the reflection coefficients of PKiKP waves observed by Hi-net</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tanaka, Satoru; Tkalčić, Hrvoje</p> <p>2015-12-01</p> <p><span class="hlt">Frequency</span>-dependent reflection coefficients of P waves at the inner <span class="hlt">core</span> boundary (ICB) are estimated from the spectral ratios of PKiKP and PcP waves observed by the high-sensitivity seismograph network (Hi-net) in Japan. The corresponding PKiKP reflection locations at the ICB are distributed beneath the western Pacific. At <span class="hlt">frequencies</span> where noise levels are sufficiently low, spectra of reflection coefficients show four distinct sets of characteristics: a flat spectrum, a spectrum with a significant spectral hole at approximately 1 or 3 Hz, a spectrum with a strong peak at approximately 2 or 3 Hz, and a spectrum containing both a sharp peak and a significant hole. The variety in observed spectra suggests complex lateral variations in ICB properties. To explain the measured differences in <span class="hlt">frequency</span> characteristics of ICB reflection coefficients, we conduct 2D finite difference simulations of seismic wavefields near the ICB. The models tested in our simulations include a liquid layer and a solid layer above the ICB, as well as sinusoidal and spike-shaped ICB topography with varying heights and scale lengths. We find that the existence of a layer above the ICB can be excluded as a possible explanation for the observed spectra. Furthermore, we find that an ICB topographic model with wavelengths and heights of several kilometers is too extreme to explain our measurements. However, restricting the ICB topography to wavelengths and heights of 1.0-1.5 km can explain the observed <span class="hlt">frequency</span>-related phenomena. The existence of laterally varying topography may be a sign of lateral variations in inner <span class="hlt">core</span> solidification.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12929123','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12929123"><span>A model of sensitivity: 1,3-butadiene increases mutant <span class="hlt">frequencies</span> and genomic <span class="hlt">damage</span> in mice lacking a functional microsomal epoxide hydrolase gene.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wickliffe, Jeffrey K; Ammenheuser, Marinel M; Salazar, James J; Abdel-Rahman, Sherif Z; Hastings-Smith, Darlene A; Postlethwait, Edward M; Lloyd, R Stephen; Ward, Jonathan B</p> <p>2003-01-01</p> <p>The specific role that polymorphisms in xenobiotic metabolizing enzymes play in modulating sensitivity to 1,3-butadiene (BD) genotoxicity has been relatively unexplored. The enzyme microsomal epoxide hydrolase (mEH) is important in detoxifying the mutagenic epoxides of BD (butadiene monoepoxide [BDO], butadiene diepoxide [BDO(2)]). Polymorphisms in the human mEH gene appear to affect the function of the enzyme. We exposed mice with normal mEH activity (WT) and knockout mice without mEH activity (KO) to 20 ppm BD (inhalation) or 30 mg/kg BDO(2) (intraperitoneal [IP] injection). We then compared Hprt mutant <span class="hlt">frequencies</span> (MFs) among these groups. KO mice exposed to BD exhibited a significant (P < 0.05) 12.4-fold increase in MF over controls and a significant 5.4-fold increase in MF over exposed WT mice. Additionally, KO mice exposed to BDO(2) exhibited a significant 4.5-fold increase in MF over controls and a significant 1.7-fold increase in MF over exposed WT mice. We also compared genomic <span class="hlt">damage</span> in WT and KO mice (comet tail moment) following IP exposure to 3 mg/kg and 30 mg/kg BDO(2). KO mice exposed to 3 mg/kg exhibited significantly more DNA <span class="hlt">damage</span> than controls (7.5-12.1-fold increase) and exposed WT mice (3 mg/kg; 4.8-fold increase). KO mice exposed to 30 mg/kg BDO(2) exhibited significantly more DNA <span class="hlt">damage</span> than all other groups (2.3-27.9-fold increase). Correlation analysis indicated that a significant, positive relationship (r(2) = 0.92) exists between comet-measured <span class="hlt">damage</span> and Hprt MFs. The lack of mEH activity increases the genetic sensitivity of mice exposed to BD and BDO(2). This model should facilitate a mechanistic understanding of the observed variation in human genetic sensitivity following exposure to BD. Copyright 2003 Wiley-Liss, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17674186','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17674186"><span>Parent-rated anxiety symptoms in children with pervasive developmental disorders: <span class="hlt">frequency</span> and association with <span class="hlt">core</span> autism symptoms and cognitive functioning.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sukhodolsky, Denis G; Scahill, Lawrence; Gadow, Kenneth D; Arnold, L Eugene; Aman, Michael G; McDougle, Christopher J; McCracken, James T; Tierney, Elaine; Williams White, Susan; Lecavalier, Luc; Vitiello, Benedetto</p> <p>2008-01-01</p> <p>In addition to the <span class="hlt">core</span> symptoms, children with Pervasive Developmental Disorders (PDD) often exhibit other problem behaviors such as aggression, hyperactivity, and anxiety, which can contribute to overall impairment and, therefore, become the focus of clinical attention. Limited data are available on the prevalence of anxiety in these children. We examined <span class="hlt">frequency</span> and correlates of parent-rated anxiety symptoms in a large sample of children with PDD. The goals of this study were to examine the <span class="hlt">frequency</span> and correlates of parent-rated anxiety symptoms in a sample of 171 medication-free children with PDD who participated in two NIH-funded medication trials. Twenty items of the Child and Adolescent Symptom Inventory (CASI) were used to measure anxiety. Forty three percent of the total sample met screening cut-off criteria for at least one anxiety disorder. Higher levels of anxiety on the 20-item CASI scale were associated with higher IQ, the presence of functional language use, and with higher levels of stereotyped behaviors. In children with higher IQ, anxiety was also associated with greater impairment in social reciprocity. Anxiety is common in PDD and warrants consideration in clinical evaluation and treatment planning. This study suggests that parent ratings could be a useful source of information about anxiety symptoms in this population. Some anxiety symptoms such as phobic and social anxiety may be closer to <span class="hlt">core</span> symptoms of PDD. Further efforts to validate tools to ascertain anxiety are needed, as are studies to empirically test approaches to treat anxiety in PDD.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhCS.830a2078I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhCS.830a2078I"><span>Ion-plasma nitriding of austenitic steel in a low-pressure low-<span class="hlt">frequency</span> inductive discharge with ferrite <span class="hlt">core</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Isupov, M. V.; Pinaev, V. A.; Mul, D. O.; Belousova, N. S.</p> <p>2017-05-01</p> <p>An experimental investigation of ion-plasma nitriding of austenitic stainless steel AISI 321 in a low-<span class="hlt">frequency</span> (100 kHz) nitrogen inductive discharge has been performed for the nitrogen pressure of 7 Pa, nitrogen ion densities of 1010-1011 cm-3, sample temperatures of 440-590 °C, the densities of current on the sample surface of 1.2-3.3 mA/cm2, sample biases of -500 and -750 V. The time of ion-plasma treatment was 20 and 60 min. It is shown that even for the short (20 min.) ion-plasma treatment in the low-<span class="hlt">frequency</span> inductive discharge, formation of nitrided layers with the thickness of up to 40 μm and microhardness of up to 9 GPa is observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3446842','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3446842"><span>Indomethacin-loaded lipid-<span class="hlt">core</span> nanocapsules reduce the <span class="hlt">damage</span> triggered by Aβ1-42 in Alzheimer’s disease models</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bernardi, Andressa; Frozza, Rudimar L; Meneghetti, André; Hoppe, Juliana B; Battastini, Ana Maria O; Pohlmann, Adriana R; Guterres, Sílvia S; Salbego, Christianne G</p> <p>2012-01-01</p> <p>Neuroinflammation, characterized by the accumulation of activated microglia and reactive astrocytes, is believed to modulate the development and/or progression of Alzheimer’s disease (AD). Epidemiological studies suggesting that nonsteroidal anti-inflammatory drugs decrease the risk of developing AD have encouraged further studies elucidating the role of inflammation in AD. Nanoparticles have become an important focus of neurotherapeutic research because they are an especially effective form of drug delivery. Here, we investigate the potential protective effect of indomethacin-loaded lipid-<span class="hlt">core</span> nanocapsules (IndOH-LNCs) against cell <span class="hlt">damage</span> and neuroinflammation induced by amyloid beta (Aβ)1-42 in AD models. Our results show that IndOH-LNCs attenuated Aβ-induced cell death and were able to block the neuroinflammation triggered by Aβ1-42 in organotypic hippocampal cultures. Additionally, IndOH-LNC treatment was able to increase interleukin-10 release and decrease glial activation and c-jun N-terminal kinase phosphorylation. As a model of Aβ-induced neurotoxicity in vivo, animals received a single intracerebroventricular injection of Aβ1-42 (1 nmol/site), and 1 day after Aβ1-42 infusion, they were administered either free IndOH or IndOH-LNCs (1 mg/kg, intraperitoneally) for 14 days. Only the treatment with IndOH-LNCs significantly attenuated the impairment of this behavior triggered by intracerebroventricular injection of Aβ1-42. Further, treatment with IndOH-LNCs was able to block the decreased synaptophysin levels induced by Aβ1-42 and suppress glial and microglial activation. These findings might be explained by the increase of IndOH concentration in brain tissue attained using drug-loaded lipid-<span class="hlt">core</span> NCs. All these findings support the idea that blockage of neuroinflammation triggered by Aβ is involved in the neuroprotective effects of IndOH-LNCs. These data provide strong evidence that IndOH-LNC treatment may represent a promising approach for treating</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20822138','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20822138"><span>Neutron Fluence, Dosimetry and <span class="hlt">Damage</span> Response Determination in In-<span class="hlt">Core/Ex-Core</span> Components of the VENUS CEN/SCK LWR Using 3-D Monte Carlo Simulations: NEA's VENUS-3 Benchmark</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Perlado, J. Manuel; Marian, Jaime; Sanz, Jesus Garcia</p> <p>2000-03-15</p> <p>Validating state-of-the-art methods used to predict fluence exposure to reactor pressure vessels (RPVs) has become an important issue in identifying the sources of uncertainty in the estimated RPV fluence for pressurized water reactors. This is a very important aspect in evaluating irradiation <span class="hlt">damage</span> leading to the hardening and embrittlement of such structural components. One of the major benchmark experiments carried out to test three-dimensional methodologies is the VENUS-3 Benchmark Experiment in which three-dimensional Monte Carlo and S{sub n} codes have proved more efficient than synthesis methods. At the Instituto de Fusion Nuclear (DENIM) at the Universidad Politecnica de Madrid, a detailed full three-dimensional model of the Venus Critical Facility has been developed making use of the Monte Carlo transport code MCNP4B. The problem geometry and source modeling are described, and results, including calculated versus experimental (C/E) ratios as well as additional studies, are presented. Evidence was found that the great majority of C/E values fell within the 10% tolerance and most within 5%. Tolerance limits are discussed on the basis of evaluated data library and fission spectra sensitivity, where a value ranging between 10 to 15% should be accepted. Also, a calculation of the atomic displacement rate has been carried out in various locations throughout the reactor, finding that values of 0.0001 displacements per atom in external components such as the <span class="hlt">core</span> barrel are representative of this type of reactor during a 30-yr time span.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE10000E..03F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE10000E..03F"><span>Current status of the dual-<span class="hlt">frequency</span> precipitation radar on the global precipitation measurement <span class="hlt">core</span> spacecraft and the new version of GPM standard products</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Furukawa, K.; Nio, T.; Konishi, T.; Masaki, T.; Kubota, T.; Oki, R.; Iguchi, T.</p> <p>2016-10-01</p> <p>The Dual-<span class="hlt">frequency</span> Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) <span class="hlt">core</span> satellite was developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT). The objective of the GPM mission is to observe global precipitation more frequently and accurately. The GPM <span class="hlt">core</span> satellite is a joint product of National Aeronautics and Space Administration (NASA), JAXA and NICT. NASA developed the satellite bus and the GPM Microwave Imager (GMI), and JAXA and NICT developed the DPR. The inclination of the GPM <span class="hlt">core</span> satellite is 65 degrees, and the nominal flight altitude is 407 km. The non-sunsynchronous circular orbit is necessary for measuring the diurnal change of rainfall. The DPR consists of two radars, which are Ku-band precipitation radar (KuPR) and Ka-band precipitation radar (KaPR). GPM <span class="hlt">core</span> observatory was successfully launched by H2A launch vehicle on Feb. 28, 2014. DPR keeps its performances on orbit after launch. DPR products were released to the public on Sep. 2, 2014. JAXA is continuing DPR trend monitoring, calibration and validation operations to confirm that DPR keeps its function and performance on orbit. JAXA have started to provide new version (Version 4) of GPM standard products on March 3, 2016. Various improvements of the DPR algorithm were implemented in the Version 4 product. Moreover, the latent heat product based on the Spectral Latent Heating (SLH) algorithm is available since Version 4 product. Current orbital operation status of the GPM/DPR and highlights of the Version 4 product are reported.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960022789','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960022789"><span>Accurate Predictions of Mean Geomagnetic Dipole Excursion and Reversal <span class="hlt">Frequencies</span>, Mean Paleomagnetic Field Intensity, and the Radius of Earth's <span class="hlt">Core</span> Using McLeod's Rule</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Voorhies, Coerte V.; Conrad, Joy</p> <p>1996-01-01</p> <p> intensity, and mean geomagnetic dipole power excursion and axial dipole reversal <span class="hlt">frequencies</span>. We conclude that McLeod's Rule helps unify geo-paleomagnetism, correctly relates theoretically predictable statistical properties of the <span class="hlt">core</span> geodynamo to magnetic observation, and provides a priori information required for stochastic inversion of paleo-, archeo-, and/or historical geomagnetic measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26300641','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26300641"><span>Caenorhabditis elegans as an alternative in vivo model to determine oral uptake, nanotoxicity, and efficacy of melatonin-loaded lipid-<span class="hlt">core</span> nanocapsules on paraquat <span class="hlt">damage</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Charão, Mariele Feiffer; Souto, Caroline; Brucker, Natália; Barth, Anelise; Jornada, Denise S; Fagundez, Daiandra; Ávila, Daiana Silva; Eifler-Lima, Vera L; Guterres, Silvia S; Pohlmann, Adriana R; Garcia, Solange Cristina</p> <p>2015-01-01</p> <p>Caenorhabditis elegans is an alternative in vivo model that is being successfully used to assess the pharmacological and toxic effects of drugs. The exponential growth of nanotechnology requires the use of alternative in vivo models to assess the toxic effects of theses nanomaterials. The use of polymeric nanocapsules has shown promising results for drug delivery. Moreover, these formulations have not been used in cases of intoxication, such as in treatment of paraquat (PQ) poisoning. Thus, the use of drugs with properties improved by nanotechnology is a promising approach to overcome the toxic effects of PQ. This research aimed to evaluate the absorption of rhodamine B-labeled melatonin (Mel)-loaded lipid-<span class="hlt">core</span> nanocapsules (LNC) by C. elegans, the application of this model in nanotoxicology, and the protection of Mel-LNC against PQ <span class="hlt">damage</span>. The formulations were prepared by self-assembly and characterized by particle sizing, zeta potential, drug content, and encapsulation efficiency. The results demonstrated that the formulations had narrow size distributions. Rhodamine B-labeled Mel-LNC were orally absorbed and distributed in the worms. The toxicity assessment of LNC showed a lethal dose 50% near the highest dose tested, indicating low toxicity of the nanocapsules. Moreover, pretreatment with Mel-LNC significantly increased the survival rate, reduced the reactive oxygen species, and maintained the development in C. elegans exposed to PQ compared to those worms that were either untreated or pretreated with free Mel. These results demonstrated for the first time the uptake and distribution of Mel-LNC by a nematode, and indicate that while LNC is not toxic, Mel-LNC prevents the effects of PQ poisoning. Thus, C. elegans may be an interesting alternative model to test the nanocapsules toxicity and efficacy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4536844','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4536844"><span>Caenorhabditis elegans as an alternative in vivo model to determine oral uptake, nanotoxicity, and efficacy of melatonin-loaded lipid-<span class="hlt">core</span> nanocapsules on paraquat <span class="hlt">damage</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Charão, Mariele Feiffer; Souto, Caroline; Brucker, Natália; Barth, Anelise; Jornada, Denise S; Fagundez, Daiandra; Ávila, Daiana Silva; Eifler-Lima, Vera L; Guterres, Silvia S; Pohlmann, Adriana R; Garcia, Solange Cristina</p> <p>2015-01-01</p> <p>Caenorhabditis elegans is an alternative in vivo model that is being successfully used to assess the pharmacological and toxic effects of drugs. The exponential growth of nanotechnology requires the use of alternative in vivo models to assess the toxic effects of theses nanomaterials. The use of polymeric nanocapsules has shown promising results for drug delivery. Moreover, these formulations have not been used in cases of intoxication, such as in treatment of paraquat (PQ) poisoning. Thus, the use of drugs with properties improved by nanotechnology is a promising approach to overcome the toxic effects of PQ. This research aimed to evaluate the absorption of rhodamine B-labeled melatonin (Mel)-loaded lipid-<span class="hlt">core</span> nanocapsules (LNC) by C. elegans, the application of this model in nanotoxicology, and the protection of Mel-LNC against PQ <span class="hlt">damage</span>. The formulations were prepared by self-assembly and characterized by particle sizing, zeta potential, drug content, and encapsulation efficiency. The results demonstrated that the formulations had narrow size distributions. Rhodamine B-labeled Mel-LNC were orally absorbed and distributed in the worms. The toxicity assessment of LNC showed a lethal dose 50% near the highest dose tested, indicating low toxicity of the nanocapsules. Moreover, pretreatment with Mel-LNC significantly increased the survival rate, reduced the reactive oxygen species, and maintained the development in C. elegans exposed to PQ compared to those worms that were either untreated or pretreated with free Mel. These results demonstrated for the first time the uptake and distribution of Mel-LNC by a nematode, and indicate that while LNC is not toxic, Mel-LNC prevents the effects of PQ poisoning. Thus, C. elegans may be an interesting alternative model to test the nanocapsules toxicity and efficacy. PMID:26300641</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNH31D..05G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNH31D..05G"><span>Watershed erosion estimated from a high-resolution sediment <span class="hlt">core</span> reveals a non-stationary <span class="hlt">frequency</span>-magnitude relationship and importance of seasonal climate drivers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gavin, D. G.; Colombaroli, D.; Morey, A. E.</p> <p>2015-12-01</p> <p>The inclusion of paleo-flood events greatly affects estimates of peak magnitudes (e.g., Q100) in flood-<span class="hlt">frequency</span> analysis. Likewise, peak events also are associated with certain synoptic climatic patterns that vary on all time scales. Geologic records preserved in lake sediments have the potential to capture the non-stationarity in <span class="hlt">frequency</span>-magnitude relationships, but few such records preserve a continuous history of event magnitudes. We present a 10-meter 2000-yr record from Upper Squaw Lake, Oregon, that contains finely laminated silt layers that reflect landscape erosion events from the 40 km2 watershed. CT-scans of the <span class="hlt">core</span> (<1 mm resolution) and a 14C-dated chronology yielded a pseudo-annual time series of erosion magnitudes. The most recent 80 years of the record correlates strongly with annual peak stream discharge and road construction. We examined the <span class="hlt">frequency</span>-magnitude relationship for the entire pre-road period and show that the seven largest events fall above a strongly linear relationship, suggesting a distinct process (e.g., severe fires or earthquakes) operating at low-<span class="hlt">frequency</span> to generate large-magnitude events. Expressing the record as cumulative sediment accumulation anomalies showed the importance of the large events in "returning the system" to the long-term mean rate. Applying <span class="hlt">frequency</span>-magnitude analysis in a moving window showed that the Q100 and Q10 of watershed erosion varied by 1.7 and 1.0 orders of magnitude, respectively. The variations in watershed erosion are weakly correlated with temperature and precipitation reconstructions at the decadal to centennial scale. This suggests that dynamics both internal (i.e., sediment production) and external (i.e., earthquakes) to the system, as well as more stochastic events (i.e., single severe wildfires) can at least partially over-ride external climate forcing of watershed erosion at decadal to centennial time scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5341068','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5341068"><span>Comparison of high <span class="hlt">frequency</span>, high temperature <span class="hlt">core</span> loss and B-H loop characteristics of an 80 Ni-Fe crystalline alloy and two iron-based amorphous alloys. [Ni; Fe</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wieserman, W.R. ); Schwarze, G.E. ); Niedra, J.M. )</p> <p>1991-01-10</p> <p>Limited experimental data exists for the specific <span class="hlt">core</span> loss and dynamic B-H loops for soft magnetic materials for the combined conditions of high <span class="hlt">frequency</span> and high temperature. This experimental study investigates the specific <span class="hlt">core</span> loss and dynamic B-H characteristics of a nickel-iron crystalline magnetic alloy (Supermalloy) and two-iron-based amorphous magnetic materials (Metglas 2605S-3A and Metglas 2605SC) over the <span class="hlt">frequency</span> range of 1--50 kHz and temperature range of 23--300 C under sinusoidal voltage excitation. The effects of maximum magnetic flux density, <span class="hlt">frequency</span>, and temperature on the specific <span class="hlt">core</span> loss and on the size and shape of the B-H loops are examined. The Supermalloy and Metglas 2605S-3A and 2605SC data are used to compare the <span class="hlt">core</span> loss of transformers with identical kVA and voltage ratings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23764910','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23764910"><span>The preventive effect of lotus seedpod procyanidins on cognitive impairment and oxidative <span class="hlt">damage</span> induced by extremely low <span class="hlt">frequency</span> electromagnetic field exposure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Duan, Yuqing; Wang, Zhigao; Zhang, Haihui; He, Yuanqing; Lu, Rongzhu; Zhang, Rui; Sun, Guibo; Sun, Xiaobo</p> <p>2013-08-01</p> <p>The present study investigated the effects of lotus seedpod procyanidins (LSPCs) administered by oral gavage on the cognitive deficits and oxidative <span class="hlt">damage</span> of mice at extremely low <span class="hlt">frequency</span> electromagnetic field (ELF-EMF) exposure (50 Hz, 8 mT, 28 days). The results showed that 90 mg kg⁻¹ LSPCs treatment significantly increased body weight compared with the ELF-EMF group at ELF-EMF exposure and effectively maintained liver index, thymus index, kidney index and spleen index close to normal. A water maze test indicated that learning and memory abilities of the ELF-EMF group deteriorated significantly with ELF-EMF exposure when compared with the control group, but the ELF-EMF + LSPCs90 group had remarkably improved learning and memory abilities compared with the ELF-EMF group. Malondialdehyde (MDA), reactive oxygen species (ROS), nitric oxide (NO) and nitric oxide synthase (NOS) mostly exhibited significant increases, while the activities of glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) decreased significantly under ELF-EMF exposure in the ELF-EMF group. LSPCs (especially 60, 90 mg kg⁻¹) administration decreased MDA, ROS, NO content and lowered NOS activity in LSPCs treatment groups. Furthermore, LSPCs (60, 90 mg kg⁻¹) treatment significantly augmented GPx, CAT, SOD activity in the hippocampus and serum. Pathological observation showed that number of pyramidal cells of the CA1 and CA3 regions of the hippocampus of the LSPCs treatment groups was significantly greater than the ELF-EMF group. All the data suggested that the LSPCs can effectively prevent learning and memory <span class="hlt">damage</span> and oxidative <span class="hlt">damage</span> caused by the ELF-EMF, most likely through the ability of LSPCs to scavenge oxygen free radicals and to stimulate antioxidant enzyme activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26593871','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26593871"><span>Relationships between range access as monitored by radio <span class="hlt">frequency</span> identification technology, fearfulness, and plumage <span class="hlt">damage</span> in free-range laying hens.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hartcher, K M; Hickey, K A; Hemsworth, P H; Cronin, G M; Wilkinson, S J; Singh, M</p> <p>2016-05-01</p> <p>Severe feather-pecking (SFP), a particularly injurious behaviour in laying hens (Gallus gallus domesticus), is thought to be negatively correlated with range use in free-range systems. In turn, range use is thought to be inversely associated with fearfulness, where fearful birds may be less likely to venture outside. However, very few experiments have investigated the proposed association between range use and fearfulness. This experiment investigated associations between range use (time spent outside), fearfulness, plumage <span class="hlt">damage</span>, and BW. Two pens of 50 ISA Brown laying hens (n=100) were fitted with radio <span class="hlt">frequency</span> identification (RFID) transponders (contained within silicone leg rings) at 26 weeks of age. Data were then collected over 13 days. A total of 95% of birds accessed the outdoor run more than once per day. Birds spent an average duration of 6.1 h outside each day over 11 visits per bird per day (51.5 min per visit). The top 15 and bottom 15 range users (n=30), as determined by the total time spent on the range over 13 days, were selected for study. These birds were tonic immobility (TI) tested at the end of the trial and were feather-scored and weighed after TI testing. Birds with longer TI durations spent less time outside (P=0.01). Plumage <span class="hlt">damage</span> was not associated with range use (P=0.68). The small group sizes used in this experiment may have been conducive to the high numbers of birds utilising the outdoor range area. The RFID technology collected a large amount of data on range access in the tagged birds, and provides a potential means for quantitatively assessing range access in laying hens. The present findings indicate a negative association between fearfulness and range use. However, the proposed negative association between plumage <span class="hlt">damage</span> and range use was not supported. The relationships between range use, fearfulness, and SFP warrant further research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22461999','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22461999"><span>Nanoscale analysis of unstained biological specimens in water without radiation <span class="hlt">damage</span> using high-resolution <span class="hlt">frequency</span> transmission electric-field system based on FE-SEM</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ogura, Toshihiko</p> <p>2015-04-10</p> <p>Scanning electron microscopy (SEM) has been widely used to examine biological specimens of bacteria, viruses and proteins. Until now, atmospheric and/or wet biological specimens have been examined using various atmospheric holders or special equipment involving SEM. Unfortunately, they undergo heavy radiation <span class="hlt">damage</span> by the direct electron beam. In addition, images of unstained biological samples in water yield poor contrast. We recently developed a new analytical technology involving a <span class="hlt">frequency</span> transmission electric-field (FTE) method based on thermionic SEM. This method is suitable for high-contrast imaging of unstained biological specimens. Our aim was to optimise the method. Here we describe a high-resolution FTE system based on field-emission SEM; it allows for imaging and nanoscale examination of various biological specimens in water without radiation <span class="hlt">damage</span>. The spatial resolution is 8 nm, which is higher than 41 nm of the existing FTE system. Our new method can be easily utilised for examination of unstained biological specimens including bacteria, viruses and protein complexes. Furthermore, our high-resolution FTE system can be used for diverse liquid samples across a broad range of scientific fields, e.g. nanoparticles, nanotubes and organic and catalytic materials. - Highlights: • We developed a high-resolution <span class="hlt">frequency</span> transmission electric-field (FTE) system. • High-resolution FTE system is introduced in the field-emission SEM. • The spatial resolution of high-resolution FTE method is 8 nm. • High-resolution FTE system enables observation of the intact IgM particles in water.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20373468','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20373468"><span>Experimental chronic low-<span class="hlt">frequency</span> resistance training produces skeletal muscle hypertrophy in the absence of muscle <span class="hlt">damage</span> and metabolic stress markers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zanchi, Nelo Eidy; Lira, Fabio Santos; Seelaender, Marilia; Lancha-Jr, Antonio Herbert</p> <p>2010-04-01</p> <p>Volitional animal resistance training constitutes an important approach to modeling human resistance training. However, the lack of standardization protocol poses a frequent impediment to the production of skeletal muscle hypertrophy and the study of related physiological variables (i.e., cellular <span class="hlt">damage</span>/inflammation or metabolic stress). Therefore, the purposes of the present study were: (1) to test whether a long-term and low <span class="hlt">frequency</span> experimental resistance training program is capable of producing absolute increases in muscle mass; (2) to examine whether cellular <span class="hlt">damage</span>/inflammation or metabolic stress is involved in the process of hypertrophy. In order to test this hypothesis, animals were assigned to a sedentary control (C, n = 8) or a resistance trained group (RT, n = 7). Trained rats performed 2 exercise sessions per week (16 repetitions per day) during 12 weeks. Our results demonstrated that the resistance training strategy employed was capable of producing absolute mass gain in both soleus and plantaris muscles (12%, p < 0.05). Furthermore, muscle tumor necrosis factor (TNF-alpha) protein expression (soleus muscle) was reduced by 24% (p < 0.01) in trained group when compared to sedentary one. Finally, serum creatine kinase (CK) activity and serum lactate concentrations were not affected in either group. Such information may have practical applications if reproduced in situations where skeletal muscle hypertrophy is desired but high mechanical stimuli of skeletal muscle and inflammation are not. Copyright (c) 2010 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2259236','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2259236"><span>High-precision <span class="hlt">frequency</span> measurements: indispensable tools at the <span class="hlt">core</span> of the molecular-level analysis of complex systems</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ruecker, C.; Meringer, M.; Gugisch, R.; Frommberger, M.; Perdue, E. M.; Witt, M.; Schmitt-Kopplin, P.</p> <p>2007-01-01</p> <p>This perspective article provides an assessment of the state-of-the-art in the molecular-resolution analysis of complex organic materials. These materials can be divided into biomolecules in complex mixtures (which are amenable to successful separation into unambiguously defined molecular fractions) and complex nonrepetitive materials (which cannot be purified in the conventional sense because they are even more intricate). Molecular-level analyses of these complex systems critically depend on the integrated use of high-performance separation, high-resolution organic structural spectroscopy and mathematical data treatment. At present, only high-precision <span class="hlt">frequency</span>-derived data exhibit sufficient resolution to overcome the otherwise common and detrimental effects of intrinsic averaging, which deteriorate spectral resolution to the degree of bulk-level rather than molecular-resolution analysis. High-precision <span class="hlt">frequency</span> measurements are integral to the two most influential organic structural spectroscopic methods for the investigation of complex materials—NMR spectroscopy (which provides unsurpassed detail on close-range molecular order) and FTICR mass spectrometry (which provides unrivalled resolution)—and they can be translated into isotope-specific molecular-resolution data of unprecedented significance and richness. The quality of this standalone de novo molecular-level resolution data is of unparalleled mechanistic relevance and is sufficient to fundamentally advance our understanding of the structures and functions of complex biomolecular mixtures and nonrepetitive complex materials, such as natural organic matter (NOM), aerosols, and soil, plant and microbial extracts, all of which are currently poorly amenable to meaningful target analysis. The discrete analytical volumetric pixel space that is presently available to describe complex systems (defined by NMR, FT mass spectrometry and separation technologies) is in the range of 108–14 voxels, and is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Nanos...8.6589W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Nanos...8.6589W"><span>Novel photoswitchable dielectric properties on nanomaterials of electronic <span class="hlt">core</span>-shell γ-FeOx@Au@fullerosomes for GHz <span class="hlt">frequency</span> applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Min; Su, Chefu; Yu, Tzuyang; Tan, Loon-Seng; Hu, Bin; Urbas, Augustine; Chiang, Long Y.</p> <p>2016-03-01</p> <p>We unexpectedly observed a large amplification of the dielectric properties associated with the photoswitching effect and the new unusual phenomenon of delayed photoinduced capacitor-like (i.e. electric polarization) behavior at the interface on samples of three-layered <span class="hlt">core</span>-shell (γ-FeOx@AuNP)@[C60(>DPAF-C9)]n2 nanoparticles (NPs) in <span class="hlt">frequencies</span> of 0.5-4.0 GHz. The detected relative dielectric constant amplification was initiated upon switching off the light followed by relaxation to give an excellent recyclability. These NPs having e--polarizable fullerosomic structures located at the outer layer were fabricated from highly magnetic <span class="hlt">core</span>-shell γ-FeOx@AuNPs. Surface-stabilized 2 in a <span class="hlt">core</span>-shell structure was found to be capable of photoinducing the surface plasmonic resonance (SPR) effect by white LED light. The accumulated SPR energy was subsequently transferred to the partially bilayered C60(>DPAF-C9) fullerosomic membrane layer in a near-field (~1.5 nm) region without producing radiation heat. Since the monostatic SAR signal is dielectric property-dependent, we used these measurements to provide evidence of derived reflectivity changes on a surface coated with 2 at 0.5-4.0 GHz upon illumination of LED white light. We found that a high, >99%, efficiency of response amplification in image amplitude can be achieved.We unexpectedly observed a large amplification of the dielectric properties associated with the photoswitching effect and the new unusual phenomenon of delayed photoinduced capacitor-like (i.e. electric polarization) behavior at the interface on samples of three-layered <span class="hlt">core</span>-shell (γ-FeOx@AuNP)@[C60(>DPAF-C9)]n2 nanoparticles (NPs) in <span class="hlt">frequencies</span> of 0.5-4.0 GHz. The detected relative dielectric constant amplification was initiated upon switching off the light followed by relaxation to give an excellent recyclability. These NPs having e--polarizable fullerosomic structures located at the outer layer were fabricated from highly magnetic <span class="hlt">core</span>-shell </p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10088E..0GA','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10088E..0GA"><span>Exploring nonlinear pulse propagation, Raman <span class="hlt">frequency</span> conversion and near octave spanning supercontinuum generation in atmospheric air-filled hollow-<span class="hlt">core</span> Kagomé fiber</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abokhamis Mousavi, Seyedmohammad; Mulvad, Hans Christian Hansen; Wheeler, Natalie; Horak, Peter; Bradley, Thomas D.; Alam, Shaif-ul; Hayes, John; Sandoghchi, Seyed Reza; Richardson, David; Poletti, Francesco</p> <p>2017-02-01</p> <p>We have demonstrated Raman <span class="hlt">frequency</span> conversion and supercontinuum light generation in a hollow <span class="hlt">core</span> Kagomé fiber filled with air at atmospheric pressure, and developed a numerical model able to explain the results with good accuracy. A solid-state disk laser was used to launch short pulses ( 6ps) at 1030nm into an in-house fabricated hollow <span class="hlt">core</span> Kagomé fiber with negative <span class="hlt">core</span> curvature and both ends were open to the atmosphere. The fiber had a 150 THz wide transmission window and a record low loss of 12 dB/km at the pump wavelength. By gradually increasing the pulse energy up to 250 μJ, we observed the onset of different Kerr and Raman based optical nonlinear processes, resulting in a supercontinuum spanning from 850 to 1600 nm at maximum input power. In order to study the pulse propagation dynamics of the experiment, we used a generalized nonlinear Schrödinger equation (GNLSE). Our simulations showed that the use of a conventional damping oscillator model for the time-dependent response of the rotational Raman component of air was not accurate enough at such high intensities and large pulse widths. Therefore, we adopted a semiquantum Raman model for air, which included the full rotational and vibrational response, and their temperature-induced broadening. With this, our GNLSE results matched well the experimental data, which allowed us to clearly identify the nonlinear phenomena involved in the process. Aside from the technological interest in the high spectral density of the supercontinuum demonstrated, the validated numerical model can provide a valuable optimization tool for gas based nonlinear processes in air-filled fibers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70035571','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70035571"><span>Comparison of clast <span class="hlt">frequency</span> and size in the resurge deposits at the Chesapeake Bay impact structure (Eyreville A and Langley <span class="hlt">cores</span>): Clues to the resurge process</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ormo, J.; Sturkell, E.; Horton, J.W.; Powars, D.S.; Edwards, L.E.</p> <p>2009-01-01</p> <p>Collapse and inward slumping of unconsolidated sedimentary strata expanded the Chesapeake Bay impact structure far beyond its central basement crater. During crater collapse, sediment-loaded water surged back to fill the crater. Here, we analyze clast <span class="hlt">frequency</span> and granulometry of these resurge deposits in one <span class="hlt">core</span> hole from the outermost part of the collapsed zone (i.e., Langley) as well as a <span class="hlt">core</span> hole from the moat of the basement crater (i.e., Eyreville A). Comparisons of clast provenance and flow dynamics show that at both locations, there is a clear change in clast <span class="hlt">frequency</span> and size between a lower unit, which we interpret to be dominated by slumped material, and an upper, water-transported unit, i.e., resurge deposit. The contribution of material to the resurge deposit was primarily controlled by stripping and erosion. This includes entrainment of fallback ejecta and sediments eroded from the surrounding seafloor, found to be dominant at Langley, and slumped material that covered the annular trough and basement crater, found to be dominant at Eyreville. Eyreville shows a higher content of crystalline clasts than Langley. There is equivocal evidence for an anti-resurge from a collapsing central water plume or, alternatively, a second resurge pulse, as well as a transition into oscillating resurge. The resurge material shows more of a debris-flow-like transport compared to resurge deposits at some other marine target craters, where the ratio of sediment to water has been relatively low. This result is likely a consequence of the combination of easily disaggregated host sediments and a relatively shallow target water depth. ?? 2009 The Geological Society of America.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27467519','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27467519"><span>Detection of Successful and Unsuccessful Pregnancies in Mice within Hours of Pairing through <span class="hlt">Frequency</span> Analysis of High Temporal Resolution <span class="hlt">Core</span> Body Temperature Data.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Smarr, Benjamin L; Zucker, Irving; Kriegsfeld, Lance J</p> <p>2016-01-01</p> <p>Many controllable factors negatively impact fetal development, underscoring the importance of early pregnancy detection and identification of events that reliably predict potential complications. Clinically, <span class="hlt">core</span> body temperature (CBT) is used to aid family planning and pregnancy detection. However, such temperature data typically are gathered in single, daily measurements. In animal studies, interventions or cell/tissue harvesting at defined stages of fetal development are arduous, requiring timed mating by trained observers. The value of continuous temperature measurements remains largely unexplored, but the advent of small, inexpensive, and increasingly ubiquitous, accurate sensor devices makes continuous measures feasible. Here, using a mouse model, we show that continuous, 1-min resolution CBT measurements reliably allow for the earliest and most accurate detection of pregnancy (100%, within 14 h of initial pairing), without requiring interaction with the animal for data collection. This method also reveals a subset of females that exhibit a pregnancy-like response following pairing that persists for a variable number of days. Application of wavelet analysis that permits <span class="hlt">frequency</span> analysis while preserving temporal resolution, uncovers significant differences in ultradian <span class="hlt">frequencies</span> of CBT; these rhythms are significantly increased in the 12 h after the day of pairing for pregnancies carried to term compared to apparent pregnancies that failed. High temporal resolution CBT and wavelet analysis permit strikingly early detection and separation of successful pregnancies and pregnancy-like events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920021154','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920021154"><span>Comparison of high temperature, high <span class="hlt">frequency</span> <span class="hlt">core</span> loss and dynamic B-H loops of a 2V-49Fe-49Co and a grain oriented 3Si-Fe alloy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wieserman, W. R.; Schwarze, G. E.; Niedra, J. M.</p> <p>1992-01-01</p> <p>The design of power magnetic components such as transformers, inductors, motors, and generators, requires specific knowledge about the magnetic and electrical characteristics of the magnetic materials used in these components. Limited experimental data exists that characterizes the performance of soft magnetic materials for the combined conditions of high temperature and high <span class="hlt">frequency</span> over a wide flux density range. An experimental investigation of a 2V-49-Fe-49Co (Supermendur) and a grain oriented 3 Si-Fe (Magnesil) alloy was conducted over the temperature range of 23 to 300 C and <span class="hlt">frequency</span> range of 0.1 to 10 kHz. The effects of temperature, <span class="hlt">frequency</span>, and maximum flux density on the <span class="hlt">core</span> loss and dynamic B-H loops for sinusoidal voltage excitation conditions are examined for each of these materials. A comparison of the <span class="hlt">core</span> loss of these two materials is also made over the temperature and <span class="hlt">frequency</span> range investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910023098','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910023098"><span>Comparison of high temperature, high <span class="hlt">frequency</span> <span class="hlt">core</span> loss and dynamic B-H loops of two 50 Ni-Fe crystalline alloys and an iron-based amorphous alloy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wieserman, W. R.; Schwarze, G. E.; Niedra, J. M.</p> <p>1991-01-01</p> <p>The availability of experimental data that characterizes the performance of soft magnetic materials for the combined conditions of high temperature and high <span class="hlt">frequency</span> is almost nonexistent. An experimental investigation was conducted over the temperature range of 23 to 300 C and <span class="hlt">frequency</span> range of 1 to 50 kHz to determine the effects of temperature and <span class="hlt">frequency</span> on the <span class="hlt">core</span> loss and dynamic B-H loops of three different soft magnetic materials; and oriented grain 50Ni-50Fe alloy, a nonoriented grain 50Ni-Fe alloy, and an iron based amorphous material (Metglas 2605SC). A comparison of these materials shows that the nonoriented grain 50Ni-50Fe alloy tends to have either the lowest or next lowest <span class="hlt">core</span> loss for all temperatures and <span class="hlt">frequencies</span> investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28275231','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28275231"><span>The ratio of monocyte <span class="hlt">frequency</span> to HDL cholesterol level as a predictor of asymptomatic organ <span class="hlt">damage</span> in patients with primary hypertension.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aydin, Emel; Ates, Ihsan; Fettah Arikan, Mehmet; Yilmaz, Nisbet; Dede, Fatih</p> <p>2017-08-01</p> <p>This study aimed to examine the relationship between the ratio of monocyte <span class="hlt">frequency</span> to high-density lipoprotein (HDL) cholesterol level (the monocyte/HDL ratio (MHR)) and asymptomatic organ <span class="hlt">damage</span> (AOD) in primary hypertension (PHT). A total of 366 participants were enrolled in the study, including 275 cases currently being followed up after a diagnosis of PHT in our clinic and 91 healthy volunteers. The MHR was higher in patients with PHT than in individuals in the control group. In the PHT group, the MHR was higher in patients with AOD (AOD+) than in patients without AOD (AOD-). In the correlation analyses performed in the PHT group, there were positive correlations between the MHR and the following AOD indicators: carotid intima media thickness, left ventricular mass index, urinary protein levels and urinary albumin levels. In a multivariate linear regression analysis, the MHR was found to be an independent risk factor associated with these indicators of AOD. In conclusion, our study shows that MHR is associated with AOD in patients with PHT.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PhDT.......171H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PhDT.......171H"><span>An effective data mining approach for structure <span class="hlt">damage</span> identification</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hong, Soonyoung</p> <p></p> <p>An efficient, neural network based, online nondestructive structural <span class="hlt">damage</span> identification procedure is developed for determining the <span class="hlt">damage</span> characteristics (the <span class="hlt">damage</span> locations and the corresponding severity) from dynamic measurements in near real-time. The procedure utilizes unique data processing techniques to track the most useful modal information based on modal strain energy and to calculate the associated data based on principal component analysis for further processing in a neural network based identification scheme. With two unique features, this approach is significantly different from currently available <span class="hlt">damage</span> identification procedures for real-time structural integrity monitoring/diagnostics. First, the most sensitive mode for the specific <span class="hlt">damage</span> is selected in an automatic process which increases the accuracy of <span class="hlt">damage</span> identification and decreases time spent on neural network training. Second, the approach creates unique data that extracts <span class="hlt">core</span> characteristics from modal information for a number of different <span class="hlt">damage</span> cases; and consequently, the accuracy of the <span class="hlt">damage</span> identification improves significantly. This approach can be operated online providing real time structural <span class="hlt">damage</span> identification. The method is tested for simulated <span class="hlt">damage</span> cases, including situations of single and multiple <span class="hlt">damage</span> in the closely-spaced <span class="hlt">frequencies</span> of Kabe's model. The philosophy behind the proposed research is to provide a means to online and nondestructively predict the degradation of a structure's integrity (i.e. <span class="hlt">damage</span> location and the corresponding severity, strength loss).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27653782','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27653782"><span>The communicative impairment as a <span class="hlt">core</span> feature of schizophrenia: <span class="hlt">Frequency</span> of pragmatic deficit, cognitive substrates, and relation with quality of life.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bambini, Valentina; Arcara, Giorgio; Bechi, Margherita; Buonocore, Mariachiara; Cavallaro, Roberto; Bosia, Marta</p> <p>2016-11-01</p> <p>Impairments in specific aspects of pragmatic competence, supporting the use of language in context, are largely documented in schizophrenia and might represent an indicator of poor outcome. Yet pragmatics is rarely included in clinical settings. This paper aims to promote a clinical consideration of pragmatics as a target of assessment and intervention. We investigated the <span class="hlt">frequency</span> of the pragmatic deficit, its cognitive substrates, and the relation with quality of life. Pragmatic abilities were compared in a sample of patients with schizophrenia and healthy controls based on a comprehensive pragmatic test (APACS). We assessed also for psychopathology, cognition, social cognition, and quality of life. We explored the co-occurrence of deficits in different domains, and we used multiple regressions to investigate the effect of cognition and social cognition on pragmatics, and of pragmatics on quality of life. Pragmatic abilities, especially comprehending discourse and non-literal meanings, were compromised in schizophrenia, with 77% of patients falling below cutoff. Pragmatic deficit co-occurred with cognitive or socio-cognitive deficits in approximately 30% of cases. Multiple regression analysis confirmed the interplay of cognition and social cognition in pragmatic behavior. Quality of life was predicted by symptoms and by pragmatic abilities. The high <span class="hlt">frequency</span> of impairment suggests that the pragmatic deficit is a <span class="hlt">core</span> feature of schizophrenia, associated with quality of life. Cognitive and socio-cognitive abilities might represent necessary though not sufficient building blocks for the acquisition of pragmatic abilities throughout development. Therefore, a more precise incorporation of pragmatics in the description of the pathology is of high clinical and translational relevance. Copyright © 2016 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1390258','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1390258"><span>Metabolic <span class="hlt">Damage</span> and Metabolic <span class="hlt">Damage</span> Control in Plants</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hanson, Andrew D.; Henry, Christopher S.; Fiehn, Oliver; Crecy-Lagard, Valerie de</p> <p>2016-01-01</p> <p>It is increasingly clear that (a) many metabolites undergo spontaneous or enzyme-catalyzed side reactions in vivo, (b) the <span class="hlt">damaged</span> metabolites formed by these reactions can be harmful, and (c) organisms have biochemical systems that limit the buildup of <span class="hlt">damaged</span> metabolites. These <span class="hlt">damage</span>-control systems either return a <span class="hlt">damaged</span> molecule to its pristine state (metabolite repair) or convert harmful molecules to harmless ones (<span class="hlt">damage</span> preemption). Because all organisms share a <span class="hlt">core</span> set of metabolites that suffer the same chemical and enzymatic <span class="hlt">damage</span> reactions, certain <span class="hlt">damage</span>-control systems are widely conserved across the kingdoms of life. Relatively few <span class="hlt">damage</span> reactions and <span class="hlt">damage</span>-control systems are well known. Uncovering new <span class="hlt">damage</span> reactions and identifying the corresponding <span class="hlt">damaged</span> metabolites, <span class="hlt">damage</span>-control genes, and enzymes demands a coordinated mix of chemistry, metabolomics, cheminformatics, biochemistry, and comparative genomics. This review illustrates the above points using examples from plants, which are at least as prone to metabolite <span class="hlt">damage</span> as other organisms.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.5739F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.5739F"><span>Automatic workflow for establishing catalogs of Low-<span class="hlt">Frequency</span> Earthquakes (LFE) and its adoption to high performance multi-<span class="hlt">core</span> CPU and GPU architectures.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Frank, William; Rozier, Olivier; Romanenko, Alexey; Shapiro, Nikolai</p> <p>2014-05-01</p> <p>Recently discovered low-<span class="hlt">frequency</span> earthquakes (LFEs) together with non-volcanic tremor and slow slip-events constitute a manifestation of slow deformation process in seismogenic zones. LFEs frequently originate from multiplet-generating sources and are difficult to observe and to characterize because of their low signal-to-noise ratios. We develop a workflow for detecting and cataloging the LFEs that include following steps: (1) automatic detection of multiplet master events via beamforming and/or cross-correlations, (2) matched filter search using the detected master events, (3) filtering out ambiguous detections, and (4) stacking of obtained detections to generate the multiplet waveform. Analysis of the long-term LFE activity requires application of this workflow to Terabytes of continuous seismic records and repeating many millions of times operations of scalar products, Fourier transforms and cross-correlation functions. Resulting volume of computations becomes very large and requires implementation on high-performance platforms. On the other side the developed workflow is highly parallelizable because it can be subdivided into many independent operations. Therefore, we develop parallelized codes for running this workflow on multi-<span class="hlt">core</span> architectures and, in particular on GPUs that produce significant acceleration. We apply the developed coded to analyze 2.5 year of continuous seismic data recorded in Guerrero Mexico. The resulting catalog of LFEs in this part of the Mexican subduction zone contains several tens of thousands of detections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27756683','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27756683"><span>Localization of dexamethasone within dendritic <span class="hlt">core</span>-multishell (CMS) nanoparticles and skin penetration properties studied by multi-<span class="hlt">frequency</span> electron paramagnetic resonance (EPR) spectroscopy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Saeidpour, S; Lohan, S B; Anske, M; Unbehauen, M; Fleige, E; Haag, R; Meinke, M C; Bittl, R; Teutloff, C</p> <p>2016-10-15</p> <p>The skin and especially the stratum corneum (SC) act as a barrier and protect epidermal cells and thus the whole body against xenobiotica of the external environment. Topical skin treatment requires an efficient drug delivery system (DDS). Polymer-based nanocarriers represent novel transport vehicles for dermal application of drugs. In this study dendritic <span class="hlt">core</span>-multishell (CMS) nanoparticles were investigated as promising candidates. CMS nanoparticles were loaded with a drug (analogue) and were applied to penetration studies of skin. We determined by dual-<span class="hlt">frequency</span> electron paramagnetic resonance (EPR) how dexamethasone (Dx) labelled with 3-carboxy-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (PCA) is associated with the CMS. The micro-environment of the drug loaded to CMS nanoparticles was investigated by pulsed high-field EPR at cryogenic temperature, making use of the fact that magnetic parameters (g-, A-matrices, and spin-lattice relaxation time) represent specific probes for the micro-environment. Additionally, the rotational correlation time of spin-labelled Dx was probed by continuous wave EPR at ambient temperature, which provides independent information on the drug environment. Furthermore, the penetration depth of Dx into the stratum corneum of porcine skin after different topical applications was investigated. The location of Dx in the CMS nanoparticles is revealed and the function of CMS as penetration enhancers for topical application is shown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9803E..26N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9803E..26N"><span>A hybrid method for <span class="hlt">damage</span> detection and quantification in advanced X-COR composite structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neerukatti, Rajesh Kumar; Rajadas, Abhishek; Borkowski, Luke; Chattopadhyay, Aditi; Huff, Daniel W.</p> <p>2016-04-01</p> <p>Advanced composite structures, such as foam <span class="hlt">core</span> carbon fiber reinforced polymer composites, are increasingly being used in applications which require high strength, high in-plane and flexural stiffness, and low weight. However, the presence of in situ <span class="hlt">damage</span> due to manufacturing defects and/or service conditions can complicate the failure mechanisms and compromise their strength and reliability. In this paper, the capability of detecting <span class="hlt">damages</span> such as delaminations and foam-<span class="hlt">core</span> separations in X-COR composite structures using non-destructive evaluation (NDE) and structural health monitoring (SHM) techniques is investigated. Two NDE techniques, flash thermography and low <span class="hlt">frequency</span> ultrasonics, were used to detect and quantify the <span class="hlt">damage</span> size and locations. Macro fiber composites (MFCs) were used as actuators and sensors to study the interaction of Lamb waves with delaminations and foam-<span class="hlt">core</span> separations. The results indicate that both flash thermography and low <span class="hlt">frequency</span> ultrasonics were capable of detecting <span class="hlt">damage</span> in X-COR sandwich structures, although low <span class="hlt">frequency</span> ultrasonic methods were capable of detecting through thickness <span class="hlt">damages</span> more accurately than flash thermography. It was also observed that the presence of foam-<span class="hlt">core</span> separations significantly changes the wave behavior when compared to delamination, which complicates the use of wave based SHM techniques. Further, a wave propagation model was developed to model the wave interaction with <span class="hlt">damages</span> at different locations on the X-COR sandwich plate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28629044','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28629044"><span>Recovery evaluation of rats' <span class="hlt">damaged</span> tibias: Implantation of <span class="hlt">core</span>-shell structured bone scaffolds made using hollow braids and a freeze-thawing process.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Jia-Horng; Lee, Mong-Chuan; Chen, Chih-Kuang; Huang, Chien-Lin; Chen, Yueh-Sheng; Wen, Shih-Peng; Kuo, Shu-Ting; Lou, Ching-Wen</p> <p>2017-10-01</p> <p>This study prepares biodegradable bone scaffolds helping the recovery of <span class="hlt">damaged</span> tibias of rats. Polyvinyl alcohol (PVA) plied yarns are fabricated into hollow braids. The braids are combined with hydroxyapatite (HA)/gelatin/PVA mixtures and processed using freeze-thawing and freeze-drying processes in order to form bone scaffolds. These bone scaffolds are observed by scanning electron scope (SEM) and tested for compression strength. Afterwards, recovery of <span class="hlt">damaged</span> bone, the morphology of the bone, and the histological observation are evaluated. Results indicate a small amount of HA helps in enhancing the compressive strength of bone scaffolds. Results of in vivo assay indicate the <span class="hlt">damaged</span> tibias of rats recover and function well eight weeks after the implantation, and exhibit a normal morphology. Histological observation confirms the bone scaffolds gradually decompose, allowing tissue infiltration and facilitating ossification. This study successfully produces bone scaffolds with satisfactory mechanical properties helping in the recovery of <span class="hlt">damaged</span> tibias of rats. Copyright © 2017 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1377296','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1377296"><span>An association, in adult Japanese, between the occurrence of rogue cells among cultured lymphocytes (JC virus activity) and the <span class="hlt">frequency</span> of "simple" chromosomal <span class="hlt">damage</span> among the lymphocytes of persons exhibiting these rogue cells.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Neel, J V</p> <p>1998-01-01</p> <p>Data from a previous study of the cytogenetic effects, in cultured lymphocytes, of exposure to the atomic bomb in Hiroshima have been reanalyzed to determine the relationship between the occurrence of "rogue" cells in an individual and the <span class="hlt">frequency</span> of "simple" chromosomal <span class="hlt">damage</span> in the nonrogue cells of the same individual. Rogue cells are cells with complex chromosomal <span class="hlt">damage</span>, currently believed to be a manifestation of the activity of a human polyoma virus termed "JC." Among a total of 1,835 persons examined, there were 45 exhibiting rogue cells. A total of 179,599 cells were scored for simple chromosomal <span class="hlt">damage</span>. In both the exposed and the control populations, there was an absolute increase of approximately 1.5% in the <span class="hlt">frequency</span> of simple chromosomal <span class="hlt">damage</span> in the nonrogue cells of those exhibiting rogue cells, when compared with the <span class="hlt">frequencies</span> observed in those not exhibiting rogue cells, which is a statistically significant difference. It is argued that this phenomenon, occurring not only in lymphocytes but possibly also in other cells/tissues, may play a contributory role in the origin of malignancies characterized by clonal chromosome abnormalities. Unexpectedly, among those exhibiting rogue cells, there was a disproportionately greater representation of persons who had received relatively high radiation exposures from the bomb. The reason for this is unclear, but it is tempting to relate the finding to some lingering effect of the exposure (or the circumstances surrounding the exposure) on immunocompetence. PMID:9683586</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SPIE.6532E..21S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SPIE.6532E..21S"><span>Study on <span class="hlt">damage</span> identification of high-rise buildings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Song, Yu; Lei, Ying; Wang, Jian-Xin</p> <p>2007-04-01</p> <p><span class="hlt">Damage</span> detection is the <span class="hlt">core</span> technique of structure health monitoring systems. Mostly, the detection is based on comparison of initial signatures (<span class="hlt">frequency</span>, mode shapes and so on) of intact structure with that of <span class="hlt">damaged</span> structure. The techniques based on the analysis of vibration data of structures have received great attention in recent years. Generally, high-rise buildings have enough security under wind or some other natural conditions. Instances of <span class="hlt">damage</span> caused by routine work can be rarely found. But under earthquake, high-rise buildings <span class="hlt">damages</span> may occur on some weakness areas. In this paper, based on establishing the stiffness matrix of the columns and beams with joint <span class="hlt">damage</span>, the finite element model of the <span class="hlt">damaged</span> frame structure is set up. Calculating the modal date by the finite element model between the intact and <span class="hlt">damaged</span> structure, simple and multi <span class="hlt">damages</span> being imitated at the locations of the joints, the curvature mode shape method is used to identify the <span class="hlt">damage</span>. The numerical example shows that the structural <span class="hlt">damage</span> can be efficiency identified by using vibration characteristics of the building.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27192925','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27192925"><span>Use of a DNA film on a self-assembled monolayer for investigating the physical process of DNA <span class="hlt">damage</span> induced by <span class="hlt">core</span> electron ionization.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Narita, Ayumi; Fujii, Kentaro; Baba, Yuji; Shimoyama, Iwao</p> <p>2016-11-01</p> <p>A novel two-layer sample composed of a deoxyribonucleic acid (DNA) film and self-assembled monolayer (SAM) was prepared on an inorganic surface to mimic the processes in which DNA is <span class="hlt">damaged</span> by soft X-ray irradiation. A mercaptopropyltrimethoxysilane (MPTS) SAM was formed on a sapphire surface, then oligonucleotide (OGN) molecules were adsorbed on the MPTS-SAM. The thicknesses and chemical states of the layers were determined by X-ray photoelectron spectroscopy (XPS) and near-edge X-ray fine structure (NEXAFS) around the phosphorus (P) and sulfur (S) K-edges. To induce the <span class="hlt">damage</span> to the OGN molecules, the sample was irradiated with synchrotron soft X-rays. The chemical state of the OGN molecules before and after irradiation was examined by NEXAFS around the nitrogen (N) K-edge region. The thickness of the MPTS-OGN layer was approximately 7.7 nm. The S atom of the OGN molecules was located at the bottom of the OGN layer. The peak shape of the N K-edge NEXAFS spectra of the MPTS-OGN layers clearly changed following irradiation. The MPTS-OGN layer formed on the sapphire surface. The chemical states and the structure of the interface were elucidated using synchrotron soft X-rays. The OGN molecules adsorbed on the MPTS films decomposed upon exposure to soft X-ray irradiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22887717','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22887717"><span><span class="hlt">Core</span>-shell structured polystyrene/BaTiO3 hybrid nanodielectrics prepared by in situ RAFT polymerization: a route to high dielectric constant and low loss materials with weak <span class="hlt">frequency</span> dependence.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Ke; Huang, Xingyi; Xie, Liyuan; Wu, Chao; Jiang, Pingkai; Tanaka, Toshikatsu</p> <p>2012-11-23</p> <p>A novel route to prepare <span class="hlt">core</span>-shell structured nanocomposites with excellent dielectric performance is reported. This approach involves the grafting of polystyrene (PS) from the surface of BaTiO(3) by an in situ RAFT polymerization. The <span class="hlt">core</span>-shell structured PS/BaTiO(3) nanocomposites not only show significantly increased dielectric constant and very low dielectric loss, but also have a weak <span class="hlt">frequency</span> dependence of dielectric properties over a wide range of <span class="hlt">frequencies</span>. In addition, the dielectric constant of the nanocomposites can also be easily tuned by varying the thickness of the PS shell. Our method is very promising for preparing high-performance nanocomposites used in energy-storage devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3743843','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3743843"><span>Visualisation of γH2AX Foci Caused by Heavy Ion Particle Traversal; Distinction between <span class="hlt">Core</span> Track versus Non-Track <span class="hlt">Damage</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nakajima, Nakako Izumi; Brunton, Holly; Watanabe, Ritsuko; Shrikhande, Amruta; Hirayama, Ryoichi; Matsufuji, Naruhiro; Fujimori, Akira; Murakami, Takeshi; Okayasu, Ryuichi; Jeggo, Penny; Shibata, Atsushi</p> <p>2013-01-01</p> <p>Heavy particle irradiation produces complex DNA double strand breaks (DSBs) which can arise from primary ionisation events within the particle trajectory. Additionally, secondary electrons, termed delta-electrons, which have a range of distributions can create low linear energy transfer (LET) <span class="hlt">damage</span> within but also distant from the track. DNA <span class="hlt">damage</span> by delta-electrons distant from the track has not previously been carefully characterised. Using imaging with deconvolution, we show that at 8 hours after exposure to Fe (∼200 keV/µm) ions, γH2AX foci forming at DSBs within the particle track are large and encompass multiple smaller and closely localised foci, which we designate as clustered γH2AX foci. These foci are repaired with slow kinetics by DNA non-homologous end-joining (NHEJ) in G1 phase with the magnitude of complexity diminishing with time. These clustered foci (containing 10 or more individual foci) represent a signature of DSBs caused by high LET heavy particle radiation. We also identified simple γH2AX foci distant from the track, which resemble those arising after X-ray exposure, which we attribute to low LET delta-electron induced DSBs. They are rapidly repaired by NHEJ. Clustered γH2AX foci induced by heavy particle radiation cause prolonged checkpoint arrest compared to simple γH2AX foci following X-irradiation. However, mitotic entry was observed when ∼10 clustered foci remain. Thus, cells can progress into mitosis with multiple clusters of DSBs following the traversal of a heavy particle. PMID:23967070</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21021211','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21021211"><span>Candu 6 severe <span class="hlt">core</span> <span class="hlt">damage</span> accident consequence analysis for steam generator tube rupture scenario using MAAP4-CANDU V4.0.5A: preliminary results</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Petoukhov, S.M.; Awadh, B.; Mathew, P.M.</p> <p>2006-07-01</p> <p>This paper describes the preliminary results of the consequence analysis for a generic AECL CANDU 6 station, when it undergoes a postulated, low probability Steam Generator multiple Tube Rupture (SGTR) severe accident with assumed unavailability of several critical plant safety systems. The Modular Accident Analysis Program for CANDU (MAAP4-CANDU) code was used for this analysis. The SGTR accident is assumed to begin with the guillotine rupture of 10 steam generator tubes in one steam generator in Primary Heat Transport System (PHTS) loop 1. For the reference case, the following systems were assumed unavailable: moderator and shield cooling, emergency <span class="hlt">core</span> cooling, crash cool-down, and main and auxiliary feed water. Two additional cases were analyzed, one with the crash cool-down system available, and another with the crash cool-down and the auxiliary feed water systems available. The three scenarios considered in this study show that most of the initial fission product inventory would be retained within the containment by various fission product retention mechanisms. For the case where the crash cool-down system was credited but the auxiliary feed water systems were not credited, the total mass of volatile fission products released to the environment including stable and radioactive isotopes was about four times more than in the reference case, because fission products could be released directly from the PHTS to the environment through the Main Steam Safety Valves (MSSVs), bypassing the containment. For the case where the crash cool-down and auxiliary feed water systems were credited, the volatile fission product release to the environment was insignificant, because the fission product release was substantially mitigated by scrubbing in the water pool in the secondary side of the steam generator (SG). (authors)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090041685','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090041685"><span><span class="hlt">Core</span>-Cutoff Tool</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gheen, Darrell</p> <p>2007-01-01</p> <p>A tool makes a cut perpendicular to the cylindrical axis of a <span class="hlt">core</span> hole at a predetermined depth to free the <span class="hlt">core</span> at that depth. The tool does not <span class="hlt">damage</span> the surrounding material from which the <span class="hlt">core</span> was cut, and it operates within the <span class="hlt">core</span>-hole kerf. <span class="hlt">Coring</span> usually begins with use of a hole saw or a hollow cylindrical abrasive cutting tool to make an annular hole that leaves the <span class="hlt">core</span> (sometimes called the plug ) in place. In this approach to <span class="hlt">coring</span> as practiced heretofore, the <span class="hlt">core</span> is removed forcibly in a manner chosen to shear the <span class="hlt">core</span>, preferably at or near the greatest depth of the <span class="hlt">core</span> hole. Unfortunately, such forcible removal often <span class="hlt">damages</span> both the <span class="hlt">core</span> and the surrounding material (see Figure 1). In an alternative prior approach, especially applicable to toxic or fragile material, a <span class="hlt">core</span> is formed and freed by means of milling operations that generate much material waste. In contrast, the present tool eliminates the <span class="hlt">damage</span> associated with the hole-saw approach and reduces the extent of milling operations (and, hence, reduces the waste) associated with the milling approach. The present tool (see Figure 2) includes an inner sleeve and an outer sleeve and resembles the hollow cylindrical tool used to cut the <span class="hlt">core</span> hole. The sleeves are thin enough that this tool fits within the kerf of the <span class="hlt">core</span> hole. The inner sleeve is attached to a shaft that, in turn, can be attached to a drill motor or handle for turning the tool. This tool also includes a cutting wire attached to the distal ends of both sleeves. The cutting wire is long enough that with sufficient relative rotation of the inner and outer sleeves, the wire can cut all the way to the center of the <span class="hlt">core</span>. The tool is inserted in the kerf until its distal end is seated at the full depth. The inner sleeve is then turned. During turning, frictional drag on the outer <span class="hlt">core</span> pulls the cutting wire into contact with the <span class="hlt">core</span>. The cutting force of the wire against the <span class="hlt">core</span> increases with the tension in the wire and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=parents%27+AND+treatment+AND+methods+AND+anxiety.&pg=2&id=EJ789871','ERIC'); return false;" href="https://eric.ed.gov/?q=parents%27+AND+treatment+AND+methods+AND+anxiety.&pg=2&id=EJ789871"><span>Parent-Rated Anxiety Symptoms in Children with Pervasive Developmental Disorders: <span class="hlt">Frequency</span> and Association with <span class="hlt">Core</span> Autism Symptoms and Cognitive Functioning</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Sukhodolsky, Denis G.; Scahill, Lawrence; Gadow, Kenneth D.; Arnold, L. Eugene; Aman, Michael G.; McDougle, Christopher J.; McCracken, James T.; Tierney, Elaine; White, Susan Williams; Lecavalier, Luc; Vitiello, Benedetto</p> <p>2008-01-01</p> <p>Background: In addition to the <span class="hlt">core</span> symptoms, children with Pervasive Developmental Disorders (PDD) often exhibit other problem behaviors such as aggression, hyperactivity, and anxiety, which can contribute to overall impairment and, therefore, become the focus of clinical attention. Limited data are available on the prevalence of anxiety in these…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=phobic+AND+anxiety&pg=2&id=EJ789871','ERIC'); return false;" href="http://eric.ed.gov/?q=phobic+AND+anxiety&pg=2&id=EJ789871"><span>Parent-Rated Anxiety Symptoms in Children with Pervasive Developmental Disorders: <span class="hlt">Frequency</span> and Association with <span class="hlt">Core</span> Autism Symptoms and Cognitive Functioning</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Sukhodolsky, Denis G.; Scahill, Lawrence; Gadow, Kenneth D.; Arnold, L. Eugene; Aman, Michael G.; McDougle, Christopher J.; McCracken, James T.; Tierney, Elaine; White, Susan Williams; Lecavalier, Luc; Vitiello, Benedetto</p> <p>2008-01-01</p> <p>Background: In addition to the <span class="hlt">core</span> symptoms, children with Pervasive Developmental Disorders (PDD) often exhibit other problem behaviors such as aggression, hyperactivity, and anxiety, which can contribute to overall impairment and, therefore, become the focus of clinical attention. Limited data are available on the prevalence of anxiety in these…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.T23E..06D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.T23E..06D"><span>A new conceptual model for <span class="hlt">damage</span> zone evolution with fault growth</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Joussineau, G.; Aydin, A.</p> <p>2006-12-01</p> <p>Faults may either impede or enhance fluid flow in the subsurface, which is relevant to a number of economic issues (hydrocarbon migration and entrapment, formation and distribution of mineral deposits) and environmental problems (movement of contaminants). Fault zones typically comprise a low-permeability <span class="hlt">core</span> made up of intensely deformed fault rock and a high-permeability <span class="hlt">damage</span> zone defined by fault-related fractures. The geometry, petrophysical properties and continuity of both the fault <span class="hlt">core</span> and the <span class="hlt">damage</span> zone have an important influence on the mechanical properties of the fault systems and on subsurface fluid flow. Information about fault components from remote seismic methods is limited and is available only for large faults (slip larger than 20-100m). It is therefore essential to characterize faults and associated <span class="hlt">damage</span> zones in field analogues, and to develop conceptual models of how faults and related structures form and evolve. Here we present such an attempt to better understand the evolution of fault <span class="hlt">damage</span> zones in the Jurassic Aztec Sandstone of the Valley of Fire State Park (SE Nevada). We document the formation and evolution of the <span class="hlt">damage</span> zone associated with strike-slip faults through detailed field studies of faults of increasing slip magnitudes. The faults initiate as sheared joints with discontinuous pockets of <span class="hlt">damage</span> zone located at fault tips and fault surface irregularities. With increasing slip (slip >5m), the <span class="hlt">damage</span> zone becomes longer and wider by progressive fracture infilling, and is organized into two distinct components with different geometrical and statistical characteristics. The first component of the <span class="hlt">damage</span> zone is the inner <span class="hlt">damage</span> zone, directly flanking the fault <span class="hlt">core</span>, with a relatively high fracture <span class="hlt">frequency</span> and a thickness that scales with the amount of fault slip. Parts of this inner zone are integrated into the fault <span class="hlt">core</span> by the development of the fault rock, contributing to the <span class="hlt">core</span>'s progressive widening. The second</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1026906','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1026906"><span>Remarkably Large Photoswitching Effect of GHZ-<span class="hlt">Frequency</span>-Responsive Permittivity Using FeOx/Au <span class="hlt">Core</span>-Shell E-Polarizable Fullerosomic-Constructs (Preprint)</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-04-08</p> <p>nanoparticles (NPs) in microwave <span class="hlt">frequencies</span> of 1.0‒4.0 GHz. The detected permittivity amplification was initiated upon switching off the light followed by... nanoparticles (NPs) in microwave <span class="hlt">frequencies</span> of 1.0‒4.0 GHz. The detected permittivity amplification was initiated upon switching off the light followed by...of phenazine and chloranilic acid. 9–11 The other example was given by the one- dimensional organic quantum magnet, tetrathiafulvalene−p-bromanil</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5336092','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5336092"><span>Dynamic Voltage-<span class="hlt">Frequency</span> and Workload Joint Scaling Power Management for Energy Harvesting Multi-<span class="hlt">Core</span> WSN Node SoC</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Xiangyu; Xie, Nijie; Tian, Xinyue</p> <p>2017-01-01</p> <p>This paper proposes a scheduling and power management solution for energy harvesting heterogeneous multi-<span class="hlt">core</span> WSN node SoC such that the system continues to operate perennially and uses the harvested energy efficiently. The solution consists of a heterogeneous multi-<span class="hlt">core</span> system oriented task scheduling algorithm and a low-complexity dynamic workload scaling and configuration optimization algorithm suitable for light-weight platforms. Moreover, considering the power consumption of most WSN applications have the characteristic of data dependent behavior, we introduce branches handling mechanism into the solution as well. The experimental result shows that the proposed algorithm can operate in real-time on a lightweight embedded processor (MSP430), and that it can make a system do more valuable works and make more than 99.9% use of the power budget. PMID:28208730</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28208730','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28208730"><span>Dynamic Voltage-<span class="hlt">Frequency</span> and Workload Joint Scaling Power Management for Energy Harvesting Multi-<span class="hlt">Core</span> WSN Node SoC.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Xiangyu; Xie, Nijie; Tian, Xinyue</p> <p>2017-02-08</p> <p>This paper proposes a scheduling and power management solution for energy harvesting heterogeneous multi-<span class="hlt">core</span> WSN node SoC such that the system continues to operate perennially and uses the harvested energy efficiently. The solution consists of a heterogeneous multi-<span class="hlt">core</span> system oriented task scheduling algorithm and a low-complexity dynamic workload scaling and configuration optimization algorithm suitable for light-weight platforms. Moreover, considering the power consumption of most WSN applications have the characteristic of data dependent behavior, we introduce branches handling mechanism into the solution as well. The experimental result shows that the proposed algorithm can operate in real-time on a lightweight embedded processor (MSP430), and that it can make a system do more valuable works and make more than 99.9% use of the power budget.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=116433','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=116433"><span>Possible attenuation of the G2 DNA <span class="hlt">damage</span> cell cycle checkpoint in HeLa cells by extremely low <span class="hlt">frequency</span> (ELF) electromagnetic fields</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Harris, Paul A; Lamb, Justin; Heaton, Brian; Wheatley, Denys N</p> <p>2002-01-01</p> <p>Background The issue remains unresolved as to whether low <span class="hlt">frequency</span> magnetic fields can affect cell behaviour, with the possibility that they may be in part responsible for the increased incidence of leukaemia in parts of the population exposed to them. Methods Combined treatment of HeLa cells with gamma-irradiation (1, 3 and 5 Grays) and extra low <span class="hlt">frequency</span> magnetic fields of ~50 Hz was carried out under rigorously controlled conditions. Results Synchronised cells progressing from S-phase arrived at mitosis on average marginally ahead of irradiation controls not exposed to ELF. In no instance out of a total of twenty separate experiments did this "double-insult" further delay entry of cells into mitosis, as had been anticipated. Conclusion This apparently "non-genotoxic" agent (ELF) appears to be capable of affecting cells that would normally arrest for longer in G2, suggesting a weakening of the stringency of the late cycle (G2) checkpoint. PMID:12069691</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25006355','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25006355"><span><span class="hlt">Core</span>-needle biopsy under CT fluoroscopy guidance and fine-needle aspiration cytology: Comparison of diagnostic yield in the diagnosis of lung and mediastinum tumors. Analysis of <span class="hlt">frequency</span> and types of complications.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Szlęzak, Przemysław; Srutek, Ewa; Gorycki, Tomasz; Kowalewski, Janusz; Studniarek, Michał</p> <p>2014-01-01</p> <p>Patients with pathological tissue mass in thoracic cage found with imaging require histopathological or cytological confirmation of malignancy before treatment. The tissue material essential for patomorphological evaluation can be acquired with fine-needle aspiration biopsies (FNAB) controlled with CT and <span class="hlt">core</span>-needle biopsy (CNB) under real-time CT fluoroscopy guidance. The purpose of this work is to carry out a retrospective analysis of the two methods with regards to their informativity, <span class="hlt">frequency</span> and the kind of complications. From January, 2012 to May 2013, 76 <span class="hlt">core</span>-needle biopsies of lung and mediastinum tumors were conducted and compared with 86 fine-needle aspiration biopsies(FNAB) of lung and mediastinum tumors, including 30 patients who underwent FNAB and were referred to CNB in order to specify the diagnosis. Complete histopathological diagnosis was made in 91% with the use of CNB and in 37% when FNAB was the chosen method. Early complications were observed in 32% patients who underwent BG and in group of 11% who underwent FNAB. Late complications, however, appeared in 29% patients after CNB and 13% after FNAB. In 24 cases CNB specified the complete diagnosis. <span class="hlt">Core</span>-needle biopsy in comparison to fine-needle aspiration biopsy has more frequent rate of negligible complications, however, it offers higher diagnostic yield for diagnostic of lung and mediastinum neoplastic disease and allows for more precise diagnosis of focal lesions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020087020','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020087020"><span>Composite <span class="hlt">Cores</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1990-01-01</p> <p>Spang & Company's new configuration of converter transformer <span class="hlt">cores</span> is a composite of gapped and ungapped <span class="hlt">cores</span> assembled together in concentric relationship. The net effect of the composite design is to combine the protection from saturation offered by the gapped <span class="hlt">core</span> with the lower magnetizing requirement of the ungapped <span class="hlt">core</span>. The uncut <span class="hlt">core</span> functions under normal operating conditions and the cut <span class="hlt">core</span> takes over during abnormal operation to prevent power surges and their potentially destructive effect on transistors. Principal customers are aerospace and defense manufacturers. <span class="hlt">Cores</span> also have applicability in commercial products where precise power regulation is required, as in the power supplies for large mainframe computers.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3748479','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3748479"><span>Molecular Detection of Malaria at Delivery Reveals a High <span class="hlt">Frequency</span> of Submicroscopic Infections and Associated Placental <span class="hlt">Damage</span> in Pregnant Women from Northwest Colombia</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Arango, Eliana M.; Samuel, Roshini; Agudelo, Olga M.; Carmona-Fonseca, Jaime; Maestre, Amanda; Yanow, Stephanie K.</p> <p>2013-01-01</p> <p>Plasmodium infection in pregnancy causes substantial maternal and infant morbidity and mortality. In Colombia, both P. falciparum and P. vivax are endemic, but the impact of either species on pregnancy is largely unknown in this country. A cross-sectional study was carried out with 96 pregnant women who delivered at their local hospital. Maternal, placental, and cord blood were tested for malaria infection by microscopy and real-time quantitative polymerase chain reaction (qPCR). A high <span class="hlt">frequency</span> of infection was detected by qPCR (45%). These infections had low concentrations of parasite DNA, and 79% were submicroscopic. Submicroscopic infections were associated with placental villitis and intervillitis. In conclusion, the overall <span class="hlt">frequency</span> of Plasmodium infection at delivery in Colombia is much higher than previously reported. These data prompt a re-examination of the local epidemiology of malaria using molecular diagnostics to establish the clinical relevance of submicroscopic infections during pregnancy as well as their consequences for mothers and newborns. PMID:23716408</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21129715','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21129715"><span><span class="hlt">Frequency</span> of conduction abnormalities after transcatheter aortic valve implantation with the Medtronic-<span class="hlt">Core</span>Valve and the effect on left ventricular ejection fraction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tzikas, Apostolos; van Dalen, Bas M; Van Mieghem, Nicolas M; Gutierrez-Chico, Juan-Luis; Nuis, Rutger-Jan; Kauer, Floris; Schultz, Carl; Serruys, Patrick W; de Jaegere, Peter P T; Geleijnse, Marcel L</p> <p>2011-01-15</p> <p>New conduction abnormalities occur frequently after transcatheter aortic valve implantation (TAVI). The relation between new conduction disorders and left ventricular (LV) systolic function after TAVI is unknown. The purpose of the present prospective, single-center study was to investigate the effect of TAVI on LV systolic function in relation to TAVI-induced conduction abnormalities. A total of 27 patients had undergone electrocardiography and transthoracic echocardiography the day before and 6 days after TAVI with the Medtronic-<span class="hlt">Core</span>Valve system. The LV ejection fraction (EF) was calculated using the biplane Simpson method. The systolic mitral annular velocities and longitudinal strain were measured using speckle tracking echocardiography. After TAVI, 18 patients (67%) had new conduction abnormalities; 4 (15%) had a new paced rhythm and 14 patients (52%) had new left bundle branch block. In the patients with new conduction abnormalities, the EF decreased from 47 ± 12% to 44 ± 10%. In contrast, in those without new conduction abnormalities, the EF increased from 49 ± 12% to 54% ± 12%. The change in EF was significantly different among those with and without new conduction abnormalities (p <0.05). In patients without new conduction abnormalities, an improvement was found in the systolic mitral annular velocities and longitudinal strain (p <0.05). In contrast, in patients with new conduction abnormalities, the changes were not significant. In conclusion, the induction of new conduction abnormalities after TAVI with the Medtronic-<span class="hlt">Core</span>Valve was associated with a lack of improvement in LV systolic function. Copyright © 2011 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26865847','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26865847"><span>Building the <span class="hlt">Frequency</span> Profile of the <span class="hlt">Core</span> Promoter Element Patterns in the Three ChromHMM Promoter States at 200bp Intervals: A Statistical Perspective.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lent, Heather; Lee, Kyung-Eun; Park, Hyun-Seok</p> <p>2015-12-01</p> <p>Recently, the Encyclopedia of DNA Elements (ENCODE) Analysis Working Group converted data from ChIP-seq analyses from the Broad Histone track into 15 corresponding chromatic maps that label sequences with different kinds of histone modifications in promoter regions. Here, we publish a <span class="hlt">frequency</span> profile of the three ChromHMM promoter states, at 200-bp intervals, with particular reference to the existence of sequence patterns of promoter elements, GC-richness, and transcription starting sites. Through detailed and diligent analysis of promoter regions, researchers will be able to uncover new and significant information about transcription initiation and gene function.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25579460','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25579460"><span>Magnetic resonance imaging-guided <span class="hlt">core</span> needle breast biopsies resulting in high-risk histopathologic findings: upstage <span class="hlt">frequency</span> and lesion characteristics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Weinfurtner, R Jared; Patel, Bhavika; Laronga, Christine; Lee, Marie C; Falcon, Shannon L; Mooney, Blaise P; Yue, Binglin; Drukteinis, Jennifer S</p> <p>2015-06-01</p> <p>Analysis of magnetic resonance imaging-guided breast biopsies yielding high-risk histopathologic features at a single institution found an overall upstage rate to malignancy of 14% at surgical excision. All upstaged lesions were associated with atypical ductal hyperplasia. Flat epithelial atypia and atypical lobular hyperplasia alone or with lobular carcinoma in situ were not associated with an upstage to malignancy. The purpose of the present study w as to determine the malignancy upstage rates and imaging features of high-risk histopathologic findings resulting from magnetic resonance imaging (MRI)-guided <span class="hlt">core</span> needle breast biopsies. These features include atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), flat epithelial atypia (FEA), and lobular carcinoma in situ (LCIS). A retrospective medical record review was performed on all MRI-guided <span class="hlt">core</span> needle breast biopsies at a single institution from June 1, 2007 to December 1, 2013 to select biopsies yielding high-risk histopathologic findings. The patient demographics, MRI lesion characteristics, and histopathologic features at biopsy and surgical excision were analyzed. A total of 257 MRI-guided biopsies had been performed, and 50 yielded high-risk histopathologic features (19%). Biopsy site and surgical excision site correlation was confirmed in 29 of 50 cases. Four of 29 lesions (14%) were upstaged: 1 case to invasive ductal carcinoma and 3 cases to ductal carcinoma in situ. ADH alone had an overall upstage rate of 7% (1 of 14), mixed ADH/ALH a rate of 75% (3 of 4), ALH alone or with LCIS a rate of 0% (0 of 7), and FEA a rate of 0% (0 of 4). Only mixed ADH/ALH had a statistically significant upstage rate to malignancy compared with the other high-risk histopathologic subtypes combined. No specific imaging characteristics on MRI were associated with an upstage to malignancy on the statistical analysis. MRI-guided breast biopsies yielding high-risk histopathologic features were associated with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19822160','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19822160"><span>Transient DNA <span class="hlt">damage</span> induced by high-<span class="hlt">frequency</span> electromagnetic fields (GSM 1.8 GHz) in the human trophoblast HTR-8/SVneo cell line evaluated with the alkaline comet assay.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Franzellitti, Silvia; Valbonesi, Paola; Ciancaglini, Nicola; Biondi, Carla; Contin, Andrea; Bersani, Ferdinando; Fabbri, Elena</p> <p>2010-01-05</p> <p>One of the most controversial issue regarding high-<span class="hlt">frequency</span> electromagnetic fields (HF-EMF) is their putative capacity to affect DNA integrity. This is of particular concern due to the increasing use of HF-EMF in communication technologies, including mobile phones. Although epidemiological studies report no detrimental effects on human health, the possible disturbance generated by HF-EMF on cell physiology remains controversial. In addition, the question remains as to whether cells are able to compensate their potential effects. We have previously reported that a 1-h exposure to amplitude-modulated 1.8 GHz sinusoidal waves (GSM-217 Hz, SAR=2 W/kg) largely used in mobile telephony did not cause increased levels of primary DNA <span class="hlt">damage</span> in human trophoblast HTR-8/SVneo cells. Nevertheless, further investigations on trophoblast cell responses after exposure to GSM signals of different types and durations were considered of interest. In the present work, HTR-8/SVneo cells were exposed for 4, 16 or 24h to 1.8 GHz continuous wave (CW) and different GSM signals, namely GSM-217 Hz and GSM-Talk (intermittent exposure: 5 min field on, 10 min field off). The alkaline comet assay was used to evaluate primary DNA <span class="hlt">damages</span> and/or strand breaks due to uncompleted repair processes in HF-EMF exposed samples. The amplitude-modulated signals GSM-217 Hz and GSM-Talk induced a significant increase in comet parameters in trophoblast cells after 16 and 24h of exposure, while the un-modulated CW was ineffective. However, alterations were rapidly recovered and the DNA integrity of HF-EMF exposed cells was similar to that of sham-exposed cells within 2h of recovery in the absence irradiation. Our data suggest that HF-EMF with a carrier <span class="hlt">frequency</span> and modulation scheme typical of the GSM signal may affect the DNA integrity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/18619','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/18619"><span>Logging <span class="hlt">damage</span></span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Ralph D. Nyland</p> <p>1989-01-01</p> <p>The best commercial logging will <span class="hlt">damage</span> at least some residual trees during all forms of partial cutting, no matter how carefully done. Yet recommendations at the end of this Note show there is much that you can do to limit <span class="hlt">damage</span> by proper road and trail layout, proper training and supervision of crews, appropriate equipment, and diligence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/285489','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/285489"><span>TMI-2 <span class="hlt">core</span> bore acquisition summary report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tolman, E.L.; Smith, R.P.; Martin, M.R.; McCardell, R.K.; Broughton, J.M.</p> <p>1987-02-01</p> <p><span class="hlt">Core</span> bore samples were obtained from the severely <span class="hlt">damaged</span> TMI-2 <span class="hlt">core</span> during July and August, 1986. A description of the TMI-2 <span class="hlt">core</span> bore drilling unit used to obtain samples; a summary and discussion of the data from the ten <span class="hlt">core</span> bore segments which were obtained; and the initial results of analysis and evaluation of these data are presented in this report. The impact of the major findings relative to our understanding of the accident scenario is also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170005389','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170005389"><span>Kinetic <span class="hlt">Damage</span> from Meteorites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cooke, William; Brown, Peter; Matney, Mark</p> <p>2017-01-01</p> <p>A Near Earth object impacting into Earth's atmosphere may produce <span class="hlt">damaging</span> effects at the surface due to airblast, thermal pulse, or kinetic impact in the form of meteorites. At large sizes (greater than many tens of meters), the <span class="hlt">damage</span> is amplified by the hypersonic impact of these large projectiles moving with cosmic velocity, leaving explosively produced craters. However, much more common is simple "kinetic" <span class="hlt">damage</span> caused by the impact of smaller meteorites moving at terminal speeds. As of this date a handful of instances are definitively known of people or structures being directly hit and/or <span class="hlt">damaged</span> by the kinetic impact of meteorites. Meteorites known to have struck humans include the Sylacauga, Alabama fall (1954) and the Mbale meteorite fall (1992). Much more common is kinetic meteorite <span class="hlt">damage</span> to cars, buildings, and even a post box (Claxton, Georgia - 1984). Historical accounts indicate that direct kinetic <span class="hlt">damage</span> by meteorites may be more common than recent accounts suggest (Yau et al., 1994). In this talk we will examine the contemporary meteorite flux and estimate the <span class="hlt">frequency</span> of kinetic <span class="hlt">damage</span> to various structures, as well as how the meteorite flux might affect the rate of human casualties. This will update an earlier study by Halliday et al (1985), adding variations expected in meteorite flux with latitude (Le Feuvre and Wieczorek, 2008) and validating these model predictions of speed and entry angle with observations from the NASA and SOMN fireball networks. In particular, we explore the physical characteristics of bright meteors which may be used as a diagnostic for estimating which fireballs produce meteorites and hence how early warning of such kinetic <span class="hlt">damage</span> may be estimated in advance through observations and modeling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170008100','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170008100"><span>Kinetic <span class="hlt">Damage</span> from Meteorites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cooke, William; Brown, Peter; Matney, Mark</p> <p>2017-01-01</p> <p>A Near Earth object impacting into Earth's atmosphere may produce <span class="hlt">damaging</span> effects at the surface due to airblast, thermal pulse, or kinetic impact in the form of meteorites. At large sizes (>many tens of meters), the <span class="hlt">damage</span> is amplified by the hypersonic impact of these large projectiles moving with cosmic velocity, leaving explosively produced craters. However, much more common is simple "kinetic" <span class="hlt">damage</span> caused by the impact of smaller meteorites moving at terminal speeds. As of this date a handful of instances are definitively known of people or structures being directly hit and/or <span class="hlt">damaged</span> by the kinetic impact of meteorites. Meteorites known to have struck humans include the Sylacauga, Alabama fall (1954) and the Mbale meteorite fall (1992). Much more common is kinetic meteorite <span class="hlt">damage</span> to cars, buildings, and even a post box (Claxton, Georgia - 1984). Historical accounts indicate that direct kinetic <span class="hlt">damage</span> by meteorites may be more common than recent accounts suggest (Yau et al., 1994). In this talk we will examine the contemporary meteorite flux and estimate the <span class="hlt">frequency</span> of kinetic <span class="hlt">damage</span> to various structures, as well as how the meteorite flux might affect the rate of human casualties. This will update an earlier study by Halliday et al (1985), adding variations expected in meteorite flux with latitude (Le Feuvre and Wieczorek, 2008) and validating these model predictions of speed and entry angle with observations from the NASA and SOMN fireball networks. In particular, we explore the physical characteristics of bright meteors which may be used as a diagnostic for estimating which fireballs produce meteorites and hence how early warning of such kinetic <span class="hlt">damage</span> may be estimated in advance through observations and modelling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002SMaS...11..269K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002SMaS...11..269K"><span><span class="hlt">Damage</span> detection in composite materials using Lamb wave methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kessler, Seth S.; Spearing, S. Mark; Soutis, Constantinos</p> <p>2002-04-01</p> <p>Cost-effective and reliable <span class="hlt">damage</span> detection is critical for the utilization of composite materials. This paper presents part of an experimental and analytical survey of candidate methods for in situ <span class="hlt">damage</span> detection of composite materials. Experimental results are presented for the application of Lamb wave techniques to quasi-isotropic graphite/epoxy test specimens containing representative <span class="hlt">damage</span> modes, including delamination, transverse ply cracks and through-holes. Linear wave scans were performed on narrow laminated specimens and sandwich beams with various <span class="hlt">cores</span> by monitoring the transmitted waves with piezoceramic sensors. Optimal actuator and sensor configurations were devised through experimentation, and various types of driving signal were explored. These experiments provided a procedure capable of easily and accurately determining the time of flight of a Lamb wave pulse between an actuator and sensor. Lamb wave techniques provide more information about <span class="hlt">damage</span> presence and severity than previously tested methods (<span class="hlt">frequency</span> response techniques), and provide the possibility of determining <span class="hlt">damage</span> location due to their local response nature. These methods may prove suitable for structural health monitoring applications since they travel long distances and can be applied with conformable piezoelectric actuators and sensors that require little power.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AAS...203.9413C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AAS...203.9413C"><span>Spectra of Hot <span class="hlt">Cores</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chakrabarti, S.; McKee, C. F.</p> <p>2003-12-01</p> <p>The turbulent <span class="hlt">core</span> model for massive star formation (McKee & Tan 2002) generalizes the standard isothermal collapse model for low-mass stars to include turbulent pressure support. This model predicts reasonable massive star formation times of order 105 years, which is short enough to overcome the radiation pressure of the newly formed star. We calculate the millimeter and infrared spectrum predicted by the turbulent <span class="hlt">core</span> model and compare with observations of several hot molecular <span class="hlt">cores</span>. We consider spherically symmetric dust envelopes and use DUSTY, a 1-D radiative transfer code (Ivezic, Nenkova, Elitzur 1997), to numerically calculate the SEDs of these hot <span class="hlt">cores</span>. We also analytically calculate the spectra in the asymptotic regions of low and high <span class="hlt">frequency</span> and join these asymptotic forms smoothly by a fitting function that minimizes the relative error between the analytic and numerical spectra. Thus, we are able to express the functional dependence of the spectra of hot <span class="hlt">cores</span> in terms of the dynamical variables of any given collapse model. This approach allows us to use observed SEDs as a diagnostic tool in inferring physical conditions in these <span class="hlt">cores</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA053482','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA053482"><span>Statistical Analysis of Japanese Structural <span class="hlt">Damage</span> Data</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1977-01-01</p> <p>Calculated Peak Overpressure Data ......... .. 36 Figure 4. <span class="hlt">Frequency</span> Functions for Assumed <span class="hlt">Damage</span> Laws ............ .. 38 Figure 5. Conversions to Value of...Buildings .... .......... .. 92 Figure 20. Effect of <span class="hlt">Damage</span> Law on Confidence Regions ............ .. 97 * Figure 21. Comparison of Confidence Limits on...Value of ad (Cumulative Log Normal <span class="hlt">Damage</span> Law ) ...... ............ .. 99 * Figure 22. Comparison of Confidence Limits on Value of ad (Cumulative Log</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020015710','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020015710"><span>Structural <span class="hlt">Damage</span> Detection Using Virtual Passive Controllers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lew, Jiann-Shiun; Juang, Jer-Nan</p> <p>2001-01-01</p> <p>This paper presents novel approaches for structural <span class="hlt">damage</span> detection which uses the virtual passive controllers attached to structures, where passive controllers are energy dissipative devices and thus guarantee the closed-loop stability. The use of the identified parameters of various closed-loop systems can solve the problem that reliable identified parameters, such as natural <span class="hlt">frequencies</span> of the open-loop system may not provide enough information for <span class="hlt">damage</span> detection. Only a small number of sensors are required for the proposed approaches. The identified natural <span class="hlt">frequencies</span>, which are generally much less sensitive to noise and more reliable than the identified natural <span class="hlt">frequencies</span>, are used for <span class="hlt">damage</span> detection. Two <span class="hlt">damage</span> detection techniques are presented. One technique is based on the structures with direct output feedback controllers while the other technique uses the second-order dynamic feedback controllers. A least-squares technique, which is based on the sensitivity of natural <span class="hlt">frequencies</span> to <span class="hlt">damage</span> variables, is used for accurately identifying the <span class="hlt">damage</span> variables.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1231807','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1231807"><span>GEOS-<span class="hlt">CORE</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p></p> <p>2014-06-24</p> <p>GEOS-<span class="hlt">CORE</span> is a code that integrates open source Libraries for linear algebra and I/O with two main LLNL-written components: (i) a set of standard finite, discrete, and discontinuous displacement element physics solvers for resolving Darcy fluid flow, explicit mechanics, implicit mechanics, and fluid-mediated fracturing, including resolution of physical behaviors both implicitly and explicitly, and (ii) a MPI-based parallelization implementation for use on generic HPC distributed memory architectures. The resultant code can be used alone for linearly elastic and quasistatic <span class="hlt">damage</span> problems; problems involving hydraulic fracturing, where the mesh topology is dynamically changed; and general granular materials behavior. The key application domain is for low-rate stimulation and fracture control in subsurface reservoirs (e.g., enhanced geothermal sites and unconventional shale gas stimulation). GEOS-<span class="hlt">CORE</span> also has interfaces to call external libraries for, e.g., material models and equations fo state; however, LLNL-developed EOS and material models, beyond the aforementioned linear elastic and quasi-static <span class="hlt">damage</span> models, will not be part of the current release. GEOS-<span class="hlt">CORE</span>'s secondary applications include granular materials behavior under different load paths.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/al1054.photos.046338p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/al1054.photos.046338p/"><span>24. A <span class="hlt">CORE</span> WORKER DISPLAYS THE <span class="hlt">CORE</span> BOX AND <span class="hlt">CORES</span> ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>24. A <span class="hlt">CORE</span> WORKER DISPLAYS THE <span class="hlt">CORE</span> BOX AND <span class="hlt">CORES</span> FOR A BRASS GATE VALVE BODY MADE ON A <span class="hlt">CORE</span> BOX, CA. 1950. - Stockham Pipe & Fittings Company, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.5662T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.5662T"><span>Distribution and growth of fractures in the <span class="hlt">damage</span> zone of a fault in outcrop</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tanner, David C.; Burchardt, Steffi; Krawczyk, Charlotte M.</p> <p>2015-04-01</p> <p>The <span class="hlt">damage</span> zone of a fault is often visualised as a zone of small fractures that decrease in <span class="hlt">frequency</span> symmetrically away from the fault <span class="hlt">core</span>. While the fault <span class="hlt">core</span> is postulated to be sealing, the <span class="hlt">damage</span> zone is thought to offer good permeability for fluid flow parallel to the fault. Very little is known about the sequential evolution of fractures within the <span class="hlt">damage</span> zone. We therefore undertook a detailed examination of the architecture of an excellently-exposed fault and its <span class="hlt">damage</span> zone that is completely exposed on the west coast of Ireland. The fault <span class="hlt">core</span> is composed of a three-metres thick homogeneous fault gouge. The fault zone walls are characterised by a sinuous geometry that dips steeply both east and west. Quartz fibres in tension gashes in the fault-<span class="hlt">core</span> walls show that the fault is an dip-slip thrust with a small component of dextral slip. Only the hanging-wall is <span class="hlt">damaged</span>; the footwall is folded, but unfractured. The hanging-wall is deformed by two distinct shear fracture systems; an early-formed antithetic set and a latter synthetic set. Using four, horizontal, metre-spaced scan-lines, we show that a simple relationship of fracture density and throw decrease with distance from the fault does not exist. Instead, the density of antithetic fractures controls the distribution of later synthetic fractures. This evidences strain-weakening processes. We postulate that fracturing of the hanging-wall is due entirely to forces that result from fault bends. Therefore fracturing of the hanging-wall is primarily dependant on fault-surface topography, but subsequent <span class="hlt">damage</span> distribution is a function of the distribution of the first increment of deformation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/7069897','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/7069897"><span><span class="hlt">Core</span> phenomenology. TEC report on CRBRP PRA Phase II, Task 6C. Final draft report, Revision 1</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p></p> <p>1984-04-04</p> <p>As part of the determination of the risk potential associated with <span class="hlt">core-damage</span> accident sequences for the CRBRP, a review of the <span class="hlt">core-damage</span> phenomenology is necessary. How <span class="hlt">core</span> <span class="hlt">damage</span> proceeds, its effects on the primary system boundary, and the timing and energetic potential associated with <span class="hlt">core</span> <span class="hlt">damage</span> are important to determining the challenge to containment and the ultimate release of fission products to the environment. This chapter addresses the phenomenology related to the <span class="hlt">core-damage</span> processes and by the use of a <span class="hlt">core</span>-response event tree, estimates are made of the probability that certain <span class="hlt">core</span>-response scenarios are followed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/212605','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/212605"><span>Large <span class="hlt">core</span> fiber optic cleaver</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Halpin, J.M.</p> <p>1996-03-26</p> <p>The present invention relates to a device and method for cleaving optical fibers which yields cleaved optical fiber ends possessing high <span class="hlt">damage</span> threshold surfaces. The device can be used to cleave optical fibers with <span class="hlt">core</span> diameters greater than 400 {micro}m. 30 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/870351','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/870351"><span>Large <span class="hlt">core</span> fiber optic cleaver</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Halpin, John M.</p> <p>1996-01-01</p> <p>The present invention relates to a device and method for cleaving optical fibers which yields cleaved optical fiber ends possessing high <span class="hlt">damage</span> threshold surfaces. The device can be used to cleave optical fibers with <span class="hlt">core</span> diameters greater than 400 .mu.m.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.5767..264O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.5767..264O"><span>Evaluation of modal-based <span class="hlt">damage</span> detection techniques for composite aircraft sandwich structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oliver, J. A.; Kosmatka, J. B.</p> <p>2005-05-01</p> <p>Composite sandwich structures are important as structural components in modern lightweight aircraft, but are susceptible to catastrophic failure without obvious forewarning. Internal <span class="hlt">damage</span>, such as disbonding between skin and <span class="hlt">core</span>, is detrimental to the structures' strength and integrity and thus must be detected before reaching critical levels. However, highly directional low density <span class="hlt">cores</span>, such as Nomex honeycomb, make the task of <span class="hlt">damage</span> detection and health monitoring difficult. One possible method for detecting <span class="hlt">damage</span> in composite sandwich structures, which seems to have received very little research attention, is analysis of global modal parameters. This study will investigate the viability of modal analysis techniques for detecting skin-<span class="hlt">core</span> disbonds in carbon fiber-Nomex honeycomb sandwich panels through laboratory testing. A series of carbon fiber prepreg and Nomex honeycomb sandwich panels-representative of structural components used in lightweight composite airframes-were fabricated by means of autoclave co-cure. All panels were of equal dimensions and two were made with predetermined sizes of disbonded areas, created by substituting areas of Teflon release film in place of epoxy film adhesive during the cure. A laser vibrometer was used to capture <span class="hlt">frequency</span> response functions (FRF) of all panels, and then real and imaginary FRFs at different locations on each plate and operating shapes for each plate were compared. Preliminary results suggest that vibration-based techniques hold promise for <span class="hlt">damage</span> detection of composite sandwich structures.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994EOSTr..75R.522.','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994EOSTr..75R.522."><span><span class="hlt">Core</span> transfer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p></p> <p></p> <p>Good news for all petroleum geoscientists, mining and environmental scientists, university researchers, and the like: Shell Oil Company has deeded its Midland <span class="hlt">core</span> and sample repository to the Bureau of Economic Geology (BEG) at the University of Texas at Austin. The Midland repository includes more than 1 million linear meters of slab, whole <span class="hlt">core</span>, and prepared cuttings. Data comprising one of the largest U.S. <span class="hlt">core</span> collections—the geologic samples from wells drilled in Texas and 39 other states—are now public data and will be incorporated into the existing BEG database. Both Shell and the University of Texas at Austin are affiliated with the American Geological Institute, which assisted in arranging the transfer as part of its goal to establish a National Geoscience Data Repository System at regional centers across the United States.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/350282','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/350282"><span>War <span class="hlt">damages</span> and reconstruction of Peruca dam</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nonveiller, E.; Rupcic, J. |; Sever, Z.</p> <p>1999-04-01</p> <p>The paper describes the heavy <span class="hlt">damages</span> caused by blasting in the Peruca rockfill dam in Croatia in January 1993. Complete collapse of the dam by overtopping was prevented through quick action of the dam owner by dumping clayey gravel on the lowest sections of the dam crest and opening the bottom outlet of the reservoir, thus efficiently lowering the water level. After the <span class="hlt">damages</span> were sufficiently established and alternatives for restoration of the dam were evaluated, it was decided to construct a diaphragm wall through the <span class="hlt">damaged</span> <span class="hlt">core</span> in the central dam part as the impermeable dam element and to rebuild the central clay <span class="hlt">core</span> at the dam abutments. Reconstruction works are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.asha.org/public/speech/disorders/RightBrainDamage.htm','NIH-MEDLINEPLUS'); return false;" href="http://www.asha.org/public/speech/disorders/RightBrainDamage.htm"><span>Right Hemisphere Brain <span class="hlt">Damage</span></span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... Language and Swallowing / Disorders and Diseases Right Hemisphere Brain <span class="hlt">Damage</span> [ en Español ] What is right hemisphere brain ... right hemisphere brain <span class="hlt">damage</span> ? What is right hemisphere brain <span class="hlt">damage</span>? Right hemisphere brain <span class="hlt">damage</span> (RHD) is <span class="hlt">damage</span> ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910000678&hterms=concept+damage&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dconcept%2Bdamage','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910000678&hterms=concept+damage&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dconcept%2Bdamage"><span>Monitoring Bearing Vibrations For Signs Of <span class="hlt">Damage</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Martinez, Carol L.</p> <p>1991-01-01</p> <p>Real-time spectral analysis of vibrations being developed for use in monitoring conditions of critical bearings in rotating machinery. Underlying concept simple and fairly well established: appearance and growth of vibrations at <span class="hlt">frequencies</span> associated with rotations of various parts of bearing system indicate wear, <span class="hlt">damage</span>, and imperfections of manufacture. <span class="hlt">Frequencies</span> include fundamental and harmonics of <span class="hlt">frequency</span> of rotation of ball cage, <span class="hlt">frequency</span> of passage of balls, and <span class="hlt">frequency</span> of rotation of shaft.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910000678&hterms=sign&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsign','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910000678&hterms=sign&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsign"><span>Monitoring Bearing Vibrations For Signs Of <span class="hlt">Damage</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Martinez, Carol L.</p> <p>1991-01-01</p> <p>Real-time spectral analysis of vibrations being developed for use in monitoring conditions of critical bearings in rotating machinery. Underlying concept simple and fairly well established: appearance and growth of vibrations at <span class="hlt">frequencies</span> associated with rotations of various parts of bearing system indicate wear, <span class="hlt">damage</span>, and imperfections of manufacture. <span class="hlt">Frequencies</span> include fundamental and harmonics of <span class="hlt">frequency</span> of rotation of ball cage, <span class="hlt">frequency</span> of passage of balls, and <span class="hlt">frequency</span> of rotation of shaft.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1231730','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1231730"><span><span class="hlt">Frequency</span> Response Tool</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Etingov, Pavel; Chassin, PNNL David; Zhang, PNNL Yu; PNNL,</p> <p>2014-03-13</p> <p>According to the North American Electric Reliability Corporation (NERC) definition: "<span class="hlt">Frequency</span> response is a measure of an Interconnection's ability to stabilize <span class="hlt">frequency</span> immediately following the sudden loss of generation or load, and is a critical component of the reliable operation of the Bulk-Power System, particularly during disturbances and recoveries. Failure to maintain <span class="hlt">frequency</span> can disrupt the operation of equipment and initiate disconnection of power plant equipment to prevent it from being <span class="hlt">damaged</span>, which could lead to wide-spread blackouts." <span class="hlt">Frequency</span> Response Tool automates the power system <span class="hlt">frequency</span> response analysis process. The tool performs initial estimation of the system <span class="hlt">frequency</span> parameters (initial <span class="hlt">frequency</span>, minimum <span class="hlt">frequency</span>, settling point). User can visually inspect and adjust these parameters. The tool also calculates the <span class="hlt">frequency</span> response performance metrics of the system, archives the historic events and baselines the system performance. <span class="hlt">Frequency</span> response performance characteristics of the system are calculated using phasor measurement unit (PMU) information. Methodology of the <span class="hlt">frequency</span> response performance assessment implemented in the tool complies with the NERC <span class="hlt">Frequency</span> response standard.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1231730','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1231730"><span><span class="hlt">Frequency</span> Response Tool</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Etingov, Pavel; Chassin, PNNL David; Zhang, PNNL Yu; PNNL,</p> <p>2014-03-13</p> <p>According to the North American Electric Reliability Corporation (NERC) definition: “<span class="hlt">Frequency</span> response is a measure of an Interconnection’s ability to stabilize <span class="hlt">frequency</span> immediately following the sudden loss of generation or load, and is a critical component of the reliable operation of the Bulk-Power System, particularly during disturbances and recoveries. Failure to maintain <span class="hlt">frequency</span> can disrupt the operation of equipment and initiate disconnection of power plant equipment to prevent it from being <span class="hlt">damaged</span>, which could lead to wide-spread blackouts.” <span class="hlt">Frequency</span> Response Tool automates the power system <span class="hlt">frequency</span> response analysis process. The tool performs initial estimation of the system <span class="hlt">frequency</span> parameters (initial <span class="hlt">frequency</span>, minimum <span class="hlt">frequency</span>, settling point). User can visually inspect and adjust these parameters. The tool also calculates the <span class="hlt">frequency</span> response performance metrics of the system, archives the historic events and baselines the system performance. <span class="hlt">Frequency</span> response performance characteristics of the system are calculated using phasor measurement unit (PMU) information. Methodology of the <span class="hlt">frequency</span> response performance assessment implemented in the tool complies with the NERC <span class="hlt">Frequency</span> response standard.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMDI41B..04J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMDI41B..04J"><span><span class="hlt">Core</span> layering</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jacobson, S. A.; Rubie, D. C.; Hernlund, J. W.; Morbidelli, A.</p> <p>2015-12-01</p> <p>We have created a planetary accretion and differentiation model that self-consistently builds and evolves Earth's <span class="hlt">core</span>. From this model, we show that the <span class="hlt">core</span> grows stably stratified as the result of rising metal-silicate equilibration temperatures and pressures, which increases the concentrations of light element impurities into each newer <span class="hlt">core</span> addition. This stable stratification would naturally resist convection and frustrate the onset of a geodynamo, however, late giant impacts could mechanically mix the distinct accreted <span class="hlt">core</span> layers creating large homogenous regions. Within these regions, a geodynamo may operate. From this model, we interpret the difference between the planetary magnetic fields of Earth and Venus as a difference in giant impact histories. Our planetary accretion model is a numerical N-body integration of the Grand Tack scenario [1]—the most successful terrestrial planet formation model to date [2,3]. Then, we take the accretion histories of Earth-like and Venus-like planets from this model and post-process the growth of each terrestrial planet according to a well-tested planetary differentiation model [4,5]. This model fits Earth's mantle by modifying the oxygen content of the pre-cursor planetesimals and embryos as well as the conditions of metal-silicate equilibration. Other non-volatile major, minor and trace elements included in the model are assumed to be in CI chondrite proportions. The results from this model across many simulated terrestrial planet growth histories are robust. If the kinetic energy delivered by larger impacts is neglected, the <span class="hlt">core</span> of each planet grows with a strong stable stratification that would significantly impede convection. However, if giant impact mixing is very efficient or if the impact history delivers large impacts late, than the stable stratification can be removed. [1] Walsh et al. Nature 475 (2011) [2] O'Brien et al. Icarus 223 (2014) [3] Jacobson & Morbidelli PTRSA 372 (2014) [4] Rubie et al. EPSL 301</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ChJME..27..673S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ChJME..27..673S"><span>Development of a drilling and <span class="hlt">coring</span> test-bed for lunar subsurface exploration and preliminary experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Xiaomeng; Deng, Zongquan; Quan, Qiquan; Tang, Dewei; Hou, Xuyan; Jiang, Shengyuan</p> <p>2014-07-01</p> <p>Drill sampling has been widely employed as an effective way to acquire deep samples in extraterrestrial exploration. A novel sampling method, namely, flexible-tube <span class="hlt">coring</span>, was adopted for the Chang'e mission to acquire drilling <span class="hlt">cores</span> without <span class="hlt">damaging</span> stratification information. Since the extraterrestrial environment is uncertain and different from the terrestrial environment, automated drill sampling missions are at risk of failure. The principles of drilling and <span class="hlt">coring</span> for the lunar subsurface should be fully tested and verified on earth before launch. This paper proposes a test-bed for conducting the aforementioned experiments on earth. The test-bed comprises a rotary-percussive drilling mechanism, penetrating mechanism, drilling medium container, and signal acquisition and control system. For granular soil, <span class="hlt">coring</span> experiments indicate that the sampling method has a high <span class="hlt">coring</span> rate greater than 80%. For hard rock, drilling experiments indicate that the percussive <span class="hlt">frequency</span> greatly affects the drilling efficiency. A multi-layered simulant composed of granular soil and hard rock is built to test the adaptability of drilling and <span class="hlt">coring</span>. To tackle complex drilling media, an intelligent drilling strategy based on online recognition is proposed to improve the adaptability of the sampling drill. The primary features of this research are the proposal of a scheme for drilling and <span class="hlt">coring</span> a test-bed for validation on earth and the execution of drilling experiments in complex media.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992sampesymp.1228H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992sampesymp.1228H"><span>Design of highly <span class="hlt">damage</span>-tolerant sandwich panels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hiel, Clement; Ishai, Ori</p> <p></p> <p>The effects of different fabrication procedures to increase the <span class="hlt">damage</span> tolerance of sandwich panels were studied. Baseline panels consisted of a 25.4 mm premolded <span class="hlt">core</span>, surfaced with 177 C cure film adhesive and carbon-bismaleimide prepreg which were subsequently cocured onto the <span class="hlt">core</span>. It was found that panels with a prefabricated skin, which was subsequently bonded onto the <span class="hlt">core</span> with room temperature cure adhesive, showed greatly increased <span class="hlt">damage</span> tolerance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/13713','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/13713"><span>Heavy snowfall <span class="hlt">damage</span> Virginia pine</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Richard H. Fenton</p> <p>1959-01-01</p> <p>In the Coastal Plain from Virginia to Pennsylvania, snowstorms heavy enough to <span class="hlt">damage</span> trees are unusual. Weather Bureau records for the general area show that heavy snowfall - 8 to 25 inches in a single storm - occurs at an average <span class="hlt">frequency</span> of about once in 7 years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080010742','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080010742"><span>STS-118 Radiator Impact <span class="hlt">Damage</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lear, Dana M.; Hyde, J.; Christiansen, E.; Herrin, J.; Lyons, F.</p> <p>2008-01-01</p> <p>During the August 2007 STS-118 mission to the International Space Station, a micro-meteoroid or orbital debris (MMOD) particle impacted and completely penetrated one of shuttle Endeavour s radiator panels and the underlying thermal control system (TCS) blanket, leaving deposits on (but no <span class="hlt">damage</span> to) the payload bay door. While it is not unusual for shuttle orbiters to be impacted by small MMOD particles, the <span class="hlt">damage</span> from this impact is larger than any previously seen on the shuttle radiator panels. A close-up photograph of the radiator impact entry hole is shown in Figure 1, and the location of the impact on Endeavour s left-side aft-most radiator panel is shown in Figure 2. The aft radiator panel is 0.5-inches thick and consists of 0.011 inch thick aluminum facesheets on the front and back of an aluminum honeycomb <span class="hlt">core</span>. The front facesheet is additionally covered by a 0.005 inch thick layer of silver-Teflon thermal tape. The entry hole in the silver-Teflon tape measured 8.1 mm by 6.4 mm (0.32 inches by 0.25 inches). The entry hole in the outer facesheet measured 7.4 mm by 5.3 mm (0.29 inches by 0.21 inches) (0.23 inches). The impactor also perforated an existing 0.012 inch doubler that had been bonded over the facesheet to repair previous impact <span class="hlt">damage</span> (an example that lightning can strike the same place twice, even for MMOD impact). The peeled-back edge around the entry hole, or lip , is a characteristic of many hypervelocity impacts. High velocity impact with the front facesheet fragmented the impacting particle and caused it to spread out into a debris cloud. The debris cloud caused considerable <span class="hlt">damage</span> to the internal honeycomb <span class="hlt">core</span> with 23 honeycomb cells over a region of 28 mm by 26 mm (1.1 inches by 1.0 inches) having either been completely destroyed or partially <span class="hlt">damaged</span>. Figure 3 is a view of the exit hole in the rear facesheet, and partially shows the extent of the honeycomb <span class="hlt">core</span> <span class="hlt">damage</span> and clearly shows the jagged petaled exit hole through the backside</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA187162','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA187162"><span>National Economic Development Procedures Manual - Agricultural Flood <span class="hlt">Damage</span>,</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1987-10-01</p> <p><span class="hlt">damaging</span> because the investment in the production of the crop is greater and the impact on the crop’s yield potential is more harmful. The 1984 flood... impacts of flooding on crop production, but many of the principles also apply to livestock, dairy, poultry, and other producing operations. Flood <span class="hlt">damage</span> to...an agricultural <span class="hlt">damage</span> evaluzition is the <span class="hlt">frequency</span> of flooding. The <span class="hlt">frequency</span> of flooding impacts on flood <span class="hlt">damage</span> and benefits in two ways. Most</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040088544&hterms=radon&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dradon','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040088544&hterms=radon&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dradon"><span>Induction and repair of HZE induced cytogenetic <span class="hlt">damage</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brooks, A. L.; Bao, S.; Rithidech, K.; Chrisler, W. B.; Couch, L. A.; Braby, L. A.</p> <p>2001-01-01</p> <p>Wistar rats were exposed to high-mass, high energy (HZE) 56Fe particles (1000 GeV/AMU) using the Alternating Gradient Synchrotron (AGS). The animals were sacrificed at 1-5 hours or after a 30-day recovery period. The <span class="hlt">frequency</span> of micronuclei in the tracheal and the deep lung epithelial cells were evaluated. The relative effectiveness of 56Fe, for the induction of initial chromosome <span class="hlt">damage</span> in the form of micronuclei, was compared to <span class="hlt">damage</span> produced in the same biological system exposed to other types of high and low-LET radiation. It was demonstrated that for animals sacrificed at short times after exposure, the tracheal and lung epithelial cells, the 56Fe particles were 3.3 and 1.3 times as effective as 60Co in production of micronuclei, respectively. The effectiveness was also compared to that for exposure to inhaled radon. With this comparison, the 56Fe exposure of the tracheal epithelial cells and the lung epithelial cells were only 0.18 and 0.20 times as effective as radon in the production of the initial cytogenetic <span class="hlt">damage</span>. It was suggested that the low relative effectiveness was related to potential for 'wasted energy' from the <span class="hlt">core</span> of the 56Fe particles. When the animals were sacrificed after 30 days, the slopes of the dose-response relationships, which reflect the remaining level of <span class="hlt">damage</span>, decreased by a factor of 10 for both the tracheal and lung epithelial cells. In both cases, the slope of the dose-response lines were no longer significantly different from zero, and the r2 values were very high. Lung epithelial cells, isolated from the animals sacrificed hours after exposure, were maintained in culture, and the micronuclei <span class="hlt">frequency</span> evaluated after 4 and 6 subcultures. These cells were harvested at 24 and 36 days after the exposure. There was no dose-response detected in these cultures and no signs of genomic instability at either sample time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040088544&hterms=culture+italians&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dculture%2Bitalians','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040088544&hterms=culture+italians&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dculture%2Bitalians"><span>Induction and repair of HZE induced cytogenetic <span class="hlt">damage</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brooks, A. L.; Bao, S.; Rithidech, K.; Chrisler, W. B.; Couch, L. A.; Braby, L. A.</p> <p>2001-01-01</p> <p>Wistar rats were exposed to high-mass, high energy (HZE) 56Fe particles (1000 GeV/AMU) using the Alternating Gradient Synchrotron (AGS). The animals were sacrificed at 1-5 hours or after a 30-day recovery period. The <span class="hlt">frequency</span> of micronuclei in the tracheal and the deep lung epithelial cells were evaluated. The relative effectiveness of 56Fe, for the induction of initial chromosome <span class="hlt">damage</span> in the form of micronuclei, was compared to <span class="hlt">damage</span> produced in the same biological system exposed to other types of high and low-LET radiation. It was demonstrated that for animals sacrificed at short times after exposure, the tracheal and lung epithelial cells, the 56Fe particles were 3.3 and 1.3 times as effective as 60Co in production of micronuclei, respectively. The effectiveness was also compared to that for exposure to inhaled radon. With this comparison, the 56Fe exposure of the tracheal epithelial cells and the lung epithelial cells were only 0.18 and 0.20 times as effective as radon in the production of the initial cytogenetic <span class="hlt">damage</span>. It was suggested that the low relative effectiveness was related to potential for 'wasted energy' from the <span class="hlt">core</span> of the 56Fe particles. When the animals were sacrificed after 30 days, the slopes of the dose-response relationships, which reflect the remaining level of <span class="hlt">damage</span>, decreased by a factor of 10 for both the tracheal and lung epithelial cells. In both cases, the slope of the dose-response lines were no longer significantly different from zero, and the r2 values were very high. Lung epithelial cells, isolated from the animals sacrificed hours after exposure, were maintained in culture, and the micronuclei <span class="hlt">frequency</span> evaluated after 4 and 6 subcultures. These cells were harvested at 24 and 36 days after the exposure. There was no dose-response detected in these cultures and no signs of genomic instability at either sample time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6521454','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6521454"><span>TMI-2 <span class="hlt">core</span> shipping preparations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ball, L.J.; ); Barkanic, R.J. ); Conaway, W.T. II ); Schmoker, D.S. )</p> <p>1988-01-01</p> <p>Shipping the <span class="hlt">damaged</span> <span class="hlt">core</span> from the Unit 2 reactor of Three Mile Island Nuclear Power Station near Harrisburg, PA, to the Idaho National Engineering Laboratory near Idaho Falls, ID, required development and implementation of a completely new spent fuel transportation system. This paper describes the equipment developed, the planning and activities used to implement the hardware systems into the facilities, and the planning involved in making the rail shipments. It also includes a summary of recommendations resulting from this experience.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=MSFC-7042417&hterms=tiny+home&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dtiny%2Bhome','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=MSFC-7042417&hterms=tiny+home&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dtiny%2Bhome"><span><span class="hlt">Damaged</span> Skylab</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1973-01-01</p> <p>The Saturn V vehicle, carrying the unmarned orbital workshop for the Skylab-1 mission, lifted off successfully and all systems performed normally. Sixty-three seconds into the flight, engineers in the operation support and control center saw an unexpected telemetry indication that signalled that <span class="hlt">damages</span> occurred on one solar array and the micrometeoroid shield during the launch. The micrometeoroid shield, a thin protective cylinder surrounding the workshop protecting it from tiny space particles and the sun's scorching heat, ripped loose from its position around the workshop. This caused the loss of one solar wing and jammed the other. Still unoccupied, the Skylab was stricken with the loss of the heat shield and sunlight beat mercilessly on the lab's sensitive skin. Internal temperatures soared, rendering the station uninhabitable, threatening foods, medicines, films, and experiments. This image, taken during a fly-around inspection by the Skylab-2 crew, shows a crippled Skylab in orbit. The crew found their home in space to be in serious shape; the heat shield gone, one solar wing gone, and the other jammed. The Marshall Space Flight Center (MSFC) developed, tested, rehearsed, and approved three repair options. These options included a parasol sunshade and a twin-pole sunshade to restore the temperature inside the workshop, and a set of metal cutting tools to free the jammed solar panel.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/4994465','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/4994465"><span>LSD and genetic <span class="hlt">damage</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dishotsky, N I; Loughman, W D; Mogar, R E; Lipscomb, W R</p> <p>1971-04-30</p> <p>Of nine studies in vitro, six have indicated some degree of induced chromosomal breakage after exposure to LSD; three failed to confirm these results. The <span class="hlt">damage</span>, when found, was generally of the chromatid type, arising during or after DNA synthesis. This <span class="hlt">damage</span>, with one exception, was the result of concentrations of drug and durations of exposure which could not be achieved in humans with reasonable dosages. There did not appear to be a dose-response relation. The magnitude of <span class="hlt">damage</span>, when found, was in the range encompassing the effects of many commonly used substances. The absence in vitro of excretory and detoxifying systems present in vivo, as well as several negative reports, cast doubt on the relevance of in vitro results. In 21 chromosomal studies in vivo, 310 subjects were examined. Of these, 126 were treated with pure LSD; the other 184 were exposed to illicit, "alleged" LSD. A maximum of only 18 of 126 (14.29 percent) of the subjects in the group exposed to pure LSD showed higher <span class="hlt">frequency</span> of chromosome aberration than the controls. In contrast, a maximum of 90 of 184 (48.91 percent) of the subjects taking illicit LSD showed an increase in <span class="hlt">frequency</span> of aberrations. Of all the subjects reported to have chromosome <span class="hlt">damage</span>, only 18 of the 108 (16.67 percent) were exposed to pure LSD. The <span class="hlt">frequency</span> of individuals with chromosomal <span class="hlt">damage</span> reported among illicit drug users was more than triple that associated with the use of pharmacologically pure LSD. We conclude that chromosome <span class="hlt">damage</span>, when found, was related to the effects of drug abuse in general and not, as initially reported, to LSD alone. We believe that pure LSD ingested in moderate dosages does not produce chromosome <span class="hlt">damage</span> detectable by available methods. No significant work on carcinogenic potential of LSD has been reported so far. No cause-and-effect relation and no increase in the incidence of neoplasia among LSD users have been demonstrated. Case reports (three in 4.0 years) of leukemia and other</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770005349','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770005349"><span>Simplifier cut <span class="hlt">core</span> inductor design</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mclyman, W. T.</p> <p>1976-01-01</p> <p>Advantages of specifying C <span class="hlt">cores</span> and cut toroids fabricated from grain oriented silicon steels for use in high <span class="hlt">frequency</span> power converters and pulse width modulated switching regulators are discussed. A method for rating <span class="hlt">cores</span> assigns to each <span class="hlt">core</span> a number which is the product of its window and <span class="hlt">core</span> cross section area, called 'Area Product A sub p.' A correlation between the A sub p numbers and current density for a given temperature rise was developed. Also, straight line relationships were developed for A sub p and volume, A sub p and surface area, and A sub p and weight. These relationships can be used to simplify and standardize the process of inductor design. They also make it possible to design inductors of small bulk and volume or to optimize efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA206232','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA206232"><span>An Integrated Software Package for Flood <span class="hlt">Damage</span> Analysis</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1989-02-01</p> <p>Table 4: : Effect of Flood Plain Management Measures Impacted Relationship’ Stage- Stage- Flow- Flow- <span class="hlt">Damage</span> - Measure flow <span class="hlt">Damage</span> <span class="hlt">Damage</span> <span class="hlt">Frequency</span>...US Army Corps of Engineers The Hydrologic Engineering Center AD-A206 232 An Integrated Software Packagi for Flood <span class="hlt">Damage</span> Analysis / DTIC nELECTE f...does not constitute an official endorsement or approval of the use of such commercial products. AN INTEGRATED SOFTWARE PACKAGE FOR FLOOD <span class="hlt">DAMAGE</span></p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740021450','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740021450"><span>Simplified cut <span class="hlt">core</span> inductor design</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mclyman, W. T.</p> <p>1974-01-01</p> <p>Although filter inductor designers have routinely tended to specify molypermalloy powder <span class="hlt">cores</span> for use in high <span class="hlt">frequency</span> power converters and pulse-width modulated switching regulators, there are sigificant advantages in specifying C <span class="hlt">cores</span> and cut toroids fabricated from grain oriented silicon steels which should not be overlooked. Such steel <span class="hlt">cores</span> can develop flux densities of 1.6 tesla, with useful linearity to 1.2 tesla, whereas molypermalloy <span class="hlt">cores</span> carrying d.c. current have useful flux density capabilities only to about 0.3 tesla. The use of silicon steel <span class="hlt">cores</span> thus makes it possible to design more compact <span class="hlt">cores</span>, and therefore inductors of reduced volume, or conversely to provide greater load capacity in inductors of a given volume. Information is available which makes it possible to obtain quick and close approximations of significant parameters such as size, weight and temperature rise for silicon steel <span class="hlt">cores</span> for breadboarding. Graphs, nomographs and tables are presented for this purpose, but more complete mathematical derivations of some of the important parameters are also included for a more rigorous treatment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=journals&pg=4&id=EJ876054','ERIC'); return false;" href="https://eric.ed.gov/?q=journals&pg=4&id=EJ876054"><span>The <span class="hlt">Core</span> Journal Concept in Black Studies</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Weissinger, Thomas</p> <p>2010-01-01</p> <p>Black Studies scholars have shown interest in the <span class="hlt">core</span> journal concept. Indeed, the idea of <span class="hlt">core</span> journals for the study of the Black experience has changed several times since 1940. While Black Studies scholars are citing Black Studies journals with <span class="hlt">frequency</span>, they also cite traditional disciplinary journals a great deal of the time. However,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=journals&pg=3&id=EJ876054','ERIC'); return false;" href="http://eric.ed.gov/?q=journals&pg=3&id=EJ876054"><span>The <span class="hlt">Core</span> Journal Concept in Black Studies</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Weissinger, Thomas</p> <p>2010-01-01</p> <p>Black Studies scholars have shown interest in the <span class="hlt">core</span> journal concept. Indeed, the idea of <span class="hlt">core</span> journals for the study of the Black experience has changed several times since 1940. While Black Studies scholars are citing Black Studies journals with <span class="hlt">frequency</span>, they also cite traditional disciplinary journals a great deal of the time. However,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160012007','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160012007"><span>Tuned Chamber <span class="hlt">Core</span> Panel Acoustic Test Results</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schiller, Noah H.; Allen, Albert R.</p> <p>2016-01-01</p> <p>This report documents acoustic testing of tuned chamber <span class="hlt">core</span> panels, which can be used to supplement the low-<span class="hlt">frequency</span> performance of conventional acoustic treatment. The tuned chamber <span class="hlt">core</span> concept incorporates low-<span class="hlt">frequency</span> noise control directly within the primary structure and is applicable to sandwich constructions with a directional <span class="hlt">core</span>, including corrugated-, truss-, and fluted-<span class="hlt">core</span> designs. These types of sandwich structures have long, hollow channels (or chambers) in the <span class="hlt">core</span>. By adding small holes through one of the facesheets, the hollow chambers can be utilized as an array of low-<span class="hlt">frequency</span> acoustic resonators. These resonators can then be used to attenuate low-<span class="hlt">frequency</span> noise (below 400 Hz) inside a vehicle compartment without increasing the weight or size of the structure. The results of this test program demonstrate that the tuned chamber <span class="hlt">core</span> concept is effective when used in isolation or combined with acoustic foam treatments. Specifically, an array of acoustic resonators integrated within the <span class="hlt">core</span> of the panels was shown to improve both the low-<span class="hlt">frequency</span> absorption and transmission loss of the structure in targeted one-third octave bands.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SMaS...20j5025H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SMaS...20j5025H"><span>On-line structural <span class="hlt">damage</span> localization and quantification using wireless sensors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hsu, Ting-Yu; Huang, Shieh-Kung; Lu, Kung-Chung; Loh, Chin-Hsiung; Wang, Yang; Lynch, Jerome Peter</p> <p>2011-10-01</p> <p>In this paper, a wireless sensing system is designed to realize on-line <span class="hlt">damage</span> localization and quantification of a structure using a <span class="hlt">frequency</span> response function change method (FRFCM). Data interrogation algorithms are embedded in the computational <span class="hlt">core</span> of the wireless sensing units to extract the necessary structural features, i.e. the <span class="hlt">frequency</span> spectrum segments around eigenfrequencies, automatically from measured structural response for the FRFCM. Instead of the raw time history of the structural response, the extracted compact structural features are transmitted to the host computer. As a result, with less data transmitted from the wireless sensors, the energy consumed by the wireless transmission is reduced. To validate the performance of the proposed wireless sensing system, a six-story steel building with replaceable bracings in each story is instrumented with the wireless sensors for on-line <span class="hlt">damage</span> detection during shaking table tests. The accuracy of the <span class="hlt">damage</span> detection results using the wireless sensing system is verified through comparison with the results calculated from data recorded of a traditional wired monitoring system. The results demonstrate that, by taking advantage of collocated computing resources in wireless sensors, the proposed wireless sensing system can locate and quantify <span class="hlt">damage</span> with acceptable accuracy and moderate energy efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15011400','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15011400"><span>A new <span class="hlt">damage</span> testing system for detailed evaluation of <span class="hlt">damage</span> behavior of bulk KDP and DKDP</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>DeMange, P; Negres, R A; Carr, C W; Radousky, H B; Demos, S G</p> <p>2004-11-17</p> <p>We describe a new <span class="hlt">damage</span> testing approach and instrumentation that provides quantitative measurements of bulk <span class="hlt">damage</span> performance versus fluence for several <span class="hlt">frequencies</span>. A major advantage of this method is that it can simultaneously provide direct information on pinpoint density and size, and beam obscuration. This allows for more accurate evaluation of material performance under operational conditions. Protocols for laser conditioning to improve <span class="hlt">damage</span> performance can also be easily and rapidly evaluated.This <span class="hlt">damage</span> testing approach has enabled us to perform complex experiments toward probing the fundamental mechanisms of <span class="hlt">damage</span> initiation and conditioning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006MSSP...20.1173G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006MSSP...20.1173G"><span>Structural <span class="hlt">damage</span> detection using information fusion technique</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guo, H. Y.</p> <p>2006-07-01</p> <p>In order to precisely identify the multiple <span class="hlt">damage</span> locations of a structure, an information fusion technique is proposed in this paper. First, the <span class="hlt">frequency</span> data and the mode shape data are regarded as two different information sources, and local decisions can be obtained using the multiple <span class="hlt">damage</span> location assurance criterion (MDLAC) method and the <span class="hlt">frequency</span> change <span class="hlt">damage</span> detection method (FCDDM), respectively. Then, the local decisions are sent to a fusion centre. In the fusion centre, three main fusion approaches are applied to integrate all the local decisions. Finally, a global decision is acquired. The measurement errors are also taken into account in the fusion process. The numerical example and analysis demonstrate that the identification results of the three information fusion methods are better than those of the MDLAC method and the <span class="hlt">frequency</span> change <span class="hlt">damage</span> detection method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003ASAJ..113..638M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003ASAJ..113..638M"><span>High intensity anthropogenic sound <span class="hlt">damages</span> fish ears</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McCauley, Robert D.; Fewtrell, Jane; Popper, Arthur N.</p> <p>2003-01-01</p> <p>Marine petroleum exploration involves the repetitive use of high-energy noise sources, air-guns, that produce a short, sharp, low-<span class="hlt">frequency</span> sound. Despite reports of behavioral responses of fishes and marine mammals to such noise, it is not known whether exposure to air-guns has the potential to <span class="hlt">damage</span> the ears of aquatic vertebrates. It is shown here that the ears of fish exposed to an operating air-gun sustained extensive <span class="hlt">damage</span> to their sensory epithelia that was apparent as ablated hair cells. The <span class="hlt">damage</span> was regionally severe, with no evidence of repair or replacement of <span class="hlt">damaged</span> sensory cells up to 58 days after air-gun exposure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1175022','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1175022"><span>Method for assaying clustered DNA <span class="hlt">damages</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Sutherland, Betsy M.</p> <p>2004-09-07</p> <p>Disclosed is a method for detecting and quantifying clustered <span class="hlt">damages</span> in DNA. In this method, a first aliquot of the DNA to be tested for clustered <span class="hlt">damages</span> with one or more lesion-specific cleaving reagents under conditions appropriate for cleavage of the DNA to produce single-strand nicks in the DNA at sites of <span class="hlt">damage</span> lesions. The number average molecular length (Ln) of double stranded DNA is then quantitatively determined for the treated DNA. The number average molecular length (Ln) of double stranded DNA is also quantitatively determined for a second, untreated aliquot of the DNA. The <span class="hlt">frequency</span> of clustered <span class="hlt">damages</span> (.PHI..sub.c) in the DNA is then calculated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002ASAJ..112.2242P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002ASAJ..112.2242P"><span>Low <span class="hlt">frequency</span> cavitation erosion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pardue, Sally J.; Chandekar, Gautam</p> <p>2002-11-01</p> <p><span class="hlt">Damage</span> of diesel engine piston sleeve liners due to cavitation of the coolant fluid can be severe. Coolant fluid additives are used to inhibit cavitation <span class="hlt">damage</span>, and are evaluated by industry suppliers using ASTM G32-98 Standard Test Method for Cavitation Erosion Using Vibratory Apparatus. The ASTM G32-98 test procedure uses an ultrasonic horn at 20 kHz to vibrate a test button in the coolant. The test button mass loss and surface appearance are studied to sort the performance of new coolant additives. Mismatch between good lab performers and actual engine test runs has raised concerns over the current lab test. The <span class="hlt">frequency</span> range of the current test has been targeted for investigation. A low <span class="hlt">frequency</span>, less than 2000 Hz, test rig was built to explore the cavitation <span class="hlt">damage</span>. The test system did produce cavitation on the surface of the test button for a period of 36 h, with minimal mass loss. The test rig experienced cyclic fatigue when test times were extended. The work is now focusing on designing a better test rig for long duration tests and on developing numerical models in order to explore the effects of cavitation excitation <span class="hlt">frequency</span> on surface erosion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1227268','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1227268"><span>Nonlinear Ultrasonic Techniques to Monitor Radiation <span class="hlt">Damage</span> in RPV and Internal Components</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jacobs, Laurence; Kim, Jin-Yeon; Qu, Jisnmin; Ramuhalli, Pradeep; Wall, Joe</p> <p>2015-11-02</p> <p>The objective of this research is to demonstrate that nonlinear ultrasonics (NLU) can be used to directly and quantitatively measure the remaining life in radiation <span class="hlt">damaged</span> reactor pressure vessel (RPV) and internal components. Specific <span class="hlt">damage</span> types to be monitored are irradiation embrittlement and irradiation assisted stress corrosion cracking (IASCC). Our vision is to develop a technique that allows operators to assess <span class="hlt">damage</span> by making a limited number of NLU measurements in strategically selected critical reactor components during regularly scheduled outages. This measured data can then be used to determine the current condition of these key components, from which remaining useful life can be predicted. Methods to unambiguously characterize radiation related <span class="hlt">damage</span> in reactor internals and RPVs remain elusive. NLU technology has demonstrated great potential to be used as a material sensor – a sensor that can continuously monitor a material’s <span class="hlt">damage</span> state. The physical effect being monitored by NLU is the generation of higher harmonic <span class="hlt">frequencies</span> in an initially monochromatic ultrasonic wave. The degree of nonlinearity is quantified with the acoustic nonlinearity parameter, β, which is an absolute, measurable material constant. Recent research has demonstrated that nonlinear ultrasound can be used to characterize material state and changes in microscale characteristics such as internal stress states, precipitate formation and dislocation densities. Radiation <span class="hlt">damage</span> reduces the fracture toughness of RPV steels and internals, and can leave them susceptible to IASCC, which may in turn limit the lifetimes of some operating reactors. The ability to characterize radiation <span class="hlt">damage</span> in the RPV and internals will enable nuclear operators to set operation time thresholds for vessels and prescribe and schedule replacement activities for <span class="hlt">core</span> internals. Such a capability will allow a more clear definition of reactor safety margins. The research consists of three tasks: (1</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15013546','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15013546"><span>3(omega) <span class="hlt">Damage</span>: Growth Mitigation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kozlowski, M; Demos, S; Wu, Z-L; Wong, J; Penetrante, B; Hrubesh, L</p> <p>2001-02-22</p> <p>The design of high power UV laser systems is limited to a large extent by the laser-initiated <span class="hlt">damage</span> performance of transmissive fused silica optical components. The 3{omega} (i.e., the third harmonic of the primary laser <span class="hlt">frequency</span>) <span class="hlt">damage</span> growth mitigation LDRD effort focused on understanding and reducing the rapid growth of laser-initiated surface <span class="hlt">damage</span> on fused silica optics. Laser-initiated <span class="hlt">damage</span> can be discussed in terms of two key issues: <span class="hlt">damage</span> initiated at some type of precursor and rapid <span class="hlt">damage</span> growth of the <span class="hlt">damage</span> due to subsequent laser pulses. The objective of the LDRD effort has been the elucidation of laser-induced <span class="hlt">damage</span> processes in order to quantify and potentially reduce the risk of <span class="hlt">damage</span> to fused silica surfaces. The emphasis of the first two years of this effort was the characterization and reduction of <span class="hlt">damage</span> initiation. In spite of significant reductions in the density of <span class="hlt">damage</span> sites on polished surfaces, statistically some amount of <span class="hlt">damage</span> initiation should always be expected. The early effort therefore emphasized the development of testing techniques that quantified the statistical nature of <span class="hlt">damage</span> initiation on optical surfaces. This work led to the development of an optics lifetime modeling strategy that has been adopted by the NIF project to address <span class="hlt">damage</span>-risk issues. During FY99 interest shifted to the <span class="hlt">damage</span> growth issue which was the focus of the final year of this project. The impact of the remaining <span class="hlt">damage</span> sites on laser performance can be minimized if the <span class="hlt">damage</span> sites did not continue to grow following subsequent illumination. The objectives of the final year of the LDRD effort were to apply a suite of state-of-the-art characterization tools to elucidate the nature of the initiated <span class="hlt">damage</span> sites, and to identify a method that effectively mitigates further <span class="hlt">damage</span> growth. Our specific goal is to understand the cause for the rapid growth of <span class="hlt">damage</span> sites so that we can develop and apply an effective means to mitigate it. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA572404','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA572404"><span>Epidemiology of Helicopter Battle <span class="hlt">Damage</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2010-05-01</p> <p>erosion . The <span class="hlt">frequency</span> of sand and dust environmental conditions is also mitigated based on the phase of the operations. The early stages of OIF...category of environmental effects includes heat, sand , dust, and other flight or atmospheric conditions in the theatre of operation. The environmental...capability of much of the equipment employed. The sand EPIDEMIOLOGY OF HELICOPTER BATTLE <span class="hlt">DAMAGE</span> RTO-EN-AVT-156 3 - 7 environment in Iraq and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012shol.book.1285H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012shol.book.1285H"><span><span class="hlt">Frequency</span> Combs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hänsch, Theodor W.; Picqué, Nathalie</p> <p></p> <p>Much of modern research in the field of atomic, molecular, and optical science relies on lasers, which were invented some 50 years ago and perfected in five decades of intense research and development. Today, lasers and photonic technologies impact most fields of science and they have become indispensible in our daily lives. Laser <span class="hlt">frequency</span> combs were conceived a decade ago as tools for the precision spectroscopy of atomic hydrogen. Through the development of optical <span class="hlt">frequency</span> comb techniques, <Secondary>technique</Secondary> a setup of the size 1 ×1 m2, good for precision measurements of any <span class="hlt">frequency</span>, and even commercially available, has replaced the elaborate previous <span class="hlt">frequency</span>-chain schemes for optical <span class="hlt">frequency</span> measurements, which only worked for selected <span class="hlt">frequencies</span>. A true revolution in optical <span class="hlt">frequency</span> measurements has occurred, paving the way for the creation of all-optical clocks <Secondary>clock</Secondary> with a precision that might approach 10-18. A decade later, <span class="hlt">frequency</span> combs are now common equipment in all <span class="hlt">frequency</span> metrology-oriented laboratories. They are also becoming enabling tools for an increasing number of applications, from the calibration of astronomical spectrographs to molecular spectroscopy. This chapter first describes the principle of an optical <span class="hlt">frequency</span> comb synthesizer. Some of the key technologies to generate such a <span class="hlt">frequency</span> comb are then presented. Finally, a non-exhaustive overview of the growing applications is given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMDI33A2423D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMDI33A2423D"><span>Investigating the translation of Earth's inner <span class="hlt">core</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Day, E. A.; Cormier, V. F.; Geballe, Z. M.; Lasbleis, M.; Youssof, M.; Yue, H.</p> <p>2012-12-01</p> <p> inner <span class="hlt">core</span>, and provides an insight into the nature of hemispheres and their compatibility with our predictions for models of a translating inner <span class="hlt">core</span>. Additionally, we investigate the structure at the base of the outer <span class="hlt">core</span> and the inner <span class="hlt">core</span> boundary by analyzing PKP-Cdiff waves. The search for observable PKP-Cdiff is particularly concentrated in regions that are predicted to be actively freezing and melting, and spans a range of <span class="hlt">frequencies</span>, allowing us to fully investigate any regional differences around the inner <span class="hlt">core</span> boundary that may result from the translation of the inner <span class="hlt">core</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/334312','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/334312"><span>Application of nonlinear wave modulation spectroscopy to discern material <span class="hlt">damage</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Johnson, P.A.; Sutin, A.; Abeele, K.E.A. van den</p> <p>1999-04-01</p> <p>Materials containing structural <span class="hlt">damage</span> have a far greater nonlinear elastic response than materials with no structural <span class="hlt">damage</span>. This is the basis for nonlinear wave diagnostics of <span class="hlt">damage</span>, methods which are remarkably sensitive to the detection and progression of <span class="hlt">damage</span> in materials. Here the authors describe one nonlinear method, the application of harmonics and sum and difference <span class="hlt">frequency</span> to discern <span class="hlt">damage</span> in materials. The method is termed Nonlinear Wave Modulation Spectroscopy (NWMS). It consists of exciting a sample with continuous waves of two separate <span class="hlt">frequencies</span> simultaneously, and inspecting the harmonics of the two waves, and their sum and difference <span class="hlt">frequencies</span> (sidebands). Undamaged materials are essentially linear in their response to the two waves, while the same material, when <span class="hlt">damaged</span>, becomes highly nonlinear, manifested by harmonics and sideband generation. The authors illustrate the method by experiments on uncracked and cracked plexiglass and sandstone samples, and by applying it to intact and <span class="hlt">damaged</span> engine components.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3529818','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3529818"><span>Glaucomatous <span class="hlt">damage</span> of the macula</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hood, Donald C.; Raza, Ali S.; de Moraes, Carlos Gustavo V.; Liebmann, Jeffrey M.; Ritch, Robert</p> <p>2012-01-01</p> <p>There is a growing body of evidence that early glaucomatous <span class="hlt">damage</span> involves the macula. The anatomical basis of this <span class="hlt">damage</span> can be studied using <span class="hlt">frequency</span> domain optical coherence tomography (fdOCT), by which the local thickness of the retinal nerve fiber layer (RNFL) and local retinal ganglion cell plus inner plexiform (RGC+) layer can be measured. Based upon averaged fdOCT results from healthy controls and patients, we show that: 1. For healthy controls, the average RGC+ layer thickness closely matches human histological data; 2. For glaucoma patients and suspects, the average RGC+ layer shows greater glaucomatous thinning in the inferior retina (superior visual field (VF)); and 3. The central test points of the 6° VF grid (24-2 test pattern) miss the region of greatest RGC+ thinning. Based upon fdOCT results from individual patients, we have learned that: 1. Local RGC+ loss is associated with local VF sensitivity loss as long as the displacement of RGCs from the foveal center is taken into consideration; and 2. Macular <span class="hlt">damage</span> is typically arcuate in nature and often associated with local RNFL thinning in a narrow region of the disc, which we call the macular vulnerability zone (MVZ). According to our schematic model of macular <span class="hlt">damage</span>, most of the inferior region of the macula projects to the MVZ, which is located largely in the inferior quadrant of the disc, a region that is particularly susceptible to glaucomatous <span class="hlt">damage</span>. A small (cecocentral) region of the inferior macula, and all of the superior macula (inferior VF), project to the temporal quadrant, a region that is less susceptible to <span class="hlt">damage</span>. The overall message is clear; clinicians need to be aware that glaucomatous <span class="hlt">damage</span> to the macula is common, can occur early in the disease, and can be missed and/or underestimated with standard VF tests that use a 6° grid, such as the 24-2 VF test. PMID:22995953</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.469..813A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.469..813A"><span><span class="hlt">Core</span> shift effect in blazars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Agarwal, A.; Mohan, P.; Gupta, Alok C.; Mangalam, A.; Volvach, A. E.; Aller, M. F.; Aller, H. D.; Gu, M. F.; Lähteenmäki, A.; Tornikoski, M.; Volvach, L. N.</p> <p>2017-07-01</p> <p>We studied the pc-scale <span class="hlt">core</span> shift effect using radio light curves for three blazars, S5 0716+714, 3C 279 and BL Lacertae, which were monitored at five <span class="hlt">frequencies</span> (ν) between 4.8 and 36.8 GHz using the University of Michigan Radio Astronomical Observatory (UMRAO), the Crimean Astrophysical Observatory (CrAO) and Metsähovi Radio Observatory for over 40 yr. Flares were Gaussian fitted to derive time delays between observed <span class="hlt">frequencies</span> for each flare (Δt), peak amplitude (A) and their half width. Using A ∝ να, we infer α in the range of -16.67-2.41 and using Δ t ∝ ν ^{1/k_r}, we infer kr ∼ 1, employed in the context of equipartition between magnetic and kinetic energy density for parameter estimation. From the estimated <span class="hlt">core</span> position offset (Ωrν) and the <span class="hlt">core</span> radius (rcore), we infer that opacity model may not be valid in all cases. The mean magnetic field strengths at 1 pc (B1) and at the <span class="hlt">core</span> (Bcore) are in agreement with previous estimates. We apply the magnetically arrested disc model to estimate black hole spins in the range of 0.15-0.9 for these blazars, indicating that the model is consistent with expected accretion mode in such sources. The power-law-shaped power spectral density has slopes -1.3 to -2.3 and is interpreted in terms of multiple shocks or magnetic instabilities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5074307','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5074307"><span>Characterization of the internal event <span class="hlt">frequencies</span> for the final NUREG-1150</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Camp, A.L.; Cramond, W.R.</p> <p>1988-06-30</p> <p>NUREG-1150 represents an attempt by the Nuclear Regulatory Commission (NRC) to characterize the risk from a selected group of commercial nuclear power plants. In support of that effort, the NRC is sponsoring the Accident Sequence Evaluation Program at Sandia National Laboratories (SNL) to provide estimates of the internal event <span class="hlt">core</span> <span class="hlt">damage</span> <span class="hlt">frequencies</span> for the Surry, Sequoyah, Peach Bottom, and Grand Gulf power plants. Initial results and the accompanying methodology were published during 1987 in several volumes as NUREG/CR-4550 to support the release of the draft NUREG-1150. The mean <span class="hlt">core</span> <span class="hlt">damage</span> <span class="hlt">frequencies</span> were relatively low, ranging from 8E-6 to 1E-4. As a result of the public comments and various peer reviews, the analyses are being revised to support issuance of the final NUREG-1150 in the late summer of 1988. This paper describes the changes in the sequence <span class="hlt">frequencies</span> that have occurred, presents the insights that have been obtained from these studies, and identifies certain limitations that still remain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9061E..2EM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9061E..2EM"><span>Experimental validation of a modal flexibility-based <span class="hlt">damage</span> detection method for a cyber-physical system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martinez-Castro, Rosana E.; Eskew, Edward L.; Jang, Shinae</p> <p>2014-03-01</p> <p>The detection and localization of <span class="hlt">damage</span> in a timely manner is critical in order to avoid the failure of structures. When a structure is subjected to an unscheduled impulsive force, the resulting <span class="hlt">damage</span> can lead to failure in a very short period of time. As such, a monitoring strategy that can adapt to variability in the environment and that anticipates changes in physical processes has the potential of detecting, locating and mitigating <span class="hlt">damage</span>. These requirements can be met by a cyber-physical system (CPS) equipped with Wireless Smart Sensor Network (WSSN) systems that is capable of measuring and analyzing dynamic responses in real time using on-board in network processing. The Eigenparameter Decomposition of Structural Flexibility Change (ED) Method is validated with real data and considered to be used in the computational <span class="hlt">core</span> of this CPS. The condition screening is implemented on a <span class="hlt">damaged</span> structure and compared to an original baseline calculation, hence providing a supervised learning environment. An experimental laboratory study on a 5-story shear building with three <span class="hlt">damage</span> conditions subjected to an impulsive force has been chosen to validate the effectiveness of the method proposed to locate and quantify the extent of <span class="hlt">damage</span>. A numerical simulation of the same building subject to band-limited white noise has also been developed with this purpose. The effectiveness of the ED Method to locate <span class="hlt">damage</span> is compared to that of the <span class="hlt">Damage</span> Index Method. With some modifications, the ED Method is capable of locating and quantifying <span class="hlt">damage</span> satisfactorily in a shear building subject to a lower <span class="hlt">frequency</span> content predominant excitation.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880009842','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880009842"><span><span class="hlt">Core-core</span> and <span class="hlt">core</span>-valence correlation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.</p> <p>1988-01-01</p> <p>The effect of (1s) <span class="hlt">core</span> correlation on properties and energy separations was analyzed using full configuration-interaction (FCI) calculations. The Be 1 S - 1 P, the C 3 P - 5 S and CH+ 1 Sigma + or - 1 Pi separations, and CH+ spectroscopic constants, dipole moment and 1 Sigma + - 1 Pi transition dipole moment were studied. The results of the FCI calculations are compared to those obtained using approximate methods. In addition, the generation of atomic natural orbital (ANO) basis sets, as a method for contracting a primitive basis set for both valence and <span class="hlt">core</span> correlation, is discussed. When both <span class="hlt">core-core</span> and <span class="hlt">core</span>-valence correlation are included in the calculation, no suitable truncated CI approach consistently reproduces the FCI, and contraction of the basis set is very difficult. If the (nearly constant) <span class="hlt">core-core</span> correlation is eliminated, and only the <span class="hlt">core</span>-valence correlation is included, CASSCF/MRCI approached reproduce the FCI results and basis set contraction is significantly easier.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6498119','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6498119"><span>Waved <span class="hlt">core</span> lamination techniques on large and bulb hydroelectric machinery</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lehoczky, K.N. )</p> <p>1988-12-01</p> <p>Stator <span class="hlt">core</span> lamination of large hydroelectric generators and motors and especially bulb type machines are often exposed to heat expansion forces causing severe <span class="hlt">damages</span>. The temperature difference between the warm <span class="hlt">core</span> lamination and the relatively colder stator frame, creates both radial and tangential stresses in these components. The consequence of these stresses depends on the axial prestressing of lamination and the internal design of the <span class="hlt">core</span>. An overriding of some critical combination of these stresses may result in buckling of lamination, fracture of <span class="hlt">core</span> tensioning and supporting components or cracks in the stator frame. The present waved lamination technique reduces the tangential and radial spring constant of <span class="hlt">core</span> and prevents the <span class="hlt">damages</span>. The research performed through theoretical and experimental methods, indicates a fundamental change in the behavior of <span class="hlt">core</span>. The waved lamination was successfully used in a large number of machines, providing the reliability and wide application range of the method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4212644','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4212644"><span>Modified Anchor Shaped Post <span class="hlt">Core</span> Design for Primary Anterior Teeth</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rajesh, R.; Baroudi, Kusai; Reddy, K. Bala Kasi; Praveen, B. H.; Kumar, V. Sumanth; Amit, S.</p> <p>2014-01-01</p> <p>Restoring severely <span class="hlt">damaged</span> primary anterior teeth is challenging to pedodontist. Many materials are tried as a post <span class="hlt">core</span> but each one of them has its own drawbacks. This a case report describing a technique to restore severely <span class="hlt">damaged</span> primary anterior teeth with a modified anchor shaped post. This technique is not only simple and inexpensive but also produces better retention. PMID:25379294</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25379294','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25379294"><span>Modified anchor shaped post <span class="hlt">core</span> design for primary anterior teeth.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rajesh, R; Baroudi, Kusai; Reddy, K Bala Kasi; Praveen, B H; Kumar, V Sumanth; Amit, S</p> <p>2014-01-01</p> <p>Restoring severely <span class="hlt">damaged</span> primary anterior teeth is challenging to pedodontist. Many materials are tried as a post <span class="hlt">core</span> but each one of them has its own drawbacks. This a case report describing a technique to restore severely <span class="hlt">damaged</span> primary anterior teeth with a modified anchor shaped post. This technique is not only simple and inexpensive but also produces better retention.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28372271','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28372271"><span>Effect of <span class="hlt">coring</span> conditions on temperature rise in bone.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Islam, Md Monirul; Wang, Xiaodu</p> <p>2017-01-01</p> <p><span class="hlt">Coring</span> is a surgical procedure in bone biopsy retrieval and dental/orthopaedic procedures, which may cause thermal <span class="hlt">damage</span> to bone tissues adjacent to the <span class="hlt">coring</span> zone. This study was performed to determine the temperature rise in bone by <span class="hlt">coring</span> using a semi-empirical thermocouple approach. Concurrently, a custom-made dynamometer was used to measure the cutting and thrust forces during <span class="hlt">coring</span> bovine cortical bone samples. The experimental results indicated that the cutting force, cutting speed, and depth of cut significantly affect the temperature rise in the cutting zone during <span class="hlt">coring</span> process. In addition, acute temperature rises in the cutting zone occurred when the cutting speed exceeded threshold levels. The limited capacity of heat dissipation during <span class="hlt">coring</span> is most likely responsible for such a sharp temperature rise with increasing cutting speed. Moreover, it was observed that the maximum size of potential thermal <span class="hlt">damage</span> zone could reach to 3.0 mm in depth from the surface of the <span class="hlt">coring</span> hole, assuming that thermal <span class="hlt">damage</span> would occur when the temperature is greater than 47°C. Thus, proper cutting conditions need to be selected to avoid the potential thermal <span class="hlt">damage</span> to bone during the <span class="hlt">coring</span> procedures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983SPIE..371...38S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983SPIE..371...38S"><span>Monitoring Of Generator Stator <span class="hlt">Core</span> Lamination Repairs Using Thermographic Techniques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stevens, D. C.</p> <p>1983-03-01</p> <p>Thermographic techniques have for years been used to locate minor interlaminar faults in the stator <span class="hlt">cores</span> of steam turbine-driven generators. The technique has been largely employed in a quality control or routine maintenance function. However similar thermo-graphic techniques can be used to detect interlaminar faults and monitor repairs of an extensively <span class="hlt">damaged</span> stator <span class="hlt">core</span> of a large hydroelectric generator.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhDT.......142L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhDT.......142L"><span>Full-scale testing and progressive <span class="hlt">damage</span> modeling of sandwich composite aircraft fuselage structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leone, Frank A., Jr.</p> <p></p> <p>A comprehensive experimental and computational investigation was conducted to characterize the fracture behavior and structural response of large sandwich composite aircraft fuselage panels containing artificial <span class="hlt">damage</span> in the form of holes and notches. Full-scale tests were conducted where panels were subjected to quasi-static combined pressure, hoop, and axial loading up to failure. The panels were constructed using plain-weave carbon/epoxy prepreg face sheets and a Nomex honeycomb <span class="hlt">core</span>. Panel deformation and notch tip <span class="hlt">damage</span> development were monitored during the tests using several techniques, including optical observations, strain gages, digital image correlation (DIC), acoustic emission (AE), and <span class="hlt">frequency</span> response (FR). Additional pretest and posttest inspections were performed via thermography, computer-aided tap tests, ultrasound, x-radiography, and scanning electron microscopy. The framework to simulate <span class="hlt">damage</span> progression and to predict residual strength through use of the finite element (FE) method was developed. The DIC provided local and full-field strain fields corresponding to changes in the state-of-<span class="hlt">damage</span> and identified the strain components driving <span class="hlt">damage</span> progression. AE was monitored during loading of all panels and data analysis methodologies were developed to enable real-time determination of <span class="hlt">damage</span> initiation, progression, and severity in large composite structures. The FR technique has been developed, evaluating its potential as a real-time nondestructive inspection technique applicable to large composite structures. Due to the large disparity in scale between the fuselage panels and the artificial <span class="hlt">damage</span>, a global/local analysis was performed. The global FE models fully represented the specific geometries, composite lay-ups, and loading mechanisms of the full-scale tests. A progressive <span class="hlt">damage</span> model was implemented in the local FE models, allowing the gradual failure of elements in the vicinity of the artificial <span class="hlt">damage</span>. A set of modifications</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009NHESS...9.1033M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009NHESS...9.1033M"><span>Significance of "high probability/low <span class="hlt">damage</span>" versus "low probability/high <span class="hlt">damage</span>" flood events</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Merz, B.; Elmer, F.; Thieken, A. H.</p> <p>2009-06-01</p> <p>The need for an efficient use of limited resources fosters the application of risk-oriented design in flood mitigation. Flood defence measures reduce future <span class="hlt">damage</span>. Traditionally, this benefit is quantified via the expected annual <span class="hlt">damage</span>. We analyse the contribution of "high probability/low <span class="hlt">damage</span>" floods versus the contribution of "low probability/high <span class="hlt">damage</span>" events to the expected annual <span class="hlt">damage</span>. For three case studies, i.e. actual flood situations in flood-prone communities in Germany, it is shown that the expected annual <span class="hlt">damage</span> is dominated by "high probability/low <span class="hlt">damage</span>" events. Extreme events play a minor role, even though they cause high <span class="hlt">damage</span>. Using typical values for flood <span class="hlt">frequency</span> behaviour, flood plain morphology, distribution of assets and vulnerability, it is shown that this also holds for the general case of river floods in Germany. This result is compared to the significance of extreme events in the public perception. "Low probability/high <span class="hlt">damage</span>" events are more important in the societal view than it is expressed by the expected annual <span class="hlt">damage</span>. We conclude that the expected annual <span class="hlt">damage</span> should be used with care since it is not in agreement with societal priorities. Further, risk aversion functions that penalise events with disastrous consequences are introduced in the appraisal of risk mitigation options. It is shown that risk aversion may have substantial implications for decision-making. Different flood mitigation decisions are probable, when risk aversion is taken into account.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001SPIE.4335..106M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001SPIE.4335..106M"><span><span class="hlt">Damage</span> detection tests of five-story steel frame with simulated <span class="hlt">damages</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morita, Koichi; Teshigawara, Masaomi; Isoda, Hiroshi; Hamamoto, Takuji; Mita, Akira</p> <p>2001-07-01</p> <p>This paper presents <span class="hlt">damage</span> detection tests of five-story steel frame with simulated <span class="hlt">damages</span>. We discuss pre-analytical study and results of experiments. Fiber brag grating (FBG) sensors, accelerometers, strain gauges and laser displacement meters are installed in this test frame. We assume <span class="hlt">damages</span> by removing studs from only one story, loosening bolts of beams, cutting part of beams and extracting braces from only one story. From the results of pre-analytical study, we can estimate which story is <span class="hlt">damaged</span> from the change of natural period and mode shape to some extent. We applied flexibility method which is one of a <span class="hlt">damage</span> identification methods using modal properties. We also apply flexibility method to results of experiments. In some cases we can estimate which story is <span class="hlt">damaged</span>, and in other cases we cannot. We also applied a method using multiple natural <span class="hlt">frequency</span> shifts. Making use of the change in five natural <span class="hlt">frequencies</span> due to <span class="hlt">damage</span>, the location of <span class="hlt">damaged</span> stories can be pinpointed. In both methods, we cannot identify <span class="hlt">damaged</span> story in some cases. Some methods other than methods using modal properties have to be tried to apply in such cases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997PhDT.......252M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997PhDT.......252M"><span>High <span class="hlt">frequency</span> pulsed electromigration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Malone, David Wayne</p> <p></p> <p>Electromigration life tests were performed on copper-alloyed aluminum test structures that were representative of modern CMOS metallization schemes, complete with Ti/TiN cladding layers and a tungsten-plug contact at the cathode. A total of 18 electrical stress treatments were applied. One was a DC current of 15 mA. The other 17 were pulsed currents, varied according to duty cycle and <span class="hlt">frequency</span>. The pulse amplitude was 15 mA (˜2.7 × 10sp6 A/cmsp2) for all treatments. Duty cycles ranged from 33.3% to 80%, and <span class="hlt">frequencies</span> fell into three rough ranges-100 KHz, 1 MHz, and 100 MHz. The ambient test temperature was 200sp°C in all experiments. Six to 9 samples were subjected to each treatment. Experimental data were gathered in the form of test stripe resistance versus time, R(t). For purposes of lifetime analysis, "failure" was defined by the criterion R(t)/R(0) = 1.10, and the median time to failure, tsb{50}, was used as the primary basis of comparison between test groups. It was found that the dependence of tsb{50} on pulse duty cycle conformed rather well to the so-called "average current density model" for duty cycles of 50% and higher. Lifetimes were less enhanced for a duty cycle of 33.3%, but they were still considerably longer than an "on-time" model would predict. No specific dependence of tsb{50} on pulse <span class="hlt">frequency</span> was revealed by the data, that is, reasonably good predictions of tsb{50} could be made by recognizing the dominant influence of duty cycle. These findings confirm that IC miniaturization can be more aggressively pursued than an on-time prediction would allow. It is significant that this was found to be true for <span class="hlt">frequencies</span> on the order of 100 MHz, where many present day digital applications operate. Post-test optical micrographs were obtained for each test subject in order to determine the location of electromigration <span class="hlt">damage</span>. The pulse duty cycle was found to influence the location. Most <span class="hlt">damage</span> occurred at the cathode contact, regardless of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Positive+AND+Stress&pg=7&id=EJ1006996','ERIC'); return false;" href="https://eric.ed.gov/?q=Positive+AND+Stress&pg=7&id=EJ1006996"><span>Academic Rigor: The <span class="hlt">Core</span> of the <span class="hlt">Core</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brunner, Judy</p> <p>2013-01-01</p> <p>Some educators see the Common <span class="hlt">Core</span> State Standards as reason for stress, most recognize the positive possibilities associated with them and are willing to make the professional commitment to implementing them so that academic rigor for all students will increase. But business leaders, parents, and the authors of the Common <span class="hlt">Core</span> are not the only…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=core&pg=7&id=EJ1006996','ERIC'); return false;" href="http://eric.ed.gov/?q=core&pg=7&id=EJ1006996"><span>Academic Rigor: The <span class="hlt">Core</span> of the <span class="hlt">Core</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brunner, Judy</p> <p>2013-01-01</p> <p>Some educators see the Common <span class="hlt">Core</span> State Standards as reason for stress, most recognize the positive possibilities associated with them and are willing to make the professional commitment to implementing them so that academic rigor for all students will increase. But business leaders, parents, and the authors of the Common <span class="hlt">Core</span> are not the only…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810011550','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810011550"><span>Extended <span class="hlt">frequency</span> turbofan model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mason, J. R.; Park, J. W.; Jaekel, R. F.</p> <p>1980-01-01</p> <p>The fan model was developed using two dimensional modeling techniques to add dynamic radial coupling between the <span class="hlt">core</span> stream and the bypass stream of the fan. When incorporated into a complete TF-30 engine simulation, the fan model greatly improved compression system <span class="hlt">frequency</span> response to planar inlet pressure disturbances up to 100 Hz. The improved simulation also matched engine stability limits at 15 Hz, whereas the one dimensional fan model required twice the inlet pressure amplitude to stall the simulation. With verification of the two dimensional fan model, this program formulated a high <span class="hlt">frequency</span> F-100(3) engine simulation using row by row compression system characteristics. In addition to the F-100(3) remote splitter fan, the program modified the model fan characteristics to simulate a proximate splitter version of the F-100(3) engine.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26072834','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26072834"><span>Deep <span class="hlt">frequency</span> modulation interferometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gerberding, Oliver</p> <p>2015-06-01</p> <p>Laser interferometry with pm/Hz precision and multi-fringe dynamic range at low <span class="hlt">frequencies</span> is a <span class="hlt">core</span> technology to measure the motion of various objects (test masses) in space and ground based experiments for gravitational wave detection and geodesy. Even though available interferometer schemes are well understood, their construction remains complex, often involving, for example, the need to build quasi-monolithic optical benches with dozens of components. In recent years techniques have been investigated that aim to reduce this complexity by combining phase modulation techniques with sophisticated digital readout algorithms. This article presents a new scheme that uses strong laser <span class="hlt">frequency</span> modulations in combination with the deep phase modulation readout algorithm to construct simpler and easily scalable interferometers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10576731','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10576731"><span><span class="hlt">Core</span> rotational dynamics and geological events</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Greff-Lefftz; Legros</p> <p>1999-11-26</p> <p>A study of Earth's fluid <span class="hlt">core</span> oscillations induced by lunar-solar tidal forces, together with tidal secular deceleration of Earth's axial rotation, shows that the rotational eigenfrequency of the fluid <span class="hlt">core</span> and some solar tidal waves were in resonance around 3.0 x 10(9), 1.8 x 10(9), and 3 x 10(8) years ago. The associated viscomagnetic frictional power at the <span class="hlt">core</span> boundaries may be converted into heat and would destabilize the D" thermal layer, leading to the generation of deep-mantle plumes, and would also increase the temperature at the fluid <span class="hlt">core</span> boundaries, perturbing the <span class="hlt">core</span> dynamo process. Such phenomena could account for large-scale episodes of continental crust formation, the generation of flood basalts, and abrupt changes in geomagnetic reversal <span class="hlt">frequency</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030093725','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030093725"><span>Performance of the NASA Digitizing <span class="hlt">Core</span>-Loss Instrumentation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schwarze, Gene E. (Technical Monitor); Niedra, Janis M.</p> <p>2003-01-01</p> <p>The standard method of magnetic <span class="hlt">core</span> loss measurement was implemented on a high <span class="hlt">frequency</span> digitizing oscilloscope in order to explore the limits to accuracy when characterizing high Q <span class="hlt">cores</span> at <span class="hlt">frequencies</span> up to 1 MHz. This method computes <span class="hlt">core</span> loss from the cycle mean of the product of the exciting current in a primary winding and induced voltage in a separate flux sensing winding. It is pointed out that just 20 percent accuracy for a Q of 100 <span class="hlt">core</span> material requires a phase angle accuracy of 0.1 between the voltage and current measurements. Experiment shows that at 1 MHz, even high quality, high <span class="hlt">frequency</span> current sensing transformers can introduce phase errors of a degree or more. Due to the fact that the Q of some quasilinear <span class="hlt">core</span> materials can exceed 300 at <span class="hlt">frequencies</span> below 100 kHz, phase angle errors can be a problem even at 50 kHz. Hence great care is necessary with current sensing and ground loops when measuring high Q <span class="hlt">cores</span>. Best high <span class="hlt">frequency</span> current sensing accuracy was obtained from a fabricated 0.1-ohm coaxial resistor, differentially sensed. Sample high <span class="hlt">frequency</span> <span class="hlt">core</span> loss data taken with the setup for a permeability-14 MPP <span class="hlt">core</span> is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22596658','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22596658"><span><span class="hlt">Frequency</span> spirals</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ottino-Löffler, Bertrand; Strogatz, Steven H.</p> <p>2016-09-15</p> <p>We study the dynamics of coupled phase oscillators on a two-dimensional Kuramoto lattice with periodic boundary conditions. For coupling strengths just below the transition to global phase-locking, we find localized spatiotemporal patterns that we call “<span class="hlt">frequency</span> spirals.” These patterns cannot be seen under time averaging; they become visible only when we examine the spatial variation of the oscillators' instantaneous <span class="hlt">frequencies</span>, where they manifest themselves as two-armed rotating spirals. In the more familiar phase representation, they appear as wobbly periodic patterns surrounding a phase vortex. Unlike the stationary phase vortices seen in magnetic spin systems, or the rotating spiral waves seen in reaction-diffusion systems, <span class="hlt">frequency</span> spirals librate: the phases of the oscillators surrounding the central vortex move forward and then backward, executing a periodic motion with zero winding number. We construct the simplest <span class="hlt">frequency</span> spiral and characterize its properties using analytical and numerical methods. Simulations show that <span class="hlt">frequency</span> spirals in large lattices behave much like this simple prototype.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMGC51H1126K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMGC51H1126K"><span>City <span class="hlt">Core</span> - detecting the anthropocene in urban lake <span class="hlt">cores</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kjaer, K. H.; Ilsøe, P.; Andresen, C. S.; Rasmussen, P.; Andersen, T. J.; Frei, R.; Schreiber, N.; Odgaard, B.; Funder, S.; Holm, J. M.; Andersen, K.</p> <p>2011-12-01</p> <p>Here, we presents the preliminary results from lake <span class="hlt">cores</span> taken in ditches associated with the historical fortifications enclosing the oldest - central Copenhagen to achieve new knowledge from sediment deposits related to anthropogenic activities. We have examined sediment <span class="hlt">cores</span> with X-ray fluorescence (XRF) analyzers to correlate element patterns from urban and industrial emissions. Thus, we aim to track these patterns back in time - long before regular routines of recording of atmospheric environment began around 1978. Furthermore, we compare our data to alternative sources of information in order to constrain and expand the temporal dating limits (approximately 1890) achieved from 210Pb activity. From custom reports and statistic sources, information on imported volumes from coal, metal and oil was obtained and related contaminants from these substances to the sediment archives. Intriguingly, we find a steep increase in import of coal and metals matching the exponential increase of lead and zinc counts from XRF-recordings of the sediment <span class="hlt">cores</span>. In this finding, we claim to have constrain the initiation of urban industrialization. In order to confirm the age resolution of the lake <span class="hlt">cores</span>, DNA was extracted from sediments, sedaDNA. Thus we attempt to trace plantation of well documented exotic plants to, for instance, the Botanical Garden. Through extraction and sampling of sedaDNA from these floral and arboreal specimens we intend to locate their strataigraphic horizons in the sediment <span class="hlt">core</span>. These findings may correlate data back to 1872, when the garden was established on the area of the former fortification. In this line of research, we hope to achieve important supplementary knowledge of sedaDNA-leaching <span class="hlt">frequencies</span> within freshwater sediments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H33F1464S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H33F1464S"><span>Applying Time-<span class="hlt">Frequency</span> Analysis to Assist Identification of Hydrogeological Structure of Groundwater Aquifers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>shiuan, C. W.; Chang, L.</p> <p>2013-12-01</p> <p>Due to global warming, climate change, and economic development, the stability of water supply is challenged using only surface water resources. Hence, groundwater becomes an important water resource for increasing water supply reliability. However, groundwater extraction many introduce <span class="hlt">damages</span> such as land subsidence and seawater intrusion. To accurately evaluate the response of groundwater aquifers, correct hydrogeological structure is a key factor. In the past, the evaluation of the hydrogeological structure relies on subjective judgment which is arbitrarily made based on available information of <span class="hlt">core</span> sampling record, fossils, geological dating, etc. This study develops a quantitative method to provide objective information for improving the judgment. This method uses observed groundwater water level and time-<span class="hlt">frequency</span> analysis. Precisely, the signal strength of the groundwater level is evaluated using Fast Fourier Transform (FFT) which is done by a commercially available software named Visual Signal. Two signal <span class="hlt">frequencies</span>, daily and annual <span class="hlt">frequency</span>, are studied. This method is applied to Lanyang Plain in Taiwan. The groundwater level record of shallow wells is selected for the signal processing. Therefore, higher signal strength of an annual signal indicates higher recharge which is an indicator of unconfined aquifer. In the case of Lanyang Plain, the low signal strength area includes fan top area and scatter areas at fan central and fantail areas. This signal information along with <span class="hlt">core</span> sampling information can provide a complete picture of the hydrogeological structure and characteristics for the studied area Ilan shallow water wells in different <span class="hlt">frequencies</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120013232','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120013232"><span><span class="hlt">Coring</span> Sample Acquisition Tool</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Haddad, Nicolas E.; Murray, Saben D.; Walkemeyer, Phillip E.; Badescu, Mircea; Sherrit, Stewart; Bao, Xiaoqi; Kriechbaum, Kristopher L.; Richardson, Megan; Klein, Kerry J.</p> <p>2012-01-01</p> <p>A sample acquisition tool (SAT) has been developed that can be used autonomously to sample drill and capture rock <span class="hlt">cores</span>. The tool is designed to accommodate <span class="hlt">core</span> transfer using a sample tube to the IMSAH (integrated Mars sample acquisition and handling) SHEC (sample handling, encapsulation, and containerization) without ever touching the pristine <span class="hlt">core</span> sample in the transfer process.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760000293&hterms=cut+uncut+PICC&qs=Ntx%3Dmode%2Bmatchany%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcut%2Buncut%2BPICC','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760000293&hterms=cut+uncut+PICC&qs=Ntx%3Dmode%2Bmatchany%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcut%2Buncut%2BPICC"><span>Toroidal converter <span class="hlt">core</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mclyman, W. T.</p> <p>1977-01-01</p> <p>Improved approach consists of cut and uncut <span class="hlt">cores</span> nested in concentric configuration. <span class="hlt">Cores</span> are made by winding steel ribbon on mandrel and impregnating with epoxy to bond layers together. Gap is made by cutting across wound and bonded <span class="hlt">core</span>. Rough ends are ground or lapped.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=core+AND+competence&pg=2&id=EJ621608','ERIC'); return false;" href="https://eric.ed.gov/?q=core+AND+competence&pg=2&id=EJ621608"><span><span class="hlt">Core</span> Competence and Education.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Holmes, Gary; Hooper, Nick</p> <p>2000-01-01</p> <p>Outlines the concept of <span class="hlt">core</span> competence and applies it to postcompulsory education in the United Kingdom. Adopts an educational perspective that suggests accreditation as the <span class="hlt">core</span> competence of universities. This economic approach suggests that the market trend toward lifetime learning might best be met by institutions developing a <span class="hlt">core</span> competence…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SPIE.7386E..1TZ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SPIE.7386E..1TZ"><span>Spherical 3D photonic crystal with conducting nanoshell and particle <span class="hlt">core</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zamudio-Lara, A.; Sánchez-Mondragón, J.; Escobedo-Alatorre, J.; Pérez-Careta, E.; Torres-Cisneros, M.; Tecpoyotl-Torres, Margarita; Vázquez-Buenos Aires, O.</p> <p>2009-06-01</p> <p>We discuss a structured 3D Dielectric Photonic Crystal with both a metallic <span class="hlt">core</span> and a metallic shell. We discuss the role of each one, the stack, the <span class="hlt">core</span> as well as the cavity formed between the <span class="hlt">core</span> and the shell. The low <span class="hlt">frequency</span> metallic <span class="hlt">core</span> features becomes much more significant as it gets smaller and get diluted by the cavity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA532257','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA532257"><span>T2 Laboratories Explosion <span class="hlt">Damage</span> Assessment</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2010-07-01</p> <p>north-east of the reactor vessel. The control room was constructed with concrete masonry unit (CMU) walls and a precast hollow <span class="hlt">core</span> roof. The...include <span class="hlt">damaged</span> buildings, deformed structural members (beams, columns, wall panels, etc.) and broken windows both at the explosion scene and at... wall with brick veneer at north elevation. 201B PBM Construction 3000 Faye Rd 1-Story wood frame structure with metal wall panels. Wood roof</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740009815','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740009815"><span>Banded transformer <span class="hlt">cores</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mclyman, C. W. T. (Inventor)</p> <p>1974-01-01</p> <p>A banded transformer <span class="hlt">core</span> formed by positioning a pair of mated, similar <span class="hlt">core</span> halves on a supporting pedestal. The <span class="hlt">core</span> halves are encircled with a strap, selectively applying tension whereby a compressive force is applied to the <span class="hlt">core</span> edge for reducing the innate air gap. A dc magnetic field is employed in supporting the <span class="hlt">core</span> halves during initial phases of the banding operation, while an ac magnetic field subsequently is employed for detecting dimension changes occurring in the air gaps as tension is applied to the strap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110016684','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110016684"><span>Improved Thermoplastic/Iron-Particle Transformer <span class="hlt">Cores</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wincheski, Russell A.; Bryant, Robert G.; Namkung, Min</p> <p>2004-01-01</p> <p>A method of fabricating improved transformer <span class="hlt">cores</span> from composites of thermoplastic matrices and iron-particles has been invented. Relative to commercially available laminated-iron-alloy transformer <span class="hlt">cores</span>, the <span class="hlt">cores</span> fabricated by this method weigh less and are less expensive. Relative to prior polymer-matrix/ iron-particle composite-material transformer <span class="hlt">cores</span>, the <span class="hlt">cores</span> fabricated by this method can be made mechanically stronger and more magnetically permeable. In addition, whereas some prior <span class="hlt">cores</span> have exhibited significant eddy-current losses, the <span class="hlt">cores</span> fabricated by this method exhibit very small eddy-current losses. The <span class="hlt">cores</span> made by this method can be expected to be attractive for use in diverse applications, including high-signal-to-noise transformers, stepping motors, and high-<span class="hlt">frequency</span> ignition coils. The present method is a product of an experimental study of the relationships among fabrication conditions, final densities of iron particles, and mechanical and electromagnetic properties of fabricated <span class="hlt">cores</span>. Among the fabrication conditions investigated were molding pressures (83, 104, and 131 MPa), and molding temperatures (250, 300, and 350 C). Each block of <span class="hlt">core</span> material was made by uniaxial-compression molding, at the applicable pressure/temperature combination, of a mixture of 2 weight percent of LaRC (or equivalent high-temperature soluble thermoplastic adhesive) with 98 weight percent of approximately spherical iron particles having diameters in the micron range. Each molded block was cut into square cross-section rods that were used as <span class="hlt">core</span> specimens in mechanical and electromagnetic tests. Some of the <span class="hlt">core</span> specimens were annealed at 900 C and cooled slowly before testing. For comparison, a low-carbon-steel <span class="hlt">core</span> was also tested. The results of the tests showed that density, hardness, and rupture strength generally increased with molding pressure and temperature, though the correlation was rather weak. The weakness of the correlation was attributed to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MGeoE..64....1S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MGeoE..64....1S"><span>Structural drilling using the high-<span class="hlt">frequency</span> (sonic) rotary method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Šporin, Jurij; Vukelić, Željko</p> <p>2017-03-01</p> <p>In Slovenia, there is widespread use of structural drilling along with classical <span class="hlt">core</span> drilling. Recently, however, the need has arisen for a highly effective <span class="hlt">core</span> drilling method with the aid of which high-quality <span class="hlt">core</span> might be obtained. In order to achieve this aim, one among several Slovenian companies dealing with geological surveying has decided to implement structural drilling using a high-<span class="hlt">frequency</span> drilling method. The following article presents the theoretical foundations for such a high-<span class="hlt">frequency</span> method, as well as the manner of its implementation. In the final part of the article, a practical comparison between the conventional and the high-<span class="hlt">frequency</span> <span class="hlt">core</span> drilling methods is also provided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999SPIE.3671..305M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999SPIE.3671..305M"><span><span class="hlt">Damage</span> detection in a framed building structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ma, Jun; Pines, Darryll J.</p> <p>1999-05-01</p> <p>Interest in infrastructure health monitoring and <span class="hlt">damage</span> detection has received a considerable amount of attention over the past two decades. Previous approaches to non- destructive evaluation of structures to assess their integrity typically involved some form of human interaction. Recent advances in smart materials and structures technology has resulted in a renewed interest in developing advanced self-diagnostic capability for assessing the state of a structure without any human interaction. The goal is to reduce human interaction while at the same time monitor the integrity of a structure. With this goal in mind, many researchers have made significant strides in developing <span class="hlt">damage</span> detection methods for civil structures based on traditional modal analysis techniques. These techniques are of the well suited for structures which can be modeled by discrete lumped-parameter elements where the presence of <span class="hlt">damage</span> leads to some low <span class="hlt">frequency</span> change in the global behavior of the system. On the other hand small defects such as cracks are obscured by modal approaches since such phenomena are high <span class="hlt">frequency</span> effects not easily discovered by examining changes in modal mass, stiffness or damping parameters. This is because at high <span class="hlt">frequency</span> modal structural models are subject to uncertainty. This uncertainty can be reduced by increasing the spatial order of discrete model, however, this increases the computational effort of modal-based <span class="hlt">damage</span> detection schemes. On the other hand, wave propagation models of structures have higher spatial order model fidelity. Thus, they are better suited for detecting and global wave propagation models to detect <span class="hlt">damage</span> in a discrete model of a farmed building structure, consisting of discrete structural elements. Simulated <span class="hlt">damage</span> in the form of mass or stiffness loss is used to determine the effect on the resonant and incident wave response of the structure. Examination of the incident transfer function response of the structure reveals the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/860120','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/860120"><span>Corrosion <span class="hlt">Damage</span> Functions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jones, Russell H.</p> <p>2002-11-30</p> <p>Corrosion <span class="hlt">damage</span> can lead to reduced operational lifetimes. Often this <span class="hlt">damage</span> is not as obvious as general corrosion but takes the form of pits, intergranular corrosion, crevice corrosion and hydrogen absorption. These types of corrosion <span class="hlt">damage</span> lead to stress corrosion cracking, hydrogen induced cracking and corrosion fatigue. A critical step in defining a corrosion <span class="hlt">damage</span> function is determining the relationship between the corrosion <span class="hlt">damage</span>, the resulting crack propagation mechanism and component lifetimes. The sequence of events is often some localized corrosion event such as pitting, transition of the pit to a planar crack, propagation of this short crack, transition of the short crack to long crack conditions and continued propagation through Stage I, II, and III of the long crack SCC regimes. A description of critical corrosion <span class="hlt">damage</span> processes and examples of the transition to long crack SCC conditions will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920004718','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920004718"><span>Structural <span class="hlt">damage</span> identification using mathematical optimization techniques</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shen, Mo-How Herman</p> <p>1991-01-01</p> <p>An identification procedure is proposed to identify <span class="hlt">damage</span> characteristics (location and size of the <span class="hlt">damage</span>) from dynamic measurements. This procedure was based on minimization of the mean-square measure of difference between measurement data (natural <span class="hlt">frequencies</span> and mode shapes) and the corresponding predictions obtained from the computational model. The procedure is tested for simulated <span class="hlt">damage</span> in the form of stiffness changes in a simple fixed free spring mass system and symmetric cracks in a simply supported Bernoulli Euler beam. It is shown that when all the mode information is used in the identification procedure it is possible to uniquely determine the <span class="hlt">damage</span> properties. Without knowing the complete set of modal information, a restricted region in the initial data space has been found for realistic and convergent solution from the identification process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1815148B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1815148B"><span>Brittle dynamic <span class="hlt">damage</span> due to earthquake rupture</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bhat, Harsha; Thomas, Marion</p> <p>2016-04-01</p> <p>The micromechanical <span class="hlt">damage</span> mechanics formulated by Ashby and Sammis, 1990, and generalized by Deshpande and Evans 2008 has been extended to allow for a more generalized stress state and to incorporate an experimentally motivated new crack growth (<span class="hlt">damage</span> evolution) law that is valid over a wide range of loading rates. This law is sensitive to both the crack tip stress field and its time derivative. Incorporating this feature produces additional strain-rate sensitivity in the constitutive response. The model is also experimentally verified by predicting the failure strength of Dionysus-Pentelicon marble over wide range of strain rates. We then implement this constitutive response to understand the role of dynamic brittle off-fault <span class="hlt">damage</span> on earthquake ruptures. We show that off-fault <span class="hlt">damage</span> plays an important role in asymmetry of rupture propagation and is a source of high-<span class="hlt">frequency</span> ground motion in the near source region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhDT.......316M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhDT.......316M"><span>Impact <span class="hlt">damage</span> in aircraft composite sandwich panels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mordasky, Matthew D.</p> <p></p> <p>An experimental study was conducted to develop an improved understanding of the <span class="hlt">damage</span> caused by runway debris and environmental threats on aircraft structures. The velocities of impacts for stationary aircraft and aircraft under landing and takeoff speeds was investigated. The impact <span class="hlt">damage</span> by concrete, asphalt, aluminum, hail and rubber sphere projectiles was explored in detail. Additionally, a kinetic energy and momentum experimental study was performed to look at the nature of the impacts in more detail. A method for recording the contact force history of the impact by an instrumented projectile was developed and tested. The sandwich composite investigated was an IM7-8552 unidirectional prepreg adhered to a NOMEXRTM <span class="hlt">core</span> with an FM300K film adhesive. Impact experiments were conducted with a gas gun built in-house specifically for delivering projectiles to a sandwich composite target in this specic velocity regime (10--140 m/s). The effect on the impact <span class="hlt">damage</span> by the projectile was investigated by ultrasonic C-scan, high speed camera and scanning electron and optical microscopy. Ultrasonic C-scans revealed the full extent of <span class="hlt">damage</span> caused by each projectile, while the high speed camera enabled precise projectile velocity measurements that were used for striking velocity, kinetic energy and momentum analyses. Scanning electron and optical images revealed specific features of the panel failure and manufacturing artifacts within the lamina and honeycomb <span class="hlt">core</span>. The <span class="hlt">damage</span> of the panels by different projectiles was found to have a similar <span class="hlt">damage</span> area for equivalent energy levels, except for rubber which had a <span class="hlt">damage</span> area that increased greatly with striking velocity. Further investigation was taken by kinetic energy and momentum based comparisons of 19 mm diameter stainless steel sphere projectiles in order to examine the dominating <span class="hlt">damage</span> mechanisms. The sandwich targets were struck by acrylic, aluminum, alumina, stainless steel and tungsten carbide spheres of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16673411','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16673411"><span>DNA <span class="hlt">damage</span>, oxidative mutagen sensitivity, and repair of oxidative DNA <span class="hlt">damage</span> in nonmelanoma skin cancer patients.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bendesky, Andrés; Michel, Alejandra; Sordo, Monserrat; Calderón-Aranda, Emma S; Acosta-Saavedra, Leonor C; Salazar, Ana M; Podoswa, Nancy; Ostrosky-Wegman, Patricia</p> <p>2006-08-01</p> <p>Nonmelanoma skin cancer (NMSC) is the most frequent type of cancer in humans. Exposure to UV radiation is a major risk factor for NMSC, and oxidative DNA <span class="hlt">damage</span>, caused either by UV radiation itself or by other agents, may be involved in its induction. Increased sensitivity to oxidative <span class="hlt">damage</span> and an altered DNA repair capacity (DRC) increase the risk of many types of cancer; however, sensitivity to oxidizing agents has not been evaluated for NMSC, and results regarding DRC in NMSC are inconclusive. In the present study, we evaluated DNA <span class="hlt">damage</span> and repair in leukocytes from 41 NMSC patients and 45 controls. The Comet assay was used to measure basal and H(2)O(2)-induced DNA <span class="hlt">damage</span>, as well as the DRC, while the cytokinesis-block micronucleus assay was used to measure the basal level of chromosome <span class="hlt">damage</span>. Although basal DNA <span class="hlt">damage</span> was higher for the controls than for the patients, this finding was mainly due to sampling more controls in the summer, which was associated with longer comet tails. In contrast, H(2)O(2)-induced DNA <span class="hlt">damage</span> was significantly higher in cases than in controls, and this parameter was not influenced by the season of the year. The DRC for the H(2)O(2)-induced <span class="hlt">damage</span> was similar for cases and controls and unrelated to seasonality. Finally, the <span class="hlt">frequency</span> of binucleated lymphocytes with micronuclei was similar for cases and controls. The results of this study indicate that NMSC patients are distinguished from controls by an increased sensitivity to oxidative DNA <span class="hlt">damage</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/811812','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/811812"><span>HYDRATE <span class="hlt">CORE</span> DRILLING TESTS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>John H. Cohen; Thomas E. Williams; Ali G. Kadaster; Bill V. Liddell</p> <p>2002-11-01</p> <p>The ''Methane Hydrate Production from Alaskan Permafrost'' project is a three-year endeavor being conducted by Maurer Technology Inc. (MTI), Noble, and Anadarko Petroleum, in partnership with the U.S. DOE National Energy Technology Laboratory (NETL). The project's goal is to build on previous and ongoing R&D in the area of onshore hydrate deposition. The project team plans to design and implement a program to safely and economically drill, <span class="hlt">core</span> and produce gas from arctic hydrates. The current work scope includes drilling and <span class="hlt">coring</span> one well on Anadarko leases in FY 2003 during the winter drilling season. A specially built on-site <span class="hlt">core</span> analysis laboratory will be used to determine some of the physical characteristics of the hydrates and surrounding rock. Prior to going to the field, the project team designed and conducted a controlled series of <span class="hlt">coring</span> tests for simulating <span class="hlt">coring</span> of hydrate formations. A variety of equipment and procedures were tested and modified to develop a practical solution for this special application. This Topical Report summarizes these <span class="hlt">coring</span> tests. A special facility was designed and installed at MTI's Drilling Research Center (DRC) in Houston and used to conduct <span class="hlt">coring</span> tests. Equipment and procedures were tested by cutting <span class="hlt">cores</span> from frozen mixtures of sand and water supported by casing and designed to simulate hydrate formations. Tests were conducted with chilled drilling fluids. Tests showed that frozen <span class="hlt">core</span> can be washed out and reduced in size by the action of the drilling fluid. Washing of the <span class="hlt">core</span> by the drilling fluid caused a reduction in <span class="hlt">core</span> diameter, making <span class="hlt">core</span> recovery very difficult (if not impossible). One successful solution was to drill the last 6 inches of <span class="hlt">core</span> dry (without fluid circulation). These tests demonstrated that it will be difficult to capture <span class="hlt">core</span> when drilling in permafrost or hydrates without implementing certain safeguards. Among the <span class="hlt">coring</span> tests was a simulated hydrate formation comprised of coarse, large</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/al1054.photos.046337p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/al1054.photos.046337p/"><span>23. <span class="hlt">CORE</span> WORKER OPERATING A COREBLOWER THAT PNEUMATICALLY FILLED <span class="hlt">CORE</span> ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>23. <span class="hlt">CORE</span> WORKER OPERATING A <span class="hlt">CORE</span>-BLOWER THAT PNEUMATICALLY FILLED <span class="hlt">CORE</span> BOXES WITH RESIGN IMPREGNATED SAND AND CREATED A <span class="hlt">CORE</span> THAT THEN REQUIRED BAKING, CA. 1950. - Stockham Pipe & Fittings Company, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070031963','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070031963"><span><span class="hlt">Damage</span> Tolerance of Composites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hodge, Andy</p> <p>2007-01-01</p> <p>Fracture control requirements have been developed to address <span class="hlt">damage</span> tolerance of composites for manned space flight hardware. The requirements provide the framework for critical and noncritical hardware assessment and testing. The need for <span class="hlt">damage</span> threat assessments, impact <span class="hlt">damage</span> protection plans, and nondestructive evaluation are also addressed. Hardware intended to be <span class="hlt">damage</span> tolerant have extensive coupon, sub-element, and full-scale testing requirements in-line with the Building Block Approach concept from the MIL-HDBK-17, Department of Defense Composite Materials Handbook.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870058746&hterms=tsai+wu&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dtsai%2Bwu','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870058746&hterms=tsai+wu&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dtsai%2Bwu"><span>Impact <span class="hlt">damage</span> of composites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wu, Hsi-Young T.; Springer, George S.</p> <p>1986-01-01</p> <p>A model is described for estimating the impact <span class="hlt">damage</span> of fiber reinforced composite plates. The displacements and stresses are calculated by a three dimensional transient, finite element method of solution of the governing equations applicable to a linearly elastic body. The region in which <span class="hlt">damage</span> occurs is estimated using the Tsai-Wu failure criterion. A computer code was developed which can be used to calculate the impact force, displacements and velocities of the plate and the impact body, stresses and strains in the plate, and the <span class="hlt">damage</span> area. Sample numerical results are presented illustrating the type of information provided by the code. Comparisons between measured and calculated <span class="hlt">damage</span> areas are also given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21361979','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21361979"><span>Intelligent-based Structural <span class="hlt">Damage</span> Detection Model</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lee, Eric Wai Ming; Yu, K.F.</p> <p>2010-05-21</p> <p>This paper presents the application of a novel Artificial Neural Network (ANN) model for the diagnosis of structural <span class="hlt">damage</span>. The ANN model, denoted as the GRNNFA, is a hybrid model combining the General Regression Neural Network Model (GRNN) and the Fuzzy ART (FA) model. It not only retains the important features of the GRNN and FA models (i.e. fast and stable network training and incremental growth of network structure) but also facilitates the removal of the noise embedded in the training samples. Structural <span class="hlt">damage</span> alters the stiffness distribution of the structure and so as to change the natural <span class="hlt">frequencies</span> and mode shapes of the system. The measured modal parameter changes due to a particular <span class="hlt">damage</span> are treated as patterns for that <span class="hlt">damage</span>. The proposed GRNNFA model was trained to learn those patterns in order to detect the possible <span class="hlt">damage</span> location of the structure. Simulated data is employed to verify and illustrate the procedures of the proposed ANN-based <span class="hlt">damage</span> diagnosis methodology. The results of this study have demonstrated the feasibility of applying the GRNNFA model to structural <span class="hlt">damage</span> diagnosis even when the training samples were noise contaminated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080006027','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080006027"><span>Apparatus for measuring high <span class="hlt">frequency</span> currents</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hagmann, Mark J. (Inventor); Sutton, John F. (Inventor)</p> <p>2003-01-01</p> <p>An apparatus for measuring high <span class="hlt">frequency</span> currents includes a non-ferrous <span class="hlt">core</span> current probe that is coupled to a wide-band transimpedance amplifier. The current probe has a secondary winding with a winding resistance that is substantially smaller than the reactance of the winding. The sensitivity of the current probe is substantially flat over a wide band of <span class="hlt">frequencies</span>. The apparatus is particularly useful for measuring exposure of humans to radio <span class="hlt">frequency</span> currents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhFl...29i6601K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhFl...29i6601K"><span>Librations induced zonal flow and differential rotation of free inner <span class="hlt">core</span> in rotating spherical cavity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kozlov, V. G.; Subbotin, S. V.</p> <p>2017-09-01</p> <p>The paper is devoted to the experimental study of the dynamics of a free solid <span class="hlt">core</span> and a liquid in a spherical cavity rotating about a horizontal axis. The cavity rotation rate consists of two components: constant and oscillating ones (librations). Under the action of centrifugal force the <span class="hlt">core</span> with the density less than the density of liquid is located near the rotation axis. The gravity field causes a small stationary displacement of the <span class="hlt">core</span> from the cavity center. In turn, this displacement induces mean retrograde differential rotation of the <span class="hlt">core</span> and the fluid. It is found that the librations generate the mean effects (zonal flow and the retrograde differential rotation of the <span class="hlt">core</span>), which manifest themselves in sum with the ones caused by gravity. The intensity of zonal flow and the <span class="hlt">core</span> differential rotation is proportional to the square of the libration amplitude. The additivity of mean effects connected with librations and gravity is observed in a wide range of the libration <span class="hlt">frequency</span> excluding the areas of very low-<span class="hlt">frequency</span> librations and resonant (close to the rotation <span class="hlt">frequency</span> and natural <span class="hlt">frequencies</span> of the <span class="hlt">core</span> translational oscillations) ones. At low-<span class="hlt">frequency</span> librations, the <span class="hlt">core</span> rotation rate changes periodically with the libration <span class="hlt">frequency</span> and is accompanied by the periodic variation of the <span class="hlt">core</span> position in the cavity. At some part of the libration period, the relaxation oscillations of the <span class="hlt">core</span> with natural <span class="hlt">frequency</span> are excited. Librations with the <span class="hlt">frequency</span> equal to the cavity rotation exert the strongest resonant effect on the <span class="hlt">core</span>, generating the <span class="hlt">core</span> translational oscillations with large amplitude and substantial change of the structure of mean zonal flows. In this case and when the libration <span class="hlt">frequency</span> coincides with the natural <span class="hlt">frequency</span> of the <span class="hlt">core</span> oscillations, the dependence of the differential rotational rate on the libration amplitude is different from the quadratic. This specific response of the system on the librations is caused</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMDI43A2654D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMDI43A2654D"><span>Inner <span class="hlt">Core</span> Imaging Using P'P'</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Day, E. A.; Ward, J. A.; Bastow, I. D.; Irving, J. C. E.</p> <p>2016-12-01</p> <p>The Earth's inner <span class="hlt">core</span> is a surprisingly complex region of our planet. Simple models of inner <span class="hlt">core</span> solidification and evolution would lead us to expect a layered structure, which has "frozen in" in information about the state of the <span class="hlt">core</span> at the time of solidification. However, seismic observations of Earth's inner <span class="hlt">core</span> are not dominated by a radial "tree-ring" like pattern, but instead have revealed a hemispherical dichotomy in addition to depth dependent variations. There is a degree-one structure in isotropic and anisotropic velocities and in attenuation between the so-called eastern and western hemispheres of the inner <span class="hlt">core</span>, with different depth distributions proposed for these varying phenomena. A range of mechanisms have been proposed to explain the hemispherical differences. These include models that require differences between the two hemispheres at the time of formation, post-solidification texturing, convection in the inner <span class="hlt">core</span>, or hybrid mechanisms. Regional observations of the inner <span class="hlt">core</span> suggest that a simple division between East and West may not be able to fully capture the structure present in the inner <span class="hlt">core</span>. More detailed seismic observations will help us to understand the puzzle of the inner <span class="hlt">core</span>'s evolution. In this study we focus on updating observations of the seismic phase P'P', an inner <span class="hlt">core</span> sensitive body wave with a more complex path than those typically used to study the inner <span class="hlt">core</span>. By making new measurements of P'P' we illuminate new regions of the <span class="hlt">core</span> with a high <span class="hlt">frequency</span> phase that is sensitive to small scale structures. We examine the differential travel times of the different branches of P'P' (PKIKPPKIKP and PKPPKP), comparing the arrival time of inner <span class="hlt">core</span> turning branch, P'P'df, with the arrival times of branches that turn in the outer <span class="hlt">core</span>. P'P' is a relatively small amplitude phase, so we use both linear and non-linear stacking methods to make observations of the P'P' signals. These measurements are sensitive to the broad scale</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6023640','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6023640"><span>Chromatin structure and DNA <span class="hlt">damage</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gale, J.M.</p> <p>1987-01-01</p> <p>This dissertation examines the structure and structural transitions of chromatin in relation to DNA <span class="hlt">damage</span>. The ability of intact and histone H1 depleted chromatin fibers to fold into higher ordered structures in vitro was examined following DNA photodamage introduced by two different agents. (1) 254-nm UV radiation and (2) trimethylpsoralen (plus near-UV radiation). Both agents are highly specific for DNA and form adducts predicted to cause different degrees of distortion in the DNA helix. The salt-induced structural transitions of intact and histone H1 depleted chromatin fibers were monitored by both analytical ultracentrifugation and light scattering. Our results show that even in the presence of extremely large, nonphysiological amounts of photodamage by either agent the ability of chromatin to fold into higher ordered structures is not affected. The compact, 30 nm fiber must therefore be able to accommodate a large amount of DNA <span class="hlt">damage</span> without any measurable changes in the overall size or degree of compaction of this structure. The distribution of pyrimidine dimers was mapped at the single nucleotide level in nucleosome <span class="hlt">core</span> DNA from UV-irradiated mononucleosomes, chromatin fibers, and human cells in culture using the 3' ..-->.. 5' exonuclease activity of T4 DNA polymerase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhDT.......165D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhDT.......165D"><span><span class="hlt">Damage</span> modeling and <span class="hlt">damage</span> detection for structures using a perturbation method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dixit, Akash</p> <p></p> <p>This thesis is about using structural-dynamics based methods to address the existing challenges in the field of Structural Health Monitoring (SHM). Particularly, new structural-dynamics based methods are presented, to model areas of <span class="hlt">damage</span>, to do <span class="hlt">damage</span> diagnosis and to estimate and predict the sensitivity of structural vibration properties like natural <span class="hlt">frequencies</span> to the presence of <span class="hlt">damage</span>. Towards these objectives, a general analytical procedure, which yields nth-order expressions governing mode shapes and natural <span class="hlt">frequencies</span> and for <span class="hlt">damaged</span> elastic structures such as rods, beams, plates and shells of any shape is presented. Features of the procedure include the following: 1. Rather than modeling the <span class="hlt">damage</span> as a fictitious elastic element or localized or global change in constitutive properties, it is modeled in a mathematically rigorous manner as a geometric discontinuity. 2. The inertia effect (kinetic energy), which, unlike the stiffness effect (strain energy), of the <span class="hlt">damage</span> has been neglected by researchers, is included in it. 3. The framework is generic and is applicable to wide variety of engineering structures of different shapes with arbitrary boundary conditions which constitute self adjoint systems and also to a wide variety of <span class="hlt">damage</span> profiles and even multiple areas of <span class="hlt">damage</span>. To illustrate the ability of the procedure to effectively model the <span class="hlt">damage</span>, it is applied to beams using Euler-Bernoulli and Timoshenko theories and to plates using Kirchhoff's theory, supported on different types of boundary conditions. Analytical results are compared with experiments using piezoelectric actuators and non-contact Laser-Doppler Vibrometer sensors. To illustrate the ability of the procedure to effectively model the <span class="hlt">damage</span>, it is applied to beams using Euler-Bernoulli and Timoshenko theories and to plates using Kirchhoff's theory, supported on different types of boundary conditions. Analytical results are compared with experiments using piezoelectric actuators and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21316865','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21316865"><span>KSI's Cross Insulated <span class="hlt">Core</span> Transformer Technology</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Uhmeyer, Uwe</p> <p>2009-08-04</p> <p>Cross Insulated <span class="hlt">Core</span> Transformer (CCT) technology improves on Insulated <span class="hlt">Core</span> Transformer (ICT) implementations. ICT systems are widely used in very high voltage, high power, power supply systems. In an ICT transformer ferrite <span class="hlt">core</span> sections are insulated from their neighboring ferrite <span class="hlt">cores</span>. Flux leakage is present at each of these insulated gaps. The flux loss is raised to the power of stages in the ICT design causing output voltage efficiency to taper off with increasing stages. KSI's CCT technology utilizes a patented technique to compensate the flux loss at each stage of an ICT system. Design equations to calculate the flux compensation capacitor value are presented. CCT provides corona free operation of the HV stack. KSI's CCT based High Voltage power supply systems offer high efficiency operation, high <span class="hlt">frequency</span> switching, low stored energy and smaller size over comparable ICT systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhCS.660a2007L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.660a2007L"><span>Ferrofluid-based Stretchable Magnetic <span class="hlt">Core</span> Inductors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lazarus, N.; Meyer, C. D.</p> <p>2015-12-01</p> <p>Magnetic materials are commonly used in inductor and transformer <span class="hlt">cores</span> to increase inductance density. The emerging field of stretchable electronics poses a new challenge since typical magnetic <span class="hlt">cores</span> are bulky, rigid and often brittle. This paper presents, for the first time, stretchable inductors incorporating ferrofluid as a liquid magnetic <span class="hlt">core</span>. Ferrofluids, suspensions of nanoscale magnetic particles in a carrier liquid, provide enhanced magnetic permeability without changing the mechanical properties of the surrounding elastomer. The inductor tested in this work consisted of a liquid metal solenoid wrapped around a ferrofluid <span class="hlt">core</span> in separate channels. The low <span class="hlt">frequency</span> inductance was found to increase from 255 nH before fill to 390 nH after fill with ferrofluid, an increase of 52%. The inductor was also shown to survive uniaxial strains of up to 100%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/48154','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/48154"><span>Animal <span class="hlt">damage</span> to birch</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>James S. Jordan; Francis M. Rushmore</p> <p>1969-01-01</p> <p>A relatively few animal species are responsible for most of the reported <span class="hlt">damage</span> to the birches. White-tailed deer, yellow-bellied sapsuckers, porcupines, moose, and hares are the major animals involved. We will review reports of <span class="hlt">damage</span>, discuss the underlying causes, and describe possible methods of control. For example, heavy deer browsing that eliminates birch...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720002416','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720002416"><span>Radiation <span class="hlt">damage</span> annealing kinetics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dresselhaus, M. S.</p> <p>1971-01-01</p> <p>Various spectral response studies are reported that assess lithium doping effects on the recovery process of electron <span class="hlt">damaged</span> silicon solar cells. Measurements of both the minority carrier lifetimes and the energy level spectrum of the defects are used to predict lifetime <span class="hlt">damage</span> constants and carrier removal rates relevant to the operation of the solar lithium-doped cell and its annealing kinetics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/3067','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/3067"><span>Animal <span class="hlt">damage</span> management handbook.</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Hugh C. Black</p> <p>1994-01-01</p> <p>This handbook treats animal <span class="hlt">damage</span> management (ADM) in the West in relation to forest, range, and recreation resources; predator management is not addressed. It provides a comprehensive reference of safe, effective, and practical methods for managing animal <span class="hlt">damage</span> on National Forest System lands. Supporting information is included in references after each chapter and...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70168780','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70168780"><span><span class="hlt">Damage</span> and intensity survey</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Reagor, G.; Brewer, L.R.</p> <p>1992-01-01</p> <p>A field team (the tuhors) from the National Earthquake Information Center (USGS) conducted a <span class="hlt">damage</span> survey of the epicentral area in the week following the earthquakes. Detailed information about <span class="hlt">damage</span> and where and how strongly the earthquakes were felt was obtained through interviews with local residents and personal observations. </p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/10969','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/10969"><span>Squirrel <span class="hlt">Damage</span> to Pines</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>USDA Forest Service</p> <p>1981-01-01</p> <p>Flagging (dead branch tips) on jack pine and red pine may be caused by insects, diseases, or mechanical <span class="hlt">damage</span>. In the Lake States, flagging is often the result of mechanical <span class="hlt">damage</span>, sometimes girdling, caused when the cones are torn off by red squirrels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900014424','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900014424"><span><span class="hlt">Core</span> sample extractor</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Akins, James; Cobb, Billy; Hart, Steve; Leaptrotte, Jeff; Milhollin, James; Pernik, Mark</p> <p>1989-01-01</p> <p>The problem of retrieving and storing <span class="hlt">core</span> samples from a hole drilled on the lunar surface is addressed. The total depth of the hole in question is 50 meters with a maximum diameter of 100 millimeters. The <span class="hlt">core</span> sample itself has a diameter of 60 millimeters and will be two meters in length. It is therefore necessary to retrieve and store 25 <span class="hlt">core</span> samples per hole. The design utilizes a control system that will stop the mechanism at a certain depth, a cam-linkage system that will fracture the <span class="hlt">core</span>, and a storage system that will save and catalogue the <span class="hlt">cores</span> to be extracted. The Rod Changer and Storage Design Group will provide the necessary tooling to get into the hole as well as to the <span class="hlt">core</span>. The mechanical design for the cam-linkage system as well as the conceptual design of the storage device are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JMMM..347....1W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JMMM..347....1W"><span>Fe-based nanocrystalline powder <span class="hlt">cores</span> with ultra-low <span class="hlt">core</span> loss</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Xiangyue; Lu, Zhichao; Lu, Caowei; Li, Deren</p> <p>2013-12-01</p> <p>Melt-spun amorphous Fe73.5Cu1Nb3Si15.5B7 alloy strip was crushed to make flake-shaped fine powders. The passivated powders by phosphoric acid were mixed with organic and inorganic binder, followed by cold compaction to form toroid-shaped bonded powder-metallurgical magnets. The powder <span class="hlt">cores</span> were heat-treated to crystallize the amorphous structure and to control the nano-grain structure. Well-coated phosphate-oxide insulation layer on the powder surface decreased the the <span class="hlt">core</span> loss with the insulation of each powder. FeCuNbSiB nanocrystalline alloy powder <span class="hlt">core</span> prepared from the powder having phosphate-oxide layer exhibits a stable permeability up to high <span class="hlt">frequency</span> range over 2 MHz. Especially, the <span class="hlt">core</span> loss could be reduced remarkably. At the other hand, the softened inorganic binder in the annealing process could effectively improve the intensity of powder <span class="hlt">cores</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MS%26E..187a2031Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MS%26E..187a2031Q"><span>Research on Creep <span class="hlt">Damage</span> and Life Forecast of Rod Fastening Rotor Based on <span class="hlt">Damage</span> Mechanics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qiang, Liu; Ai-lun, Wang</p> <p>2017-03-01</p> <p>Rod fastening rotor (RFR) is the <span class="hlt">core</span> part of gas turbine, the degradation of RFR has great effect on gas turbine’s performance. One of the main reasons which cause the RFR performance degradation is creep <span class="hlt">damage</span>, while few studies have been carried out in terms of it so far. In order to analyze the influence of preload on virtual material parameters, a dynamic model of RFR considering interface contact effect was built. Then equivalent stiffness of RFR and elements was analyzed as well. Furthermore, creep <span class="hlt">damage</span> of elements under higher stress were analyzed with <span class="hlt">damage</span> mechanics to get their influence on the total <span class="hlt">damage</span>. Likewise, RFR were analyzed with <span class="hlt">damage</span> mechanics to get the connection between the total <span class="hlt">damage</span> and rupture life. The results showed that connection between the total <span class="hlt">damage</span> and rupture life was a complicated, non-linear process. Moreover, the rods of turbine and combustion chamber were the biggest influencing factors. The results of this dissertation can be a support for structural design and life prediction of RFR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25423121','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25423121"><span>The MVAD pump: motor stator <span class="hlt">core</span> loss characterization.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mesa, Kelly J; Ferreira, Antonio; Castillo, Samir; Reyes, Carlos; Wolman, Justin; Casas, Fernando</p> <p>2015-01-01</p> <p>Investigation of the miniature ventricular assist device (MVAD) pump motor stator <span class="hlt">core</span> loss behavior was conducted. During operation, the ferromagnetic <span class="hlt">core</span> in the pump's motor is magnetized by alternating magnetic fields, which, in turn, create intrinsic energy losses in the <span class="hlt">core</span> material; these losses are known as <span class="hlt">core</span> losses. A <span class="hlt">core</span> loss fixture and a method to characterize the magnetic behavior of the MVAD pump stator over a range of <span class="hlt">frequencies</span> were developed. The MVAD pump motor design features a three phase brushless DC stator with ferromagnetic laminations and copper wire windings arranged in a six slot configuration. The stator's magnetic behavior is important because its <span class="hlt">core</span> magnetic losses impact pump system efficiency. A system to measure the <span class="hlt">core</span> loss of MVAD pump stators was developed using a custom <span class="hlt">core</span> loss fixture consisting of 16 copper wire turns wound in a closed loop geometry bundle; the stator under test was then placed within this bundle. The instrumentation consisted of a signal generator, a power amplifier, and a power analyzer. Power analyzer parameters of current, voltage, and power were collected for several runs with a sinusoidal <span class="hlt">frequency</span> sweep of 0 to 50 kHz; data were collected for the fixture with and without stators. The magnetic losses inherent to the fixture were characterized independently as a baseline presenting a flat <span class="hlt">frequency</span> response. The <span class="hlt">core</span> loss power measurements of individual stators yielded a characteristic bandpass <span class="hlt">frequency</span> response morphology with a peak <span class="hlt">core</span> loss found around 2.3 to 2.5 kHz. In conclusion, this method could be used to describe the transfer function of the stator's <span class="hlt">core</span> magnetic behavior. It also has the potential to be used for future motor evaluation and for investigation of <span class="hlt">core</span> loss performance variability between different stators during manufacturing operations. Investigational device. Limited by United States law to investigational use.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19730037391&hterms=inner+critic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dinner%2Bcritic','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19730037391&hterms=inner+critic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dinner%2Bcritic"><span>The <span class="hlt">core</span> paradox.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kennedy, G. C.; Higgins, G. H.</p> <p>1973-01-01</p> <p>Rebuttal of suggestions from various critics attempting to provide an escape from the seeming paradox originated by Higgins and Kennedy's (1971) proposed possibility that the liquid in the outer <span class="hlt">core</span> was thermally stably stratified and that this stratification might prove a powerful inhibitor to circulation of the outer <span class="hlt">core</span> fluid of the kind postulated for the generation of the earth's magnetic field. These suggestions are examined and shown to provide no reasonable escape from the <span class="hlt">core</span> paradox.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19730037391&hterms=paradox&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dparadox','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19730037391&hterms=paradox&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dparadox"><span>The <span class="hlt">core</span> paradox.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kennedy, G. C.; Higgins, G. H.</p> <p>1973-01-01</p> <p>Rebuttal of suggestions from various critics attempting to provide an escape from the seeming paradox originated by Higgins and Kennedy's (1971) proposed possibility that the liquid in the outer <span class="hlt">core</span> was thermally stably stratified and that this stratification might prove a powerful inhibitor to circulation of the outer <span class="hlt">core</span> fluid of the kind postulated for the generation of the earth's magnetic field. These suggestions are examined and shown to provide no reasonable escape from the <span class="hlt">core</span> paradox.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA289932','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA289932"><span>Structural <span class="hlt">Damage</span> Detection Using <span class="hlt">Frequency</span> Domain Error Localization.</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1994-12-01</p> <p>113 rn ~l-,I T X ~oy Ul C 114 APPENDIX D. FE MODEL / COMPUTER CODES The following is a brief description of MATLAB routines employed in this thesis...R.R., Structural Dynamics, An Introduction to Computer Methods , pp. 383-387, John Wiley and Sons, Inc., 1981. 8. Guyan , R.J., "Reduction of Stiffness...official policy or position of the Department of Defense or the U.S. Government. 12a. DISTRIBUTION/AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060004125','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060004125"><span>Magnetic and Electrical Characteristics of Permalloy Thin Tape Bobbin <span class="hlt">Cores</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schwarze, Gene E.; Wieserman, William R.; Niedra, Janis M.</p> <p>2005-01-01</p> <p>The <span class="hlt">core</span> loss, that is, the power loss, of a soft ferromagnetic material is a function of the flux density, <span class="hlt">frequency</span>, temperature, excitation type (voltage or current), excitation waveform (sine, square, etc.) and lamination or tape thickness. In previously published papers we have reported on the specific <span class="hlt">core</span> loss and dynamic B-H loop results for several polycrystalline, nanocrystalline, and amorphous soft magnetic materials. In this previous research we investigated the effect of flux density, <span class="hlt">frequency</span>, temperature, and excitation waveform for voltage excitation on the specific <span class="hlt">core</span> loss and dynamic B-H loop. In this paper, we will report on an experimental study to investigate the effect of tape thicknesses of 1, 1/2, 1/4, and 1/8-mil Permalloy type magnetic materials on the specific <span class="hlt">core</span> loss. The test <span class="hlt">cores</span> were fabricated by winding the thin tapes on ceramic bobbin <span class="hlt">cores</span>. The specific <span class="hlt">core</span> loss tests were conducted at room temperature and over the <span class="hlt">frequency</span> range of 10 kHz to 750 kHz using sine wave voltage excitation. The results of this experimental investigation will be presented primarily in graphical form to show the effect of tape thickness, <span class="hlt">frequency</span>, and magnetic flux density on the specific <span class="hlt">core</span> loss. Also, the experimental results when applied to power transformer design will be briefly discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/gip/94/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/gip/94/"><span><span class="hlt">Core</span> Research Center</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hicks, Joshua; Adrian, Betty</p> <p>2009-01-01</p> <p>The <span class="hlt">Core</span> Research Center (CRC) of the U.S. Geological Survey (USGS), located at the Denver Federal Center in Lakewood, Colo., currently houses rock <span class="hlt">core</span> from more than 8,500 boreholes representing about 1.7 million feet of rock <span class="hlt">core</span> from 35 States and cuttings from 54,000 boreholes representing 238 million feet of drilling in 28 States. Although most of the boreholes are located in the Rocky Mountain region, the geologic and geographic diversity of samples have helped the CRC become one of the largest and most heavily used public <span class="hlt">core</span> repositories in the United States. Many of the boreholes represented in the collection were drilled for energy and mineral exploration, and many of the <span class="hlt">cores</span> and cuttings were donated to the CRC by private companies in these industries. Some <span class="hlt">cores</span> and cuttings were collected by the USGS along with other government agencies. Approximately one-half of the <span class="hlt">cores</span> are slabbed and photographed. More than 18,000 thin sections and a large volume of analytical data from the <span class="hlt">cores</span> and cuttings are also accessible. A growing collection of digital images of the <span class="hlt">cores</span> are also becoming available on the CRC Web site Internet http://geology.cr.usgs.gov/crc/.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PhDT.......155A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PhDT.......155A"><span>Adaptive <span class="hlt">core</span> simulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abdel-Khalik, Hany Samy</p> <p></p> <p>The work presented in this thesis is a continuation of a master's thesis research project conducted by the author to gain insight into the applicability of inverse methods to developing adaptive simulation capabilities for <span class="hlt">core</span> physics problems. Use of adaptive simulation is intended to improve the fidelity and robustness of important <span class="hlt">core</span> attributes predictions such as <span class="hlt">core</span> power distribution, thermal margins and <span class="hlt">core</span> reactivity. Adaptive simulation utilizes a selected set of past and current reactor measurements of reactor observables, i.e. in-<span class="hlt">core</span> instrumentations readings, to adapt the simulation in a meaningful way. A meaningful adaption will result in high fidelity and robust adapted <span class="hlt">core</span> simulators models. To perform adaption, we propose an inverse theory approach in which the multitudes of input data to <span class="hlt">core</span> simulators, i.e. reactor physics and thermal-hydraulic data, are to be adjusted to improve agreement with measured observables while keeping <span class="hlt">core</span> simulators models unadapted. At a first glance, devising such adaption for typical <span class="hlt">core</span> simulators models would render the approach impractical. This follows, since <span class="hlt">core</span> simulators are based on very demanding computational models, i.e. based on complex physics models with millions of input data and output observables. This would spawn not only several prohibitive challenges but also numerous disparaging concerns. The challenges include the computational burdens of the sensitivity-type calculations required to construct Jacobian operators for the <span class="hlt">core</span> simulators models. Also, the computational burdens of the uncertainty-type calculations required to estimate the uncertainty information of <span class="hlt">core</span> simulators input data presents a demanding challenge. The concerns however are mainly related to the reliability of the adjusted input data. We demonstrate that the power of our proposed approach is mainly driven by taking advantage of this unfavorable situation. Our contribution begins with the realization that to obtain</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5386002','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5386002"><span>Tissue <span class="hlt">damage</span> thresholds during therapeutic electrical stimulation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cogan, Stuart F; Ludwig, Kip A; Welle, Cristin G; Takmakov, Pavel</p> <p>2017-01-01</p> <p>Objective Recent initiatives in bioelectronic modulation of the nervous system by the NIH (SPARC), DARPA (ElectRx, SUBNETS) and the GlaxoSmithKline Bioelectronic Medicines effort are ushering in a new era of therapeutic electrical stimulation. These novel therapies are prompting a re-evaluation of established electrical thresholds for stimulation-induced tissue <span class="hlt">damage</span>. Approach In this review, we explore what is known and unknown in published literature regarding tissue <span class="hlt">damage</span> from electrical stimulation. Main results For macroelectrodes, the potential for tissue <span class="hlt">damage</span> is often assessed by comparing the intensity of stimulation, characterized by the charge density and charge per phase of a stimulus pulse, with a <span class="hlt">damage</span> threshold identified through histological evidence from in vivo experiments as described by the Shannon equation. While the Shannon equation has proved useful in assessing the likely occurrence of tissue <span class="hlt">damage</span>, the analysis is limited by the experimental parameters of the original studies. Tissue <span class="hlt">damage</span> is influenced by factors not explicitly incorporated into the Shannon equation, including pulse <span class="hlt">frequency</span>, duty cycle, current density, and electrode size. Microelectrodes in particular do not follow the charge per phase and charge density co-dependence reflected in the Shannon equation. The relevance of these factors to tissue <span class="hlt">damage</span> is framed in the context of available reports from modeling and in vivo studies. Significance It is apparent that emerging applications, especially with microelectrodes, will require clinical charge densities that exceed traditional <span class="hlt">damage</span> thresholds. Experimental data show that stimulation at higher charge densities can be achieved without causing tissue <span class="hlt">damage</span>, suggesting that safety parameters for microelectrodes might be distinct from those defined for macroelectrodes. However, these increased charge densities may need to be justified by bench, non-clinical or clinical testing to provide evidence of device safety</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JNEng..13b1001C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JNEng..13b1001C"><span>Tissue <span class="hlt">damage</span> thresholds during therapeutic electrical stimulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cogan, Stuart F.; Ludwig, Kip A.; Welle, Cristin G.; Takmakov, Pavel</p> <p>2016-04-01</p> <p>Objective. Recent initiatives in bioelectronic modulation of the nervous system by the NIH (SPARC), DARPA (ElectRx, SUBNETS) and the GlaxoSmithKline Bioelectronic Medicines effort are ushering in a new era of therapeutic electrical stimulation. These novel therapies are prompting a re-evaluation of established electrical thresholds for stimulation-induced tissue <span class="hlt">damage</span>. Approach. In this review, we explore what is known and unknown in published literature regarding tissue <span class="hlt">damage</span> from electrical stimulation. Main results. For macroelectrodes, the potential for tissue <span class="hlt">damage</span> is often assessed by comparing the intensity of stimulation, characterized by the charge density and charge per phase of a stimulus pulse, with a <span class="hlt">damage</span> threshold identified through histological evidence from in vivo experiments as described by the Shannon equation. While the Shannon equation has proved useful in assessing the likely occurrence of tissue <span class="hlt">damage</span>, the analysis is limited by the experimental parameters of the original studies. Tissue <span class="hlt">damage</span> is influenced by factors not explicitly incorporated into the Shannon equation, including pulse <span class="hlt">frequency</span>, duty cycle, current density, and electrode size. Microelectrodes in particular do not follow the charge per phase and charge density co-dependence reflected in the Shannon equation. The relevance of these factors to tissue <span class="hlt">damage</span> is framed in the context of available reports from modeling and in vivo studies. Significance. It is apparent that emerging applications, especially with microelectrodes, will require clinical charge densities that exceed traditional <span class="hlt">damage</span> thresholds. Experimental data show that stimulation at higher charge densities can be achieved without causing tissue <span class="hlt">damage</span>, suggesting that safety parameters for microelectrodes might be distinct from those defined for macroelectrodes. However, these increased charge densities may need to be justified by bench, non-clinical or clinical testing to provide evidence of device</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26792176','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26792176"><span>Tissue <span class="hlt">damage</span> thresholds during therapeutic electrical stimulation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cogan, Stuart F; Ludwig, Kip A; Welle, Cristin G; Takmakov, Pavel</p> <p>2016-04-01</p> <p>Recent initiatives in bioelectronic modulation of the nervous system by the NIH (SPARC), DARPA (ElectRx, SUBNETS) and the GlaxoSmithKline Bioelectronic Medicines effort are ushering in a new era of therapeutic electrical stimulation. These novel therapies are prompting a re-evaluation of established electrical thresholds for stimulation-induced tissue <span class="hlt">damage</span>. In this review, we explore what is known and unknown in published literature regarding tissue <span class="hlt">damage</span> from electrical stimulation. For macroelectrodes, the potential for tissue <span class="hlt">damage</span> is often assessed by comparing the intensity of stimulation, characterized by the charge density and charge per phase of a stimulus pulse, with a <span class="hlt">damage</span> threshold identified through histological evidence from in vivo experiments as described by the Shannon equation. While the Shannon equation has proved useful in assessing the likely occurrence of tissue <span class="hlt">damage</span>, the analysis is limited by the experimental parameters of the original studies. Tissue <span class="hlt">damage</span> is influenced by factors not explicitly incorporated into the Shannon equation, including pulse <span class="hlt">frequency</span>, duty cycle, current density, and electrode size. Microelectrodes in particular do not follow the charge per phase and charge density co-dependence reflected in the Shannon equation. The relevance of these factors to tissue <span class="hlt">damage</span> is framed in the context of available reports from modeling and in vivo studies. It is apparent that emerging applications, especially with microelectrodes, will require clinical charge densities that exceed traditional <span class="hlt">damage</span> thresholds. Experimental data show that stimulation at higher charge densities can be achieved without causing tissue <span class="hlt">damage</span>, suggesting that safety parameters for microelectrodes might be distinct from those defined for macroelectrodes. However, these increased charge densities may need to be justified by bench, non-clinical or clinical testing to provide evidence of device safety.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150005474&hterms=hard+rock+drilling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dhard%2Brock%2Bdrilling','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150005474&hterms=hard+rock+drilling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dhard%2Brock%2Bdrilling"><span>Evaluating <span class="hlt">Core</span> Quality for a Mars Sample Return Mission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weiss, D. K.; Budney, C.; Shiraishi, L.; Klein, K.</p> <p>2012-01-01</p> <p>Sample return missions, including the proposed Mars Sample Return (MSR) mission, propose to collect <span class="hlt">core</span> samples from scientifically valuable sites on Mars. These <span class="hlt">core</span> samples would undergo extreme forces during the drilling process, and during the reentry process if the EEV (Earth Entry Vehicle) performed a hard landing on Earth. Because of the foreseen <span class="hlt">damage</span> to the stratigraphy of the <span class="hlt">cores</span>, it is important to evaluate each <span class="hlt">core</span> for rock quality. However, because no <span class="hlt">core</span> sample return mission has yet been conducted to another planetary body, it remains unclear as to how to assess the <span class="hlt">cores</span> for rock quality. In this report, we describe the development of a metric designed to quantitatively assess the mechanical quality of any rock <span class="hlt">cores</span> returned from Mars (or other planetary bodies). We report on the process by which we tested the metric on <span class="hlt">core</span> samples of Mars analogue materials, and the effectiveness of the <span class="hlt">core</span> assessment metric (CAM) in assessing rock <span class="hlt">core</span> quality before and after the <span class="hlt">cores</span> were subjected to shocking (g forces representative of an EEV landing).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150005474&hterms=shocking&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dshocking','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150005474&hterms=shocking&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dshocking"><span>Evaluating <span class="hlt">Core</span> Quality for a Mars Sample Return Mission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weiss, D. K.; Budney, C.; Shiraishi, L.; Klein, K.</p> <p>2012-01-01</p> <p>Sample return missions, including the proposed Mars Sample Return (MSR) mission, propose to collect <span class="hlt">core</span> samples from scientifically valuable sites on Mars. These <span class="hlt">core</span> samples would undergo extreme forces during the drilling process, and during the reentry process if the EEV (Earth Entry Vehicle) performed a hard landing on Earth. Because of the foreseen <span class="hlt">damage</span> to the stratigraphy of the <span class="hlt">cores</span>, it is important to evaluate each <span class="hlt">core</span> for rock quality. However, because no <span class="hlt">core</span> sample return mission has yet been conducted to another planetary body, it remains unclear as to how to assess the <span class="hlt">cores</span> for rock quality. In this report, we describe the development of a metric designed to quantitatively assess the mechanical quality of any rock <span class="hlt">cores</span> returned from Mars (or other planetary bodies). We report on the process by which we tested the metric on <span class="hlt">core</span> samples of Mars analogue materials, and the effectiveness of the <span class="hlt">core</span> assessment metric (CAM) in assessing rock <span class="hlt">core</span> quality before and after the <span class="hlt">cores</span> were subjected to shocking (g forces representative of an EEV landing).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18290238','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18290238"><span>Measurement of a <span class="hlt">damaged</span> layer thickness with reflection acoustic microscope.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ishikawa, I; Kanda, H; Katakura, K; Semba, T</p> <p>1989-01-01</p> <p>An acoustic microscope was used for determining the <span class="hlt">frequency</span> dependence of surface acoustic wave (SAW) velocity on a specimen whose silicon single-crystal surface was machined under various conditions. Consequently, thickness of the <span class="hlt">damaged</span> layers could be estimated from the curvature points of <span class="hlt">frequency</span> dispersion curves of the SAW velocity. It was revealed that thicknesses of the <span class="hlt">damaged</span> layers can be estimated through rough approximation by about one-half the wavelength determined by the <span class="hlt">frequency</span> at curvature points. From specimens possessing two <span class="hlt">damaged</span> layers, <span class="hlt">frequency</span> dispersion curves with two curvature lines can be obtained. From the curvature point at high <span class="hlt">frequencies</span> the thickness of the top <span class="hlt">damaged</span> layer can be determined. On the other hand, from the curvature point at low <span class="hlt">frequencies</span>, the thickness of the inner <span class="hlt">damaged</span> layer can also be determined. By choosing an acoustic lens as the condition for exciting SAWs, images can be observed while varying the <span class="hlt">frequency</span>. From observation results obtained with this method, the distribution in the depth direction can be clarified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JSV...315..591M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JSV...315..591M"><span>Large amplitude vibrations and <span class="hlt">damage</span> detection of rectangular plates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Manoach, Emil; Trendafilova, Irina</p> <p>2008-08-01</p> <p>In this work, geometrically nonlinear vibrations of fully clamped rectangular plates are used to study the sensitivity of some nonlinear vibration response parameters to the presence of <span class="hlt">damage</span>. The geometrically nonlinear version of the Mindlin plate theory is used to model the plate behaviour. <span class="hlt">Damage</span> is represented as a stiffness reduction in a small area of the plate. The plate is subjected to harmonic loading with a <span class="hlt">frequency</span> of excitation close to the first natural <span class="hlt">frequency</span> leading to large amplitude vibrations. The plate vibration response is obtained by a pseudo-load mode superposition method. The main results are focussed on establishing the influence of <span class="hlt">damage</span> on the vibration response of the plate and the change in the time-history diagrams and the Poincaré maps caused by the <span class="hlt">damage</span>. Finally, a criterion and a <span class="hlt">damage</span> index for detecting the presence and the location of the <span class="hlt">damage</span> is proposed. The criterion is based on analysing the points in the Poincaré sections of the <span class="hlt">damaged</span> and healthy plate. Numerical results for large amplitude vibrations of <span class="hlt">damaged</span> and healthy rectangular and square plates are presented and the proposed <span class="hlt">damage</span> index for the considered cases is calculated. The criterion demonstrates quite good abilities to detect and localize <span class="hlt">damage</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=rehabilitation&id=EJ1110561','ERIC'); return false;" href="http://eric.ed.gov/?q=rehabilitation&id=EJ1110561"><span>Can Psychiatric Rehabilitation Be <span class="hlt">Core</span> to <span class="hlt">CORE</span>?</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Olney, Marjorie F.; Gill, Kenneth J.</p> <p>2016-01-01</p> <p>Purpose: In this article, we seek to determine whether psychiatric rehabilitation principles and practices have been more fully incorporated into the Council on Rehabilitation Education (<span class="hlt">CORE</span>) standards, the extent to which they are covered in four rehabilitation counseling "foundations" textbooks, and how they are reflected in the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=core&pg=4&id=EJ1110561','ERIC'); return false;" href="https://eric.ed.gov/?q=core&pg=4&id=EJ1110561"><span>Can Psychiatric Rehabilitation Be <span class="hlt">Core</span> to <span class="hlt">CORE</span>?</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Olney, Marjorie F.; Gill, Kenneth J.</p> <p>2016-01-01</p> <p>Purpose: In this article, we seek to determine whether psychiatric rehabilitation principles and practices have been more fully incorporated into the Council on Rehabilitation Education (<span class="hlt">CORE</span>) standards, the extent to which they are covered in four rehabilitation counseling "foundations" textbooks, and how they are reflected in the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030016668','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030016668"><span>Probabilistic Evaluation of Blade Impact <span class="hlt">Damage</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chamis, C. C.; Abumeri, G. H.</p> <p>2003-01-01</p> <p>The response to high velocity impact of a composite blade is probabilistically evaluated. The evaluation is focused on quantifying probabilistically the effects of uncertainties (scatter) in the variables that describe the impact, the blade make-up (geometry and material), the blade response (displacements, strains, stresses, <span class="hlt">frequencies</span>), the blade residual strength after impact, and the blade <span class="hlt">damage</span> tolerance. The results of probabilistic evaluations results are in terms of probability cumulative distribution functions and probabilistic sensitivities. Results show that the blade has relatively low <span class="hlt">damage</span> tolerance at 0.999 probability of structural failure and substantial at 0.01 probability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970027072','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970027072"><span>Detecting Tooth <span class="hlt">Damage</span> in Geared Drive Trains</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nachtsheim, Philip R.</p> <p>1997-01-01</p> <p>This paper describes a method that was developed to detect gear tooth <span class="hlt">damage</span> that does not require a priori knowledge of the <span class="hlt">frequency</span> characteristic of the fault. The basic idea of the method is that a few <span class="hlt">damaged</span> teeth will cause transient load fluctuations unlike the normal tooth load fluctuations. The method attempts to measure the energy in the lower side bands of the modulated signal caused by the transient load fluctuations. The method monitors the energy in the <span class="hlt">frequency</span> interval which excludes the <span class="hlt">frequency</span> of the lowest dominant normal tooth load fluctuation and all <span class="hlt">frequencies</span> above it. The method reacted significantly to the tooth fracture <span class="hlt">damage</span> results documented in the Lewis data sets which were obtained from tests of the OH-58A transmission and tests of high contact ratio spiral bevel gears. The method detected gear tooth fractures in all four of the high contact ratio spiral bevel gear runs. Published results indicate other detection methods were only able to detect faults for three out of four runs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21054984','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21054984"><span>NDE of <span class="hlt">Damage</span> in Aircraft Flight Control Surfaces</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hsu, David K.; Barnard, Daniel J.; Dayal, Vinay</p> <p>2007-03-21</p> <p>Flight control surfaces on an aircraft, such as ailerons, flaps, spoilers and rudders, are typically adhesively bonded composite or aluminum honeycomb sandwich structures. These components can suffer from <span class="hlt">damage</span> caused by hail stone, runway debris, or dropped tools during maintenance. On composites, low velocity impact <span class="hlt">damages</span> can escape visual inspection, whereas on aluminum honeycomb sandwich, budding failure of the honeycomb <span class="hlt">core</span> may or may not be accompanied by a disbond. This paper reports a study of the <span class="hlt">damage</span> morphology in such structures and the NDE methods for detecting and characterizing them. Impact <span class="hlt">damages</span> or overload failures in composite sandwiches with Nomex or fiberglass <span class="hlt">core</span> tend to be a fracture or crinkle or the honeycomb cell wall located a distance below the facesheet-to-<span class="hlt">core</span> bondline. The <span class="hlt">damage</span> in aluminum honeycomb is usually a buckling failure, propagating from the top skin downward. The NDE methods used in this work for mapping out these <span class="hlt">damages</span> were: air-coupled ultrasonic scan, and imaging by computer aided tap tester. Representative results obtained from the field will be shown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AIPC..894..975H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AIPC..894..975H"><span>NDE of <span class="hlt">Damage</span> in Aircraft Flight Control Surfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hsu, David K.; Barnard, Daniel J.; Dayal, Vinay</p> <p>2007-03-01</p> <p>Flight control surfaces on an aircraft, such as ailerons, flaps, spoilers and rudders, are typically adhesively bonded composite or aluminum honeycomb sandwich structures. These components can suffer from <span class="hlt">damage</span> caused by hail stone, runway debris, or dropped tools during maintenance. On composites, low velocity impact <span class="hlt">damages</span> can escape visual inspection, whereas on aluminum honeycomb sandwich, budding failure of the honeycomb <span class="hlt">core</span> may or may not be accompanied by a disbond. This paper reports a study of the <span class="hlt">damage</span> morphology in such structures and the NDE methods for detecting and characterizing them. Impact <span class="hlt">damages</span> or overload failures in composite sandwiches with Nomex or fiberglass <span class="hlt">core</span> tend to be a fracture or crinkle or the honeycomb cell wall located a distance below the facesheet-to-<span class="hlt">core</span> bondline. The <span class="hlt">damage</span> in aluminum honeycomb is usually a buckling failure, propagating from the top skin downward. The NDE methods used in this work for mapping out these <span class="hlt">damages</span> were: air-coupled ultrasonic scan, and imaging by computer aided tap tester. Representative results obtained from the field will be shown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020080258','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020080258"><span>War <span class="hlt">Damage</span> Assessment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1994-01-01</p> <p>During and after the Persian Gulf war, hundreds of "oil lakes" were created in Kuwait by oil released from <span class="hlt">damaged</span> wells. The lakes are a hazard to the Kuwait atmosphere, soil and ground water and must be carefully monitored. Boston University Center for Remote Sensing, assisted by other organizations, has accurately mapped the lakes using Landsat and Spot imagery. The war <span class="hlt">damage</span> included the formation of over 300 oil lakes, oil pollution and sand dune movement. Total <span class="hlt">damage</span> area is over 5,400 square kilometers - 30 percent of Kuwait's total surface area.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=educational+AND+standards+AND+american&pg=6&id=EJ1063965','ERIC'); return false;" href="http://eric.ed.gov/?q=educational+AND+standards+AND+american&pg=6&id=EJ1063965"><span>More on the <span class="hlt">Core</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Chan, Monnica</p> <p>2013-01-01</p> <p>From a higher education perspective, new "Common <span class="hlt">Core</span>" standards could improve student college-readiness levels, reduce institutional remediation rates, and close education gaps in and between states. As a national initiative to create common educational standards for students across multiple states, the Common <span class="hlt">Core</span> State Standards…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016DPS....4811703D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016DPS....4811703D"><span>Mercury's <span class="hlt">core</span> evolution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Deproost, Marie-Hélène; Rivoldini, Attilio; Van Hoolst, Tim</p> <p>2016-10-01</p> <p>Remote sensing data of Mercury's surface by MESSENGER indicate that Mercury formed under reducing conditions. As a consequence, silicon is likely the main light element in the <span class="hlt">core</span> together with a possible small fraction of sulfur. Compared to sulfur, which does almost not partition into solid iron at Mercury's <span class="hlt">core</span> conditions and strongly decreases the melting temperature, silicon partitions almost equally well between solid and liquid iron and is not very effective at reducing the melting temperature of iron. Silicon as the major light element constituent instead of sulfur therefore implies a significantly higher <span class="hlt">core</span> liquidus temperature and a decrease in the vigor of compositional convection generated by the release of light elements upon inner <span class="hlt">core</span> formation.Due to the immiscibility in liquid Fe-Si-S at low pressure (below 15 GPa), the <span class="hlt">core</span> might also not be homogeneous and consist of an inner S-poor Fe-Si <span class="hlt">core</span> below a thinner Si-poor Fe-S layer. Here, we study the consequences of a silicon-rich <span class="hlt">core</span> and the effect of the blanketing Fe-S layer on the thermal evolution of Mercury's <span class="hlt">core</span> and on the generation of a magnetic field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Glaciers&pg=3&id=EJ572533','ERIC'); return false;" href="http://eric.ed.gov/?q=Glaciers&pg=3&id=EJ572533"><span>Making an Ice <span class="hlt">Core</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kopaska-Merkel, David C.</p> <p>1995-01-01</p> <p>Explains an activity in which students construct a simulated ice <span class="hlt">core</span>. Materials required include only a freezer, food coloring, a bottle, and water. This hands-on exercise demonstrates how a glacier is formed, how ice <span class="hlt">cores</span> are studied, and the nature of precision and accuracy in measurement. Suitable for grades three through eight. (Author/PVD)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Glaciers&id=EJ809662','ERIC'); return false;" href="http://eric.ed.gov/?q=Glaciers&id=EJ809662"><span>Ice <span class="hlt">Core</span> Investigations</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Krim, Jessica; Brody, Michael</p> <p>2008-01-01</p> <p>What can glaciers tell us about volcanoes and atmospheric conditions? How does this information relate to our understanding of climate change? Ice <span class="hlt">Core</span> Investigations is an original and innovative activity that explores these types of questions. It brings together popular science issues such as research, climate change, ice <span class="hlt">core</span> drilling, and air…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=industrial+AND+communication+AND+networks&pg=6&id=ED207612','ERIC'); return false;" href="http://eric.ed.gov/?q=industrial+AND+communication+AND+networks&pg=6&id=ED207612"><span>NFE <span class="hlt">Core</span> Bibliographies.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Michigan State Univ., East Lansing. Inst. for International Studies in Education.</p> <p></p> <p>This collection of <span class="hlt">core</span> bibliographies, which expands on an initial bibliography published in 1979 of the <span class="hlt">core</span> resources housed in the Non-Formal Education Information Center at Michigan State University, comprises a basic stock of materials on nonformal education and women in development that have been contributed by development planners,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=drilling&pg=2&id=EJ809662','ERIC'); return false;" href="https://eric.ed.gov/?q=drilling&pg=2&id=EJ809662"><span>Ice <span class="hlt">Core</span> Investigations</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Krim, Jessica; Brody, Michael</p> <p>2008-01-01</p> <p>What can glaciers tell us about volcanoes and atmospheric conditions? How does this information relate to our understanding of climate change? Ice <span class="hlt">Core</span> Investigations is an original and innovative activity that explores these types of questions. It brings together popular science issues such as research, climate change, ice <span class="hlt">core</span> drilling, and air…</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Participating+AND+Local+AND+Government&pg=4&id=EJ1063965','ERIC'); return false;" href="https://eric.ed.gov/?q=Participating+AND+Local+AND+Government&pg=4&id=EJ1063965"><span>More on the <span class="hlt">Core</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Chan, Monnica</p> <p>2013-01-01</p> <p>From a higher education perspective, new "Common <span class="hlt">Core</span>" standards could improve student college-readiness levels, reduce institutional remediation rates, and close education gaps in and between states. As a national initiative to create common educational standards for students across multiple states, the Common <span class="hlt">Core</span> State Standards…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1231229','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1231229"><span><span class="hlt">CORE</span> - Performance Feedback System</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p></p> <p>2009-10-02</p> <p><span class="hlt">CORE</span> is an architecture to bridge the gaps between disparate data integration and delivery of disparate information visualization. The <span class="hlt">CORE</span> Technology Program includes a suite of tools and user-centered staff that can facilitate rapid delivery of a deployable integrated information to users.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5383815','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5383815"><span>Modular <span class="hlt">core</span> holder</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mueller, J.; Cole, C.W.; Hamid, S.; Lucas, J.K.</p> <p>1991-03-05</p> <p>This patent describes a modular <span class="hlt">core</span> holder. It comprises: a sleeve, forming an internal cavity for receiving a <span class="hlt">core</span>. The sleeve including segments; support means, overlying the sleeve, for supporting the sleeve; and access means, positioned between at least two of the segments of the sleeve, for allowing measurement of conditions within the internal cavity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=glaciers&pg=3&id=EJ572533','ERIC'); return false;" href="https://eric.ed.gov/?q=glaciers&pg=3&id=EJ572533"><span>Making an Ice <span class="hlt">Core</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kopaska-Merkel, David C.</p> <p>1995-01-01</p> <p>Explains an activity in which students construct a simulated ice <span class="hlt">core</span>. Materials required include only a freezer, food coloring, a bottle, and water. This hands-on exercise demonstrates how a glacier is formed, how ice <span class="hlt">cores</span> are studied, and the nature of precision and accuracy in measurement. Suitable for grades three through eight. (Author/PVD)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED561977.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED561977.pdf"><span>Iowa <span class="hlt">Core</span> Annual Report</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Iowa Department of Education, 2015</p> <p>2015-01-01</p> <p>One central component of a great school system is a clear set of expectations, or standards, that educators help all students reach. In Iowa, that effort is known as the Iowa <span class="hlt">Core</span>. The Iowa <span class="hlt">Core</span> represents the statewide academic standards, which describe what students should know and be able to do in math, science, English language arts, and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..MARY16002W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..MARY16002W"><span><span class="hlt">Frequency</span> dependence of organic magnetoresistance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Fujian; Rybicki, James; Lin, Ran; Hutchinson, Kent; Hou, Jia; Wohlgenannt, Markus</p> <p>2011-03-01</p> <p>Organic magnetoresistive (OMAR) devices show a large enough magnetoresistive response (typically 10%) for potential applications as magnetic field sensors. However, applications often require sensing high <span class="hlt">frequency</span> magnetic fields, and the examination of the <span class="hlt">frequency</span>-dependent magnetoresistive response is therefore required. Analysis of time constants that limit the <span class="hlt">frequency</span> response may also shed light on the mechanism behind the OMAR effect, because different OMAR mechanisms occur at different time scales In our experiments, the AC magnetic field is supplied by a coil with a ferrite <span class="hlt">core</span> which is driven by a function generator The AC magnet shows a <span class="hlt">frequency</span> response that is almost flat up to 1MHz. We found that the OMAR <span class="hlt">frequency</span> limit is about 10 kHz for a typical organic semiconductor device and at least 100 kHz for devices made from a doped polymer film. We also performed capacitance and conductance vs. <span class="hlt">frequency</span> measurements to understand the origin of the observed limit <span class="hlt">frequencies</span>. This work was supported by Army MURI under GrantNo. W911NF-08-1-0317 and NSF under Grant No. ECS 0725280.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23999403','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23999403"><span>Errors, error detection, error correction and hippocampal-region <span class="hlt">damage</span>: data and theories.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>MacKay, Donald G; Johnson, Laura W</p> <p>2013-11-01</p> <p>This review and perspective article outlines 15 observational constraints on theories of errors, error detection, and error correction, and their relation to hippocampal-region (HR) <span class="hlt">damage</span>. The <span class="hlt">core</span> observations come from 10 studies with H.M., an amnesic with cerebellar and HR <span class="hlt">damage</span> but virtually no neocortical <span class="hlt">damage</span>. Three studies examined the detection of errors planted in visual scenes (e.g., a bird flying in a fish bowl in a school classroom) and sentences (e.g., I helped themselves to the birthday cake). In all three experiments, H.M. detected reliably fewer errors than carefully matched memory-normal controls. Other studies examined the detection and correction of self-produced errors, with controls for comprehension of the instructions, impaired visual acuity, temporal factors, motoric slowing, forgetting, excessive memory load, lack of motivation, and deficits in visual scanning or attention. In these studies, H.M. corrected reliably fewer errors than memory-normal and cerebellar controls, and his uncorrected errors in speech, object naming, and reading aloud exhibited two consistent features: omission and anomaly. For example, in sentence production tasks, H.M. omitted one or more words in uncorrected encoding errors that rendered his sentences anomalous (incoherent, incomplete, or ungrammatical) reliably more often than controls. Besides explaining these <span class="hlt">core</span> findings, the theoretical principles discussed here explain H.M.'s retrograde amnesia for once familiar episodic and semantic information; his anterograde amnesia for novel information; his deficits in visual cognition, sentence comprehension, sentence production, sentence reading, and object naming; and effects of aging on his ability to read isolated low <span class="hlt">frequency</span> words aloud. These theoretical principles also explain a wide range of other data on error detection and correction and generate new predictions for future test.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11449282','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11449282"><span>Mars' <span class="hlt">core</span> and magnetism.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stevenson, D J</p> <p>2001-07-12</p> <p>The detection of strongly magnetized ancient crust on Mars is one of the most surprising outcomes of recent Mars exploration, and provides important insight about the history and nature of the martian <span class="hlt">core</span>. The iron-rich <span class="hlt">core</span> probably formed during the hot accretion of Mars approximately 4.5 billion years ago and subsequently cooled at a rate dictated by the overlying mantle. A <span class="hlt">core</span> dynamo operated much like Earth's current dynamo, but was probably limited in duration to several hundred million years. The early demise of the dynamo could have arisen through a change in the cooling rate of the mantle, or even a switch in convective style that led to mantle heating. Presently, Mars probably has a liquid, conductive outer <span class="hlt">core</span> and might have a solid inner <span class="hlt">core</span> like Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040062389&hterms=k2&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dk2','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040062389&hterms=k2&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dk2"><span>Lunar <span class="hlt">Core</span> and Tides</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.</p> <p>2004-01-01</p> <p>Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-<span class="hlt">core</span>/solid-mantle boundary, and tidal Love number k2 [1,2]. There is weaker sensitivity to flattening of the <span class="hlt">core</span>-mantle boundary (CMB) [2,3,4] and fluid <span class="hlt">core</span> moment of inertia [1]. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to lunar rotation and orientation variations and tidal displacements. Past solutions using the LLR data have given results for dissipation due to solid-body tides and fluid <span class="hlt">core</span> [1] plus Love number [1-5]. Detection of CMB flattening, which in the past has been marginal but improving [3,4,5], now seems significant. Direct detection of the <span class="hlt">core</span> moment has not yet been achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/862581','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/862581"><span>Internal <span class="hlt">core</span> tightener</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Brynsvold, Glen V.; Snyder, Jr., Harold J.</p> <p>1976-06-22</p> <p>An internal <span class="hlt">core</span> tightener which is a linear actuated (vertical actuation motion) expanding device utilizing a minimum of moving parts to perform the lateral tightening function. The key features are: (1) large contact areas to transmit loads during reactor operation; (2) actuation cam surfaces loaded only during clamping and unclamping operation; (3) separation of the parts and internal operation involved in the holding function from those involved in the actuation function; and (4) preloaded pads with compliant travel at each face of the hexagonal assembly at the two clamping planes to accommodate thermal expansion and irradiation induced swelling. The latter feature enables use of a "fixed" outer <span class="hlt">core</span> boundary, and thus eliminates the uncertainty in gross <span class="hlt">core</span> dimensions, and potential for rapid <span class="hlt">core</span> reactivity changes as a result of <span class="hlt">core</span> dimensional change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040062389&hterms=tide&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dtide','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040062389&hterms=tide&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dtide"><span>Lunar <span class="hlt">Core</span> and Tides</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.</p> <p>2004-01-01</p> <p>Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-<span class="hlt">core</span>/solid-mantle boundary, and tidal Love number k2 [1,2]. There is weaker sensitivity to flattening of the <span class="hlt">core</span>-mantle boundary (CMB) [2,3,4] and fluid <span class="hlt">core</span> moment of inertia [1]. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to lunar rotation and orientation variations and tidal displacements. Past solutions using the LLR data have given results for dissipation due to solid-body tides and fluid <span class="hlt">core</span> [1] plus Love number [1-5]. Detection of CMB flattening, which in the past has been marginal but improving [3,4,5], now seems significant. Direct detection of the <span class="hlt">core</span> moment has not yet been achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130008790','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130008790"><span>In-Situ Wire <span class="hlt">Damage</span> Detection System</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, Martha; Roberson, Luke; Tate, Lanetra; Smith, Trent; Gibson, Tracy; Medelius, Pedro; Jolley, Scott</p> <p>2012-01-01</p> <p>An In-Situ Wire <span class="hlt">Damage</span> Detection System (ISWDDS) has been developed that is capable of detecting <span class="hlt">damage</span> to a wire insulation, or a wire conductor, or to both. The system will allow for realtime, continuous monitoring of wiring health/integrity and reduce the number of false negatives and false positives while being smaller, lighter in weight, and more robust than current systems. The technology allows for improved safety and significant reduction in maintenance hours for aircraft, space vehicles, satellites, and other critical high-performance wiring systems for industries such as energy production and mining. The integrated ISWDDS is comprised of two main components: (1) a wire with an innermost <span class="hlt">core</span> conductor, an inner insulation film, a conductive layer or inherently conductive polymer (ICP) covering the inner insulation film, an outermost insulation jacket; and (2) smart connectors and electronics capable of producing and detecting electronic signals, and a central processing unit (CPU) for data collection and analysis. The wire is constructed by applying the inner insulation films to the conductor, followed by the outer insulation jacket. The conductive layer or ICP is on the outer surface of the inner insulation film. One or more wires are connected to the CPU using the smart connectors, and up to 64 wires can be monitored in real-time. The ISWDDS uses time domain reflectometry for <span class="hlt">damage</span> detection. A fast-risetime pulse is injected into either the <span class="hlt">core</span> conductor or conductive layer and referenced against the other conductor, producing transmission line behavior. If either conductor is <span class="hlt">damaged</span>, then the signal is reflected. By knowing the speed of propagation of the pulse, and the time it takes to reflect, one can calculate the distance to and location of the <span class="hlt">damage</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMDI41A1925K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMDI41A1925K"><span>Viscosity of the Earth's inner <span class="hlt">core</span>: constraints from nutation observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koot, L.; Dumberry, M.</p> <p>2010-12-01</p> <p>Nutations are the variations in the orientation of the Earth’s rotation axis in a space-fixed reference frame. This motion shows two important normal modes, the Free <span class="hlt">Core</span> Nutation (FCN) and the Free Inner <span class="hlt">Core</span> Nutation (FICN), of which the <span class="hlt">frequencies</span> and damping depend directly on the Earth’s interior structure and dynamics. The FICN is characterized by a differential rotation of the inner <span class="hlt">core</span> relative to the mantle and outer <span class="hlt">core</span>. Its natural <span class="hlt">frequency</span> is thus directly affected both by the strength of the mechanical coupling at the inner <span class="hlt">core</span> boundary (ICB) and by the way the inner <span class="hlt">core</span> deforms due to centrifugal forces. Similarly, the damping of the mode reflects the energy dissipated both through the coupling at the ICB and through inner <span class="hlt">core</span> deformation. Estimations of the ICB coupling strength and dissipation have been obtained previously from nutation observations by assuming a purely elastic inner <span class="hlt">core</span> (Mathews et al. 2002, Koot et al. 2010). When interpreted in terms of a visco-magnetic coupling, these estimations lead to values of the magnetic field at the ICB around 6-7 mT and to a kinematic viscosity of the fluid <span class="hlt">core</span> close to the ICB in the range of 10-30 m2 s-1. This value of the ICB fluid <span class="hlt">core</span> viscosity is orders of magnitude larger than what is expected from laboratory measurements and ‘ab initio’ computations. In this work, we show that a visco-elastic inner <span class="hlt">core</span> is able to reconcile the estimation of the outer <span class="hlt">core</span> kinematic viscosity with that of laboratory measurements and ab initio computations. This reconciliation is achieved for a very narrow range of values of the inner <span class="hlt">core</span> viscosity, which can be considered as a nutation constraint on this physical quantity. Finally, we show that this nutation constraint is in very good agreement with seismic observations of shear waves attenuation in the inner <span class="hlt">core</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/ency/article/000693.htm','NIH-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/ency/article/000693.htm"><span>Diabetes and nerve <span class="hlt">damage</span></span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>Diabetic neuropathy; Diabetes - neuropathy; Diabetes - peripheral neuropathy ... In people with diabetes, the body's nerves can be <span class="hlt">damaged</span> by decreased blood flow and a high blood sugar level. This condition is ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-KSC-20161008-PH-CSH01_0174.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-KSC-20161008-PH-CSH01_0174.html"><span>Hurricane Matthew <span class="hlt">Damage</span> Survey</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2016-10-08</p> <p><span class="hlt">Damaged</span> power lines are seen during an aerial survey of NASA's Kennedy Space Center in Florida on Saturday. The survey was performed to identify structures and facilities that may have sustained <span class="hlt">damage</span> from Hurricane Matthew as the storm passed to the east of Kennedy on Oct. 6 and 7, 2016. Officials determined that the center received some isolated roof <span class="hlt">damage</span>, <span class="hlt">damaged</span> support buildings, a few downed power lines, and limited water intrusion. Beach erosion also occurred, although the storm surge was less than expected. NASA closed the center ahead of the storm’s onset and only a small team of specialists known as the Rideout Team was on the center as the storm approached and passed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Carcinogen&pg=2&id=EJ038946','ERIC'); return false;" href="https://eric.ed.gov/?q=Carcinogen&pg=2&id=EJ038946"><span>LSD and Genetic <span class="hlt">Damage</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Dishotsky, Norman I.; And Others</p> <p>1971-01-01</p> <p>Reviews studies of the effects of lysergic acid diethylamide (LSD) on man and other organisms. Concludes that pure LSD injected in moderate doses does not cause chromosome or detectable genetic <span class="hlt">damage</span> and is not a teratogen or carcinogen. (JM)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=construction+AND+cost+AND+control&pg=7&id=EJ130934','ERIC'); return false;" href="http://eric.ed.gov/?q=construction+AND+cost+AND+control&pg=7&id=EJ130934"><span>Court Disallows <span class="hlt">Damage</span> Claims</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Tomson, Bernard; Coplan, Norman</p> <p>1976-01-01</p> <p>In rejecting claims for <span class="hlt">damages</span>, the Court finds that contract's "increase or decrease of cost" language is not applicable to added overhead costs and loss of labor efficiency resulting from delays over which the contractor has no control. (Author)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Carcinogen&pg=2&id=EJ038946','ERIC'); return false;" href="http://eric.ed.gov/?q=Carcinogen&pg=2&id=EJ038946"><span>LSD and Genetic <span class="hlt">Damage</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Dishotsky, Norman I.; And Others</p> <p>1971-01-01</p> <p>Reviews studies of the effects of lysergic acid diethylamide (LSD) on man and other organisms. Concludes that pure LSD injected in moderate doses does not cause chromosome or detectable genetic <span class="hlt">damage</span> and is not a teratogen or carcinogen. (JM)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-KSC-20161008-PH-CSH01_01_0049.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-KSC-20161008-PH-CSH01_01_0049.html"><span>Hurricane Matthew <span class="hlt">Damage</span> Survey</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2016-10-08</p> <p><span class="hlt">Damage</span> to a facility roof is seen during an aerial survey of NASA's Kennedy Space Center in Florida on Saturday. The survey was performed to identify structures and facilities that may have sustained <span class="hlt">damage</span> from Hurricane Matthew as the storm passed to the east of Kennedy on Oct. 6 and 7, 2016. Officials determined that the center received some isolated roof <span class="hlt">damage</span>, <span class="hlt">damaged</span> support buildings, a few downed power lines, and limited water intrusion. Beach erosion also occurred, although the storm surge was less than expected. NASA closed the center ahead of the storm’s onset and only a small team of specialists known as the Rideout Team was on the center as the storm approached and passed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-KSC-20161008-PH-CSH01_01_0043.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-KSC-20161008-PH-CSH01_01_0043.html"><span>Hurricane Matthew <span class="hlt">Damage</span> Survey</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2016-10-08</p> <p><span class="hlt">Damage</span> to a facility roof is seen during an aerial survey of NASA's Kennedy Space Center in Florida on Saturday. The survey was performed to identify structures and facilities that may have sustained <span class="hlt">damage</span> from Hurricane Matthew as the storm passed to the east of Kennedy on Oct. 6 and 7, 2016. Officials determined that the center received some isolated roof <span class="hlt">damage</span>, <span class="hlt">damaged</span> support buildings, a few downed power lines, and limited water intrusion. Beach erosion also occurred, although the storm surge was less than expected. NASA closed the center ahead of the storm’s onset and only a small team of specialists known as the Rideout Team was on the center as the storm approached and passed</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070002671','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070002671"><span>Composites <span class="hlt">Damage</span> Tolerance Workshop</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gregg, Wayne</p> <p>2006-01-01</p> <p>The Composite <span class="hlt">Damage</span> Tolerance Workshop included participants from NASA, academia, and private industry. The objectives of the workshop were to begin dialogue in order to establish a working group within the Agency, create awareness of <span class="hlt">damage</span> tolerance requirements for Constellation, and discuss potential composite hardware for the Crew Launch Vehicle (CLV) Upper Stage (US) and Crew Module. It was proposed that a composites <span class="hlt">damage</span> tolerance working group be created that acts within the framework of the existing NASA Fracture Control Methodology Panel. The working group charter would be to identify <span class="hlt">damage</span> tolerance gaps and obstacles for implementation of composite structures into manned space flight systems and to develop strategies and recommendations to overcome these obstacles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770010121','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770010121"><span><span class="hlt">Core</span> noise measurements on a YF-102 turbofan engine</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Reshotko, M.; Karchmer, A. M.; Penko, P. F.; Mcardle, J. G.</p> <p>1977-01-01</p> <p><span class="hlt">Core</span> noise from a YF-102 high bypass ratio turbofan engine was investigated through the use of simultaneous measurements of internal fluctuating pressures and far field noise. Acoustic waveguide probes, located in the engine at the compressor exit, in the combustor, at the turbine exit, and in the <span class="hlt">core</span> nozzle, were employed to measure internal fluctuating pressures. Spectra showed that the internal signals were free of tones, except at high <span class="hlt">frequency</span> where machinery noise was present. Data obtained over a wide range of engine conditions suggest that below 60% of maximum fan speed the low <span class="hlt">frequency</span> <span class="hlt">core</span> noise contributes significantly to the far field noise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/3332492','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/3332492"><span>Mechanisms of freezing <span class="hlt">damage</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pegg, D E</p> <p>1987-01-01</p> <p>Freezing of aqueous systems involves numerous simultaneous changes but this review concentrates on direct effects of the formation of ice and the consequent concentration of solutes in the remaining liquid phase. It is generally believed that cell injury at low cooling rates is principally due to the concentration of both intracellular and extracellular electrolytes and that cryoprotectants act by reducing this build-up. New experimental data are presented to support this explanation; we find that the extent of <span class="hlt">damage</span> to human red blood cells during freezing in solutions of sodium chloride/glycerol/water can be quantitatively accounted for by the increase in solute concentration. However, we also show that a given degree of <span class="hlt">damage</span> occurs at lower concentrations of solute in the presence of higher concentrations of glycerol; it appears that glycerol contributes an element of <span class="hlt">damage</span> itself. Recently published studies from Mazur's laboratory have suggested that the dominant <span class="hlt">damaging</span> factor at low cooling rates is actually the reduction of the quantity of unfrozen water rather than the corresponding increase in salt concentration that accompanies freezing. These data are re-evaluated, and it is argued that the experimental results could equally well be explained by a susceptibility of cells to shrinkage and re-expansion as the concentration of external impermeant solutes first increases during freezing and then decreases during thawing. It is concluded that external ice probably has no directly <span class="hlt">damaging</span> effect upon dilute suspensions of cells. However, it is also argued that ice is directly <span class="hlt">damaging</span> whenever it forms intracellularly, and also when it forms extracellularly in densely packed cell suspensions. In the latter case the <span class="hlt">damage</span> is probably due to recrystallization of the ice masses during thawing. Extracellular ice also has a directly <span class="hlt">damaging</span> effect when tissues and organs are frozen. The difficulties of designing experimental methods that will yield</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-KSC-20170111-PH_DNG03_0006.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-KSC-20170111-PH_DNG03_0006.html"><span><span class="hlt">Damage</span> Detection Equipment</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2017-01-11</p> <p>The prototype Flexible <span class="hlt">Damage</span> Detection System stands in a laboratory at NASA's Kennedy Space Center in Florida. The system uses circuits printed on thin thermal film and specialized software. The system is designed to show where <span class="hlt">damage</span> to a surface occurs and how severe it may be. It could offer astronauts a real-time update on their spacecraft's condition during a mission without requiring a spacewalk.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-KSC-20170310-PH_FWM01_0033.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-KSC-20170310-PH_FWM01_0033.html"><span><span class="hlt">Damage</span> Detection Equipment</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2017-03-10</p> <p>Martha Williams, who leads the team inventing the Flexible <span class="hlt">Damage</span> Detection System, stands in a laboratory with a prototype at NASA's Kennedy Space Center in Florida. The system uses circuits printed on thin thermal film and specialized software. The system is designed to show where <span class="hlt">damage</span> to a surface occurs and how severe it may be. It could offer astronauts a real-time update on their spacecraft's condition during a mission without requiring a spacewalk.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-KSC-20170310-PH_FWM01_0089.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-KSC-20170310-PH_FWM01_0089.html"><span><span class="hlt">Damage</span> Detection Equipment</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2017-03-10</p> <p>Jamie Szafran, from left, Mark Lewis and Curtis Ihlefeld work with the prototype of the Flexible <span class="hlt">Damage</span> Detection System in a laboratory with a prototype at NASA's Kennedy Space Center in Florida. The system uses circuits printed on thin thermal film and specialized software. The system is designed to show where <span class="hlt">damage</span> to a surface occurs and how severe it may be. It could offer astronauts a real-time update on their spacecraft's condition during a mission without requiring a spacewalk.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-KSC-20170310-PH_FWM01_0063.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-KSC-20170310-PH_FWM01_0063.html"><span><span class="hlt">Damage</span> Detection Equipment</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2017-03-10</p> <p>Curtis Ihlefeld, left, and Mark Lewis work with the prototype of the Flexible <span class="hlt">Damage</span> Detection System in a laboratory with a prototype at NASA's Kennedy Space Center in Florida. The system uses circuits printed on thin thermal film and specialized software. The system is designed to show where <span class="hlt">damage</span> to a surface occurs and how severe it may be. It could offer astronauts a real-time update on their spacecraft's condition during a mission without requiring a spacewalk.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-KSC-20170111-PH_DNG03_0003.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-KSC-20170111-PH_DNG03_0003.html"><span><span class="hlt">Damage</span> Detection Equipment</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2017-01-11</p> <p>The complete prototype Flexible <span class="hlt">Damage</span> Detection System stands in a laboratory at NASA's Kennedy Space Center in Florida. The system uses circuits printed on thin thermal film and specialized software. The system is designed to show where <span class="hlt">damage</span> to a surface occurs and how severe it may be. It could offer astronauts a real-time update on their spacecraft's condition during a mission without requiring a spacewalk. Photo credit: NASA/Dimitri Gerondidakis</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/al1087.photos.046809p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/al1087.photos.046809p/"><span>34. DESPATCH <span class="hlt">CORE</span> OVENS, GREY IRON FOUNDRY <span class="hlt">CORE</span> ROOM, BAKES ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>34. DESPATCH <span class="hlt">CORE</span> OVENS, GREY IRON FOUNDRY <span class="hlt">CORE</span> ROOM, BAKES <span class="hlt">CORES</span> THAT ARE NOT MADE ON HEATED OR COLD BOX <span class="hlt">CORE</span> MACHINES, TO SET BINDING AGENTS MIXED WITH THE SAND CREATING <span class="hlt">CORES</span> HARD ENOUGH TO WITHSTAND THE FLOW OF MOLTEN IRON INSIDE A MOLD. - Stockham Pipe & Fittings Company, Grey Iron Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9983E..0TM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9983E..0TM"><span>Nanosecond laser <span class="hlt">damage</span> of optical multimode fibers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mann, Guido; Krüger, Jörg</p> <p>2016-07-01</p> <p>For pulse laser materials processing often optical step index and gradient index multimode fibers with <span class="hlt">core</span> diameters ranging from 100 to 600 μm are used. The design of a high power fiber transmission system must take into account limitations resulting from both surface and volume <span class="hlt">damage</span> effects. Especially, breakdown at the fiber end faces and selffocusing in the fiber volume critically influence the fiber performance. At least operation charts are desirable to select the appropriate fiber type for given laser parameters. In industry-relevant studies the influence of fiber <span class="hlt">core</span> diameter and end face preparation on laser-induced (surface) <span class="hlt">damage</span> thresholds (LIDT) was investigated for frequently used all-silica fiber types (manufacturer LEONI). Experiments on preform material (initial fiber material) and compact specimens (models of the cladding and coating material) accompanied the tests performed in accordance with the relevant LIDT standards ISO 21254-1 and ISO 21254-2 for 1-on-1 and S-on-1 irradiation conditions, respectively. The relation beam diameter vs. LIDT was investigated for fused silica fibers. Additionally, laser-induced (bulk) <span class="hlt">damage</span> thresholds of fused silica preform material F300 (manufacturer Heraeus) in dependence on external mechanical stress simulating fiber bending were measured. All experiments were performed with 10-ns laser pulses at 1064 and 532 nm wavelength with a Gaussian beam profile.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10170E..1WP','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10170E..1WP"><span>Precursor to <span class="hlt">damage</span> state quantification in composite materials (Conference Presentation)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Patra, Subir; Banerjee, Sourav</p> <p>2017-04-01</p> <p>Nonlinear <span class="hlt">damage</span> in the composite materials is developed with the growth of <span class="hlt">damages</span> in the material under fatigue loading. Nonlinear ultrasonic techniques are sensitive to early stage <span class="hlt">damages</span> such as, fiber breakages, matrix micro-cracking, and deboning etc. Here, in this work, early stage <span class="hlt">damages</span> are detected in Unidirectional (UD) carbon fiber composite under fatigue loading. Specimens are prepared according to American Society for Testing and Materials (ASTM) standard. Specimens are subjected to low cycle high load (LCHL) fatigue loading until 150,000 cycles. Sensors are mounted on the specimen used for actuation and sensing. A five count tone burst with low <span class="hlt">frequency</span> (fc =375 kHz) followed by high <span class="hlt">frequency</span> (fc =770 kHz) signal, was used as actuation signal. Pitch-catch experiments are collected at the interval of 5,000 cycles. Sensor signals are collected for various excitation voltage (from 5V to 20V, with 5V interval). First Fourier Transform (FFT) of the sensor signals are performed and side band <span class="hlt">frequencies</span> are observed at around 770 kHz. Severity of <span class="hlt">damages</span> in the material is quantified from the ratio of amplitude of side band <span class="hlt">frequencies</span> with the central <span class="hlt">frequency</span>. Nonlinearity in the material due to <span class="hlt">damage</span> development is also investigated from the <span class="hlt">damage</span> growth curve obtained at various excitation amplitude. Optical Microcopy imaging were also performed at the interval of 5,000 to examine developments of <span class="hlt">damages</span> inside the material. This study has a good potential in detection of early stage <span class="hlt">damages</span> in composite materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6424968','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6424968"><span>Three Mile Island Unit-2 <span class="hlt">core</span> status summary: a basis for tool development for reactor disassembly and defueling</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Croucher, D.W.</p> <p>1981-05-01</p> <p>The accident at Three Mile Island Unit-2 (TMI-2) on March 28, 1979 caused extensive <span class="hlt">damage</span> to the <span class="hlt">core</span>. A variety of analyses were performed using three general approaches to determine the extent of <span class="hlt">core</span> <span class="hlt">damage</span>. First, thermal-hydraulic events were reconstructed using available data, thermal-hydraulic principles, and computer analyses. Second, determinations of the hydrogen generated yielded estimates of the amount of zircaloy oxidized and embrittled. Third, the type and quantity of fission products released during the accident were used to estimate the location of <span class="hlt">core</span> <span class="hlt">damage</span> and the fuel temperatures which were achieved. Uncertainties exist in each type of determination due to the equivocal nature of the data. This paper reviews and summarizes the <span class="hlt">core</span> <span class="hlt">damage</span> assessments which have been made, identifies the minimum and maximum bounds of <span class="hlt">damage</span>, and establishes a reference description for the current status of the <span class="hlt">core</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110013366','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110013366"><span>Enhanced <span class="hlt">Core</span> Noise Modeling for Turbofan Engines</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stone, James R.; Krejsa, Eugene A.; Clark, Bruce J.</p> <p>2011-01-01</p> <p>This report describes work performed by MTC Technologies (MTCT) for NASA Glenn Research Center (GRC) under Contract NAS3-00178, Task Order No. 15. MTCT previously developed a first-generation empirical model that correlates the <span class="hlt">core</span>/combustion noise of four GE engines, the CF6, CF34, CFM56, and GE90 for General Electric (GE) under Contract No. 200-1X-14W53048, in support of GRC Contract NAS3-01135. MTCT has demonstrated in earlier noise modeling efforts that the improvement of predictive modeling is greatly enhanced by an iterative approach, so in support of NASA's Quiet Aircraft Technology Project, GRC sponsored this effort to improve the model. Since the noise data available for correlation are total engine noise spectra, it is total engine noise that must be predicted. Since the scope of this effort was not sufficient to explore fan and turbine noise, the most meaningful comparisons must be restricted to <span class="hlt">frequencies</span> below the blade passage <span class="hlt">frequency</span>. Below the blade passage <span class="hlt">frequency</span> and at relatively high power settings jet noise is expected to be the dominant source, and comparisons are shown that demonstrate the accuracy of the jet noise model recently developed by MTCT for NASA under Contract NAS3-00178, Task Order No. 10. At lower power settings the <span class="hlt">core</span> noise became most apparent, and these data corrected for the contribution of jet noise were then used to establish the characteristics of <span class="hlt">core</span> noise. There is clearly more than one spectral range where <span class="hlt">core</span> noise is evident, so the spectral approach developed by von Glahn and Krejsa in 1982 wherein four spectral regions overlap, was used in the GE effort. Further analysis indicates that the two higher <span class="hlt">frequency</span> components, which are often somewhat masked by turbomachinery noise, can be treated as one component, and it is on that basis that the current model is formulated. The <span class="hlt">frequency</span> scaling relationships are improved and are now based on combustor and <span class="hlt">core</span> nozzle geometries. In conjunction with the Task</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010117738&hterms=core+strength&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcore%2Bstrength','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010117738&hterms=core+strength&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcore%2Bstrength"><span>Multiple <span class="hlt">Core</span> Galaxies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Miller, R.H.; Morrison, David (Technical Monitor)</p> <p>1994-01-01</p> <p>Nuclei of galaxies often show complicated density structures and perplexing kinematic signatures. In the past we have reported numerical experiments indicating a natural tendency for galaxies to show nuclei offset with respect to nearby isophotes and for the nucleus to have a radial velocity different from the galaxy's systemic velocity. Other experiments show normal mode oscillations in galaxies with large amplitudes. These oscillations do not damp appreciably over a Hubble time. The common thread running through all these is that galaxies often show evidence of ringing, bouncing, or sloshing around in unexpected ways, even though they have not been disturbed by any external event. Recent observational evidence shows yet another phenomenon indicating the dynamical complexity of central regions of galaxies: multiple <span class="hlt">cores</span> (M31, Markarian 315 and 463 for example). These systems can hardly be static. We noted long-lived multiple <span class="hlt">core</span> systems in galaxies in numerical experiments some years ago, and we have more recently followed up with a series of experiments on multiple <span class="hlt">core</span> galaxies, starting with two <span class="hlt">cores</span>. The relevant parameters are the energy in the orbiting clumps, their relative.masses, the (local) strength of the potential well representing the parent galaxy, and the number of <span class="hlt">cores</span>. We have studied the dependence of the merger rates and the nature of the final merger product on these parameters. Individual <span class="hlt">cores</span> survive much longer in stronger background potentials. <span class="hlt">Cores</span> can survive for a substantial fraction of a Hubble time if they travel on reasonable orbits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010117738&hterms=isophotes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Disophotes','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010117738&hterms=isophotes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Disophotes"><span>Multiple <span class="hlt">Core</span> Galaxies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Miller, R.H.; Morrison, David (Technical Monitor)</p> <p>1994-01-01</p> <p>Nuclei of galaxies often show complicated density structures and perplexing kinematic signatures. In the past we have reported numerical experiments indicating a natural tendency for galaxies to show nuclei offset with respect to nearby isophotes and for the nucleus to have a radial velocity different from the galaxy's systemic velocity. Other experiments show normal mode oscillations in galaxies with large amplitudes. These oscillations do not damp appreciably over a Hubble time. The common thread running through all these is that galaxies often show evidence of ringing, bouncing, or sloshing around in unexpected ways, even though they have not been disturbed by any external event. Recent observational evidence shows yet another phenomenon indicating the dynamical complexity of central regions of galaxies: multiple <span class="hlt">cores</span> (M31, Markarian 315 and 463 for example). These systems can hardly be static. We noted long-lived multiple <span class="hlt">core</span> systems in galaxies in numerical experiments some years ago, and we have more recently followed up with a series of experiments on multiple <span class="hlt">core</span> galaxies, starting with two <span class="hlt">cores</span>. The relevant parameters are the energy in the orbiting clumps, their relative.masses, the (local) strength of the potential well representing the parent galaxy, and the number of <span class="hlt">cores</span>. We have studied the dependence of the merger rates and the nature of the final merger product on these parameters. Individual <span class="hlt">cores</span> survive much longer in stronger background potentials. <span class="hlt">Cores</span> can survive for a substantial fraction of a Hubble time if they travel on reasonable orbits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006GeoJI.166.1368M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006GeoJI.166.1368M"><span>Flexure with <span class="hlt">damage</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Manaker, David M.; Turcotte, Donald L.; Kellogg, Louise H.</p> <p>2006-09-01</p> <p>Ductile behaviour in rocks is often associated with plasticity due to dislocation motion or diffusion under high pressures and temperatures. However, ductile behaviour can also occur in brittle materials. An example would be cataclastic flow associated with folding at shallow crustal levels. Engineers utilize <span class="hlt">damage</span> mechanics to model the continuum deformation of brittle materials. In this paper we utilize a modified form of <span class="hlt">damage</span> mechanics that includes a yield stress. Here, <span class="hlt">damage</span> represents a reduction in frictional strength. We use this empirical approach to simulate bending of the lithosphere through the problem of plate flexure. We use numerical simulations to obtain quasi-static solutions to the Navier equations of elasticity. We use the program GeoFEST v. 4.5 (Geophysical Finite Element Simulation Tool), developed by NASA Jet Propulsion Laboratory, to generate solutions for each time step. When the von Mises stress exceeds the critical stress on an element we apply <span class="hlt">damage</span> to reduce the shear modulus of the element. <span class="hlt">Damage</span> is calculated at each time step by a power-law relationship of the ratio of the critical stress to the von Mises stress and the critical strain to the von Mises strain. This results in the relaxation of the material due to increasing <span class="hlt">damage</span>. To test our method, we apply our <span class="hlt">damage</span> rheology to a semi-infinite plate deforming under its own weight. Where the von Mises stress exceeds the critical stress, we simulate the formation of <span class="hlt">damage</span> and observe the time-dependent relaxation of the stress and strain to near the yield strength. We simulate a wide range of behaviours from slow relaxation to instantaneous failure, over timescales that span six orders of magnitude. Using this method, stress relaxation produces perfectly plastic behaviour in cases where failure does not occur. For cases of failure, we observe a rapid increase in <span class="hlt">damage</span>, analogous to the acceleration of microcrack formation and acoustic emissions prior to failure. Thus</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/978363','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/978363"><span>CFD Analysis of <span class="hlt">Core</span> Bypass Phenomena</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Richard W. Johnson; Hiroyuki Sato; Richard R. Schultz</p> <p>2010-03-01</p> <p>The U.S. Department of Energy is exploring the potential for the VHTR which will be either of a prismatic or a pebble-bed type. One important design consideration for the reactor <span class="hlt">core</span> of a prismatic VHTR is coolant bypass flow which occurs in the interstitial regions between fuel blocks. Such gaps are an inherent presence in the reactor <span class="hlt">core</span> because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation <span class="hlt">damage</span>. The existence of the gaps induces a flow bias in the fuel blocks and results in unexpected increase of maximum fuel temperature. Traditionally, simplified methods such as flow network calculations employing experimental correlations are used to estimate flow and temperature distributions in the <span class="hlt">core</span> design. However, the distribution of temperature in the fuel pins and graphite blocks as well as coolant outlet temperatures are strongly coupled with the local heat generation rate within fuel blocks which is not uniformly distributed in the <span class="hlt">core</span>. Hence, it is crucial to establish mechanistic based methods which can be applied to the reactor <span class="hlt">core</span> thermal hydraulic design and safety analysis. Computational Fluid Dynamics (CFD) codes, which have a capability of local physics based simulation, are widely used in various industrial fields. This study investigates <span class="hlt">core</span> bypass flow phenomena with the assistance of commercial CFD codes and establishes a baseline for evaluation methods. A one-twelfth sector of the hexagonal block surface is modeled and extruded down to whole <span class="hlt">core</span> length of 10.704m. The computational domain is divided vertically with an upper reflector, a fuel section and a lower reflector. Each side of the sector grid can be set as a symmetry boundary</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/974775','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/974775"><span>CFD Analysis of <span class="hlt">Core</span> Bypass Phenomena</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Richard W. Johnson; Hiroyuki Sato; Richard R. Schultz</p> <p>2009-11-01</p> <p>The U.S. Department of Energy is exploring the potential for the VHTR which will be either of a prismatic or a pebble-bed type. One important design consideration for the reactor <span class="hlt">core</span> of a prismatic VHTR is coolant bypass flow which occurs in the interstitial regions between fuel blocks. Such gaps are an inherent presence in the reactor <span class="hlt">core</span> because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation <span class="hlt">damage</span>. The existence of the gaps induces a flow bias in the fuel blocks and results in unexpected increase of maximum fuel temperature. Traditionally, simplified methods such as flow network calculations employing experimental correlations are used to estimate flow and temperature distributions in the <span class="hlt">core</span> design. However, the distribution of temperature in the fuel pins and graphite blocks as well as coolant outlet temperatures are strongly coupled with the local heat generation rate within fuel blocks which is not uniformly distributed in the <span class="hlt">core</span>. Hence, it is crucial to establish mechanistic based methods which can be applied to the reactor <span class="hlt">core</span> thermal hydraulic design and safety analysis. Computational Fluid Dynamics (CFD) codes, which have a capability of local physics based simulation, are widely used in various industrial fields. This study investigates <span class="hlt">core</span> bypass flow phenomena with the assistance of commercial CFD codes and establishes a baseline for evaluation methods. A one-twelfth sector of the hexagonal block surface is modeled and extruded down to whole <span class="hlt">core</span> length of 10.704m. The computational domain is divided vertically with an upper reflector, a fuel section and a lower reflector. Each side of the one-twelfth grid can be set as a symmetry boundary</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=bayer&pg=7&id=EJ276676','ERIC'); return false;" href="http://eric.ed.gov/?q=bayer&pg=7&id=EJ276676"><span>Multi-Method Strategies for Defining "<span class="hlt">Core</span>" Higher Education Journals.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Bayer, Alan E.</p> <p>1983-01-01</p> <p>Three analyses were used to determine "<span class="hlt">core</span>" journals in the field of higher education: <span class="hlt">frequency</span> of publishing higher education focused articles, <span class="hlt">frequency</span> of citation to key works in higher education, and journal rankings by higher education professionals. Little correspondence is found among the results of the three strategies. (Author/MSE)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23600239','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23600239"><span>Reconstructing patterns of temperature, phenology, and frost <span class="hlt">damage</span> over 124 years: spring <span class="hlt">damage</span> risk is increasing.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Augspurger, Carol K</p> <p>2013-01-01</p> <p>Climate change, with both warmer spring temperatures and greater temperature fluctuations, has altered phenologies, possibly leading to greater risk of spring frost <span class="hlt">damage</span> to temperate deciduous woody plants. Phenological observations of 20 woody species from 1993 to 2012 in Trelease Woods, Champaign County, Illinois, USA, were used to identify years with frost <span class="hlt">damage</span> to vegetative and reproductive phases. Local temperature records were used in combination with the phenological observations to determine what combinations of the two were associated with <span class="hlt">damage</span>. Finally, a long-term temperature record (1889-1992) was evaluated to determine if the <span class="hlt">frequency</span> of frost <span class="hlt">damage</span> has risen in recent decades. Frost < or = -1.7 degrees C occurred after bud-break in 14 of the 20 years of observation. Frost <span class="hlt">damage</span> occurred in five years in the interior and in three additional years at only the forest edge. The degree of <span class="hlt">damage</span> varied with species, life stage, tissue (vegetative or reproductive), and phenological phase. Common features associated with the occurrence of <span class="hlt">damage</span> to interior plants were (1) a period of unusual warm temperatures in March, followed by (2) a frost event in April with a minimum temperature < or = -6.1 degrees C with (3) a period of 16-33 days between the extremes. In the long-term record, 10 of 124 years met these conditions, but the yearly probability of frost <span class="hlt">damage</span> increased significantly, from 0.03 during 1889-1979 to 0.21 during 1980-2012. When the criteria were "softened" to < or = -1.7 degrees C in April and an interval of 16-37 days, 31 of 124 years met the conditions, and the yearly <span class="hlt">damage</span> probability increased significantly to 0.19 for 1889-1979 and 0.42 for 1980-2012. In this forest, the combination of warming trends and temperature variability (extremes) associated with climate change is having ecologically important effects, making previously rare frost <span class="hlt">damage</span> events more common.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990078567&hterms=core+value&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcore%2Bvalue','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990078567&hterms=core+value&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcore%2Bvalue"><span>Global <span class="hlt">Core</span> Plasma Model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gallagher, Dennis L.; Craven, P. D.; Comfort, R. H.</p> <p>1999-01-01</p> <p>Abstract. The Global <span class="hlt">Core</span> Plasma Model (GCPM) provides, empirically derived, <span class="hlt">core</span> plasma density as a function of geomagnetic and solar conditions throughout the inner magnetosphere. It is continuous in value and gradient and is composed of separate models for the ionosphere, the plasmasphere, the plasmapause, the trough, and the polar cap. The relative composition of plasmaspheric H+, He+, and O+ is included in the GCPM. A blunt plasmaspheric bulge and rotation of the bulge with changing geomagnetic conditions is included. The GCPM is an amalgam of density models, intended to serve as a framework for continued improvement as new measurements become available and are used to characterize <span class="hlt">core</span> plasma density, composition, and temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990078567&hterms=amalgam&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Damalgam','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990078567&hterms=amalgam&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Damalgam"><span>Global <span class="hlt">Core</span> Plasma Model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gallagher, Dennis L.; Craven, P. D.; Comfort, R. H.</p> <p>1999-01-01</p> <p>Abstract. The Global <span class="hlt">Core</span> Plasma Model (GCPM) provides, empirically derived, <span class="hlt">core</span> plasma density as a function of geomagnetic and solar conditions throughout the inner magnetosphere. It is continuous in value and gradient and is composed of separate models for the ionosphere, the plasmasphere, the plasmapause, the trough, and the polar cap. The relative composition of plasmaspheric H+, He+, and O+ is included in the GCPM. A blunt plasmaspheric bulge and rotation of the bulge with changing geomagnetic conditions is included. The GCPM is an amalgam of density models, intended to serve as a framework for continued improvement as new measurements become available and are used to characterize <span class="hlt">core</span> plasma density, composition, and temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1093235','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1093235"><span><span class="hlt">Core</span> shroud corner joints</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Gilmore, Charles B.; Forsyth, David R.</p> <p>2013-09-10</p> <p>A <span class="hlt">core</span> shroud is provided, which includes a number of planar members, a number of unitary corners, and a number of subassemblies each comprising a combination of the planar members and the unitary corners. Each unitary corner comprises a unitary extrusion including a first planar portion and a second planar portion disposed perpendicularly with respect to the first planar portion. At least one of the subassemblies comprises a plurality of the unitary corners disposed side-by-side in an alternating opposing relationship. A plurality of the subassemblies can be combined to form a quarter perimeter segment of the <span class="hlt">core</span> shroud. Four quarter perimeter segments join together to form the <span class="hlt">core</span> shroud.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMGC21E1010D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMGC21E1010D"><span>Assessing Tropical Cyclone <span class="hlt">Damage</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Done, J.; Czajkowski, J.</p> <p>2012-12-01</p> <p>Landfalling tropical cyclones impact large coastal and inland areas causing direct <span class="hlt">damage</span> due to winds, storm-surge flooding, tornadoes, and precipitation; as well as causing substantial indirect <span class="hlt">damage</span> such as electrical outages and business interruption. The likely climate change impact of increased tropical cyclone intensity, combined with increases in exposure, bring the possibility of increased <span class="hlt">damage</span> in the future. A considerable amount of research has focused on modeling economic <span class="hlt">damage</span> due to tropical cyclones, and a series of indices have been developed to assess <span class="hlt">damages</span> under climate change. We highlight a number of ways this research can be improved through a series of case study analyses. First, historical loss estimates are revisited to properly account for; time, impacted regions, the source of <span class="hlt">damage</span> by type, and whether the <span class="hlt">damage</span> was direct/indirect and insured/uninsured. Second, the drivers of loss from both the socio-economic and physical side are examined. A case is made to move beyond the use of maximum wind speed to more stable metrics and the use of other characteristics of the wind field such as direction, degree of gustiness, and duration is explored. A novel approach presented here is the potential to model losses directly as a function of climate variables such as sea surface temperature, greenhouse gases, and aerosols. This work is the first stage in the development of a tropical cyclone loss model to enable projections of losses under scenarios of both socio-economic change (such as population migration or altered policy) and physical change (such as shifts in tropical cyclone activity one from basin to another or within the same basin).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6779092','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6779092"><span>Laser <span class="hlt">damage</span> database at 1064 nm</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rainer, F.; Gonzales, R.P.; Morgan, A.J.</p> <p>1990-03-01</p> <p>In conjunction with our diversification of laser <span class="hlt">damage</span> testing capabilities, we have expanded upon a database of threshold measurements and parameter variations at 1064 nm. This includes all tests at low pulse-repetition <span class="hlt">frequencies</span> (PRF) ranging from single shots to 120 Hz. These tests were conducted on the Reptile laser facility since 1987 and the Variable Pulse Laser (VPL) facility since 1988. Pulse durations ranged from 1 to 16 ns. 10 refs., 14 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/474','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/474"><span>Pileated woodpecker <span class="hlt">damage</span> to red-cockaded woodpecker cavity trees in eastern Texas</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Daniel Saenz; Richard N. Conner; Clifford E. Shackelford; D. Craig Rudolph</p> <p>1998-01-01</p> <p>The authors surveyed all known red-cockaded woodpecker (Picoides borealis) cavity trees (n = 514) in the Angelina National Forest in eastern Texas for pileated woodpecker (Dryocopus pileatus) <span class="hlt">damage</span>. They compared the <span class="hlt">frequency</span> of pileated woodpecker <span class="hlt">damage</span> to red-cockaded woodpecker cavity trees in longleaf pine (Pinus palustris) habitat to <span class="hlt">damage</span> in loblolly (P....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRE..121.1264D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRE..121.1264D"><span>The forced precession of the Moon's inner <span class="hlt">core</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dumberry, Mathieu; Wieczorek, Mark A.</p> <p>2016-07-01</p> <p>The tilt angle of the 18.6 year precession of the Moon's solid inner <span class="hlt">core</span> is unknown, but it is set by a balance between gravitational and pressure torques acting on its elliptical figure. We show here that to first order, the angle of precession of the inner <span class="hlt">core</span> of a planetary body is determined by the <span class="hlt">frequency</span> of the free inner <span class="hlt">core</span> nutation, ωficn, relative to the precession <span class="hlt">frequency</span>, Ωp. If |ωficn|≪|Ωp|, the inner <span class="hlt">core</span> is blind to the gravitational influence of the mantle. If |ωficn|≫|Ωp|, the inner <span class="hlt">core</span> is gravitationally locked to the mantle and is nearly aligned with it. If ωficn≈Ωp, large inner <span class="hlt">core</span> tilt angles can result from resonant excitation. Viscous inner <span class="hlt">core</span> relaxation and electromagnetic coupling can attenuate large tilt angles. For the specific case of the Moon, we show that ωficn is to within a factor of 2 of Ωp = 2π/18.6 yr-1. For a rigid inner <span class="hlt">core</span>, this implies a tilt of 2 to 5° with respect to the mantle, and larger if ωficn is very close to Ωp. More modest tilt angles between 0 and 0.5° result if viscous relaxation within the inner <span class="hlt">core</span> occurs on a timescale of one lunar day. Predictions from our model may be used in an attempt to detect the gravity signal resulting from a tilted inner <span class="hlt">core</span>, to determine the past history of the inner <span class="hlt">core</span> tilt angle, and to assess models of dynamo generation powered by differential rotation at the <span class="hlt">core</span>-mantle and inner <span class="hlt">core</span> boundaries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850034834&hterms=Core+Collapse+Supernovae&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DCore%2BCollapse%2BSupernovae','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850034834&hterms=Core+Collapse+Supernovae&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DCore%2BCollapse%2BSupernovae"><span>Magnetorotational iron <span class="hlt">core</span> collapse</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Symbalisty, E. M. D.</p> <p>1984-01-01</p> <p>During its final evolutionary stages, a massive star, as considered in current astrophysical theory, undergoes rapid collapse, thereby triggering a sequence of a catastrophic event which results in a Type II supernova explosion. A remnant neutron star or a black hole is left after the explosion. Stellar collapse occurs, when thermonuclear fusion has consumed the lighter elements present. At this stage, the <span class="hlt">core</span> consists of iron. Difficulties arise regarding an appropriate model with respect to the <span class="hlt">core</span> collapse. The present investigation is concerned with the evolution of a Type II supernova <span class="hlt">core</span> including the effects of rotation and magnetic fields. A simple neutrino model is developed which reproduced the spherically symmetric results of Bowers and Wilson (1982). Several two-dimensional computational models of stellar collapse are studied, taking into account a case in which a 15 solar masses iron <span class="hlt">core</span> was artificially given rotational and magnetic energy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cancergenome.nih.gov/abouttcga/overview/howitworks/bcr','NCI'); return false;" href="https://cancergenome.nih.gov/abouttcga/overview/howitworks/bcr"><span>Biospecimen <span class="hlt">Core</span> Resource - TCGA</span></a></p> <p><a target="_blank" href="http://www.cancer.gov">Cancer.gov</a></p> <p></p> <p></p> <p>The Cancer Genome Atlas (TCGA) Biospecimen <span class="hlt">Core</span> Resource centralized laboratory reviews and processes blood and tissue samples and their associated data using optimized standard operating procedures for the entire TCGA Research Network.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=226233&keyword=Berlin&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=76151292&CFTOKEN=94838324','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=226233&keyword=Berlin&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=76151292&CFTOKEN=94838324"><span>Contaminated Sediment <span class="hlt">Core</span> Profiling</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Evaluating the environmental risk of sites containing contaminated sediments often poses major challenges due in part to the absence of detailed information available for a given location. Sediment <span class="hlt">core</span> profiling is often utilized during preliminary environmental investigations ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19970025852&hterms=schoenfelder&qs=N%3D0%26Ntk%3DAuthor-Name%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dschoenfelder','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19970025852&hterms=schoenfelder&qs=N%3D0%26Ntk%3DAuthor-Name%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dschoenfelder"><span>INTEGRAL <span class="hlt">core</span> programme</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gehrels, N.; Schoenfelder, V.; Ubertini, P.; Winkler, C.</p> <p>1997-01-01</p> <p>The International Gamma Ray Astrophysics Laboratory (INTEGRAL) mission is described with emphasis on the INTEGRAL <span class="hlt">core</span> program. The progress made in the planning activities for the <span class="hlt">core</span> program is reported on. The INTEGRAL mission has a nominal lifetime of two years with a five year extension option. The observing time will be divided between the <span class="hlt">core</span> program (between 30 and 35 percent during the first two years) and general observations. The <span class="hlt">core</span> program consists of three main elements: the deep survey of the Galactic plane in the central radian of the Galaxy; frequent scans of the Galactic plane in the search for transient sources, and pointed observations of several selected sources. The allocation of the observation time is detailed and the sensitivities of the observations are outlined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/866567','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/866567"><span><span class="hlt">Core</span> assembly storage structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Jones, Jr., Charles E.; Brunings, Jay E.</p> <p>1988-01-01</p> <p>A structure for the storage of <span class="hlt">core</span> assemblies from a liquid metal-cooled nuclear reactor. The structure comprises an enclosed housing having a substantially flat horizontal top plate, a bottom plate and substantially vertical wall members extending therebetween. A plurality of thimble members extend downwardly through the top plate. Each thimble member is closed at its bottom end and has an open end adjacent said top plate. Each thimble member has a length and diameter greater than that of the <span class="hlt">core</span> assembly to be stored therein. The housing is provided with an inlet duct for the admission of cooling air and an exhaust duct for the discharge of air therefrom, such that when hot <span class="hlt">core</span> assemblies are placed in the thimbles, the heat generated will by convection cause air to flow from the inlet duct around the thimbles and out the exhaust duct maintaining the <span class="hlt">core</span> assemblies at a safe temperature without the necessity of auxiliary powered cooling equipment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=226233&keyword=risk+AND+profiling&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=226233&keyword=risk+AND+profiling&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Contaminated Sediment <span class="hlt">Core</span> Profiling</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Evaluating the environmental risk of sites containing contaminated sediments often poses major challenges due in part to the absence of detailed information available for a given location. Sediment <span class="hlt">core</span> profiling is often utilized during preliminary environmental investigations ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984EOSTr..65Q.426B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984EOSTr..65Q.426B"><span>Warm <span class="hlt">core</span> rings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bell, Peter M.</p> <p></p> <p>Gulf stream phenomena have been the focus of numerous studies by U.S. and Canadian oceanographic laboratories. Two years ago, observations of warm <span class="hlt">core</span> rings associated with the Gulf Stream were reported in The Oceanography Report, (November 2, 1982, p. 834). It was noted then that the structure of warm <span class="hlt">core</span> rings can undergo rapid transformation. Recently, a multidisciplinary group of physical and biological oceanographic institutions has examined the evolution of warm <span class="hlt">core</span> rings in detail [Nature, 308, pp. 837-840, 1984]. The study has involved research vessels Endeavor, Atlantis II, and Albatross IV for surface measurements of temperature, salinity, and for measurement surface pigments to assess the concentration of marine plants. The results are that even though warm <span class="hlt">core</span> rings are often very stable, undergoing only slow changes, it turns out that major alterations in structure can and do occur in short periods of 2-5 days.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/459422','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/459422"><span>Field verification of a nondestructive <span class="hlt">damage</span> location algorithm</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Farrar, C.R.; Stubbs, N.</p> <p>1996-12-31</p> <p>Over the past 25 years, the use of modal parameters for detecting <span class="hlt">damage</span> has received considerable attention from the civil engineering community. The basic idea is that changes in the structure`s properties, primarily stiffness, will alter the dynamic properties of the structure such as <span class="hlt">frequencies</span> and mode shapes, and properties derived from these quantities such as modal-based flexibility. In this paper, a method for nondestructive <span class="hlt">damage</span> location in bridges, as determined by changes in the modal properties, is described. The <span class="hlt">damage</span> detection algorithm is applied to pre- and post-<span class="hlt">damage</span> modal properties measured on a bridge. Results of the analysis indicate that the method accurately locates the <span class="hlt">damage</span>. Subjects relating to practical implementation of this <span class="hlt">damage</span> identification algorithm that need further study are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000058165','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000058165"><span>The Moon's Molten <span class="hlt">Core</span> and Tidal Q</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.; Dickey, J. O.</p> <p>1998-01-01</p> <p>The rotation of the Moon is influenced by solid-body tides and interaction at a liquid-<span class="hlt">core</span>/solid-mantle boundary. The Lunar Laser Ranging (LLR) data are sensitive to variations in lunar rotation. Analysis of those ranges reveals four dissipation periodicities in the rotation. These signatures can be explained with the combined effects of tide plus <span class="hlt">core</span>, but not with either alone. The fluid <span class="hlt">core</span> detection exceeds three times its uncertainty. The inferred <span class="hlt">core</span> radius has a 1 -sigma upper limit of 352 km for iron and up to 374 km if sulfur is present. The tidal dissipation is strong, Q at one month is 37 +/- 5 .Q increases for longer periods and is 60 (-15, +40) at one year.Dynamical evidence for a fluid lunar <span class="hlt">core</span> has previously been presented. These-earlier solutions included three dissipation parameters. New solutions benefit from additional LLR data and an improved gravity field from Doppler tracking of Lunar Prospector. Five dissipation parameters are now solved for. There are several options for dissipation parameters: a <span class="hlt">core</span> coupling parameter, a time delay for tidal distortion of the moments of inertia, and five periodic terms in the rotation angles. Solutions with different combinations of these are compatible (a theory relates K/C and time delay to a series of periodic terms). The solutions used K/C, time delay, and one periodic term. When dissipation signatures at five rotation <span class="hlt">frequencies</span> are solved for, four amplitudes (4 to 263 milliarcseconds) are detected above the noise. Attempts to explain these results using either tides alone or <span class="hlt">core</span> alone fail (less than 3(sigma) discrepancy for the former and 9(sigma), for the latter). A combination of tides and liquid <span class="hlt">core</span> matches the results well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150010125','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150010125"><span><span class="hlt">Core</span>-Noise Research</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hultgren, Lennart S.</p> <p>2012-01-01</p> <p>This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on <span class="hlt">core</span> noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015 (N+1), 2020 (N+2), and 2025 (N+3) timeframes; SFW strategic thrusts and technical challenges; SFW advanced subsystems that are broadly applicable to N+3 vehicle concepts, with an indication where further noise research is needed; the components of <span class="hlt">core</span> noise (compressor, combustor and turbine noise) and a rationale for NASA's current emphasis on the combustor-noise component; the increase in the relative importance of <span class="hlt">core</span> noise due to turbofan design trends; the need to understand and mitigate <span class="hlt">core</span>-noise sources for high-efficiency small gas generators; and the current research activities in the <span class="hlt">core</span>-noise area, with additional details given about forthcoming updates to NASA's Aircraft Noise Prediction Program (ANOPP) <span class="hlt">core</span>-noise prediction capabilities, two NRA efforts (Honeywell International, Phoenix, AZ and University of Illinois at Urbana-Champaign, respectively) to improve the understanding of <span class="hlt">core</span>-noise sources and noise propagation through the engine <span class="hlt">core</span>, and an effort to develop oxide/oxide ceramic-matrix-composite (CMC) liners for broadband noise attenuation suitable for turbofan-<span class="hlt">core</span> application. <span class="hlt">Core</span> noise must be addressed to ensure that the N+3 noise goals are met. Focused, but long-term, <span class="hlt">core</span>-noise research is carried out to enable the advanced high-efficiency small gas-generator subsystem, common to several N+3 conceptual designs, needed to meet NASA's technical challenges. Intermediate updates to prediction tools are implemented as the understanding of the source structure and engine-internal propagation effects is improved. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMOS21A1599K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMOS21A1599K"><span><span class="hlt">Coring</span> Methane Hydrate by using Hybrid Pressure <span class="hlt">Coring</span> System of D/V Chikyu</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kubo, Y.; Mizuguchi, Y.; Inagaki, F.; Eguchi, N.; Yamamoto, K.</p> <p>2013-12-01</p> <p>Pressure <span class="hlt">coring</span> is a technique to keep in-situ conditions in recovering sub-seafloor sediment samples, which are potentially rich in soluble or hydrated gas. In regular <span class="hlt">core</span> sampling, gas fractions are easily lost through the changes in the pressure and temperature during <span class="hlt">core</span> recovery, and it has significant impact on the chemical components of the sample. Rapid degassing may also cause critical <span class="hlt">damages</span> of original structures. To study original characteristics of gaseous sub-seafloor sediment, a new Hybrid Pressure <span class="hlt">Coring</span> System (Hybrid PCS) was developed for the D/V Chikyu operation by adapting some of the existing pressure sampling technologies. Hybrid PCS is composed of three main parts: top section for the wireline operation, middle section for the accumulator and pressure controlling system, and the bottom section for the autoclave chamber. The design concept is based on that of Pressure <span class="hlt">Core</span> Sampler used in Ocean Drilling Program, and of Pressure Temperature <span class="hlt">Core</span> Sampler (PTCS) and Non-cooled PTCS of Japan Oil, Gas and Metals National Corporation (JOGMEC). Several modifications were made including that on the ball valve, which operates to close the autoclave after <span class="hlt">coring</span>. The <span class="hlt">core</span> samples are 51 mm in diameter and up to 3.5 m in length. The system is combined with the Extented Shoe <span class="hlt">Coring</span> System on the Chikyu and best suited for <span class="hlt">coring</span> of semi-consolidated formation up to about 3400 m from the sea level. Sample autoclave is compatible with Pressure <span class="hlt">Core</span> Analysis and Transfer System (PCATS) of Geotek Ltd for sub-sampling and analysis under in-situ pressure. The analysis in PCATS includes X-ray CT scan and <span class="hlt">core</span> logging with P-wave velocity and gamma density. Depressurization provides accurate volume of gas and its sub-sampling. Hybrid PCS was first tested during the Chikyu Exp. 906 at a submarine mud-volcano in the Nankai Trough. A 0.9 m of hydrate rich material was recovered from the summit (water depth: 2000 m) and the intact hydrate structure was observed</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1013662','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1013662"><span>Reducing Radiation <span class="hlt">Damage</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Blankenbecler, Richard</p> <p>2006-06-05</p> <p>This talk describes the use of a modified treatment sequence, i.e., radiation dose, geometry, dwell time, etc., to mitigate some of the deleterious effects of cancer radiotherapy by utilizing natural cell repair processes. If bad side effects can be reduced, a more aggressive therapy can be put into place. Cells contain many mechanisms that repair <span class="hlt">damage</span> of various types. If the <span class="hlt">damage</span> can not be repaired, cells will undergo apoptosis (cell death). Data will be reviewed that support the fact that a small dose of radiation will activate <span class="hlt">damage</span> repair genes within a cell. Once the mechanisms are fully active, they will efficiently repair the severe <span class="hlt">damage</span> from a much larger radiation dose. The data ranges from experiments on specific cell cultures using microarray (gene chip) techniques to experiments on complete organisms. The suggested effect and treatment is consistent with the assumption that all radiation is harmful, no matter how small the dose. Nevertheless, the harm can be reduced. These mechanisms need to be further studied and characterized. In particular, their time dependence needs to be understood before the proposed treatment can be optimized. Under certain situations it is also possible that the deleterious effects of chemotherapy can be mitigated and the <span class="hlt">damage</span> to radiation workers can be reduced.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/863271','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/863271"><span>Nuclear <span class="hlt">core</span> positioning system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Garkisch, Hans D.; Yant, Howard W.; Patterson, John F.</p> <p>1979-01-01</p> <p>A structural support system for the <span class="hlt">core</span> of a nuclear reactor which achieves relatively restricted clearances at operating conditions and yet allows sufficient clearance between fuel assemblies at refueling temperatures. Axially displaced spacer pads having variable between pad spacing and a temperature compensated radial restraint system are utilized to maintain clearances between the fuel elements. The <span class="hlt">core</span> support plates are constructed of metals specially chosen such that differential thermal expansion produces positive restraint at operating temperatures.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. Their policies may differ from this site.</small> </div> </center> <div id="footer-wrapper"> <div class="footer-content"> <div id="footerOSTI" class=""> <div class="row"> <div class="col-md-4 text-center col-md-push-4 footer-content-center"><small><a href="http://www.science.gov/disclaimer.html">Privacy and Security</a></small> <div class="visible-sm visible-xs push_footer"></div> </div> <div class="col-md-4 text-center col-md-pull-4 footer-content-left"> <img src="https://www.osti.gov/images/DOE_SC31.png" alt="U.S. Department of Energy" usemap="#doe" height="31" width="177"><map style="display:none;" name="doe" id="doe"><area shape="rect" coords="1,3,107,30" href="http://www.energy.gov" alt="U.S. Deparment of Energy"><area shape="rect" coords="114,3,165,30" href="http://www.science.energy.gov" alt="Office of Science"></map> <a ref="http://www.osti.gov" style="margin-left: 15px;"><img src="https://www.osti.gov/images/footerimages/ostigov53.png" alt="Office of Scientific and Technical Inf