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Sample records for high frequency sine

  1. Recombinant SINEs are formed at high frequency during induced retrotransposition in vivo.

    Science.gov (United States)

    Yadav, Vijay Pal; Mandal, Prabhat Kumar; Bhattacharya, Alok; Bhattacharya, Sudha

    2012-05-22

    Non-long terminal repeat Retrotransposons are referred to as long interspersed nuclear elements (LINEs) and their non-autonomous partners are short interspersed nuclear elements (SINEs). It is believed that an active SINE copy, upon retrotransposition, generates near identical copies of itself, which subsequently accumulate mutations resulting in sequence polymorphism. Here we show that when a retrotransposition-competent cell line of the parasitic protist Entamoeba histolytica, transfected with a marked SINE copy, is induced to retrotranspose, >20% of the newly retrotransposed copies are neither identical to the marked SINE nor to the mobilized resident SINEs. Rather they are recombinants of resident SINEs and the marked SINE. They are a consequence of retrotransposition and not DNA recombination, as they are absent in cells not expressing the retrotransposition functions. This high-frequency recombination provides a new explanation for the existence of mosaic SINEs, which may impact on genetic analysis of SINE lineages, and measurement of phylogenetic distances.

  2. On second order effects in a galvanic cell : Part I. Polarization by a sine wave modulated high frequency current

    NARCIS (Netherlands)

    Pol, F. van der; Sluyters-Rehbach, M.; Sluyters, J.H.

    1975-01-01

    A theoretical study is presented concerning the application of a high-frequency alternating current, amplitude modulated by a low-frequency sine wave, to a galvanic cell. Based on the correlation with the faradaic rectification technique, expressions are given for the low-frequency demodulation

  3. Use of Sine Shaped High-Frequency Rhythmic Visual Stimuli Patterns for SSVEP Response Analysis and Fatigue Rate Evaluation in Normal Subjects.

    Science.gov (United States)

    Keihani, Ahmadreza; Shirzhiyan, Zahra; Farahi, Morteza; Shamsi, Elham; Mahnam, Amin; Makkiabadi, Bahador; Haidari, Mohsen R; Jafari, Amir H

    2018-01-01

    Background: Recent EEG-SSVEP signal based BCI studies have used high frequency square pulse visual stimuli to reduce subjective fatigue. However, the effect of total harmonic distortion (THD) has not been considered. Compared to CRT and LCD monitors, LED screen displays high-frequency wave with better refresh rate. In this study, we present high frequency sine wave simple and rhythmic patterns with low THD rate by LED to analyze SSVEP responses and evaluate subjective fatigue in normal subjects. Materials and Methods: We used patterns of 3-sequence high-frequency sine waves (25, 30, and 35 Hz) to design our visual stimuli. Nine stimuli patterns, 3 simple (repetition of each of above 3 frequencies e.g., P25-25-25) and 6 rhythmic (all of the frequencies in 6 different sequences e.g., P25-30-35) were chosen. A hardware setup with low THD rate ( 90% for CCA and LASSO (for TWs > 1 s). High frequency rhythmic patterns group with low THD rate showed higher accuracy rate (99.24%) than simple patterns group (98.48%). Repeated measure ANOVA showed significant difference between rhythmic pattern features ( P rhythmic [3.85 ± 2.13] compared to the simple patterns group [3.96 ± 2.21], ( P = 0.63). Rhythmic group had lower within group VAS variation (min = P25-30-35 [2.90 ± 2.45], max = P35-25-30 [4.81 ± 2.65]) as well as least individual pattern VAS (P25-30-35). Discussion and Conclusion: Overall, rhythmic and simple pattern groups had higher and similar accuracy rates. Rhythmic stimuli patterns showed insignificantly lower fatigue rate than simple patterns. We conclude that both rhythmic and simple visual high frequency sine wave stimuli require further research for human subject SSVEP-BCI studies.

  4. Use of Sine Shaped High-Frequency Rhythmic Visual Stimuli Patterns for SSVEP Response Analysis and Fatigue Rate Evaluation in Normal Subjects

    Directory of Open Access Journals (Sweden)

    Ahmadreza Keihani

    2018-05-01

    Full Text Available Background: Recent EEG-SSVEP signal based BCI studies have used high frequency square pulse visual stimuli to reduce subjective fatigue. However, the effect of total harmonic distortion (THD has not been considered. Compared to CRT and LCD monitors, LED screen displays high-frequency wave with better refresh rate. In this study, we present high frequency sine wave simple and rhythmic patterns with low THD rate by LED to analyze SSVEP responses and evaluate subjective fatigue in normal subjects.Materials and Methods: We used patterns of 3-sequence high-frequency sine waves (25, 30, and 35 Hz to design our visual stimuli. Nine stimuli patterns, 3 simple (repetition of each of above 3 frequencies e.g., P25-25-25 and 6 rhythmic (all of the frequencies in 6 different sequences e.g., P25-30-35 were chosen. A hardware setup with low THD rate (<0.1% was designed to present these patterns on LED. Twenty two normal subjects (aged 23–30 (25 ± 2.1 yrs were enrolled. Visual analog scale (VAS was used for subjective fatigue evaluation after presentation of each stimulus pattern. PSD, CCA, and LASSO methods were employed to analyze SSVEP responses. The data including SSVEP features and fatigue rate for different visual stimuli patterns were statistically evaluated.Results: All 9 visual stimuli patterns elicited SSVEP responses. Overall, obtained accuracy rates were 88.35% for PSD and > 90% for CCA and LASSO (for TWs > 1 s. High frequency rhythmic patterns group with low THD rate showed higher accuracy rate (99.24% than simple patterns group (98.48%. Repeated measure ANOVA showed significant difference between rhythmic pattern features (P < 0.0005. Overall, there was no significant difference between the VAS of rhythmic [3.85 ± 2.13] compared to the simple patterns group [3.96 ± 2.21], (P = 0.63. Rhythmic group had lower within group VAS variation (min = P25-30-35 [2.90 ± 2.45], max = P35-25-30 [4.81 ± 2.65] as well as least individual pattern VAS (P25

  5. SINEs.

    Science.gov (United States)

    Kramerov, Dmitri A; Vassetzky, Nikita S

    2011-01-01

    Short interspersed elements (SINEs) are mobile genetic elements that invade the genomes of many eukaryotes. Since their discovery about 30 years ago, many gaps in our understanding of the biology and function of SINEs have been filled. This review summarizes the past and recent advances in the studies of SINEs. The structure and origin of SINEs as well as the processes involved in their amplification, transcription, RNA processing, reverse transcription, and integration of a SINE copy into the genome are considered. Then we focus on the significance of SINEs for the host genomes. While these genomic parasites can be deleterious to the cell, the long-term being in the genome has made SINEs a valuable source of genetic variation providing regulatory elements for gene expression, alternative splice sites, polyadenylation signals, and even functional RNA genes. Copyright © 2011 John Wiley & Sons, Ltd.

  6. The measurement of subcritical reactivity in nuclear reactors by use of a high frequency sine-wave modulated neutron source

    International Nuclear Information System (INIS)

    Guppy, C.B.

    1964-11-01

    In this report the frequency response characteristics for phase and gain of the fundamental reactor mode of the zero power kinetics are given for various subcritical reactivities in a fast reactor and in a thermal reactor. Results, of a study on harmonic effects based on a small zero energy thermal reactor are presented which demonstrate the importance of spatial harmonic effects. A harmonic theory for thermal reactors is developed. A new method of measuring, subcritical reactivity at moderately high frequencies is suggested which circumvents the harmonic problem. It is shown that at high frequencies there is more sensitivity than at low frequencies and that this could lead to an increased range over which subcritical reactivity can be measured. (author)

  7. Radial frequency stimuli and sine-wave gratings seem to be processed by distinct contrast brain mechanisms

    Directory of Open Access Journals (Sweden)

    M.L.B. Simas

    2005-03-01

    Full Text Available An assumption commonly made in the study of visual perception is that the lower the contrast threshold for a given stimulus, the more sensitive and selective will be the mechanism that processes it. On the basis of this consideration, we investigated contrast thresholds for two classes of stimuli: sine-wave gratings and radial frequency stimuli (i.e., j0 targets or stimuli modulated by spherical Bessel functions. Employing a suprathreshold summation method, we measured the selectivity of spatial and radial frequency filters using either sine-wave gratings or j0 target contrast profiles at either 1 or 4 cycles per degree of visual angle (cpd, as the test frequencies. Thus, in a forced-choice trial, observers chose between a background spatial (or radial frequency alone and the given background stimulus plus the test frequency (1 or 4 cpd sine-wave grating or radial frequency. Contrary to our expectations, the results showed elevated thresholds (i.e., inhibition for sine-wave gratings and decreased thresholds (i.e., summation for radial frequencies when background and test frequencies were identical. This was true for both 1- and 4-cpd test frequencies. This finding suggests that sine-wave gratings and radial frequency stimuli are processed by different quasi-linear systems, one working at low luminance and contrast level (sine-wave gratings and the other at high luminance and contrast levels (radial frequency stimuli. We think that this interpretation is consistent with distinct foveal only and foveal-parafoveal mechanisms involving striate and/or other higher visual areas (i.e., V2 and V4.

  8. Critical properties of the double-frequency sine-Gordon model with applications

    International Nuclear Information System (INIS)

    Fabrizio, M.; Gogolin, A.O.; Nersesyan, A.A.

    2000-01-01

    We study the properties of the double-frequency sine-Gordon model in the vicinity of the Ising quantum phase transition displayed by this model. Using a mapping onto a generalized lattice quantum Ashkin-Teller model, we obtain critical and nearly-off-critical correlation functions of various operators. We discuss applications of the double-sine-Gordon model to one-dimensional physical systems, like spin chains in a staggered external field and interacting electrons in a staggered potential

  9. Comparative evolution history of SINEs in Arabidopsis thaliana and Brassica oleracea: evidence for a high rate of SINE loss.

    Science.gov (United States)

    Lenoir, A; Pélissier, T; Bousquet-Antonelli, C; Deragon, J M

    2005-01-01

    allele and the pre-integrative allele (i.e. the "empty" allele), we observed in the different ecotypes, alleles with truncated portions of the SINE (up to the complete loss of the element) and of the immediate genomic flanking sequences. The absence of SINEs in orthologous positions between B. oleracea and A. thaliana and the presence in recently diverged A. thaliana ecotypes of alleles containing severely truncated SINEs suggest a very high rate of SINE loss in these species.

  10. Internal oscillation frequencies and anharmonic effects for the double sine-Gordon kink

    DEFF Research Database (Denmark)

    Salerno, M.; Samuelsen, Mogens Rugholm

    1989-01-01

    A simple derivation of the small oscillation frequency around 4π-kink solutions of the double sine-Gordon equation is presented. Small corrections to these frequencies due to anharmonic effects are also numerically and analytically investigated. The analysis is based on energetic considerations...

  11. Overview of multi-input frequency domain modal testing methods with an emphasis on sine testing

    Science.gov (United States)

    Rost, Robert W.; Brown, David L.

    1988-01-01

    An overview of the current state of the art multiple-input, multiple-output modal testing technology is discussed. A very brief review of the current time domain methods is given. A detailed review of frequency and spatial domain methods is presented with an emphasis on sine testing.

  12. Modified sine bar device measures small angles with high accuracy

    Science.gov (United States)

    Thekaekara, M.

    1968-01-01

    Modified sine bar device measures small angles with enough accuracy to calibrate precision optical autocollimators. The sine bar is a massive bar of steel supported by two cylindrical rods at one end and one at the other.

  13. MetaSINEs: Broad Distribution of a Novel SINE Superfamily in Animals

    OpenAIRE

    Nishihara, Hidenori; Plazzi, Federico; Passamonti, Marco; Okada, Norihiro

    2016-01-01

    SINEs (short interspersed elements) are transposable elements that typically originate independently in each taxonomic clade (order/family). However, some SINE families share a highly similar central sequence and are thus categorized as a SINE superfamily. Although only four SINE superfamilies (CORE-SINEs, V-SINEs, DeuSINEs, and Ceph-SINEs) have been reported so far, it is expected that new SINE superfamilies would be discovered by deep exploration of new SINEs in metazoan genomes. Here we de...

  14. Accurate Frequency Estimation Based On Three-Parameter Sine-Fitting With Three FFT Samples

    Directory of Open Access Journals (Sweden)

    Liu Xin

    2015-09-01

    Full Text Available This paper presents a simple DFT-based golden section searching algorithm (DGSSA for the single tone frequency estimation. Because of truncation and discreteness in signal samples, Fast Fourier Transform (FFT and Discrete Fourier Transform (DFT are inevitable to cause the spectrum leakage and fence effect which lead to a low estimation accuracy. This method can improve the estimation accuracy under conditions of a low signal-to-noise ratio (SNR and a low resolution. This method firstly uses three FFT samples to determine the frequency searching scope, then – besides the frequency – the estimated values of amplitude, phase and dc component are obtained by minimizing the least square (LS fitting error of three-parameter sine fitting. By setting reasonable stop conditions or the number of iterations, the accurate frequency estimation can be realized. The accuracy of this method, when applied to observed single-tone sinusoid samples corrupted by white Gaussian noise, is investigated by different methods with respect to the unbiased Cramer-Rao Low Bound (CRLB. The simulation results show that the root mean square error (RMSE of the frequency estimation curve is consistent with the tendency of CRLB as SNR increases, even in the case of a small number of samples. The average RMSE of the frequency estimation is less than 1.5 times the CRLB with SNR = 20 dB and N = 512.

  15. Conversion Between Sine Wave and Square Wave Spatial Frequency Response of an Imaging System

    National Research Council Canada - National Science Library

    Nill, Norman B

    2001-01-01

    ...), is a primary image quality metric that is commonly measured with a sine wave target. The FBI certification program for commercial fingerprint capture devices, which MITRE actively supports, has an MTF requirement...

  16. On the applicability of the layered sine-Gordon model for Josephson-coupled high-Tc layered superconductors

    International Nuclear Information System (INIS)

    Nandori, I; Jentschura, U D; Nagy, S; Sailer, K; Vad, K; Meszaros, S

    2007-01-01

    We find a mapping of the layered sine-Gordon model to an equivalent gas of topological excitations and determine the long-range interaction potentials of the topological defects. This enables us to make a detailed comparison to the so-called layered vortex gas, which can be obtained from the layered Ginzburg-Landau model. The layered sine-Gordon model has been proposed in the literature as a candidate field-theoretical model for Josephson-coupled high-T c superconductors, and the implications of our analysis for the applicability of the layered sine-Gordon model to high-T c superconductors are discussed. We are led to the conjecture that the layered sine-Gordon and the layered vortex gas models belong to different universality classes. The determination of the critical temperature of the layered sine-Gordon model is based on a renormalization-group analysis

  17. MetaSINEs: Broad Distribution of a Novel SINE Superfamily in Animals.

    Science.gov (United States)

    Nishihara, Hidenori; Plazzi, Federico; Passamonti, Marco; Okada, Norihiro

    2016-02-12

    SINEs (short interspersed elements) are transposable elements that typically originate independently in each taxonomic clade (order/family). However, some SINE families share a highly similar central sequence and are thus categorized as a SINE superfamily. Although only four SINE superfamilies (CORE-SINEs, V-SINEs, DeuSINEs, and Ceph-SINEs) have been reported so far, it is expected that new SINE superfamilies would be discovered by deep exploration of new SINEs in metazoan genomes. Here we describe 15 SINEs, among which 13 are novel, that have a similar 66-bp central region and therefore constitute a new SINE superfamily, MetaSINEs. MetaSINEs are distributed from fish to cnidarians, suggesting their common evolutionary origin at least 640 Ma. Because the 3' tails of MetaSINEs are variable, these SINEs most likely survived by changing their partner long interspersed elements for retrotransposition during evolution. Furthermore, we examined the presence of members of other SINE superfamilies in bivalve genomes and characterized eight new SINEs belonging to the CORE-SINEs, V-SINEs, and DeuSINEs, in addition to the MetaSINEs. The broad distribution of bivalve SINEs suggests that at least three SINEs originated in the common ancestor of Bivalvia. Our comparative analysis of the central domains of the SINEs revealed that, in each superfamily, only a restricted region is shared among all of its members. Because the functions of the central domains of the SINE superfamilies remain unknown, such structural information of SINE superfamilies will be useful for future experimental and comparative analyses to reveal why they have been retained in metazoan genomes during evolution. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  18. High SINE RNA Expression Correlates with Post-Transcriptional Downregulation of BRCA1

    Directory of Open Access Journals (Sweden)

    Giovanni Bosco

    2013-04-01

    Full Text Available Short Interspersed Nuclear Elements (SINEs are non-autonomous retrotransposons that comprise a large fraction of the human genome. SINEs are demethylated in human disease, but whether SINEs become transcriptionally induced and how the resulting transcripts may affect the expression of protein coding genes is unknown. Here, we show that downregulation of the mRNA of the tumor suppressor gene BRCA1 is associated with increased transcription of SINEs and production of sense and antisense SINE small RNAs. We find that BRCA1 mRNA is post-transcriptionally down-regulated in a Dicer and Drosha dependent manner and that expression of a SINE inverted repeat with sequence identity to a BRCA1 intron is sufficient for downregulation of BRCA1 mRNA. These observations suggest that transcriptional activation of SINEs could contribute to a novel mechanism of RNA mediated post-transcriptional silencing of human genes.

  19. Sines and Cosines. Part 1 of 3

    Science.gov (United States)

    Apostol, Tom M. (Editor)

    1992-01-01

    Applying the concept of similarities, the mathematical principles of circular motion and sine and cosine waves are presented utilizing both film footage and computer animation in this 'Project Mathematics' series video. Concepts presented include: the symmetry of sine waves; the cosine (complementary sine) and cosine waves; the use of sines and cosines on coordinate systems; the relationship they have to each other; the definitions and uses of periodic waves, square waves, sawtooth waves; the Gibbs phenomena; the use of sines and cosines as ratios; and the terminology related to sines and cosines (frequency, overtone, octave, intensity, and amplitude).

  20. Ancient Exaptation of a CORE-SINE Retroposon into a Highly Conserved Mammalian Neuronal Enhancer of the Proopiomelanocortin Gene

    Science.gov (United States)

    Bumaschny, Viviana F; Low, Malcolm J; Rubinstein, Marcelo

    2007-01-01

    The proopiomelanocortin gene (POMC) is expressed in the pituitary gland and the ventral hypothalamus of all jawed vertebrates, producing several bioactive peptides that function as peripheral hormones or central neuropeptides, respectively. We have recently determined that mouse and human POMC expression in the hypothalamus is conferred by the action of two 5′ distal and unrelated enhancers, nPE1 and nPE2. To investigate the evolutionary origin of the neuronal enhancer nPE2, we searched available vertebrate genome databases and determined that nPE2 is a highly conserved element in placentals, marsupials, and monotremes, whereas it is absent in nonmammalian vertebrates. Following an in silico paleogenomic strategy based on genome-wide searches for paralog sequences, we discovered that opossum and wallaby nPE2 sequences are highly similar to members of the superfamily of CORE-short interspersed nucleotide element (SINE) retroposons, in particular to MAR1 retroposons that are widely present in marsupial genomes. Thus, the neuronal enhancer nPE2 originated from the exaptation of a CORE-SINE retroposon in the lineage leading to mammals and remained under purifying selection in all mammalian orders for the last 170 million years. Expression studies performed in transgenic mice showed that two nonadjacent nPE2 subregions are essential to drive reporter gene expression into POMC hypothalamic neurons, providing the first functional example of an exapted enhancer derived from an ancient CORE-SINE retroposon. In addition, we found that this CORE-SINE family of retroposons is likely to still be active in American and Australian marsupial genomes and that several highly conserved exonic, intronic and intergenic sequences in the human genome originated from the exaptation of CORE-SINE retroposons. Together, our results provide clear evidence of the functional novelties that transposed elements contributed to their host genomes throughout evolution. PMID:17922573

  1. Ancient exaptation of a CORE-SINE retroposon into a highly conserved mammalian neuronal enhancer of the proopiomelanocortin gene.

    Directory of Open Access Journals (Sweden)

    Andrea M Santangelo

    2007-10-01

    Full Text Available The proopiomelanocortin gene (POMC is expressed in the pituitary gland and the ventral hypothalamus of all jawed vertebrates, producing several bioactive peptides that function as peripheral hormones or central neuropeptides, respectively. We have recently determined that mouse and human POMC expression in the hypothalamus is conferred by the action of two 5' distal and unrelated enhancers, nPE1 and nPE2. To investigate the evolutionary origin of the neuronal enhancer nPE2, we searched available vertebrate genome databases and determined that nPE2 is a highly conserved element in placentals, marsupials, and monotremes, whereas it is absent in nonmammalian vertebrates. Following an in silico paleogenomic strategy based on genome-wide searches for paralog sequences, we discovered that opossum and wallaby nPE2 sequences are highly similar to members of the superfamily of CORE-short interspersed nucleotide element (SINE retroposons, in particular to MAR1 retroposons that are widely present in marsupial genomes. Thus, the neuronal enhancer nPE2 originated from the exaptation of a CORE-SINE retroposon in the lineage leading to mammals and remained under purifying selection in all mammalian orders for the last 170 million years. Expression studies performed in transgenic mice showed that two nonadjacent nPE2 subregions are essential to drive reporter gene expression into POMC hypothalamic neurons, providing the first functional example of an exapted enhancer derived from an ancient CORE-SINE retroposon. In addition, we found that this CORE-SINE family of retroposons is likely to still be active in American and Australian marsupial genomes and that several highly conserved exonic, intronic and intergenic sequences in the human genome originated from the exaptation of CORE-SINE retroposons. Together, our results provide clear evidence of the functional novelties that transposed elements contributed to their host genomes throughout evolution.

  2. PCR-based approach to SINE isolation: simple and complex SINEs.

    Science.gov (United States)

    Borodulina, Olga R; Kramerov, Dmitri A

    2005-04-11

    Highly repeated copies of short interspersed elements (SINEs) occur in eukaryotic genomes. The distribution of each SINE family is usually restricted to some genera, families, or orders. SINEs have an RNA polymerase III internal promoter, which is composed of boxes A and B. Here we propose a method for isolation of novel SINE families based on genomic DNA PCR with oligonucleotide identical to box A as a primer. Cloning of the size-heterogeneous PCR-products and sequencing of their terminal regions allow determination of SINE structure. Using this approach, two novel SINE families, Rhin-1 and Das-1, from the genomes of great horseshoe bat (Rhinolophus ferrumequinum) and nine-banded armadillo (Dasypus novemcinctus), respectively, were isolated and studied. The distribution of Rhin-1 is restricted to two of six bat families tested. Copies of this SINE are characterized by frequent internal insertions and significant length (200-270 bp). Das-1 being only 90 bp in length is one of the shortest SINEs known. Most of Das-1 nucleotide sequences demonstrate significant similarity to alanine tRNA which appears to be an evolutionary progenitor of this SINE. Together with three other known SINEs (ID, Vic-1, and CYN), Das-1 constitutes a group of simple SINEs. Interestingly, three SINE families of this group are alanine tRNA-derived. Most probably, this tRNA gave rise to short and simple but successful SINEs several times during mammalian evolution.

  3. SINEBase: a database and tool for SINE analysis.

    Science.gov (United States)

    Vassetzky, Nikita S; Kramerov, Dmitri A

    2013-01-01

    SINEBase (http://sines.eimb.ru) integrates the revisited body of knowledge about short interspersed elements (SINEs). A set of formal definitions concerning SINEs was introduced. All available sequence data were screened through these definitions and the genetic elements misidentified as SINEs were discarded. As a result, 175 SINE families have been recognized in animals, flowering plants and green algae. These families were classified by the modular structure of their nucleotide sequences and the frequencies of different patterns were evaluated. These data formed the basis for the database of SINEs. The SINEBase website can be used in two ways: first, to explore the database of SINE families, and second, to analyse candidate SINE sequences using specifically developed tools. This article presents an overview of the database and the process of SINE identification and analysis.

  4. ALMA High Frequency Techniques

    Science.gov (United States)

    Meyer, J. D.; Mason, B.; Impellizzeri, V.; Kameno, S.; Fomalont, E.; Chibueze, J.; Takahashi, S.; Remijan, A.; Wilson, C.; ALMA Science Team

    2015-12-01

    The purpose of the ALMA High Frequency Campaign is to improve the quality and efficiency of science observing in Bands 8, 9, and 10 (385-950 GHz), the highest frequencies available to the ALMA project. To this end, we outline observing modes which we have demonstrated to improve high frequency calibration for the 12m array and the ACA, and we present the calibration of the total power antennas at these frequencies. Band-to-band (B2B) transfer and bandwidth switching (BWSW), techniques which improve the speed and accuracy of calibration at the highest frequencies, are most necessary in Bands 8, 9, and 10 due to the rarity of strong calibrators. These techniques successfully enable increased signal-to-noise on the calibrator sources (and better calibration solutions) by measuring the calibrators at lower frequencies (B2B) or in wider bandwidths (BWSW) compared to the science target. We have also demonstrated the stability of the bandpass shape to better than 2.4% for 1 hour, hidden behind random noise, in Band 9. Finally, total power observing using the dual sideband receivers in Bands 9 and 10 requires the separation of the two sidebands; this procedure has been demonstrated in Band 9 and is undergoing further testing in Band 10.

  5. High frequency energy measurements

    International Nuclear Information System (INIS)

    Stotlar, S.C.

    1981-01-01

    High-frequency (> 100 MHz) energy measurements present special problems to the experimenter. Environment or available electronics often limit the applicability of a given detector type. The physical properties of many detectors are frequency dependent and in some cases, the physical effect employed can be frequency dependent. State-of-the-art measurements generally involve a detection scheme in association with high-speed electronics and a method of data recording. Events can be single or repetitive shot requiring real time, sampling, or digitizing data recording. Potential modification of the pulse by the detector and the associated electronics should not be overlooked. This presentation will review typical applications, methods of choosing a detector, and high-speed detectors. Special considerations and limitations of some applications and devices will be described

  6. High frequency electromagnetic dosimetry

    CERN Document Server

    Sánchez-Hernández, David A

    2009-01-01

    Along with the growth of RF and microwave technology applications, there is a mounting concern about the possible adverse effects over human health from electromagnetic radiation. Addressing this issue and putting it into perspective, this groundbreaking resource provides critical details on the latest advances in high frequency electromagnetic dosimetry.

  7. Pi-kinks in a parametrically driven sine-Gordon chain

    DEFF Research Database (Denmark)

    Kivshar, Yuri S.; Grønbech-Jensen, Niels; Samuelsen, Mogens Rugholm

    1992-01-01

    We consider the sine-Gordon chain driven by a high-frequency parametric force in the presence of loss. Using an analytical approach based on the method of averaging in fast oscillations, we predict that such a parametric force may support propagation of π kinks, which are unstable in the standard...... sine-Gordon model. The steady-state velocity of the π kinks is calculated, and the analytical results are in good agreement with direct numerical simulations....

  8. Functional noncoding sequences derived from SINEs in the mammalian genome.

    Science.gov (United States)

    Nishihara, Hidenori; Smit, Arian F A; Okada, Norihiro

    2006-07-01

    Recent comparative analyses of mammalian sequences have revealed that a large number of nonprotein-coding genomic regions are under strong selective constraint. Here, we report that some of these loci have been derived from a newly defined family of ancient SINEs (short interspersed repetitive elements). This is a surprising result, as SINEs and other transposable elements are commonly thought to be genomic parasites. We named the ancient SINE family AmnSINE1, for Amniota SINE1, because we found it to be present in mammals as well as in birds, and some copies predate the mammalian-bird split 310 million years ago (Mya). AmnSINE1 has a chimeric structure of a 5S rRNA and a tRNA-derived SINE, and is related to five tRNA-derived SINE families that we characterized here in the coelacanth, dogfish shark, hagfish, and amphioxus genomes. All of the newly described SINE families have a common central domain that is also shared by zebrafish SINE3, and we collectively name them the DeuSINE (Deuterostomia SINE) superfamily. Notably, of the approximately 1000 still identifiable copies of AmnSINE1 in the human genome, 105 correspond to loci phylogenetically highly conserved among mammalian orthologs. The conservation is strongest over the central domain. Thus, AmnSINE1 appears to be the best example of a transposable element of which a significant fraction of the copies have acquired genomic functionality.

  9. The Sine-Gordon model and its applications from pendula and Josephson junctions to gravity and high-energy physics

    CERN Document Server

    Kevrekidis, Panayotis; Williams, Floyd

    2014-01-01

    The sine-Gordon model is a ubiquitous model of Mathematical Physics with a wide range of applications extending from coupled torsion pendula and Josephson junction arrays to gravitational and high-energy physics models. The purpose of this book is to present a summary of recent developments in this field, incorporating both introductory background material, but also with a strong view towards modern applications, recent experiments, developments regarding the existence, stability, dynamics and asymptotics of nonlinear waves that arise in the model. This book is of particular interest to a wide range of researchers in this field, but serves as an introductory text for young researchers and students  interested in the topic. The book consists of well-selected thematic chapters on diverse mathematical and physical aspects of the equation carefully chosen and assigned.

  10. The Perception of "Sine-Wave Speech" by Adults with Developmental Dyslexia.

    Science.gov (United States)

    Rosner, Burton S.; Talcott, Joel B.; Witton, Caroline; Hogg, James D.; Richardson, Alexandra J.; Hansen, Peter C.; Stein, John F.

    2003-01-01

    "Sine-wave speech" sentences contain only four frequency-modulated sine waves, lacking many acoustic cues present in natural speech. Adults with (n=19) and without (n=14) dyslexia were asked to reproduce orally sine-wave utterances in successive trials. Results suggest comprehension of sine-wave sentences is impaired in some adults with…

  11. High frequency asymptotic methods

    International Nuclear Information System (INIS)

    Bouche, D.; Dessarce, R.; Gay, J.; Vermersch, S.

    1991-01-01

    The asymptotic methods allow us to compute the interaction of high frequency electromagnetic waves with structures. After an outline of their foundations with emphasis on the geometrical theory of diffraction, it is shown how to use these methods to evaluate the radar cross section (RCS) of complex tri-dimensional objects of great size compared to the wave-length. The different stages in simulating phenomena which contribute to the RCS are reviewed: physical theory of diffraction, multiple interactions computed by shooting rays, research for creeping rays. (author). 7 refs., 6 figs., 3 insets

  12. Newly discovered young CORE-SINEs in marsupial genomes.

    Science.gov (United States)

    Munemasa, Maruo; Nikaido, Masato; Nishihara, Hidenori; Donnellan, Stephen; Austin, Christopher C; Okada, Norihiro

    2008-01-15

    Although recent mammalian genome projects have uncovered a large part of genomic component of various groups, several repetitive sequences still remain to be characterized and classified for particular groups. The short interspersed repetitive elements (SINEs) distributed among marsupial genomes are one example. We have identified and characterized two new SINEs from marsupial genomes that belong to the CORE-SINE family, characterized by a highly conserved "CORE" domain. PCR and genomic dot blot analyses revealed that the distribution of each SINE shows distinct patterns among the marsupial genomes, implying different timing of their retroposition during the evolution of marsupials. The members of Mar3 (Marsupialia 3) SINE are distributed throughout the genomes of all marsupials, whereas the Mac1 (Macropodoidea 1) SINE is distributed specifically in the genomes of kangaroos. Sequence alignment of the Mar3 SINEs revealed that they can be further divided into four subgroups, each of which has diagnostic nucleotides. The insertion patterns of each SINE at particular genomic loci, together with the distribution patterns of each SINE, suggest that the Mar3 SINEs have intensively amplified after the radiation of diprotodontians, whereas the Mac1 SINE has amplified only slightly after the divergence of hypsiprimnodons from other macropods. By compiling the information of CORE-SINEs characterized to date, we propose a comprehensive picture of how SINE evolution occurred in the genomes of marsupials.

  13. High Frequency Oscillatory Ventilation

    Directory of Open Access Journals (Sweden)

    AC Bryan

    1996-01-01

    Full Text Available High frequency oscillatory (HFO ventilation using low tidal volume and peak airway pressures is extremely efficient at eliminating carbon dioxide and raising pH in the newborn infant with acute respiratory failure. Improvement in oxygenation requires a strategy of sustained or repetitive inflations to 25 to 30 cm H2O in order to place the lung on the deflation limb of the pressure-volume curve. This strategy has also been shown to decrease the amount of secondary lung injury in animal models. Experience of the use of HFO ventilation as a rescue therapy as well as several published controlled trials have shown improved outcomes and a decrease in the use of extracorporeal membrane oxygenation when it has been used in newborns.

  14. SINE_scan: an efficient tool to discover short interspersed nuclear elements (SINEs) in large-scale genomic datasets.

    Science.gov (United States)

    Mao, Hongliang; Wang, Hao

    2017-03-01

    Short Interspersed Nuclear Elements (SINEs) are transposable elements (TEs) that amplify through a copy-and-paste mode via RNA intermediates. The computational identification of new SINEs are challenging because of their weak structural signals and rapid diversification in sequences. Here we report SINE_Scan, a highly efficient program to predict SINE elements in genomic DNA sequences. SINE_Scan integrates hallmark of SINE transposition, copy number and structural signals to identify a SINE element. SINE_Scan outperforms the previously published de novo SINE discovery program. It shows high sensitivity and specificity in 19 plant and animal genome assemblies, of which sizes vary from 120 Mb to 3.5 Gb. It identifies numerous new families and substantially increases the estimation of the abundance of SINEs in these genomes. The code of SINE_Scan is freely available at http://github.com/maohlzj/SINE_Scan , implemented in PERL and supported on Linux. wangh8@fudan.edu.cn. Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press.

  15. High frequency breakdown voltage

    International Nuclear Information System (INIS)

    Chu, Thanh Duy.

    1992-03-01

    This report contains information about the effect of frequency on the breakdown voltage of an air gap at standard pressure and temperature, 76 mm Hg and O degrees C, respectively. The frequencies of interest are 47 MHz and 60 MHz. Additionally, the breakdown in vacuum is briefly considered. The breakdown mechanism is explained on the basis of collision and ionization. The presence of the positive ions produced by ionization enhances the field in the gap, and thus determines the breakdown. When a low-frequency voltage is applied across the gap, the breakdown mechanism is the same as that caused by the DC or static voltage. However, when the frequency exceeds the first critical value f c , the positive ions are trapped in the gap, increasing the field considerably. This makes the breakdown occur earlier; in other words, the breakdown voltage is lowered. As the frequency increases two decades or more, the second critical frequency, f ce , is reached. This time the electrons start being trapped in the gap. Those electrons that travel multiple times across the gap before reaching the positive electrode result in an enormous number of electrons and positive ions being present in the gap. The result is a further decrease of the breakdown voltage. However, increasing the frequency does not decrease the breakdown voltage correspondingly. In fact, the associated breakdown field intensity is almost constant (about 29 kV/cm).The reason is that the recombination rate increases and counterbalances the production rate, thus reducing the effect of the positive ions' concentration in the gap. The theory of collision and ionization does not apply to the breakdown in vacuum. It seems that the breakdown in vacuum is primarily determined by the irregularities on the surfaces of the electrodes. Therefore, the effect of frequency on the breakdown, if any, is of secondary importance

  16. Binaural beats at high frequencies.

    Science.gov (United States)

    McFadden, D; Pasanen, E G

    1975-10-24

    Binaural beats have long been believed to be audible only at low frequencies, but an interaction reminiscent of a binaural beat can sometimes be heard when different two-tone complexes of high frequency are presented to the two ears. The primary requirement is that the frequency separation in the complex at one ear be slightly different from that in the other--that is, that there be a small interaural difference in the envelope periodicities. This finding is in accord with other recent demonstrations that the auditory system is not deaf to interaural time differences at high frequencies.

  17. High frequency ignition arrangement

    Energy Technology Data Exchange (ETDEWEB)

    Canup, R E

    1977-03-03

    The invention concerns an HF ignition arrangement for combustion engines with a transistor oscillator. As this oscillator requires a current of 10A, with peak currents up to about 50A, it is not sensible to take this current through the remote ignition switch for switching it on and off. According to the invention the HF high voltage transformer of the ignition is provided with a control winding, which only requires a few milliamps DC and which can therefore be switched via the ignition switch. If the ignition switch is in the 'running' position, then a premagnetising DC current flows through the control winding, which suppresses the oscillation of the oscillator which has current flowing through it, until this current is interrupted by the interruptor contacts controlled by the combustion engine, so that the oscillations of the oscillator start immediately; the oscillator only continues to oscillate during the period during which the interruptor contacts controlled by the machine are open and interrupt the premagnetisation current. The control winding is short circuited in the 'off' position of the ignition switch.

  18. Geographies of High Frequency Trading

    DEFF Research Database (Denmark)

    Grindsted, Thomas Skou

    2016-01-01

    This paper investigates the geographies of high frequency trading. Today shares shift hands within micro seconds, giving rise to a form of financial geographies termed algorithmic capitalism. This notion refers to the different spatio-temporalities produced by high frequency trading, under...... the valuation of time. As high frequency trading accelerates financial markets, the paper examines the spatio-temporalities of automated trading by the ways in which the speed of knowledge exploitation in financial markets is not only of interest, but also the expansion between different temporalities....... The paper demonstrates how the intensification of time-space compression produces radical new dynamics in the financial market and develops information rent in HFT as convertible to a time rent and a spatio-temporal rent. The final section discusses whether high frequency trading only responds to crises...

  19. The sine-Gordon wobble

    International Nuclear Information System (INIS)

    Kaelbermann, G

    2004-01-01

    Nonperturbative, oscillatory, winding number 1 solutions of the sine-Gordon equation are presented and studied numerically. We call these nonperturbative shape modes wobble solitons. Perturbed sine-Gordon kinks are found to decay to wobble solitons

  20. Conserved domains and SINE diversity during animal evolution.

    Science.gov (United States)

    Luchetti, Andrea; Mantovani, Barbara

    2013-10-01

    Eukaryotic genomes harbour a number of mobile genetic elements (MGEs); moving from one genomic location to another, they are known to impact on the host genome. Short interspersed elements (SINEs) are well-represented, non-autonomous retroelements and they are likely the most diversified MGEs. In some instances, sequence domains conserved across unrelated SINEs have been identified; remarkably, one of these, called Nin, has been conserved since the Radiata-Bilateria splitting. Here we report on two new domains: Inv, derived from Nin, identified in insects and in deuterostomes, and Pln, restricted to polyneopteran insects. The identification of Inv and Pln sequences allowed us to retrieve new SINEs, two in insects and one in a hemichordate. The diverse structural combination of the different domains in different SINE families, during metazoan evolution, offers a clearer view of SINE diversity and their frequent de novo emergence through module exchange, possibly underlying the high evolutionary success of SINEs. © 2013 Elsevier Inc. All rights reserved.

  1. High-frequency Trader Subjectivity

    DEFF Research Database (Denmark)

    Borch, Christian; Lange, Ann-Christina

    2017-01-01

    In this article, we examine the recent shift in financial markets toward high-frequency trading (HFT). This turn is being legitimized with reference to how algorithms are allegedly more rational and efficient than human traders, and less prone to emotionally motivated decisions. We argue......-techniques of the ideal high-frequency trader. We demonstrate that these traders face the challenge of avoiding emotional interference in their algorithms and that they deploy a set of disciplinary self-techniques to curb the importance of emotional attachment....

  2. Low frequency phase signal measurement with high frequency squeezing

    OpenAIRE

    Zhai, Zehui; Gao, Jiangrui

    2011-01-01

    We calculate the utility of high-frequency squeezed-state enhanced two-frequency interferometry for low-frequency phase measurement. To use the high-frequency sidebands of the squeezed light, a two-frequency intense laser is used in the interferometry instead of a single-frequency laser as usual. We find that the readout signal can be contaminated by the high-frequency phase vibration, but this is easy to check and avoid. A proof-of-principle experiment is in the reach of modern quantum optic...

  3. Genome-wide analysis of short interspersed nuclear elements SINES revealed high sequence conservation, gene association and retrotranspositional activity in wheat.

    Science.gov (United States)

    Ben-David, Smadar; Yaakov, Beery; Kashkush, Khalil

    2013-10-01

    Short interspersed nuclear elements (SINEs) are non-autonomous non-LTR retroelements that are present in most eukaryotic species. While SINEs have been intensively investigated in humans and other animal systems, they are poorly studied in plants, especially in wheat (Triticum aestivum). We used quantitative PCR of various wheat species to determine the copy number of a wheat SINE family, termed Au SINE, combined with computer-assisted analyses of the publicly available 454 pyrosequencing database of T. aestivum. In addition, we utilized site-specific PCR on 57 Au SINE insertions, transposon methylation display and transposon display on newly formed wheat polyploids to assess retrotranspositional activity, epigenetic status and genetic rearrangements in Au SINE, respectively. We retrieved 3706 different insertions of Au SINE from the 454 pyrosequencing database of T. aestivum, and found that most of the elements are inserted in A/T-rich regions, while approximately 38% of the insertions are associated with transcribed regions, including known wheat genes. We observed typical retrotransposition of Au SINE in the second generation of a newly formed wheat allohexaploid, and massive hypermethylation in CCGG sites surrounding Au SINE in the third generation. Finally, we observed huge differences in the copy numbers in diploid Triticum and Aegilops species, and a significant increase in the copy numbers in natural wheat polyploids, but no significant increase in the copy number of Au SINE in the first four generations for two of three newly formed allopolyploid species used in this study. Our data indicate that SINEs may play a prominent role in the genomic evolution of wheat through stress-induced activation. © 2013 Ben-Gurion University The Plant Journal © 2013 John Wiley & Sons Ltd.

  4. High-frequency, high-intensity photoionization

    Science.gov (United States)

    Reiss, H. R.

    1996-02-01

    Two analytical methods for computing ionization by high-frequency fields are compared. Predicted ionization rates compare well, but energy predictions for the onset of ionization differ radically. The difference is shown to arise from the use of a transformation in one of the methods that alters the zero from which energy is measured. This alteration leads to an apparent energy threshold for ionization that can, especially in the stabilization regime, differ strongly from the laboratory measurement. It is concluded that channel closings in intense-field ionization can occur at high as well as low frequencies. It is also found that the stabilization phenomenon at high frequencies, very prominent for hydrogen, is absent in a short-range potential.

  5. High-Frequency Seafloor Acoustics

    CERN Document Server

    Jackson, Darrell R

    2007-01-01

    High-Frequency Seafloor Acoustics is the first book in a new series sponsored by the Office of Naval Research on the latest research in underwater acoustics. This exciting new title provides ready access to experimental data, theory, and models relevant to high-frequency seafloor acoustics and will be of interest to sonar engineers and researchers working in underwater acoustics. The physical characteristics of the seafloor affecting acoustic propagation and scattering are covered, including physical and geoacoustic properties and surface roughness. Current theories for acoustic propagation in sediments are presented along with corresponding models for reflection, scattering, and seafloor penetration. The main text is backed up by an extensive bibliography and technical appendices.

  6. High-frequency magnetic components

    CERN Document Server

    Kazimierczuk, Marian K

    2013-01-01

    A unique text on the theory and design fundaments of inductors and transformers, updated with more coverage on the optimization of magnetic devices and many new design examples The first edition is popular among a very broad audience of readers in different areas of engineering and science. This book covers the theory and design techniques of the major types of high-frequency power inductors and transformers for a variety of applications, including switching-mode power supplies (SMPS) and resonant dc-to-ac power inverters and dc-to-dc power converters. It describes eddy-current phenomena (su

  7. High-frequency plasma oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Akhiezer, A I; Fainberg, Y B; Sitenko, A G; Stepanov, K; Kurilko, V; Gorbatenko, M; Kirochkin, U [Academy of Sciences of the Ukrainian SSR (USSR)

    1958-07-01

    It is well known that the electrical conductivity of a plasma, the ion-electron equilibration time, and the time required to heat the electron component of the plasma all increase greatly with increasing temperature. Consequently, the usual method of Joule heating a plasma may be difficult to apply in the region of high temperatures (> 10{sup 6}K), especially if the plasma current alone, without any additional measures, is used to generate magnetic fields for the confinement of the plasma. Therefore, it is of interest to study methods of plasma heating that do not directly use Joule heat, especially methods by which energy is directly supplied to the ion component during the time between collisions. Some of these methods make use of ionic resonance as well as other resonance phenomena which can occur in plasma in an external magnetic field. This paper deals with certain aspects of the theory of high-frequency plasma oscillations.

  8. SINEs, evolution and genome structure in the opossum.

    Science.gov (United States)

    Gu, Wanjun; Ray, David A; Walker, Jerilyn A; Barnes, Erin W; Gentles, Andrew J; Samollow, Paul B; Jurka, Jerzy; Batzer, Mark A; Pollock, David D

    2007-07-01

    Short INterspersed Elements (SINEs) are non-autonomous retrotransposons, usually between 100 and 500 base pairs (bp) in length, which are ubiquitous components of eukaryotic genomes. Their activity, distribution, and evolution can be highly informative on genomic structure and evolutionary processes. To determine recent activity, we amplified more than one hundred SINE1 loci in a panel of 43 M. domestica individuals derived from five diverse geographic locations. The SINE1 family has expanded recently enough that many loci were polymorphic, and the SINE1 insertion-based genetic distances among populations reflected geographic distance. Genome-wide comparisons of SINE1 densities and GC content revealed that high SINE1 density is associated with high GC content in a few long and many short spans. Young SINE1s, whether fixed or polymorphic, showed an unbiased GC content preference for insertion, indicating that the GC preference accumulates over long time periods, possibly in periodic bursts. SINE1 evolution is thus broadly similar to human Alu evolution, although it has an independent origin. High GC content adjacent to SINE1s is strongly correlated with bias towards higher AT to GC substitutions and lower GC to AT substitutions. This is consistent with biased gene conversion, and also indicates that like chickens, but unlike eutherian mammals, GC content heterogeneity (isochore structure) is reinforced by substitution processes in the M. domestica genome. Nevertheless, both high and low GC content regions are apparently headed towards lower GC content equilibria, possibly due to a relative shift to lower recombination rates in the recent Monodelphis ancestral lineage. Like eutherians, metatherian (marsupial) mammals have evolved high CpG substitution rates, but this is apparently a convergence in process rather than a shared ancestral state.

  9. High Temperature Radio Frequency Loads

    CERN Document Server

    Federmann, S; Grudiev, A; Montesinos, E; Syratchev, I

    2011-01-01

    In the context of energy saving and recovery requirements the design of reliable and robust RF power loads which permit a high outlet temperature and high pressure of the cooling water is desirable. Cooling water arriving at the outlet withmore than 150 ◦C and high pressure has a higher value than water with 50 ◦C under low pressure. Conventional RF power loads containing dielectric and magnetic materials as well as sensitive ceramic windows usually do not permit going much higher than 90 ◦C. Here we present and discuss several design concepts for "metal only" RF high power loads. One concept is the application of magnetic steel corrugated waveguides near cutoff – this concept could find practical use above several GHz. Another solution are resonant structures made of steel to be installed in large waveguides for frequencies of 500 MHz or lower. Similar resonant structures above 100 MHz taking advantage of the rather high losses of normal steel may also be used in coaxial line geometries with large di...

  10. Econometrics of financial high-frequency data

    CERN Document Server

    Hautsch, Nikolaus

    2011-01-01

    This book covers major approaches in high-frequency econometrics. It discusses implementation details, provides insights into properties of high-frequency data as well as institutional settings and presents applications.

  11. SINE transcription by RNA polymerase III is suppressed by histone methylation but not by DNA methylation

    Science.gov (United States)

    Varshney, Dhaval; Vavrova-Anderson, Jana; Oler, Andrew J.; Cowling, Victoria H.; Cairns, Bradley R.; White, Robert J.

    2015-01-01

    Short interspersed nuclear elements (SINEs), such as Alu, spread by retrotransposition, which requires their transcripts to be copied into DNA and then inserted into new chromosomal sites. This can lead to genetic damage through insertional mutagenesis and chromosomal rearrangements between non-allelic SINEs at distinct loci. SINE DNA is heavily methylated and this was thought to suppress its accessibility and transcription, thereby protecting against retrotransposition. Here we provide several lines of evidence that methylated SINE DNA is occupied by RNA polymerase III, including the use of high-throughput bisulphite sequencing of ChIP DNA. We find that loss of DNA methylation has little effect on accessibility of SINEs to transcription machinery or their expression in vivo. In contrast, a histone methyltransferase inhibitor selectively promotes SINE expression and occupancy by RNA polymerase III. The data suggest that methylation of histones rather than DNA plays a dominant role in suppressing SINE transcription. PMID:25798578

  12. A difference tracking algorithm based on discrete sine transform

    Science.gov (United States)

    Liu, HaoPeng; Yao, Yong; Lei, HeBing; Wu, HaoKun

    2018-04-01

    Target tracking is an important field of computer vision. The template matching tracking algorithm based on squared difference matching (SSD) and standard correlation coefficient (NCC) matching is very sensitive to the gray change of image. When the brightness or gray change, the tracking algorithm will be affected by high-frequency information. Tracking accuracy is reduced, resulting in loss of tracking target. In this paper, a differential tracking algorithm based on discrete sine transform is proposed to reduce the influence of image gray or brightness change. The algorithm that combines the discrete sine transform and the difference algorithm maps the target image into a image digital sequence. The Kalman filter predicts the target position. Using the Hamming distance determines the degree of similarity between the target and the template. The window closest to the template is determined the target to be tracked. The target to be tracked updates the template. Based on the above achieve target tracking. The algorithm is tested in this paper. Compared with SSD and NCC template matching algorithms, the algorithm tracks target stably when image gray or brightness change. And the tracking speed can meet the read-time requirement.

  13. Geostatistical uncertainty of assessing air quality using high-spatial-resolution lichen data: A health study in the urban area of Sines, Portugal.

    Science.gov (United States)

    Ribeiro, Manuel C; Pinho, P; Branquinho, C; Llop, Esteve; Pereira, Maria J

    2016-08-15

    In most studies correlating health outcomes with air pollution, personal exposure assignments are based on measurements collected at air-quality monitoring stations not coinciding with health data locations. In such cases, interpolators are needed to predict air quality in unsampled locations and to assign personal exposures. Moreover, a measure of the spatial uncertainty of exposures should be incorporated, especially in urban areas where concentrations vary at short distances due to changes in land use and pollution intensity. These studies are limited by the lack of literature comparing exposure uncertainty derived from distinct spatial interpolators. Here, we addressed these issues with two interpolation methods: regression Kriging (RK) and ordinary Kriging (OK). These methods were used to generate air-quality simulations with a geostatistical algorithm. For each method, the geostatistical uncertainty was drawn from generalized linear model (GLM) analysis. We analyzed the association between air quality and birth weight. Personal health data (n=227) and exposure data were collected in Sines (Portugal) during 2007-2010. Because air-quality monitoring stations in the city do not offer high-spatial-resolution measurements (n=1), we used lichen data as an ecological indicator of air quality (n=83). We found no significant difference in the fit of GLMs with any of the geostatistical methods. With RK, however, the models tended to fit better more often and worse less often. Moreover, the geostatistical uncertainty results showed a marginally higher mean and precision with RK. Combined with lichen data and land-use data of high spatial resolution, RK is a more effective geostatistical method for relating health outcomes with air quality in urban areas. This is particularly important in small cities, which generally do not have expensive air-quality monitoring stations with high spatial resolution. Further, alternative ways of linking human activities with their

  14. Short interspersed elements (SINEs) are a major source of canine genomic diversity.

    Science.gov (United States)

    Wang, Wei; Kirkness, Ewen F

    2005-12-01

    SINEs are retrotransposons that have enjoyed remarkable reproductive success during the course of mammalian evolution, and have played a major role in shaping mammalian genomes. Previously, an analysis of survey-sequence data from an individual dog (a poodle) indicated that canine genomes harbor a high frequency of alleles that differ only by the absence or presence of a SINEC_Cf repeat. Comparison of this survey-sequence data with a draft genome sequence of a distinct dog (a boxer) has confirmed this prediction, and revealed the chromosomal coordinates for >10,000 loci that are bimorphic for SINEC_Cf insertions. Analysis of SINE insertion sites from the genomes of nine additional dogs indicates that 3%-5% are absent from either the poodle or boxer genome sequences--suggesting that an additional 10,000 bimorphic loci could be readily identified in the general dog population. We describe a methodology that can be used to identify these loci, and could be adapted to exploit these bimorphic loci for genotyping purposes. Approximately half of all annotated canine genes contain SINEC_Cf repeats, and these elements are occasionally transcribed. When transcribed in the antisense orientation, they provide splice acceptor sites that can result in incorporation of novel exons. The high frequency of bimorphic SINE insertions in the dog population is predicted to provide numerous examples of allele-specific transcription patterns that will be valuable for the study of differential gene expression among multiple dog breeds.

  15. High Frequency Components Recovery in Music Signals

    Directory of Open Access Journals (Sweden)

    V. Sebesta

    1999-04-01

    Full Text Available A new technique is presented which improves the subjective quality of band-limited music by recovery of high frequency components. Sequences of harmonics are found in the band-limited signal and these sequences are expanded to the high frequency band to estimate the lost part of spectrum. High frequency signal is generated to match this estimation and is added to the band-limited signal.

  16. The Evolution of SINEs and LINEs in the genus Chironomus (Diptera).

    Science.gov (United States)

    Papusheva, Ekaterina; Gruhl, Mary C; Berezikov, Eugene; Groudieva, Tatiana; Scherbik, Svetlana V; Martin, Jon; Blinov, Alexander; Bergtrom, Gerald

    2004-03-01

    Genomic DNA amplification from 51 species of the family Chironomidae shows that most contain relatives of NLRCth1 LINE and CTRT1 SINE retrotransposons first found in Chironomus thummi. More than 300 cloned PCR products were sequenced. The amplified region of the reverse transcriptase gene in the LINEs is intact and highly conserved, suggesting active elements. The SINEs are less conserved, consistent with minimal/no selection after transposition. A mitochondrial gene phylogeny resolves the Chironomus genus into six lineages (Guryev et al. 2001). LINE and SINE phylogenies resolve five of these lineages, indicating their monophyletic origin and vertical inheritance. However, both the LINE and the SINE tree topologies differ from the species phylogeny, resolving the elements into "clusters I-IV" and "cluster V" families. The data suggest a descent of all LINE and SINE subfamilies from two major families. Based on the species phylogeny, a few LINEs and a larger number of SINEs are cladisitically misplaced. Most misbranch with LINEs or SINEs from species with the same families of elements. From sequence comparisons, cladistically misplaced LINEs and several misplaced SINEs arose by convergent base substitutions. More diverged SINEs result from early transposition and some are derived from multiple source SINEs in the same species. SINEs from two species (C. dorsalis, C. pallidivittatus), expected to belong to the clusters I-IV family, branch instead with cluster V family SINEs; apparently both families predate separation of cluster V from clusters I-IV species. Correlation of the distribution of active SINEs and LINEs, as well as similar 3' sequence motifs in CTRT1 and NLRCth1, suggests coevolving retrotransposon pairs in which CTRT1 transposition depends on enzymes active during NLRCth1 LINE mobility.

  17. Lightweight, high-frequency transformers

    Science.gov (United States)

    Schwarze, G. E.

    1983-01-01

    The 25-kVA space transformer was developed under contract by Thermal Technology Laboratory, Buffalo, N. Y. The NASA Lewis transformer technology program attempted to develop the baseline technology. For the 25-kVA transformer the input voltage was chosen as 200 V, the output voltage as 1500 V, the input voltage waveform as square wave, the duty cycle as continuous, the frequency range (within certain constraints) as 10 to 40 kHz, the operating temperatures as 85 deg. and 130 C, the baseplate temperature as 50 C, the equivalent leakage inductance as less than 10 micro-h, the operating environment as space, and the life expectancy as 10 years. Such a transformer can also be used for aircraft, ship and terrestrial applications.

  18. Universal precision sine bar attachment

    Science.gov (United States)

    Mann, Franklin D. (Inventor)

    1989-01-01

    This invention relates to an attachment for a sine bar which can be used to perform measurements during lathe operations or other types of machining operations. The attachment can be used for setting precision angles on vises, dividing heads, rotary tables and angle plates. It can also be used in the inspection of machined parts, when close tolerances are required, and in the layout of precision hardware. The novelty of the invention is believed to reside in a specific versatile sine bar attachment for measuring a variety of angles on a number of different types of equipment.

  19. Nonlinear dynamics of a parametrically driven sine-Gordon system

    DEFF Research Database (Denmark)

    Grønbech-Jensen, Niels; Kivshar, Yuri S.; Samuelsen, Mogens Rugholm

    1993-01-01

    We consider a sine-Gordon system, driven by an ac parametric force in the presence of loss. It is demonstrated that a breather can be maintained in a steady state at half of the external frequency. In the small-amplitude limit the effect is described by an effective nonlinear Schrodinger equation...

  20. The dynamic proliferation of CanSINEs mirrors the complex evolution of Feliforms

    Science.gov (United States)

    2014-01-01

    Background Repetitive short interspersed elements (SINEs) are retrotransposons ubiquitous in mammalian genomes and are highly informative markers to identify species and phylogenetic associations. Of these, SINEs unique to the order Carnivora (CanSINEs) yield novel insights on genome evolution in domestic dogs and cats, but less is known about their role in related carnivores. In particular, genome-wide assessment of CanSINE evolution has yet to be completed across the Feliformia (cat-like) suborder of Carnivora. Within Feliformia, the cat family Felidae is composed of 37 species and numerous subspecies organized into eight monophyletic lineages that likely arose 10 million years ago. Using the Felidae family as a reference phylogeny, along with representative taxa from other families of Feliformia, the origin, proliferation and evolution of CanSINEs within the suborder were assessed. Results We identified 93 novel intergenic CanSINE loci in Feliformia. Sequence analyses separated Feliform CanSINEs into two subfamilies, each characterized by distinct RNA polymerase binding motifs and phylogenetic associations. Subfamily I CanSINEs arose early within Feliformia but are no longer under active proliferation. Subfamily II loci are more recent, exclusive to Felidae and show evidence for adaptation to extant RNA polymerase activity. Further, presence/absence distributions of CanSINE loci are largely congruent with taxonomic expectations within Feliformia and the less resolved nodes in the Felidae reference phylogeny present equally ambiguous CanSINE data. SINEs are thought to be nearly impervious to excision from the genome. However, we observed a nearly complete excision of a CanSINEs locus in puma (Puma concolor). In addition, we found that CanSINE proliferation in Felidae frequently targeted existing CanSINE loci for insertion sites, resulting in tandem arrays. Conclusions We demonstrate the existence of at least two SINE families within the Feliformia suborder, one

  1. High-frequency conductivity of photoionized plasma

    Energy Technology Data Exchange (ETDEWEB)

    Anakhov, M. V.; Uryupin, S. A., E-mail: uryupin@sci.lebedev.ru [National Research Nuclear University “MEPhI,” (Russian Federation)

    2016-08-15

    The tensor of the high-frequency conductivity of a plasma created via tunnel ionization of atoms in the field of linearly or circularly polarized radiation is derived. It is shown that the real part of the conductivity tensor is highly anisotropic. In the case of a toroidal velocity distribution of photoelectrons, the possibility of amplification of a weak high-frequency field polarized at a sufficiently large angle to the anisotropy axis of the initial nonequilibrium distribution is revealed.

  2. Cooking Appliances Using High-Frequency Heating

    OpenAIRE

    木村, 秀行; Hideyuki, KIMURA; (株)日立製作所機械研究所

    2007-01-01

    We have produced a guide suitable for people with no technical knowledge of cooking appliances that use high-frequency heating. In general, cooking appliances that use an electric heat source are popular since, they are simple to use because the offer easy heat control, are safe because they do not have naked flames, and do not make kitchens dirty because there is no exhaust. In recent years, high-efficiency cooking appliances using high-frequency heating technology have surged in popularity....

  3. Guinea pig ID-like families of SINEs.

    Science.gov (United States)

    Kass, David H; Schaetz, Brian A; Beitler, Lindsey; Bonney, Kevin M; Jamison, Nicole; Wiesner, Cathy

    2009-05-01

    Previous studies have indicated a paucity of SINEs within the genomes of the guinea pig and nutria, representatives of the Hystricognathi suborder of rodents. More recent work has shown that the guinea pig genome contains a large number of B1 elements, expanding to various levels among different rodents. In this work we utilized A-B PCR and screened GenBank with sequences from isolated clones to identify potentially uncharacterized SINEs within the guinea pig genome, and identified numerous sequences with a high degree of similarity (>92%) specific to the guinea pig. The presence of A-tails and flanking direct repeats associated with these sequences supported the identification of a full-length SINE, with a consensus sequence notably distinct from other rodent SINEs. Although most similar to the ID SINE, it clearly was not derived from the known ID master gene (BC1), hence we refer to this element as guinea pig ID-like (GPIDL). Using the consensus to screen the guinea pig genomic database (Assembly CavPor2) with Ensembl BlastView, we estimated at least 100,000 copies, which contrasts markedly to just over 100 copies of ID elements. Additionally we provided evidence of recent integrations of GPIDL as two of seven analyzed conserved GPIDL-containing loci demonstrated presence/absence variants in Cavia porcellus and C. aperea. Using intra-IDL PCR and sequence analyses we also provide evidence that GPIDL is derived from a hystricognath-specific SINE family. These results demonstrate that this SINE family continues to contribute to the dynamics of genomes of hystricognath rodents.

  4. High frequency oscillations in brain hemodynamic response

    Science.gov (United States)

    Akin, Ata; Bolay, Hayrunnisa

    2007-07-01

    Tight autoregulation of vessel tone guarantees proper delivery of nutrients to the tissues. This regulation is maintained at a more delicate level in the brain since any decrease in the supply of glucose and oxygen to neuronal tissues might lead to unrecoverable injury. Functional near infrared spectroscopy has been proposed as a new tool to monitor the cerebrovascular response during cognitive activity. We have observed that during a Stroop task three distinct oscillatory patterns govern the control of the cerebrovascular reactivity: very low frequency (0.02-0.05 Hz), low frequency (0.08-0.12 Hz) and high frequency (0.12-0.18 Hz). High frequency oscillations have been shown to be related to stress level of the subjects. Our findings indicate that as the stress level is increased so does the energy of the high frequency component indicating a higher stimulation from the autonomic nervous system.

  5. 75 FR 81284 - Nationwide Use of High Frequency and Ultra High Frequency Active SONAR Technology; Draft...

    Science.gov (United States)

    2010-12-27

    ... Frequency and Ultra High Frequency Active SONAR Technology; Draft Programmatic Environmental Assessment and... Programmatic Environmental Assessment (PEA) for the Nationwide Use of High Frequency (HF) and Ultra High... potential impacts of each alternative on the human and natural environments. DATES: Comments and related...

  6. High frequency dynamics in centrifugal compressors

    NARCIS (Netherlands)

    Twerda, A.; Meulendijks, D.; Smeulers, J.P.M.; Handel, R. van den; Lier, L.J. van

    2008-01-01

    Problems with centrifugal compressors relating to high frequency, i.e. Blade passing frequency (BPF) are increasing. Pulsations and vibrations generated in centrifugal compressors can lead to nuisance, due to strong tonal noise, and even breakdown. In several cases the root cause of a failure or a

  7. Comparison of renormalization group schemes for sine-Gordon-type models

    International Nuclear Information System (INIS)

    Nandori, I.; Nagy, S.; Sailer, K.; Trombettoni, A.

    2009-01-01

    The scheme dependence of the renormalization group (RG) flow has been investigated in the local potential approximation for two-dimensional periodic, sine-Gordon type field-theoretic models discussing the applicability of various functional RG methods in detail. It was shown that scheme-independent determination of such physical parameters is possible as the critical frequency (temperature) at which Kosterlitz-Thouless-Berezinskii type phase transition takes place in the sine-Gordon and the layered sine-Gordon models, and the critical ratio characterizing the Ising-type phase transition of the massive sine-Gordon model. For the latter case, the Maxwell construction represents a strong constraint on the RG flow, which results in a scheme-independent infrared value for the critical ratio. For the massive sine-Gordon model also the shrinking of the domain of the phase with spontaneously broken periodicity is shown to take place due to the quantum fluctuations.

  8. Superconducting high frequency high power resonators

    International Nuclear Information System (INIS)

    Hobbis, C.; Vardiman, R.; Weinman, L.

    1974-01-01

    A niobium superconducting quarter-wave helical resonator has been designed and built. The resonator has been electron-beam welded and electropolished to produce a smooth flaw-free surface. This has been followed by an anodization to produce a 1000 A layer of Nb 2 0 5 . At the resonant frequency of approximately 15 MHz the unloaded Q was approximately equal to 4.6x10 6 with minimal dielectric support. With the resonator open to the helium bath to provide cooling, and rigidly supported by a teflon cylinder, 350 V of power were transferred at a doubly loaded Q of 3500. The extrapolation of the results to a Qsub(DL) of 1000 meet the power handling criteria of one kilowatt for the intended application. (author)

  9. SINE Retrotransposition: Evaluation of Alu Activity and Recovery of De Novo Inserts.

    Science.gov (United States)

    Ade, Catherine; Roy-Engel, Astrid M

    2016-01-01

    Mobile element activity is of great interest due to its impact on genomes. However, the types of mobile elements that inhabit any given genome are remarkably varied. Among the different varieties of mobile elements, the Short Interspersed Elements (SINEs) populate many genomes, including many mammalian species. Although SINEs are parasites of Long Interspersed Elements (LINEs), SINEs have been highly successful in both the primate and rodent genomes. When comparing copy numbers in mammals, SINEs have been vastly more successful than other nonautonomous elements, such as the retropseudogenes and SVA. Interestingly, in the human genome the copy number of Alu (a primate SINE) outnumbers LINE-1 (L1) copies 2 to 1. Estimates suggest that the retrotransposition rate for Alu is tenfold higher than LINE-1 with about 1 insert in every twenty births. Furthermore, Alu-induced mutagenesis is responsible for the majority of the documented instances of human retroelement insertion-induced disease. However, little is known on what contributes to these observed differences between SINEs and LINEs. The development of an assay to monitor SINE retrotransposition in culture has become an important tool for the elucidation of some of these differences. In this chapter, we present details of the SINE retrotransposition assay and the recovery of de novo inserts. We also focus on the nuances that are unique to the SINE assay.

  10. Overview of the Advanced High Frequency Branch

    Science.gov (United States)

    Miranda, Felix A.

    2015-01-01

    This presentation provides an overview of the competencies, selected areas of research and technology development activities, and current external collaborative efforts of the NASA Glenn Research Center's Advanced High Frequency Branch.

  11. Nanostructures for Very High Frequency Electronics

    National Research Council Canada - National Science Library

    Gelmont, Boris

    2002-01-01

    The study of a new class of mesoscopic high frequency semi-conductor devices based on resonant tunneling in staggered-bandgap heterostructures with III-V semi-conductor ternary alloys such as AlGaSb...

  12. High frequency system project implementation plan

    International Nuclear Information System (INIS)

    Moon, L.L.

    1976-01-01

    The High Frequency System is a new mobile, digital diagnostic recording system for use at the Nevada Test Site. Many different kinds of event data will be digitized in real-time by this system, and these data will be recorded and stored for later read-out and transmission to NADCEN. The hardware and software requirements of the High Frequency System are examined, and the parameters of the system are proposed

  13. High frequency conductivity in carbon nanotubes

    Directory of Open Access Journals (Sweden)

    S. S. Abukari

    2012-12-01

    Full Text Available We report on theoretical analysis of high frequency conductivity in carbon nanotubes. Using the kinetic equation with constant relaxation time, an analytical expression for the complex conductivity is obtained. The real part of the complex conductivity is initially negative at zero frequency and become more negative with increasing frequency, until it reaches a resonance minimum at ω ∼ ωB for metallic zigzag CNs and ω < ωB for armchair CNs. This resonance enhancement is indicative for terahertz gain without the formation of current instabilities induced by negative dc conductivity. We noted that due to the high density of states of conduction electrons in metallic zigzag carbon nanotubes and the specific dispersion law inherent in hexagonal crystalline structure result in a uniquely high frequency conductivity than the corresponding values for metallic armchair carbon nanotubes. We suggest that this phenomenon can be used to suppress current instabilities that are normally associated with a negative dc differential conductivity.

  14. Generalized sine-Gordon solitons

    International Nuclear Information System (INIS)

    Santos, C dos; Rubiera-Garcia, D

    2011-01-01

    In this paper, we construct analytical self-dual soliton solutions in (1+1) dimensions for two families of models which can be seen as generalizations of the sine-Gordon system but where the kinetic term is non-canonical. For that purpose we use a projection method applied to the sine-Gordon soliton. We focus our attention on the wall and lump-like soliton solutions of these k-field models. These solutions and their potentials reduce to those of the Klein-Gordon kink and the standard lump for the case of a canonical kinetic term. As we increase the nonlinearity on the kinetic term the corresponding potentials get modified and the nature of the soliton may change, in particular, undergoing a topology modification. The procedure constructed here is shown to be a sort of generalization of the deformation method for a specific class of k-field models. (paper)

  15. An ultra-high-speed direct digital frequency synthesizer implemented in GaAs HBT technology

    International Nuclear Information System (INIS)

    Chen Gaopeng; Wu Danyu; Jin Zhi; Liu Xinyu

    2010-01-01

    This paper presents a 10-GHz 8-bit direct digital synthesizer (DDS) microwave monolithic integrated circuit implemented in 1 μm GaAs HBT technology. The DDS takes a double-edge-trigger (DET) 8-stage pipeline accumulator with sine-weighted DAC-based ROM-less architecture, which can maximize the utilization ratio of the GaAs HBT's high-speed potential. With an output frequency up to 5 GHz, the DDS gives an average spurious free dynamic range of 23.24 dBc through the first Nyquist band, and consumes 2.4 W of DC power from a single -4.6 V DC supply. Using 1651 GaAs HBT transistors, the total area of the DDS chip is 2.4 x 2.0 mm 2 . (semiconductor integrated circuits)

  16. Investigation of 0.38 THz backward-wave oscillator based on slotted sine waveguide and pencil electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Luqi; Wei, Yanyu; Wang, Bing; Shen, Wenan; Xu, Jin; Gong, Yubin [National Key Laboratory of Science and Technology on Vacuum Electronics, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Park, Gun-Sik [The Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2016-03-15

    A novel backward wave oscillator (BWO) is presented by utilizing a slotted sine waveguide with a pencil electron beam to produce the high power terahertz wave. The high frequency characteristics including dispersion properties, interaction impedances, and transmission characteristics of the slotted sine waveguide are analyzed in detail. The high frequency system including the output coupler, slow wave structure (SWS), and reflector are designed properly. A 3-D particle-in-cell mode is applied to predict the device performance of the BWO based on the novel SWS. The investigation results demonstrate that this device can generate over 8.05 W output power in the frequency range of 363.4–383.8 GHz by using a 30 mA pencil electron beam and adjusting the beam voltage from 20 kV to 32 kV.

  17. Exact solutions to sine-Gordon-type equations

    International Nuclear Information System (INIS)

    Liu Shikuo; Fu Zuntao; Liu Shida

    2006-01-01

    In this Letter, sine-Gordon-type equations, including single sine-Gordon equation, double sine-Gordon equation and triple sine-Gordon equation, are systematically solved by Jacobi elliptic function expansion method. It is shown that different transformations for these three sine-Gordon-type equations play different roles in obtaining exact solutions, some transformations may not work for a specific sine-Gordon equation, while work for other sine-Gordon equations

  18. Unilateral retinitis pigmentosa sine pigmento.

    Science.gov (United States)

    Pearlman, J T; Saxton, J; Hoffman, G

    1976-05-01

    A patient presented with unilateral findings of night blindness shown by impaired rod function and dark adaptation, constricted visual fields with good central acuity, a barely recordable electro-retinographic b-wave, and a unilaterally impaired electro-oculogram. There were none of the pigmentary changes usually associated with retinitis pigmentosa. The unaffected right eye was normal in all respects. Therefore the case is most probably one of unilateral retinitis pigmentosa sine pigmento.

  19. Extremely high frequency RF effects on electronics.

    Energy Technology Data Exchange (ETDEWEB)

    Loubriel, Guillermo Manuel; Vigliano, David; Coleman, Phillip Dale; Williams, Jeffery Thomas; Wouters, Gregg A.; Bacon, Larry Donald; Mar, Alan

    2012-01-01

    The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit board traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings.

  20. High-Frequency Percussive Ventilation Revisited

    Science.gov (United States)

    2010-01-01

    be implemented. ‡ Follow the reverse of the ventilation sequence if respiratory alkalosis develops—however, start at ventilation goal sequence 1 not at...High-frequency percussive ventilation (HFPV) has demonstrated a potential role as a rescue option for refractory acute respiratory distress syndrome...frequency percussive ventilation (HFPV) has demon- strated a potential role as a salvage option for refrac- tory acute respiratory distress syndrome

  1. High Frequency Traders and Market Structure

    NARCIS (Netherlands)

    Menkveld, A.J.

    2014-01-01

    The arrival of high-frequency traders (HFTs) coincided with the entry of new markets and, subsequently, strong fragmentation of the order flow. These trends might be related as new markets serve HFTs who seek low fees and high speed. New markets only thrive on competitive price quotes that

  2. Mössbauer spectra linearity improvement by sine velocity waveform followed by linearization process

    Science.gov (United States)

    Kohout, Pavel; Frank, Tomas; Pechousek, Jiri; Kouril, Lukas

    2018-05-01

    This note reports the development of a new method for linearizing the Mössbauer spectra recorded with a sine drive velocity signal. Mössbauer spectra linearity is a critical parameter to determine Mössbauer spectrometer accuracy. Measuring spectra with a sine velocity axis and consecutive linearization increases the linearity of spectra in a wider frequency range of a drive signal, as generally harmonic movement is natural for velocity transducers. The obtained data demonstrate that linearized sine spectra have lower nonlinearity and line width parameters in comparison with those measured using a traditional triangle velocity signal.

  3. High-frequency and microwave circuit design

    CERN Document Server

    Nelson, Charles

    2007-01-01

    An integral part of any communications system, high-frequency and microwave design stimulates major progress in the wireless world and continues to serve as a foundation for the commercial wireless products we use every day. The exceptional pace of advancement in developing these systems stipulates that engineers be well versed in multiple areas of electronics engineering. With more illustrations, examples, and worked problems, High-Frequency and Microwave Circuit Design, Second Edition provides engineers with a diverse body of knowledge they can use to meet the needs of this rapidly progressi

  4. High frequency and pulse scattering physical acoustics

    CERN Document Server

    Pierce, Allan D

    1992-01-01

    High Frequency and Pulse Scattering investigates high frequency and pulse scattering, with emphasis on the phenomenon of echoes from objects. Geometrical and catastrophe optics methods in scattering are discussed, along with the scattering of sound pulses and the ringing of target resonances. Caustics and associated diffraction catastrophes are also examined.Comprised of two chapters, this volume begins with a detailed account of geometrically based approximation methods in scattering theory, focusing on waves transmitted through fluid and elastic scatterers and glory scattering; surface ray r

  5. RUDI, a short interspersed element of the V-SINE superfamily widespread in molluscan genomes.

    Science.gov (United States)

    Luchetti, Andrea; Šatović, Eva; Mantovani, Barbara; Plohl, Miroslav

    2016-06-01

    Short interspersed elements (SINEs) are non-autonomous retrotransposons that are widespread in eukaryotic genomes. They exhibit a chimeric sequence structure consisting of a small RNA-related head, an anonymous body and an AT-rich tail. Although their turnover and de novo emergence is rapid, some SINE elements found in distantly related species retain similarity in certain core segments (or highly conserved domains, HCD). We have characterized a new SINE element named RUDI in the bivalve molluscs Ruditapes decussatus and R. philippinarum and found this element to be widely distributed in the genomes of a number of mollusc species. An unexpected structural feature of RUDI is the HCD domain type V, which was first found in non-amniote vertebrate SINEs and in the SINE from one cnidarian species. In addition to the V domain, the overall sequence conservation pattern of RUDI elements resembles that found in ancient AmnSINE (~310 Myr old) and Au SINE (~320 Myr old) families, suggesting that RUDI might be among the most ancient SINE families. Sequence conservation suggests a monophyletic origin of RUDI. Nucleotide variability and phylogenetic analyses suggest long-term vertical inheritance combined with at least one horizontal transfer event as the most parsimonious explanation for the observed taxonomic distribution.

  6. Dry friction damping couple at high frequencies

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav; Pešek, Luděk; Košina, Jan; Radolfová, Alena

    2014-01-01

    Roč. 8, č. 1 (2014), s. 91-100 ISSN 1802-680X Institutional support: RVO:61388998 Keywords : dry friction * damping * high frequencies Subject RIV: BI - Acoustics http://www.kme.zcu.cz/acm/acm/article/view/239/265

  7. High Frequency Trading, Information, and Takeovers

    NARCIS (Netherlands)

    Humphery-Jenner, M.

    2011-01-01

    This paper (1) proposes new variables to detect informed high-frequency trading (HFT), (2) shows that HFT can help to predict takeover targets, and (3) shows that HFT in uences target announcement announcement returns. Prior literature suggests that informed trade may occur before takeovers, but has

  8. Essays on high frequency financial econometrics

    NARCIS (Netherlands)

    Yang, X.

    2015-01-01

    It has long been demonstrated that continuous-time methods are powerful tools in financial modeling. Yet only in recent years, their counterparts in empirical analysis—high frequency econometrics—began to emerge with the availability of intra-day data and relevant statistical tools. This

  9. Evolution of Very High Frequency Power Supplies

    DEFF Research Database (Denmark)

    Knott, Arnold; Andersen, Toke Meyer; Kamby, Peter

    2013-01-01

    The ongoing demand for smaller and lighter power supplies is driving the motivation to increase the switching frequencies of power converters. Drastic increases however come along with new challenges, namely the increase of switching losses in all components. The application of power circuits used...... in radio frequency transmission equipment helps to overcome those. However those circuits were not designed to meet the same requirements as power converters. This paper summarizes the contributions in recent years in application of very high frequency (VHF) technologies in power electronics, shows results...... of the recent advances and describes the remaining challenges. The presented results include a self-oscillating gate-drive, air core inductor optimizations, an offline LED driver with a power density of 8.9 W/cm3 and a 120 MHz, 9 W DC powered LED driver with 89 % efficiency as well as a bidirectional VHF...

  10. Dynamic temperature field in the ferromagnetic plate induced by moving high frequency inductor

    Directory of Open Access Journals (Sweden)

    Milošević-Mitić Vesna

    2014-01-01

    Full Text Available The subject of the paper is the temperature distribution in the thin metallic ferromagnetic plate influenced by moving linear high frequency induction heater. As a result of high frequency electromagnetic field, conducting currents appear in the part of the plate. Distribution of the eddy-current power across the plate thickness is obtained by use of complex analysis. The influences of the heater frequency, magnetic field intensity and plate thickness on the heat power density were discussed. By treating this power as a moving heat source, differential equations governing distribution of the temperature field are formulated. Temperature across the plate thickness is assumed to be in linear form. Differential equations are analytically solved by using integral-transform technique, Fourier finite-sine and finite-cosine transform and Laplace transform. The influence of the heater velocity to the plate temperature is presented on numerical examples based on theoretically obtained results. [Projekat Ministarstva nauke Republike Srbije, br. TR 35040 i br. TR 35011

  11. Mass renormalization in sine-Gordon model

    International Nuclear Information System (INIS)

    Xu Bowei; Zhang Yumei

    1991-09-01

    With a general gaussian wave functional, we investigate the mass renormalization in the sine-Gordon model. At the phase transition point, the sine-Gordon system tends to a system of massless free bosons which possesses conformal symmetry. (author). 8 refs, 1 fig

  12. Scaling in the sine-Gordon theory

    International Nuclear Information System (INIS)

    Ben-Abraham, S.I.

    1976-01-01

    It is shown that both the classical and the quantum sine-Gordon theory depend on a single scaling parameter and therefore the coupling constant cannot be freely chosen. To introduce a meaningful coupling constant it is proposed to include higher Fourier terms in the sine-Gordon potential. The two term case is exactly solvable. (Auth.)

  13. Evolutionary applications of MIRs and SINEs

    NARCIS (Netherlands)

    Buchanan, F; Crawford, A; Strobeck, C; Palsboll, P; Plante, Y

    It is believed that short interspersed elements (SINEs) are irreversibly inserted into genomes. We use this concept to try to deduce the evolution of whales using sequence and hybridization studies. The observation that microsatellites are associated with SINEs lead us to screen sequences

  14. Gauge symmetry of Sine-Gordon model

    International Nuclear Information System (INIS)

    Shen Jian-Min; Li Kang; Sheng Zhengmao.

    1993-03-01

    We have found that the strong coupled interaction of Sine-Gordon model is related to its weak coupled interaction by the su(2) gauge transformation. We therefore develop a semi-classical approach to deal with the infrared divergence in the conventional perturbation theory of the Hamiltonian of the quantum Sine-Gordon model. (author). 10 refs

  15. Evolutionary modes of emergence of short interspersed nuclear element (SINE) families in grasses.

    Science.gov (United States)

    Kögler, Anja; Schmidt, Thomas; Wenke, Torsten

    2017-11-01

    Short interspersed nuclear elements (SINEs) are non-autonomous transposable elements which are propagated by retrotransposition and constitute an inherent part of the genome of most eukaryotic species. Knowledge of heterogeneous and highly abundant SINEs is crucial for de novo (or improvement of) annotation of whole genome sequences. We scanned Poaceae genome sequences of six important cereals (Oryza sativa, Triticum aestivum, Hordeum vulgare, Panicum virgatum, Sorghum bicolor, Zea mays) and Brachypodium distachyon to examine the diversity and evolution of SINE populations. We comparatively analyzed the structural features, distribution, evolutionary relation and abundance of 32 SINE families and subfamilies within grasses, comprising 11 052 individual copies. The investigation of activity profiles within the Poaceae provides insights into their species-specific diversification and amplification. We found that Poaceae SINEs (PoaS) fall into two length categories: simple SINEs of up to 180 bp and dimeric SINEs larger than 240 bp. Detailed analysis at the nucleotide level revealed that multimerization of related and unrelated SINE copies is an important evolutionary mechanism of SINE formation. We conclude that PoaS families diversify by massive reshuffling between SINE families, likely caused by insertion of truncated copies, and provide a model for this evolutionary scenario. Twenty-eight of 32 PoaS families and subfamilies show significant conservation, in particular either in the 5' or 3' regions, across Poaceae species and share large sequence stretches with one or more other PoaS families. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  16. High-frequency Rayleigh-wave method

    Science.gov (United States)

    Xia, J.; Miller, R.D.; Xu, Y.; Luo, Y.; Chen, C.; Liu, J.; Ivanov, J.; Zeng, C.

    2009-01-01

    High-frequency (???2 Hz) Rayleigh-wave data acquired with a multichannel recording system have been utilized to determine shear (S)-wave velocities in near-surface geophysics since the early 1980s. This overview article discusses the main research results of high-frequency surface-wave techniques achieved by research groups at the Kansas Geological Survey and China University of Geosciences in the last 15 years. The multichannel analysis of surface wave (MASW) method is a non-invasive acoustic approach to estimate near-surface S-wave velocity. The differences between MASW results and direct borehole measurements are approximately 15% or less and random. Studies show that simultaneous inversion with higher modes and the fundamental mode can increase model resolution and an investigation depth. The other important seismic property, quality factor (Q), can also be estimated with the MASW method by inverting attenuation coefficients of Rayleigh waves. An inverted model (S-wave velocity or Q) obtained using a damped least-squares method can be assessed by an optimal damping vector in a vicinity of the inverted model determined by an objective function, which is the trace of a weighted sum of model-resolution and model-covariance matrices. Current developments include modeling high-frequency Rayleigh-waves in near-surface media, which builds a foundation for shallow seismic or Rayleigh-wave inversion in the time-offset domain; imaging dispersive energy with high resolution in the frequency-velocity domain and possibly with data in an arbitrary acquisition geometry, which opens a door for 3D surface-wave techniques; and successfully separating surface-wave modes, which provides a valuable tool to perform S-wave velocity profiling with high-horizontal resolution. ?? China University of Geosciences (Wuhan) and Springer-Verlag GmbH 2009.

  17. High-Order Frequency-Locked Loops

    DEFF Research Database (Denmark)

    Golestan, Saeed; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez

    2017-01-01

    In very recent years, some attempts for designing high-order frequency-locked loops (FLLs) have been made. Nevertheless, the advantages and disadvantages of these structures, particularly in comparison with a standard FLL and high-order phase-locked loops (PLLs), are rather unclear. This lack...... study, and its small-signal modeling, stability analysis, and parameter tuning are presented. Finally, to gain insight about advantages and disadvantages of high-order FLLs, a theoretical and experimental performance comparison between the designed second-order FLL and a standard FLL (first-order FLL...

  18. High Temperature, High Frequency Fuel Metering Valve, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Active Signal Technologies and its subcontractor Moog propose to develop a high-frequency actuator driven valve intended to achieve TRL 6 by the end of Phase II....

  19. 78 FR 70567 - Nationwide Use of High Frequency and Ultra High Frequency Active SONAR Technology; Final...

    Science.gov (United States)

    2013-11-26

    ... Frequency and Ultra High Frequency Active SONAR Technology; Final Programmatic Environmental Assessment and... each alternative on the human and natural environments. FOR FURTHER INFORMATION CONTACT: If you have... Programmatic Environmental Assessment The scope of the PEA focuses on potential impacts associated with the...

  20. Inverter design for high frequency power distribution

    Science.gov (United States)

    King, R. J.

    1985-01-01

    A class of simple resonantly commutated inverters are investigated for use in a high power (100 KW - 1000 KW) high frequency (10 KHz - 20 KHz) AC power distribution system. The Mapham inverter is found to provide a unique combination of large thyristor turn-off angle and good utilization factor, much better than an alternate 'current-fed' inverter. The effects of loading the Mapham inverter entirely with rectifier loads are investigated by simulation and with an experimental 3 KW 20 KHz inverter. This inverter is found to be well suited to a power system with heavy rectifier loading.

  1. Advances in Very High Frequency Power Conversion

    DEFF Research Database (Denmark)

    Kovacevic, Milovan

    Resonant and quasi-resonant converters operated at frequencies above 30 MHz have attracted special attention in the last two decades. Compared to conventional converters operated at ~100 kHz, they offer significant advantages: smaller volume and weight, lower cost, and faster transient performance....... Excellent performance and small size of magnetic components and capacitors at very high frequencies, along with constant advances in performance of power semiconductor devices, suggests a sizable shift in consumer power supplies market into this area in the near future. To operate dc-dc converter power...... method provides low complexity and low gate loss simultaneously. A direct design synthesis method is provided for resonant SEPIC converters employing this technique. Most experimental prototypes were developed using low cost, commercially available power semiconductors. Due to very fast transient...

  2. Parametric nanomechanical amplification at very high frequency.

    Science.gov (United States)

    Karabalin, R B; Feng, X L; Roukes, M L

    2009-09-01

    Parametric resonance and amplification are important in both fundamental physics and technological applications. Here we report very high frequency (VHF) parametric resonators and mechanical-domain amplifiers based on nanoelectromechanical systems (NEMS). Compound mechanical nanostructures patterned by multilayer, top-down nanofabrication are read out by a novel scheme that parametrically modulates longitudinal stress in doubly clamped beam NEMS resonators. Parametric pumping and signal amplification are demonstrated for VHF resonators up to approximately 130 MHz and provide useful enhancement of both resonance signal amplitude and quality factor. We find that Joule heating and reduced thermal conductance in these nanostructures ultimately impose an upper limit to device performance. We develop a theoretical model to account for both the parametric response and nonequilibrium thermal transport in these composite nanostructures. The results closely conform to our experimental observations, elucidate the frequency and threshold-voltage scaling in parametric VHF NEMS resonators and sensors, and establish the ultimate sensitivity limits of this approach.

  3. Characterization of three novel SINE families with unusual features in Helicoverpa armigera.

    Directory of Open Access Journals (Sweden)

    Jianjun Wang

    Full Text Available Although more than 120 families of short interspersed nuclear elements (SINEs have been isolated from the eukaryotic genomes, little is known about SINEs in insects. Here, we characterize three novel SINEs from the cotton bollworm, Helicoverpa armigera. Two of them, HaSE1 and HaSE2, share similar 5' -structure including a tRNA-related region immediately followed by conserved central domain. The 3' -tail of HaSE1 is significantly similar to that of one LINE retrotransposon element, HaRTE1.1, in H. armigera genome. The 3' -region of HaSE2 showed high identity with one mariner-like element in H. armigera. The third family, termed HaSE3, is a 5S rRNA-derived SINE and shares both body part and 3'-tail with HaSE1, thus may represent the first example of a chimera generated by recombination between 5S rRNA and tRNA-derived SINE in insect species. Further database searches revealed the presence of these SINEs in several other related insect species, but not in the silkworm, Bombyx mori, indicating a relatively narrow distribution of these SINEs in Lepidopterans. Apart from above, we found a copy of HaSE2 in the GenBank EST entry for the cotton aphid, Aphis gossypii, suggesting the occurrence of horizontal transfer.

  4. Characterization of Three Novel SINE Families with Unusual Features in Helicoverpa armigera

    Science.gov (United States)

    Wang, Jianjun; Wang, Aina; Han, Zhaojun; Zhang, Zan; Li, Fei; Li, Xianchun

    2012-01-01

    Although more than 120 families of short interspersed nuclear elements (SINEs) have been isolated from the eukaryotic genomes, little is known about SINEs in insects. Here, we characterize three novel SINEs from the cotton bollworm, Helicoverpa armigera. Two of them, HaSE1 and HaSE2, share similar 5′ -structure including a tRNA-related region immediately followed by conserved central domain. The 3′ -tail of HaSE1 is significantly similar to that of one LINE retrotransposon element, HaRTE1.1, in H. armigera genome. The 3′ -region of HaSE2 showed high identity with one mariner-like element in H. armigera. The third family, termed HaSE3, is a 5S rRNA-derived SINE and shares both body part and 3′-tail with HaSE1, thus may represent the first example of a chimera generated by recombination between 5S rRNA and tRNA-derived SINE in insect species. Further database searches revealed the presence of these SINEs in several other related insect species, but not in the silkworm, Bombyx mori, indicating a relatively narrow distribution of these SINEs in Lepidopterans. Apart from above, we found a copy of HaSE2 in the GenBank EST entry for the cotton aphid, Aphis gossypii, suggesting the occurrence of horizontal transfer. PMID:22319625

  5. Tha AGS Booster high frequency rf system

    International Nuclear Information System (INIS)

    Sanders, R.; Cameron, P.; Damn, R.

    1988-01-01

    A high level rf system, including a power amplifier and cavity has been designed for the AGS Booster. It covers a frequency range of 2.4 to 4.2 Mhz and will be used to accelerate high intensity proton, and low intensity polarized proton beams to 1.5 GeV and heavy ions to 0.35 GeV per nucleon. A total accelerating voltage of up to 90kV will be provided by two cavities, each having two gaps. The internally cross-coupled, pushpull cavities are driven by an adjacently located power amplifier. In order to accommodate the high beam intensity, up to 0.75 /times/ 10 13 protons per bunch, a low plate resistance power tetrode is used. The tube anode is magnetically coupled to one of the cavity's two paralleled cells. The amplifier is a grounded cathode configuration driven by a remotely located solid state amplifier

  6. Cultures of High-frequency Trading

    DEFF Research Database (Denmark)

    Lange, Ann-Christina; Lenglet, Marc; Seyfert, Robert

    2016-01-01

    As part of ongoing work to lay a foundation for social studies of high-frequency trading (HFT), this paper introduces the culture(s) of HFT as a sociological problem relating to knowledge and practice. HFT is often discussed as a purely technological development, where all that matters is the speed...... of allocating, processing and transmitting data. Indeed, the speed at which trades are executed and data transmitted is accelerating, and it is fair to say that algorithms are now the primary interacting agents operating in the financial markets. However, we contend that HFT is first and foremost a cultural...

  7. Experimental relationship between damping and stability of Sine-Gordon solitons in Josephson junctions

    International Nuclear Information System (INIS)

    Davidson, A.; Pedersen, N.F.; Dueholm, B.

    1985-01-01

    We show some experimental results which suggest that total damping, including surface loss, plays a fundamental role in limiting the stability of high-velocity Sine-Gordon solitons in real Josephson tunnel junctions

  8. Pulsed-High Field/High-Frequency EPR Spectroscopy

    Science.gov (United States)

    Fuhs, Michael; Moebius, Klaus

    Pulsed high-field/high-frequency electron paramagnetic resonance (EPR) spectroscopy is used to disentangle many kinds of different effects often obscured in continuous wave (cw) EPR spectra at lower magnetic fields/microwave frequencies. While the high magnetic field increases the resolution of G tensors and of nuclear Larmor frequencies, the high frequencies allow for higher time resolution for molecular dynamics as well as for transient paramagnetic intermediates studied with time-resolved EPR. Pulsed EPR methods are used for example for relaxation-time studies, and pulsed Electron Nuclear DOuble Resonance (ENDOR) is used to resolve unresolved hyperfine structure hidden in inhomogeneous linewidths. In the present article we introduce the basic concepts and selected applications to structure and mobility studies on electron transfer systems, reaction centers of photosynthesis as well as biomimetic models. The article concludes with an introduction to stochastic EPR which makes use of an other concept for investigating resonance systems in order to increase the excitation bandwidth of pulsed EPR. The limited excitation bandwidth of pulses at high frequency is one of the main limitations which, so far, made Fourier transform methods hardly feasible.

  9. Distribution, Diversity, and Long-Term Retention of Grass Short Interspersed Nuclear Elements (SINEs).

    Science.gov (United States)

    Mao, Hongliang; Wang, Hao

    2017-08-01

    Instances of highly conserved plant short interspersed nuclear element (SINE) families and their enrichment near genes have been well documented, but little is known about the general patterns of such conservation and enrichment and underlying mechanisms. Here, we perform a comprehensive investigation of the structure, distribution, and evolution of SINEs in the grass family by analyzing 14 grass and 5 other flowering plant genomes using comparative genomics methods. We identify 61 SINE families composed of 29,572 copies, in which 46 families are first described. We find that comparing with other grass TEs, grass SINEs show much higher level of conservation in terms of genomic retention: The origin of at least 26% families can be traced to early grass diversification and these families are among most abundant SINE families in 86% species. We find that these families show much higher level of enrichment near protein coding genes than families of relatively recent origin (51%:28%), and that 40% of all grass SINEs are near gene and the percentage is higher than other types of grass TEs. The pattern of enrichment suggests that differential removal of SINE copies in gene-poor regions plays an important role in shaping the genomic distribution of these elements. We also identify a sequence motif located at 3' SINE end which is shared in 17 families. In short, this study provides insights into structure and evolution of SINEs in the grass family. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  10. The JET high frequency pellet injector project

    International Nuclear Information System (INIS)

    Geraud, Alain; Dentan, M.; Whitehead, A.; Butcher, P.; Communal, D.; Faisse, F.; Gedney, J.; Gros, G.; Guillaume, D.; Hackett, L.; Hennion, V.; Homfray, D.; Lucock, R.; McKivitt, J.; Sibbald, M.; Portafaix, C.; Perin, J.P.; Reade, M.; Sands, D.; Saille, A.

    2007-01-01

    A new deuterium ice pellet injector is in preparation for JET. It is designed to inject both small pellets (variable volume within 1-2 mm 3 ) at high frequency (up to 60 Hz) for ELM mitigation experiments and large pellets (volume within 35-70 mm 3 ) at moderate frequency (up to 15 Hz) for plasma fuelling. It is based on the screw extruder technology developed by PELIN and pneumatic acceleration. An injection line will connect the injector to the flight tubes already in place to convey the pellets toward the plasma either from the low field side or from the high field side of the torus. This injection line enables: (i) the pumping of the propellant gas, (ii) the provision of the vacuum interface with the torus and (iii) the selection of the flight tube to be used via a fast selector. All the interfaces have been designed and a prototype injector is being built, to demonstrate that the required performance is achievable

  11. Experimental relationship between damping and stability of sine-Gordon solitons in Josephson junctions

    DEFF Research Database (Denmark)

    Davidson, A.; Pedersen, Niels Falsig; Dueholm, B.

    1985-01-01

    We show some experimental results which suggest that total damping, including surface loss, plays a fundamental role in limiting the stability of high-velocity sine-Gordon solitons in real Josephson tunnel junctions.......We show some experimental results which suggest that total damping, including surface loss, plays a fundamental role in limiting the stability of high-velocity sine-Gordon solitons in real Josephson tunnel junctions....

  12. High Tc superconductors at microwave frequencies

    International Nuclear Information System (INIS)

    Gruener, G.

    1991-01-01

    The author discusses various experiments conducted in the micro- and millimeter wave spectral range on thin film and single crystal specimens of the high temperature oxide superconductors. For high quality film the surface resistance R s is, except at low temperatures, due to thermally excited carriers, with extrinsic effects playing only a secondary role. Because of the low loss various passive microwave components, such as resonators, delay lines and filters, with performance far superior to those made of normal metals can be fabricated. The conductivity measured at millimeter wave frequencies displays a peak below T c . Whether this is due to coherence factors or due to the change of the relaxation rate when the materials enter the superconducting state remains to be seen

  13. High-frequency behavior of magnetic composites

    International Nuclear Information System (INIS)

    Lagarkov, Andrey N.; Rozanov, Konstantin N.

    2009-01-01

    The paper reviews recent progress in the field of microwave magnetic properties of composites. The problem under discussion is developing composites with high microwave permeability that are needed in many applications. The theory of magnetic composites is briefly sketched with the attention paid to the laws governing the magnetic frequency dispersion in magnetic materials and basic mixing rules for composites. Recent experimental reports on the microwave performance of magnetic composites, as well as data on the agreement of the mixing rules with the measured permeability of composites that are available from the literature are discussed. From the data, a conclusion is made that the validity of a mixing rule is determined by the permeability contrast in the composite, i.e., the difference between permeability of inclusions and that of the host matrix. When the contrast is low, the Maxwell Garnet mixing rule is frequently valid. When the contrast is high, which is of the most interest for obtaining high microwave permeability of a composite, no conventionally accepted theory is capable of accurately predicting the permeability of the composites. Therefore, the mixing rules do not allow the microwave properties of magnetic composites to be predicted when the permeability of inclusions is high, that is the case of the most interest. Because of that, general limitations to the microwave performance of composites are of importance. In particular, an important relation constraining the microwave permeability of composites follows from Kittel's theory of ferromagnetic resonance and analytical properties of frequency dependence of permeability. Another constraint concerning the bandwidth of electromagnetic wave absorbers follows from the Kramers-Kronig relations for the reflection coefficient. The constraints are of importance in design and analysis of electromagnetic wave absorbers and other devices that employ the microwave magnetic properties of composites, such as

  14. SINEs as driving forces in genome evolution.

    Science.gov (United States)

    Schmitz, J

    2012-01-01

    SINEs are short interspersed elements derived from cellular RNAs that repetitively retropose via RNA intermediates and integrate more or less randomly back into the genome. SINEs propagate almost entirely vertically within their host cells and, once established in the germline, are passed on from generation to generation. As non-autonomous elements, their reverse transcription (from RNA to cDNA) and genomic integration depends on the activity of the enzymatic machinery of autonomous retrotransposons, such as long interspersed elements (LINEs). SINEs are widely distributed in eukaryotes, but are especially effectively propagated in mammalian species. For example, more than a million Alu-SINE copies populate the human genome (approximately 13% of genomic space), and few master copies of them are still active. In the organisms where they occur, SINEs are a challenge to genomic integrity, but in the long term also can serve as beneficial building blocks for evolution, contributing to phenotypic heterogeneity and modifying gene regulatory networks. They substantially expand the genomic space and introduce structural variation to the genome. SINEs have the potential to mutate genes, to alter gene expression, and to generate new parts of genes. A balanced distribution and controlled activity of such properties is crucial to maintaining the organism's dynamic and thriving evolution. Copyright © 2012 S. Karger AG, Basel.

  15. Effect of high-frequency excitation on natural frequencies of spinning discs

    DEFF Research Database (Denmark)

    Hansen, Morten Hartvig

    2000-01-01

    The effect of high-frequency, non-resonant parametric excitation on the low-frequency response of spinning discs is considered. The parametric excitation is obtained through a non-constant rotation speed, where the frequency of the pulsating overlay is much higher than the lowest natural frequenc......The effect of high-frequency, non-resonant parametric excitation on the low-frequency response of spinning discs is considered. The parametric excitation is obtained through a non-constant rotation speed, where the frequency of the pulsating overlay is much higher than the lowest natural...

  16. High frequency CARM driver for rf linacs

    International Nuclear Information System (INIS)

    Danly, B.G.

    1993-01-01

    This CARM program has successfully demonstrated the first ever long-pulse CARM oscillator operation; these results demonstrate the potential of CARMs as an alternative source of millimeter waves to the gyrotron for ECRH plasma heating. The result of 1.8 MW at 27.8 GHz and 0.5 μs pulse width in the TE 11 mode represent a clear demonstration of the capabilities of the CARM oscillator for the production of high powers with large frequency upshift. It is hoped that this successful proof-of-principle demonstration.will lead to further development of the CARM as an ECRH source by the DOE Office of Fusion Energy, Development and Technology Division. This success is a direct outcome of this support of the Advanced Energy Projects Office of DOE in the form of this program. The CARM amplifier component of the program, although unsuccessful at obtaining CARM amplifier operation at 17 GHz, has succeeded by furthering the understanding of the limitations and difficulties that lie ahead for continued CARM amplifier development. The amplifier component of the program has successfully demonstrated a high power second and third harmonic gyro-TWT amplifier. Up to 5 MW of power at 17.1 GHz and >50dB gain have been obtained. These results should be viewed as an important contribution of this program to the development of viable microwave sources for powering the next linear collider. Indeed, the present gyro-amplifier, which resulted from this program, is presently being used in ongoing high-gradient accelerator research at MIT under a DOE High Energy Physics grant. As a result of both the oscillator and amplifier advances made during this program, the CARM and harmonic gyro-TWT have reached a significantly more mature level; their future role in specific applications of benefit to DOEs OFE and HEP offices may now be pursued

  17. The AGS Booster high frequency rf system

    International Nuclear Information System (INIS)

    Sanders, R.T.; Cameron, P.; Eng, W.; Goldman, M.A.; Jablonski, E.; Kasha, D.; Keane, J.; McNerney, A.; Meth, M.; Plotkin, M.; Puglisi, M.; Ratti, A.; Spitz, R.

    1991-01-01

    A high level rf system, including a power amplifier and cavity, has been designed and built for the AGS Booster. It covers a frequency range of 2.4 to 4.2 MHz and will be used to accelerate high intensity protons. Low intensity polarized protons and heavy ions, to the 1.5 GeV level. A total accelerating voltage of up to 90 kV will be provided by two cavities, each having two gaps. The internally cross coupled, pushpull cavities are driven by an adjacently located power amplifier. In order to accommodate beam intensities up to 0.75 x 10 13 protons per bunch, a low plate resistance power tetrode is used. The tube anode is magnetically coupled to one of the cavity's two parallel cells. The amplifier is a grounded cathode configuration driven by a remotely located solid-state amplifier. It has been tested in the laboratory at full gap voltage with satisfactory results. 5 refs., 2 figs., 1 tab

  18. Ground vibration test results of a JetStar airplane using impulsive sine excitation

    Science.gov (United States)

    Kehoe, Michael W.; Voracek, David F.

    1989-01-01

    Structural excitation is important for both ground vibration and flight flutter testing. The structural responses caused by this excitation are analyzed to determine frequency, damping, and mode shape information. Many excitation waveforms have been used throughout the years. The use of impulsive sine (sin omega t)/omega t as an excitation waveform for ground vibration testing and the advantages of using this waveform for flight flutter testing are discussed. The ground vibration test results of a modified JetStar airplane using impulsive sine as an excitation waveform are compared with the test results of the same airplane using multiple-input random excitation. The results indicated that the structure was sufficiently excited using the impulsive sine waveform. Comparisons of input force spectrums, mode shape plots, and frequency and damping values for the two methods of excitation are presented.

  19. HIGH FREQUENCY ELECTROSTATIC INSTABILITIES IN A PLASMA

    Energy Technology Data Exchange (ETDEWEB)

    Klein, M W; Auer, P L

    1963-06-15

    The dispersion relation is examined for a collisionless infinite plasma in the presence of an anisotropic Maxwellian velocity distribution and a uniform external magnetic field. Unstable solutions exist below the muitiples of the electron cyclotron frequency provided the temperature anisotropy is sufficiently large. The dependence of the growth rate upon harmonic number, density, angle of propagation with respect to the magnetic field, and frequency is discussed for zero as well as non-zero parallel temperatures. In the latter case, the waves are strongly damped as their frequency approaches a multiple of the gyro- frequency. (auth)

  20. Identification of a Recently Active Mammalian SINE Derived from Ribosomal RNA

    Science.gov (United States)

    Longo, Mark S.; Brown, Judy D.; Zhang, Chu; O’Neill, Michael J.; O’Neill, Rachel J.

    2015-01-01

    Complex eukaryotic genomes are riddled with repeated sequences whose derivation does not coincide with phylogenetic history and thus is often unknown. Among such sequences, the capacity for transcriptional activity coupled with the adaptive use of reverse transcription can lead to a diverse group of genomic elements across taxa, otherwise known as selfish elements or mobile elements. Short interspersed nuclear elements (SINEs) are nonautonomous mobile elements found in eukaryotic genomes, typically derived from cellular RNAs such as tRNAs, 7SL or 5S rRNA. Here, we identify and characterize a previously unknown SINE derived from the 3′-end of the large ribosomal subunit (LSU or 28S rDNA) and transcribed via RNA polymerase III. This new element, SINE28, is represented in low-copy numbers in the human reference genome assembly, wherein we have identified 27 discrete loci. Phylogenetic analysis indicates these elements have been transpositionally active within primate lineages as recently as 6 MYA while modern humans still carry transcriptionally active copies. Moreover, we have identified SINE28s in all currently available assembled mammalian genome sequences. Phylogenetic comparisons indicate that these elements are frequently rederived from the highly conserved LSU rRNA sequences in a lineage-specific manner. We propose that this element has not been previously recognized as a SINE given its high identity to the canonical LSU, and that SINE28 likely represents one of possibly many unidentified, active transposable elements within mammalian genomes. PMID:25637222

  1. Study on W-band sheet-beam traveling-wave tube based on flat-roofed sine waveguide

    Science.gov (United States)

    Fang, Shuanzhu; Xu, Jin; Jiang, Xuebing; Lei, Xia; Wu, Gangxiong; Li, Qian; Ding, Chong; Yu, Xiang; Wang, Wenxiang; Gong, Yubin; Wei, Yanyu

    2018-05-01

    A W-band sheet electron beam (SEB) traveling-wave tube (TWT) based on flat-roofed sine waveguide slow-wave structure (FRSWG-SWS) is proposed. The sine wave of the metal grating is replaced by a flat-roofed sine wave around the electron beam tunnel. The slow-wave characteristics including the dispersion properties and interaction impedance have been investigated by using the eigenmode solver in the 3-D electromagnetic simulation software Ansoft HFSS. Through calculations, the FRSWG SWS possesses the larger average interaction impedance than the conventional sine waveguide (SWG) SWS in the frequency range of 86-110 GHz. The beam-wave interaction was studied and particle-in-cell simulation results show that the SEB TWT can produce output power over 120 W within the bandwidth ranging from 90 to 100 GHz, and the maximum output power is 226 W at typical frequency 94 GHz, corresponding electron efficiency of 5.89%.

  2. Contact resistance measurement structures for high frequencies

    NARCIS (Netherlands)

    Roy, Deepu; Pijper, Ralf M.T.; Tiemeijer, Luuk F.; Wolters, Robertus A.M.

    2011-01-01

    Knowledge of the interfacial contact impedance offered by the device at its operating frequency range is crucial for accurate modelling and understanding of the device. In this article, a novel modified TLM test-structure has been devised to extract interfacial contact parameters at frequencies upto

  3. High-frequency modulation of ion-acoustic waves.

    Science.gov (United States)

    Albright, N. W.

    1972-01-01

    A large amplitude, high-frequency electromagnetic oscillation is impressed on a nonrelativistic, collisionless plasma from an external source. The frequency is chosen to be far from the plasma frequency (in fact, lower). The resulting electron velocity distribution function strongly modifies the propagation of ion-acoustic waves parallel to the oscillating electric field. The complex frequency is calculated numerically.

  4. The optimal digital filters of sine and cosine transforms for geophysical transient electromagnetic method

    Science.gov (United States)

    Zhao, Yun-wei; Zhu, Zi-qiang; Lu, Guang-yin; Han, Bo

    2018-03-01

    The sine and cosine transforms implemented with digital filters have been used in the Transient electromagnetic methods for a few decades. Kong (2007) proposed a method of obtaining filter coefficients, which are computed in the sample domain by Hankel transform pair. However, the curve shape of Hankel transform pair changes with a parameter, which usually is set to be 1 or 3 in the process of obtaining the digital filter coefficients of sine and cosine transforms. First, this study investigates the influence of the parameter on the digital filter algorithm of sine and cosine transforms based on the digital filter algorithm of Hankel transform and the relationship between the sine, cosine function and the ±1/2 order Bessel function of the first kind. The results show that the selection of the parameter highly influences the precision of digital filter algorithm. Second, upon the optimal selection of the parameter, it is found that an optimal sampling interval s also exists to achieve the best precision of digital filter algorithm. Finally, this study proposes four groups of sine and cosine transform digital filter coefficients with different length, which may help to develop the digital filter algorithm of sine and cosine transforms, and promote its application.

  5. Sheath impedance effects in very high frequency plasma experiments

    International Nuclear Information System (INIS)

    Schwarzenbach, W.; Howling, A.A.; Fivaz, M.; Brunner, S.; Hollenstein, C.

    1995-05-01

    The frequency dependence (13.56 MHz to 70 MHz) of the ion energy distribution at the ground electrode was measured by mass spectrometry in a symmetrical capacitive argon discharge. Reduced sheath impedance at Very High Frequency allows high levels of plasma power and substrate ion flux whilst maintaining low levels of ion energy and electrode voltage. The lower limit of ion bombardment energy is fixed by the sheath floating potential at high frequency, in contrast to low frequencies where only the rf voltage amplitude is determinant. The capacitive sheaths are thinner at high frequencies which accentuates the high frequency reduction in sheath impedance. It is argued that the frequency dependence of sheath impedance is responsible for the principal characteristics of Very High Frequency plasmas. The measurements are summarised by simple physical descriptions and compared with a Particle-In-Cell simulation. (author) figs., tabs., refs

  6. Virtual sine arm kinematic mount system

    International Nuclear Information System (INIS)

    Xu, Z.; Randall, K.J.

    1997-01-01

    A novel kinematic mount system for a vertical focusing mirror of the soft x-ray spectroscopy beamline at the Advanced Photon Source is described. The system contains three points in a horizontal plane. Each point consists of two horizontal linear precision stages, a spherical ball bearing, and a vertical precision stage. The horizontal linear stages are aligned orthogonally and are conjoined by a spherical ball bearing, supported by the vertical linear stage at each point. The position of each confined horizontal stage is controlled by a motorized micrometer head by spring-loading the flat tip of the micrometer head onto a tooling ball fixing on the carriage of the stage. A virtual sine arm is formed by tilting the upstream horizontal stage down and the two downstream horizontal stages up by a small angle. The fine pitch motion is achieved by adjusting the upstream stage. This supporting structure is extremely steady due to a relatively large span across the supporting points and yields extremely high resolution on the pitch motion. With a one degree tilt and a microstepping motor, the authors achieved a 0.4 nanoradian resolution on the mirror pitch motion

  7. Gravity localization in sine-Gordon braneworlds

    International Nuclear Information System (INIS)

    Cruz, W.T.; Maluf, R.V.; Sousa, L.J.S.; Almeida, C.A.S.

    2016-01-01

    In this work we study two types of five-dimensional braneworld models given by sine-Gordon potentials. In both scenarios, the thick brane is generated by a real scalar field coupled to gravity. We focus our investigation on the localization of graviton field and the behaviour of the massive spectrum. In particular, we analyse the localization of massive modes by means of a relative probability method in a Quantum Mechanics context. Initially, considering a scalar field sine-Gordon potential, we find a localized state to the graviton at zero mode. However, when we consider a double sine-Gordon potential, the brane structure is changed allowing the existence of massive resonant states. The new results show how the existence of an internal structure can aid in the emergence of massive resonant modes on the brane.

  8. HIGH FREQUENCY INDUCTION WELDING OF HIGH SILICON STEEL TUBES

    Directory of Open Access Journals (Sweden)

    Ricardo Miranda Alé

    2012-06-01

    Full Text Available High-Si steel is a low cost alternative for the fabrication of tubular structures resistant to atmospheric corrosion. However, the literature has often pointed out that steels presenting a higher Si content and/or a lower Mn/Si ratio have higher susceptibility to defects at the weld bond line during HFIW (High Frequency Induction Welding process, which has been widely used for manufacturing small diameter tubes. In this study the effect of the HFIW conditions on the quality of steel tubes with high-Si content and low Mn/Si ratio is investigated. The quality of welded tubes was determined by flare test and the defects in the bond line were identified by SEM. It has been found that higher welding speeds, V-convergence angles and power input should be applied in welding of high-Si steel, when compared to similar strength C-Mn steel.

  9. Carnivore-specific SINEs (Can-SINEs): distribution, evolution, and genomic impact.

    Science.gov (United States)

    Walters-Conte, Kathryn B; Johnson, Diana L E; Allard, Marc W; Pecon-Slattery, Jill

    2011-01-01

    Short interspersed nuclear elements (SINEs) are a type of class 1 transposable element (retrotransposon) with features that allow investigators to resolve evolutionary relationships between populations and species while providing insight into genome composition and function. Characterization of a Carnivora-specific SINE family, Can-SINEs, has, has aided comparative genomic studies by providing rare genomic changes, and neutral sequence variants often needed to resolve difficult evolutionary questions. In addition, Can-SINEs constitute a significant source of functional diversity with Carnivora. Publication of the whole-genome sequence of domestic dog, domestic cat, and giant panda serves as a valuable resource in comparative genomic inferences gleaned from Can-SINEs. In anticipation of forthcoming studies bolstered by new genomic data, this review describes the discovery and characterization of Can-SINE motifs as well as describes composition, distribution, and effect on genome function. As the contribution of noncoding sequences to genomic diversity becomes more apparent, SINEs and other transposable elements will play an increasingly large role in mammalian comparative genomics.

  10. Obtaining changes in calibration-coil to seismometer output constants using sine waves

    Science.gov (United States)

    Ringler, Adam T.; Hutt, Charles R.; Gee, Lind S.; Sandoval, Leo D.; Wilson, David C.

    2013-01-01

    The midband sensitivity of a broadband seismometer is one of the most commonly used parameters from station metadata. Thus, it is critical for station operators to robustly estimate this quantity with a high degree of accuracy. We develop an in situ method for estimating changes in sensitivity using sine‐wave calibrations, assuming the calibration coil and its drive are stable over time and temperature. This approach has been used in the past for passive instruments (e.g., geophones) but has not been applied, to our knowledge, to derive sensitivities of modern force‐feedback broadband seismometers. We are able to detect changes in sensitivity to well within 1%, and our method is capable of detecting these sensitivity changes using any frequency of sine calibration within the passband of the instrument.

  11. Electro-mechanical sine/cosine generator

    Science.gov (United States)

    Flagge, B. (Inventor)

    1972-01-01

    An electromechanical device for generating both sine and cosine functions is described. A motor rotates a cylinder about an axis parallel to and a slight distance from the central axis of the cylinder. Two noncontacting displacement sensing devices are placed ninety degrees apart, equal distances from the axis of rotation of the cylinder and short distances above the surface of cylinder. Each of these sensing devices produces an electrical signal proportional to the distance that it is away from the cylinder. Consequently, as the cylinder is rotated the outputs from the two sensing devices are the sine and cosine functions.

  12. Sines and Cosines. Part 3 of 3

    Science.gov (United States)

    Apostol, Tom M. (Editor)

    1994-01-01

    In this 'Project Mathematics' series video, the addition formulas of sines and cosines are explained and their real life applications are demonstrated. Both film footage and computer animation is used. Several mathematical concepts are discussed and include: Ptolemy's theorem concerned with quadrilaterals; the difference between a central angle and an inscribed angle; sines and chord lengths; special angles; subtraction formulas; and a application to simple harmonic motion. A brief history of the city Alexandria, its mathematicians, and their contribution to the field of mathematics is shown.

  13. On the supersymmetric sine-Gordon model

    International Nuclear Information System (INIS)

    Hruby, J.

    1977-01-01

    The sine-Gordon model as the theory of a massless scalar field in one space and one time dimension with interaction Lagrangian density proportional to cosβsub(phi) is generalized for a scalar superfield and it is shown that the solution of the supercovariant sine-Gordon equation is the ''supersoliton'', it is the superfield, which has all ordinary fields in two dimensions as a type of the soliton solution. We also obtain the massive Thirring model and the new equations of motion coupling the Fermi field and the Bose field. The notice about supersymmetric ''SLAC-BAG'' model is done

  14. Sine-Bar Attachment For Machine Tools

    Science.gov (United States)

    Mann, Franklin D.

    1988-01-01

    Sine-bar attachment for collets, spindles, and chucks helps machinists set up quickly for precise angular cuts that require greater precision than provided by graduations of machine tools. Machinist uses attachment to index head, carriage of milling machine or lathe relative to table or turning axis of tool. Attachment accurate to 1 minute or arc depending on length of sine bar and precision of gauge blocks in setup. Attachment installs quickly and easily on almost any type of lathe or mill. Requires no special clamps or fixtures, and eliminates many trial-and-error measurements. More stable than improvised setups and not jarred out of position readily.

  15. Stabilization of breathers in a parametrically driven sine-Gordon system with loss

    DEFF Research Database (Denmark)

    Grønbech-Jensen, N.; Kivshar, Yu. S.; Samuelsen, Mogens Rugholm

    1991-01-01

    We demonstrate that in a parametrically driven sine-Gordon system with loss, a breather, if driven, can be maintained in a steady state at half the external frequency. In the small-amplitude limit the system is described by the effective perturbed nonlinear Schrödinger equation. For an arbitrary...

  16. Modulated convection at high frequencies and large modulation amplitudes

    International Nuclear Information System (INIS)

    Swift, J.B.; Hohenberg, P.C.

    1987-01-01

    Modulated Rayleigh-Benard convection is analyzed for high frequencies and large modulation amplitudes. The linear theory of Gershuni and Zhukhovitskii is generalized to the nonlinear domain, and a subcritical bifurcation to convection is found in agreement with the experiments of Niemela and Donnelly. The crossover between the high-frequency (''Stokes layer'') regime and the low-frequency regime studied previously is analyzed

  17. Calculation of Leakage Inductance for High Frequency Transformers

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Jun, Zhang; Hurley, William Gerard

    2015-01-01

    Frequency dependent leakage inductance is often observed. High frequency eddy current effects cause a reduction in leakage inductance. The proximity effect between adjacent layers is responsible for the reduction of leakage inductance. This paper gives a detailed analysis of high frequency leakag...

  18. An inkjet vision measurement technique for high-frequency jetting

    International Nuclear Information System (INIS)

    Kwon, Kye-Si; Jang, Min-Hyuck; Park, Ha Yeong; Ko, Hyun-Seok

    2014-01-01

    Inkjet technology has been used as manufacturing a tool for printed electronics. To increase the productivity, the jetting frequency needs to be increased. When using high-frequency jetting, the printed pattern quality could be non-uniform since the jetting performance characteristics including the jetting speed and droplet volume could vary significantly with increases in jet frequency. Therefore, high-frequency jetting behavior must be evaluated properly for improvement. However, it is difficult to measure high-frequency jetting behavior using previous vision analysis methods, because subsequent droplets are close or even merged. In this paper, we present vision measurement techniques to evaluate the drop formation of high-frequency jetting. The proposed method is based on tracking target droplets such that subsequent droplets can be excluded in the image analysis by focusing on the target droplet. Finally, a frequency sweeping method for jetting speed and droplet volume is presented to understand the overall jetting frequency effects on jetting performance

  19. An inkjet vision measurement technique for high-frequency jetting

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Kye-Si, E-mail: kskwon@sch.ac.kr; Jang, Min-Hyuck; Park, Ha Yeong [Department of Mechanical Engineering, Soonchunhyang University 22, Soonchunhyang-Ro, Shinchang, Asan Chungnam 336-745 (Korea, Republic of); Ko, Hyun-Seok [Department of Electrical and Robot Engineering, Soonchunhyang University, 22, Soonchunhyang-Ro, Shinchang, Asan Chungnam 336-745 (Korea, Republic of)

    2014-06-15

    Inkjet technology has been used as manufacturing a tool for printed electronics. To increase the productivity, the jetting frequency needs to be increased. When using high-frequency jetting, the printed pattern quality could be non-uniform since the jetting performance characteristics including the jetting speed and droplet volume could vary significantly with increases in jet frequency. Therefore, high-frequency jetting behavior must be evaluated properly for improvement. However, it is difficult to measure high-frequency jetting behavior using previous vision analysis methods, because subsequent droplets are close or even merged. In this paper, we present vision measurement techniques to evaluate the drop formation of high-frequency jetting. The proposed method is based on tracking target droplets such that subsequent droplets can be excluded in the image analysis by focusing on the target droplet. Finally, a frequency sweeping method for jetting speed and droplet volume is presented to understand the overall jetting frequency effects on jetting performance.

  20. Analysis of the 227 bp short interspersed nuclear element (SINE) insertion of the promoter of the myostatin (MSTN) gene in different horse breeds.

    Science.gov (United States)

    Dall'Olio, Stefania; Scotti, Emilio; Fontanesi, Luca; Tassinari, Marco

    2014-01-01

    The myostatin (MSTN) gene encodes a protein known to be a negative regulator of muscle mass in mammalian species. Different polymorphisms of the horse (Equus caballus) MSTN gene have been identified, including single nucleotide polymorphisms and a short interspersed nuclear element (SINE) insertion of 227 bp within the promoter of the gene. The SINE insertion has been associated with performance traits in Thoroughbred racehorses and it was proposed as a predictor of optimum racing distance. The aims of this study were to perform in silico analysis to identify putative gains or abrogation of transcription-factor binding sites (TFBSs) generated by the SINE allele of the promoter and to analyse the frequency of the SINE insertion in horses used for racing (gallop and trot) and other purposes. The SINE insertion was genotyped in 227 horses from 10 breeds belonging to different morphological types (brachimorphic, mesomorphic, meso-dolichomorphic and dolichomorphic). The presence of the insertion was confirmed in the Quarter Horse (SINE allele frequency of 0.81) and in the Thoroughbred (0.51), whereas the SINE allele did not segregate in any of the other analysed breeds. As the SINE MSTN gene polymorphism may be population or breed specific, it is not a useful marker for association studies in all breeds.

  1. Analysis of the 227 bp short interspersed nuclear element (SINE insertion of the promoter of the myostatin (MSTN gene in different horse breeds

    Directory of Open Access Journals (Sweden)

    Stefania Dall'Olio

    2014-09-01

    Full Text Available The myostatin (MSTN gene encodes a protein known to be a negative regulator of muscle mass in mammalian species. Different polymorphisms of the horse (Equus caballus MSTN gene have been identified, including single nucleotide polymorphisms and a short interspersed nuclear element (SINE insertion of 227 bp within the promoter of the gene. The SINE insertion has been associated with performance traits in Thoroughbred racehorses and it was proposed as a predictor of optimum racing distance. The aims of this study were to perform in silico analysis to identify putative gains or abrogation of transcription-factor binding sites (TFBSs generated by the SINE allele of the promoter and to analyse the frequency of the SINE insertion in horses used for racing (gallop and trot and other purposes. The SINE insertion was genotyped in 227 horses from 10 breeds belonging to different morphological types (brachimorphic, mesomorphic, meso-dolichomorphic and dolichomorphic. The presence of the insertion was confirmed in the Quarter Horse (SINE allele frequency of 0.81 and in the Thoroughbred (0.51, whereas the SINE allele did not segregate in any of the other analysed breeds. As the SINE MSTN gene polymorphism may be population or breed specific, it is not a useful marker for association studies in all breeds.

  2. High-frequency analog integrated circuit design

    CERN Document Server

    1995-01-01

    To learn more about designing analog integrated circuits (ICs) at microwave frequencies using GaAs materials, turn to this text and reference. It addresses GaAs MESFET-based IC processing. Describes the newfound ability to apply silicon analog design techniques to reliable GaAs materials and devices which, until now, was only available through technical papers scattered throughout hundred of articles in dozens of professional journals.

  3. Coplanar stripline components for high frequency application

    Science.gov (United States)

    Goverdhanam, Kavita; Simons, Rainee N.; Dib, Nihad; Katehi, Linda P. B.

    1996-01-01

    In this paper, coplanar stripline discontinuities such as a slit, a right angle bend and a T-junction are characterized and their performance is parameterized with respect to frequency and geometry. Lumped equivalent circuits are presented for some of them. The element values are obtained from the measured discontinuity scattering (S) parameters. The experimental results are compared with theoretical data obtained using the Finite Difference Time Domain (FD-TD) technique for validation and show very good agreement.

  4. The sine-Gordon model revisited I

    Energy Technology Data Exchange (ETDEWEB)

    Niccoli, G.; Teschner, J.

    2009-10-15

    We study integrable lattice regularizations of the Sine-Gordon model with the help of the Separation of Variables method of Sklyanin and the Baxter Q-operators. This allows us to characterize the spectrum (eigenvalues and eigenstates) completely in terms of polynomial solutions of the Baxter equation with certain properties. This result is analogous to the completeness of the Bethe ansatz. (orig.)

  5. Benjamin Banneker and the Law of Sines

    Science.gov (United States)

    Mahoney, John F.

    2005-01-01

    Benjamin Banneker, a self-taught mathematician, surveyor and astronomer published annual almanacs containing his astronomical observations and predictions. Banneker who also used logarithms to apply the Law of Sines believed that the method used to solve a mathematical problem depends on the tools available.

  6. Oscillating and rotating sine-Gordon system

    DEFF Research Database (Denmark)

    Olsen, O. H.; Samuelsen, Mogens Rugholm

    1986-01-01

    The interaction between a 2π kink and the background or vacuum is investigated in the pure sine-Gordon system. For an oscillating background (i.e., the k=0 part of the phonon spectrum) the 2π kink oscillates, while for increasing or decreasing vacuum two phenomena have been observed, depending...

  7. Low velocity target detection based on time-frequency image for high frequency ground wave radar

    Institute of Scientific and Technical Information of China (English)

    YAN Songhua; WU Shicai; WEN Biyang

    2007-01-01

    The Doppler spectral broadening resulted from non-stationary movement of target and radio-frequency interference will decrease the veracity of target detection by high frequency ground wave(HEGW)radar.By displaying the change of signal energy on two dimensional time-frequency images based on time-frequency analysis,a new mathematical morphology method to distinguish target from nonlinear time-frequency curves is presented.The analyzed results from the measured data verify that with this new method the target can be detected correctly from wide Doppler spectrum.

  8. Direct excitation of a high frequency wave by a low frequency wave in a plasma

    International Nuclear Information System (INIS)

    Tanaka, Takayasu

    1993-01-01

    A new mechanism is presented of an excitation of a high frequency wave by a low frequency wave in a plasma. This mechanism works when the low frequency wave varies in time in a manner deviated from a usual periodic motion with a constant amplitude. The conversion rate is usually not large but the conversion is done without time delay after the variation of the low frequency wave. The Manley Rowe relation in the usual sense does not hold in this mechanism. This mechanism can excite also waves with same or lower frequencies. (author)

  9. Short interspersed nuclear elements (SINEs) are abundant in Solanaceae and have a family-specific impact on gene structure and genome organization.

    Science.gov (United States)

    Seibt, Kathrin M; Wenke, Torsten; Muders, Katja; Truberg, Bernd; Schmidt, Thomas

    2016-05-01

    Short interspersed nuclear elements (SINEs) are highly abundant non-autonomous retrotransposons that are widespread in plants. They are short in size, non-coding, show high sequence diversity, and are therefore mostly not or not correctly annotated in plant genome sequences. Hence, comparative studies on genomic SINE populations are rare. To explore the structural organization and impact of SINEs, we comparatively investigated the genome sequences of the Solanaceae species potato (Solanum tuberosum), tomato (Solanum lycopersicum), wild tomato (Solanum pennellii), and two pepper cultivars (Capsicum annuum). Based on 8.5 Gbp sequence data, we annotated 82 983 SINE copies belonging to 10 families and subfamilies on a base pair level. Solanaceae SINEs are dispersed over all chromosomes with enrichments in distal regions. Depending on the genome assemblies and gene predictions, 30% of all SINE copies are associated with genes, particularly frequent in introns and untranslated regions (UTRs). The close association with genes is family specific. More than 10% of all genes annotated in the Solanaceae species investigated contain at least one SINE insertion, and we found genes harbouring up to 16 SINE copies. We demonstrate the involvement of SINEs in gene and genome evolution including the donation of splice sites, start and stop codons and exons to genes, enlargement of introns and UTRs, generation of tandem-like duplications and transduction of adjacent sequence regions. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  10. High-frequency homogenization of zero frequency stop band photonic and phononic crystals

    CERN Document Server

    Antonakakis, Tryfon; Guenneau, Sebastien

    2013-01-01

    We present an accurate methodology for representing the physics of waves, for periodic structures, through effective properties for a replacement bulk medium: This is valid even for media with zero frequency stop-bands and where high frequency phenomena dominate. Since the work of Lord Rayleigh in 1892, low frequency (or quasi-static) behaviour has been neatly encapsulated in effective anisotropic media. However such classical homogenization theories break down in the high-frequency or stop band regime. Higher frequency phenomena are of significant importance in photonics (transverse magnetic waves propagating in infinite conducting parallel fibers), phononics (anti-plane shear waves propagating in isotropic elastic materials with inclusions), and platonics (flexural waves propagating in thin-elastic plates with holes). Fortunately, the recently proposed high-frequency homogenization (HFH) theory is only constrained by the knowledge of standing waves in order to asymptotically reconstruct dispersion curves an...

  11. High Frequency Acoustic Propagation using Level Set Methods

    Science.gov (United States)

    2007-01-01

    solution of the high frequency approximation to the wave equation. Traditional solutions to the Eikonal equation in high frequency acoustics are...the Eikonal equation derived from the high frequency approximation to the wave equation, ucuH ∇±=∇ )(),( xx , with the nonnegative function c(x...For simplicity, we only consider the case ucuH ∇+=∇ )(),( xx . Two difficulties must be addressed when solving the Eikonal equation in a fixed

  12. Sources for high frequency heating. Performance and limitations

    International Nuclear Information System (INIS)

    Le Gardeur, R.

    1976-01-01

    The various problems encountered in high frequency heating of plasmas can be decomposed into three spheres of action: theoretical development, antenna designing, and utilization of power sources. By classifying heating into three spectral domains, present and future needs are enumerated. Several specific antenna designs are treated. High frequency power sources are reviewed. The actual development of the gyratron is discussed in view of future needs in very high frequency heating of plasmas [fr

  13. Analyses of carnivore microsatellites and their intimate association with tRNA-derived SINEs.

    Science.gov (United States)

    López-Giráldez, Francesc; Andrés, Olga; Domingo-Roura, Xavier; Bosch, Montserrat

    2006-10-23

    The popularity of microsatellites has greatly increased in the last decade on account of their many applications. However, little is currently understood about the factors that influence their genesis and distribution among and within species genomes. In this work, we analyzed carnivore microsatellite clones from GenBank to study their association with interspersed repeats and elucidate the role of the latter in microsatellite genesis and distribution. We constructed a comprehensive carnivore microsatellite database comprising 1236 clones from GenBank. Thirty-three species of 11 out of 12 carnivore families were represented, although two distantly related species, the domestic dog and cat, were clearly overrepresented. Of these clones, 330 contained tRNALys-derived SINEs and 357 contained other interspersed repeats. Our rough estimates of tRNA SINE copies per haploid genome were much higher than published ones. Our results also revealed a distinct juxtaposition of AG and A-rich repeats and tRNALys-derived SINEs suggesting their coevolution. Both microsatellites arose repeatedly in two regions of the interspersed repeat. Moreover, microsatellites associated with tRNALys-derived SINEs showed the highest complexity and less potential instability. Our results suggest that tRNALys-derived SINEs are a significant source for microsatellite generation in carnivores, especially for AG and A-rich repeat motifs. These observations indicate two modes of microsatellite generation: the expansion and variation of pre-existing tandem repeats and the conversion of sequences with high cryptic simplicity into a repeat array; mechanisms which are not specific to tRNALys-derived SINEs. Microsatellite and interspersed repeat coevolution could also explain different distribution of repeat types among and within species genomes.Finally, due to their higher complexity and lower potential informative content of microsatellites associated with tRNALys-derived SINEs, we recommend avoiding

  14. Analyses of carnivore microsatellites and their intimate association with tRNA-derived SINEs

    Directory of Open Access Journals (Sweden)

    Bosch Montserrat

    2006-10-01

    Full Text Available Abstract Background The popularity of microsatellites has greatly increased in the last decade on account of their many applications. However, little is currently understood about the factors that influence their genesis and distribution among and within species genomes. In this work, we analyzed carnivore microsatellite clones from GenBank to study their association with interspersed repeats and elucidate the role of the latter in microsatellite genesis and distribution. Results We constructed a comprehensive carnivore microsatellite database comprising 1236 clones from GenBank. Thirty-three species of 11 out of 12 carnivore families were represented, although two distantly related species, the domestic dog and cat, were clearly overrepresented. Of these clones, 330 contained tRNALys-derived SINEs and 357 contained other interspersed repeats. Our rough estimates of tRNA SINE copies per haploid genome were much higher than published ones. Our results also revealed a distinct juxtaposition of AG and A-rich repeats and tRNALys-derived SINEs suggesting their coevolution. Both microsatellites arose repeatedly in two regions of the insterspersed repeat. Moreover, microsatellites associated with tRNALys-derived SINEs showed the highest complexity and less potential instability. Conclusion Our results suggest that tRNALys-derived SINEs are a significant source for microsatellite generation in carnivores, especially for AG and A-rich repeat motifs. These observations indicate two modes of microsatellite generation: the expansion and variation of pre-existing tandem repeats and the conversion of sequences with high cryptic simplicity into a repeat array; mechanisms which are not specific to tRNALys-derived SINEs. Microsatellite and interspersed repeat coevolution could also explain different distribution of repeat types among and within species genomes. Finally, due to their higher complexity and lower potential informative content of microsatellites

  15. Calibration of High Frequency MEMS Microphones

    Science.gov (United States)

    Shams, Qamar A.; Humphreys, William M.; Bartram, Scott M.; Zuckewar, Allan J.

    2007-01-01

    Understanding and controlling aircraft noise is one of the major research topics of the NASA Fundamental Aeronautics Program. One of the measurement technologies used to acquire noise data is the microphone directional array (DA). Traditional direction array hardware, consisting of commercially available condenser microphones and preamplifiers can be too expensive and their installation in hard-walled wind tunnel test sections too complicated. An emerging micro-machining technology coupled with the latest cutting edge technologies for smaller and faster systems have opened the way for development of MEMS microphones. The MEMS microphone devices are available in the market but suffer from certain important shortcomings. Based on early experiments with array prototypes, it has been found that both the bandwidth and the sound pressure level dynamic range of the microphones should be increased significantly to improve the performance and flexibility of the overall array. Thus, in collaboration with an outside MEMS design vendor, NASA Langley modified commercially available MEMS microphone as shown in Figure 1 to meet the new requirements. Coupled with the design of the enhanced MEMS microphones was the development of a new calibration method for simultaneously obtaining the sensitivity and phase response of the devices over their entire broadband frequency range. Over the years, several methods have been used for microphone calibration. Some of the common methods of microphone calibration are Coupler (Reciprocity, Substitution, and Simultaneous), Pistonphone, Electrostatic actuator, and Free-field calibration (Reciprocity, Substitution, and Simultaneous). Traditionally, electrostatic actuators (EA) have been used to characterize air-condenser microphones for wideband frequency ranges; however, MEMS microphones are not adaptable to the EA method due to their construction and very small diaphragm size. Hence a substitution-based, free-field method was developed to

  16. 125 GHz sine wave gating InGaAs/InP single-photon detector with a monolithically integrated readout circuit

    Science.gov (United States)

    Jiang, Wen-Hao; Liu, Jian-Hong; Liu, Yin; Jin, Ge; Zhang, Jun; Pan, Jian-Wei

    2017-12-01

    InGaAs/InP single-photon detectors (SPDs) are the key devices for applications requiring near-infrared single-photon detection. Gating mode is an effective approach to synchronous single-photon detection. Increasing gating frequency and reducing module size are important challenges for the design of such detector system. Here we present for the first time an InGaAs/InP SPD with 1.25 GHz sine wave gating using a monolithically integrated readout circuit (MIRC). The MIRC has a size of 15 mm * 15 mm and implements the miniaturization of avalanche extraction for high-frequency sine wave gating. In the MIRC, low-pass filters and a low-noise radio frequency amplifier are integrated based on the technique of low temperature co-fired ceramic, which can effectively reduce the parasitic capacitance and extract weak avalanche signals. We then characterize the InGaAs/InP SPD to verify the functionality and reliability of MIRC, and the SPD exhibits excellent performance with 27.5 % photon detection efficiency, 1.2 kcps dark count rate, and 9.1 % afterpulse probability at 223 K and 100 ns hold-off time. With this MIRC, one can further design miniaturized high-frequency SPD modules that are highly required for practical applications.

  17. Cosmic microwave background distortions at high frequencies

    International Nuclear Information System (INIS)

    Peter, W.; Peratt, A.L.

    1988-01-01

    The authors analyze the deviation of the cosmic background radiation spectrum from the 2.76+-0.02 0 Κ blackbody curve. If the cosmic background radiation is due to absorption and re-emission of synchrotron radiation from galactic-width current filaments, higher-order synchrotron modes are less thermalized than lower-order modes, causing a distortion of the blackbody curve at higher frequencies. New observations of the microwave background spectrum at short wavelengths should provide an indication of the number of synchrotron modes thermalized in this process. The deviation of the spectrum from that of a perfect blackbody can thus be correlated with astronomical observations such as filament temperatures and electron energies. The results are discussed and compared with the theoretical predictions of other models which assume the presence of intergalactic superconducting cosmic strings

  18. A novel abundant family of retroposed elements (DAS-SINEs) in the nine-banded armadillo (Dasypus novemcinctus).

    Science.gov (United States)

    Churakov, Gennady; Smit, Arian F A; Brosius, Jürgen; Schmitz, Jürgen

    2005-04-01

    About half of the mammalian genome is composed of retroposons. Long interspersed elements (LINEs) and short interspersed elements (SINEs) are the most abundant repetitive elements and account for about 21% and 13% of the human genome, respectively. SINEs have been detected in all major mammalian lineages, except for the South American order Xenarthra, also termed Edentata (armadillos, anteaters, and sloths). Investigating this order, we discovered a novel high-copy-number family of tRNA derived SINEs in the nine-banded armadillo Dasypus novemcinctus, a species that successfully crossed the Central American land bridge to North America in the Pliocene. A specific computer algorithm was developed, and we detected and extracted 687 specific SINEs from databases. Termed DAS-SINEs, we further divided them into six distinct subfamilies. We extracted tRNA(Ala)-derived monomers, two types of dimers, and three subfamilies of chimeric fusion products of a tRNA(Ala) domain and an approximately 180-nt sequence of thus far unidentified origin. Comparisons of secondary structures of the DAS-SINEs' tRNA domains suggest selective pressure to maintain a tRNA-like D-arm structure in the respective founder RNAs, as shown by compensatory mutations. By analysis of subfamily-specific genetic variability, comparison of the proportion of direct repeats, and analysis of self-integrations as well as key events of dimerization and deletions or insertions, we were able to delineate the evolutionary history of the DAS-SINE subfamilies.

  19. Short interspersed elements (SINEs) of the Geomyoidea superfamily rodents.

    Science.gov (United States)

    Gogolevsky, Konstantin P; Kramerov, Dmitri A

    2006-05-24

    A new short interspersed element (SINE) was isolated from the genome of desert kangaroo rat (Dipodomys deserti) using single-primer PCR. This SINE consists of two monomers: the left monomer (IDL) resembles rodent ID element and other tRNAAla(CGC)-derived SINEs, whereas the right one (Geo) shows no similarity with known SINE sequences. PCR and hybridization analyses demonstrated that IDL-Geo SINE is restricted to the rodent superfamily Geomyoidea (families Geomyidea and Heteromyidea). Isolation and analysis of IDL-Geo from California pocket mouse (Chaetodipus californicus) and Botta's pocket gopher (Thomomys bottae) revealed some species-specific features of this SINE family. The structure and evolution of known dimeric SINEs are discussed.

  20. High frequency response of open quantum dots

    International Nuclear Information System (INIS)

    Brunner, R.; Meisels, R.; Kuchar, F.; Ferry, D.; Elhassan, M.; Ishibashi, K.

    2002-01-01

    Full text: We investigate the response of the transport through open quantum dots to millimeterwave radiation (up to 55 GHz). In the low-field region ( 11 cm -2 and a mobility of 1.2 10 6 cm 2 /Vs. By applying a sufficiently negative voltage to the gates the 2DES is split into two regions connected only by a dot-like region (about 350 nm diameter) between them. The DC data exhibit backscattering peaks at fields of a few tenth of a Tesla. Shubnikovde- Haas (SdH) oscillations appear above 0.5 T. While the SdH oscillations show the usual temperature dependence, the backscattering peaks are temperature independent up to 2.5 K. The backscattering peak shows a reduction of 10 percent due to the millimeterwave irradiation. However, due to the temperature independence of this peak, this reduction cannot simply be attributed to electron heating. This conclusion is supported by the observation of a strong frequency dependence of the reduction of the peak height. (author)

  1. Gender Identification Using High-Frequency Speech Energy: Effects of Increasing the Low-Frequency Limit.

    Science.gov (United States)

    Donai, Jeremy J; Halbritter, Rachel M

    The purpose of this study was to investigate the ability of normal-hearing listeners to use high-frequency energy for gender identification from naturally produced speech signals. Two experiments were conducted using a repeated-measures design. Experiment 1 investigated the effects of increasing high-pass filter cutoff (i.e., increasing the low-frequency spectral limit) on gender identification from naturally produced vowel segments. Experiment 2 studied the effects of increasing high-pass filter cutoff on gender identification from naturally produced sentences. Confidence ratings for the gender identification task were also obtained for both experiments. Listeners in experiment 1 were capable of extracting talker gender information at levels significantly above chance from vowel segments high-pass filtered up to 8.5 kHz. Listeners in experiment 2 also performed above chance on the gender identification task from sentences high-pass filtered up to 12 kHz. Cumulatively, the results of both experiments provide evidence that normal-hearing listeners can utilize information from the very high-frequency region (above 4 to 5 kHz) of the speech signal for talker gender identification. These findings are at variance with current assumptions regarding the perceptual information regarding talker gender within this frequency region. The current results also corroborate and extend previous studies of the use of high-frequency speech energy for perceptual tasks. These findings have potential implications for the study of information contained within the high-frequency region of the speech spectrum and the role this region may play in navigating the auditory scene, particularly when the low-frequency portion of the spectrum is masked by environmental noise sources or for listeners with substantial hearing loss in the low-frequency region and better hearing sensitivity in the high-frequency region (i.e., reverse slope hearing loss).

  2. A high-switching-frequency flyback converter in resonant mode

    NARCIS (Netherlands)

    Li, Jianting; van Horck, Frank B.M.; Daniel, Bobby J.; Bergveld, Henk Jan

    2017-01-01

    The demand of miniaturization of power systems has accelerated the research on high-switching-frequency power converters. A flyback converter in resonant mode that features low switching losses, less transformer losses, and low switching noise at high switching frequency is investigated in this

  3. CORE-SINEs: eukaryotic short interspersed retroposing elements with common sequence motifs.

    Science.gov (United States)

    Gilbert, N; Labuda, D

    1999-03-16

    A 65-bp "core" sequence is dispersed in hundreds of thousands copies in the human genome. This sequence was found to constitute the central segment of a group of short interspersed elements (SINEs), referred to as mammalian-wide interspersed repeats, that proliferated before the radiation of placental mammals. Here, we propose that the core identifies an ancient tRNA-like SINE element, which survived in different lineages such as mammals, reptiles, birds, and fish, as well as mollusks, presumably for >550 million years. This element gave rise to a number of sequence families (CORE-SINEs), including mammalian-wide interspersed repeats, whose distinct 3' ends are shared with different families of long interspersed elements (LINEs). The evolutionary success of the generic CORE-SINE element can be related to the recruitment of the internal promoter from highly transcribed host RNA as well as to its capacity to adapt to changing retropositional opportunities by sequence exchange with actively amplifying LINEs. It reinforces the notion that the very existence of SINEs depends on the cohabitation with both LINEs and the host genome.

  4. Nanohertz frequency determination for the gravity probe B high frequency superconducting quantum interference device signal.

    Science.gov (United States)

    Salomon, M; Conklin, J W; Kozaczuk, J; Berberian, J E; Keiser, G M; Silbergleit, A S; Worden, P; Santiago, D I

    2011-12-01

    In this paper, we present a method to measure the frequency and the frequency change rate of a digital signal. This method consists of three consecutive algorithms: frequency interpolation, phase differencing, and a third algorithm specifically designed and tested by the authors. The succession of these three algorithms allowed a 5 parts in 10(10) resolution in frequency determination. The algorithm developed by the authors can be applied to a sampled scalar signal such that a model linking the harmonics of its main frequency to the underlying physical phenomenon is available. This method was developed in the framework of the gravity probe B (GP-B) mission. It was applied to the high frequency (HF) component of GP-B's superconducting quantum interference device signal, whose main frequency f(z) is close to the spin frequency of the gyroscopes used in the experiment. A 30 nHz resolution in signal frequency and a 0.1 pHz/s resolution in its decay rate were achieved out of a succession of 1.86 s-long stretches of signal sampled at 2200 Hz. This paper describes the underlying theory of the frequency measurement method as well as its application to GP-B's HF science signal.

  5. Shell structure in superdeformed nuclei at high rotational frequencies

    International Nuclear Information System (INIS)

    Ploszajczak, M.

    1980-01-01

    Properties of the shell structure in superdeformed nuclei at high rotational frequencies are discussed. Moreover, stability of the high spin compound nucleus with respect to the fission and the emission of light particles is investigated. (author)

  6. Dermatomyositis Sine Myositis with Membranoproliferative Glomerulonephritis

    Directory of Open Access Journals (Sweden)

    Mohammad Bagher Owlia

    2012-01-01

    Full Text Available Dermatomyositis (DM is an autoimmune disease that is characterized by involvement of proximal musculature and skin. We report a 52-year-old woman with a 6-year history of dermatomyositis sine myositis, who developed lower extremity edema and proteinuria. Pathological examination of renal biopsy showed membranoproliferative glomerulonephritis. She received steroid, cyclophosphamide, and mycophenolate mofetil. Over the 9 to 10 months after the beginning of treatment, the proteinuria was improved.

  7. Roughening in random sine-Gordon systems

    International Nuclear Information System (INIS)

    Schwartz, M.; Nattermann, T.

    1991-01-01

    We consider the spatial correlations of the optimal solutions of the random sine-Gordon equation as an example of the usefulness of a very simple ansatz relating the Fourier transforms of certain functions of the field Φ to the Fourier transform of the random fields. The dramatic change in the correlations when going from above to below two dimensions is directly attributed to the transfer from dominance of long range fluctuations of the randomness to the dominance of short range fluctuations. (orig.)

  8. A MEMS-based high frequency x-ray chopper

    Energy Technology Data Exchange (ETDEWEB)

    Siria, A; Schwartz, W; Chevrier, J [Institut Neel, CNRS-Universite Joseph Fourier Grenoble, BP 166, F-38042 Grenoble Cedex 9 (France); Dhez, O; Comin, F [ESRF, 6 rue Jules Horowitz, F-38043 Grenoble Cedex 9 (France); Torricelli, G [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom)

    2009-04-29

    Time-resolved x-ray experiments require intensity modulation at high frequencies (advanced rotating choppers have nowadays reached the kHz range). We here demonstrate that a silicon microlever oscillating at 13 kHz with nanometric amplitude can be used as a high frequency x-ray chopper. We claim that using micro-and nanoelectromechanical systems (MEMS and NEMS), it will be possible to achieve higher frequencies in excess of hundreds of megahertz. Working at such a frequency can open a wealth of possibilities in chemistry, biology and physics time-resolved experiments.

  9. High Accelerating Field Superconducting Radio Frequency Cavities

    Science.gov (United States)

    Orr, R. S.; Saito, K.; Furuta, F.; Saeki, T.; Inoue, H.; Morozumi, Y.; Higo, T.; Higashi, Y.; Matsumoto, H.; Kazakov, S.; Yamaoka, H.; Ueno, K.; Sato, M.

    2008-06-01

    We have conducted a study of a series of single cell superconducting RF cavities at KEK. These tests were designed to investigate the effect of surface treatment on the maximum accelerating field attainable. All of these cavities are of the ICHIRO shape, based on the Low Loss shape. Our results indicate that accelerating fields as high as the theoretical maximum of 50MV/m are attainable.

  10. Critical boundary sine-Gordon revisited

    International Nuclear Information System (INIS)

    Hasselfield, M.; Lee, Taejin; Semenoff, G.W.; Stamp, P.C.E.

    2006-01-01

    We revisit the exact solution of the two space-time dimensional quantum field theory of a free massless boson with a periodic boundary interaction and self-dual period. We analyze the model by using a mapping to free fermions with a boundary mass term originally suggested in Ref. [J. Polchinski, L. Thorlacius, Phys. Rev. D 50 (1994) 622]. We find that the entire SL (2, C) family of boundary states of a single boson are boundary sine-Gordon states and we derive a simple explicit expression for the boundary state in fermion variables and as a function of sine-Gordon coupling constants. We use this expression to compute the partition function. We observe that the solution of the model has a strong-weak coupling generalization of T-duality. We then examine a class of recently discovered conformal boundary states for compact bosons with radii which are rational numbers times the self-dual radius. These have simple expression in fermion variables. We postulate sine-Gordon-like field theories with discrete gauge symmetries for which they are the appropriate boundary states

  11. Improving mental task classification by adding high frequency band information.

    Science.gov (United States)

    Zhang, Li; He, Wei; He, Chuanhong; Wang, Ping

    2010-02-01

    Features extracted from delta, theta, alpha, beta and gamma bands spanning low frequency range are commonly used to classify scalp-recorded electroencephalogram (EEG) for designing brain-computer interface (BCI) and higher frequencies are often neglected as noise. In this paper, we implemented an experimental validation to demonstrate that high frequency components could provide helpful information for improving the performance of the mental task based BCI. Electromyography (EMG) and electrooculography (EOG) artifacts were removed by using blind source separation (BSS) techniques. Frequency band powers and asymmetry ratios from the high frequency band (40-100 Hz) together with those from the lower frequency bands were used to represent EEG features. Finally, Fisher discriminant analysis (FDA) combining with Mahalanobis distance were used as the classifier. In this study, four types of classifications were performed using EEG signals recorded from four subjects during five mental tasks. We obtained significantly higher classification accuracy by adding the high frequency band features compared to using the low frequency bands alone, which demonstrated that the information in high frequency components from scalp-recorded EEG is valuable for the mental task based BCI.

  12. Chaos in high-power high-frequency gyrotrons

    International Nuclear Information System (INIS)

    Airila, M.

    2004-01-01

    Gyrotron interaction is a complex nonlinear dynamical process, which may turn chaotic in certain circumstances. The emergence of chaos renders dynamical systems unpredictable and causes bandwidth broadening of signals. Such effects would jeopardize the prospect of advanced gyrotrons in fusion. Therefore, it is important to be aware of the possibility of chaos in gyrotrons. There are three different chaos scenarios closely related to the development of high-power gyrotrons: First, the onset of chaos in electron trajectories would lead to difficulties in the design and efficient operation of depressed potential collectors, which are used for efficiency enhancement. Second, the radio-frequency signal could turn chaotic, decreasing the output power and the spectral purity of the output signal. As a result, mode conversion, transmission, and absorption efficiencies would be reduced. Third, spatio-temporal chaos in the resonator field structure can set a limit for the use of large-diameter interaction cavities and high-order TE modes (large azimuthal index) allowing higher generated power. In this thesis, the issues above are addressed with numerical modeling. It is found that chaos in electron residual energies is practically absent in the parameter region corresponding to high efficiency. Accordingly, depressed collectors are a feasible solution also in advanced high-power gyrotrons. A new method is presented for straightforward numerical solution of the one-dimensional self-consistent time-dependent gyrotron equations, and the method is generalized to two dimensions. In 1D, a chart of gyrotron oscillations is calculated. It is shown that the regions of stationary oscillations, automodulation, and chaos have a complicated topology in the plane of generalized gyrotron variables. The threshold current for chaotic oscillations exceeds typical operating currents by a factor of ten. However, reflection of the output signal may significantly lower the threshold. 2D

  13. High frequency characterization of Galfenol minor flux density loops

    Directory of Open Access Journals (Sweden)

    Ling Weng

    2017-05-01

    Full Text Available This paper presents the first measurement of ring-shaped Galfenol’s high frequency-dependent minor flux density loops. The frequencies of applied AC magnetic field are 1k, 5k, 10k, 50k, 100k, 200k, 300k, 500 kHz. The measurements show that the cycle area between the flux density and magnetic field curves increase with increasing frequency. High frequency-dependent characterization, including coercivity, specific power loss, residual induction, and maximum relative permeability are discussed. Minor loops for different max induction are also measured and discussed at the same frequency 100 kHz. Minor loops with the same max induction 0.05 T for different frequencies 50, 100, 200, 300, 400 kHz are measured and specific power loss are discussed.

  14. High-frequency multimodal atomic force microscopy

    Directory of Open Access Journals (Sweden)

    Adrian P. Nievergelt

    2014-12-01

    Full Text Available Multifrequency atomic force microscopy imaging has been recently demonstrated as a powerful technique for quickly obtaining information about the mechanical properties of a sample. Combining this development with recent gains in imaging speed through small cantilevers holds the promise of a convenient, high-speed method for obtaining nanoscale topography as well as mechanical properties. Nevertheless, instrument bandwidth limitations on cantilever excitation and readout have restricted the ability of multifrequency techniques to fully benefit from small cantilevers. We present an approach for cantilever excitation and deflection readout with a bandwidth of 20 MHz, enabling multifrequency techniques extended beyond 2 MHz for obtaining materials contrast in liquid and air, as well as soft imaging of delicate biological samples.

  15. High quality factor gigahertz frequencies in nanomechanical diamond resonators

    OpenAIRE

    Gaidarzhy, Alexei; Imboden, Matthias; Mohanty, Pritiraj; Rankin, Janet; Sheldon, Brian W.

    2007-01-01

    We report actuation and detection of gigahertz-range resonance frequencies in nano-crystalline diamond mechanical resonators. High order transverse vibration modes are measured in coupled-beam resonators exhibiting frequencies up to 1.441 GHz. The cantilever-array design of the resonators translates the gigahertz-range resonant motion of micron-long cantilever elements to the displacement of the central supporting structure. Use of nano-crystalline diamond further increases the frequency comp...

  16. High-frequency energy in singing and speech

    Science.gov (United States)

    Monson, Brian Bruce

    While human speech and the human voice generate acoustical energy up to (and beyond) 20 kHz, the energy above approximately 5 kHz has been largely neglected. Evidence is accruing that this high-frequency energy contains perceptual information relevant to speech and voice, including percepts of quality, localization, and intelligibility. The present research was an initial step in the long-range goal of characterizing high-frequency energy in singing voice and speech, with particular regard for its perceptual role and its potential for modification during voice and speech production. In this study, a database of high-fidelity recordings of talkers was created and used for a broad acoustical analysis and general characterization of high-frequency energy, as well as specific characterization of phoneme category, voice and speech intensity level, and mode of production (speech versus singing) by high-frequency energy content. Directionality of radiation of high-frequency energy from the mouth was also examined. The recordings were used for perceptual experiments wherein listeners were asked to discriminate between speech and voice samples that differed only in high-frequency energy content. Listeners were also subjected to gender discrimination tasks, mode-of-production discrimination tasks, and transcription tasks with samples of speech and singing that contained only high-frequency content. The combination of these experiments has revealed that (1) human listeners are able to detect very subtle level changes in high-frequency energy, and (2) human listeners are able to extract significant perceptual information from high-frequency energy.

  17. Rapid fabrication and characterization of sine wave targets

    International Nuclear Information System (INIS)

    Day, R.D.; Armijo, E.; Gobby, P.; Hatch, D.; Rivera, G.; Salzer, L.; Townsend, J.

    1997-01-01

    The effect of surface perturbations on Inertial Confinement Fusion target performance is currently being researched at Los Alamos National Laboratory (LANL). These perturbations can cause hydrodynamic instabilities which in turn reduce the targets' yield. To systematically measure the growth of these instabilities requires targets to be produced which have perturbations of a known amplitude and spatial frequency. The authors have recently assembled hardware onto one of their diamond turning lathes which enables them to machine and measure these sine waves in about 15 minutes. This is a significant reduction in time from the two and one half hours required by the previous method. This paper discusses the hardware, how it works, and how well the system is working for them to produce these targets

  18. Multiple sine wave excitation of a hard spring oscillator

    International Nuclear Information System (INIS)

    Curreri, J.R.; Bezler, P.

    1976-06-01

    The vibration testing of non-linear systems has not received much attention in the literature. Frequently, linear procedures are used in the hope that large differences between the linear and non-linear responses will not occur. This may be valid for certain small ranges of the non-linearity and for a single harmonic component excitation. However, for multi-component periodic inputs, there is very little guidance in the literature for even a qualitative evaluation of the probable response. With multi-component periodic inputs, it has been shown that sub-combination frequencies can occur in cubic non-linear systems. Under these conditions, large responses can develop. The critical nature of the development of the large response has not been discussed. This is the subject of this paper. The qualitative response of a two component sine wave applied to a hard spring oscillator is shown

  19. The Influence of High-Frequency Envelope Information on Low-Frequency Vowel Identification in Noise.

    Directory of Open Access Journals (Sweden)

    Wiebke Schubotz

    Full Text Available Vowel identification in noise using consonant-vowel-consonant (CVC logatomes was used to investigate a possible interplay of speech information from different frequency regions. It was hypothesized that the periodicity conveyed by the temporal envelope of a high frequency stimulus can enhance the use of the information carried by auditory channels in the low-frequency region that share the same periodicity. It was further hypothesized that this acts as a strobe-like mechanism and would increase the signal-to-noise ratio for the voiced parts of the CVCs. In a first experiment, different high-frequency cues were provided to test this hypothesis, whereas a second experiment examined more closely the role of amplitude modulations and intact phase information within the high-frequency region (4-8 kHz. CVCs were either natural or vocoded speech (both limited to a low-pass cutoff-frequency of 2.5 kHz and were presented in stationary 3-kHz low-pass filtered masking noise. The experimental results did not support the hypothesized use of periodicity information for aiding low-frequency perception.

  20. The Influence of High-Frequency Envelope Information on Low-Frequency Vowel Identification in Noise.

    Science.gov (United States)

    Schubotz, Wiebke; Brand, Thomas; Kollmeier, Birger; Ewert, Stephan D

    2016-01-01

    Vowel identification in noise using consonant-vowel-consonant (CVC) logatomes was used to investigate a possible interplay of speech information from different frequency regions. It was hypothesized that the periodicity conveyed by the temporal envelope of a high frequency stimulus can enhance the use of the information carried by auditory channels in the low-frequency region that share the same periodicity. It was further hypothesized that this acts as a strobe-like mechanism and would increase the signal-to-noise ratio for the voiced parts of the CVCs. In a first experiment, different high-frequency cues were provided to test this hypothesis, whereas a second experiment examined more closely the role of amplitude modulations and intact phase information within the high-frequency region (4-8 kHz). CVCs were either natural or vocoded speech (both limited to a low-pass cutoff-frequency of 2.5 kHz) and were presented in stationary 3-kHz low-pass filtered masking noise. The experimental results did not support the hypothesized use of periodicity information for aiding low-frequency perception.

  1. High frequency single mode traveling wave structure for particle acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Ivanyan, M.I.; Danielyan, V.A.; Grigoryan, B.A.; Grigoryan, A.H. [CANDLE Synchrotron Research Institute, 0040 Yerevan (Armenia); Tsakanian, A.V. [CANDLE Synchrotron Research Institute, 0040 Yerevan (Armenia); Technische Universität Darmstadt, Institut TEMF, 64289 Darmstadt (Germany); Tsakanov, V.M., E-mail: tsakanov@asls.candle.am [CANDLE Synchrotron Research Institute, 0040 Yerevan (Armenia); Vardanyan, A.S.; Zakaryan, S.V. [CANDLE Synchrotron Research Institute, 0040 Yerevan (Armenia)

    2016-09-01

    The development of the new high frequency slow traveling wave structures is one of the promising directions in accomplishment of charged particles high acceleration gradient. The disc and dielectric loaded structures are the most known structures with slowly propagating modes. In this paper a large aperture high frequency metallic two-layer accelerating structure is studied. The electrodynamical properties of the slowly propagating TM{sub 01} mode in a metallic tube with internally coated low conductive thin layer are examined.

  2. Theoretical treatment of high-frequency, large-amplitude ac voltammetry applied to ideal surface-confined redox systems

    International Nuclear Information System (INIS)

    Bell, Christopher G.; Anastassiou, Costas A.; O’Hare, Danny; Parker, Kim H.; Siggers, Jennifer H.

    2012-01-01

    Highlights: ► Theory of ac voltammetry on ideal surface-confined redox systems. ► Analytical description of the harmonics and transient of the current response. ► Solution valid for high frequency, large-amplitude sinusoidal input voltage. ► Protocol for determining system parameters from experimental current responses. - Abstract: Large-amplitude ac voltammetry, where the applied voltage is a large-amplitude sinusoidal waveform superimposed onto a dc ramp, is a powerful method for investigating the reaction kinetics of surface-confined redox species. Here we consider the large-amplitude ac voltammetric current response of a quasi-reversible, ideal, surface-confined redox system, for which the redox reaction is described by Butler–Volmer theory. We derive an approximate analytical solution, which is valid whenever the angular frequency of the sine-wave is much larger than the rate of the dc ramp and the standard kinetic rate constant of the redox reaction. We demonstrate how the third harmonic and the initial transient of the current response can be used to estimate parameters of the electrochemical system, namely the kinetic rate constant, the electron transfer coefficient, the adsorption formal potential, the initial proportion of oxidised molecules and the linear double-layer capacitance.

  3. Design and development of ITER high-frequency magnetic sensor

    NARCIS (Netherlands)

    Ma, Y.; Vayakis, G.; Begrambekov, L. B.; Cooper, J.J.; Duran, I.; Hirsch, M.; Laqua, H.P.; Moreau, Ph.; Oosterbeek, J.W.; Spuig, P.; Stange, T.; Walsh, M.

    2016-01-01

    High-frequency (HF) inductive magnetic sensors are the primary ITER diagnostic set for Toroidal Alfvén Eigenmodes (TAE) detection, while they also supplement low-frequency MHD and plasma equilibrium measurements. These sensors will be installed on the inner surface of ITER vacuum vessel, operated in

  4. On d -Dimensional Lattice (co)sine n -Algebra

    International Nuclear Information System (INIS)

    Yao Shao-Kui; Zhang Chun-Hong; Zhao Wei-Zhong; Ding Lu; Liu Peng

    2016-01-01

    We present the (co)sine n-algebra which is indexed by the d-dimensional integer lattice. Due to the associative operators, this generalized (co)sine n-algebra is the higher order Lie algebra for the n even case. The particular cases are the d-dimensional lattice sine 3 and cosine 5-algebras with the special parameter values. We find that the corresponding d-dimensional lattice sine 3 and cosine 5-algebras are the Nambu 3-algebra and higher order Lie algebra, respectively. The limiting case of the d-dimensional lattice (co)sine n-algebra is also discussed. Moreover we construct the super sine n-algebra, which is the super higher order Lie algebra for the n even case. (paper)

  5. Vacuum instability in the quantum sine-gordon model

    International Nuclear Information System (INIS)

    Bogolyubov, N.M.; Izergin, A.G.; Korepin, V.E.

    1985-01-01

    A review is given of papers dealing with regularization of the sine-Gordon model and the construction of the integrable lattice sine-Gordon (LSG) model. The regularization by means of LSG model seems to be much more natural as it is done in terms of initial boson fields entering Hamiltonian which describes relativistic scalar field with essentially nonlinear self-interaction. Changes in physical vacuum due to regularizations of the sine-Gordon model is shown

  6. High density terahertz frequency comb produced by coherent synchrotron radiation

    Science.gov (United States)

    Tammaro, S.; Pirali, O.; Roy, P.; Lampin, J.-F.; Ducournau, G.; Cuisset, A.; Hindle, F.; Mouret, G.

    2015-07-01

    Frequency combs have enabled significant progress in frequency metrology and high-resolution spectroscopy extending the achievable resolution while increasing the signal-to-noise ratio. In its coherent mode, synchrotron radiation is accepted to provide an intense terahertz continuum covering a wide spectral range from about 0.1 to 1 THz. Using a dedicated heterodyne receiver, we reveal the purely discrete nature of this emission. A phase relationship between the light pulses leads to a powerful frequency comb spanning over one decade in frequency. The comb has a mode spacing of 846 kHz, a linewidth of about 200 Hz, a fractional precision of about 2 × 10-10 and no frequency offset. The unprecedented potential of the comb for high-resolution spectroscopy is demonstrated by the accurate determination of pure rotation transitions of acetonitrile.

  7. High Energy Single Frequency Resonant Amplifier, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR phase I project proposes a single frequency high energy resonant amplifier for remote sensing. Current state-of-art technologies can not provide all...

  8. Oscillographic Chronopotentiometry with High and Low Frequency Current

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A novel electroanalytical method, oscillographic chronopotentiometry with high and low frequency current, is presented in this paper. With this method, the sensitivity of almost all kinds of oscillographic chronopotentiometry can be enhanced about one order.

  9. High-Frequency Microwave Processing of Materials Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Conducts research on high-frequency microwave processing of materials using a highpower, continuous-wave (CW), 83-GHz, quasi-optical beam system for rapid,...

  10. High-frequency matrix converter with square wave input

    Science.gov (United States)

    Carr, Joseph Alexander; Balda, Juan Carlos

    2015-03-31

    A device for producing an alternating current output voltage from a high-frequency, square-wave input voltage comprising, high-frequency, square-wave input a matrix converter and a control system. The matrix converter comprises a plurality of electrical switches. The high-frequency input and the matrix converter are electrically connected to each other. The control system is connected to each switch of the matrix converter. The control system is electrically connected to the input of the matrix converter. The control system is configured to operate each electrical switch of the matrix converter converting a high-frequency, square-wave input voltage across the first input port of the matrix converter and the second input port of the matrix converter to an alternating current output voltage at the output of the matrix converter.

  11. Instrumentation for high-frequency meteorological observations from research vessel

    Digital Repository Service at National Institute of Oceanography (India)

    VijayKumar, K.; Khalap, S.; Mehra, P.

    Ship provides an attractive platform from which high-frequency meteorological observations (e.g., wind components, water vapor density, and air temperature) can be made accurately. However, accurate observations of meteorological variables depend...

  12. Computation of High-Frequency Waves with Random Uncertainty

    KAUST Repository

    Malenova, Gabriela; Motamed, Mohammad; Runborg, Olof; Tempone, Raul

    2016-01-01

    or nonlinear functionals of the wave solution and its spatial/temporal derivatives. The numerical scheme combines two techniques: a high-frequency method based on Gaussian beams [2, 3], a sparse stochastic collocation method [4]. The fast spectral

  13. Bov-B-mobilized SINEs in vertebrate genomes.

    Science.gov (United States)

    Gogolevsky, Konstantin P; Vassetzky, Nikita S; Kramerov, Dmitri A

    2008-01-15

    Two new short retroposon families (SINEs) have been found in the genome of springhare Pedetes capensis (Rodentia). One of them, Ped-1, originated from 5S rRNA, while the other one, Ped-2, originated from tRNA-derived SINE ID. In contrast to most currently active mammalian SINEs mobilized by L1 long retrotransposon (LINE), Ped-1 and Ped-2 are mobilized by Bov-B, a LINE family of the widely distributed RTE clade. The 3' part of these SINEs originates from two sequences in the 5' and 3' regions of Bov-B. Such bipartite structure of the LINE-derived part has been revealed in all Bov-B-mobilized SINEs known to date (AfroSINE, Bov-tA, Mar-1, and Ped-1/2), which distinguishes them from other SINEs with only a 3' LINE-derived part. Structural analysis and the distribution of Bov-B LINEs and partner SINEs supports the horizontal transfer of Bov-B, while the SINEs emerged independently in lineages with this LINE.

  14. High and low spatial frequencies in website evaluations.

    Science.gov (United States)

    Thielsch, Meinald T; Hirschfeld, Gerrit

    2010-08-01

    Which features of websites are important for users' perceptions regarding aesthetics or usability? This study investigates how evaluations of aesthetic appeal and usability depend on high vs. low spatial frequencies. High spatial frequencies convey information on fine details, whereas low spatial frequencies convey information about the global layout. Participants rated aesthetic appeal and usability of 50 website screenshots from different domains. Screenshots were presented unfiltered, low-pass filtered with blurred targets or high-pass filtered with high-pass filtered targets. The main result is that low spatial frequencies can be seen to have a unique contribution in perceived website aesthetics, thus confirming a central prediction from processing fluency theory. There was no connection between low spatial frequencies and usability evaluations, whereas strong correlations were found between ratings of high-pass filtered websites and those of unfiltered websites in aesthetics and usability. This study thus offers a new perspective on the biological basis of users' website perceptions. This research links ergonomics to neurocognitive models of visual processing. This paper investigates how high and low spatial frequencies, which are neurologically processed in different visual pathways, independently contribute to users' perceptions of websites. This is very relevant for theories of website perceptions and for practitioners of web design.

  15. High Order Differential Frequency Hopping: Design and Analysis

    Directory of Open Access Journals (Sweden)

    Yong Li

    2015-01-01

    Full Text Available This paper considers spectrally efficient differential frequency hopping (DFH system design. Relying on time-frequency diversity over large spectrum and high speed frequency hopping, DFH systems are robust against hostile jamming interference. However, the spectral efficiency of conventional DFH systems is very low due to only using the frequency of each channel. To improve the system capacity, in this paper, we propose an innovative high order differential frequency hopping (HODFH scheme. Unlike in traditional DFH where the message is carried by the frequency relationship between the adjacent hops using one order differential coding, in HODFH, the message is carried by the frequency and phase relationship using two-order or higher order differential coding. As a result, system efficiency is increased significantly since the additional information transmission is achieved by the higher order differential coding at no extra cost on either bandwidth or power. Quantitative performance analysis on the proposed scheme demonstrates that transmission through the frequency and phase relationship using two-order or higher order differential coding essentially introduces another dimension to the signal space, and the corresponding coding gain can increase the system efficiency.

  16. Frequencies of inaudible high-frequency sounds differentially affect brain activity: positive and negative hypersonic effects.

    Directory of Open Access Journals (Sweden)

    Ariko Fukushima

    Full Text Available The hypersonic effect is a phenomenon in which sounds containing significant quantities of non-stationary high-frequency components (HFCs above the human audible range (max. 20 kHz activate the midbrain and diencephalon and evoke various physiological, psychological and behavioral responses. Yet important issues remain unverified, especially the relationship existing between the frequency of HFCs and the emergence of the hypersonic effect. In this study, to investigate the relationship between the hypersonic effect and HFC frequencies, we divided an HFC (above 16 kHz of recorded gamelan music into 12 band components and applied them to subjects along with an audible component (below 16 kHz to observe changes in the alpha2 frequency component (10-13 Hz of spontaneous EEGs measured from centro-parieto-occipital regions (Alpha-2 EEG, which we previously reported as an index of the hypersonic effect. Our results showed reciprocal directional changes in Alpha-2 EEGs depending on the frequency of the HFCs presented with audible low-frequency component (LFC. When an HFC above approximately 32 kHz was applied, Alpha-2 EEG increased significantly compared to when only audible sound was applied (positive hypersonic effect, while, when an HFC below approximately 32 kHz was applied, the Alpha-2 EEG decreased (negative hypersonic effect. These findings suggest that the emergence of the hypersonic effect depends on the frequencies of inaudible HFC.

  17. High frequency source localization in a shallow ocean sound channel using frequency difference matched field processing.

    Science.gov (United States)

    Worthmann, Brian M; Song, H C; Dowling, David R

    2015-12-01

    Matched field processing (MFP) is an established technique for source localization in known multipath acoustic environments. Unfortunately, in many situations, particularly those involving high frequency signals, imperfect knowledge of the actual propagation environment prevents accurate propagation modeling and source localization via MFP fails. For beamforming applications, this actual-to-model mismatch problem was mitigated through a frequency downshift, made possible by a nonlinear array-signal-processing technique called frequency difference beamforming [Abadi, Song, and Dowling (2012). J. Acoust. Soc. Am. 132, 3018-3029]. Here, this technique is extended to conventional (Bartlett) MFP using simulations and measurements from the 2011 Kauai Acoustic Communications MURI experiment (KAM11) to produce ambiguity surfaces at frequencies well below the signal bandwidth where the detrimental effects of mismatch are reduced. Both the simulation and experimental results suggest that frequency difference MFP can be more robust against environmental mismatch than conventional MFP. In particular, signals of frequency 11.2 kHz-32.8 kHz were broadcast 3 km through a 106-m-deep shallow ocean sound channel to a sparse 16-element vertical receiving array. Frequency difference MFP unambiguously localized the source in several experimental data sets with average peak-to-side-lobe ratio of 0.9 dB, average absolute-value range error of 170 m, and average absolute-value depth error of 10 m.

  18. Frequencies of inaudible high-frequency sounds differentially affect brain activity: positive and negative hypersonic effects.

    Science.gov (United States)

    Fukushima, Ariko; Yagi, Reiko; Kawai, Norie; Honda, Manabu; Nishina, Emi; Oohashi, Tsutomu

    2014-01-01

    The hypersonic effect is a phenomenon in which sounds containing significant quantities of non-stationary high-frequency components (HFCs) above the human audible range (max. 20 kHz) activate the midbrain and diencephalon and evoke various physiological, psychological and behavioral responses. Yet important issues remain unverified, especially the relationship existing between the frequency of HFCs and the emergence of the hypersonic effect. In this study, to investigate the relationship between the hypersonic effect and HFC frequencies, we divided an HFC (above 16 kHz) of recorded gamelan music into 12 band components and applied them to subjects along with an audible component (below 16 kHz) to observe changes in the alpha2 frequency component (10-13 Hz) of spontaneous EEGs measured from centro-parieto-occipital regions (Alpha-2 EEG), which we previously reported as an index of the hypersonic effect. Our results showed reciprocal directional changes in Alpha-2 EEGs depending on the frequency of the HFCs presented with audible low-frequency component (LFC). When an HFC above approximately 32 kHz was applied, Alpha-2 EEG increased significantly compared to when only audible sound was applied (positive hypersonic effect), while, when an HFC below approximately 32 kHz was applied, the Alpha-2 EEG decreased (negative hypersonic effect). These findings suggest that the emergence of the hypersonic effect depends on the frequencies of inaudible HFC.

  19. Real-time and high accuracy frequency measurements for intermediate frequency narrowband signals

    Science.gov (United States)

    Tian, Jing; Meng, Xiaofeng; Nie, Jing; Lin, Liwei

    2018-01-01

    Real-time and accurate measurements of intermediate frequency signals based on microprocessors are difficult due to the computational complexity and limited time constraints. In this paper, a fast and precise methodology based on the sigma-delta modulator is designed and implemented by first generating the twiddle factors using the designed recursive scheme. This scheme requires zero times of multiplications and only half amounts of addition operations by using the discrete Fourier transform (DFT) and the combination of the Rife algorithm and Fourier coefficient interpolation as compared with conventional methods such as DFT and Fast Fourier Transform. Experimentally, when the sampling frequency is 10 MHz, the real-time frequency measurements with intermediate frequency and narrowband signals have a measurement mean squared error of ±2.4 Hz. Furthermore, a single measurement of the whole system only requires approximately 0.3 s to achieve fast iteration, high precision, and less calculation time.

  20. THE RELATION OF FREQUENCY TO THE PHYSIOLOGICAL EFFECTS OF ULTRA-HIGH FREQUENCY CURRENTS.

    Science.gov (United States)

    Christie, R V; Loomis, A L

    1929-01-31

    1. Biological effects of electromagnetic waves emitted by a vacuum tube oscillator have been studied at frequencis ranging from 8,300,000 to 158,000,000 cycles per second (1.9 to 38 meters wave-length). 2. The effects produced on animals can be fully explained on the basis of the heat generated by high frequency currents which are induced in them. 3. No evidence was obtained to support the theory that certain wave-lengths have a specific action on living cells. 4. At frequencies below 50,000,000 cycles, the effect of these radiations on animals is proportionate to the intensity of the electro-magnetic field. As the frequency is increased beyond this point, the amount of induced current is diminished and the apparent lethality of the radiation is decreased. This can be explained by changes occurring in the dielectric properties of tissues at low wave-lengths.

  1. Sines and Cosines. Part 2 of 3

    Science.gov (United States)

    Apostol, Tom M. (Editor)

    1993-01-01

    The Law of Sines and the Law of Cosines are introduced and demonstrated in this 'Project Mathematics' series video using both film footage and computer animation. This video deals primarily with the mathematical field of Trigonometry and explains how these laws were developed and their applications. One significant use is geographical and geological surveying. This includes both the triangulation method and the spirit leveling method. With these methods, it is shown how the height of the tallest mountain in the world, Mt. Everest, was determined.

  2. Deterministic tsunami hazard assessment of Sines - Portugal

    OpenAIRE

    Wronna, Martin

    2015-01-01

    Tese de mestrado em Ciências Geográficas, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2015 Neste trabalho apresenta-se uma abordagem determinística de perigo de tsunamis considerando múltiplas fontes para a cidade costeira de Sines, Portugal. Tsunamis ou maremotos são eventos extremos, energeticamente elevados mas pouco frequentes. Normalmente são geradas por um deslocamento duma grande quantidade de água seja por erupções vulcânicas, colapso de caldeiras, desli...

  3. Forecasting Value-at-Risk Using High-Frequency Information

    Directory of Open Access Journals (Sweden)

    Huiyu Huang

    2013-06-01

    Full Text Available in the prediction of quantiles of daily Standard&Poor’s 500 (S&P 500 returns we consider how to use high-frequency 5-minute data. We examine methods that incorporate the high frequency information either indirectly, through combining forecasts (using forecasts generated from returns sampled at different intraday interval, or directly, through combining high frequency information into one model. We consider subsample averaging, bootstrap averaging, forecast averaging methods for the indirect case, and factor models with principal component approach, for both direct and indirect cases. We show that in forecasting the daily S&P 500 index return quantile (Value-at-Risk or VaR is simply the negative of it, using high-frequency information is beneficial, often substantially and particularly so, in forecasting downside risk. Our empirical results show that the averaging methods (subsample averaging, bootstrap averaging, forecast averaging, which serve as different ways of forming the ensemble average from using high-frequency intraday information, provide an excellent forecasting performance compared to using just low-frequency daily information.

  4. Emotional Intelligence: The Sine Qua Non for a Clinical Leadership Toolbox

    Science.gov (United States)

    Rao, Paul R.

    2006-01-01

    Over the past decade, it has become increasingly clear that although IQ and technical skills are important, emotional intelligence is the Sine Qua Non of leadership. According to Goleman [Goleman, D. (1998). What makes a leader? "Harvard Business Review," 93-102] "effective leaders are alike in one crucial way: they all have a high degree of…

  5. Expansion of CORE-SINEs in the genome of the Tasmanian devil.

    Science.gov (United States)

    Nilsson, Maria A; Janke, Axel; Murchison, Elizabeth P; Ning, Zemin; Hallström, Björn M

    2012-05-06

    The genome of the carnivorous marsupial, the Tasmanian devil (Sarcophilus harrisii, Order: Dasyuromorphia), was sequenced in the hopes of finding a cure for or gaining a better understanding of the contagious devil facial tumor disease that is threatening the species' survival. To better understand the Tasmanian devil genome, we screened it for transposable elements and investigated the dynamics of short interspersed element (SINE) retroposons. The temporal history of Tasmanian devil SINEs, elucidated using a transposition in transposition analysis, indicates that WSINE1, a CORE-SINE present in around 200,000 copies, is the most recently active element. Moreover, we discovered a new subtype of WSINE1 (WSINE1b) that comprises at least 90% of all Tasmanian devil WSINE1s. The frequencies of WSINE1 subtypes differ in the genomes of two of the other Australian marsupial orders. A co-segregation analysis indicated that at least 66 subfamilies of WSINE1 evolved during the evolution of Dasyuromorphia. Using a substitution rate derived from WSINE1 insertions, the ages of the subfamilies were estimated and correlated with a newly established phylogeny of Dasyuromorphia. Phylogenetic analyses and divergence time estimates of mitochondrial genome data indicate a rapid radiation of the Tasmanian devil and the closest relative the quolls (Dasyurus) around 14 million years ago. The radiation and abundance of CORE-SINEs in marsupial genomes indicates that they may be a major player in the evolution of marsupials. It is evident that the early phases of evolution of the carnivorous marsupial order Dasyuromorphia was characterized by a burst of SINE activity. A correlation between a speciation event and a major burst of retroposon activity is for the first time shown in a marsupial genome.

  6. Expansion of CORE-SINEs in the genome of the Tasmanian devil

    Directory of Open Access Journals (Sweden)

    Nilsson Maria A

    2012-05-01

    Full Text Available Abstract Background The genome of the carnivorous marsupial, the Tasmanian devil (Sarcophilus harrisii, Order: Dasyuromorphia, was sequenced in the hopes of finding a cure for or gaining a better understanding of the contagious devil facial tumor disease that is threatening the species’ survival. To better understand the Tasmanian devil genome, we screened it for transposable elements and investigated the dynamics of short interspersed element (SINE retroposons. Results The temporal history of Tasmanian devil SINEs, elucidated using a transposition in transposition analysis, indicates that WSINE1, a CORE-SINE present in around 200,000 copies, is the most recently active element. Moreover, we discovered a new subtype of WSINE1 (WSINE1b that comprises at least 90% of all Tasmanian devil WSINE1s. The frequencies of WSINE1 subtypes differ in the genomes of two of the other Australian marsupial orders. A co-segregation analysis indicated that at least 66 subfamilies of WSINE1 evolved during the evolution of Dasyuromorphia. Using a substitution rate derived from WSINE1 insertions, the ages of the subfamilies were estimated and correlated with a newly established phylogeny of Dasyuromorphia. Phylogenetic analyses and divergence time estimates of mitochondrial genome data indicate a rapid radiation of the Tasmanian devil and the closest relative the quolls (Dasyurus around 14 million years ago. Conclusions The radiation and abundance of CORE-SINEs in marsupial genomes indicates that they may be a major player in the evolution of marsupials. It is evident that the early phases of evolution of the carnivorous marsupial order Dasyuromorphia was characterized by a burst of SINE activity. A correlation between a speciation event and a major burst of retroposon activity is for the first time shown in a marsupial genome.

  7. On temporal correlations in high-resolution frequency counting

    OpenAIRE

    Dunker, Tim; Hauglin, Harald; Rønningen, Ole Petter

    2016-01-01

    We analyze noise properties of time series of frequency data from different counting modes of a Keysight 53230A frequency counter. We use a 10 MHz reference signal from a passive hydrogen maser connected via phase-stable Huber+Suhner Sucoflex 104 cables to the reference and input connectors of the counter. We find that the high resolution gap-free (CONT) frequency counting process imposes long-term correlations in the output data, resulting in a modified Allan deviation that is characteristic...

  8. On the Ongoing Evolution of Very High Frequency Power Supplies

    DEFF Research Database (Denmark)

    Knott, Arnold; Andersen, Toke Meyer; Kamby, Peter

    2013-01-01

    The ongoing demand for smaller and lighter power supplies is driving the motivation to increase the switching frequencies of power converters. Drastic increases however come along with new challenges, namely the increase of switching losses in all components. The application of power circuits used...... in radio frequency transmission equipment helps to overcome those. However those circuits were not designed to meet the same requirements as power converters. This paper summarizes the contributions in recent years in application of very high frequency (VHF) technologies in power electronics, describes...

  9. Extended High Frequency Audiometry in Polycystic Ovary Syndrome

    Directory of Open Access Journals (Sweden)

    Cuneyt Kucur

    2013-01-01

    and BMI of PCOS and control groups were comparable. Each subject was tested with low (250–2000 Hz, high (4000–8000 Hz, and extended high frequency audiometry (8000–20000. Hormonal and biochemical values including LH, LH/FSH, testosterone, fasting glucose, fasting insulin, HOMA-I, and CRP were calculated. Results. PCOS patients showed high levels of LH, LH/FSH, testosterone, fasting insulin, glucose, HOMA-I, and CRP levels. The hearing thresholds of the groups were similar at frequencies of 250, 500, 1000, 2000, and 4000 Hz; statistically significant difference was observed in 8000–14000 Hz in PCOS group compared to control group. Conclusion. PCOS patients have hearing impairment especially in extended high frequencies. Further studies are needed to help elucidate the mechanism behind hearing impairment in association with PCOS.

  10. Planck 2013 results. VI. High Frequency Instrument data processing

    DEFF Research Database (Denmark)

    Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.

    2013-01-01

    We describe the processing of the 531 billion raw data samples from the High Frequency Instrument (HFI), which we performed to produce six temperature maps from the first 473 days of Planck-HFI survey data. These maps provide an accurate rendition of the sky emission at 100, 143,217, 353, 545......, these two high frequency channels are calibrated to within 5% and the 353 GHz channel to the percent level. The 100 and217 GHz channels, which together with the 143 GHz channel determine the high-multipole part of the CMB power spectrum (50

  11. HOM frequency control of SRF cavity in high current ERLs

    Science.gov (United States)

    Xu, Chen; Ben-Zvi, Ilan

    2018-03-01

    The acceleration of high-current beam in Superconducting Radio Frequency (SRF) cavities is a challenging but essential for a variety of advanced accelerators. SRF cavities should be carefully designed to minimize the High Order Modes (HOM) power generated in the cavities by the beam current. The reduction of HOM power we demonstrate in a particular case can be quite large. This paper presents a method to systematically control the HOM resonance frequencies in the initial design phase to minimize the HOM power generation. This method is expected to be beneficial for the design of high SRF cavities addressing a variety of Energy Recovery Linac (ERL) applications.

  12. Frequency- and amplitude-transitioned waveforms mitigate the onset response in high-frequency nerve block

    Science.gov (United States)

    Gerges, Meana; Foldes, Emily L.; Ackermann, D. Michael; Bhadra, Narendra; Bhadra, Niloy; Kilgore, Kevin L.

    2010-12-01

    High-frequency alternating currents (HFAC) have proven to be a reversible and rapid method of blocking peripheral nerve conduction, holding promise for treatment of disorders associated with undesirable neuronal activity. The delivery of HFAC is characterized by a transient period of neural firing at its inception, termed the 'onset response'. The onset response is minimized for higher frequencies and higher amplitudes, but requires larger currents. However, the complete block can be maintained at lower frequencies and amplitudes, using lower currents. In this in vivo study on whole mammalian peripheral nerves, we demonstrate a method to minimize the onset response by initiating the block using a stimulation paradigm with a high frequency and large amplitude, and then transitioning to a low-frequency and low-amplitude waveform, reducing the currents required to maintain the conduction block. In five of six animals, it was possible to transition from a 30 kHz to a 10 kHz waveform without inducing any transient neural firing. The minimum transition time was 0.03 s. Transition activity was minimized or eliminated with longer transition times. The results of this study show that this method is feasible for achieving a nerve block with minimal onset responses and current amplitude requirements.

  13. Carbon nanotube transistor based high-frequency electronics

    Science.gov (United States)

    Schroter, Michael

    At the nanoscale carbon nanotubes (CNTs) have higher carrier mobility and carrier velocity than most incumbent semiconductors. Thus CNT based field-effect transistors (FETs) are being considered as strong candidates for replacing existing MOSFETs in digital applications. In addition, the predicted high intrinsic transit frequency and the more recent finding of ways to achieve highly linear transfer characteristics have inspired investigations on analog high-frequency (HF) applications. High linearity is extremely valuable for an energy efficient usage of the frequency spectrum, particularly in mobile communications. Compared to digital applications, the much more relaxed constraints for CNT placement and lithography combined with already achieved operating frequencies of at least 10 GHz for fabricated devices make an early entry in the low GHz HF market more feasible than in large-scale digital circuits. Such a market entry would be extremely beneficial for funding the development of production CNTFET based process technology. This talk will provide an overview on the present status and feasibility of HF CNTFET technology will be given from an engineering point of view, including device modeling, experimental results, and existing roadblocks. Carbon nanotube transistor based high-frequency electronics.

  14. A novel singular pattern in the sine-Gordon equation

    International Nuclear Information System (INIS)

    Huang, Debin

    2003-01-01

    By the scatter problem and the Backlund transformation of the sine-Gordon equation, we find a novel solution with the singularity of jumping phenomenon, which displays pattern structure similar respectively to soliton, kink, anti-kink and double pole solution with the different choice of the purely imaginary spectrum of the sine-Gordon equation

  15. Bunched soliton states in weakly coupled sine-Gordon systems

    DEFF Research Database (Denmark)

    Grønbech-Jensen, N.; Samuelsen, Mogens Rugholm; Lomdahl, P. S.

    1990-01-01

    The interaction between solitons of two weakly coupled sine-Gordon systems is considered. In particular, the stability of bunched states is investigated, and perturbation results are compared with numerical results.......The interaction between solitons of two weakly coupled sine-Gordon systems is considered. In particular, the stability of bunched states is investigated, and perturbation results are compared with numerical results....

  16. Efficient estimation for ergodic diffusions sampled at high frequency

    DEFF Research Database (Denmark)

    Sørensen, Michael

    A general theory of efficient estimation for ergodic diffusions sampled at high fre- quency is presented. High frequency sampling is now possible in many applications, in particular in finance. The theory is formulated in term of approximate martingale estimating functions and covers a large class...

  17. Low-frequency sine wave hard-limiting technique

    Science.gov (United States)

    Anderson, T. O.

    1977-01-01

    Circuit includes serial-in/parallel-out shift register and weighting network that are used to eliminate effects of noise and other nonrepetitive circuit transients. Register and weighting network average decisions from section of signal where decisions are more dependable or where differences between two consecutive samples are larger.

  18. Origin and evolution of SINEs in eukaryotic genomes.

    Science.gov (United States)

    Kramerov, D A; Vassetzky, N S

    2011-12-01

    Short interspersed elements (SINEs) are one of the two most prolific mobile genomic elements in most of the higher eukaryotes. Although their biology is still not thoroughly understood, unusual life cycle of these simple elements amplified as genomic parasites makes their evolution unique in many ways. In contrast to most genetic elements including other transposons, SINEs emerged de novo many times in evolution from available molecules (for example, tRNA). The involvement of reverse transcription in their amplification cycle, huge number of genomic copies and modular structure allow variation mechanisms in SINEs uncommon or rare in other genetic elements (module exchange between SINE families, dimerization, and so on.). Overall, SINE evolution includes their emergence, progressive optimization and counteraction to the cell's defense against mobile genetic elements.

  19. Music students: conventional hearing thresholds and at high frequencies.

    Science.gov (United States)

    Lüders, Débora; Gonçalves, Cláudia Giglio de Oliveira; Lacerda, Adriana Bender de Moreira; Ribas, Ângela; Conto, Juliana de

    2014-01-01

    Research has shown that hearing loss in musicians may cause difficulty in timbre recognition and tuning of instruments. To analyze the hearing thresholds from 250 Hz to 16,000 Hz in a group of music students and compare them to a non-musician group in order to determine whether high-frequency audiometry is a useful tool in the early detection of hearing impairment. Study design was a retrospective observational cohort. Conventional and high-frequency audiometry was performed in 42 music students (Madsen Itera II audiometer and TDH39P headphones for conventional audiometry, and HDA 200 headphones for high-frequency audiometry). Of the 42 students, 38.1% were female students and 61.9% were male students, with a mean age of 26 years. At conventional audiometry, 92.85% had hearing thresholds within normal limits; but even within the normal limits, the worst results were observed in the left ear for all frequencies, except for 4000 Hz; compared to the non-musician group, the worst results occurred at 500 Hz in the left ear, and at 250 Hz, 6000 Hz, 9000 Hz, 10,000 Hz, and 11,200 Hz in both the ears. The periodic evaluation of high-frequency thresholds may be useful in the early detection of hearing loss in musicians. Copyright © 2014 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  20. Music students: conventional hearing thresholds and at high frequencies

    Directory of Open Access Journals (Sweden)

    Débora Lüders

    2014-07-01

    Full Text Available INTRODUCTION: Research has shown that hearing loss in musicians may cause difficulty in timbre recognition and tuning of instruments. AIM: To analyze the hearing thresholds from 250 Hz to 16,000 Hz in a group of music students and compare them to a non-musician group in order to determine whether high-frequency audiometry is a useful tool in the early detection of hearing impairment. METHODS: Study design was a retrospective observational cohort. Conventional and high-frequency audiometry was performed in 42 music students (Madsen Itera II audiometer and TDH39P headphones for conventional audiometry, and HDA 200 headphones for high-frequency audiometry. RESULTS: Of the 42 students, 38.1% were female students and 61.9% were male students, with a mean age of 26 years. At conventional audiometry, 92.85% had hearing thresholds within normal limits; but even within the normal limits, the worst results were observed in the left ear for all frequencies, except for 4000 Hz; compared to the non-musician group, the worst results occurred at 500 Hz in the left ear, and at 250 Hz, 6000 Hz, 9000 Hz, 10,000 Hz, and 11,200 Hz in both the ears. CONCLUSION: The periodic evaluation of high-frequency thresholds may be useful in the early detection of hearing loss in musicians.

  1. Control of high frequency microactuators using active structures

    International Nuclear Information System (INIS)

    Kreth, P A; Alvi, F S; Reese, B M; Oates, W S

    2015-01-01

    A fluidically driven microactuator that generates supersonic, pulsed microjets has been implemented with smart materials to actively and precisely control the frequency of the microjets in a closed-loop manner. Since this actuator relies on a number of microscale flow and acoustic phenomena to produce the pulsed microjets, its resonant frequency is determined by its geometry and other flow parameters. The design discussed in this paper integrates piezoelectric stacks by connecting them to movable sidewalls within the actuator such that the microactuator's internal geometry can be controlled by varying the voltage across the piezo-stacks. An open-loop control scheme demonstrates the frequency modulation capabilities that are enabled with this design: very large frequency deviations (up to ±500 Hz) around the actuator design frequency are attained at very high rates (up to 1 kHz). Closed-loop control of the microactuator's frequency was also demonstrated, and the results indicate that (combined with appropriate sensors) this actuator could be used effectively for active, feedback control in high-speed, resonance-dominated flowfields. This proof of concept study clearly illustrates the ability of this robust and compact actuator to produce perturbations that can be modulated and controlled based on the desired control objective. (paper)

  2. Thermal history of the plasma and high-frequency gravitons

    CERN Document Server

    Giovannini, Massimo

    2009-01-01

    Possible deviations from a radiation-dominated evolution, occurring prior the synthesis of light nuclei, impacted on the spectral energy density of high-frequency gravitons. For a systematic scrutiny of this situation, the $\\Lambda$CDM paradigm must be complemented by (at least two) physical parameters describing, respectively, a threshold frequency and a slope. The supplementary frequency scale sets the lower border of a high-frequency domain where the spectral energy grows with a slope which depends, predominantly, upon the total sound speed of the plasma right after inflation. While the infra-red region of the graviton energy spectrum is nearly scale-invariant, the expected signals for typical frequencies larger than 0.01 nHz are hereby analyzed in a model-independent framework by requiring that the total sound speed of the post-inflationary plasma is smaller than the speed of light. Current (e.g. low-frequency) upper limits on the tensor power spectra (determined from the combined analysis of the three la...

  3. Frequency and temperature dependence of high damping elastomers

    International Nuclear Information System (INIS)

    Kulak, R.F.; Hughes, T.H.

    1993-01-01

    High damping steel-laminated elastomeric seismic isolation bearings are one of the preferred devices for isolating large buildings and structures. In the US, the current reference design for the Advanced Liquid Metal Reactor (ALMR) uses laminated bearings for seismic isolation. These bearings are constructed from alternating layers of high damping rubber and steel plates. They are typically designed for shear strains between 50 and 100% and are expected to sustain two to three times these levels for beyond design basis loading conditions. Elastomeric bearings are currently designed to provide a system frequency between 0.4 and 0.8 Hz and expected to operate between -20 and 40 degrees Centigrade. To assure proper performance of isolation bearings, it is necessary to characterize the elastomer's response under expected variations of frequency and temperature. The dynamic response of the elastomer must be characterized within the frequency range that spans the bearing acceptance test frequency, which may be as low as 0.005 Hz, and the design frequency. Similarly, the variation in mechanical characteristics of the elastomer must be determined over the design temperature range, which is between -20 and 40 degrees Centigrade. This paper reports on (1) the capabilities of a testing facility at ANL for testing candidate elastomers, (2) the variation with frequency and temperature of the stiffness and damping of one candidate elastomer, and (3) the effect of these variations on bearing acceptance testing criteria and on the choice of bearing design values for stiffness and damping

  4. High frequency ultrasound imaging in pupillary block glaucoma.

    Science.gov (United States)

    Aslanides, I M; Libre, P E; Silverman, R H; Reinstein, D Z; Lazzaro, D R; Rondeau, M J; Harmon, G K; Coleman, D J

    1995-01-01

    BACKGROUND--The diagnosis of pupillary block glaucoma requires sufficient clarity of the ocular media. This is particularly important for assessment of both the presence and patency of an iridotomy, and the determination of central anterior chamber depth. METHODS--High frequency ultrasonography was used in three patients with suspected pupillary block to determine iris configuration, posterior chamber volume, and ciliary body conformation. RESULTS--All patients demonstrated high frequency ultrasonographic findings consistent with pupillary block: iris bombé, a formed posterior chamber, and a lack of anterior rotation of the ciliary processes. CONCLUSION--High frequency ultrasound imaging appears to be a valuable adjunct in making or corroborating the diagnosis of pupillary block glaucoma. Images PMID:8534666

  5. High Frequency Amplitude Detector for GMI Magnetic Sensors

    Directory of Open Access Journals (Sweden)

    Aktham Asfour

    2014-12-01

    Full Text Available A new concept of a high-frequency amplitude detector and demodulator for Giant-Magneto-Impedance (GMI sensors is presented. This concept combines a half wave rectifier, with outstanding capabilities and high speed, and a feedback approach that ensures the amplitude detection with easily adjustable gain. The developed detector is capable of measuring high-frequency and very low amplitude signals without the use of diode-based active rectifiers or analog multipliers. The performances of this detector are addressed throughout the paper. The full circuitry of the design is given, together with a comprehensive theoretical study of the concept and experimental validation. The detector has been used for the amplitude measurement of both single frequency and pulsed signals and for the demodulation of amplitude-modulated signals. It has also been successfully integrated in a GMI sensor prototype. Magnetic field and electrical current measurements in open- and closed-loop of this sensor have also been conducted.

  6. High frequency conductivity of hot electrons in carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Amekpewu, M., E-mail: mamek219@gmail.com [Department of Applied Physics, University for Development Studies, Navrongo (Ghana); Mensah, S.Y. [Department of Physics, College of Agriculture and Natural Sciences, U.C.C. (Ghana); Musah, R. [Department of Applied Physics, University for Development Studies, Navrongo (Ghana); Mensah, N.G. [Department of Mathematics, College of Agriculture and Natural Sciences, U.C.C. (Ghana); Abukari, S.S.; Dompreh, K.A. [Department of Physics, College of Agriculture and Natural Sciences, U.C.C. (Ghana)

    2016-05-01

    High frequency conductivity of hot electrons in undoped single walled achiral Carbon Nanotubes (CNTs) under the influence of ac–dc driven fields was considered. We investigated semi-classically Boltzmann's transport equation with and without the presence of the hot electrons’ source by deriving the current densities in CNTs. Plots of the normalized current density versus frequency of ac-field revealed an increase in both the minimum and maximum peaks of normalized current density at lower frequencies as a result of a strong injection of hot electrons. The applied ac-field plays a twofold role of suppressing the space-charge instability in CNTs and simultaneously pumping an energy for lower frequency generation and amplification of THz radiations. These have enormous promising applications in very different areas of science and technology.

  7. Anomalous high-frequency resistivity of a plasma

    International Nuclear Information System (INIS)

    Kruer, W.L.; Dawson, J.M.

    1971-06-01

    In one- and two-dimensional computer simulations we investigate anomalous high-frequency resistivity in a plasma driven by a large electric field oscillating near the electron plasma frequency. The large field excites the oscillating two-stream and the ion-acoustic decay instabilities in agreement with the linear theory. When the ion and electron fluctuations saturate, a strong anomalous heating of the plasma sets in. This strong heating is due to an efficient coupling of the externally imposed large electric field to the plasma by ion fluctuations. We determine the anomalous collision frequency and the saturation fluctuation amplitudes as a function of the external field amplitude and frequency, and the electron-ion mass ratio. A simple nonlinear theory gives results in reasonable agreement with simulations. 24 refs., 10 figs

  8. High frequency relay protection channels on super high voltage lines

    Energy Technology Data Exchange (ETDEWEB)

    Mikutskii, G V

    1964-08-01

    General aspects of high voltage transmission line design are discussed. The relationships between line voltage and length and line dimensions and power losses are explained. Electrical interference in the line is classified under three headings: interference under normal operating conditions, interference due to insulation faults, and interference due to variations in operating conditions of the high-voltage network.

  9. Novel SINE families from salmons validate Parahucho (Salmonidae) as a distinct genus and give evidence that SINEs can incorporate LINE-related 3'-tails of other SINEs.

    Science.gov (United States)

    Matveev, Vitaliy; Nishihara, Hidenori; Okada, Norihiro

    2007-08-01

    Short interspersed elements (SINEs) constitute a group of retroposons propagating in the genome via a mechanism of reverse transcription, in which they depend on the enzymatic machinery of long retroposons (LINEs). Over 70 SINE families have been described to date from the genomes of various eukaryotes. Here, we characterize two novel SINEs from salmons (Actinopterygii: Salmonoidei). The first family, termed SlmI, was shown to be widespread among all genera of the suborder. These SINEs have a tRNA(Leu)-related promoter region at their 5'-end, a unique central conserved domain with a subfamily-specific region, and an end with RSg-1-LINE-derived 3'-terminus preceding the A/T-rich tail. The same LINE-related segment is also shared by two other salmonid SINEs: HpaI and OS-SINE1. The structural peculiarities and overall sequence identity of the SlmI 3'-terminus suggest that it has been acquired from HpaI SINEs but not directly from the partner LINE. This region plays a crucial role in the process of retrotransposition of short interspersed elements, and the case of its SINE-to-SINE transmission is the first recorded to date. Possible scenarios and potential evolutionary implications of the observed interaction between short retroposons are discussed. Apart from the above, we found a copy of the SlmI SINE in the GenBank entry for the blood fluke, Schistosoma japonicum (Trematoda: Strigeiformes) -- a trematode causing one of the most important human helminth infections, with its genome known to host other groups of salmonoid retroposons. In the present article, we suggest our views with regard to possible ways in which such an intensive horizontal transfer of salmonoid retroposons to the schistosomal genome occurs. The second novel SINE family, termed SlmII, originates from one of the SlmI subfamilies, with which it shares the same tRNA-related region, central domain, and a part of RSg-1-derived segment, but has a different 3'-tail of unidentified origin. Its distribution

  10. High-frequency dynamics in a molten binary alloy

    International Nuclear Information System (INIS)

    Alvarez, M.; Bermejo, F.J.; Verkerk, P.; Roessli, B.

    1999-01-01

    The nature of the finite wavelength collective excitations in liquid binary mixtures composed of atoms of very different masses has been of interest for more than a decade. The most prominent fact is the high frequencies at which they appear, well above those expected for a continuation to large wave vector of hydrodynamic sound. To better understand the microscopic dynamics of such systems, an inelastic neutron scattering experiment was performed on the molten alloy Li 4 Pb. We present the high-frequency excitations of molten Li 4 Pb which indeed show features substantially deviating from those expected for the propagation of an acoustic mode. (authors)

  11. Short interspersed CAN SINE elements as prognostic markers in canine mammary neoplasia.

    Science.gov (United States)

    Gelaleti, Gabriela B; Granzotto, Adriana; Leonel, Camila; Jardim, Bruna V; Moschetta, Marina G; Carareto, Claudia M A; Zuccari, Debora Ap P C

    2014-01-01

    The genome of mammals is characterized by a large number of non-LTR retrotransposons, and among them, the CAN SINEs are characteristics of the canine species. Small amounts of DNA freely circulate in normal blood serum and high amounts are found in human patients with cancer, characterizing it as a candidate tumor-biomarker. The aim of this study was to estimate, through its absolute expression, the number of copies of CAN SINE sequences present in free circulating DNA of female dogs with mammary cancer, in order to correlate with the clinical and pathological characteristics and the follow-up period. The copy number of CAN SINE sequences was estimated by qPCR in 28 female dogs with mammary neoplasia. The univariate analysis showed an increased number of copies in female dogs with mammary tumor in female dogs >10 years old (p=0.02) and tumor time >18 months (pSINE fragments can be good markers for the detection of tumor DNA in blood and may characterize it as a marker of poor prognosis, being related to female dogs with shorter survival times. This estimate can be used as a prognostic marker in non-invasive breast cancer research and is useful in predicting tumor progression and patient monitoring.

  12. Stress induction of Bm1 RNA in silkworm larvae: SINEs, an unusual class of stress genes

    Science.gov (United States)

    Kimura, Richard H.; Choudary, Prabhakara V.; Stone, Koni K.; Schmid, Carl W.

    2001-01-01

    This study surveys the induction of RNA polymerase III (Pol III)–directed expression of short interspersed element (SINE) transcripts by various stresses in an animal model, silkworm larvae. Sublethal heat shock and exposure to several toxic compounds increase the level of Bm1 RNA, the silkworm SINE transcript, while also transiently increasing expression of a well-characterized stress-induced transcript, Hsp70 messenger RNA (mRNA). In certain cases, the Bm1 RNA response coincides with that of Hsp70 mRNA, but more often Bm1 RNA responds later in recovery. Baculovirus infection and exposure to certain toxic compounds increase Bm1 RNA but not Hsp70 mRNA, showing that SINE induction is not necessarily coupled to transcription of this particular heat shock gene. SINEs behave as an additional class of stress-inducible genes in living animals but are unusual as stress genes because of their high copy number, genomic dispersion, and Pol III–directed transcription. PMID:11599568

  13. Stochastically-driven coherence in a sine-Gordon chain

    International Nuclear Information System (INIS)

    Guerrero, L.E.; Hasmy, A.; Mata, G.J.

    1994-01-01

    We perform numerical simulations of the dynamical behavior of a sine-Gordon chain in a heat bath. The interaction with the heat bath is simulated by the Langevin formalism. The noise term is uncorrelated in both space and time. We use the Karhunen-Loeve decomposition to study the effective number of degrees of freedom as a function of temperature (i.e., of the noise dispersion). At low temperatures we find a spatially disordered regime, characterized by a high number of degrees of freedom. At a temperature of the order of the soliton rest mass we find a relatively sharp crossover to an ordered regime, characterized by a low number of degrees of freedom. The spatial structure of the modes suggests that the transition is associated to the appearance of thermally activated solitons. We also present an alternative estimate of the effective number of degrees of freedom. (orig.)

  14. Rocket measurements of electron density irregularities during MAC/SINE

    Science.gov (United States)

    Ulwick, J. C.

    1989-01-01

    Four Super Arcas rockets were launched at the Andoya Rocket Range, Norway, as part of the MAC/SINE campaign to measure electron density irregularities with high spatial resolution in the cold summer polar mesosphere. They were launched as part of two salvos: the turbulent/gravity wave salvo (3 rockets) and the EISCAT/SOUSY radar salvo (one rocket). In both salvos meteorological rockets, measuring temperature and winds, were also launched and the SOUSY radar, located near the launch site, measured mesospheric turbulence. Electron density irregularities and strong gradients were measured by the rocket probes in the region of most intense backscatter observed by the radar. The electron density profiles (8 to 4 on ascent and 4 on descent) show very different characteristics in the peak scattering region and show marked spatial and temporal variability. These data are intercompared and discussed.

  15. Ultradiscrete sine-Gordon Equation over Symmetrized Max-Plus Algebra, and Noncommutative Discrete and Ultradiscrete sine-Gordon Equations

    Directory of Open Access Journals (Sweden)

    Kenichi Kondo

    2013-11-01

    Full Text Available Ultradiscretization with negative values is a long-standing problem and several attempts have been made to solve it. Among others, we focus on the symmetrized max-plus algebra, with which we ultradiscretize the discrete sine-Gordon equation. Another ultradiscretization of the discrete sine-Gordon equation has already been proposed by previous studies, but the equation and the solutions obtained here are considered to directly correspond to the discrete counterpart. We also propose a noncommutative discrete analogue of the sine-Gordon equation, reveal its relations to other integrable systems including the noncommutative discrete KP equation, and construct multisoliton solutions by a repeated application of Darboux transformations. Moreover, we derive a noncommutative ultradiscrete analogue of the sine-Gordon equation and its 1-soliton and 2-soliton solutions, using the symmetrized max-plus algebra. As a result, we have a complete set of commutative and noncommutative versions of continuous, discrete, and ultradiscrete sine-Gordon equations.

  16. Synthesis of High-Frequency Ground Motion Using Information Extracted from Low-Frequency Ground Motion

    Science.gov (United States)

    Iwaki, A.; Fujiwara, H.

    2012-12-01

    Broadband ground motion computations of scenario earthquakes are often based on hybrid methods that are the combinations of deterministic approach in lower frequency band and stochastic approach in higher frequency band. Typical computation methods for low-frequency and high-frequency (LF and HF, respectively) ground motions are the numerical simulations, such as finite-difference and finite-element methods based on three-dimensional velocity structure model, and the stochastic Green's function method, respectively. In such hybrid methods, LF and HF wave fields are generated through two different methods that are completely independent of each other, and are combined at the matching frequency. However, LF and HF wave fields are essentially not independent as long as they are from the same event. In this study, we focus on the relation among acceleration envelopes at different frequency bands, and attempt to synthesize HF ground motion using the information extracted from LF ground motion, aiming to propose a new method for broad-band strong motion prediction. Our study area is Kanto area, Japan. We use the K-NET and KiK-net surface acceleration data and compute RMS envelope at four frequency bands: 0.5-1.0 Hz, 1.0-2.0 Hz, 2.0-4.0 Hz, .0-8.0 Hz, and 8.0-16.0 Hz. Taking the ratio of the envelopes of adjacent bands, we find that the envelope ratios have stable shapes at each site. The empirical envelope-ratio characteristics are combined with low-frequency envelope of the target earthquake to synthesize HF ground motion. We have applied the method to M5-class earthquakes and a M7 target earthquake that occurred in the vicinity of Kanto area, and successfully reproduced the observed HF ground motion of the target earthquake. The method can be applied to a broad band ground motion simulation for a scenario earthquake by combining numerically-computed low-frequency (~1 Hz) ground motion with the empirical envelope ratio characteristics to generate broadband ground motion

  17. Piezoelectric Nanotube Array for Broadband High-Frequency Ultrasonic Transducer.

    Science.gov (United States)

    Liew, Weng Heng; Yao, Kui; Chen, Shuting; Tay, Francis Eng Hock

    2018-03-01

    Piezoelectric materials are vital in determining ultrasonic transducer and imaging performance as they offer the function for conversion between mechanical and electrical energy. Ultrasonic transducers with high-frequency operation suffer from performance degradation and fabrication difficulty of the demanded piezoelectric materials. Hence, we propose 1-D polymeric piezoelectric nanostructure with controlled nanoscale features to overcome the technical limitations of high-frequency ultrasonic transducers. For the first time, we demonstrate the integration of a well-aligned piezoelectric nanotube array to produce a high-frequency ultrasonic transducer with outstanding performance. We find that nanoconfinement-induced polarization orientation and unique nanotube structure lead to significantly improved piezoelectric and ultrasonic transducing performance over the conventional piezoelectric thin film. A large bandwidth, 126% (-6 dB), is achieved at high center frequency, 108 MHz. Transmission sensitivity of nanotube array is found to be 46% higher than that of the monolithic thin film transducer attributed to the improved electromechanical coupling effectiveness and impedance match. We further demonstrate high-resolution scanning, ultrasonic imaging, and photoacoustic imaging using the obtained nanotube array transducers, which is valuable for biomedical imaging applications in the future.

  18. High frequency vibration analysis by the complex envelope vectorization.

    Science.gov (United States)

    Giannini, O; Carcaterra, A; Sestieri, A

    2007-06-01

    The complex envelope displacement analysis (CEDA) is a procedure to solve high frequency vibration and vibro-acoustic problems, providing the envelope of the physical solution. CEDA is based on a variable transformation mapping the high frequency oscillations into signals of low frequency content and has been successfully applied to one-dimensional systems. However, the extension to plates and vibro-acoustic fields met serious difficulties so that a general revision of the theory was carried out, leading finally to a new method, the complex envelope vectorization (CEV). In this paper the CEV method is described, underlying merits and limits of the procedure, and a set of applications to vibration and vibro-acoustic problems of increasing complexity are presented.

  19. A simple, tunable, and highly sensitive radio-frequency sensor.

    Science.gov (United States)

    Cui, Yan; Sun, Jiwei; He, Yuxi; Wang, Zheng; Wang, Pingshan

    2013-08-05

    We report a radio frequency (RF) sensor that exploits tunable attenuators and phase shifters to achieve high-sensitivity and broad band frequency tunability. Three frequency bands are combined to enable sensor operations from ∼20 MHz to ∼38 GHz. The effective quality factor ( Q eff ) of the sensor is as high as ∼3.8 × 10 6 with 200  μ l of water samples. We also demonstrate the measurement of 2-proponal-water-solution permittivity at 0.01 mole concentration level from ∼1 GHz to ∼10 GHz. Methanol-water solution and de-ionized water are used to calibrate the RF sensor for the quantitative measurements.

  20. High-frequency microrheology reveals cytoskeleton dynamics in living cells

    Science.gov (United States)

    Rigato, Annafrancesca; Miyagi, Atsushi; Scheuring, Simon; Rico, Felix

    2017-08-01

    Living cells are viscoelastic materials, dominated by an elastic response on timescales longer than a millisecond. On shorter timescales, the dynamics of individual cytoskeleton filaments are expected to emerge, but active microrheology measurements on cells accessing this regime are scarce. Here, we develop high-frequency microrheology experiments to probe the viscoelastic response of living cells from 1 Hz to 100 kHz. We report the viscoelasticity of different cell types under cytoskeletal drug treatments. On previously inaccessible short timescales, cells exhibit rich viscoelastic responses that depend on the state of the cytoskeleton. Benign and malignant cancer cells revealed remarkably different scaling laws at high frequencies, providing a unique mechanical fingerprint. Microrheology over a wide dynamic range--up to the frequency characterizing the molecular components--provides a mechanistic understanding of cell mechanics.

  1. Very High Frequency Switch-Mode Power Supplies

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre

    The importance of technology and electronics in our daily life is constantly increasing. At the same time portability and energy efficiency are currently some of the hottest topics. This creates a huge need for power converters in a compact form factor and with high efficiency, which can supply...... these electronic devices. This calls for new technologies in order to miniaturize the power electronics of today. One way to do this is by increasing the switching frequency dramatically and develop very high frequency switch mode power supplies. If these converters can be designed to operate efficiently, a huge...... size, weight and cost reduction can be achieved due to the smaller energy storing elements needed at these frequencies. The research presented in this thesis focuses on exactly this. First various technologies for miniaturization of power supplies are studied, e.g. piezo electric transformers, wide...

  2. Very High Frequency Galvanic Isolated Offline Power Supply

    DEFF Research Database (Denmark)

    Pedersen, Jeppe Arnsdorf

    During the last decades many researchers have turned their attention to raising the operation frequency of power converters to the very high frequency (VHF) range going from 30 MHz to 300 MHz. Increasing the operating frequency of a power converter leads to smaller energy storing components...... inverters with a single combined rectifier. The converter designed to deliver 9 W to a 60 V LED load and is achieving an efficiency of 89.4% and a power density of 2.14 W3 . The development of this converter proof that offline VHF converter can be implemented with high efficiencies even for low power applications...... are described together with the possibility of using capacitors as the power galvanic isolation, both methods of creating galvanic isolation are implemented in converters. Regarding EMC a series of converters with different filter implementations are examined. The results from the conducted mea-surement from 150...

  3. Computation of High-Frequency Waves with Random Uncertainty

    KAUST Repository

    Malenova, Gabriela

    2016-01-06

    We consider the forward propagation of uncertainty in high-frequency waves, described by the second order wave equation with highly oscillatory initial data. The main sources of uncertainty are the wave speed and/or the initial phase and amplitude, described by a finite number of random variables with known joint probability distribution. We propose a stochastic spectral asymptotic method [1] for computing the statistics of uncertain output quantities of interest (QoIs), which are often linear or nonlinear functionals of the wave solution and its spatial/temporal derivatives. The numerical scheme combines two techniques: a high-frequency method based on Gaussian beams [2, 3], a sparse stochastic collocation method [4]. The fast spectral convergence of the proposed method depends crucially on the presence of high stochastic regularity of the QoI independent of the wave frequency. In general, the high-frequency wave solutions to parametric hyperbolic equations are highly oscillatory and non-smooth in both physical and stochastic spaces. Consequently, the stochastic regularity of the QoI, which is a functional of the wave solution, may in principle below and depend on frequency. In the present work, we provide theoretical arguments and numerical evidence that physically motivated QoIs based on local averages of |uE|2 are smooth, with derivatives in the stochastic space uniformly bounded in E, where uE and E denote the highly oscillatory wave solution and the short wavelength, respectively. This observable related regularity makes the proposed approach more efficient than current asymptotic approaches based on Monte Carlo sampling techniques.

  4. Frequency-Wavenumber (FK)-Based Data Selection in High-Frequency Passive Surface Wave Survey

    Science.gov (United States)

    Cheng, Feng; Xia, Jianghai; Xu, Zongbo; Hu, Yue; Mi, Binbin

    2018-04-01

    Passive surface wave methods have gained much attention from geophysical and civil engineering communities because of the limited application of traditional seismic surveys in highly populated urban areas. Considering that they can provide high-frequency phase velocity information up to several tens of Hz, the active surface wave survey would be omitted and the amount of field work could be dramatically reduced. However, the measured dispersion energy image in the passive surface wave survey would usually be polluted by a type of "crossed" artifacts at high frequencies. It is common in the bidirectional noise distribution case with a linear receiver array deployed along roads or railways. We review several frequently used passive surface wave methods and derive the underlying physics for the existence of the "crossed" artifacts. We prove that the "crossed" artifacts would cross the true surface wave energy at fixed points in the f-v domain and propose a FK-based data selection technique to attenuate the artifacts in order to retrieve the high-frequency information. Numerical tests further demonstrate the existence of the "crossed" artifacts and indicate that the well-known wave field separation method, FK filter, does not work for the selection of directional noise data. Real-world applications manifest the feasibility of the proposed FK-based technique to improve passive surface wave methods by a priori data selection. Finally, we discuss the applicability of our approach.

  5. Frequency-Wavenumber (FK)-Based Data Selection in High-Frequency Passive Surface Wave Survey

    Science.gov (United States)

    Cheng, Feng; Xia, Jianghai; Xu, Zongbo; Hu, Yue; Mi, Binbin

    2018-07-01

    Passive surface wave methods have gained much attention from geophysical and civil engineering communities because of the limited application of traditional seismic surveys in highly populated urban areas. Considering that they can provide high-frequency phase velocity information up to several tens of Hz, the active surface wave survey would be omitted and the amount of field work could be dramatically reduced. However, the measured dispersion energy image in the passive surface wave survey would usually be polluted by a type of "crossed" artifacts at high frequencies. It is common in the bidirectional noise distribution case with a linear receiver array deployed along roads or railways. We review several frequently used passive surface wave methods and derive the underlying physics for the existence of the "crossed" artifacts. We prove that the "crossed" artifacts would cross the true surface wave energy at fixed points in the f- v domain and propose a FK-based data selection technique to attenuate the artifacts in order to retrieve the high-frequency information. Numerical tests further demonstrate the existence of the "crossed" artifacts and indicate that the well-known wave field separation method, FK filter, does not work for the selection of directional noise data. Real-world applications manifest the feasibility of the proposed FK-based technique to improve passive surface wave methods by a priori data selection. Finally, we discuss the applicability of our approach.

  6. High frequency oscillations evoked by peripheral magnetic stimulation.

    Science.gov (United States)

    Biller, S; Simon, L; Fiedler, P; Strohmeier, D; Haueisen, J

    2011-01-01

    The analysis of somatosensory evoked potentials (SEP) and / or fields (SEF) is a well-established and important tool for investigating the functioning of the peripheral and central human nervous system. A standard technique to evoke SEPs / SEFs is the stimulation of the median nerve by using a bipolar electrical stimulus. We aim at an alternative stimulation technique enabling stimulation of deep nerve structures while reducing patient stress and error susceptibility. In the current study, we apply a commercial transcranial magnetic stimulation system for peripheral magnetic stimulation of the median nerve. We compare the results of simultaneously recorded EEG signals to prove applicability of our technique to evoke SEPs including low frequency components (LFC) as well as high frequency oscillations (HFO). Therefore, we compare amplitude, latency and time-frequency characteristics of the SEP of 14 healthy volunteers after electric and magnetic stimulation. Both low frequency components and high frequency oscillations were detected. The HFOs were superimposed onto the primary cortical response N20. Statistical analysis revealed significantly lower amplitudes and increased latencies for LFC and HFO components after magnetic stimulation. The differences indicate the inability of magnetic stimulation to elicit supramaximal responses. A psycho-perceptual evaluation showed that magnetic stimulation was less unpleasant for 12 out of the 14 volunteers. In conclusion, we showed that LFC and HFO components related to median nerve stimulation can be evoked by peripheral magnetic stimulation.

  7. High-frequency strontium vapor laser for biomedical applications

    Science.gov (United States)

    Hvorostovsky, A.; Kolmakov, E.; Kudashev, I.; Redka, D.; Kancer, A.; Kustikova, M.; Bykovskaya, E.; Mayurova, A.; Stupnikov, A.; Ruzankina, J.; Tsvetkov, K.; Lukyanov, N.; Paklinov, N.

    2018-02-01

    Sr-laser with high pulse repetition rate and high peak radiation power is a unique tool for studying rapidly occurring processes in time (plasma diagnostics, photoablation, etc.). In addition, the study of the frequency characteristics of the active medium of the laser helps to reveal the physics of the formation of an inverse medium in metal vapor lasers. In this paper, an experimental study of an Sr-laser with an active volume of 5.8 cm3 in the pulse repetition frequency range from 25 to 200 kHz is carried out, and a comparison with the frequency characteristics of media with large active volumes is given. We considered the frequency characteristics of the active medium in two modes: at a constant energy in the excitation pulse CU2 / 2 and at a constant average power consumed by the rectifier. In the presented work with a small-volume GRT using the TASITR-5/12 TASITRON switch, a laser was generated for Pairs of strontium at a CSF of 200 kHz. The behavior of the characteristics of the generation lines of 6.456 μm, 1 μm, and 3 μm at increased repetition frequencies is considered. Using the example of large-volume GRT, it is shown that tubes with a large active volume increase their energy characteristics with the growth of the CSF. The possibility of laser operation at pulse repetition rates above 200 kHz is shown.

  8. High precision pulsar timing and spin frequency second derivatives

    Science.gov (United States)

    Liu, X. J.; Bassa, C. G.; Stappers, B. W.

    2018-05-01

    We investigate the impact of intrinsic, kinematic and gravitational effects on high precision pulsar timing. We present an analytical derivation and a numerical computation of the impact of these effects on the first and second derivative of the pulsar spin frequency. In addition, in the presence of white noise, we derive an expression to determine the expected measurement uncertainty of a second derivative of the spin frequency for a given timing precision, observing cadence and timing baseline and find that it strongly depends on the latter (∝t-7/2). We show that for pulsars with significant proper motion, the spin frequency second derivative is dominated by a term dependent on the radial velocity of the pulsar. Considering the data sets from three Pulsar Timing Arrays, we find that for PSR J0437-4715 a detectable spin frequency second derivative will be present if the absolute value of the radial velocity exceeds 33 km s-1. Similarly, at the current timing precision and cadence, continued timing observations of PSR J1909-3744 for about another eleven years, will allow the measurement of its frequency second derivative and determine the radial velocity with an accuracy better than 14 km s-1. With the ever increasing timing precision and observing baselines, the impact of the, largely unknown, radial velocities of pulsars on high precision pulsar timing can not be neglected.

  9. Design and development of ITER high-frequency magnetic sensor

    Czech Academy of Sciences Publication Activity Database

    Ma, Y.; Vayakis, G.; Begrambekov, L.B.; Cooper, J.-J.; Ďuran, Ivan; Hirsch, M.; Laqua, H.P.; Moreau, P.; Oosterbeek, J.W.; Spuig, P.; Stange, T.; Walsh, M.

    2016-01-01

    Roč. 112, November (2016), s. 594-612 ISSN 0920-3796 Institutional support: RVO:61389021 Keywords : ITER * High-frequency * Magnetic diagnostics * ECHa Subject RIV: JF - Nuclear Energetics OBOR OECD: Nuclear related engineering Impact factor: 1.319, year: 2016

  10. Very High Frequency Half Bridge DC/DC Converter

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    This paper presents the first, off chip, class DE (resonant half bridge) converter working in the Very High Frequency (VHF) range. The benefits of using half bridge circuits both in the inverter and rectifier part of a VHF resonant dc/dc converter are analyzed and design equations for all...

  11. Strange effects of strong high-frequency excitation

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    2003-01-01

    Three general effects of mechanical high-frequency excitation (HFE) are described: Stiffening - an apparent change in the stiffness associated with an equilibrium; Biasing - a tendency for a system to move towards a particular state which does not exist or is unstable without HFE; and Smoothening...

  12. High frequency MOSFET gate drivers technologies and applications

    CERN Document Server

    Zhang, Zhiliang

    2017-01-01

    This book describes high frequency power MOSFET gate driver technologies, including gate drivers for GaN HEMTs, which have great potential in the next generation of switching power converters. Gate drivers serve as a critical role between control and power devices.

  13. Surface modification of lignocellulosic fibers using high-frequency ultrasound

    Science.gov (United States)

    Jayant B. Gadhe; Ram B. Gupta; Thomas Elder

    2005-01-01

    Enzymatic and chemical oxidation of fiber surfaces has been reported in the literature as a method for producing medium density fiberboards without using synthetic adhesives. This work focuses on modifying the surface properties of wood fibers by the generation of free radicals using high-frequency ultrasound. A sonochemical reactor operating at 610 kHz is used to...

  14. High frequency ground temperature fluctuation in a Convective Boundary Layer

    NARCIS (Netherlands)

    Garai, A.; Kleissl, J.; Lothon, M.; Lohou, F.; Pardyjak, E.; Saïd, F.; Cuxart, J.; Steeneveld, G.J.; Yaguë, C.; Derrien, S.; Alexander, D.; Villagrasa, D.M.

    2012-01-01

    To study influence of the turbulent structures in the convective boundary layer (CBL) on the ground temperature, during the Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) observational campaign, high frequency ground temperature was recorded through infra-red imagery from 13 June - 8

  15. Elastic Modulus at High Frequency of Polymerically Stabilized Suspensions

    NARCIS (Netherlands)

    Nommensen, P.A.; Duits, Michael H.G.; van den Ende, Henricus T.M.; Mellema, J.

    2000-01-01

    The elastic moduli of polymerically stabilized suspensions consisting of colloidal silica particles coated with endgrafted PDMS (Mn = 80 000) in heptane, were measured as a function of concentration. And the elastic modulus at high frequency G'.. was quantitatively described by model calculations

  16. Modelling financial high frequency data using point processes

    DEFF Research Database (Denmark)

    Hautsch, Nikolaus; Bauwens, Luc

    In this chapter written for a forthcoming Handbook of Financial Time Series to be published by Springer-Verlag, we review the econometric literature on dynamic duration and intensity processes applied to high frequency financial data, which was boosted by the work of Engle and Russell (1997...

  17. Vacuum amplification of the high-frequency electromagnetic radiation

    OpenAIRE

    Vilkovisky, G. A.

    1998-01-01

    When an electrically charged source is capable of both emitting the electromagnetic waves and creating charged particles from the vacuum, its radiation gets so much amplified that only the backreaction of the vacuum makes it finite. The released energy and charge are calculated in the high-frequency approximation. The technique of expectation values is advanced and employed.

  18. Integrated Very High Frequency Switch Mode Power Supplies: Design Considerations

    DEFF Research Database (Denmark)

    Hertel, Jens Christian; Nour, Yasser; Knott, Arnold

    2017-01-01

    simulations. The required spiral inductors was modeled, and simulations show Q values of as high as 14 at a switching frequency of 250 MHz. Simulations of the converter show an efficiency of 55 % with a self oscillating gate drive. However the modeled inductor was not adequate for operating with the self...

  19. Collocations of High Frequency Noun Keywords in Prescribed Science Textbooks

    Science.gov (United States)

    Menon, Sujatha; Mukundan, Jayakaran

    2012-01-01

    This paper analyses the discourse of science through the study of collocational patterns of high frequency noun keywords in science textbooks used by upper secondary students in Malaysia. Research has shown that one of the areas of difficulty in science discourse concerns lexis, especially that of collocations. This paper describes a corpus-based…

  20. High resolution mid-infrared spectroscopy based on frequency upconversion

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Hu, Qi; Tidemand-Lichtenberg, Peter

    2013-01-01

    signals can be analyzed. The obtainable frequency resolution is usually in the nm range where sub nm resolution is preferred in many applications, like gas spectroscopy. In this work we demonstrate how to obtain sub nm resolution when using upconversion. In the presented realization one object point...... high resolution spectral performance by observing emission from hot water vapor in a butane gas burner....

  1. Risks and injuries in laser and high-frequency applications

    Science.gov (United States)

    Giering, K.; Philipp, Carsten M.; Berlien, Hans-Peter

    1995-01-01

    An analysis of injuries and risks using high frequency (HF) and lasers in medicine based on a literature search with MEDLINE was performed. The cases reported in the literature were classified according to the following criteria: (1) Avoidable in an optimal operational procedure. These kind of injuries are caused by a chain of unfortunate incidents. They are in principle avoidable by the 'right action at the right time' which presupposes an appropriate training of the operating team, selection of the optimal parameters for procedure and consideration of all safety instructions. (2) Avoidable, caused by malfunction of the equipment and/or accessories. The injuries classified into this group are avoidable if all safety regulations were fulfilled. This includes a pre-operational check-up and the use of medical lasers and high frequency devices only which meet the international safety standards. (3) Avoidable, caused by misuse/mistake. Injuries of this group were caused by an inappropriate selection of the procedure, wrong medical indication or mistakes during application. (4) Unavoidable, fateful. These injuries can be caused by risks inherent to the type of energy used, malfunction of the equipment and/or accessories though a pre-operational check-up was done. Some risks and complications are common to high frequency and laser application. But whereas these risks can be excluded easily in laser surgery there is often a great expenditure necessary or they are not avoidable if high frequency if used. No unavoidable risks due to laser energy occur.

  2. High-frequency Trading, Algorithmic Finance, and the Flash Crash

    DEFF Research Database (Denmark)

    Borch, Christian

    2016-01-01

    The Flash Crash of 6 May 2010 has an interesting status in discussions of high-frequency trading, i.e. fully automated, superfast computerized trading: it is invoked both as an important illustration of how this field of algorithmic trading operates and, more often, as an example of how fully aut...... about resonance in quantitative finance....

  3. Possible involvement of SINEs in mammalian-specific brain formation.

    Science.gov (United States)

    Sasaki, Takeshi; Nishihara, Hidenori; Hirakawa, Mika; Fujimura, Koji; Tanaka, Mikiko; Kokubo, Nobuhiro; Kimura-Yoshida, Chiharu; Matsuo, Isao; Sumiyama, Kenta; Saitou, Naruya; Shimogori, Tomomi; Okada, Norihiro

    2008-03-18

    Retroposons, such as short interspersed elements (SINEs) and long interspersed elements (LINEs), are the major constituents of higher vertebrate genomes. Although there are many examples of retroposons' acquiring function, none has been implicated in the morphological innovations specific to a certain taxonomic group. We previously characterized a SINE family, AmnSINE1, members of which constitute a part of conserved noncoding elements (CNEs) in mammalian genomes. We proposed that this family acquired genomic functionality or was exapted after retropositioning in a mammalian ancestor. Here we identified 53 new AmnSINE1 loci and refined 124 total loci, two of which were further analyzed. Using a mouse enhancer assay, we demonstrate that one SINE locus, AS071, 178 kbp from the gene FGF8 (fibroblast growth factor 8), is an enhancer that recapitulates FGF8 expression in two regions of the developing forebrain, namely the diencephalon and the hypothalamus. Our gain-of-function analysis revealed that FGF8 expression in the diencephalon controls patterning of thalamic nuclei, which act as a relay center of the neocortex, suggesting a role for FGF8 in mammalian-specific forebrain patterning. Furthermore, we demonstrated that the locus, AS021, 392 kbp from the gene SATB2, controls gene expression in the lateral telencephalon, which is thought to be a signaling center during development. These results suggest important roles for SINEs in the development of the mammalian neuronal network, a part of which was initiated with the exaptation of AmnSINE1 in a common mammalian ancestor.

  4. [High-frequency components of occlusal sound in sliding movement].

    Science.gov (United States)

    Nagai, K

    1990-03-01

    We postulated that high-frequency components of the occlusal sound occurring due to the characteristic vibration of teeth can be useful data for confirmation of the stability in occlusion, and studied the high-frequency components in the cases both of an experimental sliding movement and a normal occlusion. The results obtained were as follows. 1. A study on high-frequency components of the occlusal sound in an experimental sliding movement. 1) A study on wave type of the occlusal sound revealed one damped oscillation in an impact form and two in a slide form. 2) Spectrum analysis of the damped oscillation showed a similar spectrum pattern with a peak existing between 16KHz or more and 17KHz or less in both impact and slide cases. 2. A study on high-frequency components of the occlusal sound in a normal occlusion case. 1) The wave type in occlusal sound we have observed in a normal occlusion group and in a prosthetic or operative group was as follows: One damped oscillation shown in an impact form and two damped oscillation in a slide form which were the same as those shown in the case where an interference device was attached. 2) Duration of the sliding movement was short in a normal occlusion group, but was prolonged in a prosthetic or operative group. 3) The incidence of the wave type in occlusal sound was 56.7% in a prosthetic or operative group as compared to 87.8% in a normal occlusion group in an impact form. In contrast, the incidence was 43.3% in a prosthetic or operative group as compared to 12.2% in a normal occlusion group in a slide form. Such difference in the incidence between the wave types suggested that high-frequency components of occlusal sound can be an index for judgement of the stability in occlusion.

  5. High-power non linear frequency converted laser diodes

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Andersen, Peter E.; Hansen, Anders Kragh

    2015-01-01

    We present different methods of generating light in the blue-green spectral range by nonlinear frequency conversion of tapered diode lasers achieving state-of-the-art power levels. In the blue spectral range, we show results using single-pass second harmonic generation (SHG) as well as cavity enh...... enhanced sum frequency generation (SFG) with watt-level output powers. SHG and SFG are also demonstrated in the green spectral range as a viable method to generate up to 4 W output power with high efficiency using different configurations....

  6. High frequency guided wave propagation in monocrystalline silicon wafers

    OpenAIRE

    Pizzolato, M.; Masserey, B.; Robyr, J. L.; Fromme, P.

    2017-01-01

    Monocrystalline silicon wafers are widely used in the photovoltaic industry for solar panels with high conversion efficiency. The cutting process can introduce micro-cracks in the thin wafers and lead to varying thickness. High frequency guided ultrasonic waves are considered for the structural monitoring of the wafers. The anisotropy of the monocrystalline silicon leads to variations of the wave characteristics, depending on the propagation direction relative to the crystal orientation. Full...

  7. Predicting High Frequency Exchange Rates using Machine Learning

    OpenAIRE

    Palikuca, Aleksandar; Seidl,, Timo

    2016-01-01

    This thesis applies a committee of Artificial Neural Networks and Support Vector Machines on high-dimensional, high-frequency EUR/USD exchange rate data in an effort to predict directional market movements on up to a 60 second prediction horizon. The study shows that combining multiple classifiers into a committee produces improved precision relative to the best individual committee members and outperforms previously reported results. A trading simulation implementing the committee classifier...

  8. Advances in high frequency ultrasound separation of particulates from biomass.

    Science.gov (United States)

    Juliano, Pablo; Augustin, Mary Ann; Xu, Xin-Qing; Mawson, Raymond; Knoerzer, Kai

    2017-03-01

    In recent years the use of high frequency ultrasound standing waves (megasonics) for droplet or cell separation from biomass has emerged beyond the microfluidics scale into the litre to industrial scale applications. The principle for this separation technology relies on the differential positioning of individual droplets or particles across an ultrasonic standing wave field within the reactor and subsequent biomass material predisposition for separation via rapid droplet agglomeration or coalescence into larger entities. Large scale transducers have been characterised with sonochemiluminescence and hydrophones to enable better reactor designs. High frequency enhanced separation technology has been demonstrated at industrial scale for oil recovery in the palm oil industry and at litre scale to assist olive oil, coconut oil and milk fat separation. Other applications include algal cell dewatering and milk fat globule fractionation. Frequency selection depends on the material properties and structure in the biomass mixture. Higher frequencies (1 and 2MHz) have proven preferable for better separation of materials with smaller sized droplets such as milk fat globules. For palm oil and olive oil, separation has been demonstrated within the 400-600kHz region, which has high radical production, without detectable impact on product quality. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  9. Design and development of ITER high-frequency magnetic sensor

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Y., E-mail: Yunxing.Ma@iter.org [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Fircroft Engineering, Lingley House, 120 Birchwood Point, Birchwood Boulevard, Warrington, WA3 7QH (United Kingdom); Vayakis, G. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Begrambekov, L.B. [National Research Nuclear University (MEPhI), 115409, Moscow, Kashirskoe shosse 31 (Russian Federation); Cooper, J.-J. [Culham Centre for Fusion Energy (CCFE), Abingdon, Oxfordshire OX14 3DB (United Kingdom); Duran, I. [IPP Prague, Za Slovankou 1782/3, 182 00 Prague 8 (Czech Republic); Hirsch, M.; Laqua, H.P. [Max-Planck-Institut für Plasmaphysik, Teilinstitut Greifswald, Wendelsteinstraße 1, D-17491 Greifswald (Germany); Moreau, Ph. [CEA Cadarache, 13108 Saint Paul lez Durance Cedex (France); Oosterbeek, J.W. [Eindhoven University of Technology (TU/e), PO Box 513, 5600 MB Eindhoven (Netherlands); Spuig, P. [CEA Cadarache, 13108 Saint Paul lez Durance Cedex (France); Stange, T. [Max-Planck-Institut für Plasmaphysik, Teilinstitut Greifswald, Wendelsteinstraße 1, D-17491 Greifswald (Germany); Walsh, M. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex (France)

    2016-11-15

    Highlights: • ITER high-frequency magnetic sensor system has been designed. • Prototypes have been successfully manufactured. • Manufactured prototypes have been tested in various labs. • Test results experimentally validated the design. - Abstract: High-frequency (HF) inductive magnetic sensors are the primary ITER diagnostic set for Toroidal Alfvén Eigenmodes (TAE) detection, while they also supplement low-frequency MHD and plasma equilibrium measurements. These sensors will be installed on the inner surface of ITER vacuum vessel, operated in a harsh environment with considerable neutron/nuclear radiation and high thermal load. Essential components of the HF sensor system, including inductive coil, electron cyclotron heating (ECH) shield, electrical cabling and termination load, have been designed to meet ITER measurement requirements. System performance (e.g. frequency response, thermal conduction) has been assessed. A prototyping campaign was initiated to demonstrate the manufacturability of the designed components. Prototypes have been produced according to the specifications. A series of lab tests have been performed to examine assembly issues and validate electrical and thermo-mechanical aspects of the design. In-situ microwave radiation test has been conducted in the MISTRAL test facility at IPP-Greifswald to experimentally examine the microwave shielding efficiency and structural integrity of the ECH shield. Low-power microwave attenuation measurement and scanning electron microscopic inspection were conducted to probe and examine the quality of the metal coating on the ECH shield.

  10. Occupational hearing loss: tonal audiometry X high frequencies audiometry

    Directory of Open Access Journals (Sweden)

    Lauris, José Roberto Pereira

    2009-09-01

    Full Text Available Introduction: Studies on the occupational exposure show that noise has been reaching a large part of the working population around the world, and NIHL (noise-induced hearing loss is the second most frequent disease of the hearing system. Objective: To review the audiometry results of employees at the campus of the University of São Paulo, Bauru. Method: 40 audiometry results were analyzed between 2007 and 2008, whose ages comprised between 32 and 59 years, of both sexes and several professions: gardeners, maintenance technicians, drivers etc. The participants were divided into 2 groups: those with tonal thresholds within acceptable thresholds and those who presented auditory thresholds alterations, that is tonal thresholds below 25 dB (NA in any frequency (Administrative Rule no. 19 of the Ministry of Labor 1998. In addition to the Conventional Audiologic Evaluation (250Hz to 8.000Hz we also carried out High Frequencies Audiometry (9000Hz, 10000Hz, 11200Hz, 12500Hz, 14000Hz and 16000Hz. Results: According to the classification proposed by FIORINI (1994, 25.0% (N=10 they presented with NIHL suggestive audiometric configurations. The results of high frequencies Audiometry confirmed worse thresholds than those obtained in the conventional audiometry in the 2 groups evaluated. Conclusion: The use of high frequencies audiometry proved to be an important register as a hearing alteration early detection method.

  11. Compact high voltage, high peak power, high frequency transformer for converter type modulator applications.

    Science.gov (United States)

    Reghu, T; Mandloi, V; Shrivastava, Purushottam

    2016-04-01

    The design and development of a compact high voltage, high peak power, high frequency transformer for a converter type modulator of klystron amplifiers is presented. The transformer has been designed to operate at a frequency of 20 kHz and at a flux swing of ±0.6 T. Iron (Fe) based nanocrystalline material has been selected as a core for the construction of the transformer. The transformer employs a specially designed solid Teflon bobbin having 120 kV insulation for winding the high voltage secondary windings. The flux swing of the core has been experimentally found by plotting the hysteresis loop at actual operating conditions. Based on the design, a prototype transformer has been built which is per se a unique combination of high voltage, high frequency, and peak power specifications. The transformer was able to provide 58 kV (pk-pk) at the secondary with a peak power handling capability of 700 kVA. The transformation ratio was 1:17. The performance of the transformer is also presented and discussed.

  12. GaN-based High Power High Frequency Wide Range LLC Resonant Converter, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — SET Group will design, build and demonstrate a Gallium Nitride (GaN) based High Power High Frequency Wide Range LLC Resonant Converter capable of handling high power...

  13. Software for Displaying High-Frequency Test Data

    Science.gov (United States)

    Elmore, Jason L.

    2003-01-01

    An easy-to-use, intuitive computer program was written to satisfy a need of test operators and data requestors to quickly view and manipulate high-frequency test data recorded at the East and West Test Areas at Marshall Space Flight Center. By enabling rapid analysis, this program makes it possible to reduce times between test runs, thereby potentially reducing the overall cost of test operations. The program can be used to perform quick frequency analysis, using multiple fast- Fourier-transform windowing and amplitude options. The program can generate amplitude-versus-time plots with full zoom capabilities, frequency-component plots at specified time intervals, and waterfall plots (plots of spectral intensity versus frequency at successive small time intervals, showing the changing frequency components over time). There are options for printing of the plots and saving plot data as text files that can be imported into other application programs. The program can perform all of the aforementioned plotting and plot-data-handling functions on a relatively inexpensive computer; other software that performs the same functions requires computers with large amounts of power and memory.

  14. Comparative study between ultrahigh spatial frequency algorithm and high spatial frequency algorithm in high-resolution CT of the lungs

    International Nuclear Information System (INIS)

    Oh, Yu Whan; Kim, Jung Kyuk; Suh, Won Hyuck

    1994-01-01

    To date, the high spatial frequency algorithm (HSFA) which reduces image smoothing and increases spatial resolution has been used for the evaluation of parenchymal lung diseases in thin-section high-resolution CT. In this study, we compared the ultrahigh spatial frequency algorithm (UHSFA) with the high spatial frequency algorithm in the assessment of thin section images of the lung parenchyma. Three radiologists compared the UHSFA and HSFA on identical CT images in a line-pair resolution phantom, one lung specimen, 2 patients with normal lung and 18 patients with abnormal lung parenchyma. Scanning of a line-pair resolution phantom demonstrated no difference in resolution between two techniques but it showed that outer lines of the line pairs with maximal resolution looked thicker on UHSFA than those on HSFA. Lung parenchymal detail with UHSFA was judged equal or superior to HSFA in 95% of images. Lung parenchymal sharpness was improved with UHSFA in all images. Although UHSFA resulted in an increase in visible noise, observers did not found that image noise interfered with image interpretation. The visual CT attenuation of normal lung parenchyma is minimally increased in images with HSFA. The overall visual preference of the images reconstructed on UHSFA was considered equal to or greater than that of those reconstructed on HSFA in 78% of images. The ultrahigh spatial frequency algorithm improved the overall visual quality of the images in pulmonary parenchymal high-resolution CT

  15. Factors controlling high-frequency radiation from extended ruptures

    Science.gov (United States)

    Beresnev, Igor A.

    2017-09-01

    Small-scale slip heterogeneity or variations in rupture velocity on the fault plane are often invoked to explain the high-frequency radiation from earthquakes. This view has no theoretical basis, which follows, for example, from the representation integral of elasticity, an exact solution for the radiated wave field. The Fourier transform, applied to the integral, shows that the seismic spectrum is fully controlled by that of the source time function, while the distribution of final slip and rupture acceleration/deceleration only contribute to directivity. This inference is corroborated by the precise numerical computation of the full radiated field from the representation integral. We compare calculated radiation from four finite-fault models: (1) uniform slip function with low slip velocity, (2) slip function spatially modulated by a sinusoidal function, (3) slip function spatially modulated by a sinusoidal function with random roughness added, and (4) uniform slip function with high slip velocity. The addition of "asperities," both regular and irregular, does not cause any systematic increase in the spectral level of high-frequency radiation, except for the creation of maxima due to constructive interference. On the other hand, an increase in the maximum rate of slip on the fault leads to highly amplified high frequencies, in accordance with the prediction on the basis of a simple point-source treatment of the fault. Hence, computations show that the temporal rate of slip, not the spatial heterogeneity on faults, is the predominant factor forming the high-frequency radiation and thus controlling the velocity and acceleration of the resulting ground motions.

  16. Very high frequency (beyond 100 MHz) PZT kerfless linear arrays.

    Science.gov (United States)

    Wu, Da-Wei; Zhou, Qifa; Geng, Xuecang; Liu, Chang-Geng; Djuth, Frank; Shung, K Kirk

    2009-10-01

    This paper presents the design, fabrication, and measurements of very high frequency kerfless linear arrays prepared from PZT film and PZT bulk material. A 12-microm PZT thick film fabricated from PZT-5H powder/solution composite and a piece of 15-microm PZT-5H sheet were used to fabricate 32-element kerfless high-frequency linear arrays with photolithography. The PZT thick film was prepared by spin-coating of PZT sol-gel composite solution. The thin PZT-5H sheet sample was prepared by lapping a PZT-5H ceramic with a precision lapping machine. The measured results of the 2 arrays were compared. The PZT film array had a center frequency of 120 MHz, a bandwidth of 60% with a parylene matching layer, and an insertion loss of 41 dB. The PZT ceramic sheet array was found to have a center frequency of 128 MHz with a poorer bandwidth (40% with a parylene matching layer) but a better sensitivity (28 dB insertion loss).

  17. High-frequency ultrasound-responsive block copolymer micelle.

    Science.gov (United States)

    Wang, Jie; Pelletier, Maxime; Zhang, Hongji; Xia, Hesheng; Zhao, Yue

    2009-11-17

    Micelles of a diblock copolymer composed of poly(ethylene oxide) and poly(2-tetrahydropyranyl methacrylate) (PEO-b-PTHPMA) in aqueous solution could be disrupted by high-frequency ultrasound (1.1 MHz). It was found that, upon exposure to a high-intensity focused ultrasound (HIFU) beam at room temperature, the pH value of the micellar solution decreased over irradiation time. The infrared spectroscopic analysis of solid block copolymer samples collected from the ultrasound irradiated micellar solution revealed the formation of carboxylic acid dimers and hydroxyl groups. These characterization results suggest that the high-frequency HIFU beam could induce the hydrolysis reaction of THPMA at room temperature resulting in the cleavage of THP groups. The disruption of PEO-b-PTHPMA micelles by ultrasound was investigated by using dynamic light scattering, atomic force microscopy, and fluorescence spectroscopy. On the basis of the pH change, it was found that the disruption process was determined by a number of factors such as the ultrasound power, the micellar solution volume and the location of the focal spot of the ultrasound beam. This study shows the potential to develop ultrasound-sensitive block copolymer micelles by having labile chemical bonds in the polymer structure, and to use the high-frequency HIFU to trigger a chemical reaction for the disruption of micelles.

  18. High frequency modeling of power transformers. Stresses and diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Bjerkan, Eilert

    2005-05-15

    In this thesis a reliable, versatile and rigorous method for high frequency power transformer modeling is searched and established. The purpose is to apply this model to sensitivity analysis of FRA (Frequency Response Analysis) which is a quite new diagnostic method for assessing the mechanical integrity of power transformer windings on-site. The method should be versatile in terms of being able to estimate internal and external over voltages and resonances. Another important aspect is that the method chosen is suitable for real transformer geometries. In order to verify the suitability of the model for real transformers, a specific test-object is used. This is a 20MVA transformer, and details are given in chapter 1.4. The high frequency power transformer model is established from geometrical and constructional information from the manufacturer, together with available material characteristics. All circuit parameters in the lumped circuit representation are calculated based on these data. No empirical modifications need to be performed. Comparison shows capability of reasonable accuracy in the range from 10 khz to 1 MHz utilizing a disc-to-disc representation. A compromise between accuracy of model due to discretization and complexity of the model in a turn-to-turn representation is inevitable. The importance of the iron core is emphasized through a comparison of representations with/without the core included. Frequency-dependent phenomena are accurately represented using an isotropic equivalent for windings and core, even with a coarse mesh for the FEM-model. This is achieved through a frequency-dependent complex permeability representation of the materials. This permeability is deduced from an analytical solution of the frequency-dependent magnetic field inside the conductors and the core. The importance of dielectric losses in a transformer model is also assessed. Since published data on the high frequency properties of press board are limited, some initial

  19. Development of high frequency tungsten inert gas welding method

    International Nuclear Information System (INIS)

    Morisada, Yoshiaki; Fujii, Hidetoshi; Inagaki, Fuminori; Kamai, Masayoshi

    2013-01-01

    Highlights: ► A new ultrasonic wave TIG welding method was developed. ► The area of the blowholes decreased to less than about 1/8 in the normal TIG weld. ► The number of blowholes decreased with the decreasing frequency. ► The number of blowholes increased when the frequency was less than 15 kHz. ► The microstructure of the weld was refined by ultrasonic wave. -- Abstract: A new welding method, called high frequency tungsten inert gas (TIG) welding, was developed to decrease blowholes in a weld. A1050 aluminum alloy plates (100 mm l × 50 mm w × 5 mm t ) were welded at a frequency from 10 to 40 kHz. An Ar-1% hydrogen mixture was used as the shielding gas to generate blowholes in the experiments. The welding was performed in the horizontal position so that the blowholes can easily be a problem. For comparison, a normal TIG welding was also performed at 60 Hz. After welding, the distribution of the blowholes in the welds was observed in order to evaluate the effect of the sonic wave. The number of blowholes changed with the frequency. A frequency near 15 kHz is the most suitable to decrease the blowholes. Using this new method, the area of blowholes is decreased to less than about 1/8 of the normal TIG weld. This method is much more effective for decreasing the number of blowholes, compared with an ultrasonic wave vibrator which is directly fixed to the sample.

  20. Fiber lightguide-coupled high frequency analog data system

    International Nuclear Information System (INIS)

    Davies, T.J.; Nelson, M.A.; Morton, J.R.; Pruett, B.

    1976-06-01

    An experimental system is described for measuring the time history of a high voltage, high frequency electrical pulse from a radiation detector. The system employs several fibers of a 500-m graded index light-guide cable to carry modelocked laser pulses from a safe location to an electro-optical Kerr cell located near the detector. These 200-ps pulses are widened to 500 ps at the cell by fiber dispersion. They are intensity-modulated in the cell by the electrical signal and returned over other cable fibers to an optical detector and recorder located near the laser. System frequency response exceeds 500 MHz over an amplitude dynamic range of 1000:1

  1. Peripheral Circulatory Features during High-Frequency Jet Ventilation

    Directory of Open Access Journals (Sweden)

    M. B. Kontorovich

    2010-01-01

    Full Text Available The paper gives the results of a study of peripheral circulatory features during high-frequency jet ventilation (HFJV. The main specific features of peripheral circulation and oxygen transport during HFJV are formulated on the basis of a study of cardiac output (impedance cardiography, peripheral vascular resistance, peripheral vascular blood filling (photoplethysmogram analysis, adaptive peripheral blood flow reactions (spectral analysis of peripheral vascular pulsation. HFJV gives rise to the peculiar pattern of peripheral hemodynamics and tissue gas exchange, which is characterized by higher oxygen uptake without a decrease in mixed venous blood saturation, with normal extraction coefficient and preserved low peripheral vascular resistance. During HFJV, unlike traditional ventilation, the main peripheral hemodynamic feature is the increased capillary bed blood volume caused by the blood flow involvement of reserve capillaries under control of volume (parasympathetic regulation of adaptive peripheral hemodynamic reactions. Key words: high-frequency jet ventilation, oxygen transport, peripheral hemodynamics.

  2. A comparison of high-frequency cross-correlation measures

    Science.gov (United States)

    Precup, Ovidiu V.; Iori, Giulia

    2004-12-01

    On a high-frequency scale the time series are not homogeneous, therefore standard correlation measures cannot be directly applied to the raw data. There are two ways to deal with this problem. The time series can be homogenised through an interpolation method (An Introduction to High-Frequency Finance, Academic Press, NY, 2001) (linear or previous tick) and then the Pearson correlation statistic computed. Recently, methods that can handle raw non-synchronous time series have been developed (Int. J. Theor. Appl. Finance 6(1) (2003) 87; J. Empirical Finance 4 (1997) 259). This paper compares two traditional methods that use interpolation with an alternative method applied directly to the actual time series.

  3. Generation of sheet currents by high frequency fast MHD waves

    Energy Technology Data Exchange (ETDEWEB)

    Núñez, Manuel, E-mail: mnjmhd@am.uva.es

    2016-07-01

    The evolution of fast magnetosonic waves of high frequency propagating into an axisymmetric equilibrium plasma is studied. By using the methods of weakly nonlinear geometrical optics, it is shown that the perturbation travels in the equatorial plane while satisfying a transport equation which enables us to predict the time and location of formation of shock waves. For plasmas of large magnetic Prandtl number, this would result into the creation of sheet currents which may give rise to magnetic reconnection and destruction of the original equilibrium. - Highlights: • Regular solutions of quasilinear hyperbolic systems may evolve into shocks. • The shock location is found for high frequency fast MHD waves. • The result is applied to static axisymmetric equilibria. • The previous process may lead to the formation of sheet currents and destruction of the equilibrium.

  4. Ultra high frequency induction welding of powder metal compacts

    Energy Technology Data Exchange (ETDEWEB)

    Cavdar, U.; Gulsahin, I.

    2014-10-01

    The application of the iron based Powder Metal (PM) compacts in Ultra High Frequency Induction Welding (UHFIW) were reviewed. These PM compacts are used to produce cogs. This study investigates the methods of joining PM materials enforceability with UHFIW in the industry application. Maximum stress and maximum strain of welded PM compacts were determined by three point bending and strength tests. Microhardness and microstructure of induction welded compacts were determined. (Author)

  5. Ultra high frequency induction welding of powder metal compacts

    International Nuclear Information System (INIS)

    Cavdar, U.; Gulsahin, I.

    2014-01-01

    The application of the iron based Powder Metal (PM) compacts in Ultra High Frequency Induction Welding (UHFIW) were reviewed. These PM compacts are used to produce cogs. This study investigates the methods of joining PM materials enforceability with UHFIW in the industry application. Maximum stress and maximum strain of welded PM compacts were determined by three point bending and strength tests. Microhardness and microstructure of induction welded compacts were determined. (Author)

  6. High-Frequency Axial Fatigue Test Procedures for Spectrum Loading

    Science.gov (United States)

    2016-07-20

    cycle runout limit. PURPOSE 2. To develop the capability to perform High-Frequency (H-F) Spectrum Fatigue tests, an in- house Basic and...response of the test specimen to the command input signal for load cycling . These cycle -by- cycle errors accumulate over the life of the test specimen...fatigue life model. It is expected that the cycle -by- cycle P-V error may vary substantially depending on the load spectrum content, the compensation

  7. Investigation of Combined High-Frequency and Arc Discharges

    International Nuclear Information System (INIS)

    Taran, V.S.; Nezovibatko, Yu.N.; Marinin, V.G.; Shvets, O.M.; Ridozub, V.N.; Gasilin, V.V.

    2001-01-01

    In this paper we analyze experiment with arc and high-frequency (HF) plasma sources carried out in modified devise of the ''Bulat'' type. The HF-sources and combined discharges have attracted considerable attention for surface cleaning and coating. The utilization of such discharges allows decreasing droplet fraction formation and providing better adhesion and microhardness values. The existence of HF-field in plasma allows obtaining either conductive or dielectric coatings and they can be deposited on any substrates. (author)

  8. A novel high-frequency encoding algorithm for image compression

    Science.gov (United States)

    Siddeq, Mohammed M.; Rodrigues, Marcos A.

    2017-12-01

    In this paper, a new method for image compression is proposed whose quality is demonstrated through accurate 3D reconstruction from 2D images. The method is based on the discrete cosine transform (DCT) together with a high-frequency minimization encoding algorithm at compression stage and a new concurrent binary search algorithm at decompression stage. The proposed compression method consists of five main steps: (1) divide the image into blocks and apply DCT to each block; (2) apply a high-frequency minimization method to the AC-coefficients reducing each block by 2/3 resulting in a minimized array; (3) build a look up table of probability data to enable the recovery of the original high frequencies at decompression stage; (4) apply a delta or differential operator to the list of DC-components; and (5) apply arithmetic encoding to the outputs of steps (2) and (4). At decompression stage, the look up table and the concurrent binary search algorithm are used to reconstruct all high-frequency AC-coefficients while the DC-components are decoded by reversing the arithmetic coding. Finally, the inverse DCT recovers the original image. We tested the technique by compressing and decompressing 2D images including images with structured light patterns for 3D reconstruction. The technique is compared with JPEG and JPEG2000 through 2D and 3D RMSE. Results demonstrate that the proposed compression method is perceptually superior to JPEG with equivalent quality to JPEG2000. Concerning 3D surface reconstruction from images, it is demonstrated that the proposed method is superior to both JPEG and JPEG2000.

  9. Profiling high frequency accident locations using associations rules

    OpenAIRE

    GEURTS, Karolien; WETS, Geert; BRIJS, Tom; VANHOOF, Koen

    2002-01-01

    In Belgium, traffic safety is currently one of the government’s highest priorities. Identifying and profiling black spots and black zones in terms of accident related data and location characteristics must provide new insights into the complexity and causes of road accidents which, in turn, provide valuable input for government actions. In this paper, association rules are used to identify accident circumstances that frequently occur together at high frequency accident locations. Furthermore,...

  10. Profiling high-frequency accident locations using association rules

    OpenAIRE

    GEURTS, Karolien; WETS, Geert; BRIJS, Tom; VANHOOF, Koen

    2003-01-01

    In Belgium, traffic safety is currently one of the government's highest priorities. Identifying and profiling black spots and black zones in terms of accident related data and location characteristics must provide new insights into the complexity and causes of road accidents, which, in ram, provide valuable input for government actions. In this paper, association rules are used to identify accident circumstances that frequently occur together at high frequency accident locations. Furthermore...

  11. Design of 1 MHz Solid State High Frequency Power Supply

    Science.gov (United States)

    Parmar, Darshan; Singh, N. P.; Gajjar, Sandip; Thakar, Aruna; Patel, Amit; Raval, Bhavin; Dhola, Hitesh; Dave, Rasesh; Upadhay, Dishang; Gupta, Vikrant; Goswami, Niranjan; Mehta, Kush; Baruah, Ujjwal

    2017-04-01

    High Frequency Power supply (HFPS) is used for various applications like AM Transmitters, metallurgical applications, Wireless Power Transfer, RF Ion Sources etc. The Ion Source for a Neutral beam Injector at ITER-India uses inductively coupled power source at High Frequency (∼1 MHz). Switching converter based topology used to generate 1 MHz sinusoidal output is expected to have advantages on efficiency and reliability as compared to traditional RF Tetrode tubes based oscillators. In terms of Power Electronics, thermal and power coupling issues are major challenges at such a high frequency. A conceptual design for a 200 kW, 1 MHz power supply and a prototype design for a 600 W source been done. The prototype design is attempted with Class-E amplifier topology where a MOSFET is switched resonantly. The prototype uses two low power modules and a ferrite combiner to add the voltage and power at the output. Subsequently solution with Class-D H-Bridge configuration have been evaluated through simulation where module design is stable as switching device do not participate in resonance, further switching device voltage rating is substantially reduced. The rating of the modules is essentially driven by the maximum power handling capacity of the MOSFETs and ferrites in the combiner circuit. The output passive network including resonance tuned network and impedance matching network caters for soft switching and matches the load impedance to 50ohm respectively. This paper describes the conceptual design of a 200 kW high frequency power supply and experimental results of the prototype 600 W, 1 MHz source.

  12. High frequency microseismic noise as possible earthquake precursor

    OpenAIRE

    Ivica Sović; Kristina Šariri; Mladen Živčić

    2013-01-01

    Before an earthquake occurs, microseismic noise in high frequency (HF) range, i.e. 2-25 Hz, is being generated during preparation process. These signals change the microseismic noise and, consequently, the spectrum of microseismic noise. Time variation of spectra recorded at the same seismological station could imply the change of the state of noise source. We propose the image moment analysis approach to objectively compare microseismic noise spectra. The result could be used for earthquake ...

  13. Bunched soliton states in weakly coupled sine-Gordon systems

    International Nuclear Information System (INIS)

    Gronbech-Jensen, N.; Samuelsen, M.R.; Lomdahl, P.S.; Blackburn, J.A.

    1990-01-01

    The interaction between solitons of two weakly coupled sine-Gordon systems is considered. In particular, the stability of bunched states is investigated, and perturbation results are compared with numerical results

  14. Solutions of the finite type of Sine-Gordon equation

    International Nuclear Information System (INIS)

    Zhao Guosong

    1998-01-01

    We use the technique of differential geometry to prove that the solutions of finite type of the sine-Gordon equation φ xx - φ yy = sin φ cosφ can be obtained from a system of ordinary differential equations

  15. Frequency locking, quasiperiodicity, subharmonic bifurcations and chaos in high frequency modulated stripe geometry DH semiconductor lasers

    International Nuclear Information System (INIS)

    Zhao Yiguang

    1991-01-01

    The method of obtaining self-consistent solutions of the field equation and the rate equations of photon density and carrier concentration has been used to study frequecny locking, quasiperiodicity, subharmonic bifurcations and chaos in high frequency modulated stripe geometry DH semiconductor lasers. The results show that the chaotic behavior arises in self-pulsing stripe geometry semiconductor lasers. The route to chaos is not period-double, but quasiperiodicity to chaos. All of the results agree with the experiments. Some obscure points in previous theory about chaos have been cleared up

  16. Modeling the dielectric logging tool at high frequency

    International Nuclear Information System (INIS)

    Chew, W.C.

    1987-01-01

    The high frequency dielectric logging tool has been used widely in electromagnetic well logging, because by measuring the dielectric constant at high frequencies (1 GHz), the water saturation of rocks could be known without measuring the water salinity in the rocks. As such, it could be used to delineate fresh water bearing zones, as the dielectric constant of fresh water is much higher than that of oil while they may have the same resistivity. The authors present a computer model, though electromagnetic field analysis, the response of such a measurement tool in a well logging environment. As the measurement is performed at high frequency, usually with small separation between the transmitter and receivers, some small geological features could be measured by such a tool. They use the computer model to study the behavior of such a tool across geological bed boundaries, and also across thin geological beds. Such a study could be very useful in understanding the limitation on the resolution of the tool. Furthermore, they could study the standoff effect and the depth of investigation of such a tool. This could delineate the range of usefulness of the measurement

  17. Planck 2013 results. VI. High Frequency Instrument data processing

    CERN Document Server

    Ade, P.A.R.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J. -P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J.J.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Boulanger, F.; Bowyer, J.W.; Bridges, M.; Bucher, M.; Burigana, C.; Cardoso, J. -F.; Catalano, A.; Chamballu, A.; Chary, R. -R.; Chen, X.; Chiang, L. -Y; Chiang, H.C.; Christensen, P.R.; Church, S.; Clements, D.L.; Colombi, S.; Colombo, L.P.L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B.P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J. -M.; Désert, F. -X.; Dickinson, C.; Diego, J.M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Dunkley, J.; Dupac, X.; Efstathiou, G.; Enßlin, T.A.; Eriksen, H.K.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A.A.; Franceschi, E.; Galeotta, S.; Ganga, K.; Giard, M.; Giardino, G.; Girard, D.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J.E.; Hansen, F.K.; Hanson, D.; Harrison, D.; Helou, G.; Henrot-Versillé, S.; Herent, O.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hou, Z.; Hovest, W.; Huffenberger, K.M.; Hurier, G.; Jaffe, T.R.; Jaffe, A.H.; Jones, W.C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T.S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J. -M.; Lasenby, A.; Laureijs, R.J.; Lawrence, C.R.; Jeune, M. Le; Leonardi, R.; Leroy, C.; Lesgourgues, J.; Liguori, M.; Lilje, P.B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P.M.; Macías-Pérez, J.F.; MacTavish, C.J.; Maffei, B.; Mandolesi, N.; Maris, M.; Marshall, D.J.; Martin, P.G.; Martínez-González, E.; Masi, S.; Matarrese, S.; Matthai, F.; Mazzotta, P.; McGehee, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M. -A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Mottet, S.; Munshi, D.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Nørgaard-Nielsen, H.U.; North, C.; Noviello, F.; Novikov, D.; Novikov, I.; Orieux, F.; Osborne, S.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G.W.; Prézeau, G.; Prunet, S.; Puget, J. -L.; Rachen, J.P.; Racine, B.; Reach, W.T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Roudier, G.; Rowan-Robinson, M.; Rusholme, B.; Sanselme, L.; Santos, D.; Sauvé, A.; Savini, G.; Shellard, E.P.S.; Spencer, L.D.; Starck, J. -L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sureau, F.; Sutton, D.; Suur-Uski, A. -S.; Sygnet, J. -F.; Tauber, J.A.; Tavagnacco, D.; Techene, S.; Terenzi, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vibert, L.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L.A.; Wandelt, B.D.; White, S.D.M.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-01-01

    We describe the processing of the 531 billion raw data samples from the High Frequency Instrument (hereafter HFI), which we performed to produce six temperature maps from the first 473 days of Planck-HFI survey data. These maps provide an accurate rendition of the sky emission at 100, 143, 217, 353, 545, and 857 GHz with an angular resolution ranging from 9.7 to 4.6 arcmin. The detector noise per (effective) beam solid angle is respectively, 10, 6, 12 and 39 microKelvin in HFI four lowest frequency channel (100--353 GHz) and 13 and 14 kJy/sr for the 545 and 857 GHz channels. Using the 143 GHz channel as a reference, these two high frequency channels are intercalibrated within 5% and the 353 GHz relative calibration is at the percent level. The 100 and 217 GHz channels, which together with the 143 GHz channel determine the high-multipole part of the CMB power spectrum (50 < l <2500), are intercalibrated at better than 0.2 %.

  18. High-frequency hearing loss among mobile phone users.

    Science.gov (United States)

    Velayutham, P; Govindasamy, Gopala Krishnan; Raman, R; Prepageran, N; Ng, K H

    2014-01-01

    The objective of this study is to assess high frequency hearing (above 8 kHz) loss among prolonged mobile phone users is a tertiary Referral Center. Prospective single blinded study. This is the first study that used high-frequency audiometry. The wide usage of mobile phone is so profound that we were unable to find enough non-users as a control group. Therefore we compared the non-dominant ear to the dominant ear using audiometric measurements. The study was a blinded study wherein the audiologist did not know which was the dominant ear. A total of 100 subjects were studied. Of the subjects studied 53% were males and 47% females. Mean age was 27. The left ear was dominant in 63%, 22% were dominant in the right ear and 15% did not have a preference. This study showed that there is significant loss in the dominant ear compared to the non-dominant ear (P mobile phone revealed high frequency hearing loss in the dominant ear (mobile phone used) compared to the non dominant ear.

  19. High-frequency EPR on high-spin transition-metal sites

    NARCIS (Netherlands)

    Mathies, Guinevere

    2012-01-01

    The electronic structure of transition-metal sites can be probed by electron-paramagnetic-resonance (EPR) spectroscopy. The study of high-spin transition-metal sites benefits from EPR spectroscopy at frequencies higher than the standard 9.5 GHz. However, high-frequency EPR is a developing field. In

  20. On the Fresnel sine integral and the convolution

    Directory of Open Access Journals (Sweden)

    Adem Kılıçman

    2003-01-01

    Full Text Available The Fresnel sine integral S(x, the Fresnel cosine integral C(x, and the associated functions S+(x, S−(x, C+(x, and C−(x are defined as locally summable functions on the real line. Some convolutions and neutrix convolutions of the Fresnel sine integral and its associated functions with x+r, xr are evaluated.

  1. Harnessing high-dimensional hyperentanglement through a biphoton frequency comb

    Science.gov (United States)

    Xie, Zhenda; Zhong, Tian; Shrestha, Sajan; Xu, Xinan; Liang, Junlin; Gong, Yan-Xiao; Bienfang, Joshua C.; Restelli, Alessandro; Shapiro, Jeffrey H.; Wong, Franco N. C.; Wei Wong, Chee

    2015-08-01

    Quantum entanglement is a fundamental resource for secure information processing and communications, and hyperentanglement or high-dimensional entanglement has been separately proposed for its high data capacity and error resilience. The continuous-variable nature of the energy-time entanglement makes it an ideal candidate for efficient high-dimensional coding with minimal limitations. Here, we demonstrate the first simultaneous high-dimensional hyperentanglement using a biphoton frequency comb to harness the full potential in both the energy and time domain. Long-postulated Hong-Ou-Mandel quantum revival is exhibited, with up to 19 time-bins and 96.5% visibilities. We further witness the high-dimensional energy-time entanglement through Franson revivals, observed periodically at integer time-bins, with 97.8% visibility. This qudit state is observed to simultaneously violate the generalized Bell inequality by up to 10.95 standard deviations while observing recurrent Clauser-Horne-Shimony-Holt S-parameters up to 2.76. Our biphoton frequency comb provides a platform for photon-efficient quantum communications towards the ultimate channel capacity through energy-time-polarization high-dimensional encoding.

  2. Long range ultra-high frequency (UHF) radio frequency identification (RFID) antenna design

    Science.gov (United States)

    Reynolds, Nathan D.

    There is an ever-increasing demand for radio frequency identification (RFID) tags that are passive, long range, and mountable on multiple surfaces. Currently, RFID technology is utilized in numerous applications such as supply chain management, access control, and public transportation. With the combination of sensory systems in recent years, the applications of RFID technology have been extended beyond tracking and identifying. This extension includes applications such as environmental monitoring and healthcare applications. The available sensory systems usually operate in the medium or high frequency bands and have a low read range. However, the range limitations of these systems are being overcome by the development of RFID sensors focused on utilizing tags in the ultra-high frequency (UHF) band. Generally, RFID tags have to be mounted to the object that is being identified. Often the objects requiring identification are metallic. The inherent properties of metallic objects have substantial effects on nearby electromagnetic radiation; therefore, the operation of the tag antenna is affected when mounted on a metallic surface. This outlines one of the most challenging problems for RFID systems today: the optimization of tag antenna performance in a complex environment. In this research, a novel UHF RFID tag antenna, which has a low profile, long range, and is mountable on metallic surfaces, is designed analytically and simulated using a 3-D electromagnetic simulator, ANSYS HFSS. A microstrip patch antenna is selected as the antenna structure, as patch antennas are low profile and suitable for mounting on metallic surfaces. Matching and theoretical models of the microstrip patch antenna are investigated. Once matching and theory of a microstrip patch antenna is thoroughly understood, a unique design technique using electromagnetic band gap (EBG) structures is explored. This research shows that the utilization of an EBG structure in the patch antenna design yields

  3. New generation neonatal high frequency ventilators: effect of oscillatory frequency and working principles on performance.

    Science.gov (United States)

    Grazioli, Serge; Karam, Oliver; Rimensberger, Peter C

    2015-03-01

    Several new generation neonatal ventilators that incorporate conventional as well as high frequency ventilation (HFOV) have appeared on the market. Most of them offer the possibility to use HFOV in a volume-targeted mode, despite absence of any preclinical data. With a bench test, we evaluated the performances of 4 new neonatal HFOV devices and compared them to the SensorMedics HFOV device. Expiratory tidal volumes (V(T)) were measured for various ventilator settings and lung characteristics (ie, modifications of compliance and resistance of the system), to mimic several clinical conditions of pre-term and term infants. Increasing the frequency proportionally decreased the V(T) for all the ventilators, although the magnitude of the decrease was highly variable between ventilators. At 15 Hz and a pressure amplitude of 60 cm H2O, the delivered V(T) ranged from 3.5 to 5.9 mL between devices while simulating pre-term infant conditions and from 2.6 to 6.3 mL while simulating term infant conditions. Activating the volume-targeted mode in the 3 machines that offer this mode allowed the V(T) to remain constant over the range of frequencies and with changes of lung mechanical properties, for pre-term infant settings only while targeting a V(T) of 1 mL. These new generation neonatal ventilators were able to deliver adequate V(T) under pre-term infant, but not term infant respiratory system conditions. The clinical relevance of these findings will need to be determined by further studies. Copyright © 2015 by Daedalus Enterprises.

  4. PCB Embedded Inductor for High-Frequency ZVS SEPIC Converter

    DEFF Research Database (Denmark)

    Dou, Yi; Ouyang, Ziwei; Thummala, Prasanth

    2018-01-01

    The volume and temperature rise of passive components, especially inductors, limit the momentum toward high power density in high-frequency power converters. To address the limitations, PCB integration of passive components should be considered with the benefit of low profile, excellent thermal...... characteristic and cost reduction. This paper investigates an embedded structure of inductors to further increase the power density of a low power DC-DC converter. A pair of coupling inductors have been embedded into the PCB. The detailed embedded process has been described and the characteristics of embedded...

  5. High-frequency harmonic imaging of the eye

    Science.gov (United States)

    Silverman, Ronald H.; Coleman, D. Jackson; Ketterling, Jeffrey A.; Lizzi, Frederic L.

    2005-04-01

    Purpose: Harmonic imaging has become a well-established technique for ultrasonic imaging at fundamental frequencies of 10 MHz or less. Ophthalmology has benefited from the use of fundamentals of 20 MHz to 50 MHz. Our aim was to explore the ability to generate harmonics for this frequency range, and to generate harmonic images of the eye. Methods: The presence of harmonics was determined in both water and bovine vitreous propagation media by pulse/echo and hydrophone at a series of increasing excitation pulse intensities and frequencies. Hydrophone measurements were made at the focal point and in the near- and far-fields of 20 MHz and 40 MHz transducers. Harmonic images of the anterior segment of the rabbit eye were obtained by a combination of analog filtering and digital post-processing. Results: Harmonics were generated nearly identically in both water and vitreous. Hydrophone measurements showed the maximum second harmonic to be -5 dB relative to the 35 MHz fundamental at the focus, while in pulse/echo the maximum harmonic amplitude was -15dB relative to the fundamental. Harmonics were absent in the near-field, but present in the far-field. Harmonic images of the eye showed improved resolution. Conclusion: Harmonics can be readily generated at very high frequencies, and at power levels compliant with FDA guidelines for ophthalmology. This technique may yield further improvements to the already impressive resolutions obtainable in this frequency range. Improved imaging of the macular region, in particular, may provide significant improvements in diagnosis of retinal disease.

  6. High frequency noise studies at the Hartousov mofette area (CZE)

    Science.gov (United States)

    Schmidt, Andreas; Flores-Estrella, Hortencia; Pommerencke, Julia; Umlauft, Josefine

    2014-05-01

    Ambient noise analysis has been used as a reliable tool to investigate sub-surface structures at seismological quiet regions with none or less specific seismic events. Here, we consider the acoustic signals from a single mofette at the Hartoušov area (CZE) as a noise-like high frequency source caused by multiple near surface degassing processes in a restricted location. From this assumption we have used different array geometries for recording at least one hour of continuous noise. We installed triangular arrays with 3 component geophones: the first deployment consisted on two co-centric triangles with side length of 30 and 50 m with the mofette in the center; the second deployment consisted on two triangular arrays, both with side length of 30 m, co-directional to the mofette. Furthermore, we also installed profiles with 24 channels and vertical geophones locating them in different positions with respect to the mofette. In this work, we present preliminary results from the data analysis dependent on the geometry, to show the characteristics of the noise wave-field referring to frequency content and propagation features, such as directionality and surface wave velocity. The spectral analysis shows that the energy is concentrated in a frequency band among 10 and 40 Hz. However, in this interval there is no evidence of any exclusive fundamental frequencies. From this, man-induced influences can be identified as intermittent signal peaks in narrow frequency bands and can be separated to receive the revised mofette wave-field record. The inversion of dispersive surface waves, that were detected by interferometric methods, provides a velocity model down to 12 m with an S-wave velocity between 160 and 180 m/s on the uppermost layer. Furthermore, the interferometric signal properties indicate that it is not possible to characterize the mofette as a punctual source, but rather as a conglomerate of multiple sources with time and location variations.

  7. High-frequency high-voltage high-power DC-to-DC converters

    Science.gov (United States)

    Wilson, T. G.; Owen, H. A.; Wilson, P. M.

    1982-09-01

    A simple analysis of the current and voltage waveshapes associated with the power transistor and the power diode in an example current-or-voltage step-up (buck-boost) converter is presented. The purpose of the analysis is to provide an overview of the problems and design trade-offs which must be addressed as high-power high-voltage converters are operated at switching frequencies in the range of 100 kHz and beyond. Although the analysis focuses on the current-or-voltage step-up converter as the vehicle for discussion, the basic principles presented are applicable to other converter topologies as well.

  8. Insertion polymorphisms of SINE200 retrotransposons within speciation islands of Anopheles gambiae molecular forms

    Directory of Open Access Journals (Sweden)

    Tu Zhijian

    2008-08-01

    Full Text Available Abstract Background SINEs (Short INterspersed Elements are homoplasy-free and co-dominant genetic markers which are considered to represent useful tools for population genetic studies, and could help clarifying the speciation processes ongoing within the major malaria vector in Africa, Anopheles gambiae s.s. Here, we report the results of the analysis of the insertion polymorphism of a nearly 200 bp-long SINE (SINE200 within genome areas of high differentiation (i.e. "speciation islands" of M and S A. gambiae molecular forms. Methods A SINE-PCR approach was carried out on thirteen SINE200 insertions in M and S females collected along the whole range of distribution of A. gambiae s.s. in sub-Saharan Africa. Ten specimens each for Anopheles arabiensis, Anopheles melas, Anopheles quadriannulatus A and 15 M/S hybrids from laboratory crosses were also analysed. Results Eight loci were successfully amplified and were found to be specific for A. gambiae s.s.: 5 on 2L chromosome and one on X chromosome resulted monomorphic, while two loci positioned respectively on 2R (i.e. S200 2R12D and X (i.e. S200 X6.1 chromosomes were found to be polymorphic. S200 2R12D was homozygote for the insertion in most S-form samples, while intermediate levels of polymorphism were shown in M-form, resulting in an overall high degree of genetic differentiation between molecular forms (Fst = 0.46 p S200 X6.1 was found to be fixed in all M- and absent in all S-specimens. This led to develop a novel easy-to-use PCR approach to straightforwardly identify A. gambiae molecular forms. This novel approach allows to overcome the constraints associated with markers on the rDNA region commonly used for M and S identification. In fact, it is based on a single copy and irreversible SINE200 insertion and, thus, is not subjected to peculiar evolutionary patterns affecting rDNA markers, e.g. incomplete homogenization of the arrays through concerted evolution and/or mixtures of M and S IGS

  9. Dielectric and acoustical high frequency characterisation of PZT thin films

    International Nuclear Information System (INIS)

    Conde, Janine; Muralt, Paul

    2010-01-01

    Pb(Zr, Ti)O 3 (PZT) is an interesting material for bulk acoustic wave resonator applications due to its high electromechanical coupling constant, which would enable fabrication of large bandwidth frequency filters. The major challenge of the PZT solid solution system is to overcome mechanical losses generally observed in PZT ceramics. To increase the understanding of these losses in textured thin films, thin film bulk acoustic resonators (TFBAR's) based on PZT thin films with compositions either in the tetragonal region or at the morphotropic phase boundary and (111) or {100} textures were fabricated and studied up to 2 GHz. The dielectric and elastic materials coefficients were extracted from impedance measurements at the resonance frequency. The dispersion of the dielectric constant was obtained from impedance measurements up to 2 GHz. The films with varying compositions, textures and deposition methods (sol-gel or sputtering) were compared in terms of dielectric and acoustical properties.

  10. Dielectric and acoustical high frequency characterisation of PZT thin films

    Science.gov (United States)

    Conde, Janine; Muralt, Paul

    2010-02-01

    Pb(Zr, Ti)O3 (PZT) is an interesting material for bulk acoustic wave resonator applications due to its high electromechanical coupling constant, which would enable fabrication of large bandwidth frequency filters. The major challenge of the PZT solid solution system is to overcome mechanical losses generally observed in PZT ceramics. To increase the understanding of these losses in textured thin films, thin film bulk acoustic resonators (TFBAR's) based on PZT thin films with compositions either in the tetragonal region or at the morphotropic phase boundary and (111) or {100} textures were fabricated and studied up to 2 GHz. The dielectric and elastic materials coefficients were extracted from impedance measurements at the resonance frequency. The dispersion of the dielectric constant was obtained from impedance measurements up to 2 GHz. The films with varying compositions, textures and deposition methods (sol-gel or sputtering) were compared in terms of dielectric and acoustical properties.

  11. Slow high-frequency effects in mechanics: problems, solutions, potentials

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    2005-01-01

    – an apparent change in the stiffness associated with an equilibrium; Biasing – a tendency for a system to move towards a particular state which does not exist or is unstable without HFE; and Smoothening – a tendency for discontinuities to be apparently smeared out by HFE. The effects and a method for analyzing...... and compared: The Method of Direct Separation of Motions, the Method of Averaging, and the Method of Multiple Scales. The tutorial concludes by suggesting that more vibration experts, researchers and students should know about HFE effects, for the benefit not only of general vibration troubleshooting, but also......Strong high-frequency excitation (HFE) may change the ‘slow’ (i.e. effective or average) properties of mechanical systems, e.g. their stiffness, natural frequencies, equilibriums, equilibrium stability, and bifurcation paths. This tutorial describes three general HFE effects: Stiffening...

  12. Slow high-frequency effects in mechanics: problems, solutions, potentials

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    – an apparent change in the stiffness associated with an equilibrium; Biasing – a tendency for a system to move towards a particular state which does not exist or is unstable without HFE; and Smoothening – a tendency for discontinuities to be apparently smeared out by HFE. The effects and a method for analyzing...... and compared: The Method of Direct Separation of Motions, the Method of Averaging, and the Method of Multiple Scales. The tutorial concludes by suggesting that more vibration experts, researchers and students should know about HFE effects, for the benefit not only of general vibration troubleshooting, but also......Strong high-frequency excitation (HFE) may change the ‘slow’ (i.e. effective or average) properties of mechanical systems, e.g. their stiffness, natural frequencies, equilibriums, equilibrium stability, and bifurcation paths. This tutorial describes three general HFE effects: Stiffening...

  13. Dependence of synchronization frequency of Kuramoto oscillators ...

    Indian Academy of Sciences (India)

    2Department of Theoretical Physics, Physical Research Laboratory, ... on the sine of the phase difference between the oscillators and hence, ... we study the change in synchronization frequency as the symmetry is changed under the limit of.

  14. High field high frequency EPR techniques and their application to single molecule magnets

    International Nuclear Information System (INIS)

    Edwards, R.S.; Hill, S.; Goy, P.; Wylde, R.; Takahashi, S.

    2004-01-01

    We present details of a new high-field/high-frequency EPR technique, and its application to measurements of single-molecule magnets (SMMs). By using a quasi-optical set-up and microwave sources covering a continuous frequency range from 170 to 600 GHz, in conjunction with a millimetre-wave vector network analyser, we are able to measure EPR to high magnetic fields. For example, a g=2 system will exhibit EPR at about 14 T at a frequency of 400 GHz. We illustrate the technique by presenting details of recent high-frequency experiments on several SMMs which are variations of the well-known SMM Mn 12 -Ac. This material has a spin ground state of S=10 and large uniaxial anisotropy, hence frequencies above 300 GHz are required in order to observe EPR from the ground state

  15. Separation Transformation and New Exact Solutions of the (N + 1)-dimensional Dispersive Double sine-Gordon Equation

    International Nuclear Information System (INIS)

    Tian Ye; Chen Jing; Zhang Zhifei

    2012-01-01

    In this paper, the separation transformation approach is extended to the (N + 1)-dimensional dispersive double sine-Gordon equation arising in many physical systems such as the spin dynamics in the B phase of 3 He superfluid. This equation is first reduced to a set of partial differential equations and a nonlinear ordinary differential equation. Then the general solutions of the set of partial differential equations are obtained and the nonlinear ordinary differential equation is solved by F-expansion method. Finally, many new exact solutions of the (N + 1)-dimensional dispersive double sine-Gordon equation are constructed explicitly via the separation transformation. For the case of N > 2, there is an arbitrary function in the exact solutions, which may reveal more novel nonlinear structures in the high-dimensional dispersive double sine-Gordon equation.

  16. The Influence of High-Frequency Gravitational Waves Upon Muscles

    International Nuclear Information System (INIS)

    Moy, Lawrence S.; Baker, Robert M. L. Jr

    2007-01-01

    The objective of this paper is to present a theory for the possible influence of high-frequency gravitational waves or HFGWs and pulsed micro-current electromagnetic waves or EMs on biological matter specifically on muscle cells and myofibroblasts. The theory involves consideration of the natural frequency of contractions and relaxations of muscles, especially underlying facial skin, and the possible influence of HFGWs on that process. GWs pass without attenuation through all material thus conventional wisdom would dictate that GWs would have no influence on biological matter. On the other hand, GWs can temporarily modify a gravitational field in some locality if they are of high frequency and such a modification might have an influence in changing the skin muscles' natural frequency. Prior to the actual laboratory generation of HFGWs their influence can be emulated by micro-current EM pulses to the skin and some evidence presented here on that effect may predict the influence of HFGWs. We believe that the HFGW pulsations lead to increased muscle activity and may serve to reverse the aging process. A novel theoretical framework concerning these relaxation phenomena is one result of the paper. Another result is the analysis of the possible delivery system of the FBAR-generated HFGWs, the actual power of the generated HFGWs, and the system's application to nanostructural modification of the skin or muscle cells. It is concluded that a series of non-evasive experiments, which are identified, will have the potential to test theory by detecting and analyzing the possible HFGWs change in polarization, refraction, etc. after their interaction with the muscle cells

  17. Design of 1 MHz solid state high frequency power supply

    International Nuclear Information System (INIS)

    Parmar, Darshan Kumar; Singh, N.P.; Gajjar, Sandip

    2015-01-01

    A High Voltage High Frequency (HVHF) Power supply is used for various applications, like AM Transmitters, metallurgical applications, Wireless Power Transfer, RF Ion Sources, etc. The Ion Source for a Neutral beam Injector at ITER-India uses inductively coupled power source at High Frequency (∼ 1 MHz). Switching converter based topology used to generate 1 MHz sinusoidal output is expected to have advantages on efficiency and reliability as compared to traditional RF Tetrode tubes based oscillators. In terms of Power Electronics, thermal and power coupling issues are major challenges at such a high frequency. A conceptual design for a 200 kW, 1 MHz power supply and a prototype design for a 600W source been done. The prototype design is attempted with Class-E amplifier topology where a MOSFET is switched resonantly. The prototype uses two low power modules and a ferrite combiner to add the voltage and power at the output. Subsequently solution with class-D H-Bridge configuration have been evaluated through simulation where module design is stable as switching device do not participate in resonance, further switching device voltage rating is substantially reduced. The rating of the modules is essentially driven by the maximum power handling capacity of the MOSFETs and ferrites in the combiner circuit. The output passive network including resonance tuned network and impedance matching network caters for soft switching and matches the load impedance to 50 ohm respectively. This paper describes the conceptual design of a 200 kW power supply and experimental results of the prototype 600 W, 1 MHz source. (author)

  18. Short interspersed elements (SINEs) from insectivores. Two classes of mammalian SINEs distinguished by A-rich tail structure.

    Science.gov (United States)

    Borodulina, O R; Kramerov, D A

    2001-10-01

    Four tRNA-related SINE families were isolated from the genome of the shrew Sorex araneus (SOR element), mole Mogera robusta (TAL element), and hedgehog Mesechinus dauuricus (ERI-1 and ERI-2 elements). Each of these SINEs families is specific for a single Insectivora family: SOR, for Soricidae (shrews); TAL, for Talpidae (moles and desmans); ERI-1 and ERI-2, for Erinaceidae (hedgehogs). There is a long polypyrimidine region (TC-motif) in TAL, ERI-1, and ERI-2 elements located immediately upstream of an A-rich tail with polyadenylation signals (AATAAA) and an RNA polymerase III terminator (T(4-6)) or TCT(3-4)). Ten out of 14 analyzed mammalian tRNA-related SINE families have an A-rich tail similar to that of TAL, ERI-1, and ERI-2 elements. These elements were assigned to class T+. The other four SINEs including SOR element have no polyadenylation signal and transcription terminator in their A-rich tail and were assigned to class T-. Class T+ SINEs occur only in mammals, and most of them have a long polypyrimidine region. Possible models of retroposition of class T+ and T- SINEs are discussed.

  19. Low Frequency Turbulence as the Source of High Frequency Waves in Multi-Component Space Plasmas

    Science.gov (United States)

    Khazanov, George V.; Krivorutsky, Emmanuel N.; Uritsky, Vadim M.

    2011-01-01

    Space plasmas support a wide variety of waves, and wave-particle interactions as well as wavewave interactions are of crucial importance to magnetospheric and ionospheric plasma behavior. High frequency wave turbulence generation by the low frequency (LF) turbulence is restricted by two interconnected requirements: the turbulence should be strong enough and/or the coherent wave trains should have the appropriate length. These requirements are strongly relaxed in the multi-component plasmas, due to the heavy ions large drift velocity in the field of LF wave. The excitation of lower hybrid waves (LHWs), in particular, is a widely discussed mechanism of interaction between plasma species in space and is one of the unresolved questions of magnetospheric multi-ion plasmas. It is demonstrated that large-amplitude Alfven waves, in particular those associated with LF turbulence, may generate LHW s in the auroral zone and ring current region and in some cases (particularly in the inner magnetosphere) this serves as the Alfven wave saturation mechanism. We also argue that the described scenario can playa vital role in various parts of the outer magnetosphere featuring strong LF turbulence accompanied by LHW activity. Using the data from THEMIS spacecraft, we validate the conditions for such cross-scale coupling in the near-Earth "flow-braking" magnetotail region during the passage of sharp injection/dipolarization fronts, as well as in the turbulent outflow region of the midtail reconnection site.

  20. High Frequency Supercapacitors for Piezo-based Energy Harvesting

    Science.gov (United States)

    Ervin, Matthew; Pereira, Carlos; Miller, John; Outlaw, Ronald; Rastegar, Jay; Murray, Richard

    2013-03-01

    Energy harvesting is being investigated as an alternative to batteries for powering munition guidance and fuzing functions during flight. A piezoelectric system that generates energy from the oscillation of a mass on a spring (set in motion by the launch acceleration) is being developed. Original designs stored this energy in an electrolytic capacitor for use during flight. Here we replace the electrolytic capacitor with a smaller, lighter, and potentially more reliable electrochemical double layer capacitor (aka, supercapacitor). The potential problems with using supercapacitors in this application are that the piezoelectric output greatly exceeds the supercapacitor electrolyte breakdown voltage, and the frequency greatly exceeds the operating frequency of commercial supercapacitors. Here we have investigated the use of ultrafast vertically oriented graphene array-based supercapacitors for storing the energy in this application. We find that the electrolyte breakdown is not a serious limitation as it is either kinetically limited by the relatively high frequency of the piezoelectric output, or it is overcome by the self-healing nature of supercapacitors. We also find that these supercapacitors have sufficient dynamic response to efficiently store the generated energy.

  1. Planck early results. VI. The High Frequency Instrument data processing

    DEFF Research Database (Denmark)

    Colley, J.-M.; Bartlett, J.G.; Bucher, M.

    2011-01-01

    We describe the processing of the 336 billion raw data samples from the High Frequency Instrument (HFI) which we performed to produce six temperature maps from the first 295 days of Planck-HFI survey data. These maps provide an accurate rendition of the sky emission at 100, 143, 217, 353, 545...... and 857 GHz with an angular resolution ranging from 9.9 to 4.4′. The white noise level is around 1.5 μK degree or less in the 3 main CMB channels (100-217 GHz). The photometric accuracy is better than 2% at frequencies between 100 and 353 GHz and around 7% at the two highest frequencies. The maps created...... by the HFI Data Processing Centre reach our goals in terms of sensitivity, resolution, and photometric accuracy. They are already sufficiently accurate and well-characterised to allow scientific analyses which are presented in an accompanying series of early papers. At this stage, HFI data appears...

  2. Ionospheric heating with oblique high-frequency waves

    International Nuclear Information System (INIS)

    Field, E.C. Jr.; Bloom, R.M.; Kossey, P.A.

    1990-01-01

    This paper presents calculations of ionospheric electron temperature and density perturbations and ground-level signal changes produced by intense oblique high-frequency (HF) radio waves. The analysis takes into account focusing at caustics, the consequent Joule heating of the surrounding plasma, heat conduction, diffusion, and recombination processes, these being the effects of a powerful oblique modifying wave. It neglects whatever plasma instabilities might occur. The authors then seek effects on a secondary test wave that is propagated along the same path as the first. The calculations predict ground-level field strength reductions of several decibels in the test wave for modifying waves having effective radiated power (ERP) in the 85- to 90-dBW range. These field strength changes are similar in sign, magnitude, and location to ones measured in Soviet experiments. The location of the signal change is sensitive to the frequency and the model ionosphere assumed; so future experiments should employ the widest possible range of frequencies and propagation conditions. An ERP of 90 dBW seems to be a sort of threshold that, if exceeded, might result in substantial rather than small signal changes. The conclusions are based solely on Joule heating and subsequent refraction of waves passing through caustic regions

  3. L1-mediated retrotransposition of murine B1 and B2 SINEs recapitulated in cultured cells.

    Science.gov (United States)

    Dewannieux, Marie; Heidmann, Thierry

    2005-06-03

    SINEs are short interspersed nucleotide elements with transpositional activity, present at a high copy number (up to a million) in mammalian genomes. They are 80-400 bp long, non-coding sequences which derive either from the 7SL RNA (e.g. human Alus, murine B1s) or tRNA (e.g. murine B2s) polymerase III-driven genes. We have previously demonstrated that Alus very efficiently divert the enzymatic machinery of the autonomous L1 LINE (long interspersed nucleotide element) retrotransposons to transpose at a high rate. Here we show, using an ex vivo assay for transposition, that both B1 and B2 SINEs can be mobilized by murine LINEs, with the hallmarks of a bona fide retrotransposition process, including target site duplications of varying lengths and integrations into A-rich sequences. Despite different phylogenetic origins, transposition of the tRNA-derived B2 sequences is as efficient as that of the human Alus, whereas that of B1s is 20-100-fold lower despite a similar high copy number of these elements in the mouse genome. We provide evidence, via an appropriate nucleotide substitution within the B1 sequence in a domain essential for its intracellular targeting, that the current B1 SINEs are not optimal for transposition, a feature most probably selected for the host sake in the course of evolution.

  4. Low power very high frequency resonant converter with high step down ratio

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2013-01-01

    This paper presents the design of a resonant converter with a switching frequency in the very high frequency range (30-300MHz), a large step down ratio and low output power. This gives the designed converters specifications which are far from previous results. The class E inverter and rectifier...

  5. High Frequency Vibration Based Fatigue Testing of Developmental Alloys

    Science.gov (United States)

    Holycross, Casey M.; Srinivasan, Raghavan; George, Tommy J.; Tamirisakandala, Seshacharyulu; Russ, Stephan M.

    Many fatigue test methods have been previously developed to rapidly evaluate fatigue behavior. This increased test speed can come at some expense, since these methods may require non-standard specimen geometry or increased facility and equipment capability. One such method, developed by George et al, involves a base-excited plate specimen driven into a high frequency bending resonant mode. This resonant mode is of sufficient frequency (typically 1200 to 1700 Hertz) to accumulate 107 cycles in a few hours. One of the main limitations of this test method is that fatigue cracking is almost certainly guaranteed to be surface initiated at regions of high stress. This brings into question the validity of the fatigue test results, as compared to more traditional uniaxial, smooth-bar testing, since high stresses are subjecting only a small volume to fatigue damage. This limitation also brings into question the suitability of this method to screen developmental alloys, should their initiation life be governed by subsurface flaws. However, if applicable, the rapid generation of fatigue data using this method would facilitate faster design iterations, identifying more quickly, material and manufacturing process deficiencies. The developmental alloy used in this study was a powder metallurgy boron-modified Ti-6Al-4V, a new alloy currently being considered for gas turbine engine fan blades. Plate specimens were subjected to fully reversed bending fatigue. Results are compared with existing data from commercially available Ti-6Al-4V using both vibration based and more traditional fatigue test methods.

  6. High-frequency shear-horizontal surface acoustic wave sensor

    Science.gov (United States)

    Branch, Darren W

    2013-05-07

    A Love wave sensor uses a single-phase unidirectional interdigital transducer (IDT) on a piezoelectric substrate for leaky surface acoustic wave generation. The IDT design minimizes propagation losses, bulk wave interferences, provides a highly linear phase response, and eliminates the need for impedance matching. As an example, a high frequency (.about.300-400 MHz) surface acoustic wave (SAW) transducer enables efficient excitation of shear-horizontal waves on 36.degree. Y-cut lithium tantalate (LTO) giving a highly linear phase response (2.8.degree. P-P). The sensor has the ability to detect at the pg/mm.sup.2 level and can perform multi-analyte detection in real-time. The sensor can be used for rapid autonomous detection of pathogenic microorganisms and bioagents by field deployable platforms.

  7. Resonator as high frequency electromagnetic field oscillation generator

    International Nuclear Information System (INIS)

    Svoroba, O.V.; Scherbina, V.O.

    2007-01-01

    The problem of finding the u(x-vector) field potential in a specific waveguide with generalized corrugated core geometry is considered. The perturbation is brought to the system by high energy electron beam, injected in a waveguide. It is shown that the Neumann spectral problem can be reduced to finding Green approximation solution, and how it can be solved by the discretization technique. Considered parameterization allow to optimize the u(x-vector) field for specific frequency tuning. This method can be used as plasma heating method for thermonuclear temperature control

  8. A detector for high frequency modulation in auroral particle fluxes

    Science.gov (United States)

    Spiger, R. J.; Oehme, D.; Loewenstein, R. F.; Murphree, J.; Anderson, H. R.; Anderson, R.

    1974-01-01

    A high time resolution electron detector has been developed for use in sounding rocket studies of the aurora. The detector is used to look for particle bunching in the range 50 kHz-10 MHz. The design uses an electron multiplier and an onboard frequency spectrum analyzer. By using the onboard analyzer, the data can be transmitted back to ground on a single 93-kHz voltage-controlled oscillator. The detector covers the 50 kHz-10 MHz range six times per second and detects modulation on the order of a new percent of the total electron flux. Spectra are presented for a flight over an auroral arc.

  9. Low-frequency oscillations at high density in JFT-2

    International Nuclear Information System (INIS)

    Maeno, Masaki; Katagiri, Masaki; Suzuki, Norio; Fujisawa, Noboru

    1977-12-01

    Low-frequency oscillations in a plasma were measured with magnetic probes and Si surface-barrier detectors, and behaviour of the high density plasmas was studied. The plasma current profile in the phase of decreasing density after the interruption of gas input is more peaked than during gas input. The introduction of hydrogen during a discharge results in a reduction of the impurities flux. The increase of density by fast gas input is limited with a negative voltage spike. Immediately before a negative voltage spike, oscillations of m=1,2 grow, leading to the spike. (auth.)

  10. High-efficiency ventilated metamaterial absorber at low frequency

    Science.gov (United States)

    Wu, Xiaoxiao; Au-Yeung, Ka Yan; Li, Xin; Roberts, Robert Christopher; Tian, Jingxuan; Hu, Chuandeng; Huang, Yingzhou; Wang, Shuxia; Yang, Zhiyu; Wen, Weijia

    2018-03-01

    We demonstrate a ventilated metamaterial absorber operating at low frequency (90%) has been achieved in both simulations and experiments. This high-efficiency absorption under the ventilation condition originates from the weak coupling of two identical split tube resonators constituting the absorber, which leads to the hybridization of the degenerate eigenmodes and breaks the absorption upper limit of 50% for conventional transmissive symmetric acoustic absorbers. The absorber can also be extended to an array and work in free space. The absorber should have potential applications in acoustic engineering where both noise reduction and ventilation are required.

  11. RF MEMS Fractal Capacitors With High Self-Resonant Frequencies

    KAUST Repository

    Elshurafa, Amro M.

    2012-07-23

    This letter demonstrates RF microelectromechanical systems (MEMS) fractal capacitors possessing the highest reported self-resonant frequencies (SRFs) in PolyMUMPS to date. Explicitly, measurement results show SRFs beyond 20 GHz. Furthermore, quality factors higher than 4 throughout a band of 1-15 GHz and reaching as high as 28 were achieved. Additional benefits that are readily attainable from implementing fractal capacitors in MEMS are discussed, including suppressing residual stress warping, eliminating the need for etching holes, and reducing parasitics. The latter benefits were acquired without any fabrication intervention. © 2011 IEEE.

  12. Electromagnetic Modelling of MMIC CPWs for High Frequency Applications

    Science.gov (United States)

    Sinulingga, E. P.; Kyabaggu, P. B. K.; Rezazadeh, A. A.

    2018-02-01

    Realising the theoretical electrical characteristics of components through modelling can be carried out using computer-aided design (CAD) simulation tools. If the simulation model provides the expected characteristics, the fabrication process of Monolithic Microwave Integrated Circuit (MMIC) can be performed for experimental verification purposes. Therefore improvements can be suggested before mass fabrication takes place. This research concentrates on development of MMIC technology by providing accurate predictions of the characteristics of MMIC components using an improved Electromagnetic (EM) modelling technique. The knowledge acquired from the modelling and characterisation process in this work can be adopted by circuit designers for various high frequency applications.

  13. Kapitza thermal resistance studied by high-frequency photothermal radiometry

    International Nuclear Information System (INIS)

    Horny, Nicolas; Chirtoc, Mihai; Hamaoui, Georges; Fleming, Austin; Ban, Heng

    2016-01-01

    Kapitza thermal resistance is determined using high-frequency photothermal radiometry (PTR) extended for modulation up to 10 MHz. Interfaces between 50 nm thick titanium coatings and silicon or stainless steel substrates are studied. In the used configuration, the PTR signal is not sensitive to the thermal conductivity of the film nor to its optical absorption coefficient, thus the Kapitza resistance is directly determined from single thermal parameter fits. Results of thermal resistances show the significant influence of the nature of the substrate, as well as of the presence of free electrons at the interface.

  14. STIMA DE SINE – ELEMENT IMPORTANT ÎN PROIECTAREA CARIEREI

    Directory of Open Access Journals (Sweden)

    Carolina PLATON

    2015-11-01

    Full Text Available Savanţii susţin că doar o persoană cu stimă de sine înaltă are şanse să-şi dea seama de propriul potenţial. În procesul de orientare în carieră stima de sine va ajuta persoana să ia decizii corecte, să se autoevalueze şi să acţioneze în sensul aspiraţiilor sale.SELF-ESTEEM – AN IMPORTANT ELEMENT IN THE CAREER PLANNING PROCESSThe scientists support the idea about the awakening that is happening throughout the world to the fact that a human being cannot realize his potential without a healthy self-esteem. A high self-esteem will help a person to make decisions, self-assessment and to act according to his aspirations in the career planning process.

  15. Corrosion monitoring using high-frequency guided ultrasonic waves

    Science.gov (United States)

    Fromme, Paul

    2014-02-01

    Corrosion develops due to adverse environmental conditions during the life cycle of a range 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 structural integrity. The nondestructive detection and monitoring of corrosion damage in difficult to access areas can 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, guided wave modes were generated that penetrate through the complete thickness of the structure. The wave propagation and interference of the different guided wave modes depends on the thickness of the structure. Laboratory experiments were conducted and the wall thickness reduced by consecutive milling of the steel structure. Further measurements were conducted using accelerated corrosion in a salt water bath and the damage severity monitored. From the measured signal change due to the wave mode interference the wall thickness reduction was monitored. The high frequency guided waves have the potential for corrosion damage monitoring at critical and difficult to access locations from a stand-off distance.

  16. Corrosion monitoring using high-frequency guided waves

    Science.gov (United States)

    Fromme, P.

    2016-04-01

    Corrosion can develop due to adverse environmental conditions during the life cycle of a range of industrial structures, e.g., offshore oil platforms, ships, and desalination plants. Generalized corrosion leading to wall thickness loss can cause the reduction of the strength and thus degradation of the structural integrity. The monitoring of corrosion damage in difficult to access areas can be achieved using high frequency guided waves propagating along the structure from accessible areas. Using standard ultrasonic wedge transducers with single sided access to the structure, guided wave modes were selectively generated that penetrate through the complete thickness of the structure. The wave propagation and interference of the different guided wave modes depends on the thickness of the structure. Laboratory experiments were conducted for wall thickness reduction due to milling of the steel structure. From the measured signal changes due to the wave mode interference the reduced wall thickness was monitored. Good agreement with theoretical predictions was achieved. The high frequency guided waves have the potential for corrosion damage monitoring at critical and difficult to access locations from a stand-off distance.

  17. Iridoschisis: high frequency ultrasound imaging. Evidence for a genetic defect?

    Science.gov (United States)

    Danias, J; Aslanides, I M; Eichenbaum, J W; Silverman, R H; Reinstein, D Z; Coleman, D J

    1996-01-01

    AIMS: To elucidate changes in the anatomy of the anterior chamber associated with iridoschisis, a rare form of iris atrophy, and their potential contribution to angle closure glaucoma. METHODS: Both eyes of a 71-year-old woman with bilateral iridoschisis and fibrous dysplasia and her asymptomatic 50-year-old daughter were scanned with a very high frequency (50 MHz) ultrasound system. RESULTS: The symptomatic patient exhibited diffuse changes in the iris stoma with an intact posterior iris pigmented layer in both eyes. These changes were clinically compatible with the lack of iris transillumination defects. Additionally, iris bowing with a resultant narrowing of the angle occurred. The asymptomatic daughter showed discrete, but less severe iris stromal changes. CONCLUSION: This is the first detailed study of high frequency ultrasonic imaging of the iris in iridoschisis. The observed structural changes suggest angle narrowing by forward bowing of the anterior iris stroma may be a mechanism of IOP elevation in this condition. The ultrasonic detection of iris changes in the asymptomatic daughter of the symptomatic patient and the association of iridoschisis with fibrous dysplasia suggest a possible genetic component in the pathogenesis of this condition. Images PMID:9059271

  18. [High frequency electrocoagulation for treating noninvoluting congenital hemangioma].

    Science.gov (United States)

    Zhongqiang, Wang; Yafei, Wang; Jiashuang, Zhou; Quan, Zhou; Lijuan, Yang; Li, Wang

    2015-11-01

    To investigate the clinical efficiency of electrocoagulation for the treatment of noninvoluting congenital hemangioma. Sixteen infants with noninvoluting congenital hemangioma who were admitted to our hospital from January 2011 to June 2013 were included in this study. Color Doppler ultrasound was used to determine the hemangioma location, as well as its size and depth. High frequency electrocoagulation was adopted for the treatment. The output power was set at 10-20 W. The probes were inserted around the tumor or at the surface of the tumor. After switching on for 1-2 seconds, the direction and position of the probe was modulated until covering the whole tumor. After the treatment, the absorption of tumor was about 3-6 months. The efficiency was evaluated during the follow-up. Tumor atrophy was obvious after treatment in all patients. The temperature around the tumor mass was decreased, and the aberrant blood signals were decreased under the ultrasonic examination. Complete or partial atrophy were observed. The efficiency was graded as level I, II, III, IV in 0, 2, 9 and 5 patients, respectively. One patient showed local infection due to improper nursing, which was completely relieved after corresponding treatment. No severe adverse events were observed. High-frequency electrocoagulation is effective for treating noninvoluting congenital hemangioma through coagulating the aberrant blood vessels in the tumor, interrupting the vascular endothelial cell, blocking the aberrant blood flow, as well as leading to atrophy and absorption of tumor mass. Besides, no obvious scar is observed after the surgery.

  19. High relative frequency of thyroid papillary carcinoma in northern Portugal.

    Science.gov (United States)

    Sambade, M C; Gonçalves, V S; Dias, M; Sobrinho-Simões, M A

    1983-05-01

    Two hundred and twelve papillary and 40 follicular carcinomas were found in 3002 thyroid glands examined from 1931 to 1975 in four Laboratories of Pathology that fairly cover northern Portugal. There was a striking preponderance of women both in papillary (female:male = 6.9:1) and follicular carcinoma (5.7:1). Sex-specific frequency of malignancy was significantly greater in men (13.3%) than in women (8.8%). The overall papillary/follicular ratio was 5.3:1 and did not significantly change throughout the study period. Papillary/follicular ratio was not significantly greater in litoral (5.5:1) than in regions with a low iodine intake and a relatively high prevalence of goiter (3.5:1). It is advanced that this high relative frequency of papillary carcinoma in northern Portugal, even in goiter areas, may reflect the existence of a racial factor since there is not enough evidence to support the influence of dietary iodine, previous irradiation and concurrent thyroiditis.

  20. High-frequency behavior of amorphous microwires and its applications

    International Nuclear Information System (INIS)

    Marin, P.; Cortina, D.; Hernando, A.

    2005-01-01

    A magnetic microwire is a continuous filament of total diameter less than 100 μm consisting of an inner metallic magnetic nuclei covered by a glassy outer shell, usually obtained by Taylor's technique, with interesting magnetic properties connected with its high axial magnetic anisotropy. Magnetic sensors based on microwires used, as operating principle, the strong connection between the composition and the uniaxial anisotropy through a magnetostriction constant such as the large Barkhausen effect, Mateucci effect and giant magneto-impedance effect. The study of the microwave properties is also very promising technologically. In the microwave region (approaching GHz range), the ferromagnetic resonance (FMR) occurs and it is connected with the spin precession of the magnetisation vector due to the effect of the high-frequency electromagnetic field applied such that the magnetic component is perpendicular to the magnetisation vector. The natural ferromagnetic resonance (NFMR) has been also observed. The frequency depends upon the value of magnetic anisotropy and it is characterised by the single well-distinguished line in the 2-10 GHz range. Tags detector based on the microwires FMR and a new kind of electromagnetic radiation absorbers based on the microwires NFMR have been developed

  1. High-frequency response and the possibilities of frequency-tunable narrow-band terahertz amplification in resonant tunneling nanostructures

    International Nuclear Information System (INIS)

    Kapaev, V. V.; Kopaev, Yu. V.; Savinov, S. A.; Murzin, V. N.

    2013-01-01

    The characteristics of the high-frequency response of single- and double-well resonant tunneling structures in a dc electric field are investigated on the basis of the numerical solution of a time-dependent Schrödinger equation with open boundary conditions. The frequency dependence of the real part of high frequency conductivity (high-frequency response) in In 0.53 Ga 0.47 As/AlAs/InP structures is analyzed in detail for various values of the dc voltage V dc in the negative differential resistance (NDR) region. It is shown that double-well three-barrier structures are promising for the design of terahertz-band oscillators. The presence of two resonant states with close energies in such structures leads to a resonant (in frequency) response whose frequency is determined by the energy difference between these levels and can be controlled by varying the parameters of the structure. It is shown that, in principle, such structures admit narrow-band amplification, tuning of the amplification frequency, and a fine control of the amplification (oscillation) frequency in a wide range of terahertz frequencies by varying a dc electric voltage applied to the structure. Starting from a certain width of the central intermediate barrier in double-well structures, one can observe a collapse of resonances, where the structure behaves like a single-well system. This phenomenon imposes a lower limit on the oscillation frequency in three-barrier resonant tunneling structures.

  2. A High Energy and High Efficiency Spectral Shaping Single Frequency Fiber Laser, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR phase I project proposes a tunable single frequency high energy fiber laser system for coherent Lidar systems for remote sensing. Current state-of-art...

  3. A High Energy and High Efficiency Spectral Shaping Single Frequency Fiber Laser, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR phase II project proposes a single frequency high energy fiber laser system for coherent Lidar systems for remote sensing. Current state-of-art...

  4. Mechanisms and factors that influence high frequency retroviral recombination

    DEFF Research Database (Denmark)

    Delviks-Frankenberry, Krista; Galli, Andrea; Nikolaitchik, Olga

    2011-01-01

    With constantly changing environmental selection pressures, retroviruses rely upon recombination to reassort polymorphisms in their genomes and increase genetic diversity, which improves the chances for the survival of their population. Recombination occurs during DNA synthesis, whereby reverse...... transcriptase undergoes template switching events between the two copackaged RNAs, resulting in a viral recombinant with portions of the genetic information from each parental RNA. This review summarizes our current understanding of the factors and mechanisms influencing retroviral recombination, fidelity...... of the recombination process, and evaluates the subsequent viral diversity and fitness of the progeny recombinant. Specifically, the high mutation rates and high recombination frequencies of HIV-1 will be analyzed for their roles in influencing HIV-1 global diversity, as well as HIV-1 diagnosis, drug treatment...

  5. Mechanisms and Factors that Influence High Frequency Retroviral Recombination

    Science.gov (United States)

    Delviks-Frankenberry, Krista; Galli, Andrea; Nikolaitchik, Olga; Mens, Helene; Pathak, Vinay K.; Hu, Wei-Shau

    2011-01-01

    With constantly changing environmental selection pressures, retroviruses rely upon recombination to reassort polymorphisms in their genomes and increase genetic diversity, which improves the chances for the survival of their population. Recombination occurs during DNA synthesis, whereby reverse transcriptase undergoes template switching events between the two copackaged RNAs, resulting in a viral recombinant with portions of the genetic information from each parental RNA. This review summarizes our current understanding of the factors and mechanisms influencing retroviral recombination, fidelity of the recombination process, and evaluates the subsequent viral diversity and fitness of the progeny recombinant. Specifically, the high mutation rates and high recombination frequencies of HIV-1 will be analyzed for their roles in influencing HIV-1 global diversity, as well as HIV-1 diagnosis, drug treatment, and vaccine development. PMID:21994801

  6. Frequency selective surfaces based high performance microstrip antenna

    CERN Document Server

    Narayan, Shiv; Jha, Rakesh Mohan

    2016-01-01

    This book focuses on performance enhancement of printed antennas using frequency selective surfaces (FSS) technology. The growing demand of stealth technology in strategic areas requires high-performance low-RCS (radar cross section) antennas. Such requirements may be accomplished by incorporating FSS into the antenna structure either in its ground plane or as the superstrate, due to the filter characteristics of FSS structure. In view of this, a novel approach based on FSS technology is presented in this book to enhance the performance of printed antennas including out-of-band structural RCS reduction. In this endeavor, the EM design of microstrip patch antennas (MPA) loaded with FSS-based (i) high impedance surface (HIS) ground plane, and (ii) the superstrates are discussed in detail. The EM analysis of proposed FSS-based antenna structures have been carried out using transmission line analogy, in combination with the reciprocity theorem. Further, various types of novel FSS structures are considered in desi...

  7. High frequency modulation circuits based on photoconductive wide bandgap switches

    Science.gov (United States)

    Sampayan, Stephen

    2018-02-13

    Methods, systems, and devices for high voltage and/or high frequency modulation. In one aspect, an optoelectronic modulation system includes an array of two or more photoconductive switch units each including a wide bandgap photoconductive material coupled between a first electrode and a second electrode, a light source optically coupled to the WBGP material of each photoconductive switch unit via a light path, in which the light path splits into multiple light paths to optically interface with each WBGP material, such that a time delay of emitted light exists along each subsequent split light path, and in which the WBGP material conducts an electrical signal when a light signal is transmitted to the WBGP material, and an output to transmit the electrical signal conducted by each photoconductive switch unit. The time delay of the photons emitted through the light path is substantially equivalent to the time delay of the electrical signal.

  8. Development of high frequency and wide bandwidth Johnson noise thermometry

    International Nuclear Information System (INIS)

    Crossno, Jesse; Liu, Xiaomeng; Kim, Philip; Ohki, Thomas A.; Fong, Kin Chung

    2015-01-01

    We develop a high frequency, wide bandwidth radiometer operating at room temperature, which augments the traditional technique of Johnson noise thermometry for nanoscale thermal transport studies. Employing low noise amplifiers and an analog multiplier operating at 2 GHz, auto- and cross-correlated Johnson noise measurements are performed in the temperature range of 3 to 300 K, achieving a sensitivity of 5.5 mK (110 ppm) in 1 s of integration time. This setup allows us to measure the thermal conductance of a boron nitride encapsulated monolayer graphene device over a wide temperature range. Our data show a high power law (T ∼ 4) deviation from the Wiedemann-Franz law above T ∼ 100 K

  9. Articulated pipes conveying fluid pulsating with high frequency

    DEFF Research Database (Denmark)

    Jensen, Jakob Søndergaard

    1999-01-01

    Stability and nonlinear dynamics of two articulated pipes conveying fluid with a high-frequency pulsating component is investigated. The non-autonomous model equations are converted into autonomous equations by approximating the fast excitation terms with slowly varying terms. The downward hanging...... pipe position will lose stability if the mean flow speed exceeds a certain critical value. Adding a pulsating component to the fluid flow is shown to stabilize the hanging position for high values of the ratio between fluid and pipe-mass, and to marginally destabilize this position for low ratios....... An approximate nonlinear solution for small-amplitude flutter oscillations is obtained using a fifth-order multiple scales perturbation method, and large-amplitude oscillations are examined by numerical integration of the autonomous model equations, using a path-following algorithm. The pulsating fluid component...

  10. High-frequency homogenization for travelling waves in periodic media.

    Science.gov (United States)

    Harutyunyan, Davit; Milton, Graeme W; Craster, Richard V

    2016-07-01

    We consider high-frequency homogenization in periodic media for travelling waves of several different equations: the wave equation for scalar-valued waves such as acoustics; the wave equation for vector-valued waves such as electromagnetism and elasticity; and a system that encompasses the Schrödinger equation. This homogenization applies when the wavelength is of the order of the size of the medium periodicity cell. The travelling wave is assumed to be the sum of two waves: a modulated Bloch carrier wave having crystal wavevector [Formula: see text] and frequency ω 1 plus a modulated Bloch carrier wave having crystal wavevector [Formula: see text] and frequency ω 2 . We derive effective equations for the modulating functions, and then prove that there is no coupling in the effective equations between the two different waves both in the scalar and the system cases. To be precise, we prove that there is no coupling unless ω 1 = ω 2 and [Formula: see text] where Λ =(λ 1 λ 2 …λ d ) is the periodicity cell of the medium and for any two vectors [Formula: see text] the product a ⊙ b is defined to be the vector ( a 1 b 1 , a 2 b 2 ,…, a d b d ). This last condition forces the carrier waves to be equivalent Bloch waves meaning that the coupling constants in the system of effective equations vanish. We use two-scale analysis and some new weak-convergence type lemmas. The analysis is not at the same level of rigour as that of Allaire and co-workers who use two-scale convergence theory to treat the problem, but has the advantage of simplicity which will allow it to be easily extended to the case where there is degeneracy of the Bloch eigenvalue.

  11. High-Frequency Neuromuscular Electrical Stimulation Increases Anabolic Signaling.

    Science.gov (United States)

    Mettler, Joni A; Magee, Dillon M; Doucet, Barbara M

    2018-03-16

    Neuromuscular electrical stimulation (NMES) is commonly used in rehabilitation settings to increase muscle mass and strength. However, the effects of NMES on muscle growth are not clear and no human studies have compared anabolic signaling between low-frequency (LF-) and high-frequency (HF-) NMES. The purpose of this study was to determine the skeletal muscle anabolic signaling response to an acute bout of LF- and HF-NMES. Eleven young healthy volunteers (6 men; 5 women) received an acute bout of LF- (20 Hz) and HF- (60 Hz) NMES. Muscle biopsies were obtained from the vastus lateralis muscle prior to the first NMES treatment and 30-mins following each NMES treatment. Phosphorylation of the following key anabolic signaling proteins was measured by Western blot and proteins are expressed as a ratio of phosphorylated to total: mammalian target of rapamycin (mTOR), p70-S6 kinase 1 (S6K1), and eukaryotic initiation factor 4E binding protein 1 (4E-BP1). Compared to Pre-NMES, phosphorylation of mTOR was upregulated 40.2% for LF-NMES (P = 0.018) and 68.4% for HF-NMES (P 0.05). There were no differences between treatment conditions for 4E-BP1 phosphorylation (P > 0.05). An acute bout of LF- and HF-NMES upregulated anabolic signaling with HF-NMES producing a greater anabolic response compared to LF-NMES, suggesting that HF-stimulation may provide a stronger stimulus for processes that initiate muscle hypertrophy. Additionally, the stimulation frequency parameter should be considered by clinicians in the design of optimal NMES treatment protocols.

  12. Demonstration of the frequency modulation of optical signals with a high frequency deviation parameter

    International Nuclear Information System (INIS)

    Shamray, A V; Kozlov, A S; Il'ichev, I V; Petrov, M P

    2008-01-01

    A new type of an integrated optical modulator for the frequency coding of optical signals is developed and fabricated. The modulator operation is based on the original technology of the electric control of a Bragg grating. The frequency modulation of an optical signal with the frequency deviation of 25 GHz is demonstrated experimentally. The modular was used to transfer the ASCII code through an optical fibre. (optical communication)

  13. Gene conversion as a secondary mechanism of short interspersed element (SINE) evolution

    Energy Technology Data Exchange (ETDEWEB)

    Kass, D.H. [Louisiana State Univ. Medical Center, New Orleans, LA (United States). Dept. of Biochemistry and Molecular Biology; Batzer, M.A. [Lawrence Livermore National Lab., CA (United States); Deininger, P.L. [Louisiana State Univ. Medical Center, New Orleans, LA (United States). Dept. of Biochemistry and Molecular Biology]|[Alton Ochsner Medical Foundation, New Orleans, LA (United States). Lab. of Molecular Genetics

    1995-01-01

    The Alu repetitive family of short interspersed elements (SINEs) in primates can be subdivided into distinct subfamilies by specific diagnostic nucleotide changes. The older subfamilies are generally very abundant, while the younger subfamilies have fewer copies. Some of the youngest Alu elements are absent in the orthologous loci of nonhuman primates, indicative of recent retroposition events, the primary mode of SINE evolutions. PCR analysis of one young Alu subfamily (Sb2) member found in the low-density lipoprotein receptor gene apparently revealed the presence of this element in the green monkey, orangutan, gorilla, and chimpanzee genomes, as well as the human genome. However, sequence analysis of these genomes revealed a highly mutated, older, primate-specific Alu element was present at this position in the nonhuman primates. Comparison of the flanking DNA sequences upstream of this Alu insertion corresponded to evolution expected for standard primate phylogeny, but comparison of the Alu repeat sequences revealed that the human element departed from this phylogeny. The change in the human sequence apparently occurred by a gene conversion event only within the Alu element itself, converting it from one of the oldest to one of the youngest Alu subfamilies. Although gene conversions of Alu elements are clearly very rare, this finding shows that such events can occur and contribute to specific cases of SINE subfamily evolution.

  14. Retroelements (LINEs and SINEs) in vole genomes: differential distribution in the constitutive heterochromatin.

    Science.gov (United States)

    Acosta, M J; Marchal, J A; Fernández-Espartero, C H; Bullejos, M; Sánchez, A

    2008-01-01

    The chromosomal distribution of mobile genetic elements is scarcely known in Arvicolinae species, but could be of relevance to understand the origin and complex evolution of the sex chromosome heterochromatin. In this work we cloned two retrotransposon sequences, L1 and SINE-B1, from the genome of Chionomys nivalis and investigated their chromosomal distribution on several arvicoline species. Our results demonstrate first that both retroelements are the most abundant repeated DNA sequences in the genome of these species. L1 elements, in most species, are highly accumulated in the sex chromosomes compared to the autosomes. This favoured L1 insertion could have played an important role in the origin of the enlarged heterochromatic blocks existing in the sex chromosomes of some Microtus species. Also, we propose that L1 accumulation on the X heterochromatin could have been the consequence of different, independent and rapid amplification processes acting in each species. SINE elements, however, were completely lacking from the constitutive heterochromatin, either in autosomes or in the heterochromatic blocks of sex chromosomes. These data could indicate that some SINE elements are incompatible with the formation of heterochromatic complexes and hence are necessarily missing from the constitutive heterochromatin.

  15. Scenario based approach for multiple source Tsunami Hazard assessment for Sines, Portugal

    Science.gov (United States)

    Wronna, M.; Omira, R.; Baptista, M. A.

    2015-08-01

    In this paper, we present a scenario-based approach for tsunami hazard assessment for the city and harbour of Sines - Portugal, one of the test-sites of project ASTARTE. Sines holds one of the most important deep-water ports which contains oil-bearing, petrochemical, liquid bulk, coal and container terminals. The port and its industrial infrastructures are facing the ocean southwest towards the main seismogenic sources. This work considers two different seismic zones: the Southwest Iberian Margin and the Gloria Fault. Within these two regions, we selected a total of six scenarios to assess the tsunami impact at the test site. The tsunami simulations are computed using NSWING a Non-linear Shallow Water Model With Nested Grids. In this study, the static effect of tides is analysed for three different tidal stages MLLW (mean lower low water), MSL (mean sea level) and MHHW (mean higher high water). For each scenario, inundation is described by maximum values of wave height, flow depth, drawback, runup and inundation distance. Synthetic waveforms are computed at virtual tide gauges at specific locations outside and inside the harbour. The final results describe the impact at Sines test site considering the single scenarios at mean sea level, the aggregate scenario and the influence of the tide on the aggregate scenario. The results confirm the composite of Horseshoe and Marques Pombal fault as the worst case scenario. It governs the aggregate scenario with about 60 % and inundates an area of 3.5 km2.

  16. High-frequency underwater plasma discharge application in antibacterial activity

    International Nuclear Information System (INIS)

    Ahmed, M. W.; Choi, S.; Lyakhov, K.; Shaislamov, U.; Mongre, R. K.; Jeong, D. K.; Suresh, R.; Lee, H. J.

    2017-01-01

    Plasma discharge is a novel disinfection and effectual inactivation approach to treat microorganisms in aqueous systems. Inactivation of Gram-negative Escherichia coli (E. coli) by generating high-frequency, high-voltage, oxygen (O_2) injected and hydrogen peroxide (H_2O_2) added discharge in water was achieved. The effect of H_2O_2 dose and oxygen injection rate on electrical characteristics of discharge and E. coli disinfection has been reported. Microbial log reduction dependent on H_2O_2 addition with O_2 injection was observed. The time variation of the inactivation efficiency quantified by the log reduction of the initial E. coli population on the basis of optical density measurement was reported. The analysis of emission spectrum recorded after discharge occurrence illustrated the formation of oxidant species (OH"•, H, and O). Interestingly, the results demonstrated that O_2 injected and H_2O_2 added, underwater plasma discharge had fabulous impact on the E. coli sterilization. The oxygen injection notably reduced the voltage needed for generating breakdown in flowing water and escalated the power of discharge pulses. No impact of hydrogen peroxide addition on breakdown voltage was observed. A significant role of oxidant species in bacterial inactivation also has been identified. Furthermore the E. coli survivability in plasma treated water with oxygen injection and hydrogen peroxide addition drastically reduced to zero. The time course study also showed that the retardant effect on E. coli colony multiplication in plasma treated water was favorable, observed after long time. High-frequency underwater plasma discharge based biological applications is technically relevant and would act as baseline data for the development of novel antibacterial processing strategies.

  17. High-frequency underwater plasma discharge application in antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, M. W.; Choi, S.; Lyakhov, K.; Shaislamov, U. [Jeju National University, Department of Nuclear and Energy Engineering (Korea, Republic of); Mongre, R. K.; Jeong, D. K. [Jeju National University, Faculty of Biotechnology (Korea, Republic of); Suresh, R.; Lee, H. J., E-mail: hjlee@jejunu.ac.kr [Jeju National University, Department of Nuclear and Energy Engineering (Korea, Republic of)

    2017-03-15

    Plasma discharge is a novel disinfection and effectual inactivation approach to treat microorganisms in aqueous systems. Inactivation of Gram-negative Escherichia coli (E. coli) by generating high-frequency, high-voltage, oxygen (O{sub 2}) injected and hydrogen peroxide (H{sub 2}O{sub 2}) added discharge in water was achieved. The effect of H{sub 2}O{sub 2} dose and oxygen injection rate on electrical characteristics of discharge and E. coli disinfection has been reported. Microbial log reduction dependent on H{sub 2}O{sub 2} addition with O{sub 2} injection was observed. The time variation of the inactivation efficiency quantified by the log reduction of the initial E. coli population on the basis of optical density measurement was reported. The analysis of emission spectrum recorded after discharge occurrence illustrated the formation of oxidant species (OH{sup •}, H, and O). Interestingly, the results demonstrated that O{sub 2} injected and H{sub 2}O{sub 2} added, underwater plasma discharge had fabulous impact on the E. coli sterilization. The oxygen injection notably reduced the voltage needed for generating breakdown in flowing water and escalated the power of discharge pulses. No impact of hydrogen peroxide addition on breakdown voltage was observed. A significant role of oxidant species in bacterial inactivation also has been identified. Furthermore the E. coli survivability in plasma treated water with oxygen injection and hydrogen peroxide addition drastically reduced to zero. The time course study also showed that the retardant effect on E. coli colony multiplication in plasma treated water was favorable, observed after long time. High-frequency underwater plasma discharge based biological applications is technically relevant and would act as baseline data for the development of novel antibacterial processing strategies.

  18. Photoinduced High-Frequency Charge Oscillations in Dimerized Systems

    Science.gov (United States)

    Yonemitsu, Kenji

    2018-04-01

    Photoinduced charge dynamics in dimerized systems is studied on the basis of the exact diagonalization method and the time-dependent Schrödinger equation for a one-dimensional spinless-fermion model at half filling and a two-dimensional model for κ-(bis[ethylenedithio]tetrathiafulvalene)2X [κ-(BEDT-TTF)2X] at three-quarter filling. After the application of a one-cycle pulse of a specifically polarized electric field, the charge densities at half of the sites of the system oscillate in the same phase and those at the other half oscillate in the opposite phase. For weak fields, the Fourier transform of the time profile of the charge density at any site after photoexcitation has peaks for finite-sized systems that correspond to those of the steady-state optical conductivity spectrum. For strong fields, these peaks are suppressed and a new peak appears on the high-energy side, that is, the charge densities mainly oscillate with a single frequency, although the oscillation is eventually damped. In the two-dimensional case without intersite repulsion and in the one-dimensional case, this frequency corresponds to charge-transfer processes by which all the bonds connecting the two classes of sites are exploited. Thus, this oscillation behaves as an electronic breathing mode. The relevance of the new peak to a recently found reflectivity peak in κ-(BEDT-TTF)2X after photoexcitation is discussed.

  19. Earless toads sense low frequencies but miss the high notes

    DEFF Research Database (Denmark)

    Womack, Molly C; Christensen-Dalsgaard, Jakob; Coloma, Luis A

    2017-01-01

    Sensory losses or reductions are frequently attributed to relaxed selection. However, anuran species have lost tympanic middle ears many times, despite anurans' use of acoustic communication and the benefit of middle ears for hearing airborne sound. Here we determine whether pre-existing alternat......Sensory losses or reductions are frequently attributed to relaxed selection. However, anuran species have lost tympanic middle ears many times, despite anurans' use of acoustic communication and the benefit of middle ears for hearing airborne sound. Here we determine whether pre......-existing alternative sensory pathways enable anurans lacking tympanic middle ears (termed earless anurans) to hear airborne sound as well as eared species or to better sense vibrations in the environment. We used auditory brainstem recordings to compare hearing and vibrational sensitivity among 10 species (six eared......, four earless) within the Neotropical true toad family (Bufonidae). We found that species lacking middle ears are less sensitive to high-frequency sounds, however, low-frequency hearing and vibrational sensitivity are equivalent between eared and earless species. Furthermore, extratympanic hearing...

  20. Ultra High-Speed Radio Frequency Switch Based on Photonics.

    Science.gov (United States)

    Ge, Jia; Fok, Mable P

    2015-11-26

    Microwave switches, or Radio Frequency (RF) switches have been intensively used in microwave systems for signal routing. Compared with the fast development of microwave and wireless systems, RF switches have been underdeveloped particularly in terms of switching speed and operating bandwidth. In this paper, we propose a photonics based RF switch that is capable of switching at tens of picoseconds speed, which is hundreds of times faster than any existing RF switch technologies. The high-speed switching property is achieved with the use of a rapidly tunable microwave photonic filter with tens of gigahertz frequency tuning speed, where the tuning mechanism is based on the ultra-fast electro-optics Pockels effect. The RF switch has a wide operation bandwidth of 12 GHz and can go up to 40 GHz, depending on the bandwidth of the modulator used in the scheme. The proposed RF switch can either work as an ON/OFF switch or a two-channel switch, tens of picoseconds switching speed is experimentally observed for both type of switches.

  1. Dielectric and acoustical high frequency characterisation of PZT thin films

    Energy Technology Data Exchange (ETDEWEB)

    Conde, Janine; Muralt, Paul, E-mail: janine.conde@epfl.ch [Department of Materials Science, EPFL (Switzerland)

    2010-02-15

    Pb(Zr, Ti)O{sub 3} (PZT) is an interesting material for bulk acoustic wave resonator applications due to its high electromechanical coupling constant, which would enable fabrication of large bandwidth frequency filters. The major challenge of the PZT solid solution system is to overcome mechanical losses generally observed in PZT ceramics. To increase the understanding of these losses in textured thin films, thin film bulk acoustic resonators (TFBAR's) based on PZT thin films with compositions either in the tetragonal region or at the morphotropic phase boundary and (111) or {l_brace}100{r_brace} textures were fabricated and studied up to 2 GHz. The dielectric and elastic materials coefficients were extracted from impedance measurements at the resonance frequency. The dispersion of the dielectric constant was obtained from impedance measurements up to 2 GHz. The films with varying compositions, textures and deposition methods (sol-gel or sputtering) were compared in terms of dielectric and acoustical properties.

  2. High Frequency Longitudinal Damped Vibrations of a Cylindrical Ultrasonic Transducer

    Directory of Open Access Journals (Sweden)

    Mihai Valentin Predoi

    2014-01-01

    Full Text Available Ultrasonic piezoelectric transducers used in classical nondestructive testing are producing in general longitudinal vibrations in the MHz range. A simple mechanical model of these transducers would be very useful for wave propagation numerical simulations, avoiding the existing complicated models in which the real components of the transducer are modeled by finite elements. The classical model for longitudinal vibrations is not adequate because the generated longitudinal wave is not dispersive, the velocity being the same at any frequency. We have adopted the Rayleigh-Bishop model, which avoids these limitations, even if it is not converging to the first but to the second exact longitudinal mode in an elastic rod, as obtained from the complicated Pochhammer-Chree equations. Since real transducers have significant vibrations damping, we have introduced a damping term in the Rayleigh-Bishop model, increasing the imaginary part and keeping almost identical real part of the wavenumber. Common transducers produce amplitude modulated signals, completely attenuated after several periods. This can be modeled by two close frequencies, producing a “beat” phenomenon, superposed on the high damping. For this reason, we introduce a two-rod Rayleigh-Bishop model with damping. Agreement with measured normal velocity on the transducer free surface is encouraging for continuation of the research.

  3. Methods of Improving High Frequency Direct Injection Testing

    National Research Council Canada - National Science Library

    Lehr, Jane

    1997-01-01

    .... A major problem has been the frequency response of the voltage probes. This effort has identified the cause of the degradation of the voltage dividing ratio with frequency, through experiment and circuit simulation, as a capacitive effect...

  4. High-Frequency Antenna Arrays and Coupling Structures

    Data.gov (United States)

    National Aeronautics and Space Administration — We are fabricating antenna arrays and coupling structure for frequencies in the 200-300 GHz frequency bands. The primary motivation of this work is to develop...

  5. Contactless or High Frequency Conductometry or Oscillometry of Electrolytes

    OpenAIRE

    Kiumars Ghowsi; Hosein Ghowsi

    2013-01-01

    Circuit models are used to express the behavior of the conductometric cells in the radio frequency to microwave region .The capacitive cell has two era classic era and modern era as a detector for Capillary Zone Electrophoresis . Capacitive Cell where electrodes are outside the Cells and frequency of the electric signal is in the cell the radio frequency range is modeled. Both microscopic phenomena occurring at radio frequencies in electrolytes and macroscopic phenomena the circuit model for ...

  6. Low-frequency versus high-frequency synchronisation in chirp-evoked auditory brainstem responses

    DEFF Research Database (Denmark)

    Rønne, Filip Munch; Gøtsche-Rasmussen, Kristian

    2011-01-01

    This study investigates the frequency specific contribution to the auditory brainstem response (ABR) of chirp stimuli. Frequency rising chirps were designed to compensate for the cochlear traveling wave delay, and lead to larger wave-V amplitudes than for click stimuli as more auditory nerve fibr...

  7. Short interspersed elements (SINEs) in plants: origin, classification, and use as phylogenetic markers.

    Science.gov (United States)

    Deragon, Jean-Marc; Zhang, Xiaoyu

    2006-12-01

    Short interspersed elements (SINEs) are a class of dispersed mobile sequences that use RNA as an intermediate in an amplification process called retroposition. The presence-absence of a SINE at a given locus has been used as a meaningful classification criterion to evaluate phylogenetic relations among species. We review here recent developments in the characterisation of plant SINEs and their use as molecular makers to retrace phylogenetic relations among wild and cultivated Oryza and Brassica species. In Brassicaceae, further use of SINE markers is limited by our partial knowledge of endogenous SINE families (their origin and evolution histories) and by the absence of a clear classification. To solve this problem, phylogenetic relations among all known Brassicaceae SINEs were analyzed and a new classification, grouping SINEs in 15 different families, is proposed. The relative age and size of each Brassicaceae SINE family was evaluated and new phylogenetically supported subfamilies were described. We also present evidence suggesting that new potentially active SINEs recently emerged in Brassica oleracea from the shuffling of preexisting SINE portions. Finally, the comparative evolution history of SINE families present in Arabidopsis thaliana and Brassica oleracea revealed that SINEs were in general more active in the Brassica lineage. The importance of these new data for the use of Brassicaceae SINEs as molecular markers in future applications is discussed.

  8. Synchronization of vortex formation frequency with the body motion frequency at high Reynolds numbers

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Luiz Antonio Alcantara [Federal University of Itajuba (UNIFEI), MG (Brazil). Inst. of Mechanical Engineering], E-mail: luizantp@unifei.edu.br; Hirata, Miguel Hiroo [State University of Rio de Janeiro (FAT/UERJ), Resende, RJ (Brazil). Fac. de Tecnologia], E-mail: hirata@fat.uerj.br

    2010-07-01

    Understanding vortex induced vibrations is of great importance in the design of a variety of offshore engineering structures, nuclear plant components and cylindrical elements in tube-bank heat exchangers, for example. If a body is placed in a flow, it experiences alternating lift and drag forces caused by the asymmetric formation of vortices, which can cause a structure to vibrate. One of the most interesting features of this flow is the phenomenon of lock-in which is observed when the vortex shedding frequency is close to the body oscillation frequency. This paper presents the results of numerical experiments on vortex shedding from a circular cylinder vibrating in-line or transversely with an incident uniform flow at Reynolds number of 1.0 x 10{sup 5}. The frequencies of the lift and drag coefficients are compared with the body motion frequency when the frequency ratio is about unity. (author)

  9. Complex correlation approach for high frequency financial data

    Science.gov (United States)

    Wilinski, Mateusz; Ikeda, Yuichi; Aoyama, Hideaki

    2018-02-01

    We propose a novel approach that allows the calculation of a Hilbert transform based complex correlation for unevenly spaced data. This method is especially suitable for high frequency trading data, which are of a particular interest in finance. Its most important feature is the ability to take into account lead-lag relations on different scales, without knowing them in advance. We also present results obtained with this approach while working on Tokyo Stock Exchange intraday quotations. We show that individual sectors and subsectors tend to form important market components which may follow each other with small but significant delays. These components may be recognized by analysing eigenvectors of complex correlation matrix for Nikkei 225 stocks. Interestingly, sectorial components are also found in eigenvectors corresponding to the bulk eigenvalues, traditionally treated as noise.

  10. High Frequency QPOs due to Black Hole Spin

    Science.gov (United States)

    Kazanas, Demos; Fukumura, K.

    2009-01-01

    We present detailed computations of photon orbits emitted by flares at the innermost stable circular orbit (ISCO) of accretion disks around rotating black holes. We show that for sufficiently large spin parameter, i.e. a > 0.94 M, flare a sufficient number of photons arrive at an observer after multiple orbits around the black hole, to produce an "photon echo" of constant lag, i.e. independent of the relative phase between the black hole and the observer, of T approximates 14 M. This constant time delay, then, leads to a power spectrum with a QPO at a frequency nu approximates 1/14M, even for a totally random ensemble of such flares. Observation of such a QPO will provide incontrovertible evidence for the high spin of the black hole and a very accurate, independent, measurement of its mass.

  11. Effective High-Frequency Permeability of Compacted Metal Powders

    Science.gov (United States)

    Volkovskaya, I. I.; Semenov, V. E.; Rybakov, K. I.

    2018-03-01

    We propose a model for determination of the effective complex permeability of compacted metal-powder media. It is based on the equality of the magnetic moment in a given volume of the media with the desired effective permeability to the total magnetic moment of metal particles in the external high-frequency magnetic field, which arises due to excitation of electric eddy currents in the particles. Calculations within the framework of the proposed model allow us to refine the values of the real and imaginary components of the permeability of metal powder compacts in the microwave band. The conditions of applicability of the proposed model are formulated, and their fulfillment is verified for metal powder compacts in the microwave and millimeter wavelength bands.

  12. High-Performance Control in Radio Frequency Power Amplification Systems

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Kofod

    . It is clearly shown that single-phase switch-mode control systems based on oscillation (controlled unstable operation) of the whole power train provide the highest possible control bandwidth. A study of the limitations of cartesian feedback is also included. It is shown that bandwidths in excess of 4MHz can...... frequency power amplifiers (RFPAs) in conjunction with cartesian feedback (CFB) used to linearize the overall transmitter system. On a system level, it is demonstrated how envelope tracking is particularly useful for RF carriers with high peak-to-average power ratios, such as TEDS with 10dB. It is also...... demonstrated how the envelope tracking technique introduces a number of potential pitfalls to the system, namely in the form of power supply ripple intermodulation (PSIM), reduced RFPA linearity and a higherimpedance supply rail for the RFPA. Design and analysis techniques for these three issues are introduced...

  13. Ultra-high Frequency Linear Fiber Optic Systems

    CERN Document Server

    Lau, Kam

    2011-01-01

    This book provides an in-depth treatment of both linear fiber-optic systems and their key enabling devices. It presents a concise but rigorous treatment of the theory and practice of analog (linear) fiber-optics links and systems that constitute the foundation of Hybrid Fiber Coax infrastructure in present-day CATV distribution and cable modem Internet access. Emerging applications in remote fiber-optic feed for free-space millimeter wave enterprise campus networks are also described. Issues such as dispersion and interferometric noise are treated quantitatively, and means for mitigating them are explained. This broad but concise text will thus be invaluable not only to students of fiber-optics communication but also to practicing engineers. To the second edition of this book important new aspects of linear fiber-optic transmission technologies are added, such as high level system architectural issues, algorithms for deriving the optimal frequency assignment, directly modulated or externally modulated laser t...

  14. High-efficiency water-loaded microwave antenna in ultra-high-frequency band

    Science.gov (United States)

    Gong, Zilun; Bartone, Chris; Yang, Fuyi; Yao, Jie

    2018-03-01

    High-index dielectrics are widely used in microwave antennas to control the radiation characteristics. Liquid water, with a high dielectric index at microwave frequency, is an interesting material to achieving tunable functionalities. Here, we demonstrate a water-loaded microwave antenna system that has high loss-tolerance and wideband tunability enabled by fluidity. Our simulation and experimental results show that the resonance frequency can be effectively tuned by the size of loading water. Furthermore, the antenna systems with water loading can achieve high radiation efficiency (>90%) in the ultra-high-frequency (0.3-3 GHz) band. This work brings about opportunities in realistic tunable microwave antenna designs enabled by liquid.

  15. Low and High-Frequency Field Potentials of Cortical Networks ...

    Science.gov (United States)

    Neural networks grown on microelectrode arrays (MEAs) have become an important, high content in vitro assay for assessing neuronal function. MEA experiments typically examine high- frequency (HF) (>200 Hz) spikes, and bursts which can be used to discriminate between different pharmacological agents/chemicals. However, normal brain activity is additionally composed of integrated low-frequency (0.5-100 Hz) field potentials (LFPs) which are filtered out of MEA recordings. The objective of this study was to characterize the relationship between HF and LFP neural network signals, and to assess the relative sensitivity of LFPs to selected neurotoxicants. Rat primary cortical cultures were grown on glass, single-well MEA chips. Spontaneous activity was sampled at 25 kHz and recorded (5 min) (Multi-Channel Systems) from mature networks (14 days in vitro). HF (spike, mean firing rate, MFR) and LF (power spectrum, amplitude) components were extracted from each network and served as its baseline (BL). Next, each chip was treated with either 1) a positive control, bicuculline (BIC, 25μM) or domoic acid (DA, 0.3μM), 2) or a negative control, acetaminophen (ACE, 100μM) or glyphosate (GLY, 100μM), 3) a solvent control (H2O or DMSO:EtOH), or 4) a neurotoxicant, (carbaryl, CAR 5, 30μM ; lindane, LIN 1, 10μM; permethrin, PERM 25, 50μM; triadimefon, TRI 5, 65μM). Post treatment, 5 mins of spontaneous activity was recorded and analyzed. As expected posit

  16. High-frequency heating of plasma with two ion species

    International Nuclear Information System (INIS)

    Klima, R.; Longinov, A.V.; Stepanov, K.N.

    1975-01-01

    The authors consider the penetration of electromagnetic waves with a frequency of the order of the ion cyclotron frequencies and with a fixed longitudinal wave number ksub(long), so that Nsub(long)=ksub(long)c/ω>>1 deep into an inhomogeneous plasma with two ion species. The propagation of two kinds of waves (fast and slow) with widely differing polarization and transverse refraction index is possible. For both types of waves there is an evanescence region at the plasma periphery. The evanescence region is narrow for slow waves and they easily penetrate the plasma. In a dense plasma they become electrostatic and can reach the ion-ion hybrid resonance region. However, the damping of these waves due to Cherenkov interaction with electrons in a high-temperature plasma is strong and therefore they are not suitable for heating plasma of large dimensions, as they are absorbed at the plasma periphery. The fast waves have a wider evanescence region and can be excited effectively only if N 2 is not too high. These waves can be completely absorbed in the plasma (due to Cherenkov interaction with electrons) if xi approximately (v 2 sub(Ti)/v 2 sub(A))Zsub(e)(ωsub(pi)a/c)exp(-Zsub(e) 2 ) > 1, where a is the plasma radius and Zsub(e) = ω/(√2 ksub(long)vsub(Te)). Fast waves can also reach the region where they are transformed into slow waves. In this region their damping increases considerably. It is shown that the transformation region in an inhomogeneous plasma with two ion species in a non-uniform magnetic field may be at the centre of the plasma. Fast waves can be used effectively for heating plasma of large dimensions. (author)

  17. High frequency oscillatory ventilation in meconium aspiration syndrome

    Directory of Open Access Journals (Sweden)

    José Nona

    2009-03-01

    Full Text Available Objective: To evaluate and compare the management and associated morbidity in inborn and outborn babies with meconium aspiration syndrome admitted to the Neonatal Intensive Care Unit and ventilated with high frequency oscillatory ventilation. Methods: A retrospective cohort study with a review of clinical data from newborns, admitted to the Neonatal Intensive Care Unit during a six-year period (from 1999 to 2004 and ventilated with early high frequency oscillatory ventilation, first intention in inborns and immediately after Neonatal Intensive Care Unit arrival in outborns. Rresults: In the present study, 27 newborns were included: 12 inborn and 15 outborn infants. Severity criteria were similar in both groups. The pulmonary morbidity associated was severe persistent pulmonary hypertension - 12 (seven outborns, pneumothorax - five (three outborns, interstitial emphysema – two (one outborn and pulmonary hemorrhage – one outborn. Hypoxic-ischemic encephalopathy II-III occurred in six newborns (four outborns. The therapeutic procedures were surfactant administration in 22 newborns (13 outborns, nitric oxide in 12 newborns (7 outborns and magnesium sulphate in four newborns (three outborns. The median length of ventilation was six days (inborn infants: four and half days; outborn infants: ten days and the median length of oxygenation supply was ten days (inborn infants: four and half days; outborn infants: 15 days. The median length of stay was 13 days (inborn infants: 11 days; outborn infants: 16 days. One outborn infant died. Cconclusions: With this ventilation strategy, we have found no significant statistical differences between the two newborn groups, except for the length of oxygenation supply that was longer in the Outborn Group.

  18. Frequency conversion of high-intensity, femtosecond laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Banks, P S

    1997-06-01

    Almost since the invention of the laser, frequency conversion of optical pulses via non- linear processes has been an area of active interest. However, third harmonic generation using ~(~1 (THG) in solids is an area that has not received much attention because of ma- terial damage limits. Recently, the short, high-intensity pulses possible with chirped-pulse amplification (CPA) laser systems allow the use of intensities on the order of 1 TW/cm2 in thin solids without damage. As a light source to examine single-crystal THG in solids and other high field inter- actions, the design and construction of a Ti:sapphire-based CPA laser system capable of ultimately producing peak powers of 100 TW is presented. Of special interest is a novel, all-reflective pulse stretcher design which can stretch a pulse temporally by a factor of 20,000. The stretcher design can also compensate for the added material dispersion due to propagation through the amplifier chain and produce transform-limited 45 fs pulses upon compression. A series of laser-pumped amplifiers brings the peak power up to the terawatt level at 10 Hz, and the design calls for additional amplifiers to bring the power level to the 100 TW level for single shot operation. The theory for frequency conversion of these short pulses is presented, focusing on conversion to the third harmonic in single crystals of BBO, KD*P, and d-LAP (deuterated I-arginine phosphate). Conversion efficiencies of up to 6% are obtained with 500 fs pulses at 1053 nm in a 3 mm thick BBO crystal at 200 GW/cm 2. Contributions to this process by unphasematched, cascaded second harmonic generation and sum frequency generation are shown to be very significant. The angular relationship between the two orders is used to measure the tensor elements of C = xt3)/4 with Crs = -1.8 x 1O-23 m2/V2 and .15Cri + .54Crs = 4.0 x 1O-23 m2/V2. Conversion efficiency in d-LAP is about 20% that in BBO and conversion efficiency in KD*P is 1% that of BBO. It is calculated

  19. Vibro-Shock Dynamics Analysis of a Tandem Low Frequency Resonator—High Frequency Piezoelectric Energy Harvester

    Directory of Open Access Journals (Sweden)

    Darius Žižys

    2017-04-01

    Full Text Available Frequency up-conversion is a promising technique for energy harvesting in low frequency environments. In this approach, abundantly available environmental motion energy is absorbed by a Low Frequency Resonator (LFR which transfers it to a high frequency Piezoelectric Vibration Energy Harvester (PVEH via impact or magnetic coupling. As a result, a decaying alternating output signal is produced, that can later be collected using a battery or be transferred directly to the electric load. The paper reports an impact-coupled frequency up-converting tandem setup with different LFR to PVEH natural frequency ratios and varying contact point location along the length of the harvester. RMS power output of different frequency up-converting tandems with optimal resistive values was found from the transient analysis revealing a strong relation between power output and LFR-PVEH natural frequency ratio as well as impact point location. Simulations revealed that higher power output is obtained from a higher natural frequency ratio between LFR and PVEH, an increase of power output by one order of magnitude for a doubled natural frequency ratio and up to 150% difference in power output from different impact point locations. The theoretical results were experimentally verified.

  20. High frequency flow-structural interaction in dense subsonic fluids

    Science.gov (United States)

    Liu, Baw-Lin; Ofarrell, J. M.

    1995-01-01

    Prediction of the detailed dynamic behavior in rocket propellant feed systems and engines and other such high-energy fluid systems requires precise analysis to assure structural performance. Designs sometimes require placement of bluff bodies in a flow passage. Additionally, there are flexibilities in ducts, liners, and piping systems. A design handbook and interactive data base have been developed for assessing flow/structural interactions to be used as a tool in design and development, to evaluate applicable geometries before problems develop, or to eliminate or minimize problems with existing hardware. This is a compilation of analytical/empirical data and techniques to evaluate detailed dynamic characteristics of both the fluid and structures. These techniques have direct applicability to rocket engine internal flow passages, hot gas drive systems, and vehicle propellant feed systems. Organization of the handbook is by basic geometries for estimating Strouhal numbers, added mass effects, mode shapes for various end constraints, critical onset flow conditions, and possible structural response amplitudes. Emphasis is on dense fluids and high structural loading potential for fatigue at low subsonic flow speeds where high-frequency excitations are possible. Avoidance and corrective measure illustrations are presented together with analytical curve fits for predictions compiled from a comprehensive data base.

  1. Exact, multiple soliton solutions of the double sine Gordon equation

    International Nuclear Information System (INIS)

    Burt, P.B.

    1978-01-01

    Exact, particular solutions of the double sine Gordon equation in n dimensional space are constructed. Under certain restrictions these solutions are N solitons, where N <= 2q - 1 and q is the dimensionality of space-time. The method of solution, known as the base equation technique, relates solutions of nonlinear partial differential equations to solutions of linear partial differential equations. This method is reviewed and its applicability to the double sine Gordon equation shown explicitly. The N soliton solutions have the remarkable property that they collapse to a single soliton when the wave vectors are parallel. (author)

  2. Abundant Interaction Solutions of Sine-Gordon Equation

    Directory of Open Access Journals (Sweden)

    DaZhao Lü

    2012-01-01

    Full Text Available With the help of computer symbolic computation software (e.g., Maple, abundant interaction solutions of sine-Gordon equation are obtained by means of a constructed Wronskian form expansion method. The method is based upon the forms and structures of Wronskian solutions of sine-Gordon equation, and the functions used in the Wronskian determinants do not satisfy linear partial differential equations. Such interaction solutions are difficultly obtained via other methods. And the method can be automatically carried out in computer.

  3. Proton-irradiation technology for high-frequency high-current silicon welding diode manufacturing

    International Nuclear Information System (INIS)

    Lagov, P B; Drenin, A S; Zinoviev, M A

    2017-01-01

    Different proton irradiation regimes were tested to provide more than 20 kHz-frequency, soft reverse recovery “snap-less” behavior, low forward voltage drop and leakage current for 50 mm diameter 7 kA/400 V welding diode Al/Si/Mo structure. Silicon diode with such parameters is very suitable for high frequency resistance welding machines of new generation for robotic welding. (paper)

  4. Proton-irradiation technology for high-frequency high-current silicon welding diode manufacturing

    Science.gov (United States)

    Lagov, P. B.; Drenin, A. S.; Zinoviev, M. A.

    2017-05-01

    Different proton irradiation regimes were tested to provide more than 20 kHz-frequency, soft reverse recovery “snap-less” behavior, low forward voltage drop and leakage current for 50 mm diameter 7 kA/400 V welding diode Al/Si/Mo structure. Silicon diode with such parameters is very suitable for high frequency resistance welding machines of new generation for robotic welding.

  5. Design and development of high voltage and high frequency center tapped transformer for HVDC test generator

    International Nuclear Information System (INIS)

    Thaker, Urmil; Saurabh Kumar; Amal, S.; Baruah, U.K.; Bhatt, Animesh

    2015-01-01

    A High Voltage center tapped transformer for high frequency application had been designed, fabricated, and tested. It was designed as a part of 200 kV HVDC Test Generator. The High Frequency operation of transformer increases power density. Therefore it is possible to reduce power supply volume. The step up ratio in High Voltage transformer is limited due to stray capacitance and leakage inductance. The limit was overcome by winding multi secondary outputs. Switching frequency of transformer was 15.8 kHz. Input and output voltages of transformer were 270V and 16.5kV-0V-16.5kV respectively. Power rating of transformer is 7kVA. High Voltage transformer with various winding and core arrangement was fabricated to check variation in electrical characteristics. The transformer used a ferrite core (E Type) and nylon insulated primary and secondary bobbins. Two set of E-E geometry cores had been stacked in order to achieve the estimated core volume. Compared with traditional high voltage transformer, this transformer had good thermal behavior, good line insulation properties and a high power density. In this poster, design procedures, development stages and test results of high voltage and high frequency transformer are presented. Results of various parameters such as transformer loss, temperature rise, insulation properties, impedance of primary and secondary winding, and voltage regulation are discussed. (author)

  6. 5S rRNA-derived and tRNA-derived SINEs in fruit bats.

    Science.gov (United States)

    Gogolevsky, Konstantin P; Vassetzky, Nikita S; Kramerov, Dmitri A

    2009-05-01

    Most short retroposons (SINEs) descend from cellular tRNA of 7SL RNA. Here, four new SINEs were found in megabats (Megachiroptera) but neither in microbats nor in other mammals. Two of them, MEG-RS and MEG-RL, descend from another cellular RNA, 5S rRNA; one (MEG-T2) is a tRNA-derived SINE; and MEG-TR is a hybrid tRNA/5S rRNA SINE. Insertion locus analysis suggests that these SINEs were active in the recent fruit bat evolution. Analysis of MEG-RS and MEG-RL in comparison with other few 5S rRNA-derived SINEs demonstrates that the internal RNA polymerase III promoter is their most invariant region, while the secondary structure is more variable. The mechanisms underlying the modular structure of these and other SINEs as well as their variation are discussed. The scenario of evolution of MEG SINEs is proposed.

  7. High-frequency TRNS reduces BOLD activity during visuomotor learning.

    Directory of Open Access Journals (Sweden)

    Catarina Saiote

    Full Text Available Transcranial direct current stimulation (tDCS and transcranial random noise stimulation (tRNS consist in the application of electrical current of small intensity through the scalp, able to modulate perceptual and motor learning, probably by changing brain excitability. We investigated the effects of these transcranial electrical stimulation techniques in the early and later stages of visuomotor learning, as well as associated brain activity changes using functional magnetic resonance imaging (fMRI. We applied anodal and cathodal tDCS, low-frequency and high-frequency tRNS (lf-tRNS, 0.1-100 Hz; hf-tRNS 101-640 Hz, respectively and sham stimulation over the primary motor cortex (M1 during the first 10 minutes of a visuomotor learning paradigm and measured performance changes for 20 minutes after stimulation ceased. Functional imaging scans were acquired throughout the whole experiment. Cathodal tDCS and hf-tRNS showed a tendency to improve and lf-tRNS to hinder early learning during stimulation, an effect that remained for 20 minutes after cessation of stimulation in the late learning phase. Motor learning-related activity decreased in several regions as reported previously, however, there was no significant modulation of brain activity by tDCS. In opposition to this, hf-tRNS was associated with reduced motor task-related-activity bilaterally in the frontal cortex and precuneous, probably due to interaction with ongoing neuronal oscillations. This result highlights the potential of lf-tRNS and hf-tRNS to differentially modulate visuomotor learning and advances our knowledge on neuroplasticity induction approaches combined with functional imaging methods.

  8. Grid Cell Relaxation Effects on the High Frequency Vibration Characteristics

    International Nuclear Information System (INIS)

    Ryu, Joo-Young; Eom, Kyong-Bo; Jeon, Sang-Youn; Kim, Jae-Ik

    2015-01-01

    The plate structure of the grid of fuel assembly is always exposed to serious vortex induced vibration. Also, High Frequency flow induced Vibration (HFV) is primarily generated by vortex-shedding effect. When it comes to grid design as a fuel assembly component, HFV should be considered in advance since it is one of the critical factors. Excessive HFV has a possibility of making degradation of the fuel reliability that is directly related to the fuel robustness and operating performance. KEPCO NF (KNF) has performed HFV tests with various grid designs. While studying the HFV characteristics through the HFV tests, it has been observed that HFV amplitudes show different levels according to grid cell relaxation. It means that the testing could give different interpretations due to the condition of grid cell. Since the amount of relaxation is different under operating conditions and environments in a reactor, test specimens should be modified as much as possible to the real state of the fuel. Therefore, in order to consider the grid cell relaxation effects on the HFV tests, it is important to use cell sized or non-cell sized grids. The main focus of this study is to find out how the HFV characteristics such as amplitude and frequency are affected by grid cell relaxation. Three cases of the grid cell sized specimen which is nickel alloy were prepared and tested. Through the comparison of the test results, it could be concluded that HFV amplitudes show decreasing trend according to the grid cell relaxation in the case of nickel alloy grid. It is also possible to expect the tendency of grid cell relaxation of a zirconium alloy grid based on test results

  9. 1.25  GHz sine wave gating InGaAs/InP single-photon detector with a monolithically integrated readout circuit.

    Science.gov (United States)

    Jiang, Wen-Hao; Liu, Jian-Hong; Liu, Yin; Jin, Ge; Zhang, Jun; Pan, Jian-Wei

    2017-12-15

    InGaAs/InP single-photon detectors (SPDs) are the key devices for applications requiring near-infrared single-photon detection. The gating mode is an effective approach to synchronous single-photon detection. Increasing gating frequency and reducing the module size are important challenges for the design of such a detector system. Here we present for the first time, to the best of our knowledge, an InGaAs/InP SPD with 1.25 GHz sine wave gating (SWG) using a monolithically integrated readout circuit (MIRC). The MIRC has a size of 15  mm×15  mm and implements the miniaturization of avalanche extraction for high-frequency SWG. In the MIRC, low-pass filters and a low-noise radio frequency amplifier are integrated based on the technique of low temperature co-fired ceramic, which can effectively reduce the parasitic capacitance and extract weak avalanche signals. We then characterize the InGaAs/InP SPD to verify the functionality and reliability of the MIRC, and the SPD exhibits excellent performance with 27.5% photon detection efficiency, a 1.2 kcps dark count rate, and 9.1% afterpulse probability at 223 K and 100 ns hold-off time. With this MIRC, one can further design miniaturized high-frequency SPD modules that are highly required for practical applications.

  10. FPGA implementation of high-frequency multiple PWM for variable voltage variable frequency controller

    Energy Technology Data Exchange (ETDEWEB)

    Boumaaraf, Abdelâali, E-mail: aboumaaraf@yahoo.fr [Université Abbès Laghrour, Laboratoire des capteurs, Instrumentations et procédés (LCIP), Khenchela (Algeria); University of Farhat Abbas Setif1, Sétif, 19000 (Algeria); Mohamadi, Tayeb [University of Farhat Abbas Setif1, Sétif, 19000 (Algeria); Gourmat, Laïd [Université Abbès Laghrour, Khenchela, 40000 (Algeria)

    2016-07-25

    In this paper, we present the FPGA implementation of the multiple pulse width modulation (MPWM) signal generation with repetition of data segments, applied to the variable frequency variable voltage systems and specially at to the photovoltaic water pumping system, in order to generate a signal command very easily between 10 Hz to 60 Hz with a small frequency and reduce the cost of the control system.

  11. Low temperature high frequency coaxial pulse tube for space application

    Energy Technology Data Exchange (ETDEWEB)

    Charrier, Aurelia; Charles, Ivan; Rousset, Bernard; Duval, Jean-Marc [SBT, UMR-E CEA / UJF-Grenoble 1, INAC, 17, rue des Martyrs, Grenoble, F-38054 (France); Daniel, Christophe [CNES, 18, avenue Edouard Belin, Toulouse, F-31401 (France)

    2014-01-29

    The 4K stage is a critical step for space missions. The Hershel mission is using a helium bath, which is consumed day by day (after depletion, the space mission is over) while the Plank mission is equipped with one He4 Joule-Thomson cooler. Cryogenic chain without helium bath is a challenge for space missions and 4.2K Pulse-Tube working at high frequency (around 30Hz) is one option to take it up. A low temperature Pulse-Tube would be suitable for the ESA space mission EChO (Exoplanet Characterisation Observatory, expected launch in 2022), which requires around 30mW cooling power at 6K; and for the ESA space mission ATHENA (Advanced Telescope for High ENergy Astrophysics), to pre-cool the sub-kelvin cooler (few hundreds of mW at 15K). The test bench described in this paper combines a Gifford-McMahon with a coaxial Pulse-Tube. A thermal link is joining the intercept of the Pulse-Tube and the second stage of the Gifford-McMahon. This intercept is a separator between the hot and the cold regenerators of the Pulse-Tube. The work has been focused on the cold part of this cold finger. Coupled with an active phase shifter, this Pulse-Tube has been tested and optimized and temperatures as low as 6K have been obtained at 30Hz with an intercept temperature at 20K.

  12. Fantoni’s Tracheostomy using Catheter High Frequency Jet Ventilation

    Directory of Open Access Journals (Sweden)

    P. Török

    2012-01-01

    Full Text Available Background: It has been shown previously that conventional ventilation delivered through a long cuffed endotracheal tube is associated with a high flow-resistance and frequent perioperative complications. Aim: We attempted to supersede the conventional ventilation by high-frequency jet ventilation through a catheter (HFJV-C and assess safety of the procedure. Material and methods: Using a translaryngeal tracheostomy kit, we performed a translaryngeal (Fantoni tracheostomy (TLT. Subsequently, we introduced a special 2-way prototype ventilatory catheter into the trachea via the TLT under bronchoscopic control. Satisfactory HFJV-C ventilation through the catheter was achieved in 218 patients. Results: There were no significant adverse effects on vital signs observed in the cohort during the study. The pH, SpO2, PaO2, and PaCO2 did not change significantly following the HFJV-C. The intrinsic PEEPi measured in trachea did not exceed 4—5 cm H2O during its application, which was significantly less than during the classical ventilation via the endotracheal tube fluctuating between 12 and 17 cm H2O. No serious medical complications occurred. Conclusion: The HFJV during Fantoni’s tracheostomy using the catheter HFJV-C proved to be a safe and effective method of lung ventilation at the intensive care unit. Key words: Translaryngeal tracheostomy, HFJV via catheter.

  13. Velocity field measurements on high-frequency, supersonic microactuators

    Science.gov (United States)

    Kreth, Phillip A.; Ali, Mohd Y.; Fernandez, Erik J.; Alvi, Farrukh S.

    2016-05-01

    The resonance-enhanced microjet actuator which was developed at the Advanced Aero-Propulsion Laboratory at Florida State University is a fluidic-based device that produces pulsed, supersonic microjets by utilizing a number of microscale, flow-acoustic resonance phenomena. The microactuator used in this study consists of an underexpanded source jet that flows into a cylindrical cavity with a single, 1-mm-diameter exhaust orifice through which an unsteady, supersonic jet issues at a resonant frequency of 7 kHz. The flowfields of a 1-mm underexpanded free jet and the microactuator are studied in detail using high-magnification, phase-locked flow visualizations (microschlieren) and two-component particle image velocimetry. These are the first direct measurements of the velocity fields produced by such actuators. Comparisons are made between the flow visualizations and the velocity field measurements. The results clearly show that the microactuator produces pulsed, supersonic jets with velocities exceeding 400 m/s for roughly 60 % of their cycles. With high unsteady momentum output, this type of microactuator has potential in a range of ow control applications.

  14. High frequency guided wave propagation in monocrystalline silicon wafers

    Science.gov (United States)

    Pizzolato, Marco; Masserey, Bernard; Robyr, Jean-Luc; Fromme, Paul

    2017-04-01

    Monocrystalline silicon wafers are widely used in the photovoltaic industry for solar panels with high conversion efficiency. The cutting process can introduce micro-cracks in the thin wafers and lead to varying thickness. High frequency guided ultrasonic waves are considered for the structural monitoring of the wafers. The anisotropy of the monocrystalline silicon leads to variations of the wave characteristics, depending on the propagation direction relative to the crystal orientation. Full three-dimensional Finite Element simulations of the guided wave propagation were conducted to visualize and quantify these effects for a line source. The phase velocity (slowness) and skew angle of the two fundamental Lamb wave modes (first anti-symmetric mode A0 and first symmetric mode S0) for varying propagation directions relative to the crystal orientation were measured experimentally. Selective mode excitation was achieved using a contact piezoelectric transducer with a custom-made wedge and holder to achieve a controlled contact pressure. The out-of-plane component of the guided wave propagation was measured using a noncontact laser interferometer. Good agreement was found with the simulation results and theoretical predictions based on nominal material properties of the silicon wafer.

  15. Optical Transmitter Terminal for Selective RF High Frequency Bans

    Data.gov (United States)

    National Aeronautics and Space Administration — Recent improvements in multiplexing systems and tunable laser semiconductor diodes make the use of Wavelength Division Multiplexing to combine multiple frequency...

  16. Adequacy of Frequency Reserves for High Wind Power Generation

    DEFF Research Database (Denmark)

    Das, Kaushik; Litong-Palima, Marisciel; Maule, Petr

    2017-01-01

    In this article, a new methodology is developed to assess the adequacy of frequency reserves to handle power imbalances caused by wind power forecast errors. The goal of this methodology is to estimate the adequate volume and speed of activation of frequency reserves required to handle power...

  17. A high frequency, high power CARM proposal for the DEMO ECRH system

    International Nuclear Information System (INIS)

    Mirizzi, Francesco; Spassovsky, Ivan; Ceccuzzi, Silvio; Dattoli, Giuseppe; Di Palma, Emanuele; Doria, Andrea; Gallerano, Gianpiero; Lampasi, Alessandro; Maffia, Giuseppe; Ravera, GianLuca; Sabia, Elio; Tuccillo, Angelo Antonio; Zito, Pietro

    2015-01-01

    Highlights: • ECRH system for DEMO. • Cyclotron Auto-Resonance Maser (CARM) devices. • Relativistic electron beams. • Bragg reflectors. • High voltage pulse modulators. - Abstract: ECRH&CD systems are extensively used on tokamak plasmas due to their capability of highly tailored power deposition, allowing very localised heating and non-inductive current drive, useful for MHD and profiles control. The high electron temperatures expected in DEMO will require ECRH systems with operating frequency in the 200–300 GHz range, equipped with a reasonable number of high power (P ≥ 1 MW) CW RF sources, for allowing central RF power deposition. In this frame the ENEA Fusion Department (Frascati) is coordinating a task force aimed at the study and realisation of a suitable high power, high frequency reliable source.

  18. A high frequency, high power CARM proposal for the DEMO ECRH system

    Energy Technology Data Exchange (ETDEWEB)

    Mirizzi, Francesco, E-mail: francesco.mirizzi@enea.it [Consorzio CREATE, Via Claudio 21, I-80125 Napoli (Italy); Spassovsky, Ivan [Unità Tecnica Applicazioni delle Radiazioni – ENEA, C.R. Frascati, via E. Fermi 45, I-00044 Frascati (Italy); Ceccuzzi, Silvio [Unità Tecnica Fusione – ENEA C. R. Frascati, via E. Fermi 45, 00044 Frascati, Roma (Italy); Dattoli, Giuseppe; Di Palma, Emanuele; Doria, Andrea; Gallerano, Gianpiero [Unità Tecnica Applicazioni delle Radiazioni – ENEA, C.R. Frascati, via E. Fermi 45, I-00044 Frascati (Italy); Lampasi, Alessandro; Maffia, Giuseppe; Ravera, GianLuca [Unità Tecnica Fusione – ENEA C. R. Frascati, via E. Fermi 45, 00044 Frascati, Roma (Italy); Sabia, Elio [Unità Tecnica Applicazioni delle Radiazioni – ENEA, C.R. Frascati, via E. Fermi 45, I-00044 Frascati (Italy); Tuccillo, Angelo Antonio; Zito, Pietro [Unità Tecnica Fusione – ENEA C. R. Frascati, via E. Fermi 45, 00044 Frascati, Roma (Italy)

    2015-10-15

    Highlights: • ECRH system for DEMO. • Cyclotron Auto-Resonance Maser (CARM) devices. • Relativistic electron beams. • Bragg reflectors. • High voltage pulse modulators. - Abstract: ECRH&CD systems are extensively used on tokamak plasmas due to their capability of highly tailored power deposition, allowing very localised heating and non-inductive current drive, useful for MHD and profiles control. The high electron temperatures expected in DEMO will require ECRH systems with operating frequency in the 200–300 GHz range, equipped with a reasonable number of high power (P ≥ 1 MW) CW RF sources, for allowing central RF power deposition. In this frame the ENEA Fusion Department (Frascati) is coordinating a task force aimed at the study and realisation of a suitable high power, high frequency reliable source.

  19. Construction of a dog training device with high frequency and high power pulses

    International Nuclear Information System (INIS)

    Viaud Trejos, Rafael Alfonso

    2013-01-01

    An electronic device is built to produce high frequency and high power sound. The device is used in training and control of dogs. Commercial ultrasonic devices used for dog training are analyzed. The best strategies and components of the design are determined from an electronic device to produce sounds in frequency from 15kHz to 50Khz. Effectiveness tests are performed to establish the adequate design of the ultrasonic electronic device. The test results are analyzed to find opportunities of improvement in the design or construction of the device [es

  20. The potential for very high-frequency gravitational wave detection

    International Nuclear Information System (INIS)

    Cruise, A M

    2012-01-01

    The science case for observing gravitational waves at frequencies in the millihertz-kilohertz range using LIGO, VIRGO, GEO600 or LISA is very strong and the first results are expected at these frequencies. However, as gravitational wave astronomy progresses beyond the first detections, other frequency bands may be worth exploring. Early predictions of gravitational wave emission from discrete sources at very much higher frequencies (megahertz and above) have been published and more recent studies of cosmological signals from inflation, Kaluza-Klein modes from gravitational interactions in brane worlds and plasma instabilities surrounding violent astrophysical events, are all possible sources. This communication examines current observational possibilities and the detector technology required to make meaningful observations at these frequencies. (paper)

  1. A note on the three dimensional sine--Gordon equation

    OpenAIRE

    Shariati, Ahmad

    1996-01-01

    Using a simple ansatz for the solutions of the three dimensional generalization of the sine--Gordon and Toda model introduced by Konopelchenko and Rogers, a class of solutions is found by elementary methods. It is also shown that these equations are not evolution equations in the sense that solution to the initial value problem is not unique.

  2. On Darboux transformation of the supersymmetric sine-Gordon equation

    International Nuclear Information System (INIS)

    Siddiq, M; Hassan, M; Saleem, U

    2006-01-01

    Darboux transformation is constructed for superfields of the super sine-Gordon equation and the superfields of the associated linear problem. The Darboux transformation is shown to be related to the super Baecklund transformation and is further used to obtain N super soliton solutions

  3. Phonons and solitons in the "thermal" sine-Gordon system

    DEFF Research Database (Denmark)

    Salerno, Mario; Jørgensen, E.; Samuelsen, Mogens Rugholm

    1984-01-01

    Standard methods of stochastic processes are used to study the coupling of the sine-Gordon system with a heat reservoir. As a result we find thermal phonons with an average energy of kB T per mode. The translational mode (zero mode) is found to carry an average energy of 1 / 2kBT. This last value...

  4. Experimental Investigation of Trapped Sine-Gordon Solitons

    DEFF Research Database (Denmark)

    Davidson, A.; Dueholm, B.; Kryger, B.

    1985-01-01

    We have observed for the first time a single sine-Gordon soliton trapped in an annular Josephson junction. This system offers a unique possibility to study undisturbed soliton motion. In the context of perturbation theory, the soliton may be viewed as a relativistic particle moving under a uniform...

  5. Soliton annihilation in the perturbed sine-Gordon system

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Samuelsen, Mogens Rugholm; Welner, D.

    1984-01-01

    Fluxon-antifluxon annihilation in the perturbed sine-Gordon equation with loss and driving terms is investigated. For the infinite line we find a simple analytic expression for the threshold driving term corresponding to annihilation. With the application of the results to a Josephson junction...

  6. Boson-soliton scattering in the sine-Gordon model

    International Nuclear Information System (INIS)

    Lowe, M.

    1979-01-01

    In this paper the author calculates the boson-soliton scattering amplitudes for various processes in the sine-Gordon model to obtain results in agreement with the prediction of no-particle production and equality of ingoing and outgoing sets of momenta. (Auth.)

  7. Quantum Hall bilayers and the chiral sine-Gordon equation

    International Nuclear Information System (INIS)

    Naud, J.D.; Pryadko, Leonid P.; Sondhi, S.L.

    2000-01-01

    The edge state theory of a class of symmetric double-layer quantum Hall systems with interlayer electron tunneling reduces to the sum of a free field theory and a field theory of a chiral Bose field with a self-interaction of the sine-Gordon form. We argue that the perturbative renormalization group flow of this chiral sine-Gordon theory is distinct from the standard (non-chiral) sine-Gordon theory, contrary to a previous assertion by Renn, and that the theory is manifestly sensible only at a discrete set of values of the inverse period of the cosine interaction (β-circumflex). We obtain exact solutions for the spectra and correlation functions of the chiral sine-Gordon theory at the two values of β-circumflex at which electron tunneling in bilayers is not irrelevant. Of these, the marginal case (β-circumflex 2 =4) is of greatest interest: the spectrum of the interacting theory is that of two Majorana fermions with different, dynamically generated, velocities. For the experimentally observed bilayer 331 state at filling factor 1/2, this implies the trifurcation of electrons added to the edge. We also present a method for fermionizing the theory at the discrete points (β-circumflex 2 is an element of Z + ) by the introduction of auxiliary degrees of freedom that could prove useful in other problems involving quantum Hall multi-layers

  8. Explicitly solvable complex Chebyshev approximation problems related to sine polynomials

    Science.gov (United States)

    Freund, Roland

    1989-01-01

    Explicitly solvable real Chebyshev approximation problems on the unit interval are typically characterized by simple error curves. A similar principle is presented for complex approximation problems with error curves induced by sine polynomials. As an application, some new explicit formulae for complex best approximations are derived.

  9. Prediction and phylogenetic analysis of mammalian short interspersed elements (SINEs).

    Science.gov (United States)

    Rogozin, I B; Mayorov, V I; Lavrentieva, M V; Milanesi, L; Adkison, L R

    2000-09-01

    The presence of repetitive elements can create serious problems for sequence analysis, especially in the case of homology searches in nucleotide sequence databases. Repetitive elements should be treated carefully by using special programs and databases. In this paper, various aspects of SINE (short interspersed repetitive element) identification, analysis and evolution are discussed.

  10. Perturbation analysis of a parametrically changed sine-Gordon equation

    DEFF Research Database (Denmark)

    Sakai, S.; Samuelsen, Mogens Rugholm; Olsen, O. H.

    1987-01-01

    A long Josephson junction with a spatially varying inductance is a physical manifestation of a modified sine-Gordon equation with parametric perturbation. Soliton propagation in such Josephson junctions is discussed. First, for an adiabatic model where the inductance changes smoothly compared...

  11. Rotationally symmetric numerical solutions to the sine-Gordon equation

    DEFF Research Database (Denmark)

    Olsen, O. H.; Samuelsen, Mogens Rugholm

    1981-01-01

    We examine numerically the properties of solutions to the spherically symmetric sine-Gordon equation given an initial profile which coincides with the one-dimensional breather solution and refer to such solutions as ring waves. Expanding ring waves either exhibit a return effect or expand towards...

  12. The Sine Method: An Alternative Height Measurement Technique

    Science.gov (United States)

    Don C. Bragg; Lee E. Frelich; Robert T. Leverett; Will Blozan; Dale J. Luthringer

    2011-01-01

    Height is one of the most important dimensions of trees, but few observers are fully aware of the consequences of the misapplication of conventional height measurement techniques. A new approach, the sine method, can improve height measurement by being less sensitive to the requirements of conventional techniques (similar triangles and the tangent method). We studied...

  13. Homoclinic tubes and chaos in perturbed sine-Gordon equation

    International Nuclear Information System (INIS)

    Li, Y. Charles

    2004-01-01

    Sine-Gordon equation under a quasi-periodic perturbation or a chaotic perturbation is studied. Existence of a homoclinic tube is proved. Established are chaos associated with the homoclinic tube, and 'chaos cascade' referring to the embeddings of smaller scale chaos in larger scale chaos

  14. The sine-Gordon model in the presence of defects

    International Nuclear Information System (INIS)

    Avan, Jean; Doikou, Anastasia

    2013-01-01

    The sine-Gordon model in the presence of dynamical integrable defects is investigated. This is an application of the algebraic formulation introduced for integrable defects in earlier works. The quantities in involution as well as the associated Lax pairs are explicitly extracted. Integrability i also shown using certain sewing constraints, which emerge as suitable continuity conditions.

  15. Swept-sine noise-induced damage as a hearing loss model for preclinical assays

    Directory of Open Access Journals (Sweden)

    Lorena eSanz

    2015-02-01

    Full Text Available Mouse models are key tools for studying cochlear alterations in noise-induced hearing loss and for evaluating new therapies. Stimuli used to induce deafness in mice are usually white and octave band noises that include very low frequencies, considering the large mouse auditory range. We designed different sound stimuli, enriched in frequencies up to 20 kHz (violet noises to examine their impact on hearing thresholds and cochlear cytoarchitecture after short exposure. In addition, we developed a cytocochleogram to quantitatively assess the ensuing structural degeneration and its functional correlation. Finally, we used this mouse model and cochleogram procedure to evaluate the potential therapeutic effect of transforming growth factor β1 inhibitors P17 and P144 on noise-induced hearing loss. CBA mice were exposed to violet swept-sine noise with different frequency ranges (2-20 or 9-13 kHz and levels (105 or 120 dB SPL for 30 minutes. Mice were evaluated by auditory brainstem response and otoacoustic emission tests prior to and 2, 14 and 28 days after noise exposure. Cochlear pathology was assessed with gross histology; hair cell number was estimated by a stereological counting method. Our results indicate that functional and morphological changes induced by violet swept-sine noise depend on the sound level and frequency composition. Partial hearing recovery followed the exposure to 105 dB SPL, whereas permanent cochlear damage resulted from the exposure to 120 dB SPL. Exposure to 9-13 kHz noise caused an auditory threshold shift in those frequencies that correlated with hair cell loss in the corresponding areas of the cochlea that were spotted on the cytocochleogram. In summary, we present mouse models of noise-induced hearing loss, which depending on the sound properties of the noise, cause different degrees of cochlear damage, and could therefore be used to study molecules which are potential players in hearing loss protection and repair.

  16. Challenges in graphene integration for high-frequency electronics

    Science.gov (United States)

    Giannazzo, F.; Fisichella, G.; Greco, G.; Roccaforte, F.

    2016-06-01

    This paper provides an overview of the state-of-the-art research on graphene (Gr) for high-frequency (RF) devices. After discussing current limitations of lateral Gr RF transistors, novel vertical devices concepts such as the Gr Base Hot Electron Transistor (GBHET) will be introduced and the main challenges in Gr integration within these architectures will be discussed. In particular, a GBHET device based on Gr/AlGaN/GaN heterostructure will be considered. An approach to the fabrication of this heterostructure by transfer of CVD grown Gr on copper to the AlGaN surface will be presented. The morphological and electrical properties of this system have been investigated at nanoscale by atomic force microscopy (AFM) and conductive atomic force microscopy (CAFM). In particular, local current-voltage measurements by the CAFM probe revealed the formation of a Schottky contact with low barrier height (˜0.41 eV) and excellent lateral uniformity between Gr and AlGaN. Basing on the electrical parameters extracted from this characterization, the theoretical performances of a GBHET formed by a metal/Al2O3/Gr/AlGaN/GaN stack have been evaluated.

  17. Three-Dimensional Electromagnetic High Frequency Axisymmetric Cavity Scars.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry Kevin; Jorgenson, Roy Eberhardt

    2014-10-01

    This report examines the localization of high frequency electromagnetic fi elds in three-dimensional axisymmetric cavities along periodic paths between opposing sides of the cavity. The cases where these orbits lead to unstable localized modes are known as scars. This report treats both the case where the opposing sides, or mirrors, are convex, where there are no interior foci, and the case where they are concave, leading to interior foci. The scalar problem is treated fi rst but the approximations required to treat the vector fi eld components are also examined. Particular att ention is focused on the normalization through the electromagnetic energy theorem. Both projections of the fi eld along the scarred orbit as well as point statistics are examined. Statistical comparisons are m ade with a numerical calculation of the scars run with an axisymmetric simulation. This axisymmetric cas eformstheoppositeextreme(wherethetwomirror radii at each end of the ray orbit are equal) from the two -dimensional solution examined previously (where one mirror radius is vastly di ff erent from the other). The enhancement of the fi eldontheorbitaxiscanbe larger here than in the two-dimensional case. Intentionally Left Blank

  18. Algorithmic and high-frequency trading in Borsa Istanbul

    Directory of Open Access Journals (Sweden)

    Oguz Ersan

    2016-12-01

    Full Text Available This paper investigates the levels of algorithmic trading (AT and high-frequency trading (HFT in an emerging market, Borsa Istanbul (BIST, utilizing a dataset of 354 trading days between January 2013 and May 2014. We find an upward trend in AT by using common proxies: number of messages per minute and algo_trad of Hendershott et al. (2011. Mean algo_trad for BIST 100 index constituents varies between −18 and −13 which is parallel to 2003–2005 levels of NASDAQ large cap stocks. Initially, we measure HFT involvement by detecting linked messages as in the way proposed in Hasbrouck and Saar (2013. Next, we propose an extended HFT measure which captures various HFT strategies. This measure attributes approximately 6% of the orders to HFT. HFT involvement is higher in large orders (11.96%, in orders submitted by portfolio/fund management firms (10.40%, after improvement of BIST's order submission platform and tick size reduction for certain stocks.

  19. High-Frequency Chest Compression: A Summary of the Literature

    Directory of Open Access Journals (Sweden)

    Cara F Dosman

    2005-01-01

    Full Text Available The purpose of the present literature summary is to describe high-frequency chest compression (HFCC, summarize its history and outline study results on its effect on mucolysis, mucus transport, pulmonary function and quality of life. HFCC is a mechanical method of self-administered chest physiotherapy, which induces rapid air movement in and out of the lungs. This mean oscillated volume is an effective method of mucolysis and mucus clearance. HFCC can increase independence. Some studies have shown that HFCC leads to more mucus clearance and better lung function compared with conventional chest physiotherapy. However, HFCC also decreases end-expiratory lung volume, which can lead to increased airway resistance and a decreased oscillated volume. Adding positive end-expiratory pressure to HFCC has been shown to prevent this decrease in end-expiratory lung volume and to increase the oscillated volume. It is possible that the HFCC-induced decrease in end-expiratory lung volume may result in more mucus clearance in airways that remain open by reducing airway size. Adjunctive methods, such as positive end-expiratory pressure, may not always be needed to make HFCC more effective.

  20. High-frequency, transient magnetic susceptibility of ferroelectrics

    Science.gov (United States)

    Grimes, Craig A.

    1996-10-01

    A significant high-frequency magnetic susceptibility was measured both in weakly polarized and nonpolarized samples of barium titanate, lead zirconate titanate, and carnauba wax. Magnetic susceptibility measurements were made from 10 to 500 MHz using a thin film permeameter at room temperature; initial susceptibilities ranged from 0.1 to 2.5. These values are larger than expected for paramagnets and smaller than expected for ferromagnets. It was found that the magnetic susceptibility decreases rapidly with exposure to the exciting field. The origin of the magnetic susceptibility is thought to originate with the applied time varying electric field associated with the susceptibility measurements. An electric field acts to rotate an electric dipole, creating a magnetic quadrupole if the two moments are balanced, and a net magnetic dipole moment if imbalanced. It is thought that local electrostatic fields created at ferroelectric domain discontinuities associated with grain boundaries create an imbalance in the anion rotation that results in a net, measurable, magnetic moment. The origin of the magnetic aftereffect may be due to the local heating of the material through the moving charges associated with the magnetic moment.

  1. Improving NASICON Sinterability through Crystallization under High Frequency Electrical Fields

    Directory of Open Access Journals (Sweden)

    Ilya eLisenker

    2016-03-01

    Full Text Available The effect of high frequency (HF electric fields on the crystallization and sintering rates of a lithium aluminum germanium phosphate (LAGP ion conducting ceramic was investigated. LAGP with the nominal composition Li1.5Al0.5Ge1.5(PO43 was crystallized and sintered, both conventionally and under effect of electrical field. Electrical field application, of 300V/cm at 1MHz, produced up to a 40% improvement in sintering rate of LAGP that was crystallized and sintered under the HF field. Heat sink effect of the electrodes appears to arrest thermal runaway and subsequent flash behavior. Sintered pellets were characterized using XRD, SEM, TEM and EIS to compare conventionally and field sintered processes. The as-sintered structure appears largely unaffected by the field as the sintering curves tend to converge beyond initial stages of sintering. Differences in densities and microstructure after 1 hour of sintering were minor with measured sintering strains of 31% vs. 26% with and without field, respectively . Ionic conductivity of the sintered pellets was evaluated and no deterioration due to the use of HF field was noted, though capacitance of grain boundaries due to secondary phases was significantly increased.

  2. High-frequency Stark effect and two-quantum transitions

    International Nuclear Information System (INIS)

    Hildebrandt, J

    2007-01-01

    A problem which motivated a great deal of work about 20 years ago, namely, satellite lines occurring for atomic emitters undergoing a harmonic perturbation, is revisited. On a theoretical point of view, two photon mechanisms or equivalent are involved to explain those satellites due to high-frequency electric fields. Although today the activity on these problems is rather low, interest in observing such effects in the domain of x-ray spectroscopy exists, namely for hot and dense plasmas. More generally, satellites can be also seen as connected to turbulence diagnostics. This mainly motivates the design of plasmas and improvements of x-ray spectroscopy techniques. However, up to now, attempts to extend the methods of nonlinear spectroscopy to this domain have been rather disappointing. As a promotion for a resurgence of the field, an improved theory, founded on formalisms of nonlinear optics, is developed to suggest a new interpretation of the experiments. Previous publications are modified and an old problem is closed. Hopefully, this will help us to stimulate new applications of two-photon techniques in plasmas

  3. Ultra high frequency induction welding of powder metal compacts

    Directory of Open Access Journals (Sweden)

    Çavdar, Uǧur

    2014-06-01

    Full Text Available The application of the iron based Powder Metal (PM compacts in Ultra High Frequency Induction Welding (UHFIW were reviewed. These PM compacts are used to produce cogs. This study investigates the methods of joining PM materials enforceability with UHFIW in the industry application. Maximum stress and maximum strain of welded PM compacts were determined by three point bending and strength tests. Microhardness and microstructure of induction welded compacts were determined.Soldadura por inducción de ultra alta frecuencia de polvos de metal compactados. Se ha realizado un estudio de la aplicación de polvos de metal (PM de base hierro compactados por soldadura por inducción de ultra alta frecuencia (UHFIW. Estos polvos de metal compactados se utilizan para producir engranajes. Este estudio investiga los métodos de uni.n de los materiales de PM con UHFIW en su aplicación en la industria. La máxima tensión y la máxima deformación de los polvos de metal compactados soldados fueron determinadas por flexión en tres puntos y prueba de resistencia. Se determinó la microdureza y la microestructura de los polvos compactados por soldadura por inducción.

  4. High-Frequency Gravitational Wave Induced Nuclear Fusion

    International Nuclear Information System (INIS)

    Fontana, Giorgio; Baker, Robert M. L. Jr.

    2007-01-01

    Nuclear fusion is a process in which nuclei, having a total initial mass, combine to produce a single nucleus, having a final mass less than the total initial mass. Below a given atomic number the process is exothermic; that is, since the final mass is less than the combined initial mass and the mass deficit is converted into energy by the nuclear fusion. On Earth nuclear fusion does not happen spontaneously because electrostatic barriers prevent the phenomenon. To induce controlled, industrial scale, nuclear fusion, only a few methods have been discovered that look promising, but net positive energy production is not yet possible because of low overall efficiency of the systems. In this paper we propose that an intense burst of High Frequency Gravitational Waves (HFGWs) could be focused or beamed to a target mass composed of appropriate fuel or target material to efficiently rearrange the atomic or nuclear structure of the target material with consequent nuclear fusion. Provided that efficient generation of HFGW can be technically achieved, the proposed fusion reactor could become a viable solution for the energy needs of mankind and alternatively a process for beaming energy to produce a source of fusion energy remotely - even inside solid materials

  5. High-frequency EPR of surface impurities on nanodiamond

    Science.gov (United States)

    Peng, Zaili; Stepanov, Viktor; Takahashi, Susumu

    Diamond is a fascinating material, hosting nitrogen-vacancy (NV) defect centers with unique magnetic and optical properties. There have been many reports that suggest the existence of paramagnetic impurities near surface of various kinds of diamonds. Electron paramagnetic resonance (EPR) investigation of mechanically crushed nanodiamonds (NDs) as well as detonation NDs revealed g 2 like signals that are attributed to structural defects and dangling bonds near the diamond surface. In this presentation, we investigate paramagnetic impurities in various sizes of NDs using high-frequency (HF) continuous wave (cw) and pulsed EPR spectroscopy. Strong size dependence on the linewidth of HF cw EPR spectra reveals the existence of paramagnetic impurities in the vicinity of the diamond surface. We also study the size dependence of the spin-lattice and spin-spin relaxation times (T1 and T2) of single substitutional nitrogen defects in NDs Significant deviations from the temperature dependence of the phonon-assisted T1 process were observed in the ND samples, and were attributed to the contribution from the surface impurities. This work was supported by the Searle Scholars Program and the National Science Foundation (DMR-1508661 and CHE-1611134).

  6. Design of the ITER high-frequency magnetic diagnostic coils

    International Nuclear Information System (INIS)

    Toussaint, M.; Testa, D.; Baluc, N.; Chavan, R.; Fournier, Y.; Lister, J.B.; Maeder, T.; Marmillod, P.; Sanchez, F.; Stoeck, M.

    2011-01-01

    This paper is an overview of work carried out on the design of the ITER high-frequency magnetic diagnostic coil (HF sensor). In the first part, the ITER requirements for the HF sensor are presented. In the second part, the ITER reference design of the HF sensor has been assessed and showed some potential weaknesses, which led us to the conclusion that alternative designs could usefully be examined. Several options have been explored, and are presented in the third part: (a) direct laser cutting a metallic tube, (b) stacking of plane windings manufactured from a tungsten plate by electrical discharge machining, (c) coil using the conventional spring manufacture. In the fourth part, sensors using the low temperature co-fired ceramic technology (LTCC) are presented: (d) monolithic 1D magnetic flux sensors based on LTCC technology, and (e) monolithic 3D magnetic flux sensors based on the same LTCC technology. The solution which showed the best results is the monolithic 3D magnetic flux sensor based on LTCC.

  7. Bioinformatic analysis of Entamoeba histolytica SINE1 elements

    Directory of Open Access Journals (Sweden)

    Butcher Sarah A

    2010-05-01

    Full Text Available Abstract Background Invasive amoebiasis, caused by infection with the human parasite Entamoeba histolytica remains a major cause of morbidity and mortality in some less-developed countries. Genetically E. histolytica exhibits a number of unusual features including having approximately 20% of its genome comprised of repetitive elements. These include a number of families of SINEs - non-autonomous elements which can, however, move with the help of partner LINEs. In many eukaryotes SINE mobility has had a profound effect on gene expression; in this study we concentrated on one such element - EhSINE1, looking in particular for evidence of recent transposition. Results EhSINE1s were detected in the newly reassembled E. histolytica genome by searching with a Hidden Markov Model developed to encapsulate the key features of this element; 393 were detected. Examination of their sequences revealed that some had an internal structure showing one to four 26-27 nt repeats. Members of the different classes differ in a number of ways and in particular those with two internal repeats show the properties expected of fairly recently transposed SINEs - they are the most homogeneous in length and sequence, they have the longest (i.e. the least decayed target site duplications and are the most likely to show evidence (in a cDNA library of active transcription. Furthermore we were able to identify 15 EhSINE1s (6 pairs and one triplet which appeared to be identical or very nearly so but inserted into different sites in the genome; these provide good evidence that if mobility has now ceased it has only done so very recently. Conclusions Of the many families of repetitive elements present in the genome of E. histolytica we have examined in detail just one - EhSINE1. We have shown that there is evidence for waves of transposition at different points in the past and no evidence that mobility has entirely ceased. There are many aspects of the biology of this parasite which

  8. Detailed Analysis of Torque Ripple in High Frequency Signal Injection based Sensor less PMSM Drives

    Directory of Open Access Journals (Sweden)

    Ravikumar Setty A.

    2017-01-01

    Full Text Available High Frequency Signal Injection based techniques are robust and well proven to estimate the rotor position from stand still to low speed. However, Injected high frequency signal introduces, high frequency harmonics in the motor phase currents and results in significant Output Torque ripple. There is no detailed analysis exist in the literature, to study the effect of injected signal frequency on Torque ripple. Objective of this work is to study the Torque Ripple resulting from High Frequency signal injection in PMSM motor drives. Detailed MATLAB/Simulink simulations are carried to quantify the Torque ripple at different Signal frequencies.

  9. Experimental study of a high intensity radio-frequency cooler

    Directory of Open Access Journals (Sweden)

    Ramzi Boussaid

    2015-07-01

    Full Text Available Within the framework of the DESIR/SPIRAL-2 project, a radio-frequency quadrupole cooler named SHIRaC has been studied. SHIRaC is a key device of SPIRAL-2, designed to enhance the beam quality required by DESIR. The preliminary study and development of this device has been carried out at Laboratoire de Physique Corpusculaire de CAEN (LPC Caen, France. The goal of this paper is to present the experimental studies conducted on a SHIRaC prototype. The main peculiarity of this cooler is its efficient handling and cooling of ion beams with currents going up as high as 1  μA which has never before been achieved in any of the previous coolers. Much effort has been made lately into these studies for development of appropriate optics, vacuum and rf systems which allow cooling of beams of large emittance (∼80π  mm mrad and high current. The dependencies of SHIRaC’s transmission and the cooled beam parameters in terms of geometrical transverse emittance and the longitudinal energy spread have also been discussed. Investigation of beam purity at optimum cooling condition has also been done. Results from the experiments indicate that an emittance reduction of less than 2.5π  mm mrad and a longitudinal energy spread reduction of less than 4 eV are obtained with more than 70% of ion transmission. The emittance is at expected values whereas the energy spread is not.

  10. Tay-Sachs disease: high gene frequency in a non-Jewish population.

    Science.gov (United States)

    Kelly, T E; Chase, G A; Kaback, M M; Kumor, K; McKusick, V A

    1975-01-01

    A non-Amish "Pennsylvania Dutch" semi-isolate was found to have a high frequency of Tay-Sachs gene. This high frequency could be ascribed to founder effect and may represent, in microcosm, how this mechanism could have produced the high gene frequency among Ashkenazi Jews. PMID:803011

  11. Sensitive high frequency hearing in earless and partially eared harlequin frogs ()

    DEFF Research Database (Denmark)

    Womack, Molly C; Christensen-Dalsgaard, Jakob; Coloma, Luis A

    2018-01-01

    Harlequin frogs, genus Atelopus, communicate at high frequencies despite most species lacking a complete tympanic middle ear that facilitates high frequency hearing in most anurans and other tetrapods. Here we test whether Atelopus are better at sensing high frequency acoustic sound compared to o...

  12. The R and D of half-sine pulser for eddy-current septum magnet

    International Nuclear Information System (INIS)

    Fu Luxin; Han Qian; Kang Wen

    2002-01-01

    The SSRF requires high-amplitude half-sine pulse current (10kA) and relatively narrow pulse width (∼60μs) for its eddy-current septum magnets. Moreover the machine will need a very high level of performance from the pulsers, particularly in terms of pulse amplitude stability and regulating range. For the convenience of maintenance the pulsers will be installed in the power supply hall and cabled to their eddy-current septum magnets by RG220/U. The author presents the pulser design and R and D results

  13. The R and D of half-sine pulser for eddy-current septum magnet

    CERN Document Server

    Fu Lu Xin; Kang Wen

    2002-01-01

    The SSRF requires high-amplitude half-sine pulse current (10kA) and relatively narrow pulse width (approx 60 mu s) for its eddy-current septum magnets. Moreover the machine will need a very high level of performance from the pulsers, particularly in terms of pulse amplitude stability and regulating range. For the convenience of maintenance the pulsers will be installed in the power supply hall and cabled to their eddy-current septum magnets by RG220/U. The author presents the pulser design and R and D results

  14. Classical particle-like behavior of Sine--Gordon solitons in scattering potentials and applied fields

    International Nuclear Information System (INIS)

    Fogel, M.B.; Trullinger, S.E.; Bishop, A.R.; Krumhansl, J.A.

    1976-02-01

    We show that classical Sine-Gordon solitons maintain their integrity to a high degree in the presence of external perturbations. Two examples, of particular importance in condensed matter, are described in detail: (i) a model impurity is found to bind low-velocity solitons but merely phase-shift those with high-velocities, (ii) external static driving terms with damping accelerate the soliton to a terminal velocity. The importance of a translation mode is emphasized and it is concluded that the soliton behaves as a classical particle in all essential respects

  15. Compact printed two dipole array antenna with a high front-back ratio for ultra-high-frequency radio-frequency identification handheld reader applications

    DEFF Research Database (Denmark)

    Liu, Qi; Zhang, Shuai; He, Sailing

    2015-01-01

    A printed two-dipole array antenna with a high front-back ratio is proposed for ultra-high-frequency (UHF) radio-frequency identification handheld readers. The proposed antenna is a parasitic dual-element array with the ends of both elements folded back towards each other for additional coupling....

  16. Sine-squared shifted pulses for recoupling interactions in solid-state NMR

    Science.gov (United States)

    Jain, Mukul G.; Rajalakshmi, G.; Equbal, Asif; Mote, Kaustubh R.; Agarwal, Vipin; Madhu, P. K.

    2017-06-01

    Rotational-Echo DOuble-Resonance (REDOR) is a versatile experiment for measuring internuclear distance between two heteronuclear spins in solid-state NMR. At slow to intermediate magic-angle spinning (MAS) frequencies, the measurement of distances between strongly coupled spins is challenging due to rapid dephasing of magnetisation. This problem can be remedied by employing the pulse-shifted version of REDOR known as Shifted-REDOR (S-REDOR) that scales down the recoupled dipolar coupling. In this study, we propose a new variant of the REDOR sequence where the positions of the π pulses are determined by a sine-squared function. This new variant has scaling properties similar to S-REDOR. We use theory, numerical simulations, and experiments to compare the dipolar recoupling efficiencies and the experimental robustness of the three REDOR schemes. The proposed variant has advantages in terms of radiofrequency field requirements at fast MAS frequencies.

  17. Wave parameters comparisons between High Frequency (HF) radar system and an in situ buoy: a case study

    Science.gov (United States)

    Fernandes, Maria; Alonso-Martirena, Andrés; Agostinho, Pedro; Sanchez, Jorge; Ferrer, Macu; Fernandes, Carlos

    2015-04-01

    The coastal zone is an important area for the development of maritime countries, either in terms of recreation, energy exploitation, weather forecasting or national security. Field measurements are in the basis of understanding how coastal and oceanic processes occur. Most processes occur over long timescales and over large spatial ranges, like the variation of mean sea level. These processes also involve a variety of factors such as waves, winds, tides, storm surges, currents, etc., that cause huge interference on such phenomena. Measurement of waves have been carried out using different techniques. The instruments used to measure wave parameters can be very different, i.e. buoys, ship base equipment like sonar and satellites. Each equipment has its own advantage and disadvantage depending on the study subject. The purpose of this study is to evaluate the behaviour of a different technology available and presently adopted in wave measurement. In the past few years the measurement of waves using High Frequency (HF) Radars has had several developments. Such a method is already established as a powerful tool for measuring the pattern of surface current, but its use in wave measurements, especially in the dual arrangement is recent. Measurement of the backscatter of HF radar wave provides the raw dataset which is analyzed to give directional data of surface elevation at each range cell. Buoys and radars have advantages, disadvantages and its accuracy is discussed in this presentation. A major advantage with HF radar systems is that they are unaffected by weather, clouds or changing ocean conditions. The HF radar system is a very useful tool for the measurement of waves over a wide area with real-time observation, but it still lacks a method to check its accuracy. The primary goal of this study was to show how the HF radar system responds to high energetic variations when compared to wave buoy data. The bulk wave parameters used (significant wave height, period and

  18. Source conductance scaling for high frequency superconducting quasiparticle receivers

    Science.gov (United States)

    Ke, Qing; Feldman, M. J.

    1992-01-01

    It has been suggested that the optimum source conductance G(sub s) for the superconductor-insulator-superconductor (SIS) quasiparticle mixer should have a l/f dependence. This would imply that the critical current density of SIS junctions used for mixing should increase as frequency squared, a stringent constraint on the design of submillimeter SIS mixers, rather than in simple proportion to frequency as previously believed. We have used Tucker's quantum theory of mixing for extensive numerical calculations to determine G(sub s) for an optimized SIS receiver. We find that G(sub s) is very roughly independent of frequency (except for the best junctions at low frequency), and discuss the implications of our results for the design of submillimeter SIS mixers.

  19. Advanced High Frequency Communication and Optoelectronic Radar Systems

    National Research Council Canada - National Science Library

    2001-01-01

    We have demonstrated photonic time-stretching (PTS) of radio frequency (RF) signals using our novel polymer modulators and two techniques to reduce the power penalty from the effects of fiber chromatic dispersion. A Single-sideband (SSB...

  20. RF MEMS Fractal Capacitors With High Self-Resonant Frequencies

    KAUST Repository

    Elshurafa, Amro M.; Emira, Ahmed; Radwan, Ahmed Gomaa; Salama, Khaled N.

    2012-01-01

    This letter demonstrates RF microelectromechanical systems (MEMS) fractal capacitors possessing the highest reported self-resonant frequencies (SRFs) in PolyMUMPS to date. Explicitly, measurement results show SRFs beyond 20 GHz. Furthermore, quality

  1. High precision synchronization of time and frequency and its applications

    International Nuclear Information System (INIS)

    Wang Lijun

    2014-01-01

    We discuss the concept and methods for remote synchronization of time and frequency. We discuss a recent experiment that demonstrated time and frequency synchronization via a commercial fiber network, reaching accuracy of 7 × 10 -15 /s, 5 × 10 -19 /day, and a maximum time uncertainty of less than 50 femtoseconds. We discuss synchronization methods applicable to different topologies and their important scientific applications. (authors)

  2. High-frequency parameters of magnetic films showing magnetization dispersion

    International Nuclear Information System (INIS)

    Sidorenkov, V.V.; Zimin, A.B.; Kornev, Yu.V.

    1988-01-01

    Magnetization dispersion leads to skewed resonance curves shifted towards higher magnetizing fields, together with considerable reduction in the resonant absorption, while the FMR line width is considerably increased. These effects increase considerably with frequency, in contrast to films showing magnetic-anisotropy dispersion, where they decrease. It is concluded that there may be anomalies in the frequency dependence of the resonance parameters for polycrystalline magnetic films

  3. Development of sine/cosine coil based on cross-section modulation

    International Nuclear Information System (INIS)

    Harada, Takahiro; Kondoh, Junji; Tsuji-Iio, Shunji; Shimada, Ryuichi

    1996-01-01

    New type sine and cosine coils whose areas of cross sections vary as sine and cosine are proposed. The measurements of current position by the new coils showed their availability. Traditional sine or cosine coil is wound with a pitch which varies as sine or cosine. However these coils have a problem of manufacturing, i.e. it is not easy to wind wire exactly with a pitch of sine or cosine. This new modulation, i.e. varying cross section, provides handy and accurate measurements of the current position. (author)

  4. Identification and insertion polymorphisms of short interspersed nuclear elements (SINEs) in Brassica genomes

    International Nuclear Information System (INIS)

    Nouroz, F.; Naveed, M.

    2018-01-01

    The non-LTR retrotransposons (retroposons) are abundant in plant genomes including members of Brassicaceae. Of the retroposons, long interspersed nuclear elements (LINEs) are more copious followed by short interspersed nuclear elements (SINEs) in sequenced eukaryotic genomes. The SINEs are short elements and ranged from 100-500 bps flanked by variable sized target site duplications, 5' tRNA region with polymerase III promoter, internal tRNA unrelated region, 3' LINEs derived region and a poly adenosine tail. Different computational approaches were used for the identification and characterization of SINEs, while PCR was used to detect the SINEs insertion polymorphisms in various Brassica genotypes. Ten previously unidentified families of SINEs were identified and characterized from Brassica genomes. The structural features of these SINEs were studied in detail, which showed typical SINE features displaying small sizes, target site duplications, head regions, internal regions (body) of variable sizes and a poly (A) tail at the 3' terminus. The elements from various families ranged from 206-558 bp, where BoSINE2 family displayed smallest SINE element (206 bp), while larger members belonged to BoSINE9 family (524-558 bp). The distribution and abundance of SINEs in various Brassica species and genotypes (40) at a particular site/locus were investigated by SINEs based PCR markers. Various SINE insertion polymorphisms were detected from different genotypes, where higher PCR bands amplified the SINE insertions, while lower bands amplified the pre-insertion sites (flanking regions). The analysis of Brassica SINEs copy numbers from 10 identified families revealed that around 860 and 1712 copies of SINEs were calculated from B. rapa and B. oleracea Whole-genome shotgun contigs (WGS) respectively. Analysis of insertion sites of Brassica SINEs revealed that the members from all 10 SINE families had shown an insertion preference in AT rich regions. The present

  5. Study and realisation of a high frequency analyzer; Etude et realisation d'un analyseur de signaux a haute frequence

    Energy Technology Data Exchange (ETDEWEB)

    Bourbigot, J [Commissariat a l' Energie Atomique, Fontenay aux Roses (France). Centre d' Etudes Nucleaires

    1966-07-01

    This device is designed for the amplitude and frequency analysis of electric or electromagnetic signals in the frequency range of 0 to 55 MHz. The frequency spectrum of a preset bandwidth is displayed on the screen of an oscilloscope. Conceived to analyse the electromagnetic oscillations that can be generated in a plasma, its main characteristics are the following: extended bandwidth of analysed frequencies, on both sides of the ion cyclotron frequency in a magnetic field up to 20 kGs; linear amplitude and frequency response; possibility of analysing a narrow band; high sensitivity; analysis repetition rate of 25 per second. The different parts of the analyzer are described after a discussion of the choice of the techniques used in their design. In addition to its present use, the device can be applied to perform all the functions of a commercial spectral analyzer. (author) [French] Cet appareil est destine a l'analyse en frequence et amplitude de signaux electriques ou electromagnetiques dans une gamme de frequences de 0 a 55 MHz. Couple a un oscillographe, il permet de faire apparaitre sur l'ecran, le spectre de frequences dans une gamme choisie. Etudie dans le but d'analyser les oscillations electromagnetiques pouvant apparaitre dans un plasma, ses principales caracteristiques sont les suivantes: une bande etendue de frequences analysees, de part et d'autre de la frequence cyclotronique des ions dans un champ magnetique pouvant atteindre 20 kGs (valeur maximum 55 MHz); une reponse lineaire en amplitude et en frequence; la possibilite d'analyser, une bande restreinte de frequences; une grande sensibilite La frequence d'analyse est de 25 periodes par seconde. Les diverses parties de l'analyseur sont decrites apres l'expose des motifs ayant guide le choix des solutions adoptees pour sa realisation. Les schemas electriques sont egalement presentes. En dehors du but precis qui a motive la realisation de cet appareil, son usage peut s'etendre a toutes les applications

  6. National High Frequency Radar Network (hfrnet) and Pacific Research Efforts

    Science.gov (United States)

    Hazard, L.; Terrill, E. J.; Cook, T.; de Paolo, T.; Otero, M. P.; Rogowski, P.; Schramek, T. A.

    2016-12-01

    The U.S. High Frequency Radar Network (HFRNet) has been in operation for over ten years with representation from 31 organizations spanning academic institutions, state and local government agencies, and private organizations. HFRNet currently holds a collection from over 130 radar installations totaling over 10 million records of surface ocean velocity measurements. HFRNet is a primary example of inter-agency and inter-institutional partnerships for improving oceanographic research and operations. HF radar derived surface currents have been used in several societal applications including coastal search and rescue, oil spill response, water quality monitoring and marine navigation. Central to the operational success of the large scale network is an efficient data management, storage, access, and delivery system. The networking of surface current mapping systems is characterized by a tiered structure that extends from the individual field installations to local regional operations maintaining multiple sites and on to centralized locations aggregating data from all regions. The data system development effort focuses on building robust data communications from remote field locations (sites) for ingestion into the data system via data on-ramps (Portals or Site Aggregators) to centralized data repositories (Nodes). Centralized surface current data enables the aggregation of national surface current grids and allows for ingestion into displays, management tools, and models. The Coastal Observing Research and Development Center has been involved in international relationships and research in the Philippines, Palau, and Vietnam. CORDC extends this IT architecture of surface current mapping data systems leveraging existing developments and furthering standardization of data services for seamless integration of higher level applications. Collaborations include the Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA), The Coral Reef Research

  7. Tsunami Arrival Detection with High Frequency (HF Radar

    Directory of Open Access Journals (Sweden)

    Donald Barrick

    2012-05-01

    Full Text Available Quantitative real-time observations of a tsunami have been limited to deep-water, pressure-sensor observations of changes in the sea surface elevation and observations of sea level fluctuations at the coast, which are essentially point measurements. Constrained by these data, models have been used for predictions and warning of the arrival of a tsunami, but to date no system exists for local detection of an actual incoming wave with a significant warning capability. Networks of coastal high frequency (HF-radars are now routinely observing surface currents in many countries. We report here on an empirical method for the detection of the initial arrival of a tsunami, and demonstrate its use with results from data measured by fourteen HF radar sites in Japan and USA following the magnitude 9.0 earthquake off Sendai, Japan, on 11 March 2011. The distance offshore at which the tsunami can be detected, and hence the warning time provided, depends on the bathymetry: the wider the shallow continental shelf, the greater this time. We compare arrival times at the radars with those measured by neighboring tide gauges. Arrival times measured by the radars preceded those at neighboring tide gauges by an average of 19 min (Japan and 15 min (USA The initial water-height increase due to the tsunami as measured by the tide gauges was moderate, ranging from 0.3 to 2 m. Thus it appears possible to detect even moderate tsunamis using this method. Larger tsunamis could obviously be detected further from the coast. We find that tsunami arrival within the radar coverage area can be announced 8 min (i.e., twice the radar spectral time resolution after its first appearance. This can provide advance warning of the tsunami approach to the coastline locations.

  8. The effect of high-frequency ground motion on the MAPLE-X10 reactor

    International Nuclear Information System (INIS)

    Bhan, S.; Dunbar, S.

    1989-06-01

    The effect of high-frequency ground motion on structures and equipment in nuclear reactors is examined by subjecting simple linear models to selected recorded ground motions which exhibit low and high frequencies. Computed damage measures indicate that high-frequency short-duration ground motion, such as that observed in eastern North America, have a minimal effect on structures with low natural frequencies. Response spectra of high-frequency ground motion indicate that higher forces are induced in structures with high natural frequencies as compared to those induced by low-frequency ground motion. However, reported observations of earthquake damage in eastern North America suggest that high-frequency ground motion causes little of no damage to structures. This may be due to the energy absorption capability of structures. It is concluded that the response spectrum representative of ground motion observed in eastern North America may give an over-conservative measure of the response of structures with high natural frequencies, since it does not account for the typically observed short duration of high-frequency ground motion and for the energy absorption capability of structures. Detailed nonlinear analysis of specific structures with high natural frequencies should be performed to better predict the actual response. Recommendations for a nonlinear analysis of typical structures with high natural frequencies are made

  9. Evaluation of the high-voltage high-frequency transformer insulating materials for satellites

    International Nuclear Information System (INIS)

    Kurita, Hiroshi; Hasegawa, Taketoshi; Hirasawa, Eiichi; Gonai, Toshio; Ohsuga, Hiroyuki.

    1987-01-01

    Environment resistance evaluation was made of the insulating materials of impregnated injection type for high-voltage high-frequency transformers mounted in satellites. (1) The stress occurring in the impregnated injection type resin is small in silicon resin and urethane resin and large in epoxy resin. (2) The dielectric characteristic at high frequency is good in silicone resin. In epoxy resin, when the transformer is operated at high temperature, its thermal runaway may take place. (3) The radiation deterioration at 1 Mrad - 10 Mrad is slight in urethane resin. (4) The degassing is not good in silicone resin. (5) The adhesive power is good in urethane resin. (6) From the above results, in silicone resin there is problem in degassing and adhesive power. In epoxy resin there is problem in stress and dielectric characteristic. (Mori, K.)

  10. Modulation of high frequency noise by engine tones of small boats.

    Science.gov (United States)

    Pollara, Alexander; Sutin, Alexander; Salloum, Hady

    2017-07-01

    The effect of modulation of high frequency ship noise by propeller rotation frequencies is well known. This modulation is observed with the Detection of Envelope Modulation on Noise (DEMON) algorithm. Analysis of the DEMON spectrum allows the revolutions per minute and number of blades of the propeller to be determined. This work shows that the high frequency noise of a small boat can also be modulated by engine frequencies. Prior studies have not reported high frequency noise amplitude modulated at engine frequencies. This modulation is likely produced by bubbles from the engine exhaust system.

  11. Selective activation of primary afferent fibers evaluated by sine-wave electrical stimulation

    Directory of Open Access Journals (Sweden)

    Katafuchi Toshihiko

    2005-03-01

    Full Text Available Abstract Transcutaneous sine-wave stimuli at frequencies of 2000, 250 and 5 Hz (Neurometer are thought to selectively activate Aβ, Aδ and C afferent fibers, respectively. However, there are few reports to test the selectivity of these stimuli at the cellular level. In the present study, we analyzed action potentials (APs generated by sine-wave stimuli applied to the dorsal root in acutely isolated rat dorsal root ganglion (DRG preparations using intracellular recordings. We also measured excitatory synaptic responses evoked by transcutaneous stimuli in substantia gelatinosa (SG neurons of the spinal dorsal horn, which receive inputs predominantly from C and Aδ fibers, using in vivo patch-clamp recordings. In behavioral studies, escape or vocalization behavior of rats was observed with both 250 and 5 Hz stimuli at intensity of ~0.8 mA (T5/ T250, whereas with 2000 Hz stimulation, much higher intensity (2.14 mA, T2000 was required. In DRG neurons, APs were generated at T5/T250 by 2000 Hz stimulation in Aβ, by 250 Hz stimulation both in Aβ and Aδ, and by 5 Hz stimulation in all three classes of DRG neurons. However, the AP frequencies elicited in Aβ and Aδ by 5 Hz stimulation were much less than those reported previously in physiological condition. With in vivo experiments large amplitude of EPSCs in SG neurons were elicited by 250 and 5 Hz stimuli at T5/ T250. These results suggest that 2000 Hz stimulation excites selectively Aβ fibers and 5 Hz stimulation activates noxious transmission mediated mainly through C fibers. Although 250 Hz stimulation activates both Aδ and Aβ fibers, tactile sensation would not be perceived when painful sensation is produced at the same time. Therefore, 250 Hz was effective stimulus frequency for activation of Aδ fibers initiating noxious sensation. Thus, the transcutaneous sine-wave stimulation can be applied to evaluate functional changes of sensory transmission by comparing thresholds with the three

  12. Switching transients in high-frequency high-power converters using power MOSFET's

    Science.gov (United States)

    Sloane, T. H.; Owen, H. A., Jr.; Wilson, T. G.

    1979-01-01

    The use of MOSFETs in a high-frequency high-power dc-to-dc converter is investigated. Consideration is given to the phenomena associated with the paralleling of MOSFETs and to the effect of stray circuit inductances on the converter circuit performance. Analytical relationships between various time constants during the turning-on and turning-off intervals are derived which provide estimates of plateau and peak levels during these intervals.

  13. Soliton scatterings by impurities in a short-length sine-Gordon chain

    International Nuclear Information System (INIS)

    Dikande, A.M.; Kofane, T.C.

    1995-07-01

    The scattering of soliton by impurities at the frontiers of a finite-length region of an infinite sine-Gordon chain is analyzed. The impurities consist of two isotopic inhomogeneities installed at the boundaries of the finite-length region. The soliton solution in the region is found in term of snoidal sine-Gordon soliton which properly takes into account the effects of the boundaries. By contrast, the soliton solutions in the neighboring sides of the region are obtained in terms of the so-called large-amplitude, localized kinks with limiting spatial extensions at x → ± ∞, which is equal ±π. Using the continuity of these soliton solutions at the frontiers as well as appropriate boundary conditions, it is shown that the soliton may be either i) reflected by the incident impurity; ii) trapped (with oscillating motions) between the two impurities (i.e. inside the infinite region); or iii) transmitted by the second impurity into the third, infinitely extended region. The threshold velocities for the reflection and transmission into different regions are found and shown to vary exponentially as a function of the length of the bounded region. The frequency of soliton oscillations between the impurities has also been calculated in some acceptable limit. (author). 28 refs, 1 fig

  14. Sauria SINEs: Novel short interspersed retroposable elements that are widespread in reptile genomes.

    Science.gov (United States)

    Piskurek, Oliver; Austin, Christopher C; Okada, Norihiro

    2006-05-01

    SINEs are short interspersed retrotransposable elements that invade new genomic sites. Their retrotransposition depends on reverse transcriptase and endonuclease activities encoded by partner LINEs (long interspersed elements). Recent genomic research has demonstrated that retroposons account for at least 40% of the human genome. Hitherto, more than 30 families of SINEs have been characterized in mammalian genomes, comprising approximately 4600 extant species; the distribution and extent of SINEs in reptilian genomes, however, are poorly documented. With more than 7400 species of lizards and snakes, Squamata constitutes the largest and most diverse group of living reptiles. We have discovered and characterized a novel SINE family, Sauria SINEs, whose members are widely distributed among genomes of lizards, snakes, and tuataras. Sauria SINEs comprise a 5' tRNA-related region, a tRNA-unrelated region, and a 3' tail region (containing short tandem repeats) derived from LINEs. We distinguished eight Sauria SINE subfamilies in genomes of four major squamate lineages and investigated their evolutionary relationships. Our data illustrate the overall efficacy of Sauria SINEs as novel retrotransposable markers for elucidation of squamate evolutionary history. We show that all Sauria SINEs share an identical 3' sequence with Bov-B LINEs and propose that they utilize the enzymatic machinery of Bov-B LINEs for their own retrotransposition. This finding, along with the ubiquity of Bov-B LINEs previously demonstrated in squamate genomes, suggests that these LINEs have been an active partner of Sauria SINEs since this SINE family was generated more than 200 million years ago.

  15. Research on the Vibration Insulation of High-Speed Train Bogies in Mid and High Frequency

    Directory of Open Access Journals (Sweden)

    Jia Liu

    2018-01-01

    Full Text Available According to a large amount of the test data, the mid and high frequency vibrations of high-speed bogies are very notable, especially in the 565~616 Hz range, which are just the passing frequencies corresponding to the 22nd to 24th polygonal wear of the wheel. In order to investigate the main cause of wheel higher-order polygon formation, a 3D flexible model of a Chinese high-speed train bogie is developed using the explicit finite element method. The results show that the couple vibration of bogie and wheelset may lead to the high-order wears of wheel. In order to reduce the coupled resonance of the wheelset and the bogie frame, the effects of the stiffness and damping of the primary suspensions, wheelset axle radius, and bogie frame strength on the vibration transmissibility are discussed carefully. The numerical results show that the resonance peaks in high frequency range can be reduced by reducing the stiffness of axle box rotary arm joint, reducing the wheelset axle radius or strengthening the bogie frame location. The related results may provide a reference for structure improvement of the existing bogies and structure design of the new high-speed bogies.

  16. Cluster observations of high-frequency waves in the exterior cusp

    Directory of Open Access Journals (Sweden)

    Y. Khotyaintsev

    2004-07-01

    Full Text Available We study wave emissions, in the frequency range from above the lower hybrid frequency up to the plasma frequency, observed during one of the Cluster crossings of a high-beta exterior cusp region on 4 March 2003. Waves are localized near narrow current sheets with a thickness a few times the ion inertial length; currents are strong, of the order of 0.1-0.5μA/m2 (0.1-0.5mA/m2 when mapped to ionosphere. The high frequency part of the waves, frequencies above the electron-cyclotron frequency, is analyzed in more detail. These high frequency waves can be broad-band, can have spectral peaks at the plasma frequency or spectral peaks at frequencies below the plasma frequency. The strongest wave emissions usually have a spectral peak near the plasma frequency. The wave emission intensity and spectral character change on a very short time scale, of the order of 1s. The wave emissions with strong spectral peaks near the plasma frequency are usually seen on the edges of the narrow current sheets. The most probable generation mechanism of high frequency waves are electron beams via bump-on-tail or electron two-stream instability. Buneman and ion-acoustic instability can be excluded as a possible generation mechanism of waves. We suggest that high frequency waves are generated by electron beams propagating along the separatrices of the reconnection region.

  17. Optical frequency comb for high resolution hydrogen spectroscopy

    International Nuclear Information System (INIS)

    Arnoult, O.

    2006-11-01

    In this work, we perform an absolute frequency measurement of the 1S-3S transition in atomic hydrogen, in order to improve the uncertainties on both the Rydberg constant and the Lamb shift L1S. In the experiment, a CW stabilized Ti:Sa laser is doubled twice in LBO (LiB 3 O 5 ) and BBO (β-BaB 2 O 4 ) crystals. The 1S-3S transition is excited by two photons at 205 nm in an optical cavity colinear with the atomic beam, at room temperature. The remaining second-order Doppler effect is compensated by a quadratic Stark effect resulting from an applied static magnetic field. An optical frequency comb is used to compare directly the Ti:Sa frequency with the microwave frequency standard. We detect fluorescence at 656 nm thanks to a CCD camera. Fitting the experimental data with our calculated line shapes leads to a value of the second-order Doppler effect in disagreement with approximative predictions for the 1S-3S frequency. We suggest the existence of stray electric fields as a possible systematic effect. The slides of the defence of the thesis have been added at the end of the document. (author)

  18. A New High Frequency Injection Method Based on Duty Cycle Shifting without Maximum Voltage Magnitude Loss

    DEFF Research Database (Denmark)

    Wang, Dong; Lu, Kaiyuan; Rasmussen, Peter Omand

    2015-01-01

    The conventional high frequency signal injection method is to superimpose a high frequency voltage signal to the commanded stator voltage before space vector modulation. Therefore, the magnitude of the voltage used for machine torque production is limited. In this paper, a new high frequency...... amplitude. This may be utilized to develop new position estimation algorithm without involving the inductance in the medium to high speed range. As an application example, a developed inductance independent position estimation algorithm using the proposed high frequency injection method is applied to drive...... injection method, in which high frequency signal is generated by shifting the duty cycle between two neighboring switching periods, is proposed. This method allows injecting a high frequency signal at half of the switching frequency without the necessity to sacrifice the machine fundamental voltage...

  19. Active Control of High-Speed Free Jets Using High-Frequency Excitation

    Science.gov (United States)

    Upadhyay, Puja

    Control of aerodynamic noise generated by high-performance jet engines continues to remain a serious problem for the aviation community. Intense low frequency noise produced by large-scale coherent structures is known to dominate acoustic radiation in the aft angles. A tremendous amount of research effort has been dedicated towards the investigation of many passive and active flow control strategies to attenuate jet noise, while keeping performance penalties to a minimum. Unsteady excitation, an active control technique, seeks to modify acoustic sources in the jet by leveraging the naturally-occurring flow instabilities in the shear layer. While excitation at a lower range of frequencies that scale with the dynamics of large-scale structures, has been attempted by a number of studies, effects at higher excitation frequencies remain severely unexplored. One of the major limitations stems from the lack of appropriate flow control devices that have sufficient dynamic response and/or control authority to be useful in turbulent flows, especially at higher speeds. To this end, the current study seeks to fulfill two main objectives. First, the design and characterization of two high-frequency fluidic actuators (25 and 60 kHz) are undertaken, where the target frequencies are guided by the dynamics of high-speed free jets. Second, the influence of high-frequency forcing on the aeroacoustics of high-speed jets is explored in some detail by implementing the nominally 25 kHz actuator on a Mach 0.9 (Re D = 5 x 105) free jet flow field. Subsequently, these findings are directly compared to the results of steady microjet injection experiments performed in the same rig and to prior jet noise control studies, where available. Finally, limited acoustic measurements were also performed by implementing the nominally 25 kHz actuators on jets at higher Mach numbers, including shock containing jets, and elevated temperatures. Using lumped element modeling as an initial guide, the current

  20. Accurate modeling of high frequency microelectromechanical systems (MEMS switches in time- and frequency-domainc

    Directory of Open Access Journals (Sweden)

    F. Coccetti

    2003-01-01

    Full Text Available In this contribution we present an accurate investigation of three different techniques for the modeling of complex planar circuits. The em analysis is performed by means of different electromagnetic full-wave solvers in the timedomain and in the frequency-domain. The first one is the Transmission Line Matrix (TLM method. In the second one the TLM method is combined with the Integral Equation (IE method. The latter is based on the Generalized Transverse Resonance Diffraction (GTRD. In order to test the methods we model different structures and compare the calculated Sparameters to measured results, with good agreement.

  1. High-frequency applications of high-temperature superconductor thin films

    Science.gov (United States)

    Klein, N.

    2002-10-01

    High-temperature superconducting thin films offer unique properties which can be utilized for a variety of high-frequency device applications in many areas related to the strongly progressing market of information technology. One important property is an exceptionally low level of microwave absorption at temperatures attainable with low power cryocoolers. This unique property has initiated the development of various novel type of microwave devices and commercialized subsystems with special emphasis on application in advanced microwave communication systems. The second important achievement related to efforts in oxide thin and multilayer technology was the reproducible fabrication of low-noise Josephson junctions in high-temperature superconducting thin films. As a consequence of this achievement, several novel nonlinear high-frequency devices, most of them exploiting the unique features of the ac Josephson effect, have been developed and found to exhibit challenging properties to be utilized in basic metrology and Terahertz technology. On the longer timescale, the achievements in integrated high-temperature superconductor circuit technology may offer a strong potential for the development of digital devices with possible clock frequencies in the range of 100 GHz.

  2. Multiscale Thermo-Mechanical Design and Analysis of High Frequency and High Power Vacuum Electron Devices

    Science.gov (United States)

    Gamzina, Diana

    Diana Gamzina March 2016 Mechanical and Aerospace Engineering Multiscale Thermo-Mechanical Design and Analysis of High Frequency and High Power Vacuum Electron Devices Abstract A methodology for performing thermo-mechanical design and analysis of high frequency and high average power vacuum electron devices is presented. This methodology results in a "first-pass" engineering design directly ready for manufacturing. The methodology includes establishment of thermal and mechanical boundary conditions, evaluation of convective film heat transfer coefficients, identification of material options, evaluation of temperature and stress field distributions, assessment of microscale effects on the stress state of the material, and fatigue analysis. The feature size of vacuum electron devices operating in the high frequency regime of 100 GHz to 1 THz is comparable to the microstructure of the materials employed for their fabrication. As a result, the thermo-mechanical performance of a device is affected by the local material microstructure. Such multiscale effects on the stress state are considered in the range of scales from about 10 microns up to a few millimeters. The design and analysis methodology is demonstrated on three separate microwave devices: a 95 GHz 10 kW cw sheet beam klystron, a 263 GHz 50 W long pulse wide-bandwidth sheet beam travelling wave tube, and a 346 GHz 1 W cw backward wave oscillator.

  3. High-frequency applications of high-temperature superconductor thin films

    International Nuclear Information System (INIS)

    Klein, N.

    2002-01-01

    High-temperature superconducting thin films offer unique properties which can be utilized for a variety of high-frequency device applications in many areas related to the strongly progressing market of information technology. One important property is an exceptionally low level of microwave absorption at temperatures attainable with low power cryocoolers. This unique property has initiated the development of various novel type of microwave devices and commercialized subsystems with special emphasis on application in advanced microwave communication systems. The second important achievement related to efforts in oxide thin and multilayer technology was the reproducible fabrication of low-noise Josephson junctions in high-temperature superconducting thin films. As a consequence of this achievement, several novel nonlinear high-frequency devices, most of them exploiting the unique features of the ac Josephson effect, have been developed and found to exhibit challenging properties to be utilized in basic metrology and Terahertz technology. On the longer timescale, the achievements in integrated high-temperature superconductor circuit technology may offer a strong potential for the development of digital devices with possible clock frequencies in the range of 100 GHz. (author)

  4. Detecting high-frequency gravitational waves with optically levitated sensors.

    Science.gov (United States)

    Arvanitaki, Asimina; Geraci, Andrew A

    2013-02-15

    We propose a tunable resonant sensor to detect gravitational waves in the frequency range of 50-300 kHz using optically trapped and cooled dielectric microspheres or microdisks. The technique we describe can exceed the sensitivity of laser-based gravitational wave observatories in this frequency range, using an instrument of only a few percent of their size. Such a device extends the search volume for gravitational wave sources above 100 kHz by 1 to 3 orders of magnitude, and could detect monochromatic gravitational radiation from the annihilation of QCD axions in the cloud they form around stellar mass black holes within our galaxy due to the superradiance effect.

  5. Collective Thomson scattering measurements with high frequency resolution at TEXTOR

    DEFF Research Database (Denmark)

    Stejner Pedersen, Morten; Nielsen, Stefan Kragh; Korsholm, Søren Bang

    2010-01-01

    We discuss the development and first results of a receiver system for the collective Thomson scattering (CTS) diagnostic at TEXTOR with frequency resolution in the megahertz range or better. The improved frequency resolution expands the diagnostic range and utility of CTS measurements in general ...... and is a prerequisite for measurements of ion Bernstein wave signatures in CTS spectra. The first results from the new acquisition system are shown to be consistent with theory and with simultaneous measurements by the standard receiver system. © 2010 EURATOM...

  6. High-frequency microinstabilities in hot-electron plasmas

    International Nuclear Information System (INIS)

    Chen, Y.J.; Nevins, W.M.; Smith, G.R.

    1981-01-01

    Instabilities with frequencies in the neighborhood of the electron cyclotron frequency are of interest in determining stable operating regimes of hot-electron plasmas in EBT devices and in tandem mirrors. Previous work used model distributions significantly different than those suggested by recent Fokker-Planck studies. We use much more realistic model distributions in a computer code that solves the full electromagnetic dispersion relation governing longitudinal and transverse waves in a uniform plasma. We allow for an arbitrary direction of wave propagation. Results for the whistler and upper-hybrid loss-cone instabilities are presented

  7. Digital intermediate frequency QAM modulator using parallel processing

    Science.gov (United States)

    Pao, Hsueh-Yuan [Livermore, CA; Tran, Binh-Nien [San Ramon, CA

    2008-05-27

    The digital Intermediate Frequency (IF) modulator applies to various modulation types and offers a simple and low cost method to implement a high-speed digital IF modulator using field programmable gate arrays (FPGAs). The architecture eliminates multipliers and sequential processing by storing the pre-computed modulated cosine and sine carriers in ROM look-up-tables (LUTs). The high-speed input data stream is parallel processed using the corresponding LUTs, which reduces the main processing speed, allowing the use of low cost FPGAs.

  8. A High Performance Frequency Standard and Distribution System for Cassini Ka-Band Experiment

    National Research Council Canada - National Science Library

    Wang, R. T; Calhoun, M. D; Kirk, A; Diener, W. A; Dick, G. J; Tjoelker, R. L

    2005-01-01

    ...), and 10 Kelvin Cryocooled Sapphire Oscillator (10K CSO) and frequency-lock-loop, are integrated to achieve the very high performance, ground based frequency reference at a remote antenna site located 16 km from the hydrogen maser...

  9. High frequency nonlinear scattering from a micrometer to submicrometer sized lipid encapsulated contrast agent

    NARCIS (Netherlands)

    Goertz, David E.; Frijlink, Martijn E.; de Jong, N.; van der Steen, A.F.W.

    2006-01-01

    An experimental lipid encapsulated contrast agent comprised substantially of micrometer to submicrometer diameter bubbles was evaluated for its capacity to produce nonlinear scattering in response to high transmit frequencies. Agent characterization experiments were conducted at transmit frequencies

  10. Amplitude modulation reduces loudness adaptation to high-frequency tones.

    Science.gov (United States)

    Wynne, Dwight P; George, Sahara E; Zeng, Fan-Gang

    2015-07-01

    Long-term loudness perception of a sound has been presumed to depend on the spatial distribution of activated auditory nerve fibers as well as their temporal firing pattern. The relative contributions of those two factors were investigated by measuring loudness adaptation to sinusoidally amplitude-modulated 12-kHz tones. The tones had a total duration of 180 s and were either unmodulated or 100%-modulated at one of three frequencies (4, 20, or 100 Hz), and additionally varied in modulation depth from 0% to 100% at the 4-Hz frequency only. Every 30 s, normal-hearing subjects estimated the loudness of one of the stimuli played at 15 dB above threshold in random order. Without any amplitude modulation, the loudness of the unmodulated tone after 180 s was only 20% of the loudness at the onset of the stimulus. Amplitude modulation systematically reduced the amount of loudness adaptation, with the 100%-modulated stimuli, regardless of modulation frequency, maintaining on average 55%-80% of the loudness at onset after 180 s. Because the present low-frequency amplitude modulation produced minimal changes in long-term spectral cues affecting the spatial distribution of excitation produced by a 12-kHz pure tone, the present result indicates that neural synchronization is critical to maintaining loudness perception over time.

  11. High frequency of celiac disease in Down syndrome

    NARCIS (Netherlands)

    George, E. K.; Mearin, M. L.; Bouquet, J.; von Blomberg, B. M.; Stapel, S. O.; van Elburg, R. M.; de Graaf, E. A.

    1996-01-01

    We screened 115 children with Down syndrome for celiac disease, using antigliadin, antiendomysium, and antireticulin serum antibodies and an intestinal permeability test, Celiac disease was diagnosed in eight children, giving a frequency of 7.0%. We recommend screening for celiac disease in all

  12. High frequency body mass measurement, feedback, and health behaviors

    NARCIS (Netherlands)

    Kooreman, P.; Scherpenzeel, A.

    We analyze weight and fat percentage measurements of respondents in an online general population panel in the Netherlands, collected using wireless scales, with an average frequency of 1.6 measurements per week. First, we document the existence of a weekly cycle; body mass is lowest on Fridays and

  13. High frequency of celiac disease in Down syndrome

    NARCIS (Netherlands)

    George, EK; Mearin, ML; Bouquet, J; vonBlomberg, ME; Stapel, SO; vanElburg, RM; deGraaf, EAB

    We screened 115 children with Down syndrome for celiac disease, using antigliadin, antiendomysium, and antireticulin serum antibodies and an intestinal permeability test, Celiac disease was diagnosed in eight children, giving a frequency of 7.0%. We recommend screening for celiac disease in all

  14. Rapid Fear Detection Relies on High Spatial Frequencies

    NARCIS (Netherlands)

    Stein, T.; Seymour, K.; Hebart, M.N.; Sterzer, P.

    Signals of threat—such as fearful faces—are processed with priority and have privileged access to awareness. This fear advantage is commonly believed to engage a specialized subcortical pathway to the amygdala that bypasses visual cortex and processes predominantly low-spatial-frequency information

  15. Micronuclei frequency in albino rats exposed to high natural radiation

    International Nuclear Information System (INIS)

    Aneesh, D.; Godwin Wesley, S.

    2013-01-01

    Genotoxicity and DNA damage endpoints are used to evaluate results in the context of cell survival. Genotoxicity in mammalian cells is monitored mostly by using cytokinesis-block micronucleus (CBMN) assay. The score of micronuclei (MN) in peripheral blood lymphocytes can be used as a biomarker and also as a bio-dosimeter of radiation exposure. In the present study the effect of natural radiation on albino rats has been investigated, to find out if there is any increase in MN frequency in peripheral blood lymphocytes. Animals at the age of 2-3 weeks were exposed to natural radiation, at the dose of 10.38 μGyh -1 for a period of 6 months. A parallel control set was also maintained (0.12 μGy h -1 '). Blood samples were collected from both test (exposed to natural radiation) and control rats. Lymphocyte culture was done following 'microculture techniques' for 72 h. Cytochalasin B, at a concentration of 6.0 μg/ml, was added to the lymphocyte cultures at 44 h to block cytokinesis. The frequency of MN was evaluated by scoring a total of 1000 binucleated (BN) cells from one slide. The frequency of MN among the rats exposed to natural radiation was found to be 1.83±0.05 per 1000 BN cells and in the control it was 1.82±0.07 per 1000 BN cells. No statistically significant difference in the MN frequencies of exposed and control groups (p>0.05) was seen. The lower MN frequency in natural radiation exposed rats could be an indication of adaptive response. (author)

  16. In vivo photoacoustics and high frequency ultrasound imaging of mechanical high intensity focused ultrasound (HIFU) ablation.

    Science.gov (United States)

    Daoudi, Khalid; Hoogenboom, Martijn; den Brok, Martijn; Eikelenboom, Dylan; Adema, Gosse J; Fütterer, Jürgen J; de Korte, Chris L

    2017-04-01

    The thermal effect of high intensity focused ultrasound (HIFU) has been clinically exploited over a decade, while the mechanical HIFU is still largely confined to laboratory investigations. This is in part due to the lack of adequate imaging techniques to better understand the in-vivo pathological and immunological effects caused by the mechanical treatment. In this work, we explore the use of high frequency ultrasound (US) and photoacoustics (PA) as a potential tool to evaluate the effect of mechanical ablation in-vivo , e.g. boiling histotripsy. Two mice bearing a neuroblastoma tumor in the right leg were ablated using an MRI-HIFU system conceived for small animals and monitored using MRI thermometry. High frequency US and PA imaging were performed before and after the HIFU treatment. Afterwards, the tumor was resected for further assessment and evaluation of the ablated region using histopathology. High frequency US imaging revealed the presence of liquefied regions in the treated area together with fragmentized tissue which appeared with different reflecting proprieties compared to the surrounding tissue. Photoacoustic imaging on the other hand revealed the presence of deoxygenated blood within the tumor after the ablation due to the destruction of blood vessel network while color Doppler imaging confirmed the blood vessel network destruction within the tumor. The treated area and the presence of red blood cells detected by photoacoustics were further confirmed by the histopathology. This feasibility study demonstrates the potential of high frequency US and PA approach for assessing in-vivo the effect of mechanical HIFU tumor ablation.

  17. Stress Recovery Effects of High- and Low-Frequency Amplified Music on Heart Rate Variability.

    Science.gov (United States)

    Nakajima, Yoshie; Tanaka, Naofumi; Mima, Tatsuya; Izumi, Shin-Ichi

    Sounds can induce autonomic responses in listeners. However, the modulatory effect of specific frequency components of music is not fully understood. Here, we examined the role of the frequency component of music on autonomic responses. Specifically, we presented music that had been amplified in the high- or low-frequency domains. Twelve healthy women listened to white noise, a stress-inducing noise, and then one of three versions of a piece of music: original, low-, or high-frequency amplified. To measure autonomic response, we calculated the high-frequency normalized unit (HFnu), low-frequency normalized unit, and the LF/HF ratio from the heart rate using electrocardiography. We defined the stress recovery ratio as the value obtained after participants listened to music following scratching noise, normalized by the value obtained after participants listened to white noise after the stress noise, in terms of the HFnu, low-frequency normalized unit, LF/HF ratio, and heart rate. Results indicated that high-frequency amplified music had the highest HFnu of the three versions. The stress recovery ratio of HFnu under the high-frequency amplified stimulus was significantly larger than that under the low-frequency stimulus. Our results suggest that the high-frequency component of music plays a greater role in stress relief than low-frequency components.

  18. Analysis of transistor and snubber turn-off dynamics in high-frequency high-voltage high-power converters

    Science.gov (United States)

    Wilson, P. M.; Wilson, T. G.; Owen, H. A., Jr.

    Dc to dc converters which operate reliably and efficiently at switching frequencies high enough to effect substantial reductions in the size and weight of converter energy storage elements are studied. A two winding current or voltage stepup (buck boost) dc-to-dc converter power stage submodule designed to operate in the 2.5-kW range, with an input voltage range of 110 to 180 V dc, and an output voltage of 250 V dc is emphasized. In order to assess the limitations of present day component and circuit technologies, a design goal switching frequency of 10 kHz was maintained. The converter design requirements represent a unique combination of high frequency, high voltage, and high power operation. The turn off dynamics of the primary circuit power switching transistor and its associated turn off snubber circuitry are investigated.

  19. Absolute measurements of the high-frequency magnetic dynamics in high-Tc superconductors

    International Nuclear Information System (INIS)

    Hayden, S.M.; Dai, P.; Mook, H.A.; Perring, T.G.; Cheong, S.W.; Fisk, Z.; Dogan, F.; Mason, T.E.

    1997-01-01

    The authors review recent measurements of the high-frequency dynamic magnetic susceptibility in the high-T c superconducting systems La 2-x Sr x CuO 4 and YBa 2 Cu 3 O 6+x . Experiments were performed using the chopper spectrometers HET and MARI at the ISIS spallation source. The authors have placed their measurements on an absolute intensity scale, this allows systematic trends to be seen and comparisons with theory to be made. They find that the insulating S = 1/2 antiferromagnetic parent compounds show a dramatic renormalization in the spin wave intensity. The effect of doping on the response is to cause broadenings in wave vector and large redistributions of spectral weight in frequency

  20. Sine-Gordon breather form factors and quantum field equations

    International Nuclear Information System (INIS)

    Babujian, H; Karowski, M

    2002-01-01

    Using the results of previous investigations on sine-Gordon form factors, exact expressions of all breather matrix elements are obtained for several operators: all powers of the fundamental Bose field, general exponentials of it, the energy-momentum tensor and all higher currents. Formulae for the asymptotic behaviour of bosonic form factors are presented which are motivated by Weinberg's power counting theorem in perturbation theory. It is found that the quantum sine-Gordon field equation holds, and an exact relation between the 'bare' mass and the renormalized mass is obtained. Also a quantum version of a classical relation for the trace of the energy-momentum is proved. The eigenvalue problem for all higher conserved charges is solved. All results are compared with perturbative Feynman graph expansions and full agreement is found

  1. Invariant solutions of the supersymmetric sine-Gordon equation

    International Nuclear Information System (INIS)

    Grundland, A M; Hariton, A J; Snobl, L

    2009-01-01

    A comprehensive symmetry analysis of the N=1 supersymmetric sine-Gordon equation is performed. Two different forms of the supersymmetric system are considered. We begin by studying a system of partial differential equations corresponding to the coefficients of the various powers of the anticommuting independent variables. Next, we consider the super-sine-Gordon equation expressed in terms of a bosonic superfield involving anticommuting independent variables. In each case, a Lie (super)algebra of symmetries is determined and a classification of all subgroups having generic orbits of codimension 1 in the space of independent variables is performed. The method of symmetry reduction is systematically applied in order to derive invariant solutions of the supersymmetric model. Several types of algebraic, hyperbolic and doubly periodic solutions are obtained in explicit form.

  2. Light-front quantization of the sine-Gordon model

    International Nuclear Information System (INIS)

    Burkardt, M.

    1993-01-01

    It is shown how to modify the canonical light-front quantization of the (1+1)-dimensional sine-Gordon model such that the zero-mode problem of light-front quantization is avoided. The canonical sine-Gordon Lagrangian is replaced by an effective Lagrangian which does not lead to divergences as k + =(k 0 +k 1 )/ √2 →0. After canonically quantizing the effective Lagrangian, one obtains the effective light-front Hamiltonian which agrees with the naive light-front (LF) Hamiltonian, up to one additional renormalization. The spectrum of the effective LF Hamiltonian is determined using discrete light-cone quantization and agrees with results from equal-time quantization

  3. Advanced Sine Wave Modulation of Continuous Wave Laser System for Atmospheric CO2 Differential Absorption Measurements

    Science.gov (United States)

    Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.

    2014-01-01

    NASA Langley Research Center in collaboration with ITT Exelis have been experimenting with Continuous Wave (CW) laser absorption spectrometer (LAS) as a means of performing atmospheric CO2 column measurements from space to support the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission.Because range resolving Intensity Modulated (IM) CW lidar techniques presented here rely on matched filter correlations, autocorrelation properties without side lobes or other artifacts are highly desirable since the autocorrelation function is critical for the measurements of lidar return powers, laser path lengths, and CO2 column amounts. In this paper modulation techniques are investigated that improve autocorrelation properties. The modulation techniques investigated in this paper include sine waves modulated by maximum length (ML) sequences in various hardware configurations. A CW lidar system using sine waves modulated by ML pseudo random noise codes is described, which uses a time shifting approach to separate channels and make multiple, simultaneous online/offline differential absorption measurements. Unlike the pure ML sequence, this technique is useful in hardware that is band pass filtered as the IM sine wave carrier shifts the main power band. Both amplitude and Phase Shift Keying (PSK) modulated IM carriers are investigated that exibit perfect autocorrelation properties down to one cycle per code bit. In addition, a method is presented to bandwidth limit the ML sequence based on a Gaussian filter implemented in terms of Jacobi theta functions that does not seriously degrade the resolution or introduce side lobes as a means of reducing aliasing and IM carrier bandwidth.

  4. Deterministic approach for multiple-source tsunami hazard assessment for Sines, Portugal

    Science.gov (United States)

    Wronna, M.; Omira, R.; Baptista, M. A.

    2015-11-01

    In this paper, we present a deterministic approach to tsunami hazard assessment for the city and harbour of Sines, Portugal, one of the test sites of project ASTARTE (Assessment, STrategy And Risk Reduction for Tsunamis in Europe). Sines has one of the most important deep-water ports, which has oil-bearing, petrochemical, liquid-bulk, coal, and container terminals. The port and its industrial infrastructures face the ocean southwest towards the main seismogenic sources. This work considers two different seismic zones: the Southwest Iberian Margin and the Gloria Fault. Within these two regions, we selected a total of six scenarios to assess the tsunami impact at the test site. The tsunami simulations are computed using NSWING, a Non-linear Shallow Water model wIth Nested Grids. In this study, the static effect of tides is analysed for three different tidal stages: MLLW (mean lower low water), MSL (mean sea level), and MHHW (mean higher high water). For each scenario, the tsunami hazard is described by maximum values of wave height, flow depth, drawback, maximum inundation area and run-up. Synthetic waveforms are computed at virtual tide gauges at specific locations outside and inside the harbour. The final results describe the impact at the Sines test site considering the single scenarios at mean sea level, the aggregate scenario, and the influence of the tide on the aggregate scenario. The results confirm the composite source of Horseshoe and Marques de Pombal faults as the worst-case scenario, with wave heights of over 10 m, which reach the coast approximately 22 min after the rupture. It dominates the aggregate scenario by about 60 % of the impact area at the test site, considering maximum wave height and maximum flow depth. The HSMPF scenario inundates a total area of 3.5 km2.

  5. Thermodynamic Bethe ansatz for boundary sine-Gordon model

    International Nuclear Information System (INIS)

    Lee, Taejun; Rim, Chaiho

    2003-01-01

    (R-channel) TBA is elaborated to find the effective central charge dependence on the boundary parameters for the massless boundary sine-Gordon model with the coupling constant (8π)/β 2 =1+λ with λ a positive integer. Numerical analysis of the massless boundary TBA demonstrates that at an appropriate boundary parameter range (cusp point) there exists a singularity crossing phenomena and this effect should be included in TBA to have the right behavior of the effective central charge

  6. Exact solutions to some modified sine-Gordon equations

    International Nuclear Information System (INIS)

    Saermark, K.

    1983-01-01

    Exact, translational solutions to a number of modified sine-Gordon equations are presented. In deriving the equations and the solutions use is made of results from the theory of ordinary differential equations without moving critical points as given by Ince. It is found that kink-like solutions exist also in cases where the coefficients of the trigonometric terms are space- and time-dependent. (Auth.)

  7. Comparison of sine dwell and broadband methods for modal testing

    Science.gov (United States)

    Chen, Jay-Chung

    1989-01-01

    The objectives of modal tests for large complex spacecraft structural systems are outlined. The comparison criteria for the modal test methods, namely, the broadband excitation and the sine dwell methods, are established. Using the Galileo spacecraft modal test and the Centaur G Prime upper stage vehicle modal test as examples, the relative advantage or disadvantage of each method is examined. The usefulness or shortcomings of the methods are given from a practical engineering viewpoint.

  8. On sine dwell or broadband methods for modal testing

    Science.gov (United States)

    Chen, Jay-Chung; Wada, Ben K.

    1987-01-01

    For large, complex spacecraft structural systems, the objectives of the modal test are outlined. Based on these objectives, the comparison criteria for the modal test methods, namely, the broadband excitation and the sine dwell methods are established. Using the Galileo spacecraft modal test and the Centaur G Prime upper stage vehicle modal test as examples, the relative advantages or disadvantages of each method are examined. The usefulness or shortcoming of the methods are given from a practicing engineer's view point.

  9. COMPETITIVENESS OF THE PORT OF SINES: THE RBV CONTRIBUTION

    OpenAIRE

    Azevedo, Susana; Ferreira, João

    2008-01-01

    The main objective of this paper is to analyze the competitiveness of the main maritime Port sited in Portugal - Port of Sines. This paper is developed under the Resource-based view approach. A literature review about the Resource-based view is presented with a special highlight on the contribution of organizations owns’ resources to the competitiveness. With this paper we intend to emphasize the applicability of a management theory to a different type of organizations which only recently st...

  10. Retinal detachment and retinal holes in retinitis pigmentosa sine pigmento.

    Science.gov (United States)

    Csaky, K; Olk, R J; Mahl, C F; Bloom, S M

    1991-01-01

    Retinal detachment and retinal holes in two family members with retinitis pigmentosa sine pigmento are reported. We believe these are the first such cases reported in the literature. We describe the presenting symptoms and management, including cryotherapy, scleral buckling procedure, and sulfur hexafluoride injection (SF6), resulting in stable visual acuity in one case and retinal reattachment and improved visual acuity in the other case.

  11. Multifocal amelanotic conjunctival melanoma and acquired melanosis sine pigmento.

    Science.gov (United States)

    Paridaens, A D; McCartney, A C; Hungerford, J L

    1992-03-01

    Clinical and histopathological features of four cases of multifocal amelanotic malignant melanoma of the conjunctiva in association with 'acquired melanosis sine pigmento' are reported. The absence of conjunctival pigmentation in this extremely rare combination of lesions prevented early diagnosis and clinical monitoring. As a result orbital exenteration was required in three cases. This multicentric non-pigmented variety of conjunctival malignant melanoma tends to present later than pigmented forms and may require exenteration of the orbit as a primary procedure.

  12. High frequency electromechanical memory cells based on telescoping carbon nanotubes.

    Science.gov (United States)

    Popov, A M; Lozovik, Y E; Kulish, A S; Bichoutskaia, E

    2010-07-01

    A new method to increase the operational frequency of electromechanical memory cells based on the telescoping motion of multi-walled carbon nanotubes through the selection of the form of the switching voltage pulse is proposed. The relative motion of the walls of carbon nanotubes can be controlled through the shape of the interwall interaction energy surface. This allows the use of the memory cells in nonvolatile or volatile regime, depending on the structure of carbon nanotube. Simulations based on ab initio and semi-empirical calculations of the interwall interaction energies are used to estimate the switching voltage and the operational frequency of volatile cells with the electrodes made of carbon nanotubes. The lifetime of nonvolatile memory cells is also predicted.

  13. Benefits and Drawbacks of A High Frequency Gan Zvzcps Converter

    Directory of Open Access Journals (Sweden)

    Blanes J. M.

    2017-01-01

    Full Text Available This paper presents the benefits and drawbacks of replacing the traditional Si Mosfets transistors with enhancement mode GaN transistors in a Half-Bridge Zero Voltage and Zero Current Switching Power Switching (ZVZCPS converter. This type of converters is usually used as Electronic Power Converters (EPC for telecommunication satellites travelling-wave tube amplifiers (TWTAs. In this study, firstly the converter is theoretically analysed, obtaining its operation, losses and efficiency equations. From these equations, optimizations maps based on the main system parameters are obtained. These optimization maps are the key to quantify the potential benefits of GaN transistors in this type of converters. Theoretical results show that using GaN transistors, the frequency of the converter can be pushed from 125kHz to 830kHz without sacrificing the converter efficiency. This frequency increase is directly related to reduction on the EPC size and weight.

  14. Prediction of high frequency core loss for electrical steel using the data provided by manufacturer

    Science.gov (United States)

    Roy, Rakesh; Dalal, Ankit; Kumar, Praveen

    2016-07-01

    This paper describes a technique to determine the core loss data, at high frequencies, using the loss data provided by the lamination manufacturer. Steinmetz equation is used in this proposed method to determine core loss at high frequency. This Steinmetz equation consists of static hysteresis and eddy current loss. The presented technique considers the coefficients of Steinmetz equation as variable with frequency and peak magnetic flux density. The high frequency core loss data, predicted using this model is compared with the catalogue data given by manufacturer and very good accuracy has been obtained for a wide range of frequency.

  15. A real scale simulator for high frequency LEMP

    Science.gov (United States)

    Gauthier, D.; Serafin, D.

    1991-01-01

    The real scale simulator is described which was designed by the Centre d'Etudes de Gramat (CEG) to study the coupling of fast rise time Lightning Electromagnetic pulse in a fighter aircraft. The system capability of generating the right electromagnetic environment was studied using a Finite Difference Time Domain (FDTD) computer program. First, data of inside stresses are shown. Then, a time domain and a frequency domain approach is exposed and compared.

  16. Particle acceleration through the resonance of high magnetic field and high frequency electromagnetic wave

    International Nuclear Information System (INIS)

    Hong, Liu; He, X.T.; Chen, S.G.; Zhang, W.Y.; He, X.T.; Hong, Liu

    2004-01-01

    We propose a new particle acceleration mechanism. Electrons can be accelerated to relativistic energy within a few electromagnetic wave cycles through the mechanism which is named electromagnetic and magnetic field resonance acceleration (EMRA). We find that the electron acceleration depends not only on the electromagnetic wave intensity, but also on the ratio between electron Larmor frequency and electromagnetic wave frequency. As the ratio approaches to unity, a clear resonance peak is observed, corresponding to the EMRA. Near the resonance regime, the strong magnetic fields still affect the electron acceleration dramatically. We derive an approximate analytical solution of the relativistic electron energy in adiabatic limit, which provides a full understanding of this phenomenon. In typical parameters of pulsar magnetospheres, the mechanism allows particles to increase their energies through the resonance of high magnetic field and high frequency electromagnetic wave in each electromagnetic wave period. The energy spectra of the accelerated particles exhibit the synchrotron radiation behavior. These can help to understand the remaining emission of high energy electron from radio pulsar within supernova remnant. The other potential application of our theory in fast ignition scheme of inertial confinement fusion is also discussed. (authors)

  17. High frequency, high amplitude and low energy earthquake study of nuclear power plants

    International Nuclear Information System (INIS)

    Bernero, R.M.; Lee, A.J.H.; Sobel, P.A.

    1988-01-01

    Nuclear power plants are designed for a seismic input spectrum based on U.S. acceleration time histories. However, data recorded near several earthquakes, mostly in the Eastern U.S., are richer in high frequency energy. This paper focuses on the evaluation of one of these events, i.e., the 1986 Ohio earthquake approximately 10 miles from the Perry nuclear power plant. The Perry Seismic Category I structures were reanalyzed using the in-structure recorded earthquake motions. The calculated in-structure response spectra and recorded response spectra have the same general trends, which shows the buildings are capable of responding to high frequency earthquake motion. Dynamic stresses calculated using the Ohio earthquake recorded motions are substantially lower than the design stresses. The seismic qualification of a wide sample of equipment was reassessed using the Ohio earthquake recorded motions and the margins were found to be larger than one. The 1986 Ohio earthquake was also shown to possess much lower energy content and ductility demand than the design spectra. For the Perry case, the seismic design was shown to have adequate safety margins to accommodate the 1986 Ohio earthquake, even though the design spectra were exceeded at about 20 Hz. The NRC is evaluating the need to generically modify design spectra in light of the recent high frequency recordings. (orig.)

  18. Large power electron tubes for high frequency heating

    International Nuclear Information System (INIS)

    Okamoto, Tadashi; Sato, Hisaaki.

    1988-01-01

    On the large power electron tubes used for electron cyclotron heating, lower hybrid resonance frequency heating, and ion cyclotron range of frequency heating, namely gyrotron, klystron and quadrupole tube, the features, the present status of development, the construction, the principle and so on are explained. The research and development of gyrotrons are most advanced in USSR, the inventor. The course of the development of gyrotrons in foreign countries and in Japan is described. There are many variants of gyrotrons, for example whispering gallery mode, klystron type, backward wave oscillator type, gyro-peniotron and others. The principle of gyrotrons is explained, and about the examples of the developed gyrotrons, the design parameters are shown. For the purpose of using for the LHRF heating in JT-60, a superlarge power klystron of 1 MW output at 2 GHz frequency, which is the largest class in the world, has been developed. Its total length is 2.7 m, and weight is 1.5 t. It features, construction, function and performance are reported. The trend of large power quadrupole tubes is toward stable action with large power in VHF zone, and the typical products in USA and Europe are shown. (Kako, I.)

  19. The elliptic sine-Gordon equation in a half plane

    International Nuclear Information System (INIS)

    Pelloni, B; Pinotsis, D A

    2010-01-01

    We consider boundary value problems for the elliptic sine-Gordon equation posed in the half plane y > 0. This problem was considered in Gutshabash and Lipovskii (1994 J. Math. Sci. 68 197–201) using the classical inverse scattering transform approach. Given the limitations of this approach, the results obtained rely on a nonlinear constraint on the spectral data derived heuristically by analogy with the linearized case. We revisit the analysis of such problems using a recent generalization of the inverse scattering transform known as the Fokas method, and show that the nonlinear constraint of Gutshabash and Lipovskii (1994 J. Math. Sci. 68 197–201) is a consequence of the so-called global relation. We also show that this relation implies a stronger constraint on the spectral data, and in particular that no choice of boundary conditions can be associated with a decaying (possibly mod 2π) solution analogous to the pure soliton solutions of the usual, time-dependent sine-Gordon equation. We also briefly indicate how, in contrast to the evolutionary case, the elliptic sine-Gordon equation posed in the half plane does not admit linearisable boundary conditions

  20. Polypteridae (Actinopterygii: Cladistia) and DANA-SINEs insertions.

    Science.gov (United States)

    Morescalchi, Maria Alessandra; Barucca, Marco; Stingo, Vincenzo; Capriglione, Teresa

    2010-06-01

    SINE sequences are interspersed throughout virtually all eukaryotic genomes and greatly outnumber the other repetitive elements. These sequences are of increasing interest for phylogenetic studies because of their diagnostic power for establishing common ancestry among taxa, once properly characterized. We identified and characterized a peculiar family of composite tRNA-derived short interspersed SINEs, DANA-SINEs, associated with mutational activities in Danio rerio, in a group of species belonging to one of the most basal bony fish families, the Polypteridae, in order to investigate their own inner specific phylogenetic relationships. DANA sequences were identified, sequenced and then localized, by means of fluorescent in situ hybridization (FISH), in six Polypteridae species (Polypterus delhezi, P. ornatipinnis, P. palmas, P. buettikoferi P. senegalus and Erpetoichthys calabaricus) After cloning, the sequences obtained were aligned for phylogenetic analysis, comparing them with three Dipnoan lungfish species (Protopterus annectens, P. aethiopicus, Lepidosiren paradoxa), and Lethenteron reissneri (Petromyzontidae)was used as outgroup. The obtained overlapping MP, ML and NJ tree clustered together the species belonging to the two taxonomically different Osteichthyans groups: the Polypteridae, by one side, and the Protopteridae by the other, with the monotypic genus Erpetoichthys more distantly related to the Polypterus genus comprising three distinct groups: P. palmas and P. buettikoferi, P. delhezi and P. ornatipinnis and P. senegalus. In situ hybridization with DANA probes marked along the whole chromosome arms in the metaphases of all the Polypteridae species examined. Copyright © 2010 Elsevier B.V. All rights reserved.