Science.gov

Sample records for side harmonic contributions

  1. Multi-Orbital contributions in High Harmonic Generation

    NASA Astrophysics Data System (ADS)

    Guehr, Markus

    2009-05-01

    The high harmonic spectrum generated from atoms or molecules in a strong laser field contains information about the electronic structure of the generation medium. In the high harmonic generation (HHG) process, a free electron wave packet tunnel-ionizes from the molecular orbital in a strong laser field. After being accelerated by the laser electric field, the free electron wave packet coherently recombines to the orbital from which is was initially ionized, thereby emitting the harmonic spectrum. Interferences between the free electron wave packet and the molecular orbital will shape the spectrum in a characteristic way. These interferences have been used to tomographically image the highest occupied molecular orbital (HOMO) of N2 [1]. Molecular electronic states energetically below the HOMO should contribute to laser-driven high harmonic generation (HHG), but this behavior has not been observed previously. We have observed evidence of HHG from multiple orbitals in aligned N2 [2]. The tunneling ionization (and therefore the harmonic generation) is most efficient if the orbital has a large extension in the direction of the harmonic generation polarization. The HOMO with its σg symmetry therefore dominates the harmonic spectrum if the molecular axis is parallel to the harmonic generation polarization, the lower bound πu HOMO-1 dominates in the perpendicular case. The HOMO contributions appear as a regular plateau with a cutoff in the HHG spectrum. In contrast, the HOMO-1 signal is strongly peaked in the cutoff region. We explain this by semi-classical simulations of the recombination process that show constructive interferences between the HOMO-1 and the recombining wave packet in the cutoff region. The ability to monitor several orbitals opens the route to imaging coherent superpositions of electronic orbitals. [1] J. Itatani et al., Nature 432, 867 (2004)[2] B. K. McFarland, J. P. Farrell, P. H. Bucksbaum and M. Gühr, Science 322, 1232 (2008)

  2. An analysis of cochlear response harmonics: Contribution of neural excitation.

    PubMed

    Chertoff, M E; Kamerer, A M; Peppi, M; Lichtenhan, J T

    2015-11-01

    In this report an analysis of cochlear response harmonics is developed to derive a mathematical function to estimate the gross mechanics involved in the in vivo transfer of acoustic sound into neural excitation (f(Tr)). In a simulation it is shown that the harmonic distortion from a nonlinear system can be used to estimate the nonlinearity, supporting the next phase of the experiment: Applying the harmonic analysis to physiologic measurements to derive estimates of the unknown, in vivo f(Tr). From gerbil ears, estimates of f(Tr) were derived from cochlear response measurements made with an electrode at the round window niche from 85 Hz tone bursts. Estimates of f(Tr) before and after inducing auditory neuropathy-loss of auditory nerve responses with preserved hair cell responses from neurotoxic treatment with ouabain-showed that the neural excitation from low-frequency tones contributes to the magnitude of f(Tr) but not the sigmoidal, saturating, nonlinear morphology. PMID:26627769

  3. Object perception and masking: contributions of sides and convexities.

    PubMed

    Poirier, Frédéric J A M; Wilson, Hugh R

    2007-10-01

    Object perception uses a variety of visual cues, including shape cues derived from sides and convexities. Two recent masking studies using radial frequency patterns have argued, respectively, for a predominant role of convexity [Habak, C., Wilkinson, F., Zakher, B., & Wilson, H. R. (2004). Curvature population coding for complex shapes in human vision. Vision Research, 44 (24), 2815-2823] or side information [Hess, R. F., Wang, Y. -Z., & Dakin, S. C. (1999). Are judgements of circularity local or global? Vision Research, 39, 4354-4360]. Here we resolve the controversy by separating the masks into their parts (e.g., convexities and sides), and measuring the relative masking influences of the different mask components. We found that both side and convexity information contribute to masking. However, masking due to side information was much less dependent on alignment compared to masking due to convexities. This supports a theory where convexities constitute a prime source of information for shape processing, and sides do also contribute but to a smaller extent. PMID:17889924

  4. Qualitative and quantitative effects of harmonic echocardiographic imaging on endocardial edge definition and side-lobe artifacts

    NASA Technical Reports Server (NTRS)

    Rubin, D. N.; Yazbek, N.; Garcia, M. J.; Stewart, W. J.; Thomas, J. D.

    2000-01-01

    Harmonic imaging is a new ultrasonographic technique that is designed to improve image quality by exploiting the spontaneous generation of higher frequencies as ultrasound propagates through tissue. We studied 51 difficult-to-image patients with blinded side-by-side cineloop evaluation of endocardial border definition by harmonic versus fundamental imaging. In addition, quantitative intensities from cavity versus wall were compared for harmonic versus fundamental imaging. Harmonic imaging improved left ventricular endocardial border delineation over fundamental imaging (superior: harmonic = 71.1%, fundamental = 18.7%; similar: 10.2%; P <.001). Quantitative analysis of 100 wall/cavity combinations demonstrated brighter wall segments and more strikingly darker cavities during harmonic imaging (cavity intensity on a 0 to 255 scale: fundamental = 15.6 +/- 8.6; harmonic = 6.0 +/- 5.3; P <.0001), which led to enhanced contrast between the wall and cavity (1.89 versus 1.19, P <.0001). Harmonic imaging reduces side-lobe artifacts, resulting in a darker cavity and brighter walls, thereby improving image contrast and endocardial delineation.

  5. UV by the fourth harmonic generation of compact side-pumped Yb:YAG laser emission

    NASA Astrophysics Data System (ADS)

    Cole, Brian; McIntosh, Chris; Hays, Alan; Dilazaro, Tom; Goldberg, Lew

    2016-03-01

    We present a compact, side pumped passively Q-switched Yb:YAG laser that was operated in a burst mode with pump durations of 2-4 ms at low duty cycles. Intra-pump pulse Q-switched pulse repetition frequencies varied from 5-20 kHz depending on the transmission of the Cr:YAG saturable absorber, which was varied from 70% to 94%. Pump duration, pulse repetition frequency and output coupler reflectivity were optimized to yield maximum Yb:YAG laser average power and laser efficiency, while providing sufficient peak intensity, typically 0.3-1 MW, to enable efficient forth harmonic generation (FHG). Pulse energies and durations were in ranges of 0.3-1.8 mJ and 1.5-7ns, respectively, dependent on the unbleached transmission of the Cr:YAG saturable absorber. We achieved an optical efficiency of greater than 15% for the Yb:YAG laser. Extra-cavity 515 nm second harmonic generation (SHG) was achieved using a 5mm long KTP crystal. The 515 nm light was then frequency doubled by focusing it into a 7mm long BBO crystal, resulting in a 15% conversion efficiency from 1030nm to 257.5 nm, with an average UV power greater than 100 mW.

  6. Artificial Satellite Theory: Contribution of the Tesseral Harmonic Coefficients

    NASA Astrophysics Data System (ADS)

    Palacián, J. F.

    2006-01-01

    In the context of artificial satellite theory, we study the case of an artificial satellite around an Earth-like planet. The perturbation force taken into account is produced by the gravity attraction of the planet, and in particular, it is caused by its inhomogenous potential. Our analysis is purely analytical and we begin by truncating the Hamiltonian equations at second order, that is, considering the influence of the zonal and the tesseral harmonics to order two. The system is formulated as a Hamiltonian with three degrees of freedom. Then, by means of three successive Lie transforms, we normalise the system to order five in a small parameter. We do not use Taylor expansions of the eccentricity nor Fourier series in the anomalies. After these transformations are performed, the truncated and reduced Hamiltonian defines a system of one degree of freedom which can be written in terms of a collection of variables in a phase space which takes into account all of the symmetries of the problem. Next, an analysis of the system is performed, obtaining up to four relative equilibria and two types of bifurcations. The connection with the original system establishes the existence of various families of invariant tori, quasiperiodic and periodic trajectories with the same type of bifurcations as the reduced problem.

  7. Anthropometry for WorldSID, a World-Harmonized Midsize Male Side Impact Crash Dummy

    SciTech Connect

    S. Moss; Z. Wang; M. Salloum; M. Reed; M. Van Ratingen; D. Cesari; R. Scherer; T. Uchimura; M. Beusenberg

    2000-06-19

    The WorldSID project is a global effort to design a new generation side impact crash test dummy under the direction of the International Organization for Standardization (ISO). The first WorldSID crash dummy will represent a world-harmonized mid-size adult male. This paper discusses the research and rationale undertaken to define the anthropometry of a world standard midsize male in the typical automotive seated posture. Various anthropometry databases are compared region by region and in terms of the key dimensions needed for crash dummy design. The Anthropometry for Motor Vehicle Occupants (AMVO) dataset, as established by the University of Michigan Transportation Research Institute (UMTRI), is selected as the basis for the WorldSID mid-size male, updated to include revisions to the pelvis bone location. The proposed mass of the dummy is 77.3kg with full arms. The rationale for the selected mass is discussed. The joint location and surface landmark database is appended to this paper.

  8. Contributions of Spherical Harmonics to Magnetic and Gravitational Fields

    NASA Technical Reports Server (NTRS)

    Roithmayr, Carlos M.

    2004-01-01

    Gravitational forces are of cardinal importance in the dynamics of spacecraft; magnetic attractions sometime play a significant role also, as was the case with the Long Duration Exposure Facility, and as is now true for the first segment of Space Station Freedom. Both satellites depend on gravitational moment and a device known as a magnetic damper to stabilize their orientation. Magnetic fields are mathematically similar to gravitational fields in one important respect: each can be regarded as a gradient of a potential function that, in turn, can be described as an infinite series of spherical harmonics. Consequently, the two fields can be computed, in part, with quantities that need only be evaluated once, resulting in a savings of time when both fields are needed. The objective of this material is to present magnetic field and gravitational force expressions, and point out the terms that belong to both this is accomplished in Section 1 and 2. Section 3 contains the deductive reasoning with which one obtains the expressions of interest. Finally, examples in Section 4 show these equations can be used to reproduce others that arise in connection with special cases such as the magnetic field produced by a tilted dipole, and gravitational force exerted by an oblate spheroid. The mathematics are discussed in the context of terrestrial fields; however, by substituting appropriate constants, the results can be made applicable to fields belonging to other celestial bodies. The expressions presented here share the characteristics of algorithms set forth for computing gravitational force. In particular, computation is performed speedily by means of recursion formulae, and the expressions do not suffer from the shortcoming of a singularity when evaluated at points that lie on the polar axis.

  9. Harmonically mode-locked femtosecond fiber laser using non-uniform, WS2-particle deposited side-polished fiber

    NASA Astrophysics Data System (ADS)

    Lee, Junsu; Park, June; Koo, Joonhoi; Jhon, Young Min; Lee, Ju Han

    2016-03-01

    We investigated the feasibility of using a WS2-deposited side-polished fiber as a harmonic mode-locker to produce a femtosecond fiber laser with a frequency of 1.51 GHz. Our work focuses on using a side-polished fiber platform with non-uniform WS2 particles prepared through liquid phase exfoliation method without centrifugation. Femtosecond optical pulses were generated from an all-fiberized erbium-doped fiber-based ring cavity by increasing the pump power to achieve a tunable pulse repetition rate from 14.57 MHz to 1.51 GHz (104th harmonic). The characteristics of the output pulse were systematically investigated to analyze the pulse repetition rate, harmonic order, average output power, pulse energy, and pulse width as a function of the pump power. The output performance of the laser was compared to that of a laser based on a microfiber-based WS2 film SA described in (Yan et al 2015 Opt. Mater. Express 5 479-89). This experimental demonstration reaffirms that a side-polished fiber is an effective platform to implement an ultrafast harmonic mode-locker, and non-uniform WS2 particles prepared via simple liquid phase exfoliation method without centrifugation provide a suitable saturable absorption response at 1.55 μm.

  10. Contributions to the theory of side edge flap noise

    NASA Technical Reports Server (NTRS)

    Howe, M. S.

    1981-01-01

    High and low frequency asymptotic formulas are derived which express the acoustic frequency spectrum in terms of the wavenumber-frequency spectrum of surface pressure fluctuations on the upper surface of a part span flap, measured in-board of the side edge. Interpolations between the results are used to predict the field shape and its dependence on the subsonic forward flight speed over the whole frequency range. The radiation has the characteristics of a semibaffled dipole at small values of the Strouhal number based on the chord of the flap and the forward flight speed. The degree of Doppler amplification due to forward flight speed of the aircraft is dependent on the Strouhal number; the radiation efficiency of side-edge noise sources is governed by the value of the mean side-edge gap Strouhal number, and is larger when this number is small. Theoretical predictions extrapolated to full scale suggest that the noise generated at a single side edge can exceed that generated along the whole of the trailing edge of the flap by 3 dB.

  11. Bulk quadrupole and interface dipole contribution for second harmonic generation in Si(111)

    NASA Astrophysics Data System (ADS)

    Reitböck, Cornelia; Stifter, David; Alejo-Molina, Adalberto; Hingerl, Kurt; Hardhienata, Hendradi

    2016-03-01

    The second harmonic generation (SHG) response was measured for arbitrarily oriented linear input polarization on Si(111) surfaces in rotational anisotropy experiments. We show for the first time, using the simplified bond hyperpolarizability model (SBHM), that the observed angular shifts of the nonlinear peaks and symmetry features—related to changes in the input polarization—help to identify the corresponding interface dipolar and bulk quadrupolar SHG sources, yielding excellent agreement with the experiment. Additionally, we evaluate for the s-in/p-out (sp) and p-in/p-out (pp)-polarization SHG intensities the contributions from the individual Si bonds. Furthermore, a relation between the four parameters arising from SBHM and six coefficients of the phenomenological SHG theory needed to reproduce experimental data is established.

  12. High-order-harmonic generation in homonuclear and heteronuclear diatomic molecules: Exploration of multiple orbital contributions

    SciTech Connect

    Heslar, John; Telnov, Dmitry; Chu, Shih-I

    2011-04-15

    We present a time-dependent density functional theory (TDDFT) approach with proper asymptotic long-range potential for nonperturbative treatment of high-order harmonic generation (HHG) of diatomic molecules with their molecular axis parallel to the laser field polarization. A time-dependent two-center generalized pseudospectral method in prolate spheroidal coordinate system is used for accurate and efficient treatment of the TDDFT equations in space and time. The theory is applied to a detailed all-electron nonperturbative investigation of HHG processes of homonuclear (N{sub 2} and F{sub 2}) and heteronuclear (CO, BF, and HF) molecules in intense ultrashort laser pulses with the emphasis on the role of multiple molecular orbitals (MOs). The results reveal intriguing and substantially different nonlinear optical response behaviors for homonuclear and heteronuclear molecules. In particular, we found that the HHG spectrum for homonuclear molecules features a destructive interference of MO contributions while heteronuclear molecules show mostly constructive interference of orbital contributions.

  13. Rare Copy Number Variants Contribute to Congenital Left-Sided Heart Disease

    PubMed Central

    Hitz, Marc-Phillip; Lemieux-Perreault, Louis-Philippe; Marshall, Christian; Feroz-Zada, Yassamin; Davies, Robbie; Yang, Shi Wei; Lionel, Anath Christopher; D'Amours, Guylaine; Lemyre, Emmanuelle; Cullum, Rebecca; Bigras, Jean-Luc; Thibeault, Maryse; Chetaille, Philippe; Montpetit, Alexandre; Khairy, Paul; Overduin, Bert; Klaassen, Sabine; Hoodless, Pamela; Nemer, Mona; Stewart, Alexandre F. R.; Boerkoel, Cornelius; Scherer, Stephen W.; Richter, Andrea; Dubé, Marie-Pierre; Andelfinger, Gregor

    2012-01-01

    Left-sided congenital heart disease (CHD) encompasses a spectrum of malformations that range from bicuspid aortic valve to hypoplastic left heart syndrome. It contributes significantly to infant mortality and has serious implications in adult cardiology. Although left-sided CHD is known to be highly heritable, the underlying genetic determinants are largely unidentified. In this study, we sought to determine the impact of structural genomic variation on left-sided CHD and compared multiplex families (464 individuals with 174 affecteds (37.5%) in 59 multiplex families and 8 trios) to 1,582 well-phenotyped controls. 73 unique inherited or de novo CNVs in 54 individuals were identified in the left-sided CHD cohort. After stringent filtering, our gene inventory reveals 25 new candidates for LS-CHD pathogenesis, such as SMC1A, MFAP4, and CTHRC1, and overlaps with several known syndromic loci. Conservative estimation examining the overlap of the prioritized gene content with CNVs present only in affected individuals in our cohort implies a strong effect for unique CNVs in at least 10% of left-sided CHD cases. Enrichment testing of gene content in all identified CNVs showed a significant association with angiogenesis. In this first family-based CNV study of left-sided CHD, we found that both co-segregating and de novo events associate with disease in a complex fashion at structural genomic level. Often viewed as an anatomically circumscript disease, a subset of left-sided CHD may in fact reflect more general genetic perturbations of angiogenesis and/or vascular biology. PMID:22969434

  14. Spectrally resolved multi-channel contributions to the harmonic emission in N2

    NASA Astrophysics Data System (ADS)

    Diveki, Z.; Camper, A.; Haessler, S.; Auguste, T.; Ruchon, T.; Carré, B.; Salières, P.; Guichard, R.; Caillat, J.; Maquet, A.; Taïeb, R.

    2012-02-01

    When generated in molecules, high-order harmonics can be emitted through different ionization channels. The coherent and ultrafast electron dynamics occurring in the ion during the generation process is directly imprinted in the harmonic signal, i.e. in its amplitude and spectral phase. In aligned N2 molecules, we find evidence for a fast variation of this phase as a function of the harmonic order when varying the driving laser intensity. Basing our analysis on a three-step model, we find that this phase variation is a signature of transitions from a single- to a multi-channel regime. In particular, we show that significant nuclear dynamics may occur in the ionization channels on the attosecond timescale, affecting both the amplitude and the phase of the harmonic signal.

  15. A note about Norbert Wiener and his contribution to Harmonic Analysis and Tauberian Theorems

    NASA Astrophysics Data System (ADS)

    Almira, J. M.; Romero, A. E.

    2009-05-01

    In this note we explain the main motivations Norbert Wiener had for the creation of his Generalized Harmonic Analysis [13] and his Tauberian Theorems [14]. Although these papers belong to the most pure mathematical tradition, they were deeply based on some Engineering and Physics Problems and Wiener was able to use them for such diverse areas as Optics, Brownian motion, Filter Theory, Prediction Theory and Cybernetics.

  16. Contribution of cutinase serine 42 side chain to the stabilization of the oxyanion transition state.

    PubMed

    Nicolas, A; Egmond, M; Verrips, C T; de Vlieg, J; Longhi, S; Cambillau, C; Martinez, C

    1996-01-16

    Cutinase from the fungus Fusarium solani pisi is a lipolytic enzyme able to hydrolyze both aggregated and soluble substrates. It therefore provides a powerful tool for probing the mechanisms underlying lipid hydrolysis. Lipolytic enzymes have a catalytic machinery similar to those present in serine proteinases. It is characterized by the triad Ser, His, and Asp (Glu) residues, by an oxyanion binding site that stabilizes the transition state via hydrogen bonds with two main chain amide groups, and possibly by other determinants. It has been suggested on the basis of a covalently bond inhibitor that the cutinase oxyanion hole may consist not only of two main chain amide groups but also of the Ser42 O gamma side chain. Among the esterases and the serine and the cysteine proteases, only Streptomyces scabies esterase, subtilisin, and papain, respectively, have a side chain residue which is involved in the oxyanion hole formation. The position of the cutinase Ser42 side chain is structurally conserved in Rhizomucor miehei lipase with Ser82 O gamma, in Rhizopus delemar lipase with Thr83 O gamma 1, and in Candida antartica B lipase with Thr40 O gamma 1. To evaluate the increase in the tetrahedral intermediate stability provided by Ser42 O gamma, we mutated Ser42 into Ala. Furthermore, since the proper orientation of Ser42 O gamma is directed by Asn84, we mutated Asn84 into Ala, Leu, Asp, and Trp, respectively, to investigate the contribution of this indirect interaction to the stabilization of the oxyanion hole. The S42A mutation resulted in a drastic decrease in the activity (450-fold) without significantly perturbing the three-dimensional structure. The N84A and N84L mutations had milder kinetic effects and did not disrupt the structure of the active site, whereas the N84W and N84D mutations abolished the enzymatic activity due to drastic steric and electrostatic effects, respectively. PMID:8555209

  17. Entanglement negativity in a two dimensional harmonic lattice: area law and corner contributions

    NASA Astrophysics Data System (ADS)

    De Nobili, Cristiano; Coser, Andrea; Tonni, Erik

    2016-08-01

    We study the logarithmic negativity and the moments of the partial transpose in the ground state of a two dimensional massless harmonic square lattice with nearest neighbour interactions for various configurations of adjacent domains. At leading order for large domains, the logarithmic negativity and the logarithm of the ratio between the generic moment of the partial transpose and the moment of the reduced density matrix at the same order satisfy an area law in terms of the length of the curve shared by the adjacent regions. We give numerical evidence that the coefficient of the area law term in these quantities is related to the coefficient of the area law term in the Rényi entropies. Whenever the curve shared by the adjacent domains contains vertices, a subleading logarithmic term occurs in these quantities and the numerical values of the corner function for some pairs of angles are obtained. In the special case of vertices corresponding to explementary angles, we provide numerical evidence that the corner function of the logarithmic negativity is given by the corner function of the Rényi entropy of order 1/2.

  18. Time-synchronous-averaging of gear-meshing-vibration transducer responses for elimination of harmonic contributions from the mating gear and the gear pair

    NASA Astrophysics Data System (ADS)

    Mark, William D.

    2015-10-01

    The transmission-error frequency spectrum of meshing gear pairs, operating at constant speed and constant loading, is decomposed into harmonics arising from the fundamental period of the gear pair, rotational harmonics of the individual gears of the pair, and tooth-meshing harmonics. In the case of hunting-tooth gear pairs, no rotational harmonics from the individual gears, other than the tooth-meshing harmonics, are shown to occur at the same frequencies. Time-synchronous averages utilizing a number of contiguous revolutions of the gear of interest equal to an integer multiple of the number of teeth on the mating gear is shown to eliminate non-tooth-meshing transmission-error rotational-harmonic contributions from the mating gear, and those from the gear pair, in the case of hunting-tooth gear pairs, and to minimize these contributions in the case of non-hunting-tooth gear pairs. An example computation is shown to illustrate the effectiveness of the suggested time-synchronous-averaging procedure.

  19. Nonlinear optical effects and third-harmonic generation in superconductors: Cooper pairs versus Higgs mode contribution

    NASA Astrophysics Data System (ADS)

    Cea, T.; Castellani, C.; Benfatto, L.

    2016-05-01

    The recent observation of a transmitted THz pulse oscillating at three times the frequency of the incident light paves the way to a powerful protocol to access resonant excitations in a superconductor. Here we show that this nonlinear optical process is dominated by light-induced excitation of Cooper pairs, while the collective amplitude (Higgs) fluctuations of the superconducting order parameter give in general a negligible contribution. We also predict a nontrivial dependence of the signal on the direction of the light polarization with respect to the lattice symmetry, which can be tested in systems such as, e.g., cuprate superconductors.

  20. Topological analysis of the periodic structures in a harmonically driven bubble oscillator near Blake's critical threshold: Infinite sequence of two-sided Farey ordering trees

    NASA Astrophysics Data System (ADS)

    Hegedűs, Ferenc

    2016-03-01

    The topology of the stable periodic orbits of a harmonically driven bubble oscillator, the Rayleigh-Plesset equation, in the space of the excitation parameters (pressure amplitude and frequency) has been revealed numerically. This topology is governed by a hierarchy of two-sided Farey trees initiated from a unique primary structure defined also by a simple asymmetric Farey tree. The sub-topology of each of these building blocks is driven by a homoclinic tangency of a periodic saddle. This self-similar organisation is a suitable basis for a general description, since it is in good agreement with partial results obtained in other periodically forced oscillators and iterated maps. The applied ambient pressure in the model is near but still below Blake's critical threshold. Therefore, this paper is also a straightforward continuation of the work of Hegedűs [1], who first found numerical evidence for the existence of stable, period 1 solutions beyond Blake's threshold. The present findings are crucial for the extension of the available numerical results from period 1 to arbitrary periodicity.

  1. Side chain and backbone contributions of Phe508 to CFTR folding

    SciTech Connect

    Thibodeau, Patrick H.; Brautigam, Chad A.; Machius, Mischa; Thomas, Philip J.

    2010-12-07

    Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), an integral membrane protein, cause cystic fibrosis (CF). The most common CF-causing mutant, deletion of Phe508, fails to properly fold. To elucidate the role Phe508 plays in the folding of CFTR, missense mutations at this position were generated. Only one missense mutation had a pronounced effect on the stability and folding of the isolated domain in vitro. In contrast, many substitutions, including those of charged and bulky residues, disrupted folding of full-length CFTR in cells. Structures of two mutant nucleotide-binding domains (NBDs) reveal only local alterations of the surface near position 508. These results suggest that the peptide backbone plays a role in the proper folding of the domain, whereas the side chain plays a role in defining a surface of NBD1 that potentially interacts with other domains during the maturation of intact CFTR.

  2. Endothelial Side Population Cells Contribute to Tumor Angiogenesis and Antiangiogenic Drug Resistance.

    PubMed

    Naito, Hisamichi; Wakabayashi, Taku; Kidoya, Hiroyasu; Muramatsu, Fumitaka; Takara, Kazuhiro; Eino, Daisuke; Yamane, Keitaro; Iba, Tomohiro; Takakura, Nobuyuki

    2016-06-01

    Angiogenesis plays a crucial role in tumor growth, with an undisputed contribution of resident endothelial cells (EC) to new blood vessels in the tumor. Here, we report the definition of a small population of vascular-resident stem/progenitor-like EC that contributes predominantly to new blood vessel formation in the tumor. Although the surface markers of this population are similar to other ECs, those from the lung vasculature possess colony-forming ability in vitro and contribute to angiogenesis in vivo These specific ECs actively proliferate in lung tumors, and the percentage of this population significantly increases in the tumor vasculature relative to normal lung tissue. Using genetic recombination and bone marrow transplant models, we show that these cells are phenotypically true ECs and do not originate from hematopoietic cells. After treatment of tumors with antiangiogenic drugs, these specific ECs selectively survived and remained in the tumor. Together, our results established that ECs in the peripheral vasculature are heterogeneous and that stem/progenitor-like ECs play an indispensable role in tumor angiogenesis as EC-supplying cells. The lack of susceptibility of these ECs to antiangiogenic drugs may account for resistance of the tumor to this drug type. Thus, inhibiting these ECs might provide a promising strategy to overcome antiangiogenic drug resistance. Cancer Res; 76(11); 3200-10. ©2016 AACR. PMID:27197162

  3. SURFACE ENHANCED SECOND HARMONIC GENERATION

    SciTech Connect

    Chen, C. K.; de Castro, A. R.B.; Shen, Y. R.

    1980-09-01

    Second harmonic generation at a silver-air interface was enhanced due to surface roughness by a factor of 10{sup 4}. The local field enhancement is believed to be responsible for the effect. An unusually broad luminescence background extending far beyond the antiStokes side of the second harmonic was also observed.

  4. A pharmacokinetic approach to resolving spinal and systemic contributions to epidural alfentanil analgesia and side-effects.

    PubMed

    Coda, B A; Brown, M C; Schaffer, R L; Donaldson, G; Shen, D D

    1995-09-01

    A pilot study was conducted in 7 normal volunteers to demonstrate the feasibility of employing pharmacokinetic tailoring to achieve matching plasma opioid concentration-time curves after epidural (e.p.) and intravenous (i.v.) alfentanil administration. Each subject participated in 1 pretest and 2 test sessions. Our pain model was cutaneous electrical stimulation of the finger and toe, adjusted to produce a baseline pain report of 5 (strong pain on a 0-5 scale). On test day 1, subjects received e.p. alfentanil (750 micrograms) and an i.v. saline infusion. Serial measurements of analgesia, end tidal CO2, pupil size, subjective side effects, and plasma alfentanil concentrations were conducted before and at various time intervals over a 4-h period after alfentanil administration. On test day 2, subjects received e.p. saline and a pharmacokinetically tailored i.v. infusion (using individual pharmacokinetics determined on the pretest day) designed to achieve a plasma concentration-time profile identical to that observed on the epidural day. The same battery of effect measurements was administered as on the 1st test day. Plasma alfentanil was measured to verify the accuracy of the tailored infusion. Plasma alfentanil concentration profiles were nearly identical on both test days. Peak plasma alfentanil concentrations were near the reported minimum effective analgesic concentration (MEAC). Overall, analgesia was slightly greater with e.p. administration. Onset of pain relief was rapid, and duration was approximately 1.5 h with e.p. and 1 h with i.v. alfentanil. There were no differences in pupil size, ETCO2, or subjective side effects between e.p. versus i.v. administration. We conclude that systemic redistribution from the epidural space appears to account for most, but not all, of the analgesia. PMID:8657433

  5. Contributions of a disulfide bond and a reduced cysteine side chain to the intrinsic activity of the high-density lipoprotein receptor SR-BI.

    PubMed

    Yu, Miao; Lau, Thomas Y; Carr, Steven A; Krieger, Monty

    2012-12-18

    The high-density lipoprotein (HDL) receptor scavenger receptor class B, type I (SR-BI), binds HDL and mediates selective cholesteryl ester uptake. SR-BI's structure and mechanism are poorly understood. We used mass spectrometry to assign the two disulfide bonds in SR-BI that connect cysteines within the conserved Cys(321)-Pro(322)-Cys(323) (CPC) motif and connect Cys(280) to Cys(334). We used site-specific mutagenesis to evaluate the contributions of the CPC motif and the side chain of extracellular Cys(384) to HDL binding and lipid uptake. The effects of CPC mutations on activity were context-dependent. Full wild-type (WT) activity required Pro(322) and Cys(323) only when Cys(321) was present. Reduced intrinsic activities were observed for CXC and CPX, but not XXC, XPX, or XXX mutants (X ≠ WT residue). Apparently, a free thiol side chain at position 321 that cannot form an intra-CPC disulfide bond with Cys(323) is deleterious, perhaps because of aberrant disulfide bond formation. Pro(322) may stabilize an otherwise strained CPC disulfide bond, thus supporting WT activity, but this disulfide bond is not absolutely required for normal activity. C(384)X (X = S, T, L, Y, G, or A) mutants exhibited altered activities that varied with the side chain's size: larger side chains phenocopied WT SR-BI treated with its thiosemicarbazone inhibitor BLT-1 (enhanced binding, weakened uptake); smaller side chains produced almost inverse effects (increased uptake:binding ratio). C(384)X mutants were BLT-1-resistant, supporting the proposal that Cys(384)'s thiol interacts with BLT-1. We discuss the implications of our findings on the functions of the extracellular loop cysteines in SR-BI and compare our results to those presented by other laboratories. PMID:23205738

  6. Contributions of a disulfide bond and a reduced cysteine side chain to the intrinsic activity of the HDL receptor SR-BI

    PubMed Central

    Yu, Miao; Lau, Thomas Y.; Carr, Steven A.; Krieger, Monty

    2013-01-01

    The high density lipoprotein (HDL) receptor, scavenger receptor class B, type I (SR-BI), binds HDL and mediates selective cholesteryl ester uptake. SR-BI's structure and mechanism are poorly understood. We used mass spectrometry to assign the two disulfide bonds in SR-BI that connect cysteines within the conserved Cys321-Pro322-Cys323 (CPC) motif and connect Cys280 to Cys334. We used site-specific mutagenesis to evaluate the contributions of the CPC motif and the side chain of extracellular Cys384 to HDL binding and lipid uptake. The effects of CPC mutations on activity were context dependent. Full wild-type (WT) activity required Pro322 and Cys323 only when Cys321 was present. Reduced intrinsic activities were observed for CXC and CPX, but not XXC, XPX or XXX mutants (X≠WT residue). Apparently, a free thiol side chain at position 321 that cannot form an intra-CPC disulfide bond with Cys323 is deleterious, perhaps because of aberrant disulfide bond formation. Pro322 may stabilize an otherwise strained CPC disulfide bond, thus supporting WT activity, but this disulfide bond is not absolutely required for activity. C384X (X=S,T,L,Y,G,A) mutants exhibited altered activities that varied with the side chain's size: larger side chains phenocopied WT SR-BI treated with its thiosemicarbazone inhibitor BLT-1 (increased binding, decreased uptake); smaller side chains produced almost inverse effects (increased uptake:binding ratio). C384X mutants were BLT-1 resistant, supporting the proposal that Cys384's thiol interacts with BLT-1. We discuss the implications of our findings on the functions of the extracellular loop cysteines in SR-BI and compare our results to those presented by other laboratories. PMID:23205738

  7. Two Sides of Meaning: The Scalp-Recorded N400 Reflects Distinct Contributions from the Cerebral Hemispheres

    PubMed Central

    Wlotko, Edward W.; Federmeier, Kara D.

    2013-01-01

    The N400, a component of the event-related potential (ERP) associated with the processing of meaning, is sensitive to a wide array of lexico-semantic, sentence-level, and discourse-level manipulations across modalities. In sentence contexts, N400 amplitude varies inversely and nearly linearly with the predictability of a word in its context. However, recent theories and empirical evidence from studies employing the visual half-field technique (to selectively bias processing to one cerebral hemisphere) suggest that the two hemispheres use sentence context information in different ways. Thus, each hemisphere may not respond to manipulations of contextual predictability in an equivalent manner. This possibility was investigated by recording ERPs while presenting [in the left and right visual fields (VFs)] sentence-final words that varied over the full range of sentence-level predictability. RVF/left hemisphere items were facilitated (as evidenced by reduced N400 amplitudes) over a broader range of predictability compared with LVF/right hemisphere items, although both strongly predictable and completely unexpected items evoked similar responses in each VF/hemisphere. Further, the pattern of N400 amplitudes over the full range of predictability significantly differed from a linear response function for both VFs/hemispheres. This suggests that the N400 response recorded with standard central field presentation comprises different contributions from both cerebral hemispheres, neither of which on its own is sensitive to contextual predictability in an evenly graded manner. These data challenge the notion of a singular or unitary mode of comprehension and instead support the view that the left and right hemispheres instantiate unique, complementary language comprehension architectures in parallel. PMID:23630506

  8. Side Effects

    MedlinePlus

    ... 2014 Select a Language: Fact Sheet 550 Side Effects WHAT ARE SIDE EFFECTS? WHO GETS SIDE EFFECTS? ... t assume that you will get every side effect that’s listed! Most people have few or only ...

  9. Harmonic engine

    DOEpatents

    Bennett, Charles L.

    2009-10-20

    A high efficiency harmonic engine based on a resonantly reciprocating piston expander that extracts work from heat and pressurizes working fluid in a reciprocating piston compressor. The engine preferably includes harmonic oscillator valves capable of oscillating at a resonant frequency for controlling the flow of working fluid into and out of the expander, and also preferably includes a shunt line connecting an expansion chamber of the expander to a buffer chamber of the expander for minimizing pressure variations in the fluidic circuit of the engine. The engine is especially designed to operate with very high temperature input to the expander and very low temperature input to the compressor, to produce very high thermal conversion efficiency.

  10. The contribution of primary and secondary somatosensory cortices to the representation of body parts and body sides: an fMRI adaptation study.

    PubMed

    Tamè, Luigi; Braun, Christoph; Lingnau, Angelika; Schwarzbach, Jens; Demarchi, Gianpaolo; Li Hegner, Yiwen; Farnè, Alessandro; Pavani, Francesco

    2012-12-01

    Although the somatosensory homunculus is a classically used description of the way somatosensory inputs are processed in the brain, the actual contributions of primary (SI) and secondary (SII) somatosensory cortices to the spatial coding of touch remain poorly understood. We studied adaptation of the fMRI BOLD response in the somatosensory cortex by delivering pairs of vibrotactile stimuli to the finger tips of the index and middle fingers. The first stimulus (adaptor) was delivered either to the index or to the middle finger of the right or left hand, and the second stimulus (test) was always administered to the left index finger. The overall BOLD response evoked by the stimulation was primarily contralateral in SI and was more bilateral in SII. However, our fMRI adaptation approach also revealed that both somatosensory cortices were sensitive to ipsilateral as well as to contralateral inputs. SI and SII adapted more after subsequent stimulation of homologous as compared with nonhomologous fingers, showing a distinction between different fingers. Most importantly, for both somatosensory cortices, this finger-specific adaptation occurred irrespective of whether the tactile stimulus was delivered to the same or to different hands. This result implies integration of contralateral and ipsilateral somatosensory inputs in SI as well as in SII. Our findings suggest that SI is more than a simple relay for sensory information and that both SI and SII contribute to the spatial coding of touch by discriminating between body parts (fingers) and by integrating the somatosensory input from the two sides of the body (hands). PMID:22849401

  11. Harmonic engine

    DOEpatents

    Bennett, Charles L.; Sewall, Noel; Boroa, Carl

    2014-08-19

    An engine based on a reciprocating piston engine that extracts work from pressurized working fluid. The engine includes a harmonic oscillator inlet valve capable of oscillating at a resonant frequency for controlling the flow of working fluid into of the engine. In particular, the inlet valve includes an inlet valve head and a spring arranged together as a harmonic oscillator so that the inlet valve head is moveable from an unbiased equilibrium position to a biased closed position occluding an inlet. Upon releasing the inlet valve the inlet valve head undergoes a single oscillation past the equilibrium positio to a maximum open position and returns to a biased return position close to the closed position to choke the flow and produce a pressure drop across the inlet valve causing the inlet valve to close. Protrusions carried either by the inlet valve head or piston head are used to bump open the inlet valve from the closed position and initiate the single oscillation of the inlet valve head, and protrusions carried either by the outlet valve head or piston head are used to close the outlet valve ahead of the bump opening of the inlet valve.

  12. Entanglement negativity in the harmonic chain out of equilibrium

    NASA Astrophysics Data System (ADS)

    Eisler, Viktor; Zimborás, Zoltán

    2014-12-01

    We study the entanglement in a chain of harmonic oscillators driven out of equilibrium by preparing the two sides of the system at different temperatures, and subsequently joining them together. The steady state is constructed explicitly and the logarithmic negativity is calculated between two adjacent segments of the chain. We find that, for low temperatures, the steady-state entanglement is a sum of contributions pertaining to left- and right-moving excitations emitted from the two reservoirs. In turn, the steady-state entanglement is a simple average of the Gibbs-state values and thus its scaling can be obtained from conformal field theory. A similar averaging behaviour is observed during the entire time evolution. As a particular case, we also discuss a local quench where both sides of the chain are initialized in their respective ground states.

  13. The contribution of radio-frequency rectification to field-aligned losses of high-harmonic fast wave power to the divertor in the National Spherical Torus eXperiment

    SciTech Connect

    Perkins, R. J. Hosea, J. C.; Jaworski, M. A.; Diallo, A.; Bell, R. E.; Bertelli, N.; Gerhardt, S.; Kramer, G. J.; LeBlanc, B. P.; Phillips, C. K.; Podestà, M.; Roquemore, L.; Taylor, G.; Wilson, J. R.; Ahn, J.-W.; Gray, T. K.; McLean, A.; Sabbagh, S.

    2015-04-15

    The National Spherical Torus eXperiment (NSTX) can exhibit a major loss of high-harmonic fast wave (HHFW) power along scrape-off layer (SOL) field lines passing in front of the antenna, resulting in bright and hot spirals on both the upper and lower divertor regions. One possible mechanism for this loss is RF sheaths forming at the divertors. Here, we demonstrate that swept-voltage Langmuir probe characteristics for probes under the spiral are shifted relative to those not under the spiral in a manner consistent with RF rectification. We estimate both the magnitude of the RF voltage across the sheath and the sheath heat flux transmission coefficient in the presence of the RF field. Although precise comparison between the computed heat flux and infrared (IR) thermography cannot yet be made, the computed heat deposition compares favorably with the projections from IR camera measurements. The RF sheath losses are significant and contribute substantially to the total SOL losses of HHFW power to the divertor for the cases studied. This work will guide future experimentation on NSTX-U, where a wide-angle IR camera and a dedicated set of coaxial Langmuir probes for measuring the RF sheath voltage directly will quantify the contribution of RF sheath rectification to the heat deposition from the SOL to the divertor.

  14. Color harmonization for images

    NASA Astrophysics Data System (ADS)

    Tang, Zhen; Miao, Zhenjiang; Wan, Yanli; Wang, Zhifei

    2011-04-01

    Color harmonization is an artistic technique to adjust a set of colors in order to enhance their visual harmony so that they are aesthetically pleasing in terms of human visual perception. We present a new color harmonization method that treats the harmonization as a function optimization. For a given image, we derive a cost function based on the observation that pixels in a small window that have similar unharmonic hues should be harmonized with similar harmonic hues. By minimizing the cost function, we get a harmonized image in which the spatial coherence is preserved. A new matching function is proposed to select the best matching harmonic schemes, and a new component-based preharmonization strategy is proposed to preserve the hue distribution of the harmonized images. Our approach overcomes several shortcomings of the existing color harmonization methods. We test our algorithm with a variety of images to demonstrate the effectiveness of our approach.

  15. A neural network model of harmonic detection

    NASA Astrophysics Data System (ADS)

    Lewis, Clifford F.

    2003-04-01

    Harmonic detection theories postulate that a virtual pitch is perceived when a sufficient number of harmonics is present. The harmonics need not be consecutive, but higher harmonics contribute less than lower harmonics [J. Raatgever and F. A. Bilsen, in Auditory Physiology and Perception, edited by Y. Cazals, K. Horner, and L. Demany (Pergamon, Oxford, 1992), pp. 215-222 M. K. McBeath and J. F. Wayand, Abstracts of the Psychonom. Soc. 3, 55 (1998)]. A neural network model is presented that has the potential to simulate this operation. Harmonics are first passed through a bank of rounded exponential filters with lateral inhibition. The results are used as inputs for an autoassociator neural network. The model is trained using harmonic data for symphonic musical instruments, in order to test whether it can self-organize by learning associations between co-occurring harmonics. It is shown that the trained model can complete the pattern for missing-fundamental sounds. The Performance of the model in harmonic detection will be compared with experimental results for humans.

  16. Simple Harmonic Motion in Harmonic Plane Waves.

    ERIC Educational Resources Information Center

    Benumof, Reuben

    1980-01-01

    Discusses the distribution of kinetic and potential energy in transverse and longitudinal waves and examines the transmission of power and momentum. This discussion is intended to aid in understanding the simple harmonic motion of a particle involved in the propagation of a harmonic mechanical plane wave. (HM)

  17. Harmonization of Biodiesel Specifications

    SciTech Connect

    Alleman, T. L.

    2008-02-01

    Worldwide biodiesel production has grown dramatically over the last several years. Biodiesel standards vary across countries and regions, and there is a call for harmonization. For harmonization to become a reality, standards have to be adapted to cover all feedstocks. Additionally, all feedstocks cannot meet all specifications, so harmonization will require standards to either tighten or relax. For harmonization to succeed, the biodiesel market must be expanded with the alignment of test methods and specification limits, not contracted.

  18. Effective ATI channels in high harmonic generation

    NASA Astrophysics Data System (ADS)

    Kuchiev, M. Yu; Ostrovsky, V. N.

    2001-02-01

    Harmonic generation by an atom in a laser field is described by the three-step mechanism as proceeding via above-threshold ionization (ATI) followed by electron propagation in the laser-dressed continuum and subsequent laser-assisted recombination (LAR). The amplitude of the harmonic production is given by the coherent sum of contributions from different intermediate ATI channels labelled by the number, m, of absorbed laser photons. The range of m-values that give a substantial contribution is explored and found to be rather broad for high harmonic generation. The coherence effects are of crucial importance as they are responsible for the characteristic pattern of harmonic intensities with a plateau domain followed by a cut-off region. Due to the multiphoton nature of the process, an efficient summation of m-contributions can be carried out within the framework of the saddle-point method. The saddle points correspond to some complex-valued labels m = mc associated with the intermediate effective ATI channels in the three-step harmonic generation process. The advantage of this approach stems from the fact that summation over a large number of conventional ATI m-channels is replaced by summation over a small number of effective mc-channels. The equation governing mc has a transparent physical meaning: the electron ejected from the atom on the first (ATI) stage should return to the core to make LAR possible. The effective channel labels m move along characteristic trajectories in the complex plane as the system parameters vary. In the cut-off region of the harmonic spectrum a single effective channel contributes. For lower harmonics, in the plateau domain, two effective ATI channels become essential. The interference of their contributions leads to an oscillatory pattern in the harmonic generation rates. The calculated rates are in good agreement with the results obtained by other approaches.

  19. Seasonal and sex differences in responsiveness to adrenocorticotropic hormone contribute to stress response plasticity in red-sided garter snakes (Thamnophis sirtalis parietalis).

    PubMed

    Dayger, Catherine A; Lutterschmidt, Deborah I

    2016-04-01

    As in many vertebrates, hormonal responses to stress vary seasonally in red-sided garter snakes (Thamnophis sirtalis parietalis). For example, males generally exhibit reduced glucocorticoid responses to a standard stressor during the spring mating season. We asked whether variation in adrenal sensitivity to adrenocorticotropic hormone (ACTH) explains why glucocorticoid responses to capture stress vary with sex, season and body condition in red-sided garter snakes. We measured glucocorticoids at 0, 1 and 4 h after injection with ACTH (0.1 IU g(-1)body mass) or vehicle in males and females during the spring mating season and autumn pre-hibernation period. Because elevated glucocorticoids can influence sex steroids, we also examined androgen and estradiol responses to ACTH. ACTH treatment increased glucocorticoids in both sexes and seasons. Spring-collected males had a smaller integrated glucocorticoid response to ACTH than autumn-collected males. The integrated glucocorticoid response to ACTH differed with sex during the spring, with males having a smaller glucocorticoid response than females. Although integrated glucocorticoid responses to ACTH did not vary with body condition, we observed an interaction among season, sex and body condition. In males, ACTH treatment did not alter androgen levels in either season, but androgen levels decreased during the sampling period. Similar to previous studies, plasma estradiol was low or undetectable during the spring and autumn, and therefore any effect of ACTH treatment on estradiol could not be determined. These data provide support for a mechanism that partly explains how the hypothalamus-pituitary-adrenal (HPA) axis integrates information about season, sex and body condition: namely, variation in adrenal responsiveness to ACTH. PMID:26896543

  20. Effects of neuromuscular fatigue on perceptual-cognitive skills between genders in the contribution to the knee joint loading during side-stepping tasks.

    PubMed

    Khalid, Abdul Jabbar; Harris, Sujae Ian; Michael, Loke; Joseph, Hamill; Qu, Xingda

    2015-01-01

    This study investigated whether neuromuscular fatigue affects the neuromuscular control of an athlete within a sports context setting and whether these effects were more pronounced in the females. Lower limb joint kinetics of 6 male and 6 female inter-varsity soccer players performing side-stepping tasks in non-fatigue versus fatigue and anticipated versus unanticipated conditions were quantified using 10 Motion Analysis Corporation cameras and a Kistler(™) force platform. The Yo-Yo intermittent recovery Level 1 fatigue protocol was employed. Stance foot initial contact and peak forces, and peak joint knee moments of the lower limb were submitted to a 3-way mixed-model repeated measure ANOVA. The results suggested that males tend to elicit significantly higher knee joint loadings when fatigued. In addition, males elicited significantly higher peak proximal tibia anterior/posterior shear force, vertical ground reaction force at initial contact and peak internal rotational moments than females. These findings suggested that males were at greater overall injury risk than females, especially in the sagittal plane. Neuromuscular control-based training programmes/interventions that are designed to reduce the risk of the non-contact ACL injury need to be customised for the different genders. PMID:25562469

  1. Lunar gravity - A harmonic analysis

    NASA Technical Reports Server (NTRS)

    Ferrari, A. J.

    1977-01-01

    A sixteenth-degree and sixteenth-order spherical harmonic lunar gravity field has been derived from the long-term Keplerian variations in the orbits of the Apollo subsatellites and Lunar Orbiter 5. This model resolves the major mascon gravity anomalies of the lunar near side and is in very good agreement with line-of-sight acceleration results. The far-side map shows the major ringed basins to be strong localized negative anomalies located in broad regions of positive gravity which correspond closely to the highlands. The rms pressure levels calculated from equivalent-surface height variations show that the moon and earth support nearly equal pressures, whereas Mars is appreciably stronger. The moon appears to support larger loads than earth owing to its weaker central gravity field and perhaps a colder upper lithosphere. Significant differences between the low-degree gravity and topography spectra indicate that the longer-wavelength topographic features are isostatically compensated.

  2. Single-sided deafness and directional hearing: contribution of spectral cues and high-frequency hearing loss in the hearing ear.

    PubMed

    Agterberg, Martijn J H; Hol, Myrthe K S; Van Wanrooij, Marc M; Van Opstal, A John; Snik, Ad F M

    2014-01-01

    Direction-specific interactions of sound waves with the head, torso, and pinna provide unique spectral-shape cues that are used for the localization of sounds in the vertical plane, whereas horizontal sound localization is based primarily on the processing of binaural acoustic differences in arrival time (interaural time differences, or ITDs) and sound level (interaural level differences, or ILDs). Because the binaural sound-localization cues are absent in listeners with total single-sided deafness (SSD), their ability to localize sound is heavily impaired. However, some studies have reported that SSD listeners are able, to some extent, to localize sound sources in azimuth, although the underlying mechanisms used for localization are unclear. To investigate whether SSD listeners rely on monaural pinna-induced spectral-shape cues of their hearing ear for directional hearing, we investigated localization performance for low-pass filtered (LP, <1.5 kHz), high-pass filtered (HP, >3kHz), and broadband (BB, 0.5-20 kHz) noises in the two-dimensional frontal hemifield. We tested whether localization performance of SSD listeners further deteriorated when the pinna cavities of their hearing ear were filled with a mold that disrupted their spectral-shape cues. To remove the potential use of perceived sound level as an invalid azimuth cue, we randomly varied stimulus presentation levels over a broad range (45-65 dB SPL). Several listeners with SSD could localize HP and BB sound sources in the horizontal plane, but inter-subject variability was considerable. Localization performance of these listeners strongly reduced after diminishing of their spectral pinna-cues. We further show that inter-subject variability of SSD can be explained to a large extent by the severity of high-frequency hearing loss in their hearing ear. PMID:25071433

  3. Workshop on Harmonic Oscillators

    NASA Technical Reports Server (NTRS)

    Han, D. (Editor); Kim, Y. S. (Editor); Zachary, W. W. (Editor)

    1993-01-01

    Proceedings of a workshop on Harmonic Oscillators held at the College Park Campus of the University of Maryland on March 25 - 28, 1992 are presented. The harmonic oscillator formalism is playing an important role in many branches of physics. This is the simplest mathematical device which can connect the basic principle of physics with what is observed in the real world. The harmonic oscillator is the bridge between pure and applied physics.

  4. Harmon Craig (1926-2003)

    NASA Astrophysics Data System (ADS)

    Weiss, Ray

    Harmon Craig, one of the great pioneers of isotope geochemistry died on 14 March after suffering a massive heart attack at his home in La Jolla, California. He was one day shy of his 77th birthday. Through an academic career of more than fifty years, Craig—or simply “Harmon,” as he was known throughout the world of geochemistry—made a remarkable number of fundamental and far-reaching contributions in a wide range of important areas concerned with the chemical and physical processes by which the solid Earth, the oceans, the atmosphere, and the solar system interact. While his research was broad in scope, it was also characterized by a strong emphasis on meticulous field and laboratory work, and on original and insightful interpretations of the resulting observations.

  5. Covariant harmonic oscillators and coupled harmonic oscillators

    NASA Technical Reports Server (NTRS)

    Han, Daesoo; Kim, Young S.; Noz, Marilyn E.

    1995-01-01

    It is shown that the system of two coupled harmonic oscillators shares the basic symmetry properties with the covariant harmonic oscillator formalism which provides a concise description of the basic features of relativistic hadronic features observed in high-energy laboratories. It is shown also that the coupled oscillator system has the SL(4,r) symmetry in classical mechanics, while the present formulation of quantum mechanics can accommodate only the Sp(4,r) portion of the SL(4,r) symmetry. The possible role of the SL(4,r) symmetry in quantum mechanics is discussed.

  6. Reexamining the high-order harmonic generation of HD molecule in non-Born-Oppenheimer approximation

    NASA Astrophysics Data System (ADS)

    Du, Hongchuan; Yue, Shengjun; Wang, Huiqiao; Wu, Hongmei; Hu, Bitao

    2016-03-01

    The high-order harmonic generation of the HD molecule is studied in non-Born-Oppenheimer approximation. It is found that there are only the odd harmonics in the harmonic spectrum of the HD molecule though the generation of even harmonics is possible in principle. Theoretical analysis [T. Kreibich et al., Phys. Rev. Lett. 87, 103901 (2001)] reveals that the nuclear dipole moment can contribute to the generation of the even harmonics, but the acceleration of the nucleus is about three orders of magnitude less than that of the electron. Hence, the even harmonics cannot be observed in the harmonic spectrum of the HD molecule.

  7. Discriminating between west-side sources of nutrients and organiccarbon contributing to algal growth and oxygen demand in the San JoaquinRiver

    SciTech Connect

    Wstringfellow@lbl.gov

    2002-07-24

    The purpose of this study was to investigate the Salt and Mud Slough tributaries as sources of oxygen demanding materials entering the San Joaquin River (SJR). Mud Slough and Salt Slough are the main drainage arteries of the Grasslands Watershed, a 370,000-acre area west of the SJR, covering portions of Merced and Fresno Counties. Although these tributaries of the SJR are typically classified as agricultural, they are also heavily influenced by Federal, State and private wetlands. The majority of the surface water used for both irrigation and wetland management in the Grassland Watershed is imported from the Sacramento-San Joaquin Delta through the Delta-Mendota Canal. In this study, they measured algal biomass (as chlorophyll a), organic carbon, ammonia, biochemical oxygen demand (BOD), and other measures of water quality in drainage from both agricultural and wetland sources at key points in the Salt Slough and Mud Slough tributaries. This report includes the data collected between June 16th and October 4th, 2001. The objective of the study was to compare agricultural and wetland drainage in the Grasslands Watershed and to determine the relative importance of each return flow source to the concentration and mass loading of oxygen demanding materials entering the SJR. Additionally, they compared the quality of water exiting our study area to water entering our study area. This study has demonstrated that Salt and Mud Sloughs both contribute significant amounts of oxygen demand to the SJR. Together, these tributaries could account for 35% of the oxygen demand observed below their confluence with the SJR. This study has characterized the sources of oxygen demanding materials entering Mud Slough and evaluated the oxygen demand conditions in Salt Slough. Salt Slough was found to be the dominant source of oxygen demand load in the study area, because of the higher flows in this tributary. The origins of oxygen demand in Salt Slough still remain largely uninvestigated

  8. Eliminating upper harmonic noise in vibroseis data via numerical simulation

    NASA Astrophysics Data System (ADS)

    Abd El-Aal, Abd El-Aziz Khairy

    2010-06-01

    In conventional vibroseis signal processing, algorithms including cross-correlation and deconvolution are applied to convert the raw trace data into a seismic section. However, their performance deteriorates when the trace data are corrupted by the harmonic noise. An important issue of vibroseis data enhancement is the treatment or suppression upper harmonics. In this contribution, I present algorithm to eliminate the harmonic distortion, all at once, in both down- and up-sweep conventional vibroseis data using a simulation process for harmonic distortion in the correlated data. This technique consists of four steps: (1) cross-correlating the raw data with fundamental sweep then dividing the trace to several windows and detecting the windows contain fundamental energy for each response reflector; (2) calculating the harmonic amplitude ratio when applying the Fourier transform on the upper harmonic components and the fundamental, and dividing the upper harmonic components by the fundamental to remove the unknown convolutional effects; (3) using the harmonic amplitude ratio to simulate the upper harmonics associated with the fundamental energy in down- and up-sweep data. When the harmonic amplitude ratio is convolved with a portion of data containing the fundamental energy in the correlated data in time domain, I can get simulation for the upper harmonics existed in the original data and (4) subtracting the simulated harmonics from correlated traces using direct optimization procedure. Accordingly, I developed a procedure for attenuating upper harmonics in the positive and negative times of the correlated traces depending on accurate simulation for the correlated harmonics. The procedure was tested on both synthetic and field data sets. The correlated trace thus obtained will be freed substantially of correlation noise; that is the correlation-ghost sweeps (produced by severe harmonic distortion at positive and negative correlation times) are eliminated without

  9. Index calculation by means of harmonic expansion

    NASA Astrophysics Data System (ADS)

    Imamura, Yosuke

    2015-11-01

    We review derivation of superconformal indices by means of supersymmetric localization and spherical harmonic expansion for 3d mathcal {N}=2, 4d mathcal {N}=1, and 6d mathcal {N}=(1,0) supersymmetric gauge theories. We demonstrate calculation of indices for vector multiplets in each dimension by analyzing energy eigenmodes in {boldsymbol S}^p × mathbb {R}. For the 6d index we consider the perturbative contribution only. We focus on the technical details of harmonic expansion rather than physical applications.

  10. Optical harmonic generator

    DOEpatents

    Summers, Mark A.; Eimerl, David; Boyd, Robert D.

    1985-01-01

    A pair of uniaxial birefringent crystal elements are fixed together to form a serially arranged, integral assembly which, alternatively, provides either a linearly or elliptically polarized second-harmonic output wave or a linearly polarized third-harmonic output wave. The "extraordinary" or "e" directions of the crystal elements are oriented in the integral assembly to be in quadrature (90.degree.). For a second-harmonic generation in the Type-II-Type-II angle tuned case, the input fundamental wave has equal amplitude "o" and "e" components. For a third-harmonic generation, the input fundamental wave has "o" and "e" components whose amplitudes are in a ratio of 2:1 ("o":"e" reference first crystal). In the typical case of a linearly polarized input fundamental wave this can be accomplished by simply rotating the crystal assembly about the input beam direction by 10.degree.. For both second and third harmonic generation input precise phase-matching is achieved by tilting the crystal assembly about its two sensitive axes ("o").

  11. Optical harmonic generator

    DOEpatents

    Summers, M.A.; Eimerl, D.; Boyd, R.D.

    1982-06-10

    A pair of uniaxial birefringent crystal elements are fixed together to form a serially arranged, integral assembly which, alternatively, provides either a linearly or elliptically polarized second-harmonic output wave or a linearly polarized third-harmonic output wave. The extraordinary or e directions of the crystal elements are oriented in the integral assembly to be in quadrature (90/sup 0/). For a second-harmonic generation in the Type-II-Type-II angle tuned case, the input fundamental wave has equal amplitude o and e components. For a third-harmonic generation, the input fundamental wave has o and e components whose amplitudes are in a ratio of 2:1 (o:e reference first crystal). In the typical case of a linearly polarized input fundamental wave this can be accomplished by simply rotating the crystal assembly about the input beam direction by 10/sup 0/. For both second and third harmonic generation input precise phase-matching is achieved by tilting the crystal assembly about its two sensitive axeses (o).

  12. Harmonic uniflow engine

    DOEpatents

    Bennett, Charles L.

    2016-03-22

    A reciprocating-piston uniflow engine includes a harmonic oscillator inlet valve capable of oscillating at a resonant frequency for controlling the flow of working fluid into the engine. In particular, the inlet valve includes an inlet valve head and a spring arranged together as a harmonic oscillator so that the inlet valve head is moveable from an unbiased equilibrium position to a biased closed position occluding an inlet. When released, the inlet valve head undergoes a single oscillation past the equilibrium position to a maximum open position and returns to a biased return position close to the closed position to choke the flow and produce a pressure drop across the inlet valve causing the inlet valve to close. In other embodiments, the harmonic oscillator arrangement of the inlet valve enables the uniflow engine to be reversibly operated as a uniflow compressor.

  13. Harmonic Frequency Lowering

    PubMed Central

    Kirchberger, Martin

    2016-01-01

    A novel algorithm for frequency lowering in music was developed and experimentally tested in hearing-impaired listeners. Harmonic frequency lowering (HFL) combines frequency transposition and frequency compression to preserve the harmonic content of music stimuli. Listeners were asked to make judgments regarding detail and sound quality in music stimuli. Stimuli were presented under different signal processing conditions: original, low-pass filtered, HFL, and nonlinear frequency compressed. Results showed that participants reported perceiving the most detail in the HFL condition. In addition, there was no difference in sound quality across conditions. PMID:26834122

  14. Booster double harmonic setup notes

    SciTech Connect

    Gardner, C. J.

    2015-02-17

    The motivation behind implementing a booster double harmonic include the reduced transverse space charge force from a reduced peak beam current and reduced momentum spread of the beam, both of which can be achieved from flattening the RF bucket. RF capture and acceleration of polarized protons (PP) is first set up in the single harmonic mode with RF harmonic h=1. Once capture and acceleration have been set up in the single harmonic mode, the second harmonic system is brought on and programmed to operate in concert with the single harmonic system.

  15. Experimental Harmonic Motion

    NASA Astrophysics Data System (ADS)

    Searle, G. F. C.

    2014-05-01

    1. Elementary theory of harmonic motion; 2. Experimental work in harmonic motion; Experiment 1. Determination of g by a simple pendulum; Experiment 2. Harmonic motion of a body suspended by a spring; Experiment 3. Harmonic motion of a rigid body suspended by a torsion wire; Experiment 4. Study of a system with variable moment of inertia; Experiment 5. Dynamical determination of ratio of couple to twist for a torsion wire; Experiment 6. Comparison of the moments of inertia of two bodies; Experiment 7. Experiment with a pair of inertia bars; Experiment 8. Determination of the moment of inertia of a rigid pendulum; Experiment 9. Experiment on a pendulum with variable moment of inertia; Experiment 10. Determination of g by a rigid pendulum; Experiment 11. Pendulum on a yielding support; Experiment 12. Determination of the radius of curvature of a concave mirror by the oscillations of a sphere rolling in it; Experiment 13. Determination of g by the oscillations of a rod rolling on a cylinder; Experiment 14. Study of a vibrating system with two degrees of freedom; Note 1. On the vibration of a body suspended from a light spring; Note 2. Periodic time of a pendulum vibrating through a finite arc; Note 3. Periodic time for finite motion; Note 4. Periodic times of a pendulum with two degrees of freedom.

  16. A Harmonic Motion Experiment

    ERIC Educational Resources Information Center

    Gluck, P.; Krakower, Zeev

    2010-01-01

    We present a unit comprising theory, simulation and experiment for a body oscillating on a vertical spring, in which the simultaneous use of a force probe and an ultrasonic range finder enables one to explore quantitatively and understand many aspects of simple and damped harmonic motions. (Contains 14 figures.)

  17. Harmonically excited orbital variations

    SciTech Connect

    Morgan, T.

    1985-08-06

    Rephrasing the equations of motion for orbital maneuvers in terms of Lagrangian generalized coordinates instead of Newtonian rectangular cartesian coordinates can make certain harmonic terms in the orbital angular momentum vector more readily apparent. In this formulation the equations of motion adopt the form of a damped harmonic oscillator when torques are applied to the orbit in a variationally prescribed manner. The frequencies of the oscillator equation are in some ways unexpected but can nonetheless be exploited through resonant forcing functions to achieve large secular variations in the orbital elements. Two cases are discussed using a circular orbit as the control case: (1) large changes in orbital inclination achieved by harmonic excitation rather than one impulsive velocity change, and (2) periodic and secular changes to the longitude of the ascending node using both stable and unstable excitation strategies. The implications of these equations are also discussed for both artificial satellites and natural satellites. For the former, two utilitarian orbits are suggested, each exploiting a form of harmonic excitation. 5 refs.

  18. Introducing Simple Harmonic Motion.

    ERIC Educational Resources Information Center

    Roche, John

    2002-01-01

    Explains the origin and significance of harmonic motion which is an important topic that has wide application in the world. Describes the phenomenon by using an auxiliary circle to help illustrate the key relationships between acceleration, displacement, time, velocity, and phase. (Contains 16 references.) (Author/YDS)

  19. Stress in Harmonic Serialism

    ERIC Educational Resources Information Center

    Pruitt, Kathryn Ringler

    2012-01-01

    This dissertation proposes a model of word stress in a derivational version of Optimality Theory (OT) called Harmonic Serialism (HS; Prince and Smolensky 1993/2004, McCarthy 2000, 2006, 2010a). In this model, the metrical structure of a word is derived through a series of optimizations in which the "best" metrical foot is chosen…

  20. Distribution system harmonic filter planning

    SciTech Connect

    Ortmeyer, T.H.; Hiyama, Takashi

    1996-10-01

    A planning methodology for distribution system harmonic filtering is proposed. The method is intended for use on radial distribution systems with no large harmonic sources. It is proposed that 60 hertz var planning be done first to allocate the var resources. Following this process, the harmonic filter planning can be readily accomplished. Characteristics of the distribution systems and the harmonic sources are exploited to provide a practical filter planning technique which is effective and efficient.

  1. Quaternionic Harmonic Analysis of Texture

    Energy Science and Technology Software Center (ESTSC)

    2012-10-01

    QHAT uses various functions and data structures native to MATLAB to analyze crystallographic texture information using harmonic functions on the space of rotations represented as normalized quaternions. These harmonic functions generalize the spherical harmonics in three dimensions, and form the basis for the irreducible representations of the four-dimensional rotation group. This allows the basis of harmonic functions to be reduced to linearly independent combinations that satisfy the crystal and sample symmetry point groups.

  2. Harmonized Medical Device Regulation: Need, Challenges, and Risks of not Harmonizing the Regulation in Asia

    PubMed Central

    Kaushik, A; Saini, KS; Anil, B; Rambabu, S

    2010-01-01

    Medical device sector is one of the most complex and challenging business segments of the healthcare industry with close collaboration between science and engineering. Despite the fact that Asia has 60% of the world population providing large market potential, Asian healthcare expenditure constitutes only 15% of the global healthcare expenditure. The accelerated ageing population and increasing prevalence of chronic disease are the key drivers that contribute toward the increase in the total healthcare expenditure on medical devices in the region. Several policies clearly showed the eagerness of the government to provide better healthcare infrastructure with better medical devices and facilities. The fundamental objective of the regulatory harmonization is to improve the efficiency of national economies and their ability to adopt to change and remain competitive. After the era of liberalization and globalization, the desires of developing economies is to ensure safety and performance of the product brought to their markets and for this harmonized regulation is an important tool for strengthening the same. If we talk about the industry need, then this approach will eliminate redundant requirements that do not contribute to safety and effectiveness. In addition, Asia is diverse in many respects and with it come the various challenges to harmonizing the regulation which includes diversity in culture, politics, economy, historical issues, etc. If, by any reason, the regulation of medical devices is not harmonized and consequently, the harmonized regulation is not adopted, then it leads to serious concerns like delayed or absent access to innovative technology, continued rise in the cost of medical therapies, etc. So this issue is written to attract all stakeholders to move toward the concept of harmonization, keeping in mind their need, challenges, and risks of not harmonizing the regulation as well. PMID:21331201

  3. Harmonization, Trade, and the Environment.

    ERIC Educational Resources Information Center

    Stevens, Candice

    1993-01-01

    Discusses the harmonization of international methods for the development and administration of product standards. Defines the term "harmonization" and discusses the harmonization of environmental policies and purposes involving product standards; environmental regulations on production methods, technologies, and practices; and life-cycle…

  4. Second harmonic inversion for ultrasound contrast harmonic imaging

    NASA Astrophysics Data System (ADS)

    Pasovic, Mirza; Danilouchkine, Mike; Faez, Telli; van Neer, Paul L. M. J.; Cachard, Christian; van der Steen, Antonius F. W.; Basset, Olivier; de Jong, Nico

    2011-06-01

    Ultrasound contrast agents (UCAs) are small micro-bubbles that behave nonlinearly when exposed to an ultrasound wave. This nonlinear behavior can be observed through the generated higher harmonics in a back-scattered echo. In past years several techniques have been proposed to detect or image harmonics produced by UCAs. In these proposed works, the harmonics generated in the medium during the propagation of the ultrasound wave played an important role, since these harmonics compete with the harmonics generated by the micro-bubbles. We present a method for the reduction of the second harmonic generated during nonlinear-propagation-dubbed second harmonic inversion (SHI). A general expression for the suppression signals is also derived. The SHI technique uses two pulses, p' and p'', of the same frequency f0 and the same amplitude P0 to cancel out the second harmonic generated by nonlinearities of the medium. Simulations show that the second harmonic is reduced by 40 dB on a large axial range. Experimental SHI B-mode images, from a tissue-mimicking phantom and UCAs, show an improvement in the agent-to-tissue ratio (ATR) of 20 dB compared to standard second harmonic imaging and 13 dB of improvement in harmonic power Doppler.

  5. B1 magnet harmonics

    SciTech Connect

    Barnes, P D

    2000-05-30

    During the B0 Overpass construction for the CDF detector at Fermilab, 33 B1 magnets were measured using a bucked tangential coil. Measurements were made on the midplane, at the centerline and at {+-} 1 inch horizontal displacement. Since the coil was only 62 inches long, measurements were made at four longitudinal positions. Because of the design of the Main Ring, it was sufficient to combine data from all positions and report the harmonic spectrum for the magnet as a whole. For modeling the Scrounge-atron, it is more useful to treat each measurement position separately. The author reports here an analysis of the harmonic spectra at each probe position, based on the original data.

  6. Harmonic electron correlation operator.

    PubMed

    Rassolov, Vitaly A

    2011-07-21

    An appealing way to model electron correlation within the single determinant wave function formalism is through the expectation value of a linear two-electron operator. For practical reasons, it is desirable for such an operator to be universal, i.e., not depend on the positions and types of nuclei in a molecule. We show how a perturbation theory applied to a hookium atom provides for a particular form of a correlation operator, hence called the harmonic correlation operator. The correlation operator approach is compared and contrasted to the traditional ways to describe electron correlation. To investigate the two-electron approximation of this operator, we apply it to many-electron hookium systems. To investigate the harmonic approximation, we apply it to the small atomic systems. Directions of future research are also discussed. PMID:21786991

  7. Harmonic multiplication using resonant tunneling

    NASA Technical Reports Server (NTRS)

    Sollner, T. C. L. G.; Brown, E. R.; Goodhue, W. D.; Correa, C. A.

    1988-01-01

    This paper demonstrates the use of resonant-tunneling diodes as varistors for harmonic multiplication. It is shown that efficient odd-harmonic conversion is possible and that even harmonics do not appear because of the antisymmetry of the current-voltage (I-V) curve. It is also shown that, with the proper choice of resonant-tunneling structure and pump amplitude, most of the harmonic output power can be confined to a single odd-harmonic frequency. Fifth-harmonic multiplication was demonstrated with an output at 21.75 GHz and a power conversion efficiency of 0.5 percent, and a fifth-harmonic efficiency of 2.7 percent was achieved in a circuit simulation using an improved I-V curve.

  8. Higher Harmonic Forces in Purely Crossflow Vortex-Induced Vibrations

    NASA Astrophysics Data System (ADS)

    Modarres-Sadeghi, Yahya; Seyed-Aghazadeh, Banafsheh; Bourguet, Remi; Karniadakis, George; Triantafyllou, Michael

    2013-11-01

    In vortex-induced vibrations (VIV) of flexibly-mounted rigid cylinders free to oscillate both in the inline and crossflow directions, higher (3rd) harmonic forces have already been observed in the crossflow direction. In the present work, we report higher harmonic force components for a flexibly-mounted rigid cylinder with only one degree of freedom in the crossflow direction. We show that the inline displacement is not necessary to observe higher harmonic components in the crossflow force spectrum. Due to the relative velocity of the cylinder with respect to the oncoming flow, the lift and drag forces make an angle with respect to the crossflow and inline directions, and the contribution of the components of each of these forces in the crossflow direction results in a 3rd harmonic force component. These higher harmonic components have been observed in self-excited VIV experiments, performed in a water tunnel for a Reynolds number range of Re = 400-1000, as well as in numerical simulation results at Re = 100. We also find that the maximum ratio of the 3rd harmonic to the 1st harmonic occurs when the phase between the crossflow force and displacement changes from 0 to 180 degrees, resulting in a small first harmonic component.

  9. Spectrally Resolved Maker Fringes in High-Order Harmonic Generation

    NASA Astrophysics Data System (ADS)

    Heyl, C. M.; Güdde, J.; Höfer, U.; L'Huillier, A.

    2011-07-01

    We investigate macroscopic interference effects in high-order harmonic generation using a Ti:sapphire laser operating at a 100 kHz repetition rate. The structure and behavior of spectral and spatial interference fringes are explained and analytically described by transient phase matching of the long electron trajectory contribution. Time-frequency mapping due to the temporal chirp of the harmonic emission allows us to observe Maker fringes directly in the spectral domain.

  10. Spectral modulation of higher harmonic spontaneous emission from an optical klystron.

    PubMed

    Sei, Norihiro; Ogawa, Hiroshi; Yamada, Kawakatsu; Koike, Masaki; Ohgaki, Hideaki

    2014-07-01

    Higher harmonics of spontaneous emission from an optical klystron have been observed. The modulation factor of the spontaneous emission spectrum for the higher harmonics can be described by considering the observation system. When the dispersive gap of the optical klystron was fixed, the microstructure interval of the spontaneous emission spectrum at a certain resonant wavelength became narrower as the order of the higher harmonic became larger. Some unique characteristics of the higher harmonics have been clarified, and these studies are likely to contribute to the development of free-electron lasers using higher harmonics of an optical klystron in the shorter-wavelengths region. PMID:24971958

  11. Suppression of harmonics in a model of thermoacoustic refrigerator based on an acoustic metamaterial.

    PubMed

    Fan, Li; Ding, Jin; Zhu, Jun-jie; Chen, Zhe; Zhang, Shu-yi; Zhang, Hui; Li, Xiao-juan

    2015-10-01

    A model of thermoacoustic refrigerator on the basis of an acoustic metamaterial is presented, in which an array of side pipes is adopted to suppress harmonic waves in the thermoacoustic resonator. The array of side pipes traps the acoustic waves with Fabry-Perot resonant frequencies and induces narrow forbidden bands of transmission. When the resonant frequency of the thermoacoustic refrigerator is chosen as the operating frequency, the harmonic wave can be exactly located in the forbidden band by properly adapting the structural parameters of the system. Therefore, the component of the harmonic wave in the thermoacoustic resonator can be efficiently suppressed. PMID:26520357

  12. Next generation data harmonization

    NASA Astrophysics Data System (ADS)

    Armstrong, Chandler; Brown, Ryan M.; Chaves, Jillian; Czerniejewski, Adam; Del Vecchio, Justin; Perkins, Timothy K.; Rudnicki, Ron; Tauer, Greg

    2015-05-01

    Analysts are presented with a never ending stream of data sources. Often, subsets of data sources to solve problems are easily identified but the process to align data sets is time consuming. However, many semantic technologies do allow for fast harmonization of data to overcome these problems. These include ontologies that serve as alignment targets, visual tools and natural language processing that generate semantic graphs in terms of the ontologies, and analytics that leverage these graphs. This research reviews a developed prototype that employs all these approaches to perform analysis across disparate data sources documenting violent, extremist events.

  13. Second harmonic FEL oscillation

    NASA Astrophysics Data System (ADS)

    Neil, George R.; Benson, S. V.; Biallas, G.; Freund, H. P.; Gubeli, J.; Jordan, K.; Myers, S.; Shinn, M. D.

    2002-05-01

    We have produced and measured for the first time second harmonic oscillation in the infrared region by the high-average-power Jefferson Lab Infrared Free Electron Laser. The finite geometry and beam emittance allows sufficient gain for lasing to occur. We were able to lase at pulse rates up to 74.85 MHz and could produce over 4.5 W average and 40 kW peak of IR power in a 40 nm FWHM bandwidth at 2925 nm. In agreement with predictions, the source preferentially lased in a TEM 01 mode. We present results of initial source performance measurements and comparisons with theory and simulation.

  14. Second Harmonic FEL Oscillation

    NASA Astrophysics Data System (ADS)

    Neil, George R.; Benson, S. V.; Biallas, G.; Gubeli, J.; Jordan, K.; Myers, S.; Shinn, M. D.

    2001-08-01

    We have produced and measured for the first time second harmonic oscillation in the infrared region by a free electron laser. Although such lasing is ideally forbidden, since the gain of a plane wave is zero on axis for an electron beam perfectly aligned with a wiggler, a transverse mode antisymmetry allows sufficient gain in this experiment for lasing to occur. We lased at pulse rates up to 74.85 MHz and could produce over 4.5 W average and 40 kW peak of IR power in a 40 nm FWHM bandwidth at 2925 nm. In agreement with predictions, the source preferentially lased in a TEM01 mode.

  15. Harmonic generation in optical fibers

    SciTech Connect

    Sherborn, H.P.

    1990-05-01

    This patent describes an apparatus for providing second harmonic generated radiation. It comprises: an optical fiber disposed in a laser cavity, the optical fiber having a substantially single-mode core which is doped with an active laser material, the laser material being self-organizable to produce radiation by second harmonic generation, the laser material further being substantially transparent to the second harmonic generated radiation; and means for pumping the core of the optical fiber to produce laser radiation therein and the laser cavity further comprising means for extracting at least a portion of the second harmonic generated radiation.

  16. Harmonic generation at high intensities

    SciTech Connect

    Schafer, K.J.; Krause, J.L.; Kulander, K.C.

    1993-06-01

    Atomic electrons subject to intense laser fields can absorb many photons, leading either to multiphoton ionization or the emission of a single, energetic photon which can be a high multiple of the laser frequency. The latter process, high-order harmonic generation, has been observed experimentally using a range of laser wavelengths and intensities over the past several years. Harmonic generation spectra have a generic form: a steep decline for the low order harmonics, followed by a plateau extending to high harmonic order, and finally an abrupt cutoff beyond which no harmonics are discernible. During the plateau the harmonic production is a very weak function of the process order. Harmonic generation is a promising source of coherent, tunable radiation in the XUV to soft X-ray range which could have a variety of scientific and possibly technological applications. Its conversion from an interesting multiphoton phenomenon to a useful laboratory radiation source requires a complete understanding of both its microscopic and macroscopic aspects. We present some recent results on the response of single atoms at intensities relevant to the short pulse experiments. The calculations employ time-dependent methods, which we briefly review in the next section. Following that we discuss the behavior of the harmonics as a function of laser intensity. Two features are notable: the slow scaling of the harmonic intensities with laser intensity, and the rapid variation in the phase of the individual harmonics with respect to harmonic order. We then give a simple empirical formula that predicts the extent of the plateau for a given ionization potential, wavelength and intensity.

  17. Influence of multiple orbital effect on shifts of minima in harmonic spectra

    NASA Astrophysics Data System (ADS)

    Wu, Yan; Li, Chaorong; Gong, Cheng; Yu, Yongli; Gong, Shangqing

    2014-09-01

    Using the Lewenstein model combined with the molecular Ammosov-Delone-Krainov ionization theory, laser induced harmonics generated from aligned N2 molecules are calculated. We focus attention on shifts in minima of the harmonic spectra due to interference between harmonics generated from different molecular orbitals (MOs). When harmonic spectra generated from different MOs are of the same intensity (i.e., the “cross” region of the harmonic spectra), interference is most pronounced. We find that contributions to the harmonic spectrum from different MOs respond differently to the change of the laser intensity. This difference in response results in two phenomena. On the one hand, by changing the laser intensity, harmonics generated from an individual MO may become more or less prominent, thus, structure-induced minima can appear. On the other hand, when the laser intensity increases, the “cross” region shifts, and multiple-orbital-interference-induced minima appear at different energies.

  18. Impact of harmonics on the interpolated DFT frequency estimator

    NASA Astrophysics Data System (ADS)

    Belega, Daniel; Petri, Dario; Dallet, Dominique

    2016-01-01

    The paper investigates the effect of the interference due to spectral leakage on the frequency estimates returned by the Interpolated Discrete Fourier Transform (IpDFT) method based on the Maximum Sidelobe Decay (MSD) windows when harmonically distorted sine-waves are analyzed. The expressions for the frequency estimation error due to both the image of the fundamental tone and harmonics, and the frequency estimator variance due to the combined effect of both the above disturbances and wideband noise are derived. The achieved expressions allow us to identify which harmonics significantly contribute to frequency estimation uncertainty. A new IpDFT-based procedure capable to compensate all the significant effects of harmonics on the frequency estimation accuracy is then proposed. The derived theoretical results are verified through computer simulations. Moreover, the accuracy of the proposed procedure is compared with those of other state-of-the-art frequency estimation methods by means of both computer simulations and experimental results.

  19. Group sparsity based spectrum estimation of harmonic speech signals

    NASA Astrophysics Data System (ADS)

    Zhang, Yimin D.; Wang, Ben

    2015-05-01

    Spectrum analysis of speech signals is important for their detection, recognition, and separation. Speech signals are nonstationary with time-varying frequencies which, when analyzed by Fourier analysis over a short time window, exhibit harmonic spectra, i.e., the fundamental frequencies are accompanied by multiple associated harmonic frequencies. With proper modeling, such harmonic signal components can be cast as group sparse and solved using group sparse signal reconstruction methods. In this case, all harmonic components contribute to effective signal detection and fundamental frequency estimation with improved reliability and spectrum resolution. The estimation of the fundamental frequency signature is implemented using the block sparse Bayesian learning technique, which is known to provide high-resolution spectrum estimations. Simulation results confirm the superiority of the proposed technique when compared to the conventional STFT-based methods.

  20. MODEL HARMONIZATION POTENTIAL AND BENEFITS

    EPA Science Inventory

    The IPCS Harmonization Project, which is currently ongoing under the auspices of the WHO, in the context of chemical risk assessment or exposure modeling, does not imply global standardization. Instead, harmonization is thought of as an effort to strive for consistency among appr...

  1. Harmonic Series Meets Fibonacci Sequence

    ERIC Educational Resources Information Center

    Chen, Hongwei; Kennedy, Chris

    2012-01-01

    The terms of a conditionally convergent series may be rearranged to converge to any prescribed real value. What if the harmonic series is grouped into Fibonacci length blocks? Or the harmonic series is arranged in alternating Fibonacci length blocks? Or rearranged and alternated into separate blocks of even and odd terms of Fibonacci length?

  2. 3D field harmonics

    SciTech Connect

    Caspi, S.; Helm, M.; Laslett, L.J.

    1991-03-30

    We have developed an harmonic representation for the three dimensional field components within the windings of accelerator magnets. The form by which the field is presented is suitable for interfacing with other codes that make use of the 3D field components (particle tracking and stability). The field components can be calculated with high precision and reduced cup time at any location (r,{theta},z) inside the magnet bore. The same conductor geometry which is used to simulate line currents is also used in CAD with modifications more readily available. It is our hope that the format used here for magnetic fields can be used not only as a means of delivering fields but also as a way by which beam dynamics can suggest correction to the conductor geometry. 5 refs., 70 figs.

  3. Harmonic diffractive lenses

    SciTech Connect

    Sweeney, D.W.; Sommargren, G.E.

    1995-05-10

    The harmonic diffractive lens is a diffractive imaging lens for which the optical path-length transition between adjacent facets is an integer multiple {ital m} of the design wavelength {lambda}{sub 0}. The total lens thickness in air is {ital m}{lambda}{sub 0}/({ital n} {minus} 1), which is {ital m} times thicker than the so-called modulo 2{pi} diffractive lens. Lenses constructed in this way have hybrid properties of both refractive and diffractive lenses. Such a lens will have a diffraction-limited, common focus for a number of discrete wavelengths across the visible spectrum. A 34.75-diopter, 6-mm-diameter lens is diamond turned in aluminum and replicated in optical materials. The sag of the lens is 23 {mu}m. Modulation transfer function measurements in both monochromatic and white light verify the performance of the lens. The lens approaches the diffraction limit for 10 discrete wavelengths across the visible spectrum.

  4. Galilean covariant harmonic oscillator

    NASA Technical Reports Server (NTRS)

    Horzela, Andrzej; Kapuscik, Edward

    1993-01-01

    A Galilean covariant approach to classical mechanics of a single particle is described. Within the proposed formalism, all non-covariant force laws defining acting forces which become to be defined covariantly by some differential equations are rejected. Such an approach leads out of the standard classical mechanics and gives an example of non-Newtonian mechanics. It is shown that the exactly solvable linear system of differential equations defining forces contains the Galilean covariant description of harmonic oscillator as its particular case. Additionally, it is demonstrated that in Galilean covariant classical mechanics the validity of the second Newton law of dynamics implies the Hooke law and vice versa. It is shown that the kinetic and total energies transform differently with respect to the Galilean transformations.

  5. Synchronous Discrete Harmonic Oscillator

    SciTech Connect

    Antippa, Adel F.; Dubois, Daniel M.

    2008-10-17

    We introduce the synchronous discrete harmonic oscillator, and present an analytical, numerical and graphical study of its characteristics. The oscillator is synchronous when the time T for one revolution covering an angle of 2{pi} in phase space, is an integral multiple N of the discrete time step {delta}t. It is fully synchronous when N is even. It is pseudo-synchronous when T/{delta}t is rational. In the energy conserving hyperincursive representation, the phase space trajectories are perfectly stable at all time scales, and in both synchronous and pseudo-synchronous modes they cycle through a finite number of phase space points. Consequently, both the synchronous and the pseudo-synchronous hyperincursive modes of time-discretization provide a physically realistic and mathematically coherent, procedure for dynamic, background independent, discretization of spacetime. The procedure is applicable to any stable periodic dynamical system, and provokes an intrinsic correlation between space and time, whereby space-discretization is a direct consequence of background-independent time-discretization. Hence, synchronous discretization moves the formalism of classical mechanics towards that of special relativity. The frequency of the hyperincursive discrete harmonic oscillator is ''blue shifted'' relative to its continuum counterpart. The frequency shift has the precise value needed to make the speed of the system point in phase space independent of the discretizing time interval {delta}t. That is the speed of the system point is the same on the polygonal (in the discrete case) and the circular (in the continuum case) phase space trajectories.

  6. Nonlinear propagation in ultrasonic fields: measurements, modelling and harmonic imaging.

    PubMed

    Humphrey, V F

    2000-03-01

    In high amplitude ultrasonic fields, such as those used in medical ultrasound, nonlinear propagation can result in waveform distortion and the generation of harmonics of the initial frequency. In the nearfield of a transducer this process is complicated by diffraction effects associated with the source. The results of a programme to study the nonlinear propagation in the fields of circular, focused and rectangular transducers are described, and comparisons made with numerical predictions obtained using a finite difference solution to the Khokhlov-Zabolotskaya-Kuznetsov (or KZK) equation. These results are extended to consider nonlinear propagation in tissue-like media and the implications for ultrasonic measurements and ultrasonic heating are discussed. The narrower beamwidths and reduced side-lobe levels of the harmonic beams are illustrated and the use of harmonics to form diagnostic images with improved resolution is described. PMID:10829672

  7. Side Effects (Management)

    MedlinePlus

    ... Cancer is Treated Side Effects Dating, Sex, and Reproduction Advanced Cancer For Children For Teens For Young ... Cancer is Treated Side Effects Dating, Sex, and Reproduction Advanced Cancer For Children For Teens For Young ...

  8. Emotional Side Effects

    MedlinePlus

    ... window. My Saved Articles » My ACS » Emotional Side Effects In this section you can learn more about ... Finding and Paying for Treatment Treatments and Side Effects Survivorship: During and After Treatment Children and Cancer ...

  9. Virtual pitch extraction from harmonic structures by absolute-pitch musicians

    NASA Astrophysics Data System (ADS)

    Hsieh, I.-Hui; Saberi, Kourosh

    2009-03-01

    The ability of absolute-pitch (AP) musicians to identify or produce virtual pitch from harmonic structures without feedback or an external acoustic referent was examined in three experiments. Stimuli consisted of pure tones, missing-fundamental harmonic complexes, or piano notes highpass filtered to remove their fundamental frequency and lower harmonics. Results of Experiment I showed that relative to control (non-AP) musicians, AP subjects easily (>90%) identified pitch of harmonic complexes in a 12-alternative forced-choice task. Increasing harmonic order (i.e., lowest harmonic number in the complex), however, resulted in a monotonic decline in performance. Results suggest that AP musicians use two pitch cues from harmonic structures: 1) spectral spacing between harmonic components, and 2) octave-related cues to note identification in individually resolved harmonics. Results of Experiment II showed that highpass filtered piano notes are identified by AP subjects at better than 75% accuracy even when the note’s energy is confined to the 4th and higher harmonics. Identification of highpass piano notes also appears to be better than that expected from pure or complex tones, possibly due to contributions from familiar timbre cues to note identity. Results of Experiment III showed that AP subjects can adjust the spectral spacing between harmonics of a missing-fundamental complex to accurately match the expected spacing from a target musical note. Implications of these findings for mechanisms of AP encoding are discussed.

  10. Side Effects of Hormone Therapy

    MedlinePlus

    ... Men Living with Prostate Cancer Side Effects of Hormone Therapy Side Effects Urinary Dysfunction Bowel Dysfunction Erectile Dysfunction Loss of Fertility Side Effects of Hormone Therapy Side Effects of Chemotherapy Side Effects: When ...

  11. Relativistic harmonic oscillator revisited

    SciTech Connect

    Bars, Itzhak

    2009-02-15

    The familiar Fock space commonly used to describe the relativistic harmonic oscillator, for example, as part of string theory, is insufficient to describe all the states of the relativistic oscillator. We find that there are three different vacua leading to three disconnected Fock sectors, all constructed with the same creation-annihilation operators. These have different spacetime geometric properties as well as different algebraic symmetry properties or different quantum numbers. Two of these Fock spaces include negative norm ghosts (as in string theory), while the third one is completely free of ghosts. We discuss a gauge symmetry in a worldline theory approach that supplies appropriate constraints to remove all the ghosts from all Fock sectors of the single oscillator. The resulting ghost-free quantum spectrum in d+1 dimensions is then classified in unitary representations of the Lorentz group SO(d,1). Moreover, all states of the single oscillator put together make up a single infinite dimensional unitary representation of a hidden global symmetry SU(d,1), whose Casimir eigenvalues are computed. Possible applications of these new results in string theory and other areas of physics and mathematics are briefly mentioned.

  12. Phase properties of the cutoff high-order harmonics

    NASA Astrophysics Data System (ADS)

    Khokhlova, M. A.; Strelkov, V. V.

    2016-04-01

    The cutoff regime of high-order harmonic generation (HHG) by atoms in an intense laser field is studied numerically and analytically. We find that the cutoff regime is characterized by equal dephasing between the successive harmonics. The change of the harmonic phase locking when HHG evolves from the cutoff to the plateau regime determines the optimal bandwidth of the spectral region which should be used for attosecond pulse generation via the amplitude gating technique. The minimal pulse duration which can be obtained with this technique in argon without using dispersion elements is approximately 0.08-0.1 of the laser cycle for different intensities and frequencies of the fundamental. The cutoff regime is also characterized by a linear dependence of the harmonic phase on the fundamental intensity. The proportionality coefficient grows as the cube of the fundamental wavelength, thus this dependence becomes very important for the HHG by midinfrared fields. Moreover, for every high harmonic there is a range of laser intensities providing the generation in the cutoff regime and the atomic response magnitude in this regime can be greater than that in the plateau regime. Thus, the cutoff regime substantially contributes to the harmonic energy emitted under typical experimental conditions where the laser intensity varies in time and space.

  13. Limitations and improvements for harmonic generation measurements

    SciTech Connect

    Best, Steven; Croxford, Anthony; Neild, Simon

    2014-02-18

    A typical acoustic harmonic generation measurement comes with certain limitations. Firstly, the use of the plane wave-based analysis used to extract the nonlinear parameter, β, ignores the effects of diffraction, attenuation and receiver averaging which are common to most experiments, and may therefore limit the accuracy of a measurement. Secondly, the method usually requires data obtained from a through-transmission type setup, which may not be practical in a field measurement scenario where access to the component is limited. Thirdly, the technique lacks a means of pinpointing areas of damage in a component, as the measured nonlinearity represents an average over the length of signal propagation. Here we describe a three-dimensional model of harmonic generation in a sound beam, which is intended to provide a more realistic representation of a typical experiment. The presence of a reflecting boundary is then incorporated into the model to assess the feasibility of performing single-sided measurements. Experimental validation is provided where possible. Finally, a focusing acoustic source is modelled to provide a theoretical indication of the afforded advantages when the nonlinearity is localized.

  14. Pythagorean Triples from Harmonic Sequences.

    ERIC Educational Resources Information Center

    DiDomenico, Angelo S.; Tanner, Randy J.

    2001-01-01

    Shows how all primitive Pythagorean triples can be generated from harmonic sequences. Use inductive and deductive reasoning to explore how Pythagorean triples are connected with another area of mathematics. (KHR)

  15. Echo-Enabled Harmonic Generation

    SciTech Connect

    Stupakov, Gennady; /SLAC

    2012-06-28

    A recently proposed concept of the Echo-Enabled Harmonic Generation (EEHG) FEL uses two laser modulators in combination with two dispersion sections to generate a high-harmonic density modulation in a relativistic beam. This seeding technique holds promise of a one-stage soft x-ray FEL that radiates not only transversely but also longitudinally coherent pulses. Currently, an experimental verification of the concept is being conducted at the SLAC National Accelerator Laboratory aimed at the demonstration of the EEHG.

  16. Numerical studies of third-harmonic generation in laser filament in air perturbed by plasma spot

    SciTech Connect

    Feng Liubin; Lu Xin; Liu Xiaolong; Li Yutong; Chen Liming; Ma Jinglong; Dong Quanli; Wang Weimin; Xi Tingting; Sheng Zhengming; Zhang Jie; He Duanwei

    2012-07-15

    Third-harmonic emission from laser filament intercepted by plasma spot is studied by numerical simulations. Significant enhancement of the third-harmonic generation is obtained due to the disturbance of the additional plasma. The contribution of the pure plasma effect and the possible plasma-enhanced third-order susceptibility on the third-harmonic generation enhancement are compared. It is shown that the plasma induced cancellation of destructive interference [Y. Liu et al., Opt. Commun. 284, 4706 (2011)] of two-colored filament is the dominant mechanism of the enhancement of third-harmonic generation.

  17. An Analysis of Shot Noise Propagation and Amplificationin Harmonic Cascade FELs

    SciTech Connect

    Huang, Z.; /SLAC

    2006-12-11

    The harmonic generation process in a harmonic cascade (HC) FEL is subject to noise degradation which is proportional to the square of the total harmonic order. In this paper, we study the shot noise evolution in the first-stage modulator and radiator of a HC FEL that produces the dominant noise contributions. We derive the effective input noise for a modulator operating in the low-gain regime, and analyze the radiator noise for a density-modulated beam. The significance of these noise sources in different harmonic cascade designs is also discussed.

  18. High intensity direct third harmonic generation in BBO

    SciTech Connect

    Banks, P.S., LLNL

    1998-02-23

    The azimuthal dependence of second- and third-order coupling are used to measure the relative contributions of each to direct third harmonic generation with efficiencies up to 6%. The values of {xi}{sub ij}{sup (3)} are measured.

  19. Mesoscopic harmonic mapping of electromechanical response in a relaxor ferroelectric

    NASA Astrophysics Data System (ADS)

    Vasudevan, Rama K.; Zhang, Shujun; Ding, Jilai; Okatan, M. Baris; Jesse, Stephen; Kalinin, Sergei V.; Bassiri-Gharb, Nazanin

    2015-06-01

    Relaxor-ferroelectrics are renowned for very large electrostrictive response, enabling applications in transducers, actuators, and energy harvesters. However, insight into the dissimilar contributions (polarization rotation, wall motion) to the electromechanical response from electrostrictive strain, and separation of such contributions from linear piezoelectric response are largely ignored at the mesoscale. Here, we employ a band-excitation piezoresponse force microscopy (BE-PFM) technique to explore the first and second harmonics of the piezoelectric response in prototypical relaxor-ferroelectric 0.72Pb(Mg1/3Nb2/3)O3-0.28PbTiO3 (PMN-0.28PT) single crystals. Third order polynomial fitting of the second harmonic reveals considerable correlation between the cubic coefficient map and the first harmonic piezoresponse amplitude. These results are interpreted under a modified Rayleigh framework, as evidence for domain wall contributions to enhanced electromechanical response. These studies highlight the contribution of domain wall motion in the electromechanical response of relaxor ferroelectrics, and further show the utility of harmonic BE-PFM measurements in spatially mapping the mesoscopic variability inherent in disordered systems.

  20. Compact, harmonic multiplying gyrotron amplifiers

    SciTech Connect

    Guo, H.Z.; Granatstein, V.L.; Antonsen, T.M. Jr.; Levush, B.; Tate, J.; Chen, S.H.

    1995-12-31

    A compact, harmonic multiplying gyrotron traveling wave amplifier is being developed. The device is a three-stage tube with the output section running as a fourth harmonic gyro-TWT, the input section running as a fundamental gyro-TWT, and the middle operating at the second harmonic of the cyclotron frequency. Radiation is suppressed by servers between the sections. The operating beam of the tube is produced by a magnetron injection gun (MIG). A TE{sub 0n} mode selective interaction circuit consisting of mode converters and a filter waveguide is employed for both input and output sections to solve the mode competition problem, which is pervasive in gyro-TWT operation. The input section has an input coupler designed as a TE{sub 0n} mode launcher. It excites a signal at the fundamental cyclotron frequency (17.5 GHz), which is amplified in the first TWT interaction region. So far the device is similar to a two-stage harmonic gyro-TWT. The distinction is that in the three-stage device the second section will be optimized not for output power but for fourth harmonic bunching of the beam. A gyroklystron amplifier has also been designed. The configuration is similar to the gyro-TWT but with the traveling wave interaction structures replaced by mode selective special complex cavities. Cold test results of the wideband input coupler and the TE{sub 0n} mode selective interaction circuit have been obtained.

  1. Polynomial harmonic GMDH learning networks for time series modeling.

    PubMed

    Nikolaev, Nikolay Y; Iba, Hitoshi

    2003-12-01

    This paper presents a constructive approach to neural network modeling of polynomial harmonic functions. This is an approach to growing higher-order networks like these build by the multilayer GMDH algorithm using activation polynomials. Two contributions for enhancement of the neural network learning are offered: (1) extending the expressive power of the network representation with another compositional scheme for combining polynomial terms and harmonics obtained analytically from the data; (2) space improving the higher-order network performance with a backpropagation algorithm for further gradient descent learning of the weights, initialized by least squares fitting during the growing phase. Empirical results show that the polynomial harmonic version phGMDH outperforms the previous GMDH, a Neurofuzzy GMDH and traditional MLP neural networks on time series modeling tasks. Applying next backpropagation training helps to achieve superior polynomial network performances. PMID:14622880

  2. Harmonic Nanoparticles for Regenerative Research

    PubMed Central

    Ronzoni, Flavio; Magouroux, Thibaud; Vernet, Remi; Extermann, Jérôme; Crotty, Darragh; Prina-Mello, Adriele; Ciepielewski, Daniel; Volkov, Yuri; Bonacina, Luigi; Wolf, Jean-Pierre; Jaconi, Marisa

    2014-01-01

    In this visualized experiment, protocol details are provided for in vitro labeling of human embryonic stem cells (hESC) with second harmonic generation nanoparticles (HNPs). The latter are a new family of probes recently introduced for labeling biological samples for multi-photon imaging. HNPs are capable of doubling the frequency of excitation light by the nonlinear optical process of second harmonic generation with no restriction on the excitation wavelength. Multi-photon based methodologies for hESC differentiation into cardiac clusters (maintained as long term air-liquid cultures) are presented in detail. In particular, evidence on how to maximize the intense second harmonic (SH) emission of isolated HNPs during 3D monitoring of beating cardiac tissue in 3D is shown. The analysis of the resulting images to retrieve 3D displacement patterns is also detailed. PMID:24836220

  3. Harmonic nanoparticles for regenerative research.

    PubMed

    Ronzoni, Flavio; Magouroux, Thibaud; Vernet, Remi; Extermann, Jérôme; Crotty, Darragh; Prina-Mello, Adriele; Ciepielewski, Daniel; Volkov, Yuri; Bonacina, Luigi; Wolf, Jean-Pierre; Jaconi, Marisa

    2014-01-01

    In this visualized experiment, protocol details are provided for in vitro labeling of human embryonic stem cells (hESC) with second harmonic generation nanoparticles (HNPs). The latter are a new family of probes recently introduced for labeling biological samples for multi-photon imaging. HNPs are capable of doubling the frequency of excitation light by the nonlinear optical process of second harmonic generation with no restriction on the excitation wavelength. Multi-photon based methodologies for hESC differentiation into cardiac clusters (maintained as long term air-liquid cultures) are presented in detail. In particular, evidence on how to maximize the intense second harmonic (SH) emission of isolated HNPs during 3D monitoring of beating cardiac tissue in 3D is shown. The analysis of the resulting images to retrieve 3D displacement patterns is also detailed. PMID:24836220

  4. Two Droplets Burning Side by Side

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The Fiber-Supported Droplet Combustion (FSDC) experiment team got more than twice as many burns have been completed as were originally scheduled for STS-95. This image was taken July 12, 1997, MET:10/08:13 (approximate). As shown here, scientists were able to burn two droplets side by side, more closely mimicking behavior of burning fuel in an engine. This shows ignition of a single drop that subsequently burned while a fan blew through the chamber, giving the scientists data on burning with convection, but no buoyancy -- an important distinction when you're trying to solve a problem by breaking it into parts. FSDC-2 studied fundamental phenomena related to liquid fuel droplet combustion in air. Pure fuels and mixtures of fuels were burned as isolated single and dual droplets with and without forced air convection. The FSDC guest investigator was Forman Williams, University of California, San Diego. The experiment was part of the space research investigations conducted during the Microgravity Science Laboratory-1R mission (STS-94, July 1-17 1997). Advanced combustion experiments will be a part of investigations plarned for the International Space Station. (1.1 MB, 11-second MPEG, screen 320 x 240 pixels; downlinked video, higher quality not available) A still JPG composite of this movie is available at http://mix.msfc.nasa.gov/ABSTRACTS/MSFC-0300176.html.

  5. Topological vector spaces of harmonic functions and the trace operator

    NASA Astrophysics Data System (ADS)

    Sansò, F.; Venuti, G.

    2005-07-01

    Many problems in physical geodesy can be formulated in terms of boundary-value problems (BVPs) for the gravitational potential; many of them can be ultimately formulated as a Dirichlet problem. For this reason, there is a flourishing literature of geodetic contributions to potential theory. In this paper, the authors pick up some classical arguments from the mathematical analysis of BVPs and show, by using only Hilbert spaces of harmonic functions, how they can be systematically cast into a functional scheme clarifying the role of duality when dealing with the harmonic subspaces of classical Sobolev spaces, of any real order. The analysis is here restricted to the case of functions harmonic in spherical domains to make the results transparent and more readable by geodesists. A further step is then taken showing how to generalize the Dirichlet problem for the space of all the functions that are harmonic outside a sphere, which exploits the more general theory of Fréchet topological spaces. Basically, the result is that any functions harmonic in the exterior of a sphere can be uniquely identified by a suitably defined trace on the sphere. The paper concludes with comments and discussion of future work.

  6. Localization and vector spherical harmonics

    NASA Astrophysics Data System (ADS)

    von Brecht, James H.

    2016-01-01

    This paper establishes the following localization property for vector spherical harmonics: a wide class of non-local, vector-valued operators reduce to local, multiplication-type operations when applied to a vector spherical harmonic. As localization occurs in a very precise, quantifiable and explicitly computable fashion, the localization property provides a set of useful formulae for analyzing vector-valued fractional diffusion and non-local differential equations defined on S d - 1. As such analyses require a detailed understanding of operators for which localization occurs, we provide several applications of the result in the context of non-local differential equations.

  7. Side Effects of Chemotherapy

    MedlinePlus

    ... reactions to the different drugs. The doctors, nurses, and pharmacists will describe what to look out for in ... will be monitored very closely by doctors, nurses, and pharmacists to make sure that all side effects are ...

  8. Semiclassical-wave-function perspective on high-harmonic generation

    NASA Astrophysics Data System (ADS)

    Mauger, François; Abanador, Paul M.; Lopata, Kenneth; Schafer, Kenneth J.; Gaarde, Mette B.

    2016-04-01

    We introduce a semiclassical-wave-function (SCWF) model for strong-field physics and attosecond science. When applied to high-harmonic generation (HHG), this formalism allows one to show that the natural time-domain separation of the contribution of ionization, propagation, and recollisions to the HHG process leads to a frequency-domain factorization of the harmonic yield into these same contributions, for any choice of atomic or molecular potential. We first derive the factorization from the natural expression of the dipole signal in the temporal domain by using a reference system, as in the quantitative rescattering (QRS) formalism [J. Phys. B 43, 122001 (2010), 10.1088/0953-4075/43/12/122001]. Alternatively, we show how the trajectory component of the SCWF can be used to express the factorization, which also allows one to attribute individual contributions to the spectrum to the underlying trajectories.

  9. Time-resolved electric-field-induced second harmonic

    NASA Astrophysics Data System (ADS)

    Meshulam, Guilia; Berkovic, Garry; Kotler, Zvi

    2001-12-01

    One limitation of using electric field induced second harmonic (EFISH) to determine the molecular first hyperpolarizability (beta) of nonlinear optical molecules lies in the fact that part of the second harmonic signal comes from the second hyperpolarizability (gamma) produced by mixing two optical fields with the DC field. In analyzing EFISH results, the second hyperpolarizability contribution of the studied molecules is generally neglected. We present a modified time resolved EFISH technique that allows us, in a single experiment, to determine separately the beta and the gamma contributions. We study para-nitro aniline dissolved in Glycerol, a highly viscous solvent, and apply the DC field via a high voltage pulse with a fast rise time of approximately 40 nsec. As a result, the orientation of the molecules under the applied electric field is slow relative to the build-up of the field, enabling us to directly measure only the DC induced second harmonic (gamma contribution), at the beginning of the HV pulse. The pure beta contribution is determined from the difference between this signal and the conventional EFISH signal at the plateau of the HV pulse. Our result confirm that the gamma contribution is indeed less than 10% of the total.

  10. Spatial properties of odd and even low order harmonics generated in gas

    PubMed Central

    Lambert, G.; Andreev, A.; Gautier, J.; Giannessi, L.; Malka, V.; Petralia, A.; Sebban, S.; Stremoukhov, S.; Tissandier, F.; Vodungbo, B.; Zeitoun, Ph.

    2015-01-01

    High harmonic generation in gases is developing rapidly as a soft X-ray femtosecond light-source for applications. This requires control over all the harmonics characteristics and in particular, spatial properties have to be kept very good. In previous literature, measurements have always included several harmonics contrary to applications, especially spectroscopic applications, which usually require a single harmonic. To fill this gap, we present here for the first time a detailed study of completely isolated harmonics. The contribution of the surrounding harmonics has been totally suppressed using interferential filtering which is available for low harmonic orders. In addition, this allows to clearly identify behaviors of standard odd orders from even orders obtained by frequency-mixing of a fundamental laser and of its second harmonic. Comparisons of the spatial intensity profiles, of the spatial coherence and of the wavefront aberration level of 5ω at 160 nm and 6ω at 135 nm have then been performed. We have established that the fundamental laser beam aberrations can cause the appearance of a non-homogenous donut-shape in the 6ω spatial intensity distribution. This undesirable effect can be easily controlled. We finally conclude that the spatial quality of an even harmonic can be as excellent as in standard generation. PMID:25585715

  11. Second and Third Harmonic Measurements at the Linac Coherent Light Source

    SciTech Connect

    Ratner, D.; Brachmann, A.; Decker, F.J.; Ding, Y.; Dowell, D.; Emma, P.; Fisher, A.; Frisch, J.; Gilevich, S.; Huang, Z.; Hering, P.; Iverson, R.; Krzywinski, J.; Loos, H.; Messerschmidt, M.; Nuhn, H.D.; Smith, T.; Turner, J.; Welch, J.; White, W.; Wu, J.; /SLAC

    2011-01-03

    The Linac Coherent Light Source (LCLS) started user commissioning in October of 2009, producing Free Electron Laser (FEL) radiation between 800 eV and 8 keV [1]. The fundamental wavelength of the FEL dominates radiation in the beamlines, but the beam also produces nonnegligible levels of radiation at higher harmonics. The harmonics may be desirable as a source of harder X-rays, but may also contribute backgrounds to user experiments. In this paper we present preliminary measurements of the second and third harmonic content in the FEL. We also measure the photon energy cutoff of the soft X-ray mirrors to determine the extent to which higher harmonics reach the experimental stations. We present preliminary second and third harmonic measurements for LCLS. At low energies (below 1 keV fundamental) we measure less than 0.1% second harmonic content. The second harmonic will be present in the soft X-ray beam line for fundamental photon energies below approximately 1.1 keV. At low and high energies, we measure third harmonic content ranging from 0.5% to 3%, which is consistent with expectations. For both second and third harmonics, experimental work is ongoing. More rigorous analysis of the data will be completed soon.

  12. [Psychoanalysis and Side Effect].

    PubMed

    Shirahase, Joichiro

    2015-01-01

    A study of psychoanalysis from the perspective of side effects reveals that its history was a succession of measures to deal with its own side effects. This, however, does not merely suggest that, as a treatment method, psychoanalysis is incomplete and weak: rather, its history is a record of the growth and development of psychoanalysis that discovered therapeutic significance from phenomena that were initially regarded as side effects, made use of these discoveries, and elaborated them as a treatment method. The approach of research seen during the course of these developments is linked to the basic therapeutic approach of psychoanalysis. A therapist therefore does not draw conclusions about a patient's words and behaviors from a single aspect, but continues to make efforts to actively discover a variety of meanings and values from them, and to make the patient's life richer and more productive. This therapeutic approach is undoubtedly one of the unique aspects of psychoanalysis. I discuss the issue of psychoanalysis and side effects with the aim of clarifying this unique characteristic of psychoanalysis. The phenomenon called resistance inevitably emerges during the process of psychoanalytic treatment. Resistance can not only obstruct the progress of therapy; it also carries the risk of causing a variety of disadvantages to the patient. It can therefore be seen as an adverse effect. However, if we re-examine this phenomenon from the perspective of transference, we find that resistance is in fact a crucial tool in psychoanalysis, and included in its main effect, rather than a side effect. From the perspective of minimizing the character of resistance as a side effect and maximizing its character as a main effect, I have reviewed logical organization, dynamic evaluation, the structuring of treatment, the therapist's attitudes, and the training of therapists. I conclude by stating that psychoanalysis has aspects that do not match the perspective known as a side

  13. Analysis of higher harmonic contamination with a modified approach using a grating analyser

    NASA Astrophysics Data System (ADS)

    Gupta, Rajkumar; Modi, Mohammed H.; Kumar, M.; Chakera, J. A.; Lodha, G. S.

    2014-04-01

    Soft x-ray spectra of the toroidal grating monochromator (TGM) at the reflectivity beamline of Indus-1 synchrotron source are analyzed for higher harmonic contribution. A diffraction grating of central line spacing 1200 l/mm is used to disperse the monochromatic beam received from TGM to quantify the harmonic contents in the 50-360 Å wavelength range. In order to calculate the harmonic contamination, conventionally the intensity of higher order peak is divided by first order peak intensity of the desired wavelength. This approach is found to give wrong estimate as first order peak itself is overlapped by higher order peaks. In the present study, a modified approach has been proposed to calculate harmonic contamination where the intensity contributions of overlapping orders have been removed from the first order diffraction peak of the desired wavelength. It is found that the order contamination in the TGM spectra is less than 15% in the wavelength range of 90-180 Å. The total harmonic contribution increases from 6%-60% in the wavelength range of 150-260 Å. The critical wavelength of Indus-1 is 61 Å hence the harmonic contamination below 90 Å is significantly low. The results obtained with modified approach match well with those obtained by quantitative analysis of multilayer reflectivity data. The obtained higher harmonics data are used to fit the transmission of aluminum edge filter in the 120-360 Å wavelength range.

  14. Analysis of higher harmonic contamination with a modified approach using a grating analyser.

    PubMed

    Gupta, Rajkumar; Modi, Mohammed H; Kumar, M; Chakera, J A; Lodha, G S

    2014-04-01

    Soft x-ray spectra of the toroidal grating monochromator (TGM) at the reflectivity beamline of Indus-1 synchrotron source are analyzed for higher harmonic contribution. A diffraction grating of central line spacing 1200 l/mm is used to disperse the monochromatic beam received from TGM to quantify the harmonic contents in the 50-360 Å wavelength range. In order to calculate the harmonic contamination, conventionally the intensity of higher order peak is divided by first order peak intensity of the desired wavelength. This approach is found to give wrong estimate as first order peak itself is overlapped by higher order peaks. In the present study, a modified approach has been proposed to calculate harmonic contamination where the intensity contributions of overlapping orders have been removed from the first order diffraction peak of the desired wavelength. It is found that the order contamination in the TGM spectra is less than 15% in the wavelength range of 90-180 Å. The total harmonic contribution increases from 6%-60% in the wavelength range of 150-260 Å. The critical wavelength of Indus-1 is 61 Å hence the harmonic contamination below 90 Å is significantly low. The results obtained with modified approach match well with those obtained by quantitative analysis of multilayer reflectivity data. The obtained higher harmonics data are used to fit the transmission of aluminum edge filter in the 120-360 Å wavelength range. PMID:24784593

  15. Analysis of higher harmonic contamination with a modified approach using a grating analyser

    SciTech Connect

    Gupta, Rajkumar Modi, Mohammed H.; Lodha, G. S.; Kumar, M.; Chakera, J. A.

    2014-04-15

    Soft x-ray spectra of the toroidal grating monochromator (TGM) at the reflectivity beamline of Indus-1 synchrotron source are analyzed for higher harmonic contribution. A diffraction grating of central line spacing 1200 l/mm is used to disperse the monochromatic beam received from TGM to quantify the harmonic contents in the 50–360 Å wavelength range. In order to calculate the harmonic contamination, conventionally the intensity of higher order peak is divided by first order peak intensity of the desired wavelength. This approach is found to give wrong estimate as first order peak itself is overlapped by higher order peaks. In the present study, a modified approach has been proposed to calculate harmonic contamination where the intensity contributions of overlapping orders have been removed from the first order diffraction peak of the desired wavelength. It is found that the order contamination in the TGM spectra is less than 15% in the wavelength range of 90–180 Å. The total harmonic contribution increases from 6%–60% in the wavelength range of 150–260 Å. The critical wavelength of Indus-1 is 61 Å hence the harmonic contamination below 90 Å is significantly low. The results obtained with modified approach match well with those obtained by quantitative analysis of multilayer reflectivity data. The obtained higher harmonics data are used to fit the transmission of aluminum edge filter in the 120–360 Å wavelength range.

  16. Multi-scale modeling of mycosubtilin lipopeptides at the air/water interface: structure and optical second harmonic generation.

    PubMed

    Loison, Claire; Nasir, Mehmet Nail; Benichou, Emmanuel; Besson, Françoise; Brevet, Pierre-François

    2014-02-01

    Monolayers of the lipopeptide mycosubtilin are studied at the air/water interface. Their structure is investigated using molecular dynamics simulations. All-atom models suggest that the lipopeptide is flexible and aggregates at the interface. To achieve simulation times of several microseconds, a coarse-grained (CG) model based on the MARTINI force field was also used. These CG simulations describe the formation of half-micelles at the interface for surface densities up to 1 lipopeptide per nm(2). In these aggregates, the tyrosine side chain orientation is found to be constrained: on average, its main axis, as defined along the C-OH bond, aligns along the interface normal and points towards the air side. The origin of the optical second harmonic generation (SHG) from mycosubtilin monolayers at the air/water interface is also investigated. The molecular hyperpolarizability of the lipopeptide is obtained from quantum chemistry calculations. The tyrosine side chain contribution to the hyperpolarizability is found to be dominant. The orientation distribution of tyrosine, associated with a dominant hyperpolarizability component along the C-OH bond of the tyrosine, yields a ratio of the susceptibility elements χ((2))(ZZZ)/χ((2))(ZXX) consistent with the experimental measurements recently reported by M. N. Nasir et al. [Phys. Chem. Chem. Phys., 2013, 15, 19919]. PMID:24346061

  17. Side pocket mandrel

    SciTech Connect

    Crawford, D.W.; Crawford, M.S.; Crawford, W.B.

    1987-12-29

    A side pocket mandrel is described comprising: a tubular body section having a hollow interior that defines a main bore to one side thereof and another bore to the other side thereof; and a short-length seating section welded to one end of the body section. The seating section has a main bore formed to one side thereof aligned with the main bore in the body section, and a valve seating bore formed on the other side thereof generally aligned with the other bore. The seating bore has a polish section adjacent its outer end. The outer end opening through an exterior end surface of the mandrel. The seating bore has a recessed section adjacent the polish section. That provides an inwardly facing stop shoulder at one end thereof and a latch shoulder at the other end thereof facing the stop shoulder; and a tubular member welded to the seating section in axial alignment with the main bores. The axis of the polish section of the seating bore is inclined toward the axes of the main bores at a small angle.

  18. Univalent harmonic mappings convex in one direction

    NASA Astrophysics Data System (ADS)

    Ponnusamy, S.; Kaliraj, A. Sairam

    2014-09-01

    In this paper, we present a criterion for a harmonic function to be convex in one direction. Also, we discuss the class of harmonic functions starlike in one direction in the unit disk and obtain a method to construct univalent harmonic functions convex in one direction. Although the converse of classical Alexander's theorem for harmonic functions was proved to be false, we obtain a version of converse of it under a suitable additional condition.

  19. 3. VIEW NORTH, SOUTHWEST FRONT, SOUTHEAST SIDE Front and side ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW NORTH, SOUTHWEST FRONT, SOUTHEAST SIDE Front and side elevation. Note gasoline sign post added. Flush store window not altered, 1900 clapboard siding and panelling remaining. - 510 Central Avenue (Commercial Building), Ridgely, Caroline County, MD

  20. 15. WEST SIDE OF 1900 BLOCK, PACIFIC AVE. FROM RIGHT; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. WEST SIDE OF 1900 BLOCK, PACIFIC AVE. FROM RIGHT; 1920-22 PACIFIC AVE., WIEGAL COMPANY CANDY FACTORY (1904); 1924-26 PACIFIC AVE., CAMPBELL BUILDING (DAVIS BUILDING) (1890); 1928-30 PACIFIC AVE., REESE-CRANDALL & REDMAN BUILDING, (1890); 1932-36 PACIFIC AVE., MC DONALD & SMITH BUILDING (1890); 1938-48 PACIFIC AVE., F.S. HARMON COMPANY WAREHOUSE (1908), DESIGNED BY CARL AUGUST DARMER. - Union Depot Area Study, Tacoma, Pierce County, WA

  1. Initial fluctuation effect on harmonic flows in high-energy heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Han, L. X.; Ma, G. L.; Ma, Y. G.; Cai, X. Z.; Chen, J. H.; Zhang, S.; Zhong, C.

    2011-12-01

    Within the framework of a multiphase transport model, harmonic flows vn (n=2,3, and 4) are investigated for Au-Au collisions at sNN=200 GeV and Pb-Pb collisions at sNN=2.76 TeV. The event-by-event geometry fluctuations significantly contribute to harmonic flows. Triangular flow (v3) originates from initial triangularity (ɛ3) and is developed by partonic interactions. The conversion efficiency (vn/ɛn) decreases with the harmonic order and increases with the partonic interaction cross section. A mass ordering in the low-pT region and a constituent quark number scaling in the middle-pT region seem to work roughly for nth harmonic flows at both energies. All features of harmonic flows show similar qualitative behaviors at BNL Relativistic Heavy Ion Collider and CERN Large Hadron Collider energies, which implies that the formed partonic matters are similar at the two energies.

  2. Efficient second- and third-harmonic radiation generation from relativistic laser-plasma interactions

    SciTech Connect

    Singh, Mamta; Gupta, D. N.; Suk, H.

    2015-06-15

    We propose an idea to enhance the efficiency of second- and third-harmonic generation by considering the amplitude-modulation of the fundamental laser pulse. A short-pulse laser of finite spot size is modeled as amplitude modulated in time. Amplitude-modulation of fundamental laser contributes in quiver velocity of the plasma electrons and produces the strong plasma-density perturbations, thereby increase in current density at second- and third-harmonic frequency. In a result, the conversion efficiency of harmonic generation increases significantly. Power conversion efficiency of harmonic generation process is the increasing function of the amplitude-modulation parameter of the fundamental laser beam. Harmonic power generated by an amplitude modulated laser is many folds higher than the power obtained in an ordinary case.

  3. High-order harmonic generation in the presence of a resonance

    SciTech Connect

    Tudorovskaya, Maria; Lein, Manfred

    2011-07-15

    We investigate high-order harmonic generation from laser-irradiated systems that support a shape resonance. From the numerical solution of the time-dependent Schroedinger equation, we calculate the harmonic spectra and the time-frequency analysis of the harmonic intensity and phase. The analysis reveals the separate contributions of the short and long trajectories as well as the resonance. A range of harmonics is strongly enhanced by the presence of the resonance irrespective of the pulse length. The signature of the resonance remains significant after coherent summation over intensities as a simple method to simulate macroscopic effects. The time-frequency analysis supports the recently proposed four-step mechanism of the enhanced harmonic generation process.

  4. Harmonic analysis of precipitation climatology in Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Tarawneh, Qassem

    2016-04-01

    Annual rainfall records of 20 stations for 30 years are used in order to detect rainfall regimes and climatic features of Saudi Arabia using harmonic analysis techniques. In this study, the percentages of variance, amplitudes, and phase angles are calculated in order to depict the spatial and temporal characteristics of the country's rainfall. The first harmonic explains 42 % of rainfall variation in the western (W) region. This percentage increases toward east (E) and north (N) with 69 and 67 %, respectively. In the southwest (SW) region, the percentages explain 43 % of rainfall variation. The percentages of variance in W and SW are lower than in the E, NW, and central (C) regions. This implies significant contributions of the second harmonic in W and SW regions with 26 and 16 %, respectively. The high percentages of the second and third harmonics in W and SW regions suggest that these two regions are affected by different weather systems at different times. The SW region has the highest amplitudes of the first, second, and third harmonics. The amplitude of the first harmonic reaches to 21 mm in SW and 9 mm in both C and E regions. The time of maximum rainfall is calculated using phase angle; the result reflects that maximum rainfall is shifted forward on the time axis toward the spring season in SW and C regions, January in E and NW regions, and October and November in the W region. This reveals that the SW region is a completely different climatic region, though some of what affects this region also affects the central region. Conditions in the E and NW regions are mainly affected by Mediterranean weather systems, while the W region is affected by unstable conditions caused by the active Red Sea Trough (RST) in October and November.

  5. From Both Sides.

    ERIC Educational Resources Information Center

    Glew, Frank

    1998-01-01

    Ontario Agri-Food Education's curriculum unit, "From Both Sides," applies a cooperative-learning method of conflict resolution to environmental issues. Two groups of students are assigned polar views on an issue such as pesticide use. Five steps involve preparing and presenting a position, refuting opposing positions, reversing perspectives, and…

  6. Harmonic auroral kilometric radiation of natural origin

    NASA Astrophysics Data System (ADS)

    Benson, R. F.

    1982-09-01

    When the ISIS 1 satellite passes through the auroral kilometric radiation (AKR) source region the sounder receiver often detects harmonic bands of radiation associated with the fundamental AKR band. These harmonic components were earlier attributed to a nonlinear instrumental response to the strong wide-band bursty AKR fundamental signal. Evidence is here presented that indicates that these harmonics are of natural origin, namely: (1) all the harmonic signals are sometimes observed to have nearly the same bandwidth, (2) when the fundamental signal has two components the harmonic signal sometimes corresponds to the weaker rather than the stronger component, (3) a weak harmonic can be observed to be associated with a weak fundamental, and (4) a 'harmonic' signal can be observed when there is no fundamental.

  7. Harmonic auroral kilometric radiation of natural origin

    NASA Technical Reports Server (NTRS)

    Benson, R. F.

    1982-01-01

    When the ISIS 1 satellite passes through the auroral kilometric radiation (AKR) source region the sounder receiver often detects harmonic bands of radiation associated with the fundamental AKR band. These harmonic components were earlier attributed to a nonlinear instrumental response to the strong wide-band bursty AKR fundamental signal. Evidence is here presented that indicates that these harmonics are of natural origin, namely: (1) all the harmonic signals are sometimes observed to have nearly the same bandwidth, (2) when the fundamental signal has two components the harmonic signal sometimes corresponds to the weaker rather than the stronger component, (3) a weak harmonic can be observed to be associated with a weak fundamental, and (4) a 'harmonic' signal can be observed when there is no fundamental.

  8. 4. VIEW EAST, SOUTHWEST FRONT, NORTHWEST SIDE Side elevation. Note ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW EAST, SOUTHWEST FRONT, NORTHWEST SIDE Side elevation. Note the ground floor windows which were added. Siding is vinyl, but the burned area exposes asbestos siding added when the rear and upper areas were converted to living spaces. - 510 Central Avenue (Commercial Building), Ridgely, Caroline County, MD

  9. Group velocity matching in high-order harmonic generation driven by mid-infrared lasers

    NASA Astrophysics Data System (ADS)

    Hernández-García, C.; Popmintchev, T.; Murnane, M. M.; Kapteyn, H. C.; Plaja, L.; Becker, A.; Jaron-Becker, A.

    2016-07-01

    We analyze the role of group-velocity matching (GVM) in the macroscopic build up of the high-harmonic signal generated in gas targets at high pressures. A definition of the walk-off length, associated with GVM, in the non-perturbative intensity regime of high-harmonic generation is given. Semiclassical predictions based on this definition are in excellent agreement with full quantum simulations. We demonstrate that group velocity matching is a relevant factor in high harmonic generation and the isolation of attosecond pulses driven by long wavelength lasers and preferentially selects contributions from the short quantum trajectories.

  10. Results of the harmonics measurement program at the John F. Long photovoltaic house

    SciTech Connect

    Campen, G.L.

    1982-03-01

    Photovoltaic (PV) systems used in single-family dwellings require an inverter to act as an interface between the direct-current (dc) power output of the PV unit and the alternating-current (ac) power needed by house loads. A type of inverter known as line-commutated injects harmonic currents on the ac side and requires large amounts of reactive power. Large numbers of such PV installations could lead to unacceptable levels of harmonic voltages on the utility system, and the need to increase the utility's delivery of reactive power could result in significant cost increases. The harmonics and power-factor effects are examined for a single PV installation using a line-commutated inverter. The data were obtained during a five-day measurement program conducted at the John F. Long House, which is a prototype residential PV installation located in Phoenix, Arizona. The magnitude and phase of various currents and voltages from the fundamental to the 13th harmonic were recorded both with and without the operation of the PV system. The inverter can be looked upon as an ideal current source that injects definable amounts of current at any particular harmonic frequency; the harmonic currents that were normally conducted by the house loads underwent very little change as a result of currents injected by the inverter; the harmonic voltages seen by the house loads were slightly altered due to the passage of the inverter harmonic currents through system impedances, but no effect on the voltage harmonics was observed at the distribution transformer primary; and the inverter's reactive power demands more than doubled the maximum demand that would be expected for a normal home. Sufficient information was obtained to provide for a conservative modeling of a representative PV system to be used in a computer program designed to evaluate the effects of larger concentrations of PV systems.

  11. Simulations: The dark side

    NASA Astrophysics Data System (ADS)

    Frenkel, D.

    2013-01-01

    This paper discusses the Monte Carlo and Molecular Dynamics methods. Both methods are, in principle, simple. However, simple does not mean risk-free. In the literature, many of the pitfalls in the field are mentioned, but usually as a footnote --and these footnotes are scattered over many papers. The present paper focuses on the "dark side" of simulation: it is one big footnote. I should stress that "dark", in this context, has no negative moral implication. It just means: under-exposed.

  12. "Side" effects: a misnomer.

    PubMed Central

    Joyce, C. R.

    1976-01-01

    The tragic results for the babies of patients prescribed thalidomide, although they can indeed be termed "side" effects, hardly warrant so slight an epithet, and Dr Joyce in his paper would like the term to be dropped in favour of "additional" effects of drugs. Despite extensive clinical trials before drugs are put before the prescribing doctor, side effects cannot be entirely anticipated or eliminated, and indeed many are not harmful. However, it is important, Dr Joyce argues, for information to the doctor from the patient and from the doctor to the manufacturer to be collected and evaluated. Only in this way can effects of drugs other than those intended be drawn to the notice of the manufacturer. The commentary by two practising physicians emphasizes the ambiguities in the descriptive literature accompanying a new drug. Dr Herxheimer and Dr Higgs would like to see some sort of panel to be established to reassess drugs in the light of observations on their effects and "side" effects on patients, a task which the existing Committee on Safety of Medicines could not at the moment undertake. A medical need for a new drug should be established before it is manufactured, let alone offered to the general practitioner. PMID:823336

  13. Orthogonality of Harmonic Potentials and Fields in Spheroidal Coordinates (Petrus Peregrinus Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Lowes, F. J.

    2012-04-01

    Spherical harmonic scalar potentials are the independent solutions of the Laplace equation relevant in a spherical geometry; they are used widely in global geomagnetism and geodesy to represent the situation in the source-free region outside the Earth. It is well known that these harmonics are orthogonal over the sphere, as are the vector fields that are the gradients of the harmonics. If we have data (potential or field) over the sphere, this orthogonality enables us to use spherical harmonic analysis to determine separately the numerical coefficient relevant for each harmonic potential. But the Earth is better approximated by an oblate spheroid; and for sources near the surface it is more relevant to use a spheroidal coordinate system; in this case the appropriate solutions of the Laplace equation are now spheroidal harmonics. However these SPHEROIDAL harmonics are NOT orthogonal over the SPHEROID, and neither are the corresponding vector potential gradients. I show how this problem can be overcome by using an appropriate weighting factor that depends only on colatitude; the factor is different for potential and for field. By using the appropriate weighting factor it is then possible to do the spheroidal equivalent of spherical harmonic analysis, either for the scalar potential or the corresponding vector field. In the spherical case, because of the orthogonality it is possible to separate the total mean-square potential over the sphere into parts contributed by harmonics of different degrees, e.g. the 'degree variance' in geodesy. Similarly, in geomagnetism we have the 'power spectrum' that separates the total mean-square vector field into contributions from different degrees. But in the spheroidal case such a separation (of potential or field) is possible only if we use a WEIGHTED mean-square.

  14. Symmetries of coupled harmonic oscillators

    NASA Technical Reports Server (NTRS)

    Han, D.; Kim, Y. S.

    1993-01-01

    It is shown that the system of two coupled harmonic oscillators possesses many interesting symmetries. It is noted that the symmetry of a single oscillator is that of the three-parameter group Sp(2). Thus two uncoupled oscillator exhibits a direct product of two Sp(2) groups, with six parameters. The coupling can be achieved through a rotation in the two-dimensional space of two oscillator coordinates. The closure of the commutation relations for the generators leads to the ten-parameter group Sp(4) which is locally isomorphic to the deSitter group O(3,2).

  15. Making space for harmonic oscillators

    SciTech Connect

    Michelotti, Leo; /Fermilab

    2004-11-01

    If we restrict the number of harmonic oscillator energy eigenstates to some finite value, N, then the discrete spectrum of the corresponding position operator comprise the roots of the Hermite polynomial H{sub N+1}. Its range is just large enough to accommodate classical motion at high energy. A negative energy term must be added to the Hamiltonian which affects only the last eigenstate, |N>, suggesting it is concentrated at the extrema of this finite ''space''. Calculations support a conjecture that, in the limit of large N, the global distribution of points approaches the differential form for classical action.

  16. Harmonics and Resonance Issues with Wind Plants

    SciTech Connect

    Bradt, M.; Badrzadeh, Babak; Camm, E H; Castillo, Nestor; Mueller, David; Siebert, T.; Schoene, Jens; Smith, Travis M; Starke, Michael R; Walling, R.

    2011-01-01

    Wind plants are susceptible to lightly-damped resonances which can attract and amplify ambient grid harmonic distortion and magnify wind turbine harmonic generation. Long-accepted harmonic modeling assumptions and practices are not appropriate for wind plants. VSCs are not ideal current sources and grid impedance is important. Attention to modeling detail and thorough evaluation over range of conditions is critical to meaningful analysis. In general, wind turbines are very slight sources of harmonics. Most harmonic issues are a result of resonance, caused by capacitor banks (for reactive power compensation) or from the extensive underground cabling in a collector system. Converter controls instability can be exacerbated by power system resonances. In some cases this has caused severe voltage distorDon and other problems. The IEEE 519 recommended guidelines are very restrictive. I recommend that they are used to resolve serious harmonic issues, and not to create petty problems.

  17. Killing vector fields and harmonic superfield theories

    SciTech Connect

    Groeger, Josua

    2014-09-15

    The harmonic action functional allows a natural generalisation to semi-Riemannian supergeometry, also referred to as harmonic, which resembles the supersymmetric sigma models studied in high energy physics. We show that Killing vector fields are infinitesimal supersymmetries of this harmonic action and prove three different Noether theorems in this context. En passant, we provide a homogeneous treatment of five characterisations of Killing vector fields on semi-Riemannian supermanifolds, thus filling a gap in the literature.

  18. Killing vector fields and harmonic superfield theories

    NASA Astrophysics Data System (ADS)

    Groeger, Josua

    2014-09-01

    The harmonic action functional allows a natural generalisation to semi-Riemannian supergeometry, also referred to as harmonic, which resembles the supersymmetric sigma models studied in high energy physics. We show that Killing vector fields are infinitesimal supersymmetries of this harmonic action and prove three different Noether theorems in this context. En passant, we provide a homogeneous treatment of five characterisations of Killing vector fields on semi-Riemannian supermanifolds, thus filling a gap in the literature.

  19. Data-Aware Retrodiction for Asynchronous Harmonic Measurement in a Cyber-Physical Energy System.

    PubMed

    Liu, Youda; Wang, Xue; Liu, Yanchi; Cui, Sujin

    2016-01-01

    Cyber-physical energy systems provide a networked solution for safety, reliability and efficiency problems in smart grids. On the demand side, the secure and trustworthy energy supply requires real-time supervising and online power quality assessing. Harmonics measurement is necessary in power quality evaluation. However, under the large-scale distributed metering architecture, harmonic measurement faces the out-of-sequence measurement (OOSM) problem, which is the result of latencies in sensing or the communication process and brings deviations in data fusion. This paper depicts a distributed measurement network for large-scale asynchronous harmonic analysis and exploits a nonlinear autoregressive model with exogenous inputs (NARX) network to reorder the out-of-sequence measuring data. The NARX network gets the characteristics of the electrical harmonics from practical data rather than the kinematic equations. Thus, the data-aware network approximates the behavior of the practical electrical parameter with real-time data and improves the retrodiction accuracy. Theoretical analysis demonstrates that the data-aware method maintains a reasonable consumption of computing resources. Experiments on a practical testbed of a cyber-physical system are implemented, and harmonic measurement and analysis accuracy are adopted to evaluate the measuring mechanism under a distributed metering network. Results demonstrate an improvement of the harmonics analysis precision and validate the asynchronous measuring method in cyber-physical energy systems. PMID:27548171

  20. High harmonic generation from Bloch electron in Solids

    NASA Astrophysics Data System (ADS)

    Wu, Mengxi; Ghimire, Shambhu; Reis, David; Schafer, Kenneth; Gaarde, Mette

    2015-05-01

    We study the generation of high harmonic radiation by Bloch electrons in a model solid driven by a strong mid-infrared laser field. We solve the single-electron time-dependent Schrödinger equation (TDSE) using a velocity-gauge method [New J. Phys. 15, 013006 (2013)]. The resulting harmonic spectrum exhibits a primary plateau due to the coupling of the valence band to the first conduction band, with a cutoff energy that scales linearly with field strength and laser wavelength. We also find a weaker second plateau due to coupling to higher-lying conduction bands, with a cutoff that is also approximately linear in the field strength. To facilitate the analysis of the time-frequency characteristics of the emitted harmonics, we also solve the TDSE in the Houston states [Phys. Rev. B 33, 5494 (1986)], which allows us to separate inter- and intra-band contributions to the current. We find that the inter- and intra-band contributions display very different time-frequency characteristics. We show that solutions in these two bases are equivalent under an unitary transformation but that, unlike the velocity gauge method, the Houston state treatment is numerically unstable when more than a few low lying energy bands are used.

  1. Harmonic generation in free-electron lasers

    NASA Astrophysics Data System (ADS)

    Freund, H. P.; Chang, C. L.; Bluem, H.

    1987-10-01

    The question of harmonic generation in FELs is addressed by considering a relativistic electron beam propagating through a loss-free rectangular waveguide in the presence of a linearly polarized wiggler magnetic field. Substantial growth rates and efficiencies at the higher harmonics are shown to be obtainable at the cost of more stringent requirements on beam quality. It is also found that the harmonic emission is far more sensitive to the effect of the thermal spread than is the fundamental. It is suggested that the higher beam currents obtainable on the forthcoming super-ACO storage ring could lead to coherent harmonic generation.

  2. South (front) side. Metal railing to either side supports a ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    South (front) side. Metal railing to either side supports a door when it is open. - Fitzsimons General Hospital, Root Cellar, West Pennington Avenue, North of Building No. 121, Aurora, Adams County, CO

  3. VIEW FROM SOUTHWEST SIDE SHOWING SOUTH AND WEST SIDES OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM SOUTHWEST SIDE SHOWING SOUTH AND WEST SIDES OF BUILDING - U.S. Naval Base, Pearl Harbor, Drum & Can Loading Facility, South of Arizona Street near Kamehameha Highway, Pearl City, Honolulu County, HI

  4. VIEW FROM NORTHEAST SIDE SHOWING NORTH AND EAST SIDES OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM NORTHEAST SIDE SHOWING NORTH AND EAST SIDES OF BUILDING - U.S. Naval Base, Pearl Harbor, Drum & Can Loading Facility, South of Arizona Street near Kamehameha Highway, Pearl City, Honolulu County, HI

  5. North side, westcentral part, showing two doorways to the side ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    North side, west-central part, showing two doorways to the side aisle of the audience seating section. - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  6. 4. Detail of siding beneath plywood on west side of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Detail of siding beneath plywood on west side of claim house, also showing closed off door - George Spangerberger Farmstead, John Siegrist Claim House, 2012 West Illinois Avenue, South Hutchinson, Reno County, KS

  7. 14. CO'S STATEROOM, STERN SIDE (LEFT) AND STARBOARD SIDE. NOTE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. CO'S STATEROOM, STERN SIDE (LEFT) AND STARBOARD SIDE. NOTE WOODEN WINDOW FRAMES. - U.S. Coast Guard Cutter WHITE LUPINE, U.S. Coast Guard Station Rockland, east end of Tillson Avenue, Rockland, Knox County, ME

  8. OBLIQUE VIEW OF SOUTHWEST SIDE (LEFT) AND SOUTHEAST SIDE (RIGHT). ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OBLIQUE VIEW OF SOUTHWEST SIDE (LEFT) AND SOUTHEAST SIDE (RIGHT). NOTE THE FIXED LOUVER ROOF VENTS. VIEW FACING NORTH. - Hickam Field, Fort Kamehameha Officers' Housing Type Z, 19 Worchester Avenue, Honolulu, Honolulu County, HI

  9. 59. SIDE VIEW OF TENSION CARRIAGE: Side view towards the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    59. SIDE VIEW OF TENSION CARRIAGE: Side view towards the south of the California Street cable's tension carriage. - San Francisco Cable Railway, Washington & Mason Streets, San Francisco, San Francisco County, CA

  10. FACILITY 859, DETAIL OF SOUTHWEST SIDE (WILSON STREET SIDE), SHOWING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FACILITY 859, DETAIL OF SOUTHWEST SIDE (WILSON STREET SIDE), SHOWING CHEVRON DESIGN OVER FORMER PASSAGEWAY, VIEW FACING NORTHEAST. - Schofield Barracks Military Reservation, Quadrangle K Barracks Type, Between Wilson Street & Capron Avenue near Williston Avenue, Wahiawa, Honolulu County, HI

  11. FACILITY 858, PORTION OF NORTHEAST SIDE (APRON AVENUE SIDE), SHOWING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FACILITY 858, PORTION OF NORTHEAST SIDE (APRON AVENUE SIDE), SHOWING CHEVRON DESIGN OVER FORMER PASSAGEWAY, OBLIQUE VIEW FACING WEST. - Schofield Barracks Military Reservation, Quadrangle K Barracks Type, Between Wilson Street & Capron Avenue near Williston Avenue, Wahiawa, Honolulu County, HI

  12. VIEW OF FRONT SIDE OF BUILDING 23 FROM EAST SIDE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF FRONT SIDE OF BUILDING 23 FROM EAST SIDE OF COURTYARD UNDER ARCADE, FACING WEST - Roosevelt Base, Auditorium-Gymnasium, West Virginia Street between Richardson & Reeves Avenues, Long Beach, Los Angeles County, CA

  13. Front (west side) and south side of building Fitzsimons ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Front (west side) and south side of building - Fitzsimons General Hospital, Golf Course Waiting Shelter, Southwest area of Golf Course, 700 feet Northeast of intersection of West Harlow Avenue & Peoria Street, Aurora, Adams County, CO

  14. North side and a portion of the front (east side) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    North side and a portion of the front (east side) of the building - Fitzsimons General Hospital, Officers' Quarters, West Charlie Kelly Boulevard & South Hutton Street, Southwest Corner, Aurora, Adams County, CO

  15. East side and part of the front (south side) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    East side and part of the front (south side) - Fitzsimons General Hospital, Semi-Infirmary Tubercular Ward, East Charlie Kelly Boulevard & South Page Street, northwest corner, Aurora, Adams County, CO

  16. 1. SOUTH VIEW OF NORTHWEST SIDE, WITH NORTHEAST SIDE OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. SOUTH VIEW OF NORTHWEST SIDE, WITH NORTHEAST SIDE OF MINE OFFICE ON RIGHT OF PHOTO - Juniata Mill Complex, Assay Office, 22.5 miles Southwest of Hawthorne, between Aurora Crater & Aurora Peak, Hawthorne, Mineral County, NV

  17. Imaging the bipolarity of myosin filaments with Interferometric Second Harmonic Generation microscopy

    PubMed Central

    Rivard, Maxime; Couture, Charles-André; Miri, Amir K.; Laliberté, Mathieu; Bertrand-Grenier, Antony; Mongeau, Luc; Légaré, François

    2013-01-01

    We report that combining interferometry with Second Harmonic Generation (SHG) microscopy provides valuable information about the relative orientation of noncentrosymmetric structures composing tissues. This is confirmed through the imaging of rat medial gastrocnemius muscle. The inteferometric Second Harmonic Generation (ISHG) images reveal that each side of the myosin filaments composing the A band of the sarcomere generates π phase shifted SHG signal which implies that the myosin proteins at each end of the filaments are oriented in opposite directions. This highlights the bipolar structural organization of the myosin filaments and shows that muscles can be considered as a periodically poled biological structure. PMID:24156065

  18. Second harmonic generation and enhancement in microfibers and loop resonators

    NASA Astrophysics Data System (ADS)

    Gouveia, Marcelo A.; Lee, Timothy; Ismaeel, Rand; Ding, Ming; Broderick, Neil G. R.; Cordeiro, Cristiano M. B.; Brambilla, Gilberto

    2013-05-01

    We model and experimentally investigate second harmonic generation in silica microfibers and loop resonators, in which the second order nonlinearity arises from the glass-air surface dipole and bulk multipole contributions. In the loop resonator, the recirculation of the pump light on resonance is used to increase the conversion. The effect of the loop parameters, such as coupling and loss, is theoretically studied to determine their influence on the resonance enhancement. Experimentally, microfibers were fabricated with diameters around 0.7 μm to generate the intermodally phase matched second harmonic with an efficiency up to 4.2 × 10-8 when pumped with 5 ns 1.55 μm pulses with a peak power of 90 W. After reconfiguring the microfiber into a 1 mm diameter loop, the efficiency was resonantly enhanced by 5.7 times.

  19. A Comprehensive and Harmonized Digital Forensic Investigation Process Model.

    PubMed

    Valjarevic, Aleksandar; Venter, Hein S

    2015-11-01

    Performing a digital forensic investigation (DFI) requires a standardized and formalized process. There is currently neither an international standard nor does a global, harmonized DFI process (DFIP) exist. The authors studied existing state-of-the-art DFIP models and concluded that there are significant disparities pertaining to the number of processes, the scope, the hierarchical levels, and concepts applied. This paper proposes a comprehensive model that harmonizes existing models. An effort was made to incorporate all types of processes proposed by the existing models, including those aimed at achieving digital forensic readiness. The authors introduce a novel class of processes called concurrent processes. This is a novel contribution that should, together with the rest of the model, enable more efficient and effective DFI, while ensuring admissibility of digital evidence. Ultimately, the proposed model is intended to be used for different types of DFI and should lead to standardization. PMID:26258644

  20. Effect of Nuclear Motion on Molecular High-Order Harmonics and on Generation of Attosecond Pulses in Intense Laser Pulses

    NASA Astrophysics Data System (ADS)

    Bandrauk, André D.; Chelkowski, Szczepan; Kawai, Shinnosuke; Lu, Huizhong

    2008-10-01

    We calculate harmonic spectra and shapes of attosecond-pulse trains using numerical solutions of Non-Born-Oppenheimer time-dependent Shrödinger equation for 1D H2 molecules in an intense laser pulse. A very strong signature of nuclear motion is seen in the time profiles of high-order harmonics. In general the nuclear motion shortens the part of the attosecond-pulse train originating from the first electron contribution, but it may enhance the second electron contribution for longer pulses. The shape of time profiles of harmonics can thus be used for monitoring the nuclear motion.

  1. Molecular harmonic extension and enhancement from H2 + ions in the presence of spatially inhomogeneous fields

    NASA Astrophysics Data System (ADS)

    Feng, Liqiang

    2015-11-01

    Molecular high-order harmonic generation from the H2 + ion driven by spatial inhomogeneous fields consisting of the chirped pulse and a terahertz pulse has been theoretically investigated by numerically solving the non-Born-Oppenheimer time-dependent Schrödinger equation. It shows that with the introduction of the chirp as well as the spatial inhomogeneity of the pulse, not only the harmonic cutoff is remarkably extended, but also the single short quantum path is selected to contribute to the harmonic spectra. Moreover, through investigation the effects of the laser and the molecular parameters on the inhomogeneous harmonic generation, we found 1.92- and 3.3-dB enhanced fields for the chirp-free and chirped inhomogeneous pulses, respectively. Isotopic effect shows that intense harmonics can be generated from the lighter molecule. Furthermore, with the enhancement of the initial vibrational state and by properly adding a terahertz controlling pulse, the harmonic yield is enhanced by almost five orders of magnitude compared with the initial single chirped case. As a result, a 362-eV supercontinuum (which corresponds to a 4.0-dB laser field enhancement) with five orders of magnitude improvement is obtained. Finally, by properly superposing the harmonics, a series of intense extreme ultraviolet pulses with durations from 22 to 52 as can be produced.

  2. Night Side Jovian Aurora

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Jovian aurora on the night side of the planet. The upper bright arc is auroral emission seen 'edge on' above the planetary limb with the darkness of space as a background. The lower bright arc is seen against the dark clouds of Jupiter. The aurora is easier to see on the night side of Jupiter because it is fainter than the clouds when they are illuminated by sunlight. Jupiter's north pole is out of view to the upper right. The images were taken in the clear filter (visible light) and are displayed in shades of blue.

    As on Earth, the auroral emission is caused by electrically charged particles striking the upper atmosphere from above. The particles travel along the magnetic field lines of the planet, but their origin is not fully understood. The field lines where the aurora is most intense cross the Jovian equator at large distances (many Jovian radii) from the planet. The faint background throughout the image is scattered light in the camera. This stray light comes from the sunlit portion of Jupiter, which is out of the image to the right. In multispectral observations the aurora appears red, consistent with glow from atomic hydrogen in Jupiter's atmosphere. Galileo's unique perspective allows it to view the night side of the planet at short range, revealing details that cannot be seen from Earth. These detailed features are time dependent, and can be followed in sequences of Galileo images.

    North is at the top of the picture. A grid of planetocentric latitude and west longitude is overlain on the images. The images were taken on November 5, 1997 at a range of 1.3 million kilometers by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the

  3. Nonlinear Spectroscopic Theory of Displaced Harmonic Oscillators with Differing Curvatures: A Correlation Function Approach

    NASA Astrophysics Data System (ADS)

    Fidler, Andrew F.; Engel, Gregory S.

    2013-10-01

    We present a theory for a bath model in which we approximate the adiabatic nuclear potential surfaces on the ground and excited electronic states by displaced harmonic oscillators that differ in curvature. Calculations of the linear and third-order optical response functions employ an effective short-time approximation coupled with the cumulant expansion. In general, all orders of correlation contribute to the optical response, indicating that the solvation process cannot be described as Gaussian within the model. Calculations of the linear absorption and fluorescence spectra resulting from the theory reveal a stronger temperature dependence of the Stokes shift along with a general asymmetry between absorption and fluorescence line shapes, resulting purely from the difference in the phonon side band. We discuss strategies for controlling spectral tuning and energy-transfer dynamics through the manipulation of the excited-state and ground-state curvature. Calculations of the nonlinear response also provide insights into the dynamics of the system-bath interactions and reveal that multidimensional spectroscopies are sensitive to a difference in curvature between the ground- and excited-state adiabatic surfaces. This extension allows for the elucidation of short-time dynamics of dephasing that are accessible in nonlinear spectroscopic methods.

  4. Imaging with Second-Harmonic Generation Nanoparticles

    NASA Astrophysics Data System (ADS)

    Hsieh, Chia-Lung

    Second-harmonic generation nanoparticles show promise as imaging probes due to their coherent and stable signal with a broad flexibility in the choice of excitation wavelength. In this thesis, we developed and demonstrated barium titanate nanoparticles as second-harmonic radiation imaging probes. We studied the absolute second-harmonic generation efficiency of the nanoparticles on single-particle level. The polarization dependent second-harmonic signal of single nanoparticles was studied in detail. From the measured polar response, we were able to find the orientation of the nanoparticle. We developed a biochemical interface for using the second-harmonic nanoprobes as biomarkers, including in vitro cellular imaging and in vivo live animal imaging. The nanoparticles were surface functionalized with primary amine groups for stable colloidal dispersion. We achieved specific labeling of the second-harmonic nanoprobes via immunostaining where the antibodies were covalently conjugated onto the nanoparticles. We observed no toxicity of the functionalized nanoparticles to biological cells. The coherent second-harmonic signal radiated from the nanoparticles offers opportunities for new imaging techniques. Using interferometric detection, namely harmonic holography, both amplitude and phase of the second-harmonic field can be captured. Through digital beam propagation, three-dimensional field distribution, reflecting three-dimensional distribution of the nanoparticles, can be reconstructed. We achieved a scan-free three-dimensional imaging of nanoparticles in biological cells with sub-micron spatial resolution by using the harmonic holographic microscope. We further exploited the coherent second-harmonic signal for imaging through scattering media by performing optical phase conjugation of the second-harmonic signal. We demonstrated an all-digital optical phase conjugation of the second-harmonic signal originated from a nanoparticle by combining harmonic holography and

  5. Time on Your Side.

    ERIC Educational Resources Information Center

    Webber, Ross Arkell

    1989-01-01

    Six ways for development officers to handle overload are identified: distinguish between urgency and importance; selectively ignore time demands; focus on where to make the greatest contribution; delegate tasks; tend interpersonal relationships; and make progress on critical long-term objectives. (MLW)

  6. West-Side Story

    NASA Astrophysics Data System (ADS)

    Marochnik, L. S.

    2005-12-01

    This paper deals with the history of Density-Wave Spiral Theories in the 1960s. The motivation to write the paper was the publication of two papers on the history of these theories (Pasha 2004a, b). Pasha's papers tell only a part of the story that took place on the Western side of the Iron Curtain in the 1960s. But giving only a part of the full story is a distortion of historical truth. Important work done on the Eastern side of the Iron Curtain is still little known in the West. In this paper, I fill the gaps and correct chronological inaccuracies in Pasha's story and mention facts that are still unknown (or little known) to the astronomical community in the West. I also give my recollection of the development of Density-Wave Spiral Theories in the 1960s. The paper gives examples of important results in the theory of density waves in galaxies that are mistakenly attributed to C. C. Lin, F. H. Shu, Y.Y. Lau, C. Yuan and others, meanwhile they were obtained earlier by L. Marochnik, A. Suchkov and others. Below is another example. Both "famous" paper of Lin, Yuan and Shu (1969) and Marochnik and Suchkov (1969a) have appeared simultaneously in March of 1969. Both papers dealt, in particular, with the comparison of theory with observations. However, in the frame of their WKB approximation, Lin, Yuan and Shu (1969) employed an incorrect approach. It was a direct consequence of Marochnik and Suchkov (1969a) analysis and led to the far-going consequences. The paper has been published at the http://arxiv.org/abs/astro-ph/0501170 web site.

  7. Managing Chemotherapy Side Effects: Infection

    MedlinePlus

    ... ational C ancer I nstitute Managing Chemotherapy Side Effects Infection “I am extra careful to stay away ... doctor or nurse right away. Managing Chemotherapy Side Effects: Infection Take these steps to lower your chances ...

  8. Managing Chemotherapy Side Effects: Diarrhea

    MedlinePlus

    ... ational C ancer I nstitute Managing Chemotherapy Side Effects U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES National ... before taking medicine for diarrhea. Managing Chemotherapy Side Effects: Diarrhea These foods and drinks may help if ...

  9. Modeling non-harmonic behavior of materials from experimental inelastic neutron scattering and thermal expansion measurements.

    PubMed

    Bansal, Dipanshu; Aref, Amjad; Dargush, Gary; Delaire, Olivier

    2016-09-28

    Based on thermodynamic principles, we derive expressions quantifying the non-harmonic vibrational behavior of materials, which are rigorous yet easily evaluated from experimentally available data for the thermal expansion coefficient and the phonon density of states. These experimentally-derived quantities are valuable to benchmark first-principles theoretical predictions of harmonic and non-harmonic thermal behaviors using perturbation theory, ab initio molecular-dynamics, or Monte-Carlo simulations. We illustrate this analysis by computing the harmonic, dilational, and anharmonic contributions to the entropy, internal energy, and free energy of elemental aluminum and the ordered compound [Formula: see text] over a wide range of temperature. Results agree well with previous data in the literature and provide an efficient approach to estimate anharmonic effects in materials. PMID:27438881

  10. Modeling non-harmonic behavior of materials from experimental inelastic neutron scattering and thermal expansion measurements

    NASA Astrophysics Data System (ADS)

    Bansal, Dipanshu; Aref, Amjad; Dargush, Gary; Delaire, Olivier

    2016-09-01

    Based on thermodynamic principles, we derive expressions quantifying the non-harmonic vibrational behavior of materials, which are rigorous yet easily evaluated from experimentally available data for the thermal expansion coefficient and the phonon density of states. These experimentally-derived quantities are valuable to benchmark first-principles theoretical predictions of harmonic and non-harmonic thermal behaviors using perturbation theory, ab initio molecular-dynamics, or Monte-Carlo simulations. We illustrate this analysis by computing the harmonic, dilational, and anharmonic contributions to the entropy, internal energy, and free energy of elemental aluminum and the ordered compound \\text{FeSi} over a wide range of temperature. Results agree well with previous data in the literature and provide an efficient approach to estimate anharmonic effects in materials.

  11. Modeling non-harmonic behavior of materials from experimental inelastic neutron scattering and thermal expansion measurements

    DOE PAGESBeta

    Bansal, Dipanshu; Aref, Amjad; Dargush, Gary; Delaire, Olivier A.

    2016-07-20

    Based on thermodynamic principles, we derive expressions quantifying the non-harmonic vibrational behavior of materials, which are rigorous yet easily evaluated from experimentally available data for the thermal expansion coefficient and the phonon density of states. These experimentally-derived quantities are valuable to benchmark first-principles theoretical predictions of harmonic and non-harmonic thermal behaviors using perturbation theory, ab initio molecular-dynamics, or Monte-Carlo simulations. In this study, we illustrate this analysis by computing the harmonic, dilational, and anharmonic contributions to the entropy, internal energy, and free energy of elemental aluminum and the ordered compound FeSi over a wide range of temperature. Our results agreemore » well with previous data in the literature and provide an efficient approach to estimate anharmonic effects in materials.« less

  12. Multi-channel electronic and vibrational dynamics in polyatomic resonant high-order harmonic generation

    PubMed Central

    Ferré, A.; Boguslavskiy, A. E.; Dagan, M.; Blanchet, V.; Bruner, B. D.; Burgy, F.; Camper, A.; Descamps, D.; Fabre, B.; Fedorov, N.; Gaudin, J.; Geoffroy, G.; Mikosch, J.; Patchkovskii, S.; Petit, S.; Ruchon, T.; Soifer, H.; Staedter, D.; Wilkinson, I.; Stolow, A.; Dudovich, N.; Mairesse, Y.

    2015-01-01

    High-order harmonic generation in polyatomic molecules generally involves multiple channels of ionization. Their relative contribution can be strongly influenced by the presence of resonances, whose assignment remains a major challenge for high-harmonic spectroscopy. Here we present a multi-modal approach for the investigation of unaligned polyatomic molecules, using SF6 as an example. We combine methods from extreme-ultraviolet spectroscopy, above-threshold ionization and attosecond metrology. Fragment-resolved above-threshold ionization measurements reveal that strong-field ionization opens at least three channels. A shape resonance in one of them is found to dominate the signal in the 20–26 eV range. This resonance induces a phase jump in the harmonic emission, a switch in the polarization state and different dynamical responses to molecular vibrations. This study demonstrates a method for extending high-harmonic spectroscopy to polyatomic molecules, where complex attosecond dynamics are expected. PMID:25608712

  13. Multi-channel electronic and vibrational dynamics in polyatomic resonant high-order harmonic generation.

    PubMed

    Ferré, A; Boguslavskiy, A E; Dagan, M; Blanchet, V; Bruner, B D; Burgy, F; Camper, A; Descamps, D; Fabre, B; Fedorov, N; Gaudin, J; Geoffroy, G; Mikosch, J; Patchkovskii, S; Petit, S; Ruchon, T; Soifer, H; Staedter, D; Wilkinson, I; Stolow, A; Dudovich, N; Mairesse, Y

    2015-01-01

    High-order harmonic generation in polyatomic molecules generally involves multiple channels of ionization. Their relative contribution can be strongly influenced by the presence of resonances, whose assignment remains a major challenge for high-harmonic spectroscopy. Here we present a multi-modal approach for the investigation of unaligned polyatomic molecules, using SF6 as an example. We combine methods from extreme-ultraviolet spectroscopy, above-threshold ionization and attosecond metrology. Fragment-resolved above-threshold ionization measurements reveal that strong-field ionization opens at least three channels. A shape resonance in one of them is found to dominate the signal in the 20-26 eV range. This resonance induces a phase jump in the harmonic emission, a switch in the polarization state and different dynamical responses to molecular vibrations. This study demonstrates a method for extending high-harmonic spectroscopy to polyatomic molecules, where complex attosecond dynamics are expected. PMID:25608712

  14. Noise path identification using face-to-face and side-by-side microphone arrangements

    NASA Technical Reports Server (NTRS)

    Atwal, M.; Bernhard, R.

    1984-01-01

    In large complex structures, with several major sound transmission paths and high levels of background noise, it can be a complex task to locate and rank the contribution of an individual sound transmission path. The two microphone acoustic intensity techniques are investigated as a tool for path identification. Laboratory tests indicate that, if the intensity transmitted through a particular section of the fuselage is measured in the presence and absence of flanking paths using the face to face and side by side microphone arrangements, then no significant difference exists between the two measured intensities if the face to face microphone arrangement is used. However, if the side by side arrangement is used, then considerable difference exists between the two measured intensities.

  15. HIV Medicines and Side Effects

    MedlinePlus

    Side Effects of HIV Medicines HIV Medicines and Side Effects (Last updated 1/7/2016; last reviewed 1/7/2016) Key Points HIV medicines help people with ... will depend on a person’s individual needs. Can HIV medicines cause side effects? HIV medicines help people ...

  16. Organometallic Salts Generate Optical Second Harmonics

    NASA Technical Reports Server (NTRS)

    Marder, Seth R.; Perry, Joseph W.

    1991-01-01

    Series of organometallic salts exhibit large second-order dielectric susceptibilities, as evidenced by generation of second harmonics when illuminated at visible and near-infrared wavelengths. Investigations of these and related compounds continue with view toward development of materials for use as optical second-harmonic generators, electro-optical modulators, optical switches, piezoelectric sensors, and parametric crystals.

  17. Sunspots and Their Simple Harmonic Motion

    ERIC Educational Resources Information Center

    Ribeiro, C. I.

    2013-01-01

    In this paper an example of a simple harmonic motion, the apparent motion of sunspots due to the Sun's rotation, is described, which can be used to teach this subject to high-school students. Using real images of the Sun, students can calculate the star's rotation period with the simple harmonic motion mathematical expression.

  18. Practical Tools to Foster Harmonic Understanding

    ERIC Educational Resources Information Center

    Johnson, Erik

    2013-01-01

    Among the elements required to develop a comprehensive understanding of music is students' ability to perceive, recognize, and label the harmonies they hear. Harmonic dictation is among the strategies that teachers have traditionally chosen to help students develop harmonic awareness. However, the highly idiosyncratic ways that students approach…

  19. High Power Amplifier Harmonic Output Level Measurement

    NASA Technical Reports Server (NTRS)

    Perez, R. M.; Hoppe, D. J.; Khan, A. R.

    1995-01-01

    A method is presented for the measurement of the harmonic output power of high power klystron amplifiers, involving coherent hemispherical radiation pattern measurements of the radiated klystron output. Results are discussed for the operation in saturated and unsaturated conditions, and with a waveguide harmonic filter included.

  20. Quasi-optical harmonic gyrotron and gyroklystron

    NASA Astrophysics Data System (ADS)

    Manheimer, W.; Levush, B.

    1985-12-01

    This patent discloses a method and apparatus for suppressing lower order cyclotron harmonics in order to permit resonance within a quasi-optical gyrotron/gyroklystron configuration of a desired high order harmonic. In the gyrotron/gyroklystron configuration at least one open resonator defined by at least two mirrors is positioned downstream from an electron beam source for receiving therethrough the beam of electrons and for exchanging energy therewith. This method includes the steps for choosing a mirror radius size large enough relative to the spot size of a desired radiation cyclotron harmonic so that the harmonic oscillates within the at least one resonator, but small enough so that the spot size for the next lower cyclotron harmonic is larger than the mirror so that harmonic does not oscillate due to diffraction losses. This method further includes the step of generating an electron beam bias the electron beam source with a beam current which is greater than or equal to the starting current for the desired nth cyclotron harmonic, but less than the starting current for the nth cyclotron harmonic.

  1. Harmonic oscillator states in aberration optics

    NASA Technical Reports Server (NTRS)

    Wolf, Kurt Bernardo

    1993-01-01

    The states of the three-dimensional quantum harmonic oscillator classify optical aberrations of axis-symmetric systems due to the isomorphism between the two mathematical structures. Cartesian quanta and angular momentum classifications have their corresponding aberration classifications. The operation of concatenation of optical elements introduces a new operation between harmonic oscillator states.

  2. Higher Harmonics in Heavy Ion Collisions

    NASA Astrophysics Data System (ADS)

    Jeon, Sangyong

    2013-03-01

    As the QGP expands and cools, it carries much information on its creation and evolution imprinted on the patterns of higher harmonic flow. In this proceeding we report on the progress in simulating and understanding the higher harmonics by the McGill group using the 3+1D event-by-event viscous hydrodynamics simulation suite named MUSIC.

  3. Dynamics and control of instrumented harmonic drives

    NASA Technical Reports Server (NTRS)

    Kazerooni, H.; Ellis, S. R. (Principal Investigator)

    1995-01-01

    Since torque in harmonic drives is transmitted by a pure couple, harmonic drives do not generate radial forces and therefore can be instrumented with torque sensors without interference from radial forces. The installation of torque sensors on the stationary component of harmonic drives (the Flexipline cup in this research work) produce backdrivability needed for robotic and telerobotic compliant maneuvers. Backdrivability of a harmonic drive, when used as torque increaser, means that the output shaft can be rotated via finite amount of torque. A high ratio harmonic drive is non-backdrivable because its output shaft cannot be turned by applying a torque on it. This article first develops the dynamic behavior of a harmonic drive, in particular the non-backdrivability, in terms of a sensitivity transfer function. The instrumentation of the harmonic drive with torque sensor is then described. This leads to a description of the control architecture which allows modulation of the sensitivity transfer function within the limits established by the closed-loop stability. A set of experiments on an active hand controller, powered by a DC motor coupled to an instrumented harmonic drive, is given to exhibit this method's limitations.

  4. Electron cyclotron harmonic wave acceleration

    NASA Technical Reports Server (NTRS)

    Karimabadi, H.; Menyuk, C. R.; Sprangle, P.; Vlahos, L.

    1987-01-01

    A nonlinear analysis of particle acceleration in a finite bandwidth, obliquely propagating electromagnetic cyclotron wave is presented. It has been suggested by Sprangle and Vlahos in 1983 that the narrow bandwidth cyclotron radiation emitted by the unstable electron distribution inside a flaring solar loop can accelerate electrons outside the loop by the interaction of a monochromatic wave propagating along the ambient magnetic field with the ambient electrons. It is shown here that electrons gyrating and streaming along a uniform, static magnetic field can be accelerated by interacting with the fundamental or second harmonic of a monochromatic, obliquely propagating cyclotron wave. It is also shown that the acceleration is virtually unchanged when a wave with finite bandwidth is considered. This acceleration mechanism can explain the observed high-energy electrons in type III bursts.

  5. Point-based manifold harmonics.

    PubMed

    Liu, Yang; Prabhakaran, Balakrishnan; Guo, Xiaohu

    2012-10-01

    This paper proposes an algorithm to build a set of orthogonal Point-Based Manifold Harmonic Bases (PB-MHB) for spectral analysis over point-sampled manifold surfaces. To ensure that PB-MHB are orthogonal to each other, it is necessary to have symmetrizable discrete Laplace-Beltrami Operator (LBO) over the surfaces. Existing converging discrete LBO for point clouds, as proposed by Belkin et al., is not guaranteed to be symmetrizable. We build a new point-wisely discrete LBO over the point-sampled surface that is guaranteed to be symmetrizable, and prove its convergence. By solving the eigen problem related to the new operator, we define a set of orthogonal bases over the point cloud. Experiments show that the new operator is converging better than other symmetrizable discrete Laplacian operators (such as graph Laplacian) defined on point-sampled surfaces, and can provide orthogonal bases for further spectral geometric analysis and processing tasks. PMID:22879345

  6. Quantum wormholes and harmonic oscillators

    NASA Technical Reports Server (NTRS)

    Garay, Luis J.

    1993-01-01

    The quantum state of a wormhole can be represented by a path integral over all asymptotically Euclidean four-geometries and all matter fields which have prescribed values, the arguments of the wave function, on a three-surface which divides the space time manifold into two disconnected parts. Minisuperspace models which consist of a homogeneous massless scalar field coupled to a Friedmann-Robertson-Walker space time are considered. Once the path integral over the lapse function is performed, the requirement that the space time be asymptotically Euclidean can be accomplished by fixing the asymptotic gravitational momentum in the remaining path integral. It is argued that there does not exist any wave function which corresponds to asymptotic field configurations such that the effective gravitational constant is negative in the asymptotic region. Then, the wormhole wave functions can be written as linear combinations of harmonic oscillator wave functions.

  7. Libsharp - spherical harmonic transforms revisited

    NASA Astrophysics Data System (ADS)

    Reinecke, M.; Seljebotn, D. S.

    2013-06-01

    We present libsharp, a code library for spherical harmonic transforms (SHTs), which evolved from the libpsht library and addresses several of its shortcomings, such as adding MPI support for distributed memory systems and SHTs of fields with arbitrary spin, but also supporting new developments in CPU instruction sets like the Advanced Vector Extensions (AVX) or fused multiply-accumulate (FMA) instructions. The library is implemented in portable C99 and provides an interface that can be easily accessed from other programming languages such as C++, Fortran, Python, etc. Generally, libsharp's performance is at least on par with that of its predecessor; however, significant improvements were made to the algorithms for scalar SHTs, which are roughly twice as fast when using the same CPU capabilities. The library is available at http://sourceforge.net/projects/libsharp/ under the terms of the GNU General Public License.

  8. Power Factor Correction to Mitigate Harmonic Distortion

    NASA Astrophysics Data System (ADS)

    Kochetkov, Gary

    Many direct current (DC) devices must receive their power from the alternating current (AC) grid. Rectifiers use diodes to create DC for these devices. Due to diodes' non-linear nature however, harmonics are created and these travel back into the grid. A significant presence of harmonics causes component heating and possible malfunction. A harmonic mitigation procedure is needed. With the correct usage of transistors, the current drawn by a rectifier can be manipulated to remove almost all harmonics. This process is called power factor correction (PFC), and formally acts to reduce the total harmonic distortion (THD) of the current. To investigate this, a three phase active rectifier was computer simulated and a controller was designed to provide switching signals for the transistors. Finally, the device was constructed in the laboratory to drive a DC motor, verifying its operating principle outside of the idealities of simulation.

  9. Second harmonic generation polarization properties of myofilaments

    NASA Astrophysics Data System (ADS)

    Samim, Masood; Prent, Nicole; Dicenzo, Daniel; Stewart, Bryan; Barzda, Virginijus

    2014-05-01

    Second harmonic generation (SHG) polarization microscopy was used to investigate the organization of myosin nanomotors in myofilaments of muscle cells. The distribution of the second-order nonlinear susceptibility component ratio χzzz(2)/χzxx(2) along anisotropic bands of sarcomeres revealed differences between the headless and head-containing regions of myofilaments. The polarization-in polarization-out SHG measurements of headless myosin mutants of indirect flight muscle in Drosophila melanogaster confirmed a lower susceptibility component ratio compared to the head-containing myocytes with wild-type myosins. The increase in the ratio is assigned to the change in the deflection angle of the myosin S2 domain and possible contribution of myosin heads. The nonlinear susceptibility component ratio is a sensitive indicator of the myosin structure, and therefore, it can be used for conformational studies of myosin nanomotors. The measured ratio values can also be used as the reference for ab initio calculations of nonlinear optical properties of different parts of myosins.

  10. High Harmonic Generation from Rotationally Excited Molecules

    NASA Astrophysics Data System (ADS)

    Lock, Robynne M.

    2011-12-01

    High harmonic generation (HHG) is understood through a three-step model. A strong laser field ionizes an atom or molecule. The free electron propagates in the laser field and may recombine with the atom or molecule leading to the generation of extreme ultraviolet or soft x-ray light at odd harmonics of the fundamental. Since the wavelength of the recombining electron is on the order of internuclear distances in molecules, HHG acts as a probe of molecular structure and dynamics. Conversely, control of the molecules leads to control of the properties (intensity, phase, and polarization) of the harmonic emission. Rotationally exciting molecules provides field-free molecular alignment at time intervals corresponding to fractions of the rotational period of the molecule. Alignment is necessary for understanding how the harmonic emission depends on molecular structure and alignment. Additionally, HHG acts as a probe of the rotational wavepackets. This thesis reports three experiments on HHG from rotationally excited molecules. Before we can use HHG as a probe of complex molecular dynamics or control harmonic properties through molecules, the harmonic emission from aligned, linear molecules must first be understood. To that end, the first experiment measures the intensity and phase of harmonics generated from N 2O and N2 near times of strong alignment revealing interferences during recombination. The second experiment demonstrates HHG as a sensitive probe of rotational wavepacket dynamics in CO2 and N2O, revealing new revival features not detected by any other probe. The final experiment focuses on understanding and controlling the polarization state of the harmonic emission. Generating elliptically polarized harmonics would be very useful for probing molecular and materials systems. We observe an elliptical dichroism in polarization-resolved measurements of the harmonic emission from aligned N2 and CO2 molecules, revealing evidence for electron-hole dynamics between the

  11. High order harmonic generation in rare gases

    SciTech Connect

    Budil, K.S.

    1994-05-01

    The process of high order harmonic generation in atomic gases has shown great promise as a method of generating extremely short wavelength radiation, extending far into the extreme ultraviolet (XUV). The process is conceptually simple. A very intense laser pulse (I {approximately}10{sup 13}-10{sup 14} W/cm{sup 2}) is focused into a dense ({approximately}10{sup l7} particles/cm{sup 3}) atomic medium, causing the atoms to become polarized. These atomic dipoles are then coherently driven by the laser field and begin to radiate at odd harmonics of the laser field. This dissertation is a study of both the physical mechanism of harmonic generation as well as its development as a source of coherent XUV radiation. Recently, a semiclassical theory has been proposed which provides a simple, intuitive description of harmonic generation. In this picture the process is treated in two steps. The atom ionizes via tunneling after which its classical motion in the laser field is studied. Electron trajectories which return to the vicinity of the nucleus may recombine and emit a harmonic photon, while those which do not return will ionize. An experiment was performed to test the validity of this model wherein the trajectory of the electron as it orbits the nucleus or ion core is perturbed by driving the process with elliptically, rather than linearly, polarized laser radiation. The semiclassical theory predicts a rapid turn-off of harmonic production as the ellipticity of the driving field is increased. This decrease in harmonic production is observed experimentally and a simple quantum mechanical theory is used to model the data. The second major focus of this work was on development of the harmonic {open_quotes}source{close_quotes}. A series of experiments were performed examining the spatial profiles of the harmonics. The quality of the spatial profile is crucial if the harmonics are to be used as the source for experiments, particularly if they must be refocused.

  12. Mode conversion and absorption of fast waves at high ion cyclotron harmonics in inhomogeneous magnetic fields

    SciTech Connect

    Cho, Suwon; Kwak, Jong-Gu

    2014-04-15

    The propagation and absorption of high harmonic fast waves is of interest for non-inductive current drives in fusion experiments. The fast wave can be coupled with the ion Bernstein wave that propagates in the high magnetic field side of an ion cyclotron harmonic resonance layer. This coupling and the absorption are analyzed using the hot plasma dispersion relation and a wave equation that was converted from an approximate dispersion relation for the case where λ{sub i}=k{sub ⊥}{sup 2}ρ{sub i}{sup 2}/2≳1 (where k{sub ⊥} is the perpendicular wave number and ρ{sub i} is the ion Larmor radius). It is found that both reflection and conversion may occur near the harmonic resonance layer but that they decrease rapidly, giving rise to a sharp increase in the absorption as the parallel wave number increases.

  13. The additive effect of harmonics on conservative and dissipative interactions

    NASA Astrophysics Data System (ADS)

    Santos, Sergio; Gadelrab, Karim R.; Barcons, Victor; Font, Josep; Stefancich, Marco; Chiesa, Matteo

    2012-12-01

    Multifrequency atomic force microscopy holds promise as a tool for chemical and topological imaging with nanoscale resolution. Here, we solve the equation of motion exactly for the fundamental mode in terms of the cantilever mean deflection, the fundamental frequency of oscillation, and the higher harmonic amplitudes and phases. The fundamental frequency provides information about the mean force, dissipation, and variations in the magnitude of the attractive and the repulsive force components during an oscillation cycle. The contributions of the higher harmonics to the position, velocity, and acceleration can be added gradually where the details of the true instantaneous force are recovered only when tens of harmonics are included. A formalism is developed here to decouple and quantify the viscous term of the force in the short and long range. It is also shown that the viscosity independent paths on tip approach and tip retraction can also be decoupled by simply acquiring a FFT at two different cantilever separations. The two paths correspond to tip distances at which metastability is present as, for example, in the presence of capillary interactions and where there is surface energy hysteresis.

  14. High harmonic generation from impulsively aligned SO2

    NASA Astrophysics Data System (ADS)

    Devin, Julien; Wang, Song; Kaldun, Andreas; Bucksbaum, Phil

    2016-05-01

    Previous work in high harmonics generation (HHG) in aligned molecular gases has mainly focused on rotational dynamics in order to determine the contributions of different orbitals to the ionization step. In our experiment, we focus on the shorter timescale of vibrational dynamics. We generate high harmonics from impulsively aligned SO2 molecules in a gas jet and record the emitted attosecond pulse trains in a home-built high resolution vacuum ultra violet (VUV) spectrometer. Using the high temporal resolution of our setup, we are able to map out the effects of vibrational wavepackets with a sub-femtosecond resolution. The target molecule, SO2 gas, is impulsively aligned by a near-infrared laser pulse and has accessible vibrations on the timescale of the short laser pulse used. We present first experimental results for the response to this excitation in high-harmonics. We observe both fast oscillations in the time domain as well as shifts of the VUV photon energy outside of the pulse overlaps. Research supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), Chemical Sciences, Geosciences, and Biosciences Division and by the National Science Foundation Graduate Research Fellowship.

  15. Phase effects in masking by harmonic complexes: Speech recognition

    PubMed Central

    Deroche, Mickael L. D.; Culling, John F.; Chatterjee, Monita

    2013-01-01

    Harmonic complexes that generate highly modulated temporal envelopes on the basilar membrane (BM) mask a tone less effectively than complexes that generate relatively flat temporal envelopes, because the non-linear active gain of the BM selectively amplifies a low-level tone in the dips of a modulated masker envelope. The present study examines a similar effect in speech recognition. Speech reception thresholds (SRTs) were measured for a voice masked by harmonic complexes with partials in sine phase (SP) or in random phase (RP). The masker’s fundamental frequency (F0) was 50, 100 or 200 Hz. SRTs were considerably lower for SP than for RP maskers at 50-Hz F0, but the two converged at 100-Hz F0, while at 200-Hz F0, SRTs were a little higher for SP than RP maskers. The results were similar whether the target voice was male or female and whether the masker’s spectral profile was flat or speech-shaped. Although listening in the masker dips has been shown to play a large role for artificial stimuli such as Schroeder-phase complexes at high levels, it contributes weakly to speech recognition in the presence of harmonic maskers with different crest factors at more moderate sound levels (65 dB SPL). PMID:24076425

  16. Accurate prediction of interference minima in linear molecular harmonic spectra by a modified two-center model

    NASA Astrophysics Data System (ADS)

    Xin, Cui; Di-Yu, Zhang; Gao, Chen; Ji-Gen, Chen; Si-Liang, Zeng; Fu-Ming, Guo; Yu-Jun, Yang

    2016-03-01

    We demonstrate that the interference minima in the linear molecular harmonic spectra can be accurately predicted by a modified two-center model. Based on systematically investigating the interference minima in the linear molecular harmonic spectra by the strong-field approximation (SFA), it is found that the locations of the harmonic minima are related not only to the nuclear distance between the two main atoms contributing to the harmonic generation, but also to the symmetry of the molecular orbital. Therefore, we modify the initial phase difference between the double wave sources in the two-center model, and predict the harmonic minimum positions consistent with those simulated by SFA. Project supported by the National Basic Research Program of China (Grant No. 2013CB922200) and the National Natural Science Foundation of China (Grant Nos. 11274001, 11274141, 11304116, 11247024, and 11034003), and the Jilin Provincial Research Foundation for Basic Research, China (Grant Nos. 20130101012JC and 20140101168JC).

  17. A high-fidelity harmonic drive model.

    SciTech Connect

    Preissner, C.; Royston, T. J.; Shu, D.

    2012-01-01

    In this paper, a new model of the harmonic drive transmission is presented. The purpose of this work is to better understand the transmission hysteresis behavior while constructing a new type of comprehensive harmonic drive model. The four dominant aspects of harmonic drive behavior - nonlinear viscous friction, nonlinear stiffness, hysteresis, and kinematic error - are all included in the model. The harmonic drive is taken to be a black box, and a dynamometer is used to observe the input/output relations of the transmission. This phenomenological approach does not require any specific knowledge of the internal kinematics. In a novel application, the Maxwell resistive-capacitor hysteresis model is applied to the harmonic drive. In this model, sets of linear stiffness elements in series with Coulomb friction elements are arranged in parallel to capture the hysteresis behavior of the transmission. The causal hysteresis model is combined with nonlinear viscous friction and spectral kinematic error models to accurately represent the harmonic drive behavior. Empirical measurements are presented to quantify all four aspects of the transmission behavior. These measurements motivate the formulation of the complete model. Simulation results are then compared to additional measurements of the harmonic drive performance.

  18. Near BPS skyrmions and restricted harmonic maps

    NASA Astrophysics Data System (ADS)

    Speight, J. M.

    2015-06-01

    Motivated by a class of near BPS Skyrme models introduced by Adam, Sánchez-Guillén and Wereszczyński, the following variant of the harmonic map problem is introduced: a map φ :(M, g) →(N, h) between Riemannian manifolds is restricted harmonic if it locally extremizes E2 on its SDiff(M) orbit, where SDiff(M) denotes the group of volume preserving diffeomorphisms of (M, g), and E2 denotes the Dirichlet energy. It is conjectured that near BPS skyrmions tend to restricted harmonic maps in the BPS limit. It is shown that φ is restricted harmonic if and only if φ∗ h has exact divergence, and a linear stability theory of restricted harmonic maps is developed, from which it follows that all weakly conformal maps are stable restricted harmonic. Examples of restricted harmonic maps in every degree class R3 → SU(2) and R2 →S2 are constructed. It is shown that the axially symmetric BPS skyrmions on which all previous analytic studies of near BPS Skyrme models have been based, are not restricted harmonic, casting doubt on the phenomenological predictions of such studies. The problem of minimizing E2 for φ :Rk → N over all linear volume preserving diffeomorphisms is solved explicitly, and a deformed axially symmetric family of Skyrme fields constructed which are candidates for approximate near BPS skyrmions at low baryon number. The notion of restricted harmonicity is generalized to restricted F-criticality where F is any functional on maps (M, g) →(N, h) which is, in a precise sense, geometrically natural. The case where F is a linear combination of E2 and E4, the usual Skyrme term, is studied in detail, and it is shown that inverse stereographic projection R3 →S3 ≡ SU(2) is stable restricted F-critical for every such F.

  19. High Harmonic Generation from Multiple Orbitals in N2

    SciTech Connect

    McFarland, B.; Farrell, Joseph P.; Bucksbaum, Philip H.; Guehr, Markus; /SLAC, Pulse /Stanford U., Phys. Dept.

    2009-03-05

    Molecular electronic states energetically below the highest occupied molecular orbital (HOMO) should contribute to laser-driven high harmonic generation (HHG), but this behavior has not been observed previously. Our measurements of the HHG spectrum of N{sub 2} molecules aligned perpendicular to the laser polarization showed a maximum at the rotational half-revival. This feature indicates the influence of electrons occupying the orbital just below the N{sub 2} HOMO, referred to as the HOMO-1. Such observations of lower-lying orbitals are essential to understanding subfemtosecond/subangstrom electronic motion in laser-excited molecules.

  20. Asymptotic porosity of planar harmonic measure

    NASA Astrophysics Data System (ADS)

    Graczyk, Jacek; Świaţek, Grzegorz

    2013-04-01

    We study the distribution of harmonic measure on connected Julia sets of unicritical polynomials. Harmonic measure on a full compact set in ℂ is always concentrated on a set which is porous for a positive density of scales. We prove that there is a topologically generic set {A} in the boundary of the Mandelbrot set such that for every cin {A}, β>0, and λ∈(0,1), the corresponding Julia set is a full compact set with harmonic measure concentrated on a set which is not β-porous in scale λ n for n from a set with positive density amongst natural numbers.

  1. Electric vs. harmonic scalpel in treatment of primary focal hyperhidrosis with thoracoscopic sympathectomy

    PubMed Central

    Kuhajda, Ivan; Durić, Dejan; Koledin, Milos; Ilic, Miroslav; Tsavlis, Drosos; Kioumis, Ioannis; Tsirgogianni, Katerina; Zarogoulidis, Konstantinos; Organtzis, John; Kosmidis, Christoforos; Baka, Sofia; Karapantzos, Ilias; Karapantzou, Chrysanthi; Tsakiridis, Kosmas; Sachpekidis, Nikolaos; Bijelovic, Milorad

    2015-01-01

    Background Hyperhidrosis is defined as excessive sweating beyond the physiologic needs of a person. Palmar hyperhidrosis in the adolescent period may have an impact on school work and may cause psychological problems. Thoracoscopic sympathectomy is now used routinely to treat patients with disabling primary hyperhidrosis or facial blushing. Patients and methods From January 2008 to December of 2009 bilateral thoracoscopic sympathectomy Th2-Th4 was performed to 79 patients aged from 17 to 55, who suffered from palmar, axillar or craniofacial hyperhidrosis. For the first 39 patients (group A) thoracoscopic sympathectomy was performed using electric scalpel and for the next 40 patients (group B) thoracoscopic sympathectomy was performed using harmonic scalpel. Results Based on our results we did not find any significant differences between electric or harmonic scalpel usages for thoracoscopic sympathectomy. Moreover, there was no significant difference between complications and the severity of pain, with slightly higher intensity of pain with harmonic scalpel usage. Both electric and harmonic scalpel provided adequate treatment for primary hyperhidrosis, with the fact that non-disposable electric scalpel costs were less than that of the disposable harmonic scalpel. Conclusions Sympathectomy should be preferred for palmar hyperhidrosis treatment, as it is much technically shorter, simpler to implement, and also easier to learn. Thoracoscopic sympathectomy is safe and effective for the treatment of primary palmar hyperhidrosis in the adolescent period without any major side effects. PMID:26488007

  2. The DarkSide awakens

    NASA Astrophysics Data System (ADS)

    Davini, S.; Agnes, P.; Agostino, L.; Albuquerque, I. F. M.; Alexander, T.; Alton, A. K.; Arisaka, K.; Back, H. O.; Baldin, B.; Biery, K.; Bonfini, G.; Bossa, M.; Bottino, B.; Brigatti, A.; Brodsky, J.; Budano, F.; Bussino, S.; Cadeddu, M.; Cadonati, L.; Cadoni, M.; Calaprice, F.; Canci, N.; Candela, A.; Cao, H.; Cariello, M.; Carlini, M.; Catalanotti, S.; Cavalcante, P.; Chepurnov, A.; Cocco, A. G.; Covone, G.; D’Angelo, D.; D’Incecco, M.; De Cecco, S.; De Deo, M.; De Vincenzi, M.; Derbin, A.; Devoto, A.; Di Eusanio, F.; Di Pietro, G.; Edkins, E.; Empl, A.; Fan, A.; Fiorillo, G.; Fomenko, K.; Foster, G.; Franco, D.; Gabriele, F.; Galbiati, C.; Giganti, C.; Goretti, A. M.; Granato, F.; Grandi, L.; Gromov, M.; Guan, M.; Guardincerri, Y.; Hackett, B. R.; Herner, K. R.; Hungerford, E. V.; Ianni, Aldo; Ianni, Andrea; James, I.; Jollet, C.; Keeter, K.; Kendziora, C. L.; Kobychev, V.; Koh, G.; Korablev, D.; Korga, G.; Kubankin, A.; Li, X.; Lissia, M.; Lombardi, P.; Luitz, S.; Ma, Y.; Machulin, I. N.; Mandarano, A.; Mari, S. M.; Maricic, J.; Marini, L.; Martoff, C. J.; Meregaglia, A.; Meyers, P. D.; Miletic, T.; Milincic, R.; Montanari, D.; Monte, A.; Montuschi, M.; Monzani, M. E.; Mosteiro, P.; Mount, B. J.; Muratova, V. N.; Musico, P.; Napolitano, J.; Orsini, M.; Ortica, F.; Pagani, L.; Pallavicini, M.; Pantic, E.; Parmeggiano, S.; Pelczar, K.; Pelliccia, N.; Perasso, S.; Pocar, A.; Pordes, S.; Pugachev, D. A.; Qian, H.; Randle, K.; Ranucci, G.; Razeto, A.; Reinhold, B.; Renshaw, A. L.; Romani, A.; Rossi, B.; Rossi, N.; Rountree, S. D.; Sablone, D.; Saggese, P.; Saldanha, R.; Sands, W.; Sangiorgio, S.; Savarese, C.; Segreto, E.; Semenov, D. A.; Shields, E.; Singh, P. N.; Skorokhvatov, M. D.; Smirnov, O.; Sotnikov, A.; Stanford, C.; Suvorov, Y.; Tartaglia, R.; Tatarowicz, J.; Testera, G.; Tonazzo, A.; Trinchese, P.; Unzhakov, E. V.; Vishneva, A.; Vogelaar, B.; Wada, M.; Walker, S.; Wang, H.; Wang, Y.; Watson, A. W.; Westerdale, S.; Wilhelmi, J.; Wojcik, M. M.; Xiang, X.; Xu, J.; Yang, C.; Yoo, J.; Zavatarelli, S.; Zec, A.; Zhong, W.; Zhu, C.; Zuzel, G.

    2016-05-01

    The DarkSide program at LNGS aims to perform background-free WIMP searches using two phase liquid argon time projection chambers, with the ultimate goal of covering all parameters down to the so-called neutrino floor. One of the distinct features of the program is the use of underground argon with has a reduced content of the radioactive 39Ar compared to atmospheric argon. The DarkSide Collaboration is currently operating the DarkSide-50 experiment, the first such WIMP detector using underground argon. Operations with underground argon indicate a suppression of 39Ar by a factor (1.4 ± 0.2) × 103 relative to atmospheric argon. The new results obtained with DarkSide-50 and the plans for the next steps of the DarkSide program, the 20t fiducial mass DarkSide-20k detector and the 200 t fiducial Argo, are reviewed in this proceedings.

  3. Proposed Standards for Variable Harmonization Documentation and Referencing: A Case Study Using QuickCharmStats 1.1.

    PubMed

    Winters, Kristi; Netscher, Sebastian

    2016-01-01

    Comparative statistical analyses often require data harmonization, yet the social sciences do not have clear operationalization frameworks that guide and homogenize variable coding decisions across disciplines. When faced with a need to harmonize variables researchers often look for guidance from various international studies that employ output harmonization, such as the Comparative Survey of Election Studies, which offer recoding structures for the same variable (e.g. marital status). More problematically there are no agreed documentation standards or journal requirements for reporting variable harmonization to facilitate a transparent replication process. We propose a conceptual and data-driven digital solution that creates harmonization documentation standards for publication and scholarly citation: QuickCharmStats 1.1. It is free and open-source software that allows for the organizing, documenting and publishing of data harmonization projects. QuickCharmStats starts at the conceptual level and its workflow ends with a variable recording syntax. It is therefore flexible enough to reflect a variety of theoretical justifications for variable harmonization. Using the socio-demographic variable 'marital status', we demonstrate how the CharmStats workflow collates metadata while being guided by the scientific standards of transparency and replication. It encourages researchers to publish their harmonization work by providing researchers who complete the peer review process a permanent identifier. Those who contribute original data harmonization work to their discipline can now be credited through citations. Finally, we propose peer-review standards for harmonization documentation, describe a route to online publishing, and provide a referencing format to cite harmonization projects. Although CharmStats products are designed for social scientists our adherence to the scientific method ensures our products can be used by researchers across the sciences. PMID:26859494

  4. Proposed Standards for Variable Harmonization Documentation and Referencing: A Case Study Using QuickCharmStats 1.1

    PubMed Central

    Winters, Kristi; Netscher, Sebastian

    2016-01-01

    Comparative statistical analyses often require data harmonization, yet the social sciences do not have clear operationalization frameworks that guide and homogenize variable coding decisions across disciplines. When faced with a need to harmonize variables researchers often look for guidance from various international studies that employ output harmonization, such as the Comparative Survey of Election Studies, which offer recoding structures for the same variable (e.g. marital status). More problematically there are no agreed documentation standards or journal requirements for reporting variable harmonization to facilitate a transparent replication process. We propose a conceptual and data-driven digital solution that creates harmonization documentation standards for publication and scholarly citation: QuickCharmStats 1.1. It is free and open-source software that allows for the organizing, documenting and publishing of data harmonization projects. QuickCharmStats starts at the conceptual level and its workflow ends with a variable recording syntax. It is therefore flexible enough to reflect a variety of theoretical justifications for variable harmonization. Using the socio-demographic variable ‘marital status’, we demonstrate how the CharmStats workflow collates metadata while being guided by the scientific standards of transparency and replication. It encourages researchers to publish their harmonization work by providing researchers who complete the peer review process a permanent identifier. Those who contribute original data harmonization work to their discipline can now be credited through citations. Finally, we propose peer-review standards for harmonization documentation, describe a route to online publishing, and provide a referencing format to cite harmonization projects. Although CharmStats products are designed for social scientists our adherence to the scientific method ensures our products can be used by researchers across the sciences. PMID

  5. Harmonic regression and scale stability.

    PubMed

    Lee, Yi-Hsuan; Haberman, Shelby J

    2013-10-01

    Monitoring a very frequently administered educational test with a relatively short history of stable operation imposes a number of challenges. Test scores usually vary by season, and the frequency of administration of such educational tests is also seasonal. Although it is important to react to unreasonable changes in the distributions of test scores in a timely fashion, it is not a simple matter to ascertain what sort of distribution is really unusual. Many commonly used approaches for seasonal adjustment are designed for time series with evenly spaced observations that span many years and, therefore, are inappropriate for data from such educational tests. Harmonic regression, a seasonal-adjustment method, can be useful in monitoring scale stability when the number of years available is limited and when the observations are unevenly spaced. Additional forms of adjustments can be included to account for variability in test scores due to different sources of population variations. To illustrate, real data are considered from an international language assessment. PMID:24092490

  6. A nonlinear acoustic metamaterial: Realization of a backwards-traveling second-harmonic sound wave.

    PubMed

    Quan, Li; Qian, Feng; Liu, Xiaozhou; Gong, Xiufen

    2016-06-01

    An ordinary waveguide with periodic vibration plates and side holes can realize an acoustic metamaterial that simultaneously possesses a negative bulk modulus and a negative mass density. The study is further extended to a nonlinear case and it is predicted that a backwards-traveling second-harmonic sound wave can be obtained through the nonlinear propagation of a sound wave in such a metamaterial. PMID:27369164

  7. Advanced Control Strategy for Single-Phase Voltage-Source Active Rectifier with Low Harmonic Emission

    NASA Astrophysics Data System (ADS)

    Blahník, Vojtĕch; Peroutka, Zdenĕk; Talla, Jakub

    2014-03-01

    This paper introduces the advanced control of single-phase voltage-source active rectifier. This control provide direct control of trolley-wire current and active damping of low-frequency disturbances at the converter ac side. Our proposed control strategy combines PR controller with feed-forward model and low-frequency harmonic compensator based on resonant controllers. Achieved experimental results show excellent converter behavior, where converter is fed by strongly distorted supply voltage.

  8. Dependence of high-order-harmonic generation on dipole moment in Si O2 crystals

    NASA Astrophysics Data System (ADS)

    Yu, Chao; Zhang, Xirui; Jiang, Shicheng; Cao, Xu; Yuan, Guanglu; Wu, Tong; Bai, Lihua; Lu, Ruifeng

    2016-07-01

    High-order-harmonic generation in α-quartz Si O2 is theoretically investigated under a strong laser field by solving the extended semiconductor Bloch equations. The accurate band structures as well as dipole moments between different bands are obtained from state-of-the-art first-principles calculations. We find that the shapes of k -space-dependent dipole moments play an important role in harmonic generation. The calculated results show that harmonic conversion efficiency is significantly enhanced and the cutoff energy is distinctly increased when the dipole moments change greatly along a valley in the k direction in the solid. Based on that dependence on the dipole moment, we also show that symmetry groups greatly affect the harmonic spectra from the solid materials. Moreover, a two-color synthesized field is used to achieve a supercontinuum harmonic spectrum near the cutoff region, and isolated attosecond pulses can be obtained directly by filtering out the harmonic radiation. We hope the contribution presented in this work provides a useful reference for future studies on laser-crystal interactions.

  9. Carrier-envelope phase- and spectral control of fractional high-harmonic combs

    NASA Astrophysics Data System (ADS)

    Raith, Philipp; Ott, Christian; Meyer, Kristina; Kaldun, Andreas; Laux, Martin; Ceci, Matteo; Anderson, Christopher P.; Pfeifer, Thomas

    2013-11-01

    We experimentally and numerically control high-harmonic generation (HHG) by time delaying variable segments of a few-cycle driving laser spectrum. In this configuration combs of fractional high harmonics can be produced by interference of two temporally spaced attosecond pulse trains. We explain the observed beating of the high-harmonic intensity with the time delay and study the influence of the spectral segmentation on the high harmonics. By the implementation of additional carrier-envelope phase (CEP) control, we extend the control configuration and demonstrate independent multi-parameter controllability of HHG purely enabled by the CEP and the time delay between two spectral segments. We present how specific properties of the fractional harmonics can be optimized. Analyzing the measured fractional harmonic combs by a spectral interferometry method, we find that the relative phase between the two contributing attosecond pulse trains can be freely set by the CEP of the driving laser field. We also discuss how, in the future, this method can be applied to simultaneously measure transient dispersion and absorption in the extreme ultraviolet spectral region.

  10. View northeast, west side, and south side (showing National Defense ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View northeast, west side, and south side (showing National Defense University Academic Operations Center Building in background) - Fort McNair, Film Store House, Fort Lesley J. McNair, P Street between Third & Fourth Streets, Southwest, Washington, District of Columbia, DC

  11. 3. VIEW OF INTERIOR, EAST SIDE (SIDE A) OF BUILDING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW OF INTERIOR, EAST SIDE (SIDE A) OF BUILDING 883. INSTALLATION OF EQUIPMENT FOR THE MOLTEN SALT BATHS AND ROLLING MILLS PROCESSES. (4/25/57) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  12. PACIFIC NORTHWEST SIDE-BY-SIDE PROTOCOL COMPARISON TEST

    EPA Science Inventory

    Eleven state, tribal, and federal agencies participated during summer 2005 in a side-by-side comparison of protocols used to measure common in-stream physical attributes to help determine which protocols are best for determining status and trend of stream/watershed condition. Th...

  13. Tracking Comb Filter Suppresses Welder Harmonics

    NASA Technical Reports Server (NTRS)

    Delcher, Ray C.

    1992-01-01

    Tracking comb filter includes charge-coupled-device delay line and phase-locked loop. Filter removes harmonics of frequency of repetition of welding-current pulses from acoustic-emission signal. Spurious signals reduced almost to fundamental limit.

  14. New ladder operators for the monopole harmonics

    NASA Astrophysics Data System (ADS)

    Fakhri, H.; Dehghani, A.; Jafari, A.

    2007-02-01

    Using the ladder operators shifting the index m of the associated Jacobi functions, for a given n, the monopole harmonics and their corresponding angular momentum operators are, respectively, extracted as the irreducible representation space and generators of su(2) Lie algebra. The indices n and m play the role of principal and azimuthal quantum numbers. By introducing the ladder operators shifting the index n of the same associated Jacobi functions, we also get a new type of the raising and lowering relations which are realized by the operators shifting only the index n of the monopole harmonics. Moreover, other symmetries, including the transformation of the irreducible representation spaces into each other, are derived based on the operators that shift the indices n and m of the monopole harmonics simultaneously and agreeably as well as simultaneously and inversely. Our results are reduced to spherical harmonics by eliminating magnetic charge of the monopole.

  15. High-harmonic generation in cavitated plasmas

    SciTech Connect

    Schroeder, C. B.; Esarey, E.; Comier-Michel, E.; Leemans, W. P.

    2008-05-15

    A method is proposed for producing coherent x-rays via high-harmonic generation using ultraintense lasers interacting with highly stripped ions in cavitated plasmas. This method relies on plasma cavitation by the wake of an intense drive beam (laser or electron beam) to produce an ion cavity. An ultrashort pulse laser propagating in the plasma-electron-free ion cavity generates laser harmonics. The longitudinal electron motion, which inhibits high-harmonic generation at high laser intensities, can be suppressed by the space-charge field in the ion cavity or by using a counterpropagating laser pulse. Periodic suppression of the longitudinal electron motion may also be used to quasi-phase-match. This method enables harmonic generation to be extended to the sub-A regime.

  16. Semiclassical approaches to below-threshold harmonics

    SciTech Connect

    Hostetter, James A.; Tate, Jennifer L.; Schafer, Kenneth J.; Gaarde, Mette B.

    2010-08-15

    We study the generation of below-threshold harmonics in a model atom by extending the three-step semiclassical model of harmonic generation to include effects of the atomic potential. We explore the generalization of semiclassical trajectories of the electron in the presence of the combined laser-atom potential and calculate the intensity-dependent dipole phase associated with these trajectories. Our results are in good agreement with fully quantum mechanical calculations, as well as with recent experimental observations. We show that the so-called long trajectory readily generalizes to below-threshold harmonic generation and is relatively insensitive to the choice of initial conditions. We also find that the short trajectory can only lead to low-energy harmonics for electrons that have been released close to the ion core in a process that is closer to multiphoton than to tunnel ionization.

  17. New ladder operators for the monopole harmonics

    SciTech Connect

    Fakhri, H.; Dehghani, A.; Jafari, A.

    2007-02-15

    Using the ladder operators shifting the index m of the associated Jacobi functions, for a given n, the monopole harmonics and their corresponding angular momentum operators are, respectively, extracted as the irreducible representation space and generators of su(2) Lie algebra. The indices n and m play the role of principal and azimuthal quantum numbers. By introducing the ladder operators shifting the index n of the same associated Jacobi functions, we also get a new type of the raising and lowering relations which are realized by the operators shifting only the index n of the monopole harmonics. Moreover, other symmetries, including the transformation of the irreducible representation spaces into each other, are derived based on the operators that shift the indices n and m of the monopole harmonics simultaneously and agreeably as well as simultaneously and inversely. Our results are reduced to spherical harmonics by eliminating magnetic charge of the monopole.

  18. Semiclassical approaches to below-threshold harmonics

    NASA Astrophysics Data System (ADS)

    Hostetter, James A.; Tate, Jennifer L.; Schafer, Kenneth J.; Gaarde, Mette B.

    2010-08-01

    We study the generation of below-threshold harmonics in a model atom by extending the three-step semiclassical model of harmonic generation to include effects of the atomic potential. We explore the generalization of semiclassical trajectories of the electron in the presence of the combined laser-atom potential and calculate the intensity-dependent dipole phase associated with these trajectories. Our results are in good agreement with fully quantum mechanical calculations, as well as with recent experimental observations. We show that the so-called long trajectory readily generalizes to below-threshold harmonic generation and is relatively insensitive to the choice of initial conditions. We also find that the short trajectory can only lead to low-energy harmonics for electrons that have been released close to the ion core in a process that is closer to multiphoton than to tunnel ionization.

  19. Geomagnetic local and regional harmonic analyses.

    USGS Publications Warehouse

    Alldredge, L.R.

    1982-01-01

    Procedures are developed for using rectangular and cylindrical harmonic analyses in local and regional areas. Both the linear least squares analysis, applicable when component data are available, and the nonlinear least squares analysis, applicable when only total field data are available, are treated. When component data are available, it is advantageous to work with residual fields obtained by subtracting components derived from a harmonic potential from the observed components. When only total field intensity data are available, they must be used directly. Residual values cannot be used. Cylindrical harmonic analyses are indicated when fields tend toward cylindrical symmetry; otherwise, rectangular harmonic analyses will be more advantageous. Examples illustrating each type of analysis are given.-Author

  20. SEVENTH HARMONIC 20 GHz CO-GENERATOR

    SciTech Connect

    Hirshfield, Jay L

    2014-04-08

    To satisfy the need for multi-MW rf sources in frequency ranges where commercial sources do not exist, a study was undertaken on a class of devices based on gyro-harmonic frequency multiplication. This mechanism relies upon adding energy in gyrating motion to a linear electron beam that traverses a rotating-mode TE111-mode drive cavity in a dc magnetic field. The beam then drifts along the magnetic field into a second cavity, operating in the TEn11-mode tuned to the nth harmonic of the drive cavity. Studies of this configuration have been carried out for 2 < n < 7. Results are given for multi-MW, efficient operation of a 7th harmonic device operating at 20 GHz, and a 2nd harmonic device operating at 22.4 GHz.

  1. Transformation of complex spherical harmonics under rotations

    NASA Astrophysics Data System (ADS)

    Romanowski, Zbigniew; Krukowski, Stanislaw

    2007-12-01

    The algorithm rotating the complex spherical harmonics is presented. The convenient and ready to use formulae for ell = 0, 1, 2, 3 are listed. Any rotation in {\\bb R}^3 space is determined by the rotation axis and the rotation angle. The complex spherical harmonics defined in the fixed coordinate system is expanded as a linear combination of the spherical harmonics defined in the rotated coordinate system having 2ell + 1 terms, which are given explicitly. The derived formulae could be applied in quantum molecular calculations. The algorithm is based on the Cartesian representation of the spherical harmonics. The possible application of the algorithm to the evaluation of molecular integrals between slater type orbitals (STO) is described.

  2. Quantum harmonic oscillator with superoscillating initial datum

    SciTech Connect

    Buniy, R. V.; Struppa, D. C.; Colombo, F.; Sabadini, I.

    2014-11-15

    In this paper, we study the evolution of superoscillating initial data for the quantum driven harmonic oscillator. Our main result shows that superoscillations are amplified by the harmonic potential and that the analytic solution develops a singularity in finite time. We also show that for a large class of solutions of the Schrödinger equation, superoscillating behavior at any given time implies superoscillating behavior at any other time.

  3. Measuring Spherical Harmonic Coefficients on a Sphere

    SciTech Connect

    Pollaine, S; Haan, S W

    2003-05-16

    The eigenfunctions of Rayleigh-Taylor modes on a spherical capsule are the spherical harmonics Y{sub l,m} These can be measured by measuring the surface perturbations along great circles and fitting them to the first few modes by a procedure described in this article. For higher mode numbers, it is more convenient to average the Fourier power spectra along the great circles, and then transform them to spherical harmonic modes by an algorithm derived here.

  4. HARMONIC CAVITY PERFORMANCE FOR NSLS-II

    SciTech Connect

    BLEDNYKH, A.; KRINSKY, S.; PODOBEDOV, B.; ROSE, J.; TOWNE, N.; WANG, J.M.

    2005-05-15

    NSLS-II is a 3 GeV ultra-high brightness storage ring planned to succeed the present NSLS rings at BNL. Ultralow emittance combined with short bunch length means that it is critical to minimize the effects of Touschek scattering and coherent instabilities. Improved lifetime and stability can be achieved by including a third-harmonic RF cavity in the baseline design. This paper describes the required harmonic RF parameters and the expected system performance.

  5. The Case of the Missing Harmonic Structure

    SciTech Connect

    Arp, U.

    2007-01-19

    Classical synchrotron radiation theory predicts emission in harmonics of the revolution frequency of the radiating particles. The Synchrotron Ultraviolet Radiation Facility SURF is an electron storage ring based on the weak focusing principle. The particles travel on a near perfect circular path, which makes SURF an ideal test-bed for synchrotron radiation theory. The harmonic structure of the radiation emitted by the electrons stored in SURF will be explored.

  6. Two-center interference and ellipticity in high-order harmonic generation from H{sub 2}{sup +}

    SciTech Connect

    Zwan, Elmar V. van der; Lein, Manfred

    2010-09-15

    We present a theoretical investigation into the two-center interference in aligned H{sub 2}{sup +}. The influence of the laser field on the recombination step is investigated by comparing laser-induced harmonic generation with harmonic generation from field-free collisions of Gaussian wave packets with the core. We find that for different Gaussian wave packets colliding with the molecule, the interference minimum occurs at the same alignment angle. The same result is obtained for the laser-induced spectrum when only a single electronic trajectory per harmonic contributes. When multiple electronic trajectories contribute, we find an effect on the minimum position because the interference between short and long trajectories is alignment dependent. The two-center interference and the influence of the Coulombic potential are clearly seen not only in the harmonic intensity and phase but also in the polarization direction and ellipticity. We observe significant ellipticity of the emitted radiation around the two-center interference minimum.

  7. Higher-Order Harmonic Generation from Fullerene by Means of the Plasma Harmonic Method

    SciTech Connect

    Ganeev, R. A.; Bom, L. B. Elouga; Abdul-Hadi, J.; Ozaki, T.; Wong, M. C. H.; Brichta, J. P.; Bhardwaj, V. R.

    2009-01-09

    We demonstrate, for the first time, high-order harmonic generation from C{sub 60} by an intense femtosecond Ti:sapphire laser. Laser-produced plasmas from C{sub 60}-rich epoxy and C{sub 60} films were used as the nonlinear media. Harmonics up to the 19th order were observed. The harmonic yield from fullerene-rich plasma is about 25 times larger compared with those produced from a bulk carbon target. Structural studies of plasma debris confirm the presence and integrity of fullerenes within the plasma plume, indicating fullerenes as the source of high-order harmonics.

  8. Interference between selected dipoles and octupoles in the optical second-harmonic generation from spherical gold nanoparticles.

    PubMed

    Butet, J; Bachelier, G; Russier-Antoine, I; Jonin, C; Benichou, E; Brevet, P-F

    2010-08-13

    Optical second-harmonic generation from gold nanoparticles is investigated both experimentally and theoretically. The contribution of octupoles is reported for the first time in the second-harmonic emission pattern, by using an harmonic polarization in the scattering plane. The experimental results presented here for particle sizes up to 100 nm are in excellent agreement with finite element method simulations involving the normal surface term only in the nonlinear polarization source. In addition, analytical calculations based on nonlinear Mie scattering theory clearly evidence the constructive and destructive interferences occurring between the dipolar and octupolar responses selected with this polarization configuration. PMID:20868074

  9. Automatic recognition of harmonic bird sounds

    NASA Astrophysics Data System (ADS)

    Heller, Jason R.; Pinezich, John D.

    2005-09-01

    The method of sound recognition relies on a transformation of a sound into a spectrogram followed by extraction of the harmonics as curves. The extracted curves are called frequency tracks. A procedure called find-feasible-sets is used to extract sets of tracks that may correspond to harmonic sounds. If a set of tracks overlap each other sufficiently in time, then the set is designated a feasible set. Following the extraction of the feasible sets, the procedure find-maximal-subsets is applied to each feasible set. This procedure uses a function called harmonic-relate that determines if two tracks are harmonically related. All tracks that are not harmonically related to any other tracks in the feasible set are discarded. Furthermore, the feasible set is divided into maximal subsets. A maximal subset is a subset of the feasible set in which every track is harmonically related to one fixed track in the set called the reference track but no other tracks in the feasible set are related to the reference track. Each frequency track in a track set is transformed into a feature vector whose components describe the frequency, slope, and shape of the track. The species of birds analyzed are bluejay and herring gull.

  10. Harmonic Oscillators as Bridges between Theories

    NASA Astrophysics Data System (ADS)

    Kim, Y. S.; Noz, Marilyn E.

    2005-03-01

    Other than scattering problems where perturbation theory is applicable, there are basically two ways to solve problems in physics. One is to reduce the problem to harmonic oscillators, and the other is to formulate the problem in terms of two-by-two matrices. If two oscillators are coupled, the problem combines both two-by-two matrices and harmonic oscillators. This method then becomes a powerful research tool to cover many different branches of physics. Indeed, the concept and methodology in one branch of physics can be translated into another through the common mathematical formalism. It is noted that the present form of quantum mechanics is largely a physics of harmonic oscillators. Special relativity is the physics of the Lorentz group which can be represented by the group of by two-by-two matrices commonly called SL(2, c). Thus the coupled harmonic oscillators can therefore play the role of combining quantum mechanics with special relativity. Both Paul A. M. Dirac and Richard P. Feynman were fond of harmonic oscillators, while they used different approaches to physical problems. Both were also keenly interested in making quantum mechanics compatible with special relativity. It is shown that the coupled harmonic oscillators can bridge these two different approaches to physics.

  11. Mechanism of Anomalous Ellipticity Dependence of Near-threshold Harmonics in H 2 +

    NASA Astrophysics Data System (ADS)

    Nasiri Avanaki, Kobra; Telnov, Dmitry A.; Chu, Shih-I.

    2016-05-01

    We have studied the mechanism of anomalous dependence of near-threshold harmonics in H2+on ellipticity of driving field with the carrier wavelength 780 nm. The numerical procedure is based on accurate solution of the time-dependent Schrödinger equation in prolate spheroidal coordinates with the help of generalized pseudospectral method. Our analysis reveals that the origin of this phenomenon is mainly in the near-resonant excitation of πu molecular orbitals in H2+.For the lowest affected harmonic, the maximum in the ellipticity dependence of the radiation energy is exclusively due to excitation of the 1πu state; however, for higher near-threshold harmonics, higher-lying excited πu states are playing significant role as well. The closer the harmonic to the threshold, the larger number of excited states make considerable contributions. All these contributions interfere, resulting in the anomalous ellipticity dependence with a maximum at some non-zero value of the ellipticity parameter. In the vicinity of this value, the harmonics with the anomalous dependence are linearly polarized along the minor axis of the polarization ellipse of the driving field and may show strong elliptical polarization as well. This work is partially supported by DOE.

  12. The Dark Side of Creativity

    ERIC Educational Resources Information Center

    Cropley, David H., Ed.; Cropley, Arthur J., Ed.; Kaufman, James C., Ed.; Runco, Mark A., Ed.

    2010-01-01

    With few exceptions, scholarship on creativity has focused on its positive aspects while largely ignoring its dark side. This includes not only creativity deliberately aimed at hurting others, such as crime or terrorism, or at gaining unfair advantages, but also the accidental negative side effects of well-intentioned acts. This book brings…

  13. Evidence of multipolar response of Bacteriorhodopsin by noncollinear second harmonic generation.

    PubMed

    Bovino, F A; Larciprete, M C; Sibilia, C; Váró, G; Gergely, C

    2012-06-18

    Noncollinear second harmonic generation from a Bacteriorhodopsin (BR) oriented multilayer film was systematically investigated by varying the polarization state of both fundamental beams. Both experimental results and theoretical simulations, show that the resulting polarization mapping is an useful tool to put in evidence the optical chirality of the investigated film as well as the corresponding multipolar contributions to the nonlinear. PMID:22714524

  14. High-harmonic generation from Bloch electrons in solids

    NASA Astrophysics Data System (ADS)

    Wu, Mengxi; Ghimire, Shambhu; Reis, David A.; Schafer, Kenneth J.; Gaarde, Mette B.

    2015-04-01

    We study the generation of high-harmonic radiation by Bloch electrons in a model transparent solid driven by a strong midinfrared laser field. We solve the single-electron time-dependent Schrödinger equation (TDSE) using a velocity-gauge method [M. Korbman et al., New J. Phys. 15, 013006 (2013), 10.1088/1367-2630/15/1/013006] that is numerically stable as the laser intensity and number of energy bands are increased. The resulting harmonic spectrum exhibits a primary plateau due to the coupling of the valence band to the first conduction band, with a cutoff energy that scales linearly with field strength and laser wavelength. We also find a weaker second plateau due to coupling to higher-lying conduction bands, with a cutoff that is also approximately linear in the field strength. To facilitate the analysis of the time-frequency characteristics of the emitted harmonics, we also solve the TDSE in a time-dependent basis set, the Houston states [J. B. Krieger and G. J. Iafrate, Phys. Rev. B 33, 5494 (1986), 10.1103/PhysRevB.33.5494], which allows us to separate interband and intraband contributions to the time-dependent current. We find that the interband and intraband contributions display very different time-frequency characteristics. We show that solutions in these two bases are equivalent under a unitary transformation but that, unlike the velocity-gauge method, the Houston state treatment is numerically unstable when more than a few low-lying energy bands are used.

  15. A first study of a harmonic doubling gyro-TWT

    NASA Astrophysics Data System (ADS)

    Chen, Wenjun

    A frequency doubling, two-stage Ka band gyro-TWT amplifier that is based on the concept of harmonic multiplication has been demonstrated for the first time in an experiment at the University of Maryland. The input waveguide operates at the fundamental cyclotron harmonic in Ku band while the output waveguide operates at the second cyclotron harmonic in Ka band. An output peak power of 126 kW, a 3 dB bandwidth of 3.2%, a maximum gain of 27 dB and a highest efficiency of 12% were achieved when a 50 kV, 22 A beam was employed. The highest achieved output power is 180 kW when a 50 kV, 33 A beam was employed. The operating modes in the input and output waveguides were TE 02 and TE03, respectively. The achieved gain and bandwidth represent an advance in the state-of-the-art for a gyro-TWT with output at the second harmonic of the electron cyclotron frequency; moreover, the frequency doubling feature and operation in a high order symmetric mode are new features that have practical advantages. The present dissertation emphasizes the contributions of Wenjun Chen who was part of the team investigating the harmonic multiplying gyro-TWT at the University of Maryland. His major contributions to the analysis, design and execution of the experiment are summarized in the following paragraphs. It was found during the experiment that the attainable level of the output power of the frequency doubling gyro- TWT was limited because of insufficient power injected into the amplifier due in part to the reflection of the waves by the input coupler. Therefore, a new input coupling structure was proposed and a X-band prototype was fabricated and tested. The reflection measurement of the X-band input coupler prototype showed that 40% bandwidth was achievable for this new coupler. A magnetic system that is capable of producing a magnetic field up to 7 kG was designed for the successful operation of the harmonic doubling gyro-TWT. It consisted of two sets of gun coils and four sets of main

  16. Dual aperture dipole magnet with second harmonic component

    DOEpatents

    Praeg, W.F.

    1983-08-31

    An improved dual aperture dipole electromagnet includes a second-harmonic frequency magnetic guide field winding which surrounds first harmonic frequency magnetic guide field windings associated with each aperture. The second harmonic winding and the first harmonic windings cooperate to produce resultant magnetic waveforms in the apertures which have extended acceleration and shortened reset portions of electromagnet operation.

  17. Dual aperture dipole magnet with second harmonic component

    DOEpatents

    Praeg, Walter F.

    1985-01-01

    An improved dual aperture dipole electromagnet includes a second-harmonic frequency magnetic guide field winding which surrounds first harmonic frequency magnetic guide field windings associated with each aperture. The second harmonic winding and the first harmonic windings cooperate to produce resultant magnetic waveforms in the apertures which have extended acceleration and shortened reset portions of electromagnet operation.

  18. On the largest prime divisor of an odd harmonic number

    NASA Astrophysics Data System (ADS)

    Chishiki, Yusuke; Goto, Takeshi; Ohno, Yasuo

    2007-09-01

    A positive integer is called a (Ore's) harmonic number if its positive divisors have integral harmonic mean. Ore conjectured that every harmonic number greater than 1 is even. If Ore's conjecture is true, there exist no odd perfect numbers. In this paper, we prove that every odd harmonic number greater than 1 must be divisible by a prime greater than 10^5 .

  19. 2. LOOKING NORTH ON COMMERCE ST. SHOWING HARMON MATTRESS FACTORY. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. LOOKING NORTH ON COMMERCE ST. SHOWING HARMON MATTRESS FACTORY. BRIDGE CONNECTS HARMON MATTRESS FACTORY WITH HARMON WAREHOUSE (SEE PHOTO HABS WA-165-15). BUILDING IN LEFT FOREGROUND IS LINDSTROM-BERG CABINET FACTORY (SEE PHOTO HABS WA-165-36). - Union Depot Area Study, F. S. Harmon Mattress Company, 1953 South C Street, Tacoma, Pierce County, WA

  20. Multi-Harmonic Cavities for Increasing RF Breakdown Threshold

    SciTech Connect

    Jiang, Y.; Kazakov, S. Yu.; Kuzikov, S. V.; Hirshfield, J. L.

    2010-11-04

    A multi-harmonic asymmetric cavity is predicted to sustain higher acceleration gradients than a conventional pillbox cavity, 55% higher in one example, when driven by external RF harmonic sources. Simulations of multi-harmonic excitation in such a cavity are described, either by a charged drive beam or by external RF sources. An accelerator structure based on multi-harmonic cavity is proposed.

  1. The flip-flopping wake pattern behind two side-by-side circular cylinders: A global stability analysis

    NASA Astrophysics Data System (ADS)

    Bai, Xiao-Dong; Zhang, Wei; Guo, An-Xin; Wang, Yong

    2016-04-01

    A global stability analysis is performed for the flip-flopping wake pattern behind two side-by-side cylinders with emphasis on the unstable vorticity field. The combination of direct numerical simulation with the state-of-art lattice Boltzmann method and dynamic mode decomposition is used to analyse such wake pattern for the first time. The vorticity mode of the secondary instability is extracted from the flow. Such mode is found to be symmetrical with respect to the geometric axis of symmetry. Furthermore, a new scenario is found for the high order harmonics that there is a pair of two tertiary modes as a result of nonlinear interaction between the mode related to the secondary instability and the global mode of the in-phase synchronized vortex shedding base flow. Besides, the reason for the Fourier spectra of the lift on the two cylinders being the same is also illustrated for this case.

  2. Second Harmonic Generation Mediated by Aligned Water in Starch Granules.

    PubMed

    Cisek, Richard; Tokarz, Danielle; Krouglov, Serguei; Steup, Martin; Emes, Michael J; Tetlow, Ian J; Barzda, Virginijus

    2014-12-26

    The origin of second harmonic generation (SHG) in starch granules was investigated using ab initio quantum mechanical modeling and experimentally examined using polarization-in, polarization-out (PIPO) second harmonic generation microscopy. Ab initio calculations revealed that the largest contribution to the SHG signal from A- and B-type allomorphs of starch originates from the anisotropic organization of hydroxide and hydrogen bonds mediated by aligned water found in the polymers. The hypothesis was experimentally tested by imaging maize starch granules under various hydration and heat treatment conditions that alter the hydrogen bond network. The highest SHG intensity was found in fully hydrated starch granules, and heat treatment diminished the SHG intensity. The PIPO SHG imaging showed that dried starch granules have a much higher nonlinear optical susceptibility component ratio than fully hydrated granules. In contrast, deuterated starch granules showed a smaller susceptibility component ratio demonstrating that SHG is highly sensitive to the organization of the hydroxyl and hydrogen bond network. The polarization SHG imaging results of potato starch granules, representing starch allomorph B, were compared to those of maize starch granules representing allomorph A. The results showed that the amount of aligned water was higher in the maize granules. Nonlinear microscopy of starch granules provides evidence that varying hydration conditions leads to significant changes in the nonlinear susceptibility ratio as well as the SHG intensity, supporting the hypothesis from ab initio calculations that the dominant contribution to SHG is due to the ordered hydroxide and hydrogen bond network. PMID:25427055

  3. Theoretical investigation of resonant frequencies of unstrapped magnetron with arbitrary side resonators

    SciTech Connect

    Yue, Song; Zhang, Zhao-chuan; Gao, Dong-ping

    2015-04-15

    In this paper, a sector steps approximation method is proposed to investigate the resonant frequencies of magnetrons with arbitrary side resonators. The arbitrary side resonator is substituted with a series of sector steps, in which the spatial harmonics of electromagnetic field are also considered. By using the method of admittance matching between adjacent steps, as well as field continuity conditions between side resonators and interaction regions, the dispersion equation of magnetron with arbitrary side resonators is derived. Resonant frequencies of magnetrons with five common kinds of side resonators are calculated with sector steps approximation method and computer simulation softwares, in which the results have a good agreement. The relative error is less than 2%, which verifies the validity of sector steps approximation method.

  4. Side effects with amiodarone therapy.

    PubMed Central

    Shukla, R.; Jowett, N. I.; Thompson, D. R.; Pohl, J. E.

    1994-01-01

    Amiodarone hydrochloride is increasingly being used in the treatment of ventricular and supraventricular arrhythmias. Although a highly effective anti-arrhythmic agent, its use is restricted by the high incidence of side effects. To elucidate the value of monitoring serum level of both the parent drug and its active metabolite in predicting the occurrence of side effects, the investigators examined 109 patients from a register of patients treated with amiodarone for the prevalence of known side effects of the drug. The register contained over 90% of patients treated with amiodarone at the Leicester General Hospital during the period of the study. The findings suggest cutaneous side effects and abnormal thyroid function tests (without overt gland dysfunction) are more likely to occur with increasing duration of treatment and cumulative dosage. However, neither the serum amiodarone level nor the serum metabolite level had any predictive power for the occurrence of side effects. In view of this finding, it is recommended that close attention be paid to the continued clinical monitoring of side effects and that there is utility in measuring the serum amiodarone level in each patient to avoid the prescription of unnecessarily high doses. This is necessary not only to lessen the occurrence of cumulative dose-related side effects, but also because the variable but very long half-life of the drug leads to difficulties in relating spot drug levels to long-term effects. PMID:7937427

  5. 2. VIEW OF INTERIOR, EAST SIDE (SIDE A) OF BUILDING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW OF INTERIOR, EAST SIDE (SIDE A) OF BUILDING 883. INSTALLATION OF ROLLING MILLS AND MOLTEN SALT BATH EQUIPMENT FOR DEPLETED URANIUM FABRICATION. THE CRANE NEAR THE CEILING WAS USED TO INSTALL THE EQUIPMENT. BOXES ON THE FLOOR CONTAINED EQUIPMENT TO BE INSTALLED. (1/23/57) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  6. The DarkSide project

    NASA Astrophysics Data System (ADS)

    DarkSide project, The

    2016-02-01

    DarkSide is a graded experimental project based on radiopure argon, and is now, and will be, used in direct dark matter searches. The present DarkSide-50 detector, operating at the Gran Sasso National Laboratory, is a dual-phase, 50 kg, liquid argon time-projection-chamber surrounded by an active liquid scintillator veto. It is designed to be background free in 3 years of operation. DS-50 performances, when filled with atmospheric argon, are reported. However DS-50 filled with underground argon, shows impressive reduction of the 39Ar isotope. The application of this powerful technology in a future generation of the DarkSide program is discussed.

  7. Modified ADALINE algorithm for harmonic estimation and selective harmonic elimination in inverters

    NASA Astrophysics Data System (ADS)

    Vasumathi, B.; Moorthi, S.

    2011-11-01

    In digital signal processing, algorithms are very well developed for the estimation of harmonic components. In power electronic applications, an objective like fast response of a system is of primary importance. An effective method for the estimation of instantaneous harmonic components, along with conventional harmonic elimination technique, is presented in this article. The primary function is to eliminate undesirable higher harmonic components from the selected signal (current or voltage) and it requires only the knowledge of the frequency of the component to be eliminated. A signal processing technique using modified ADALINE algorithm has been proposed for harmonic estimation. The proposed method stays effective as it converges to a minimum error and brings out a finer estimation. A conventional control based on pulse width modulation for selective harmonic elimination is used to eliminate harmonic components after its estimation. This method can be applied to a wide range of equipment. The validity of the proposed method to estimate and eliminate voltage harmonics is proved with a dc/ac inverter as a simulation example. Then, the results are compared with existing ADALINE algorithm for illustrating its effectiveness.

  8. Multielectron Correlation in High-Harmonic Generation: A 2D Model Analysis

    SciTech Connect

    Sukiasyan, Suren; McDonald, Chris; Destefani, Carlos; Brabec, Thomas; Ivanov, Misha Yu.

    2009-06-05

    We analyze the role of multielectron dynamics in high-harmonic generation spectroscopy, using an example of a two-electron system. We identify and systematically quantify the importance of correlation and exchange effects. One of the main sources for correlation is identified to be the polarization of the ion by the recombining continuum electron. This effect, which plays an important qualitative and quantitative role, seriously undermines the validity of the standard approaches to high-harmonic generation, which ignore the contribution of excited ionic states to the radiative recombination of the continuum electron.

  9. Research Needs: Glass Solar Reflectance and Vinyl Siding

    SciTech Connect

    Hart, Robert; Curcija, Charlie; Arasteh, Dariush; Goudey, Howdy; Kohler, Christian; Selkowitz, Stephen

    2011-07-07

    The subject of glass solar reflectance and its contribution to permanent vinyl siding distortion has not been extensively studied, and some phenomena are not yet well understood. This white paper presents what is known regarding the issue and identifies where more research is needed. Three primary topics are discussed: environmental factors that control the transfer of heat to and from the siding surface; vinyl siding properties that may affect heat build-up and permanent distortion; and factors that determine the properties of reflected solar radiation from glass surfaces, including insulating window glass. Further research is needed to fully characterize the conditions associated with siding distortion, the scope of the problem, physical properties of vinyl siding, insulating window glass reflection characteristics, and possible mitigation or prevention strategies.

  10. Possible role of cochlear nonlinearity in the detection of mistuning of a harmonic component in a harmonic complex

    NASA Astrophysics Data System (ADS)

    Stoelinga, Christophe; Heo, Inseok; Long, Glenis; Lee, Jungmee; Lutfi, Robert; Chang, An-Chieh

    2015-12-01

    The human auditory system has a remarkable ability to "hear out" a wanted sound (target) in the background of unwanted sounds. One important property of sound which helps us hear-out the target is inharmonicity. When a single harmonic component of a harmonic complex is slightly mistuned, that component is heard to separate from the rest. At high harmonic numbers, where components are unresolved, the harmonic segregation effect is thought to result from detection of modulation of the time envelope (roughness cue) resulting from the mistuning. Neurophysiological research provides evidence that such envelope modulations are represented early in the auditory system, at the level of the auditory nerve. When the mistuned harmonic is a low harmonic, where components are resolved, the harmonic segregation is attributed to more centrally-located auditory processes, leading harmonic components to form a perceptual group heard separately from the mistuned component. Here we consider an alternative explanation that attributes the harmonic segregation to detection of modulation when both high and low harmonic numbers are mistuned. Specifically, we evaluate the possibility that distortion products in the cochlea generated by the mistuned component introduce detectable beating patterns for both high and low harmonic numbers. Distortion product otoacoustic emissions (DPOAEs) were measured using 3, 7, or 12-tone harmonic complexes with a fundamental frequency (F0) of 200 or 400 Hz. One of two harmonic components was mistuned at each F0: one when harmonics are expected to be resulted and the other from unresolved harmonics. Many non-harmonic DPOAEs are present whenever a harmonic component is mistuned. These non-harmonic DPOAEs are often separated by the amount of the mistuning (ΔF). This small frequency difference will generate a slow beating pattern at ΔF, because this beating is only present when a harmonic component is mistuned, it could provide a cue for behavioral detection