WorldWideScience

Sample records for wave feed line

  1. Submillimeter Wave Antenna With Slow Wave Feed Line

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Krozer, Viktor; Kotiranta, Mikko

    2009-01-01

    of the electromagnetic spectrum, and to create innovative imaging and sensing techniques that hold enormous potential in biomedical, metrological and security applications. Considering that realization of submillimeter wave components and antennas is still heavily constrained by problems arising from technological...

  2. Explosive Line Wave Generators

    Science.gov (United States)

    2013-12-01

    curvature produced by each line wave generator. Piezoelectric pins were used for an additional assessment of the explosive lens design...to a visual assessment of the wave curvature from the high speed camera images, the explosive lens design was also evaluated using piezoelectric pins...High Explosive Firing Complex (HEFC). The various explosive line wave generators were taped vertically on a supporting board and the detonation wave

  3. OPTIMIZATION OF TRANSIENT FEEDING TO PARALLEL-PLATE TRANSMISSION LINES FROM COAXIAL LINE

    Institute of Scientific and Technical Information of China (English)

    Tian Chunming; Wang Jianguo; Meng Fenxia; Zhang Maoyu; Ge Debiao

    2001-01-01

    The transient feeding to parallel-plate transmission lines from coaxial line is optimized by using the Finite-Difference Time-Domain (FDTD) method and a simple FDTD feed model. Observing the reflected voltages, this letter presents the optimal feeding position and ratio of width to height for a given input impedance of the coaxial line.

  4. Line geometry and electromagnetism II: wave motion

    CERN Document Server

    Delphenich, D H

    2013-01-01

    The fundamental role of line geometry in the study of wave motion is first introduced in the general context by way of the tangent planes to the instantaneous wave surfaces, in which it is first observed that the possible frequency-wave number 1-forms are typically constrained by a dispersion law that is derived from a constitutive law by way of the field equations. After a general review of the basic concepts that relate to quadratic line complexes, these geometric notions are applied to the study of electromagnetic waves, in particular.

  5. The impact of feeding line on dairy production revenue

    Directory of Open Access Journals (Sweden)

    Vesna Očić

    2012-12-01

    Full Text Available In the Republic of Croatia declining trend in the number of milk suppliers is registered, (69.3 % decline in the year 2010 compared to the 2002. Since the EU expects to abolish production quotas in the future (after the years 2014/2015, and reduce different protections for milk producers, there will be a decrease in the price of European milk. According to some predictions price will decrease for 5-15 % in the most of the EU countries, and this will be subsequently reflected in the Republic of Croatia. Mentioned facts will force milk producers to maximize business rationalization. At dairy farm, the highest cost is for animal feed, it is an ideal starting point for the implementation of business rationalization procedures. Previous studies show that the production of own animal feed can reduce the feeding cost by 30-50 %, compared to purchased fodder. Therefore, this study seeks to determine the effect of different forage courses on dairy farm profitability and cost of milk per kg. To create a technological-economic model, which is used to calculate basic economic and technological parameters for the three types of commercial farms in Croatia, data from 210 farms from the Pannonian regions of Croatia was used. The existing forage feeding line and four recommended by experts (technologists were taken into consideration. The results were used as input data for AHP multi-criteria analysis, which rankes feeding line. According to the overall feeding lines priorities for all three types of dairy farms, the rank will start with feeding line 3, which consists of a mixture of peas and grains, corn silage, barley, Italian ryegrass and DTS, while the worst option is existing feeding line.

  6. Leaky Wave Enhanced Feeds for Multi-Beam Reflector Systems

    NARCIS (Netherlands)

    Neto, A.; Gerini, G.; Llombart, N.; Ettorre, M.; Maagt, P. de

    2011-01-01

    Abstract—This paper discusses the use of dielectric superlayers to shape the radiation pattern of focal plane feeds of a multi-beam reflector system. The shaping of the pattern is obtained by exciting a pair (TE/TM) of leaky waves that radiate incrementally as they propagate between the ground plane

  7. Analysis of powder phenomena inside a Fette 3090 feed frame using in-line NIR spectroscopy.

    Science.gov (United States)

    Mateo-Ortiz, Daniel; Colon, Yleana; Romañach, Rodolfo J; Méndez, Rafael

    2014-11-01

    New analytical methods are needed to understand and optimize the processes by which tablets are produced. Fette 3090 tablet presses are commonly used in the pharmaceutical industry. A near-infrared (NIR) probe was installed into a Fette 3090 feed frame to understand and monitor the die filling process. The second objective was to analyze in detail the different factors that could affect the prediction of the developed NIR calibration models. Two monitoring positions for NIR spectrometers were evaluated; one at each side of the feed frame. A powder wave behavior caused by the paddle motion was observed inside the feed frame. The study also revealed that NIR spectra can help in the understanding of powder flow inside the feed frame. It was demonstrated that NIR spectra baselines can also be used to determine changes in mass inside the feed frame. The new NIR method showed that the paddle wheel speed has a significant impact in the powder dynamics inside the feed frame. The baselines of the NIR spectra depended on the mass hold-up inside the feed frame and paddle wheel speed. Studies using blends were performed to develop a NIR calibration model based on the feed frame system dynamics to determine acetaminophen drug concentration variability during the die filling process. The study found that variation in the distance from the powder to the probe due to paddle wheel speed has a significant effect on the NIR prediction. This study found that with NIR spectroscopy, blend uniformity can be assessed with high accuracy during the die filling process using the corresponding paddle wheel speed in-line calibration model. NIR was demonstrated to be a good development tool for the in-line monitoring of powder during the die filling process.

  8. Usage of Lightning Arrester Line to Feed Light Electrical Loads

    Directory of Open Access Journals (Sweden)

    Hani B. Odeh

    2009-01-01

    Full Text Available In remote areas, light loads (tens of kilowatts are scattered and situated in the field of high voltage lines (66KV and above. These loads are very far from the main feeders/sub-stations (33KV-0.380KV. Feeding such loads in the traditional ways like provision of Diesel-Powered Stations, installation of new distribution lines from the Feeding Centers, or building new Sub-Stations are not practical ways from the economical point of view, because it requires huge additional expenses and will increase electrical power losses. These expenses are not worthy for such loads and therefore, it is necessary to search for other methods to supply them. One of these methods is to use the lightning arrester line as capacitive divider to supply the light loads. In this research, the induced voltage of the lightning arrester line was calculated when it is isolated from the earth. We found the capacitance between lightning arrester line versus the phases and lightning arrester. It was also found the selective power out of the lightning arrester line and the required length which is to be isolated from the earth keeping the main function of the lightning arrester line. When economically comparing between supplying the light electrical loads by traditional ways and the method of lightning arrester, it was found the advantage of using lightning arresters to supply such loads. Also, by using the traditional methods, it was noted that there is a power loss in the power transmission lines by a percentage of 1.8%.

  9. Front-Side Microstrip Line Feeding a Raised Antenna Patch

    Science.gov (United States)

    Hodges, Richard; Hoppe, Daniel

    2005-01-01

    An improved design concept for a printed-circuit patch antenna and the transmission line that feeds the patch calls for (1) a microstrip transmission line on the front (radiative) side of a printed-circuit board based on a thin, high-permittivity dielectric substrate; (2) using the conductor covering the back side of the circuit board as a common ground plane for both the microstrip line and the antenna patch; (3) supporting the antenna patch in front of the circuit board on a much thicker, lower-permittivity dielectric spacer layer; and (4) connecting the microstrip transmission line to the patch by use of a thin wire or narrow ribbon that extends through the thickness of the spacer and is oriented perpendicularly to the circuit-board plane. The thickness of the substrate is typically chosen so that a microstrip transmission line of practical width has an impedance between 50 and 100 ohms. The advantages of this design concept are best understood in the context of the disadvantages of prior design concepts, as explained

  10. On-Line Generation of 3D-Waves

    DEFF Research Database (Denmark)

    Frigaard, Peter

    1992-01-01

    The paper describes the technique of filtering white noise for on-line generation of 3D-waves on a small computer in the laboratory. The wave generation package is implemented and tested in the 3D-wave basin at the University of Aalborg.......The paper describes the technique of filtering white noise for on-line generation of 3D-waves on a small computer in the laboratory. The wave generation package is implemented and tested in the 3D-wave basin at the University of Aalborg....

  11. Kelvin Waves and Dynamic Knots on Perturbative Helical Vortex Lines

    CERN Document Server

    Kou, Su-Peng

    2016-01-01

    Vortex lines are one-dimensional extended objects in three-dimensional superfluids. Vortex lines have many interesting properties, including Kelvin waves, exotic statistics, and possible entanglement. In this paper, an emergent "quantum world" is explored by projecting helical vortex lines. A one-dimensional quantum Fermionic model is developed to effectively describe the local fluctuations of helical vortex lines. The elementary excitations are knots with half winding-number that obey emergent quantum mechanics. The Biot-Savart equation, and its Kelvin wave solutions on helical vortex lines become Schrodinger equation, and the wave functions of probability waves for finding knots, respectively. This work shows an alternative approach to simulating quantum many-body physics based on classical systems.

  12. A comprehensive comparative study of Bandwidth enhancement of an antenna by non contacting feed lines with Rectangular Microstrip Patch (RMP using superstrate at ku band

    Directory of Open Access Journals (Sweden)

    POORNANAND DUBEY

    2012-04-01

    Full Text Available So far as this paper is concerned, this paper presents a comparative study of a rectangular Microstrip patch antenna at Gigahertz (GHz frequency using non contacting microstrip feed lines of length 14 to 14.9 mm (we didn’t extend the feed line up to 15mm length as in this case it would start contacting with the patch with superstrate. This means we created capacitive coupling between patch and feed line by varying the length of feed line up to which it doesn’t come into contact with the patch. The results presented here are obtained usingAnsoft High Frequency Structure Simulator (HFSS 11.0 software which is based on full wave finite element method. As a matter of fact, here five different feed line lengths antennas outcomes are shown and their comparative results are also shown in the tabular form. In this study a superstrate of thickness 5mm is also introduced to get the more precise results. Here it is very important to mention that the best performance of antenna i.e., below -10dB that we achieved at the feed line length of 14.9 mm i.e. spacing between the feed line and patch is 0.1 mm and we got bandwidth of 41.5% and resonance frequency of 17.8 GHz at solution frequency of 17.8 GHz.

  13. HOW TO ADJUST THE QUARTER WAVE LINE ON THE HALF-WAVE OPERATING MODE

    Directory of Open Access Journals (Sweden)

    Patsiuk V.I

    2008-08-01

    Full Text Available On the basis of the equations of the established mode the closed formulas for distribution of voltage, currents and active capacity along a non-uniform line with the concentrated elements are received. Inclusion of throttles and condenser batteries in a quarter wave line is examined with the purpose of giving to it of properties half-wave.

  14. Search for an emission line of a gravitational wave background

    CERN Document Server

    Nishizawa, Atsushi

    2015-01-01

    In the light of the history of researches on electromagnetic wave spectrum, a sharp emission line of gravitational-wave background (GWB) would be an interesting observational target. Here we study an efficient method to detect a line GWB by correlating data of multiple ground-based detectors. We find that the width of frequency bin for coarse graining is a critical parameter, and the commonly-used value 0.25 Hz is far from optimal, decreasing the signal-to-noise ratio by up to a factor of seven. By reanalyzing the existing data with a smaller bin width, we might detect a precious line signal from the early universe.

  15. MHD oscillations and waves near a magnetic null line

    Energy Technology Data Exchange (ETDEWEB)

    Bulanov, S.V.; Syrovatskii, S.I.

    1980-11-01

    An informative picture is drawn of the propagation of Alfven and magnetosonic waves in a two-dimensional magnetic field with a hyperbolic null point in the approximation of a cold plasma. The magnetosonic waves asymptotically transform into cylindrical waves. The wave amplitude increases toward the null point. A distortion of the plasma boundary produces excitation of noncylindrical magnetosonic waves. If the frequency of these waves is below the critical value, they will not penetrate into the plasma. Dissipation leads to a reflection of magnetosonic waves near the null line. Any arbitrarily slight dissipation leads to the appearance of a discrete spectrum of weakly damped Alfven oscillations. Oscillations of this type also occur in adiabatic confinement systems in which the magnetic field has null points. The nonlinear distortion of magnetosonic waves which leads to wave breaking and to the appearance of weak shock waves is studied. The amplitude of the magnetic field perturbations in a shock wave propagating toward the center asymptotically approaches a constant value.

  16. Reconfigurable Wave Velocity Transmission Lines for Phased Arrays

    Science.gov (United States)

    Host, Nick; Chen, Chi-Chih; Volakis, John L.; Miranda, Felix

    2013-01-01

    Phased array antennas showcase many advantages over mechanically steered systems. However, they are also more complex, heavy and most importantly costly. This presentation paper presents a concept which overcomes these detrimental attributes by eliminating all of the phase array backend (including phase shifters). Instead, a wave velocity reconfigurable transmission line is used in a series fed array arrangement to allow phase shifting with one small (100mil) mechanical motion. Different configurations of the reconfigurable wave velocity transmission line are discussed and simulated and experimental results are presented.

  17. Transformation of design formulae for feed line of triangular microstrip antenna

    Science.gov (United States)

    Mathur, Monika; Singh, Ghanshyam; Bhatnagar, S. K.; Swami, Swati; Vats, Abhijat

    2016-03-01

    In wireless communication system microstrip antenna is the key component. Popular shapes of patch for microstrip are rectangular, triangular and circular. A new transformation design formulae for feed line of rectangular microstrip antenna by using equivalent design concept were presented by the authors. That says one designed antenna for a given frequency on any substrate can be transformed into another substrate material for the same design frequency by simply multiply a factor ψ to the all dimensions of patch, length of feed line and some power of ψ for feed line width (where ψ is the square root of the ratio of dielectric constants of those two designs). This paper presents that the same formulae of that rectangular transformation feed line can also be applicable for triangular shape microstrip antenna transformation. The process was repeated for the triangular shape patch microstrip antenna as applied for rectangular shape and the simulation results were surprisingly the same for it by applying the same transformation formulae.

  18. Note: Efficient diode laser line narrowing using dual, feed-forward + feed-back laser frequency control

    Science.gov (United States)

    Lintz, M.; Phung, D. H.; Coulon, J.-P.; Faure, B.; Lévèque, T.

    2017-02-01

    We have achieved distributed feedback laser diode line narrowing by simultaneously acting on the diode current via a feed-back loop and on an external electrooptic phase modulator in feed-forward actuator. This configuration turns out to be very efficient in reaching large bandwidth in the phase correction: up to 15 MHz with commercial laser control units. About 98% of the laser power undergoes narrowing. The full width at half maximum of the narrowed optical spectrum is of less than 4 kHz. This configuration appears to be very convenient as the delay in the feed-forward control electronics is easily compensated for by a 20 m optical fiber roll.

  19. Interfacial waves generated by electrowetting-driven contact line motion

    Science.gov (United States)

    Ha, Jonghyun; Park, Jaebum; Kim, Yunhee; Shin, Bongsu; Bae, Jungmok; Kim, Ho-Young

    2016-10-01

    The contact angle of a liquid-fluid interface can be effectively modulated by the electrowetting-on-dielectric (EWOD) technology. Rapid movement of the contact line can be achieved by swift changes of voltage at the electrodes, which can give rise to interfacial waves under the strong influence of surface tension. Here we experimentally demonstrate EWOD-driven interfacial waves of overlapping liquids and compare their wavelength and decay length with the theoretical results obtained by a perturbation analysis. Our theory also allows us to predict the temporal evolution of the interfacial profiles in either rectangular or cylindrical containers, as driven by slipping contact lines. This work builds a theoretical framework to understand and predict the dynamics of capillary waves of a liquid-liquid interface driven by EWOD, which has practical implications on optofluidic devices used to guide light.

  20. Slow waves in locally resonant metamaterials line defect waveguides

    CERN Document Server

    Kaina, Nadège; Bourlier, Yoan; Fink, Mathias; Berthelot, Thomas; Lerosey, Geoffroy

    2016-01-01

    The ability of electromagnetic waves to interact with matter governs many fascinating effects involved in fundamental and applied, quantum and classical physics. It is necessary to enhance these otherwise naturally weak effects by increasing the probability of wave/matter interactions, either through field confinement or slowing down of waves. This is commonly achieved with structured materials such as photonic crystal waveguides or coupled resonator optical waveguides. Yet their minimum structural scale is limited to the order of the wavelength which not only forbids ultra-small confinement but also severely limits their performance for slowing down waves. Here we show that line defect waveguides in locally resonant metamaterials can outperform these proposals due to their deep subwavelength scale. We experimentally demonstrate our approach in the microwave domain using 3D printed resonant wire metamaterials, achieving group indices ng as high as 227 over relatively wide frequency bands. Those results corres...

  1. Synthesis of circularly polarized multiprobe feed radial line slot array

    OpenAIRE

    Sierra Pérez, Manuel; Salamanca, José Manuel; Vera Isasa, María; Sierra Castañer, Manuel

    1998-01-01

    In previous articles, we presented an easy way to analyze a slot array fed through a radial line and the design of an array of slots placed in an Archimedes spiral. The analysis was based on a circuit approach where the circuit parameters have been estimated using the first propagation mode in the radial line and the far field theory. The Archimedes spiral design, obtained with only one probe, has an efficiency problem due to the reflected field, that can be solved with this multiprobe design...

  2. Expression profile of hypothalamic neuropeptides in chicken lines selected for high or low residual feed intake.

    Science.gov (United States)

    Sintubin, P; Greene, E; Collin, A; Bordas, A; Zerjal, T; Tesseraud, S; Buyse, J; Dridi, S

    2014-08-01

    The R(+) and R(-) chicken lines have been divergently selected for high (R(+)) or low (R(-)) residual feed intake. For the same body weight and egg production, the R(+) chickens consume 40% more food than their counterparts R(-) lines. In the present study we sought to determine the hypothalamic expression profile of feeding-related neuropeptides in these lines maintained under fed or food-deprived conditions. In the fed condition, the suppressor of cytokine signaling 3 (SOCS3) was 17-fold lower (Pfeeding-related genes that are differently expressed in the hypothalamus of R(+) and R(-) chickens and that might explain the difference in feed intake observed between the two lines. Published by Elsevier Ltd.

  3. Finite-amplitude waves in cylindrical lined ducts

    Science.gov (United States)

    Nayfeh, A. H.; Tsai, M.-S.

    1974-01-01

    A second-order uniformly valid expansion is obtained for nonlinear waves propagating in a cylindrical duct lined with a point-reacting acoustic material that consists of a porous sheet followed by honey-comb cavities and backed by the impervious walls of the duct. The effect of the liner is taken into account by coupling the waves in the duct with those in the liner. As in the two-dimensional case, the nonlinearity increases the attenuation rate at all frequencies except in narrow bandwidths around the resonant frequencies, irrespective of the geometrical dimensions of the liner or the acoustic properties of the porous sheet.

  4. Excitation of knotted vortex lines in matter waves

    Science.gov (United States)

    Maucher, F.; Gardiner, S. A.; Hughes, I. G.

    2016-06-01

    We study the creation of knotted ultracold matter waves in Bose-Einstein condensates via coherent two-photon Raman transitions with a Λ level configuration. The Raman transition allows an indirect transfer of atoms from the internal state | a> to the target state | b> via an excited state | e> , that would be otherwise dipole-forbidden. This setup enables us to imprint three-dimensional knotted vortex lines embedded in the probe field to the density in the target state. We elaborate on experimental feasibility as well as on subsequent dynamics of the matter wave.

  5. Interdigital Line Antennas for Launching LH Waves in MST

    Science.gov (United States)

    Thomas, M. A.; Goetz, J. A.; Oliva, S. P.

    2002-11-01

    RF current drive has been proposed as a method for reducing the tearing fluctuations that are responsible for anomalous energy transport in the RFP. A system for launching lower hybrid slow waves at 800 MHz and n_||= 7.5 is now in operation on MST. The antenna is an enclosed interdigital line using λ/4 resonators with an opening in the cavity through which the wave is coupled to the plasma. A new antenna has been built incorporating several design improvements. These include larger vacuum feedthroughs, better impedance matching, internal instrumentation and improved directionality. Power handling is 3-4 times that of the original and continues to improve with conditioning. Further design improvements are underway to optimize impedance matching and damping rate along the traveling wave structure.

  6. Direct and correlated responses to selection in two lines of rabbits selected for feed efficiency under ad libitum and restricted feeding: II. Carcass and meat quality.

    Science.gov (United States)

    Molette, C; Gilbert, H; Larzul, C; Balmisse, E; Ruesche, J; Manse, H; Tircazes, A; Theau-Clément, M; Joly, T; Gidenne, T; Garreau, H; Drouilhet, L

    2016-01-01

    To get insights into selection criteria for feed efficiency, 2 rabbit lines have been created: the ConsoResidual line was selected for residual feed intake (RFI) with ad libitum feeding and the ADGrestrict line was selected for ADG under restricted feeding. The aim of the present study was to evaluate the impact on carcass and meat quality of the genetic selections. This comparison was performed using 2 different feeding strategies corresponding to the selection design. Carcass and meat quality traits were recorded for the 3 lines (ConsoResidual, ADGrestrict, and an unselected control [generation 0 {G0}]) in the 2 feeding systems (ad libitum and restricted) for 163 animals. Concerning the line effect, the BW at 63 d old was higher for the ADGrestrict line compared with the G0 and ConsoResidual lines ( rabbits did not exhibit a different carcass yield but showed different carcass traits. Indeed, the ConsoResidual rabbits had a higher hind leg yield ( rabbits. The ADGrestrict line had an intermediate perirenal fat yield compared with the other 2 lines. The G0 line always exhibited higher fat yields. Concerning meat quality, the ConsoResidual rabbits showed a lower ultimate pH ( rabbits. The feeding level had a strong effect on the gastrointestinal tract ( = 0.0004) and the carcass yield ( = 0.001). The latter was decreased in restricted rabbits. The effects of feeding strategy on meat quality were detrimental in the case of restricted feeding. Even if the ultimate pH was slightly higher in restricted rabbits ( = 0.0002), the carcass chilling loss ( = 0.0005) and the drip loss during 6 d ( feed seems to be less adversely correlated with carcass traits and meat quality traits but it leads to an increase in the live weight of the rabbits. Adversely, the selection on RFI, without affecting growth rate, would not modify age at slaughter because growth rate is not affected, but it might induce detrimental effects on meat quality.

  7. Mathematical model of delay lines based on magnetostatic waves

    Directory of Open Access Journals (Sweden)

    E. V. Kudinov

    2010-12-01

    Full Text Available On the example of the delay line have demonstrated the possibility of applying the principle of decomposition  to  construct  mathematical  models  of  microwave  devices  using  magnetostatic waves (MSW in a magnetized epitaxial ferrite films, which allows for a unified methodological basis and the lowest cost to the experimental optimization design of MSW devices for various applications

  8. Nonlinear longitudinal oscillations of fuel in rockets feed lines with gas-liquid damper

    Science.gov (United States)

    Avramov, K. V.; Filipkovsky, S.; Tonkonogenko, A. M.; Klimenko, D. V.

    2016-03-01

    The mathematical model of the fuel oscillations in the rockets feed lines with gas-liquid dampers is derived. The nonlinear model of the gas-liquid damper is suggested. The vibrations of fuel in the feed lines with the gas-liquid dampers are considered nonlinear. The weighted residual method is applied to obtain the finite degrees of freedom nonlinear model of the fuel oscillations. Shaw-Pierre nonlinear normal modes are applied to analyze free vibrations. The forced oscillations of the fuel at the principle resonances are analyzed. The stability of the forced oscillations is investigated. The results of the forced vibrations analysis are shown on the frequency responses.

  9. Quantum metamaterials: Electromagnetic waves in Josephson qubit lines

    Energy Technology Data Exchange (ETDEWEB)

    Zagoskin, A.M. [Frontier Research System, Institute of Physical and Chemical Research (RIKEN),Wako-shi, Saitama (Japan); Department of Physics, Loughborough University, Loughborough (United Kingdom); Physics and Astronomy Department, University of British Columbia, Vancouver, B.C. (Canada); Rakhmanov, A.L. [Frontier Research System, Institute of Physical and Chemical Research (RIKEN),Wako-shi, Saitama (Japan); Institute for Theoretical and Applied Electrodynamics RAS, Moscow (Russian Federation); Savel' ev, Sergey [Frontier Research System, Institute of Physical and Chemical Research (RIKEN),Wako-shi, Saitama (Japan); Department of Physics, Loughborough University, Loughborough (United Kingdom); Nori, Franco [Frontier Research System, Institute of Physical and Chemical Research (RIKEN),Wako-shi, Saitama (Japan); Department of Physics, Center for Theoretical Physics, Applied Physics Program, Center for the Study of Complex Systems, University of Michigan, Ann Arbor, MI (United States)

    2009-05-15

    We consider the propagation of a classical electromagnetic wave through a transmission line, formed by identical superconducting charge qubits inside a superconducting resonator. Since the qubits can be in a coherent superposition of quantum states, we show that such a system demonstrates interesting new effects, such as a ''breathing'' photonic crystal with an oscillating bandgap. Similar behaviour is expected from a transmission line formed by flux qubits. The key ingredient of these effects is that the optical properties of the Josephson transmission line are controlled by the quantum coherent state of the qubits (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. A MILLIMETER WAVE MICROSTRIP PATCH ANTENNA WITH CPW FEED

    Directory of Open Access Journals (Sweden)

    GARIMA SANYAL

    2013-01-01

    Full Text Available In this work a coplanar waveguide fed rectangular microstrip patch antenna with U slot at 40 Ghz is designed and simulated. Simulated results are presented by using Ansoft HFSS 13 software, a full wave electromagnetic field simulator for arbitrary 3D volumetric passive device modeling that takes advantage of the familiar Microsoft Windows graphical user interface.The patch element is been placed on FR4 Epoxy substrate with relative permittivity 4.4 at a height of 1.8 mm. The gain of the proposed antenna is 5dB.This antenna is smallsize,cheap,compact,easy to fabricate ,achieve return loss of -17.8dB at 40GHz which ranges to -25 dB at 10 0GHz and good VSWR.The approach presented in this paper offers major advantages in millimeter waveapplications as in radar communication.

  11. Fast wave power flow along SOL field lines in NSTX

    Science.gov (United States)

    Perkins, R. J.; Bell, R. E.; Diallo, A.; Gerhardt, S.; Hosea, J. C.; Jaworski, M. A.; Leblanc, B. P.; Kramer, G. J.; Phillips, C. K.; Roquemore, L.; Taylor, G.; Wilson, J. R.; Ahn, J.-W.; Gray, T. K.; Green, D. L.; McLean, A.; Maingi, R.; Ryan, P. M.; Jaeger, E. F.; Sabbagh, S.

    2012-10-01

    On NSTX, a major loss of high-harmonic fast wave (HHFW) power can occur along open field lines passing in front of the antenna over the width of the scrape-off layer (SOL). Up to 60% of the RF power can be lost and at least partially deposited in bright spirals on the divertor floor and ceiling [1,2]. The flow of HHFW power from the antenna region to the divertor is mostly aligned along the SOL magnetic field [3], which explains the pattern of heat deposition as measured with infrared (IR) cameras. By tracing field lines from the divertor back to the midplane, the IR data can be used to estimate the profile of HHFW power coupled to SOL field lines. We hypothesize that surface waves are being excited in the SOL, and these results should benchmark advanced simulations of the RF power deposition in the SOL (e.g., [4]). Minimizing this loss is critical optimal high-power long-pulse ICRF heating on ITER while guarding against excessive divertor erosion.[4pt] [1] J.C. Hosea et al., AIP Conf Proceedings 1187 (2009) 105. [0pt] [2] G. Taylor et al., Phys. Plasmas 17 (2010) 056114. [0pt] [3] R.J. Perkins et al., to appear in Phys. Rev. Lett. [0pt] [4] D.L. Green et al., Phys. Rev. Lett. 107 (2011) 145001.

  12. Finite amplitude waves in two-dimensional lined ducts

    Science.gov (United States)

    Nayfeh, A. H.; Tsai, M.-S.

    1974-01-01

    A second-order uniform expansion is obtained for nonlinear wave propagation in a two-dimensional duct lined with a point-reacting acoustic material consisting of a porous sheet followed by honeycomb cavities and backed by the impervious wall of the duct. The waves in the duct are coupled with those in the porous sheet and the cavities. An analytical expression is obtained for the absorption coefficient in terms of the sound frequency, the physical properties of the porous sheet, and the geometrical parameters of the flow configuration. The results show that the nonlinearity flattens and broadens the absorption vs. frequency curve, irrespective of the geometrical dimensions or the porous material acoustic properties, in agreement with experimental observations.

  13. Genetic parameters of feeding behavior traits and their relationship with live performance traits in modern broiler lines.

    Science.gov (United States)

    Howie, J A; Avendano, S; Tolkamp, B J; Kyriazakis, I

    2011-06-01

    Current selection goals in broiler breeding focus on the improvement of live performance traits, such as feed intake, BW, and feed conversion ratio (FCR). The use of electronic feeders allows measurement of feed intake of individuals housed in groups as well as the identification of different feeding behaviors. Feed intake can thus be split into underlying feeding behavior traits, allowing the estimation of genetic correlations and assessment of the genetic consequences of selecting for performance traits on feeding behavior traits. To investigate the genetic relationships between performance traits and feeding behavior, data of visits to feeders by birds from 4 lines of broilers that differed in selection focus on growth and FCR were analyzed. Visits were recorded electronically and grouped into meals using an existing model for estimating meal criteria. Mean individual feeding behavior traits were then calculated across the entire test period (2 to 5 wk of age). Records were available for between 14,000 and 18,000 birds/line. Analyzed feeding behavior traits were meals per day, meal size, visits per meal, meal duration, nonfeeding time in meal, time feeding per day, proportion of meal spent feeding, feeding rate, and ADFI. Analyzed performance traits were 35-d BW, total feed intake over the entire test period, and FCR. All feeding behavior traits showed moderate to high heritabilities (0.24 to 0.57) but low genetic correlations with performance traits (-0.20 to 0.18), except for ADFI, which was moderately correlated with total intake on test (0.57) and highly correlated with FCR (0.91). The low genetic correlations indicate that the difference in selection intensity among lines for these performance traits has had limited effect on feeding behavior. Different feeding strategies that would result in favorable breeding values for FCR were identified, adding opportunities for further improvements in feed efficiency within and across environments.

  14. Proposed Feed Forward Correction for the CLIC Ring-To-Main-Linac Transfer Lines

    CERN Document Server

    Apsimon, Robert; Uythoven, Jan

    2014-01-01

    To achieve the design luminosity for the CLIC main beam an unprecedented degree of machine stability is required. Extremely stringent tolerances are placed on the damping ring extraction system in order to limit emittance growth along the ring-to-main-linac transfer line; particularly through the pre-linac betatron collimation system. In this paper we propose feed forward systems situated across the central arcs and turnaround loops of the transfer lines as an elegant solution to relax the damping ring extraction requirements as well as to significantly reduce emittance growth through the betatron collimation system. The optics for the beam position monitor and kicker regions are presented and the results of tracking simulations shown to verify the performance of the feed forward systems.

  15. On-line current feed and computer aided control tactics for automatic balancing head

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In the designed automatic balancing head,a non-contact induction transformer is used to deliver driving energy to solve the problem of current fed and controlling on-line.Computer controlled automatic balancing experiments with phase-magnitude control tactics were performed on a flexible rotor system.Results of the experiments prove that the energy feeding method and the control tactics are effective in the automatic balancing head for vibration controlling.

  16. Loss of feed flow, steam generator tube rupture and steam line break thermohydraulic experiments

    Energy Technology Data Exchange (ETDEWEB)

    Mendler, O J; Takeuchi, K; Young, M Y

    1986-10-01

    The Westinghouse Model Boiler No. 2 (MB-2) steam generator test model at the Engineering Test Facility in Tampa, Florida, was reinstrumented and modified for performing a series of tests simulating steam generator accident transients. The transients simulated were: loss of feed flow, steam generator tube rupture, and steam line break events. This document presents a description of (1) the model boiler and the associated test facility, (2) the tests performed, and (3) the analyses of the test results.

  17. Detection of artificial water flows by the lateral line system of a benthic feeding cichlid fish.

    Science.gov (United States)

    Schwalbe, Margot A B; Sevey, Benjamin J; Webb, Jacqueline F

    2016-04-01

    The mechanosensory lateral line system of fishes detects water motions within a few body lengths of the source. Several types of artificial stimuli have been used to probe lateral line function in the laboratory, but few studies have investigated the role of flow sensing in benthic feeding teleosts. In this study, we used artificial flows emerging from a sandy substrate to assess the contribution of flow sensing to prey detection in the peacock cichlid, Aulonocara stuartgranti, which feeds on benthic invertebrates in Lake Malawi. Using a positive reinforcement protocol, we trained fish to respond to flows lacking the visual and chemical cues generated by tethered prey in prior studies with A. stuartgranti Fish successfully responded to artificial flows at all five rates presented (characterized using digital particle image velocimetry), and showed a range of flow-sensing behaviors, including an unconditioned bite response. Immediately after lateral line inactivation, fish rarely responded to flows and the loss of vital fluorescent staining of hair cells (with 4-di-2-ASP) verified lateral line inactivation. Within 2 days post-treatment, some aspects of flow-sensing behavior returned and after 7 days, flow-sensing behavior and hair cell fluorescence both returned to pre-treatment levels, which is consistent with the reported timing of hair cell regeneration in other vertebrates. The presentation of ecologically relevant water flows to assess flow-sensing behaviors and the use of a positive reinforcement protocol are methods that present new opportunities to study the role of flow sensing in the feeding ecology of benthic feeding fishes.

  18. Mini-Scale Power Distribution Network Feeding Trapezoidal-Wave Voltages to Power Electronic Loads with Diode Rectifiers

    Science.gov (United States)

    Noguchi, Toshihiko; Imoto, Masaru; Sato, Yoshikazu

    This paper proposes a novel three-phase power distribution system feeding trapezoidal voltages to various power electronic loads with diode rectifier front-ends. The network distributes trapezoidal voltages generated by synchronous superposition of wave-shaping voltages onto sinusoidal voltages available from a utility power grid. The power distribution by the trapezoidal voltages allows reducing harmonics of the line currents without electronic switching devices because of a spontaneously widened conduction period of the current waveforms. The reduction of the harmonic currents also contributes to improve total power factor at the load input terminals and efficiency of the power transmission cables. Since the diodes of the rectifiers successively commutate the trapezoidal waves during periods of their flat parts, not only total harmonic distortion of the currents is improved, but also voltage ripple across the dc-buses of the rectifiers can effectively be reduced with less filter capacitors. In addition, the system offers an uninterruptible power supply function by immediately changing its outputs from the wave-shaping voltages to the trapezoidal voltages when interruption occurs in the power grid. In this paper, a prototype of the system is experimentally examined from various angles of operating characteristics and test results are presented to prove feasibility of the proposed system.

  19. Thermal waves induced by a rapidly moving line source

    Science.gov (United States)

    Rostami, A. A.; Shamsai, M.

    For the cases involving a fast moving heat source or extremely short pulses emitted by lasers or short time after the start of transients, the classical theory of heat conduction breaks down since the wave nature of heat transport dominates. In this study, the temperature field due to a fast moving line source was determined analytically using the wave concept. The results are given for different values of thermal Mach number (M=V/C). For M>1 the heat affected zone is confined in a wedge shape region behind the source. The wedge half angle is equal to sin-1 (1/M). It was confirmed that the difference between the results of diffusion and wave models depends on the corresponding time scale and the relaxation time. Zusammenfassung Im Falle schnell bewegter Wärmequellen oder extrem kurzer Laserpulse sowie unmittelbar nach Beginn transienter Vorgänge versagt die klassische Theorie der Wärmeleitung, da die Wellennatur des Wärmetransportes dominiert. In der vorliegenden Studie wurde das durch eine raschbewegte Linienquelle ausgelöste Temperaturfeld auf der Basis des Wellenkonzepts analytisch bestimmt, und zwar für verschiedene Werte der thermischen Mach-Zahl (M=V/C). Für M>1 bleibt der von der Wärmeausbreitung erfaßte Bereich auf eine keilförmige Zone hinter der Quelle beschränkt, wobei der halbe Keilwinkel gleich sin-1 (1/M) ist. Es konnte gezeigt werden, daß der Unterschied zwischen den Ergebnissen des Diffusions- und des Wellenmodells von der entsprechenden Zeitskala und von der Relaxationszeit abhängt.

  20. Theory of a Traveling Wave Feed for a Planar Slot Array Antenna

    Science.gov (United States)

    Rengarajan, Sembiam

    2012-01-01

    Planar arrays of waveguide-fed slots have been employed in many radar and remote sensing applications. Such arrays are designed in the standing wave configuration because of high efficiency. Traveling wave arrays can produce greater bandwidth at the expense of efficiency due to power loss in the load or loads. Traveling wave planar slot arrays may be designed with a long feed waveguide consisting of centered-inclined coupling slots. The feed waveguide is terminated in a matched load, and the element spacing in the feed waveguide is chosen to produce a beam squinted from the broadside. The traveling wave planar slot array consists of a long feed waveguide containing resonant-centered inclined coupling slots in the broad wall, coupling power into an array of stacked radiating waveguides orthogonal to it. The radiating waveguides consist of longitudinal offset radiating slots in a standing wave configuration. For the traveling wave feed of a planar slot array, one has to design the tilt angle and length of each coupling slot such that the amplitude and phase of excitation of each radiating waveguide are close to the desired values. The coupling slot spacing is chosen for an appropriate beam squint. Scattering matrix parameters of resonant coupling slots are used in the design process to produce appropriate excitations of radiating waveguides with constraints placed only on amplitudes. Since the radiating slots in each radiating waveguide are designed to produce a certain total admittance, the scattering (S) matrix of each coupling slot is reduced to a 2x2 matrix. Elements of each 2x2 S-matrix and the amount of coupling into the corresponding radiating waveguide are expressed in terms of the element S11. S matrices are converted into transmission (T) matrices, and the T matrices are multiplied to cascade the coupling slots and waveguide sections, starting from the load end and proceeding towards the source. While the use of non-resonant coupling slots may provide an

  1. Genetic analysis of production and feed efficiency traits in an Orlopp turkey line (Meleagris gallopavo).

    Science.gov (United States)

    Willems, O W; Buddiger, N J H; Wood, B J

    2014-01-01

    1. Genetic parameters for production and feed efficiency traits in the Orlopp line of turkeys were estimated to determine breeding goals and future potential of the line in a long-term genetic improvement programme. 2. Body weight, egg production and fertility traits were recorded and feed conversion ratio (FCR) was assessed from 16-20 weeks of age. 3. Moderate heritabilities were found for feed intake and body weight gain (0.25 to 0.31). Average FCR was 3.14, with heritability of 0.10. Body weight, breast conformation score and egg production traits showed moderate heritabilities (0.22 to 0.52), while both fertility and hatch of fertile eggs were low (0.04 and 0.09, respectively). 4. Genetic correlations between breast confirmation score, 10- and 18-week body weights were moderate, 0.50 and 0.45, respectively. Average egg weight also showed moderate genetic correlations with 10- and 18-week body weights (0.59 and 0.42).

  2. A Tutorial on Optical Feeding of Millimeter-Wave Phased Array Antennas for Communication Applications

    Directory of Open Access Journals (Sweden)

    Ivan Aldaya

    2015-01-01

    Full Text Available Given the interference avoidance capacity, high gain, and dynamical reconfigurability, phased array antennas (PAAs have emerged as a key enabling technology for future broadband mobile applications. This is especially important at millimeter-wave (mm-wave frequencies, where the high power consumption and significant path loss impose serious range constraints. However, at mm-wave frequencies the phase and amplitude control of the feeding currents of the PAA elements is not a trivial issue because electrical beamforming requires bulky devices and exhibits relatively narrow bandwidth. In order to overcome these limitations, different optical beamforming architectures have been presented. In this paper we review the basic principles of phased arrays and identify the main challenges, that is, integration of high-speed photodetectors with antenna elements and the efficient optical control of both amplitude and phase of the feeding current. After presenting the most important solutions found in the literature, we analyze the impact of the different noise sources on the PAA performance, giving some guidelines for the design of optically fed PAAs.

  3. Reconfigurable Transmission Line for a Series-Fed Ku-Band Phased Array Using a Single Feed

    Science.gov (United States)

    Host, Nicholas K.; Chen, Chi-Chih; Volakis, John L.; Miranda. Felix, A.

    2013-01-01

    The paper presents a novel approach to realize a lowcost phased array using a simple feeding mechanism. Specifically, a single coplanar stripline (CPS) transmission line is used to feed the antenna array elements. By controlling the CPS's dielectric properties using a movable dielectric plunger, scanning is achieved. Due to its simplicity, single feed, and no phase shifters, this approach leads to a dramatic reduction in cost which does not scale for larger arrays.

  4. Millimeter-wave molecular line observations of the Tornado nebula

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, D. [Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Oka, T.; Tanaka, K.; Matsumura, S.; Miura, K.; Takekawa, S., E-mail: sakai.daisuke@nao.ac.jp [Department of Physics, Institute of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama, Kanagawa 223-8522 (Japan)

    2014-08-10

    We report the results of millimeter-wave molecular line observations of the Tornado Nebula (G357.7-0.1), which is a bright radio source behind the Galactic center region. A 15' × 15' area was mapped in the J = 1-0 lines of CO, {sup 13}CO, and HCO{sup +} with the Nobeyama Radio Observatory 45 m telescope. The Very Large Array archival data of OH at 1720 MHz were also reanalyzed. We found two molecular clouds with separate velocities, V{sub LSR} = –14 km s{sup –1} and +5 km s{sup –1}. These clouds show rough spatial anti-correlation. Both clouds are associated with OH 1720 MHz emissions in the area overlapping with the Tornado Nebula. The spatial and velocity coincidence indicates violent interaction between the clouds and the Tornado Nebula. Modestly excited gas prefers the position of the Tornado 'head' in the –14 km s{sup –1} cloud, also suggesting the interaction. Virial analysis shows that the +5 km s{sup –1} cloud is more tightly bound by self-gravity than the –14 km s{sup –1} cloud. We propose a formation scenario for the Tornado Nebula; the +5 km s{sup –1} cloud collided into the –14 km s{sup –1} cloud, generating a high-density layer behind the shock front, which activates a putative compact object by Bondi-Hoyle-Lyttleton accretion to eject a pair of bipolar jets.

  5. Technicians complete foaming around Atlantis', OV-104, 17' ET feed line

    Science.gov (United States)

    1990-01-01

    Technicians complete foaming around the area of Atlantis, Orbiter Vehicle (OV) 104, 17 inch diameter external tank (ET) feed line in preparation for the second liquid hydrogen tanking test at the Kennedy Space Center (KSC). An elaborate network of sensors, leak detectors, and baggies were set up on OV-104 by technicians. Engineers hope this extra instrumentation will help pinpoint the exact location of the leak. OV-104 is scheduled to be launched for the STS-38 mission, a classified Department of Defense (DOD) flight. View provided by KSC with alternate number KSC-90PC-988.

  6. Spectral Line Non-thermal Broadening and MHD Waves in the Solar Corona

    Science.gov (United States)

    Zaqarashvili, T. V.

    2009-04-01

    The rapid temperature rise from the solar surface (6000 K) up to the corona (1 MK) and acceleration of solar wind particles still are unresolved problems in solar physics. The energy source for the coronal heating and the wind acceleration probably lies in the solar photosphere. MHD waves are believed to carry the photospheric energy into the corona. Recent observations from space based telescopes made significant progress in understanding the process of MHD wave propagation from the solar surface towards the corona. Some of MHD wave modes have been observed through intensity variations and Doppler shift oscillations in spectral lines. Another powerful mechanism is to detect the waves through the non-thermal broadening of spectral lines. The lecture gives the basic points of wave induced effects in solar coronal spectral lines and recent progress in wave observations through spectral line non-thermal broadening.

  7. Research of Bipolar HVDC Transmission Lines Based on Traveling Wave Differential Protection

    Directory of Open Access Journals (Sweden)

    Baina He

    2013-07-01

    Full Text Available The principle of the traveling wave based differential protection for bipolar HVDC transmission lines is proposed in the paper. Unlike the traditional current differential protection, the quantity of current is replaced by the quantity of the traveling wave for comparison. The traveling wave at the remote end is transferred to the local end for comparison to the local traveling wave. For the bipolar DC transmission lines, the polar-mode (aerial mode traveling waves are employed to establish the discriminative criterion. The ground-mode traveling waves are utilized for faulty line detector for bipolar operation modes. The entire protection scheme is simulated in PSCAD/EMTDC associated with the standard ±500kV HVDC transmission system. The simulation results show that the new protection has the advantages of higher sensitivity, reliability and security. The fault resistance can be coverd by the traveling wave based differential protection reaches to 500 Ohm.    

  8. Excitation of Love waves in a thin film layer by a line source.

    Science.gov (United States)

    Tuan, H.-S.; Ponamgi, S. R.

    1972-01-01

    The excitation of a Love surface wave guided by a thin film layer deposited on a semiinfinite substrate is studied in this paper. Both the thin film and the substrate are considered to be elastically isotropic. Amplitudes of the surface wave in the thin film region and the substrate are found in terms of the strength of a line source vibrating in a direction transverse to the propagating wave. In addition to the surface wave, the bulk shear wave excited by the source is also studied. Analytical expressions for the bulk wave amplitude as a function of the direction of propagation, the acoustic powers transported by the surface and bulk waves, and the efficiency of surface wave excitation are obtained. A numerical example is given to show how the bulk wave radiation pattern depends upon the source frequency, the film thickness and other important parameters of the problem. The efficiency of surface wave excitation is also calculated for various parameter values.

  9. Effect of a progressive sound wave on the profiles of spectral lines. 2: Asymmetry of faint Fraunhofer lines. [absorption spectra

    Science.gov (United States)

    Kostyk, R. I.

    1974-01-01

    The absorption coefficient profile was calculated for lines of different chemical elements in a medium with progressive sound waves. Calculations show that (1) the degree and direction of asymmetry depend on the atomic ionization potential and the potential of lower level excitation of the individual line; (2) the degree of asymmetry of a line decreases from the center toward the limb of the solar disc; and (3) turbulent motions 'suppress' the asymmetry.

  10. PROPAGATION CHARACTERISTICS OF ELECTROMAGNETIC WAVES IN GRADIENT TRANSMISSION LINE

    OpenAIRE

    Nesterov Iurii Gavriilovitch; Silin Nikolay Vitalievich

    2015-01-01

    Propagation characteristics of transmission lines with smooth continuous spatial distribution of capacitance and inductance (gradient transmission line) is considered in the framework of recently developed mathematical model. Strong heterogeneity-induced artificial dispersion is described by means of this model. Reflectance and transmittance spectra are shown on example of different gradient transmission lines. In conclusion, applicability of gradient transmission lines in areas o...

  11. High precision ultrasonic guided wave technique for inspection of power transmission line

    Science.gov (United States)

    Cheng, Jun; Qiu, Jinhao; Ji, Hongli; Wang, Enrong; Takagi, Toshiyuki; Uchimoto, Tetsuya

    2017-01-01

    Due to the merits of high inspection speed and long detecting distance, Ultrasonic Guided Wave(UGW) method has been commonly applied to the on-line maintenance of power transmission line. However, the guided wave propagation in this structure is very complicated, leading to the unfavorable defect localization accuracy. Aiming at this situation, a high precision UGW technique for inspection of local surface defect in power transmission line is proposed. The technique is realized by adopting a novel segmental piezoelectric ring transducer and transducer mounting scheme, combining with the comprehensive characterization of wave propagation and circumferential defect positioning with multiple piezoelectric elements. Firstly, the propagation path of guided waves in the multi-wires of transmission line under the proposed technique condition is investigated experimentally. Next, the wave velocities are calculated by dispersion curves and experiment test respectively, and from comparing of the two results, the guided wave mode propagated in transmission line is confirmed to be F(1,1) mode. Finally, the axial and circumferential positioning of local defective wires in transmission line are both achieved, by using multiple piezoelectric elements to surround the stands and send elastic waves into every single wire. The proposed research can play a role of guiding the development of highly effective UGW method and detecting system for multi-wire transmission line.

  12. Effects of millimeter wave carbon fibers on filter-feeding freshwater invertebrates.

    Science.gov (United States)

    Soucek, David J; Dickinson, Amy; Cropek, Donald M

    2010-05-01

    The purpose of our study was to investigate the sub-lethal effects of millimeter wave carbon fibers (MWCF), a military obscurant, on filter-feeding freshwater invertebrates. We observed decreased survival, reproduction, and oxygen consumption in Daphnia magna at realistic loading rates. In experiments with the Asiatic clam (Corbicula fluminea), soft tissue dry weight and tissue condition index were not significantly different among control and MWCF exposed treatments; however, using a (15)N labeled alga as food, we observed decreased nitrogen turnover in tissues of clams exposed to MWCF, suggesting lower filtering or ingestion rates. Our findings combined with previous demonstrations of MWCF toxicity to green algae suggest that over a period of several months, bivalve growth may be inhibited, and cladoceran populations may be even more strongly affected by MWCF. Given that these fibers are persistent, further experiments should be conducted to determine the longer-term effects of contamination of water bodies with MWCF.

  13. Survivability mode and extreme loads on the mooring lines of the Wave Dragon Wave Energy Converter

    Energy Technology Data Exchange (ETDEWEB)

    Parmeggiani, S.; Kofoed, J.P.

    2010-11-15

    This report is a product of the cooperation agreement between Wave Dragon and Aalborg University regarding phase 2 of the development of the Wave Dragon Wave Energy Converter. The research is carried out by testing the 1:51.8 scale model of the Wave Dragon, aiming at the assessment of the survivability of the device in extreme waves and evaluation of the design loads for the mooring component. The outcome of the research will be used as input for future research work aimed at the design of the mooring system and the certification of the structural design for the full scale Wave Dragon demonstrator. (Author)

  14. The wave phase velocity in superconducting transmission lines near T{sub c}

    Energy Technology Data Exchange (ETDEWEB)

    Kuzhakhmetov, A.R.; Lobov, G.D.; Shtykov, V.V.; Zhgoon, S.A. [Moscow Power Engineering Inst. (Russian Federation). Radio Engineering Dept.

    1998-06-01

    A peculiarity in behavior of electromagnetic waves phase velocity ({nu}{sub ph}), propagating in superconducting planar transmission lines, in the vicinity of the transition temperature (T{sub c}) was observed in experiment and deduced theoretically. (orig.) 5 refs.

  15. Radiation of planar electromagnetic waves by a line source in anisotropic metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Cheng Qiang; Jiang Weixiang; Cui Tiejun, E-mail: tjcui@seu.edu.c [State Key Laboratory of Millimeter Waves, Department of Radio Engineering, Southeast University, Nanjing 210096 (China)

    2010-08-25

    We show experimentally that a line source in an anisotropic metamaterial directly radiates planar electromagnetic waves instead of cylindrical waves, when one component of the permeability tensor approaches zero. The impedance of this material can be perfectly matched to that of free space, which can significantly reduce the reflections between the source and the superstrate, as in traditional highly directive antennas based on zero index metamaterials. Such a unique property determines the two-way propagation of electromagnetic waves excited by a line source, instead of all-way propagation. From this feature, a highly directive emission of electromagnetic waves is achieved using the anisotropic metamaterial with arbitrary shape. We have designed and fabricated the anisotropic metamaterial in the microwave region, and observed the generation of plane waves and their highly directive emission. The proposed plane-wave emission is independent of the shape variance of the anisotropic metamaterial, which can be utilized in the design of conformal antennas.

  16. Radiation of planar electromagnetic waves by a line source in anisotropic metamaterials

    Science.gov (United States)

    Cheng, Qiang; Jiang, Wei Xiang; Cui, Tie Jun

    2010-08-01

    We show experimentally that a line source in an anisotropic metamaterial directly radiates planar electromagnetic waves instead of cylindrical waves, when one component of the permeability tensor approaches zero. The impedance of this material can be perfectly matched to that of free space, which can significantly reduce the reflections between the source and the superstrate, as in traditional highly directive antennas based on zero index metamaterials. Such a unique property determines the two-way propagation of electromagnetic waves excited by a line source, instead of all-way propagation. From this feature, a highly directive emission of electromagnetic waves is achieved using the anisotropic metamaterial with arbitrary shape. We have designed and fabricated the anisotropic metamaterial in the microwave region, and observed the generation of plane waves and their highly directive emission. The proposed plane-wave emission is independent of the shape variance of the anisotropic metamaterial, which can be utilized in the design of conformal antennas.

  17. Lamb Wave Line Sensing for Crack Detection in a Welded Stiffener

    OpenAIRE

    Yun-Kyu An; Jae Hong Kim; Hong Jae Yim

    2014-01-01

    This paper proposes a novel Lamb wave line sensing technique for crack detection in a welded stiffener. The proposed technique overcomes one of the biggest technical challenges of Lamb wave crack detection for real structure applications: crack-induced Lamb waves are often mixed with multiple reflections from complex waveguides. In particular, crack detection in a welded joint, one of the structural hot spots due to stress concentration, is accompanied by reflections from the welded joint as...

  18. Anisotropies of Gravitational Wave Backgrounds: A Line Of Sight Approach

    CERN Document Server

    Contaldi, Carlo R

    2016-01-01

    In the weak field regime, gravitational waves can be considered as being made up of collisionless, relativistic tensor modes that travel along null geodesics of the perturbed background metric. We work in this geometric optics picture to calculate the anisotropies in gravitational wave backgrounds resulting from astrophysical and cosmological sources. Our formalism yields expressions for the angular power spectrum of the anisotropies. We show how the anisotropies are sourced by intrinsic, Doppler, Sachs-Wolfe, and Integrated Sachs-Wolfe terms in analogy with Cosmic Microwave Background photons.

  19. Simulation of "Tsunami Waves" Propagating along Non-Linear Transmission Lines

    Directory of Open Access Journals (Sweden)

    J. Valsa

    2005-09-01

    Full Text Available The paper compares three methods for computer simulation oftransients on transmission lines with losses and nonlinear behavior,namely distributed LC model, FDTD (Finite-Difference Time-Domainmethod, and a new and very effective Method of Slices. The losses areresponsible for attenuation and shape changes of the waves as functionof time and distance from the source. Special behavior of the line dueto voltage-dependent capacitance of the line is considered in detail.The non-linear nature of the line causes that the higher is the voltagethe higher is the velocity of propagation. Then, the waves tend to tiltover so that their top moves faster than their base. As a result"tsunami waves" are created on the line. Fundamental algorithms arepresented in Matlab language. Several typical situations are solved asan illustration of individual methods.

  20. Contact-line dynamics for water waves and high-Re flows

    Science.gov (United States)

    Jiang, Lei; Liu, Ziyuan; Perlin, Marc; Schultz, William W.

    1997-11-01

    An appropriate contact-line model at the gas/liquid/solid trijunction is critical to the prediction of both low-Re flows and high-Re flows such as occur with water waves. Contact-line condition for water waves was proposed by Hocking (1987) and later by Miles (1991) based on Navier's slip relation. However, Cocciaro et al. (1993) and Ting & Perlin (1995) showed that strongly nonlinear contact-line dynamics are present experimentally, and that these dynamics are more complex than Hocking and Miles' models. We present results on the frequency and damping of Faraday water waves in various wave tanks and under different wetting conditions. The surface-elevation decay is analyzed with a complex demodulation technique. Frequency detuning and contact-line damping are found to obey power laws in the wave amplitude. The power-law exponent depends on the wetting condition and the material of which the tank is constructed. A preliminary analysis suggests that an averaged contact-line condition similar to the Tanner's law gives the correct amplitude dependence in frequency and damping. This condition also agrees qualitatively with contact-line data from Ting & Perlin. Preliminary analysis of the boundary layer structure near a moving contact line is carried out in the large-Re limit. Influence of corner flow and some implications from the self-similar Falkner-Skan equation are presented. This research is supported by ONR and NASA Microgravity Fluid Physics Program.

  1. Modern Travelling Wave Based Fault Location Techniques for HVDC Transmission Lines

    Institute of Scientific and Technical Information of China (English)

    CHEN Ping; XU Bingyin; LI Jing; GE Yaozhong

    2008-01-01

    The modern travelling wave based fault location principles for transmission lines are ana-lyzed. In order to apply the travelling wave principles to HVDC transmission lines, the special tech-nical problems are studied. Based on this, a fault locating system for HVDC transmission lines is developed. The system can support modern double ended and single ended travelling wave princi-ples simultaneously, and it is composed of three different parts: travelling wave data acquisition and processing system, communication network and PC based master station. In the system, the fault generated transients are induced from the ground leads of the over-voltage suppression ca-pacitors of an HVDC line through specially developed travelling wave couplers.The system was applied to 500 Kv Gezhouba-Nanqiao(Shanghai)HVDC transmission line in China. Some field op- eration experiences are summarized, showing that the system has very high reliability and accu- racy,and the maximum location error is about 3 km(not more than 0.3% of the total line length). Obviously, the application of the system is successful, and the fault location problem has finally been solved completely since the line operation.

  2. 3D WKB solution for fast magnetoacoustic wave behaviour around an X-line

    CERN Document Server

    McLaughlin, J A; Regnier, S; Spoors, D L

    2016-01-01

    We study the propagation of a fast magnetoacoustic wave in a 3D magnetic field created from two magnetic dipoles. The magnetic topology contains an X-line. We aim to contribute to the overall understanding of MHD wave propagation within inhomogeneous media, specifically around X-lines. We investigate the linearised, 3D MHD equations under the assumptions of ideal and cold plasma. We utilise the WKB approximation and Charpit's method during our investigation. It is found that the behaviour of the fast magnetoacoustic wave is entirely dictated by the local, inhomogeneous, equilibrium Alfv\\'en speed profile. All parts of the wave experience refraction during propagation, where the magnitude of the refraction effect depends on the location of an individual wave element within the inhomogeneous magnetic field. The X-line, along which the Alfv\\'en speed is identically zero, acts as a focus for the refraction effect. There are two main types of wave behaviour: part of the wave is either trapped by the X-line or esca...

  3. Solution dynamics by line shape analysis, resonance light scattering and femtosecond four-wave mixing

    NARCIS (Netherlands)

    Nibbering, Erik T.J.; Duppen, Koos; Wiersma, Douwe A.

    1992-01-01

    The results of line shape analysis, resonance light scattering and femtosecond four-wave mixing measurements are reported on several organic molecules in solution. It is shown that a Brownian oscillator model for line broadening provides a full description for the optical dynamics in aprotic solutio

  4. Detection of Perturbation in Chromatic and Luminance-Defined Lines and Square-Waves

    Directory of Open Access Journals (Sweden)

    R.J Sharman

    2014-08-01

    Full Text Available The composition of a stimulus may affect how cues are combined. A thin luminance ring surrounding a uniform chromatic test facilitates contrast detection as much as a uniform luminance pedestal (Cole, Stromeyer & Kronauer, 1990, JOSA A, 7(1, 128-140. This could suggest that there is a specific facilitatory relationship between luminance lines and chromatic edges that is not present in other combinations. Therefore, combining luminance lines and chromatic edges could also improve performance in edge detection tasks. Here we use a novel task, perturbation detection, target gratings were sinusoidally perturbed in space and subjects were asked to detect which of two stimuli was not straight. Perturbation thresholds, were measured for chromatic and luminance defined line and square-wave gratings alone and in combination. The introduction of a line mask produced increased thresholds in all conditions. However, the introduction of a chromatic square-wave mask improved perception of perturbation in luminance lines, whereas the introduction of a luminance defined square-wave mask has little effect on the perturbation thresholds for chromatic lines. This could suggest that when a luminance line is presented with a chromatic edge, such as the chromatic boundaries in a square-wave grating, the chromatic information becomes ‘tied’ to the luminance information. The perceived location of the chromatic edge may be determined by the location of the luminance line.

  5. Extreme Loads on the Mooring Lines and Survivability Mode for the Wave Dragon Wave Energy Converter

    DEFF Research Database (Denmark)

    Parmeggiani, Stefano; Kofoed, Jens Peter; Friis-Madsen, E.

    2011-01-01

    One of the main challenges Wave Energy Converters have to face on the road towards commercialization is to ensure survivability in extreme condition at a reasonable capital costs. For a floating device like the Wave Dragon, a reliable mooring system is essential. The control strategy of the Wave...... by approximately 20-30% by lowering the crest level and balancing the device to lean a little towards the front....

  6. Fault location method for transmission line based on traveling waves

    Institute of Scientific and Technical Information of China (English)

    ZHENG Na; ZHAO Yulin

    2007-01-01

    The single phase grounding fault location is the focus which researchers pay attention to and study in power system. The accurate fault location can lighten the patrolling burden, and enhance the reliability of the power network. It adopts A/D which has high speed, and uses TMS320VC5402 DSP chip as the system core. This paper presented theory of operation based on traveling waves and achieved software and hardware in detail.

  7. Dynamic Response of Underground Circular Lining Tunnels Subjected to Incident P Waves

    Directory of Open Access Journals (Sweden)

    Hua Xu

    2014-01-01

    Full Text Available Dynamic stress concentration in tunnels and underground structures during earthquakes often leads to serious structural damage. A series solution of wave equation for dynamic response of underground circular lining tunnels subjected to incident plane P waves is presented by Fourier-Bessel series expansion method in this paper. The deformation and stress fields of the whole medium of surrounding rock and tunnel were obtained by solving the equations of seismic wave propagation in an elastic half space. Based on the assumption of a large circular arc, a series of solutions for dynamic stress were deduced by using a wave function expansion approach for a circular lining tunnel in an elastic half space rock medium subjected to incident plane P waves. Then, the dynamic response of the circular lining tunnel was obtained by solving a series of algebraic equations after imposing its boundary conditions for displacement and stress of the circular lining tunnel. The effects of different factors on circular lining rock tunnels, including incident frequency, incident angle, buried depth, rock conditions, and lining stiffness, were derived and several application examples are presented. The results may provide a good reference for studies on the dynamic response and aseismic design of tunnels and underground structures.

  8. Effect of thermal heat stress on energy utilization in two lines of pigs divergently selected for residual feed intake.

    Science.gov (United States)

    Renaudeau, D; Frances, G; Dubois, S; Gilbert, H; Noblet, J

    2013-03-01

    Castrated males from 2 lines of purebred French Large White obtained from a divergent selection experiment for their residual feed intake (RFI) over 7 generations were measured for their energy utilization during thermal acclimation to increased ambient temperature. The RFI(+) line consumed more feed than predicted from its performance, whereas the RFI- line consumed less feed. Each pig was exposed to 24°C for 7 d (P0) and thereafter to a constant temperature of 32°C for 3 consecutive periods of 7 d (P1, P2, P3). Feed intake, feeding behavior parameters, digestibility, components of heat production (HP; measured by indirect calorimetry in respiration chambers), and energy, nitrogen, fat, and water balance were measured in pigs offered feed and water ad libitum and individually housed in respiratory chambers. Two identical respiratory chambers were simultaneously used, and 5 pigs of each line were measured successively. Whatever the trait, the interaction between line and period was not significant (P > 0.10). On average, ADFI was greater in the RFI+ than in the RFI- line (1,945 vs. 1,639 g/d; P = 0.051) in relation to an increase of the mean size of each feeding bout (128 vs. 82 g/visit; P intake and HP declined by about 38% and 20%, respectively, from P0 to P1 (P intake, HP gradually decreased (P < 0.05) from P1 to P3 in connection with a reduction of the activity related HP. The evaporative heat loss represented 30% on the total heat loss on P0, and this proportion significantly increased on P1 (61%; P < 0.001) and remained constant thereafter. In conclusion, our results suggest that thermal heat acclimation in pigs is mainly related to a biphasic reduction of HP rather than a change in the ability of losing heat, and it did not significantly differ between RFI+ and RFI- lines despite a decreased HP in the latter ones.

  9. Genetic parameters and effect of selection for body weight in lines of mink (Neovion vison) on ad libitum and restricted feeding

    DEFF Research Database (Denmark)

    Nielsen, Vivi Hunnicke; Møller, Steen Henrik; Hansen, Bente Krog;

    2012-01-01

    .60 in females in the FF-, AL-, and RF-line). The results indicate that selection on AL feeding increased appetite and thereby improved feed conversion ratio while selection on RF improved feed utilization. Furthermore, the results suggest that selection for August weight produces lean mink while selection...

  10. Pencil-Beam Single-point-fed Dirac Leaky-Wave Antenna on a Transmission-Line Grid

    CERN Document Server

    Dorrah, Ayman H

    2016-01-01

    Leaky-wave antennas (LWAs) are widely used as single-point-fed linear antenna arrays. The extension of LWAs to 2D implies that they can be used as single-point-fed 2D antenna arrays without requiring a complex feeding network. However, generating a pencil beam from 2D LWAs is not straightforward and due care has to be taken for the design of the LWA. On the other hand, transmission-line (TL) grids have demonstrated interesting behaviors, such as an effective negative refractive index and growing of evanescent waves. In this paper, a singlepoint-fed TL-grid 2D Dirac leaky-wave antenna (DLWA) design is proposed that generates a pencil beam at both broadside and slightly tilted angles. The TL-grid unit cell is analytically treated in light of its scattering and impedance matrices. The optimized TL-grid unit cell is shown to exhibit a closed bandgap in the dispersion relation which is also linearly varying with frequency (hence it is a DLWA). The proposed 2D DLWA design is fabricated and the experimental results ...

  11. Particle digital in-line holography with spherical wave recording

    Institute of Scientific and Technical Information of China (English)

    Baozhen Ge(葛宝臻); Qieni Lü(吕且妮); Yimo Zhang(张以谟)

    2003-01-01

    In this paper, we propose a method of digital in-line holography of particle. A diverging spherical beam is used for illumination in recording hologram, the complex amplitude distribution generated by particle field at a single plane located in the Fresnel diffraction region is recorded by CCD, and a plane beam for reconstructing hologram, then, the magnified image can be obtained by numerical reconstruction in computer. This procedure can be interpreted by Fourier optical theory and the theoretical analysis have been done in detail, the experimental results, the air freshener being subject, are also given.

  12. A new surface acoustic wave (SAW) delay line sensor

    Science.gov (United States)

    Jha, Shashank S.; Yadava, R. D. S.

    2013-06-01

    We propose a new configuration for SAW chemical sensing. A polymer coated SAW delay line device provides the coupling for synchronization of two stable self-sustained limit cycle oscillators. The dependence of synchronization frequency on the SAW delay time has been made the basis for chemical sensing. The analysis has carried out under conditions of weak phase coupling [1]. The dependence of synchronization modes on coupling parameters is analyzed. The sensitivity of a synchronization branch for vapor sorption induced delay perturbations is analyzed. This analysis shows the possibility of realizing high performance SAW sensors by this approach.

  13. A Love Wave Reflective Delay Line with Polymer Guiding Layer for Wireless Sensor Application.

    Science.gov (United States)

    Wang, Wen; He, Shitang

    2008-12-05

    This paper presents an optimal design for a Love wave reflective delay line on 41(o) YX LiNbO₃ with a polymer guiding layer for wireless sensor applications. A theoretical model was established to describe the Love wave propagation along the larger piezoelectric substrate with polymer waveguide, and the lossy mechanism from the viscoelastic waveguide was discussed, which results in the optimal guiding layer thickness. Coupling of modes (COM) was used to determine the optimal design parameters of the reflective delay line structured by single phase unidirectional transducers (SPUDTs) and shorted grating reflectors. Using the network analyzer, the fabricated Love wave reflective delay line was characterized, high signal noise ratio (S/N), sharp reflection peaks, and few spurious noise between the peaks were found, and the measured result agrees well with the simulated one. Also, the optimal guiding layer thickness of 1.5~1.8μm was extracted experimentally, and it is consistent with the theoretical analysis.

  14. Continuous manufacturing of tablets with PROMIS-line - Introduction and case studies from continuous feeding, blending and tableting.

    Science.gov (United States)

    Simonaho, Simo-Pekka; Ketolainen, Jarkko; Ervasti, Tuomas; Toiviainen, Maunu; Korhonen, Ossi

    2016-07-30

    Drug manufacturing technology is in the midst of modernization and continuous manufacturing of drug products is especially the focus of great interest. The adoption of new manufacturing approaches requires extensive cooperation between industry, regulatory bodies, academics and equipment manufacturers. In this paper we introduce PROMIS-line which is a continuous tableting line built at the University of Eastern Finland, School of Pharmacy, PROMIS-centre. PROMIS-line is modular and tablets can be produced via dry granulation or direct compression. In three case studies, continuous feeding, blending and tablet performance is studied to illustrate some basic features of PROMIS-line. In conclusion, the PROMIS-line is an excellent tool for studying the fundamentals of continuous manufacturing of tablets.

  15. A Love Wave Reflective Delay Line with Polymer Guiding Layer for Wireless Sensor Application

    OpenAIRE

    Shitang He; Wen Wang

    2008-01-01

    This paper presents an optimal design for a Love wave reflective delay line on 41o YX LiNbO3 with a polymer guiding layer for wireless sensor applications. A theoretical model was established to describe the Love wave propagation along the larger piezoelectric substrate with polymer waveguide, and the lossy mechanism from the viscoelastic waveguide was discussed, which results in the optimal guiding layer thickness. Coupling of modes (COM) was used to determine the optimal design parameters o...

  16. An open-styled dielectric-lined azimuthally periodic circular waveguide for a millimeter wave traveling-wave tube

    Institute of Scientific and Technical Information of China (English)

    Liu Yang; Wei Yan-Yu; Xu Jin; Yin Hai-Rong; Yue Ling-Na; Gong Yu-Bin; Wang Wen-Xiang

    2012-01-01

    An open-styled dielectric-lined azimuthally periodic circular waveguide (ODLAP-CW) for a millimeter-wave traveling-wave tube (TWT) is proposed,which is a modified form of a dielectric-lined azimuthally periodic circular waveguide (DLAP-CW).The slow-wave characteristics of the open-styled DLAP-CW are studied by using the spatial harmonics method,which includes normalized phase velocity and interaction impedance.The complicated dispersion equations are numerically solved with MATLAB and the results are in good agreement with the simulation results obtained from HFSS.The influence of structural parameters on the RF properties is investigated based on our theory.The numerical results show that the optimal thickness of the metal rod can increase the interaction impedance,with the dielectric constant held fixed.Finally,the slow-wave characteristics and transmission properties of an open-styled structure are compared with those of the DLAP-CW.The results validate that the mode competition is eliminated in the improved structure with only a slight influence on the dispersion characteristics,which may significantly improve the stability of an open-styled DLAP-CW-based TWT,and the interaction efficiency is also improved.

  17. Non-linear wave propagation in acoustically lined circular ducts

    Science.gov (United States)

    Nayfeh, A. H.; Tsai, M.-S.

    1974-01-01

    An analysis is presented of the nonlinear effects of the gas motion as well as of the acoustic lining material on the transmission and attenuation of sound in a circular duct with a uniform cross-section and no mean flow. The acoustic material is characterized by an empirical, nonlinear impedance in which the instantaneous resistance is a nonlinear function of both the frequency and the acoustic velocity. The results show that there exist frequency bandwidths around the resonant frequencies in which the nonlinearity decreases the attenuation rate, and outside which the nonlinearity increases the attenuation rate, in qualitative agreement with experimental observations. Moreover, the effect of the gas nonlinearity increases with increasing sound frequency, whereas the effect of the material nonlinearity decreases with increasing sound frequency.

  18. Mm-Wave Spectroscopic Sensors, Catalogs, and Uncatalogued Lines

    Science.gov (United States)

    Medvedev, Ivan; Neese, Christopher F.; De Lucia, Frank C.

    2014-06-01

    Analytical chemical sensing based on high resolution rotational molecular spectra has been recognized as a viable technique for decades. We recently demonstrated a compact implementation of such a sensor. Future generations of these sensors will rely on automated algorithms for quantification of chemical dilutions based on their spectral libraries, as well as identification of spectral features not present in spectral catalogs. Here we present an algorithm aimed at detection of unidentified lines in complex molecular species based on spectroscopic libraries developed in our previous projects. We will discuss the approaches suitable for data mining in feature-rich rotational molecular spectra. Neese, C.F., I.R. Medvedev, G.M. Plummer, A.J. Frank, C.D. Ball, and F.C. De Lucia, "A Compact Submillimeter/Terahertz Gas Sensor with Efficient Gas Collection, Preconcentration, and ppt Sensitivity." Sensors Journal, IEEE, 2012. 12(8): p. 2565-2574

  19. Wagging the contact line: transverse and longitudinal waves.

    Science.gov (United States)

    Saritha, S; Neogi, P

    2006-02-14

    Kinetics of wetting has been explored where the contact line not only sees a steady spreading but also has longitudinal or transverse oscillations imposed on it. The latter case is realized when spreading takes place over a rough surface. The effects of the imposed motion are small, which seem to be due to low spreading rates and small dynamic contact angles used in this study. However, a singularity is seen in viscous dissipation during the movement on the model rough surface, which is interpreted here as an instability that is similar to Haines' jumps and stick-slip phenomena, with possible entrainment of the displaced fluid. This is the first time that all of these have been associated with each other.

  20. Survivability Mode and Extreme Loads on the Mooring Lines of the Wave Dragon Wave Energy Converter

    DEFF Research Database (Denmark)

    Parmeggiani, Stefano; Kofoed, Jens Peter

    of the survivability of the device in extreme waves and evaluation of the design loads for the mooring component. The testing has been carried out in October 2010 by PhD student Stefano Parmeggiani and Master students Giovanna Bevilacqua and Giacomo Girardi Ferruzza at the Hydraulic and Coastal Laboratories...... of the department of Civil Engineering at Aalborg University. The outcome of the research will be used as input for future research work aimed at the design of the mooring system and the certification of the structural design for the full scale Wave Dragon demonstrator....

  1. Dealing with Instrumental Lines in Searches for Continuous Gravitational Waves in LIGO Data

    Science.gov (United States)

    Sauter, Orion; LIGO-Virgo Collaboration

    2017-01-01

    Although the first observing run of Advanced LIGO (O1) gave us two definitive detections of gravitational waves from binary black hole mergers, searches for a continuous-wave (CW) source are computationally very demanding and still ongoing. CW sources are expected to be much weaker, requiring integration of the signal for several months. PowerFlux is one analysis pipeline designed for such searches; in following up outliers, the program uses a loosely coherent algorithm to improve the signal-to-noise ratio and to separate astrophysical signals from instrumental artifacts. Unfortunately, the O1 data has many sharp spectral artifacts (lines) that create spurious outliers in the low-frequency region, 20-135 Hz. The effects of these lines on the PowerFlux analysis will be discussed, along with methods used to mitigate those effects, including a line-cleaning process. Prospects for contending with instrumental line effects in the second observing run (O2) will also be presented.

  2. Near-isogenic lines of Triticum aestivum with distinct modes of resistance exhibit dissimilar transcriptional regulation during Diuraphis noxia feeding

    Directory of Open Access Journals (Sweden)

    Anna-Maria Botha

    2014-10-01

    Full Text Available Russian wheat aphid (Diuraphis noxia, Kurdjumov feeding on susceptible Triticum aestivum L. leads to leaf rolling, chlorosis and plant death – symptoms not present in resistant lines. Although the effects of several D. noxia (Dn resistance genes are known, none have been isolated or characterized. Wheat varieties expressing different Dn genes exhibit distinct modes of D. noxia resistance, such as antibiosis (Dn1, tolerance (Dn2, and antixenosis (Dn5. However, the mechanism whereby feeding aphids are perceived, and how subsequent transcriptional responses are partitioned into resistance categories, remains unclear. Here we report on downstream events in near-isogenic wheat lines containing different Dn genes after D. noxia biotype SA1 feeding. Transcripts involved in stress, signal transduction, photosynthesis, metabolism and gene regulation were differentially regulated during D. noxia feeding. Expression analyses using RT-qPCR and RNA hybridization, as well as enzyme activity profiling, provide evidence that the timing and intensity of pathways induced are critical in the development of particular modes of resistance. Pathways involved include the generation of kinase signalling cascades that lead to a sustained oxidative burst, and a hypersensitive response that is active during antibiosis. Tolerance is a passive resistance mechanism that acts through repair or de novo synthesis of photosystem proteins. Results further suggest that ethylene-mediated pathways are possibly involved in generating volatile compounds and cell wall fortification during the antixenosic response.

  3. Abbott Wave-Triggered Runaway in Line-Driven Winds from Stars and Accretion Disks

    OpenAIRE

    2001-01-01

    Line-driven winds from stars and accretion disks are accelerated by scattering in numerous line transitions. The wind is believed to adopt a unique critical solution, out of the infinite variety of shallow and steep solutions. We study the inherent dynamics of the transition towards the critical wind. A new runaway wind mechanism is analyzed in terms of radiative-acoustic (Abbott) waves which are responsible for shaping the wind velocity law and fixing the mass loss. Three different flow type...

  4. Impact of hygiene of housing conditions on performance and health of two pig genetic lines divergent for residual feed intake.

    Science.gov (United States)

    Chatelet, A; Gondret, F; Merlot, E; Gilbert, H; Friggens, N C; Le Floc'h, N

    2017-06-27

    Pigs selected for high performance may be more at risk of developing diseases. This study aimed to assess the health and performance of two pig lines divergently selected for residual feed intake (RFI) (low RFI (LRFI) v. high RFI (HRFI)) and housed in two contrasted hygiene conditions (poor v. good) using a 2×2 factorial design (n=40/group). The challenge period (Period 1), started on week zero (W0) when 12-week-old pigs were transferred to good or poor housing conditions. At week 6 (W6), half of the pigs in each group were slaughtered. During a recovery period (Period 2) from W6 to W13 to W14, the remaining pigs (n=20/group) were transferred in good hygiene conditions before being slaughtered. Blood was collected every three (Period 1) or 2 weeks (Period 2) to assess blood indicators of immune and inflammatory responses. Pulmonary lesions at slaughter and performance traits were evaluated. At W6, pneumonia prevalence was greater for pigs housed in poor than in good conditions (51% v. 8%, respectively, Pfeed ratio were less affected by poor hygiene in LRFI pigs than in HRFI pigs (hygiene×line, P=0.001 and P=0.02, respectively). Low residual feed intake pigs in poor conditions ate more than the other groups (hygiene×line, P=0.002). Irrespective of the line, fasting plasma glucose concentrations were higher in poor conditions, whereas fasting free fatty acids concentrations were lower than in good conditions. At the end of Period 2, pneumonia prevalence was similar for both housing conditions (39% v. 38%, respectively). During Period 2, plasma protein concentrations were greater for pigs previously housed in poor than in good conditions during Period 1. Immune traits, gain-to-feed ratio, BW gain and feed consumption did not differ during Period 2. Nevertheless, at W12, BW of HRFI previously housed in poor conditions was 13.4 kg lower than BW of HRFI pigs (Pfeed efficient LRFI pigs was less impaired by poor hygiene conditions. This line was able to preserve its

  5. Novel Micromachined Coplanar Waveguide Transmission Lines for Application in Millimeter-Wave Circuits

    Science.gov (United States)

    Park, Jae-Hyoung; Baek, Chang-Wook; Jung, Sanghwa; Kim, Hong-Teuk; Kwon, Youngwoo; Kim, Yong-Kweon

    2000-12-01

    In this paper, novel micromachined coplanar waveguide(CPW) transmission lines for application in millimeter-wave circuits are proposed. Two types of transmission lines with the length of 1 cm are fabricated and the measured characteristics are compared with those of the conventional CPW transmission line. One is the elevated CPW(ECPW) transmission line and the other is the overlay CPW(OCPW) line. These transmission lines are composed of 3-μm-thick electroplated gold lines with overhanging parts. By elevating the metal lines from the substrate using micromachining technology, the conductor and substrate dielectric loss can be reduced and easily integrated with conventional monolithic microwave integrated circuits. Compared with the conventional CPW line showing 2.65 dB/cm insertion loss at 50 GHz, the loss can be reduced to 1.9 dB/cm and 1.25 dB/cm at 50 GHz in the case of the ECPW and OCPW transmission lines, respectively. Also, the OCPW transmission line shows that the insertion loss does not vary with the change of the characteristic impedance. As shown in the measured and simulated results, the insertion loss is maintained below 1.4 dB/cm over wide impedance ranges.

  6. Contested Waterlines: The Wave-Line Theory and Shipbuilding in the Nineteenth Century.

    Science.gov (United States)

    Ferreiro, Larrie D; Pollara, Alexander

    2016-04-01

    Ship hydrodynamics in the nineteenth century was dominated by John Scott Russell's wave-line theory. Russell, a prominent British shipbuilder and scientist, argued that wavemaking was the primary source of resistance for ships, and that by designing ships according to trigonometric curves and proportions (the wave line) this resistance could effectively be eliminated. From the 1840s to the 1880s, shipbuilders such as John Willis Griffiths, Donald McKay and George Steers designed their clipper ships (like Sea Witch and Flying Cloud) and yachts (America) with wave-line hulls, while authors like Jules Verne referenced Russell's theory. The wave line slowly faded after William Froude developed his laws of ship resistance. The article examines how Russell's theory became accepted by technical experts and the wider public to become the most widely known ship hydrodynamic theory of the 1800s-a reminder of how a persuasive idea can take hold of an entire profession, and even the public, for a long time.

  7. Effect of nonlinear wave collapse on line shapes in a plasma

    Science.gov (United States)

    Hannachi, I.; Stamm, R.; Rosato, J.; Marandet, Y.

    2016-04-01

    The nonlinear interaction of waves can change the structural and radiative properties of plasmas. We describe the main features of a fully ionized unmagnetized plasma affected by strong Langmuir turbulence characterized by nonlinear wave collapse, and propose a simple model for evaluating the changes expected on a hydrogen line shape affected by such conditions. Our model is based on a stochastic renewal model using an exponential waiting time distribution and a half-normal probability density function for the electric-field magnitude of the turbulent wave packet. The first results obtained with a simulation calculation of the hydrogen \\text{L}α line show that strong Langmuir turbulence can provide an additional broadening to a Stark profile.

  8. Investigation of Motion of Two Hinged Bodies Moored by Mooring Lines in Waves

    Institute of Scientific and Technical Information of China (English)

    纪亨腾; 范菊; 黄祥鹿

    2002-01-01

    In this paper, the motions are studied of a multi-body which is composed of two plates hinged together and mooredby eight mooring lines in regular waves. The experimental results are compared with computational results. The linear po-tential theory and the perturbation method are combined to study this complicated system. The former is used to calculatethe wave forces acting on the plates and the motion responses of them, while the latter is used to describe the dynamiccharacter of the eight mooring lines coupled with the two hinged plates. Some response results of each plate are presentedand comparisons between calculated results and experimental data are given. All the calculations are confined to regularbeam waves.

  9. Anterior-to-posterior wave of buccal expansion in suction feeding fishes is critical for optimizing fluid flow velocity profile.

    Science.gov (United States)

    Bishop, Kristin L; Wainwright, Peter C; Holzman, Roi

    2008-11-01

    In fishes that employ suction feeding, coordinating the timing of peak flow velocity with mouth opening is likely to be an important feature of prey capture success because this will allow the highest forces to be exerted on prey items when the jaws are fully extended and the flow field is at its largest. Although it has long been known that kinematics of buccal expansion in feeding fishes are characterized by an anterior-to-posterior wave of expansion, this pattern has not been incorporated in most previous computational models of suction feeding. As a consequence, these models have failed to correctly predict the timing of peak flow velocity, which according to the currently available empirical data should occur around the time of peak gape. In this study, we use a simple fluid dynamic model to demonstrate that the inclusion of an anterior-to-posterior wave of buccal expansion can correctly reproduce the empirically determined flow velocity profile, although only under very constrained conditions, whereas models that do not allow this wave of expansion inevitably predict peak velocity earlier in the strike, when the gape is less than half of its maximum. The conditions that are required to produce a realistic velocity profile are as follows: (i) a relatively long time lag between mouth opening and expansion of the more posterior parts of the mouth, (ii) a short anterior portion of the mouth relative to more posterior sections, and (iii) a pattern of movement that begins slowly and then rapidly accelerates. Greater maximum velocities were generated in simulations without the anterior-to-posterior wave of expansion, suggesting a trade-off between maximizing fluid speed and coordination of peak fluid speed with peak gape.

  10. An ultrasonic guided wave approach for the inspection of overhead transmission line cables

    DEFF Research Database (Denmark)

    Kappatos, Vasileios; Yücel, Mehmet K.; Legg, Mathew

    2017-01-01

    Inspection of overhead transmission line cables is performed using various non-destructive testing techniques, such as visual, temperature, and eddy current-based inspection; yet each of these techniques have their respective shortcomings and safety concerns. The use of ultrasonic guided waves...... as a non-destructive testing technique is well established for simple geometries such as plates, pipes, and rods. However, its application for multi-wire cables is still in development. In this study, ultrasonic guided waves excited by a shear mode transducer collar are utilised as a defect detection...... technique for untensioned aluminium conductor steel reinforced cable specimens. The identification and analysis of wave propagation for a broad range of frequencies is performed using a laser scanning vibrometer, and the effect of defect size on wave propagation is studied. Signal processing algorithms...

  11. BayesLine: Bayesian Inference for Spectral Estimation of Gravitational Wave Detector Noise

    CERN Document Server

    Littenberg, Tyson B

    2014-01-01

    Gravitational wave data from ground-based detectors is dominated by instrument noise. Signals will be comparatively weak, and our understanding of the noise will influence detection confidence and signal characterization. Mis-modeled noise can produce large systematic biases in both model selection and parameter estimation. Here we introduce a multi-component, variable dimension, parameterized model to describe the Gaussian-noise power spectrum for data from ground-based gravitational wave interferometers. Called BayesLine, the algorithm models the noise power spectral density using cubic splines for smoothly varying broad-band noise and Lorentzians for narrow-band line features in the spectrum. We describe the algorithm and demonstrate its performance on data from the fifth and sixth LIGO science runs. Once fully integrated into LIGO/Virgo data analysis software, BayesLine will produce accurate spectral estimation and provide a means for marginalizing inferences drawn from the data over all plausible noise s...

  12. Enhanced ion acoustic lines due to strong ion cyclotron wave fields

    Directory of Open Access Journals (Sweden)

    H. Bahcivan

    2008-07-01

    Full Text Available The Fast Auroral Snapshot Explorer (FAST satellite detected intense and coherent 5–20 m electric field structures in the high-latitude topside auroral ionosphere between the altitudes of 350 km and 650 km. These electric fields appear to belong to electrostatic ion cyclotron (EIC waves in terms of their frequency and wavelengths. Numerical simulations of the response of an electron plasma to the parallel components of these fields show that the waves are likely to excite a wave-driven parallel ion acoustic (IA instability, through the creation of a highly non-Maxwellian electron distribution function, which when combined with the (assumed Maxwellian ion distribution function provides inverse Landau damping. Because the counter-streaming threshold for excitation of EIC waves is well below that for excitation of IA waves (assuming Maxwellian statistics our results suggest a possible two step mechanism for destabilization of IA waves. Combining this simulation result with the observational fact that these EIC waves share a common phenomenology with the naturally enhanced IA lines (NEIALS observed by incoherent scatter radars, especially that they both occur near field-aligned currents, leads to the proposition that this two-step mechanism is an alternative path to NEIALS.

  13. Controlling the feed rate of propanol to optimize erythromycin fermentation by on-line capacitance and oxygen uptake rate measurement.

    Science.gov (United States)

    Guo, Qian; Chu, Ju; Zhuang, Yingping; Gao, Yang

    2016-02-01

    The aim of the present study was to optimize the feeding proportion of glucose and propanol for erythromycin biosynthesis by real-time monitoring and exploring its limited ratio by the on-line multi-frequency permittivity measurement. It was found that the capacitance values were sensitive to the variation of biomass concentration and microbial morphology as well as the true state of cell growth. It was most favorable to both cell growth and secondary metabolism to keep the ratio of glucose to propanol at 4.3 (g/g). The specific growth rate calculated by the capacitance measurement correctly and accurately reflected the cell physiological state. An appropriate feed rate of propanol was crucial for cell growth and secondary metabolism, as well as to improve the quality of erythromycin-A. In addition, the erythromycin production titer (10,950 U/mL) was further enhanced by 4 % when the propanol feed was regulated by step-down strategy based on both OUR (oxygen uptake rate) and the on-line monitoring capacitance.

  14. Lamb Wave Line Sensing for Crack Detection in a Welded Stiffener

    Science.gov (United States)

    An, Yun-Kyu; Kim, Jae Hong; Yim, Hong Jae

    2014-01-01

    This paper proposes a novel Lamb wave line sensing technique for crack detection in a welded stiffener. The proposed technique overcomes one of the biggest technical challenges of Lamb wave crack detection for real structure applications: crack-induced Lamb waves are often mixed with multiple reflections from complex waveguides. In particular, crack detection in a welded joint, one of the structural hot spots due to stress concentration, is accompanied by reflections from the welded joint as well as a crack. Extracting and highlighting crack-induced Lamb wave modes from Lamb wave responses measured at multi-spatial points along a single line can be accomplished through a frequency-wavenumber domain analysis. The advantages of the proposed technique enable us not only to enhance the crack detectability in the welded joint but also to minimize false alarms caused by environmental and operational variations by avoiding the direct comparison with the baseline data previously accumulated from the pristine condition of a target structure. The proposed technique is experimentally and numerically validated in vertically stiffened metallic structures, revealing that it successfully identifies and localizes subsurface cracks, regardless of the coexistence with the vertical stiffener. PMID:25046014

  15. Lamb Wave Line Sensing for Crack Detection in a Welded Stiffener

    Directory of Open Access Journals (Sweden)

    Yun-Kyu An

    2014-07-01

    Full Text Available This paper proposes a novel Lamb wave line sensing technique for crack detection in a welded stiffener. The proposed technique overcomes one of the biggest technical challenges of Lamb wave crack detection for real structure applications: crack-induced Lamb waves are often mixed with multiple reflections from complex waveguides. In particular, crack detection in a welded joint, one of the structural hot spots due to stress concentration, is accompanied by reflections from the welded joint as well as a crack. Extracting and highlighting crack-induced Lamb wave modes from Lamb wave responses measured at multi-spatial points along a single line can be accomplished through a frequency-wavenumber domain analysis. The advantages of the proposed technique enable us not only to enhance the crack detectability in the welded joint but also to minimize false alarms caused by environmental and operational variations by avoiding the direct comparison with the baseline data previously accumulated from the pristine condition of a target structure. The proposed technique is experimentally and numerically validated in vertically stiffened metallic structures, revealing that it successfully identifies and localizes subsurface cracks, regardless of the coexistence with the vertical stiffener.

  16. Lamb wave line sensing for crack detection in a welded stiffener.

    Science.gov (United States)

    An, Yun-Kyu; Kim, Jae Hong; Yim, Hong Jae

    2014-07-18

    This paper proposes a novel Lamb wave line sensing technique for crack detection in a welded stiffener. The proposed technique overcomes one of the biggest technical challenges of Lamb wave crack detection for real structure applications: crack-induced Lamb waves are often mixed with multiple reflections from complex waveguides. In particular, crack detection in a welded joint, one of the structural hot spots due to stress concentration, is accompanied by reflections from the welded joint as well as a crack. Extracting and highlighting crack-induced Lamb wave modes from Lamb wave responses measured at multi-spatial points along a single line can be accomplished through a frequency-wavenumber domain analysis. The advantages of the proposed technique enable us not only to enhance the crack detectability in the welded joint but also to minimize false alarms caused by environmental and operational variations by avoiding the direct comparison with the baseline data previously accumulated from the pristine condition of a target structure. The proposed technique is experimentally and numerically validated in vertically stiffened metallic structures, revealing that it successfully identifies and localizes subsurface cracks, regardless of the coexistence with the vertical stiffener.

  17. Pulse-driven nonlinear Alfv\\'en waves and their role in the spectral line broadening

    CERN Document Server

    Chmielewski, P; Murawski, K; Musielak, Z E

    2012-01-01

    We study the impulsively generated non-linear Alfv\\'en waves in the solar atmosphere, and describe their most likely role in the observed non-thermal broadening of some spectral lines in solar coronal holes. We solve numerically the time-dependent magnetohydrodynamic equations to find temporal signatures of large-amplitude Alfv\\'en waves in the model atmosphere of open and expanding magnetic field configuration, with a realistic temperature distribution. We calculate the temporally and spatially averaged, instantaneous transversal velocity of non-linear Alfv\\'en waves at different heights of the model atmosphere, and estimate its contribution to the unresolved non-thermal motions caused by the waves. We find that the pulse-driven nonlinear Alfv\\'en waves with the amplitude $A_{\\rm v}$=50 km s$^{-1}$ are the most likely candidates for the non-thermal broadening of Si VIII $\\lambda$1445.75 \\AA\\ line profiles in the polar coronal hole as reported by Banerjee et al. (1998). We also demonstrate that the Alfv\\'en w...

  18. Millimeter-wave Line Ratios and Sub-beam Volume Density Distributions

    Science.gov (United States)

    Leroy, Adam K.; Usero, Antonio; Schruba, Andreas; Bigiel, Frank; Kruijssen, J. M. Diederik; Kepley, Amanda; Blanc, Guillermo A.; Bolatto, Alberto D.; Cormier, Diane; Gallagher, Molly; Hughes, Annie; Jiménez-Donaire, Maria J.; Rosolowsky, Erik; Schinnerer, Eva

    2017-02-01

    We explore the use of mm-wave emission line ratios to trace molecular gas density when observations integrate over a wide range of volume densities within a single telescope beam. For observations targeting external galaxies, this case is unavoidable. Using a framework similar to that of Krumholz & Thompson, we model emission for a set of common extragalactic lines from lognormal and power law density distributions. We consider the median density of gas that produces emission and the ability to predict density variations from observed line ratios. We emphasize line ratio variations because these do not require us to know the absolute abundance of our tracers. Patterns of line ratio variations have the potential to illuminate the high-end shape of the density distribution, and to capture changes in the dense gas fraction and median volume density. Our results with and without a high-density power law tail differ appreciably; we highlight better knowledge of the probability density function (PDF) shape as an important area. We also show the implications of sub-beam density distributions for isotopologue studies targeting dense gas tracers. Differential excitation often implies a significant correction to the naive case. We provide tabulated versions of many of our results, which can be used to interpret changes in mm-wave line ratios in terms of adjustments to the underlying density distributions.

  19. Experimental imaging research on continuous-wave terahertz in-line digital holography

    Science.gov (United States)

    Huang, Haochong; Wang, Dayong; Rong, Lu; Wang, Yunxin

    2014-09-01

    The terahertz (THz) imaging is an advanced technique on the basis of the unique characteristics of terahertz radiation. Due to its noncontact, non-invasive and high-resolution capabilities, it has already shown great application prospects in biomedical observation, sample measurement, and quality control. The continuous-wave terahertz in-line digital holography is a combination of terahertz technology and in-line digital holography of which the source is a continuous-wave terahertz laser. Over the past decade, many researchers used different terahertz sources and detectors to undertake experiments. In this paper, the pre-process of the hologram is accomplished after the holograms' recording process because of the negative pixels in the pyroelectric detector and the air vibration caused by the chopper inside the camera. To improve the quality of images, the phase retrieval algorithm is applied to eliminate the twin images. In the experiment, the pin which terahertz wave can't penetrate and the TPX slice carved letters "THz" are chosen for the samples. The amplitude and phase images of samples are obtained and the twin image and noise in the reconstructed images are suppressed. The results validate the feasibility of the terahertz in-line digital holographic imaging technique. This work also shows the terahertz in-line digital holography technique's prospects in materials science and biological samples' detection.

  20. Plate acoustic waves for low frequency delay line delaying signals up to 0.5 ms

    Science.gov (United States)

    Zaitsev, B. D.; Kuznetsova, I. E.; Zemnyukov, N. E.; Proidakov, V. I.; Teplykh, A. A.

    2010-01-01

    At present time there exists the problem of development of main memory elements based on the delay of electromagnetic signal with frequency of ˜100 kHz on hundreds microseconds. This paper is devoted to theoretical and experimental investigation of the possibility of development of corresponding acoustic delay lines. It was supposed to use the antisymmetric acoustic waves of zero order propagating in thin (compared to wavelength) metal plates. In this connection, we theoretically studied the parameters of A0 waves propagating in plates of various metals such as brass, bronze, copper, steel, and aluminum. For analysis of wave propagation in aforementioned plates, we used the standard motion equation and constitutive material equation for investigated medium as well as corresponding mechanical boundary conditions. As a result, the phase and group velocities versus parameter hf (h= plate thickness, f= wave frequency) were calculated for A0 wave propagating in mentioned above plates. It has been found that for steel plate the delay time about 0.5 ms can be achieved at the lengths of waveguide L=0.373, 0.737, and 0.971 m for h=0.175, 0.5, and 1.0 mm, respectively at f=120 kHz. The theoretical results were verified by experiment, which showed the possibility of development of corresponding delay lines with delay time ˜500 mks and acceptable insertion loss. In experiments, the excitation and reception of A0 waves were performed by the standard piezoelectric transducers of longitudinal waves and prismatic steel concentrators. The details of theoretical analysis and experiment are described.

  1. Effects of feeding diets varying in energy and nutrient density to Hy-Line W-36 laying hens on production performance and economics.

    Science.gov (United States)

    dePersio, S; Utterback, P L; Utterback, C W; Rochell, S J; O'Sullivan, N; Bregendahl, K; Arango, J; Parsons, C M; Koelkebeck, K W

    2015-02-01

    The objectives of this study were to evaluate the effects of feeding 5 different energy and nutrient dense diets to Hy-Line W-36 hens on long-term performance and economics. A total of 480 19 wk old Hy-Line W-36 Single Comb White Leghorn hens were weighed and randomly allocated to 6 replicate groups of 16 hens each (2 adjacent cages containing 8 hens per cage, 60.9×58.4 cm) per dietary treatment in a randomized complete block design. The hens were fed 5 treatment diets formulated to contain 85, 90, 95, 100, and 105% of the energy and nutrient recommendations stated in the 2009 Hy-Line Variety W-36 Commercial Management Guide. Production performance was measured for 52 wk from 19 to 70 wk age. Over the course of the trial, a significant increasing linear response to increasing energy and nutrient density was seen for hen-day egg production, egg weight, egg mass, feed efficiency, energy intake, and body weight (BW). Feed intake showed no significant linear level response to increasing energy and nutrient density except during the early production cycle. No consistent responses were noted for egg quality, percent yolk, and percent egg solids throughout the study. Significant linear responses due to energy and nutrient density were seen for egg income, feed cost, and income minus feed cost. In general, as energy and nutrient density increased, egg income and feed cost per hen increased, but income minus feed cost decreased. Overall, these results indicate that feeding Hy-Line W-36 hens increasing energy and nutrient-dense diets will increase egg production, egg weight, egg mass, feed efficiency, energy intake, BW, egg income, and feed cost, but decrease egg income minus feed cost. However, these benefits do not take effect in early production and seem to be most effective in later stages of the production cycle, perhaps "priming" the birds for better egg-production persistency with age.

  2. Study of transmission line attenuation in broad band millimeter wave frequency range

    Energy Technology Data Exchange (ETDEWEB)

    Pandya, Hitesh Kumar B. [ITER-India, IPR, Gandhinagar, Gujarat (India); Austin, M. E. [Institute for Fusion Studies, the University of Texas at Austin, Austin, Texas (United States); Ellis, R. F. [Laboratory for Plasma and Fusion Energy Studies, University of Maryland, College Park, Maryland 20742 (United States)

    2013-10-15

    Broad band millimeter wave transmission lines are used in fusion plasma diagnostics such as electron cyclotron emission (ECE), electron cyclotron absorption, reflectometry and interferometry systems. In particular, the ECE diagnostic for ITER will require efficient transmission over an ultra wide band, 100 to 1000 GHz. A circular corrugated waveguide transmission line is a prospective candidate to transmit such wide band with low attenuation. To evaluate this system, experiments of transmission line attenuation were performed and compared with theoretical loss calculations. A millimeter wave Michelson interferometer and a liquid nitrogen black body source are used to perform all the experiments. Atmospheric water vapor lines and continuum absorption within this band are reported. Ohmic attenuation in corrugated waveguide is very low; however, there is Bragg scattering and higher order mode conversion that can cause significant attenuation in this transmission line. The attenuation due to miter bends, gaps, joints, and curvature are estimated. The measured attenuation of 15 m length with seven miter bends and eighteen joints is 1 dB at low frequency (300 GHz) and 10 dB at high frequency (900 GHz), respectively.

  3. Testing the Kerr black hole hypothesis: Comparison between the gravitational wave and the iron line approaches

    Directory of Open Access Journals (Sweden)

    Alejandro Cárdenas-Avendaño

    2016-09-01

    Full Text Available The recent announcement of the detection of gravitational waves by the LIGO/Virgo Collaboration has opened a new window to test the nature of astrophysical black holes. Konoplya & Zhidenko have shown how the LIGO data of GW 150914 can constrain possible deviations from the Kerr metric. In this letter, we compare their constraints with those that can be obtained from accreting black holes by fitting their X-ray reflection spectrum, the so-called iron line method. We simulate observations with eXTP, a next generation X-ray mission, finding constraints much stronger than those obtained by Konoplya & Zhidenko. Our results can at least show that, contrary to what is quite commonly believed, it is not obvious that gravitational waves are the most powerful approach to test strong gravity. In the presence of high quality data and with the systematics under control, the iron line method may provide competitive constraints.

  4. Testing the Kerr black hole hypothesis: comparison between the gravitational wave and the iron line approaches

    CERN Document Server

    Cardenas-Avendano, Alejandro; Bambi, Cosimo

    2016-01-01

    The recent announcement of the detection of gravitational waves by the LIGO/Virgo collaboration has opened a new window to test the nature of astrophysical black holes. Konoplya & Zhidenko have shown how the LIGO data of GW 150914 can constrain possible deviations from the Kerr metric. In this letter, we compare their constraints with those that can be obtained from accreting black holes by fitting their reflected X-ray spectrum, the so-called iron line method. We simulate observations with eXTP, a next generation X-ray mission, finding constraints much stronger than those obtained by Konoplya & Zhidenko. Our results can at least show that, contrary to what is quite commonly believed, it is not obvious that gravitational waves are the most powerful approach to test strong gravity. In the presence of high quality data and with the systematics under control, the iron line method may provide competitive constraints.

  5. A Love Wave Reflective Delay Line with Polymer Guiding Layer for Wireless Sensor Application

    Directory of Open Access Journals (Sweden)

    Shitang He

    2008-12-01

    Full Text Available This paper presents an optimal design for a Love wave reflective delay line on 41o YX LiNbO3 with a polymer guiding layer for wireless sensor applications. A theoretical model was established to describe the Love wave propagation along the larger piezoelectric substrate with polymer waveguide, and the lossy mechanism from the viscoelastic waveguide was discussed, which results in the optimal guiding layer thickness. Coupling of modes (COM was used to determine the optimal design parameters of the reflective delay line structured by single phase unidirectional transducers (SPUDTs and shorted grating reflectors. Using the network analyzer, the fabricated Love wave reflective delay line was characterized, high signal noise ratio (S/N, sharp reflection peaks, and few spurious noise between the peaks were found, and the measured result agrees well with the simulated one. Also, the optimal guiding layer thickness of 1.5~1.8μm was extracted experimentally, and it is consistent with the theoretical analysis.

  6. Corporate-Feed Multilayer Bow-Tie Antenna Array Design Using a Simple Transmission Line Model

    Directory of Open Access Journals (Sweden)

    S. Didouh

    2012-01-01

    Full Text Available A transmission line model is used to design corporate-fed multilayered bow-tie antennas arrays; the simulated antennas arrays are designed to resonate at the frequencies 2.4 GHz, 5 GHz, and 8 GHz corresponding to RFID, WIFI, and radars applications. The contribution of this paper consists of modeling multilayer bow-tie antenna array fed through an aperture using transmission line model. The transmission line model is simple and precise and allows taking into account the whole geometrical, electrical, and technological characteristics of the antennas arrays. The proposed transmission line model showed its interest in the design of different multilayered bow-tie antennas and predicted the correct resonance frequency for different applications in telecommunications. To validate the proposed transmission line model, the simulation results obtained are compared with those obtained by the method of moments. The results of simulations are presented and discussed. Using this transmission line approach, the resonant frequency, input impedance, and return loss can be determined simultaneously. The paper reports several simulation results that confirm the validity of the developed model. The obtained results are then presented and discussed.

  7. Leaky wave enhanced feeds for multibeam reflectors to be used for telecom satellite based links

    NARCIS (Netherlands)

    Neto, A.; Ettorre, M.; Gerini, G.; Maagt, P. de

    2012-01-01

    The use of dielectric super-layers for shaping the radiation pattern of focal plane feeds of a multibeam reflector system is discussed. Using the super-layers, it is possible to reduce the spillover from the reflectors without increasing the dimension of each aperture. The effect has been demonstrat

  8. Onset of dispersion in Nb microstrip transmission lines at submillimeter wave frequencies

    Science.gov (United States)

    Javadi, H. H. S.; Mcgrath, William R.; Bumble, B.; Leduc, Henry G.

    1992-01-01

    We have measured the dispersion in phase velocity of a Nb-SiO(x)-Nb microstrip transmission line resonator over a frequency range from 50 GHz to 800 GHz. A submicron Nb/Al-AlO(x)/Nb Josephson junction was used as a voltage-controlled oscillator to excite the high order modes in the resonator. The same junction is used as a direct detector resulting in a series of step-like structures in the DC current-voltage characteristic at the position of each mode frequency. The transmission line is dispersionless up to about 500 GHz where the phase velocity begins to decrease. This is well below the gap frequency f(sub g) approx. equals 700 GHz. Results agree qualitatively with the expected theoretical behavior near f(sub g). This onset of dispersion and loss in Nb transmission lines will have a significant impact on the design of submillimeter wave RF circuits.

  9. Probing the feeding and feedback of AGN through molecular line maps

    CERN Document Server

    García-Burillo, S; Usero, A; Gracia-Carpio, J

    2006-01-01

    Current mm-interferometers can provide a complete view of the distribution and kinematics of molecular gas in the circumnuclear disks of nearby galaxies. High-resolution CO maps are paramount in order to track down the feeding of active nuclei and quantitatively address the issue of how and for how long nuclear activity can be sustained in galaxies. Going beyond CO mapping, the use of more specific molecular tracers of dense gas can probe the feedback influence of activity on the chemistry and energy balance/redistribution in the interstellar medium of nearby galaxies, a prerequisite to interpret how feedback may operate at higher redshift galaxies. In this context we present the latest results issued from the NUclei of GAlaxies (NUGA) project, a high-resolution (0.5''-1'') CO survey of low luminosity AGNs conducted with the IRAM interferometer. The efficiency of gravity torques as a mechanism to account for the feeding of low luminosity AGNs (LLAGNs) can be analyzed. We discuss an evolutionary scenario in wh...

  10. Threaded-Field-Lines Model for the Low Solar Corona Powered by the Alfven Wave Turbulence

    CERN Document Server

    Sokolov, Igor V; Manchester, Ward B; Ozturk, Doga Can Su; Szente, Judit; Taktakishvili, Aleksandre; Tóth, Gabor; Jin, Meng; Gombosi, Tamas I

    2016-01-01

    We present an updated global model of the solar corona, including the transition region. We simulate the realistic tree-dimensional (3D) magnetic field using the data from the photospheric magnetic field measurements and assume the magnetohydrodynamic (MHD) Alfv\\'en wave turbulence and its non-linear dissipation to be the only source for heating the coronal plasma and driving the solar wind. In closed field regions the dissipation efficiency in a balanced turbulence is enhanced. In the coronal holes we account for a reflection of the outward propagating waves, which is accompanied by generation of weaker counter-propagating waves. The non-linear cascade rate degrades in strongly imbalanced turbulence, thus resulting in colder coronal holes. The distinctive feature of the presented model is the description of the low corona as almost-steady-state low-beta plasma motion and heat flux transfer along the magnetic field lines. We trace the magnetic field lines through each grid point of the lower boundary of the g...

  11. Application of autofocusing methods in continuous-wave terahertz in-line digital holography

    Science.gov (United States)

    Huang, Haochong; Wang, Dayong; Rong, Lu; Zhou, Xun; Li, Zeyu; Wang, Yunxin

    2015-07-01

    Terahertz digital holography is a combination of terahertz imaging and digital holography. During reconstruction, the key point is to find accurately the propagation distance from which the distribution of focused samples can be reconstructed. In this paper, we use a continuous-wave terahertz in-line digital holographic imaging system to record holograms. Moreover, the autofocusing algorithms through which the reconstructed distance can be calculated are applied to the reconstruction. The in-line schematic is beneficial to the terahertz wave imaging, which, however, inevitably produces the object's twin image. In the refocusing process, both the reconstructed image with low signal-to-noise ratio and contrast and the twin image induce the formation of false peaks corresponding to improper distances on the autofocusing curves. To restrain the disturbance factors and improve the accuracy of the judgment, a phase retrieval method is implemented in the reconstruction. The results demonstrate the feasibility of the autofocusing method with phase retrieval in terahertz in-line digital holographic imaging system. The proposed method provides an automated and efficient evaluation which helps to obtain the optimized propagation distance.

  12. Continuous-wave terahertz multi-plane in-line digital holography

    Science.gov (United States)

    Huang, Haochong; Wang, Dayong; Li, Weihua; Rong, Lu; Taylor, Zachary D.; Deng, Qinghua; Li, Bin; Wang, Yunxin; Wu, Weidong; Panezai, Spozmai

    2017-07-01

    Terahertz digital holography is a non-scanning and real time method for reconstructing the absorption and phase distributions of the wave-front diffracted by a given sample simultaneously in the terahertz region. A continuous-wave terahertz in-line digital holographic multi-plane imaging method is presented here for achieving a three-dimensional shape of a specific portion of a sample with the best possible focus. The three enhancement techniques of synthetic aperture, autofocusing and phase retrieval are applied to the single plane recordings for achieving a high resolution, good quality and optimally focused reconstructed image. Later, multi-plane reconstructed images are processed with the threshold mask and a three dimensional profile of the sample is obtained. Experimental verification confirms that the proposed method is a valid tool for acquiring multi-plane information of a target in the terahertz range.

  13. Line-robust statistics for continuous gravitational waves: safety in the case of unequal detector sensitivities

    CERN Document Server

    Keitel, David

    2014-01-01

    The multi-detector F-statistic is close to optimal for detecting continuous gravitational waves (CWs) in Gaussian noise. However, it is susceptible to false alarms from instrumental artefacts, for example quasi-monochromatic disturbances ('lines'), which resemble a CW signal more than Gaussian noise. In a recent paper [KPPLS2014], a Bayesian model selection approach was used to derive line-robust detection statistics for CW signals, generalising both the F-statistic and the F-statistic consistency veto technique and yielding improved performance in line-affected data. Here we investigate a generalisation of the assumptions made in that paper: if a CW analysis uses data from two or more detectors with very different sensitivities, the line-robust statistics could be less effective. We investigate the boundaries within which they are still safe to use, in comparison with the F-statistic. Tests using synthetic draws show that the optimally-tuned version of the original line-robust statistic remains safe in most ...

  14. Millimeter-Wave Line Ratios and Sub-beam Volume Density Distributions

    CERN Document Server

    Leroy, Adam K; Schruba, Andreas; Bigiel, Frank; Kruijssen, J M Diederik; Kepley, Amanda; Blanc, Guillermo A; Bolatto, Alberto D; Cormier, Diane; Gallagher, Molly; Hughes, Annie; Jimenez-Donaire, Maria J; Rosolowsky, Erik; Schinnerer, Eva

    2016-01-01

    We explore the use of mm-wave emission line ratios to trace molecular gas density when observations integrate over a wide range of volume densities within a single telescope beam. For observations targeting external galaxies, this case is unavoidable. Using a framework similar to that of Krumholz and Thompson (2007), we model emission for a set of common extragalactic lines from lognormal and power law density distributions. We consider the median density of gas producing emission and the ability to predict density variations from observed line ratios. We emphasize line ratio variations, because these do not require knowing the absolute abundance of our tracers. Patterns of line ratio variations have the prospect to illuminate the high-end shape of the density distribution, and to capture changes in the dense gas fraction and median volume density. Our results with and without a high density power law tail differ appreciably; we highlight better knowledge of the PDF shape as an important area. We also show th...

  15. Observational Approach to Molecular Cloud Evolutation with the Submillimeter-Wave CI Lines

    Science.gov (United States)

    Oka, T.; Yamamoto, S.

    Neutral carbon atoms (CI) play important roles both in chemistry and cooling processes of interstellar molecular clouds. It is thus crucial to explore its large area distribution to obtain information on formation processes and thermal balance of molecular clouds. However, observations of the submillimeter-wave CI lines have been limited to small areas around some representative objects. We have constructed a 1.2 m submillimeter-wave telescope at the summit of Mt.Fuji. The telescope was designed for the exclusive use of surveying molecular clouds in two submillimeter-wave CI lines, 3 P1 -3 P0 (492GHz) and 3 P2 -3 P1 (809 GHz), of atomic carbon. A superconductor-insulator-superconductor (SIS) mixer receiver was equipped on the Nasmyth focus of the telescope. The receiver noise temperatures [Trx(DSB)] are 300 K and 1000 K for the 492 GHz and the 809 GHz mixers, respectively. The intermediate frequency is centered at 2 GHz, having a 700 MHz bandwidth. An acousto-optical spectrometer (AOS) with 1024 channel outputs is used as a receiver backend. The telescope was installed at Nishi-yasugawara (alt. 3725 m), which is 200 m north of the highest peak, Kengamine (3776 m), in July 1998. It has b en operatede successfully during 4 observing seasons in a remote way from the Hongo campus of the University of Tokyo. We have already observed more than 40 square degrees of the sky with the CI 492 GHz line. The distribution of CI emission is found to be different from those of the 13 CO or C1 8 O emission in some clouds. These differences are discussed in relation to formation processes of molecular clouds.

  16. Modeling multimode feed-horn coupled bolometers for millimeter-wave and terahertz astronomical instrumentation

    Science.gov (United States)

    Kalinauskaite, Eimante; Murphy, Anthony; McAuley, Ian; Trappe, Neil A.; Bracken, Colm P.; McCarthy, Darragh N.; Doherty, Stephen; Gradziel, Marcin L.; O'Sullivan, Creidhe; Maffei, Bruno; Lamarre, Jean-Michel A.; Ade, Peter A. R.; Savini, Giorgio

    2016-07-01

    Multimode horn antennas can be utilized as high efficiency feeds for bolometric detectors, providing increased throughput and sensitivity over single mode feeds, while also ensuring good control of beam pattern characteristics. Multimode horns were employed in the highest frequency channels of the European Space Agency Planck Telescope, and have been proposed for future terahertz instrumentation, such as SAFARI for SPICA. The radiation pattern of a multimode horn is affected by the details of the coupling of the higher order waveguide modes to the bolometer making the modeling more complicated than in the case of a single mode system. A typical cavity coupled bolometer system can be most efficiently simulated using mode matching, typically with smooth walled waveguide modes as the basis and computing an overall scattering matrix for the horn-waveguide-cavity system that includes the power absorption by the absorber. In this paper we present how to include a cavity coupled bolometer, modelled as a thin absorbing film with particular interest in investigating the cavity configuration for optimizing power absorption. As an example, the possible improvements from offsetting the axis of a cylindrically symmetric absorbing cavity from that of a circular waveguide feeding it (thus trapping more power in the cavity) are discussed. Another issue is the effect on the optical efficiency of the detectors of the presence of any gaps, through which power can escape. To model these effects required that existing in-house mode matching software, which calculates the scattering matrices for axially symmetric waveguide structures, be extended to be able to handle offset junctions and free space gaps. As part of this process the complete software code 'PySCATTER' was developed in Python. The approach can be applied to proposed terahertz systems, such as SPICASAFARI.

  17. Optimal Feed Forward MLPArchitecture for Off-Line Cursive Numeral Recognition

    Directory of Open Access Journals (Sweden)

    Vijaypal Singh Dhaka

    2010-01-01

    Full Text Available The purpose of this work is to analyze the performance of back-propagation feed-forward algorithm using various different activation functions for the neurons of hidden and output layer and varying the number of neurons in the hidden layer. For sample creation, 250 numerals were gathered form 35 people of different ages including male and female. After binarization, these numerals were clubbed together to form training patterns for the neural network. Network was trained to learn its behavior by adjusting the connection strengths at every iteration. The conjugate gradient descent of each presented training pattern was calculated to identify the minima on the error surface for each training pattern. Experiments were performed by selecting different combinations of two activation functions out of the three activation functions logsig, tansig and purelin for the neurons of the hidden and output layers and the results revealed that as the number of neurons in the hidden layer is increased, the network gets trained in small number of epochs and the percentage recognition accuracy of the neural network was observed to increase up to certain level and then it starts decreasing when number of hidden neurons exceeds a certain level.

  18. Simulation of Wave Forces on A Semi-Circular Breakwater Using Multilayer Feed Forward Network

    Institute of Scientific and Technical Information of China (English)

    徐杰; 陶建华

    2003-01-01

    In this paper, the Artificial Neural Network (ANN) is used to study the wave forces on a semi-circular breakwater. The process of establishing the network model for a specific physical problem is presented. Networks with double implicit layers have been studied by numerical experiments. 117 sets of experimental data are used to train and test the ANN. According to the results of ANN simulation, this method is proved to have good precision compared with experimental and numerical results.

  19. TEM wave propagation in a microstrip line on a substrate of circular segment cross section

    Science.gov (United States)

    Malits, P.; Haridim, M.; Chulski, S.

    2015-12-01

    TEM mode wave propagation in a microstrip transmission line on a dielectric substrate of circular segment cross section is of concern. A suggested design of a microstrip is convenient for manufacturing and allows to miniaturize microstrips since there is no lateral fringing effect of the substrate in the transmitted fundamental TEM mode. By using the bipolar orthogonal coordinates, the plane potential problem is reformulated in the form of trigonometric dual integral equations. The discontinuous integrals containing Legendre functions of complex degree and the Abel integral equation are employed to reduce the dual equations to a Fredholm equation of the second kind. The structure of the Fredholm integral equation allows to obtain a simple approximate solution. Basing on this solution, rigorous approximate formulas for the characteristic impedance are derived. The characteristic impedance of a microstrip transmission line on a silicon substrate is computed and plotted as an example.

  20. Design, construction and testing of a prototype fin-line magic-tee and fin-line monopulse system suitable for millimeter-wave applications

    Science.gov (United States)

    Rowley, J. W.

    1985-12-01

    This thesis describes a fin-line 180 degree hybrid (magic-tee) that is suitable for use in monopulse radar antennas at microwave and millimeter-wave frequencies. The three-dimensional junction of a waveguide magic-tee is replaced with fin-line slots, coupled fin-line slots and microstrip lines mounted in a waveguide fixture. The planar geometry on the substrate provides significant reduction in size and eliminates the waveguide rat race that is associated with conventional hybrids. Ports one and two are flared into fin-line horns to produce a fin-line monopulse system. Suggestions for further development of the fin-line magic-tee and monopulse system are presented.

  1. Line-robust statistics for continuous gravitational waves: safety in the case of unequal detector sensitivities

    Science.gov (United States)

    Keitel, David; Prix, Reinhard

    2015-02-01

    The multi-detector F-statistic is close to optimal for detecting continuous gravitational waves (CWs) in Gaussian noise. However, it is susceptible to false alarms from instrumental artefacts, for example quasi-monochromatic disturbances (‘lines’), which resemble a CW signal more than Gaussian noise. In a recent paper (Keitel et al 2014 Phys. Rev. D 89 064023), a Bayesian model selection approach was used to derive line-robust detection statistics for CW signals, generalizing both the F-statistic and the F-statistic consistency veto technique and yielding improved performance in line-affected data. Here we investigate a generalization of the assumptions made in that paper: if a CW analysis uses data from two or more detectors with very different sensitivities, the line-robust statistics could be less effective. We investigate the boundaries within which they are still safe to use, in comparison with the F-statistic. Tests using synthetic draws show that the optimally-tuned version of the original line-robust statistic remains safe in most cases of practical interest. We also explore a simple idea on further improving the detection power and safety of these statistics, which we, however, find to be of limited practical use.

  2. Non-invasive evaluation of skin tension lines with elastic waves

    CERN Document Server

    Deroy, Claire; Alinden, Aidan Mc; Annaidh, Aisling Ni

    2016-01-01

    Background: Since their discovery by Karl Langer in the 19th Century, Skin Tension Lines (STLs) have been used by surgeons to decide the location and orientation of an incision. Although these lines are patient-specific, most surgeons rely on generic maps to determine their orientation. Beyond the imprecise pinch test, there remains no accepted method for determining STLs in vivo. Methods: (i) The speed of an elastic motion travelling radially on the skin of canine cadavers was measured with a commercial device called the Reviscometer. (ii) Similar to the original experiments conducted by Karl Langer, circular excisions were made on the skin and the geometric changes to the resulting wounds and excised samples were used to determine the orientation of STLs. Results: A marked anisotropy in the speed of the elastic wave travelling radially was observed. The orientation of the fastest wave was found to correlate with the orientation of the elongated wound (P<0.001, R^2 = 74%). Similarly, the orientation of fa...

  3. SiO line emission from C-type shock waves : interstellar jets and outflows

    CERN Document Server

    Gusdorf, A; Flower, D R; Forets, G Pineau des

    2008-01-01

    We study the production of SiO in the gas phase of molecular outflows, through the sputtering of Si--bearing material in refractory grain cores, which are taken to be olivine; we calculate also the rotational line spectrum of the SiO. The sputtering is driven by neutral particle impact on charged grains, in steady--state C-type shock waves, at the speed of ambipolar diffusion. The emission of the SiO molecule is calculated by means of an LVG code. A grid of models has been generated. We compare our results with those of an earlier study (Schilke et al. 1997). Improvements in the treatment of the coupling between the charged grains and the neutral fluid lead to narrower shock waves and lower fractions of Si being released into the gas phase. More realistic assumptions concerning the initial fractional abundance of O2 lead to SiO formation being delayed, so that it occurs in the cool, dense postshock flow. Good agreement is obtained with recent observations of SiO line intensities in the L1157 and L1448 molecul...

  4. Abbott Wave-Triggered Runaway in Line-Driven Winds from Stars and Accretion Disks

    CERN Document Server

    Feldmeier, A; Feldmeier, Achim; Shlosman, Isaac

    2001-01-01

    Line-driven winds from stars and accretion disks are accelerated by scattering in numerous line transitions. The wind is believed to adopt a unique critical solution, out of the infinite variety of shallow and steep solutions. We study the inherent dynamics of the transition towards the critical wind. A new runaway wind mechanism is analyzed in terms of radiative-acoustic (Abbott) waves which are responsible for shaping the wind velocity law and fixing the mass loss. Three different flow types result, depending on the location of perturbations. First, if the shallow solution is perturbed sufficiently far downstream, a single critical point forms in the flow, which is a barrier for Abbott waves, and the solution tends to the critical one. Second, if the shallow solution is perturbed upstream from this critical point, mass overloading results, and the critical point is shifted inwards. This wind exhibits a broad, stationary region of decelerating flow and its velocity law has kinks. Third, for perturbations eve...

  5. Travelling Waves for a Density Dependent Diffusion Nagumo Equation over the Real Line

    Institute of Scientific and Technical Information of China (English)

    Robert A. Van Gorder

    2012-01-01

    We consider the density dependent diffusion Nagumo equation, where the diffusion coefficient is a simple power function. This equation is used in modelling electrical pulse propagation in nerve axons and in population genetics (amongst other areas). In the present paper, the δ-expansion method is applied to a travelling wave reduction of the problem, so that we may obtain globally valid perturbation solutions (in the sense that the perturbation solutions are valid over the entire infinite domain, not just locally; hence the results are a generalization of the local solutions considered recently in the literature). The resulting boundary value problem is solved on the real line subject to conditions at z →±∞. Whenever a perturbative method is applied, it is important to discuss the accuracy and convergence properties of the resulting perturbation expansions. We compare our results with those of two different numerical methods (designed for initial and boundary value problems, respectively) and deduce that the perturbation expansions agree with the numerical results after a reasonable number of iterations. Finally, we are able to discuss the influence of the wave speed c and the asymptotic concentration value α on the obtained solutions. Upon recasting the density dependent diffusion Nagumo equation as a two-dimensional dynamical system, we are also able to discuss the influence of the nonlinear density dependence (which is governed by a power-law parameter m) on oscillations of the travelling wave solutions.

  6. Pulse-driven non-linear Alfvén waves and their role in the spectral line broadening

    Science.gov (United States)

    Chmielewski, P.; Srivastava, A. K.; Murawski, K.; Musielak, Z. E.

    2013-01-01

    We study the impulsively generated non-linear Alfvén waves in the solar atmosphere and describe their most likely role in the observed non-thermal broadening of some spectral lines in solar coronal holes. We solve numerically the time-dependent magnetohydrodynamic equations to find temporal signatures of large-amplitude Alfvén waves in the solar atmosphere model of open and expanding magnetic field configuration, with a realistic temperature distribution. We calculate the temporally and spatially averaged, instantaneous transversal velocity of non-linear Alfvén waves at different heights of the model atmosphere and estimate its contribution to the unresolved non-thermal motions caused by the waves. We find that the pulse-driven non-linear Alfvén waves with the amplitude Av = 50 km s- 1 are the most likely candidates for the non-thermal broadening of Si viii λ1445.75 Å line profiles in the polar coronal hole as reported by Banerjee et al. We also demonstrate that the Alfvén waves driven by comparatively smaller velocity pulse with amplitude Av = 25 km s- 1 may contribute to the spectral line width of the same line at various heights in coronal hole broadening. We conclude that the non-linear Alfvén waves excited impulsively in the lower solar atmosphere may be responsible for the observed spectral line broadening in polar coronal holes. This is an important result as it allows us to conclude that such large amplitude and pulse-driven Alfvén waves may indeed exist in solar coronal holes. The existence of these waves may impart the required momentum to accelerate the solar wind.

  7. The Sharpshooter X-wave: Correlation of an Electrical Penetration Graph (EPG) Waveform with Xylem Penetration During Feeding of Glassy-winged Sharpshooter

    Science.gov (United States)

    Electrical penetration graph (EPG) monitoring is a rigorous means of observing and quantifying the feeding of any piercing-sucking insect. Previous studies with aphid and leafhopper pests of agricultural crops have demonstrated the unique value of what is termed the X wave, i.e. the waveform that r...

  8. [Simultaneous determination of 16 organic acids in feed additives by on-line enrichment and ion chromatography-mass spectrometry].

    Science.gov (United States)

    Xiong, Zhiyu; Dong, Ying; Zhou, Hongbin; Yu, Yang; Li, Jing; Sun, Li

    2014-02-01

    A novel analytical method for simultaneous determination of sixteen organic acids by on-line enrichment and ion chromatography-mass spectrometry (IC-MS) was developed. Online enrichment and separation of the organic acids were performed by ion chromatography on a homemade enrichment column and a homemade separation column. The qualitative and quantitative analyses of the organic acids were performed by mass spectrometry in selected ion monitoring (SIM) mode on the basis of atmospheric pressure chemical ionization (APCI) source in negative mode. The sample of 200 microL was injected for the analysis, and the on-line enrichment time was 3 min. The sodium hydroxide solution was used as a gradient elution system. The two columns made it possible to have a low limit of detection due to the good enrichment and separation capability. The sixteen organic acids were separated completely within 30 min. All curves showed good linearity within the test concentration ranges. The limits of detection (LODs) were between 0.01 and 0.22 mg/L, and the average recoveries were between 70.6% and 110.8%. The relative standard deviations (RSDs) were less than 6.3%. The results indicate that this method is simple, rapid, sensitive and accurate for the determination of the organic acids in feed additives.

  9. SiO line emission from C-type shock waves: interstellar jets and outflows

    Science.gov (United States)

    Gusdorf, A.; Cabrit, S.; Flower, D. R.; Pineau Des Forêts, G.

    2008-05-01

    We study the production of SiO in the gas phase of molecular outflows, through the sputtering of Si-bearing material in refractory grain cores, which are taken to be olivine. We calculate also the rotational line spectrum of the SiO. The sputtering is driven by neutral particle impact on charged grains, in steady-state C-type shock waves, at the speed of ambipolar diffusion. The emission of the SiO molecule is calculated by means of an LVG code. A grid of models, with shock speeds in the range 20 Schilke et al. 1997). Improvements in the treatment of the coupling between the charged grains and the neutral fluid lead to narrower shock waves and lower fractions of Si (⪉10%) being released into the gas phase. Erosion of grain cores is significant (⪆1%) only for C-type shock speeds vs > 25 km s-1, given the adopted properties of olivine. More realistic assumptions concerning the initial fractional abundance of O2 lead to SiO formation being delayed, so that it occurs in the cool, dense postshock flow. Good agreement is obtained with recent observations of SiO line intensities in the L1157 and L1448 molecular outflows. The inferred temperature, opacity, and SiO column density in the emission region differ significantly from those estimated by means of LVG “slab” models. The fractional abundance of SiO is deduced and found to be in the range 4 × 10-8 ⪉ n(SiO)/nH ⪉ 3 × 10-7. Observed line profiles are wider than predicted and imply multiple, unresolved shock regions within the beam.

  10. RELAP5/MOD3 assessment using the Semiscale 50% Feed Line Break test S-FS-11

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E.J.; Chung, B.D.; Kim, H.J. [Korea Inst. of Nuclear Safety, Taejon (Korea, Republic of)

    1993-06-01

    The RELAP5/MOD3 5m5 code was assessed using the 1/1705 volume scaled Semiscale 50% Feed Line Break (FLB) test S-FS-11. Test S-FS-11 was designed in three phases: (a) blowdown phase, (b) stabilization phase, and (c) refill phase. The first objective was to assess the code applicability to 50% FLB situation, the second was to evaluate the FSAR conservatisms regarding SG heat transfer degradation, steam line check valve failure, break flow state, and peak primary system pressure, and the third was to validate the EOP effectiveness. The code was able to simulate the major T/H parameters except for the two-phase break flow and the secondary convective heat transfer rate. The two-phase break flow had still deficiencies. The current boiling heat transfer rate was developed from the data for flow inside of a heated tube, not for flow around heated tubes in a tube bundle. Results indicated that the assumption of 100% heat transfer until the liquid inventory depletion was not conservative, the failed affected steam generator main steam line check valve assumption was not either conservative, the measured break flow experienced all types of flow conditions, the relative proximity to the 110% design pressure limit was conservative. The automatic actions during the blowdown phase were effective in mitigating the consequences. The stabilization operation performed by operator actions were effective to permit natural circulation cooldown and depressurization. The voided secondary refill operations also verified the effectiveness of the operations while recovering the inventory in a voided steam generator.

  11. An IBEM solution to the scattering of plane SH-waves by a lined tunnel in elastic wedge space

    Institute of Scientific and Technical Information of China (English)

    Zhongxian Liu; Lei Liu

    2015-01-01

    The indirect boundary element method (IBEM) is developed to solve the scattering of plane SH-waves by a lined tunnel in elastic wedge space.According to the theory of single-layer potential,the scattered-wave field can be constructed by applying virtual uniform loads on the surface of lined tunnel and the nearby wedge surface.The densities of virtual loads can be solved by establishing equations through the continuity conditions on the interface and zero-traction conditions on free surfaces.The total wave field is obtained by the superposition of free field and scattered-wave field in elastic wedge space.Numerical results indicate that the IBEM can solve the diffraction of elastic wave in elastic wedge space accurately and efficiently.The wave motion feature strongly depends on the wedge angle,the angle of incidence,incident frequency,the location of lined tunnel,and material parameters.The waves interference and amplification effect around the tunnel in wedge space is more significant,causing the dynamic stress concentration factor on rigid tunnel and the displacement amplitude of flexible tunnel up to 50.0 and 17.0,respectively,more than double that of the case of half-space.Hence,considerable attention should be paid to seismic resistant or anti-explosion design of the tunnel built on a slope or hillside.

  12. Tunable band-notched line-defect waveguide in a surface-wave photonic crystal

    CERN Document Server

    Gao, Zhen; Zhang, Youming; Xu, Hongyi; Zhang, Baile

    2016-01-01

    We propose and experimentally demonstrate a tunable band-notched line-defect waveguide in a surface-wave photonic crystal, which consists of a straight line-defect waveguide and side-coupled defect cavities. A tunable narrow stopband can be observed in the broadband transmission spectra. We also demonstrate that both the filtering levels and filtering frequencies of the band-notched line-defect waveguide can be conveniently tuned through changing the total number and the pillar height of the side-coupled defect cavities. The band-notch function is based on the idea that the propagating surface modes with the resonance frequencies of the side-coupled defect cavities will be tightly localized around the defect sites, being filtered from the waveguide output. Transmission spectra measurements and direct near-field profiles imaging are performed at microwave frequencies to verify our idea and design. These results may enable new band-notched devices design and provide routes for the realization of tunable surface...

  13. Numerical simulation and analysis of a prefrontal squall line. I - Observations and basic simulation results. II - Propagation of the squall line as an internal gravity wave

    Science.gov (United States)

    Cram, Jennifer M.; Pielke, Roger A.; Cotton, William R.

    1992-01-01

    Results of an observational and numerical study of the squall line that occurred on June 17-18, 1978, are presented. This squall line was initially triggered by the strong surface convergence along a cold front and stretched from Illinois to the Texas Panhandle. The squall line was aligned with the surface front during its initial development, but then propagated faster than the front, resulting in a separation of approximately 200 km by 0300 UTC and 300-400 km by 0600 UTC. The Colorado State University Regional Atmospheric Modeling System is used to model the squall-line development and propagation. Results are described from several experiments that tested the sensitivity to the use of the Kuo-type cumulus parameterization scheme and grid-scale microphysical processes. The movement of the squall line in the model is shown to be due to the propagation of a deep tropospheric internal gravity wave in a CISK-like process. The thermal and dynamic perturbations associated with the hypothesized wave are shown to be consistent with internal gravity wave theory.

  14. Novel Composite Right/Left-Handed Metamaterial-Based Leaky-Wave Transmission-Lines

    Science.gov (United States)

    Hashemi, Mohammed Reza Mahmoodi

    The focus of this dissertation is on the design procedure as well as analysis of a very interesting category of metamaterial-based structures namely composite right/left-handed (CRLH) Leaky-wave (LW) transmission-lines (TL). As a result several unique CRLH-TLs are designed and presented. Each of the discussed CRLH LW-TLs has exceptional and beneficial characteristics, which is only realizable due to their composite right/left-handed nature and dispersion characteristics. The operation mechanism of CRLH-TL is explained in the first chapter by the overview of the theory behind the CRLH concept. The dispersion diagram of a CRLH unit-cell shows that the phase constant (beta) is a non-linear function of frequency with a beta = 0 point at a non-zero frequency. Furthermore, a CRLH-TL supports left-handed slow-wave (guided-wave) and fast-wave (leaky-wave) modes, where the phase velocity and the group velocity are anti-parallel and phase advanced is achievable, as well as right-handed slow-wave and fast-wave modes, where the two velocities are parallel and phase delay can be observed. The subject of the second chapter is conformal CRLH LW-TLs. The effect of conformation of a planar uniform CRLH LW-TL on a convex and a concave surface are investigated. It is shown when the CRLH LW-TL is operating in the fast-wave region the conformation affects its radiation characteristics and the radiation pattern becomes wider in both convex and concave cases. A dispersion engineering method is introduced to modify the conformal structure such that it provides comparable performance to that of the planar version in terms of radiation characteristics. Then taking advantage of the proposed modification method a multifunctional electronically controlled conformal CRLH LW-TL is introduced in a later part of this chapter. Varactor diodes are introduced in the unit-cells to electronically control its guided and radiation characteristics. This CRLH-TL has the ability to operate partially in the

  15. Adaptive Line Enhancers filters for Gravitational Waves Detection from coalescing binaries

    CERN Document Server

    Acernese, F; De Rosa, R; Eleuteri, A; Milano, L

    2004-01-01

    In this paper we propose a new strategy for gravitational waves detection from coalescing binaries, using IIR Adaptive Line Enhancer (ALE) filters. This strategy is a classical hierarchical strategy in which the ALE filters have the role of triggers, used to select data chunks which may contain gravitational events, to be further analyzed with more refined optimal techniques, like the the classical Matched Filter Technique. After a direct comparison of the performances of ALE filters with the Wiener-Komolgoroff optimum filters (matched filters), necessary to discuss their performance and to evaluate the statistical limitation in their use as triggers, we performed a series of tests, demonstrating that these filters are quite promising both for the relatively small computational power needed and for the robustness of the algorithms used. The performed tests have shown a weak point of ALE filters, that we fixed by introducing a further strategy, based on a dynamic bank of ALE filters, running simultaneously, bu...

  16. Comment on "Dynamics and properties of waves in a modified Noguchi electrical transmission line"

    Science.gov (United States)

    Kenmogne, Fabien; Yemélé, David; Marquié, Patrick

    2016-09-01

    A recent paper [Phys. Rev. E 91, 022925 (2015), 10.1103/PhysRevE.91.022925] presents the derivation of the nonlinear equation modeling envelope waves in a specific case of band passed filter discrete nonlinear electrical transmission line (NLTL), called "A modified Noguchi electrical transmission line" according to the authors. Using the reductive perturbation approach in the semidiscrete approximation, they showed that the modulated waves propagating in this NLTL are described by the ordinary nonlinear Schrödinger (NLS) equation. On the basis of their results, the authors claimed that all previous works on the band passed filter NLTL, which considered the vanishing of the dc component of the signal voltage, are incorrect, and this dc term is nonzero. As a consequence, the dispersion and nonlinearity coefficients of the NLS equation are strongly different from those usually obtained, and they found, according to the sign of the product P Q , the existence of one more region (compared to the work of Marquié et al. [Phys. Rev. E 49, 828 (1994)], 10.1103/PhysRevE.49.828) in the dispersion curve that allows the motion of envelope solitons of higher frequency in the system. In this Comment we provide sufficient theoretical and numerical evidence showing that the evidence obtained by the authors otherwise is due to certain terms missed in their mathematical developments when they derived the NLS equation. Our results also suggest that the previous work of Marquié and co-workers correctly predict the fact that the dc term of the signal voltage does not exist and there exist only two regions in the dispersion curve according to the sign of the product P Q .

  17. Line nodes and surface Majorana flat bands in static and kicked p -wave superconducting Harper model

    Science.gov (United States)

    Wang, Huai-Qiang; Chen, M. N.; Bomantara, Raditya Weda; Gong, Jiangbin; Xing, D. Y.

    2017-02-01

    We investigate the effect of introducing nearest-neighbor p -wave superconducting pairing to both the static and kicked extended Harper model with two periodic phase parameters acting as artificial dimensions to simulate three-dimensional systems. It is found that in both the static model and the kicked model, by varying the p -wave pairing order parameter, the system can switch between a fully gapped phase and a gapless phase with point nodes or line nodes. The topological property of both the static and kicked model is revealed by calculating corresponding topological invariants defined in the one-dimensional lattice dimension. Under open boundary conditions along the physical dimension, Majorana flat bands at energy zero (quasienergy zero and π ) emerge in the static (kicked) model at the two-dimensional surface Brillouin zone. For certain values of pairing order parameter, (Floquet) Su-Schrieffer-Heeger-like edge modes appear in the form of arcs connecting different (Floquet) Majorana flat bands. Finally, we find that in the kicked model, it is possible to generate two controllable Floquet Majorana modes, one at quasienergy zero and the other at quasienergy π , at the same parameter values.

  18. Effects of blast wave to main steam piping under high energy line break condition by TNT model

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Hyun; Lee, Eung Seok; Chang, Yoon Suk [Kyung Hee University, Yongin (Korea, Republic of)

    2016-05-15

    The aim of this study is to examine effect of the blast wave according to pipe break position through FE (Finite Element) analyses. If HELB (High Energy Line Break) accident occurs in nuclear power plants, not only environmental effect such as release of radioactive material but also secondary structural defects should be considered. Sudden pipe rupture causes ejection of high temperature and pressure fluid, which acts as a blast wave around the break location. The blast wave caused by the HELB has a possibility to induce structural defects around the components such as safe-related injection pipes and other structures.

  19. Compositional and toxicological analysis of a GM potato line with reduced α-solanine content--a 90-day feeding study in the Syrian Golden hamster.

    Science.gov (United States)

    Langkilde, Søren; Schrøder, Malene; Frank, Thomas; Shepherd, Louise V T; Conner, Sean; Davies, Howard V; Meyer, Otto; Danier, Jürgen; Rychlik, Michael; Belknap, William R; McCue, Kent F; Engel, Karl-Heinz; Stewart, Derek; Knudsen, Ib; Poulsen, Morten

    2012-10-01

    Steroidal glycoalkaloids (GAs) are toxins, produced by plants of the Solanaceae family. The potato plant (Solanum tuberosum L.) and its tubers predominantly contain the two GAs α-chaconine and α-solanine. These compounds are believed to act in synergy, and the degree of toxicity may therefore depend on their ratio in the potato. To determine the influence of α-solanine: α-chaconine ratio in potatoes on toxicity, a GM potato line (SGT 9-2) with reduced α-solanine content, and the parental control line (Desirée wild-type) having a traditional α-solanine: α-chaconine ratio were (1) studied for compositional similarity by analysing for a range of potato constituents, and (2) used in a 90-day feeding trial with the Syrian Golden hamster to study differential toxicity. The animal feeding study used diets with up to 60% freeze-dried potato powder from either line. Whilst data indicated some compositional differences between the GM line and its wildtype control these did not raise concerns related to nutritional value or safety. Results of the feeding trials showed a low number of significant differences between potato lines with different α-solanine: α-chaconine ratio but none were considered to raise safety concerns with regard to human (or animal) consumption.

  20. Compositional and toxicological analysis of a GM potato line with reduced α-solanine content – A 90-day feeding study in the Syrian Golden hamster

    DEFF Research Database (Denmark)

    Langkilde, Søren; Schrøder, Malene; Frank, Thomas

    2012-01-01

    Steroidal glycoalkaloids (GAs) are toxins, produced by plants of the Solanaceae family. The potato plant (Solanum tuberosum L.) and its tubers predominantly contain the two GAs α-chaconine and α-solanine. These compounds are believed to act in synergy, and the degree of toxicity may therefore...... depend on their ratio in the potato. To determine the influence of α-solanine: α-chaconine ratio in potatoes on toxicity, a GM potato line (SGT 9-2) with reduced α-solanine content, and the parental control line (Desirée wild-type) having a traditional α-solanine: α-chaconine ratio were (1) studied...... for compositional similarity by analysing for a range of potato constituents, and (2) used in a 90-day feeding trial with the Syrian Golden hamster to study differential toxicity. The animal feeding study used diets with up to 60% freeze-dried potato powder from either line. Whilst data indicated some compositional...

  1. Research on a Lamb Wave and Particle Filter-Based On-Line Crack Propagation Prognosis Method.

    Science.gov (United States)

    Chen, Jian; Yuan, Shenfang; Qiu, Lei; Cai, Jian; Yang, Weibo

    2016-03-03

    Prognostics and health management techniques have drawn widespread attention due to their ability to facilitate maintenance activities based on need. On-line prognosis of fatigue crack propagation can offer information for optimizing operation and maintenance strategies in real-time. This paper proposes a Lamb wave-particle filter (LW-PF)-based method for on-line prognosis of fatigue crack propagation which takes advantages of the possibility of on-line monitoring to evaluate the actual crack length and uses a particle filter to deal with the crack evolution and monitoring uncertainties. The piezoelectric transducers (PZTs)-based active Lamb wave method is adopted for on-line crack monitoring. The state space model relating to crack propagation is established by the data-driven and finite element methods. Fatigue experiments performed on hole-edge crack specimens have validated the advantages of the proposed method.

  2. Research on a Lamb Wave and Particle Filter-Based On-Line Crack Propagation Prognosis Method

    Directory of Open Access Journals (Sweden)

    Jian Chen

    2016-03-01

    Full Text Available Prognostics and health management techniques have drawn widespread attention due to their ability to facilitate maintenance activities based on need. On-line prognosis of fatigue crack propagation can offer information for optimizing operation and maintenance strategies in real-time. This paper proposes a Lamb wave-particle filter (LW-PF-based method for on-line prognosis of fatigue crack propagation which takes advantages of the possibility of on-line monitoring to evaluate the actual crack length and uses a particle filter to deal with the crack evolution and monitoring uncertainties. The piezoelectric transducers (PZTs-based active Lamb wave method is adopted for on-line crack monitoring. The state space model relating to crack propagation is established by the data-driven and finite element methods. Fatigue experiments performed on hole-edge crack specimens have validated the advantages of the proposed method.

  3. Measurement of viscosity and shear wave velocity of a liquid or slurry for on-line process control.

    Science.gov (United States)

    Greenwood, Margaret Stautberg; Bamberger, Judith Ann

    2002-08-01

    An on-line sensor to measure the density of a liquid or slurry, based on longitudinal wave reflection at the solid-fluid interface, has been developed by the staff at Pacific Northwest National Laboratory. The objective of this research is to employ shear wave reflection at the solid-fluid interface to provide an on-line measurement of viscosity as well. Both measurements are of great interest for process control in many industries. Shear wave reflection measurements were conducted for a variety of liquids. By analyzing multiple reflections within the solid (only 0.63 cm thick-similar to pipe wall thickness) we increased the sensitivity of the measurement. At the sixth echo, sensitivity was increased sufficiently and this echo was used for fluid interrogation. Shear wave propagation of ultrasound in liquids is dependent upon the viscosity and the shear modulus. The data are analyzed using the theory for light liquids (such as water and sugar water solutions) and also using the theory for highly viscous liquids (such as silicone oils). The results show that, for light liquids, the shear wave reflection measurements interrogate the viscosity. However, for highly viscous liquids, it is the shear wave modulus that dominates the shear wave reflection. Since the density is known, the shear wave velocity in the liquid can be determined from the shear wave modulus. The results show that shear wave velocities in silicone oils are very small and range from 315 to 2389 cm/s. Shear wave reflection measurements are perhaps the only way that shear wave velocity in liquids can be determined, because the shear waves in liquids are highly attenuated. These results show that, depending on the fluid characteristics, either the viscosity or the shear wave velocity can be used for process control. There are several novel features of this sensor: (1) The sensor can be mounted as part of the wall of a pipeline or tank or submerged in a tank. (2) The sensor is very compact and can be

  4. Topics in millimeter wave technology

    CERN Document Server

    Button, Kenneth

    1988-01-01

    Topics in Millimeter Wave Technology, Volume 1 presents topics related to millimeter wave technology, including fin-lines and passive components realized in fin-lines, suspended striplines, suspended substrate microstrips, and modal power exchange in multimode fibers. A miniaturized monopulse assembly constructed in planar waveguide with multimode scalar horn feeds is also described. This volume is comprised of five chapters; the first of which deals with the analysis and synthesis techniques for fin-lines as well as the various passive components realized in fin-line. Tapers, discontinuities,

  5. Bloch wave symmetries in electron diffraction: applications to Friedels law, Gjonnes-Moodie lines and refraction at interfaces.

    Science.gov (United States)

    Valset, K; Tafto, J

    2011-06-01

    We classify the point symmetries at the different points in the Brillouin zone for the 17 two-dimensional space groups and the symmetries of the Bloch waves for the 10 two-dimensional crystallographic point groups. Simple examples involving breakdown of Friedels law, Gjonnes-Moodie lines, and reflection and refraction at interfaces are presented.

  6. Analytical study of dynamics of matter-wave solitons in lossless nonlinear discrete bi-inductance transmission lines.

    Science.gov (United States)

    Kengne, E; Lakhssassi, A

    2015-03-01

    We consider a lossless one-dimensional nonlinear discrete bi-inductance electrical transmission line made of N identical unit cells. When lattice effects are considered, we use the reductive perturbation method in the semidiscrete limit to show that the dynamics of modulated waves can be modeled by the classical nonlinear Schrödinger (CNLS) equation, which describes the modulational instability and the propagation of bright and dark solitons on a continuous-wave background. Our theoretical analysis based on the CNLS equation predicts either two or four frequency regions with different behavior concerning the modulational instability of a plane wave. With the help of the analytical solutions of the CNLS equation, we investigate analytically the effects of the linear capacitance CS on the dynamics of matter-wave solitons in the network. Our results reveal that the linear parameter CS can be used to manipulate the motion of bright, dark, and kink soliton in the network.

  7. A Ku-band magnetically insulated transmission line oscillator with overmoded slow-wave-structure

    Science.gov (United States)

    Jiang, Tao; He, Jun-Tao; Zhang, Jian-De; Li, Zhi-Qiang; Ling, Jun-Pu

    2016-12-01

    In order to enhance the power capacity, an improved Ku-band magnetically insulated transmission line oscillator (MILO) with overmoded slow-wave-structure (SWS) is proposed and investigated numerically and experimentally. The analysis of the dispersion relationship and the resonant curve of the cold test indicate that the device can operate at the near π mode of the TM01 mode, which is useful for mode selection and control. In the particle simulation, the improved Ku-band MILO generates a microwave with a power of 1.5 GW and a frequency of 12.3 GHz under an input voltage of 480 kV and input current of 42 kA. Finally, experimental investigation of the improved Ku-band MILO is carried out. A high-power microwave (HPM) with an average power of 800 MW, a frequency of 12.35 GHz, and pulse width of 35 ns is generated under a diode voltage of 500 kV and beam current of 43 kA. The consistency between the experimental and simulated far-field radiation pattern confirms that the operating mode of the improved Ku-band MILO is well controlled in π mode of the TM01 mode. Project supported partly by the National Natural Science Foundation of China (Grant No. 61171021).

  8. On-line surveillance of lubricants in bearings by means of surface acoustic waves.

    Science.gov (United States)

    Lindner, Gerhard; Schmitt, Martin; Schubert, Josephine; Krempel, Sandro; Faustmann, Hendrik

    2010-01-01

    The acoustic wave propagation in bearings filled with lubricants and driven by pulsed excitation of surface acoustic waves has been investigated with respect to the presence and the distribution of different lubricants. Experimental setups, which are based on the mode conversion between surface acoustic waves and compression waves at the interface between a solid substrate of the bearing and a lubricant are described. The results of preliminary measurements at linear friction bearings, rotation ball bearings and axial cylinder roller bearings are presented.

  9. Measurement of the Electron Bernstein Wave Emission with One of the Power Transmission Lines for ECH in LHD%Measurement of the Electron Bernstein Wave Emission with One of the Power Transmission Lines for ECH in LHD

    Institute of Scientific and Technical Information of China (English)

    Hiroe IGAMI; Hiroshi IDEI; Shin KUBO; Yasuo YOSHIMURA; Takashi SHIMOZUMA; Hiromi TAKAHASHI

    2011-01-01

    Possibility of the measurement of radiated waves derived from the thermally emitted electron Bernstein wave (EBW) is numerically investigated based on the assumption of the super dense core (SDC) plasma generated in LHD. EBW that is thermally emitted in the electron cyclotron resonance (ECR) layer may couple with the electromagnetic wave and be emitted to the vacuum via the EBW-extraordinary-ordinary (B-X-O) mode conversion process. We consider the use of one of the transmission lines for electron cyclotron heating (ECH) in LHD as a receiving system of the emission. It is derived that the waves in the fundamental cyclotron frequency range are emitted as the EBW near their upper hybrid resonance (UHR) layer outside the last close flux surface (LCFS). On the other hand, waves in the second harmonics cyclotron frequency range are emitted in the core region. It means that successful measurement of waves of the second harmonic frequency range emitted from extremely high dense core plasma with setting an aim angle for receiving indicates a possibility of the second harmonic ECH by EBW in the core region with setting the same aim angle and the same polarization for launching.

  10. Dynamic interaction of twin vertically overlapping lined tunnels in an elastic half space subjected to incident plane waves

    Science.gov (United States)

    Liu, Zhongxian; Wang, Yirui; Liang, Jianwen

    2016-06-01

    The scattering of plane harmonic P and SV waves by a pair of vertically overlapping lined tunnels buried in an elastic half space is solved using a semi-analytic indirect boundary integration equation method. Then the effect of the distance between the two tunnels, the stiffness and density of the lining material, and the incident frequency on the seismic response of the tunnels is investigated. Numerical results demonstrate that the dynamic interaction between the twin tunnels cannot be ignored and the lower tunnel has a significant shielding effect on the upper tunnel for high-frequency incident waves, resulting in great decrease of the dynamic hoop stress in the upper tunnel; for the low-frequency incident waves, in contrast, the lower tunnel can lead to amplification effect on the upper tunnel. It also reveals that the frequency-spectrum characteristics of dynamic stress of the lower tunnel are significantly different from those of the upper tunnel. In addition, for incident P waves in low-frequency region, the soft lining tunnels have significant amplification effect on the surface displacement amplitude, which is slightly larger than that of the corresponding single tunnel.

  11. Behavior of Torsional Alfven Waves and Field Line Resonance on Rotating Magnetars

    CERN Document Server

    Kojima, T O Y

    2005-01-01

    Torsional Alfven waves are likely excited with bursts in rotating magnetars. These waves are probably propagated through corotating atmospheres toward a vacuum exterior. We have studied the physical effects of the azimuthal wave number and the characteristic height of the plasma medium on wave transmission. In this work, explicit calculations were carried out based on the three-layered cylindrical model. We found that the coupling strength between the internal shear and the external Alfven modes is drastically enhanced, when resonance occurs in the corotating plasma cavity. The spatial structure of the electromagnetic fields in the resonance cavity is also investigated when Alfven waves exhibit resonance.

  12. Increased range of ultrasonic guided wave testing of overhead transmission line cables using dispersion compensation.

    Science.gov (United States)

    Legg, Mathew; Yücel, Mehmet K; Kappatos, Vassilios; Selcuk, Cem; Gan, Tat-Hean

    2015-09-01

    Overhead Transmission Line (OVTL) cables can experience structural defects and are, therefore, inspected using Non-Destructive Testing (NDT) techniques. Ultrasonic Guided Waves (UGW) is one NDT technique that has been investigated for inspection of these cables. For practical use, it is desirable to be able to inspect as long a section of cable as possible from a single location. This paper investigates increasing the UGW inspection range on Aluminium Conductor Steel Reinforced (ACSR) cables by compensating for dispersion using dispersion curve data. For ACSR cables, it was considered to be difficult to obtain accurate dispersion curves using modelling due to the complex geometry and unknown coupling between wire strands. Group velocity dispersion curves were, therefore, measured experimentally on an untensioned, 26.5m long cable and a method of calculating theoretical dispersion curves was obtained. Attenuation and dispersion compensation were then performed for a broadband Maximum Length Sequence (MLS) excitation signal. An increase in the Signal to Noise Ratio (SNR) of about 4-8dB compared to that of the dispersed signal was obtained. However, the main benefit was the increased ability to resolve the individual echoes from the end of the cable and an introduced defect in the form of a cut, which was 7 to at least 13dB greater than that of the dispersed signal. Five echoes were able to be clearly detected using MLS excitation signal, indicating the potential for an inspection range of up to 130m in each direction. To the best of the authors knowledge, this is the longest inspection range for ACSR cables reported in the literature, where typically cables, which were only one or two meter long, have been investigated previously. Narrow band tone burst and Hann windowed tone burst excitation signal also showed increased SNR and ability to resolve closely spaced echoes. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. 'Dancing on a thin line': evaluation of an infant feeding information team to implement the WHO code of marketing of breast-milk substitutes.

    Science.gov (United States)

    Dykes, Fiona; Richardson-Foster, Helen; Crossland, Nicola; Thomson, Gill

    2012-12-01

    to conduct an in-depth evaluation of the Infant Feeding Information Team (IFIT) to implement the WHO Code of Marketing of Breast-milk Substitutes in North West England. The evaluation included consultations with inter-disciplinary professionals to explore their perceptions of the IFIT and related contextual issues. a qualitative, descriptive study involving seven focus groups (n=34) and semi-structured, in-depth interviews (face to face or via telephone; n=68) with a total of 102 participants. Thematic networks analysis was conducted to generate global, organising and basic themes. two maternity/primary health-care facilities located in the North-West of England. six global themes were generated; this paper focuses upon one of these themes: 'Dancing on a thin line'. This reflects the difficulties health-care staff face in negotiating political, professional and socio-cultural influences on infant feeding practices and how they struggle to implement best available evidence, guidance and practice when they experience incomplete, conflicting and competing messages around infant feeding. IFIT offers an innovative means to sustain contact with the formula industry without their unprecedented access to health facilities or personnel. Focused training opportunities should be provided to enable health-care staff to appreciate the constituent limitations of artificial milks and provide consistent, sensitive and comprehensive infant feeding information. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Millimeter wave spectral line surveys and line mapping studies of NGC6334I and I(N)

    CERN Document Server

    Thorwirth, S; Wyrowski, F; Schilke, P; Beuther, H; Hunter, T R; Comito, C; Leurini, S; Tieftrunk, A R; Burton, M G; Menten, K M

    2007-01-01

    NGC6334I and I(N) have been observed with the Swedish-ESO Submillimetre Telescope, SEST, at wavelengths of 3, 2, and 1.3 mm. Especially NGC6334 I shows rich emission from many different molecules, comparable in line density to prototypical hot cores such as Orion-KL and SgrB2(N). In addition, a 4' by 4' region enfolding NGC 6334 I and I(N) has been mapped at a wavelength of 3 mm (75 to 116 GHz) with the Mopra telescope.

  15. Metal Emission Lines as Diagnostic Tools for Shock Waves in Outer Atmospheres of M-type Mira Stars

    Science.gov (United States)

    Richter, He.; Sedlmayr, E.; Wood, P. R.

    One way to reveal the thermo- and hydrodynamical conditions in M-type Mira atmospheres is to study the various emission lines which are emitted behind a shock front and can be observed over a substantial portion of the pulsation period. Analysing a time-resolved series of these emission lines offers the possibility to determine these conditions in different atmospheric layers influenced by the passing shock wave. In particular, the metal emission lines are a diagnostic tool to probe the hydrodynamical conditions of the outer, dust-forming layers of the atmosphere, because they appear late in the pulsation cycle when the shock wave has reached these layers. We present quantitive data on radial velocities, shapes, widths and fluxes of metal emission lines obtained by spectral observations in the optical wavelength region for a sample of six M-type Miras (periods 281-389 days), namely R Aql, RR Sco, R Car, R Leo, S Scl and R Hya (cf. Richter & Wood 2001, A&A 369, 1027-1047). Because of the multiple phase coverage of our observations, the data shows the history of the shock as it emerges through the deep photosphere and then moves out through the atmosphere. The observations are analysed and discussed with regard to the atmospheric conditions.

  16. Simulation, Modeling, and Analysis of Soliton Waves Interaction and Propagation in CNN Transmission Lines for Innovative Data Communication and Processing

    Directory of Open Access Journals (Sweden)

    G. Borgese

    2015-01-01

    Full Text Available We present an innovative approach to study the interaction between oblique solitons, using nonlinear transmission lines, based on Cellular Neural Network (CNN paradigm. A single transmission line consists of a 1D array of cells that interact with neighboring cells, through both linear and nonlinear connections. Each cell is controlled by a nonlinear Ordinary Differential Equation, in particular the Korteweg de Vries equation, which defines the cell status and behavior. Two typologies of CNN transmission lines are modelled: crisscross and ring lines. In order to solve KdV equations two different methods are used: 4th-order Runge-Kutta and Forward Euler methods. This is done to evaluate their accuracy and stability with the purpose of implementing CNN transmission lines on embedded systems such as FPGA and microcontrollers. Simulation/analysis Graphic User Interface platforms are designed to conduct numerical simulations and to display elaboration results. From this analysis it is possible both to identify the presence and the propagation of soliton waves on the transmission lines and to highlight the interaction between solitons and rich nonlinear dynamics. With this approach it is possible to simulate and develop the transmission and processing of information within large brain networks and high density sensor systems.

  17. The nearby spiral density-wave structure of the Galaxy: line-of-sight and longitudinal velocities of 223 Cepheids

    Science.gov (United States)

    Griv, Evgeny; Hou, Li-Gang; Jiang, Ing-Guey; Ngeow, Chow-Choong

    2017-02-01

    The data of 223 stars within 4 kpc from the Sun and 400 pc from the plane are collected from Melnik et al., who listed photometric distances and velocities of 674 long-period Cepheids in the disc of our Galaxy. Both line-of-sight and transverse along the Galactic longitude velocities of the selected stars are analysed on the assumption that the system is the subject to Lin-Shu-type moderately unstable, low-amplitude, tightly wound and rigidly rotating density waves. Minimization of the least-squares estimator S of measured and modelled velocities of stars was performed in the geometrical parameters of waves. The wave structures defined from the two independent samples of velocities are nearly similar. Different radial scales (wavelengths) of velocity inhomogeneity of about 1, 2 and 4 kpc, which do not depend on the number of spiral arms m, were found. But for now it is unclear if one can identify these scales as fully independent global modes of collective oscillations or they are Fourier harmonics of a single wave, or they just reveal the segments of large-scale Orion, Sagittarius and Perseus arms. The dominant mode is the one-armed wave for the main minimum of all S considered. However, because the S values for fits with m = 1-4 are almost equal the latter conclusion must be regarded as tentative until more extensive data are available. High-precision Gaia observations could reveal in the near future whether the wave-like velocity fluctuations near the Sun reported here do indeed exist.

  18. Detection of the excited carbon lines at decameter waves in some galactic objects

    Energy Technology Data Exchange (ETDEWEB)

    Konovalenko, A.A.

    1984-12-01

    The absorption lines C638..cap alpha..-C641..cap alpha.. are detected at 25 MHz in the region with galactic coordinates l/sub 2/=75 deg; b/sub 2/=0 deg and near the NGC 2024 nebulae. The observed parameters of lines can be only explained in the frame of the low-temperature dielectronic recombination mechanism. The advantages of decametric observations of carbon recombination lines in the various components of the interstellar medium are pointed out.

  19. Low frequency modulation of transionospheric radio wave amplitude at low-latitudes: possible role of field line oscillations

    Directory of Open Access Journals (Sweden)

    A. K. Sinha

    Full Text Available Ionospheric scintillations of radio waves at low-latitudes are associated with electron density irregularities. These irregularities are field-aligned and can provide excitation energy all along the field line to non-local field-aligned oscillations, such as the local field line oscillations. Eigen-periods of toroidal field line oscillations at low-latitudes, computed by using the dipole magnetic field and ion distributions obtained from the International Reference Ionosphere (IRI for typical nighttime conditions, fall in the range of 20–25 s. When subjected to spectral analysis, signal strength of the radio waves recorded on the 250 MHz beacon at Pondicherry (4.5° N dip, Mumbai (13.4° N dip and Ujjain (18.6° N dip exhibit periodicities in the same range. For the single event for which simultaneous ground magnetic data were available, the geomagnetic field also oscillated at the same periodicity. The systematic presence of a significant peak in the 20–25 s range during periods of strong radio wave scintillations, and its absence otherwise suggests the possibility that field line oscillations are endogenously excited by the irregularities, and the oscillations associated with the excited field line generate the modulation characteristics of the radio waves received on the ground. The frequency of modulation is found to be much lower than the characteristic frequencies that define the main body of scintillations, and they probably correspond to scales that are much larger than the typical Fresnel scale. It is possible that the refractive mechanism associated with larger scale long-lived irregularities could be responsible for the observed phenomenon. Results of a preliminary numerical experiment that uses a sinusoidal phase irregularity in the ionosphere as a refracting media are presented. The results show that phase variations which are large enough to produce a focal plane close to the ground can reproduce features that are not

  20. Millimeter-wave Spectral Line Surveys toward the Galactic Circumnuclear Disk and Sgr A*

    OpenAIRE

    Takekawa, Shunya; Oka, Tomoharu; TANAKA, Kunihiko; Matsumura, Shinji; Miura, Kodai; Sakai, Daisuke

    2014-01-01

    We have performed unbiased spectral line surveys at 3 mm band toward the Galactic circumnuclear disk (CND) and Sgr A* using the Nobeyama Radio Observatory (NRO) 45 m radio telescope. The target positions are two tangential points of the CND and the direction of Sgr A*. We have obtained three wide-band spectra which cover the frequency range from 81.3 GHz to 115.8 GHz, detecting 46 molecular lines from 30 species including 10 rare isotopomers and four hydrogen recombination lines. Each line pr...

  1. Line Nodes and Time Reversal Symmetry Breaking in p-wave Sr2RuO4

    Science.gov (United States)

    Annett, Jf; Gyorffy, Bl; Litak, G.; Wysokinski, Ki

    2001-03-01

    The superconductor Sr_2RuO4 exhibits broken time reversal symmetry and has a contant Knight shift below Tc. These experiments suggest a pairing state of the ^3He-A type, d(k) = (k_x+ik_y)hatz. On the other hand specific heat measurements of Nishizaki Maeno and Mao (J. Phys. Soc. Japan 69, 572 (2000)) imply that the gap has line nodes. To resolve this contradiction we calculate the energy gap and heat capacity in several alternative scenarios for the pairing interaction. We find that on-site Hunds rule exchange cannot produce the observed T_c. Nearest neighbour spin independent attraction leads to d-wave pairing, while nearest neighbour parallel spin interaction leads to a p-wave state with no line nodes. However we can also obtain a state with line nodes on the alpha-beta Fermi surface sheets, and time reversal symmetry breaking on the gamma sheet. We discuss the possible physical origin of this state and the comparison with available experimental data.

  2. Resistance of the soybean breeding line GatIR 81-296 to foliar feeding by three Spodoptera sp

    National Research Council Canada - National Science Library

    Beach, RM; Todd, JW

    1987-01-01

    The soybean, Glycine max (L.) Merrill, insect-resistant breeding line GatIR 81-296 was tested for resistance against three polyphagous species of Spodoptera , the fall armyworm (FAW), S. frugiperda (J.E. Smith...

  3. MILLIMETER-WAVE SPECTRAL LINE SURVEYS TOWARD THE GALACTIC CIRCUMNUCLEAR DISK AND Sgr A*

    Energy Technology Data Exchange (ETDEWEB)

    Takekawa, Shunya; Oka, Tomoharu; Matsumura, Shinji; Miura, Kodai [School of Fundamental Science and Technology, Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama, Kanagawa 223-8522 (Japan); Tanaka, Kunihiko [Department of Physics, Institute of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama, Kanagawa 223-8522 (Japan); Sakai, Daisuke, E-mail: shunya@z2.keio.jp [Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2014-09-01

    We have performed unbiased spectral line surveys at the 3 mm band toward the Galactic circumnuclear disk (CND) and Sgr A* using the Nobeyama Radio Observatory 45 m radio telescope. The target positions are two tangential points of the CND and the direction of Sgr A*. We have obtained three wide-band spectra that cover the frequency range from 81.3 GHz to 115.8 GHz, detecting 46 molecular lines from 30 species, including 10 rare isotopomers and 4 hydrogen recombination lines. Each line profile consists of multiple velocity components which arise from the CND, +50 km s{sup –1} and +20 km {sup –1} giant molecular clouds (GMCs), and the foreground spiral arms. We define the specific velocity ranges that represent the CND and the GMCs toward each direction, and classify the detected lines into three categories: the CND, GMC, HBD types, based on the line intensities integrated over the defined velocity ranges. The CND and GMC types are the lines that mainly trace the CND and the GMCs, respectively. The HBD types possesses the both characteristics of the CND and GMC types. We also present lists of line intensities and other parameters, as well as intensity ratios, which must be useful to investigate the difference between the nuclear environments of our Galaxy and others.

  4. Ion shell distributions as free energy source for plasma waves on auroral field lines mapping to plasma sheet boundary layer

    Directory of Open Access Journals (Sweden)

    A. Olsson

    2004-06-01

    Full Text Available Ion shell distributions are hollow spherical shells in velocity space that can be formed by many processes and occur in several regions of geospace. They are interesting because they have free energy that can, in principle, be transmitted to ions and electrons. Recently, a technique has been developed to estimate the original free energy available in shell distributions from in-situ data, where some of the energy has already been lost (or consumed. We report a systematic survey of three years of data from the Polar satellite. We present an estimate of the free energy available from ion shell distributions on auroral field lines sampled by the Polar satellite below 6 RE geocentric radius. At these altitudes the type of ion shells that we are especially interested in is most common on auroral field lines close to the polar cap (i.e. field lines mapping to the plasma sheet boundary layer, PSBL. Our analysis shows that ion shell distributions that have lost some of their free energy are commonly found not only in the PSBL, but also on auroral field lines mapping to the boundary plasma sheet (BPS, especially in the evening sector auroral field lines. We suggest that the PSBL ion shell distributions are formed during the so-called Velocity Dispersed Ion Signatures (VDIS events. Furthermore, we find that the partly consumed shells often occur in association with enhanced wave activity and middle-energy electron anisotropies. The maximum downward ion energy flux associated with a shell distribution is often 10mWm-2 and sometimes exceeds 40mWm-2 when mapped to the ionosphere and thus may be enough to power many auroral processes. Earlier simulation studies have shown that ion shell distributions can excite ion Bernstein waves which, in turn, energise electrons in the parallel direction. It is possible that ion shell distributions are the link between the X-line and the auroral wave activity and electron

  5. Extrapolation of extreme response for different mooring line systems of floating wave energy converters

    DEFF Research Database (Denmark)

    Ambühl, Simon; Sterndorff, Martin; Sørensen, John Dalsgaard

    2014-01-01

    Mooring systems for floating wave energy converters (WECs) are a major cost driver. Failure of mooring systems often occurs due to extreme loads. This paper introduces an extrapolation method for extreme response which accounts for the control system of a WEC that controls the loads onto the stru......Mooring systems for floating wave energy converters (WECs) are a major cost driver. Failure of mooring systems often occurs due to extreme loads. This paper introduces an extrapolation method for extreme response which accounts for the control system of a WEC that controls the loads onto...... the structure and the harvested power of the device as well as the fact that extreme loads may occur during operation and not at extreme wave states when the device is in storm protection mode. The extrapolation method is based on shortterm load time series and applied to a case study where up-scaled surge load...

  6. Observation of genuine wave vector (k or β) gap in a dynamic transmission line and temporal photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Ayona, J. R.; Halevi, P., E-mail: halevi@inaoep.mx [Electronics Department, Instituto Nacional de Astrofísica, Óptica y Electrónica, Tonantzintla, Puebla 72840 (Mexico)

    2015-08-17

    By definition, a temporal photonic crystal (TPC) has a permittivity ε(t) that varies periodically with time. We prove that, in the long wavelength limit, a TPC is accurately mimicked by a dynamic transmission line (DTL) having a capacitance (inductance) per unit length equal to ε(t) (μ). Employing a DTL in the microwave region, we measured the photonic band structure, which results to display a genuine wave vector (k or β) gap, in very good agreement with our theoretical model and the equivalent TPC.

  7. Observation of genuine wave vector (k or β) gap in a dynamic transmission line and temporal photonic crystals

    Science.gov (United States)

    Reyes-Ayona, J. R.; Halevi, P.

    2015-08-01

    By definition, a temporal photonic crystal (TPC) has a permittivity ɛ(t) that varies periodically with time. We prove that, in the long wavelength limit, a TPC is accurately mimicked by a dynamic transmission line (DTL) having a capacitance (inductance) per unit length equal to ɛ(t) (μ). Employing a DTL in the microwave region, we measured the photonic band structure, which results to display a genuine wave vector (k or β) gap, in very good agreement with our theoretical model and the equivalent TPC.

  8. Millimeter-wave Spectral Line Surveys toward the Galactic Circumnuclear Disk and Sgr A*

    CERN Document Server

    Takekawa, Shunya; Tanaka, Kunihiko; Matsumura, Shinji; Miura, Kodai; Sakai, Daisuke

    2014-01-01

    We have performed unbiased spectral line surveys at 3 mm band toward the Galactic circumnuclear disk (CND) and Sgr A* using the Nobeyama Radio Observatory (NRO) 45 m radio telescope. The target positions are two tangential points of the CND and the direction of Sgr A*. We have obtained three wide-band spectra which cover the frequency range from 81.3 GHz to 115.8 GHz, detecting 46 molecular lines from 30 species including 10 rare isotopomers and four hydrogen recombination lines. Each line profile consists of multiple velocity components which arise from the CND, +50 km/s and +20 km/s clouds (GMCs), and the foreground spiral arms. We define the specific velocity ranges which represent the CND and the GMCs toward each direction, and classify the detected lines into three categories: the CND-/GMC-/HBD-types, based on the line intensities integrated over the defined velocity ranges. The CND- and GMC-types are the lines which mainly trace the CND and the GMCs, respectively. The HBD-type possesses the both charact...

  9. Solar Energetic Particle Acceleration in the Solar Corona with Simulated Field Line Random Walk and Wave Generation

    Science.gov (United States)

    Arthur, A. D.; le Roux, J. A.

    2014-12-01

    Observations of extreme solar energetic particle (SEP) events associated with coronal mass ejection driven shocks have detected particle energies up to a few GeV at 1 AU within the first ~10 minutes to 1 hour of shock acceleration. It is currently not well understood whether or not shock acceleration can act alone in these events or if some combination of successive shocks or solar flares is required. To investigate this, we updated our current model which has been successfully applied to the termination shock and traveling interplanetary shocks. The model solves the time-dependent Focused Transport Equation including particle preheating due to the cross shock electric field and the divergence, adiabatic compression, and acceleration of the solar wind. Particle interaction with MHD wave turbulence is modeled in terms of gyro-resonant interactions with parallel propagating Alfvén waves and diffusive shock acceleration is included via the first-order Fermi mechanism for parallel shocks. The observed onset times of the extreme SEP events place the shock in the corona when the particles escape upstream, therefore, we extended our model to include coronal conditions for the solar wind and magnetic field. Additional features were introduced to investigate two aspects of MHD wave turbulence in contributing to efficient particle acceleration at a single fast parallel shock; (1) We simulate field-line random walk on time scales much larger than a particle gyro-period to investigate how the stochastic element added to particle injection and the first-order Fermi mechanism affects the efficiency of particle acceleration. (2) Previous modeling efforts show that the ambient solar wind turbulence is too weak to quickly accelerate SEPs to GeV energies. To improve the efficiency of acceleration for a single shock, we included upstream Alfvén wave amplification due to gyro-resonant interactions with SEPs and we constrained the wave growth to not violate the Bohm limit.

  10. Side Branch Interaction with Main Line Standing Waves and Related Signal Handling Approaches

    Directory of Open Access Journals (Sweden)

    Arthur Ruggles

    2013-01-01

    Full Text Available Data from a low pressure air test facility are used to quantify the influence of the acoustic field in the main line on side branch resonance behavior. The main line of diameter = 7.6 cm may accumulate acoustic energy broadcast from a resonating branch of diameter = 1.9 cm ( = 0.25. The side branch resonance amplitude is a strong function of branch position along the main line with the normalized pressure rising to 1.2 in the most favorable branch positions with Strouhal number near 0.3. Large time variation of the side branch and main line resonance amplitude is apparent for most branch positions. A moving window is used on the time history to collect an array of power spectral densities (PSDs. Peak amplitude values from the PSD array are represented in a probability density function (PDF that provides a repeatable characterization of data from the system.

  11. LINES

    Directory of Open Access Journals (Sweden)

    Minas Bakalchev

    2015-10-01

    Full Text Available The perception of elements in a system often creates their interdependence, interconditionality, and suppression. The lines from a basic geometrical element have become the model of a reductive world based on isolation according to certain criteria such as function, structure, and social organization. Their traces are experienced in the contemporary world as fragments or ruins of a system of domination of an assumed hierarchical unity. How can one release oneself from such dependence or determinism? How can the lines become less “systematic” and forms more autonomous, and less reductive? How is a form released from modernistic determinism on the new controversial ground? How can these elements or forms of representation become forms of action in the present complex world? In this paper, the meaning of lines through the ideas of Le Corbusier, Leonidov, Picasso, and Hitchcock is presented. Spatial research was made through a series of examples arising from the projects of the architectural studio “Residential Transformations”, which was a backbone for mapping the possibilities ranging from playfulness to exactness, as tactics of transformation in the different contexts of the contemporary world.

  12. Performance evaluation of MLP and RBF feed forward neural network for the recognition of off-line handwritten characters

    Science.gov (United States)

    Rishi, Rahul; Choudhary, Amit; Singh, Ravinder; Dhaka, Vijaypal Singh; Ahlawat, Savita; Rao, Mukta

    2010-02-01

    In this paper we propose a system for classification problem of handwritten text. The system is composed of preprocessing module, supervised learning module and recognition module on a very broad level. The preprocessing module digitizes the documents and extracts features (tangent values) for each character. The radial basis function network is used in the learning and recognition modules. The objective is to analyze and improve the performance of Multi Layer Perceptron (MLP) using RBF transfer functions over Logarithmic Sigmoid Function. The results of 35 experiments indicate that the Feed Forward MLP performs accurately and exhaustively with RBF. With the change in weight update mechanism and feature-drawn preprocessing module, the proposed system is competent with good recognition show.

  13. Experimental study of the effects of couple weak waves on laminar-turbulent transition on attachment-line of a swept cylinder

    Science.gov (United States)

    Yermolaev, Yu. G.; Yatskih, A. A.; Kosinov, A. D.; Semionov, N. V.; Kolosov, G. L.; Panina, A. V.

    2016-10-01

    An experiment on a swept cylinder with 68°-sweep angle at Mach number M = 2.5 is described. The flow attachment line was disturbed by two weak shock waves. Shock waves were generated by a two-dimensional surface inhomogeneity on the wall of the test section of wind tunnel. It was found that the laminar-turbulent transition on the attachment-line of the cylinder is accompanied by an uneven growth of pulsations. Influence of Mach waves on the transition when their fall on the cylinder far away from domain of measuring is not observed. The laminar-turbulent transition occurs at a much lower unit Reynolds numbers in the case when a pair of waves falling on the attachment-line near the measurement field.

  14. Properties of leaky waves supported by grounded dielectric super-layers and implications on the design of reflector feeds

    NARCIS (Netherlands)

    Neto, A.; Llombart, N.; Gerini, G.; Bonnedal, M.; Maagt, P. de

    2007-01-01

    The design strategy that uses dielectric super-layers with neighboring wave-guides closed in matched loads constitutes a worst case scenario as far as the performance enhancement is concerned and finds applicability in radiometric imaging arrays. On the other side the design strategy that uses diele

  15. Properties of leaky waves supported by grounded dielectric super-layers and implications on the design of reflector feeds

    NARCIS (Netherlands)

    Neto, A.; Llombart, N.; Gerini, G.; Bonnedal, M.; Maagt, P. de

    2007-01-01

    The design strategy that uses dielectric super-layers with neighboring wave-guides closed in matched loads constitutes a worst case scenario as far as the performance enhancement is concerned and finds applicability in radiometric imaging arrays. On the other side the design strategy that uses diele

  16. Ground-Wave Propagation Effects on Transmission Lines through Error Images

    Directory of Open Access Journals (Sweden)

    Uribe-Campos Felipe Alejandro

    2014-07-01

    Full Text Available Electromagnetic transient calculation of overhead transmission lines is strongly influenced by the natural resistivity of the ground. This varies from 1-10K (Ω·m depending on several media factors and on the physical composition of the ground. The accuracy on the calculation of a system transient response depends in part in the ground return model, which should consider the line geometry, the electrical resistivity and the frequency dependence of the power source. Up to date, there are only a few reports on the specialized literature about analyzing the effects produced by the presence of an imperfectly conducting ground of transmission lines in a transient state. A broad range analysis of three of the most often used ground-return models for calculating electromagnetic transients of overhead transmission lines is performed in this paper. The behavior of modal propagation in ground is analyzed here into effects of first and second order. Finally, a numerical tool based on relative error images is proposed in this paper as an aid for the analyst engineer to estimate the incurred error by using approximate ground-return models when calculating transients of overhead transmission lines.

  17. Analytical and experimental procedures for determining propagation characteristics of millimeter-wave gallium arsenide microstrip lines

    Science.gov (United States)

    Romanofsky, Robert R.

    1989-01-01

    In this report, a thorough analytical procedure is developed for evaluating the frequency-dependent loss characteristics and effective permittivity of microstrip lines. The technique is based on the measured reflection coefficient of microstrip resonator pairs. Experimental data, including quality factor Q, effective relative permittivity, and fringing for 50-omega lines on gallium arsenide (GaAs) from 26.5 to 40.0 GHz are presented. The effects of an imperfect open circuit, coupling losses, and loading of the resonant frequency are considered. A cosine-tapered ridge-guide text fixture is described. It was found to be well suited to the device characterization.

  18. Small Footprint Multilayered Millimeter-Wave Antennas and Feeding Networks for Multi-Dimensional Scanning and High-Density Integrated Systems

    Directory of Open Access Journals (Sweden)

    T. Djerafi

    2012-12-01

    Full Text Available This paper overviews the state-of-the-art of substrate integrated waveguide (SIW techniques in the design and realization of innovative low-cost, low-profile and low-loss (L3 millimeter-wave antenna elements, feeding networks and arrays for various wireless applications. Novel classes of multilayered antenna structures and sys-tems are proposed and studied to exploit the vertical di-mension of planar structures to overcome certain limita-tions in standard two-dimensional (2-D topologies. The developed structures are based on two techniques, namely multi-layer stacked structures and E-plane corners. Differ-ent E-plane structures realised with SIW waveguide are presented, thereby demonstrating the potential of the proposed techniques as in multi-polarization antenna feeding. An array of 128 elements shows low SLL and height gain with just 200g of the total weight. Two versions of 2-D scanning multi-beam are presented, which effectively combine frequency scanning with beam forming networks. Adding the benefits of wide band performance to the multilayer structure, two bi-layer structures are investigated. Different stacked antennas and arrays are demonstrated to optimise the targeted antenna performances in the smallest footprint possible. These structures meet the requirement for developing inexpensive compact millimeter-wave antennas and antenna systems. Different structures and architectures are theoretically and experimentally studied and discussed for specific space- and ground-based appli-cations. Practical issues such as high-density integration and high-volume manufacturability are also addressed.

  19. Simultaneous determination of three banned psychiatric drugs in pig feed and tissue using solid-phase reactor on-line oxidizing and HPLC-fluorescence detection.

    Science.gov (United States)

    Qi, Liang; Duan, Li-Min; Sun, Xiao-Huan; Zhang, Jing; Zhang, Zhi-Qi

    2015-10-01

    The banned addition of psychiatric drugs such as phenothiazines to animal feed and foodstuffs increases the risk of human organ lesion. Phenothiazines usually exhibit weak native fluorescence and can be oxidized to strongly fluorescent compounds. In this study, a novel, sensitive and convenient method of HPLC-fluorescence detection based on post-column on-line oxidizing with lead dioxide solid-phase reactor has been developed for simultaneous determination of three banned psychotropic drugs, promethazine, chlorpromazine and thioridazine. Three compounds were successfully separated on an Agilent TC-C18 column with mobile phase of acetonitrile (A) and water (B), both containing 0.5% (v/v) formic acid. A gradient elution was programmed and fluorimetric detection was performed at λex /λem of 332/373 nm for promethazine, 340/380 nm for chlorpromazine and 352/432 nm for thioridazine. The calibration graphs gave good linearity over the concentration ranges of 30.0-4976.4 µg/L for promethazine, 2.0-2153.2 µg/L for chlorpromazine, and 15.0-3088.0 µg/L for thioridazine, and correlation coefficients (r) were ≥0.995. The method was applied to the determination of phenothiazines in pig feed and pig tissue, and the average spiked recoveries were in the range 69.1-115.4%.

  20. Performance and feeding behaviour of two biotypes of the black currant-lettuce aphid, Nasonovia ribisnigri, on resistant and susceptible Lactuca sativa near-isogenic lines.

    Science.gov (United States)

    ten Broeke, Cindy J M; Dicke, Marcel; van Loon, Joop J A

    2013-10-01

    The black currant-lettuce aphid, Nasonovia ribisnigri, is an important pest of cultivated lettuce, Lactuca sativa. Since 1982, the control of this aphid on lettuce is largely based on host plant resistance, conferred by the Nr gene, introgressed from Lactuca virosa. The resistance mechanism remains to be identified. N. ribisnigri populations virulent on the Nr-based resistance in lettuce have emerged in several locations in Europe since 2007. The objective of this study was to investigate the resistance mechanism mediated by the Nr gene in lettuce by detailed studies of aphid feeding behaviour and performance. Both avirulent (Nr:0) and virulent (Nr:1)biotypes of N. ribisnigri were studied on five resistant and two susceptible near isogenic lines (NILs). In addition, survival and colony development were quantified.Nr:0 aphids showed a strong decrease in sieve element ingestion and took longer to accept a sieve element on resistant NILs compared with susceptible NILs, and no aphids survived on the resistant NIL. Nr:1 aphids fed and performed equally well on the resistant and susceptible NILs. The resistance mechanism against Nr:0 aphids encoded by the Nr gene seems to be located in the phloem, although we also observed differences in feeding behaviour during the pathway phase to the phloem. Nr:1 aphids were highly virulent to the resistance conferred by the Nr gene. The consequences of the appearance of Nr:1 aphids for control of N. ribisnigri are discussed.

  1. High efficiency cell-recycle continuous sodium gluconate production by Aspergillus niger using on-line physiological parameters association analysis to regulate feed rate rationally.

    Science.gov (United States)

    Lu, Fei; Li, Chao; Wang, Zejian; Zhao, Wei; Chu, Ju; Zhuang, Yingping; Zhang, Siliang

    2016-11-01

    In this paper, a system of cell-recycle continuous fermentation for sodium gluconate (SG) production by Aspergillus niger (A. niger) was established. Based on initial continuous fermentation result (100.0h) with constant feed rate, an automatic feedback strategy to regulate feed rate using on-line physiological parameters (OUR and DO) was proposed and applied successfully for the first time in the improved continuous fermentation (240.5h). Due to less auxiliary time, highest SG production rate (31.05±0.29gL(-1)h(-1)) and highest yield (0.984±0.067molmol(-1)), overall SG production capacity (975.8±5.8gh(-1)) in 50-L fermentor of improved continuous fermentation increased more than 300.0% compared to that of batch fermentation. Improvement of mass transfer and dispersed mycelia morphology were the two major reasons responsible for the high SG production rate. This system had been successfully applied to industrial fermentation and SG production was greatly improved.

  2. Many-lined sun skinks (Mabuya multifasciata) do not compensate for the costs of tail loss by increasing feeding rate or digestive efficiency.

    Science.gov (United States)

    Sun, Yan-Yan; Yang, Jing; Ji, Xiang

    2009-02-01

    We used the many-lined sun skink (Mabuya multifasciata) as a model system to evaluate the energetic and locomotor costs of tail loss, and to examine whether tailless skinks compensate for the costs of tail loss by increasing feeding rate or digestive efficiency. We successively removed three tail segments from each of the 20 experimental skinks initially having intact tails. Energy content in each removed tail segment was measured, and swimming performance was measured for each experimental skink before and after each tail-removing treatment. Another independent sample of 19 skinks with intact tails were measured for swimming performance to serve as controls for successive measurements taken for the experimental skinks. Tailless experimental skinks and control skinks were then measured for food intake and digestive efficiency. Tail loss affected swimming speed, but the adverse influence was not significant until more than 55% of the tail (in length) was lost. Our data show that partial tail loss may not severely affect energy stores or locomotor performance in M. multifasciata. However, as tail breaks occurred more frequently in the proximal portion of the tail in skinks collected from the field, we conclude that caudal autotomy occurring in nature often incurs substantial energetic and locomotor costs. As tailless and tailed skinks did not differ in food intake, apparent digestive coefficient and assimilation efficiency, we conclude that tailless individuals do not compensate for the costs of tail loss by increasing feeding rate or digestive efficiency in M. multifasciata.

  3. Characterization and Analyses of Valves, Feed Lines and Tanks used in Propellant Delivery Systems at NASA SSC

    Science.gov (United States)

    Ryan, Harry M.; Coote, David J.; Ahuja, Vineet; Hosangadi, Ashvin

    2006-01-01

    Accurate modeling of liquid rocket engine test processes involves assessing critical fluid mechanic and heat and mass transfer mechanisms within a cryogenic environment, and accurately modeling fluid properties such as vapor pressure and liquid and gas densities as a function of pressure and temperature. The Engineering and Science Directorate at the NASA John C. Stennis Space Center has developed and implemented such analytic models and analysis processes that have been used over a broad range of thermodynamic systems and resulted in substantial improvements in rocket propulsion testing services. In this paper, we offer an overview of the analyses techniques used to simulate pressurization and propellant fluid systems associated with the test stands at the NASA John C. Stennis Space Center. More specifically, examples of the global performance (one-dimensional) of a propellant system are provided as predicted using the Rocket Propulsion Test Analysis (RPTA) model. Computational fluid dynamic (CFD) analyses utilizing multi-element, unstructured, moving grid capability of complex cryogenic feed ducts, transient valve operation, and pressurization and mixing in propellant tanks are provided as well.

  4. Wave

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo

    2008-01-01

    Estimates for the amount of potential wave energy in the world range from 1-10 TW. The World Energy Council estimates that a potential 2TW of energy is available from the world’s oceans, which is the equivalent of twice the world’s electricity production. Whilst the recoverable resource is many t...

  5. Millimeter-wave integrated circuits based on novel probe microstrip line and coplanar stripline exciters

    OpenAIRE

    Iezhov, Oleksandr; Omelianenko, Mykhaylo

    2009-01-01

    Novel designs of compact integrated waveguide exciters of microstrip line and coplanar stipline are presented in the paper. An E-plane microstrip 0-π phase-shift modulator with independent p-i-n diode control networks has been designed at 24 GHz on the basis of proposed exciters. The total length of the integrated circuit substrate including exciters is no more than 0.62 of waveguide wavelength.

  6. Molecular Line Emission from Multifluid Shock Waves. I. Numerical Methods and Benchmark Tests

    CERN Document Server

    Ciolek, Glenn E

    2013-01-01

    We describe a numerical scheme for studying time-dependent, multifluid, magnetohydrodynamic shock waves in weakly ionized interstellar clouds and cores. Shocks are modeled as propagating perpendicular to the magnetic field and consist of a neutral molecular fluid plus a fluid of ions and electrons. The scheme is based on operator splitting, wherein time integration of the governing equations is split into separate parts. In one part independent homogeneous Riemann problems for the two fluids are solved using Godunov's method. In the other equations containing the source terms for transfer of mass, momentum, and energy between the fluids are integrated using standard numerical techniques. We show that, for the frequent case where the thermal pressures of the ions and electrons are << magnetic pressure, the Riemann problems for the neutral and ion-electron fluids have a similar mathematical structure which facilitates numerical coding. Implementation of the scheme is discussed and several benchmark tests ...

  7. Molecular Line Emission from Multifluid Shock Waves. I. Numerical Methods and Benchmark Tests

    Science.gov (United States)

    Ciolek, Glenn E.; Roberge, Wayne G.

    2013-05-01

    We describe a numerical scheme for studying time-dependent, multifluid, magnetohydrodynamic shock waves in weakly ionized interstellar clouds and cores. Shocks are modeled as propagating perpendicular to the magnetic field and consist of a neutral molecular fluid plus a fluid of ions and electrons. The scheme is based on operator splitting, wherein time integration of the governing equations is split into separate parts. In one part, independent homogeneous Riemann problems for the two fluids are solved using Godunov's method. In the other, equations containing the source terms for transfer of mass, momentum, and energy between the fluids are integrated using standard numerical techniques. We show that, for the frequent case where the thermal pressures of the ions and electrons are Lt magnetic pressure, the Riemann problems for the neutral and ion-electron fluids have a similar mathematical structure which facilitates numerical coding. Implementation of the scheme is discussed and several benchmark tests confirming its accuracy are presented, including (1) MHD wave packets ranging over orders of magnitude in length- and timescales, (2) early evolution of multifluid shocks caused by two colliding clouds, and (3) a multifluid shock with mass transfer between the fluids by cosmic-ray ionization and ion-electron recombination, demonstrating the effect of ion mass loading on magnetic precursors of MHD shocks. An exact solution to an MHD Riemann problem forming the basis for an approximate numerical solver used in the homogeneous part of our scheme is presented, along with derivations of the analytic benchmark solutions and tests showing the convergence of the numerical algorithm.

  8. MOLECULAR LINE EMISSION FROM MULTIFLUID SHOCK WAVES. I. NUMERICAL METHODS AND BENCHMARK TESTS

    Energy Technology Data Exchange (ETDEWEB)

    Ciolek, Glenn E.; Roberge, Wayne G., E-mail: cioleg@rpi.edu, E-mail: roberw@rpi.edu [New York Center for Astrobiology (United States); Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180 (United States)

    2013-05-01

    We describe a numerical scheme for studying time-dependent, multifluid, magnetohydrodynamic shock waves in weakly ionized interstellar clouds and cores. Shocks are modeled as propagating perpendicular to the magnetic field and consist of a neutral molecular fluid plus a fluid of ions and electrons. The scheme is based on operator splitting, wherein time integration of the governing equations is split into separate parts. In one part, independent homogeneous Riemann problems for the two fluids are solved using Godunov's method. In the other, equations containing the source terms for transfer of mass, momentum, and energy between the fluids are integrated using standard numerical techniques. We show that, for the frequent case where the thermal pressures of the ions and electrons are << magnetic pressure, the Riemann problems for the neutral and ion-electron fluids have a similar mathematical structure which facilitates numerical coding. Implementation of the scheme is discussed and several benchmark tests confirming its accuracy are presented, including (1) MHD wave packets ranging over orders of magnitude in length- and timescales, (2) early evolution of multifluid shocks caused by two colliding clouds, and (3) a multifluid shock with mass transfer between the fluids by cosmic-ray ionization and ion-electron recombination, demonstrating the effect of ion mass loading on magnetic precursors of MHD shocks. An exact solution to an MHD Riemann problem forming the basis for an approximate numerical solver used in the homogeneous part of our scheme is presented, along with derivations of the analytic benchmark solutions and tests showing the convergence of the numerical algorithm.

  9. High-performance traveling-wave electroabsorption modulators utilizing mushroom-type waveguide and periodic transmission line loading

    Institute of Scientific and Technical Information of China (English)

    Kambiz Abedi

    2012-01-01

    For the first time,periodic loaded electrodes and mushroom-type waveguide are combined to improve the performance of traveling-wave electroabsorption modulators (TWEAMs) based on the asymmetric intra-step-barrier coupled double strained quantum well (AICD-SQW).The electrical modulation response of periodic mushroom-type TWEAM is obtained by using equivalent circuit model,and is compared with simulation result of conventional mushroom-type TWEAM counterpart.The equivalent circuit model simulation results indicate that for the exemplary modulation length of 300 μm,the mushroom-type TWEAM with periodic transmission line loading can achieve much wider bandwidth about 99.7 GHz and 43.1GHz than the conventional counterpart with about 43 GHz and 33 GHz for 35 Ω and 45 Ω terminations,respectively.

  10. Simulations of the Mg II k and Ca II 8542 lines from an Alfv\\'en Wave-heated flare chromosphere

    CERN Document Server

    Kerr, Graham S; Russell, Alexander J B; Allred, Joel C

    2016-01-01

    We use radiation hydrodynamic simulations to examine two models of solar flare chromospheric heating: Alfv\\'en wave dissipation and electron beam collisional losses. Both mechanisms are capable of strong chromospheric heating, and we show that the distinctive atmospheric evolution in the mid-to-upper chromosphere results in Mg II k-line emission that should be observably different between wave-heated and beam-heated simulations. We also present Ca II 8542A profiles which are formed slightly deeper in the chromosphere. The Mg II k-line profiles from our wave-heated simulation are quite different from those from a beam-heated model and are more consistent with IRIS observations. The predicted differences between the Ca II 8542A in the two models are small. We conclude that careful observational and theoretical study of lines formed in the mid-to-upper chromosphere holds genuine promise for distinguishing between competing models for chromospheric heating in flares.

  11. Identification of acoustic wave propagation in a duct line and its application to detection of impact source location based on signal processing

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Yong Woo; Kim, Min Soo; Lee, Sang Kwon [Inha University, Seoul (Korea, Republic of)

    2010-12-15

    For the detection of the impact location in a pipeline system, the correlation method has been the conventional method. For the application of the correlation method, the diameter of a duct should be small so that the acoustic wave inside the duct can propagate with nondispersive characteristics, in the form of, for example, a plane wave. This correlation method calculates the cross-correlation between acoustic waves measured at two acceleration sensors attached to a buried duct. It also gives information about the arrival time delay of an acoustic wave between two sensors. These arrival time delays are used for the estimation of the impact location. However, when the diameter of the duct is large, the acoustic waves inside the duct propagate with dispersive characteristics owing to the reflection of the acoustic wave off of the wall of the duct. This dispersive characteristic is related to the acoustic modes inside a duct. Therefore, the correlation method does not work correctly for the detection of the impact location. This paper proposes new methods of accurately measuring the arrival time delay between two sensors attached to duct line system. This method is based on the time-frequency analyses of the short time Fourier transform (STFT) and continuous wavelet transform (CWT). These methods can discriminate direct waves (non-dispersive waves) and reflective waves (dispersive waves) from the measured wave signals through the time-frequency analysis. The direct wave or the reflective wave is used to estimate the arrival time delay. This delay is used for the identification of the impact location. This systematic method can predict the impact location due to the impact forces of construction equipment with more accuracy than the correlation method

  12. Comment on "Compact envelope dark solitary wave in a discrete nonlinear electrical transmission line" [Phys. Lett. A 373 (2009) 3801-3809

    Science.gov (United States)

    Yamgoué, Serge Bruno; Pelap, François Beceau

    2016-05-01

    We revisit the derivation of the equation modeling envelope waves in a discrete nonlinear electrical transmission line (NLTL) considered a few years back in Physics Letters A 373 (2009) 3801-3809. Using a combination of rotating wave approximation and the Gardner-Morikawa transformation, we show that the modulated waves are described by a new type of extended nonlinear Schrödinger equation. In addition the expressions of several coefficients of this equation are found to be strongly different from those given earlier. As a consequence, key relationships between these coefficients that sustained the previous analysis are broken.

  13. On line power spectra identification and whitening for the noise in interferometric gravitational wave detectors

    CERN Document Server

    Cuoco, E; Fabbroni, L; Losurdo, G; Mazzoni, M; Stanga, R M; Vetrano, F

    2001-01-01

    In this paper we address both to the problem of identifying the noise Power Spectral Density of interferometric detectors by parametric techniques and to the problem of the whitening procedure of the sequence of data. We will concentrate the study on a Power Spectral Density like the one of the Italian-French detector VIRGO and we show that with a reasonable finite number of parameters we succeed in modeling a spectrum like the theoretical one of VIRGO, reproducing all its features. We propose also the use of adaptive techniques to identify and to whiten on line the data of interferometric detectors. We analyze the behavior of the adaptive techniques in the field of stochastic gradient and in the Least Squares ones.

  14. On-line crack prognosis in attachment lug using Lamb wave-deterministic resampling particle filter-based method

    Science.gov (United States)

    Yuan, Shenfang; Chen, Jian; Yang, Weibo; Qiu, Lei

    2017-08-01

    Fatigue crack growth prognosis is important for prolonging service time, improving safety, and reducing maintenance cost in many safety-critical systems, such as in aircraft, wind turbines, bridges, and nuclear plants. Combining fatigue crack growth models with the particle filter (PF) method has proved promising to deal with the uncertainties during fatigue crack growth and reach a more accurate prognosis. However, research on prognosis methods integrating on-line crack monitoring with the PF method is still lacking, as well as experimental verifications. Besides, the PF methods adopted so far are almost all sequential importance resampling-based PFs, which usually encounter sample impoverishment problems, and hence performs poorly. To solve these problems, in this paper, the piezoelectric transducers (PZTs)-based active Lamb wave method is adopted for on-line crack monitoring. The deterministic resampling PF (DRPF) is proposed to be used in fatigue crack growth prognosis, which can overcome the sample impoverishment problem. The proposed method is verified through fatigue tests of attachment lugs, which are a kind of important joint component in aerospace systems.

  15. On-line structural integrity monitoring and defect diagnosis of steam generators using analysis of guided acoustic waves

    Science.gov (United States)

    Lu, Baofu

    2005-11-01

    Integrity monitoring and flaw diagnostics of flat beams and tubular structures was investigated in this research using guided acoustic signals. The primary objective was to study the feasibility of using imbedded sensors for monitoring steam generator and heat exchanger tubing. A piezo-sensor suite was deployed to activate and collect Lamb wave signals that propagate along metallic specimens. The dispersion curves of Lamb waves along plate and tubular structures were generated through numerical analysis. Several advanced techniques were explored to extract representative features from acoustic time series. Among them, the Hilbert-Huang transform (HHT) is a recently developed technique for the analysis of non-linear and transient signals. A moving window method was introduced to generate the local peak characters from acoustic time series, and a zooming window technique was developed to localize the structural flaws. The dissertation presents the background of the analysis of acoustic signals acquired from piezo-electric transducers for structural defect monitoring. A comparison of the use of time-frequency techniques, including the Hilbert-Huang transform, is presented. It also presents the theoretical study of Lamb wave propagation in flat beams and tubular structures, and the need for mode separation in order to effectively perform defect diagnosis. The results of an extensive experimental study of detection, location, and isolation of structural defects in flat aluminum beams and brass tubes are presented. The time-frequency analysis and pattern recognition techniques were combined for classifying structural defects in brass tubes. Several types of flaws in brass tubes were tested, both in the air and in water. The techniques also proved to be effective under background/process noise. A detailed theoretical analysis of Lamb wave propagation was performed and simulations were carried out using the finite element software system ABAQUS. This analytical study

  16. Developing a narrow-line laser spectrometer based on a tunable continuous-wave dye laser

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chun; Lv, Shasha; Bi, Jin [Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Fang [College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093 (China); Li, Liufeng; Chen, Lisheng [Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan 430071, China and Laboratory of Atomic Frequency Standards, Chinese Academy of Sciences, Wuhan 430071 (China)

    2014-08-15

    We present the development of a dye-laser-based spectrometer operating at 550–600 nm. The spectrometer will be used to detect an ultra-narrow clock transition ({sup 1}S{sub 0}-{sup 3}P{sub 0}) in an Ytterbium optical lattice clock and perform high-resolution spectroscopy of iodine molecules trapped in the sub-nanometer channels of zeolite crystal (AlPO{sub 4}-11). Two-stage Pound-Drever-Hall frequency stabilization is implemented on the tunable continuous-wave dye laser to obtain a reliable operation and provide stable laser radiations with two different spectral linewidths. In the first-stage frequency locking, a compact home-built intracavity electro-optic modulator is adopted for suppressing fast frequency noise. With an acquisition time of 0.1 s the 670-kHz linewidth of the free-running dye laser is reduced to 2 kHz when locked to a pre-stabilization optical cavity with a finesse of 1170. When the pre-stabilized laser is locked to a high-finesse optical cavity, a linewidth of 1.4 Hz (2 s) is observed and the frequency stability is 3.7 × 10{sup −15} (3 s). We also measure and analyze the individual noise contributions such as those from residual amplitude modulation and electronic noise. The ongoing upgrades include improving long-term frequency stability at time scales from 10 to 100 s and implementing continuous frequency scan across 10 GHz with radio-frequency precision.

  17. A Love Wave Delay Line with Discontinuous Waveguide%波导层不连续的Love波延迟线

    Institute of Scientific and Technical Information of China (English)

    刘建生; 刘明华; 何世堂

    2009-01-01

    Acommon Love sensor consists of different waveguide and adsorption,a guide layer is fabricated on the device and then an absorption layer is plated on the waveguide in the sensitive area;however,thus the insertion loss of delay line will increase.A Love wave delay line with discontinuous guide layer was designed.An absorption layer is directly plated on the substrate as a waveguide the same time and another waveguide is plated on the other area.An experimental device is fabricated on a substrate of ST-90°X quartz;an Au layer is fabricated on the middle area as waveguide and absorption layer;SU-8 photo-resist is plated on the other area as wave guiding layer.The experimental results showed that the insertion loss designed in the paper was less than common structure delay line more than 2 dB.%Love波传感器的波导层和吸附层通常是不同材料的,一般先在整个器件表面覆盖一层声波导层材料,然后在感应区域对应的波导层上涂镀吸附层,但是这样会增大延迟线的插入损耗.文中设计了一种不连续波导层的Love波延迟线,即在感应区域,吸附层直接镀在压电基片上,同时兼作声波导层;在其他区域覆盖声波导层材料.实验器件制作在ST-90°X石英晶体上,中间感应区域用Au作波导层和吸附层,其他区域采用SU-8光刻胶作声波导层,结果表明,采用这种结构的延迟线可以降低损耗2 dB以上.

  18. Genomewide association analysis of sow lactation performance traits in lines of Yorkshire pigs divergently selected for residual feed intake during grow-finish phase.

    Science.gov (United States)

    Thekkoot, D M; Young, J M; Rothschild, M F; Dekkers, J C M

    2016-06-01

    Lactation is an economically and biologically important phase in the life cycle of sows. Short generation intervals in nucleus herds and low heritability of traits associated with lactation along with challenges associated with collecting accurate lactation performance phenotypes emphasize the importance of using genomic tools to examine the underlying genetics of these traits. We report the first genomewide association study (GWAS) on traits associated with lactation and efficiency in 2 lines of Yorkshire pigs that were divergently selected for residual feed intake during grow-finish phase. A total of 862 farrowing records from 2 parities were analyzed using a Bayesian whole genome variable selection model (Bayes B) to locate 1-Mb regions that were most strongly associated with each trait. The GWAS was conducted separately for parity 1 and 2 records. Marker-based heritabilities ranged from 0.03 to 0.39 for parity 1 traits and from 0.06 to 0.40 for parity 2 traits. For all traits studied, around 90% of genetic variance came from a large number of genomic regions with small effects, whereas genomic regions with large effects were found to be different for the same trait measured in parity 1 and 2. The highest percentage of genetic variance explained by a 1-Mb window for each trait ranged from 0.4% for feed intake during lactation to 4.2% for back fat measured at farrowing in parity 1 sows and from 0.2% for lactation feed intake to 5.4% for protein mass loss during lactation in parity 2 sows. A total of thirteen 1-Mb nonoverlapping windows were found to explain more than 1.5% of genetic variance for either a single trait or across multiple traits. These 1-Mb windows were on chromosomes 2, 3, 6, 7, 8, 11, 14, 15, 17, and 18. The major positional candidate genes within 1 Mb upstream and downstream of these windows were , (SSC2), (SSC6) (SSC7), (SSC8), (SSC11), (SSC14), (SSC17). Further validation studies on larger populations are required to validate these findings and

  19. In-line broadband 270 degrees (3lambda/4) chevron four-reflection wave retarders.

    Science.gov (United States)

    Azzam, R M A; Khanfar, H K

    2008-09-20

    The net differential phase shift Delta(t) introduced between the orthogonal p and s linear polarizations after four successive total internal reflections inside an in-line chevron dual-Fresnel-rhomb retarder is a function of the first internal angle of incidence phi and prism refractive index n. Retardance of 3lambda/4 (i.e., Delta(t)=270 degrees) is achieved with minimum angular sensitivity when phi=45 degrees and n=1.900822. Several optical glasses with this refractive index are identified. For Schott glass SF66 the deviation of Delta(t) from 270 degrees is three octaves (0.5 to 4.5 microm) in the visible, near-, and mid-IR spectral range. Another mid-IR 3lambda/4 retarder uses a Si prism, which is coated by an optically thick silicon oxynitride film of the proper composition, to achieve retardance that differs from 270 degrees by < 0.5 degrees over the 3-5 microm spectral range.

  20. APPLICATION OF COLUMN EXTRACTION METHOD FOR IMPURITIES ANALYSIS ON HB-LINE PLUTONIUM OXIDE IN SUPPORT OF MOX FEED PRODUCT SPECIFICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Jones, M.; Diprete, D.; Wiedenman, B.

    2012-03-20

    The current mission at H-Canyon involves the dissolution of an Alternate Feedstocks 2 (AFS-2) inventory that contains plutonium metal. Once dissolved, HB-Line is tasked with purifying the plutonium solution via anion exchange, precipitating the Pu as oxalate, and calcining to form plutonium oxide (PuO{sub 2}). The PuO{sub 2} will provide feed product for the Mixed Oxide (MOX) Fuel Fabrication Facility, and the anion exchange raffinate will be transferred to H-Canyon. The results presented in this report document the potential success of the RE resin column extraction application on highly concentrated Pu samples to meet MOX feed product specifications. The original 'Hearts Cut' sample required a 10000x dilution to limit instrument drift on the ICP-MS method. The instrument dilution factors improved to 125x and 250x for the sample raffinate and sample eluent, respectively. As noted in the introduction, the significantly lower dilutions help to drop the total MRL for the analyte. Although the spike recoveries were half of expected in the eluent for several key elements, they were between 94-98% after Nd tracer correction. It is seen that the lower ICD limit requirements for the rare earths are attainable because of less dilution. Especially important is the extremely low Ga limit at 0.12 {mu}g/g Pu; an ICP-MS method is now available to accomplish this task on the sample raffinate. While B and V meet the column A limits, further development is needed to meet the column B limits. Even though V remained on the RE resin column, an analysis method is ready for investigation on the ICP-MS, but it does not mean that V cannot be measured on the ICP-ES at a low dilution to meet the column B limits. Furthermore, this column method can be applicable for ICP-ES as shown in Table 3-2, in that it trims the sample of Pu, decreasing and sometimes eliminating Pu spectral interferences.

  1. FTS Measurements of Submillimeter-Wave Atmospheric Opacity at Pampa la Bola: III. Water Vapor, Liquid Water, and 183GHz Water Vapor Line Opacities

    Science.gov (United States)

    Matsushita, Satoki; Matsuo, Hiroshi

    2003-02-01

    Further analysis has been made on the millimeter- and submillimeter-wave (100-1600GHz or 3mm-188 μm) atmospheric opacity data taken with the Fourier Transform Spectrometer (FTS) at Pampa la Bola, 4800 m above the sea level in northern Chile, which is the site of the Atacama Large Millimeter/submillimeter Array (ALMA). Time-sequence plots of millimeter- and submillimeter-wave opacities show similar variations to each other, except for during the periods with liquid water (fog or clouds) in the atmosphere. Using millimeter- and submillimeter-wave opacity correlations under two conditions, which are affected and not affected by liquid water, we succeeded to separate the measured opacity into water vapor and liquid water opacity components. The water vapor opacity shows a good correlation with the 183GHz water vapor line opacity, which is also covered in the measured spectra. On the other hand, the liquid water opacity and the 183GHz line opacity show no correlation. S ince only the water vapor component is expected to affect the phase of interferometers significantly, and the submillimeter-wave opacity is less affected by the liquid water component, it may be possible to use the submillimeter-wave opacity for a phase correction of submillimeter interferometers.

  2. Design of Coplanar Waveguide Interdigital Slow Wave Delay Line%共面波导交指慢波延迟线设计

    Institute of Scientific and Technical Information of China (English)

    梅亮; 张华; 王继财

    2012-01-01

    This paper presents a design of coplanar waveguide interdigital slow wave delay line, describes the theory of slow wave delay line, and obtains optimized parameters of delay line by electromagnetic simulating software. The delay line which works on X wave band, has 7λ (about 700 ps) delay on center frequency and insertion loss of 2. 0 dB. The measured results are in good agreement with the simulated ones.%提出了一种共面波导交指慢波延迟线的设计,介绍了慢波延迟线工作原理,利用电磁仿真软件优化得到了延迟线的各项参数.该延迟线工作在x波段,具有中心频率7λ(约700 ps)的延迟,延迟线的插入损耗约2.0 dB.延迟线的实测与仿真结果吻合较好.

  3. Improvement of specific growth rate of Pichia pastoris for effective porcine interferon-α production with an on-line model-based glycerol feeding strategy.

    Science.gov (United States)

    Gao, Min-Jie; Zheng, Zhi-Yong; Wu, Jian-Rong; Dong, Shi-Juan; Li, Zhen; Jin, Hu; Zhan, Xiao-Bei; Lin, Chi-Chung

    2012-02-01

    Effective expression of porcine interferon-α (pIFN-α) with recombinant Pichia pastoris was conducted in a bench-scale fermentor. The influence of the glycerol feeding strategy on the specific growth rate and protein production was investigated. The traditional DO-stat feeding strategy led to very low cell growth rate resulting in low dry cell weight (DCW) of about 90 g/L during the subsequent induction phase. The previously reported Artificial Neural Network Pattern Recognition (ANNPR) model-based glycerol feeding strategy improved the cell density to 120 g DCW/L, while the specific growth rate decreased from 0.15 to 0.18 to 0.03-0.08 h(-1) during the last 10 h of the glycerol feeding stage leading to a variation of the porcine interferon-α production, as the glycerol feeding scheme had a significant effect on the induction phase. This problem was resolved by an improved ANNPR model-based feeding strategy to maintain the specific growth rate above 0.11 h(-1). With this feeding strategy, the pIFN-α concentration reached a level of 1.43 g/L, more than 1.5-fold higher than that obtained with the previously adopted feeding strategy. Our results showed that increasing the specific growth rate favored the target protein production and the glycerol feeding methods directly influenced the induction stage. Consequently, higher cell density and specific growth rate as well as effective porcine interferon-α production have been achieved by our novel glycerol feeding strategy.

  4. Correlation Analysis Algorithm for Transmission Line Fault Location Based on Travelling Wave%行波相关法的输电线路故障定位

    Institute of Scientific and Technical Information of China (English)

    杜林; 庞军; 司马文霞

    2008-01-01

    This paper introduced correlation method to locate transmission line fault. First it described the principle of transmission line fault location based on traveling waves. The principle of correlation analysis is introduced, then the method using correlation analysis in fault location is given. Transmission line model is established with EMTP-ATP. Basing on the model, some kinds of fault are simulated. The feasibility of this algorithm is proved based on simulation results. By comparing with the classical wavelet analysis, this paper gave the advantages of this algorithm in two cases:noise influence suppression and accuracy of near distance fault location. Experiment is established to simulate transmission line grounding fault. The experiment result showed the correlation algorithm's validity . All the analysis result indicated that the correlation algorithm have a high precision.

  5. Ultra-High-Speed Travelling Wave Protection of Transmission Line Using Polarity Comparison Principle Based on Empirical Mode Decomposition

    Directory of Open Access Journals (Sweden)

    Dong Wang

    2015-01-01

    Full Text Available The traditional polarity comparison based travelling wave protection, using the initial wave information, is affected by initial fault angle, bus structure, and external fault. And the relationship between the magnitude and polarity of travelling wave is ignored. Because of the protection tripping and malfunction, the further application of this protection principle is affected. Therefore, this paper presents an ultra-high-speed travelling wave protection using integral based polarity comparison principle. After empirical mode decomposition of the original travelling wave, the first-order intrinsic mode function is used as protection object. Based on the relationship between the magnitude and polarity of travelling wave, this paper demonstrates the feasibility of using travelling wave magnitude which contains polar information as direction criterion. And the paper integrates the direction criterion in a period after fault to avoid wave head detection failure. Through PSCAD simulation with the typical 500 kV transmission system, the reliability and sensitivity of travelling wave protection were verified under different factors’ affection.

  6. TEM Wave in an Elliptic Cylinder Transmission Line and the Characteristic Impedance%椭圆柱传输线内的TEM波及其特性阻抗

    Institute of Scientific and Technical Information of China (English)

    王福谦

    2011-01-01

    利用复数坐标系z上的儒可夫斯基变换,给出椭圆柱传输线内的TEM波的电磁场分布规律,利用数学软件Matlab绘制出TEM波在椭圆柱传输线横向截面上的场结构图,并计算出其特性阻抗。%By using Roucofeskie's conversion in complex coordinate system the distribution law of the electromagnetic field of the TEM wave in an elliptic cylinder transmission line is given, and by using Matlab software the map of the electromagnetic field structure of TEM wave in the cross-section of the elliptic cylinder transmission line is plotted, and its characteristic impedance is calculated.

  7. 一种新型微带曲折线慢波结构的设计%Design of a New Microstrip Meander-Line Slow Wave Structure

    Institute of Scientific and Technical Information of China (English)

    陈常婷; 宫玉彬; 沈飞; 魏彦玉; 王文祥

    2011-01-01

    设计了一种新型微带曲折线慢波结构,该结构采用双介质杆支撑式的V型平面曲折线慢波电路.利用电磁场仿真软件HFSS对这种新型结构和传统微带曲折线慢波结构进行了分析比较,研究结果表明,新型微带曲折线慢波结构在不改变色散强弱的情况下,工作频段向高频端拓展且耦合阻抗有了很大提高,可以更好地工作在短毫米波段.并仿真分析了结构参数对高频特性的影响,所获得的仿真结果为器件的粒子模拟及计算慢波结构的工作效率奠定了基础.%A new microstrip meander-line slow wave structure was designed, which uses the V-type plane meander-line slow wave circuit with twin dielectric-strips.The performances of the new microstrip meander-line slow wave structure and the traditional meander-line slow wave structure were compared by using of the electromagnetic simulation software HFSS.The effects of different structural parameters on the new structure were analyzed.The simulation results show that the new microstrip meander-line slow wave structure has a similar dispersion characteristic with the traditional structure, and the center frequency expands to the higher frequency, and the coupling impedance is greatly improved.Hence the new structure can work much better in millimeter wave band.The results lay a good foundation for particle-in-cell (PIC) simulation and efficiency caculation.

  8. Simulations of the Mg II k and Ca II 8542 lines from an AlfvÉn Wave-heated Flare Chromosphere

    Science.gov (United States)

    Kerr, Graham S.; Fletcher, Lyndsay.; Russell, Alexander J. B.; Allred, Joel C.

    2016-08-01

    We use radiation hydrodynamic simulations to examine two models of solar flare chromospheric heating: Alfvén wave dissipation and electron beam collisional losses. Both mechanisms are capable of strong chromospheric heating, and we show that the distinctive atmospheric evolution in the mid-to-upper chromosphere results in Mg ii k-line emission that should be observably different between wave-heated and beam-heated simulations. We also present Ca ii 8542 Å profiles that are formed slightly deeper in the chromosphere. The Mg ii k-line profiles from our wave-heated simulation are quite different from those from a beam-heated model and are more consistent with Interface Region Imaging Spectrograph observations. The predicted differences between the Ca ii 8542 Å in the two models are small. We conclude that careful observational and theoretical study of lines formed in the mid-to-upper chromosphere holds genuine promise for distinguishing between competing models for chromospheric heating in flares.

  9. Stimulated electromagnetic emission and plasma line during pump wave frequency stepping near 4th electron gyroharmonic at HAARP

    Science.gov (United States)

    Grach, Savely; Sergeev, Evgeny; Shindin, Alexey; Mishin, Evgeny; Watkins, Brenton

    Concurrent observations of stimulated (secondary) electromagnetic emissions (SEE) and incoherent plasma line (PL) backscatter from the MUIR radar during HF pumping of the ionosphere by the HAARP heating facility (62.4(°) °N, 145.15(°) W, magnetic inclination α = 75.8^circ) with the pump wave (PW) frequency sweeps about the fourth electron gyroharmonic (4f_c) are presented. The PW frequency f0 was changed every 0.2 s in a 1-kHz step, i.e. with the rate of r_{f_0}=5 kHz/s. PW was transmitted at the magnetic zenith (MZ). Prior to sweeping, PW was transmitted continuously (CW) during 2 min at f_0 = 5730 kHz 4f_c, namely BUM_S and BUM_D. The former (stationary broad upshifted maxiμm) peaks at Delta f_{BUMs} approx f0 - nfc (d) + 15-20 kHz and is a typical SEE spectral feature. The latter, the dynamic BUM_D at smaller Delta f, is observed only at high pump powers (ERP=1.7 GW) and corresponds to artificial descending plasma layers created in the F-region ionosphere [1]. In the experiment in question, the BUM_D was present for f_0> f^*, where f^* was 5805-5815 kHz during stepping up and sim 10 kHz less for stepping down, and located 8-10 km below the background F-layer. The miniμm DM which indicated that f_0=4f_c=f_{uh} in the background ionospheric plasma, was sim 5760 kHz. The PL was observed only for f_0 4f_c. In this case we obtained Delta f_g sim 8-13 kHz corresponding to Delta h sim - 4 km. The PL has never been observed for f_0>f^*$. \\ 1. Sergeev E., Grach S., et al. //Phys. Rev. Lett., 110 (2013), 065002.

  10. The oxygen red OI 630.0 nm line nightglow intensity as an indicator of atmospheric waves propagation in the mid-latitude ionosphere F2 region

    Science.gov (United States)

    Javakhishvili, Giorgi; Didebulidze, Goderdzi; Gudadze, Nikoloz; Toriashvili, Lexo

    2016-04-01

    The behavior of the oxygen red OI 630.0 nm line nightglow intensity under influence of atmospheric gravity waves (AGWs) is considered, taking into account nightly changes of the thermosphere meridional wind by observations from Abastumani (41.75 N; 42.82 E). The vortical type perturbations, which can be in situ excited, are also considered. On the basis of theoretical model, the 630.0 nm line integral intensity variations are estimated taking into account thermosphere wind field changes and atmospheric waves propagation influence on the nighttime ionosphere F2 layer. A possibility of identification of waves propagation from polar and equatorial regions during various helio-geophysical conditions is noted. The cases of detected large scale traveling ionosphere disturbances -TIDs (mostly generated in the polar regions) and traveling atmospheric disturbances -TADs (which can be generated both in polar and equatorial regions) are demonstrated. Acknowledgements: This work has been supported by Shota Rustaveli National Science Foundation Grant no. 31/56.

  11. Finish line plant-insect interactions mediated by insect feeding mode and plant interference: a case study of Brassica interactions with diamondback moth and turnip aphid.

    Science.gov (United States)

    Soufbaf, Mahmoud; Fathipour, Yaghoub; Harvey, Jeffrey A; Hui, Cang

    2017-01-16

    There are gaps in our understanding of plant responses under different insect phytophagy modes and their subsequent effects on the insect herbivores' performance at late season. Here we compared different types of insect feeding by an aphid, Lipaphis erysimi, and a lepidopteran, Plutella xylostella, and how this affected defensive metabolites in leaves of 2 Brassica species when plants gain maturity. Thiocyanate concentrations after P. xylostella and L. erysimi feeding activities were the same. Total phenolics was higher after the phloem feeder feeding than the folivore activity. The plants compensatory responses (i.e., tolerance) to L. erysimi feeding was significantly higher than the responses to P. xylostella. This study showed that L. erysimi had higher carbon than P. xylostella whereas nitrogen in P. xylostella was 1.42 times that in L. erysimi. Population size of the phloem feeder was not affected by plant species or insect coexistence. However, there was no correlation between plant defensive metabolites and both insects' population size and biomass. This suggests that plant root biomass and tolerance index after different insect herbivory modes are not necessarily unidirectional. Importantly, the interaction between the folivore and the phloem feeder insects is asymmetric and the phloem feeder might be a trickier problem for plants than the folivore. Moreover, as both plants' common and special defenses decreased under interspecific interference, we suggest that specialist insect herbivores can be more challenged in ecosystems in which plants are not involved in interspecific interference. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  12. A Novel High-Frequency Voltage Standing-Wave Ratio-Based Grounding Electrode Line Fault Supervision in Ultra-High Voltage DC Transmission Systems

    Directory of Open Access Journals (Sweden)

    Yufei Teng

    2017-03-01

    Full Text Available In order to improve the fault monitoring performance of grounding electrode lines in ultra-high voltage DC (UHVDC transmission systems, a novel fault monitoring approach based on the high-frequency voltage standing-wave ratio (VSWR is proposed in this paper. The VSWR is defined considering a lossless transmission line, and the characteristics of the VSWR under different conditions are analyzed. It is shown that the VSWR equals 1 when the terminal resistance completely matches the characteristic impedance of the line, and when a short circuit fault occurs on the grounding electrode line, the VSWR will be greater than 1. The VSWR will approach positive infinity under metallic earth fault conditions, whereas the VSWR in non-metallic earth faults will be smaller. Based on these analytical results, a fault supervision criterion is formulated. The effectiveness of the proposed VSWR-based fault supervision technique is verified with a typical UHVDC project established in Power Systems Computer Aided Design/Electromagnetic Transients including DC(PSCAD/EMTDC. Simulation results indicate that the proposed strategy can reliably identify the grounding electrode line fault and has strong anti-fault resistance capability.

  13. Atmospheres of RR Lyrae Stars: Hypersonic Shock waves, Helium line detection and Magnetic fields. A few spectra for George Preston on the occasion of his birthday

    CERN Document Server

    Chadid, Merieme

    2011-01-01

    During intensive/comparative studies with Preston's spectroscopic works (1961, 1962, 1964 & 1965) on RR Lyrae atmospheric phenomena, I unexpectedly found the existence of hypersonic shock waves (Chadid 1996 & 2008), that are strongly connected with the turbulence amplification mechanism (Chadid 1996b) and the Blazhko modulation (1997). Here I will show how the hypersonic shocks are at the origin of helium line formation and connected with the helium emission and line doubling detected by Preston (2009, 2011). I will present new neutral and single ionized helium line data in the hypersonic Blazhko star S Arae. The He II appears as a weak emission and its origin is strongly connected with the hypersonic shock in S Arae. The shock is extremely strong and can reach a Mach number >30. The HeI lines first appear in emission, over ~2% of the pulsation period, followed by the HeI absorption doubling phenomenon occurring simultaneously with the neutral metallic absorption line phenomenon over ~8% of the pulsat...

  14. Finite-difference theory for sound propagation in a lined duct with uniform flow using the wave envelope concept

    Science.gov (United States)

    Baumeister, K. J.

    1977-01-01

    Finite difference equations are derived for sound propagation in a two dimensional, straight, soft wall duct with a uniform flow by using the wave envelope concept. This concept reduces the required number of finite difference grid points by one to two orders of magnitude depending on the length of the duct and the frequency of the sound. The governing acoustic difference equations in complex notation are derived. An exit condition is developed that allows a duct of finite length to simulate the wave propagation in an infinitely long duct. Sample calculations presented for a plane wave incident upon the acoustic liner show the numerical theory to be in good agreement with closed form analytical theory. Complete pressure and velocity printouts are given to some sample problems and can be used to debug and check future computer programs.

  15. On advanced variational formulation of the method of lines and its application to the wave propagation problems

    CSIR Research Space (South Africa)

    Shatalov, M

    2012-09-01

    Full Text Available of elastic wave over the bar and . If we add initial conditions and to the system of ordinary differential equations (3.5) the initial problem will be formulated and could be solved by one of the available numerical methods (Runge-Kutta, Adams, etc...

  16. Excitation of plasma waves by unstable photoelectron and thermal electron populations on closed magnetic field lines in the Martian ionosphere

    Directory of Open Access Journals (Sweden)

    N. Borisov

    2005-06-01

    Full Text Available It is argued that anisotropic electron pitch angle distributions in the closed magnetic field regions of the Martian ionosphere gives rise to excitation of plasma instabilities. We discuss two types of instabilities that are excited by two different populations of electrons. First, the generation of Langmuir waves by photoelectrons with energies of the order of 10eV is investigated. It is predicted that the measured anisotropy of their pitch angle distribution at the heights z≈400km causes excitation of waves with frequencies f~30kHz and wavelengths λ~30m. Near the terminators the instability of the electrostatic waves with frequencies of the order of or less than the electron gyrofrequency exited by thermal electrons is predicted. The typical frequencies of these waves depend on the local magnitude of the magnetic field and can achieve values f~3-5kHz above strong crustal magnetic fields.

  17. Distinguishing transient signals and instrumental disturbances in semi-coherent searches for continuous gravitational waves with line-robust statistics

    Science.gov (United States)

    Keitel, David

    2016-05-01

    Non-axisymmetries in rotating neutron stars emit quasi-monochromatic gravitational waves. These long-duration ‘continuous wave’ signals are among the main search targets of ground-based interferometric detectors. However, standard detection methods are susceptible to false alarms from instrumental artefacts that resemble a continuous-wave signal. Past work [Keitel, Prix, Papa, Leaci and Siddiqi 2014, Phys. Rev. D 89 064023] showed that a Bayesian approach, based on an explicit model of persistent single-detector disturbances, improves robustness against such artefacts. Since many strong outliers in semi-coherent searches of LIGO data are caused by transient disturbances that last only a few hours or days, I describe in a recent paper [Keitel D 2015, LIGO-P1500159] how to extend this approach to cover transient disturbances, and demonstrate increased sensitivity in realistic simulated data. Additionally, neutron stars could emit transient signals which, for a limited time, also follow the continuous-wave signal model. As a pragmatic alternative to specialized transient searches, I demonstrate how to make standard semi-coherent continuous-wave searches more sensitive to transient signals. Focusing on the time-scale of a single segment in the semi-coherent search, Bayesian model selection yields a simple detection statistic without a significant increase in computational cost. This proceedings contribution gives a brief overview of both works.

  18. Analyzing the Influence of Constructing Daxi Passenger Transport Railway Line on Water Environment of Lancun Spring-feeding Area%大西客运专线建设对兰村泉域水环境影响分析

    Institute of Scientific and Technical Information of China (English)

    陈珊

    2012-01-01

    从站点给排水、隧道建设、桥梁建设、路基建设、站场建设、电气化建设和铁路运营等几个方面分析大西客专施工与运营对兰村泉域水环境的影响。%The paper analyzes the influence of constructing Daxi passenger transport railway line on water environment of Lancun spring-feeding area from several aspects: railway station drainage,tunnel construction,bridge construction,railway base construction,station construction,electrification construction and railway operation.

  19. A New Impedance Matching Method for an Ultra-Wide Band and Dual Circularly Polarised Feed

    Science.gov (United States)

    Li, Sha; Yan, Yi Hua; Wang, Wei; Chen, Zhi Jun; Liu, Dong Hao; Zhang, Fu Shun; Jeffrey, Natasha

    2016-12-01

    In traditional antenna design, metal components are not placed in the central part of the antenna as they change the characteristics of near field radiation. However, we show that placing a metal ring in the centre of the strip lines, which connect the ends of folded high-frequency dipoles, does not damage the performance of the feed. Instead it significantly improves the voltage standing wave ratio of the feed whilst other performance indicators are not compromised. Thus, our findings show an excellent way of improving the wide band feed. Based on this foundation, a new circularly polarised feed for operation between 0.4 to 2 GHz is introduced for the Chinese Spectral Radioheliograph in this paper. The issue of a feed impedance matching network is investigated. By optimising the impedance matching, the performance of the feed is enhanced with respect to the previous realisations of the Eleven feed. The simulation and experimental results show that the gain of the feed is about 10 dBi, and the VSWR is less than 2:1. In addition, the feed has a low axial ratio, fixed phase centre location, and constant beam width in the range of 0.4 to 2 GHz.

  20. THE CM-, MM-, AND SUB-MM-WAVE SPECTRUM OF ALLYL ISOCYANIDE AND RADIOASTRONOMICAL OBSERVATIONS IN ORION KL AND THE SgrB2 LINE SURVEYS

    Energy Technology Data Exchange (ETDEWEB)

    Haykal, I.; Margulès, L.; Huet, T. R.; Motyienko, R. A. [Laboratoire de Physique des Lasers, Atomes, et Molécules, UMR CNRS 8523, Université de Lille 1, F-59655 Villeneuve d' Ascq Cédex (France); Écija, P.; Cocinero, E. J.; Basterretxea, F.; Fernández, J. A.; Castaño, F. [Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Barrio Sarriena s/n, E-48940 Leioa (Spain); Lesarri, A. [Departamento de Química Física y Química Inorgánica, Facultad de Ciencias, Universidad de Valladolid, E-47011 Valladolid (Spain); Guillemin, J. C. [Institut des Sciences Chimiques de Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, Allèe de Beaulieu, CS 50837, F-35708 Rennes Cedex 7 (France); Tercero, B.; Cernicharo, J., E-mail: laurent.margules@univ-lille1.fr [Centro de Astrobiología (CSIC-INTA), Laboratory of Molecular Astrophysics, Department of Astrophysics, Ctra. De Ajalvir, km 4, E-28850 Torrejón de Ardoz, Madrid (Spain)

    2013-11-10

    Organic isocyanides have an interesting astrochemistry and some of these molecules have been detected in the interstellar medium (ISM). However, rotational spectral data for this class of compounds are still scarce. We provide laboratory spectra of the four-carbon allyl isocyanide covering the full microwave region, thus allowing a potential astrophysical identification in the ISM. We assigned the rotational spectrum of the two cis (synperiplanar) and gauche (anticlinal) conformations of allyl isocyanide in the centimeter-wave region (4-18 GHz), resolved its {sup 14}N nuclear quadrupole coupling (NQC) hyperfine structure, and extended the measurements into the millimeter and submillimeter-wave (150-900 GHz) ranges for the title compound. Rotational constants for all the monosubstituted {sup 13}C and {sup 15}N isotopologues are additionally provided. Laboratory observations are supplemented with initial radioastronomical observations. Following analysis of an extensive dataset (>11000 rotational transitions), accurate ground-state molecular parameters are reported for the cis and gauche conformations of the molecule, including rotational constants, NQC parameters, and centrifugal distortion terms up to octic contributions. Molecular parameters have also been obtained for the two first excited states of the cis conformation, with a dataset of more than 3300 lines. The isotopic data allowed determining substitution and effective structures for the title compound. We did not detect allyl isocyanide either in the IRAM 30 m line survey of Orion KL or in the PRIMOS survey toward SgrB2. Nevertheless, we provided an upper limit to its column density in Orion KL.

  1. Field-aligned particle acceleration on auroral field lines by interaction with transient density cavities stimulated by kinetic Alfvén waves

    Directory of Open Access Journals (Sweden)

    P. A. Bespalov

    2006-09-01

    Full Text Available We consider the field-aligned acceleration of energetic ions and electrons which takes place on auroral field lines due to their interaction with time-varying density cavities stimulated by the strong oscillating field-aligned currents of kinetic Alfvén waves. It is shown that when the field-aligned current density of these waves increases, such that the electron drift speed exceeds the electron thermal speed, ion acoustic perturbations cease to propagate along the field lines and instead form purely-growing density perturbations. The rarefactions in these perturbations are found to grow rapidly to form density cavities, limited by the pressure of the bipolar electric fields which occur within them. The time scale for growth and decay of the cavities is much shorter than the period of the kinetic Alfvén waves. Energetic particles traversing these growing and decaying cavities will be accelerated by their time-varying field-aligned electric fields in a process that is modelled as a series of discrete random perturbations. The evolution of the particle distribution function is thus determined by the Fokker-Planck equation, with an energy diffusion coefficient that is proportional to the square of the particle charge, but is independent of the mass and energy. Steady-state solutions for the distribution functions of the accelerated particles are obtained for the case of an arbitrary energetic particle population incident on a scattering layer of finite length along the field lines, showing how the reflected and transmitted distributions depend on the typical "random walk" energy change of the particles within the layer compared to their initial energy. When this typical energy change is large compared to the initial energy, the reflected population is broadly spread in energy about a mean which is comparable with the initial energy, while the transmitted population has the form of a strongly accelerated field-aligned beam. We suggest that these

  2. Origin of asymmetries in X-ray emission lines from the blast wave of the 2014 outburst of nova V745 Sco

    Science.gov (United States)

    Orlando, Salvatore; Drake, Jeremy J.; Miceli, Marco

    2017-02-01

    The symbiotic nova V745 Sco was observed in outburst on 2014 February 6. Its observations by the Chandra X-ray Observatory at days 16 and 17 have revealed a spectrum characterized by asymmetric and blueshifted emission lines. Here we investigate the origin of these asymmetries through 3D hydrodynamic simulations describing the outburst during the first 20 d of evolution. The model takes into account thermal conduction and radiative cooling, and assumes that a blast wave propagates through an equatorial density enhancement (EDE). From these simulations, we synthesize the X-ray emission and derive the spectra as they would be observed with Chandra. We find that both the blast wave and the ejecta distribution are efficiently collimated in polar directions due to the presence of the EDE. The majority of the X-ray emission originates from the interaction of the blast with the EDE and is concentrated on the equatorial plane as a ring-like structure. Our `best-fitting' model requires a mass of ejecta in the outburst Mej ≈ 3 × 10-7 M⊙ and an explosion energy Eb ≈ 3 × 1043 erg, and reproduces the distribution of emission measure versus temperature and the evolution of shock velocity and temperature inferred from the observations. The model predicts asymmetric and blueshifted line profiles similar to those observed and explains their origin as due to substantial X-ray absorption of redshifted emission by ejecta material. The comparison of predicted and observed Ne and O spectral line ratios reveals no signs of strong Ne enhancement and suggests that the progenitor is a CO white dwarf.

  3. Fermented liquid feed for pigs.

    Science.gov (United States)

    Missotten, Joris A M; Michiels, Joris; Ovyn, Anneke; De Smet, Stefaan; Dierick, Noël A

    2010-12-01

    Since the announcement of the ban on the use of antibiotics as antimicrobial growth promoters in the feed of pigs in 2006 the investigation towards alternative feed additives has augmented considerably. Although fermented liquid feed is not an additive, but a feeding strategy, the experimental work examining its possible advantages also saw a rise. The use of fermented liquid feed (FLF) has two main advantages, namely that the simultaneous provision of feed and water may result in an alleviation of the transition from the sow milk to solid feed and may also reduce the time spent to find both sources of nutrients, and secondly, that offering FLF with a low pH may strengthen the potential of the stomach as a first line of defence against possible pathogenic infections. Because of these two advantages, FLF is often stated as an ideal feed for weaned piglets. The results obtained so far are rather variable, but in general they show a better body weight gain and worse feed/gain ratio for the piglets. However, for growing-finishing pigs on average a better feed/gain ratio is found compared to pigs fed dry feed. This better performance is mostly associated with less harmful microbiota and better gut morphology. This review provides an overview of the current knowledge of FLF for pigs,dealing with the FLF itself as well as its effect on the gastrointestinal tract and animal performance.

  4. Ill-posedness of the cubic nonlinear half-wave equation and other fractional NLS on the real line

    OpenAIRE

    Choffrut, Antoine; Pocovnicu, Oana

    2016-01-01

    In this paper, we study ill-posedness of cubic fractional nonlinear Schr\\"odinger equations. First, we consider the cubic nonlinear half-wave equation (NHW) on $\\mathbb R$. In particular, we prove the following ill-posedness results: (i) failure of local uniform continuity of the solution map in $H^s(\\mathbb R)$ for $s\\in (0,\\frac 12)$, and also for $s=0$ in the focusing case; (ii) failure of $C^3$-smoothness of the solution map in $L^2(\\mathbb R)$; (iii) norm inflation and, in particular, fa...

  5. 2D ground motion at a soft viscoelastic layer/hard substratum site in response to SH cylindrical seismic waves radiated by deep and shallow line sources

    CERN Document Server

    Wirgin, A; Wirgin, Armand

    2004-01-01

    We show, essentially by theoretical means, that for a site with the chosen simple geometry and mechanical properties (horizontal, homogeneous, soft viscoelastic layer of infinite lateral extent overlying, and in welded contact with, a homogeneous, hard elastic substratum of half-infinite radial extent, shear-horizontal motion): 1) coupling to Love modes is all the weaker the farther the seismic source (modeled as a line, assumed to lie in the substratum) is from the lower boundary of the soft layer, 2) for a line source close to the lower boundary of the soft layer, the ground response is characterized by possible beating phenomena, and is of significantly-longer duration than for excitation by cylindrical waves radiated by deep sources. Numerical applications of the theory show, for instance, that a line source, located 40m below the lower boundary of a 60m thick soft layer in a hypothetical Mexico City-like site, radiating a SH pulse of 4s duration, produces substantial ground motion during 200s, with marke...

  6. Development of wireless, chipless neural stimulator by using one-port surface acoustic wave delay line and diode-capacitor interface

    Science.gov (United States)

    Kim, Jisung; Kim, Saehan; Lee, Keekeun

    2017-06-01

    For the first time, a wireless and chipless neuron stimulator was developed by utilizing a surface acoustic wave (SAW) delay line, a diode-capacitor interface, a sharp metal tip, and antennas for the stimulation of neurons in the brain. The SAW delay line supersedes presently existing complex wireless transmission systems composed of a few thousands of transistors, enabling the fabrication of wireless and chipless transceiver systems. The diode-capacitor interface was used to convert AC signals to DC signals and induce stimulus pulses at a sharp metal probe. A 400 MHz RF energy was wirelessly radiated from antennas and then stimulation pulses were observed at a sharp gold probe. A ˜5 m reading distance was obtained using a 1 mW power from a network analyzer. The cycles of electromagnetic (EM) radiation from an antenna were controlled by shielding the antenna with an EM absorber. Stimulation pulses with different amplitudes and durations were successfully observed at the probe. The obtained pulses were ˜0.08 mV in amplitude and 3-10 Hz in frequency. Coupling-of-mode (COM) and SPICE modeling simulations were also used to determine the optimal structural parameters for SAW delay line and the values of passive elements. On the basis of the extracted parameters, the entire system was experimentally implemented and characterized.

  7. New evidence for the asthenospheric origin of the Cameroon Volcanic Line from 1D shear wave velocities

    CSIR Research Space (South Africa)

    Tokam, AP

    2013-10-01

    Full Text Available of Tertiary to Recent, generally alkaline, volcanoes stretching from the Atlantic island of Pagalu to the interior of the African continent (Lee et al. 1994). The line has been recently investigated using earthquake seismology data (Tabod et al., 1992... of a plate to lateral density variations at the surface or within the plate. From their analysis, Poudjom et al. (1995) concluded that lithosphere is relatively weak beneath the CVL and other active rifts (the Benue trough and its extension...

  8. High frame rate and high line density ultrasound imaging for local pulse wave velocity estimation using motion matching: A feasibility study on vessel phantoms.

    Science.gov (United States)

    Li, Fubing; He, Qiong; Huang, Chengwu; Liu, Ke; Shao, Jinhua; Luo, Jianwen

    2016-04-01

    Pulse wave imaging (PWI) is an ultrasound-based method to visualize the propagation of pulse wave and to quantitatively estimate regional pulse wave velocity (PWV) of the arteries within the imaging field of view (FOV). To guarantee the reliability of PWV measurement, high frame rate imaging is required, which can be achieved by reducing the line density of ultrasound imaging or transmitting plane wave at the expense of spatial resolution and/or signal-to-noise ratio (SNR). In this study, a composite, full-view imaging method using motion matching was proposed with both high temporal and spatial resolution. Ultrasound radiofrequency (RF) data of 4 sub-sectors, each with 34 beams, including a common beam, were acquired successively to achieve a frame rate of ∼507 Hz at an imaging depth of 35 mm. The acceleration profiles of the vessel wall estimated from the common beam were used to reconstruct the full-view (38-mm width, 128-beam) image sequence. The feasibility of mapping local PWV variation along the artery using PWI technique was preliminarily validated on both homogeneous and inhomogeneous polyvinyl alcohol (PVA) cryogel vessel phantoms. Regional PWVs for the three homogeneous phantoms measured by the proposed method were in accordance with the sparse imaging method (38-mm width, 32-beam) and plane wave imaging method. Local PWV was estimated using the above-mentioned three methods on 3 inhomogeneous phantoms, and good agreement was obtained in both the softer (1.91±0.24 m/s, 1.97±0.27 m/s and 1.78±0.28 m/s) and the stiffer region (4.17±0.46 m/s, 3.99±0.53 m/s and 4.27±0.49 m/s) of the phantoms. In addition to the improved spatial resolution, higher precision of local PWV estimation in low SNR circumstances was also obtained by the proposed method as compared with the sparse imaging method. The proposed method might be helpful in disease detections through mapping the local PWV of the vascular wall.

  9. Short Wave upwelling Radiative Flux (SWupRF) within NIR range for the selected greenhouse wavelength bands of O2, H2O, CO2 and CH4 by Argus 1000 along with GENSPECT line by line radiative transfer model

    CERN Document Server

    Siddiqui, Rehan; Salem, Naif Al; Quine, Brendan M

    2016-01-01

    This new study develops an algorithm for Short Wave upwelling Radiative Flux (SWupRF) for the spectral variations within near infrared (NIR) from 1100 to 1700 nm wavelength band based on remote sensing data set of Argus 1000 micro-spectrometer observations. We calculate the SWupRF by investigating the total radiative flux due to O2, H2O, CO2 and CH4 and also by the individual gas within the selected wavelength bands of interest. A GENSPECT synthetic line by line radiative transfer model is applied to perform radiative transfer simulations to calculate the radiative flux by varying surface albedo, mixing ratios of the selected greenhouse gases, surface temperature, solar sun and zenith angles with different latitude and longitude of the instrument. Finally, the SWupRFsyn estimated from GENSPECT was compared with SWupRFobs from Argus 1000 over a period of four years (2009 and 2013) covering all seasons. We calculate and compare both the synthetic and real measured observed data set. The synthetic model gives SW...

  10. The Rotational Spectrum of CHF 3 in the Submillimeter-Wave and Far-Infrared Region: Observation of the K = 3 Line Splitting

    Science.gov (United States)

    Cazzoli, G.; Cludi, L.; Cotti, G.; Dore, L.; Esposti, C. D.; Bellini, M.; Denatale, P.

    1994-02-01

    The milimeter-wave, submillimeter-wave. and FIR spectra of the ground state of CHF 3 have been observed and analyzed up to J = 78. The resulting spectroscopic constants are: B0/MHz = 10 348.8706(2), D J/kHz= 11.34482(13), D JK/kHz = -18.11765(50), H JJJ/Hz= 0.020069(24), H JJK/Hz = -0.08598(10), H KKJ/Hz 0.11372(27), L J/mHz = -0.669(16) × 10 -4, L JJK/mHz = 0.4953(80) × 10 -3, L JK/mHz = -0.1189(17) × 10 -2, and L JKK/mHz = -0.1115(31) × 10 -2. The splitting of the K = 3 ground state lines has been observed starting from the J = 29 ← 28 transition and the determined values of the splitting constants are h3/Hz = 0.29689(45) ×10 -2 and δ h3/Hz = -0.2054(52) × 10 -7.

  11. Origin of asymmetries in X-ray emission lines from the blast wave of the 2014 outburst of nova V745 Sco

    CERN Document Server

    Orlando, S; Miceli, M

    2016-01-01

    The symbiotic nova V745 Sco was observed in outburst on 2014 February 6. Its observations by the Chandra X-ray Observatory at days 16 and 17 have revealed a spectrum characterized by asymmetric and blue-shifted emission lines. Here we investigate the origin of these asymmetries through three-dimensional hydrodynamic simulations describing the outburst during the first 20 days of evolution. The model takes into account thermal conduction and radiative cooling and assumes a blast wave propagates through an equatorial density enhancement. From the simulations, we synthesize the X-ray emission and derive the spectra as they would be observed with Chandra. We find that both the blast wave and the ejecta distribution are efficiently collimated in polar directions due to the presence of the equatorial density enhancement. The majority of the X-ray emission originates from the interaction of the blast with the equatorial density enhancement and is concentrated on the equatorial plane as a ring-like structure. Our "be...

  12. The - - and Submm-Wave Spectrum of Allyl Isocyanide and Radioastronomical Observations in Orion KL and the Primos Line Survey

    Science.gov (United States)

    Haykal, I.; Motiyenko, R. A.; Margules, L.; Huet, T. R.; Ecija, P.; Cocinero, E. J.; Basterretxea, F.; Fernandez, J. A.; Castano, F.; Tercero, B.; Cernicharo, J.; Lesarri, A.; Guillemin, J. C.

    2013-06-01

    Last year we presented the first rotational analysis of the ground state of the two conformers of allyl isocyanide from 4 GHz to 905 GHz. The analysis of the rotational spectrum of the cis conformer of allyl isocyanide was extended. We resolved Coriolis interactions of a and b types between the excited vibrational states ν_1=1 and ν_2=1, calculated to be at 156 cm^{-1} (A^{'}) and 167 cm^{-1} (A^{''}) respectively (MP2/aug-cc-pvtz), from 150 GHz to 600 GHz. Strong perturbations were observed in the 150-310 GHz range for low values of the quantum number K_a starting from K_a = 0, 1. The anharmonicities appeared as well at higher frequencies for larger quantum numbers. The two modes were fitted together with the SPFIT/SPCAT suite of programs and a set of Coriolis parameters was accurately determined. The fit contains more than 3000 lines up to J = 99 and K_a = 12 for both modes. We did not detect these species neither in the IRAM 30-m line survey of Orion KL nor in the PRIMOS survey towards SgrB2. Nevertheless, we provided upper limits to their column density in Orion KL. This work was supported by the CNES and the Action sur Projets de l'INSU, PCMI. I. Haykal et al. manuscript in preparation H. Pickett J. Mol. Spec.{148}, 371-377, 1991.

  13. Characterization of the HIV-1 TAR RNA-Tat peptide and drug interactions by on-line acoustic wave sensor

    Science.gov (United States)

    Tassew, Nardos Gobena

    This thesis presents the application of the thickness shear-mode (TSM) acoustic wave sensor to the study of RNA-protein and RNA-drug interactions at the solid-liquid interface. The binding of the human immunodeficiency virus-type 1 Tat protein to the trans-activation responsive RNA element (TAR) has been studied using this sensor. Data from such measurements show that the sensor is able to discriminate between different Tat peptides derived from the parent protein based on size. The effects of mutations introduced at specific sites in the protein and RNA on the TAR-Tat binding have also been examined in detail. Reduced level of response in acoustic parameters due to mutations was observed indicating that the decrease in binding in response to site specific mutations can be acoustically detected. Data from acoustic wave sensor measurements indicate that the TAR-Tat binding is also affected by ionic strength. Both the frequency and motional resistance signals show periodic responses when varying concentrations of salt are introduced on a TAR-modified surface. The binding of the two molecules seems to be a function of the response of the nucleic acid to salt concentrations. The kinetics of binding of Tat peptides to TAR RNA and to a bulge mutant analogue (MTAR) is also examined from the rate of change of the series resonant frequency. Results from such analysis illustrate longer Tat peptides formed more stable complexes with TAR RNA and exhibited increased discrimination between mutant and wild type TAR. The binding of two aminoglycoside antibiotics, neomycin and streptomycin, to TAR RNA and their effectiveness in preventing TAR-Tat complex formation has been studied in detail. Binding affinity is directly correlated with the inhibitory potency of these molecules and the TSM sensor shows that neomycin exhibits at least a ten fold greater affinity to TAR and that it is also a more potent inhibitor than streptomycin. The results from this research involving TAR-Tat and

  14. Finsler p p -waves

    Science.gov (United States)

    Fuster, Andrea; Pabst, Cornelia

    2016-11-01

    In this work we present Finsler gravitational waves. These are a Finslerian version of the well-known p p -waves, generalizing the very special relativity line element. Our Finsler p p -waves are an exact solution of Finslerian Einstein's equations in vacuum and describe gravitational waves propagating in an anisotropic background.

  15. On-line monitoring of polymer deposition for tailoring the waveguide characteristics of love-wave biosensors.

    Science.gov (United States)

    Bender, Florian; Länge, Kerstin; Barié, Nicole; Kondoh, Jun; Rapp, Michael

    2004-03-16

    The Love-wave sensor is an acoustic sensing device which is particularly suitable for sensing in a liquid environment. The superior characteristics of the device are achieved by the use of an acoustic waveguide, consisting of a thin layer deposited on the surface of the substrate material. The exact thickness and material properties of the layer will not only determine sensitivity and sensing performance of the resulting device but can also be adjusted to generate higher-order Love modes. Thus, to obtain a sensing device with the desired specifications, precise control over the process of waveguide deposition is required. This has been realized by implementation of a vapor deposition polymerization system where the transmission curve (amplitude vs frequency) of one of the sensing devices is continuously monitored during deposition. As soon as the desired device specifications are reached, the deposition can be interrupted immediately. From the recorded transmission curves, information about the sensitivity of the device can be deduced, and the formation of higher-order Love modes can be visualized. The system has been used to produce biosensors based on various Love modes. It is shown that sensors operated on higher-order Love modes have a high mass sensitivity which, together with their excellent shielding properties, makes them advantageous for biosensing in conducting buffer solutions.

  16. Potential transfer of neurotoxic amino acid β-N-methylamino-alanine (BMAA) from mother to infant during breast-feeding: Predictions from human cell lines.

    Science.gov (United States)

    Andersson, Marie; Ersson, Lisa; Brandt, Ingvar; Bergström, Ulrika

    2017-04-01

    β-N-methylamino-alanine (BMAA) is a non-protein amino acid produced by cyanobacteria, diatoms and dinoflagellates. BMAA has potential to biomagnify in a terrestrial food chain, and to bioaccumulate in fish and shellfish. We have reported that administration of [(14)C]l-BMAA to lactating mice and rats results in a mother to off-spring transfer via the milk. A preferential enantiomer-specific uptake of [(14)C]l-BMAA has also been demonstrated in differentiated murine mammary epithelium HC11 cells. These findings, together with neurotoxic effects of BMAA demonstrated both in vitro and in vivo, highlight the need to determine whether such transfer could also occur in humans. Here, we used four cell lines of human origin to examine and compare the transport of the two BMAA enantiomers in vitro. The uptake patterns of [(14)C]l- and [(14)C]d-BMAA in the human mammary MCF7 cell line were in agreement with the results in murine HC11 cells, suggesting a potential secretion of BMAA into human breast milk. The permeability coefficients for both [(14)C]l- and [(14)C]d-BMAA over monolayers of human intestinal Caco2 cells supported an efficient absorption from the human intestine. As a final step, transport experiments confirmed that [(14)C]l-and [(14)C]d-BMAA can be taken up by human SHSY5Y neuroblastoma cells and even more efficiently by human U343 glioblastoma cells. In competition experiments with various amino acids, the ASCT2 specific inhibitor benzylserine was the most effective inhibitor of [(14)C]l-BMAA uptake tested here. Altogether, our results suggest that BMAA can be transferred from an exposed mother, via the milk, to the brain of the nursed infant. Copyright © 2017. Published by Elsevier Inc.

  17. On-line gas analysis in animal cell cultivation: II. Methods for oxygen uptake rate estimation and its application to controlled feeding of glutamine.

    Science.gov (United States)

    Eyer, K; Oeggerli, A; Heinzle, E

    1995-01-05

    Different methods for oxygen uptake rate (OUR) determinations in animal cell cultivation were investigated using a high quality mass spectrometer. Dynamic measurements have considerable disadvantages because of disturbances of the growing cells by the necessary variations of dissolved oxygen concentration. Only infrequent discrete measurements are possible using this method. Stationary liquid phase balance yielded better results with much higher frequency. Gas phase balancing has the advantage of not requiring dissolved oxygen measurement and knowledge of K(L)a, both of them are easily biased. It was found that simple gas phase balancing is either very inaccurate (error larger than expected signal) or very slow, with gas phase residence times of several hours. Therefore, a new method of aeration was designed. Oxygen and CO(2) transfer are mainly achieved via sparging. The gas released to the headspace is diluted with a roughly 100-fold stream of an inert gas (helium). Through this dilution, gas ratios are not changed for O(2), CO(2), Ar, and N(2). The measurement of lower concentrations (parts per million and below) is easy using mass spectrometry with a secondary electron multiplier. With this new method an excellent accuracy and sufficient speed of analysis were obtained. All these on-line methods for OUR measurement were tested during the cultivation of animal cells. The new method allowed better study of the kinetics of animal cell cultures as was shown with a hybridoma cell line (HFN 7.1, ATCC CRL 1606) producing monoclonal antibodies against human fibronectin. With the aid of these methods it was possible to find a correlation between a rapid decrease in oxygen uptake rate (OUR) and glutamine concentration. The sudden decrease in OUR can be attributed to glutamine depletion. This provided a basis for the controlled addition of glutamine to reduce the formation of ammonia produced by hydrolysis. This control method based on OUR measurement resulted in

  18. Improved 60 GHz Millimeter-Wave Generator Based on Feed-Forward Modulation%一种改进的基于前向调制技术生成60 GHz毫米波方案

    Institute of Scientific and Technical Information of China (English)

    许丽丽; 宁提纲; 李晶; 裴丽; 油海东; 陈宏尧; 张婵

    2013-01-01

    光载无线通信(ROF)技术是通信业宽带化和无线化的产物,该技术将光纤通信技术与毫米波通信技术进行融合,具有广阔的应用前景.目前世界众多国家在60 GHz毫米波频段相继划出免许可连续频谱,这使得60 GHz毫米波无线通信成为近距离无线通信领域的研究热点之一.为了降低ROF系统的成本,提高系统的性能,提出了一种改进的基于前向调制(FFM)技术生成60 GHz毫米波方案,分析了系统各光电器件的工作原理,仿真了不同的参量设置对系统性能的影响曲线.该方案结合了前向调制技术和光波分复用技术的优点,简化了整个系统的复杂程度,降低了ROF系统的造价成本,同时减小了误码率,提高了系统的性能.%A radio over fiber (ROF) system is a product of the broad band and wireless in the communication industry. It combines the optical fiber communication technology and millimeter-wave communication technology, and has a broad application prospect. At present many countries mark off unlicensed continuous-frequency spectra in 60 GHz millimeter wave frequency band, which makes 60 GHz millimeter-wave wireless communication become one of the hot researches in the field of close wireless communication. In order to reduce the cost of a ROF system and improve its performance, an improved 60 GHz millimeter-wave generator based on feed-forward modulation (FFM) technique is proposed. The principle of the photoelectric device is analysed and the effect of different parameters setting in the performance of the system curve is simulated. The scheme combines with the advantages of forward modulation technology and light wavelength division multiplexing technology. It simplifies the complexity of the system, reduces the cost of the ROF system, reduces the error rate and improves the performance of the whole system.

  19. The shaped millimeter-wave antenna with offset feed and dual-reflector%毫米波赋形偏馈双反射面天线技术

    Institute of Scientific and Technical Information of China (English)

    陈鑫; 屈劲; 潘文武; 余川; 陈世韬; 施美友

    2012-01-01

    A shaped scheme based on geometric optics for offset fed dual reflector antenna is presented. A ray tube emerging from a symmetric feed horn is transformed, after reflections, into a circular beam with a uniform phased and a prescribed radial power distribution on the aperture. Snell' s law was imposed on the subreflector. Based on this design solution, theoretical analysis, numerical simulation and experimental test were carried out for a 110 cm dish baseline system with a angle of 20 degrees between X axis and the beam. The experiment shows that at 95 GHz, the antenna has a 78% aperture efficiency and the minor lobe meets a -19 dB criterion and the gain is 59. 7dB.%为了实现一种具有高口面辐射效率、斜波束出射能力的口径天线,采用几何光学方法设计了一种偏馈双反射面天线.天线主反射面采用赋形设计,副反射面的设计过程中采用Snell定理作为约束条件.通过理论公式、数值模拟仿真和实验测试研究,实现了一种出射波束口径为110 cm、天线口面场分布为抛物形分布、波束出射方向与竖直方向成20°夹角的赋形偏馈双反射面天线.在中心频率95 GHz下,实测天线增益为59.7 dB,第一副瓣电平为-19dB,天线口径效率达到78%.

  20. Expression of feeding-related peptide receptors mRNA in GT1-7 cell line and roles of leptin and orexins in control of GnRH secretion

    Institute of Scientific and Technical Information of China (English)

    Ying YANG; Li-bin ZHOU; Shang-quan LIU; Jing-feng TANG; Feng-yin LI; Rong-ying LI; Huai-dong SONG; Ming-dao CHEN

    2005-01-01

    Aim: To investigate the expression of feeding-related peptide receptors mRNA in GT1-7 cell line and roles of leptin and orexins in the control of GnRH secretion.Methods: Receptors of bombesin3, cholecystokinin (CCK)-A, CCK-B, glucagonlike peptide (GLP)1, melanin-concentrating hormone (MCH)1, orexinl, orexin2,neuromedin-B, neuropeptide Y (NPY) 1 and NPY5, neurotensin (NT) 1, NT2, NT3,and leptin receptor long form mRNA in GT1-7 cells were detected by reversed transcriptase-polymerase chain reaction. GT1-7 cells were treated with leptin,orexin A and orexin B at a cohort of concentrations for different lengths of time,and GnRH in medium was determined by radioimmunoassay (RIA). Results:Receptors of bombesin 3, CCK-B, GLP1, MCH1, orexinl, neuromedin-B, NPY1,NPY5, NT1, NT3, and leptin receptor long form mRNA were expressed in GT1-7cells, of which, receptors of GLP1, neuromedin-B, NPY1, and NT3 were highly expressed. No amplified fragments of orexin2, NT2, and CCK-A receptor cDNA were generated with GT1-7 RNA, indicating that the GT1-7 cells did not express mRNA of them. Leptin induced a significant stimulation of GnRH release, the results being most significant at 0.1 nmol/L for 15 min. In contrast to other studies in hypothalamic explants, neither orexin A nor orexin B affected basal GnRH secretion over a wide range of concentrations ranging from 1 nmol/L to 500 nmol/Lat 15, 30, and 60 min. Conclusion: Feeding and reproductive function are closely linked. Many orexigenic and anorexigenic signals may control feeding behavior as well as alter GnRH secretion through their receptors on GnRH neurons.

  1. Millimeter-wave sensor based on a λ/2-line resonator for identification and dielectric characterization of non-ionic surfactants.

    Science.gov (United States)

    Rodilla, H; Kim, A A; Jeffries, G D M; Vukusic, J; Jesorka, A; Stake, J

    2016-01-20

    Studies of biological and artificial membrane systems, such as niosomes, currently rely on the use of fluorescent tags, which can influence the system under investigation. For this reason, the development of label-free, non-invasive detection techniques is of great interest. We demonstrate an open-volume label-free millimeter-wave sensing platform based on a coplanar waveguide, developed for identification and characterization of niosome constituents. A design based on a λ/2-line resonator was used and on-wafer measurements of transmission and reflection parameters were performed up to 110 GHz. Our sensor was able to clearly distinguish between common niosome constituents, non-ionic surfactants Tween 20 and Span 80, measuring a resonance shift of 3 GHz between them. The complex permittivities of the molecular compounds have been extracted. Our results indicate insignificant frequency dependence in the investigated frequency range (3 GHz - 110 GHz). Values of permittivity around 3.0 + 0.7i and 2.2 + 0.4i were obtained for Tween 20 and Span 80, respectively.

  2. Investigation of the effect of a bend in a transfer line that separates a pulse tube cold head and a pressure wave generator

    Science.gov (United States)

    Dev, A. A.; Atrey, M. D.; Vanapalli, S.

    2017-02-01

    A transfer line between a pulse tube cold head and a pressure wave generator is usually required to isolate the cold head from the vibrations of the compressor. Although it is a common practice to use a thin and narrow straight tube, a bent tube would allow design flexibility and easy mounting of the cold head, such as in a split Stirling type pulse tube cryocooler. In this paper, we report a preliminary investigation on the effect of the bending of the tube on the flow transfer characteristics. A numerical study using commercial computational fluid dynamics model is performed to gain insight into the flow characteristics in the bent tube. Oscillating flow experiments are performed with a straight and a bent tube at a filling pressure of 15 bar and an operating frequency of 40, 50 and 60 Hz. The data and the corresponding numerical simulations point to the hypothesis that the secondary flow in the bent tube causes a decrease in flow at a fixed pressure amplitude.

  3. The Optimization Program of Steel Plate Feeding Device for LASW Pipe Production Line%直缝埋弧焊管生产线钢板上料装置优选方案

    Institute of Scientific and Technical Information of China (English)

    李钢; 张增全; 韩保材; 汤跃先; 汤圣先

    2015-01-01

    In this article, it described the main structure and constitute of 3 kinds of commonly used feeding device of JCOE/UOE LSAW pipe production line, including the combined converyor of roller and chain, chain conveyor and vacuum suction cups hanging conveyer, and compared the main structure and constitute with several aspects, such as equipment structure and operation, operation and maintenance workload, equipment investment, installed capacity, production running cost, plate scratch, etc. The results indicated that vacuum suction cups hanging conveyer device is with some advantages, such as simple structure, easy operation, low workload for operation and maintenance, small investment, small installed capacity, low production running cost, and production rhythm can completely meet the design requirements, which is the best optimization program for LASW pipe production line steel plate feeding device.%对JCOE/UOE直缝埋弧焊管生产线上通常采用的三种上料装置, 即平辊和链条组合输送装置、 链条输送装置以及真空吸盘吊输送装置的主要结构和组成进行了描述, 并从设备结构与操作、运行与维护工作量、 设备投资、 装机容量、 生产运行成本、 钢板划伤等主要方面进行了对比. 结果表明, 采用真空吸盘吊输送装置具有设备结构简单、 操作方便、 运行与维护的工作量相对较低、 资金投入相对较少、 装机容量小、 生产运行成本低、 生产节奏完全能满足设计要求等优点, 是直缝埋弧焊管生产线钢板上料的最佳优选方案.

  4. Efficient Wave Energy Amplification with Wave Reflectors

    DEFF Research Database (Denmark)

    Kramer, Morten Mejlhede; Frigaard, Peter Bak

    2002-01-01

    Wave Energy Converters (WEC's) extract wave energy from a limited area, often a single point or line even though the wave energy is generally spread out along the wave crest. By the use of wave reflectors (reflecting walls) the wave energy is effectively focused and increased to approximately 130......-140%. In the paper a procedure for calculating the efficiency and optimizing the geometry of wave reflectors are described, this by use of a 3D boundary element method. The calculations are verified by laboratory experiments and a very good agreement is found. The paper gives estimates of possible power benifit...... for different geometries of the wave reflectors and optimal geometrical design parameters are specified. On this basis inventors of WEC's can evaluate whether a specific WEC possible could benefit from wave reflectors....

  5. Feeding Your Newborn

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Feeding Your Newborn KidsHealth > For Parents > Feeding Your Newborn ... giving up the breast. previous continue About Formula Feeding Commercially prepared infant formula is a nutritious alternative ...

  6. 板式催化剂生产线原料加料系统设计与改进%Design and Improvement for Raw material Feeding System of Plate Catalyst Production Line

    Institute of Scientific and Technical Information of China (English)

    郑承霞; 杨光; 梅辉

    2015-01-01

    A SCR catalyst production line is introduce by a steel mill,artificial form of raw materials is used in mixing ma-chine.The efficiency is low and worker's labor load is heavy.In order to improve the efficiency and lighten the labor load,The au-thor designs a raw material feeding system which exposes some problems in practical application.Improvement should be made to perfect the system.%某钢厂引进SCR脱硝板式催化剂生产线,原料市场采购,原料加入混料机采用人工形式,加料效率低,劳动负荷大,为了提高生产效率,降低工人劳动负荷,作者设计了一套原料加料系统,但实际使用中,出现了一些问题,需要改进。

  7. Daily Feed Intake, Energy Intake, Growth Rate and Measures of Dietary Energy Efficiency of Pigs from Four Sire Lines Fed Diets with High or Low Metabolizable and Net Energy Concentrations

    Directory of Open Access Journals (Sweden)

    A. P. Schinckel

    2012-03-01

    Full Text Available A trial was conducted to: i evaluate the BW growth, energy intakes and energetic efficiency of pigs fed high and low density diets from 27 to 141 kg BW, ii evaluate sire line and sex differences when fed both diets, and iii to compare ME to NE as predictor of pig performance. The experiment had a replicated factorial arrangement of treatments including four sire lines, two sexes (2,192 barrows and 2,280 gilts, two dietary energy densities and a light or heavy target BW, 118 and 131.5 kg in replicates 1 to 6 and 127 and 140.6 kg in replicates 7 to 10. Pigs were allocated to a series of low energy (LE, 3.27 Mcal ME/kg corn-soybean meal based diets with 16% wheat midds or high energy diets (HE, 3.53 to 3.55 Mcal ME/kg with 4.5 to 4.95% choice white grease. All diets contained 6% DDGS. The HE and LE diets of each of the four phases were formulated to have equal lysine:Mcal ME ratios. Pigs were weighed and pen feed intake (11 or 12 pigs/pen recorded at 28-d intervals. The barrow and gilt daily feed (DFI, ME (MEI and NE (NEI intake data were fitted to a Bridges function of BW. The BW data of each sex were fitted to a generalized Michaelis-Menten function of days of age. ME and NE required for maintenance (Mcal/d were predicted using functions of BW (0.255 and 0.179 BW^0.60 respectively. Pigs fed LE diets had decreased ADG (915 vs. 945 g/d, p<0.001 than pigs fed HE diets. Overall, DFI was greater (p<0.001 for pigs fed the LE diets (2.62 vs. 2.45 kg/d. However, no diet differences were observed for MEI (8.76 vs. 8.78 Mcal/d, p = 0.49 or NEI (6.39 vs. 6.44 Mcal/d, p = 0.13, thereby indicating that the pigs compensated for the decreased energy content of the diet. Overall ADG:DFI (0.362 vs. 0.377 and ADG:Mcal MEI (0.109 vs. 0.113 was less (p<0.001 for pigs fed LE compared to HE diets. Pigs fed HE diets had 3.6% greater ADG:Mcal MEI above maintenance and only 1.3% greater ADG:Mcal NEI (0.152 versus 0.150, therefore NEI is a more accurate predictor of

  8. Daily Feed Intake, Energy Intake, Growth Rate and Measures of Dietary Energy Efficiency of Pigs from Four Sire Lines Fed Diets with High or Low Metabolizable and Net Energy Concentrations

    Science.gov (United States)

    Schinckel, A. P.; Einstein, M. E.; Jungst, S.; Matthews, J. O.; Booher, C.; Dreadin, T.; Fralick, C.; Wilson, E.; Boyd, R. D.

    2012-01-01

    A trial was conducted to: i) evaluate the BW growth, energy intakes and energetic efficiency of pigs fed high and low density diets from 27 to 141 kg BW, ii) evaluate sire line and sex differences when fed both diets, and iii) to compare ME to NE as predictor of pig performance. The experiment had a replicated factorial arrangement of treatments including four sire lines, two sexes (2,192 barrows and 2,280 gilts), two dietary energy densities and a light or heavy target BW, 118 and 131.5 kg in replicates 1 to 6 and 127 and 140.6 kg in replicates 7 to 10. Pigs were allocated to a series of low energy (LE, 3.27 Mcal ME/kg) corn-soybean meal based diets with 16% wheat midds or high energy diets (HE, 3.53 to 3.55 Mcal ME/kg) with 4.5 to 4.95% choice white grease. All diets contained 6% DDGS. The HE and LE diets of each of the four phases were formulated to have equal lysine:Mcal ME ratios. Pigs were weighed and pen feed intake (11 or 12 pigs/pen) recorded at 28-d intervals. The barrow and gilt daily feed (DFI), ME (MEI) and NE (NEI) intake data were fitted to a Bridges function of BW. The BW data of each sex were fitted to a generalized Michaelis-Menten function of days of age. ME and NE required for maintenance (Mcal/d) were predicted using functions of BW (0.255 and 0.179 BW^0.60 respectively). Pigs fed LE diets had decreased ADG (915 vs. 945 g/d, p<0.001) than pigs fed HE diets. Overall, DFI was greater (p<0.001) for pigs fed the LE diets (2.62 vs. 2.45 kg/d). However, no diet differences were observed for MEI (8.76 vs. 8.78 Mcal/d, p = 0.49) or NEI (6.39 vs. 6.44 Mcal/d, p = 0.13), thereby indicating that the pigs compensated for the decreased energy content of the diet. Overall ADG:DFI (0.362 vs. 0.377) and ADG:Mcal MEI (0.109 vs. 0.113) was less (p<0.001) for pigs fed LE compared to HE diets. Pigs fed HE diets had 3.6% greater ADG:Mcal MEI above maintenance and only 1.3% greater ADG:Mcal NEI (0.152 versus 0.150), therefore NEI is a more accurate predictor of

  9. A Millimeter-Wave Cavity-Backed Suspended Substrate Stripline Antenna

    Science.gov (United States)

    Simons, Rainee N.

    1999-01-01

    Future generation satellite communication systems in near-Earth orbit will operate at frequencies in the higher mm-wave frequency bands. These satellite systems require low-profile, high gain, light weight and low cost antennas for communications to and from Earth as well as for inter-satellite links (ISL). At higher mm-wave frequencies, the conductor loss of conventional microstrip line is high and consequently the feed network loss of patch antenna arrays is also high. The high loss lowers the array efficiency, and in addition lowers the G/T ratio in a receiving array. Recently a radial line slot antenna array has been demonstrated to have high gain and efficiency at 60 GHz. In this paper, the design, fabrication and characterization of a V-Band (50-75 GHz), cavity backed, circular aperture antenna with suspended substrate stripline (SSS) feed is presented.

  10. Pedigree and genomic analyses of feed consumption and residual feed intake in laying hens.

    Science.gov (United States)

    Wolc, Anna; Arango, Jesus; Jankowski, Tomasz; Settar, Petek; Fulton, Janet E; O'Sullivan, Neil P; Fernando, Rohan; Garrick, Dorian J; Dekkers, Jack C M

    2013-09-01

    Efficiency of production is increasingly important with the current escalation of feed costs and demands to minimize the environmental footprint. The objectives of this study were 1) to estimate heritabilities for daily feed consumption and residual feed intake and their genetic correlations with production and egg-quality traits; 2) to evaluate accuracies of estimated breeding values from pedigree- and marker-based prediction models; and 3) to localize genomic regions associated with feed efficiency in a brown egg layer line. Individual feed intake data collected over 2-wk trial periods were available for approximately 6,000 birds from 8 generations. Genetic parameters were estimated with a multitrait animal model; methods BayesB and BayesCπ were used to estimate marker effects and find genomic regions associated with feed efficiency. Using pedigree information, feed efficiency was found to be moderately heritable (h(2) = 0.46 for daily feed consumption and 0.47 for residual feed intake). Hens that consumed more feed and had greater residual feed intake (lower efficiency) had a genetic tendency to lay slightly more eggs with greater yolk weights and albumen heights. Regions on chromosomes 1, 2, 4, 7, 13, and Z were found to be associated with feed intake and efficiency. The accuracy from genomic prediction was higher and more persistent (better maintained across generations) than that from pedigree-based prediction. These results indicate that genomic selection can be used to improve feed efficiency in layers.

  11. SeaBuoySoft – an On-line Automated Windows based Ocean Wave height Data Acquisition and Analysis System for Coastal Field’s Data Collection

    Directory of Open Access Journals (Sweden)

    P.H.Tarudkar

    2014-12-01

    Full Text Available Measurement of various hydraulic parameters such as wave heights for the research and the practical purpose in the coastal fields is one of the critical and challenging but equally important criteria in the field of ocean engineering for the design and the development of hydraulic structures such as construction of sea walls, break waters, oil jetties, fisheries harbors, all other structures, and the ships maneuvering, embankments, berthing on jetties. This paper elucidates the development of “SeaBuoySoft online software system for coastal field‟s wave height data collection” for the coastal application work. The system could be installed along with the associated hardware such as a Digital Waverider Receiver unit and a Waverider Buoy at the shore. The ocean wave height data, transmitted by wave rider buoy installed in the shallow/offshore waters of sea is received by the digital waverider receiver unit and it is interfaced to the SeaBuoySoft software. The design and development of the software system has been worked out in-house at Central Water and Power Research Station, Pune, India. The software has been developed as a Windows based standalone version and is unique of its kind for the reception of real time ocean wave height data, it takes care of its local storage of wave height data for its further analysis work as and when required. The system acquires real time ocean wave height data round the clock requiring no operator intervention during data acquisition process on site.

  12. Feeding tube insertion - gastrostomy

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002937.htm Feeding tube insertion - gastrostomy To use the sharing features on this page, please enable JavaScript. A gastrostomy feeding tube insertion is the placement of a feeding ...

  13. Breastfeeding vs. Formula Feeding

    Science.gov (United States)

    ... 1- to 2-Year-Old Breastfeeding vs. Formula Feeding KidsHealth > For Parents > Breastfeeding vs. Formula Feeding Print ... a lactation specialist. previous continue All About Formula Feeding Commercially prepared infant formulas are a nutritious alternative ...

  14. Animal Feeding Operations

    Science.gov (United States)

    ... What's this? Submit Button Healthy Water Home Animal Feeding Operations Recommend on Facebook Tweet Share Compartir On ... Concentrated Animal Feeding Operations (CAFOs) What are Animal Feeding Operations (AFOs)? According to the United States Environmental ...

  15. Breastfeeding vs. Formula Feeding

    Science.gov (United States)

    ... A What's in this article? All About Breastfeeding Breastfeeding Challenges All About Formula Feeding Formula Feeding Challenges Making a Choice en español Lactancia materna versus lactancia artificial Choosing whether to breastfeed or formula feed their ...

  16. Reflectors to Focus Wave Energy

    DEFF Research Database (Denmark)

    Kramer, Morten; Frigaard, Peter

    2005-01-01

    Wave Energy Converters (WEC’s) extract wave energy from a limited area, often a single point or line even though the wave energy is generally spread out along the wave crest. By the use of wave reflectors (reflecting walls) the wave energy is effectively focused and increased by approximately 30......-50%. Clearly longer wave reflectors will focus more wave energy than shorter wave reflectors. Thus the draw back is the increased wave forces for the longer wave reflectors. In the paper a procedure for calculating the energy efficiency and the wave forces on the reflectors are described, this by use of a 3D...... boundary element method. The calculations are verified by laboratory experiments and a very good agreement is found. The paper gives estimates of possible power benefit for different wave reflector geometries and optimal geometrical design parameters are specified. On this basis inventors of WEC’s can...

  17. 2D Traveling Wave Array Employing a Trapezoidal Dielectric Wedge for Beam Steering

    Science.gov (United States)

    Host, Nicholas K.; Chen, Chi-Chih; Volakis, John L.; Miranada, Felix A.

    2014-01-01

    This presentation addresses the progress made so far in the development of an antenna array with reconfigurable transmission line feeds connecting each element in series. In particular, 2D traveling wave array employing trapezoidal Dielectric Wedge for Beam Steering will be discussed. The presentation includes current status of the effort and suggested future work. The work is being done as part of the NASA Office of the Chief Technologist's Space Technology Research Fellowship (NSTRF).

  18. lamb波在耐腐蚀高压容器衬里层无损检测中的应用研究%The application research of lamb waves in corrosion resistant lining layer nondestructive testing of high pressure vessel

    Institute of Scientific and Technical Information of China (English)

    吴後飞; 张艳飞

    2011-01-01

    耐腐蚀高压容器衬里层的背侧裂纹是影响设备安全性的的重要因素之一.采用常规无损检测方法对其进行检测时常存在漏检、难检等问题,对容器的安全性造成很大的威胁.通过对lamb波传播特性的分析,对自行设计制作的8mm厚的316Mod尿素级不锈钢板的人工设计制作缺陷试块进行了lamb波探伤的实验研究,研究结果表明,lamb波探伤能够实现对耐腐蚀高压容器衬里背侧裂纹的快速检测.%Dorsal crack of Corrosion resistant lining layer of high pressure vessel is one of the important factors in the safety equipment.Using conventional NDT methods often exist undetection or difficult test,and it is a great threat to the safety of vessel. It based on the analysis of the lamb wave propagation characteristics of itself,to 8mm thick 316Mod tainless steel plate artificially design flaws for the test experiments used lamb wave and verifies the lamb waves can achieve the fast test for crack detection dorsal of corrosion pressure vessel lining.

  19. 深圳地铁11号线隧道空气压力波研究%Study on Air Pressure Waves in Tunnels on Shenzhen Metro Line 11

    Institute of Scientific and Technical Information of China (English)

    张海天; 陈健

    2011-01-01

    The article proposes pressure comfort standards in high-speed metro tunnels. By using the tunnel pressure wave analysis software ThermoTun, authors analyzed tunnel pressure waves and comfort of pressure considering different section design for tunnels on Shenzhen metro line 11. They also put forward design proposals for tunnel pressure relief system and tunnel profile.%分析并提出高速地铁隧道压力舒适度标准.采用隧道压力波分析软件ThermoTun,对深圳地铁11号线隧道段不同断面设计情况下的压力波及压力舒适度进行分析,提出对隧道泄压系统及隧道断面的设计建议.

  20. 基于静态小波变换的T型输电线路行波测距方法%Travelling Wave Fault Location for Three-Terminal Transmission ~Line Based on Static Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    张永健; 胥杰; 孙嘉

    2012-01-01

    In view of the defect in existing travelling wave fault location algorithm that this algorithm is easily affected by wave velocity, a new method for travelling wave fault location of three-terminal transmission line is proposed. Using Clarke's transform the phase currents are turned into independent mode currents, then static wavelet transform (SWT) is applied to mode currents to determine the moments at which travelling wave surges arrive the bus terminals. Firstly the memberships are defined by three initial moments at which the first wave front arrives T-connected buses, and based on the memberships the criterion for distinguishing faulty branch is given. To implement fault location of three-terminal transmission line, based on existing fault location formula for two-terminal transmission line the fault location formula for three-terminal transmission line is derived. Three possible fault conditions near the T-connected node are researched, and a three-time fault location method is put forward to resolve the fault location for the faults occurred near the T-connected node. Comparing with existing fault location methods, due to time-invariance of SWT, making full use of the data measured at three terminals of the three-terminal transmission line and that the wave velocity does not appear in the derived fault location formula, the proposed method can provide more accurate fault location results. Results of simulation using ATP/EMTP show that the proposed fault location method for three-terminal transmission line is simple, reliable and not affected by such factors as transition resistance and fault types and so on.%针对现有T型输电线路行波测距算法易受行波波速影响的不足,提出一种新的T型输电线路行波测距方法。采用Clarke变换将相电流转换为独立的模电流,对模电流进行静态小波变换(staticwavelettransform,SwT)处理,实现各行波浪涌到达各母线端时刻的标定。首先利用

  1. Determination of virginiamycin in feeds.

    Science.gov (United States)

    Ragheb, H S; Black, L J; Waisner, D L

    1979-05-01

    Virginiamycin was extracted from the feed by ethanol-pH 2.5 phosphate buffer (1 + 1). The pH during extraction was adjusted (when necessary) to between 4 and 5. Sample dilutions and the standard dose response line were prepared to contain ethanol pH 6 phosphate buffer (2 + 8), and the test organism was Sarcina lutea. Three feeds (a poultry ration, a swine finishing ration, and a swine starter ration) showed virginiamycin recovery of 88.8--108.9% when standard solutions were added at concentrations of 4.54--90.8 g/ton. The coefficient of variation (4--20%) was larger for low potency feeds (10 g/ton) compared to the higher feeds (100 g/ton). Similarly, excellent recovery was obtained when the swine starter feed was fortified by a commercial premix. Amprolium, roxarsone, and monensin can be present at 20 times the concentration of virginiamycin with little or no interference in the antibiotic determination. Lasalocid at 10 times the concentration of virginiamycin caused a slightly positive bias (recovery, 107.4%).

  2. Effect of selection for residual feed intake on feeding behavior and daily feed intake patterns in Yorkshire swine.

    Science.gov (United States)

    Young, J M; Cai, W; Dekkers, J C M

    2011-03-01

    Residual feed intake (RFI) is a measure of feed efficiency defined as the difference between observed and predicted feed intake based on average requirements for growth and maintenance. The objective of this study was to evaluate the effect of selection for decreased RFI on feeding behavior traits and to estimate their relationships with RFI. Three data sets from the 4th and 5th generations of a selection experiment with a line selected for reduced RFI (LRFI) and a randomly selected control line (CTRL) were analyzed. Lines were mixed in pens of 16 and evaluated for feeding behavior traits obtained from a single-space electronic feeder over a growing period of ~3 mo before ~115 kg. The following traits were evaluated as averages over the entire test period and over the first and second half of the test period: number of visits per day and hour; occupation time per day, visit, and hour; feed intake (FI) per day, visit, and hour; and FI rate per visit. Models used included fixed effects of line and feeder, covariates of on-test age and FI per day, and random effects of pen, on-test group, sire, and litter. Repeated measures models were used to analyze feeding patterns during the day. The LRFI pigs had significantly less FI per day than CTRL pigs for all 3 data sets. With adjustment for FI per day, line differences of all traits were in the same direction for all 3 data sets but differed in significance and size. Feed intake per visit and hour and visits per day and hour did not differ between lines, but the trend was for LRFI pigs to have fewer visits, in particular during peak eating times. The LRFI pigs had a greater feeding rate and less occupation time per day, visit, and hour than CTRL pigs, but this was not significant for all data sets. Correlations of RFI with FI per day and visit and visits per day were positive. Average daily gain was positively correlated with FI per day and visit and occupation time per visit but negatively correlated with visits per day

  3. Traveling-wave photodetector

    Science.gov (United States)

    Hietala, Vincent M.; Vawter, Gregory A.

    1993-01-01

    The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size.

  4. 架空线-电缆混合线路故障行波信号识别的研究%Research on Signal Recognition of Fault Traveling Wave for Cable-Overhead Mixed Line

    Institute of Scientific and Technical Information of China (English)

    王升; 徐伟

    2016-01-01

    ABSTRACT:This paper deals with fault recognition of the cable-overhead mixed line. With focus on the high resistance instantaneous ground fault and overhead line lightning fault of the mixed line,the paper proposes that the spectrum energy ratio of two characteristic frequency bands and waveform factor in the fault current traveling wave be used to distinguish non lightning strike fault,lightning fault and high impedance arc ground fault. The simulation model of the electromagnetic transient software is used to simulate the lightning strike on the cable-overhead mixed line;meanwhile, the fault traveling wave signal is identified. The simulation results show that the method proposed can effectively identify three kinds of faults.%针对架空-电缆混合线路中的高阻瞬时接地故障和架空线路雷击故障,提出采用电流故障行波的2个特征频带中的频谱能量比和波形系数来有效区分雷击非故障与雷击故障、高阻弧光接地故障的思想。利用电磁暂态软件建立仿真模型对架空-电缆混合线路的各种雷击情况进行了仿真,并且对故障行波信号进行了识别研究。仿真结果表明,采用的雷击识别方法可以有效识别不同类型的故障。

  5. Full-Wave Analysis of Field-to-Line Coupling Effects Using 1D FDTD Method under Exciting Source with Different Bandwidths

    Directory of Open Access Journals (Sweden)

    Qi Zhang

    2014-01-01

    Full Text Available With the aim to analyze field-to-line coupling effects based on energy spectrum, parallel finite-difference time-domain (FDTD method is applied to calculate the induced voltage on overhead lines under high-power electromagnetic (HPEM environment. Firstly, the energy distribution laws of HEMP (IEC 61000-2-9, HEMP (Bell Laboratory, HEMP (Paulino et al., 2010, and LEMP (IEC61000-4-5 are given. Due to the air-earth stratified medium, both the absorbing boundary and the connecting boundary applied to scattering by finite-length objects are separately set in aerial and underground parts. Moreover, the influence of line length on induced voltage is analyzed and discussed. The results indicate that the half-peak width is wider with the increase of the line length. But the steepness of induced voltage on the overhead line is invariable. There is no further increase in the peak of induced voltage especially when the line length increases to be equivalent to the wavelength of the frequency bands with the maximum energy.

  6. Binding affinity and inhibitory potency of neomycin and streptomycin on the Tat peptide interaction with HIV-1 TAR RNA detected by on-line acoustic wave sensor.

    Science.gov (United States)

    Tassew, Nardos; Thompson, Michael

    2003-10-07

    The binding of two aminoglycoside antibiotics, neomycin and streptomycin, to a segment of the transactivation responsive region (TAR) RNA of the human immunodeficiency virus, and their inhibitory potency to disrupt the interaction of the RNA with a regulatory Tat protein-derived peptide, have been studied using a flow-through acoustic wave detector system. Binding affinity is directly correlated with the inhibitory potency of these molecules and the acoustic wave detection system shows that neomycin exhibits at least a ten-fold greater affinity for TAR RNA and that it is also a more potent inhibitor than streptomycin. These results are in agreement with previous studies. However, unlike the time-consuming batch-based assays, use of the flow-through format offers considerable potential for the rapid screening of the chemistry of relatively small-molecule-nucleic acid binding events.

  7. 脉冲激光线源热弹激发超声导波的数值研究%Numerical Simulation of Ultrasonic Guide Waves Generated by Pulsed Laser Line Source in Thermoelastic Regime

    Institute of Scientific and Technical Information of China (English)

    关建飞

    2011-01-01

    考虑激光作用过程中材料热物理参数随温度变化的非线性效应,在两维平面内建立了平面应变有限元模型,基于热弹耦合理论数值模拟了脉冲激光线源辐照金属铝板表面激发超声导波的物理过程.数值模拟分别得到了脉冲激光线源在厚度为1 cm与0.2 mm的铝板中激发出的声表面波与Lamb波的时域波形.其中声表面波包括掠面纵波、表面横波与瑞利波3种模式,而Lamb波主要包含低阶对称与反对称模式.最后讨论了不同半宽的激光线源对声表面波以及Lamb波位移信号时域波形的影响,初步建立了线源激光脉冲输入参数与超声导波波形特征之间的对应关系.为激光超声用于材料性能的表征提供了定量的基础.%Two dimensional plane strain finite element model have been presented to simulate the laser generated surface acoustic waves on the top surface of aluminum plate, which considered the temperature dependent physical parameters of sample. Numerical results have demonstrated that laser generated sur-face acoustic wave forms are calculated in Al plate of 1 cm thickness, which usually involve skimming lon-gitudinal mode, skimming shear mode and Rayleigh mode; meantime, the guide wave excited by a pulsed line source on a 0.2-mm-thickness Al plate is typical Lamb waves and the surface vibration is mainly de-termined by the lowest order of the symmetric mode ( s0 ) and antisymmetric mode ( a0) . It is also indica-ted that the amplitude of the guide waves are strongly dependent with the half width of the line-shaped la-ser source,which can be an important basis for the research on nondestructive evaluation fields.

  8. Uniplanar Millimeter-Wave Log-Periodic Dipole Array Antenna Fed by Coplanar Waveguide

    Directory of Open Access Journals (Sweden)

    Guohua Zhai

    2013-01-01

    Full Text Available A uniplanar millimeter-wave broadband printed log-periodic dipole array (PLPDA antenna fed by coplanar waveguide (CPW is introduced. This proposed structure consists of several active dipole elements, feeding lines, parallel coupled line, and the CPW, which are etched on a single metallic layer of the substrate. The parallel coupled line can be optimized to act as a transformer between the CPW and the PLPDA antenna. Meanwhile, this transform performs the task of a balun to achieve a wideband, low cost, low loss, simple directional antenna. The uniplanar nature makes the antenna suitable to be integrated into modern printed communication circuits, especially the monolithic millimeter-wave integrated circuits (MMIC. The antenna has been carefully examined and measured to present the return loss, far-field patterns, and antenna gain.

  9. Air flow exploration of abrasive feed tube

    Science.gov (United States)

    Zhang, Shijin; Li, Xiaohong; Gu, Yilei

    2009-12-01

    An abrasive water-jet cutting process is one in which water pressure is raised to a very high pressure and forced through a very small orifice to form a very thin high speed jet beam. This thin jet beam is then directed through a chamber and then fed into a secondary nozzle, or mixing tube. During this process, a vacuum is generated in the chamber, and garnet abrasives and air are pulled into the chamber, through an abrasive feed tube, and mixes with this high speed stream of water. Because of the restrictions introduced by the abrasive feed tube geometry, a vacuum gradient is generated along the tube. Although this phenomenon has been recognized and utilized as a way to monitor nozzle condition and abrasive flowing conditions, yet, until now, conditions inside the abrasive feed line have not been completely understood. A possible reason is that conditions inside the abrasive feed line are complicated. Not only compressible flow but also multi-phase, multi-component flow has been involved in inside of abrasive feed tube. This paper explored various aspects of the vacuum creation process in both the mixing chamber and the abrasive feed tube. Based on an experimental exploration, an analytical framework is presented to allow theoretical calculations of vacuum conditions in the abrasive feed tube.

  10. 基于 LabVIEW 的输电线路故障行波分析平台%A Traveling Wave Analysis Platform for Transmission Line Faults Based on LabVIEW

    Institute of Scientific and Technical Information of China (English)

    徐丽丽; 黄欣; 陈平; 姜伟昌; 王建鹏

    2016-01-01

    提出了基于虚拟仪器技术的输电线路故障行波分析平台的总体设计方案,完成了基于 LabVIEW 完成了输电线路故障行波分析平台的设计,包括接收并分析不同数据类型仿真数据、多种行波测距方法的设计、计算与分析结果的图形化显示、给出不同测距方法的数据结果、数据结果的存储与读取。仿真实例表明本平台测试结果准确、界面友好、性能稳定。%This paper presents a general design scheme of the traveling wave analysis platform for transmission line faults based on virtual instrument technology,and gives a design of the traveling wave analysis platform for transmission line faults based on LabVIEW, including the design of reception and analysis of different types of simulation data and several traveling wave fault location methods, graphical display of calculation and analysis results,data result of different location methods,as well as storage and reading of data results.Simulation results show that the platform has accurate test result,friendly interface and stable performance.

  11. Feeding Your Baby

    Medline Plus

    Full Text Available ... Baby Feeding your baby Other Baby topics ') document.write(' Caring for your baby ') document.write('') } ') document.write(' Feeding your baby ') document.write('') } ') document. ...

  12. Feeding tube - infants

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007235.htm Feeding tube - infants To use the sharing features on this page, please enable JavaScript. A feeding tube is a small, soft, plastic tube placed ...

  13. Jejunostomy feeding tube

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000181.htm Jejunostomy feeding tube To use the sharing features on this ... vomiting Your child's stomach is bloated Alternate Names Feeding - jejunostomy tube; G-J tube; J-tube; Jejunum ...

  14. Nasogastric feeding tube

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000182.htm Nasogastric feeding tube To use the sharing features on this ... the nose. It can be used for all feedings or for giving a person extra calories. It ...

  15. Feeding Your Newborn

    Science.gov (United States)

    ... for your child. These guidelines on breastfeeding and bottle feeding can help you make the decision that's right ... formula is a nutritious alternative to breast milk. Bottle feeding can offer more freedom and flexibility for moms, ...

  16. GNA Confers Resistance to Rice Brown Planthopper in Transgenic Rice Pure Lines by Both Bioassay and Feeding Tests%生物鉴定和喂养试验证明GNA赋予转基因水稻纯系对褐飞虱的抗性

    Institute of Scientific and Technical Information of China (English)

    唐克轩; 孙小芬; 万丙良; 戚华雄; 卢兴桂

    2001-01-01

    Two transgenic rice pure lines, generated by particle bombardment, were challeng ed by the first-instar nymphs of rice brown planthopper (Nilaparvata lugens, BPH) biotype I using the standard BPH bioassay and feeding test protocol essen tially the same as described by Rao et al. (1998). Both lines contained and expressed the selectable marker hygromycin phosphotransferase gene(hpt), the reporter β-glucuronidase gene(gusA) and the snowdrop (Galanthus niv alis) lectin gene (gna). Insect bioassay and feeding test results showed t hat both lines had significant deterrent effect on BPH by decreasing BPH surviva l and overall fecundity, retarding BPH development and declining BPH feeding.%参照Rao等(1998)的褐飞虱生物鉴定和喂养方法,用水稻褐飞虱生物Ⅰ型的一龄若虫食喂, 用基因枪法获得2个转基因水稻纯系. 这2个纯系均含有并表达潮霉素抗性基因(hpt)、 gusA报告基因和雪花莲凝集素基因(gna). 褐飞虱生物鉴定和喂养试验表明,水稻 纯系对褐飞虱具有显著的抑制作用. 具体表现为降低褐飞虱成活率和繁殖力、延缓褐飞虱发 育以及减少褐飞虱进食量. 通过褐飞虱生物鉴定和喂养试验证明,表达GNA的转基因水稻纯系对严重危害水稻生产的褐飞虱具有抗性作用.

  17. Widely tunable, narrow line width and low optical noise continuous-wave all fiber Er:Yb co-doped double-clad ring laser

    Science.gov (United States)

    Guesmi, Khmaies; Bahloul, Faouzi; Semaan, Georges; Meng, Yichang; Salhi, Mohamed; Sanchez, François

    2017-01-01

    In this paper, we report a widely tunable, narrow linewidth, low noise continuous-wave double-clad Er:Yb doped fiber ring laser. Tunability is demonstrated in wide range spanning from 1520 to almost 1620 nm covering the C and L spectral bands. The cavity design is optimized in order to achieve the largest tuning range with very high optical signal-to-noise ratio (SNR). The output coupling ratio greatly influences the tuning range of the laser while the position of the spectral filter determines the SNR. The obtained laser exhibits a tuning range over 98 nm with a nearly constant SNR of about 58.5 dB.

  18. Waveguide Slot Array Antenna with a Hybrid-Phase Feed for Grating Lobe Reduction

    Directory of Open Access Journals (Sweden)

    Son Trinh-Van

    2016-01-01

    Full Text Available The design of a 112-element millimeter-wave waveguide slot array antenna to reduce the grating lobe level is presented. A hybrid-phase feeding technique combining a cophase feed and an alternating-phase feed is applied to facilitate the suppression of grating lobes. In addition, a stepped feed waveguide and offset coupling slots aligned in a line are employed to realize a tapered aperture distribution. As a result, grating lobe suppression of 8.1 dB was achieved on the diagonal planes compared to a conventional alternating-phase-fed waveguide slot array antenna. A prototype of the proposed antenna was fabricated and measured. The measured results show that the proposed antenna exhibits a −15 dB reflection bandwidth of 3.4% and an average realized gain of 26.72 dBi within the measured frequency range. Good agreement between the simulated and measured radiation patterns is also observed.

  19. Ku-Band Traveling Wave Slot Array Using Simple Scanning Control

    Science.gov (United States)

    Host, Nicholas K.; Chen, Chi-Chih; Volakis, John L.; Miranda, Felix A.

    2015-01-01

    This paper introduces a feeding concept aimed at simplifying the backend (phase shifters) of traditional phased arrays. As an alternative to traditional phased arrays, we employ a traveling wave array (TWA) using a single feedline whose propagation constant is controlled via a single, small mechanical movement without a need for phase shifters to enable scanning. Specifically, a dielectric plunger is positioned within a parallel plate waveguide (PPW) transmission line (TL) that feeds the TWA. By adjusting the position of the dielectric plunger within the PPW feeding the TWA, beam steering is achieved. A 20 element array is designed at 13GHz shown to give stable realized gain across the angular range of -25 deg. less than or equal to theta less than or equal to 25 deg. A proof of concept array is fabricated and measured to demonstrate and validate the concept's operation.

  20. Breast-Feeding Twins: Making Feedings Manageable

    Science.gov (United States)

    ... more than one baby? Here's help breast-feeding twins or other multiples, from getting positioned and ensuring ... babies who are born prematurely, as are many twins and higher order multiples. Breast milk is easier ...

  1. Feed safety in the feed supply chain

    Directory of Open Access Journals (Sweden)

    Pinotti, L.

    2011-01-01

    Full Text Available A number of issues have weakened the public's confidence in the quality and wholesomeness of foods of animal origin. As a result farmers, nutritionists, industry and governments have been forced to pay serious attention to animal feedstuff production processes, thereby acknowledging that animal feed safety is an essential prerequisite for human food safety. Concerns about these issues have produced a number of important effects including the ban on the use of processed animal proteins, the ban on the addition of most antimicrobials to farm animals diets for growth‐promotion purposes, and the implementation of feed contaminant regulations in the EU. In this context it is essential to integrate knowledge on feed safety and feed supply. Consequently, purchase of new and more economic sources of energy and protein in animal diets, which is expected to conform to adequate quality, traceability, environmental sustainability and safety standards, is an emerging issue in livestock production system.

  2. Diurnal variation of mountain waves

    Directory of Open Access Journals (Sweden)

    R. M. Worthington

    2006-11-01

    Full Text Available Mountain waves could be modified as the boundary layer varies between stable and convective. However case studies show mountain waves day and night, and above e.g. convective rolls with precipitation lines over mountains. VHF radar measurements of vertical wind (1990–2006 confirm a seasonal variation of mountain-wave amplitude, yet there is little diurnal variation of amplitude. Mountain-wave azimuth shows possible diurnal variation compared to wind rotation across the boundary layer.

  3. Dual-frequency feed system for 26-meter antenna conversion

    Science.gov (United States)

    Hartop, R. W.

    1977-01-01

    New cassegrain feed cone assemblies were designed as part of the upgrade of three 26-meter diameter antennas to 34-meter diameter with improved performance. The new dual-frequency feed cone (SXD) will provide both S- and X-band feed systems and traveling wave masers, with a reflex reflector system to permit simultaneous operation analogous to the 64-meter antennas. Tasks involved in adding the X-band receiving capability and improving the S-band feed performance in support of Voyager and later missions described in.

  4. User's Manual for LINER: FORTRAN Code for the Numerical Simulation of Plane Wave Propagation in a Lined Two-Dimensional Channel

    Science.gov (United States)

    Reichert, R, S.; Biringen, S.; Howard, J. E.

    1999-01-01

    LINER is a system of Fortran 77 codes which performs a 2D analysis of acoustic wave propagation and noise suppression in a rectangular channel with a continuous liner at the top wall. This new implementation is designed to streamline the usage of the several codes making up LINER, resulting in a useful design tool. Major input parameters are placed in two main data files, input.inc and nurn.prm. Output data appear in the form of ASCII files as well as a choice of GNUPLOT graphs. Section 2 briefly describes the physical model. Section 3 discusses the numerical methods; Section 4 gives a detailed account of program usage, including input formats and graphical options. A sample run is also provided. Finally, Section 5 briefly describes the individual program files.

  5. 基于随机子空间法和固有频率法的线路故障定位%Fault Location of Transmission Lines Based on Stochastic Subspace Identification Method and Travelling Wave Natural Frequency

    Institute of Scientific and Technical Information of China (English)

    张凯

    2015-01-01

    输电线路发生故障后,进行准确快速的故障距离判断在实际生产运行中具有很大的意义。线路故障后,将产生一系列的故障暂态行波,且从频域的角度看,行波可看作为谐波形式。提出基于随机子空间法和行波固有频率法相结合的方法进行线路故障定位。首先通过相模变换得到输电线路中的模电流分量,然后基于随机子空间算法进行辨识得到行波固有频率,进而计算此频率下的行波波速和模阻抗导纳矩阵,最后可求得故障距离。在PSCAD中搭建两端系统仿真模型,经过仿真验证表明,此方法可有效进行线路故障定位,且准确度较高。%The question of how to judge fault distance accurately and rapidly has great significance in the actual production run when a short circuit fault of transmission lines happens.When faults happen they produce transient state travelling waves.The frequency spectra of travelling waves are a fundamental characteristic frequency.This paper research on fault location is based on stochastic subspace identification and the natural frequency of traveling waves.Firstly, we use module current component based on phase-mode transformation, secondly we identify the natural frequency of traveling waves based on stochastic subspace identification.Then we calculate the wave veloci-ty and module impedance admittance matrix at the natural frequency.Finally, we arrive at the distance to fault. Building the two-terminal system using PSCAD program, the simulation’ s result show the way to find fault location with high accuracy.

  6. Five Waves of Innovation

    DEFF Research Database (Denmark)

    Østergaard, Claus Møller; Rosenstand, Claus Andreas Foss; Gertsen, Frank

    2012-01-01

    Building on previous well-argued work by Jon Sundbo (1995a), on how innovation has evolved in three phases or waves since 1880, this paper’s contribution is extending the historical line, by offering arguments and explanations for two additional waves of innovation that explain the most recent...... developments. The paper also adds new interpretations of the previous work by Sundbo (1995a) in suggesting that the waves are triggered by societal and economic crisis. The result is a new theoretical and historical framework, proposing five waves of innovation triggered by societal and economic crises....... The innovation within each wave is constituted by different drivers of innovation: Cost-driven, development-driven, market-driven, user-driven, and remains of these waves are accumulated to form the complex character of today’s network-driven innovation....

  7. On the spectral domain approach to long-range propagation of high-frequency waves along a strip conductor above a PEC surface

    CERN Document Server

    Norgren, Martin

    2012-01-01

    A generic problem of high frequency wave propagation along a metallic strip in parallel above a PEC ground plane is considered. The wave is excited by an elemental electric dipole at an arbitrary location above the PEC plane. The full wave problem, for arbitrary widths of the strip, is solved by means of a mode matching approach and expansion of the strip surface current into Chebyshev polynomials. For narrow strips, an approximate method using only longitudinal currents is derived, and compared numerically with the full wave method. Utilizing the concept of equivalent radius, the approximate method for narrow strips is evaluated numerically against results for thin circular wires. It is concluded that the approximate method is suitable for handling multiple wires in layered structures, wherefore the method has potential usefulness for estimating long range propagation of high frequency waves in wire structures like power lines and railway feeding systems, containing over-head wires and wires submerged into g...

  8. Nonlinear elastic waves in materials

    CERN Document Server

    Rushchitsky, Jeremiah J

    2014-01-01

    The main goal of the book is a coherent treatment of the theory of propagation in materials of nonlinearly elastic waves of displacements, which corresponds to one modern line of development of the nonlinear theory of elastic waves. The book is divided on five basic parts: the necessary information on waves and materials; the necessary information on nonlinear theory of elasticity and elastic materials; analysis of one-dimensional nonlinear elastic waves of displacement – longitudinal, vertically and horizontally polarized transverse plane nonlinear elastic waves of displacement; analysis of one-dimensional nonlinear elastic waves of displacement – cylindrical and torsional nonlinear elastic waves of displacement; analysis of two-dimensional nonlinear elastic waves of displacement – Rayleigh and Love nonlinear elastic surface waves. The book is addressed first of all to people working in solid mechanics – from the students at an advanced undergraduate and graduate level to the scientists, professional...

  9. Traveling-wave solutions of a modified Hodgkin-Huxley type neural model via Novel analytical results for nonlinear transmission lines with arbitrary I(V characteristics

    Directory of Open Access Journals (Sweden)

    Valentino Anthony Simpao

    2000-01-01

    Full Text Available Herein an enhanced Hodgkin-Huxley (H-H type model of neuron dynamics is solved analytically via formal methods. Our model is a variant of an earlier one by M.A. Mahrous and H.Y. Alkahby [1]. Their modified model is realized by a hyperbolic quasi-linear diffusion operator with time-delay parameters; this compared to the original H-H model with standard parabolic quasi-linear diffusion operator and no time-delay parameters. Besides these features, the present model also incorporates terms describing signal dissipation into the background substrate (e.g., conductance to ground, making it more experimentally amenable. The solutions which results via the present scheme are of traveling-wave profile, which agree qualitatively with those observed in actual electro-physiological measurements made on the neural systems originally studied by H-H These results confirm the physiological soundness of the enhanced model and of the preliminary assumptions which motivated the present solution strategy; the comparison of the present results with actual electro-physiological data displays shall appear in later publications.

  10. Is gastric sham feeding really sham feeding?

    Science.gov (United States)

    Sclafani, A; Nissenbaum, J W

    1985-03-01

    Rats were fitted with gastric cannulas, food deprived, and allowed to drink a sugar solution that drained out of the opened cannula; i.e., the rats sham-fed. Although this procedure is thought to prevent absorption of ingested food, it was found that the sham feeding of a 32% glucose or sucrose solution significantly elevated blood glucose levels. The addition of acarbose, a drug that inhibits the digestion of sucrose, to the 32% sucrose solution blocked the blood glucose rise, as did closing the pylorus with an inflatable pyloric cuff. Neither the drug nor the cuff, however, reduced the amount of sucrose solution consumed. These findings indicate that gastric sham feeding does not necessarily prevent the digestion and absorption of food, although absorption is not essential for the appearance of a vigorous sham-feeding response. Nevertheless the possibility that neural or hormonal feedback from the stomach contributes to the sham-feeding response cannot be excluded, and until this issue is resolved the results of gastric sham-feeding studies should be interpreted with caution.

  11. Complex Feeding Decisions

    Directory of Open Access Journals (Sweden)

    Anna Miles PhD

    2016-08-01

    Full Text Available Objective: Where swallowing difficulties are chronic or progressive, or a patient is palliative, tube feeding is often not deemed appropriate. Instead, patients continue to eat and drink despite the risks of pneumonia and death. There is currently little evidence to guide clinical practice in this field often termed “risk feeding.” This qualitative study investigated staff, patient, and family member perceptions of risk feeding practices in one New Zealand hospital. Method: Twenty-nine staff members and six patients and/or their family were interviewed. Results: Thematic analysis revealed four global themes: supporting practice, communication, complexity of feeding decisions, and patient and family-centered care. Staff described limited education and organizational policy around risk feeding decisions. Communication was considered a major factor in the success. Conclusion: Feeding decisions are complex in the hospital environment. The themes identified in this study provide a foundation for hospital guideline development and implementation.

  12. Post-pyloric feeding

    Institute of Scientific and Technical Information of China (English)

    Eva Niv; Zvi Fireman; Nachum Vaisman

    2009-01-01

    Postpyloric feeding is an important and promising alternative to parenteral nutrition. The indications for this kind of feeding are increasing and include a variety of clinical conditions, such as gastroparesis, acute pancreatitis, gastric outlet stenosis, hyperemesis (including gravida), recurrent aspiration, tracheoesophageal fistula and stenosis in gastroenterostomy. This review discusses the differences between pre- and postpyloric feeding, indications and contraindications, advantages and disadvantages, and provides an overview of the techniques of placement of various postpyloric devices.

  13. Infant feeding: formula, solids.

    Science.gov (United States)

    Barness, L A

    1985-04-01

    This article discusses and evaluates current formulas, traces their continual improvement (based largely on new information on breast milk composition), and then discusses the question of supplemental feedings.

  14. Danger of zooplankton feeding

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Jiang, H.; Colin, S.P.

    2010-01-01

    Zooplankton feed in any of three ways: they generate a feeding current while hovering, cruise through the water or are ambush feeders. Each mode generates different hydrodynamic disturbances and hence exposes the grazers differently to mechanosensory predators. Ambush feeders sink slowly and ther......Zooplankton feed in any of three ways: they generate a feeding current while hovering, cruise through the water or are ambush feeders. Each mode generates different hydrodynamic disturbances and hence exposes the grazers differently to mechanosensory predators. Ambush feeders sink slowly...

  15. Dusting off the Lecher lines

    Science.gov (United States)

    Thompson, Frank

    2017-01-01

    Experiments with Lecher Lines have always been important in the physics curriculum for demonstrating standing waves and the important concept that waves can be guided as well as being emitted into space. A system operating at low power (less than 10 mW) and in the frequency range 300 MHz to 800MHz is described and the wavelength of the radiation is measured.

  16. 饱和半空间中隧道衬砌对平面SV波的散射IBIEM求解%IBIEM solution to scattering of plane SV waves by tunnel lining in saturated poroelastic half-space

    Institute of Scientific and Technical Information of China (English)

    刘中宪; 琚鑫; 梁建文

    2015-01-01

    基于Biot两相介质理论,采用一种高精度的间接边界积分方程法(IBIEM),研究了平面SV波在饱和半空间中隧道衬砌周围散射的基本规律,并给出了不同参数下地表位移幅值、衬砌动应力集中因子及表面孔隙水压分布图和相应的频谱结果.数值分析表明:饱和半空间隧道衬砌对SV波的散射特征取决于围岩介质孔隙率、入射波的频率和角度、隧道埋深等因素;隧道外壁透水状态对地表位移和隧道应力影响不大;不同角度SV波入射下,隧道应力集中部位有很大差别,且随半空间介质孔隙率增大,应力集中越发显著;衬砌外壁孔隙水压峰值可达到入射波应力幅值的4倍,且 30°斜入射下幅值明显大于 0°垂直入射情况;衬砌上方附近不同点位位移频谱特征差异显著,斜入射情况位移放大效应明显;随埋深增大,地表位移幅值和衬砌表面动应力谱振荡更为剧烈,但幅值会有所降低.另外,按波速比等效的单相介质模型可以近似计算SV波入射下隧道-饱和围岩的位移场和应力场.%Based on the Biot's theory of two-phase medium, a high-precision indirect boundary integral equation method (IBIEM) is proposed to solve the scattering of SV waves by a two-dimensional tunnel lining in saturated poroelastic half-space. The ground displacement amplitudes, dynamic stress concentration of the tunnel and pore pressure on the outer surface of the tunnel are investigated under different circumstances, and the frequency spectrum analysis is also made. Numerical analysis shows that the propagation and scattering characteristics of seismic waves depend on the porosity of the surrounding medium, frequency and angle of the incident waves, tunnel depth, etc. The drainage state of tunnel outer surface has little impact on the ground displacement amplitudes and dynamic stress concentration of the tunnel. The features of the dynamic stress concentration in the tunnel strongly

  17. Electromagnetic Waves

    DEFF Research Database (Denmark)

    This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis...

  18. Selection of Feed Intake or Feed Efficiency

    DEFF Research Database (Denmark)

    Veerkamp, Roel F; Pryce, Jennie E; Spurlock, Diane

    2013-01-01

    . In February 2013, the co-authors discussed how information on DMI should be incorporated in the breeding decisions. The aim of this paper is to present the overall discussion and main positions taken by the group on four topics related to feed efficiency: i) breeding goal definition; ii) biological variation...

  19. Selection of Feed Intake or Feed Efficiency

    DEFF Research Database (Denmark)

    Veerkamp, Roel F; Pryce, Jennie E; Spurlock, Diane

    2013-01-01

    . In February 2013, the co-authors discussed how information on DMI should be incorporated in the breeding decisions. The aim of this paper is to present the overall discussion and main positions taken by the group on four topics related to feed efficiency: i) breeding goal definition; ii) biological variation...

  20. Feeding biology of Cerambycids

    Science.gov (United States)

    Robert A. Haack

    2017-01-01

    There are more than 36,000 species of Cerambycidae recognized throughout the world (see Chapter 1), occurring on all continents except Antarctica (Linsley 1959). Given such numbers, it is not surprising that cerambycids display great diversity in their feeding habits. Both adults and larvae are almost exclusively phytophagous. Some adults appear not to feed at all,...

  1. Creep Feeding Beef Calves

    OpenAIRE

    2005-01-01

    Creep feeding is the managerial practice of supplying supplemental feed (usually concentrates) to the nursing calf. Milk from a lactating beef cow furnishes only about 50 percent of the nutrients that a 3-4 month-old calf needs for maximum growth.

  2. Feeding Your Baby

    Medline Plus

    Full Text Available ... Baby Caring for your baby Feeding your baby Common illnesses Family health & safety Complications & Loss Pregnancy complications ... write(' Feeding your baby ') document.write('') } ') document.write(' Common illnesses ') document.write('') } ') document.write(' Family health & safety ') ...

  3. Challenges in measuring feed efficiency

    Science.gov (United States)

    The term feed efficiency is vague, and is defined differently by people. Historically, feed efficiency has been defined as the feed:gain (F:G) ratio or the inverse (G:F). Indexes have been developed to rank animals for feed efficiency. These indexes include residual feed intake (RFI) and residual...

  4. The Enzymes Assay of the Fermentation of CHE Feed on Line%CHE饲料发酵过程中蛋白酶活力的在线监测

    Institute of Scientific and Technical Information of China (English)

    任健; 童应凯; 黄亮; 王斌; 陈连华; 吕洪海

    2011-01-01

    蛋白酶(包括酸性蛋白酶、碱性蛋白酶及中性蛋白酶)是饲料复合酶制剂中最主要的酶之一.此文对CHE饲料中的酸性蛋白酶、碱性蛋白酶、中性蛋白酶进行了提取并进行了活性测定.结果表明各个酶的活性并不相同,其中酸性蛋白酶的活性最大,碱性蛋白酶最小,并且酸性蛋白的最适温度是40℃左右活性,最大值为5.203 μg/min,中性蛋白酶的最适温度是30℃左右性,最大值为2.9754 μg/min,而碱性蛋白酶的最适温度是22℃左右性,最大值为0.4482 μg/min.%Protease (including acid protease, alkaline protease and neutral protease) is the one of the most important enzymes in the feed compound enzymes. In this paper, acid protease, alkaline protease and neutral protease of the CHE feed were extracted and the assay of their activity were carried out. The results showed that the enzyme activity was not the same in all of them, acidic protease activity was the highest, the smallest one was alkaline protease, and the optimum temperature of acidic protein activity was about 40℃ and the maximum of acidic protein activity was 5.203 μg/min, the optimum temperature of neutral protease was about 30℃ and the maximum of neutral protease was 2.9754 μg/min, while the optimum temperature of alkaline protease was about 25℃ and the maximum of alkaline protease was 0.4482 μg/min.

  5. 基于Prony算法的固有频率法输电线路故障定位%Fault Location of High Voltage Power Transmission Lines Using Travelling Wave Natural Frequency Based on Prony Method

    Institute of Scientific and Technical Information of China (English)

    徐俊明; 魏文伟; 夏沛

    2011-01-01

    When a short circuit fault of transmission lines happened, it will produce transient state travelling waves.The frequency spectra of the travelling waves is a fundamental characteristic frequency, called natural frequencies. Accurate extracting the natural frequencies, which contains informations of position of fault,is able to realize fault location.As a traditional method, Fast Fourier Transform algorithm has not a high frequency resolution and cannot extract the natural frequencies precisely. In allusion to this problem, the paper brings forward applying the Prony Method, which has high precision of fitting, to extract the natural frequencies. The results of simulations by PSCAD and MATLAB show that Prony method can accurate extract the natural frequencies, and the location result is more accurate than Fast Fourier Transform method.%输电线路发生短路故障时,将会产生故障暂态行波.行波在频域上表现为一定的谐波形式,称为行波的固有频率.固有频率包含故障点位置信息,准确提取固有频率能实现输电线路的故障定位.针对传统的FFT算法频域分辨率不高,不能准确提取行波固有频率的问题,提出利用拟合精度较高的Prony算法提取固有频率.EMTDC联合MATLAB仿真结果表明,Prony算法能准确提取固有频率,较FFT方法有更高的定位精度.

  6. 一种计算毫米波微带天线阵馈线损耗的方法%A Method of Calculating Millimeter Wave Microstrip Antenna Array Feed Line Loss

    Institute of Scientific and Technical Information of China (English)

    彭金花; 王华栋

    2006-01-01

    微带阵列天线增益的计算必须计入微带线损耗才有可靠精度,为此提出了一种计算毫米波微带天线阵整体馈线损耗的方法,导出了256元并馈阵、192元串并馈阵的损耗计算表达式,计算值与现有实测值相比较证实了本方法的有效性.

  7. Modelling and Identification of a Digital Feed Drive

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In many cases, the cutting method is usually adopted for the efficient machining of non-circular body of revolution and a feed drive is needed to actuate the cutting tool to and fro according to input signal wave. The feed drive for the purpose is required of fast response and accurate positioning. Both of these are highly dependent upon the actuating elements. Several schemes of actuation are specially interested. One is the introduction of piezoelectric actuation. However, the tiny working stroke of ...

  8. NON PREFERENCE FOR OVIPOSITION AND FEEDING OF Weevil Zabrotes subfasciatus (BOHEMANN, 1833 (COLEOPTERA-BRUCHIDAE IN BEAN LINES (Phaseolus vulgaris L. BEARERS OF ARCELIN NÃO-PREFERÊNCIA PARA OVIPOSIÇÃO E ALIMENTAÇÃO DE Zabrotes subfasciatus (BOHEMANN, 1833 (COLEOPTERA: BRUCHIDAE EM CULTIVARES DE FEIJÃO (Phaseolus vulgaris L. PORTADORES DE ARCELINA

    Directory of Open Access Journals (Sweden)

    Eliane Divina de Tolêdo Souza

    2007-09-01

    Full Text Available

    Arcelin is a seed protein only found in wild beans which gives resistance to bean weevil (Zabrotes subfasciatus Bohemann, 1833. In this study the non preference for oviposition and feeding of the bean weevil was evaluated on a series of near isogenic bean lines: Arc 1, Arc 2, Arc 3 and Arc 4. The bean cultivars Porrillo 70 and Goiano Precoce were utilized as susceptible checks. There wasn’t oviposition preference among the six genotypes studied. The near isogenic lines that contain Arcelin 1 and Arcelin 2 were the last in preference for feeding.

    KEY-WORDS: Resistance; non preference.

    A arcelina é uma proteína encontrada somente em feijões silvestres e é o fator que confere resistência ao caruncho Zabrotes subfasciatus (Bohemann, 1833. Procurou-se verificar a não-preferência para oviposição e alimentação de Z. subfasciatus em uma série de linhagens de feijão quase isogênicas contendo diferentes alelos de arcelina: Arc 1, Arc 2, Arc 3 e Arc 4. Os controles suscetíveis utilizados foram Porrillo 70 e Goiano Precoce. Não houve preferência para oviposição entre os seis genótipos estudados. As linhagens quase isogênicas contendo Arcelina 1 e Arcelina 2 foram as menos preferidas para alimentação.

    PALAVRAS-CHAVE: Resistência; Phaseolus; Zabrotes; não-preferência.

  9. Porous Si as a substrate for the monolithic integration of RF and millimeter-wave passive devices (transmission lines, inductors, filters, and antennas): Current state-of-art and perspectives

    Science.gov (United States)

    Sarafis, Panagiotis; Nassiopoulou, Androula G.

    2017-09-01

    The increasing need for miniaturization, reliability, and cost efficiency in modern telecommunications has boosted the idea of system-on-chip integration, incorporating the RF front-end circuitry and the passive elements such as RF transmission lines, inductors, antennas, and filters. However, the performance of the passive elements of these circuits is highly degraded when integrated on standard CMOS Si, due to its low resistivity. Porous silicon (PSi) has emerged as a promising local substrate material for the on-chip monolithic integration of high performance passive RF and mm-wave devices, because it combines high resistivity and low permittivity along with CMOS compatibility. This review paper aims at summarizing the obtained results so far in the above area, including transmission lines, inductors, filters, and miniaturized antennas, monolithically integrated on porous Si in a CMOS-compatible environment. In this respect, we first present the requirements for a low-loss, CMOS-compatible RF substrates and we then argue on how PSi fulfills the set requirements. Then, we present the methods used so far to extract the dielectric properties of PSi, which are necessary inputs for designing RF devices. The performance of different passive RF devices such as coplanar waveguides, inductors, filters, and antennas on the local porous Si substrate is then reviewed and compared with the performance of other state-of-the-art RF passive devices based on different technologies. Finally, we discuss the progress made so far towards the industrialization of PSi local RF substrate technology and the challenges that are currently faced towards this objective.

  10. Fermented liquid feed for pigs

    OpenAIRE

    Missotten, Joris; Michiels, Joris; Ovyn, Anneke; De Smet, Stefaan; Dierick, Noël

    2010-01-01

    Since the announcement of the ban on the use of antibiotics as antimicrobial growth promoters in the feed of pigs in 2006 the investigation towards alternative feed additives has augmented considerably. Although fermented liquid feed is not an additive, but a feeding strategy, the experimental work examining its possible advantages also saw a rise. The use of fermented liquid feed (FLF) has two main advantages, namely that the simultaneous provision of feed and water may result in an alleviat...

  11. Just How Does Sound Wave?

    Science.gov (United States)

    Shipman, Bob

    2006-01-01

    When children first hear the term "sound wave" perhaps they might associate it with the way a hand waves or perhaps the squiggly line image on a television monitor when sound recordings are being made. Research suggests that children tend to think sound somehow travels as a discrete package, a fast-moving invisible thing, and not something that…

  12. Feeding Your Baby

    Medline Plus

    Full Text Available ... sign in | my dashboard | sign out our cause health topics stories & media research & professionals get involved Search ... your baby Feeding your baby Common illnesses Family health & safety Complications & Loss Pregnancy complications Preterm labor & premature ...

  13. Feeding Your Baby

    Medline Plus

    Full Text Available ... bond with her. Breast milk is the best food for your baby during the first year of ... feeding safe. And then get ready for solid foods ! In This Topic Breastfeeding help Breastfeeding is best ...

  14. Feeding Your Baby

    Medline Plus

    Full Text Available ... for your baby Feeding your baby Common illnesses Family health & safety Complications & Loss Pregnancy complications Preterm labor & premature birth The newborn intensive care unit (NICU) Birth defects & other health conditions Loss & ...

  15. Feeding Your Baby

    Medline Plus

    Full Text Available ... discomforts when breastfeeding Starting your baby on solid foods Using a breast pump Baby Feeding your ... health & safety ') document.write('') } Ask our experts! Have a question? ...

  16. Feeding Your Baby

    Medline Plus

    Full Text Available ... your baby Feeding your baby E-mail to a friend Please fill in all fields. Please enter ... hear about breakthroughs for babies and families. Ask a question Our health experts can answer questions about ...

  17. Feeding Your Baby

    Medline Plus

    Full Text Available ... bottle-feeding safe. And then get ready for solid foods ! In This Topic Breastfeeding help Breastfeeding is ... and discomforts when breastfeeding Starting your baby on solid foods Using a breast pump In This Topic ...

  18. Feeding Your Baby

    Medline Plus

    Full Text Available ... for your baby Feeding your baby Common illnesses Family health & safety Complications & Loss Pregnancy complications Preterm labor & ... health research Prematurity research centers For providers NICU Family Support® Prematurity Campaign Collaborative Info for your patients ...

  19. Z-Spec: A broadband spectrometer for millimeter-wave astrophysics---Instrument development and results of a molecular line survey of nearby star-forming galaxy NGC 253

    Science.gov (United States)

    Earle, Lieko

    We have built Z-Spec, a broadband spectrometer for millimeter-wave astrophysics. The instrument's instantaneous bandwidth of 185-305 GHz covers the entire 1 millimeter atmospheric transmission window with a moderate resolving power ( R = n/Dn) of 250-350. The spectrometer employs a novel architecture called WaFIRS (Waveguide Far-Infrared Spectrometer) which confines the light propagation for a curved diffraction grating within a parallel-plate waveguide, resulting in a minimum mechanical envelope. An array of 160 silicon- nitride micromesh bolometers is cooled to 60 mK via an adiabatic demagnetization refrigerator (ADR) backed by a closed-cycle 3 He- 4 He sorption pump refrigerator. Z-Spec's compact design serves as a concept demonstration for a future far-infrared spectrometer aboard a cold telescope in space. Routine observations with Z-Spec from the Caltech Submillimeter Observatory on Mauna Kea have been conducted since April 2006, and the instrument currently achieves good sensitivities that are within a factor of two of the photon background limit set by the atmosphere and telescope. Z-Spec's primary science objectives are to determine the redshifts of faint submillimeter galaxies using the 12 CO rotational ladder, and to conduct systematic line surveys of local galaxies. The millimeter waveband hosts low- to mid- J rotational transitions for several molecular species which trace the dense interstellar gas associated with active star formation. Z-Spec's bandwidth offers a unique advantage over the traditional single-dish heterodyne approach: the spectral lines and the corresponding continua are all observed simultaneously, greatly reducing relative uncertainties in flux calibration and line-to-continuum ratios. The starburst galaxy NGC 253 was observed with Z-Spec in November 2006, for a total integration of 3.49 hours over two nights. NGC 253 is one of the brightest neighbors outside the Local Group of galaxies and its compact nuclear region is a site of

  20. Cable Fault Traveling Wave on Line Monitoring System Based on LabVIEW%基于LabVIEW的电缆故障行波在线监测系统

    Institute of Scientific and Technical Information of China (English)

    段金英

    2011-01-01

    The buried cables effected by complex, uneven electric field and thermal field, the surrounding environment and many other factors,has high rate of accidents. This paper presented a better real-time monitoring system,with the use of the development platform of National Instruments Corporation Lab VIEW virtual instrument and data acquisition cards, collects the continuous voltage,current of cable line and other parameters,to monitor the operation of transmission lines,The monitoring system realizes the fault current on-line monitoring through the device at the scene access to the Hall sensor cable voltage and current signals from the data acquisition card on the fault wave pop electric high-speed sampling and storage control, with the use of graphical programming language designed to monitor PC interface. Experimental results show that the system can accurately record fault current waveforms, amplitude, provide important data analysis of fault type and location.%针对埋地电缆敷设复杂,发生事故率高的情况,提出了使用LabVIEW和数据采集卡,不间断采集电缆线路上的电压、电流等参数,监视输电线路运行状况,并通过TCP节点,构建了一个实时性较好的监测系统.该监控系统通过装在现场的霍尔传感器获取电缆的电压电流信号,由数据采集卡对故障电流行波进行高速采样和存储控制,利用具有图形化的编程语言设计上位机监控界面,实现了故障电流的在线监测.试验结果表明:该系统能够准确地记录故障电流波形、幅值,为故障类型分析和定位提供了重要数据.

  1. Breast feeding in IMD.

    Science.gov (United States)

    MacDonald, A; Depondt, E; Evans, S; Daly, A; Hendriksz, C; Chakrapani A, A; Saudubray, J-M

    2006-01-01

    Breast feeding has proven benefits for many infants with inherited metabolic disorders (IMDs) but, with the exception of phenylketonuria, there are few reports in other conditions. A questionnaire, completed by dietitians and clinicians from 27 IMD centres from 15 countries (caring for a total of over 8000 patients with IMDs on diet) identified breast feeding experience in IMD. Successful, demand breast feeding (in combination with an infant amino acid formula free of precursor amino acids) was reported in 17 infants with MSUD, 14 with tyrosinaemia type I, and 5 with homocystinuria. Eighty-nine per cent were still breast fed at 16 weeks. Fewer infants with organic acidaemias were demand breast fed (7 with propionic acidaemia; 6 with methylmalonic acidaemia and 13 with isovaleric acidaemia) (usually preceded by complementary feeds of a protein-free infant formula or infant amino acid formula free of precursor amino acids). Only 12 infants with urea cycle disorders were given demand breast feeds, but this was unsuccessful beyond 8 days in CPS deficiency. Further work is needed in developing guidelines for feeding and for clinical and biochemical monitoring for breast-fed infants with IMDs.

  2. Investigation of microalgae with photon density waves

    Science.gov (United States)

    Frankovitch, Christine; Reich, Oliver; Löhmannsröben, Hans-Gerd

    2007-09-01

    Phototropic microalgae have a large potential for producing valuable substances for the feed, food, cosmetics, pigment, bioremediation, and pharmacy industries as well as for biotechnological processes. Today it is estimated that the microalgal aquaculture worldwide production is 5000 tons of dry matter per year (not taking into account processed products) making it an approximately $1.25 billion U.S. per year industry. For effective observation of the photosynthetic growth processes, fast on-line sensor systems that analyze the relevant biological and technical process parameters are preferred. The optical properties of the microalgae culture influence the transport of light in the photobioreactor and can be used to extract relevant information for efficient cultivation practices. Microalgae cultivation media show a combination of light absorption and scattering, which are influenced by the concentrations and the physical and chemical properties of the different absorbing and scattering species (e.g. pigments, cell components, etc.). Investigations with frequency domain photon density waves (PDW) allow for the examination of absorption and scattering properties of turbid media, namely the absorption and reduced scattering coefficient. The reduced scattering coefficient can be used to characterize physical and morphological properties of the medium, including the cell concentration, whereas the absorption coefficient correlates with the pigment content. Nannochloropsis oculata, a single-cell species of microalgae, were examined in a nutrient solution with photon density waves. The absorption and reduced scattering coefficients were experimentally determined throughout the cultivation process, and applied to gain information about the cell concentration and average cell radius.

  3. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Uranium feed; natural uranium feed... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed....

  4. Wave Dissipation and Balance - NOPP Wave Project

    Science.gov (United States)

    2014-09-30

    interactions between them, and it is not clear how to transform each type of measurement into a clear constraint for the functional form and magnitude of...white with a uniform current U = 0.15 m/s towards the trigonometric angle 99 degrees. The white dashed line marks approximately the separation between...A. Roland, A. van der Westhuysen, P. Queffeulou, J.-M. Lefevre, L. Aouf, and F. Collard. Semi-empirical dissipation source functions for wind-wave

  5. Wave phenomena in sunspots

    Science.gov (United States)

    Löhner-Böttcher, Johannes

    2016-03-01

    Context: The dynamic atmosphere of the Sun exhibits a wealth of magnetohydrodynamic (MHD) waves. In the presence of strong magnetic fields, most spectacular and powerful waves evolve in the sunspot atmosphere. Allover the sunspot area, continuously propagating waves generate strong oscillations in spectral intensity and velocity. The most prominent and fascinating phenomena are the 'umbral flashes' and 'running penumbral waves' as seen in the sunspot chromosphere. Their nature and relation have been under intense discussion in the last decades. Aims: Waves are suggested to propagate upward along the magnetic field lines of sunspots. An observational study is performed to prove or disprove the field-guided nature and coupling of the prevalent umbral and penumbral waves. Comprehensive spectroscopic observations at high resolution shall provide new insights into the wave characteristics and distribution across the sunspot atmosphere. Methods: Two prime sunspot observations were carried out with the Dunn Solar Telescope at the National Solar Observatory in New Mexico and with the Vacuum Tower Telescope at the Teide Observatory on Tenerife. The two-dimensional spectroscopic observations were performed with the interferometric spectrometers IBIS and TESOS. Multiple spectral lines are scanned co-temporally to sample the dynamics at the photospheric and chromospheric layers. The time series (1 - 2.5 h) taken at high spatial and temporal resolution are analyzed according to their evolution in spectral intensities and Doppler velocities. A wavelet analysis was used to obtain the wave power and dominating wave periods. A reconstruction of the magnetic field inclination based on sunspot oscillations was developed. Results and conclusions: Sunspot oscillations occur continuously in spectral intensity and velocity. The obtained wave characteristics of umbral flashes and running penumbral waves strongly support the scenario of slow-mode magnetoacoustic wave propagation along the

  6. Surface-wave photonic quasicrystal

    CERN Document Server

    Gao, Zhen; Zhang, Youming; Xu, Hongyi; Zhang, Baile

    2016-01-01

    In developing strategies of manipulating surface electromagnetic waves, it has been recently recognized that a complete forbidden band gap can exist in a periodic surface-wave photonic crystal, which has subsequently produced various surface-wave photonic devices. However, it is not obvious whether such a concept can be extended to a non-periodic surface-wave system that lacks translational symmetry. Here we experimentally demonstrate that a surface-wave photonic quasicrystal that lacks periodicity can also exhibit a forbidden band gap for surface electromagnetic waves. The lower cutoff of this forbidden band gap is mainly determined by the maximum separation between nearest neighboring pillars. Point defects within this band gap show distinct properties compared to a periodic photonic crystal for the absence of translational symmetry. A line-defect waveguide, which is crafted out of this surface-wave photonic quasicrystal by shortening a random row of metallic rods, is also demonstrated to guide and bend sur...

  7. Plasma waves

    CERN Document Server

    Swanson, DG

    1989-01-01

    Plasma Waves discusses the basic development and equations for the many aspects of plasma waves. The book is organized into two major parts, examining both linear and nonlinear plasma waves in the eight chapters it encompasses. After briefly discussing the properties and applications of plasma wave, the book goes on examining the wave types in a cold, magnetized plasma and the general forms of the dispersion relation that characterize the waves and label the various types of solutions. Chapters 3 and 4 analyze the acoustic phenomena through the fluid model of plasma and the kinetic effects. Th

  8. Cryogenic Propellant Feed System Analytical Tool Development

    Science.gov (United States)

    Lusby, Brian S.; Miranda, Bruno M.; Collins, Jacob A.

    2011-01-01

    The Propulsion Systems Branch at NASA s Lyndon B. Johnson Space Center (JSC) has developed a parametric analytical tool to address the need to rapidly predict heat leak into propellant distribution lines based on insulation type, installation technique, line supports, penetrations, and instrumentation. The Propellant Feed System Analytical Tool (PFSAT) will also determine the optimum orifice diameter for an optional thermodynamic vent system (TVS) to counteract heat leak into the feed line and ensure temperature constraints at the end of the feed line are met. PFSAT was developed primarily using Fortran 90 code because of its number crunching power and the capability to directly access real fluid property subroutines in the Reference Fluid Thermodynamic and Transport Properties (REFPROP) Database developed by NIST. A Microsoft Excel front end user interface was implemented to provide convenient portability of PFSAT among a wide variety of potential users and its ability to utilize a user-friendly graphical user interface (GUI) developed in Visual Basic for Applications (VBA). The focus of PFSAT is on-orbit reaction control systems and orbital maneuvering systems, but it may be used to predict heat leak into ground-based transfer lines as well. PFSAT is expected to be used for rapid initial design of cryogenic propellant distribution lines and thermodynamic vent systems. Once validated, PFSAT will support concept trades for a variety of cryogenic fluid transfer systems on spacecraft, including planetary landers, transfer vehicles, and propellant depots, as well as surface-based transfer systems. The details of the development of PFSAT, its user interface, and the program structure will be presented.

  9. Research on Solar Feeding System for Monitoring System of Transmission Line%一种应用于输电线路监控系统的太阳能供电系统

    Institute of Scientific and Technical Information of China (English)

    俞登科; 余向森; 许金彤

    2011-01-01

    According to the present situation of remote power supply for monitoring system at transmission line,with the principles of environmental protection,energy saving and continuous power supply,a solar power supply system,based on lithium battery as energy storage devices,is designed.Through the redesign of management control circuit,this system solves the charging and discharging problems of lithium battery,and protects the lithium batteries at the same time.Then an actual calculation is made based on the engineering practice.%针对装设在输电线路杆塔上的监控系统独立供电困难的问题,结合环保、节能、长时间持续供电的原则,设计了以锂电池为储能设备的太阳能供电系统。通过设计管理控制电路,解决锂电池的充放电,同时对锂电池进行保护。以工程应用为背景进行了实例计算。

  10. Trace Level Determination of Polyether Ionophores in Feed

    Directory of Open Access Journals (Sweden)

    Mervi Rokka

    2013-01-01

    Full Text Available A liquid chromatography-mass spectrometric method was developed and validated to determine six polyether ionophores (lasalocid sodium, monensin sodium, salinomycin sodium, narasin, maduramicin ammonium alpha, and semduramicin sodium in feed samples. The method developed was very straightforward, involving extraction with 84% acetonitrile of the coccidiostats from the feed samples and filtration of the raw extract prior to chromatographic analysis. Method validation included the determination of selectivity, linearity, specificity, repeatability, the limit of detection, limit of quantification, decision limit (CCα, detection capability (CCβ, and recovery. Feed samples from the Finnish national feed control programme and suspected carry-over samples from a feed manufacturer were analysed in parallel with an existing liquid chromatography method coupled with ultraviolet detection. All feed control samples were negative in LC-UV, but with the developed MS method, monensin, salinomycin, and narasin were detected at concentrations of <0.025–0.73 mg/kg, <0.025–0.027 mg/kg, and <0.025–1.6 mg/kg, respectively. In suspected carry-over samples after an output of 2.0 tonnes of unmedicated feed in the pelletizer line, the concentrations of monensin, salinomycin, and narasin varied from undetected to 16 mg/kg. In the mixer line, after 3.2 tonnes of unmedicated feed output, the concentrations of monensin, salinomycin, and narasin varied from undetected to 2.4 mg/kg.

  11. Broadband wave manipulation in surface-wave photonic crystal

    CERN Document Server

    Gao, Zhen

    2016-01-01

    The ability to perfectly guide surface electromagnetic waves around ultra-sharp corners without back-scattering and radiation is in great demand for various photonic and plasmonic applications. This is fundamentally difficult to realize because of the dramatic momentum mismatch and wave nature of radiation at the sharp corners. Here we experimentally demonstrate that a simple photonic structure, a periodic square array of metallic cylinders standing on a metal surface, can behaves as a surface-wave photonic crystal with complete photonic band gap to overcome this bottleneck simply. A line-defect waveguide can support and guide surface waves around ultra-sharp corners without perceptible radiation and reflection, achieving almost perfect transmission efficiency in a broad frequency range. We also demonstrate an ideal T-shaped splitter to split input surface waves equally into two arms and a square radiation-suppressed plasmonic open resonator with high quality factors by simply inducing line-defects in this fu...

  12. Nonlinear magnetoinductive transmission lines

    CERN Document Server

    Lazarides, Nikos; Tsironis, G P

    2011-01-01

    Power transmission in one-dimensional nonlinear magnetic metamaterials driven at one end is investigated numerically and analytically in a wide frequency range. The nonlinear magnetic metamaterials are composed of varactor-loaded split-ring resonators which are coupled magnetically through their mutual inductances, forming thus a magnetoiductive transmission line. In the linear limit, significant power transmission along the array only appears for frequencies inside the linear magnetoinductive wave band. We present analytical, closed form solutions for the magnetoinductive waves transmitting the power in this regime, and their discrete frequency dispersion. When nonlinearity is important, more frequency bands with significant power transmission along the array may appear. In the equivalent circuit picture, the nonlinear magnetoiductive transmission line driven at one end by a relatively weak electromotive force, can be modeled by coupled resistive-inductive-capacitive (RLC) circuits with voltage-dependent cap...

  13. Superconducting travelling wave ring with high gradient accelerating section

    Energy Technology Data Exchange (ETDEWEB)

    Avrakhov, P.; Solyak, N.; /Fermilab

    2007-06-01

    Use of a superconducting traveling wave accelerating (STWA) structure instead of a standing wave cavity has major advantages in increasing the accelerating gradient in the ILC. In contrast with standing wave cavity STWA requires feedback loop, which sends wave from the structure output to input, making a superconducting traveling wave ring (STWR). One or few input couplers need to excite STWR and compensate power dissipations due to beam loading. To control traveling wave regime in the structure two independent knobs can be used for tuning both resonant ring frequency and backward wave. We discuss two variants of the STWR with one and two feed couplers.

  14. Enteral feeding without pancreatic stimulation

    DEFF Research Database (Denmark)

    Kaushik, Neeraj; Pietraszewski, Marie; Holst, Jens Juul

    2005-01-01

    OBJECTIVE: All forms of commonly practiced enteral feeding techniques stimulate pancreatic secretion, and only intravenous feeding avoids it. In this study, we explored the possibility of more distal enteral infusions of tube feeds to see whether activation of the ileal brake mechanism can result...... in enteral feeding without pancreatic stimulation, with particular reference to trypsin, because the avoidance of trypsin stimulation may optimize enteral feeding in acute pancreatitis. METHODS: The pancreatic secretory responses to feeding were studied in 36 healthy volunteers by standard double......-lumen duodenal perfusion/aspiration techniques over 6 hours. Subjects were assigned to no feeding (n = 7), duodenal feeding with a polymeric diet (n = 7) or low-fat elemental diet (n = 6), mid-distal jejunal feeding (n = 11), or intravenous feeding (n = 5). All diets provided 40 kcal/kg ideal body weight/d and 1...

  15. Heat Waves

    Science.gov (United States)

    Heat Waves Dangers we face during periods of very high temperatures include: Heat cramps: These are muscular pains and ... having trouble with the heat. If a heat wave is predicted or happening… - Slow down. Avoid strenuous ...

  16. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Brorsen, Michael; Frigaard, Peter

    Denne rapport beskriver numeriske beregninger af forskellige flydergeometrier for bølgeenergianlæget Wave Star.......Denne rapport beskriver numeriske beregninger af forskellige flydergeometrier for bølgeenergianlæget Wave Star....

  17. On-line brain-computer interface system design based on alpha wave and motor imagery%基于脑电alpha波及运动想象的在线脑机接口系统设计

    Institute of Scientific and Technical Information of China (English)

    王磊; 王江; 刘丽芳; 杨硕; 徐桂芝; 颜威利

    2011-01-01

    背景:目前在线脑机接口系统绝大多数采用同步式设计,无法区分"工作"状态与"空闲"状态.目的:设计一种能够自由在"工作"与"空闲"状态间切换,方便灵活的脑机接口系统.方法:设计了综合睁眼产生的alpha波阻断现象,以及进行运动想象时产生事件相关同步及去同步现象这些生理特征的在线脑机接口系统.通过检测使用者枕部脑电信号alpha波状况,来切换"空闲"与"工作"状态;在"工作"状态下,通过想象不同的肢体运动,分析运动皮质脑电信号的频率特征,来实现对外界的信息传输.结果与结论:实验证明,经过训练的使用者在该在线脑机接口平台上可以自如的在不同状态间进行切换,并且能以很高的分类正确率发出控制命令.采用此方法进行设计,脑机接口系统的实用性得到了增强.%BACKGROUND: At present, most of on-line brain-computer interface (BCI) systems adopt synchronous design, which cannot tell the switch between "active" state and "idle" state.OBJECTIVE: To design an effective BCI system design, which is free to switch between "active" state and "idle" state.METHODS: In this paper, an on-line BCI system was designed based on a series of physiological phenomenon, such as alpha wave-block, event related synchronization (ERS) and event related desynchronization (ERD). Through detecting the EEG recorded from occipital area, the two states being "active" and "idle" could be switched. Under the statement of "active", EEG captured from motor cortex was processed, and the frequency feature was extracted during different motor imagery tasks, in the end, the mind that user wanted to express was estimated.RESULTS AND CONCLUSION: The results show that the subject can switch freely between the two states by using this on-line BCI system after training. Using this method, the practicability of on-line BCI system is getting improved greatly.

  18. Wave Dragon

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Frigaard, Peter; Sørensen, H. C.

    1998-01-01

    This paper concerns with the development of the wave energy converter (WEC) Wave Dragon. This WEC is based on the overtopping principle. An overview of the performed research done concerning the Wave Dragon over the past years is given, and the results of one of the more comprehensive studies......, concerning a hydraulic evaluation and optimisation of the geometry of the Wave Dragon, is presented. Furthermore, the plans for the future development projects are sketched....

  19. Design of T-Split Power Divider Using Double Ended Spur-Line DMS

    Science.gov (United States)

    Moyra, Tamasi; Parui, Susanta Kumar; Das, Santanu

    2016-09-01

    Power dividers and power combiners are passive microwave components for power dividing and power combining. In this article one T-split equal power divider has been designed by using conventional 50 Ω microstrip line and double ended spur line renamed as defected microstrip structures (DMS). Introducing DMS provides one stop band characteristics, changes the effective inductance and capacitance of the line by increasing effective dielectric constant, reduces the phase velocity and supports slow-wave propagation. Thus, increases the effective line impedance of the microstrip line. Consequently, all passive and active components that are implemented using DMS have a miniaturized size compared to conventional components. In this paper one 3 dB or equal power divider has been designed at 1.6 GHz in the first step. Where, 100 Ω output line is implemented using double ended spur type DMS on conventional 50 Ω microstrip line. In the second step each output port power has been divided equally into 6 dB in the next level of the branch. Design of those dividers are very simple and have wide applications in microwave circuits and feeds of array antennas.

  20. Electromagnetic Waves

    DEFF Research Database (Denmark)

    This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis......, material characterization, electromagnetic properties of plasma, analysis and applications of periodic structures and waveguide components, etc....

  1. Wave phenomena

    CERN Document Server

    Towne, Dudley H

    1988-01-01

    This excellent undergraduate-level text emphasizes optics and acoustics, covering inductive derivation of the equation for transverse waves on a string, acoustic plane waves, boundary-value problems, polarization, three-dimensional waves and more. With numerous problems (solutions for about half). ""The material is superbly chosen and brilliantly written"" - Physics Today. Problems. Appendices.

  2. Assimilation of Wave Imaging Radar Observations for Real-time Wave-by-Wave Forecasting

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Alexandra [Oregon State Univ., Corvallis, OR (United States); Haller, Merrick; Walker, David [SRI International, Menlo Park, CA (United States); Lynett, Pat [Univ. of Southern California, Los Angeles, CA (United States)

    2017-08-29

    This project addressed Topic 3: “Wave Measurement Instrumentation for Feed Forward Controls” under the FOA number DE-FOA-0000971. The overall goal of the program was to develop a phase-resolving wave forecasting technique for application to the active control of Wave Energy Conversion (WEC) devices. We have developed an approach that couples a wave imaging marine radar with a phase-resolving linear wave model for real-time wave field reconstruction and forward propagation of the wave field in space and time. The scope of the project was to develop and assess the performance of this novel forecasting system. Specific project goals were as follows: Develop and verify a fast, GPU-based (Graphical Processing Unit) wave propagation model suitable for phase-resolved computation of nearshore wave transformation over variable bathymetry; Compare the accuracy and speed of performance of the wave model against a deep water model in their ability to predict wave field transformation in the intermediate water depths (50 to 70 m) typical of planned WEC sites; Develop and implement a variational assimilation algorithm that can ingest wave imaging radar observations and estimate the time-varying wave conditions offshore of the domain of interest such that the observed wave field is best reconstructed throughout the domain and then use this to produce model forecasts for a given WEC location; Collect wave-resolving marine radar data, along with relevant in situ wave data, at a suitable wave energy test site, apply the algorithm to the field data, assess performance, and identify any necessary improvements; and Develop a production cost estimate that addresses the affordability of the wave forecasting technology and include in the Final Report. The developed forecasting algorithm (“Wavecast”) was evaluated for both speed and accuracy against a substantial synthetic dataset. Early in the project, performance tests definitively demonstrated that the system was capable of

  3. Quantification of Feeding Effects of Spot Feeding Ductile Iron Castings made in Vertically Parted Moulds

    DEFF Research Database (Denmark)

    Vedel-Smith, Nikolaj Kjelgaard; Tiedje, Niels Skat; Sällström, J.

    In vertically parted molds it is traditionally difficult to feed heavy sections that cannot be reached by traditional side/top feeders or other conventional methods. This project aims at quantifying the effects of using molded-in ram-up spot feeders as a means of feeding isolated sections...... analyses the effect of different exothermic and insulating spot feeders and their interaction with traditional parting line feeders, with respect to porosities and surface shrinkage. Experiments were performed using EN-GJS-500-7 and EN-GJS-450-10 alloys. The experiment shows that the geometry cannot...

  4. Representing infant feeding: content analysis of British media portrayals of bottle feeding and breast feeding

    OpenAIRE

    Henderson, L.; KITZINGER, Jenny; Green, J.

    2001-01-01

    Objective: To examine how breast feeding and bottle feeding are represented by the British media.\\ud Design: Content analysis.\\ud Subjects: Television programmes and newspaper articles that made reference to infant feeding during March 1999.\\ud Setting: UK mass media.\\ud Main outcome measures: Visual and verbal references to breast or bottle feeding in newspapers and television programmes.\\ud Results: Overall, 235 references to infant feeding were identified in the television sample and 38 in...

  5. Measure Lines

    Science.gov (United States)

    Crissman, Sally

    2011-01-01

    One tool for enhancing students' work with data in the science classroom is the measure line. As a coteacher and curriculum developer for The Inquiry Project, the author has seen how measure lines--a number line in which the numbers refer to units of measure--help students not only represent data but also analyze it in ways that generate…

  6. Radio frequency and microwave subsystems section. Dual-frequency feed cone assemblies for 34-meter antennas

    Science.gov (United States)

    Hartop, R. W.

    1978-01-01

    New Cassegrain cone assemblies were designed for the upgrade of three 26 meter-diameter antennas to 34 meter-diameter with improved performance. The new dual-frequency feed cone (SXD) provided both S- and X-band feed systems and traveling wave masers with a reflex reflector system to permit simultaneous operation analogous to the 64-meter antennas.

  7. Low Emission Feed

    NARCIS (Netherlands)

    Klop, G.

    2016-01-01

    Research into manipulating methane (CH4) production as a result of enteric fermentation in ruminants currently receives global interest. Using feed additives may be a feasible strategy to mitigate CH4 as they are supplied in such amounts that the basal diet composition will not be largely affected.

  8. Feed sources for livestock

    NARCIS (Netherlands)

    Zanten, van H.H.E.

    2016-01-01

    Production of food has re-emerged at the top of the global political agenda, driven by two contemporary challenges: the challenge to produce enough nutritious food to feed a growing and more prosperous human population, and the challenge to produce this food in an environmentally sustainable way. Cu

  9. Low Emission Feed

    NARCIS (Netherlands)

    Klop, G.

    2016-01-01

    Research into manipulating methane (CH4) production as a result of enteric fermentation in ruminants currently receives global interest. Using feed additives may be a feasible strategy to mitigate CH4 as they are supplied in such amounts that the basal diet composition will not be largely affected.

  10. Feed sources for livestock

    NARCIS (Netherlands)

    Zanten, van H.H.E.

    2016-01-01

    Production of food has re-emerged at the top of the global political agenda, driven by two contemporary challenges: the challenge to produce enough nutritious food to feed a growing and more prosperous human population, and the challenge to produce this food in an environmentally sustainable way.

  11. [History of complementary feeding].

    Science.gov (United States)

    Turck, D

    2010-12-01

    Complementary feeding, which embraces all solid and liquid foods other than breast milk or infant formula, is strongly influenced by cultural, familial and economic factors. For many times, there was a strong taboo on the use of colostrum ("the white blood") during the first week after delivery, sometimes even the first month. Therefore, the newborn baby received complementary foods as gruel, or panada. However, in the Greek civilization, wet nurses were asked by contract to breastfeed exclusively for the first 6 months and to start complementary feeding thereafter. From the sixteenth century onwards, many writers deplored the practice of giving gruel and panada during the first six months before the teeth erupted. In 1921, a Swedish pediatrician, Jundell, reported for the first time that starting complementary feeding at 6 months of age was associated with a better growth and resistance to infections. The recommendation of the World Health Organization to start complementary feeding after a 6-month period of exclusive breastfeeding is often in contradiction with the habits of the populations to propose very early other food sources than breast milk. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  12. Feeding of Diarmis Proboscis

    Science.gov (United States)

    Young, Jocelyn

    2005-01-01

    The feeding of Diarmis proboscis is an exciting outdoor laboratory activity that demonstrates a single concept of adaptations--cryptic colorations. The students are "transformed" into D. proboscis (no Harry Potter magic needed) in order to learn how adaptations work in the natural world. Prior to beginning this activity, students should have a…

  13. Feed sources for livestock

    NARCIS (Netherlands)

    Zanten, van H.H.E.

    2016-01-01

    Production of food has re-emerged at the top of the global political agenda, driven by two contemporary challenges: the challenge to produce enough nutritious food to feed a growing and more prosperous human population, and the challenge to produce this food in an environmentally sustainable way. Cu

  14. Feeding Your Baby

    Medline Plus

    Full Text Available ... healthy Problems and discomforts when breastfeeding Starting your baby on solid foods Using a breast pump In This Topic Breastfeeding ... healthy Problems and discomforts when breastfeeding Starting your baby on solid foods Using a breast pump Baby Feeding your baby ...

  15. Feed intake, growth and feed utilization patterns of pigs highly ...

    African Journals Online (AJOL)

    in genetically lean and obese pigs, and showed that feed intake is ... apportionment of consumed energy towards protein and ..... alia, genetic potential for protein deposition and its ... The content and dietary balance of feed nutrients, such as ...

  16. Generation of rogue waves in a wave tank

    Science.gov (United States)

    Lechuga, A.

    2012-04-01

    Rogue waves have been reported as causing damages and ship accidents all over the oceans of the world. For this reason in the past decades theoretical studies have been carried out with the double aim of improving the knowledge of their main characteristics and of attempting to predict its sudden appearance. As an effort on this line we are trying to generate them in a water tank. The description of the procedure to do that is the objective of this presentation. After Akhmediev et al. (2011) we use a symmetric spectrum as input on the wave maker to produce waves with a rate(Maximun wave height/ significant wave height) of 2.33 and a kurtosis of 4.77, clearly between the limits of rogue waves. As it was pointed out by Janssen (2003), Onorato et al. (2006) and Kharif, Pelinovsky and Slunyaev (2009) modulation instability is enhanced when waves depart from Gaussian statistics (i.e. big kurtosis) and therefore both numbers enforce the criterion that we are generating genuine rogue waves. The same is confirmed by Shemer (2010) and Dudley et al.(2009) from a different perspective. If besides being symmetrical the spectrum is triangular, following Akhmediev(2011),the generated waves are even more conspicuously rogue waves.

  17. Prospects of complete feed system in ruminant feeding: A review

    Directory of Open Access Journals (Sweden)

    Yasir Afzal Beigh

    2017-04-01

    Full Text Available Effective utilization of available feed resources is the key for economical livestock rearing. Complete feed system is one of the latest developments to exploit the potential of animal feed resources in the best possible way. The complete feed is a quantitative mixture of all dietary ingredients, blended thoroughly to prevent separation and selection, fed as a sole source of nutrients except water and is formulated in a desired proportion to meet the specific nutrient requirements. The concentrate and roughage levels may vary according to the nutrient requirement of ruminants for different production purposes. The complete feed with the use of fibrous crop residue is a noble way to increase the voluntary feed intake and thus animal's production performance. In this system of feeding, the ruminant animals have continuous free choice availability of uniform feed mixture, resulting in more uniform load on the rumen and less fluctuation in release of ammonia which supports more efficient utilization of ruminal non-protein nitrogen. Feeding complete diet stabilizes ruminal fermentation, thereby improves nutrient utilization. This feeding system allows expanded use of agro-industrial byproducts, crop residues and nonconventional feeds in ruminant ration for maximizing production and minimizing feeding cost, thus being increasingly appreciated. However, to extend the concept extensively to the field and make this technology successful and viable for farmers, more efforts are needed to be taken.

  18. Prospects of complete feed system in ruminant feeding: A review

    Science.gov (United States)

    Beigh, Yasir Afzal; Ganai, Abdul Majeed; Ahmad, Haidar Ali

    2017-01-01

    Effective utilization of available feed resources is the key for economical livestock rearing. Complete feed system is one of the latest developments to exploit the potential of animal feed resources in the best possible way. The complete feed is a quantitative mixture of all dietary ingredients, blended thoroughly to prevent separation and selection, fed as a sole source of nutrients except water and is formulated in a desired proportion to meet the specific nutrient requirements. The concentrate and roughage levels may vary according to the nutrient requirement of ruminants for different production purposes. The complete feed with the use of fibrous crop residue is a noble way to increase the voluntary feed intake and thus animal’s production performance. In this system of feeding, the ruminant animals have continuous free choice availability of uniform feed mixture, resulting in more uniform load on the rumen and less fluctuation in release of ammonia which supports more efficient utilization of ruminal non-protein nitrogen. Feeding complete diet stabilizes ruminal fermentation, thereby improves nutrient utilization. This feeding system allows expanded use of agro-industrial by­products, crop residues and nonconventional feeds in ruminant ration for maximizing production and minimizing feeding cost, thus being increasingly appreciated. However, to extend the concept extensively to the field and make this technology successful and viable for farmers, more efforts are needed to be taken. PMID:28507415

  19. Effect of feed presentation on feeding patterns of dairy calves.

    Science.gov (United States)

    Miller-Cushon, E K; Bergeron, R; Leslie, K E; Mason, G J; DeVries, T J

    2013-01-01

    The objectives of this study were to determine the effect of feed presentation on meal frequency and duration, as well as diurnal feeding patterns of dairy calves, and to assess any longer-term differences in feeding patterns resulting from previous experience. Twenty Holstein bull calves were exposed from wk 1 to 8 of life to 1 of 2 feed presentation treatments: concentrate and chopped grass hay (spent more time feeding than calves fed COM (56.7 vs. 46.8 min/d). In wk 8, calves fed MIX spent more time feeding (174.0 vs. 139.1 min/d) and had a lower rate of intake (11.5 vs. 14.7 g/min) compared with calves fed COM. Meal frequency was similar between treatments (12.2 meals/d). Diurnal feeding patterns in wk 8 were also affected by feed presentation, with calves fed MIX spending less time feeding at time of feed delivery and more time feeding throughout the rest of the daylight hours than calves fed COM. Diurnal feeding patterns of hay and concentrate in wk 8 differed for calves fed COM, with more time spent consuming hay at time of feed delivery and less time spent consuming hay throughout the rest of the day. Once calves previously fed COM were transitioned to the MIX diet in wk 9, meal frequency, meal duration, and diurnal feeding patterns were similar between treatments: both treatments spent similar amounts of time feeding (173.9 min/d) and had similar peaks in feeding activity at time of feed delivery, sunrise, and sunset. Provision of hay and concentrate to young calves as a mixed ration, compared with separate components, increases time spent feeding and results in more evenly distributed diurnal feeding patterns. However, differences in feeding patterns resulting from feed presentation did not persist after 8 wk of age, when all calves were fed a mixed ration. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  20. Feeding performance of king Mackerel, Scomberomorus cavalla.

    Science.gov (United States)

    Ferguson, Amber R; Huber, Daniel R; Lajeunesse, Marc J; Motta, Philip J

    2015-08-01

    Feeding performance is an organism's ability to capture and handle prey. Although bite force is a commonly used metric of feeding performance, other factors such as bite pressure and strike speed are also likely to affect prey capture. Therefore, this study investigated static bite force, dynamic speeds, and predator and prey forces resulting from ram strikes, as well as bite pressure of the king mackerel, Scomberomorus cavalla, in order to examine their relative contributions to overall feeding performance. Theoretical posterior bite force ranged from 14.0-318.7 N. Ram speed, recorded with a rod and reel incorporated with a line counter and video camera, ranged from 3.3-15.8B L/s. Impact forces on the prey ranged from 0.1-1.9 N. Bite pressure, estimated using theoretical bite forces at three gape angles and tooth cross-sectional areas, ranged from 1.7-56.9 MPa. Mass-specific bite force for king mackerel is relatively low in comparison with other bony fishes and sharks, with relatively little impact force applied to the prey during the strike. This suggests that king mackerel rely on high velocity chases and high bite pressure generated via sharp, laterally compressed teeth to maximize feeding performance.

  1. Global coherence of dust density waves

    Energy Technology Data Exchange (ETDEWEB)

    Killer, Carsten; Melzer, André [Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald (Germany)

    2014-06-15

    The coherence of self-excited three-dimensional dust density waves has been experimentally investigated by comparing global and local wave properties. For that purpose, three-dimensional dust clouds have been confined in a radio frequency plasma with thermophoretic levitation. Global wave properties have been measured from the line-of-sight integrated dust density obtained from homogenous light extinction measurements. Local wave properties have been obtained from thin, two-dimensional illuminated laser slices of the cloud. By correlating the simultaneous global and local wave properties, the spatial coherence of the waves has been determined. We find that linear waves with small amplitudes tend to be fragmented, featuring an incoherent wave field. Strongly non-linear waves with large amplitudes, however, feature a strong spatial coherence throughout the dust cloud, indicating a high level of synchronization.

  2. Radio and line transmission 2

    CERN Document Server

    Roddy, Dermot

    2013-01-01

    Radio and Line Transmission, Volume 2 gives a detailed treatment of the subject as well as an introduction to additional advanced subject matter. Organized into 14 chapters, this book begins by explaining the radio wave propagation, signal frequencies, and bandwidth. Subsequent chapters describe the transmission lines and cables; the aerials; tuned and coupled circuits; bipolar transistor amplifiers; field-effect transistors and circuits; thermionic valve amplifiers; LC oscillators; the diode detectors and modulators; and the superheterodyne receiver. Other chapters explore noise and interfere

  3. Feed the dogs

    DEFF Research Database (Denmark)

    Knudsen, Gry Høngsmark; Bajde, Domen

    2016-01-01

    MedieKultur | Journal of media and communication research | ISSN 1901-9726Article – Open sectionPublished by SMID | Society of Media researchers In Denmark | www.smid.dkTh e online version of this text can be found open access at www.mediekultur.dk196Feed the dogsA case of humanitarian communicat......MedieKultur | Journal of media and communication research | ISSN 1901-9726Article – Open sectionPublished by SMID | Society of Media researchers In Denmark | www.smid.dkTh e online version of this text can be found open access at www.mediekultur.dk196Feed the dogsA case of humanitarian...

  4. An Ultra-Wideband Millimeter-Wave Phased Array

    Science.gov (United States)

    Novak, Markus H.; Miranda, Felix A.; Volakis, John L.

    2016-01-01

    Wideband millimeter-wave arrays are of increasing importance due to their growing use in high data rate systems, including 5G communication networks. In this paper, we present a new class of ultra-wideband millimeter wave arrays that operate from nearly 20 GHz to 90 GHz. The array is based on tightly coupled dipoles. Feeding designs and fabrication challenges are presented, and a method for suppressing feed resonances is provided.

  5. Making waves

    Science.gov (United States)

    Kruse, Karsten

    2017-01-01

    Traveling waves propagating along surfaces play an important role for intracellular organization. Such waves can appear spontaneously in reaction-diffusion systems, but only few general criteria for their existence are known. Analyzing the dynamics of the Min proteins in Escherichia coli, Levine and Kessler (2016 New J. Phys. 18 122001) now identified a new mechanism for the emergence of traveling waves that relies on conservation laws. From their analysis one can expect traveling waves to be a generic feature of systems made of proteins that have a cytoplasmic and a membrane-bound state.

  6. Janus Waves

    OpenAIRE

    2016-01-01

    We show the existence of a family of waves that share a common interesting property affecting the way they propagate and focus. These waves are a superposition of twin waves, which are conjugate to each other under inversion of the propagation direction. In analogy to holography, these twin "real" and "virtual" waves are related respectively to the converging and the diverging part of the beam and can be clearly visualized in real space at two distinct foci under the action of a focusing lens...

  7. Live feeds in aquaculture

    OpenAIRE

    Dhert, Ph.; Sorgeloos, P

    1995-01-01

    Over the past two decades intensive larviculture of several fish and shellfish species has expanded into a multimillion dollar industry. Although much progress has been made in identifying the dietary requirements of the larvae of various aquaculture species, the mass culture of their early larval stages still requires the use of live feeds. Selected either through trial and error approaches or because of their convenience in mass production and use, hatcheries are relying today on three grou...

  8. Feed sources for livestock

    OpenAIRE

    Zanten, van, H.H.E.

    2016-01-01

    Production of food has re-emerged at the top of the global political agenda, driven by two contemporary challenges: the challenge to produce enough nutritious food to feed a growing and more prosperous human population, and the challenge to produce this food in an environmentally sustainable way. Current levels of production of especially animal-source food (ASF), pose severe pressure on the environment via their emissions to air, water, and soil; and their use of scarce resources, such as la...

  9. Residual Feed Intake

    OpenAIRE

    Sainz, Roberto D.; Paulino, Pedro V.

    2004-01-01

    Introduction Low rates of return on investment for livestock operations are a fact of life. Producers have little impact on the market price for their cattle; therefore management must be focused on the things producers can actually do something about. For many years, genetic selection programs have focused on production (output) traits, with little attention given to production costs (inputs). Recently, this view has begun to change, and the efficiency of conversion of feed (i.e., t...

  10. First feeding of larval herring

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Munk, Peter; Støttrup, Josianne

    1985-01-01

    The transition period from endogenous to exogenous feeding by larval herring was investigated in the laboratory for four herring stocks in order to evaluate the chances of survival at the time of fiest feeding. Observations on larval activity, feeding and growth were related to amount of yolk, vi...

  11. Coupling between crossed dipole feeds

    DEFF Research Database (Denmark)

    Andersen, J.; Schjær-Jacobsen, Hans; Lessow, H.

    1974-01-01

    as a function of orientation and feeding network properties. The antennas are used as feeds for a parabolic reflector, and the effect of coupling on the secondary fields is analyzed. Especially significant is the polarization loss and it may, to some extent, be reduced by a proper choice of feeding network....

  12. Food Safety Information RSS feed

    Data.gov (United States)

    U.S. Department of Health & Human Services — This is an RSS Feed of Food Safety information that’s produced in real-time by the CDC. This RSS feed is the integration of two other XML feeds, one from the USDA's...

  13. Relationship between group size and feeding success of cattle egrets (Bubulcus ibis in the central Free State

    Directory of Open Access Journals (Sweden)

    Hennie Butler

    2008-09-01

    Full Text Available Regardless of habitat or time of day, cattle egrets feeding independently of hosts generally occurring larger groups than those feeding in close association with ungulates. The average group size of three individuals feeding in association with hosts stays remarkably constant with regard to divergent situations. Based on the type of habitat and the grazing speed of the host concerned, cattle egrets achieve the highest feeding success (number of prey items with the least energy inputs (number of paces in association with cattle, and to a lesser extent with the closely related buffalo. Compared to solitary birds, cattle egrets feeding in groups experience without exceptional higher feeding success. Results of feeding experiments, as well as the exceptional occurrence of so-called feeding lines, confirm the phenomenon that the feeding success of cattle egrets correlates closely with the size of the feeding group.

  14. Multiple part feeding

    DEFF Research Database (Denmark)

    Hvilshøj, Mads; Bøgh, Simon; Nielsen, Oluf Skov

    2012-01-01

    Purpose - The purpose of this paper is to present experience from a real-world demonstration of autonomous industrial mobile manipulation (AIMM) based on the mobile manipulator "Little Helper" performing multiple part feeding at the pump manufacturer Grundfos A/S. Design/methodology/approach - Th......Purpose - The purpose of this paper is to present experience from a real-world demonstration of autonomous industrial mobile manipulation (AIMM) based on the mobile manipulator "Little Helper" performing multiple part feeding at the pump manufacturer Grundfos A/S. Design....../methodology/approach - The necessary AIMM technologies exist at a mature level - the reason that no mobile manipulators have yet been implemented in industrial environments, is that research in the right applications have not been carried out. We propose a pragmatic approach consisting of: a commercial-off-the-shelf (COTS) mobile...... manipulator system design ("Little Helper"), a suitable and comprehensive industrial application (multiple part feeding), and a general implementation concept for industrial environments (the "Bartender Concept"). Findings - Results from the three days of real-world demonstration show that "Little Helper...

  15. The Nature of Running Penumbral Waves Revealed

    CERN Document Server

    Bloomfield, D Shaun; Solanki, Sami K

    2007-01-01

    We seek to clarify the nature of running penumbral (RP) waves: are they chromospheric trans-sunspot waves or a visual pattern of upward-propagating waves? Full Stokes spectropolarimetric time series of the photospheric Si I 10827 \\AA line and the chromospheric He I 10830 \\AA multiplet were inverted using a Milne-Eddington atmosphere. Spatial pixels were paired between the outer umbral/inner penumbral photosphere and the penumbral chromosphere using inclinations retrieved by the inversion and the dual-height pairings of line-of-sight velocity time series were studied for signatures of wave propagation using a Fourier phase difference analysis. The dispersion relation for radiatively cooling acoustic waves, modified to incorporate an inclined propagation direction, fits well the observed phase differences between the pairs of photospheric and chromospheric pixels. We have thus demonstrated that RP waves are in effect low-beta slow-mode waves propagating along the magnetic field.

  16. Wrapped-IMLI: Thermal Insulation for Cryogenic Feed Lines Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA Exploration vehicles require improved technologies for passive thermal insulation for zero boil-off of cryopropellants during extended LEO and lunar surface...

  17. The assembly line feeding problem: classification and literature review

    OpenAIRE

    Schmid, Nico; Limère, Veronique

    2017-01-01

    In recent years some trends in several product assembly systems emerged, namely mass-customization [Boysen et al., 2007], integration of new product functionalities [Göpfert et al., 2016] and increase in the number of models (e.g. BMW, a German car manufacturer, increased the average number of models offered per year to 37.85 in the period between 2010 and 2016, compared to only 22.3 in the period between 2000 and 2010). These trends have a significant impact on assembly systems since all of ...

  18. Prototype testing of the wave energy converter wave dragon

    Energy Technology Data Exchange (ETDEWEB)

    Kofoed, Jens Peter; Frigaard, Peter [Hydraulics and Coastal Engineering Laboratory, Department of Civil Engineering, Aalborg University, Sohngaardsholmsvej 57, Aalborg 9000 (Denmark); Friis-Madsen, Erik [Loewenmark F.R.I., Copenhagen (Denmark); Soerensen, Hans Chr. [SPOK, Copenhagen (Denmark)

    2006-02-01

    The Wave Dragon is an offshore wave energy converter of the overtopping type. It consists of two wave reflectors focusing the incoming waves towards a ramp, a reservoir for collecting the overtopping water and a number of hydro turbines for converting the pressure head into power. In the period from 1998 to 2001 extensive wave tank testing on a scale model was carried at Aalborg University. Then, a 57x27m wide and 237tonnes heavy (incl. ballast) prototype of the Wave Dragon, placed in Nissum Bredning, Denmark, was grid connected in May 2003 as the world's first offshore wave energy converter. The prototype is fully equipped with hydro turbines and automatic control systems, and is instrumented in order to monitor power production, wave climate, forces in mooring lines, stresses in the structure and movements of the Wave Dragon. In the period May 2003 to January 2005 an extensive measuring program has been carried out, establishing the background for optimal design of the structure and regulation of the power take off system. Planning for deployment of a 4MW power production unit in the Atlantic by 2007 is in progress. (author)

  19. Modeling Technology in Traveling-Wave Fault Location

    Directory of Open Access Journals (Sweden)

    Tang Jinrui

    2013-06-01

    Full Text Available Theoretical research and equipment development of traveling-wave fault location seriously depend on digital simulation. Meanwhile, the fault-generated transient traveling wave must be transferred through transmission line, mutual inductor and secondary circuit before it is used. So this paper would maily analyze and summarize the modeling technology of transmission line and mutual inductor on the basis of the research achievement. Firstly several models of transmission line (multiple Π or T line model, Bergeron line model and frequency-dependent line model are compared in this paper with analysis of wave-front characteristics and characteristic frequency of traveling wave. Then modeling methods of current transformer, potential transformer, capacitive voltage transformer, special traveling-wave sensor and secondary cable are given. Finally, based on the difficult and latest research achievements, the future trend of modeling technology in traveling-wave fault location is prospected.  

  20. Wave Dragon

    DEFF Research Database (Denmark)

    Tedd, James; Kofoed, Jens Peter; Friis-Madsen, Erik

    2008-01-01

    Since March 2003 a prototype of Wave Dragon has been tested in an inland sea in Denmark. This has been a great success with all subsystems tested and improved through working in an offshore environment. The project has proved the Wave Dragon device and has enabled the next stage, a production sized...

  1. Wave Dragon

    DEFF Research Database (Denmark)

    Tedd, James; Kofoed, Jens Peter; Friis-Madsen, Erik;

    2008-01-01

    Since March 2003 a prototype of Wave Dragon has been tested in an inland sea in Denmark. This has been a great success with all subsystems tested and improved through working in an offshore environment. The project has proved the Wave Dragon device and has enabled the next stage, a production sized...

  2. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Brorsen, Michael; Frigaard, Peter

    Nærværende rapport beskriver numeriske beregninger af den hydrodynamiske interaktion mellem 5 flydere i bølgeenergianlægget Wave Star.......Nærværende rapport beskriver numeriske beregninger af den hydrodynamiske interaktion mellem 5 flydere i bølgeenergianlægget Wave Star....

  3. Design of Absorbing Wave Maker based on Digital Filters

    DEFF Research Database (Denmark)

    Christensen, Morten; Frigaard, Peter

    An absorbing wave maker operated by means of on-line signals from digital FIR filters is presented. Surface elevations are measured in two positions in front of the wave maker. The reflected wave train is seperated by the sum of the incident and reflected wave trains by means of digital filtering...... and subsequent superposition of the measured surface elevations. The motion of the wave paddle required to absorb reflected waves is determined and added to the original wave paddle control signal. Irregular wave tests involving test structures with different degrees of reflection show that excellent absorption...

  4. First feeding of larval herring

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Munk, Peter; Støttrup, Josianne

    1985-01-01

    The transition period from endogenous to exogenous feeding by larval herring was investigated in the laboratory for four herring stocks in order to evaluate the chances of survival at the time of fiest feeding. Observations on larval activity, feeding and growth were related to amount of yolk......, visual experience with potential prey organisms prior to first feeding and prey density. Herring larvae did not initiate exogenous feeding until around the time of yolk resorption. The timing of first feeding was not influenced by prior exposure to potential prey organisms during the yolk sac stage....... In the light of these observations, the ecological significance of the yolk sac stage is discussed. Initiation of exogenous feeding was delayed by 1-4 days at a low (7.5 nauplii .cntdot. l-1) compared to a high (120 nauplii .cntdot. l-1) prey density, but even at prey densities corresponding to the lower end...

  5. Wave Solutions

    CERN Document Server

    Christov, Ivan C

    2012-01-01

    In classical continuum physics, a wave is a mechanical disturbance. Whether the disturbance is stationary or traveling and whether it is caused by the motion of atoms and molecules or the vibration of a lattice structure, a wave can be understood as a specific type of solution of an appropriate mathematical equation modeling the underlying physics. Typical models consist of partial differential equations that exhibit certain general properties, e.g., hyperbolicity. This, in turn, leads to the possibility of wave solutions. Various analytical techniques (integral transforms, complex variables, reduction to ordinary differential equations, etc.) are available to find wave solutions of linear partial differential equations. Furthermore, linear hyperbolic equations with higher-order derivatives provide the mathematical underpinning of the phenomenon of dispersion, i.e., the dependence of a wave's phase speed on its wavenumber. For systems of nonlinear first-order hyperbolic equations, there also exists a general ...

  6. Analysis of self-feeding in children with feeding disorders.

    Science.gov (United States)

    Rivas, Kristi M; Piazza, Cathleen C; Roane, Henry S; Volkert, Valerie M; Stewart, Victoria; Kadey, Heather J; Groff, Rebecca A

    2014-01-01

    In the current investigation, we evaluated a method for increasing self-feeding with 3 children with a history of food refusal. The children never (2 children) or rarely (1 child) self-fed bites of food when the choice was between self-feeding and escape from eating. When the choice was between self-feeding 1 bite of food or being fed an identical bite of food, self-feeding was low (2 children) or variable (1 child). Levels of self-feeding increased for 2 children when the choice was between self-feeding 1 bite of food or being fed multiple bites of the same food. For the 3rd child, self-feeding increased when the choice was between self-feeding 1 bite of food or being fed multiple bites of a less preferred food. The results showed that altering the contingencies associated with being fed increased the probability of self-feeding, but the specific manipulations that produced self-feeding were unique to each child.

  7. Feeding and Swallowing Disorders (Dysphagia) in Children

    Science.gov (United States)

    ... for the Public / Speech, Language and Swallowing / Swallowing Feeding and Swallowing Disorders (Dysphagia) in Children What are ... children with feeding and swallowing disorders ? What are feeding and swallowing disorders? Feeding disorders include problems gathering ...

  8. Feeding Tips For Your Baby with CHD

    Science.gov (United States)

    ... How To Feed Your Baby Either breast- or bottle-feeding works well for babies with heart problems, but ... do best with a combination of breast- and bottle-feeding. Breast-Feeding Your Baby If your baby is ...

  9. Re-feeding syndrome.

    Science.gov (United States)

    Shadaba, A; Paine, J; Adlard, R; Dilkes, M

    2001-09-01

    The effect of a therapeutically administered high calorie diet in a severely malnourished patient is discussed in this case report. In patients with advanced head and neck cancer prolonged periods of malnutrition prior to admission are frequently encountered. This case report highlights the need to constantly monitor the electrolyte and vitamin levels during the early stages of instituting enteral or parenteral nutrition. By vigilant monitoring and a high index of suspicion re-feeding syndrome or severe hypophosphataemia and its associated complications can be avoided.

  10. Feeding the Beast

    DEFF Research Database (Denmark)

    Hellström, Anders; Hervik, Peter

    2014-01-01

    of fear, we argue, this predisposes people to vote for anti-immigration parties. Our analysis highlights the position of anti-immigration parties; hence, the Sweden Democrats (SD) in Sweden and the Danish People’s Party (DPP) in Denmark. We use frame analysis to detect recurrent frames in the media debate...... as such plays a similar role and provides the DPP with an identity. We conclude that we are confronted with a two-faced beast that feeds on perceptions of the people as ultimately afraid of what are not recognized as native goods....

  11. Food and feed enzymes.

    Science.gov (United States)

    Fraatz, Marco Alexander; Rühl, Martin; Zorn, Holger

    2014-01-01

    Humans have benefited from the unique catalytic properties of enzymes, in particular for food production, for thousands of years. Prominent examples include the production of fermented alcoholic beverages, such as beer and wine, as well as bakery and dairy products. The chapter reviews the historic background of the development of modern enzyme technology and provides an overview of the industrial food and feed enzymes currently available on the world market. The chapter highlights enzyme applications for the improvement of resource efficiency, the biopreservation of food, and the treatment of food intolerances. Further topics address the improvement of food safety and food quality.

  12. Susceptibility of brassicaceous plants to feeding by flea beetles, Phyllotreta spp. (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Soroka, Juliana; Grenkow, Larry

    2013-12-01

    Crucifer-feeding flea beetles, Phyllotreta spp., are chronic insect pests in Canadian prairie canola production. Multiple laboratory and field feeding bioassays were conducted to determine the susceptibility of a wide range of crucifer species, cultivars, and accessions to feeding by flea beetles with the goal of discovering sources of resistant germplasm. In 62 bioassays of 218 entries, no consistent decreased feeding by flea beetles was seen on any entries of Brassica carinata A. Braun, Brassica juncea (L.) Czern., Brassica napus L., or Brassica rapa L. There was reduced feeding on condiment mustard Sinapis alba L. lines but not on canola-quality lines with reduced amounts of glucosinolates, which were fed on at levels equal to B. napus. Analyses of glucosinolate content found decreased quantities of hydroxybenzyl and butyl glucosinolates in preferred canola-quality S. alba lines and increased levels of hydroxybutenyl glucosinolates compared with levels in condiment S. alba lines. Eruca sativa Mill. was an excellent flea beetle host; Camelina sativa (L.) Crantz lines experienced little feeding. Lines of Crambe abyssinica Hochst. ex R. E. Fries and Crambe hispanica L. had reduced feeding levels compared with Brassica entries, but Crambe glabrata DC did not. The results indicate possible sources of resistance to Phyllotreta flea beetles, while highlighting the complicated roles that glucosinolates may play in Phyllotreta host preference.

  13. Waves, damped wave and observation

    CERN Document Server

    Phung, Kim Dang

    2009-01-01

    We consider the wave equation in a bounded domain (eventually convex). Two kinds of inequality are described when occurs trapped ray. Applications to control theory are given. First, we link such kind of estimate with the damped wave equation and its decay rate. Next, we describe the design of an approximate control function by an iterative time reversal method.

  14. Gravity waves

    Science.gov (United States)

    Fritts, David

    1987-02-01

    Gravity waves contributed to the establishment of the thermal structure, small scale (80 to 100 km) fluctuations in velocity (50 to 80 m/sec) and density (20 to 30%, 0 to peak). Dominant gravity wave spectrum in the middle atmosphere: x-scale, less than 100 km; z-scale, greater than 10 km; t-scale, less than 2 hr. Theorists are beginning to understand middle atmosphere motions. There are two classes: Planetary waves and equatorial motions, gravity waves and tidal motions. The former give rise to variability at large scales, which may alter apparent mean structure. Effects include density and velocity fluctuations, induced mean motions, and stratospheric warmings which lead to the breakup of the polar vortex and cooling of the mesosphere. On this scale are also equatorial quasi-biennial and semi-annual oscillations. Gravity wave and tidal motions produce large rms fluctuations in density and velocity. The magnitude of the density fluctuations compared to the mean density is of the order of the vertical wavelength, which grows with height. Relative density fluctuations are less than, or of the order of 30% below the mesopause. Such motions may cause significant and variable convection, and wind shear. There is a strong seasonal variation in gravity wave amplitude. Additional observations are needed to address and quantify mean and fluctuation statistics of both density and mean velocity, variability of the mean and fluctuations, and to identify dominant gravity wave scales and sources as well as causes of variability, both temporal and geographic.

  15. High Line

    DEFF Research Database (Denmark)

    Kiib, Hans

    2015-01-01

    At just over 10 meters above street level, the High Line extends three kilometers through three districts of Southwestern Manhattan in New York. It consists of simple steel construction, and previously served as an elevated rail line connection between Penn Station on 34th Street and the many....... The High Line project has been carried out as part of an open conversion strategy. The result is a remarkable urban architectural project, which works as a catalyst for the urban development of Western Manhattan. The greater project includes the restoration and reuse of many old industrial buildings...... in close proximity to the park bridge and new projects being added to fit the context. The outcome is a conglomeration of non-contemporary urban activities along the High Line, where mechanical workshops, small wholesale stores. etc. mix with new exclusive residential buildings, eminent cafés...

  16. High Line

    DEFF Research Database (Denmark)

    Kiib, Hans

    2015-01-01

    in close proximity to the park bridge and new projects being added to fit the context. The outcome is a conglomeration of non-contemporary urban activities along the High Line, where mechanical workshops, small wholesale stores. etc. mix with new exclusive residential buildings, eminent cafés......At just over 10 meters above street level, the High Line extends three kilometers through three districts of Southwestern Manhattan in New York. It consists of simple steel construction, and previously served as an elevated rail line connection between Penn Station on 34th Street and the many...... factories and warehouses on Gansevoort Street. Today the High Line is a beautiful park covered with new tiles, viewing platforms and smaller recreational areas. The park bridge has simple, uniform, urban fittings and features a variety of flowering plants, grasses, shrubs and trees from around the world...

  17. Wave diffraction by a cosmic string

    CERN Document Server

    Fernández-Núñez, Isabel

    2016-01-01

    We show that if a cosmic string exists, it may be identified through characteristic diffraction pattern in the energy spectrum of the observed signal. In particular, if the string is on the line of sight, the wave field is shown to fit the Cornu spiral. We suggest a simple procedure, based on Keller's geometrical theory of diffraction, which allows to explain wave effects in conical spacetime of a cosmic string in terms of interference of four characteristic rays. Our results are supposed to be valid for scalar massless waves, including gravitational waves, electromagnetic waves, or even sound in case of condensed matter systems with analogous topological defects.

  18. Wave diffraction by a cosmic string

    Science.gov (United States)

    Fernández-Núñez, Isabel; Bulashenko, Oleg

    2016-08-01

    We show that if a cosmic string exists, it may be identified through characteristic diffraction pattern in the energy spectrum of the observed signal. In particular, if the string is on the line of sight, the wave field is shown to fit the Cornu spiral. We suggest a simple procedure, based on Keller's geometrical theory of diffraction, which allows to explain wave effects in conical spacetime of a cosmic string in terms of interference of four characteristic rays. Our results are supposed to be valid for scalar massless waves, including gravitational waves, electromagnetic waves, or even sound in case of condensed matter systems with analogous topological defects.

  19. Wideband Dual-linear Polarized Stacked Patch Antenna with Asymmery Feeding

    Directory of Open Access Journals (Sweden)

    Song Lizhong

    2013-07-01

    Full Text Available The narrow working bandwidth of microstrip antennas limits their applications in in radar and communication systems. Staked patch antenna based on aperture coupling and asymmetry feeding technique was proposed in this paper. A cross-shape aperture imbedded in the ground plane with asymmetry feeding structure provided a relative wideband electromagnetic coupling and allowed a high isolation between two orthogonal ports.The asymmetry feeding structure was composed of two microtrip lines locating above and under the ground plane. U-shape microtrip line adjusted microstrip feeding line characteristic impendence with antenna input impendence in a broad band. Experimental results indicated that an impendence bandwidth of 35.3%, better than 4.5dBi antenna gain, better than 30dB isolation and good cross-polarization were available. Measured results proved that stacked patches using asymmetry feeding structure through aperture coupling to expand working frequency and realize dual-linear polarization was effective.

  20. A first course in vibrations and waves

    CERN Document Server

    Samiullah, Mohammad

    2015-01-01

    This book builds on introductory physics and emphasizes understanding of vibratory motion and waves based on first principles. The book is divided into three parts. Part I contains a preliminary chapter that serves as a review of relevant ideas of mechanics and complex numbers. Part II is devoted to a detailed discussion of vibrations of mechanical systems. This part covers a simple harmonic oscillator, coupled oscillators, normal coordinates, beaded string, continuous string, standing waves, and Fourier series. Part II ends with a presentation of stationary solutions of driven finite systems. Part III is concerned with waves. Here, the emphasis is on the discussion of common aspects of all types of waves. The applications to sound, electromagnetic, and matter waves are illustrated. The book also includes examples from water waves and electromagnetic waves on a transmission line. The emphasis of the book is to bring out the similarities among various types of waves. The book includes treatment of reflection a...

  1. Wave Dragon

    DEFF Research Database (Denmark)

    Tedd, James; Kofoed, Jens Peter; Knapp, W.

    2006-01-01

    Wave Dragon is a floating wave energy converter working by extracting energy principally by means of overtopping of waves into a reservoir. A 1:4.5 scale prototype has been sea tested for 20 months. This paper presents results from testing, experiences gained and developments made during...... this extended period. The prototype is highly instrumented. The overtopping characteristic and the power produced are presented here. This has enabled comparison between the prototype and earlier results from both laboratory model and computer simulation. This gives the optimal operating point and the expected...

  2. Adaptive method of lines

    CERN Document Server

    Saucez, Ph

    2001-01-01

    The general Method of Lines (MOL) procedure provides a flexible format for the solution of all the major classes of partial differential equations (PDEs) and is particularly well suited to evolutionary, nonlinear wave PDEs. Despite its utility, however, there are relatively few texts that explore it at a more advanced level and reflect the method''s current state of development.Written by distinguished researchers in the field, Adaptive Method of Lines reflects the diversity of techniques and applications related to the MOL. Most of its chapters focus on a particular application but also provide a discussion of underlying philosophy and technique. Particular attention is paid to the concept of both temporal and spatial adaptivity in solving time-dependent PDEs. Many important ideas and methods are introduced, including moving grids and grid refinement, static and dynamic gridding, the equidistribution principle and the concept of a monitor function, the minimization of a functional, and the moving finite elem...

  3. Advanced Liquid Feed Experiment

    Science.gov (United States)

    Distefano, E.; Noll, C.

    1993-06-01

    The Advanced Liquid Feed Experiment (ALFE) is a Hitchhiker experiment flown on board the Shuttle of STS-39 as part of the Space Test Payload-1 (STP-1). The purpose of ALFE is to evaluate new propellant management components and operations under the low gravity flight environment of the Space Shuttle for eventual use in an advanced spacecraft feed system. These components and operations include an electronic pressure regulator, an ultrasonic flowmeter, an ultrasonic point sensor gage, and on-orbit refill of an auxiliary propellant tank. The tests are performed with two transparent tanks with dyed Freon 113, observed by a camera and controlled by ground commands and an on-board computer. Results show that the electronic pressure regulator provides smooth pressure ramp-up, sustained pressure control, and the flexibility to change pressure settings in flight. The ultrasonic flowmeter accurately measures flow and detects gas ingestion. The ultrasonic point sensors function well in space, but not as a gage during sustained low-gravity conditions, as they, like other point gages, are subject to the uncertainties of propellant geometry in a given tank. Propellant transfer operations can be performed with liquid-free ullage equalization at a 20 percent fill level, gas-free liquid transfer from 20-65 percent fill level, minimal slosh, and can be automated.

  4. Oxytocin, feeding and satiety

    Directory of Open Access Journals (Sweden)

    Nancy eSabatier

    2013-03-01

    Full Text Available Oxytocin neurones have a physiological role in food intake and energy balance. Central administration of oxytocin is powerfully anorexigenic, reducing food intake and meal duration. The central mechanisms underlying this effect of oxytocin have become better understood in the past few years. Parvocellular neurones of the paraventricular nucleus project to the caudal brainstem to regulate feeding via autonomic functions including the gastrointestinal vago-vagal reflex. In contrast, magnocellular neurones of the supraoptic and paraventricular nuclei release oxytocin from their dendrites to diffuse to distant hypothalamic targets involved in satiety.The ventromedial hypothalamus, for example, expresses a high density of oxytocin receptors but does not contain detectable oxytocin nerve fibres. Magnocellular neurones represent targets for the anorexigenic neuropeptide α-melanocyte stimulating hormone. . In addition to homeostatic control, oxytocin may also have a role in reward-related feeding. Evidence suggests that oxytocin can selectively suppress sugar intake and that it may have a role in limiting the intake of palatable food by inhibiting the reward pathway.

  5. Development of Local Chicken Production Based on Local Feed Ingredients

    Directory of Open Access Journals (Sweden)

    Cecep Hidayat

    2012-06-01

    Full Text Available Development of local chicken production based on local feed ingredient is in line with the vision of Indonesian goverment to fulfill meat and egg national requirement based on local resources. There are two big problem which become stumblingblock in developing local chicken production. The first problem is the difficulty to get day old chick of local chicken. This problem can be solved by integrating breeder institutions belong to goverment with research institution and with local chicken producer association. The second problem is the low performance of local chicken. To improve local chicken performance, it can be done by improving the breed, feed and management. Several research results show that good performance of local chicken were obtained by inclusion of local feed ingredients in the ration. Therefore, development of local chicken production based an local feed resources can be applied.

  6. Harmonic-Resonance Analysis in a Maglev Feeding System

    Science.gov (United States)

    Shigeeda, Hidenori; Okui, Akinobu; Akagi, Hirofumi

    A feeding circuit for a superconducting magnetic levitation train system, or the so-called “maglev” consists of feeder cables and armature coils which show characteristics of a distributed-parameter line. Electric power is supplied to the cables and coils by PWM inverters whose output voltage contains a large amount of harmonics. As a result, a harmonic resonance may occur in the feeding circuit. Besides the above characteristics, the connecting point of sections (groups of armature coils) or the feeder cables length changes according to the movement of a maglev train, thus causing changes in the harmonic-resonance characteristics of the feeding circuit. This paper describes analytical results of the harmonic resonance in the feeding circuit for the maglev, with the focus on changes in the connecting point of sections and the feeder cables length.

  7. Impact of surface waves in a Regional Climate Model

    DEFF Research Database (Denmark)

    Rutgersson, Anna; Sætra, Oyvind; Semedo, Alvaro

    2010-01-01

    A coupled regional atmosphere-wave model system is developed with the purpose of investigating the impact of climate changes on the wave field, as well as feed-back effects of the wave field on the atmospheric parameters. This study focuses on the effects of introducing a two-way atmosphere-wave...... coupling on the atmosphere as well as on wave parameters. The model components are the regional climate model RCA, and the third generation wave model WAM. Two different methods are used for the coupling, using the roughness length and only including the effect of growing sea, and using the wave age...... and introducing the reduction of roughness due to decaying sea (swell). Introducing a two-way coupling results in an altered frequency distribution of wind speed and wave heights. When only including growing sea the impact of waves on the long term mean atmospheric parameters is limited, inducing a reduction...

  8. Relationship between behavioural reactivity and feed efficiency in housed sheep

    DEFF Research Database (Denmark)

    Williams, Charlotte Amdi; Williams, Andrew Richard; Maloney, S.K.

    2010-01-01

    In this study we test the hypothesis that selecting sheep for a low behavioural reactivity to stressful situations will improve their metabolic efficiency, and thereby feed efficiency, during a controlled trial in an animal house. Twenty-four Merino wethers were used, 12 each from lines selected ...

  9. Solitary Wave and Wave Front as Viewed From Curvature

    Institute of Scientific and Technical Information of China (English)

    LIU Shi-Kuo; FU Zun-Tao; LIU Shi-Da; LIANG Fu-Ming; XIN Guo-Jun

    2004-01-01

    The solitary wave and wave front are two important behaviors of nonlinear evolution equations. Geometri cally, solitary wave and wave front are all plane curve. In this paper, they can be represented in terms of curvature c(s), which varies with arc length s. For solitary wave when s →±∞, then its curvature c(s) approaches zero, and when s = 0, the curvature c(s) reaches its maximum. For wave front, when s →±∞, then its curvature c(s) approaches zero, and when s = 0, the curvature c(s) is still zero, but c'(s) ≠ 0. That is, s = 0 is a turning point. When c(s) is given, the variance at some point (x, y) in stream line with arc length s satisfies a 2-order linear variable-coefficient ordinary differential equation. From this equation, it can be determined qualitatively whether the given curvature is a solitary wave or wave front.

  10. Solitary Wave and Wave Front as Viewed From Curvature

    Institute of Scientific and Technical Information of China (English)

    LIUShi-Kuo; FUZun-Tao; LIUShi-Da; LIANGFu-Ming; XINGuo-Jun

    2004-01-01

    The solitary wave and wave front are two important behaviors of nonlinear evolution equations. Geometrically, solitary wave and wave front are all plane curve. In this paper, they can be represented in terms of curvature c(s),which varies with arc length s. For solitary wave when s→±∞, then its curvature c(s) approaches zero, and whens = 0, the curvature c(s) reaches its maximum. For wave front, when s→±∞, then its curvature c(s) approaches zero,and when s = 0, the curvature c(s) is still zero, but c'(s)≠0. That is, s = 0 is a turning point. When c(s) is given,the variance at some point (x, y) in stream line with arc length s satisfies a 2-order linear variable-coeffcient ordinary differential equation. From this equation, it can be determined qualitatively whether the given curvature is a solitary wave or wave front.

  11. Janus Waves

    CERN Document Server

    Papazoglou, Dimitris G; Tzortzakis, Stelios

    2016-01-01

    We show the existence of a family of waves that share a common interesting property affecting the way they propagate and focus. These waves are a superposition of twin waves, which are conjugate to each other under inversion of the propagation direction. In analogy to holography, these twin "real" and "virtual" waves are related respectively to the converging and the diverging part of the beam and can be clearly visualized in real space at two distinct foci under the action of a focusing lens. Analytic formulas for the intensity distribution after focusing are derived, while numerical and experimental demonstrations are given for some of the most interesting members of this family, the accelerating Airy and ring-Airy beams.

  12. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Frigaard, Peter

    Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Byggeri og Anlæg med bølgeenergianlæget Wave Star.......Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Byggeri og Anlæg med bølgeenergianlæget Wave Star....

  13. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Andersen, Thomas Lykke

    Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star.......Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star....

  14. Blast Waves

    CERN Document Server

    Needham, Charles E

    2010-01-01

    The primary purpose of this text is to document many of the lessons that have been learned during the author’s more than forty years in the field of blast and shock. The writing therefore takes on an historical perspective, in some sense, because it follows the author’s experience. The book deals with blast waves propagating in fluids or materials that can be treated as fluids. It begins by distinguishing between blast waves and the more general category of shock waves. It then examines several ways of generating blast waves, considering the propagation of blast waves in one, two and three dimensions as well as through the real atmosphere. One section treats the propagation of shocks in layered gases in a more detailed manner. The book also details the interaction of shock waves with structures in particular reflections, progressing from simple to complex geometries, including planar structures, two-dimensional structures such as ramps or wedges, reflections from heights of burst, and three-dimensional st...

  15. Topological nodal line semimetals

    Science.gov (United States)

    Fang, Chen; Weng, Hongming; Dai, Xi; Fang, Zhong

    2016-11-01

    We review the recent, mainly theoretical, progress in the study of topological nodal line semimetals in three dimensions. In these semimetals, the conduction and the valence bands cross each other along a one-dimensional curve in the three-dimensional Brillouin zone, and any perturbation that preserves a certain symmetry group (generated by either spatial symmetries or time-reversal symmetry) cannot remove this crossing line and open a full direct gap between the two bands. The nodal line(s) is hence topologically protected by the symmetry group, and can be associated with a topological invariant. In this review, (i) we enumerate the symmetry groups that may protect a topological nodal line; (ii) we write down the explicit form of the topological invariant for each of these symmetry groups in terms of the wave functions on the Fermi surface, establishing a topological classification; (iii) for certain classes, we review the proposals for the realization of these semimetals in real materials; (iv) we discuss different scenarios that when the protecting symmetry is broken, how a topological nodal line semimetal becomes Weyl semimetals, Dirac semimetals, and other topological phases; and (v) we discuss the possible physical effects accessible to experimental probes in these materials. Project partially supported by the National Key Research and Development Program of China (Grant Nos. 2016YFA0302400 and 2016YFA0300604), partially by the National Natural Science Foundation of China (Grant Nos. 11274359 and 11422428), the National Basic Research Program of China (Grant No. 2013CB921700), and the “Strategic Priority Research Program (B)” of the Chinese Academy of Sciences (Grant No. XDB07020100).

  16. Spectra of {gamma} rays feeding superdeformed bands

    Energy Technology Data Exchange (ETDEWEB)

    Lauritsen, T.; Khoo, T.L.; Henry, R.G. [and others

    1995-08-01

    The spectrum of {gamma}rays coincident with SD transitions contains the transitions which populate the SD band. This spectrum can provide information on the feeding mechanism and on the properties (moment of inertia, collectivity) of excited SD states. We used a model we developed to explain the feeding of SD bands, to calculate the spectrum of feeding {gamma}rays. The Monte Carlo simulations take into account the trigger conditions present in our Eurogam experiment. Both experimental and theoretical spectra contain a statistical component and a broad E2 peak (from transitions occurring between excited states in the SD well). There is good resemblance between the measured and calculated spectra although the calculated multiplicity of an E2 bump is low by {approximately}30%. Work is continuing to improve the quality of the fits, which will result in a better understanding of excited SD states. In addition, a model for the last steps, which cool the {gamma} cascade into the SD yrast line, needs to be developed. A strong M1/E2 low-energy component, which we believe is responsible for this cooling, was observed.

  17. Design and Experimental Evaluation of Modified Square Loop Feeding for UHF RFID Tags: e0132530

    National Research Council Canada - National Science Library

    Md Rokunuzzaman; Mohammad Tariqul Islam; Haslina Arshad; Mandeep Jit Singh; Norbahiah Misran

    2015-01-01

      This paper addresses the performance evaluation of a modified square loop antenna design for UHF RFID applications that is excited through a narrow feed line connected to a square loop, an impedance matching network...

  18. Design and Experimental Evaluation of Modified Square Loop Feeding for UHF RFID Tags

    National Research Council Canada - National Science Library

    Rokunuzzaman, Md; Islam, Mohammad Tariqul; Arshad, Haslina; Jit Singh, Mandeep; Misran, Norbahiah

    2015-01-01

    This paper addresses the performance evaluation of a modified square loop antenna design for UHF RFID applications that is excited through a narrow feed line connected to a square loop, an impedance matching network...

  19. Short communication: Effect of feed barrier design on the behavior of loose-housed lactating dairy cows.

    Science.gov (United States)

    Endres, M I; DeVries, T J; von Keyserlingk, M A G; Weary, D M

    2005-07-01

    The objective of this study was to evaluate the effects of 2 feed barrier systems on feeding and social behavior of dairy cows. Forty-eight lactating Holstein cows were subjected to each of 2 treatments in a cross-over design. The treatments were 2 types of feed-line barriers: 1) post-and-rail, and 2) headlock. Time-lapse video was used to quantify the feeding behavior and incidence of aggressive displacements of the cows at the feed bunk. Average daily feeding time did not differ when cows used the headlock barrier compared with the post-and-rail barrier. However, there were certain changes in feeding time during periods of peak feeding activity: cows that had lower feeding times relative to group mates when using the post-and-rail barrier showed more similar feeding times to group mates when using the headlock barrier. There were 21% fewer displacements at the feed bunk when cows accessed feed by the headlock barrier compared with the post-and-rail barrier. These results suggest that using a headlock barrier reduces aggression at the feed bunk and improves access to feed for socially subordinate cows during peak feeding periods.

  20. Wave Generation Theory

    DEFF Research Database (Denmark)

    Frigaard, Peter; Høgedal, Michael; Christensen, Morten

    The intention of this manual is to provide some formulas and techniques which can be used for generating waves in hydraulic laboratories. Both long crested waves (2-D waves) and short crested waves (3-D waves) are considered....

  1. Wave Generation Theory

    OpenAIRE

    Frigaard, Peter; Høgedal, Michael; Christensen, Morten

    1993-01-01

    The intention of this manual is to provide some formulas and techniques which can be used for generating waves in hydraulic laboratories. Both long crested waves (2-D waves) and short crested waves (3-D waves) are considered.

  2. Transition feeding of sows

    DEFF Research Database (Denmark)

    Theil, Peter Kappel

    2015-01-01

    The transition period from late gestation to early lactation is rather short, but it is nonetheless of major importance for the productivity of high-prolific sows. The transition period, here defined as the last 10 d of gestation and the first 10 d of lactation, encompasses substantial changes...... for the sow. More specifically, fetal growth, mammary growth, colostrum production and sow maintenance require substantial amounts of nutrients during late gestation. After parturition, nutrients are mainly required for milk synthesis and sow maintenance, but the regressing uterus supplies considerable...... practices do not acknowledge these changes. Development of new feeding strategies specifically adapted for the transition sow is likely of importance to match the rapid changes in nutrient requirements....

  3. The Fourth Wave in Deterrence Research

    OpenAIRE

    Knopf, Jeffrey W.

    2010-01-01

    The article of record as published may be located at http://dx.doi.org/10.1080/13523261003640819 A new line of work on deterrence began emerging after the end of the Cold War and gained momentum after the September 11 terrorist attacks. Building on a previous characterization by Robert Jervis that identified three waves of deterrence research,1 this work is here designated the fourth wave. The fourth wave reflects a change from a focus on relatively symmetrical situations of mu...

  4. Prey perception in feeding-current feeding copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Goncalves, Rodrigo J.; Florian Couespel, Damien

    2016-01-01

    We reply to the comments of Paffenhöfer and Jiang () who argues that remote chemical prey perception is necessary for feeding-current feeding copepods to fulfill their nutritional requirements in a dilute ocean, that remote chemical prey detection may only be observed at very low prey concentrati...

  5. Nonlinear wave-wave interactions and wedge waves

    Institute of Scientific and Technical Information of China (English)

    Ray Q.Lin; Will Perrie

    2005-01-01

    A tetrad mechanism for exciting long waves,for example edge waves,is described based on nonlinear resonant wave-wave interactions.In this mechanism,resonant interactions pass energy to an edge wave,from the three participating gravity waves.The estimated action flux into the edge wave can be orders of magnitude greater than the transfer fluxes derived from other competing mechanisms,such as triad interactions.Moreover,the numerical results show that the actual transfer rates into the edge wave from the three participating gravity waves are two-to three- orders of magnitude greater than bottom friction.

  6. Nonlinear ship waves and computational fluid dynamics

    National Research Council Canada - National Science Library

    MIYATA, Hideaki; ORIHARA, Hideo; SATO, Yohei

    2014-01-01

    .... Finding of the occurrence of nonlinear waves (named Free-Surface Shock Waves) in the vicinity of a ship advancing at constant speed provided the start-line for the progress of innovative technologies in the ship hull-form design...

  7. Sea breeze generated waves and coastal morphology

    NARCIS (Netherlands)

    Verhagen, H.J.; Savov, B.

    1999-01-01

    For the determination of the stability of coastlines, coastal erosion and the design of erosion protection studies, the “local” wave climate is the most important input parameter. For morphology, “local” means just outside the breaker line. On relatively calm days the local wave climate is strongly

  8. Aquaculture and feeding ecology: Feeding behaviour in turbot larvae

    DEFF Research Database (Denmark)

    Bruno, Eleonora

    challenging for larval rearing. After the start of exogenous feeding, another intense and likely critical period of change occurs in the early life stages of fish. This stage is the metamorphosis, during which the larvae transform organs and body morphology to become juveniles. Compared to other teleosts...... metamorphosis in flatfish species is often unsuccessful, resulting in different types of abnormal development. The objective of this thesis was to analyse the feeding behaviour of the flatfish species turbot (Psetta maxima L.) larvae during the two crucial life periods, 1) first feeding and 2) metamorphosis....... To analyse whether these two periods are critical for the correct development and survival of turbot, feeding behaviours of larvae during the period of first feeding and during the first stages of metamorphosis was studied using video recordings. This provided qualitative and quantitative descriptions...

  9. Level of Aflatoxin in Some Fish Feeds from Fish Farming Processes, Feed Factories and Imported Feeds

    OpenAIRE

    ALTUĞ, Gülşen

    2014-01-01

    Aflatoxins that are toxic metabolites for human and animals were determined in some fish feed. Eighty-five unit samples taken from "fish farming processes", "feed factories" and "imported feeds" in 1998, 1999 and 2000 were analyzed. In the analysis, thin layer chromatography (TLC) and enzyme linked immunosorbent assay (ELISA) technique were used. Consequently, aflatoxin levels above 20 ppb were detected in 20 samples and from 21.2 to 42.4...

  10. Breathing spiral waves in the chlorine dioxide-iodine-malonic acid reaction-diffusion system

    Science.gov (United States)

    Berenstein, Igal; Muñuzuri, Alberto P.; Yang, Lingfa; Dolnik, Milos; Zhabotinsky, Anatol M.; Epstein, Irving R.

    2008-08-01

    Breathing spiral waves are observed in the oscillatory chlorine dioxide-iodine-malonic acid reaction-diffusion system. The breathing develops within established patterns of multiple spiral waves after the concentration of polyvinyl alcohol in the feeding chamber of a continuously fed, unstirred reactor is increased. The breathing period is determined by the period of bulk oscillations in the feeding chamber. Similar behavior is obtained in the Lengyel-Epstein model of this system, where small amplitude parametric forcing of spiral waves near the spiral wave frequency leads to the formation of breathing spiral waves in which the period of breathing is equal to the period of forcing.

  11. When Shock Waves Collide

    CERN Document Server

    Hartigan, P; Frank, A; Hansen, E; Yirak, K; Liao, A S; Graham, P; Wilde, B; Blue, B; Martinez, D; Rosen, P; Farley, D; Paguio, R

    2016-01-01

    Supersonic outflows from objects as varied as stellar jets, massive stars and novae often exhibit multiple shock waves that overlap one another. When the intersection angle between two shock waves exceeds a critical value, the system reconfigures its geometry to create a normal shock known as a Mach stem where the shocks meet. Mach stems are important for interpreting emission-line images of shocked gas because a normal shock produces higher postshock temperatures and therefore a higher-excitation spectrum than an oblique one does. In this paper we summarize the results of a series of numerical simulations and laboratory experiments designed to quantify how Mach stems behave in supersonic plasmas that are the norm in astrophysical flows. The experiments test analytical predictions for critical angles where Mach stems should form, and quantify how Mach stems grow and decay as intersection angles between the incident shock and a surface change. While small Mach stems are destroyed by surface irregularities and ...

  12. Enteral Tube Feeding and Pneumonia

    Science.gov (United States)

    Gray, David Sheridan; Kimmel, David

    2006-01-01

    To determine the effects of enteral tube feeding on the incidence of pneumonia, we performed a retrospective review of all clients at our institution who had gastrostomy or jejunostomy tubes placed over a 10-year period. Ninety-three subjects had a history of pneumonia before feeding tube insertion. Eighty had gastrostomy and 13, jejunostomy…

  13. 胶束毛细管电动色谱法在线富集联用技术灵敏检测乳制品和饲料样品中的三聚氰胺%On-line Preconcentration and Sensitive Determination of Melamine in Milk Powder and Animal Feeds Samples by Micellar Electrokinetic Chromatography

    Institute of Scientific and Technical Information of China (English)

    陈新; 袁红萍; 曹玉华; 陈秋

    2011-01-01

    建立了胶束毛细管电泳(MEKC)在线富集技术灵敏检测三聚氰胺的方法,采用场放大进样(FASS)联用胶束扫集(Sweep)测定多种样品中的三聚氰胺.试样用乙腈反复提取3次,在优化实验条件下,三聚氰胺的检测灵敏度提高了约1000倍,检出限由原来的2 mg/L降到1.8 μg/L(S/N=3).本方法用于配方奶粉和动物饲料中三聚氰胺残留的检测,回收率在97.2%~105.0%之间;相对标准偏差均小于4.5%(n=4).本方法具有检测灵敏、方便易行、预处理简单、干扰少,经济环保和适用范围广等优点.%A sensitive analytical method using micellar electrokinetic chromatography with on-line pre-concentration technique was developed for rapid determination of melamine in various samples. Two online preconcentration techniques including field-amplified sample stacking and sweeping micellar electrokinetic chromatographic technique (FASS- sweep MEKC) were used. The samples were extracted by acetonitrile for three times. Under the optimum conditions, the sensitivity was improved about 1000 times. The LODs was decreased from 2. 0 mg/L to 1. 8 μg/L. The RSD were less than 4. 5%. The recoveries were range in 97. 2% -105%. This method is sensitive, reliable, economic and . pretreatment-free for complex samples' and can be easily used for product quality control of milk powder and animal feeds.

  14. The genetic parameters of feed efficiency and its component traits in the turkey (Meleagris gallopavo).

    Science.gov (United States)

    Case, Lindsay A; Wood, Benjamin J; Miller, Stephen P

    2012-01-23

    Residual feed intake (RFI) and feed conversion ratio (FCR) can be incorporated into a breeding program as traits to select for feed efficiency. Alternatively, the direct measures used to calculate RFI and FCR can be analyzed to determine the underlying variation in the traits that impact overall efficiency. These constituent traits can then be appropriately weighted in an index to achieve genetic gain. To investigate feed efficiency in the turkey, feed intake and weight gain were measured on male primary breeder line turkeys housed in individual feeding cages from 15 to 19 weeks of age. The FCR and RFI showed moderate heritability values of 0.16 and 0.21, respectively. Feed intake, body weight, and weight gain were also moderately heritable (0.25, 0.35, and 0.18, respectively). Weight gain was negatively correlated to feed conversion ratio and was not genetically correlated to RFI. Body weight had a small and positive genetic correlation to RFI (0.09) and FCR (0.12). Feed intake was positively genetically correlated to RFI (0.62); however, there was no genetic correlation between feed intake and FCR. These estimates of heritability and the genetic correlations can be used in the development of an index to improve feed efficiency and reduce the cost of production.

  15. The genetic parameters of feed efficiency and its component traits in the turkey (Meleagris gallopavo

    Directory of Open Access Journals (Sweden)

    Case Lindsay A

    2012-01-01

    Full Text Available Abstract Residual feed intake (RFI and feed conversion ratio (FCR can be incorporated into a breeding program as traits to select for feed efficiency. Alternatively, the direct measures used to calculate RFI and FCR can be analyzed to determine the underlying variation in the traits that impact overall efficiency. These constituent traits can then be appropriately weighted in an index to achieve genetic gain. To investigate feed efficiency in the turkey, feed intake and weight gain were measured on male primary breeder line turkeys housed in individual feeding cages from 15 to 19 weeks of age. The FCR and RFI showed moderate heritability values of 0.16 and 0.21, respectively. Feed intake, body weight, and weight gain were also moderately heritable (0.25, 0.35, and 0.18, respectively. Weight gain was negatively correlated to feed conversion ratio and was not genetically correlated to RFI. Body weight had a small and positive genetic correlation to RFI (0.09 and FCR (0.12. Feed intake was positively genetically correlated to RFI (0.62; however, there was no genetic correlation between feed intake and FCR. These estimates of heritability and the genetic correlations can be used in the development of an index to improve feed efficiency and reduce the cost of production.

  16. Shallow Water Waves and Solitary Waves

    CERN Document Server

    Hereman, Willy

    2013-01-01

    Encyclopedic article covering shallow water wave models used in oceanography and atmospheric science. Sections: Definition of the Subject; Introduction and Historical Perspective; Completely Integrable Shallow Water Wave Equations; Shallow Water Wave Equations of Geophysical Fluid Dynamics; Computation of Solitary Wave Solutions; Numerical Methods; Water Wave Experiments and Observations; Future Directions, and Bibliography.

  17. [Force-feeding of hunger-striking prisoners].

    Science.gov (United States)

    Glick, Shimon

    2014-09-01

    In contrast to the position of the World Medical Association and the Ethics Council of the Israel Medical Association, the author argues for forced-feeding of hunger-striking prisoners when their condition reaches a stage of danger of death or permanent injury. This position is based on the priority of human life over autonomy, and of a communitarian ethic. This position is supported by a District Court decision ordering the feeding of a hunger-striking prisoner, by a Supreme Court decision imposing surgery on a non-consenting prisoner, and in line with Israel's Patient's Right Law.

  18. Rotary feeding system for metallic coating installation by electrodeposition

    Science.gov (United States)

    Stănescu, A.; Alecusan, A. M.; Dimitescu, A.

    2016-08-01

    The paper aims to present an alternative feeding system for metallic coatings lines by electrodeposition which lends itself to the circular arrangement of the cuvettes used in such plants. The novelty lies both, in the arrangement of the electrodeposition installation components and mechanical feeding and transport system for parts to be electrodeposited. The control and actuation system of this type of installation simplifies. Nevertheless, all these increase the system reliability and run lower maintenance costs, without adversely affecting the quality of the end product. The paper presents the justification for reducing the total energy consumption in the electrodeposition process, too.

  19. Nonreciprocal spin wave spectroscopy of thin Ni–Fe stripes

    NARCIS (Netherlands)

    Khalili Amiri, P.K.; Rejaei, B.; Vroubel, M.; Zhuang, Y.

    2007-01-01

    The authors report on the observation of nonreciprocal spin wave propagation in a thin ( ∼ 200 nm) patterned Ni–Fe stripe. The spin wave transmission spectrum is measured using a pair of microstrip lines as antennas. The nonreciprocity of surface wave dispersion brought about by an adjacent aluminum

  20. Horizontal circulation and jumps in Hamiltonian wave models

    NARCIS (Netherlands)

    Gagarina, E.; Vegt, van der J.; Bokhove, O.

    2013-01-01

    We are interested in the numerical modeling of wave-current interactions around surf zones at beaches. Any model that aims to predict the onset of wave breaking at the breaker line needs to capture both the nonlinearity of the wave and its dispersion. We have therefore formulated the Hamiltonian dyn

  1. Waves & vibrations

    OpenAIRE

    Nicolas, Maxime

    2016-01-01

    Engineering school; This course is designed for students of Polytech Marseille, engineering school. It covers first the physics of vibration of the harmonic oscillator with damping and forcing, coupled oscillators. After a presentation of the wave equation, the vibration of strings, beams and membranes are studied.

  2. Wave Dragon

    DEFF Research Database (Denmark)

    Kramer, Morten; Frigaard, Peter

    På foranledning af Löwenmark F.R.I, er der udført numeriske beregninger af Wave Dragons (herefter WD) armes effektivitet for forskellige geometriske udformninger. 5 geometriske modeller, hvor WD's arme er forkortet/forlænget er undersøgt for 3 forskellige drejninger af armene. I alt er 15...

  3. Wave Dragon

    DEFF Research Database (Denmark)

    Kramer, Morten; Frigaard, Peter

    På foranledning af Löwenmark F.R.I, er der udført numeriske beregninger af Wave Dragons (herefter WD) armes effektivitet for forskellige geometriske udformninger. 5 geometriske modeller, hvor WD's arme er forkortet/forlænget er undersøgt for 3 forskellige drejninger af armene. I alt er 15...

  4. HI Absorption Lines Detected from the Arecibo Legacy Fast ALFA Survey Data

    Science.gov (United States)

    Zhong-zu, Wu; Martha P, Haynes; Riccardo, Giovanelli; Ming, Zhu; Ru-rong, Chen

    2015-10-01

    We present some preliminary results of an on-going study of HI 21-cm absorption lines based on the 40% survey data released by the Arecibo Legacy Fast Arecibo L-band Feed Array (ALFALFA). (1) Ten HI candidate absorbers have been detected. Five of them are previously published in the literature, and the rest of them are new detections that need further confirmation. (2) For those sources with no detected absorptions, we have calculated the upper limit of their foreground HI column density NHI. The statistical result of the NHI distribution indicates that the ratio Ts/f between the averaged spin temperature and coverage factor for DLAs (the damped Lyα systems) might be larger than 500 K. The radio frequency interference (RFI) and standing wave are the main factors affecting the detection of HI absorption lines, which have been analyzed and discussed as well in order to find a method of solution. Our study can serve as a pathfinder for the future large-scale search of HI 21-cm absorption lines using the Five-Hundred-Meter Aperture Spherical Radio Telescope (FAST), which is an Arecibo-type radio telescope currently under construction in China with greatly increased sensitivity, bandwidth, and observational sky area. As prospects, we have discussed two types of observational studies of HI absorption lines toward extragalactic sources using the FAST telescope.

  5. New X-band antenna feeds for the DSN 64-meter stations

    Science.gov (United States)

    Hartop, R.

    1979-01-01

    New X-band antenna feed assemblies with dual-polarization capability are being implemented in the DSN 64-meter stations. Together with dual X-band traveling wave masers, they permit the simultaneous reception of right- and left-hand circular polarization from the Voyager spacecraft. The new feed also includes a dual hybrid mode feedhorn which increases the antenna gain by 0.36 dB over the present feedhorn.

  6. Shear wave speed and dispersion measurements using crawling wave chirps.

    Science.gov (United States)

    Hah, Zaegyoo; Partin, Alexander; Parker, Kevin J

    2014-10-01

    This article demonstrates the measurement of shear wave speed and shear speed dispersion of biomaterials using a chirp signal that launches waves over a range of frequencies. A biomaterial is vibrated by two vibration sources that generate shear waves inside the medium, which is scanned by an ultrasound imaging system. Doppler processing of the acquired signal produces an image of the square of vibration amplitude that shows repetitive constructive and destructive interference patterns called "crawling waves." With a chirp vibration signal, successive Doppler frames are generated from different source frequencies. Collected frames generate a distinctive pattern which is used to calculate the shear speed and shear speed dispersion. A special reciprocal chirp is designed such that the equi-phase lines of a motion slice image are straight lines. Detailed analysis is provided to generate a closed-form solution for calculating the shear wave speed and the dispersion. Also several phantoms and an ex vivo human liver sample are scanned and the estimation results are presented.

  7. Biomechanics of milk extraction during breast-feeding.

    Science.gov (United States)

    Elad, David; Kozlovsky, Pavel; Blum, Omry; Laine, Andrew F; Po, Ming Jack; Botzer, Eyal; Dollberg, Shaul; Zelicovich, Mabel; Ben Sira, Liat

    2014-04-08

    How do infants extract milk during breast-feeding? We have resolved a century-long scientific controversy, whether it is sucking of the milk by subatmospheric pressure or mouthing of the nipple-areola complex to induce a peristaltic-like extraction mechanism. Breast-feeding is a dynamic process, which requires coupling between periodic motions of the infant's jaws, undulation of the tongue, and the breast milk ejection reflex. The physical mechanisms executed by the infant have been intriguing topics. We used an objective and dynamic analysis of ultrasound (US) movie clips acquired during breast-feeding to explore the tongue dynamic characteristics. Then, we developed a new 3D biophysical model of the breast and lactiferous tubes that enables the mimicking of dynamic characteristics observed in US imaging during breast-feeding, and thereby, exploration of the biomechanical aspects of breast-feeding. We have shown, for the first time to our knowledge, that latch-on to draw the nipple-areola complex into the infant mouth, as well as milk extraction during breast-feeding, require development of time-varying subatmospheric pressures within the infant's oral cavity. Analysis of the US movies clearly demonstrated that tongue motility during breast-feeding was fairly periodic. The anterior tongue, which is wedged between the nipple-areola complex and the lower lips, moves as a rigid body with the cycling motion of the mandible, while the posterior section of the tongue undulates in a pattern similar to a propagating peristaltic wave, which is essential for swallowing.

  8. 7 CFR 205.237 - Livestock feed.

    Science.gov (United States)

    2010-01-01

    ... specific stage of life; (3) Feed plastic pellets for roughage; (4) Feed formulas containing urea or manure... additives, and feed supplements in violation of the Federal Food, Drug, and Cosmetic Act. ...

  9. Schistosome feeding and regurgitation.

    Directory of Open Access Journals (Sweden)

    Patrick J Skelly

    2014-08-01

    Full Text Available Schistosomes are parasitic flatworms that infect >200 million people worldwide, causing the chronic, debilitating disease schistosomiasis. Unusual among parasitic helminths, the long-lived adult worms, continuously bathed in blood, take up nutrients directly across the body surface and also by ingestion of blood into the gut. Recent proteomic analyses of the body surface revealed the presence of hydrolytic enzymes, solute, and ion transporters, thus emphasising its metabolic credentials. Furthermore, definition of the molecular mechanisms for the uptake of selected metabolites (glucose, certain amino acids, and water establishes it as a vital site of nutrient acquisition. Nevertheless, the amount of blood ingested into the gut per day is considerable: for males ∼100 nl; for the more actively feeding females ∼900 nl, >4 times body volume. Ingested erythrocytes are lysed as they pass through the specialized esophagus, while leucocytes become tethered and disabled there. Proteomics and transcriptomics have revealed, in addition to gut proteases, an amino acid transporter in gut tissue and other hydrolases, ion, and lipid transporters in the lumen, implicating the gut as the site for acquisition of essential lipids and inorganic ions. The surface is the principal entry route for glucose, whereas the gut dominates amino acid acquisition, especially in females. Heme, a potentially toxic hemoglobin degradation product, accumulates in the gut and, since schistosomes lack an anus, must be expelled by the poorly understood process of regurgitation. Here we place the new observations on the proteome of body surface and gut, and the entry of different nutrient classes into schistosomes, into the context of older studies on worm composition and metabolism. We suggest that the balance between surface and gut in nutrition is determined by the constraints of solute diffusion imposed by differences in male and female worm morphology. Our conclusions have

  10. Feed palatability and the alternative protein sources in shrimp feed

    Directory of Open Access Journals (Sweden)

    Chutima Tantikitti

    2014-02-01

    Full Text Available Feed palatability in carnivorous aquaculture species, shrimps in particular, has been crucially related to the presence of compounds acting as attractants that are commonly associated with the prey components under wild conditions. Thus a nutritionally adequate and organoleptically-pleasing diet is essential to achieve satisfactory intake and growth in shrimps. Historically, fishmeal has been an essential dietary component of intensive shrimp cultures because of its nutrient composition and compounds of high attractability. However, in recent years the fishmeal supplies have been dwindling due to over hunting, a diminishing natural fish-stock, elevating prices and market volatility. This has led to search for cheaper sources of suitable protein as fishmeal substitutes. To improve the palatability of diets, various substances have been investigated for their effectiveness in aqua-feed including natural feed ingredients and synthetic flavor substances. For crustacean, attractants characteristically are of low molecular weight, water and ethanol soluble, and amphoteric or basic compounds that are released from potential prey items. Compounds such as free amino acids, especially taurine, hydroxyproline, glycine, arginine, glutamic acid and alanine have been identified to stimulate feeding in shrimps. The same has been identified with organic acids, nucleotides and nucleosides, betaine, and some small peptides. Palatability also has been associated with animal’s past experience with the feed. Understanding the factors that regulate feed palatability is therefore primary for successful shrimp culture.

  11. production lines

    Directory of Open Access Journals (Sweden)

    Jingshan Li

    2000-01-01

    Full Text Available In this work, serial production lines with finished goods buffers operating in the pull regime are considered. The machines are assumed to obey Bernoulli reliability model. The problem of satisfying customers demand is addressed. The level of demand satisfaction is quantified by the due-time performance (DTP, which is defined as the probability to ship to the customer a required number of parts during a fixed time interval. Within this scenario, the definitions of DTP bottlenecks are introduced and a method for their identification is developed.

  12. Impact of Wave Dragon on Wave Climate

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Tedd, James; Kramer, Morten

    This report is an advisory paper for use in determining the wave dragon effects on hydrography, by considering the effect on the wave climate in the region of a wave dragon. This is to be used in the impact assessment for the Wave Dragon pre-commercial demonstrator.......This report is an advisory paper for use in determining the wave dragon effects on hydrography, by considering the effect on the wave climate in the region of a wave dragon. This is to be used in the impact assessment for the Wave Dragon pre-commercial demonstrator....

  13. Food and Feed Commodity Vocabulary

    Science.gov (United States)

    Food and Feed Vocabulary was developed to consolidate all the major OPP Commodity Vocabularies into one standardized vocabulary. The EPA-preferred term is the only term that can be used in setting tolerances.

  14. Feeding profiles of tame moose

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is on the feeding profiles of tame moose. 3 moose were observed for 99 hours while in natural range, each bite plant species, browse conditions and size...

  15. Ion cyclotron waves at Titan

    Science.gov (United States)

    Russell, C. T.; Wei, H. Y.; Cowee, M. M.; Neubauer, F. M.; Dougherty, M. K.

    2016-03-01

    During the interaction of Titan's thick atmosphere with the ambient plasma, it was expected that ion cyclotron waves would be generated by the free energy of the highly anisotropic velocity distribution of the freshly ionized atmospheric particles created in the interaction. However, ion cyclotron waves are rarely observed near Titan, due to the long growth times of waves associated with the major ion species from Titan's ionosphere, such as CH4+ and N2+. In the over 100 Titan flybys obtained by Cassini to date, there are only two wave events, for just a few minutes during T63 flyby and for tens of minutes during T98 flyby. These waves occur near the gyrofrequencies of proton and singly ionized molecular hydrogen. They are left-handed, elliptically polarized, and propagate nearly parallel to the field lines. Hybrid simulations are performed to understand the wave growth under various conditions in the Titan environment. The simulations using the plasma and field conditions during T63 show that pickup protons with densities ranging from 0.01 cm-3 to 0.02 cm-3 and singly ionized molecular hydrogens with densities ranging from 0.015 cm-3 to 0.25 cm-3 can drive ion cyclotron waves with amplitudes of ~0.02 nT and of ~0.04 nT within appropriate growth times at Titan, respectively. Since the T98 waves were seen farther upstream than the T63 waves, it is possible that the instability was stronger and grew faster on T98 than T63.

  16. Relativistic spherical plasma waves

    Science.gov (United States)

    Bulanov, S. S.; Maksimchuk, A.; Schroeder, C. B.; Zhidkov, A. G.; Esarey, E.; Leemans, W. P.

    2012-02-01

    Tightly focused laser pulses that diverge or converge in underdense plasma can generate wake waves, having local structures that are spherical waves. Here we study theoretically and numerically relativistic spherical wake waves and their properties, including wave breaking.

  17. Fermented liquid feed for pigs: an ancient technique for the future.

    Science.gov (United States)

    Missotten, Joris Am; Michiels, Joris; Degroote, Jeroen; De Smet, Stefaan

    2015-01-01

    Fermented liquid feed is feed that has been mixed with water at a ratio ranging from 1:1.5 to 1:4. By mixing with water, lactic acid bacteria and yeasts naturally occurring in the feed proliferate and produce lactic acid, acetic acid and ethanol which reduces the pH of the mixture. This reduction in pH inhibits pathogenic organisms from developing in the feed. In addition, when this low pH mixture is fed, it reduces the pH in the stomach of pigs and prevents the proliferation of pathogens such as coliforms and Salmonella in the gastrointestinal tract. For piglets, the use of fermented liquid feed offers the possibility of simultaneously providing feed and water, which may facilitate an easier transition from sow's milk to solid feed. Secondly, offering properly produced fermented liquid feed may strengthen the role of the stomach as the first line of defense against possible pathogenic infections by lowering the pH in the gastrointestinal tract thereby helping to exclude enteropathogens. Finally, feeding fermented liquid feed to pigs has been shown to improve the performance of suckling pigs, weaner pigs and growing-finishing pigs. In this review, current knowledge about the use of fermented liquid feed in pig diets will be discussed. This will include a discussion of the desirable properties of fermented liquid feed and factors affecting fermentation. In addition, advantages and disadvantages of fermented liquid feed will be discussed including its effects on gastrointestinal health, intestinal pH and the types of bacteria found in the gastrointestinal tract as well as the effects of fermented liquid feeds on pig performance.

  18. Compact Circular/Linear Polarization Dual-Band Prime-Focus Feed for Space Communication

    Directory of Open Access Journals (Sweden)

    Rastislav Galuscak

    2012-01-01

    Full Text Available We propose a novel, compact, prime-focus antenna feed for space communication. The feed requires full-wave simulator optimization for a given parabolic reflector and is designed to operate simultaneously on two bands, offering LHC/RHC polarizations for the 13 cm band and V/H polarizations for the 70 cm band. With performance results confirmed by measurement, it has been verified in practice that this compact feed is suitable for use in a low-noise Earth-Moon-Earth communication link.

  19. Infant feeding practices in Malaysia.

    Science.gov (United States)

    Chen, S T

    1978-12-01

    Retrospective nutritional data on 100 children, aged 6 months to 2 1/2 years, who were admitted to the University Hospital in Kuala Lumpur, Malaysia, was obtained by interviewing the mothers of the children. Analysis of the data revealed that 1) only 49% of the children were breast-fed as infants; 2) 50% of the mothers who did breast-feed discontinued breast-feeding before the children were 3 months old; and 3) the weaning diet of at least 1/3 of the children was inadequate. 18% of the children were Malays, 49% were Chinese, and 33% were Indian. The proportion of breast-fed children was highest among the Malays and lowest among the Chinese. Mothers with higher incomes tended to stop breast-feeding earlier than mothers with lower incomes. 67% of the women said they stopped breast-feeding due to inadequate lactation. Most of the children received supplementary foods at relatively early ages. 50% of the infants received starchy foods by the time they were 3 1/2 months old, and 50% received fruit or fruit juice by the time they were 3 1/2 months old. Vegetable products, meat, fish, and eggs were not added to the diet until the children were considerably older. Recommendations, based on the study findings, were 1) hospitals should discontinue the practice of deferring breast-feeding initiation for 24 hours after delivery; 2) mothers should be encouraged to breast-feed fully; and 3) health personnel should discourage the widespread use of costly precooked cereals for supplementary feeding. Tables depicted 1) the frequency distribution of the 100 children by income and by milk feeding patterns according to ethnic affiliation and 2) the cost of serving precooked cereals as compared to the cost of serving home cooked meals.

  20. Social theory and infant feeding

    Science.gov (United States)

    2011-01-01

    Clinicians, public health advisors, nutritionists and others have been attempting to increase breastfeeding rates for the last few decades, with varying degrees of success. We need social science researchers to help us understand the role of infant feeding in the family. Some researchers in the area of food and nutrition have found Pierre Bourdieu's theoretical framework helpful. In this editorial, I introduce some of Bourdieu's ideas and suggest researchers interested in infant feeding should consider testing these theories. PMID:21676218

  1. Gravitational waves

    CERN Document Server

    Ciufolini, I; Moschella, U; Fre, P

    2001-01-01

    Gravitational waves (GWs) are a hot topic and promise to play a central role in astrophysics, cosmology, and theoretical physics. Technological developments have led us to the brink of their direct observation, which could become a reality in the coming years. The direct observation of GWs will open an entirely new field: GW astronomy. This is expected to bring a revolution in our knowledge of the universe by allowing the observation of previously unseen phenomena, such as the coalescence of compact objects (neutron stars and black holes), the fall of stars into supermassive black holes, stellar core collapses, big-bang relics, and the new and unexpected.With a wide range of contributions by leading scientists in the field, Gravitational Waves covers topics such as the basics of GWs, various advanced topics, GW detectors, astrophysics of GW sources, numerical applications, and several recent theoretical developments. The material is written at a level suitable for postgraduate students entering the field.

  2. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Frigaard, Peter; Brorsen, Michael

    Nærværende rapport beskriver foreløbige hovedkonklusioner på modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star i perioden 13/9 2004 til 12/11 2004.......Nærværende rapport beskriver foreløbige hovedkonklusioner på modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star i perioden 13/9 2004 til 12/11 2004....

  3. Exploration of underground basement structures in Kanto plain using the spatial autocorrelation method. 1. S-wave velocity structure along the line from Hatoyama, Saitama to Noda, Chiba; Kukan jiko sokanho ni yoru Kanto heiya no kiban kozo tansa. 1. Saitamaken Hatoyama machi - Chibaken Nodashi kan no S ha sokudo kozo

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, T.; Umezawa, N.; Shiraishi, H. [Saitama Institute of Environmental Pollution, Saitama (Japan)

    1997-05-27

    The Saitama prefectural government has been conducting basement structure exploration using the spatial autocorrelation method by dividing the entire plain area into meshes, for the purpose of improving the accuracy of estimating large-scale seismic damages. This paper reports the result of explorations on meshes in the east-west direction in the central part of Saitama Prefecture. The present exploration was intended on ten meshes in the east-west direction along the north latitude 36-degree line. The number of exploration points is 13 comprising three points on the hilly area bordering on the eastern edge of the Kanto mountainous area and ten points on the plain area. The arrangement constitutes a traverse line with a total distance of about 33 km from the west edge (Hatoyama-machi in Saitama Prefecture) to the east edge (Noda City in Chiba Prefecture). The phase velocities were estimated from the result of the array microtremor observations using the spatial autocorrelation method applied with the FET. The phase velocities were used to estimate underground structures by using an inverse analysis. As a result, detailed two-dimensional S-wave velocity structures were revealed on the traverse line. The velocity cross section expresses change in the basement structures with sufficient resolution, and at the same time the information is judged highly harmonious with existing deep boring data and the result of artificial earthquake exploration. 15 refs., 6 figs.

  4. Wave Propagation

    CERN Document Server

    Ferrarese, Giorgio

    2011-01-01

    Lectures: A. Jeffrey: Lectures on nonlinear wave propagation.- Y. Choquet-Bruhat: Ondes asymptotiques.- G. Boillat: Urti.- Seminars: D. Graffi: Sulla teoria dell'ottica non-lineare.- G. Grioli: Sulla propagazione del calore nei mezzi continui.- T. Manacorda: Onde nei solidi con vincoli interni.- T. Ruggeri: "Entropy principle" and main field for a non linear covariant system.- B. Straughan: Singular surfaces in dipolar materials and possible consequences for continuum mechanics

  5. Shock Waves

    CERN Document Server

    Jiang, Z

    2005-01-01

    The International Symposium on Shock Waves (ISSW) is a well established series of conferences held every two years in a different location. A unique feature of the ISSW is the emphasis on bridging the gap between physicists and engineers working in fields as different as gas dynamics, fluid mechanics and materials sciences. The main results presented at these meetings constitute valuable proceedings that offer anyone working in this field an authoritative and comprehensive source of reference.

  6. Feed quality in swine diet

    Directory of Open Access Journals (Sweden)

    Živković Branislav

    2002-01-01

    Full Text Available The paper will demonstrate the quality of some feed used in swine diet. The emphasis will be on feed whose incorporation into mixes could result in unfavorable effects on production, health and economic production of swine. Data will be presented on maize and its possible negative effects, having in mind toxins. Soybean meal, or genetically modified soybean meal, will also be observed. The next feed which will be discussed will be soybean whey obtained by different procedures and the potential dangers of its use in swine diet rations. Sunflower meal, feed of animal origin, with emphasis on fish flour and meat-bone flour will also be covered in the work. A feed which has been attracting particular attention lately is yeast imported from Italy. Its quality characteristics will be discussed, the so-called non-protein nitrogen. Analyses of mineral feed will include sources of phosphorus, phosphates (monocalciumphosphate, dicalcium phosphate phytases and resolving the problem of phosphorus in swine rations. Finally, an inevitable segment are synthetic amino acids, especially lysine and its role in swine diet.

  7. The new Israeli feed safety law: challenges in relation to animal and public health.

    Science.gov (United States)

    Barel, Shimon; Elad, Dani; Cuneah, Olga; Shimshoni, Jakob A

    2017-03-01

    The Israeli feed safety legislation, which came to prominence in the early 1970s, has undergone a major change from simple feed safety and quality regulations to a more holistic concept of control of feed safety and quality throughout the whole feed production chain, from farm to the end user table. In February 2014, a new law was approved by the Israeli parliament, namely the Control of Animal Feed Law, which is expected to enter into effect in 2017. The law is intended to regulate the production and marketing of animal feed, guaranteeing the safety and quality of animal products throughout the production chain. The responsibility on the implementation of the new feed law was moved from the Plant Protection Inspection Service to the Veterinary Services and Animal Health. In preparation for the law's implementation, we have characterized the various sources and production lines of feed for farm and domestic animals in Israel and assessed the current feed safety challenges in terms of potential hazards or undesirable substances. Moreover, the basic requirements for feed safety laboratories, which are mandatory for analyzing and testing for potential contaminants, are summarized for each of the contaminants discussed. © 2016 Society of Chemical Industry.

  8. Topological Constraints on Scroll and Spiral Waves in Excitable Media

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong; HU Bambi; LI Bing-Wei; DUAN Yi-Shi

    2007-01-01

    A conservation equation for topological charges of phase singularities (scroll and spiral waves) in excitable media is given. It provides some topological properties of scroll (spiral) waves: for example, the topological charge of the generated or annihilated spiral pair must be opposite. Additionally, we obtain another equation on scroll waves, which shows that singular filaments of scroll waves occur on a set of one-dimensional curves which may be either closed loops or infinite lines.

  9. TRAVELING WAVE SOLUTIONS FOR A CLASS OF NONLINEAR DISPERSIVE EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The method of the phase plane is emploied to investigate the solitary and periodic traveling waves for a class of nonlinear dispersive partial differential equations.By using the bifurcation theory of dynamical systems to do qualitative analysis,all possible phase portraits in the parametric space for the traveling wave systems are obtained.It can be shown that the existence of a singular straight line in the traveling wave system is the reason why smooth solitary wave solutions converge to solitary cusp wave solution when parameters are varied.The different parameter conditions for the existence of solitary and periodic wave solutions of different kinds are rigorously determined.

  10. Parallel Lines

    Directory of Open Access Journals (Sweden)

    James G. Worner

    2017-05-01

    Full Text Available James Worner is an Australian-based writer and scholar currently pursuing a PhD at the University of Technology Sydney. His research seeks to expose masculinities lost in the shadow of Australia’s Anzac hegemony while exploring new opportunities for contemporary historiography. He is the recipient of the Doctoral Scholarship in Historical Consciousness at the university’s Australian Centre of Public History and will be hosted by the University of Bologna during 2017 on a doctoral research writing scholarship.   ‘Parallel Lines’ is one of a collection of stories, The Shapes of Us, exploring liminal spaces of modern life: class, gender, sexuality, race, religion and education. It looks at lives, like lines, that do not meet but which travel in proximity, simultaneously attracted and repelled. James’ short stories have been published in various journals and anthologies.

  11. Newborn First Feed and Prelacteal Feeds in Mansoura, Egypt

    Directory of Open Access Journals (Sweden)

    Abdel-Hady El-Gilany

    2014-01-01

    Full Text Available Background. Prelacteal feed (feeding any other substance before first breastfeeding appears to be common despite its harmful effects. By definition a child provided with prelacteal feed (PLF is not exclusively breastfed and PLF has many implications for the success and early initiation of breastfeeding. Objectives. To describe the prevalence of, nature of, and reasons for and factors associated with PLF. Methods. 647 mother-infant dyads were studied. Data was collected about the sociodemographic features of the family and baby, maternity care, the type of first feed before suckling, and causes of PLF. Maternal weight and height were measured and body mass index was calculated. Results. About 58% of newborns received prelacteal feeds. The commonest PLF was sugar/glucose water (39.6%. The most frequent reasons for giving PLF are tradition (61.0% and mother’s/mother in law’s advice (58.3%. The logistic regression revealed that the independent predictors of PLF are urban residence; maternal education; father’s education; low, middle, and high social class; maternal obesity; receiving antenatal care at private clinics and no antenatal care; Caesarean section; female babies; low birth weight; and admission to neonatal intensive care. Conclusion. Indiscriminate use of PLF should be discouraged in medical education and in antenatal maternal health education.

  12. Broad band antennas and feed methods

    Energy Technology Data Exchange (ETDEWEB)

    Benzel, David M.; Twogood, Richard E.

    2017-04-18

    Two or more Vivaldi antennas, consisting of two plates each, each with the antenna's natural impedance of approximately 100 ohms, are placed in parallel to achieve a 50 ohm impedance in the case of two antennas or other impedances (100/n ohms) for more than two antennas. A single Vivaldi antenna plate (half Vivaldi antenna) over a ground plane can also be used to achieve a 50 ohm impedance, or two or more single plates over a ground plane to achieve other impedances. Unbalanced 50 ohm transmission lines, e.g. coaxial cables, can be used to directly feed, the dual Vivaldi (four plate) antenna in a center fed angled center departure, or more desirably, a center fed offset departure configuration.

  13. Broad band antennas and feed methods

    Science.gov (United States)

    Benzel, David M.; Twogood, Richard E.

    2017-04-18

    Two or more Vivaldi antennas, consisting of two plates each, each with the antenna's natural impedance of approximately 100 ohms, are placed in parallel to achieve a 50 ohm impedance in the case of two antennas or other impedances (100/n ohms) for more than two antennas. A single Vivaldi antenna plate (half Vivaldi antenna) over a ground plane can also be used to achieve a 50 ohm impedance, or two or more single plates over a ground plane to achieve other impedances. Unbalanced 50 ohm transmission lines, e.g. coaxial cables, can be used to directly feed, the dual Vivaldi (four plate) antenna in a center fed angled center departure, or more desirably, a center fed offset departure configuration.

  14. The effects of feeding commercial feed formulated for semi-intensive systems on Litopenaeus vannamei production and its profitability in a hyper-intensive biofloc-dominated system

    Directory of Open Access Journals (Sweden)

    André Braga

    2016-05-01

    Full Text Available The present study evaluated the production of Litopenaeus vannamei in a high density biofloc-dominated system using two commercial feeds; a less expensive feed (US$0.99 kg−1 formulated for semi-intensive systems and the more expensive (US$1.75 kg−1 which was designed for hyper-intensive systems. A 67-days study was conducted in six 40 m3 lined with Ethylene Propylene Diene Monomer membrane raceways (RWs filled with mixture of seawater (22 m3, and biofloc-rich water (18 m3. Each RW was stocked (500 shrimp m−3 using juveniles (2.66 g produced from Taura-Resistant and Fast-Growth breeding lines. The study was composed of two feed treatments with three replicates each; the cheaper feed (SI-35 contained 35% crude protein (CP, 7% lipid and 4% fiber while the more expensive one (HI-35 had the same levels of CP and lipid but only 2% fiber. The SI-35 treatment required more solids removal, oxygen, and bicarbonate supplementation than the HI-35 treatment. Weekly growth, total biomass, yield were significantly lower in the SI-35 treatment, whereas feed conversion ratio was higher. The economic analysis indicates that both feeds would be commercially viable, nevertheless, the less-expensive feed financially underperformed the other.

  15. Pharmacological therapy of feed intolerance in the critically ills

    Institute of Scientific and Technical Information of China (English)

    Nam; Q; Nguyen

    2014-01-01

    Feed intolerance in the setting of critical illness is associated with higher morbidity and mortality,and thusrequires promptly and effective treatment. Prokineticagents are currently considered as the first-line therapygiven issues relating to parenteral nutrition and post-pyloric placement. Currently,the agents of choice areerythromycin and metoclopramide,either alone or incombination,which are highly effective with relativelylow incidence of cardiac,hemodynamic or neurologicaladverse effects. Diarrhea,however,can occur in up to 49% of patients who are treated with the dual prokinetic therapy,which is not associated with Clostridiumdifficile infection and settled soon after the cessation ofthe drugs. Hence,the use of prokinetic therapy over along period or for prophylactic purpose must be avoided,and the indication for ongoing use of the drug(s)must be reviewed frequently. Second line therapy,suchas total parenteral nutrition and post-pyloric feeding,must be considered once adverse effects relating theprokinetic therapy develop.

  16. Complementary feeding patterns in India.

    Science.gov (United States)

    Kuriyan, R; Kurpad, A V

    2012-10-01

    There are far too many children in the world who suffer from under-nutrition and growth faltering, with life time consequences such as reduced work capacity, increased infections, impaired intellectual performance and an increased risk of non communicable diseases later in life. These changes occur early in life, and consequently, complementary feeding has been receiving increased attention in the international nutrition community. In India, common problems relate not only to insufficient breastfeeding, but also to detrimental feeding practices. Only about 20% of children aged 6-23 months were fed according to the three recommended Infant and Child Feeding practices. The most common types of solid or semi-solid foods fed to both breastfeeding and non-breastfeeding children under 3 years of age were foods made from grains and roots. These complementary feeding practices were found to be significantly associated with poor socioeconomic status, undesirable socio-cultural beliefs, maternal illiteracy, and ignorance. Although many initiatives have been carried out in India to promote Infant and Young Child Feeding, the progress in reducing the number of undernourished children in India over the last decade has been slow and modest. Equally, with the growing evidence and interest in the role of infant nutrition in the development of over nutrition and non-communicable disease, it is important to plan appropriate complementary feeding interventions that result in optimal growth. Contact opportunities with parents, specifically mothers, must be used for counseling through multiple communication channels such as local media, in order to constantly educate the population with consistent and simple messages on child feeding. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Making Waves: Seismic Waves Activities and Demonstrations

    Science.gov (United States)

    Braile, S. J.; Braile, L. W.

    2011-12-01

    The nature and propagation of seismic waves are fundamental concepts necessary for understanding the exploration of Earth's interior structure and properties, plate tectonics, earthquakes, and seismic hazards. Investigating seismic waves is also an engaging approach to learning basic principles of the physics of waves and wave propagation. Several effective educational activities and demonstrations are available for teaching about seismic waves, including the stretching of a spring to demonstrate elasticity; slinky wave propagation activities for compressional, shear, Rayleigh and Love waves; the human wave activity to demonstrate P- and S- waves in solids and liquids; waves in water in a simple wave tank; seismic wave computer animations; simple shake table demonstrations of model building responses to seismic waves to illustrate earthquake damage to structures; processing and analysis of seismograms using free and easy to use software; and seismic wave simulation software for viewing wave propagation in a spherical Earth. The use of multiple methods for teaching about seismic waves is useful because it provides reinforcement of the fundamental concepts, is adaptable to variable classroom situations and diverse learning styles, and allows one or more methods to be used for authentic assessment. The methods described here have been used effectively with a broad range of audiences, including K-12 students and teachers, undergraduate students in introductory geosciences courses, and geosciences majors.

  18. 9 CFR 89.5 - Feeding pens.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Feeding pens. 89.5 Section 89.5... TWENTY-EIGHT HOUR LAW § 89.5 Feeding pens. (a) Stock pens and other enclosures for feeding, watering, and... same time, (2) properly designed facilities for feeding and watering the livestock, (3) reasonably...

  19. High-Fibre feeding in gestation

    NARCIS (Netherlands)

    Meunier-Salaün, M.C.; Bolhuis, J.E.

    2015-01-01

    Gestating sows are usually fed low levels of feed, which may not provide sufficient satiety, and does not allow sows to fully fulfil their motivation to express foraging and feeding behaviours. Feed restriction may therefore lead to high occurrences of non-feeding oral activities, including stereoty

  20. Geometrical vs wave optics under gravitational waves

    CERN Document Server

    Angélil, Raymond

    2015-01-01

    We present some new derivations of the effect of a plane gravitational wave on a light ray. A simple interpretation of the results is that a gravitational wave causes a phase modulation of electromagnetic waves. We arrive at this picture from two contrasting directions, namely null geodesics and Maxwell's equations, or, geometric and wave optics. Under geometric optics, we express the geodesic equations in Hamiltonian form and solve perturbatively for the effect of gravitational waves. We find that the well-known time-delay formula for light generalizes trivially to massive particles. We also recover, by way of a Hamilton-Jacobi equation, the phase modulation obtained under wave optics. Turning then to wave optics, rather than solving Maxwell's equations directly for the fields, as in most previous approaches, we derive a perturbed wave equation (perturbed by the gravitational wave) for the electromagnetic four-potential. From this wave equation it follows that the four-potential and the electric and magnetic...

  1. A new integrated slot element feed array for multibeam systems

    Science.gov (United States)

    Yngvesson, K. Sigfrid; Johansson, Joakim F.; Kollberg, Erik L.

    1986-01-01

    A feed array consisting of constant width slot antennas (CWSA), fed from a block containing fin-line transitions, has been developed. The array has a two-dimensional configuration, with five elements each on five parallel substrates. Beamwidths are compatible with use in f/D = 1.0 multibeam systems, with optimum taper. Array element spacings are close to a factor of two smaller than for other typical arrays, and spillover efficiency is about 65 percent.

  2. EARLY ENTERAL FEEDING AND DELAYED ENTERAL FEEDING- A COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    Alli Muthiah

    2017-03-01

    Full Text Available BACKGROUND Nutrients form the fuel for the body, which comes in the form of carbohydrates, proteins and lipids. The body is intended to burn fuels in order to perform work. Starvation with malnutrition affects the postoperative patients and patients with acute pancreatitis. There is an increased risk of nosocomial infections and a delay in the wound healing may be noted. They are more prone for respiratory tract infections. Enteral Nutrition (EN delivers nutrition to the body through gastrointestinal tract. This also includes the oral feeding. This study will review the administration, rationale and assess the pros and cons associated with the early initiation of enteral feeding. The aim of this study is to evaluate if early commencement of enteral nutrition compared to traditional management (delayed enteral feeding is associated with fewer complications and improved outcome-  In patients undergoing elective/emergency gastrointestinal surgery.  In patients with acute pancreatitis. It is also used to determine whether a period of starvation (nil by mouth after gastrointestinal surgery or in the early days of acute pancreatitis is beneficial in terms of specific outcomes. MATERIALS AND METHODS A prospective cohort interventional study was conducted using 100 patients from July 2012 to November 2012. Patients satisfying the inclusion and exclusion criteria were included in the study. Patients admitted in my unit for GIT surgeries or acute pancreatitis constituted the test group, while patients admitted in other units for similar disease processes constituted the control group. RESULTS Our study concluded that early enteral feeding resulted in reduced incidence of surgical site infections. When the decreased length of stay, shorter convalescent period and the lesser post-interventional fatigue were taken into account, early enteral feeding has a definite cost benefit.CONCLUSION Early enteral feeding was beneficial associated with fewer

  3. Feeding the Monster

    Science.gov (United States)

    2005-10-01

    Near-infrared images of the active galaxy NGC 1097, obtained with the NACO adaptive optics instrument on ESO's Very Large Telescope, disclose with unprecedented detail a complex central network of filamentary structure spiralling down to the centre of the galaxy. These observations provide astronomers with new insights on how super-massive black holes lurking inside galaxies get fed. "This is possibly the first time that a detailed view of the channelling process of matter, from the main part of the galaxy down to the very end in the nucleus is released," says Almudena Prieto (Max-Planck Institute, Heidelberg, Germany), lead author of the paper describing these results. Located at a distance of about 45 million light-years in the southern constellation Fornax (the Furnace), NGC 1097 is a relatively bright, barred spiral galaxy seen face-on. At magnitude 9.5, and thus just 25 times fainter than the faintest object that can be seen with the unaided eye, it appears in small telescopes as a bright, circular disc. NGC 1097 is a very moderate example of an Active Galactic Nucleus (AGN), whose emission is thought to arise from matter (gas and stars) falling into oblivion in a central black hole. However, NGC 1097 possesses a comparatively faint nucleus only, and the black hole in its centre must be on a very strict "diet": only a small amount of gas and stars is apparently being swallowed by the black hole at any given moment. Astronomers have been trying to understand for a long time how the matter is "gulped" down towards the black hole. Watching directly the feeding process requires very high spatial resolution at the centre of galaxies. This can be achieved by means of interferometry as was done with the VLTI MIDI instrument on the central parts of another AGN, NGC 1068 (see ESO PR 17/03), or with adaptive optics [1]. Thus, astronomers [2] obtained images of NGC 1097 with the adaptive optics NACO instrument attached to Yepun, the fourth Unit Telescope of ESO's VLT

  4. CMS-Wave

    Science.gov (United States)

    2014-10-27

    2014 2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE CMS -Wave 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...Program CMS -Wave CMS -Wave is a two-dimensional spectral wind-wave generation and transformation model that employs a forward-marching, finite...difference method to solve the wave action conservation equation. Capabilities of CMS -Wave include wave shoaling, refraction, diffraction, reflection

  5. China's Feed Companies Eye Safety Control

    Institute of Scientific and Technical Information of China (English)

    Richard Zhu

    2011-01-01

    @@ China's feed companies in China are looking to strengthen safety control substantially according to the highest international standard.The first step will be improving the feed safety control in the pre-mixture and compound feed production.The next step will be extending this control to the whole feed supply chain, covering feed ingredients and services like transport and storage.Besides, a joint program will be defined in cooperation with GMP+ International.

  6. Sequentially pulsed traveling wave accelerator

    Science.gov (United States)

    Caporaso, George J.; Nelson, Scott D.; Poole, Brian R.

    2009-08-18

    A sequentially pulsed traveling wave compact accelerator having two or more pulse forming lines each with a switch for producing a short acceleration pulse along a short length of a beam tube, and a trigger mechanism for sequentially triggering the switches so that a traveling axial electric field is produced along the beam tube in synchronism with an axially traversing pulsed beam of charged particles to serially impart energy to the particle beam.

  7. Some thoughts about infant feeding.

    Science.gov (United States)

    Hendrickse, R G

    1983-12-01

    This article summarizes the nutritional considerations, impact on infection and immunity, and psychosocial aspects of the breast versus bottle feeding debate and concludes with guidelines for reorganizing government health services to promote breastfeeding. Its aim is to encourage reappraisal on the part of physicians of the direct implications of infant feeding for the health and well-being of people in all societies, but especially in developing countries. As a result of widespread abandonment of breastfeeding in developing countries, marasmus and infant diarrhea have increased. Although the biologic advatages of breast over bottle feeding are indisputable, the social and economic advantages are more difficult to quantify. Many Third World women curtail breastfeeding to meet the conditions of employment; however, the economic advantages of artificial feeding diminish as one descends down the pay scale. The counterproductive trend toward bottle feeding has been compounded by adoption of this method on the part of the educated elite in Third World countries, including medical and nursing professionals, thus conferring on it as status associated with progress and affluence. The present trend can be reversed only if communities are convinced of the advantages of breastfeeding and make adjustments to facilitate this practice. Preparation for motherhood must be viewed as an integral function of the health care system, with emphasis placed on the nutrition of pregnant and lactating women, preparation for breastfeeding, and the initiation and continuation of breastfeeding. Obstetric units must actively discourage the removal of infants from their mothers or routine artificial feeding. In addition, facilities must be provided at workplaces for breastfeeding, the working day should be modified to allow brestfeeding, maternity leaves should be extended, and appropriate payments should be made to nursing mothers. The nutrition needs of infants must be viewed as a shared

  8. Enteral Feeding Set Handling Techniques.

    Science.gov (United States)

    Lyman, Beth; Williams, Maria; Sollazzo, Janet; Hayden, Ashley; Hensley, Pam; Dai, Hongying; Roberts, Cristine

    2017-04-01

    Enteral nutrition therapy is common practice in pediatric clinical settings. Often patients will receive a pump-assisted bolus feeding over 30 minutes several times per day using the same enteral feeding set (EFS). This study aims to determine the safest and most efficacious way to handle the EFS between feedings. Three EFS handling techniques were compared through simulation for bacterial growth, nursing time, and supply costs: (1) rinsing the EFS with sterile water after each feeding, (2) refrigerating the EFS between feedings, and (3) using a ready-to-hang (RTH) product maintained at room temperature. Cultures were obtained at baseline, hour 12, and hour 21 of the 24-hour cycle. A time-in-motion analysis was conducted and reported in average number of seconds to complete each procedure. Supply costs were inventoried for 1 month comparing the actual usage to our estimated usage. Of 1080 cultures obtained, the overall bacterial growth rate was 8.7%. The rinse and refrigeration techniques displayed similar bacterial growth (11.4% vs 10.3%, P = .63). The RTH technique displayed the least bacterial growth of any method (4.4%, P = .002). The time analysis in minutes showed the rinse method was the most time-consuming (44.8 ± 2.7) vs refrigeration (35.8 ± 2.6) and RTH (31.08 ± 0.6) ( P < .0001). All 3 EFS handling techniques displayed low bacterial growth. RTH was superior in bacterial growth, nursing time, and supply costs. Since not all pediatric formulas are available in RTH, we conclude that refrigerating the EFS between uses is the next most efficacious method for handling the EFS between bolus feeds.

  9. Floral arrangements and hummingbird feeding.

    Science.gov (United States)

    Hainsworth, F Reed; Mercier, Theresa; Wolf, Larry L

    1983-05-01

    The influence of simulated inflorescence design on feeding behavior of 3 male Eugenes fulgens (Rivoli's hummingbird) and one female Lampornis clemenciae (Bluethroated hummingbird) was studied in the laboratory using artificial flowers. Five two-dimensional and three three-dimensional arrangements provided constant rewards per artificial flower. Visits to two-dimensional arrangements had more flower visits per feeding bout, proportionally more flower revisits, and shorter time between flowers than visits to three-dimensional arrangements. This suggests inflorescence design may influence pollen movement by hummingbirds.

  10. Optimal Control of a Surge-Mode WEC in Random Waves

    Energy Technology Data Exchange (ETDEWEB)

    Chertok, Allan [Resolute Marine Energy, Inc., Boston, MA (United States); Ceberio, Olivier [Resolute Marine Energy, Inc., Boston, MA (United States); Staby, Bill [Resolute Marine Energy, Inc., Boston, MA (United States); Previsic, Mirko [Re Vision Consulting, Sacramento, CA (United States); Scruggs, Jeffrey [Univ. of Michigan, Ann Arbor, MI (United States); Van de Ven, James [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-08-30

    The objective of this project was to develop one or more real-time feedback and feed-forward (MPC) control algorithms for an Oscillating Surge Wave Converter (OSWC) developed by RME called SurgeWEC™ that leverages recent innovations in wave energy converter (WEC) control theory to maximize power production in random wave environments. The control algorithms synthesized innovations in dynamic programming and nonlinear wave dynamics using anticipatory wave sensors and localized sensor measurements; e.g. position and velocity of the WEC Power Take Off (PTO), with predictive wave forecasting data. The result was an advanced control system that uses feedback or feed-forward data from an array of sensor channels comprised of both localized and deployed sensors fused into a single decision process that optimally compensates for uncertainties in the system dynamics, wave forecasts, and sensor measurement errors.

  11. Effect of lining anisotropy on sound attenuation in lined ducts

    Science.gov (United States)

    Kim, Jeong-Woo; Bolton, J. Stuart; Alexander, Jonathan H.

    2005-09-01

    In this paper, the effect of duct-lining anisotropy, with respect to flow resistivity, in particular, is considered. The duct lining is modeled by using a fully poroelastic theory derived from the Biot theory. The lining is considered to occupy only a part of the duct cross section, and is imagined to be infinite in length. When the appropriate solutions for the sound fields within the airway and the anisotropic porous material are substituted into the boundary conditions of the problem, a homogeneous system of equations results. The propagation characteristics of the duct modes can then be found by identifying the conditions under which the determinant of that system of equations is zero. Corresponding experiments have been conducted using samples of aviation-grade glass fiber partially lining a square-section, four-microphone standing wave tube. Excellent agreement between measured attenuations and predictions was found. It will be shown that the modal attenuation is primarily sensitive to the flow resistivity of the lining in the axial direction.

  12. Estimation of seabed shear-wave velocity profiles using shear-wave source data.

    Science.gov (United States)

    Dong, Hefeng; Nguyen, Thanh-Duong; Duffaut, Kenneth

    2013-07-01

    This paper estimates seabed shear-wave velocity profiles and their uncertainties using interface-wave dispersion curves extracted from data generated by a shear-wave source. The shear-wave source generated a seismic signature over a frequency range between 2 and 60 Hz and was polarized in both in-line and cross-line orientations. Low-frequency Scholte- and Love-waves were recorded. Dispersion curves of the Scholte- and Love-waves for the fundamental mode and higher-order modes are extracted by three time-frequency analysis methods. Both the vertically and horizontally polarized shear-wave velocity profiles in the sediment are estimated by the Scholte- and Love-wave dispersion curves, respectively. A Bayesian approach is utilized for the inversion. Differential evolution, a global search algorithm is applied to estimate the most-probable shear-velocity models. Marginal posterior probability profiles are computed by Metropolis-Hastings sampling. The estimated vertically and horizontally polarized shear-wave velocity profiles fit well with the core and in situ measurements.

  13. Increased expressions of genes and proteins involved in mitochondrial oxidation and antioxidant pathway in adipose tissue of pigs selected for a low residual feed intake.

    Science.gov (United States)

    Louveau, I; Vincent, A; Tacher, S; Gilbert, H; Gondret, F

    2016-12-01

    Adipose tissue is a primary sensor for nutrient availability and regulates many functions including feed intake and energy homeostasis. This study was undertaken to determine the molecular responses of adipose tissue to differences in feed intake and feed efficiency. Subcutaneous adipose tissue was collected from two lines of pigs divergently selected for residual feed intake (RFI), a measure of feed efficiency defined as the difference between actual and expected feed intake, and from a subset of high-RFI pigs that were feed-restricted at the level of the voluntary feed intake of low-RFI pigs during the growing-finishing period. Transcriptomics analyses indicated that the number of genes that were differentially expressed ( feed-restricted high-RFI ( = 8) pigs. They included in silico pathway analyses of the differentially expressed (DE) genes ( feed restriction. This indicates that the responses of adipose tissue to RFI difference shared only some common mechanisms with feed intake modulation, notably the regulation of cell cycle (including ) and transferase activity pathway. Two carboxylesterase genes (, ) involved in lipolysis, were among the most overexpressed genes in the low-RFI pigs; they were also affected by feed restriction within the high-RFI line. About 60% of the molecular changes between low- and high-RFI pigs were specific to genetic divergence in feed efficiency, independently of feed intake. Different genes and proteins known to be associated with mitochondrial oxidative metabolism were overexpressed in adipose tissue of low-RFI pigs compared with high-RFI pigs; other proteins participating in the generation of energy were also affected by feed restriction within the high-RFI line. Finally, mitochondrial antioxidant genes were upregulated in low-RFI pigs vs. high-RFI pigs. Altogether, increased oxidative and antioxidant processes in adipose tissue might be associated with improved feed efficiency.

  14. Wave-particle and wave-wave interactions in hot plasmas: a French historical point of view

    Science.gov (United States)

    Laval, Guy; Pesme, Denis; Adam, Jean-Claude

    2016-11-01

    The first researches on nuclear fusion for energy applications marked the entrance of hot plasmas into the laboratory. It became necessary to understand the behavior of such plasmas and to learn how to manipulate them. Theoreticians and experimentalists, building on the foundations of empirical laws, had to construct this new plasma physics from first principles and to explain the results of more and more complicated experiments. Along this line, two important topics emerged: wave-particle and wave-wave interactions. Here, their history is recalled as it has been lived by a French team from the end of the sixties to the beginning of the twenty-first century.

  15. Local feed resources for poultry

    NARCIS (Netherlands)

    Leenstra, F.R.

    2013-01-01

    In poultry ‘no input’, ‘low input’ and commercial production can be distinguished. ‘No input’ implies scavenging poultry with some kitchen waste or crop residues as supplemental feed. Input is negligible and economic efficiency is high, provided there is any output. Commercial production is capital

  16. Parental concerns about complementary feeding

    DEFF Research Database (Denmark)

    Nielsen, Annemette; Michaelsen, Kim F.; Holm, Lotte

    2013-01-01

    Background/objectives:To investigate and analyze differences in parental concerns during earlier and later phases of complementary feeding.Subject/methods:Eight focus group interviews were conducted with 45 mothers of children aged 7 or 13 months. Deductive and inductive coding procedures were ap......:10.1038/ejcn.2013.165....

  17. Alfalfa non-feed uses

    Science.gov (United States)

    Non-feed uses for alfalfa such as biomass energy and phytoremediation could increase alfalfa acreage and improve farm profitability. The new bio-energy alfalfa and production system increased forage yield and ethanol production. New alfalfas with enhanced nitrogen cycling capacities would protect wa...

  18. Food and feed safety assessment

    NARCIS (Netherlands)

    Kuiper, H.A.; Paoletti, Claudia

    2015-01-01

    The general principles for safety and nutritional evaluation of foods and feed and the potential health risks associated with hazardous compounds are described as developed by the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) and further elaborated in the

  19. Catalytic reforming feed characterisation technique

    Energy Technology Data Exchange (ETDEWEB)

    Larraz Mora, R.; Arvelo Alvarez, R. [Univ. of La Laguna, Chemical Engineering Dept., La Laguna (Spain)

    2002-09-01

    The catalytic reforming of naphtha is one of the major refinery processes, designed to increase the octane number of naphtha or to produce aromatics. The naphtha used as catalytic reformer feedstock usually contains a mixture of paraffins, naphthenes, and aromatics in the carbon number range C{sub 6} to C{sub 10}. The detailed chemical composition of the feed is necessary to predict the aromatics and hydrogen production as well as the operation severity. The analysis of feed naphtha is usually reported in terms of its ASTM distillation curve and API or specific gravity. Since reforming reactions are described in terms of lumped chemical species (paraffins, naphthenes and aromatics), a feed characterisation technique should be useful in order to predict reforming operating conditions and detect feed quality changes. Unfortunately online analyzer applications as cromatography or recently introduced naphtha NMR [1] are scarce in most of refineries. This work proposes an algorithmic characterisation method focusing on its main steps description. The method could help on the subjects previously described, finally a calculation example is shown. (orig.)

  20. When Shock Waves Collide

    Science.gov (United States)

    Hartigan, P.; Foster, J.; Frank, A.; Hansen, E.; Yirak, K.; Liao, A. S.; Graham, P.; Wilde, B.; Blue, B.; Martinez, D.; Rosen, P.; Farley, D.; Paguio, R.

    2016-06-01

    Supersonic outflows from objects as varied as stellar jets, massive stars, and novae often exhibit multiple shock waves that overlap one another. When the intersection angle between two shock waves exceeds a critical value, the system reconfigures its geometry to create a normal shock known as a Mach stem where the shocks meet. Mach stems are important for interpreting emission-line images of shocked gas because a normal shock produces higher postshock temperatures, and therefore a higher-excitation spectrum than does an oblique shock. In this paper, we summarize the results of a series of numerical simulations and laboratory experiments designed to quantify how Mach stems behave in supersonic plasmas that are the norm in astrophysical flows. The experiments test analytical predictions for critical angles where Mach stems should form, and quantify how Mach stems grow and decay as intersection angles between the incident shock and a surface change. While small Mach stems are destroyed by surface irregularities and subcritical angles, larger ones persist in these situations and can regrow if the intersection angle changes to become more favorable. The experimental and numerical results show that although Mach stems occur only over a limited range of intersection angles and size scales, within these ranges they are relatively robust, and hence are a viable explanation for variable bright knots observed in Hubble Space Telescope images at the intersections of some bow shocks in stellar jets.