WorldWideScience

Sample records for entanglement-preserving frequency conversion

  1. Frequency conversion of structured light.

    Science.gov (United States)

    Steinlechner, Fabian; Hermosa, Nathaniel; Pruneri, Valerio; Torres, Juan P

    2016-02-15

    Coherent frequency conversion of structured light, i.e. the ability to manipulate the carrier frequency of a wave front without distorting its spatial phase and intensity profile, provides the opportunity for numerous novel applications in photonic technology and fundamental science. In particular, frequency conversion of spatial modes carrying orbital angular momentum can be exploited in sub-wavelength resolution nano-optics and coherent imaging at a wavelength different from that used to illuminate an object. Moreover, coherent frequency conversion will be crucial for interfacing information stored in the high-dimensional spatial structure of single and entangled photons with various constituents of quantum networks. In this work, we demonstrate frequency conversion of structured light from the near infrared (803 nm) to the visible (527 nm). The conversion scheme is based on sum-frequency generation in a periodically poled lithium niobate crystal pumped with a 1540-nm Gaussian beam. We observe frequency-converted fields that exhibit a high degree of similarity with the input field and verify the coherence of the frequency-conversion process via mode projection measurements with a phase mask and a single-mode fiber. Our results demonstrate the suitability of exploiting the technique for applications in quantum information processing and coherent imaging.

  2. Nonlinear frequency conversion in fiber lasers

    DEFF Research Database (Denmark)

    Svane, Ask Sebastian

    The concept of nonlinear frequency conversion entails generating light at new frequencies other than those of the source light. The emission wavelength of typical fiber laser systems, relying on rare-earth dopants, are constrained within specific bands of the infrared region. By exploiting...... nonlinear processes, light from these specific wavelength bands can be used to generate light at new frequencies otherwise not obtainable by rare-earth elements. This thesis describes work covering Raman fiber lasers (RFLs) and amplifiers for nonlinear frequency down-conversion, and also the method...... of fiberoptic Cherenkov radiation (FCR) using ultrafast pulses as a means for generating tunable visible (VIS) light at higher frequencies. Two different polarization maintaining (PM) RFL cavities are studied with an emphasis on stability and spectral broadening. The cavities are formed by inscription of fiber...

  3. Experiments on quantum frequency conversion of photons

    International Nuclear Information System (INIS)

    Ramelow, S.

    2011-01-01

    Coherently converting photons between different states offers intriguing new possibilities and applications in quantum optical experiments. In this thesis three experiments on this theme are presented. The first experiment demonstrates the quantum frequency conversion of polarization entangled photons. Coherent frequency conversion of single photons offers an elegant solution for the often difficult trade-off of choosing the optimal photon wavelength, e.g. regarding optimal transmission and storage of photons in quantum memory based quantum networks. In our experiments, we verify the successful entanglement conversion by violating a Clauser-Horne-Shimony-Holt (CHSH) Bell inequality and fully characterised our close to unity fidelity entanglement transfer using quantum state- and process tomography. Our implementation is robust and flexible, making it a practical building block for future quantum technologies.The second part of the thesis introduces a deterministic scheme for photonic quantum information processing. While single photons offer many advantages for quantum information technologies, key unresolved challenges are scalable on-demand single photon sources; deterministic two-photon interactions; and near 100%-efficient detection. All these can be solved with a single versatile process - a novel four-wave mixing process that we introduce here as a special case of the more general scheme of coherent photon conversion (CPC). It can provide valuable photonic quantum processing tools, from scalably creating single- and multi-photon states to implementing deterministic entangling gates and high-efficiency detection. Notably, this would enable scalable photonic quantum computing. Using photonic crystal fibres, we experimentally demonstrate a nonlinear process suited for coherent photon conversion. We observe correlated photon-pair production at the predicted wavelengths and experimentally characterise the enhancement of the interaction strength by varying the pump

  4. Nova frequency conversion and focusing system

    International Nuclear Information System (INIS)

    Summers, M.A.; Seppala, L.G.; Williams, J.D.

    1985-01-01

    New developments in crystal array technology provided significant improvements in the mechanical design and optical performance of the Nova 2 omega/3 omega array hardware. The final Nova array configuration was tested on the Novette laser and on the first arm of Nova. Ten Nova 2 omega/3 omega crystal arrays were assembled and tested for crystal alignment and wave front distortion before installation on the Nova target chamber. Ten Nova focus lens positioners were assembled and tested last year. The positioning accuracy and repeatability of each assembly were evaluated before installation on the target chamber. A cylindrical focusing system was also developed for installation in the Nova lens positioner assembly. Finally, 10 completed frequency conversion and focusing systems were activated

  5. Integral criterion for selecting nonlinear crystals for frequency conversion

    International Nuclear Information System (INIS)

    Grechin, Sergei G

    2009-01-01

    An integral criterion, which takes into account all parameters determining the conversion efficiency, is offered for selecting nonlinear crystals for frequency conversion. The angular phase-matching width is shown to be related to the beam walk-off angle. (nonlinear optical phenomena)

  6. Advances in Very High Frequency Power Conversion

    DEFF Research Database (Denmark)

    Kovacevic, Milovan

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

  7. Efficient frequency conversion through absorptive bands of the nonlinear crystal

    OpenAIRE

    Porat, Gil; Arie, Ady

    2012-01-01

    Two simultaneous three wave mixing processes are analyzed, where an input frequency is converted to an output frequency via an intermediate stage. By employing simultaneous phase-matching and an adiabatic modulation of the nonlinear coupling strengths, the intermediate frequency is kept dark throughout the interaction, while obtaining high conversion efficiency. This feat is accomplished in a manner analogous to population transfer in atomic stimulated Raman adiabatic passage (STIRAP). Applic...

  8. Functional possibilities of nonlinear crystals for frequency conversion: uniaxial crystals

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, Yu M [Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch of the Russian Academy of Sciences, Tomsk (Russian Federation); Arapov, Yu D; Kasyanov, I V [E.I. Zababakhin All-Russian Scientific-Research Institute of Technical Physics, Russian Federal Nuclear Centre, Snezhinsk, Chelyabinsk region (Russian Federation); Grechin, S G; Nikolaev, P P [N.E. Bauman Moscow State Technical University, Moscow (Russian Federation)

    2016-01-31

    The method and results of the analysis of phase-matching and nonlinear properties for all point groups of symmetry of uniaxial crystals that determine their functional possibilities for solving various problems of nonlinear frequency conversion of laser radiation are presented. (nonlinear optical phenomena)

  9. Word and phoneme frequency of occurrence in conversational ...

    African Journals Online (AJOL)

    Frequency of occurrence of Setswana consonant phonemes in a conversational sample of 49 358 Setswana-words was deter- mined. The percentage of occurrence of each consonant in each of the three positions of words was found to be 53.9% in the initial, 41.8% in the medial and 4.1% in the final positions. In addition ...

  10. Word Inventory and Frequency Analysis of French Conversations.

    Science.gov (United States)

    Malecot, Andre

    This word frequency list was extracted from a corpus of fifty half-hour conversations recorded in Paris during the academic year 1967-68. The speakers, who did not know that they were being recorded, were all well-educated professionals and all speakers of the most standard dialect of French. The list is made up of all phonetically discrete words…

  11. Efficient broadband third harmonic frequency conversion via angular dispersion

    International Nuclear Information System (INIS)

    Pennington, D.M.; Henesian, M.A.; Milam, D.; Eimerl, D.

    1995-01-01

    In this paper we present experimental measurements and theoretical modeling of third harmonic (3ω) conversion efficiency with optical bandwidth. Third harmonic conversion efficiency drops precipitously as the input bandwidth significantly exceeds the phase matching limitations of the conversion crystals. For Type I/Type II frequency tripling, conversion efficiency be-gins to decrease for bandwidths greater than ∼60 GHz. However, conversion efficiency corresponding to monochromatic phase-matched beams can be recovered provided that the instantaneous Propagation vectors are phase matched at all times. This is achieved by imposing angular spectral dispersion (ASD) on the input beam via a diffraction grating, with a dispersion such that the phase mismatch for each frequency is zero. Experiments were performed on the Optical Sciences Laser (OSL), a 1--100 J class laser at LLNL. These experiments used a 200 GHz bandwidth source produced by a multipassed electro-optic phase modulator. The spectrum produced was composed of discrete frequency components spaced at 3 GHz intervals. Angular dispersion was incorporated by the addition of a 1200 gr/mm diffraction grating oriented at the Littrow angle, and capable of rotation about the beam direction. Experiments were performed with a pulse length of 1-ns and a 1ω input intensity of ∼ 4 GW/cm 2 for near optimal dispersion for phase matching, 5.2 μrad/GHz, with 0.1, 60, and 155 GHz bandwidth, as well as for partial dispersion compensation, 1.66 μrad/GHz, with 155 GHz and 0.1 GHz bandwidth. The direction of dispersion was varied incrementally 360 degrees about the beam diameter. The addition of the grating to the beamline reduced the narrowband conversion efficiency by approximately 10%

  12. Nonreciprocal frequency conversion in a multimode microwave optomechanical circuit

    Science.gov (United States)

    Feofanov, A. K.; Bernier, N. R.; Toth, L. D.; Koottandavida, A.; Kippenberg, T. J.

    Nonreciprocal devices such as isolators, circulators, and directional amplifiers are pivotal to quantum signal processing with superconducting circuits. In the microwave domain, commercially available nonreciprocal devices are based on ferrite materials. They are barely compatible with superconducting quantum circuits, lossy, and cannot be integrated on chip. Significant potential exists for implementing non-magnetic chip-scale nonreciprocal devices using microwave optomechanical circuits. Here we demonstrate a possibility of nonreciprocal frequency conversion in a multimode microwave optomechanical circuit using solely optomechanical interaction between modes. The conversion scheme and the results reflecting the actual progress on the experimental implementation of the scheme will be presented.

  13. Engineering quadratic nonlinear photonic crystals for frequency conversion of lasers

    Science.gov (United States)

    Chen, Baoqin; Hong, Lihong; Hu, Chenyang; Zhang, Chao; Liu, Rongjuan; Li, Zhiyuan

    2018-03-01

    Nonlinear frequency conversion offers an effective way to extend the laser wavelength range. Quadratic nonlinear photonic crystals (NPCs) are artificial materials composed of domain-inversion structures whose sign of nonlinear coefficients are modulated with desire to implement quasi-phase matching (QPM) required for nonlinear frequency conversion. These structures can offer various reciprocal lattice vectors (RLVs) to compensate the phase-mismatching during the quadratic nonlinear optical processes, including second-harmonic generation (SHG), sum-frequency generation and the cascaded third-harmonic generation (THG). The modulation pattern of the nonlinear coefficients is flexible, which can be one-dimensional or two-dimensional (2D), be periodic, quasi-periodic, aperiodic, chirped, or super-periodic. As a result, these NPCs offer very flexible QPM scheme to satisfy various nonlinear optics and laser frequency conversion problems via design of the modulation patterns and RLV spectra. In particular, we introduce the electric poling technique for fabricating QPM structures, a simple effective nonlinear coefficient model for efficiently and precisely evaluating the performance of QPM structures, the concept of super-QPM and super-periodically poled lithium niobate for finely tuning nonlinear optical interactions, the design of 2D ellipse QPM NPC structures enabling continuous tunability of SHG in a broad bandwidth by simply changing the transport direction of pump light, and chirped QPM structures that exhibit broadband RLVs and allow for simultaneous radiation of broadband SHG, THG, HHG and thus coherent white laser from a single crystal. All these technical, theoretical, and physical studies on QPM NPCs can help to gain a deeper insight on the mechanisms, approaches, and routes for flexibly controlling the interaction of lasers with various QPM NPCs for high-efficiency frequency conversion and creation of novel lasers.

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

    Energy Technology Data Exchange (ETDEWEB)

    Banks, P S

    1997-06-01

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

  15. Microwave generation and frequency conversion using intense relativistic electron beams

    International Nuclear Information System (INIS)

    Buzzi, J.M.; Doucet, H.J.; Etlicher, B.

    1977-01-01

    Some aspects of the microwave generation and frequency conversion by relativistic electron beams are studied. Using an electron synchrotron maser, the excitation of microwaves by an annular relativistic electron beam propagating through a circular wave guide immersed in a longitudinal magnetic field is analyzed. This theoretical model is somewhat more realistic than the previous one because the guiding centers are not on the wave guide axis. Microwave reflection is observed on a R.E.B. front propagating into a gas filled waveguide. The frequency conversion from the incident X-band e.m. waves and the reflected Ka band observed signal is consistent with the Doppler model for β = 0.7. This value agrees with the average beam front velocity as measured from time-of-flight using two B/sub theta/ probes. The reflection is found to occur during the current rise time. With a low impedance device (2 Ω, 400 keV) a GW X-band emission has been observed using thin anodes and a gas filled waveguide. This emission is probably due to the self-fields of the beam and could be used as a diagnostic

  16. Solid state frequency conversion technology for remote sensing

    International Nuclear Information System (INIS)

    Velsko, S.P.; Webb, M.S.; Cook, W.M.; Neuman, W.A.

    1994-07-01

    Long range remote sensing from airborne or other highly mobile platforms will require high average power tunable radiation from very compact and efficient laser systems. The solid state laser pumped optical parametric oscillator (OPO) has emerged as a leading candidate for such high average power, widely tunable sources. In contrast to laboratory systems, efficiency and simplicity can be the decisive issues which determine the practicality of a particular airborne remote sensing application. The recent advent of diode laser pumped solid state lasers has produced high average power OPO pump sources which are themselves both compact and efficient. However, parametric oscillator technology which can efficiently convert the average powers provided by these pump sources remains to be demonstrated. In addition to the average power requirement, many airborne long range sensing tasks will require a high degree of frequency multiplexing to disentangle data from multiple chemical species. A key advantage in system simplicity can be obtained, for example, if a single OPO can produce easily controlled multispectral output. In this paper the authors address several topics pertaining to the conversion efficiency, power handling, and multispectral capabilities of OPOs which they are currently investigating. In Section 2, single pulse conversion efficiency issues are addressed, while average power effects are treated in Section 3. Section 4 is concerned with multispectral performance of a single OPO. The last section contains a short summary and some concluding remarks

  17. Optimization of Quantum-state-preserving Frequency Conversion by Changing the Input Signal

    DEFF Research Database (Denmark)

    Andersen, Lasse Mejling; Reddy, D. V.; McKinstrie, C. J.

    We optimize frequency conversion based on four-wave mixing by using the input modes of the system. We find a 10-25 % higher conversion efficiency relative to a pump-shaped input signal.......We optimize frequency conversion based on four-wave mixing by using the input modes of the system. We find a 10-25 % higher conversion efficiency relative to a pump-shaped input signal....

  18. On the frequency and field linewidth conversion of ferromagnetic resonance spectra

    International Nuclear Information System (INIS)

    Wei, Yajun; Svedlindh, Peter; Liang Chin, Shin

    2015-01-01

    Both frequency swept and field swept ferromagnetic resonance measurements have been carried out for a number of different samples with negligible, moderate and significant extrinsic frequency independent linewidth contribution to analyze the correlation between the experimentally measured frequency and field linewidths. Contrary to the belief commonly held by many researchers, it is found that the frequency and field linewidth conversion relation does not hold for all cases. Instead it holds only for samples with negligible frequency independent linewidth contributions. For samples with non-negligible frequency independent linewidth contribution, the field linewidth values converted from the measured frequency linewidth are larger than the experimentally measured field linewidth. A close examination of the literature reveals that previously reported results support our findings, with successful conversions related to samples with negligible frequency independent linewidth contributions and unsuccessful conversions related to samples with significant frequency independent linewidth. The findings are important in providing guidance in ferromagnetic resonance linewidth conversions. (paper)

  19. Effects of Raman scattering in quantum state-preserving frequency conversion

    DEFF Research Database (Denmark)

    Friis, Søren Michael Mørk; Andersen, Lasse Mejling; Castaneda, Mario A. Usuga

    2014-01-01

    We analyse frequency conversion by Bragg scattering numerically including Raman scattering. The frequency configuration that performs the best under influence of Raman noise results in 95% conversion over a 3.25 THz bandwidth with a 2.5-dB noise figure.......We analyse frequency conversion by Bragg scattering numerically including Raman scattering. The frequency configuration that performs the best under influence of Raman noise results in 95% conversion over a 3.25 THz bandwidth with a 2.5-dB noise figure....

  20. Two-step frequency conversion for connecting distant quantum memories by transmission through an optical fiber

    Science.gov (United States)

    Tamura, Shuhei; Ikeda, Kohei; Okamura, Kotaro; Yoshii, Kazumichi; Hong, Feng-Lei; Horikiri, Tomoyuki; Kosaka, Hideo

    2018-06-01

    Long-distance quantum communication requires entanglement between distant quantum memories. For this purpose, photon transmission is necessary to connect the distant memories. Here, for the first time, we develop a two-step frequency conversion process (from a visible wavelength to a telecommunication wavelength and back) involving the use of independent two-frequency conversion media where the target quantum memories are nitrogen-vacancy centers in diamonds (with an emission/absorption wavelength of 637.2 nm), and experimentally characterize the performance of this process acting on light from an attenuated CW laser. A total conversion efficiency of approximately 7% is achieved. The noise generated in the frequency conversion processes is measured, and the signal-to-noise ratio is estimated for a single photon signal emitted by a nitrogen-vacancy (NV) center. The developed frequency conversion system has future applications via transmission through a long optical fiber channel at a telecommunication wavelength for a quantum repeater network.

  1. Frequency conversion through spontaneous degenerate four wave mixing in large mode area hybrid photonic crystal fibers

    DEFF Research Database (Denmark)

    Petersen, Sidsel Rübner; Alkeskjold, Thomas Tanggaard; Olausson, Christina Bjarnal Thulin

    2014-01-01

    Frequency conversion through spontaneous degenerate four wave mixing (FWM) is investigated in large mode area hybrid photonic crystal fibers. Different FWM processes are observed, phasematching between fiber modes of orthogonal polarization, intermodal phasematching across bandgaps, and intramodal...

  2. Photon - axion conversions in a periodic electromagnetic field with axion frequency

    International Nuclear Information System (INIS)

    Dang Van Soa

    1998-09-01

    The conversion of photons into axions in a periodic external electromagnetic field with axion frequency is considered in detail by Feynman methods. The differential cross sections are given. It is shown that there is a resonant conversion for the considered process. (author)

  3. Quantum Frequency Conversion by Four-wave Mixing Using Bragg Scattering

    DEFF Research Database (Denmark)

    Andersen, Lasse Mejling; Rottwitt, Karsten; McKinstrie, C. J.

    2012-01-01

    Two theoretical models for frequency conversion (FC) using nondegenerate four-wave mixing are compared, and their range of validity are discussed. Quantum-statepreserving FC allows for arbitrary reshaping of states for an appropriate pump selection.......Two theoretical models for frequency conversion (FC) using nondegenerate four-wave mixing are compared, and their range of validity are discussed. Quantum-statepreserving FC allows for arbitrary reshaping of states for an appropriate pump selection....

  4. Reconfigurable optical-to-optical frequency conversion method and apparatus

    Science.gov (United States)

    Zortman, William A.; Lentine, Anthony L.

    2017-04-18

    A photonic device is provided for impressing a modulation pattern on an optical carrier. The device includes a unit in which a photodetector and an optical microresonator are monolithically integrated. The device further includes an optical waveguide evanescently coupled to the optical microresonator and having at least an upstream portion configured to carry at least one optical carrier toward the microresonator. The optical microresonator is tunable so as to resonate with the optical carrier frequency. The optical microresonator and the photodetector are mutually coupled such that in operation, charge carriers photogenerated in the photodetector are injected into the microresonator, where the photocurrent changes the resonant conditions. In some embodiments the device is operable as an optical-to-optical frequency converter. In other embodiments the device is operable as an oscillator.

  5. An estimate of spherical impactor energy transfer for mechanical frequency up-conversion energy harvester

    Directory of Open Access Journals (Sweden)

    L. R. Corr

    2016-08-01

    Full Text Available Vibration energy harvesters, which use the impact mechanical frequency up-conversion technique, utilize an impactor, which gains kinetic energy from low frequency ambient environmental vibrations, to excite high frequency systems that efficiently convert mechanical energy to electrical energy. To take full advantage of the impact mechanical frequency up-conversion technique, it is prudent to understand the energy transfer from the low frequency excitations, to the impactor, and finally to the high frequency systems. In this work, the energy transfer from a spherical impactor to a multi degree of freedom spring / mass system, due to Hertzian impact, is investigated to gain insight on how best to design impact mechanical frequency up-conversion energy harvesters. Through this academic work, it is shown that the properties of the contact (or impact area, i.e., radius of curvature and material properties, only play a minor role in energy transfer and that the equivalent mass of the target system (i.e., the spring / mass system dictates the total amount of energy transferred during the impact. The novel approach of utilizing the well-known Hertzian impact methodology to gain an understanding of impact mechanical frequency up-conversion energy harvesters has made it clear that the impactor and the high frequency energy generating systems must be designed together as one system to ensure maximum energy transfer, leading to efficient ambient vibration energy harvesters.

  6. Quantum frequency conversion with ultra-broadband tuning in a Raman memory

    Science.gov (United States)

    Bustard, Philip J.; England, Duncan G.; Heshami, Khabat; Kupchak, Connor; Sussman, Benjamin J.

    2017-05-01

    Quantum frequency conversion is a powerful tool for the construction of hybrid quantum photonic technologies. Raman quantum memories are a promising method of conversion due to their broad bandwidths. Here we demonstrate frequency conversion of THz-bandwidth, fs-duration photons at the single-photon level using a Raman quantum memory based on the rotational levels of hydrogen molecules. We shift photons from 765 nm to wavelengths spanning from 673 to 590 nm—an absolute shift of up to 116 THz. We measure total conversion efficiencies of up to 10% and a maximum signal-to-noise ratio of 4.0(1):1, giving an expected conditional fidelity of 0.75, which exceeds the classical threshold of 2/3. Thermal noise could be eliminated by cooling with liquid nitrogen, giving noiseless conversion with wide tunability in the visible and infrared.

  7. Causes and frequency of conversion during laparoscopic cholecystectomy in own material

    Directory of Open Access Journals (Sweden)

    Bogdan Kopeć

    2010-12-01

    Full Text Available Aim: To assess the causes, frequency and time of conversion from laparoscopic to classic cholecystectomy in our ownmaterial.Material and methods: 547 patients were qualified for laparoscopic cholecystectomy in the Surgery Department ofthe Mogilno District Hospital in Strzelno during the period of 1999-2005; 515 minimally invasive operations were performedand 32 patients required conversion.Results: The 547 patients were qualified for the laparoscopic operation; of these 148 were operated on as emergencycases and 399 as elective cases. There were 20 conversions among emergency patients and 12 conversions amongelective patients. On average the decision to convert was made in the 35th min of the operation. The shortest time toconversion was 15 min and the longest was 90 min. Five conversions were performed in the 25th and 35th minand 4 in the 20th, 30th, and 40th mine. Most frequently conversions occurred between the 20th and 40th min of theprocedure. Intentional conversions were performed in 27 patients. Adhesions and clumps around the gallbladder werethe cause of conversion in 10 patients and that was the most frequent reason for the operative modality change. Thenext cause of conversion was changes observed in the course of acute cholecystitis in the form of gallbladder empyemaor cholecystocele (9 patients. Small, fibrotic gallbladder, immersed in the liver, was the reason for conversion ina further 4 patients. In 4 cases the conversion was caused by difficulties in the identification of anatomical structures.Four cases of forced conversions and 1 anticipated conversion were found in the analysed material.Conclusions: A change of operative modality during laparoscopic cholecystectomy was made on average in 5.85% ofoperations. The average time before the conversion was 35 min. Emergency patients required a change of operativemodality 4 times more often. The most frequent were intentional conversions (84%, caused by pericystic adhesionsand by

  8. [High gene conversion frequency between genes encoding 2-deoxyglucose-6-phosphate phosphatase in 3 Saccharomyces species].

    Science.gov (United States)

    Piscopo, Sara-Pier; Drouin, Guy

    2014-05-01

    Gene conversions are nonreciprocal sequence exchanges between genes. They are relatively common in Saccharomyces cerevisiae, but few studies have investigated the evolutionary fate of gene conversions or their functional impacts. Here, we analyze the evolution and impact of gene conversions between the two genes encoding 2-deoxyglucose-6-phosphate phosphatase in S. cerevisiae, Saccharomyces paradoxus and Saccharomyces mikatae. Our results demonstrate that the last half of these genes are subject to gene conversions among these three species. The greater similarity and the greater percentage of GC nucleotides in the converted regions, as well as the absence of long regions of adjacent common converted sites, suggest that these gene conversions are frequent and occur independently in all three species. The high frequency of these conversions probably result from the fact that they have little impact on the protein sequences encoded by these genes.

  9. Low-frequency wideband vibration energy harvesting by using frequency up-conversion and quin-stable nonlinearity

    Science.gov (United States)

    Wang, Chen; Zhang, Qichang; Wang, Wei

    2017-07-01

    This work presents models and experiments of an impact-driven and frequency up-converted wideband piezoelectric-based vibration energy harvester with a quintuple-well potential induced by the combination effect of magnetic nonlinearity and mechanical piecewise-linearity. Analysis shows that the interwell motions during coupled vibration period enable to increase electrical power output in comparison to conventional frequency up-conversion technology. Besides, the quintuple-well potential with shallower potential wells could extend the harvester's operating bandwidth to lower frequencies. Experiments demonstrate our proposed approach can dramatically boost the measured power of the energy harvester as much as 35 times while its lower cut-off frequency is two times lower than that of a conventional counterpart. These results reveal our proposed approach shows promise for powering portable wireless smart devices from low-intensity, low-frequency vibration sources.

  10. A frequency conversion mode for dispenser in the service station based on flow rate signal

    International Nuclear Information System (INIS)

    Liu, Y J; Tang, D; Huang, J B; Liu, J; Jia, P F

    2012-01-01

    Dispenser is an integrated fuel transport and measurement system at the service station. In this paper, we developed a frequency conversion mode for the dispenser, based on the flow rate signal which is obtained from the converter measuring flow capacity. After introducing the frequency conversion mode to dispenser, we obtained that pump rotates at a high speed when fuelled with high flow rate, and it rotates at a low speed when fuelled with low flow rate. This makes the fuel dispenser more energy-efficient and controllable. We also did some valve optimizations on the dispenser and developed a new control mode for preset refuelling based on the frequency conversion mode, Experimental and theoretical studies have shown that the new dispenser not only can meet the national standards, but also performs better than the ordinary one especially in preset refuelling.

  11. Extended exergy concept to facilitate designing and optimization of frequency-dependent direct energy conversion systems

    International Nuclear Information System (INIS)

    Wijewardane, S.; Goswami, Yogi

    2014-01-01

    Highlights: • Proved exergy method is not adequate to optimize frequency-dependent energy conversion. • Exergy concept is modified to facilitate the thermoeconomic optimization of photocell. • The exergy of arbitrary radiation is used for a practical purpose. • The utility of the concept is illustrated using pragmatic examples. - Abstract: Providing the radiation within the acceptable (responsive) frequency range(s) is a common method to increase the efficiency of the frequency-dependent energy conversion systems, such as photovoltaic and nano-scale rectenna. Appropriately designed auxiliary items such as spectrally selective thermal emitters, optical filters, and lenses are used for this purpose. However any energy conversion method that utilizes auxiliary components to increase the efficiency of a system has to justify the potential cost incurred by those auxiliary components through the economic gain emerging from the increased system efficiency. Therefore much effort should be devoted to design innovative systems, effectively integrating the auxiliary items and to optimize the system with economic considerations. Exergy is the widely used method to design and optimize conventional energy conversion systems. Although the exergy concept is used to analyze photovoltaic systems, it has not been used effectively to design and optimize such systems. In this manuscript, we present a modified exergy method in order to effectively design and economically optimize frequency-dependent energy conversion systems. Also, we illustrate the utility of this concept using examples of thermophotovoltaic, Photovoltaic/Thermal and concentrated solar photovoltaic

  12. Temporal mode selectivity by frequency conversion in second-order nonlinear optical waveguides

    DEFF Research Database (Denmark)

    Reddy, D. V.; Raymer, M. G.; McKinstrie, C. J.

    2013-01-01

    in a transparent optical network using temporally orthogonal waveforms to encode different channels. We model the process using coupled-mode equations appropriate for wave mixing in a uniform second-order nonlinear optical medium pumped by a strong laser pulse. We find Green functions describing the process...... in this optimal regime. We also find an operating regime in which high-efficiency frequency conversion without temporal-shape selectivity can be achieved while preserving the shapes of a wide class of input pulses. The results are applicable to both classical and quantum frequency conversion....

  13. A chip-scale, telecommunications-band frequency conversion interface for quantum emitters.

    Science.gov (United States)

    Agha, Imad; Ates, Serkan; Davanço, Marcelo; Srinivasan, Kartik

    2013-09-09

    We describe a chip-scale, telecommunications-band frequency conversion interface designed for low-noise operation at wavelengths desirable for common single photon emitters. Four-wave-mixing Bragg scattering in silicon nitride waveguides is used to demonstrate frequency upconversion and downconversion between the 980 nm and 1550 nm wavelength regions, with signal-to-background levels > 10 and conversion efficiency of ≈ -60 dB at low continuous wave input pump powers ( 25 % in existing geometries. Finally, we present waveguide designs that can be used to connect shorter wavelength (637 nm to 852 nm) quantum emitters with 1550 nm.

  14. Frequency-agile THz-wave generation and detection system using nonlinear frequency conversion at room temperature.

    Science.gov (United States)

    Guo, Ruixiang; Ikar'i, Tomofumi; Zhang, Jun; Minamide, Hiroaki; Ito, Hiromasa

    2010-08-02

    A surface-emitting THz parametric oscillator is set up to generate a narrow-linewidth, nanosecond pulsed THz-wave radiation. The THz-wave radiation is coherently detected using the frequency up-conversion in MgO: LiNbO(3) crystal. Fast frequency tuning and automatic achromatic THz-wave detection are achieved through a special optical design, including a variable-angle mirror and 1:1 telescope devices in the pump and THz-wave beams. We demonstrate a frequency-agile THz-wave parametric generation and THz-wave coherent detection system. This system can be used as a frequency-domain THz-wave spectrometer operated at room-temperature, and there are a high possible to develop into a real-time two-dimensional THz spectral imaging system.

  15. 60 GHz Antenna Diagnostics from Planar Near Field Antenna Measurement Without External Frequency Conversion

    DEFF Research Database (Denmark)

    Popa, Paula Irina; Pivnenko, Sergey; Breinbjerg, Olav

    2015-01-01

    ,J.M. Nielsen, O. Breinbjerg, 60 GHz Antenna Measurement Setup using a VNA without External Frequency Conversion,36th Annual Symposium of the Antenna Measurement Technique Association ,October 12-17,Tucson, Arizona, 2014]. In this work we extend the validation of this 60 GHz planar near-field (PNF) set...

  16. Optimized Wavelength-Tuned Nonlinear Frequency Conversion Using a Liquid Crystal Clad Waveguide

    Science.gov (United States)

    Stephen, Mark A. (Inventor)

    2018-01-01

    An optimized wavelength-tuned nonlinear frequency conversion process using a liquid crystal clad waveguide. The process includes implanting ions on a top surface of a lithium niobate crystal to form an ion implanted lithium niobate layer. The process also includes utilizing a tunable refractive index of a liquid crystal to rapidly change an effective index of the lithium niobate crystal.

  17. Controllable frequency entanglement via auto-phase-matched spontaneous parametric down-conversion

    International Nuclear Information System (INIS)

    Sergienko, A.V.; Walton, Z.D.; Booth, M.C.; Saleh, B.E.A.; Teich, M.C.

    2005-01-01

    Full text: A new method for generating entangled photons with controllable frequency correlation via spontaneous parametric down-conversion (SPDC) is presented. The method entails initiating counter-propagating SPDC in a single-mode nonlinear waveguide by pumping with a pulsed beam perpendicular to the waveguide. In a typical spontaneous parametric down-conversion (SPDC) experiment, a photon from a monochromatic pump beam decays into two photons (often referred to as signal and idler) via interaction with a nonlinear optical crystal. While the signal and idler may be broadband individually, conservation of energy requires that the sum of their respective frequencies equals the single frequency of the monochromatic pump. This engenders frequency anti-correlation in the down-converted beams. Two developments in quantum information theory have renewed interest in the generalized states of frequency correlation. First, quantum information processes requiring the synchronized creation of multiple photon pairs have been devised, such as quantum teleportation. The requisite temporal control can be achieved by pumping the crystal with a brief pulse. The availability of pump photons of differing frequencies relaxes the strict frequency anti-correlation in the down-converted beams. Second, applications such as entanglement-enhanced clock synchronization and one-way auto-compensating quantum cryptography have been introduced that specifically require frequency correlation, as opposed to the usual frequency anticorrelation. Our method for obtaining controllable frequency entanglement entails initiating type-I SPDC (signal and idler identically polarized) in a single-mode nonlinear waveguide by pumping with a pulsed beam perpendicular to the waveguide. The down-converted photons emerge from opposite ends of the waveguide with a joint spectrum that can be varied from frequency anti-correlated to frequency correlated by adjusting the temporal and spatial characteristics of the

  18. Broadband electromagnetic power harvester from vibrations via frequency conversion by impact oscillations

    International Nuclear Information System (INIS)

    Yuksek, N. S.; Almasri, M.; Feng, Z. C.

    2014-01-01

    In this paper, we propose an electromagnetic power harvester that uses a transformative multi-impact approach to achieve a wide bandwidth response from low frequency vibration sources through frequency-up conversion. The device consists of a pick-up coil, fixed at the free edge of a cantilever beam with high resonant frequency, and two cantilever beams with low excitation frequencies, each with an impact mass attached at its free edge. One of the two cantilevers is designed to resonate at 25 Hz, while the other resonates at 50 Hz within the range of ambient vibration frequency. When the device is subjected to a low frequency vibration, the two low-frequency cantilevers responded by vibrating at low frequencies, and thus their thick metallic masses made impacts with the high resonance frequency cantilever repeatedly at two locations. This has caused it along with the pick-up coil to oscillate, relative to the permanent magnet, with decaying amplitude at its resonance frequency, and results in a wide bandwidth response from 10 to 63 Hz at 2 g. A wide bandwidth response between 10–51 Hz and 10–58 Hz at acceleration values of 0.5 g and 2 g, respectively, were achieved by adjusting the impact cantilever frequencies closer to each other (25 Hz and 45 Hz). A maximum output power of 85 μW was achieved at 5 g at 30 Hz across a load resistor, 2.68 Ω.

  19. General solution of undersampling frequency conversion and its optimization for parallel photodisplacement imaging.

    Science.gov (United States)

    Nakata, Toshihiko; Ninomiya, Takanori

    2006-10-10

    A general solution of undersampling frequency conversion and its optimization for parallel photodisplacement imaging is presented. Phase-modulated heterodyne interference light generated by a linear region of periodic displacement is captured by a charge-coupled device image sensor, in which the interference light is sampled at a sampling rate lower than the Nyquist frequency. The frequencies of the components of the light, such as the sideband and carrier (which include photodisplacement and topography information, respectively), are downconverted and sampled simultaneously based on the integration and sampling effects of the sensor. A general solution of frequency and amplitude in this downconversion is derived by Fourier analysis of the sampling procedure. The optimal frequency condition for the heterodyne beat signal, modulation signal, and sensor gate pulse is derived such that undesirable components are eliminated and each information component is converted into an orthogonal function, allowing each to be discretely reproduced from the Fourier coefficients. The optimal frequency parameters that maximize the sideband-to-carrier amplitude ratio are determined, theoretically demonstrating its high selectivity over 80 dB. Preliminary experiments demonstrate that this technique is capable of simultaneous imaging of reflectivity, topography, and photodisplacement for the detection of subsurface lattice defects at a speed corresponding to an acquisition time of only 0.26 s per 256 x 256 pixel area.

  20. A small-form-factor piezoelectric vibration energy harvester using a resonant frequency-down conversion

    Directory of Open Access Journals (Sweden)

    Kyung Ho Sun

    2014-10-01

    Full Text Available While environmental vibrations are usually in the range of a few hundred Hertz, small-form-factor piezoelectric vibration energy harvesters will have higher resonant frequencies due to the structural size effect. To address this issue, we propose a resonant frequency-down conversion based on the theory of dynamic vibration absorber for the design of a small-form-factor piezoelectric vibration energy harvester. The proposed energy harvester consists of two frequency-tuned elastic components for lowering the first resonant frequency of an integrated system but is so configured that an energy harvesting beam component is inverted with respect to the other supporting beam component for a small form factor. Furthermore, in order to change the unwanted modal characteristic of small separation of resonant frequencies, as is the case with an inverted configuration, a proof mass on the supporting beam component is slightly shifted toward a second proof mass on the tip of the energy harvesting beam component. The proposed small-form-factor design capability was experimentally verified using a fabricated prototype with an occupation volume of 20 × 39 × 6.9 mm3, which was designed for a target frequency of as low as 100 Hz.

  1. A small-form-factor piezoelectric vibration energy harvester using a resonant frequency-down conversion

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Kyung Ho; Kim, Young-Cheol [Department of System Dynamics, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Yuseong-Gu, Daejeon 305-343 (Korea, Republic of); Kim, Jae Eun, E-mail: jekim@cu.ac.kr [School of Mechanical and Automotive Engineering, Catholic University of Daegu, 13-13 Hayang-Ro, Hayang-Eup, Gyeongsan-Si, Gyeongsangbuk-Do 712-702 (Korea, Republic of)

    2014-10-15

    While environmental vibrations are usually in the range of a few hundred Hertz, small-form-factor piezoelectric vibration energy harvesters will have higher resonant frequencies due to the structural size effect. To address this issue, we propose a resonant frequency-down conversion based on the theory of dynamic vibration absorber for the design of a small-form-factor piezoelectric vibration energy harvester. The proposed energy harvester consists of two frequency-tuned elastic components for lowering the first resonant frequency of an integrated system but is so configured that an energy harvesting beam component is inverted with respect to the other supporting beam component for a small form factor. Furthermore, in order to change the unwanted modal characteristic of small separation of resonant frequencies, as is the case with an inverted configuration, a proof mass on the supporting beam component is slightly shifted toward a second proof mass on the tip of the energy harvesting beam component. The proposed small-form-factor design capability was experimentally verified using a fabricated prototype with an occupation volume of 20 × 39 × 6.9 mm{sup 3}, which was designed for a target frequency of as low as 100 Hz.

  2. Recent laser physics results on power balance and frequency conversion with the Phebus laser system

    International Nuclear Information System (INIS)

    Thiell, G.; Paye, J.; Graillot, H.; Mathieu, F.; Boscheron, A.; Reynier, F.; Estraillier, P.; Bruneau, J.L.

    1995-01-01

    The Phebus laser system has been mainly devoted to plasma physics experiments such as implosion and hydrodynamical instability studies since it was completed in 1985. But during the last two years, the three Phebus beamlines (2 main beams and a backlighter beam) are also utilized to perform some laser physics studies in view of the Megajoule laser project. The goal of the laser physics experiments conducted at the Phebus facility in 1994--1995 is to validate some design issues of the Megajoule Laser project concerning namely power balance and frequency conversion

  3. Time Reversal of Arbitrary Photonic Temporal Modes via Nonlinear Optical Frequency Conversion

    OpenAIRE

    Raymer, Michael G; Reddy, Dileep V; van Enk, Steven J; McKinstrie, Colin J

    2017-01-01

    Single-photon wave packets can carry quantum information between nodes of a quantum network. An important general operation in photon-based quantum information systems is blind reversal of a photon's temporal wave-packet envelope, that is, the ability to reverse an envelope without knowing the temporal state of the photon. We present an all-optical means for doing so, using nonlinear-optical frequency conversion driven by a short pump pulse. This scheme allows for quantum operations such as a...

  4. Conversion of Dielectric Data from the Time Domain to the Frequency Domain

    Directory of Open Access Journals (Sweden)

    Vladimir Durman

    2005-01-01

    Full Text Available Polarisation and conduction processes in dielectric systems can be identified by the time domain or the frequency domain measurements. If the systems is a linear one, the results of the time domain measurements can be transformed into the frequency domain, and vice versa. Commonly, the time domain data of the absorption conductivity are transformed into the frequency domain data of the dielectric susceptibility. In practice, the relaxation are mainly evaluated by the frequency domain data. In the time domain, the absorption current measurement were prefered up to now. Recent methods are based on the recovery voltage measurements. In this paper a new method of the recovery data conversion from the time the frequency domain is proposed. The method is based on the analysis of the recovery voltage transient based on the Maxwell equation for the current density in a dielectric. Unlike the previous published solutions, the Laplace fransform was used to derive a formula suitable for practical purposes. the proposed procedure allows also calculating of the insulation resistance and separating the polarisation and conduction losses.

  5. A Novel Tunable Multi-Frequency Hybrid Vibration Energy Harvester Using Piezoelectric and Electromagnetic Conversion Mechanisms

    Directory of Open Access Journals (Sweden)

    Zhenlong Xu

    2016-01-01

    Full Text Available This paper presents a novel tunable multi-frequency hybrid energy harvester (HEH. It consists of a piezoelectric energy harvester (PEH and an electromagnetic energy harvester (EMEH, which are coupled with magnetic interaction. An electromechanical coupling model was developed and numerically simulated. The effects of magnetic force, mass ratio, stiffness ratio, and mechanical damping ratios on the output power were investigated. A prototype was fabricated and characterized by experiments. The measured first peak power increases by 16.7% and 833.3% compared with that of the multi-frequency EMEH and the multi-frequency PEH, respectively. It is 2.36 times more than the combined output power of the linear PEH and linear EMEH at 22.6 Hz. The half-power bandwidth for the first peak power is also broadened. Numerical results agree well with the experimental data. It is indicated that magnetic interaction can tune the resonant frequencies. Both magnetic coupling configuration and hybrid conversion mechanism contribute to enhancing the output power and widening the operation bandwidth. The magnitude and direction of magnetic force have significant effects on the performance of the HEH. This proposed HEH is an effective approach to improve the generating performance of the micro-scale energy harvesting devices in low-frequency range.

  6. Spike train generation and current-to-frequency conversion in silicon diodes

    Science.gov (United States)

    Coon, D. D.; Perera, A. G. U.

    1989-01-01

    A device physics model is developed to analyze spontaneous neuron-like spike train generation in current driven silicon p(+)-n-n(+) devices in cryogenic environments. The model is shown to explain the very high dynamic range (0 to the 7th) current-to-frequency conversion and experimental features of the spike train frequency as a function of input current. The devices are interesting components for implementation of parallel asynchronous processing adjacent to cryogenically cooled focal planes because of their extremely low current and power requirements, their electronic simplicity, and their pulse coding capability, and could be used to form the hardware basis for neural networks which employ biologically plausible means of information coding.

  7. Low Noise Quantum Frequency Conversion from Rb Wavelengths to Telecom O-band

    Science.gov (United States)

    Li, Xiao; Solmeyer, Neal; Stack, Daniel; Quraishi, Qudsia

    2015-05-01

    Ideal quantum repeaters would be composed of long-lived quantum memories entangled with flying qubits. They are becoming essential elements to achieve quantum communication over long distances in a quantum network. However, quantum memories based on neutral atoms operate at wavelengths in the near infrared, unsuitable for long distance communication. The ability to coherently convert photons entangled with quantum memories into telecom wavelengths reduces the transmission loss in optical fibers and therefore dramatically improves the range of a quantum repeater. Furthermore, quantum frequency conversion (QFC) can enable entanglement and communication between different types of quantum memories, thus creating a versatile hybrid quantum network. A recent experiment has shown the conversion of heralded photons from Rb-based memories to the telecom C-band. We implement a setup using a nonlinear PPLN waveguide for the QFC into a wavelength region where the noise-floor would be limited by dark counts rather than pump photons. Our approach uses a pump laser at a much longer wavelength. It has the advantage that the strong pump itself and the broad background in the PPLN can be nearly completely filtered from the converted signal. Such low background level allows for the conversion to be done on the heralding photon, which enables the generated entanglement to be used in a scalable way to multiple nodes remotely situated and to subsequent protocols.

  8. Nitrogen conversion during rapid pyrolysis of coal and petroleum coke in a high-frequency furnace

    International Nuclear Information System (INIS)

    Yuan, Shuai; Zhou, Zhi-jie; Li, Jun; Wang, Fu-chen

    2012-01-01

    Highlights: ► Use a high-frequency furnace to study N-conversion during rapid pyrolysis of coal. ► Scarcely reported N-conversion during rapid pyrolysis of petroleum coke was studied. ► Both of NH 3 and HCN can be formed directly from coal during rapid pyrolysis. ► NH 3 –N yields are higher than HCN–N yields in most conditions. ► NH 3 –N yields of petroleum coke increase with temperature and no HCN detected. -- Abstract: Rapid pyrolysis of three typical Chinese coals, lignite from Inner Mongolia, bituminous from Shenfu coalfield, and anthracite from Guizhou, as well as a petroleum coke were carried out in a drop-style high-frequency furnace. The reactor was induction coil heated and had a very small high-temperature zone, which could restrain secondary conversions of nitrogen products. The effects of temperature and coal rank on conversions of fuel-N to primary nitrogen products (char-N, HCN–N, NH 3 –N and (tar + N 2 )–N) have been investigated. The results showed that, the increasing temperature reduced the yields of char-N and promoted the conversion of fuel-N to N 2 . Char-N yields increased, while volatile-N yields decreased as the coal rank increased. In most of the conditions, NH 3 –N yields were higher than HCN–N yields during rapid pyrolysis of coal. In the case of petroleum coke, NH 3 –N yields increased gradually with the increasing temperature, but no HCN was detected. We argue that NH 3 –N can be formed directly through the primary pyrolysis without secondary reactions. Although volatile-N yields of lignite were higher than those of bituminous, yields of (HCN + NH 3 )–N in volatile-N of lignite were lower than those of bituminous. While the (HCN + NH 3 )–N yields of anthracite were the lowest of the three coals. Both of the (HCN + NH 3 )–N yields and (HCN + NH 3 )–N proportions in volatile-N of petroleum coke were lower than the three coals.

  9. Microwave-to-optical frequency conversion using a cesium atom coupled to a superconducting resonator

    Science.gov (United States)

    Gard, Bryan T.; Jacobs, Kurt; McDermott, R.; Saffman, M.

    2017-07-01

    A candidate for converting quantum information from microwave to optical frequencies is the use of a single atom that interacts with a superconducting microwave resonator on one hand and an optical cavity on the other. The large electric dipole moments and microwave transition frequencies possessed by Rydberg states allow them to couple strongly to superconducting devices. Lasers can then be used to connect a Rydberg transition to an optical transition to realize the conversion. Since the fundamental source of noise in this process is spontaneous emission from the atomic levels, the resulting control problem involves choosing the pulse shapes of the driving lasers so as to maximize the transfer rate while minimizing this loss. Here we consider the concrete example of a cesium atom, along with two specific choices for the levels to be used in the conversion cycle. Under the assumption that spontaneous emission is the only significant source of errors, we use numerical optimization to determine the likely rates for reliable quantum communication that could be achieved with this device. These rates are on the order of a few megaqubits per second.

  10. Hybrid Intelligent Control Method to Improve the Frequency Support Capability of Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Shin Young Heo

    2015-10-01

    Full Text Available This paper presents a hybrid intelligent control method that enables frequency support control for permanent magnet synchronous generators (PMSGs wind turbines. The proposed method for a wind energy conversion system (WECS is designed to have PMSG modeling and full-scale back-to-back insulated-gate bipolar transistor (IGBT converters comprising the machine and grid side. The controller of the machine side converter (MSC and the grid side converter (GSC are designed to achieve maximum power point tracking (MPPT based on an improved hill climb searching (IHCS control algorithm and de-loaded (DL operation to obtain a power margin. Along with this comprehensive control of maximum power tracking mode based on the IHCS, a method for kinetic energy (KE discharge control of the supporting primary frequency control scheme with DL operation is developed to regulate the short-term frequency response and maintain reliable operation of the power system. The effectiveness of the hybrid intelligent control method is verified by a numerical simulation in PSCAD/EMTDC. Simulation results show that the proposed approach can improve the frequency regulation capability in the power system.

  11. The effect of temperature and loading frequency on the converse piezoelectric response of soft PZT ceramics

    Science.gov (United States)

    Dapeng, Zhu; Qinghui, Jiang; Yingwei, Li

    2017-12-01

    The converse piezoelectric coefficient d 33 of soft PZT ceramics was measured from 20 °C to 150 °C under different loading frequency. Results showed that in the tested temperature range, the evolution of d 33 obeys the Rayleigh-law behavior. The influence of temperature on d 33 is a little complicated. For instance, the maximum d 33 was observed at 150 °C when the applied electric field E was at 0.1 kV mm-1. When E increased to 0.3 kV mm-1 and 0.4 kV mm-1, the maximum d 33 was observed at 120 °C and 100 °C, respectively. Such behaviors are rationalized by the evolution of the Rayleigh parameters d init and α. For d init, it increases as temperature increases. While for α, it first increases and then decreases with the increase of temperature due to the evolution of the spontaneous strain and the volume of the switched domains. In the tested loading frequency, d 33 decreased linearly with the logarithm of the frequency of electric field. With the increase of temperature, the influence of frequency on d 33 gradually weakened, implying that at high temperature, the motion of domain walls became active and the pinning effect of defects nearly disappeared.

  12. Inherited differences in crossing over and gene conversion frequencies between wild strains of Sordaria fimicola from "Evolution Canyon".

    Science.gov (United States)

    Saleem, M; Lamb, B C; Nevo, E

    2001-12-01

    Recombination generates new combinations of existing genetic variation and therefore may be important in adaptation and evolution. We investigated whether there was natural genetic variation for recombination frequencies and whether any such variation was environment related and possibly adaptive. Crossing over and gene conversion frequencies often differed significantly in a consistent direction between wild strains of the fungus Sordaria fimicola isolated from a harsher or a milder microscale environment in "Evolution Canyon," Israel. First- and second-generation descendants from selfing the original strains from the harsher, more variable, south-facing slope had higher frequencies of crossing over in locus-centromere intervals and of gene conversion than those from the lusher north-facing slopes. There were some significant differences between strains within slopes, but these were less marked than between slopes. Such inherited variation could provide a basis for natural selection for optimum recombination frequencies in each environment. There were no significant differences in meiotic hybrid DNA correction frequencies between strains from the different slopes. The conversion analysis was made using only conversions to wild type, because estimations of conversion to mutant were affected by a high frequency of spontaneous mutation. There was no polarized segregation of chromosomes at meiosis I or of chromatids at meiosis II.

  13. Potential for efficient frequency conversion at high average power using solid state nonlinear optical materials

    International Nuclear Information System (INIS)

    Eimerl, D.

    1985-01-01

    High-average-power frequency conversion using solid state nonlinear materials is discussed. Recent laboratory experience and new developments in design concepts show that current technology, a few tens of watts, may be extended by several orders of magnitude. For example, using KD*P, efficient doubling (>70%) of Nd:YAG at average powers approaching 100 KW is possible; and for doubling to the blue or ultraviolet regions, the average power may approach 1 MW. Configurations using segmented apertures permit essentially unlimited scaling of average power. High average power is achieved by configuring the nonlinear material as a set of thin plates with a large ratio of surface area to volume and by cooling the exposed surfaces with a flowing gas. The design and material fabrication of such a harmonic generator are well within current technology

  14. Entanglement and nonclassicality in four-mode Gaussian states generated via parametric down-conversion and frequency up-conversion

    Czech Academy of Sciences Publication Activity Database

    Arkhipov, Ie.I.; Peřina Jr., J.; Haderka, Ondřej; Allevi, A.; Bondani, M.

    2016-01-01

    Roč. 6, Sep (2016), 1-12, č. článku 33802. ISSN 2045-2322 Institutional support: RVO:68378271 Keywords : four-mode Gaussian states * parametric down-conversion Subject RIV: BH - Optics, Masers, Lasers Impact factor: 4.259, year: 2016

  15. A Voltage and Frequency Control Strategy for Stand-Alone Full Converter Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Andrés Peña Asensio

    2018-02-01

    Full Text Available This paper addresses the design and analysis of a voltage and frequency control (VFC strategy for full converter (FC-based wind energy conversion systems (WECSs and its applicability for the supply of an isolated load. When supplying an isolated load, the role of the back-to-back converters in the FC must change with respect to a grid-connected application. Voltage and frequency are established by the FC line side converter (LSC, while the generator side converter (GSC is responsible for maintaining constant voltage in the DC link. Thus, the roles of the converters in the WECS are inverted. Under such control strategies, the LSC will automatically supply the load power and hence, in order to maintain a stable operation of the WECS, the wind turbine (WT power must also be controlled in a load-following strategy. The proposed VFC is fully modelled and a stability analysis is performed. Then, the operation of the WECS under the proposed VFC is simulated and tested on a real-time test bench, demonstrating the performance of the VFC for the isolated operation of the WECS.

  16. High-fidelity frequency down-conversion of visible entangled photon pairs with superconducting single-photon detectors

    International Nuclear Information System (INIS)

    Ikuta, Rikizo; Kato, Hiroshi; Kusaka, Yoshiaki; Yamamoto, Takashi; Imoto, Nobuyuki; Miki, Shigehito; Yamashita, Taro; Terai, Hirotaka; Wang, Zhen; Fujiwara, Mikio; Sasaki, Masahide; Koashi, Masato

    2014-01-01

    We experimentally demonstrate a high-fidelity visible-to-telecommunicationwavelength conversion of a photon by using a solid-state-based difference frequency generation. In the experiment, one half of a pico-second visible entangled photon pair at 780 nm is converted to a 1522-nm photon. Using superconducting single-photon detectors with low dark count rates and small timing jitters, we observed a fidelity of 0.93±0.04 after the wavelength conversion

  17. Mode-Selective Photon Counting Via Quantum Frequency Conversion Using Spectrally-Engineered Pump Pulses

    Science.gov (United States)

    Manurkar, Paritosh

    Most of the existing protocols for quantum communication operate in a two-dimensional Hilbert space where their manipulation and measurement have been routinely investigated. Moving to higher-dimensional Hilbert spaces is desirable because of advantages in terms of longer distance communication capabilities, higher channel capacity and better information security. We can exploit the spatio-temporal degrees of freedom for the quantum optical signals to provide the higher-dimensional signals. But this necessitates the need for measurement and manipulation of multidimensional quantum states. To that end, there have been significant theoretical studies based on quantum frequency conversion (QFC) in recent years even though the experimental progress has been limited. QFC is a process that allows preservation of the quantum information while changing the frequency of the input quantum state. It has deservedly garnered a lot of attention because it serves as the connecting bridge between the communications band (C-band near 1550 nm) where the fiber-optic infrastructure is already established and the visible spectrum where high efficiency single-photon detectors and optical memories have been demonstrated. In this experimental work, we demonstrate mode-selective frequency conversion as a means to measure and manipulate photonic signals occupying d -dimensional Hilbert spaces where d=2 and 4. In the d=2 case, we demonstrate mode contrast between two temporal modes (TMs) which serves as the proof-of-concept demonstration. In the d=4 version, we employ six different TMs for our detailed experimental study. These TMs also include superposition modes which are a crucial component in many quantum key distribution protocols. Our method is based on producing pump pulses which allow us to upconvert the TM of interest while ideally preserving the other modes. We use MATLAB simulations to determine the pump pulse shapes which are subsequently produced by controlling the amplitude and

  18. 60 GHz antenna measurement setup using a VNA without external frequency conversion

    DEFF Research Database (Denmark)

    Popa, Paula Irina; Pivnenko, Sergey; Nielsen, Jeppe Majlund

    2014-01-01

    an alternative solution which makes use of a standard wideband VNA without external frequency conversion units. The operational capability of the Planar Near-Field (PNF) Antenna Measurement Facility at the Technical University of Denmark was recently extended to 60 GHz employing an Agilent E8361A VNA (up to 67...... GHz). The upgrade involved procurement of very few additional components: two cables operational up to 65 GHz and an openended waveguide probe for tests in U-band (40-60 GHz). The first tests have shown good performance of the PNF setup: 50-60 dB dynamic range and small thermal drift in magnitude...... and phase, 0.06 dB and 6 degrees peak-to-peak deviations over 4 hours. A PNF measurement of a 25 dBi Standard Gain Horn was carried out and the results were compared to those from the DTU-ESA Spherical Near-Field Facility with a good agreement in the validity region. Uncertainty investigations regarding...

  19. Long-Distance Single Photon Transmission from a Trapped Ion via Quantum Frequency Conversion

    Science.gov (United States)

    Walker, Thomas; Miyanishi, Koichiro; Ikuta, Rikizo; Takahashi, Hiroki; Vartabi Kashanian, Samir; Tsujimoto, Yoshiaki; Hayasaka, Kazuhiro; Yamamoto, Takashi; Imoto, Nobuyuki; Keller, Matthias

    2018-05-01

    Trapped atomic ions are ideal single photon emitters with long-lived internal states which can be entangled with emitted photons. Coupling the ion to an optical cavity enables the efficient emission of single photons into a single spatial mode and grants control over their temporal shape. These features are key for quantum information processing and quantum communication. However, the photons emitted by these systems are unsuitable for long-distance transmission due to their wavelengths. Here we report the transmission of single photons from a single 40Ca+ ion coupled to an optical cavity over a 10 km optical fiber via frequency conversion from 866 nm to the telecom C band at 1530 nm. We observe nonclassical photon statistics of the direct cavity emission, the converted photons, and the 10 km transmitted photons, as well as the preservation of the photons' temporal shape throughout. This telecommunication-ready system can be a key component for long-distance quantum communication as well as future cloud quantum computation.

  20. A high conversion-gain Q-band InP DHBT subharmonic mixer using LO frequency doubler

    DEFF Research Database (Denmark)

    Johansen, Tom Keinicke; Vidkjær, Jens; Krozer, Viktor

    2008-01-01

    The paper presents analysis and design of a Q-band subharmonic mixer (SHM) with high conversion gain. The SHM consists of a local oscillator (LO) frequency doubler, RF pre-amplifier, and single-ended mixer. The SHM has been fabricated in a high-speed InP double heterojunction bipolar transistor (...

  1. Modeling of large aperture third harmonic frequency conversion of high power Nd:glass laser systems

    International Nuclear Information System (INIS)

    Henesian, M.A.; Wegner, P.J.; Speck, D.R.; Bibeau, C.; Ehrlich, R.B.; Laumann, C.W.; Lawson, J.K.; Weiland, T.L.

    1991-01-01

    To provide high-energy, high-power beams at short wavelengths for inertial-confinement-fusion experiments, we routinely convert the 1.053-μm output of the Nova, Nd:phosphate-glass, laser system to its third-harmonic wavelength. We describe performance and conversion efficiency modeling of the 3 x 3 arrays potassium-dihydrogen-phosphate crystal plates used for type II/type II phase-matched harmonic conversion of Nova 0.74-m diameter beams, and an alternate type I/type II phase-matching configuration that improves the third-harmonic conversion efficiency. These arrays provide energy conversion of up to 65% and intensity conversion to 70%. 19 refs., 11 figs

  2. Ultralow power continuous-wave frequency conversion in hydrogenated amorphous silicon waveguides.

    Science.gov (United States)

    Wang, Ke-Yao; Foster, Amy C

    2012-04-15

    We demonstrate wavelength conversion through nonlinear parametric processes in hydrogenated amorphous silicon (a-Si:H) with maximum conversion efficiency of -13 dB at telecommunication data rates (10 GHz) using only 15 mW of pump peak power. Conversion bandwidths as large as 150 nm (20 THz) are measured in continuous-wave regime at telecommunication wavelengths. The nonlinear refractive index of the material is determined by four-wave mixing (FWM) to be n(2)=7.43×10(-13) cm(2)/W, approximately an order of magnitude larger than that of single crystal silicon. © 2012 Optical Society of America

  3. Increased acceptance bandwidths in optical frequency conversion by use of multiple walk-off-compensating nonlinear crystals

    International Nuclear Information System (INIS)

    Smith, A.V.; Armstrong, D.J.; Alford, W.J.

    1998-01-01

    We show by experiment and mathematical model that angular and frequency acceptance bandwidths for frequency mixing in a nonlinear crystal can often be improved by segmenting the crystal and reversing the spatial or temporal walk-off in alternating segments. We analyze nonlinear mixing primarily in real space, (x,t), rather than Fourier space, (k,ω), and show that acceptance bands for sum- and difference-frequency mixing can be increased by up to a factor equal to the number of crystal segments. We consider both high- and low-efficiency mixing as well as parametric gain, and show that in many cases of practical interest the increased bandwidth substantially improves conversion efficiency. We also attempt to clarify the role of acceptance bandwidths in frequency mixing. copyright 1998 Optical Society of America

  4. An experimentally validated model for geometrically nonlinear plucking-based frequency up-conversion in energy harvesting

    Science.gov (United States)

    Kathpalia, B.; Tan, D.; Stern, I.; Erturk, A.

    2018-01-01

    It is well known that plucking-based frequency up-conversion can enhance the power output in piezoelectric energy harvesting by enabling cyclic free vibration at the fundamental bending mode of the harvester even for very low excitation frequencies. In this work, we present a geometrically nonlinear plucking-based framework for frequency up-conversion in piezoelectric energy harvesting under quasistatic excitations associated with low-frequency stimuli such as walking and similar rigid body motions. Axial shortening of the plectrum is essential to enable plucking excitation, which requires a nonlinear framework relating the plectrum parameters (e.g. overlap length between the plectrum and harvester) to the overall electrical power output. Von Kármán-type geometrically nonlinear deformation of the flexible plectrum cantilever is employed to relate the overlap length between the flexible (nonlinear) plectrum and the stiff (linear) harvester to the transverse quasistatic tip displacement of the plectrum, and thereby the tip load on the linear harvester in each plucking cycle. By combining the nonlinear plectrum mechanics and linear harvester dynamics with two-way electromechanical coupling, the electrical power output is obtained directly in terms of the overlap length. Experimental case studies and validations are presented for various overlap lengths and a set of electrical load resistance values. Further analysis results are reported regarding the combined effects of plectrum thickness and overlap length on the plucking force and harvested power output. The experimentally validated nonlinear plectrum-linear harvester framework proposed herein can be employed to design and optimize frequency up-conversion by properly choosing the plectrum parameters (geometry, material, overlap length, etc) as well as the harvester parameters.

  5. A methodology for low-speed broadband rotational energy harvesting using piezoelectric transduction and frequency up-conversion

    International Nuclear Information System (INIS)

    Fu, Hailing; Yeatman, Eric M.

    2017-01-01

    Energy harvesting from vibration for low-power electronics has been investigated intensively in recent years, but rotational energy harvesting is less investigated and still has some challenges. In this paper, a methodology for low-speed rotational energy harvesting using piezoelectric transduction and frequency up-conversion is analysed. The system consists of a piezoelectric cantilever beam with a tip magnet and a rotating magnet on a revolving host. The angular kinetic energy of the host is transferred to the vibration energy of the piezoelectric beam via magnetic coupling between the magnets. Frequency up-conversion is achieved by magnetic plucking, converting low frequency rotation into high frequency vibration of the piezoelectric beam. A distributed-parameter theoretical model is presented to analyse the electromechanical behaviour of the rotational energy harvester. Different configurations and design parameters were investigated to improve the output power of the device. Experimental studies were conducted to validate the theoretical estimation. The results illustrate that the proposed method is a feasible solution to collecting low-speed rotational energy from ambient hosts, such as vehicle tires, micro-turbines and wristwatches. - Highlights: • A topology to harvest low-frequency broad-band rotational energy is studied. • Different configurations were considered; arrangement (a)-repulsive was the best. • Theoretical analysis shows the harvester has a wide bandwidth at low frequency. • The ripples of output power are related to the beam's natural frequency. • Experimental results show a good performance (over 20 μW) from 15 Hz to 35 Hz.

  6. Frequency up-conversion and spectral breaking of a high power microwave pulse propagation in a self-generated plasma

    International Nuclear Information System (INIS)

    Kuo, S.P.; Ren, A.

    1993-01-01

    The main concern of the propagation of high power microwave pulse is the energy loss of the pulse before reaching the destination. The loss is caused by self-generated plasma. There are two processes which are responsible for the energy loss (so called tail erosion). They are collisional damping and cutoff reflection. In very high power region, the cutoff reflection is much more severe than the collisional damping. A frequency up-conversion process may help to avoid the cutoff reflection of powerful electromagnetic pulse propagating in a self-generated plasma. Both chamber experiments and numerical simulation are performed. When the field amplitude only slightly exceeds the breakdown threshold field of the background gas, the result shows that the carrier frequency ω of the pulse shifts upward during the growth of local plasma frequency ωpe 2 . Thus, the self-generated plasma remains underdense to the pulse. However, the spectrum of the pulse starts to break up into two major peaks when the amplitude of the pulse is further increased. The frequency of one of the peaks is lower than the original carrier frequency and that of the other peak is higher than the original carrier frequency. These phenomena are observed both experimentally and numerically. The frequency down shift result is believed to be caused by damping mechanisms. Good agreement between the experimental results and the numerical simulation is obtained

  7. New harmonic materials: index engineering. Thin-thick quadrature frequency conversion

    International Nuclear Information System (INIS)

    Eimerl, D.

    1985-01-01

    The quadrature conversion scheme is a method of generating the second harmonic. The scheme, which uses two crystals in series, has several advantages over single-crystal or other two crystal schemes. The most important is that it is capable of high conversion efficiency over a large dynamic range of drive intensity and detuning angle. Consider a pair of KDP crystals cut for type-II phase matching. In the quadrature scheme, the optic axes of the crystals are arranged so that the plans containing the direction of the laser beam and their optic axes (the kz planes) are mutually perpendicular. This arrangement has two important properties. First, in type-II phase matching, the incident wave is polarized at 45 deg to the kz plane of the crystal. This, in the quadrature scheme, if the incident wave is correctly polarized for efficient conversion in the first crystal, it is also correctly polarized for efficient conversion in the second crystal. Both crystals can therefore convert efficiently

  8. Efficient continuous-wave nonlinear frequency conversion in high-Q gallium nitride photonic crystal cavities on silicon

    Directory of Open Access Journals (Sweden)

    Mohamed Sabry Mohamed

    2017-03-01

    Full Text Available We report on nonlinear frequency conversion from the telecom range via second harmonic generation (SHG and third harmonic generation (THG in suspended gallium nitride slab photonic crystal (PhC cavities on silicon, under continuous-wave resonant excitation. Optimized two-dimensional PhC cavities with augmented far-field coupling have been characterized with quality factors as high as 4.4 × 104, approaching the computed theoretical values. The strong enhancement in light confinement has enabled efficient SHG, achieving a normalized conversion efficiency of 2.4 × 10−3 W−1, as well as simultaneous THG. SHG emission power of up to 0.74 nW has been detected without saturation. The results herein validate the suitability of gallium nitride for integrated nonlinear optical processing.

  9. Polarisation-preserving photon frequency conversion from a trapped-ion-compatible wavelength to the telecom C-band

    Science.gov (United States)

    Krutyanskiy, V.; Meraner, M.; Schupp, J.; Lanyon, B. P.

    2017-09-01

    We demonstrate polarisation-preserving frequency conversion of single-photon-level light at 854 nm, resonant with a trapped-ion transition and qubit, to the 1550-nm telecom C band. A total photon in / fiber-coupled photon out efficiency of ˜30% is achieved, for a free-running photon noise rate of ˜60 Hz. This performance would enable telecom conversion of 854 nm polarisation qubits, produced in existing trapped-ion systems, with a signal-to-noise ratio greater than 1. In combination with near-future trapped-ion systems, our converter would enable the observation of entanglement between an ion and a photon that has travelled more than 100 km in optical fiber: three orders of magnitude further than the state-of-the-art.

  10. Mode-conversion process and overdense-plasma heating in the electron cyclotron range of frequencies

    International Nuclear Information System (INIS)

    Nakajima, S.; Abe, H.

    1988-01-01

    Through a particle-simulation investigation, a new mode-conversion process, through which an incident fast extraordinary mode (fast X mode) is converted into an electron Bernstein mode (B mode) via a (slow extraordinary mode slow X mode), is discovered in plasmas whose maximum density exceeds the cutoff density of the slow X mode. The converted B mode is found to heat the electrons efficiently in an overdense plasma region, when the plasma has the optimum density gradient at the plasma surface

  11. Low phase noise microwave extraction from femtosecond laser by frequency conversion pair and IF-domain processing.

    Science.gov (United States)

    Dai, Yitang; Cen, Qizhuang; Wang, Lei; Zhou, Yue; Yin, Feifei; Dai, Jian; Li, Jianqiang; Xu, Kun

    2015-12-14

    Extraction of a microwave component from a low-time-jitter femtosecond pulse train has been attractive for current generation of spectrally pure microwave. In order to avoid the transfer from the optical amplitude noise to microwave phase noise (AM-PM), we propose to down-convert the target component to intermediate frequency (IF) before the opto-electronic conversion. Due to the much lower carrier frequency, the AM-PM is greatly suppressed. The target is then recovered by up-conversion with the same microwave local oscillation (LO). As long as the time delay of the second LO matches that of the IF carrier, the phase noise of the LO shows no impact on the extraction process. The residual noise of the proposed extraction is analyzed in theory, which is also experimentally demonstrated as averagely around -155 dBc/Hz under offset frequency larger than 1 kHz when 10-GHz tone is extracted from a home-made femtosecond fiber laser. Large tunable extraction from 1 GHz to 10 GHz is also reported.

  12. Studies on the Effect of Radio Frequency Field in a Cusp-Type Charge Separation Device for Direct Energy Conversion

    OpenAIRE

    HAMABE, Masaki; IZAWA, Hiroaki; TAKENO, Hiromasa; NAKAMOTO, Satoshi; ICHIMURA, Kazuya; NAKASHIMA, Yousuke

    2016-01-01

    In D-3He fusion power generation, an application of direct energy conversion is expected in which separation of charged particles is necessary. A cusp-type direct energy converter (CuspDEC) was proposed as a charge separation device, but its performance was degraded for a high density plasma. The goal of the present study is to establish an additional method to assist charge separation by using a nonlinear effect of a radio frequency (rf) electric field. Following to the previous study, we ex...

  13. Fully-resonant, tunable, monolithic frequency conversion as a coherent UVA source.

    Science.gov (United States)

    Zielińska, Joanna A; Zukauskas, Andrius; Canalias, Carlota; Noyan, Mehmet A; Mitchell, Morgan W

    2017-01-23

    We demonstrate a monolithic frequency converter incorporating up to four tuning degrees of freedom, three temperature and one strain, allowing resonance of pump and generated wavelengths simultaneous with optimal phase-matching. With a Rb-doped periodically-poled potassium titanyl phosphate (KTP) implementation, we demonstrate efficient continuous-wave second harmonic generation from 795 to 397, with low-power efficiency of 72% and high-power slope efficiency of 4.5%. The measured performance shows good agreement with theoretical modeling of the device. We measure optical bistability effects, and show how they can be used to improve the stability of the output against pump frequency and amplitude variations.

  14. Microwave-to-optical frequency conversion with a Rydberg atom coupled to a coplanar waveguide

    Science.gov (United States)

    Gard, Bryan; Jacobs, Kurt; McDermott, Robert; Saffman, Mark

    2017-04-01

    A primary candidate for converting quantum information from microwave to optical frequencies is the use of Rydberg states of a single atom trapped near a surface. The fact that the Rydberg states possess both large electric dipole moments and microwave transition frequencies allows them to interact with superconducting mesoscopic circuits. By considering a concrete example, that of a Cesium atom, and using numerical search methods to optimize the control protocols, we determine the fidelities and transmission rates that could be achievable with such a device. We show that while protocols that exploit the adiabatic STIRAP mechanism provide the best raw transfer fidelities, the fastest communication speeds can be obtained by using heralding, which allows one to remove the adiabatic constraint. Support from Oak Ridge Associated Universities.

  15. Wideband Isolation by Frequency Conversion in a Josephson-Junction Transmission Line

    Science.gov (United States)

    Ranzani, Leonardo; Kotler, Shlomi; Sirois, Adam J.; DeFeo, Michael P.; Castellanos-Beltran, Manuel; Cicak, Katarina; Vale, Leila R.; Aumentado, José

    2017-11-01

    Nonreciprocal transmission and isolation at microwave frequencies are important in many practical applications. In particular, compact isolators are useful in protecting sensitive quantum circuits operating at cryogenic temperatures from amplifier backaction and other environmental noise such as black-body radiation from higher temperature stages. However, the size of commercial cryogenic isolators limits the ability to measure multiple quantum circuits because of space constraints in typical dilution refrigerator systems. Furthermore, isolators usually require the use of ferrite components that cannot be integrated at the chip level and, since they also need large biasing magnetic fields, are incompatible with superconducting quantum circuits. In this work we show one way to accomplish isolation in a superconducting chip-scale device, a traveling-wave unidirectional frequency converter based on a parametrically pumped superconducting Josephson-junction transmission line, demonstrating better than 4.8 dB of inferred signal isolation from 6.6 to 11.4 GHz, with a maximum of 12 dB at 9.5 GHz. By using frequency diplexing techniques a conventional isolator could be implemented over this bandwidth.

  16. Nanotechnology in lithium niobate for integrated optic frequency conversion in the UV

    Science.gov (United States)

    Busacca, Alessandro C.; Santini, Claudia; Oliveri, Luigi; Riva-Sanseverino, Stefano; Parisi, Antonino; Cino, Alfonso C.; Assanto, Gaetano

    2017-11-01

    In the domain of Earth Explorer satellites nanoengineered nonlinear crystals can optimize UV tunable solid-state laser converters. Lightweight sources can be based on Lithium Niobate (LN) domain engineering by electric field poling and guided wave interactions. In this Communication we report the preliminary experimental results and the very first demonstration of UltraViolet second-harmonic generation by first-order quasi-phase-matching in a surface-periodically-poled proton-exchanged LN waveguide. The pump source was a Ti-Sapphire laser with a tunability range of 700- 980 nm and a 40 GHz linewidth. We have measured UV continuous-wave light at 390 nm by means of a lock-in amplifier and of a photodiode with enhanced response in the UV. Measured conversion efficiency was about 1%W-1cm-2. QPM experiments show good agreement with theory and pave the way for a future implementation of the technique in materials less prone to photorefractive damage and wider transparency in the UV, such as Lithium Tantalate.

  17. High-frequency thermal-electrical cycles for pyroelectric energy conversion

    International Nuclear Information System (INIS)

    Bhatia, Bikram; Damodaran, Anoop R.; Cho, Hanna; Martin, Lane W.; King, William P.

    2014-01-01

    We report thermal to electrical energy conversion from a 150 nm thick BaTiO 3 film using pyroelectric cycles at 1 kHz. A microfabricated platform enables temperature and electric field control with temporal resolution near 1 μs. The rapid electric field changes as high as 11 × 10 5  kV/cm-s, and temperature change rates as high as 6 × 10 5  K/s allow exploration of pyroelectric cycles in a previously unexplored operating regime. We investigated the effect of phase difference between electric field and temperature cycles, and electric field and temperature change rates on the electrical energy generated from thermal-electrical cycles based on the pyroelectric Ericsson cycle. Complete thermodynamic cycles are possible up to the highest cycle rates tested here, and the energy density varies significantly with phase shifts between temperature and electric field waveforms. This work could facilitate the design and operation of pyroelectric cycles at high cycle rates, and aid in the design of new pyroelectric systems

  18. Demonstrations of analog-to-digital conversion using a frequency domain stretched processor.

    Science.gov (United States)

    Reibel, Randy Ray; Harrington, Calvin; Dahl, Jason; Ostrander, Charles; Roos, Peter Aaron; Berg, Trenton; Mohan, R Krishna; Neifeld, Mark A; Babbitt, Wm R

    2009-07-06

    The first proof-of-concept demonstrations are presented for a broadband photonic-assisted analog-to-digital converter (ADC) based on spatial spectral holography (SSH). The SSH-ADC acts as a frequency-domain stretch processor converting high bandwidth input signals to low bandwidth output signals, allowing the system to take advantage of high performance, low bandwidth electronic ADCs. Demonstrations with 50 MHz effective bandwidth are shown to highlight basic performance with approximately 5 effective bits of vertical resolution. Signal capture with 1600 MHz effective bandwidth is also shown. Because some SSH materials span over 100 GHz and have large time apertures (approximately 10 micros), this technique holds promise as a candidate for the next generation of ADCs.

  19. Cascade photonic integrated circuit architecture for electro-optic in-phase quadrature/single sideband modulation or frequency conversion.

    Science.gov (United States)

    Hasan, Mehedi; Hall, Trevor

    2015-11-01

    A photonic integrated circuit architecture for implementing frequency upconversion is proposed. The circuit consists of a 1×2 splitter and 2×1 combiner interconnected by two stages of differentially driven phase modulators having 2×2 multimode interference coupler between the stages. A transfer matrix approach is used to model the operation of the architecture. The predictions of the model are validated by simulations performed using an industry standard software tool. The intrinsic conversion efficiency of the proposed design is improved by 6 dB over the alternative functionally equivalent circuit based on dual parallel Mach-Zehnder modulators known in the prior art. A two-tone analysis is presented to study the linearity of the proposed circuit, and a comparison is provided over the alternative. The proposed circuit is suitable for integration in any platform that offers linear electro-optic phase modulation such as LiNbO(3), silicon, III-V, or hybrid technology.

  20. Diffraction-limited real-time terahertz imaging by optical frequency up-conversion in a DAST crystal.

    Science.gov (United States)

    Fan, Shuzhen; Qi, Feng; Notake, Takashi; Nawata, Kouji; Takida, Yuma; Matsukawa, Takeshi; Minamide, Hiroaki

    2015-03-23

    Real-time terahertz (THz) wave imaging has wide applications in areas such as security, industry, biology, medicine, pharmacy, and the arts. This report describes real-time room-temperature THz imaging by nonlinear optical frequency up-conversion in an organic 4-dimethylamino-N'-methyl-4'-stilbazolium tosylate (DAST) crystal, with high resolution reaching the diffraction limit. THz-wave images were converted to the near infrared region and then captured using an InGaAs camera in a tandem imaging system. The resolution of the imaging system was analyzed. Diffraction and interference of THz wave were observed in the experiments. Videos are supplied to show the interference pattern variation that occurs with sample moving and tilting.

  1. Studies on the effect of radio frequency field in a cusp-type charge separation device for direct energy conversion

    International Nuclear Information System (INIS)

    Hamabe, Masaki; Izawa, Hiroaki; Takeno, Hiromasa; Nakamoto, Satoshi; Ichimura, Kazuya; Nakashima, Yousuke

    2016-01-01

    In D- 3 He fusion power generation, an application of direct energy conversion is expected in which separation of charged particles is necessary. A cusp-type direct energy converter (CuspDEC) was proposed as a charge separation device, but its performance was degraded for a high density plasma. The goal of the present study is to establish an additional method to assist charge separation by using a nonlinear effect of a radio frequency (rf) electric field. Following to the previous study, we experimentally examine the effect of an rf field to electron motion in a CuspDEC device. Two ring electrodes were newly installed in a CuspDEC simulator and the current flowing into the electron collector located in the line cusp region was measured on an rf field application. The significant variation in the current was found, and an improvement of the charge separation can be expected by using the phenomenon appropriately. (author)

  2. Injection frequency and anatomic outcomes 1 year following conversion to aflibercept in patients with neovascular age-related macular degeneration.

    Science.gov (United States)

    Messenger, Wyatt B; Campbell, J Peter; Faridi, Ambar; Shippey, Loton; Bailey, Steven T; Lauer, Andreas K; Flaxel, Christina J; Hwang, Thomas S

    2014-09-01

    To evaluate the clinical, anatomic and functional effects of conversion to aflibercept following ranibizumab and/or bevacizumab in patients with neovascular age-related macular degeneration (AMD). A retrospective review of patients with neovascular AMD treated with intravitreal ranibizumab and/or bevacizumab who were switched to aflibercept was performed. The primary outcome was change in injection frequency in the year following the change. Secondary outcomes included change in central macular thickness (CMT) at 6 months and 1 year, presence of intraretinal and subretinal fluid at 6 months and visual acuity at 1 year. A total of 109 eyes with neovascular AMD were switched to aflibercept and met inclusion criteria. Overall, aflibercept injection frequency was unchanged with patients receiving 7.4 antivascular endothelial growth factor (VEGF) injections the year prior to conversion compared with 7.2 aflibercept injections in the year following (p=0.47). However, the change to aflibercept was associated with improvement in CMT from 324 to 295 μm (p=0.0001) at 6 months and 299 μm (p=0.0047) at 1 year. There was no effect on visual acuity at 1 year. In a subgroup analysis, patients who had received ≥10 anti-VEGF injections in the year prior had fewer injections (11.1 to 8.4, p<0.0001) and clinic visits (13.9 to 9.6, p<0.0001) as well as a significant decrease in CMT (-35 μm, p=0.02). In our population, switching to aflibercept therapy was not associated with a change in injection frequency nor improved visual acuity, but was associated with improved CMT at 6 months and 1 year. In patients who received at least 10 anti-VEGF injections in the year prior, transitioning to aflibercept was associated with a reduced injection frequency and CMT, suggesting potential cost savings in this population. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  3. Intracavity quasi-phase-matched self-frequency conversion in a periodically poled Nd:Mg:LiNbO3 crystal

    International Nuclear Information System (INIS)

    Laptev, G D; Novikov, Aleksei A

    2001-01-01

    The theory of intracavity quasi-phase-matched self-frequency conversion in an active nonlinear periodically poled structure is developed. The processes of quasi-phase-matched self-frequency doubling, self-halving and mixing using the pump wave in a periodically poled Nd:Mg:LiNbO 3 crystal are studied. The dependences of the efficiency of nonlinear optical conversion in these processes on the reflection coefficient of the output mirror and on linear losses in the medium are investigated. (nonlinear optical phenomena)

  4. Glass-ceramic optical fiber containing Ba2TiSi2O8 nanocrystals for frequency conversion of lasers.

    Science.gov (United States)

    Fang, Zaijin; Xiao, Xusheng; Wang, Xin; Ma, Zhijun; Lewis, Elfed; Farrell, Gerald; Wang, Pengfei; Ren, Jing; Guo, Haitao; Qiu, Jianrong

    2017-03-30

    A glass-ceramic optical fiber containing Ba 2 TiSi 2 O 8 nanocrystals fabricated using a novel combination of the melt-in-tube method and successive heat treatment is reported for the first time. For the melt-in-tube method, fibers act as a precursor at the drawing temperature for which the cladding glass is softened while the core glass is melted. It is demonstrated experimentally that following heat treatment, Ba 2 TiSi 2 O 8 nanocrystals with diameters below 10 nm are evenly distributed throughout the fiber core. Comparing to the conventional rod-in-tube method, the melt-in-tube method is superior in terms of controllability of crystallization to allow for the fabrication of low loss glass-ceramic fibers. When irradiated using a 1030 nm femtosecond laser, an enhanced green emission at a wavelength of 515 nm is observed in the glass-ceramic fiber, which demonstrates second harmonic generation of a laser action in the fabricated glass-ceramic fibers. Therefore, this new glass-ceramic fiber not only provides a highly promising development for frequency conversion of lasers in all optical fiber based networks, but the melt-in-tube fabrication method also offers excellent opportunities for fabricating a wide range of novel glass-ceramic optical fibers for multiple future applications including fiber telecommunications and lasers.

  5. Full 3D modelling of pulse propagation enables efficient nonlinear frequency conversion with low energy laser pulses in a single-element tripler

    Science.gov (United States)

    Kardaś, Tomasz M.; Nejbauer, Michał; Wnuk, Paweł; Resan, Bojan; Radzewicz, Czesław; Wasylczyk, Piotr

    2017-02-01

    Although new optical materials continue to open up access to more and more wavelength bands where femtosecond laser pulses can be generated, light frequency conversion techniques are still indispensable in filling the gaps on the ultrafast spectral scale. With high repetition rate, low pulse energy laser sources (oscillators) tight focusing is necessary for a robust wave mixing and the efficiency of broadband nonlinear conversion is limited by diffraction as well as spatial and temporal walk-off. Here we demonstrate a miniature third harmonic generator (tripler) with conversion efficiency exceeding 30%, producing 246 fs UV pulses via cascaded second order processes within a single laser beam focus. Designing this highly efficient and ultra compact frequency converter was made possible by full 3-dimentional modelling of propagation of tightly focused, broadband light fields in nonlinear and birefringent media.

  6. Ka-band to L-band frequency down-conversion based on III-V-on-silicon photonic integrated circuits

    Science.gov (United States)

    Van Gasse, K.; Wang, Z.; Uvin, S.; De Deckere, B.; Mariën, J.; Thomassen, L.; Roelkens, G.

    2017-12-01

    In this work, we present the design, simulation and characterization of a frequency down-converter based on III-V-on-silicon photonic integrated circuit technology. We first demonstrate the concept using commercial discrete components, after which we demonstrate frequency conversion using an integrated mode-locked laser and integrated modulator. In our experiments, five channels in the Ka-band (27.5-30 GHz) with 500 MHz bandwidth are down-converted to the L-band (1.5 GHz). The breadboard demonstration shows a conversion efficiency of - 20 dB and a flat response over the 500 MHz bandwidth. The simulation of a fully integrated circuit indicates that a positive conversion gain can be obtained on a millimeter-sized photonic integrated circuit.

  7. Exploring Communication and Course Format: Conversation Frequency and Duration, Student Motives, and Perceived Teacher Approachability for Out-of-Class Contact

    Science.gov (United States)

    Brooks, Catherine F.; Young, Stacy L.

    2016-01-01

    This study explored how course instructional format (i.e., online, face-to-face, or hybrid) is related to the frequency and duration of out-of-class communication (OCC) between college instructors and students, to student motives for communicating with teachers, and to perceived teacher approachability for conversation outside of class. Though…

  8. NOLM-based all-optical 40 Gbit/s format conversion through sum-frequency generation (SFG) in a PPLN waveguide

    Science.gov (United States)

    Wang, Jian; Sun, Junqiang

    2005-11-01

    A novel all-optical format conversion scheme from NRZ to RZ based on sum-frequency generation (SFG) in a periodically poled LiNbO 3 (PPLN) waveguide is proposed, using a nonlinear optical loop mirror (NOLM). The conversion mechanism relies on the combination of attenuation and nonlinear phase shift induced on the clockwise signal field during the SFG process. The SFG between pump, and co- and counter- propagating signals in the PPLN waveguide are numerically studied, showing that counter-propagating SFG can be ignored when quasi-phase matching (QPM) for SFG during co-propagating interaction. The nonlinear phase shift induced on the clockwise signal field is analyzed in detail, showing that it is more effective to yield large values for nonlinear phase shift when appropriately phase mismatched for the SFG process. Two tuning schemes are proposed depend on whether the sum-frequency wavelength is variable or fixed. It is found that the latter has a rather wide 3dB signal conversion bandwidth approximately 154nm. Finally, the influence of reversible process of SFG is discussed and the optimum arrangement of pump and signal peak powers is theoretically demonstrated. The result shows that proper power arrangement, pump width, and waveguide length are necessary for achieving a good conversion effect.

  9. Measuring high-frequency responses of an electro-optic phase modulator based on dispersion induced phase modulation to intensity modulation conversion

    Science.gov (United States)

    Zhang, Shangjian; Wang, Heng; Wang, Yani; Zou, Xinhai; Zhang, Yali; Liu, Shuang; Liu, Yong

    2014-11-01

    We investigate the phase modulation to intensity modulation conversion in dispersive fibers for measuring frequency responses of electro-optic phase modulators, and demonstrate two typical measurements with cascade path and fold-back path. The measured results achieve an uncertainty of less than 2.8% within 20 GHz. Our measurements show stable and repeatable results because the optical carrier and its phase-modulated sidebands are affected by the same fiber impairments. The proposed method requires only dispersive fibers and works without any small-signal assumption, which is applicable for swept frequency measurement at different driving levels and operating wavelengths.

  10. Towards terahertz detection and calibration through spontaneous parametric down-conversion in the terahertz idler-frequency range generated by a 795 nm diode laser system

    Directory of Open Access Journals (Sweden)

    Vladimir V. Kornienko

    2018-05-01

    Full Text Available We study a calibration scheme for terahertz wave nonlinear-optical detectors based on spontaneous parametric down-conversion. Contrary to the usual low wavelength pump in the green, we report here on the observation of spontaneous parametric down-conversion originating from an in-growth poled lithium niobate crystal pumped with a continuous wave 50 mW, 795 nm diode laser system, phase-matched to a terahertz frequency idler wave. Such a system is more compact and allows for longer poling periods as well as lower losses in the crystal. Filtering the pump radiation by a rubidium-87 vapor cell allowed the frequency-angular spectra to be obtained down to ∼0.5 THz or ∼1 nm shift from the pump radiation line. The presence of an amplified spontaneous emission “pedestal” in the diode laser radiation spectrum significantly hampers the observation of spontaneous parametric down-conversion spectra, in contrast to conventional narrowband gas lasers. Benefits of switching to longer pump wavelengths are pointed out, such as collinear optical-terahertz phase-matching in bulk crystals.

  11. Towards terahertz detection and calibration through spontaneous parametric down-conversion in the terahertz idler-frequency range generated by a 795 nm diode laser system

    Science.gov (United States)

    Kornienko, Vladimir V.; Kitaeva, Galiya Kh.; Sedlmeir, Florian; Leuchs, Gerd; Schwefel, Harald G. L.

    2018-05-01

    We study a calibration scheme for terahertz wave nonlinear-optical detectors based on spontaneous parametric down-conversion. Contrary to the usual low wavelength pump in the green, we report here on the observation of spontaneous parametric down-conversion originating from an in-growth poled lithium niobate crystal pumped with a continuous wave 50 mW, 795 nm diode laser system, phase-matched to a terahertz frequency idler wave. Such a system is more compact and allows for longer poling periods as well as lower losses in the crystal. Filtering the pump radiation by a rubidium-87 vapor cell allowed the frequency-angular spectra to be obtained down to ˜0.5 THz or ˜1 nm shift from the pump radiation line. The presence of an amplified spontaneous emission "pedestal" in the diode laser radiation spectrum significantly hampers the observation of spontaneous parametric down-conversion spectra, in contrast to conventional narrowband gas lasers. Benefits of switching to longer pump wavelengths are pointed out, such as collinear optical-terahertz phase-matching in bulk crystals.

  12. Experimental demonstration of wavelength conversion between ps-pulses based on cascaded sum- and difference frequency generation (SFG+DFG) in LiNbO3 waveguides

    Science.gov (United States)

    Wang, Jian; Sun, Junqiang; Lou, Chuanhong; Sun, Qizhen

    2005-09-01

    All-optical wavelength conversion between ps-pulses based on cascaded sum- and difference frequency generation (SFG+DFG) is proposed and experimentally demonstrated in periodically poled LiNbO3 (PPLN) waveguides. The signal pulse with 40-GHz repetition rate and 1.57- ps pulse width is adopted. The converted idler wavelength can be tuned from 1527.4 to 1540.5nm as the signal wavelength is varied from 1561.9 to 1548.4nm. No obvious changes of the pulse shape and width, also no chirp are observed in the converted idler pulse. The results imply that single-to-multiple channel wavelength conversions can be achieved by appropriately tuning the two pump wavelengths.

  13. The mercury laser system - An average power, gas-cooled, Yb:S-FAP based system with frequency conversion and wavefront correction

    Energy Technology Data Exchange (ETDEWEB)

    Bibeau, C.; Bayramian, A.; Armstrong, P.; Ault, E.; Beach, R.; Benapfl, M.; Campbell, R.; Dawson, J.; Ebbers, C.; Freitas, B.; Kent, R.; Liao, Z.; Ladran, T.; Menapace, J.; Molander, B.; Moses, E.; Oberhelman, S.; Payne, S.; Peterson, N.; Schaffers, K.; Stolz, C.; Sutton, S.; Tassano, J.; Telford, S.; Utterback, E. [Lawrence Livermore National Lab., Livermore, CA (United States); Randles, M. [Northrop Grumman Space Technologies, Charlotte, NC (United States); Chain, B.; Fei, Y. [Crystal Photonics, Sanford, Fl (United States)

    2006-06-15

    We report on the operation of the Mercury laser with fourteen 4*6 cm{sup 2} Yb:S-FAP amplifier slabs pumped by eight 100 kW peak power diode arrays. The system was continuously run at 55 J and 10 Hz for several hours, (2*10{sup 5} cumulative shots) with over 80% of the energy in a 6 times diffraction limited spot at 1.047 {mu}m. Improved optical quality was achieved in Yb:S-FAP amplifiers with magneto-rheological finishing, a deterministic polishing method. In addition, average power frequency conversion employing YCOB crystal was demonstrated at 50% conversion efficiency or 22.6 J at 10 Hz. (authors)

  14. Novel Cavities in Vertical External Cavity Surface Emitting Lasers for Emission in Broad Spectral Region by Means of Nonlinear Frequency Conversion

    Science.gov (United States)

    Lukowski, Michal L.

    Optically pumped semiconductor vertical external cavity surface emitting lasers (VECSEL) were first demonstrated in the mid 1990's. Due to the unique design properties of extended cavity lasers VECSELs have been able to provide tunable, high-output powers while maintaining excellent beam quality. These features offer a wide range of possible applications in areas such as medicine, spectroscopy, defense, imaging, communications and entertainment. Nowadays, newly developed VECSELs, cover the spectral regions from red (600 nm) to around 5 microm. By taking the advantage of the open cavity design, the emission can be further expanded to UV or THz regions by the means of intracavity nonlinear frequency generation. The objective of this dissertation is to investigate and extend the capabilities of high-power VECSELs by utilizing novel nonlinear conversion techniques. Optically pumped VECSELs based on GaAs semiconductor heterostructures have been demonstrated to provide exceptionally high output powers covering the 900 to 1200 nm spectral region with diffraction limited beam quality. The free space cavity design allows for access to the high intracavity circulating powers where high efficiency nonlinear frequency conversions and wavelength tuning can be obtained. As an introduction, this dissertation consists of a brief history of the development of VECSELs as well as wafer design, chip fabrication and resonator cavity design for optimal frequency conversion. Specifically, the different types of laser cavities such as: linear cavity, V-shaped cavity and patented T-shaped cavity are described, since their optimization is crucial for transverse mode quality, stability, tunability and efficient frequency conversion. All types of nonlinear conversions such as second harmonic, sum frequency and difference frequency generation are discussed in extensive detail. The theoretical simulation and the development of the high-power, tunable blue and green VECSEL by the means of type I

  15. Design of a SiGe BiCMOS canceller for low frequency noise reduction in direct conversion receivers

    DEFF Research Database (Denmark)

    Squartecchia, Michele; Johansen, Tom Keinicke; Michaelsen, Rasmus Schandorph

    of the local oscillator (LO) toward the RF port of the mixer (Figure 1(a)). This causes the LO self-mixing phenomenon, which is responsible of a significant DC offset at the output of the receiver (Figure 1(b)). In turn, this DC offset gives rise to a high level of low frequency noise affecting the signal...

  16. Anisotropic nanolaminated CoNiFe cores integrated into microinductors for high-frequency dc–dc power conversion

    International Nuclear Information System (INIS)

    Kim, Jooncheol; Kim, Minsoo; Herrault, Florian; Kim, Jung-Kwun; Allen, Mark G

    2015-01-01

    This paper presents a rectangular, anisotropic nanolaminated CoNiFe core that possesses a magnetically hard axis in the long geometric axis direction. Previously, we have developed nanolaminated cores comprising tens to hundreds of layers of 300–1000 nm thick metallic alloys (i.e. Ni 80 Fe 20 or Co 44 Ni 37 Fe 19 ) based on sequential electrodeposition, demonstrating suppressed eddy-current losses at MHz frequencies. In this work, magnetic anisotropy was induced to the nanolaminated CoNiFe cores by applying an external magnetic field (50–100 mT) during CoNiFe film electrodeposition. The fabricated cores comprised tens to hundreds of layers of 500–1000 nm thick CoNiFe laminations that have the hard-axis magnetic property. Packaged in a 22-turn solenoid test inductor, the anisotropic core showed 10% increased effective permeability and 25% reduced core power losses at MHz operation frequency, compared to an isotropic core of the identical geometry. Operating the anisotropic nanolaminated CoNiFe core in a step-down dc–dc converter (15 V input to 5 V output) demonstrated 81% converter efficiency at a switching frequency of 1.1 MHz and output power of 6.5 W. A solenoid microinductor with microfabricated windings integrated with the anisotropic nanolaminated CoNiFe core was fabricated, demonstrating a constant inductance of 600 nH up to 10 MHz and peak quality factor exceeding 20 at 4 MHz. The performance of the microinductor with the anisotropic nanolaminated CoNiFe core is compared with other previously reported microinductors. (fast track communication)

  17. Mid-IR femtosecond frequency conversion by soliton-probe collision in phase-mismatched quadratic nonlinear crystals

    DEFF Research Database (Denmark)

    Liu, Xing; Zhou, Binbin; Guo, Hairun

    2015-01-01

    in a quadratic nonlinear crystal (beta-barium borate) in the normal dispersion regime due to cascaded (phase-mismatched) second-harmonic generation, and the mid-IR converted wave is formed in the anomalous dispersion regime between. lambda = 2.2-2.4 mu m as a resonant dispersive wave. This process relies...... on nondegenerate four-wave mixing mediated by an effective negative cross-phase modulation term caused by cascaded soliton-probe sum-frequency generation. (C) 2015 Optical Society of America...

  18. All-solid-state quasi-CW yellow laser with intracavity self-Raman conversion and sum frequency generation

    International Nuclear Information System (INIS)

    Kananovich, A; Grabtchikov, A; Orlovich, V; Demidovich, A; Danailov, M

    2010-01-01

    Quasi continuous-wave (qCW) yellow emission (pulse duration 5 ms, repetition rate 20 Hz) at 559 nm is demonstrated through intracavity sum frequency generation (SFG) of Stokes and fundamental fields in Nd:YVO 4 diode pumped self-Raman laser for the first time. Average in pulse output power at 559 nm was 0.47 W for 22 W of pump power, which corresponds to 2.1% of diode-to-yellow efficiency. The pulsed mode of operation was due to diode pump modulation and was used to reduce thermal stress of the crystal

  19. Cis-acting regulatory sequences promote high-frequency gene conversion between repeated sequences in mammalian cells.

    Science.gov (United States)

    Raynard, Steven J; Baker, Mark D

    2004-01-01

    In mammalian cells, little is known about the nature of recombination-prone regions of the genome. Previously, we reported that the immunoglobulin heavy chain (IgH) mu locus behaved as a hotspot for mitotic, intrachromosomal gene conversion (GC) between repeated mu constant (Cmu) regions in mouse hybridoma cells. To investigate whether elements within the mu gene regulatory region were required for hotspot activity, gene targeting was used to delete a 9.1 kb segment encompassing the mu gene promoter (Pmu), enhancer (Emu) and switch region (Smu) from the locus. In these cell lines, GC between the Cmu repeats was significantly reduced, indicating that this 'recombination-enhancing sequence' (RES) is necessary for GC hotspot activity at the IgH locus. Importantly, the RES fragment stimulated GC when appended to the same Cmu repeats integrated at ectopic genomic sites. We also show that deletion of Emu and flanking matrix attachment regions (MARs) from the RES abolishes GC hotspot activity at the IgH locus. However, no stimulation of ectopic GC was observed with the Emu/MARs fragment alone. Finally, we provide evidence that no correlation exists between the level of transcription and GC promoted by the RES. We suggest a model whereby Emu/MARS enhances mitotic GC at the endogenous IgH mu locus by effecting chromatin modifications in adjacent DNA.

  20. Energy conversion by ‘T-shaped’ cantilever type electromagnetic vibration based micro power generator from low frequency vibration sources

    International Nuclear Information System (INIS)

    Siddique, Abu Raihan Mohammad; Mahmud, Shohel; Van Heyst, Bill

    2017-01-01

    Highlights: • A T-shaped cantilever type electromagnetic vibration based MPG has been described. • The designed EVMPG is useful for low frequency based vibration sources. • Both experimental tests and theoretical analysis have been performed. • The final compact prototype was tested at different conditions of human movements. • The prototype can generate 35.2 mV and 0.22 mW at 7 Hz with 5.6 Ω. - Abstract: The design, development, and analyses of low-frequency vibration based T-shaped cantilever type electromagnetic micro power generators (EVMPGs) are presented in this paper. Four different configurations (Configurations A to D) of EVMPGs were designed and fabricated and subsequently characterized using detailed experimental and limited analytical techniques. Configuration A and B consisted of a single and a double cylindrical moving magnets (NdFeB), respectively, while Configuration C consisted of four rectangular moving magnets with respect to a fixed copper coil. In contrast, Configuration D used a moving coil between four rectangular magnets with a back-iron bar. The open circuit RMS voltage output was observed to be a maximum from Configuration D (98.2 mV at 6.29 Hz) with a base vibration acceleration of 0.8 m s"−"2. Therefore, Configuration D was selected for further experimental investigations, which included changing the back-iron bar thickness, changing the base acceleration level, and changing the air gap separation between the magnets in order to optimize this configuration. The maximum load RMS voltage and power outputs of Configuration D were 105.4 mV and 1.35 mW at 6.29 Hz for load resistance 8.2 Ω and a base acceleration of 0.8 m s"−"2 with a 4.2 mm back-iron bar when the air gap between the magnets was 20 mm. Finally, a small portable EVMPG prototype was developed based on the Configuration D and was tested at different human movement conditions (i.e., walking, quick walking, and running). The developed EVMPG prototype was capable of

  1. Partial fast-to-slow conversion of regenerating rat fast-twitch muscle by chronic low-frequency stimulation.

    Science.gov (United States)

    Pette, Dirk; Sketelj, Janez; Skorjanc, Dejan; Leisner, Elmi; Traub, Irmtrud; Bajrović, Fajko

    2002-01-01

    Chronic low-frequency stimulation (CLFS) of rat fast-twitch muscles induces sequential transitions in myosin heavy chain (MHC) expression from MHCIIb --> MHCIId/x --> MHCIIa. However, the 'final' step of the fast-to-slow transition, i.e., the upregulation of MHCI, has been observed only after extremely long stimulation periods. Assuming that fibre degeneration/regeneration might be involved in the upregulation of slow myosin, we investigated the effects of CLFS on extensor digitorum longus (EDL) muscles regenerating after bupivacaine-induced fibre necrosis. Normal, non-regenerating muscles responded to both 30- and 60-day CLFS with fast MHC isoform transitions (MHCIIb --> MHCIId --> MHCIIa) and only slight increases in MHCI. CLFS of regenerating EDL muscles caused similar transitions among the fast isoforms but, in addition, caused significant increases in MHCI (to approximately 30% relative concentration). Stimulation periods of 30 and 60 days induced similar changes in the regenerating bupivacaine-treated muscles, indicating that the upregulation of slow myosin was restricted to regenerating fibres, but only during an early stage of regeneration. These results suggest that satellite cells and/or regenerating fast rat muscle fibres are capable of switching directly to a slow program under the influence of CLFS and, therefore, appear to be more malleable than adult fibres.

  2. Tunable error-free optical frequency conversion of a 4ps optical short pulse over 25 nm by four-wave mixing in a polarisation-maintaining optical fibre

    Science.gov (United States)

    Morioka, T.; Kawanishi, S.; Saruwatari, M.

    1994-05-01

    Error-free, tunable optical frequency conversion of a transform-limited 4.0 ps optical pulse signalis demonstrated at 6.3 Gbit/s using four-wave mixing in a polarization-maintaining optical fibre. The process generates 4.0-4.6 ps pulses over a 25nm range with time-bandwidth products of 0.31-0.43 and conversion power penalties of less than 1.5 dB.

  3. Nonlinear materials for frequency conversion

    International Nuclear Information System (INIS)

    Velsko, S.P.; Eimerl, D.

    1988-01-01

    Two figures of merit, the threshold power (P/sub th/) and the limiting volume (V/sub min/) can be used to compare the relative efficiency and economy of new harmonic generating crystals. The properties of barium metaborate and L-Arginine phosphate are used to illustrate the effect of nonlinearity, birefringence, and damage threshold on these figures of merit

  4. Frequency up-conversion in nonpolar a-plane GaN/AlGaN based multiple quantum wells optimized for applications with silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Radosavljević, S.; Radovanović, J., E-mail: radovanovic@etf.bg.ac.rs; Milanović, V. [School of Electrical Engineering, University of Belgrade, Bulevar kralja Aleksandra 73, 11200 Belgrade (Serbia); Tomić, S. [Joule Physics Laboratory, School of Computing, Science and Engineering, University of Salford, Manchester M5 4WT (United Kingdom)

    2014-07-21

    We have described a method for structural parameters optimization of GaN/AlGaN multiple quantum well based up-converter for silicon solar cells. It involves a systematic tuning of individual step quantum wells by use of the genetic algorithm for global optimization. In quantum well structures, the up-conversion process can be achieved by utilizing nonlinear optical effects based on intersubband transitions. Both single and double step quantum wells have been tested in order to maximize the second order susceptibility derived from the density matrix formalism. The results obtained for single step wells proved slightly better and have been further pursued to obtain a more complex design, optimized for conversion of an entire range of incident photon energies.

  5. Group velocity effects in broadband frequency conversion on OMEGA. 1998 summer research program for high school juniors at the University of Rochester's Laboratory for Laser Energetic. Student research reports

    International Nuclear Information System (INIS)

    Grossman, P.

    1999-03-01

    The powerful lasers needed for ICF can only produce light in the infrared wavelengths. However, the one micron wavelength produced by the neodymium glass that powers OMEGA and other lasers used for fusion research does not efficiently compress the fuel pellet. This happens because the infrared light is not well absorbed by the target, and because of the creation of suprathermal electrons. These suprathermal electrons preheat the fuel, adding extra resistance to compression. To eliminate these problems associated with longer wavelengths of light, the process of frequency converting the laser beam was invented. This process efficiently converts the initial beam to a beam which has three times the frequency and one third the wavelength. The third-harmonic beam, in the UV range, has a better absorption rate. The PV-WAVE computer program that the author has written has shown that increasing the frequency of SSD (Smoothing by Spectral Dispersion) on OMEGA to approximately 10 GHz as planned will not hurt the third harmonic generation conversion efficiency significantly. The increased bandwidth and increased frequency of SSD will make the laser beams that strike the target on OMEGA much smoother and more uniform than ever before. Therefore it is both safe and advisable to add a second tripler crystal to the OMEGA system and decrease the SSD time cycle to around 100 picoseconds. Since the conversion efficiency remains high up to approximately 30 GHz, more experiments on OMEGA may be carried out with even higher modulation frequencies. These modifications to the existing OMEGA laser should make target irradiation more uniform, leading to more uniform compression and hopefully, a higher energy yield

  6. Tvindkraft: Implementing a 500 kW 21-IGBT-Based Frequency Converter for a 1.7 MW Wind Power Conversion System

    DEFF Research Database (Denmark)

    Gonzalez, Pablo Casado; Pang, Ying; Reigosa, Paula Diaz

    2013-01-01

    The 54-meter-high Tvindkraft windmill was built by a group of volunteers during 1975-1978, as an argument for renewable energy sources as well as an argument against nuclear power. At that time it was the world’s biggest windmill. So far, Tvindkraft has been running for 35 years, proving...... that a wellconstructed wind turbine is a sustainable approach to renewable energy utilization. This paper deals with the analysis, simulation, implementation and experimental testing of a new 500 kW 21- IGBT-based frequency converter that will run in parallel with the former 12-Thyristor-based frequency converter...... to fully utilize the capacity of the windmill. Simulations and experimental results are presented side-by-side to verify the proper functionalities of the frequency converter described in this paper....

  7. Study and development of different techniques for the generation, conversion, propagation, and radiation of high power microwaves for the electronic cyclotron frequency plasma heating

    International Nuclear Information System (INIS)

    Rebuffi, L.

    1987-10-01

    The development and optimization of a microwave technique, concerning the high frequency (electronic cyclotron frequency) plasma heating is presented. The experiments are effectuated on the Fontenay-aux-Roses TFR tokamak, with 660 kw whole power, during 100 msec, produced at 60 GHz. Low power tests are performed on the different transmission line components (there are 3, formed by metallic circular waveguides). The work also includes: the development of a lens formed by thin metallic plans; the study of slotted surface mirror; the development of a system for the accurate measurement (5.10 -6 ) of the gyrotronic frequency; a theory, based on the equivalent circuits method, generalized to the rotational and polarization mirrors; the development of a numerical simulation code. A practical scheme, for the optimization of the parameters concerning the optical transmission line project, is given. The results of this work can be applied to the experiment involving power levels, frequencies and times of impulsion increasingly higher (respectively about MW, 100 GHz and 10s) than the reported ones. Moreover, they can also be used in any experiment in the microwave field [fr

  8. Production of spectrally reconstructed uv-radiation by means of a nonlinear conversion of the generation frequency of a dye laser with lamp pumping

    Energy Technology Data Exchange (ETDEWEB)

    Anufrik, S S; Mostovnikov, V A; Rubinov, A N

    1976-03-01

    By doubling the generation frequency of an organic dye laser with lamp pumping, radiation is obtained in the spectral region of 285 to 305 nm. Depending on the mode of operation of a given laser the spectral width of the uv-radiation was 0.5 or approximately 0.003 nm. The maximum energy of second harmonic pulses was equal to approximately 0.01 J. (SJR)

  9. Uranium conversion

    International Nuclear Information System (INIS)

    Oliver, Lena; Peterson, Jenny; Wilhelmsen, Katarina

    2006-03-01

    FOI, has performed a study on uranium conversion processes that are of importance in the production of different uranium compounds in the nuclear industry. The same conversion processes are of interest both when production of nuclear fuel and production of fissile material for nuclear weapons are considered. Countries that have nuclear weapons ambitions, with the intention to produce highly enriched uranium for weapons purposes, need some degree of uranium conversion capability depending on the uranium feed material available. This report describes the processes that are needed from uranium mining and milling to the different conversion processes for converting uranium ore concentrate to uranium hexafluoride. Uranium hexafluoride is the uranium compound used in most enrichment facilities. The processes needed to produce uranium dioxide for use in nuclear fuel and the processes needed to convert different uranium compounds to uranium metal - the form of uranium that is used in a nuclear weapon - are also presented. The production of uranium ore concentrate from uranium ore is included since uranium ore concentrate is the feed material required for a uranium conversion facility. Both the chemistry and principles or the different uranium conversion processes and the equipment needed in the processes are described. Since most of the equipment that is used in a uranium conversion facility is similar to that used in conventional chemical industry, it is difficult to determine if certain equipment is considered for uranium conversion or not. However, the chemical conversion processes where UF 6 and UF 4 are present require equipment that is made of corrosion resistant material

  10. Conversation Analysis.

    Science.gov (United States)

    Schiffrin, Deborah

    1990-01-01

    Summarizes the current state of research in conversation analysis, referring primarily to six different perspectives that have developed from the philosophy, sociology, anthropology, and linguistics disciplines. These include pragmatics; speech act theory; interactional sociolinguistics; ethnomethodology; ethnography of communication; and…

  11. Growth and characterization of an efficient new NLO single crystal L-phenylalanine D-methionine for frequency conversion and optoelectronic applications

    Science.gov (United States)

    Sangeetha, P.; Jayaprakash, P.; Nageshwari, M.; Rathika Thaya Kumari, C.; Sudha, S.; Prakash, M.; Vinitha, G.; Lydia Caroline, M.

    2017-11-01

    Optically active single crystals of L-phenylalanine D-methionine (LPDM) were grown by slow evaporation technique by co-crystallization of amino acids L-phenylalanine and D-methionine in water. The unit cell dimensions have been identified from single crystal X-ray diffraction technique. The existences of various hydrocarbyls were examined by FTIR and FT-Raman spectroscopy. The carbon and hydrogen environment of the grown crystals were analyzed by FT NMR spectrum. The optical absorption studies show that the crystal is transparent in the visible region with a lower cut-off wavelength of 259 nm and there by optical band gap energy Eg is calculated to be 5.35 eV. The Urbach energy, extinction coefficient, reflectance were calculated from UV-absorption data. Further, the thermal stability and accurate melting point has been investigated by TG/DSC techniques. The Kurtz powder SHG was confirmed using Nd:YAG laser with fundamental wavelength of 1064 nm. The dielectric behavior of the specimen has been determined for various temperatures (313 K, 333 K, 353 K, 373 K) at different frequencies. Fluorescence study and the time resolved decay calculation was also performed for the LPDM crystal. Optical nonlinear susceptibility was measured in LPDM and the real and imaginary part of χ3 was evaluated by Z-scan technique using open and closed apertures.

  12. Pictorial Conversations.

    Science.gov (United States)

    Hooper, Kristina

    1982-01-01

    Provides the rationale for considering communication in a graphic domain and suggests a specific goal for designing work stations which provide graphic capabilities in educational settings. The central element of this recommendation is the "pictorial conversation", a highly interactive exchange that includes pictures as the central elements.…

  13. Quantum conversion

    OpenAIRE

    Mazilu, Michael

    2015-01-01

    ICOAM 2015 The electromagnetic momentum transferred transferred to scattering particles is proportional to the intensity of the incident fields, however, the momentum of single photons ℏk does not naturally appear in these classical expressions. Here, we discuss an alternative to Maxwell's stress tensor that renders the classical electromagnetic field momentum compatible to the quantum mechanical one. This is achieved through the introduction of the quantum conversion which allows the tran...

  14. Conversational sensemaking

    Science.gov (United States)

    Preece, Alun; Webberley, Will; Braines, Dave

    2015-05-01

    Recent advances in natural language question-answering systems and context-aware mobile apps create opportunities for improved sensemaking in a tactical setting. Users equipped with mobile devices act as both sensors (able to acquire information) and effectors (able to act in situ), operating alone or in collectives. The currently- dominant technical approaches follow either a pull model (e.g. Apple's Siri or IBM's Watson which respond to users' natural language queries) or a push model (e.g. Google's Now which sends notifications to a user based on their context). There is growing recognition that users need more flexible styles of conversational interaction, where they are able to freely ask or tell, be asked or told, seek explanations and clarifications. Ideally such conversations should involve a mix of human and machine agents, able to collaborate in collective sensemaking activities with as few barriers as possible. Desirable capabilities include adding new knowledge, collaboratively building models, invoking specific services, and drawing inferences. As a step towards this goal, we collect evidence from a number of recent pilot studies including natural experiments (e.g. situation awareness in the context of organised protests) and synthetic experiments (e.g. human and machine agents collaborating in information seeking and spot reporting). We identify some principles and areas of future research for "conversational sensemaking".

  15. Conversational sensing

    Science.gov (United States)

    Preece, Alun; Gwilliams, Chris; Parizas, Christos; Pizzocaro, Diego; Bakdash, Jonathan Z.; Braines, Dave

    2014-05-01

    Recent developments in sensing technologies, mobile devices and context-aware user interfaces have made it pos- sible to represent information fusion and situational awareness for Intelligence, Surveillance and Reconnaissance (ISR) activities as a conversational process among actors at or near the tactical edges of a network. Motivated by use cases in the domain of Company Intelligence Support Team (CoIST) tasks, this paper presents an approach to information collection, fusion and sense-making based on the use of natural language (NL) and controlled nat- ural language (CNL) to support richer forms of human-machine interaction. The approach uses a conversational protocol to facilitate a ow of collaborative messages from NL to CNL and back again in support of interactions such as: turning eyewitness reports from human observers into actionable information (from both soldier and civilian sources); fusing information from humans and physical sensors (with associated quality metadata); and assisting human analysts to make the best use of available sensing assets in an area of interest (governed by man- agement and security policies). CNL is used as a common formal knowledge representation for both machine and human agents to support reasoning, semantic information fusion and generation of rationale for inferences, in ways that remain transparent to human users. Examples are provided of various alternative styles for user feedback, including NL, CNL and graphical feedback. A pilot experiment with human subjects shows that a prototype conversational agent is able to gather usable CNL information from untrained human subjects.

  16. Parametric frequency conversion in long Josephson junctions

    International Nuclear Information System (INIS)

    Irie, F.; Ashihara, S.; Yoshida, K.

    1976-01-01

    Current steps at voltages corresponding to the parametric coupling between an applied r.f. field and junction resonant modes have been observed in long Josephson tunnel junctions in the flux-flow state. The observed periodic variations of the step height due to the applied magnetic field are explained quantitatively by a perturbational analysis using Josephson phase equations. The present study demonstrates that the moving vortex array can serve as a coherent pump wave for signal waves propagating in the barrier region, which indicates, as a result, the possibility of traveling-wave parametric devices with long Josephson tunnel junctions. (author)

  17. Generation of broadly tunable picosecond mid-infrared laser and sensitive detection of a mid-infrared signal by parametric frequency up-conversion in MgO:LiNbO3 optical parametric amplifiers

    International Nuclear Information System (INIS)

    Zhang Qiu-Lin; Zhang Jing; Qiu Kang-Sheng; Zhang Dong-Xiang; Feng Bao-Hua; Zhang Jing-Yuan

    2012-01-01

    Picosecond optical parametric generation and amplification in the near-infrared region within 1.361–1.656 μm and the mid-infrared region within 2.976–4.875 μm is constructed on the basis of bulk MgO:LiNbO 3 crystals pumped at 1.064 μm. The maximum pulse energy reaches 1.3 mJ at 1.464 μm and 0.47 mJ at 3.894 μm, corresponding to a pump-to-idler photon conversion efficiency of 25%. By seeding the hard-to-measure mid-infrared radiation as the idler in the optical parametric amplification and measuring the amplified and frequency up-converted signal in the near-infrared or even visible region, one can measure very week mid-infrared radiation with ordinary detectors, which are insensitive to mid-infrared radiation, with a very high gain. A maximum gain factor of about 7 × 10 7 is achieved at the mid-infrared wavelength of 3.374 μm and the corresponding energy detection limit is as low as about 390 aJ per pulse. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  18. Conversion of Questionnaire Data

    International Nuclear Information System (INIS)

    Powell, Danny H.; Elwood, Robert H. Jr.

    2011-01-01

    During the survey, respondents are asked to provide qualitative answers (well, adequate, needs improvement) on how well material control and accountability (MC and A) functions are being performed. These responses can be used to develop failure probabilities for basic events performed during routine operation of the MC and A systems. The failure frequencies for individual events may be used to estimate total system effectiveness using a fault tree in a probabilistic risk analysis (PRA). Numeric risk values are required for the PRA fault tree calculations that are performed to evaluate system effectiveness. So, the performance ratings in the questionnaire must be converted to relative risk values for all of the basic MC and A tasks performed in the facility. If a specific material protection, control, and accountability (MPC and A) task is being performed at the 'perfect' level, the task is considered to have a near zero risk of failure. If the task is performed at a less than perfect level, the deficiency in performance represents some risk of failure for the event. As the degree of deficiency in performance increases, the risk of failure increases. If a task that should be performed is not being performed, that task is in a state of failure. The failure probabilities of all basic events contribute to the total system risk. Conversion of questionnaire MPC and A system performance data to numeric values is a separate function from the process of completing the questionnaire. When specific questions in the questionnaire are answered, the focus is on correctly assessing and reporting, in an adjectival manner, the actual performance of the related MC and A function. Prior to conversion, consideration should not be given to the numeric value that will be assigned during the conversion process. In the conversion process, adjectival responses to questions on system performance are quantified based on a log normal scale typically used in human error analysis (see A

  19. Autonomous renewable energy conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Valtchev, V. [Technical University of Varna (Bulgaria). Dept. of Electronics; Bossche, A. van den; Ghijselen, J.; Melkebeek, J. [University of Gent (Belgium). Dept. of Electrical Power Engineering

    2000-02-01

    This paper briefly reviews the need for renewable power generation and describes a medium-power Autonomous Renewable Energy Conversion System (ARECS), integrating conversion of wind and solar energy sources. The objectives of the paper are to extract maximum power from the proposed wind energy conversion scheme and to transfer this power and the power derived by the photovoltaic system in a high efficiency way to a local isolated load. The wind energy conversion operates at variable shaft speed yielding an improved annual energy production over constant speed systems. An induction generator (IG) has been used because of its reduced cost, robustness, absence of separate DC source for excitation, easier dismounting and maintenance. The maximum energy transfer of the wind energy is assured by a simple and reliable control strategy adjusting the stator frequency of the IG so that the power drawn is equal to the peak power production of the wind turbine at any wind speed. The presented control strategy also provides an optimal efficiency operation of the IG by applying a quadratic dependence between the IG terminal voltage and frequency V {approx} f{sup 2}. For improving the total system efficiency, high efficiency converters have been designed and implemented. The modular principle of the proposed DC/DC conversion provides the possibility for modifying the system structure depending on different conditions. The configuration of the presented ARECS and the implementation of the proposed control algorithm for optimal power transfer are fully discussed. The stability and dynamic performance as well as the different operation modes of the proposed control and the operation of the converters are illustrated and verified on an experimental prototype. (author)

  20. Special issue: Plasma Conversion

    NARCIS (Netherlands)

    Nozaki, T.; Bogaerts, A.; Tu, X.; van de Sanden, M. C. M.

    2017-01-01

    With growing concern of energy and environmental issues, the combination of plasma and heterogeneous catalysts receives special attention in greenhouse gas conversion, nitrogen fixation and hydrocarbon chemistry. Plasma gas conversion driven by renewable electricity is particularly important for the

  1. A Model for Conversation

    DEFF Research Database (Denmark)

    Ayres, Phil

    2012-01-01

    This essay discusses models. It examines what models are, the roles models perform and suggests various intentions that underlie their construction and use. It discusses how models act as a conversational partner, and how they support various forms of conversation within the conversational activity...

  2. Direct Conversion of Energy.

    Science.gov (United States)

    Corliss, William R.

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. Direct energy conversion involves energy transformation without moving parts. The concepts of direct and dynamic energy conversion plus the laws governing energy conversion are investigated. Among the topics…

  3. submitter Development of a 100 kW, 12.5 kV, 22 kHz and 30 kV insulated medium frequency transformer for compact and reliable medium voltage power conversion

    CERN Document Server

    Isler, Stephane; Aguglia, Davide; Bonnin, Xavier Abel

    2017-01-01

    This paper presents the critical design aspects addressed during the development of a 100 kW, 12.5 kV, 22 kHz, and 30 kV insulated medium frequency transformer used in a power converter. The transformers are used in a resonant multilevel converter topology producing HV DC voltage from a three phase 400 V AC industrial grid. The power converter is used to supply radio frequency systems in particle accelerators. Considerations about material selection, dielectric, magnetic and thermal design are discussed and experimental results on the full scale transformer and power converter are presented.

  4. Elements of energy conversion

    CERN Document Server

    Russell, Charles R

    2013-01-01

    Elements of Energy Conversion brings together scattered information on the subject of energy conversion and presents it in terms of the fundamental thermodynamics that apply to energy conversion by any process. Emphasis is given to the development of the theory of heat engines because these are and will remain most important power sources. Descriptive material is then presented to provide elementary information on all important energy conversion devices. The book contains 10 chapters and opens with a discussion of forms of energy, energy sources and storage, and energy conversion. This is foll

  5. Iterated multidimensional wave conversion

    International Nuclear Information System (INIS)

    Brizard, A. J.; Tracy, E. R.; Johnston, D.; Kaufman, A. N.; Richardson, A. S.; Zobin, N.

    2011-01-01

    Mode conversion can occur repeatedly in a two-dimensional cavity (e.g., the poloidal cross section of an axisymmetric tokamak). We report on two novel concepts that allow for a complete and global visualization of the ray evolution under iterated conversions. First, iterated conversion is discussed in terms of ray-induced maps from the two-dimensional conversion surface to itself (which can be visualized in terms of three-dimensional rooms). Second, the two-dimensional conversion surface is shown to possess a symplectic structure derived from Dirac constraints associated with the two dispersion surfaces of the interacting waves.

  6. Computers and conversation

    CERN Document Server

    Luff, Paul; Gilbert, Nigel G

    1986-01-01

    In the past few years a branch of sociology, conversation analysis, has begun to have a significant impact on the design of human*b1computer interaction (HCI). The investigation of human*b1human dialogue has emerged as a fruitful foundation for interactive system design.****This book includes eleven original chapters by leading researchers who are applying conversation analysis to HCI. The fundamentals of conversation analysis are outlined, a number of systems are described, and a critical view of their value for HCI is offered.****Computers and Conversation will be of interest to all concerne

  7. Wind Energy Conversion Systems Technology and Trends

    CERN Document Server

    2012-01-01

    Wind Energy Conversion System covers the technological progress of wind energy conversion systems, along with potential future trends. It includes recently developed wind energy conversion systems such as multi-converter operation of variable-speed wind generators, lightning protection schemes, voltage flicker mitigation and prediction schemes for advanced control of wind generators. Modeling and control strategies of variable speed wind generators are discussed, together with the frequency converter topologies suitable for grid integration. Wind Energy Conversion System also describes offshore farm technologies including multi-terminal topology and space-based wind observation schemes, as well as both AC and DC based wind farm topologies. The stability and reliability of wind farms are discussed, and grid integration issues are examined in the context of the most recent industry guidelines. Wind power smoothing, one of the big challenges for transmission system operators, is a particular focus. Fault ride th...

  8. Spontaneous and radiation induced gene conversion in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Rao, B.S.; Murthy, M.S.S.

    1977-01-01

    Spontaneous and radiation induced gene conversion to arginine independence was studied in a heteroallelic diploid strain of yeast Saccharomyces cerevisiae BZ 34. When stationary phase cells were incubated in phosphate buffer (pH 7 ) at 30 0 C under aerated condition for 48 hours, the conversion frequency increased by a factor of about 1000 times the background. This was found to be so even when the cells were incubated in saline (0.85%) or distilled water. Various conditions influencing this enhancement have been investigated. Conversion frequency enhancement was not significant under anoxic conditions and was absent at low temperatures and in log phase cells. Caffeine could inhibit this enhancement when present in the suspension medium. These results can be explained on the basis of the induction of meiosis in cells held in buffer. Microscopic examination confirmed this view. Under conditions not favourable for the onset of meiosis there is no significant enhancement in conversion frequency. In stationary phase cells exposed to series of gamma doses, the conversion frequency increases with dose. Post irradiation incubation in buffer further increases the conversion frequency. However, the increase expressed as the ratio of the conversion frequency on buffer holding to that on immediate plating decreased with increasing dose. This decrease in enhancement with increasing dose may be due to the dose dependent inhibition of meiosis. (author)

  9. Energy conversion alternatives study

    Science.gov (United States)

    Shure, L. T.

    1979-01-01

    Comparison of coal based energy systems is given. Study identifies and compares various advanced energy conversion systems using coal or coal derived fuels for baselaoad electric power generation. Energy Conversion Alternatives Study (ECAS) reports provede government, industry, and general public with technically consistent basis for comparison of system's options of interest for fossilfired electric-utility application.

  10. Hydrothermal conversion of biomass

    NARCIS (Netherlands)

    Knezevic, D.

    2009-01-01

    This thesis presents research of hydrothermal conversion of biomass (HTC). In this process, hot compressed water (subcritical water) is used as the reaction medium. Therefore this technique is suitable for conversion of wet biomass/ waste streams. By working at high pressures, the evaporation of

  11. Conversations in African Philosophy

    African Journals Online (AJOL)

    JONATHAN

    Conversational philosophy is articulated by Jonathan O. Chimakonam as the new wave of philosophical practice both in “place” and in “space”. This journal adopts and promotes this approach to philosophizing for African philosophy. Readers are encouraged to submit their conversational piece (maximum of 2000 words) ...

  12. Microwave plasma mode conversion

    International Nuclear Information System (INIS)

    Torres, H.S.; Sakanaka, P.H.; Villarroel, C.H.

    1985-01-01

    The behavior of hot electrons during the process of laser-produced plasma is studied. The basic equations of mode conversion from electromagnetic waves to electrostatic waves are presented. It is shown by mode conversion, that, the resonant absorption and parametric instabilities appear simultaneously, but in different plasma regions. (M.C.K.) [pt

  13. Political conversations on Facebook

    DEFF Research Database (Denmark)

    Sørensen, Mads P.

    2016-01-01

    Political conversations are according to theories on deliberative democracy essential to well-functioning democracies. Traditionally these conversations have taken place in face-to-face settings, in e.g. party meetings and town meetings. However, social media such as Facebook and Twitter offers new...... possibilities for online political conversations between citizens and politicians. This paper examines the presence on Facebook and Twitter of Members of the Danish national Parliament, the Folketing, and focusses on a quantitative mapping of the political conversation activities taking place in the threads...... following Facebook posts from Danish Members of Parliament (MPs). The paper shows that, in comparison with previous findings from other countries, Danish MPs have a relatively high degree of engagement in political conversations with citizens on Facebook – and that a large number of citizens follow MPs...

  14. Photon - axion conversion cross sections in an electromagnetic field

    International Nuclear Information System (INIS)

    Dang Van Soa; Ha Huy Bang

    1999-12-01

    Photon - axion conversions in static magnetic fields and in a periodic field with frequency equal to the axion mass are reconsidered in detail by Feynman methods. The differential cross sections are presented and numerical evaluations are given. It is shown that there is a resonant conversion for the considered process. Some estimates for experiments are given from our results. (author)

  15. Uranium conversion; Urankonvertering

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, Lena; Peterson, Jenny; Wilhelmsen, Katarina [Swedish Defence Research Agency (FOI), Stockholm (Sweden)

    2006-03-15

    FOI, has performed a study on uranium conversion processes that are of importance in the production of different uranium compounds in the nuclear industry. The same conversion processes are of interest both when production of nuclear fuel and production of fissile material for nuclear weapons are considered. Countries that have nuclear weapons ambitions, with the intention to produce highly enriched uranium for weapons purposes, need some degree of uranium conversion capability depending on the uranium feed material available. This report describes the processes that are needed from uranium mining and milling to the different conversion processes for converting uranium ore concentrate to uranium hexafluoride. Uranium hexafluoride is the uranium compound used in most enrichment facilities. The processes needed to produce uranium dioxide for use in nuclear fuel and the processes needed to convert different uranium compounds to uranium metal - the form of uranium that is used in a nuclear weapon - are also presented. The production of uranium ore concentrate from uranium ore is included since uranium ore concentrate is the feed material required for a uranium conversion facility. Both the chemistry and principles or the different uranium conversion processes and the equipment needed in the processes are described. Since most of the equipment that is used in a uranium conversion facility is similar to that used in conventional chemical industry, it is difficult to determine if certain equipment is considered for uranium conversion or not. However, the chemical conversion processes where UF{sub 6} and UF{sub 4} are present require equipment that is made of corrosion resistant material.

  16. Solar energy conversion systems

    CERN Document Server

    Brownson, Jeffrey R S

    2013-01-01

    Solar energy conversion requires a different mind-set from traditional energy engineering in order to assess distribution, scales of use, systems design, predictive economic models for fluctuating solar resources, and planning to address transient cycles and social adoption. Solar Energy Conversion Systems examines solar energy conversion as an integrative design process, applying systems thinking methods to a solid knowledge base for creators of solar energy systems. This approach permits different levels of access for the emerging broad audience of scientists, engineers, architects, planners

  17. Energy conversion statics

    CERN Document Server

    Messerle, H K; Declaris, Nicholas

    2013-01-01

    Energy Conversion Statics deals with equilibrium situations and processes linking equilibrium states. A development of the basic theory of energy conversion statics and its applications is presented. In the applications the emphasis is on processes involving electrical energy. The text commences by introducing the general concept of energy with a survey of primary and secondary energy forms, their availability, and use. The second chapter presents the basic laws of energy conversion. Four postulates defining the overall range of applicability of the general theory are set out, demonstrating th

  18. Uranium Conversion & Enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-06

    The isotopes of uranium that are found in nature, and hence in ‘fresh’ Yellowcake’, are not in relative proportions that are suitable for power or weapons applications. The goal of conversion then is to transform the U3O8 yellowcake into UF6. Conversion and enrichment of uranium is usually required to obtain material with enough 235U to be usable as fuel in a reactor or weapon. The cost, size, and complexity of practical conversion and enrichment facilities aid in nonproliferation by design.

  19. Postoperative conversion disorder.

    Science.gov (United States)

    Afolabi, Kola; Ali, Sameer; Gahtan, Vivian; Gorji, Reza; Li, Fenghua; Nussmeier, Nancy A

    2016-05-01

    Conversion disorder is a psychiatric disorder in which psychological stress causes neurologic deficits. A 28-year-old female surgical patient had uneventful general anesthesia and emergence but developed conversion disorder 1 hour postoperatively. She reported difficulty speaking, right-hand numbness and weakness, and right-leg paralysis. Neurologic examination and imaging revealed no neuronal damage, herniation, hemorrhage, or stroke. The patient mentioned failing examinations the day before surgery and discontinuing her prescribed antidepressant medication, leading us to diagnose conversion disorder, with eventual confirmation by neuroimaging and follow-up examinations. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Uranium conversion wastes

    International Nuclear Information System (INIS)

    Vicente, R.; Dellamano, J.C.

    1989-12-01

    A set of mathematical equations was developed and used to estimate the radiological significance of each radionuclide potentially present in the uranium refining industry effluents. The equations described the evolution in time of the radionuclides activities in the uranium fuel cycle, from mining and milling, through the yellowcake, till the conversion effluents. Some radionuclides that are not usually monitored in conversion effluents (e.g. Pa-231 and Ac-227) were found to be potentially relevant from the radiological point of view in conversion facilities, and are certainly relevant in mining and milling industry, at least in a few waste streams. (author) [pt

  1. Freely flowing conversations

    DEFF Research Database (Denmark)

    Aakjær, Marie Kirstejn; Andrade, David; Dexters, Peter

    and in regards to rehabilitation efforts. In the context of prisons UDI is inspired by the complexity approach (Stacey 2005). We seek to facilitate freely flowing conversations between inmates, staff and managers – pushing the boundaries of existing norms, roles and beliefs. In the end however we rely...... relations by changing conversations. Through the theoretical framework of the complexity approach, we discuss how this may lead to organizational change. Finally we suggest that inviting inmates to take part in conversations about core organizational development may be a fundamental strategy in trying...

  2. Conversion of electromagnetic waves at the ionisation front

    International Nuclear Information System (INIS)

    Chegotov, M V

    2001-01-01

    It is shown that a weak electromagnetic pulse interacting with a copropagating ionisation front is converted in the general case into three electromagnetic pulses with higher and lower frequencies, which propagate in different directions. The coefficients of conversion to these pulses (for intensities) were found as functions of the frequency. The electromagnetic energy is shown to decrease during this conversion because of the losses for the residual electron energy. (interaction of laser radiation with matter. laser plasma)

  3. Mining Conversational Social Video

    OpenAIRE

    Biel, Joan-Isaac

    2013-01-01

    The ubiquity of social media in our daily life, the intense user participation, and the explo- sion of multimedia content have generated an extraordinary interest from computer and social scientists to investigate the traces left by users to understand human behavior online. From this perspective, YouTube can be seen as the largest collection of audiovisual human behavioral data, among which conversational video blogs (vlogs) are one of the basic formats. Conversational vlogs have evolved fro...

  4. Persuasion detection in conversation

    OpenAIRE

    Gilbert, Henry T.

    2010-01-01

    Approved for public release; distribution is unlimited In this thesis, we present a system for annotating persuasion in conversation based on a social-psychological model. We augmented the social model developed by James Cialdini with some of our own categories for annotators to label. The conversations consisted of 37 hostage negotiation transcripts from private and public sources, with all personal information removed from the private source transcripts. We evaluated the level of agre...

  5. Perspective on direct conversion

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, W B

    1963-10-15

    The objective of direct conversion is high electrical output for minimum total cost, and not always high conversion efficiency. The wide range of techniques embracing cryogenics and hot plasma derives from the special requirements of source, environment, and application. Sources include solar and other radiation, nuclear fission and fusion, chemical energy, and heat. Environments and applications range from space vehicles to submarines and from giant power networks to isolated buoys and pocket devices. (auth)

  6. The calcium and rare earth oxo-borates, Ca4ReO(BO3)3 (Re = Gd, Y, La): synthesis and investigations of new non-critical phase matching configurations for frequency conversion at specific laser wavelengths

    International Nuclear Information System (INIS)

    Reino, E.

    2002-12-01

    Visible and UV lasers are currently investigated for many applications as data storage, medicine, etc. Intracavity frequency doubling appears as a good solution. Thus, the non-linear family Ca 4 REO(BO 3 ) 3 (RE = rare earth, RECOB) has shown a considerable interest to produce compact visible laser. In addition, it is possible to tune the compositions of RECOB by partial substitutions in order to achieve non-critical phase matching (NCPM). In the present work, various cationic substitutions have been studied in solid solutions as Gd 1-x Y x COB, Gd 1-x La x COB, Gd 1-x Sc x COB (for the first time), Re 1-x Bi x COB (REe = Gd or Y) and (Ca 1-x Sr x ) 4 GdO(BO 3 ) 3 in order to investigate their crystal growth and adjust the NCPM wavelength by composition. The wavelength range is related to neodymium doped laser materials emitting on the 4F3/2-4I9/2 transition, for example Nd:YAP (YAlO 3 ) at 930 nm, Nd:YAG (Y 3 Al 5 O 12 ) at 946 nm or Nd:ASL (Sr 1-x Nd y La x-y Mg x Al 11-x O 19 ) at 900 nm. We have also demonstrated that the compositions for NCPM can be determined from the refractive index of both lattices M 1-x M' x COB (M, M' RE) with x = 0 or 1, using the Clausius-Mosotti relation. Two new blue laser systems, constituted of a laser crystal and a non-linear crystal optimized for type-I NCPM second harmonic generation, were achieved: a 946 nm Nd:YAG laser with Gd 0.87 Y 0.13 COB and a 900 nm Nd:ASL laser with Gd 0.56 Y 0.44 COB. Moreover, we have performed for the first time a CW laser action at 900 nm with Nd:ASL. (author)

  7. Conversational flow promotes solidarity.

    Science.gov (United States)

    Koudenburg, Namkje; Postmes, Tom; Gordijn, Ernestine H

    2013-01-01

    Social interaction is fundamental to the development of various aspects of "we-ness". Previous research has focused on the role the content of interaction plays in establishing feelings of unity, belongingness and shared reality (a cluster of variables referred to as solidarity here). The present paper is less concerned with content, but focuses on the form of social interaction. We propose that the degree to which conversations flow smoothly or not is, of itself, a cue to solidarity. We test this hypothesis in samples of unacquainted and acquainted dyads who communicate via headsets. Conversational flow is disrupted by introducing a delay in the auditory feedback (vs. no delay). Results of three studies show that smoothly coordinated conversations (compared with disrupted conversations and a control condition) increase feelings of belonging and perceptions of group entitativity, independently of conversation content. These effects are driven by the subjective experience of conversational flow. Our data suggest that this process occurs largely beyond individuals' control. We conclude that the form of social interaction is a powerful cue for inferring group solidarity. Implications for the impact of modern communication technology on developing a shared social identity are discussed.

  8. Conversational flow promotes solidarity.

    Directory of Open Access Journals (Sweden)

    Namkje Koudenburg

    Full Text Available Social interaction is fundamental to the development of various aspects of "we-ness". Previous research has focused on the role the content of interaction plays in establishing feelings of unity, belongingness and shared reality (a cluster of variables referred to as solidarity here. The present paper is less concerned with content, but focuses on the form of social interaction. We propose that the degree to which conversations flow smoothly or not is, of itself, a cue to solidarity. We test this hypothesis in samples of unacquainted and acquainted dyads who communicate via headsets. Conversational flow is disrupted by introducing a delay in the auditory feedback (vs. no delay. Results of three studies show that smoothly coordinated conversations (compared with disrupted conversations and a control condition increase feelings of belonging and perceptions of group entitativity, independently of conversation content. These effects are driven by the subjective experience of conversational flow. Our data suggest that this process occurs largely beyond individuals' control. We conclude that the form of social interaction is a powerful cue for inferring group solidarity. Implications for the impact of modern communication technology on developing a shared social identity are discussed.

  9. Wideband FM Demodulation and Multirate Frequency Transformations

    Science.gov (United States)

    2016-12-15

    Noble identities to extend the proposed approach to larger wideband to narrowband conversion factors and more practical implementations. We further...framework . . . . . . . . . . . . . . . . . . . . . 8 2 Block diagrams of the alternative MFT system for large conversion factors (a) and the Noble Identity ...of both MFT frameworks with conversion factor R = 128 and normalized radian frequency shift wd = 0.1π under the extreme senario with modulation index

  10. EVALUATION OF DIFFERENT FEEDING FREQUENCIES ON ...

    African Journals Online (AJOL)

    USER

    EVALUATION OF DIFFERENT FEEDING FREQUENCIES ON GROWTH .... using one-way analysis of variance (ANOVA) and ... SGR = Specific Growth Rate, FCR = Food Conversion Ratio, K = Condition Factor and SR = Survival Rate.

  11. Thermal birefringence-compensated linear intracavity frequency ...

    Indian Academy of Sciences (India)

    2014-02-09

    Feb 9, 2014 ... is demonstrated. The corresponding optical to optical conversion efficiency is estimated to be ... and reasonably good beam quality is an attractive source for various industrial and sci- entific applications. ... ity frequency doubled Nd:YAG laser with ∼12.7% pump to green conversion efficiency. The laser is ...

  12. Astrophysicists' conversational connections on Twitter.

    Directory of Open Access Journals (Sweden)

    Kim Holmberg

    Full Text Available Because Twitter and other social media are increasingly used for analyses based on altmetrics, this research sought to understand what contexts, affordance use, and social activities influence the tweeting behavior of astrophysicists. Thus, the presented study has been guided by three research questions that consider the influence of astrophysicists' activities (i.e., publishing and tweeting frequency and of their tweet construction and affordance use (i.e. use of hashtags, language, and emotions on the conversational connections they have on Twitter. We found that astrophysicists communicate with a variety of user types (e.g. colleagues, science communicators, other researchers, and educators and that in the ego networks of the astrophysicists clear groups consisting of users with different professional roles can be distinguished. Interestingly, the analysis of noun phrases and hashtags showed that when the astrophysicists address the different groups of very different professional composition they use very similar terminology, but that they do not talk to each other (i.e. mentioning other user names in tweets. The results also showed that in those areas of the ego networks that tweeted more the sentiment of the tweets tended to be closer to neutral, connecting frequent tweeting with information sharing activities rather than conversations or expressing opinions.

  13. Boiler conversions for biomass

    Energy Technology Data Exchange (ETDEWEB)

    Kinni, J [Tampella Power Inc., Tampere (Finland)

    1997-12-31

    Boiler conversions from grate- and oil-fired boilers to bubbling fluidized bed combustion have been most common in pulp and paper industry. Water treatment sludge combustion, need for additional capacity and tightened emission limits have been the driving forces for the conversion. To accomplish a boiler conversion for biofuel, the lower part of the boiler is replaced with a fluidized bed bottom and new fuel, ash and air systems are added. The Imatran Voima Rauhalahti pulverized-peat-fired boiler was converted to bubbling fluidized bed firing in 1993. In the conversion the boiler capacity was increased by 10 % to 295 MWth and NO{sub x} emissions dropped. In the Kymmene Kuusankoski boiler, the reason for conversion was the combustion of high chlorine content biosludge. The emissions have been under general European limits. During the next years, the emission limits will tighten and the boilers will be designed for most complete combustion and compounds, which can be removed from flue gases, will be taken care of after the boiler. (orig.) 3 refs.

  14. Boiler conversions for biomass

    Energy Technology Data Exchange (ETDEWEB)

    Kinni, J. [Tampella Power Inc., Tampere (Finland)

    1996-12-31

    Boiler conversions from grate- and oil-fired boilers to bubbling fluidized bed combustion have been most common in pulp and paper industry. Water treatment sludge combustion, need for additional capacity and tightened emission limits have been the driving forces for the conversion. To accomplish a boiler conversion for biofuel, the lower part of the boiler is replaced with a fluidized bed bottom and new fuel, ash and air systems are added. The Imatran Voima Rauhalahti pulverized-peat-fired boiler was converted to bubbling fluidized bed firing in 1993. In the conversion the boiler capacity was increased by 10 % to 295 MWth and NO{sub x} emissions dropped. In the Kymmene Kuusankoski boiler, the reason for conversion was the combustion of high chlorine content biosludge. The emissions have been under general European limits. During the next years, the emission limits will tighten and the boilers will be designed for most complete combustion and compounds, which can be removed from flue gases, will be taken care of after the boiler. (orig.) 3 refs.

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

    International Nuclear Information System (INIS)

    Tanaka, Takayasu

    1993-01-01

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

  16. Photovoltaic solar energy conversion

    CERN Document Server

    Bauer, Gottfried H

    2015-01-01

    This concise primer on photovoltaic solar energy conversion invites readers to reflect on the conversion of solar light into energy at the most fundamental level and encourages newcomers to the field to help find meaningful answers on how photovoltaic solar energy conversion can work (better), eventually contributing to its ongoing advancement. The book is based on lectures given to graduate students in the Physics Department at the University of Oldenburg over the last two decades, yet also provides an easy-to-follow introduction for doctoral and postdoctoral students from related disciplines such as the materials sciences and electrical engineering. Inspired by classic textbooks in the field, it reflects the author’s own ideas on how to understand, visualize and eventually teach the microscopic physical mechanisms and effects, while keeping the text as concise as possible so as to introduce interested readers to the field and balancing essential knowledge with open questions.

  17. Catalytic Conversion of Carbohydrates

    DEFF Research Database (Denmark)

    Osmundsen, Christian Mårup

    a renewable route to aromatics. The conversion of biomass by high temperature processes is a desirable prospect due to the high volumetric production rates which can be achieved, and the ability of these types of processes to convert a wide range of substrates. Current processes however typically have rather...... with the production of commodity chemicals from the most abundantly available renewable source of carbon, carbohydrates. The production of alkyl lactates by the Lewis acid catalyzed conversion of hexoses is an interesting alternative to current fermentation based processes. A range of stannosilicates were...... to be an efficient initial conversion step in the utilization of biomass for chemicals production. The shift from an oil based chemical industry to one based on renewable resources is bound to happen sooner or later, however the environmental problems associated with the burning of fossil resources means...

  18. Predictability of Conversation Partners

    Science.gov (United States)

    Takaguchi, Taro; Nakamura, Mitsuhiro; Sato, Nobuo; Yano, Kazuo; Masuda, Naoki

    2011-08-01

    Recent developments in sensing technologies have enabled us to examine the nature of human social behavior in greater detail. By applying an information-theoretic method to the spatiotemporal data of cell-phone locations, [C. Song , ScienceSCIEAS0036-8075 327, 1018 (2010)] found that human mobility patterns are remarkably predictable. Inspired by their work, we address a similar predictability question in a different kind of human social activity: conversation events. The predictability in the sequence of one’s conversation partners is defined as the degree to which one’s next conversation partner can be predicted given the current partner. We quantify this predictability by using the mutual information. We examine the predictability of conversation events for each individual using the longitudinal data of face-to-face interactions collected from two company offices in Japan. Each subject wears a name tag equipped with an infrared sensor node, and conversation events are marked when signals are exchanged between sensor nodes in close proximity. We find that the conversation events are predictable to a certain extent; knowing the current partner decreases the uncertainty about the next partner by 28.4% on average. Much of the predictability is explained by long-tailed distributions of interevent intervals. However, a predictability also exists in the data, apart from the contribution of their long-tailed nature. In addition, an individual’s predictability is correlated with the position of the individual in the static social network derived from the data. Individuals confined in a community—in the sense of an abundance of surrounding triangles—tend to have low predictability, and those bridging different communities tend to have high predictability.

  19. Predictability of Conversation Partners

    Directory of Open Access Journals (Sweden)

    Taro Takaguchi

    2011-09-01

    Full Text Available Recent developments in sensing technologies have enabled us to examine the nature of human social behavior in greater detail. By applying an information-theoretic method to the spatiotemporal data of cell-phone locations, [C. Song et al., Science 327, 1018 (2010SCIEAS0036-8075] found that human mobility patterns are remarkably predictable. Inspired by their work, we address a similar predictability question in a different kind of human social activity: conversation events. The predictability in the sequence of one’s conversation partners is defined as the degree to which one’s next conversation partner can be predicted given the current partner. We quantify this predictability by using the mutual information. We examine the predictability of conversation events for each individual using the longitudinal data of face-to-face interactions collected from two company offices in Japan. Each subject wears a name tag equipped with an infrared sensor node, and conversation events are marked when signals are exchanged between sensor nodes in close proximity. We find that the conversation events are predictable to a certain extent; knowing the current partner decreases the uncertainty about the next partner by 28.4% on average. Much of the predictability is explained by long-tailed distributions of interevent intervals. However, a predictability also exists in the data, apart from the contribution of their long-tailed nature. In addition, an individual’s predictability is correlated with the position of the individual in the static social network derived from the data. Individuals confined in a community—in the sense of an abundance of surrounding triangles—tend to have low predictability, and those bridging different communities tend to have high predictability.

  20. Converse Barrier Certificate Theorem

    DEFF Research Database (Denmark)

    Wisniewski, Rafael; Sloth, Christoffer

    2013-01-01

    This paper presents a converse barrier certificate theorem for a generic dynamical system.We show that a barrier certificate exists for any safe dynamical system defined on a compact manifold. Other authors have developed a related result, by assuming that the dynamical system has no singular...... points in the considered subset of the state space. In this paper, we redefine the standard notion of safety to comply with generic dynamical systems with multiple singularities. Afterwards, we prove the converse barrier certificate theorem and illustrate the differences between ours and previous work...

  1. Dose conversion factors

    International Nuclear Information System (INIS)

    Kocher, D.C.; Eckerman, K.F.

    1992-01-01

    The following is discussed in this report: concepts and quantities used in calculating radiation dose from internal and external exposure. Tabulations of dose conversion factor for internal and external exposure to radionuclides. Dose conversion factors give dose per unit intake (internal) or dose per unit concentration in environment (external). Intakes of radionuclides for internal exposure and concentrations of radionuclides in environment for external exposure are assumed to be known. Intakes and concentrations are obtained, e.g., from analyses of environmental transport and exposure pathways. differences between dosimetry methods for radionuclides and hazardous chemicals are highlighted

  2. Ocean wave energy conversion

    CERN Document Server

    McCormick, Michael E

    2007-01-01

    This volume will prove of vital interest to those studying the use of renewable resources. Scientists, engineers, and inventors will find it a valuable review of ocean wave mechanics as well as an introduction to wave energy conversion. It presents physical and mathematical descriptions of the nine generic wave energy conversion techniques, along with their uses and performance characteristics.Author Michael E. McCormick is the Corbin A. McNeill Professor of Naval Engineering at the U.S. Naval Academy. In addition to his timely and significant coverage of possible environmental effects associa

  3. Magnetohydrodynamic energy conversion

    International Nuclear Information System (INIS)

    Rosa, R.J.

    1987-01-01

    The object of this book is to present a review of the basic principles and practical aspects of magnetohydrodynamic (MHD) energy conversion. The author has tried to give qualitative semiphysical arguments where possible for the benefit of the reader who is unfamiliar with plasma physics. The aim of MHD energy conversion is to apply to a specific practical goal a part of what has become a vast area of science called plasma physics. The author has attempted to note in the text where a broader view might be fruitful and to give appropriate references

  4. Frequency standards

    CERN Document Server

    Riehle, Fritz

    2006-01-01

    Of all measurement units, frequency is the one that may be determined with the highest degree of accuracy. It equally allows precise measurements of other physical and technical quantities, whenever they can be measured in terms of frequency.This volume covers the central methods and techniques relevant for frequency standards developed in physics, electronics, quantum electronics, and statistics. After a review of the basic principles, the book looks at the realisation of commonly used components. It then continues with the description and characterisation of important frequency standards

  5. Catalytic Conversion of Biofuels

    DEFF Research Database (Denmark)

    Jørgensen, Betina

    This thesis describes the catalytic conversion of bioethanol into higher value chemicals. The motivation has been the unavoidable coming depletion of the fossil resources. The thesis is focused on two ways of utilising ethanol; the steam reforming of ethanol to form hydrogen and the partial oxida...

  6. Electrochemical solar energy conversion

    International Nuclear Information System (INIS)

    Gerischer, H.

    1991-01-01

    The principles of solar energy conversion in photoelectrochemical cells are briefly reviewed. Cells for the generation of electric power and for energy storage in form of electrochemical energy are described. These systems are compared with solid state photovoltaic devices, and the inherent difficulties for the operation of the electrochemical systems are analyzed. (author). 28 refs, 10 figs

  7. Converse Barrier Certificate Theorems

    DEFF Research Database (Denmark)

    Wisniewski, Rafael; Sloth, Christoffer

    2016-01-01

    This paper shows that a barrier certificate exists for any safe dynamical system. Specifically, we prove converse barrier certificate theorems for a class of structurally stable dynamical systems. Other authors have developed a related result by assuming that the dynamical system has neither...

  8. Wavelength conversion devices

    DEFF Research Database (Denmark)

    Mikkelsen, Benny; Durhuus, Terji; Jørgensen, Carsten

    1996-01-01

    system requirements. The ideal wavelength converter should be transparent to the bit rate and signal format and provide an unchirped output signal with both a high extinction ratio and a large signal-to-noise ratio. It should allow conversion to both shorter and longer wavelengths with equal performance...

  9. Conversation and research

    NARCIS (Netherlands)

    Schuurman, Jan Gerrit; Veermans, K.H.

    2001-01-01

    Gordon Pask’s conversation theory was created in the 1970s. The theory encompasses a high-level framework for studying interactions between actors in artificial situations where people co-operate, have conflicts, follow rules, negotiate outcomes, invent new rules together, etc. Sadly, the theory is

  10. Catalyst for hydrocarbon conversion

    International Nuclear Information System (INIS)

    Duhaut, P.; Miquel, J.

    1975-01-01

    A description is given for a catalyst and process for hydrocarbon conversions, e.g., reforming. The catalyst contains an alumina carrier, platinum, iridium, at least one metal selected from uranium, vanadium, and gallium, and optionally halogen in the form of metal halide of one of the aforesaid components. (U.S.)

  11. The Nanticoke conversion study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-04-01

    A study was conducted to assess the conversion of the Nanticoke coal-fired power plant to cleaner burning natural gas combined-cycle gas turbines. The Nanticoke Generating Station on Lake Erie is responsible for more than 50 per cent of Ontario Power Generation's (OPG) coal-fired electricity production. The OPG is proposing to work towards compliance with the newly signed Ozone Annex to the 1991 Canada-United States Air Quality Agreement which will require fossil-fueled power plants in southern Ontario to reduce their smog-causing nitrogen oxides emissions by about 50 per cent by 2007. This study assessed the emission reduction benefits and financial costs of conversion compared to continuing to operate Nanticoke as a coal-fired plant. The analysis includes a base case set of data on fuel prices, retrofit costs, fuel efficiencies, annual capacity factors and other parameters. It was determined that conversion would cost the average household less than $3 per month on their electricity bill. Conversion would also reduce emissions nitrogen oxide, a major smog pollutant, by 83 per cent and the particulates that form the most health-threatening portion of smog would be reduced by 100 per cent. 15 tabs., 1 fig.

  12. Leadership is a conversation.

    Science.gov (United States)

    Groysberg, Boris; Slind, Michael

    2012-06-01

    Globalization and new technologies have sharply reduced the efficacy of command-and-control management and its accompanying forms of corporate communication. In the course of a recent research project, the authors concluded that by talking with employees, rather than simply issuing orders, leaders can promote operational flexibility, employee engagement, and tight strategic alignment. Groysberg and Slind have identified four elements of organizational conversation that reflect the essential attributes of interpersonal conversation: intimacy, interactivity, inclusion, and intentionality. Intimacy shifts the focus from a top-down distribution of information to a bottom-up exchange of ideas. Organizational conversation is less corporate in tone and more casual. And it's less about issuing and taking orders than about asking and answering questions. Interactivity entails shunning the simplicity of monologue and embracing the unpredictable vitality of dialogue. Traditional one-way media-print and broadcast, in particular-give way to social media buttressed by social thinking. Inclusion turns employees into full-fledged conversation partners, entitling them to provide their own ideas, often on company channels. They can create content and act as brand ambassadors, thought leaders, and storytellers. Intentionality enables leaders and employees to derive strategically relevant action from the push and pull of discussion and debate.

  13. Predicting AD conversion

    DEFF Research Database (Denmark)

    Liu, Yawu; Mattila, Jussi; Ruiz, Miguel �ngel Mu�oz

    2013-01-01

    To compare the accuracies of predicting AD conversion by using a decision support system (PredictAD tool) and current research criteria of prodromal AD as identified by combinations of episodic memory impairment of hippocampal type and visual assessment of medial temporal lobe atrophy (MTA) on MRI...

  14. Conversion tables. Appendix I

    International Nuclear Information System (INIS)

    McKerrell, H.

    1975-01-01

    Tables are presented for the conversion of standard (5568 year half-life) C-14 dates to calendar years. The major part of the data converts C-14 dates to tree-ring years: additional data are given, based on the Egyptian historical curve. (U.K.)

  15. Wavelength conversion technology

    DEFF Research Database (Denmark)

    Stubkjær, Kristian

    1998-01-01

    Optical wavelength conversion is currently attracting much interest. This is because it enables full flexibility and eases management of WDM fibre networks. The tutorial will review existing and potential application areas. Examples of node architectures and network demonstrators that use wavelen...

  16. Our Digital Conversion

    Science.gov (United States)

    Edwards, Mark

    2012-01-01

    In this article, the author describes their digital conversion initiative at Mooresville Graded School District. The project has placed a MacBook Air laptop in the hands of every 3rd through 12th grader and their teachers in the district over the past four years, with over 5,000 computers distributed. But they believe their academic successes have…

  17. Frequency Synthesiser

    NARCIS (Netherlands)

    Drago, Salvatore; Sebastiano, Fabio; Leenaerts, Dominicus M.W.; Breems, Lucien J.; Nauta, Bram

    2016-01-01

    A low power frequency synthesiser circuit (30) for a radio transceiver, the synthesiser circuit comprising: a digital controlled oscillator configured to generate an output signal having a frequency controlled by an input digital control word (DCW); a feedback loop connected between an output and an

  18. Frequency synthesiser

    NARCIS (Netherlands)

    Drago, S.; Sebastiano, Fabio; Leenaerts, Dominicus Martinus Wilhelmus; Breems, Lucien Johannes; Nauta, Bram

    2010-01-01

    A low power frequency synthesiser circuit (30) for a radio transceiver, the synthesiser circuit comprising: a digital controlled oscillator configured to generate an output signal having a frequency controlled by an input digital control word (DCW); a feedback loop connected between an output and an

  19. Organic nonlinear crystals and high power frequency conversion

    International Nuclear Information System (INIS)

    Velsko, S.P.; Davis, L.; Wang, F.; Monaco, S.; Eimerl, D.

    1987-12-01

    We are searching for a new second- and third-harmonic generators among the salts of chiral organic acids and bases. We discuss the relevant properties of crystals from this group of compounds, including their nonlinear and phasematching characteristics, linear absorption, damage threshold and crystal growth. In addition, we summarize what is known concerning other nonlinear optical properties of these crystals, such as two-photon absorption, nonlinear refractive index, and stimulated Raman thresholds. A preliminary assessment is made of the potential of these materials for use in future high power, large aperture lasers such as those used for inertial confinement fusion experiments. 14 refs., 1 fig., 3 tabs

  20. Nonlinear Frequency Conversion in III-V Semiconductor Photonic Crystals

    Science.gov (United States)

    2012-03-01

    benefited early in my PhD from the assistance of Dirk Englund and Vanessa Sih. Subsequently, I was fortunate to collab- orate with newer members of the...to defense practice talks. I would also like to acknowledge Seth Lloyd, Vicky Wen, Jason Pelc, Qiang Zhang, Peter McMahon, Liz Edwards , Stephanie...2006. [67] Z. Yang, P. Chak, A. D. Bristow, H. M. van Driel, R. Iyer, J. S. Aitchison, A. L. Smirl, and J. E. Sipe, “Enhanced second-harmonic

  1. Frequency Conversion of Single Photons: Physics, Devices, and Applications

    Science.gov (United States)

    2012-07-01

    Anton Zeilinger , Alexan- der V. Sergienko, and Yanhua Shih. New high-intensity source of polarization- entangled photon pairs. Physical Review Letters...interface. Nature, 437(7055):116–120, 2005. [36] S. Ramelow, A. Fedrizzi, A. Poppe, N. K. Langford, and A. Zeilinger . Polarization-entanglement-conserving

  2. Organic nonlinear crystals and high power frequency conversion

    International Nuclear Information System (INIS)

    Velsko, S.P.; Davis, L.; Wang, F.; Monaco, S.; Eimerl, D.

    1987-01-01

    The authors are searching for new second and third harmonic generators among the salts of organic acids and bases. They discuss the relevant properties of crystals from this group of compounds, including their nonlinear and phasematching characteristics, linear absorption, damage threshold and crystal growth. In addition, they summarize what is known concerning other nonlinear optical properties of these crystals, such as two-photon absorption, nonlinear refractive index, and stimulated Raman thresholds. A preliminary assessment is made of the potential of these materials for use in future high power, large aperture lasers such as those used for inertial confinement fusion experiments

  3. Theoretical yields of frequency converters using KDP crystals

    International Nuclear Information System (INIS)

    Adolf, A.

    1982-12-01

    Frequency conversion is operated with power lasers for their interest in laser-matter interaction. Using electromagnetic wave propagation in non linear media; computer codes for different conversion yield rate calculations have been developed. The code utilization allowed to calculate yield rates of frequency doubler and tripler using KDP (potassium dihydrogen phosphate) crystals. The calculation results are presented here [fr

  4. Wind energy conversion system

    Science.gov (United States)

    Longrigg, Paul

    1987-01-01

    The wind energy conversion system includes a wind machine having a propeller connected to a generator of electric power, the propeller rotating the generator in response to force of an incident wind. The generator converts the power of the wind to electric power for use by an electric load. Circuitry for varying the duty factor of the generator output power is connected between the generator and the load to thereby alter a loading of the generator and the propeller by the electric load. Wind speed is sensed electro-optically to provide data of wind speed upwind of the propeller, to thereby permit tip speed ratio circuitry to operate the power control circuitry and thereby optimize the tip speed ratio by varying the loading of the propeller. Accordingly, the efficiency of the wind energy conversion system is maximized.

  5. Clinical linguistics: conversational reflections.

    Science.gov (United States)

    Crystal, David

    2013-04-01

    This is a report of the main points I made in an informal "conversation" with Paul Fletcher and the audience at the 14th ICPLA conference in Cork. The observations arose randomly, as part of an unstructured 1-h Q&A, so they do not provide a systematic account of the subject, but simply reflect the issues which were raised by the conference participants during that time.

  6. Conversations with Miss Jane

    Directory of Open Access Journals (Sweden)

    Geneviève Fabre

    2006-05-01

    Full Text Available Considering the wide range of conversations in the autobiography, this essay will attempt to appraise the importance of these verbal exchanges in relation to the overall narrative structure of the book and to the prevalent oral tradition in Louisiana culture, as both an individual and communal expression. The variety of circumstances, the setting and staging, the interlocutors , and the complex intersection of time and place, of stories and History, will be examined; in these conversations with Miss Jane many actors participate, from  the interviewer-narrator, to most characters; even the reader becomes involved.Speaking, hearing, listening, keeping silent is an elaborate ritual that performs many functions; besides conveying news or rumors, it imparts information on the times and on the life of a “representative” woman whose existence - spanning a whole century- is both singular and emblematic. Most importantly this essay will analyse the resonance of an eventful and often dramatic era on her sensibility and conversely show how her evolving sensibility informs that history and draws attention to aspects that might have passed unnoticed or be forever silenced. Jane’s desire for liberty and justice is often challenged as she faces the possibilities of life or death.Conversations build up a complex, often contradictory, but compelling portrait: torn between silence and vehemence, between memories and the urge to meet the future, Jane summons body and mind to find her way through the maze of a fast changing world; self-willed and obstinate she claims her right to speak, to express with wit and wisdom her firm belief in the word, in the ability to express deep seated convictions and faith and a whole array of feelings and emotions.

  7. Microturbine Power Conversion Technology Review

    Energy Technology Data Exchange (ETDEWEB)

    Staunton, R.H.

    2003-07-21

    In this study, the Oak Ridge National Laboratory (ORNL) is performing a technology review to assess the market for commercially available power electronic converters that can be used to connect microturbines to either the electric grid or local loads. The intent of the review is to facilitate an assessment of the present status of marketed power conversion technology to determine how versatile the designs are for potentially providing different services to the grid based on changes in market direction, new industry standards, and the critical needs of the local service provider. The project includes data gathering efforts and documentation of the state-of-the-art design approaches that are being used by microturbine manufacturers in their power conversion electronics development and refinement. This project task entails a review of power converters used in microturbines sized between 20 kW and 1 MW. The power converters permit microturbine generators, with their non-synchronous, high frequency output, to interface with the grid or local loads. The power converters produce 50- to 60-Hz power that can be used for local loads or, using interface electronics, synchronized for connection to the local feeder and/or microgrid. The power electronics enable operation in a stand-alone mode as a voltage source or in grid-connect mode as a current source. Some microturbines are designed to automatically switch between the two modes. The information obtained in this data gathering effort will provide a basis for determining how close the microturbine industry is to providing services such as voltage regulation, combined control of both voltage and current, fast/seamless mode transfers, enhanced reliability, reduced cost converters, reactive power supply, power quality, and other ancillary services. Some power quality improvements will require the addition of storage devices; therefore, the task should also determine what must be done to enable the power conversion circuits to

  8. Frequency spirals

    International Nuclear Information System (INIS)

    Ottino-Löffler, Bertrand; Strogatz, Steven H.

    2016-01-01

    We study the dynamics of coupled phase oscillators on a two-dimensional Kuramoto lattice with periodic boundary conditions. For coupling strengths just below the transition to global phase-locking, we find localized spatiotemporal patterns that we call “frequency spirals.” These patterns cannot be seen under time averaging; they become visible only when we examine the spatial variation of the oscillators' instantaneous frequencies, where they manifest themselves as two-armed rotating spirals. In the more familiar phase representation, they appear as wobbly periodic patterns surrounding a phase vortex. Unlike the stationary phase vortices seen in magnetic spin systems, or the rotating spiral waves seen in reaction-diffusion systems, frequency spirals librate: the phases of the oscillators surrounding the central vortex move forward and then backward, executing a periodic motion with zero winding number. We construct the simplest frequency spiral and characterize its properties using analytical and numerical methods. Simulations show that frequency spirals in large lattices behave much like this simple prototype.

  9. Frequency spirals

    Energy Technology Data Exchange (ETDEWEB)

    Ottino-Löffler, Bertrand; Strogatz, Steven H., E-mail: strogatz@cornell.edu [Center for Applied Mathematics, Cornell University, Ithaca, New York 14853 (United States)

    2016-09-15

    We study the dynamics of coupled phase oscillators on a two-dimensional Kuramoto lattice with periodic boundary conditions. For coupling strengths just below the transition to global phase-locking, we find localized spatiotemporal patterns that we call “frequency spirals.” These patterns cannot be seen under time averaging; they become visible only when we examine the spatial variation of the oscillators' instantaneous frequencies, where they manifest themselves as two-armed rotating spirals. In the more familiar phase representation, they appear as wobbly periodic patterns surrounding a phase vortex. Unlike the stationary phase vortices seen in magnetic spin systems, or the rotating spiral waves seen in reaction-diffusion systems, frequency spirals librate: the phases of the oscillators surrounding the central vortex move forward and then backward, executing a periodic motion with zero winding number. We construct the simplest frequency spiral and characterize its properties using analytical and numerical methods. Simulations show that frequency spirals in large lattices behave much like this simple prototype.

  10. Nuclear spin conversion in formaldehyde

    OpenAIRE

    Chapovsky, Pavel L.

    2000-01-01

    Theoretical model of the nuclear spin conversion in formaldehyde (H2CO) has been developed. The conversion is governed by the intramolecular spin-rotation mixing of molecular ortho and para states. The rate of conversion has been found equal 1.4*10^{-4}~1/s*Torr. Temperature dependence of the spin conversion has been predicted to be weak in the wide temperature range T=200-900 K.

  11. Microbial Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, Merry [American Society for Microbiology (ASM), Washington, DC (United States); Wall, Judy D. [Univ. of Missouri, Columbia, MO (United States)

    2006-10-01

    The American Academy of Microbiology convened a colloquium March 10-12, 2006, in San Francisco, California, to discuss the production of energy fuels by microbial conversions. The status of research into various microbial energy technologies, the advantages and disadvantages of each of these approaches, research needs in the field, and education and training issues were examined, with the goal of identifying routes for producing biofuels that would both decrease the need for fossil fuels and reduce greenhouse gas emissions. Currently, the choices for providing energy are limited. Policy makers and the research community must begin to pursue a broader array of potential energy technologies. A diverse energy portfolio that includes an assortment of microbial energy choices will allow communities and consumers to select the best energy solution for their own particular needs. Funding agencies and governments alike need to prepare for future energy needs by investing both in the microbial energy technologies that work today and in the untested technologies that will serve the world’s needs tomorrow. More mature bioprocesses, such as ethanol production from starchy materials and methane from waste digestors, will find applications in the short term. However, innovative techniques for liquid fuel or biohydrogen production are among the longer term possibilities that should also be vigorously explored, starting now. Microorganisms can help meet human energy needs in any of a number of ways. In their most obvious role in energy conversion, microorganisms can generate fuels, including ethanol, hydrogen, methane, lipids, and butanol, which can be burned to produce energy. Alternatively, bacteria can be put to use in microbial fuel cells, where they carry out the direct conversion of biomass into electricity. Microorganisms may also be used some day to make oil and natural gas technologies more efficient by sequestering carbon or by assisting in the recovery of oil and

  12. Infrared up-conversion microscope

    DEFF Research Database (Denmark)

    2014-01-01

    There is presented an up-conversion infrared microscope (110) arranged for imaging an associated object (130), wherein the up-conversion infrared microscope (110) comprises a non-linear crystal (120) arranged for up-conversion of infrared electromagnetic radiation, and wherein an objective optical...

  13. Infrared up-conversion telescope

    DEFF Research Database (Denmark)

    2014-01-01

    There is presented to an up-conversion infrared telescope (110) arranged for imaging an associated scene (130), wherein the up-conversion infrared telescope (110) comprises a non-linear crystal (120) arranged for up-conversion of infrared electromagnetic radiation, and wherein a first optical...

  14. The FLIC conversion codes

    International Nuclear Information System (INIS)

    Basher, J.C.

    1965-05-01

    This report describes the FORTRAN programmes, FLIC 1 and FLIC 2. These programmes convert programmes coded in one dialect of FORTRAN to another dialect of the same language. FLIC 1 is a general pattern recognition and replacement programme whereas FLIC 2 contains extensions directed towards the conversion of FORTRAN II and S2 programmes to EGTRAN 1 - the dialect now in use on the Winfrith KDF9. FII or S2 statements are replaced where possible by their E1 equivalents; other statements which may need changing are flagged. (author)

  15. Zinc phosphate conversion coatings

    Science.gov (United States)

    Sugama, Toshifumi

    1997-01-01

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

  16. The FLIC conversion codes

    Energy Technology Data Exchange (ETDEWEB)

    Basher, J C [General Reactor Physics Division, Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

    1965-05-15

    This report describes the FORTRAN programmes, FLIC 1 and FLIC 2. These programmes convert programmes coded in one dialect of FORTRAN to another dialect of the same language. FLIC 1 is a general pattern recognition and replacement programme whereas FLIC 2 contains extensions directed towards the conversion of FORTRAN II and S2 programmes to EGTRAN 1 - the dialect now in use on the Winfrith KDF9. FII or S2 statements are replaced where possible by their E1 equivalents; other statements which may need changing are flagged. (author)

  17. Moodle 20 Course Conversion

    CERN Document Server

    Wild, Ian

    2011-01-01

    With clear instructions and plenty of screenshots, this book provides all the support and guidance you will need as you begin to convert your teaching to Moodle. Step-by-step tutorials use real-world examples to show you how to convert to Moodle in the most efficient and effective ways possible. Moodle Course Conversion carefully illustrates how Moodle can be used to teach content and ideas and clearly demonstrates the advantages of doing so. This book is for teachers, tutors, and lecturers who already have a large body of teaching material and want to use Moodle to enhance their course, rathe

  18. Solar energy conversion

    CERN Document Server

    Likhtenshtein, Gertz I

    2012-01-01

    Finally filling a gap in the literature for a text that also adopts the chemist?s view of this hot topic, Prof Likhtenshtein, an experienced author and internationally renowned scientist, considers different physical and engineering aspects in solar energy conversion. From theory to real-life systems, he shows exactly which chemical reactions take place when converting light energy, providing an overview of the chemical perspective from fundamentals to molecular harvesting systems and solar cells. This essential guide will thus help researchers in academia and industry better understa

  19. Development of GT-MGR plant power conversion unit design

    International Nuclear Information System (INIS)

    Kostin, V.I.; Kodochigov, N.G.; Belov, S.E.; Vasyaev, A.V.; Golovko, V.F.; Shenoj, A.

    2007-01-01

    The General Atomic Company (USA) and the Pilot Design Bureau for Machine-Building (Russia) are involved in the efforts to design the GT-MGR modular helium cooled reactor and the energy conversion unit with the direct gas turbine cycle. The reactor capacity is equal to 600 MW, it is cooled by helium under 7 MPa pressure. The energy conversion unit consists of a gas turbine, a recuperator, preliminary and intermediate coolers, a generator. The turbine shaft rotation frequency is equal to 4400 rotation/minute. One analyzed the alternate designs of the energy conversion unit to choose its configuration [ru

  20. Conversion program in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Jonsson, E.B. [Studsvik Nuclear AB, Nykoeping (Sweden)

    1997-08-01

    The conversion of the Swedish 50 MW R2 reactor from HEU to LEU fuel has been successfully accomplished over a 16 cycles long process. The conversion started in January 1991 with the introduction of 6 LEU assemblies in the 8*8 core. The first all LEU core was loaded in March 1993 and physics measurements were performed for the final licensing reports. A total of 142 LEU fuel assemblies have been irradiated up until September 1994 without any fuel incident. The operating licence for the R2 reactor was renewed in mid 1994 taking into account new fuel type. The Swedish Nuclear Inspectorate (SKI) pointed out one crucial problem with the LEU operation, that the back end of the LEU fuel cycle has not yet been solved. For the HEU fuel Sweden had the reprocessing alternative. The country is now relying heavily on the success of the USDOEs Off Site Fuels Policy to take back the spent fuel from the research reactors. They have in the meantime increased their intermediate storage facilities. There is, however, a limit both in time and space for storage of MTR-type of assemblies in water. The penalty of the lower thermal neutron flux in LEU cores has been reduced by improvements of the new irradiation rigs and by fine tuning the core calculations. The Studsvik code package, CASMO-SIMULATE, widely used for ICFM in LWRs has been modified to suit the compact MTR type of core.

  1. Microbial conversion technologies

    Energy Technology Data Exchange (ETDEWEB)

    Lau, P. [National Research Council of Canada, Ottawa, ON (Canada). Bioconversion and Sustainable Development

    2006-07-01

    Microbes are a biomass and an valuable resource. This presentation discussed microbial conversion technologies along with background information on microbial cells, their characteristics and microbial diversity. Untapped opportunities for microbial conversion were identified. Metagenomic and genome mining approaches were also discussed, as they can provide access to uncultivated or unculturable microorganisms in communal populations and are an unlimited resource for biocatalysts, novel genes and metabolites. Genome mining was seen as an economical approach. The presentation also emphasized that the development of microbial biorefineries would require significant insights into the relevant microorganisms and that biocatalysts were the ultimate in sustainability. In addition, the presentation discussed the natural fibres initiative for biochemicals and biomaterials. Anticipated outputs were identified and work in progress of a new enzyme-retting cocktail to provide diversity and/or consistency in fibre characteristics for various applications were also presented. It was concluded that it is necessary to leverage understanding of biological processes to produce bioproducts in a clean and sustainable manner. tabs., figs.

  2. Communal biomass conversion plants

    International Nuclear Information System (INIS)

    1991-06-01

    The Coordinating Committee set up by the Danish government in 1986 were given the responsibility of investigating the potentials for biomass conversion plants in Denmark, especially in relation to agricultural, environmental and energy aspects. The results of the Committee's plan of management for this project are presented. This main report covers 13 background reports which deal with special aspects in detail. The report describes the overall plan of management, the demonstration and follow-up programme and the individual biogas demonstration plants. Information gained from these investigations is presented. The current general status, (with emphasis on the technical and economical aspects) and the prospects for the future are discussed. The interest other countries have shown in Danish activities within the field of biogas production is described, and the possibilities for Danish export of technology and know-how in this relation are discussed. It is claimed that Denmark is the first country that has instigated a coordinated development programme for biomass conversion plants. (AB) 24 refs

  3. Cell phone conversing while driving in New Zealand: prevalence, risk perception and legislation.

    Science.gov (United States)

    Hallett, Charlene; Lambert, Anthony; Regan, Michael A

    2011-05-01

    This study investigated (i) the prevalence of conversing on a cell phone while driving in New Zealand, (ii) respondents' perception of risk regarding this behaviour and (iii) attitudes towards legislation banning cell phone use while driving. In addition, the study examined the association between the prevalence of conversing on a cell phone and risk perception. Anonymous, self-reported, survey data was collected via the internet from 1057 drivers nationwide regarding the frequency of conversing on a cell phone, including hands-free and hand-held conversing, risk perception, views on legislation, and demographic information. A positive relationship was found between the frequency of conversing on a cell phone and risk perception; that is, as the frequency of conversing on a cell phone increased, the perceived risk of this behaviour decreased. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. Letter Knowledge in Parent–Child Conversations

    Science.gov (United States)

    Robins, Sarah; Treiman, Rebecca; Rosales, Nicole

    2014-01-01

    Learning about letters is an important component of emergent literacy. We explored the possibility that parent speech provides information about letters, and also that children’s speech reflects their own letter knowledge. By studying conversations transcribed in CHILDES (MacWhinney, 2000) between parents and children aged one to five, we found that alphabetic order influenced use of individual letters and letter sequences. The frequency of letters in children’s books influenced parent utterances throughout the age range studied, but children’s utterances only after age two. Conversations emphasized some literacy-relevant features of letters, such as their shapes and association with words, but not letters’ sounds. Describing these patterns and how they change over the preschool years offers important insight into the home literacy environment. PMID:25598577

  5. Photon energy conversion by near-zero permittivity nonlinear materials

    Science.gov (United States)

    Luk, Ting S.; Sinclair, Michael B.; Campione, Salvatore

    2017-12-19

    Efficient harmonic light generation can be achieved with ultrathin films by coupling an incident pump wave to an epsilon-near-zero (ENZ) mode of the thin film. As an example, efficient third harmonic generation from an indium tin oxide nanofilm (.lamda./42 thick) on a glass substrate for a pump wavelength of 1.4 .mu.m was demonstrated. A conversion efficiency of 3.3.times.10.sup.-6 was achieved by exploiting the field enhancement properties of the ENZ mode with an enhancement factor of 200. This nanoscale frequency conversion method is applicable to other plasmonic materials and reststrahlen materials in proximity of the longitudinal optical phonon frequencies.

  6. Oscillating thermionic conversion for high-density space power

    International Nuclear Information System (INIS)

    Jacobson, D.L.; Morris, J.F.

    1988-01-01

    The compactness, maneuverability, and productive weight utilization of space nuclear reactors benefit from the use of thermionic converters at high temperature. Nuclear-thermionic-conversion power requirements are discussed, and the role of oscillations in thermionic energy conversion (TEC) history is examined. Proposed TEC oscillations are addressed, and the results of recent studies of TEC oscillations are reviewed. The possible use of high-frequency TEC oscillations to amplify low-frequency ones is considered. The accomplishments of various programs studying the use of high-temperature thermionic oscillators are examined. 16 references

  7. Conversation with Meir Sternberg

    Directory of Open Access Journals (Sweden)

    Federico Pianzola

    2011-07-01

    Full Text Available Below are the videos of the interview recorded the 21st May 2011 in Fribourg (CH, in occasion of the first RRN conference. Conversation with Meir Sternberg. Part 1 of 8 - Narratology: classical and postclassical studies. Part 2 of 8 - The development of an original theoretical framework. Part 3 of 8 - Sternberg and Genette: different ways for the same problems. Part 4 of 8 - «There are no forms except in terms of functions». Part 5 of 8 - A life writing articles: so many papers and just four books. Part 6 of 8 - Two arguments against mimetical approaches to narrative. Part 7 of 8 - «Narrative is not given, it is a construct». Part 8 of 8 - The proteus principle. the many-to-many correspondence between forms and functions.

  8. Thermodynamics and energy conversion

    CERN Document Server

    Struchtrup, Henning

    2014-01-01

    This textbook gives a thorough treatment of engineering thermodynamics with applications to classical and modern energy conversion devices.   Some emphasis lies on the description of irreversible processes, such as friction, heat transfer and mixing, and the evaluation of the related work losses. Better use of resources requires high efficiencies, therefore the reduction of irreversible losses should be seen as one of the main goals of a thermal engineer. This book provides the necessary tools.   Topics include: car and aircraft engines,  including Otto, Diesel and Atkinson cycles, by-pass turbofan engines, ramjet and scramjet;  steam and gas power plants, including advanced regenerative systems, solar tower, and compressed air energy storage; mixing and separation, including reverse osmosis, osmotic powerplants, and carbon sequestration; phase equilibrium and chemical equilibrium, distillation, chemical reactors, combustion processes, and fuel cells; the microscopic definition of entropy.    The book i...

  9. Communal biomass conversion plants

    International Nuclear Information System (INIS)

    Holm-Nielsen, J.B.; Huntingford, S.; Halberg, N.

    1993-03-01

    The aim was to show the agricultural advantages of farmers being in connection with Communal Biogas Plant. Whether a more environmentally protectire distribution of plant nutrients from animal manure takes place through a biogas plants distribution system, whether the nitrogen in the digested slurry is better utilized and whether the connection results in slurry transportation-time reduction, are discussed. The average amount of nitrogen from animal manure used per hectare was reduced. The area of manure distribution was larger. The nitrogen efficiency was increased when using digested slurry and purchase of N mineral fertilizer decreased, resulting in considerable reduction in nitrogen leaching. The amount of slurry delivered to the local storage tanks was approximately 45 per cent of the total amount treated on the biogas plant. Conditions of manure transport improved greatly as this was now the responsibility of the communal biomass conversion plant administrators. (AB) (24 refs.)

  10. Power conversion technologies

    Energy Technology Data Exchange (ETDEWEB)

    Newton, M. A.

    1997-02-01

    The Power Conversion Technologies thrust area identifies and sponsors development activities that enhance the capabilities of engineering at Lawrence Livermore National Laboratory (LLNL) in the area of solid- state power electronics. Our primary objective is to be a resource to existing and emerging LLNL programs that require advanced solid-state power electronic technologies.. Our focus is on developing and integrating technologies that will significantly impact the capability, size, cost, and reliability of future power electronic systems. During FY-96, we concentrated our research efforts on the areas of (1) Micropower Impulse Radar (MIR); (2) novel solid-state opening switches; (3) advanced modulator technology for accelerators; (4) compact accelerators; and (5) compact pulse generators.

  11. The Role of Conversation Policy in Carrying Out Agent Conversations

    International Nuclear Information System (INIS)

    Link, Hamilton E.; Phillips, Laurence R.

    1999-01-01

    Structured conversation diagrams, or conversation specifications, allow agents to have predictable interactions and achieve predefined information-based goals, but they lack the flexibility needed to function robustly in an unpredictable environment. We propose a mechanism that combines a typical conversation structure with a separately established policy to generate an actual conversation. The word ''policy'' connotes a high-level direction external to a specific planned interaction with the environment. Policies, which describe acceptable procedures and influence decisions, can be applied to broad sets of activity. Based on their observation of issues related to a policy, agents may dynamically adjust their communication patterns. The policy object describes limitations, constraints, and requirements that may affect the conversation in certain circumstances. Using this new mechanism of interaction simplifies the description of individual conversations and allows domain-specific issues to be brought to bear more easily during agent communication. By following the behavior of the conversation specification when possible and deferring to the policy to derive behavior in exceptional circumstances, an agent is able to function predictably under normal situations and still act rationally in abnormal situations. Different conversation policies applied to a given conversation specification can change the nature of the interaction without changing the specification

  12. Paradoxical therapy in conversion disorder

    OpenAIRE

    ATAOĞLU, Ahmet

    1998-01-01

    Paradoxical therapy consists of suggesting that the patient intentionally engages in the unwanted behaviour, such as performing complusive ritual or bringing on a conversion attack. In this study paradoxical intention (PI) was used with to half of the patients with conversion disorders, while the other half were treated with diazepam in order to examine the efficiency of the PI versus diazepam in conversion disorder. Patients treated with PI appeared to have a greater improvement r...

  13. Experiments on topographies lacking tidal conversion

    Science.gov (United States)

    Maas, Leo; Paci, Alexandre; Yuan, Bing

    2015-11-01

    In a stratified sea, internal tides are supposedly generated when the tide passes over irregular topography. It has been shown that for any given frequency in the internal wave band there are an infinite number of exceptions to this rule of thumb. This ``stealth-like'' property of the topography is due to a subtle annihilation of the internal waves generated during the surface tide's passage over the irregular bottom. We here demonstrate this in a lab-experiment. However, for any such topography, subsequently changing the surface tide's frequency does lead to tidal conversion. The upshot of this is that a tidal wave passing over an irregular bottom is for a substantial part trapped to this irregularity, and only partly converted into freely propagating internal tides. Financially supported by the European Community's 7th Framework Programme HYDRALAB IV.

  14. Parametric Conversion Using Custom MOS Varactors

    Directory of Open Access Journals (Sweden)

    Iniewski Krzysztof (Kris

    2006-01-01

    Full Text Available The possible role of customized MOS varactors in amplification, mixing, and frequency control of future millimeter wave CMOS RFICs is outlined. First, the parametric conversion concept is revisited and discussed in terms of modern RF communications systems. Second, the modeling, design, and optimization of MOS varactors are reconsidered in the context of their central role in parametric circuits. Third, a balanced varactor structure is proposed for robust oscillator frequency control in the presence of large extrinsic noise expected in tightly integrated wireless communicators. Main points include the proposal of a subharmonic pumping scheme based on the MOS varactor, a nonequilibrium elastance-voltage model, optimal varactor layout suggestions, custom m-CMOS varactor design and measurement, device-level balanced varactor simulations, and parametric circuit evaluation based on measured device characteristics.

  15. Nanomaterials for photovoltaic conversion

    International Nuclear Information System (INIS)

    Davenas, J.; Ltaief, A.; Barlier, V.; Boiteux, G.; Bouazizi, A.

    2008-01-01

    A promising route for photovoltaic conversion has emerged from the combination of electroactive nanomaterials and small bandgap polymers. The formation of bulk heterojunctions resulting from the extended interfaces leads to efficient dissociation of the charge pairs generated under sunlight shown by the rapid extinction of the polymer photoluminescence for increasing contents of fullerenes or TiO 2 nanoparticles in MEH-PPV or PVK. Unconventional elaboration routes of the blends have been developed to increase the nanofiller dispersion and inhibit phase separation at high concentration. The size reduction of the acceptor domains led to a complete quenching of the radiative recombinations, obtained by specific solvent processing of MEH-PPV / C 60 nanocomposites or sol gel elaboration of TiO 2 nanoparticles in a PVK film. A simultaneous increase of the photocurrents could be achieved by the dispersion and size optimisation of the nanofillers. In situ generation of silver particles in MEH-PPV provides an example of enhanced charge separation induced by the plasmon resonance at the metal/polymer interface. The strong influence of the molecular morphology on the nanocomposite properties emphasizes the large improvements which can still be gained on the performances of organic solar cells

  16. Overview of fuel conversion

    International Nuclear Information System (INIS)

    Green, A.E.S.

    1991-01-01

    The conversion of solid fuels to cleaner-burning and more user-friendly solid liquid or gaseous fuels spans many technologies. In this paper, the authors consider coal, residual oil, oil shale, tar sends tires, municipal oil waste and biomass as feedstocks and examine the processes which can be used in the production of synthetic fuels for the transportation sector. The products of mechanical processing to potentially usable fuels include coal slurries, micronized coal, solvent refined coal, vegetable oil and powdered biomall. The thermochemical and biochemical processes considered include high temperature carbide production, liquefaction, gasification, pyrolysis, hydrolysis-fermentation and anaerobic digestion. The products include syngas, synthetic natural gas, methanol, ethanol and other hydrocarbon oxygenates synthetic gasoline and diesel and jet engine oils. The authors discuss technical and economic aspects of synthetic fuel production giving particular attention and literature references to technologies not discussed in the five chapters which follow. Finally the authors discuss economic energy, and environmental aspects of synthetic fuels and their relationship to the price of imported oil

  17. Geothermal energy conversion facility

    Energy Technology Data Exchange (ETDEWEB)

    Kutscher, C.F.

    1997-12-31

    With the termination of favorable electricity generation pricing policies, the geothermal industry is exploring ways to improve the efficiency of existing plants and make them more cost-competitive with natural gas. The Geothermal Energy Conversion Facility (GECF) at NREL will allow researchers to study various means for increasing the thermodynamic efficiency of binary cycle geothermal plants. This work has received considerable support from the US geothermal industry and will be done in collaboration with industry members and utilities. The GECF is being constructed on NREL property at the top of South Table Mountain in Golden, Colorado. As shown in Figure 1, it consists of an electrically heated hot water loop that provides heating to a heater/vaporizer in which the working fluid vaporizes at supercritical or subcritical pressures as high as 700 psia. Both an air-cooled and water-cooled condenser will be available for condensing the working fluid. In order to minimize construction costs, available equipment from the similar INEL Heat Cycle Research Facility is being utilized.

  18. Switching-mode Audio Power Amplifiers with Direct Energy Conversion

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    has been replaced with a high frequency AC link. When compared to the conventional Class D amplifiers with a separate DC power supply, the proposed single conversion stage amplifier provides simple and compact solution with better efficiency and higher level of integration, leading to reduced...

  19. Diffusion and conversion impedance in solid oxide fuel cells

    DEFF Research Database (Denmark)

    Jacobsen, Torben; Hendriksen, Peter Vang; Koch, Søren

    2008-01-01

    to consumption of reactants and accumulation of products. For simplicity this model is restricted to cases dominated by mass transfer and conversion of the gas supply. Qualitatively the predictions by both models are alike. At high frequencies a Warburg diffusion impedance is seen. Depending on the dimensions...

  20. Tree value conversion standards revisited

    Science.gov (United States)

    Paul S. DeBald; Martin E. Dale; Martin E. Dale

    1991-01-01

    Updated tree value conversion standards (TVCS) are presented for 12 important hardwood species of the oak-hickory forest. These updated standards-developed for each species by butt-log grade, merchantable height, and diameter at breast height-reflect the changes in lumber prices and in conversion costs which have occurred since 1976 when the original TVCS were...

  1. Optimization theory for ballistic conversion

    NARCIS (Netherlands)

    Xie, Yanbo; Versluis, Michel; van den Berg, Albert; Eijkel, Jan C.T.

    2016-01-01

    The growing demand of renewable energy stimulates the exploration of new materials and methods for clean energy. We recently demonstrated a high efficiency and power density energy conversion mechanism by using jetted charged microdroplets, termed as ballistic energy conversion. Hereby, we model and

  2. Career conversations in vocational schools

    NARCIS (Netherlands)

    Mittendorff, K.M.; Brok, den P.J.; Beijaard, D.

    2010-01-01

    The purpose of this study was to examine career conversations between teachers and students in competence-based vocational education in the Netherlands. A total of 32 career conversations were observed and analysed with respect to four elements: content, teacher activities, student activities and

  3. [Neuropsychological assessment in conversion disorder].

    Science.gov (United States)

    Demır, Süleyman; Çelıkel, Feryal Çam; Taycan, Serap Erdoğan; Etıkan, İlker

    2013-01-01

    Conversion disorder is characterized by functional impairment in motor, sensory, or neurovegetative systems that cannot be explained by a general medical condition. Diagnostic systems emphasize the absence of an organic basis for the dysfunction observed in conversion disorder. Nevertheless, there is a growing body of data on the specific functional brain correlates of conversion symptoms, particularly those obtained via neuroimaging and neurophysiological assessment. The present study aimed to determine if there are differences in measures of cognitive functioning between patients with conversion disorder and healthy controls. The hypothesis of the study was that the patients with conversion disorder would have poorer neurocognitive performance than the controls. The patient group included 43 patients diagnosed as conversion disorder and other psychiatric comorbidities according to DSM-IV-TR. Control group 1 included 44 patients diagnosed with similar psychiatric comorbidities, but not conversion diosorder, and control group 2 included 43 healthy individuals. All participants completed a sociodemographic questionnaire and were administered the SCID-I and a neuropsychological test battery of 6 tests, including the Serial Digit Learning Test (SDLT), Auditory Verbal Learning Test (AVLT), Wechsler Memory Scale, Stroop Color Word Interference Test, Benton Judgment of Line Orientation Test (BJLOT), and Cancellation Test. The patient group had significantly poorer performance on the SDLT, AVLT, Stroop Color Word Interference Test, and BJLOT than both control groups. The present findings highlight the differences between the groups in learning and memory, executive and visuospatial functions, and attention, which seemed to be specific to conversion disorder.

  4. Conversion of Deletions during Recombination in Pneumococcal Transformation

    Science.gov (United States)

    Lefevre, J. C.; Mostachfi, P.; Gasc, A. M.; Guillot, E.; Pasta, F.; Sicard, M.

    1989-01-01

    Genetic analysis of 16 deletions obtained in the amiA locus of pneumococcus is described. When present on donor DNA, all deletions increased drastically the frequency of wild-type recombinants in two-point crosses. This effect was maximal for deletions longer than 200 bases. It was reduced for heterologies shorter than 76 bases and did not exist for very short deletions. In three-point crosses in which the deletion was localized between two point mutations, we demonstrated that this excess of wild-type recombinants was the result of a genetic conversion. This conversion extended over several scores of bases outside the deletion. Conversion takes place during the heteroduplex stage of recombination. Therefore, in pneumococcal transformation, long heterologies participated in this heteroduplex configuration. As this conversion did not require an active DNA polymerase A gene it is proposed that the mechanism of conversion is not a DNA repair synthesis but involves breakage and ligation between DNA molecules. Conversion of deletions did not require the Hex system of correction of mismatched bases. It differs also from localized conversion. It appears that it is a process that evolved to correct errors of replication which lead to long heterologies and which are not eliminated by other systems. PMID:2599365

  5. Methods for locating ground faults and insulation degradation condition in energy conversion systems

    Science.gov (United States)

    Agamy, Mohamed; Elasser, Ahmed; Galbraith, Anthony William; Harfman Todorovic, Maja

    2015-08-11

    Methods for determining a ground fault or insulation degradation condition within energy conversion systems are described. A method for determining a ground fault within an energy conversion system may include, in part, a comparison of baseline waveform of differential current to a waveform of differential current during operation for a plurality of DC current carrying conductors in an energy conversion system. A method for determining insulation degradation within an energy conversion system may include, in part, a comparison of baseline frequency spectra of differential current to a frequency spectra of differential current transient at start-up for a plurality of DC current carrying conductors in an energy conversion system. In one embodiment, the energy conversion system may be a photovoltaic system.

  6. Tidal conversion by a knife-edge

    Science.gov (United States)

    Llewellyn Smith, S. G.; Young, W. R.

    2003-04-01

    We obtain an analytic solution for the generation of internal gravity waves by tidal flow past a vertical barrier of height b in a uniformly stratified ocean of depth h>b and buoyancy frequency N. If b/h is small and N is constant, the radiated power (watts per metre of barrier) is (pi/4) ρ_0 b^2 U^2 N sqrt{1-(f/ω)^2} where ρ_0 is the mean density of seawater, U \\cos (ω t) the incident tidal velocity, and f the Coriolis frequency. The radiated power increases rapidly with b/h; as b/h to 1 the radiated power diverges as ln[(h-b)/b]. By solving an integral equation numerically, we calculate the conversion in a realistically stratified ocean in which the buoyancy frequency increases by a factor of fifty between the abyss and the thermocline. The radiated power is greater by a factor of about three than that of a uniformly stratified ocean with N equal to the vertically averaged buoyancy frequency.

  7. Improvement of skeleton conversion in ICRP reference phantom conversion project

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhao Jun; Yeom, Yeon Soo; Thang, Nguyen Tat; Kim, Han Sung; Han, Min Cheol; Kim, Chan Hyeong [Dept. of Nuclear Engineering, Hanyang University, Seoul (Korea, Republic of); Kim, Seong Hoon [Dept. of Radiation Oncology, College of Medicine, Hanyang University, Seoul (Korea, Republic of)

    2014-11-15

    In the previous skeleton conversion, most bones were directly converted from the ICRP voxel phantoms by using the 3D rendering method whereas several complex-shape bones (cranium, ribs, spines, feet, and hands) were not able to be directly converted. We alternatively employed the corresponding well-defined polygonal models and attempted to adjust them to match the voxel models. However, this approach was unsatisfactory. The shapes of the alternative models were significantly different from those of the voxel models, making it virtually impossible to exactly match the voxel models as shown in Fig. 3 (left). In order to overcome the difficulty in the complex bone conversion, the present study developed a new conversion method and converted these complex bones voxel models of the ICRP male phantom to polygonal models. The present study developed the new conversion method and successfully improved polygonal models for cranium, ribs, and spines for the ICRP male phantom. The new conversion method will be also applied to the complex bone conversion for the ICRP female phantom as well as other complex organ conversion in the future.

  8. Improvement of skeleton conversion in ICRP reference phantom conversion project

    International Nuclear Information System (INIS)

    Wang, Zhao Jun; Yeom, Yeon Soo; Thang, Nguyen Tat; Kim, Han Sung; Han, Min Cheol; Kim, Chan Hyeong; Kim, Seong Hoon

    2014-01-01

    In the previous skeleton conversion, most bones were directly converted from the ICRP voxel phantoms by using the 3D rendering method whereas several complex-shape bones (cranium, ribs, spines, feet, and hands) were not able to be directly converted. We alternatively employed the corresponding well-defined polygonal models and attempted to adjust them to match the voxel models. However, this approach was unsatisfactory. The shapes of the alternative models were significantly different from those of the voxel models, making it virtually impossible to exactly match the voxel models as shown in Fig. 3 (left). In order to overcome the difficulty in the complex bone conversion, the present study developed a new conversion method and converted these complex bones voxel models of the ICRP male phantom to polygonal models. The present study developed the new conversion method and successfully improved polygonal models for cranium, ribs, and spines for the ICRP male phantom. The new conversion method will be also applied to the complex bone conversion for the ICRP female phantom as well as other complex organ conversion in the future

  9. Effect of feeding frequency and feeding rate on growth of ...

    African Journals Online (AJOL)

    Effect of feeding frequency and feeding rate on growth of Oreochromis mossambicus (Teleostei: Cichlidae) fry. ... Weight gain, specific growth rate and gross food conversion ratio were significantly affected by ... AJOL African Journals Online.

  10. Direct conversion of fusion energy

    International Nuclear Information System (INIS)

    Johansson, Markus

    2003-03-01

    Deuterium and tritium are expected to be used as fuel in the first fusion reactors. Energy is released as kinetic energy of ions and neutrons, when deuterium reacts with tritium. One way to convert the kinetic energy to electrical energy, is to let the ions and neutrons hit the reactor wall and convert the heat that is caused by the particle bombardment to electrical energy with ordinary thermal conversion. If the kinetic energy of the ions instead is converted directly to electrical energy, a higher efficiency of the energy conversion is possible. The majority of the fusion energy is released as kinetic energy of neutrons, when deuterium reacts with tritium. Fusion reactions such as the D-D reactions, the D- 3 He reaction and the p- 11 B reaction, where a larger part of the fusion energy becomes kinetic energy of charged particles, appears therefore more suitable for direct conversion. Since they have lower reactivity than the D-T reaction, they need a larger βB 2 0 to give sufficiently high fusion power density. Because of this, the fusion configurations spherical torus (ST) and field-reversed configuration (FRC), where high β values are possible, appear interesting. Rosenbluth and Hinton come to the conclusion that efficient direct conversion isn't possible in closed field line systems and that open geometries, which facilitate direct conversion, provide inadequate confinement for D- 3 He. It is confirmed in this study that it doesn't seem possible to achieve as high direct conversion efficiency in closed systems as in open systems. ST and FRC fusion power plants that utilize direct conversion seem however interesting. Calculations with the help of Maple indicate that the reactor parameters needed for a D-D ST and a D 3 He ST hopefully are possible to achieve. The best energy conversion option for a D-D or D 3 He ST appears to be direct electrodynamic conversion (DEC) together with ordinary thermal conversion or liquid metal MHD conversion (LMMHD). For a D

  11. Conversion of Abbandoned Military Areas

    Directory of Open Access Journals (Sweden)

    Daiva Marcinkevičiūtė

    2011-03-01

    Full Text Available The article analyses the situation of abandoned military sites, their value and significance of their conservation. It also reviews their impact on their environment and their potential in tourism, environmental, economic and social spheres. Further the positive experiences in military sites' conversion are studied. The importance of society's involvement in the conversions is discussed. The situation of XIX-XX age's military object's, the significance of their conservation and their potential in tourism market is separately analysed. The results of two researches are introduced, one of which inquires about the Lithuanian military objects' potential in tourism sphere, another one explores the possibilities of conversion. Article in Lithuanian

  12. Direct conversion of fusion energy

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Markus

    2003-03-01

    Deuterium and tritium are expected to be used as fuel in the first fusion reactors. Energy is released as kinetic energy of ions and neutrons, when deuterium reacts with tritium. One way to convert the kinetic energy to electrical energy, is to let the ions and neutrons hit the reactor wall and convert the heat that is caused by the particle bombardment to electrical energy with ordinary thermal conversion. If the kinetic energy of the ions instead is converted directly to electrical energy, a higher efficiency of the energy conversion is possible. The majority of the fusion energy is released as kinetic energy of neutrons, when deuterium reacts with tritium. Fusion reactions such as the D-D reactions, the D-{sup 3}He reaction and the p-{sup 11}B reaction, where a larger part of the fusion energy becomes kinetic energy of charged particles, appears therefore more suitable for direct conversion. Since they have lower reactivity than the D-T reaction, they need a larger {beta}B{sup 2}{sub 0} to give sufficiently high fusion power density. Because of this, the fusion configurations spherical torus (ST) and field-reversed configuration (FRC), where high {beta} values are possible, appear interesting. Rosenbluth and Hinton come to the conclusion that efficient direct conversion isn't possible in closed field line systems and that open geometries, which facilitate direct conversion, provide inadequate confinement for D-{sup 3}He. It is confirmed in this study that it doesn't seem possible to achieve as high direct conversion efficiency in closed systems as in open systems. ST and FRC fusion power plants that utilize direct conversion seem however interesting. Calculations with the help of Maple indicate that the reactor parameters needed for a D-D ST and a D{sub 3} He ST hopefully are possible to achieve. The best energy conversion option for a D-D or D{sub 3} He ST appears to be direct electrodynamic conversion (DEC) together with ordinary thermal conversion

  13. Conversion of carbon dioxide to value-added chemicals in atmospheric pressure dielectric barrier discharges

    International Nuclear Information System (INIS)

    Paulussen, Sabine; Verheyde, Bert; Tu Xin; Sels, Bert; De Bie, Christophe; Martens, Tom; Petrovic, Dragana; Bogaerts, Annemie

    2010-01-01

    The aim of this work consists of the evaluation of atmospheric pressure dielectric barrier discharges for the conversion of greenhouse gases into useful compounds. Therefore, pure CO 2 feed flows are administered to the discharge zone at varying discharge frequency, power input, gas temperature and feed flow rates, aiming at the formation of CO and O 2 . The discharge obtained in CO 2 is characterized as a filamentary mode with a microdischarge zone in each half cycle of the applied voltage. It is shown that the most important parameter affecting the CO 2 -conversion levels is the gas flow rate. At low flow rates, both the conversion and the CO-yield are significantly higher. In addition, also an increase in the gas temperature and the power input give rise to higher conversion levels, although the effect on the CO-yield is limited. The optimum discharge frequency depends on the power input level and it cannot be unambiguously stated that higher frequencies give rise to increased conversion levels. A maximum CO 2 conversion of 30% is achieved at a flow rate of 0.05 L min -1 , a power density of 14.75 W cm -3 and a frequency of 60 kHz. The most energy efficient conversions are achieved at a flow rate of 0.2 L min -1 , a power density of 11 W cm -3 and a discharge frequency of 30 kHz.

  14. 5 CFR 317.302 - Conversion procedures.

    Science.gov (United States)

    2010-01-01

    ... conversion. (2) Pay. Upon conversion to the Senior Executive Service, an employee's SES rate will be... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Conversion procedures. 317.302 Section... IN THE SENIOR EXECUTIVE SERVICE Conversion to the Senior Executive Service § 317.302 Conversion...

  15. Conversational evidence in therapeutic dialogue.

    Science.gov (United States)

    Strong, Tom; Busch, Robbie; Couture, Shari

    2008-07-01

    Family therapists' participation in therapeutic dialogue with clients is typically informed by evidence of how such dialogue is developing. In this article, we propose that conversational evidence, the kind that can be empirically analyzed using discourse analyses, be considered a contribution to widening psychotherapy's evidence base. After some preliminaries about what we mean by conversational evidence, we provide a genealogy of evaluative practice in psychotherapy, and examine qualitative evaluation methods for their theoretical compatibilities with social constructionist approaches to family therapy. We then move on to examine the notion of accomplishment in therapeutic dialogue given how such accomplishments can be evaluated using conversation analysis. We conclude by considering a number of research and pedagogical implications we associate with conversational evidence.

  16. HYDROKINETIC ENERGY CONVERSION SYSTEMS: PROSPECTS ...

    African Journals Online (AJOL)

    eobe

    Hydrokinetic energy conversion systems utilize the kinetic energy of flowing water bodies with little or no head to generate ... generator. ... Its principle of operation is analogous to that of wind ..... Crisis-solar and wind power systems, 2009,.

  17. Conversion electrons in the SDC

    International Nuclear Information System (INIS)

    Wicklund, A.B.

    1991-01-01

    We summarize a preliminary analysis of the rates for conversion electrons in the SDC detector, relative to other interesting sources of prompt electrons. We have used Papageno V3.30, and other available NLO calculations to estimate inclusive rates in the central region (η less than 2.0), and we have cross checked these using CDF data at 1.8 TeV. We have considered three sources of ''isolated'' electrons, namely inclusive W/Z production; top quark (Mt=140); and QCD prompt photon production, followed by conversion in 10% XO. This value approximates the inner silicon detector at SDC. Additional conversions will occur in the outer tracking chamber, but the trigger and track reconstruction efficiency will be lower. We have also considered ''nonisolated'' leptons coming from inclusive bottom production, photon conversions resulting from π 0 ,η production in jets, and high pt hadrons faking electrons

  18. Energy conversion at dipolarization fronts

    Science.gov (United States)

    Khotyaintsev, Yu. V.; Divin, A.; Vaivads, A.; André, M.; Markidis, S.

    2017-02-01

    We use multispacecraft observations by Cluster in the Earth's magnetotail and 3-D particle-in-cell simulations to investigate conversion of electromagnetic energy at the front of a fast plasma jet. We find that the major energy conversion is happening in the Earth (laboratory) frame, where the electromagnetic energy is being transferred from the electromagnetic field to particles. This process operates in a region with size of the order several ion inertial lengths across the jet front, and the primary contribution to E·j is coming from the motional electric field and the ion current. In the frame of the front we find fluctuating energy conversion with localized loads and generators at sub-ion scales which are primarily related to the lower hybrid drift instability excited at the front; however, these provide relatively small net energy conversion.

  19. Ocean energy conversion - A reality

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.

    -depth analysis of application and achievements of OTEC, tidal energy, impact of astronomical forces on tide, prospects of tidal power plants, wave energy conversion and its mathematical approach for both linear and non-linear waves, economic viability, problems...

  20. Enzymes for improved biomass conversion

    Science.gov (United States)

    Brunecky, Roman; Himmel, Michael E.

    2016-02-02

    Disclosed herein are enzymes and combinations of the enzymes useful for the hydrolysis of cellulose and the conversion of biomass. Methods of degrading cellulose and biomass using enzymes and cocktails of enzymes are also disclosed.

  1. Hydrogen photoproduction by photoelectrochemical conversion

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    The water-splitting reaction by photoelectrochemical processes has gained much more attention than any of many reactions proposed for solar generation of energy-rich molecules (fuels). The conversion efficiency of the photosystem is the key factor. The higher the efficiency, the more economically feasible will be the conversion scheme. The conversion efficiency is a function of the semiconductor properties, light intensity, spectral quality, properties of the electrolyte, counterelectrode, cell configuration, etc. The semiconductor parameters include band gap, absorption coefficient and diffusion length. The area and material used for a counterelectrode are important when considering polarization losses in a two-electrode system. Besides, the stability problem is also a very important one to meet the requirement for practical applications. This paper reviews some important issues on photoelectrochemical generation of hydrogen by water splitting. It includes energy conversion efficiency, market assessment and cost goal, state of the technology, and future directions for research

  2. Effective communication during difficult conversations.

    Science.gov (United States)

    Polito, Jacquelyn M

    2013-06-01

    A strong interest and need exist in the workplace today to master the skills of conducting difficult conversations. Theories and strategies abound, yet none seem to have found the magic formula with universal appeal and success. If it is such an uncomfortable skill to master is it better to avoid or initiate such conversations with employees? Best practices and evidence-based management guide us to the decision that quality improvement dictates effective communication, even when difficult. This brief paper will offer some suggestions for strategies to manage difficult conversations with employees. Mastering the skills of conducting difficult conversations is clearly important to keeping lines of communication open and productive. Successful communication skills may actually help to avert confrontation through employee engagement, commitment and appropriate corresponding behavior

  3. Electron spectrometers with internal conversion

    International Nuclear Information System (INIS)

    Suita, J.C.; Lemos Junior, O.F.; Auler, L.T.; Silva, A.G. da

    1981-01-01

    The efforts that the Department of Physics (DEFI) of Institute of Nuclear Engineering (IEN) are being made aiming at adjusting the electron spectrometers with internal conversion to its necessity, are shown. (E.G.) [pt

  4. A Conversation Well Worth Remembering

    Science.gov (United States)

    Woolven-Allen, John

    2009-01-01

    To mark the 200th anniversary of Charles Darwin's birth, a special event was held at Oxford, which included a "Conversation" between Professor Richard Dawkins and Bishop Richard Harries. Here we present a personal reminiscence of the event.

  5. Computer code conversion using HISTORIAN

    International Nuclear Information System (INIS)

    Matsumoto, Kiyoshi; Kumakura, Toshimasa.

    1990-09-01

    When a computer program written for a computer A is converted for a computer B, in general, the A version source program is rewritten for B version. However, in this way of program conversion, the following inconvenient problems arise. 1) The original statements to be rewritten for B version are lost. 2) If the original statements of the A version rewritten for B version would remain as comment lines, the B version source program becomes quite large. 3) When update directives of the program are mailed from the organization which developed the program or when some modifications are needed for the program, it is difficult to point out the part to be updated or modified in the B version source program. To solve these problems, the conversion method using the general-purpose software management aid system, HISTORIAN, has been introduced. This conversion method makes a large computer code a easy-to-use program for use to update, modify or improve after the conversion. This report describes the planning and procedures of the conversion method and the MELPROG-PWR/MOD1 code conversion from the CRAY version to the JAERI FACOM version as an example. This report would provide useful information for those who develop or introduce large programs. (author)

  6. Conversion factors and oil statistics

    International Nuclear Information System (INIS)

    Karbuz, Sohbet

    2004-01-01

    World oil statistics, in scope and accuracy, are often far from perfect. They can easily lead to misguided conclusions regarding the state of market fundamentals. Without proper attention directed at statistic caveats, the ensuing interpretation of oil market data opens the door to unnecessary volatility, and can distort perception of market fundamentals. Among the numerous caveats associated with the compilation of oil statistics, conversion factors, used to produce aggregated data, play a significant role. Interestingly enough, little attention is paid to conversion factors, i.e. to the relation between different units of measurement for oil. Additionally, the underlying information regarding the choice of a specific factor when trying to produce measurements of aggregated data remains scant. The aim of this paper is to shed some light on the impact of conversion factors for two commonly encountered issues, mass to volume equivalencies (barrels to tonnes) and for broad energy measures encountered in world oil statistics. This paper will seek to demonstrate how inappropriate and misused conversion factors can yield wildly varying results and ultimately distort oil statistics. Examples will show that while discrepancies in commonly used conversion factors may seem trivial, their impact on the assessment of a world oil balance is far from negligible. A unified and harmonised convention for conversion factors is necessary to achieve accurate comparisons and aggregate oil statistics for the benefit of both end-users and policy makers

  7. Differing types of cellular phone conversations and dangerous driving.

    Science.gov (United States)

    Dula, Chris S; Martin, Benjamin A; Fox, Russell T; Leonard, Robin L

    2011-01-01

    This study sought to investigate the relationship between cell phone conversation type and dangerous driving behaviors. It was hypothesized that more emotional phone conversations engaged in while driving would produce greater frequencies of dangerous driving behaviors in a simulated environment than more mundane conversation or no phone conversation at all. Participants were semi-randomly assigned to one of three conditions: (1) no call, (2) mundane call, and, (3) emotional call. While driving in a simulated environment, participants in the experimental groups received a phone call from a research confederate who either engaged them in innocuous conversation (mundane call) or arguing the opposite position of a deeply held belief of the participant (emotional call). Participants in the no call and mundane call groups differed significantly only on percent time spent speeding and center line crossings, though the mundane call group consistently engaged in more of all dangerous driving behaviors than did the no call participants. Participants in the emotional call group engaged in significantly more dangerous driving behaviors than participants in both the no call and mundane call groups, with the exception of traffic light infractions, where there were no significant group differences. Though there is need for replication, the authors concluded that whereas talking on a cell phone while driving is risky to begin with, having emotionally intense conversations is considerably more dangerous. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Theory of mind understanding and conversational patterns in middle childhood.

    Science.gov (United States)

    Bosacki, Sandra Leanne

    2013-01-01

    The author investigated the longitudinal relations between theory of mind (ToM) understanding and perceptions of self and social conversations in 17 school-aged children (12 girls, 5 boys, age 8-12 years). ToM was assessed at Time 1 (T1; M age = 8 years 5 months, SD = 8.7 months, and perceptions of self and conversational experiences assessed two years later at Time 2 (T2; M age = 10 years 4 months, SD = 7.9 months. Most importantly, longitudinal findings showed that children who scored relatively high on ToM at T1 reported relatively lower perceptions of self-worth and higher number of mental states verbs in their perceptions of peer and family conversations at T2. Significant negative longitudinal associations were found between children's number of siblings and their perceptions of self-worth (T1) and number of cognitive terms in their perceptions of peer and family conversations (T2). Frequency analysis suggested that girls' perceptions of conversations referred to more social and psychological aspects of self and relationships, whereas boys focused mainly on physical activities. Most children were more likely to prefer listening to talking during social conversations. The majority of children reported feelings of mixed or ambiguous emotions during experiences of silence. Implications for socioemotional and cognitive development in early adolescents are discussed.

  9. Information for Consumers about Alternative Fuel Conversions

    Science.gov (United States)

    Here are some factors to be aware of if you are considering fuel conversion, including background information on fuel conversion, instructions for demonstrating compliance, and other related information.

  10. Advanced power conversion based on the Aerocapacitor{trademark}. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Roark, D.

    1997-03-05

    This report summarizes work performed under contract No. DE-FC07-94ID13283, {open_quotes}Advanced Power Conversion Based on the Aerocapacitors{trademark}.{close_quotes} Under this contract high power density, high energy density, organic electrolyte Aerocapacitors{trademark} were developed and characterized for power conversion applications. Pilot facilities for manufacturing prototype AA-size Aerocapacitors{trademark} were put in place. The low ESR and good frequency response of these devices show that they are ideal components for high discharge rate and low to moderate frequency (< 10 kHz) applications such as power conversion.

  11. Analysis of internal conversion coefficients

    International Nuclear Information System (INIS)

    Coursol, N.; Gorozhankin, V.M.; Yakushev, E.A.; Briancon, C.; Vylov, Ts.

    2000-01-01

    An extensive database has been assembled that contains the three most widely used sets of calculated internal conversion coefficients (ICC): [Hager R.S., Seltzer E.C., 1968. Internal conversion tables. K-, L-, M-shell Conversion coefficients for Z=30 to Z=103, Nucl. Data Tables A4, 1-237; Band I.M., Trzhaskovskaya M.B., 1978. Tables of gamma-ray internal conversion coefficients for the K-, L- and M-shells, 10≤Z≤104, Special Report of Leningrad Nuclear Physics Institute; Roesel F., Fries H.M., Alder K., Pauli H.C., 1978. Internal conversion coefficients for all atomic shells, At. Data Nucl. Data Tables 21, 91-289] and also includes new Dirac-Fock calculations [Band I.M. and Trzhaskovskaya M.B., 1993. Internal conversion coefficients for low-energy nuclear transitions, At. Data Nucl. Data Tables 55, 43-61]. This database is linked to a computer program to plot ICCs and their combinations (sums and ratios) as a function of Z and energy, as well as relative deviations of ICC or their combinations for any pair of tabulated data. Examples of these analyses are presented for the K-shell and total ICCs of the gamma-ray standards [Hansen H.H., 1985. Evaluation of K-shell and total internal conversion coefficients for some selected nuclear transitions, Eur. Appl. Res. Rept. Nucl. Sci. Tech. 11.6 (4) 777-816] and for the K-shell and total ICCs of high multipolarity transitions (total, K-, L-, M-shells of E3 and M3 and K-shell of M4). Experimental data sets are also compared with the theoretical values of these specific calculations

  12. Mechanisms of Ectopic Gene Conversion

    Directory of Open Access Journals (Sweden)

    P.J. Hastings

    2010-11-01

    Full Text Available Gene conversion (conversion, the unidirectional transfer of DNA sequence information, occurs as a byproduct of recombinational repair of broken or damaged DNA molecules. Whereas excision repair processes replace damaged DNA by copying the complementary sequence from the undamaged strand of duplex DNA, recombinational mechanisms copy similar sequence, usually in another molecule, to replace the damaged sequence. In mitotic cells the other molecule is usually a sister chromatid, and the repair does not lead to genetic change. Less often a homologous chromosome or homologous sequence in an ectopic position is used. Conversion results from repair in two ways. First, if there was a double-strand gap at the site of a break, homologous sequence will be used as the template for synthesis to fill the gap, thus transferring sequence information in both strands. Second, recombinational repair uses complementary base pairing, and the heteroduplex molecule so formed is a source of conversion, both as heteroduplex and when donor (undamaged template information is retained after correction of mismatched bases in heteroduplex. There are mechanisms that favour the use of sister molecules that must fail before ectopic homology can be used. Meiotic recombination events lead to the formation of crossovers required in meiosis for orderly segregation of pairs of homologous chromosomes. These events result from recombinational repair of programmed double-strand breaks, but in contrast with mitotic recombination, meiotic recombinational events occur predominantly between homologous chromosomes, so that transfer of sequence differences by conversion is very frequent. Transient recombination events that do not form crossovers form both between homologous chromosomes and between regions of ectopic homology, and leave their mark in the occurrence of frequent non-crossover conversion, including ectopic conversion.

  13. Frequency Doubling Broadband Light in Multiple Crystals

    International Nuclear Information System (INIS)

    Alford, William J.; Smith, Arlee V.

    2000-01-01

    The authors compare frequency doubling of broadband light in a single nonlinear crystal with doubling in five crystals with intercrystal temporal walk off compensation, and with doubling in five crystals adjusted for offset phase matching frequencies. Using a plane-wave, dispersive numerical model of frequency doubling they study the bandwidth of the second harmonic and the conversion efficiency as functions of crystal length and fundamental irradiance. For low irradiance the offset phase matching arrangement has lower efficiency than a single crystal of the same total length but gives a broader second harmonic bandwidth. The walk off compensated arrangement gives both higher conversion efficiency and broader bandwidth than a single crystal. At high irradiance, both multicrystal arrangements improve on the single crystal efficiency while maintaining broad bandwidth

  14. Temperature dependence of mode conversion in warm, unmagnetized plasmas with a linear density profile

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Dae Jung; Lee, Dong-Hun [School of Space Research, Kyung Hee University, Yongin (Korea, Republic of); Kim, Kihong [Division of Energy Systems Research, Ajou University, Suwon (Korea, Republic of)

    2013-06-15

    We study theoretically the linear mode conversion between electromagnetic waves and Langmuir waves in warm, stratified, and unmagnetized plasmas, using a numerically precise calculation based on the invariant imbedding method. We verify that the principle of reciprocity for the forward and backward mode conversion coefficients holds precisely regardless of temperature. We also find that the temperature dependence of the mode conversion coefficient is substantially stronger than that previously reported. Depending on the wave frequency and the incident angle, the mode conversion coefficient is found to increase or decrease with the increase of temperature.

  15. Engineered nanomaterials for solar energy conversion.

    Science.gov (United States)

    Mlinar, Vladan

    2013-02-01

    Understanding how to engineer nanomaterials for targeted solar-cell applications is the key to improving their efficiency and could lead to breakthroughs in their design. Proposed mechanisms for the conversion of solar energy to electricity are those exploiting the particle nature of light in conventional photovoltaic cells, and those using the collective electromagnetic nature, where light is captured by antennas and rectified. In both cases, engineered nanomaterials form the crucial components. Examples include arrays of semiconductor nanostructures as an intermediate band (so called intermediate band solar cells), semiconductor nanocrystals for multiple exciton generation, or, in antenna-rectifier cells, nanomaterials for effective optical frequency rectification. Here, we discuss the state of the art in p-n junction, intermediate band, multiple exciton generation, and antenna-rectifier solar cells. We provide a summary of how engineered nanomaterials have been used in these systems and a discussion of the open questions.

  16. Toroidal mode-conversion in the ICRF

    International Nuclear Information System (INIS)

    Jaun, A.; Hellsten, T.; Chiu, S.C.

    1997-08-01

    Mode-conversion is studied in the ion-cyclotron range of frequencies (ICRF) taking into account the toroidal geometry relevant for tokamaks. The global wavefields obtained using the gyrokinetic toroidal PENN code illustrate how the fast wave propagates to the neighborhood of the ion-ion hybrid resonance, where it is converted to a slow wave which deposits the wave energy through resonant interactions with the particles. The power deposition profiles obtained are dramatically different from the toroidal resonance absorption, showing that Budden's model is not a good approximation in the torus. Radially and poloidally localized wavefield structures characteristic of slow wave eigenmodes are predicted and could in experiments be driven to large amplitudes so as to interact efficiently with fast particles. (author) 5 figs., 1 tab., 48 refs

  17. [Conversation analysis for improving nursing communication].

    Science.gov (United States)

    Yi, Myungsun

    2007-08-01

    Nursing communication has become more important than ever before because quality of nursing services largely depends on the quality of communication in a very competitive health care environment. This article was to introduce ways to improve nursing communication using conversation analysis. This was a review study on conversation analysis, critically examining previous studies in nursing communication and interpersonal relationships. This study provided theoretical backgrounds and basic assumptions of conversation analysis which was influenced by ethnomethodology, phenomenology, and sociolinguistic. In addition, the characteristics and analysis methods of conversation analysis were illustrated in detail. Lastly, how conversation analysis could help improve communication was shown, by examining researches using conversation analysis not only for ordinary conversations but also for extraordinary or difficult conversations such as conversations between patients with dementia and their professional nurses. Conversation analysis can help in improving nursing communication by providing various structures and patterns as well as prototypes of conversation, and by suggesting specific problems and problem-solving strategies in communication.

  18. Energy conversion and utilization technologies

    International Nuclear Information System (INIS)

    1988-01-01

    The DOE Energy Conversion and Utilization Technologies (ECUT) Program continues its efforts to expand the generic knowledge base in emerging technological areas that support energy conservation initiatives by both the DOE end-use sector programs and US private industry. ECUT addresses specific problems associated with the efficiency limits and capabilities to use alternative fuels in energy conversion and end-use. Research is aimed at understanding and improving techniques, processes, and materials that push the thermodynamic efficiency of energy conversion and usage beyond the state of the art. Research programs cover the following areas: combustion, thermal sciences, materials, catalysis and biocatalysis, and tribology. Six sections describe the status of direct contact heat exchange; the ECUT biocatalysis project; a computerized tribology information system; ceramic surface modification; simulation of internal combustion engine processes; and materials-by-design. These six sections have been indexed separately for inclusion on the database. (CK)

  19. Environmental effects of energy conversion

    International Nuclear Information System (INIS)

    Hansmeyer, K.H.; Fortak, H.; Knoepp, H.; Lindackers, K.H.; Schafhausen, F.; Schoedel, J.P.

    1984-01-01

    The article presents an analysis of energy conversion systems by the ''Council of Environmental Experts'' in order to correct the erroneous assumption that small energy conversion systems will also be small-scale and negligible emitters of pollutants. The additional pollution caused by Neurath power plant is considered to be low, at least in its immediate vicinity, owing to the implementation of the most recent technical developments. The environmental effects of energy conversion processes are discussed, including the waste heat problem and processes for water-cooling of power plants. General aspects of a new concept of energy taxation are discussed which is to reduce energy consumption. The problem of radioactive waste is discussed from spent fuel storage and reprocessing to the decommissioning of older power plants. The author points out that also new fossil-fuel technologies will pollute the environment. (orig.) [de

  20. Blind-date Conversation Joining

    Directory of Open Access Journals (Sweden)

    Luca Cesari

    2013-07-01

    Full Text Available We focus on a form of joining conversations among multiple parties in service-oriented applications where a client may asynchronously join an existing conversation without need to know in advance any information about it. More specifically, we show how the correlation mechanism provided by orchestration languages enables a form of conversation joining that is completely transparent to clients and that we call 'blind-date joining'. We provide an implementation of this strategy by using the standard orchestration language WS-BPEL. We then present its formal semantics by resorting to COWS, a process calculus specifically designed for modelling service-oriented applications. We illustrate our approach by means of a simple, but realistic, case study from the online games domain.

  1. [Hydroxylamine conversion by anammox enrichment].

    Science.gov (United States)

    Hu, Anhui; Zheng, Ping; Lu, Huifeng; Ding, Shuang; Wang, Caihua

    2010-04-01

    Hydroxylamine is an important intermediate product of anammox. This study was focused on the characteristics of hydroxylamine and nitrite conversions by anammox enrichment. The changes of nitrogenous substrates and related products with time were measured using batch tests with anammox enrichment as inoculum. Since hydroxylamine didn't react with nitrite in uninoculated control culture, these two compounds were chemically stable. Both of them decreased with time in anammox enrichment inoculated cultures, in which ammonia as intermediate product would be produced and converted with the maximum concentration being 0.338 mg/L. The total nitrogen concentration decreased from 4.694 mmol/L to 0.812 mmol/L with conversion rate 82.7% in the end. When hydroxylamine and nitrite concentrations were about 2.5 mmol/L respectively, the maximum specific sludge conversion rates of hydroxylamine was 0.535 mmol/(gVSS.h), which was 1.81 times bigger than that of ammonia in ammonia reaction system; the maximum specific sludge rate of total nitrogen was slightly higher than that in ammonia reaction system. When hydroxylamine concentration increased to 5.0 mmol/L, the hydroxylamine and nitrite conversion rates promoted by 26.7% and 120.7% respectively; and the maximum ammonia accumulated was 1.810 mmol/L. When nitrite concentration increased to 5.0 mmol/L, the hydroxylamine and nitrite conversion rates promoted by 6.9% and 9.0% respectively; and the maximum ammonia accumulated was 0.795 mmol/L. Anammox enrichment was capable of converting hydroxylamine and nitrite simultaneously and had the higher conversion rate of hydroxylamine than ammonia conversion rate. Hydroxylamine and nitrite conversion rates were less affected by increase in nitrite concentration, but more significantly influenced by increase in hydroxylamine. The maximum ammonia concentration accumulated would rise as the result of increasing both hydroxylamine and nitrite. The result of experiment was consistent with pathway

  2. Wavelength conversion techniques and devices

    DEFF Research Database (Denmark)

    Danielsen, Søren Lykke; Mikkelsen, Benny; Hansen, Peter Bukhave

    1997-01-01

    Taking into account the requirements to the converters e.g., bit rate transparency (at least up to 10 Gbit/s), polarisation independence, wavelength independence, moderate input power levels, high signal-to-noise ratio and high extinction ratio interferometric wavelength convertors are very...... interesting for use in WDM optical fibre networks. However, the perfect converter has probably not yet been fabricated and new techniques such as conversion relying on cross-absorption modulation in electro-absorption modulators might also be considered in pursue of effective conversion devices...

  3. Solar energy conversion. Chemical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Likhtenshtein, Gertz [Ben-Gurion Univ. of the Negev, Beersheba (Israel). Dept. of Chemistry

    2012-07-01

    Finally filling a gap in the literature for a text that also adopts the chemist's view of this hot topic, Professor Likhtenshtein, an experienced author and internationally renowned scientist, considers different physical and engineering aspects in solar energy conversion. From theory to real-life systems, he shows exactly which chemical reactions take place when converting light energy, providing an overview of the chemical perspective from fundamentals to molecular harvesting systems and solar cells. This essential guide will thus help researchers in academia and industry better understand solar energy conversion, and so ultimately help this promising, multibillion euro/dollar field to expand. (orig.)

  4. A perspective on direct conversion

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, W. B.

    1963-10-15

    As flowing energy, electricity is sought for its versatility. Its generation from some other flow or release of energy without mechanical power, or even sometimes heat, as intermediary is called direct conversion. The objective is high electrical output for minimum total cost and not always high conversion efficiency. The wide range of techniques embracing cryogenics and hot plasma derives from the special requirements of source, environment and application. Sources include solar and other radiation, nuclear fission and fusion, chemical energy and heat. Environments and applications range from space vehicles to submarines and from giant power networks to isolated buoys and pocket devices. (author)

  5. A perspective on direct conversion

    International Nuclear Information System (INIS)

    Lewis, W.B.

    1963-10-01

    As flowing energy, electricity is sought for its versatility. Its generation from some other flow or release of energy without mechanical power, or even sometimes heat, as intermediary is called direct conversion. The objective is high electrical output for minimum total cost and not always high conversion efficiency. The wide range of techniques embracing cryogenics and hot plasma derives from the special requirements of source, environment and application. Sources include solar and other radiation, nuclear fission and fusion, chemical energy and heat. Environments and applications range from space vehicles to submarines and from giant power networks to isolated buoys and pocket devices. (author)

  6. Self-induced neutrino flavor conversion without flavor mixing

    International Nuclear Information System (INIS)

    Chakraborty, S.; Izaguirre, I.; Raffelt, G.G.; Hansen, R. S.

    2016-01-01

    Neutrino-neutrino refraction in dense media can cause self-induced flavor conversion triggered by collective run-away modes of the interacting flavor oscillators. The growth rates were usually found to be of order a typical vacuum oscillation frequency Δ m 2 /2E. However, even in the simple case of a ν e beam interacting with an opposite-moving ν-bar e beam, and allowing for spatial inhomogeneities, the growth rate of the fastest-growing Fourier mode is of order μ=√2 G F  n ν , a typical ν–ν interaction energy. This growth rate is much larger than the vacuum oscillation frequency and gives rise to flavor conversion on a much shorter time scale. This phenomenon of 'fast flavor conversion' occurs even for vanishing Δ m 2 /2E and thus does not depend on energy, but only on the angle distributions. Moreover, it does not require neutrinos to mix or to have masses, except perhaps for providing seed disturbances. We also construct a simple homogeneous example consisting of intersecting beams and study a schematic supernova model proposed by Ray Sawyer, where ν e and ν-bar e emerge with different zenith-angle distributions, the key ingredient for fast flavor conversion. What happens in realistic astrophysical scenarios remains to be understood

  7. Translational errors as an early event in prion conversion.

    Science.gov (United States)

    Hatin, I; Bidou, L; Cullin, C; Rousset, J P

    2001-01-01

    A prion is an infectious, altered form of a cellular protein which can self-propagate and affect normal phenotype. Prion conversion has been observed for mammalian and yeast proteins but molecular mechanisms that trigger this process remain unclear. Up to now, only post-translational models have been explored. In this work, we tested the hypothesis that co-translational events may be implicated in the conformation changes of the Ure2p protein of Saccharomyces cerevisiae. This protein can adopt a prion conformation leading to an [URE3] phenotype which can be easily assessed and quantified. We analyzed the effect of two antibiotics, known to affect translation, on [URE3] conversion frequency. For cells treated with G418 we observed a parallel increase of translational errors rate and frequency of [URE3] conversion. By contrast, cycloheximide which was not found to affect translational fidelity, has no influence on the induction of [URE3] phenotype. These results raise the possibility that the mechanism of prion conversion might not only involve alternative structures of strictly identical molecules but also aberrant proteins resulting from translational errors.

  8. Gene conversion in the rice genome

    DEFF Research Database (Denmark)

    Xu, Shuqing; Clark, Terry; Zheng, Hongkun

    2008-01-01

    -chromosomal conversions distributed between chromosome 1 and 5, 2 and 6, and 3 and 5 are more frequent than genome average (Z-test, P ... is not tightly linked to natural selection in the rice genome. To assess the contribution of segmental duplication on gene conversion statistics, we determined locations of conversion partners with respect to inter-chromosomal segment duplication. The number of conversions associated with segmentation is less...... involved in conversion events. CONCLUSION: The evolution of gene families in the rice genome may have been accelerated by conversion with pseudogenes. Our analysis suggests a possible role for gene conversion in the evolution of pathogen-response genes....

  9. Frequency noise in frequency swept fiber laser

    DEFF Research Database (Denmark)

    Pedersen, Anders Tegtmeier; Rottwitt, Karsten

    2013-01-01

    This Letter presents a measurement of the spectral content of frequency shifted pulses generated by a lightwave synthesized frequency sweeper. We found that each pulse is shifted in frequency with very high accuracy. We also discovered that noise originating from light leaking through the acousto......- optical modulators and forward propagating Brillouin scattering appear in the spectrum. © 2013 Optical Society of America....

  10. Evolution of energy conversion plants

    International Nuclear Information System (INIS)

    Osnaghi, C.

    2001-01-01

    The paper concerns the evolution and the future development of energy conversion plants and puts into evidence the great importance of the scientific and technological improvement in machines design, in order to optimize the use of energy resources and to improve ambient compatibility [it

  11. Direct digital conversion detector technology

    Science.gov (United States)

    Mandl, William J.; Fedors, Richard

    1995-06-01

    Future imaging sensors for the aerospace and commercial video markets will depend on low cost, high speed analog-to-digital (A/D) conversion to efficiently process optical detector signals. Current A/D methods place a heavy burden on system resources, increase noise, and limit the throughput. This paper describes a unique method for incorporating A/D conversion right on the focal plane array. This concept is based on Sigma-Delta sampling, and makes optimum use of the active detector real estate. Combined with modern digital signal processors, such devices will significantly increase data rates off the focal plane. Early conversion to digital format will also decrease the signal susceptibility to noise, lowering the communications bit error rate. Computer modeling of this concept is described, along with results from several simulation runs. A potential application for direct digital conversion is also reviewed. Future uses for this technology could range from scientific instruments to remote sensors, telecommunications gear, medical diagnostic tools, and consumer products.

  12. Restarts in Conversation and Literature.

    Science.gov (United States)

    Person, Raymond F., Jr.

    1996-01-01

    Analyzes restarts, a common feature of conversation, in literary discourse. The term "restart" refers to the repetition of a word or words within an utterance by the same speaker. Restarts in literary discourse are of two types: (1) those produced by the characters in their "real" narrative world and (2) those produced by the narrators themselves.…

  13. Direct Energy Conversion Literature Abstracts

    Science.gov (United States)

    1962-12-01

    TMMOELECTRIC 6 CONVERSION SYSTEMS. compiled by Edda 7p.. Aug.1960. (Spec. Bibl. 430) Barber. 48p., Mar. 1962. (Lit. Search 392) (Contract NAS 7-100) Covers...2865 BaranskiiP.I ............... 2905, 2945 Brogan, T.R. .............. 3322 Barber, Edda ................. . 2866 Brooklyn Polytechnic

  14. Photovoltaic conversion of laser energy

    Science.gov (United States)

    Stirn, R. J.

    1976-01-01

    The Schottky barrier photovoltaic converter is suggested as an alternative to the p/n junction photovoltaic devices for the conversion of laser energy to electrical energy. The structure, current, output, and voltage output of the Schottky device are summarized. The more advanced concepts of the multilayer Schottky barrier cell and the AMOS solar cell are briefly considered.

  15. Conversations to Transform Geometry Class

    Science.gov (United States)

    Szydlik, Jennifer Earles; Parrott, Amy; Belnap, Jason Knight

    2016-01-01

    Classroom culture is negotiated and established through both conversations and practices. Traditionally, teachers and researchers have focused primarily on the individual and social construction of mathematical content--that is, students' conceptual understanding and procedural skills--through mathematical actions and practices. This article…

  16. Conversation Analysis and Applied Linguistics.

    Science.gov (United States)

    Schegloff, Emanuel A.; Koshik, Irene; Jacoby, Sally; Olsher, David

    2002-01-01

    Offers biographical guidance on several major areas of conversation-analytic work--turn-taking, repair, and word selection--and indicates past or potential points of contact with applied linguistics. Also discusses areas of applied linguistic work. (Author/VWL)

  17. Facilitating Conversations about Managerial Identities

    DEFF Research Database (Denmark)

    Madsen, Mona Toft

    -based organization in the engineering consulting sector b) a reflection meeting, where the same three managers were gathered, and conversations were facilitated based on identity work in the context of earlier interviews. More specifically, three themes were discussed; flat organizational structure, tensions between...

  18. Humor and Embodied Conversational Agents

    NARCIS (Netherlands)

    Nijholt, Antinus

    This report surveys the role of humor in human-to-human interaction and the possible role of humor in human-computer interaction. The aim is to see whether it is useful for embodied conversational agents to integrate humor capabilities in their internal model of intelligence, emotions and

  19. Energy Conversion and Storage Program

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, E.J.

    1992-03-01

    The Energy Conversion and Storage Program applies chemistry and materials science principles to solve problems in (1) production of new synthetic fuels, (2) development of high-performance rechargeable batteries and fuel cells, (3) development of advanced thermochemical processes for energy conversion, (4) characterization of complex chemical processes, and (5) application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis. Electrochemistry research aims to develop advanced power systems for electric vehicle and stationary energy storage applications. Topics include identification of new electrochemical couples for advanced rechargeable batteries, improvements in battery and fuel-cell materials, and the establishment of engineering principles applicable to electrochemical energy storage and conversion. Chemical Applications research includes topics such as separations, catalysis, fuels, and chemical analyses. Included in this program area are projects to develop improved, energy-efficient methods for processing waste streams from synfuel plants and coal gasifiers. Other research projects seek to identify and characterize the constituents of liquid fuel-system streams and to devise energy-efficient means for their separation. Materials Applications research includes the evaluation of the properties of advanced materials, as well as the development of novel preparation techniques. For example, the use of advanced techniques, such as sputtering and laser ablation, are being used to produce high-temperature superconducting films.

  20. The national conversion pilot project

    International Nuclear Information System (INIS)

    Van Der Puy, M.; Francis, G.; Konczal, M.

    1994-01-01

    The Department of Energy is now faced with the prospect of terminating traditional defense production missions at several Department of Energy sites. Because of this, there is a critical need to develop a DOE process to convert former defense production facilities to private use so that underutilized workers and facilities may be used to minimize the impact on the United States economy. The purpose of the National Conversation Pilot Project (NCPP) at Rocky Flats near Denver, Colorado is to explore and demonstrate the feasibility of economic conversion of DOE facilities, in a manner consistent with ongoing site waste management and cleanup activities, and non-prejudicial to future land use planning decisions. The NCPP is divided into three stages: The first stage, now under way, is one of detailed planning for cleanup and building maintenance activities. The second stage involves building cleanup necessary to support the proposed industrial activities, maintenance of equipment and building infrastructure necessary to assure protection of human health and the environment, declassification work, and some small scale research and development activities. Stage III would involve DOE metals recycling. Specific approval from the DOE is required prior to each project stage. To ensure stakeholder involvement, a steering committee will advise the DOE on the desirability to proceed with the project from stage to stage. A key question in the conversion process is whether a competitive economic and regulatory environment can be created on a DOE facility, allowing an onsite conversion business to effectively compete with offsite businesses. If successful, the Rocky Flats project could become the model for economic conversion at other DOE facilities

  1. Multi-frequency excitation

    KAUST Repository

    Younis, Mohammad I.

    2016-01-01

    Embodiments of multi-frequency excitation are described. In various embodiments, a natural frequency of a device may be determined. In turn, a first voltage amplitude and first fixed frequency of a first source of excitation can be selected

  2. Efecto de reducir la frecuencia de alimentación en la supervivencia, crecimiento, conversión y conducta alimenticia en juveniles de salmón del Atlántico Salmo salar (Linnaeus, 1758: experiencia a nivel productivo Effect of reducing the feeding frequency on the survival, growth, conversion, and feeding behavior of juvenile Atlantic salmon Salmo salar (Linnaeus, 1758: an experience at the productive level

    Directory of Open Access Journals (Sweden)

    Héctor Flores

    2012-09-01

    Full Text Available En Chile, la mayoría de las empresas de cultivo de salmones en la fase parr alimentan a los peces con 24 raciones/día; por otra parte, el alimento en el estómago de los peces, puede permanecer cerca de 4 a 5 h. Este trabajo evalúa en base a procedimientos y protocolos productivos, la disminución en la frecuencia de raciones de alimento y su efecto en la supervivencia, crecimiento, conversión y conducta de alimentación de los peces. Se trabajó en condiciones normales de producción comercial, con aproximadamente 1.200.000 peces de 0,17 g durante cuatro meses. Hubo dos tratamientos, el control con 24 raciones/día y el ensayo, que al inicio de la experiencia se entrego 12 raciones/día y al finalizar la experiencia se proporcionó 4 raciones/día. Se emplearon cinco estanques de 18 m³ para cada tratamiento. La disminución en la frecuencia de alimentación, no afectó la supervivencia de Salmo salar, se obtuvo mayor crecimiento en los peces del ensayo, con mejor conversión de alimento, se logró reducción de alimento depositado en el fondo de los estanques y se visualizó mejor apetito en los peces.In Chile, most salmon-farming companies feed fish in the parr phase 24 rations/day. However, food can remain in fish stomachs for around four or five hours. Using productive procedures and protocols, this study evaluates less frequent food rations and how they affect the survival, growth, conversion, and feeding behavior of the fish. The study was conducted over four months under normal commercial production conditions, using approximately 1,200,000 fish of 0.17 g each. There were two treatments: the control, which received 24 rations/day, and the assay, which received 12 rations/day at the onset of the study and 4 rations/day at the end of this. Five tanks, each 18 m³, were used for each treatment. The lower feeding frequency did not affect the survival of Salmo salar. The fish in the assay obtained greater growth and had better food

  3. Optical parametric amplification and oscillation assisted by low-frequency stimulated emission

    OpenAIRE

    Longhi, Stefano

    2016-01-01

    Optical parametric amplification/oscillation provide a powerful tool for coherent light generation in spectral regions inaccessible to lasers. Parametric gain is based on a frequency {\\it down-conversion} process, and thus it can not be realized for signal waves at a frequency $\\omega_3$ {\\it higher} than the frequency of the pump wave $\\omega_1$. In this work we suggest a route toward the realization of {\\it up-conversion} optical parametric amplification and oscillation, i.e. amplification ...

  4. Frequency Up-Converted Low Frequency Vibration Energy Harvester Using Trampoline Effect

    International Nuclear Information System (INIS)

    Ju, S; Chae, S H; Choi, Y; Jun, S; Park, S M; Lee, S; Ji, C-H; Lee, H W

    2013-01-01

    This paper presents a non-resonant vibration energy harvester based on magnetoelectric transduction mechanism and mechanical frequency up-conversion using trampoline effect. The harvester utilizes a freely movable spherical permanent magnet which bounces off the aluminum springs integrated at both ends of the cavity, achieving frequency up-conversion from low frequency input vibration. Moreover, bonding method of magnetoelectric laminate composite has been optimized to provide higher strain to piezoelectric material and thus obtain a higher output voltage. A proof-of-concept energy harvesting device has been fabricated and tested. Maximum open-circuit voltage of 11.2V has been obtained and output power of 0.57μW has been achieved for a 50kΩ load, when the fabricated energy harvester was hand-shaken

  5. Frequency Up-Converted Low Frequency Vibration Energy Harvester Using Trampoline Effect

    Science.gov (United States)

    Ju, S.; Chae, S. H.; Choi, Y.; Jun, S.; Park, S. M.; Lee, S.; Lee, H. W.; Ji, C.-H.

    2013-12-01

    This paper presents a non-resonant vibration energy harvester based on magnetoelectric transduction mechanism and mechanical frequency up-conversion using trampoline effect. The harvester utilizes a freely movable spherical permanent magnet which bounces off the aluminum springs integrated at both ends of the cavity, achieving frequency up-conversion from low frequency input vibration. Moreover, bonding method of magnetoelectric laminate composite has been optimized to provide higher strain to piezoelectric material and thus obtain a higher output voltage. A proof-of-concept energy harvesting device has been fabricated and tested. Maximum open-circuit voltage of 11.2V has been obtained and output power of 0.57μW has been achieved for a 50kΩ load, when the fabricated energy harvester was hand-shaken.

  6. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel

    2017-01-01

    This textbook is appropriate for use in graduate-level curricula in analog-to-digital conversion, as well as for practicing engineers in need of a state-of-the-art reference on data converters. It discusses various analog-to-digital conversion principles, including sampling, quantization, reference generation, nyquist architectures and sigma-delta modulation. This book presents an overview of the state of the art in this field and focuses on issues of optimizing accuracy and speed, while reducing the power level. This new, third edition emphasizes novel calibration concepts, the specific requirements of new systems, the consequences of 22-nm technology and the need for a more statistical approach to accuracy. Pedagogical enhancements to this edition include additional, new exercises, solved examples to introduce all key, new concepts and warnings, remarks and hints, from a practitioner’s perspective, wherever appropriate. Considerable background information and practical tips, from designing a PCB, to lay-o...

  7. Hemicellulose conversion by anaerobic digestion

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, S; Honry, M P; Christopher, R W

    1985-01-01

    This research was undertaken to study the digestibility of the hemicellulose fractions of an aquatic biomass, a land-based biomass and a biomass-waste blend under various fermentation conditions. The conversion of hemicellulose was higher than those of cellulose and protein under the mesophilic condition. Hemicellulose was converted at a much lower efficency than cellulose during thermophilic digestion. In contrast, cellulose conversion was about the same under mesophilic and thermophilic conditions. Cellulose was utilized in preference to hemicellulose during mesophilic fermentation of nitrogen-supplemented Bermuda grass. It was speculated that Bermuda grass cellulose was converted at a higher efficiency than hemicellulose in the pressure of external nitrogen because the metabolism of the breakdown product (glucose) of cellulose required the least investment of enzymes and energy. 4 references.

  8. IMAGE CONVERSION FOR LASER PYROGRAPHY

    Directory of Open Access Journals (Sweden)

    Adrian PETRU

    2015-12-01

    Full Text Available All previous studies of pyrography have been focussed on colour obtained through modifying the work parameters. This paper analyses colour nuances obtained by laser woodworking by measuring colour changes digitally. The investigated parameter is colour reproduction by laser technology, using different image conversion methods (Halftone Round, Jarvis, and so on. The changes of image reproduction are analysed globally and colour by colour. The results show that the colour nuances are represented to a more and less degree, according to the conversion method selected. To evaluate the aesthetic changes, CIEL*a*b* colour measurements were applied. The results show that laser burning on wood surfaces has a great influence on wood colour. These findings will be useful to develop innovative design possibilities for wood surfaces for furniture and other products.

  9. Progress in understanding conversion disorder

    Science.gov (United States)

    Allin, Matthew; Streeruwitz, Anna; Curtis, Vivienne

    2005-01-01

    Conversion disorder has a history that may reach back into antiquity, and it continues to present a clinical challenge to both psychiatrists and neurologists. This article reviews the current state of knowledge surrounding the prevalence, etiology, and neurobiology of conversion disorder. There have been improvements in the accuracy of diagnosis that are possibly related to improved technologies such as neuroimaging. Once the diagnosis is made, it is important to develop a therapeutic alliance between the patient and the medical team, and where comorbid psychiatric diagnoses have been made, these need to be adequately treated. While there have been no formal trials of medication or psychoanalytic treatments in this disorder, case reports suggest that a combination of antidepressants, psychotherapy, and a multidisciplinary approach to rehabilitation may be beneficial. PMID:18568070

  10. The calcium and rare earth oxo-borates, Ca{sub 4}ReO(BO{sub 3}){sub 3} (Re = Gd, Y, La): synthesis and investigations of new non-critical phase matching configurations for frequency conversion at specific laser wavelengths; Les oxoborates de calcium et de lanthanide, Ca{sub 4}LnO(BO{sub 3}){sub 3} (Ln = Gd, Y, La): synthese et recherche d'angles d'accord de phase non critique pour la conversion de frequence de longueurs d'onde Laser specifiques

    Energy Technology Data Exchange (ETDEWEB)

    Reino, E

    2002-12-15

    Visible and UV lasers are currently investigated for many applications as data storage, medicine, etc. Intracavity frequency doubling appears as a good solution. Thus, the non-linear family Ca{sub 4}REO(BO{sub 3}){sub 3} (RE = rare earth, RECOB) has shown a considerable interest to produce compact visible laser. In addition, it is possible to tune the compositions of RECOB by partial substitutions in order to achieve non-critical phase matching (NCPM). In the present work, various cationic substitutions have been studied in solid solutions as Gd{sub 1-x}Y{sub x}COB, Gd{sub 1-x}La{sub x}COB, Gd{sub 1-x}Sc{sub x}COB (for the first time), Re{sub 1-x}Bi{sub x}COB (REe = Gd or Y) and (Ca{sub 1-x}Sr{sub x}){sub 4}GdO(BO{sub 3}){sub 3} in order to investigate their crystal growth and adjust the NCPM wavelength by composition. The wavelength range is related to neodymium doped laser materials emitting on the 4F3/2-4I9/2 transition, for example Nd:YAP (YAlO{sub 3}) at 930 nm, Nd:YAG (Y{sub 3}Al{sub 5}O{sub 12}) at 946 nm or Nd:ASL (Sr{sub 1-x}Nd{sub y}La{sub x-y}Mg{sub x}Al{sub 11-x}O{sub 19}) at 900 nm. We have also demonstrated that the compositions for NCPM can be determined from the refractive index of both lattices M{sub 1-x}M'{sub x}COB (M, M' RE) with x = 0 or 1, using the Clausius-Mosotti relation. Two new blue laser systems, constituted of a laser crystal and a non-linear crystal optimized for type-I NCPM second harmonic generation, were achieved: a 946 nm Nd:YAG laser with Gd{sub 0.87}Y{sub 0.13}COB and a 900 nm Nd:ASL laser with Gd{sub 0.56}Y{sub 0.44}COB. Moreover, we have performed for the first time a CW laser action at 900 nm with Nd:ASL. (author)

  11. Rating Instructional Conversations: A Guide

    OpenAIRE

    Rueda, Robert; Goldenberg, Claude; Gallimore, Ronald

    1992-01-01

    The current focus on more effective ways to foster literacy in school-age children, especially language minority students, has led to the development of alternative instructional approaches. One such approach is the instructional conversation (IC), based on early work in the Hawaiian Kamehameha Elementary Education Project (KEEP), on neo-Vygotskian theory, and on recent classroom-based research on reading comprehension. The present report outlines preliminary efforts to operationaliz...

  12. FRM-II conversion revisited

    International Nuclear Information System (INIS)

    Glaser, A.; Pistner, C.; Liebert, W.

    2000-01-01

    The possibilities for a conversion of the currently constructed research reactor FRM-II has been extensively discussed at various RERTR meetings over the past years. In order to support the ongoing decision-making process in Germany, we prepared computer simulations providing extra information on the scientific usability of the converted reactor based on designs proposed by ANL and TUM. The most important results of these calculations are presented and discussed. Special attention is thereby given to the specific German context. (author)

  13. Conversation Analysis and Classroom Interaction

    Institute of Scientific and Technical Information of China (English)

    DING A-ning; LI Fan; CUI Jing

    2015-01-01

    Conversation Analysis shows the evidence of the social nature of people’s action including talk-in-interaction from a micro-level perspective. The method for basing its analysis on the authentic data rather than the retrospective interviews for gain⁃ing the participants’perception makes it unique in discovering the emic perspective of the social interaction. CA, often called as a“micro”methodology, provides theoretical insights and useful analytical tool for exploring the interaction in classrooms.

  14. A Conversation with Adam Heller

    OpenAIRE

    Heller, A; Cairns, EJ

    2015-01-01

    © 2015 by Annual Reviews. All rights reserved. Adam Heller, Ernest Cockrell Sr. Chair in Engineering Emeritus of the John J. McKetta Department of Chemical Engineering at The University of Texas at Austin, recalls his childhood in the Holocaust and his contributions to science and technology that earned him the US National Medal of Technology and Innovation in a conversation with Elton J. Cairns, Professor of Chemical and Biomolecular Engineering at the University of California, Berkeley. Dr....

  15. The National Conversion Pilot Project

    International Nuclear Information System (INIS)

    Roberts, A.V.

    1995-01-01

    The National Conversion Pilot Project (NCPP) is a recycling project under way at the U.S. Department of Energy (DOE) Rocky Flats Environmental Technology Site (RFETS) in Colorado. The recycling aim of the project is threefold: to reuse existing nuclear weapon component production facilities for the production of commercially marketable products, to reuse existing material (uranium, beryllium, and radioactively contaminated scrap metals) for the production of these products, and to reemploy former Rocky Flats workers in this process

  16. Metylcyclohexane conversion to light olefins

    Directory of Open Access Journals (Sweden)

    SCOFIELD C.F.

    1998-01-01

    Full Text Available This study consists in the evaluation of the catalytic properties of zeolites with different structures in the conversion of methylcyclohexane to light olefins. Results obtained suggest that the steric constrictions of the catalysts used play an important role in hydrogen transfer reactions. Higher selectivities for light olefins (C3= and C4= were observed for zeolites having more closed structures, like MFI and ferrerite, when compared to those having more open ones, like beta, omega and faujasite.

  17. Metylcyclohexane conversion to light olefins

    OpenAIRE

    SCOFIELD, C.F.; BENAZZI, E.; CAUFFRIEZ, H.; MARCILLY, C.

    1998-01-01

    This study consists in the evaluation of the catalytic properties of zeolites with different structures in the conversion of methylcyclohexane to light olefins. Results obtained suggest that the steric constrictions of the catalysts used play an important role in hydrogen transfer reactions. Higher selectivities for light olefins (C3= and C4=) were observed for zeolites having more closed structures, like MFI and ferrerite, when compared to those having more open ones, like beta, omega and fa...

  18. High conversion burner type reactor

    International Nuclear Information System (INIS)

    Higuchi, Shin-ichi; Kawashima, Masatoshi

    1987-01-01

    Purpose: To simply and easily dismantle and reassemble densified fuel assemblies taken out of a high conversion ratio area thereby improve the neutron and fuel economy. Constitution: The burner portion for the purpose of fuel combustion is divided into a first burner region in adjacent with the high conversion ratio area at the center of the reactor core, and a second burner region formed to the outer circumference thereof and two types of fuels are charged therein. Densified fuel assemblies charged in the high conversion ratio area are separatably formed as fuel assemblies for use in the two types of burners. In this way, dense fuel assembly is separated into two types of fuel assemblies for use in burner of different number and arranging density of fuel elements which can be directly charged to the burner portion and facilitate the dismantling and reassembling of the fuel assemblies. Further, since the two types of fuel assemblies are charged in the burner portion, utilization factor for the neutron fuels can be improved. (Kamimura, M.)

  19. Measurements of weak conversion lines

    International Nuclear Information System (INIS)

    Feoktistov, A.I.; Frantsev, Yu.E.

    1979-01-01

    Described is a new methods for measuring weak conversion lines with the help of the β spectrometer of the π √ 2 type which permits to increase the reliability of the results obtained. According to this method the measurements were carried out by short series with the storage of the information obtained on the punched tape. The spectrometer magnetic field was stabilized during the measuring of the conversion spectra with the help of three nmr recorders. Instead of the dependence of the pulse calculation rate on the magnetic field value was measured the dependence of the calculation rate on the value of the voltage applied between the source and the spectrometer chamber. A short description of the automatic set-up for measuring conversion lines according to the method proposed is given. The main set-up elements are the voltage multiplexer timer, printer, scaler and the pulse analyzer. With the help of the above methods obtained is the K 1035, 8 keV 182 Ta line. It is obtained as a result of the composition of 96 measurement series. Each measurement time constitutes 640 s 12 points are taken on the line

  20. Geomagnetic activity effects on plasma sheet energy conversion

    Directory of Open Access Journals (Sweden)

    M. Hamrin

    2010-10-01

    Full Text Available In this article we use three years (2001, 2002, and 2004 of Cluster plasma sheet data to investigate what happens to localized energy conversion regions (ECRs in the plasma sheet during times of high magnetospheric activity. By examining variations in the power density, E·J, where E is the electric field and J is the current density obtained by Cluster, we have studied the influence on Concentrated Load Regions (CLRs and Concentrated Generator Regions (CGRs from variations in the geomagnetic disturbance level as expressed by the Kp, the AE, and the Dst indices. We find that the ECR occurrence frequency increases during higher magnetospheric activities, and that the ECRs become stronger. This is true both for CLRs and for CGRs, and the localized energy conversion therefore concerns energy conversion in both directions between the particles and the fields in the plasma sheet. A higher geomagnetic activity hence increases the general level of energy conversion in the plasma sheet. Moreover, we have shown that CLRs live longer during magnetically disturbed times, hence converting more electromagnetic energy. The CGR lifetime, on the other hand, seems to be unaffected by the geomagnetic activity level. The evidence for increased energy conversion during geomagnetically disturbed times is most clear for Kp and for AE, but there are also some indications that energy conversion increases during large negative Dst. This is consistent with the plasma sheet magnetically mapping to the auroral zone, and therefore being more tightly coupled to auroral activities and variations in the AE and Kp indices, than to variations in the ring current region as described by the Dst index.

  1. Experimental techniques of conversion coefficient measurements

    International Nuclear Information System (INIS)

    Hamilton, J.H.

    1975-01-01

    Discusses briefly the history of conversion electron spectra measurements, and the interpretation of the collected data. Then provides a comprehensive review of techniques presently available to measure the conversion coefficients. (Auth.)

  2. Conversion Disorder Presenting As Neuritic Leprosy

    Directory of Open Access Journals (Sweden)

    Sayal SK

    2000-01-01

    Full Text Available Conversion disorder is not normally listed amongst the conditions in differential diagnosis of leprosy neuropathy. A case conversion reaction who was initially diagnosed as neuritic leprosy is reported. Patient responded to narcosuggestion and psychotherapy.

  3. Interrogative suggestibility in patients with conversion disorders.

    Science.gov (United States)

    Foong, J; Lucas, P A; Ron, M A

    1997-09-01

    We tested the hypothesis that increased interrogative suggestibility may contribute to the shaping and maintaining of conversions symptoms. Interrogative suggestibility was measured in 12 patients with conversion disorder and 10 control patients with confirmed neurological disease matched for age, premorbid intelligence, and as closely as possible in terms of their neurological symptoms to the patients with conversion disorder. Our observations do not support the contention that individual differences in interrogative suggestibility are of importance in the etiology of conversion disorders.

  4. Vertical Scan-Conversion for Filling Purposes

    OpenAIRE

    Hersch, R. D.

    1988-01-01

    Conventional scan-conversion algorithms were developed independently of filling algorithms. They cause many problems, when used for filling purposes. However, today's raster printers and plotters require extended use of filling, especially for the generation of typographic characters and graphic line art. A new scan-conversion algorithm, called vertical scan-conversion has been specifically designed to meet the requirements of parity scan line fill algorithms. Vertical scan-conversion ensures...

  5. Multi-frequency excitation

    KAUST Repository

    Younis, Mohammad I.

    2016-03-10

    Embodiments of multi-frequency excitation are described. In various embodiments, a natural frequency of a device may be determined. In turn, a first voltage amplitude and first fixed frequency of a first source of excitation can be selected for the device based on the natural frequency. Additionally, a second voltage amplitude of a second source of excitation can be selected for the device, and the first and second sources of excitation can be applied to the device. After applying the first and second sources of excitation, a frequency of the second source of excitation can be swept. Using the methods of multi- frequency excitation described herein, new operating frequencies, operating frequency ranges, resonance frequencies, resonance frequency ranges, and/or resonance responses can be achieved for devices and systems.

  6. Frequency selectivity at very low centre frequencies

    DEFF Research Database (Denmark)

    Orellana, Carlos Andrés Jurado; Pedersen, Christian Sejer; Marquardt, Torsten

    2010-01-01

    measurements based on OAE suppression techniques and notched-noise masking data psychophysically measured for centre frequencies in the range 50-125 Hz, this study examines how individual differences in frequency selectivity, as well as in masking, may occur at very low CFs due to individual differences...

  7. Outer hair cell piezoelectricity: frequency response enhancement and resonance behavior.

    Science.gov (United States)

    Weitzel, Erik K; Tasker, Ron; Brownell, William E

    2003-09-01

    Stretching or compressing an outer hair cell alters its membrane potential and, conversely, changing the electrical potential alters its length. This bi-directional energy conversion takes place in the cell's lateral wall and resembles the direct and converse piezoelectric effects both qualitatively and quantitatively. A piezoelectric model of the lateral wall has been developed that is based on the electrical and material parameters of the lateral wall. An equivalent circuit for the outer hair cell that includes piezoelectricity shows a greater admittance at high frequencies than one containing only membrane resistance and capacitance. The model also predicts resonance at ultrasonic frequencies that is inversely proportional to cell length. These features suggest all mammals use outer hair cell piezoelectricity to support the high-frequency receptor potentials that drive electromotility. It is also possible that members of some mammalian orders use outer hair cell piezoelectric resonance in detecting species-specific vocalizations.

  8. Adaptive Feedback Improving Learningful Conversations at Workplace

    Science.gov (United States)

    Gaeta, Matteo; Mangione, Giuseppina Rita; Miranda, Sergio; Orciuoli, Francesco

    2013-01-01

    This work proposes the definition of an Adaptive Conversation-based Learning System (ACLS) able to foster computer-mediated tutorial dialogues at the workplace in order to increase the probability to generate meaningful learning during conversations. ACLS provides a virtual assistant selecting the best partner to involve in the conversation and…

  9. 5 CFR 534.506 - Conversion provisions.

    Science.gov (United States)

    2010-01-01

    ... conversion, other than to the minimum rate under 5 U.S.C. 5376, the increase must be approved by the head of... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Conversion provisions. 534.506 Section... OTHER SYSTEMS Pay for Senior-Level and Scientific and Professional Positions § 534.506 Conversion...

  10. 5 CFR 536.303 - Geographic conversion.

    Science.gov (United States)

    2010-01-01

    ... after geographic conversion is the employee's existing payable rate of basic pay in effect immediately before the action. (b) Geographic conversion when a retained rate employee's official worksite is changed... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Geographic conversion. 536.303 Section...

  11. Valproate in Conversion Disorder: A Case Report

    OpenAIRE

    Messina, Antonino; Fogliani, Anna Maria

    2010-01-01

    Few data are in literature about the pharmacological treatment of conversion disorder and there are not any studies about the use of Valproate extended release (ER) in treating conversion disorder. In this article, we are reporting a case of an Italian woman with a diagnosis of conversion disorder treated effectively and quickly by Valproate ER.

  12. 47 CFR 80.761 - Conversion graphs.

    Science.gov (United States)

    2010-10-01

    ... MARITIME SERVICES Standards for Computing Public Coast Station VHF Coverage § 80.761 Conversion graphs. The following graphs must be employed where conversion from one to the other of the indicated types of units is... 47 Telecommunication 5 2010-10-01 2010-10-01 false Conversion graphs. 80.761 Section 80.761...

  13. Clinicians' recognition and management of emotions during difficult healthcare conversations.

    Science.gov (United States)

    Martin, Elliott B; Mazzola, Natalia M; Brandano, Jessica; Luff, Donna; Zurakowski, David; Meyer, Elaine C

    2015-10-01

    To examine the most commonly reported emotions encountered among healthcare practitioners when holding difficult conversations, including frequency and impact on care delivery. Interprofessional learners from a range of experience levels and specialties completed self-report questionnaires prior to simulation-based communication workshops. Clinicians were asked to describe up to three emotions they experienced when having difficult healthcare conversations; subsequent questions used Likert-scales to measure frequency of each emotion, and whether care was affected. 152 participants completed questionnaires, including physicians, nurses, and psychosocial professionals. Most commonly reported emotions were anxiety, sadness, empathy, frustration, and insecurity. There were significant differences in how clinicians perceived these different emotions affecting care. Empathy and anxiety were emotions perceived to influence care more than sadness, frustration, and insecurity. Most clinicians, regardless of clinical experience and discipline, find their emotional state influences the quality of their care delivery. Most clinicians rate themselves as somewhat to quite capable of recognizing and managing their emotions, acknowledging significant room to grow. Further education designed to increase clinicians' recognition of, reflection on, and management of emotion would likely prove helpful in improving their ability to navigate difficult healthcare conversations. Interventions aimed at anxiety management are particularly needed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. Algal Energy Conversion and Capture

    Science.gov (United States)

    Hazendonk, P.

    2015-12-01

    We address the potential for energy conversions and capture for: energy generation; reduction in energy use; reduction in greenhouse gas emissions; remediation of water and air pollution; protection and enhancement of soil fertility. These processes have the potential to sequester carbon at scales that may have global impact. Energy conversion and capture strategies evaluate energy use and production from agriculture, urban areas and industries, and apply existing and emerging technologies to reduce and recapture energy embedded in waste products. The basis of biocrude production from Micro-algal feedstocks: 1) The nutrients from the liquid fraction of waste streams are concentrated and fed into photo bioreactors (essentially large vessels in which microalgae are grown) along with CO2 from flue gasses from down stream processes. 2) The algae are processed to remove high value products such as proteins and beta-carotenes. The advantage of algae feedstocks is the high biomass productivity is 30-50 times that of land based crops and the remaining biomass contains minimal components that are difficult to convert to biocrude. 3) The remaining biomass undergoes hydrothermal liquefaction to produces biocrude and biochar. The flue gasses of this process can be used to produce electricity (fuel cell) and subsequently fed back into the photobioreactor. The thermal energy required for this process is small, hence readily obtained from solar-thermal sources, and furthermore no drying or preprocessing is required keeping the energy overhead extremely small. 4) The biocrude can be upgraded and refined as conventional crude oil, creating a range of liquid fuels. In principle this process can be applied on the farm scale to the municipal scale. Overall, our primary food production is too dependent on fossil fuels. Energy conversion and capture can make food production sustainable.

  15. Conversion of Semipalatinsk test site

    International Nuclear Information System (INIS)

    Cherepnin, Yu. S.

    1997-01-01

    The conversion of the former defense enterprises of STS (Semipalatinsk Test Sate) started under very difficult conditions, when not only research and production activity, but all social life of Kurchatov city were conversed which was caused by a fast curtailment and restationing of Russian military units from the test site. A real risk of a complete destruction of the whole research and production structure of the city existed. From this point of view, the decision of the Republic of Kazakhstan Government to create the National Nuclear Center on the base of the test site research enterprises was actual and timely. During 1993, three research institutes of NNC RK - Institute of Atomic Energy, Institute of Geophysics Research and Institute of Radiation Safety and Environment were established. This decision, under conditions of the Ussr disintegration and liquidation of the test site military divisions, allowed to preserve the qualified personnel, to provide and follow-up the operation of nuclear dangerous facilities, to develop and start the realization of the full scale conversion program.At present time, directions and structure of basic research work in NNC RK are as follows: - liquidation of nuclear explosions consequences; - liquidation of technological infrastructure used for preparation and conduction of nuclear weapon testing; - creation of technology, equipment and places for acceptance and storage of radioactive wastes; - working out of atomic energy development conception in Kazakhstan; - study of reactor core melt behavior under severe accidents in NPP; - development of methods and means of nuclear testing detection, continuous monitoring of nuclear explosions; - experimental work on a study of structure materials behavior of ITER thermonuclear reactor; - creation of industries requiring a lage implementation of science

  16. Natural gas conversion. Part VI

    International Nuclear Information System (INIS)

    Iglesia, E.; Spivey, J.J.; Fleisch, T.H.

    2001-01-01

    This volume contains peer-reviewed manuscripts describing the scientific and technological advances presented at the 6th Natural Gas Conversion Symposium held in Alaska in June 2001. This symposium continues the tradition of excellence and the status as the premier technical meeting in this area established by previous meetings. The 6th Natural Gas Conversion Symposium is conducted under the overall direction of the Organizing Committee. The Program Committee was responsible for the review, selection, editing of most of the manuscripts included in this volume. A standing International Advisory Board has ensured the effective long-term planning and the continuity and technical excellence of these meetings. The titles of the contributions are: Impact of syngas generation technology selection on a GTL FPSO; Methane conversion via microwave plasma initiated by a metal initiator; Mechanism of carbon deposit/removal in methane dry reforming on supported metal catalysts; Catalyst-assisted oxidative dehydrogenation of light paraffins in short contact time reactors; Catalytic dehydrogenation of propane over a PtSn/SiO 2 catalyst with oxygen addition: selective oxidation of H2 in the presence of hydrocarbons; Hydroconversion of a mixture of long chain n-paraffins to middle distillate: effect of the operating parameters and products properties; Decomposition/reformation processes and CH4 combustion activity of PdO over Al2O3 supported catalysts for gas turbine applications; Lurgi's mega-methanol technology opens the door for a new era in down-stream applications;Expanding markets for GTL fuels and specialty products; Some critical issues in the analysis of partial oxidation reactions in monolith reactors

  17. Conversion disorder: a problematic diagnosis.

    Science.gov (United States)

    Nicholson, Timothy R J; Stone, Jon; Kanaan, Richard A A

    2011-11-01

    The diagnosis of conversion disorder is problematic. Since doctors have conceptually and practically differentiated the symptoms from neurological ('organic') disease it has been presumed to be a psychological disorder, but the psychological mechanism, and how this differs from feigning (conscious simulation), has remained elusive. Although misdiagnosis of neurological disease as conversion disorder is uncommon, it remains a concern for clinicians, particularly for psychiatrists who may be unaware of the positive ways in which neurologists can exclude organic disease. The diagnosis is anomalous in psychiatry in that current diagnostic systems require that feigning is excluded and that the symptoms can be explained psychologically. In practice, feigning is very difficult to either disprove or prove, and a psychological explanation cannot always be found. Studies of childhood and adult psychological precipitants have tended to support the relevance of stressful life events prior to symptom onset at the group level but they are not found in a substantial proportion of cases. These problems highlight serious theoretical and practical issues not just for the current diagnostic systems but for the concept of the disorder itself. Psychology, physiology and functional imaging techniques have been used in attempts to elucidate the neurobiology of conversion disorder and to differentiate it from feigning, but while intriguing results are emerging they can only be considered preliminary. Such work looks to a future that could refine our understanding of the disorder. However, until that time, the formal diagnostic requirement for associated psychological stressors and the exclusion of feigning are of limited clinical value. Simplified criteria are suggested which will also encourage cooperation between neurology and psychiatry in the management of these patients.

  18. High temperature thermoelectric energy conversion

    International Nuclear Information System (INIS)

    Wood, C.

    1986-01-01

    Considerable advances were made in the late '50's and early early '60's in the theory and development of materials for high-temperature thermoelectric energy conversion. This early work culminated in a variety of materials, spanning a range of temperatures, with the product of the figure of merit, Z, and temperature, T, i.e., the dimensionless figure of merit, ZT, of the order of one. This experimental limitation appeared to be universal and led a number of investigators to explore the possibility that a ZT - also represents a theoretical limitation. It was found not to be so

  19. Nonlinear Dynamics of Photonics for Optical Signal Processing - Optical Frequency Conversion and Optical DSB-to-SSB Conversion

    Science.gov (United States)

    2015-09-17

    photonic system. ML: master laser; SL: slave laser; L; lens; PBS: polarizing beam splitter ; M: mirror; HW: half-wave plate; FR: Faraday rotator; V...microwave generation and stabilization, and photonic microwave amplification. 15. SUBJECT TERMS Non -linear Dynamics, Add-drop

  20. Responsive turns in Indonesian informal conversation

    Directory of Open Access Journals (Sweden)

    M.J. van Naerssen

    2015-04-01

    Full Text Available People have all sorts of expectations about how interlocutors will and should behave linguistically when engaged in a conversation. These conversational norms are usually implicit and are sometimes difficult to master in a language that is new to you. This paper presents a model of different types of responses in informal conversation, illustrated with Indonesian examples. It builds upon the conversation analytic notion of preference; distinguishing preferred – or constructive – responses and dispreferred – or competitive – responses. The model is meant as a tool to cross-linguistically compare response behaviour to gain insight in language specific expectations about interaction in informal conversation.

  1. Biomass thermochemical conversion program: 1987 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Schiefelbein, G.F.; Stevens, D.J.; Gerber, M.A.

    1988-01-01

    The objective of the Biomass Thermochemical Conversion Program is to generate a base of scientific data and conversion process information that will lead to establishment of cost-effective processes for conversion of biomass resources into clean fuels. To accomplish this objective, in fiscal year 1987 the Thermochemical Conversion Program sponsored research activities in the following four areas: Liquid Hydrocarbon Fuels Technology; Gasification Technology; Direct Combustion Technology; Program Support Activities. In this report an overview of the Thermochemical Conversion Program is presented. Specific research projects are then described. Major accomplishments for 1987 are summarized.

  2. Biomass thermochemical conversion program. 1985 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Schiefelbein, G.F.; Stevens, D.J.; Gerber, M.A.

    1986-01-01

    Wood and crop residues constitute a vast majority of the biomass feedstocks available for conversion, and thermochemical processes are well suited for conversion of these materials. The US Department of Energy (DOE) is sponsoring research on this conversion technology for renewable energy through its Biomass Thermochemical Conversion Program. The Program is part of DOE's Biofuels and Municipal Waste Technology Division, Office of Renewable Technologies. This report briefly describes the Thermochemical Conversion Program structure and summarizes the activities and major accomplishments during fiscal year 1985. 32 figs., 4 tabs.

  3. Overview of biomass conversion technologies

    International Nuclear Information System (INIS)

    Noor, S.; Latif, A.; Jan, M.

    2011-01-01

    A large part of the biomass is used for non-commercial purposes and mostly for cooking and heating, but the use is not sustainable, because it destroys soil-nutrients, causes indoor and outdoor pollution, adds to greenhouse gases, and results in health problems. Commercial use of biomass includes household fuelwood in industrialized countries and bio-char (charcoal) and firewood in urban and industrial areas in developing countries. The most efficient way of biomass utilization is through gasification, in which the gas produced by biomass gasification can either be used to generate power in an ordinary steam-cycle or be converted into motor fuel. In the latter case, there are two alternatives, namely, the synthesis of methanol and methanol-based motor fuels, or Fischer-Tropsch hydrocarbon synthesis. This paper deals with the technological overview of the state-of-the-art key biomass-conversion technologies that can play an important role in the future. The conversion routes for production of Heat, power and transportation fuel have been summarized in this paper, viz. combustion, gasification, pyrolysis, digestion, fermentation and extraction. (author)

  4. Bilingualism accentuates children's conversational understanding.

    Directory of Open Access Journals (Sweden)

    Michael Siegal

    Full Text Available BACKGROUND: Although bilingualism is prevalent throughout the world, little is known about the extent to which it influences children's conversational understanding. Our investigation involved children aged 3-6 years exposed to one or more of four major languages: English, German, Italian, and Japanese. In two experiments, we examined the children's ability to identify responses to questions as violations of conversational maxims (to be informative and avoid redundancy, to speak the truth, be relevant, and be polite. PRINCIPAL FINDINGS: In Experiment 1, with increasing age, children showed greater sensitivity to maxim violations. Children in Italy who were bilingual in German and Italian (with German as the dominant language L1 significantly outperformed Italian monolinguals. In Experiment 2, children in England who were bilingual in English and Japanese (with English as L1 significantly outperformed Japanese monolinguals in Japan with vocabulary age partialled out. CONCLUSIONS: As the monolingual and bilingual groups had a similar family SES background (Experiment 1 and similar family cultural identity (Experiment 2, these results point to a specific role for early bilingualism in accentuating children's developing ability to appreciate effective communicative responses.

  5. Electromagnetic wave energy conversion research

    Science.gov (United States)

    Bailey, R. L.; Callahan, P. S.

    1975-01-01

    Known electromagnetic wave absorbing structures found in nature were first studied for clues of how one might later design large area man-made radiant-electric converters. This led to the study of the electro-optics of insect dielectric antennae. Insights were achieved into how these antennae probably operate in the infrared 7-14um range. EWEC theoretical models and relevant cases were concisely formulated and justified for metal and dielectric absorber materials. Finding the electromagnetic field solutions to these models is a problem not yet solved. A rough estimate of losses in metal, solid dielectric, and hollow dielectric waveguides indicates future radiant-electric EWEC research should aim toward dielectric materials for maximum conversion efficiency. It was also found that the absorber bandwidth is a theoretical limitation on radiant-electric conversion efficiency. Ideally, the absorbers' wavelength would be centered on the irradiating spectrum and have the same bandwith as the irradiating wave. The EWEC concept appears to have a valid scientific basis, but considerable more research is needed before it is thoroughly understood, especially for the complex randomly polarized, wide band, phase incoherent spectrum of the sun. Specific recommended research areas are identified.

  6. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel J. M

    2013-01-01

    This textbook is appropriate for use in graduate-level curricula in analog to digital conversion, as well as for practicing engineers in need of a state-of-the-art reference on data converters.  It discusses various analog-to-digital conversion principles, including sampling, quantization, reference generation, nyquist architectures and sigma-delta modulation.  This book presents an overview of the state-of-the-art in this field and focuses on issues of optimizing accuracy and speed, while reducing the power level. This new, second edition emphasizes novel calibration concepts, the specific requirements of new systems, the consequences of 45-nm technology and the need for a more statistical approach to accuracy.  Pedagogical enhancements to this edition include more than twice the exercises available in the first edition, solved examples to introduce all key, new concepts and warnings, remarks and hints, from a practitioner’s perspective, wherever appropriate.  Considerable background information and pr...

  7. [Neurology of hysteria (conversion disorder)].

    Science.gov (United States)

    Sonoo, Masahiro

    2014-07-01

    Hysteria has served as an important driving force in the development of both neurology and psychiatry. Jean Martin Charcot's devotion to mesmerism for treating hysterical patients evoked the invention of psychoanalysis by Sigmund Freud. Meanwhile, Joseph Babinski took over the challenge to discriminate between organic and hysterical patients from Charcot and found Babinski's sign, the greatest milestone in modern neurological symptomatology. Nowadays, the usage of the term hysteria is avoided. However, new terms and new classifications are complicated and inconsistent between the two representative taxonomies, the DSM-IV and ICD-10. In the ICD-10, even the alternative term conversion disorder, which was becoming familiar to neurologists, has also disappeared as a group name. The diagnosis of hysteria remains important in clinical neurology. Extensive exclusive diagnoses and over investigation, including various imaging studies, should be avoided because they may prolong the disease course and fix their symptoms. Psychological reasons that seem to explain the conversion are not considered reliable. Positive neurological signs suggesting nonorganic etiologies are the most reliable measures for diagnosing hysteria, as Babinski first argued. Hysterical paresis has several characteristics, such as giving-way weakness or peculiar distributions of weakness. Signs to uncover nonorganic paresis utilizing synergy include Hoover's test and the Sonoo abductor test.

  8. Light-voltage conversion apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Fujioka, Yoshiki

    1987-09-19

    In a light-voltage conversion unit, when input signal is applied, the output signal to the control circuit has quick rise-up time and slow breaking time. In order to improve this, a short-circuit transistor is placed at the diode, and this transistor is forced ON, when an output signal to the control circuit is lowered down to a constant voltage, to short-circuit between the output terminals. This, however, has a demerit of high power consumption by a transistor. In this invention, by connecting a light-emitting element which gets ON at the first transition and a light-emitting element which gets ON at the last transition, placing a light receiving element in front of each light-emitting element, when an input signal is applied; thus a load is driven only with ON signal of each light-emitting element, eliminating the delay in the last transition. All of these give a quick responsive light-voltage conversion without unnecessary power consumption. (5 figs)

  9. Effect of toroidicity during lower hybrid mode conversion

    International Nuclear Information System (INIS)

    Riyopoulos, S.; Mahajan, S.

    1985-11-01

    The effect of toroidicity during lower hybrid mode conversion is examined by treating the wave propagation in an inhomogeneous medium as an eigenvalue problem for ω 2 (m,n),m,n poloidal and toroidal wave numbers. Since the frequency regime near ω 2 = ω/sub LH/ 2 is an accumulation point for the eigenvalue spectrum, the degenerate perturbation technique must be applied. The toroidal eigenmodes are constructed by a zeroth order superposition of monochromatic solutions with different poloidal dependence m, thus they generically exhibit a wide spectrum in k/sub parallel/ for given fixed ω 2 even for small inverse aspect ratio epsilon. In case that the average is in the neighborhood of k/sub min/, the minimum wave number for accessibility of the mode conversion regime, it is expected that excitation of toroidal modes rather than geometric optics will determine the wave coupling to the plasma

  10. The conversational interface talking to smart devices

    CERN Document Server

    McTear, Michael; Griol, David

    2016-01-01

    This book provides a comprehensive introduction to the conversational interface, which is becoming the main mode of interaction with virtual personal assistants, smart devices, various types of wearables, and social robots. The book consists of four parts: Part I presents the background to conversational interfaces, examining past and present work on spoken language interaction with computers; Part II covers the various technologies that are required to build a conversational interface along with practical chapters and exercises using open source tools; Part III looks at interactions with smart devices, wearables, and robots, and then goes on to discusses the role of emotion and personality in the conversational interface; Part IV examines methods for evaluating conversational interfaces and discusses future directions. · Presents a comprehensive overview of the various technologies that underlie conversational user interfaces; · Combines descriptions of conversational user interface technologies with a gui...

  11. Biomass Thermochemical Conversion Program: 1986 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Schiefelbein, G.F.; Stevens, D.J.; Gerber, M.A.

    1987-01-01

    Wood and crop residues constitute a vast majority of the biomass feedstocks available for conversion, and thermochemical processes are well suited for conversion of these materials. Thermochemical conversion processes can generate a variety of products such as gasoline hydrocarbon fuels, natural gas substitutes, or heat energy for electric power generation. The US Department of Energy is sponsoring research on biomass conversion technologies through its Biomass Thermochemical Conversion Program. Pacific Northwest Laboratory has been designated the Technical Field Management Office for the Biomass Thermochemical Conversion Program with overall responsibility for the Program. This report briefly describes the Thermochemical Conversion Program structure and summarizes the activities and major accomplishments during fiscal year 1986. 88 refs., 31 figs., 5 tabs.

  12. AUTOMATIC FREQUENCY CONTROL SYSTEM

    Science.gov (United States)

    Hansen, C.F.; Salisbury, J.D.

    1961-01-10

    A control is described for automatically matching the frequency of a resonant cavity to that of a driving oscillator. The driving oscillator is disconnected from the cavity and a secondary oscillator is actuated in which the cavity is the frequency determining element. A low frequency is mixed with the output of the driving oscillator and the resultant lower and upper sidebands are separately derived. The frequencies of the sidebands are compared with the secondary oscillator frequency. deriving a servo control signal to adjust a tuning element in the cavity and matching the cavity frequency to that of the driving oscillator. The driving oscillator may then be connected to the cavity.

  13. Conversion from non-orthogonally to orthogonally polarized optical single-sideband modulation using optically injected semiconductor lasers.

    Science.gov (United States)

    Hung, Yu-Han; Tseng, Chin-Hao; Hwang, Sheng-Kwang

    2018-06-01

    This Letter investigates an optically injected semiconductor laser for conversion from non-orthogonally to orthogonally polarized optical single-sideband modulation. The underlying mechanism relies solely on nonlinear laser characteristics and, thus, only a typical semiconductor laser is required as the key conversion unit. This conversion can be achieved for a broadly tunable frequency range up to at least 65 GHz. After conversion, the microwave phase quality, including linewidth and phase noise, is mostly preserved, and simultaneous microwave amplification up to 23 dB is feasible.

  14. Static electromagnetic frequency changers

    CERN Document Server

    Rozhanskii, L L

    1963-01-01

    Static Electromagnetic Frequency Changers is about the theory, design, construction, and applications of static electromagnetic frequency changers, devices that used for multiplication or division of alternating current frequency. It is originally published in the Russian language. This book is organized into five chapters. The first three chapters introduce the readers to the principles of operation, the construction, and the potential applications of static electromagnetic frequency changers and to the principles of their design. The two concluding chapters use some hitherto unpublished work

  15. Eastern Frequency Response Study

    Energy Technology Data Exchange (ETDEWEB)

    Miller, N.W.; Shao, M.; Pajic, S.; D' Aquila, R.

    2013-05-01

    This study was specifically designed to investigate the frequency response of the Eastern Interconnection that results from large loss-of-generation events of the type targeted by the North American Electric Reliability Corp. Standard BAL-003 Frequency Response and Frequency Bias Setting (NERC 2012a), under possible future system conditions with high levels of wind generation.

  16. DDC Descriptor Frequencies.

    Science.gov (United States)

    Klingbiel, Paul H.; Jacobs, Charles R.

    This report summarizes the frequency of use of the 7144 descriptors used for indexing technical reports in the Defense Documentation Center (DDC) collection. The descriptors are arranged alphabetically in the first section and by frequency in the second section. The frequency data cover about 427,000 AD documents spanning the interval from March…

  17. Conversation Simulation and Sensible Surprises

    Science.gov (United States)

    Hutchens, Jason L.

    I have entered the Loebner Prize five times, winning the "most humanlike program" category in 1996 with a surly ELIZA-clone named HeX, but failed to repeat the performance in subsequent years with more sophisticated techniques. Whether this is indicative of an unanticipated improvement in "conversation simulation" technology, or whether it highlights the strengths of ELIZA-style trickery, is as an exercise for the reader. In 2000, I was invited to assume the role of Chief Scientist at Artificial Intelligence Ltd. (Ai) on a project inspired by the advice given by Alan Turing in the final section of his classic paper - our quest was to build a "child machine" that could learn and use language from scratch. In this chapter, I will discuss both of these experiences, presenting my thoughts regarding the Chinese Room argument and Artificial Intelligence (AI) in between.

  18. Fundamentals of thermophotovoltaic energy conversion

    CERN Document Server

    Chubb, Donald L

    2007-01-01

    This is a text book presenting the fundamentals of thermophotovoltaic(TPV) energy conversion suitable for an upper undergraduate or first year graduate course. In addition it can serve as a reference or design aid for engineers developing TPV systems. Mathematica design programs for interference filters and a planar TPV system are included on a CD-Rom disk. Each chapter includes a summary and concludes with a set of problems. The first chapter presents the electromagnetic theory and radiation transfer theory necessary to calculate the optical properties of the components in a TPV optical cavity. Using a simplified model, Chapter 2 develops expressions for the maximum efficiency and power density for an ideal TPV system. The next three chapters consider the three major components in a TPV system; the emitter, filter and photovoltaic(PV) array. Chapter 3 applies the electromagnetic theory and radiation transfer theory presented in Chapter 1 in the calculation of spectral emittance. From the spectral emittance t...

  19. Supported Conversation for hospital staff

    DEFF Research Database (Denmark)

    Forchhammer, Hysse B; Løvholt, Annelise P.; Mathiesen, Lone Lundbak

    in communication and interaction, Supported Conversation for Adults with Aphasia (SCA) was adapted and implemented in a large neurological department at Rigshospitalet-Glostrup in Copenhagen. Method 152 staff members representing different health professionals were assigned to one of eleven courses during a six...... month period. Each course had 10-12 participants and lasted 6 hours, including instruction in the SCA principles, video analysis, interdisciplinary group work, and practice sessions with PWAs. Self-assessed learning outcomes were evaluated with a brief questionnaire filled out by staff members...... in communication, also showed significant improvements across all staff groups. After the course, more time to spend with patients was perceived as the most important factor to further increase communication success with PWA. Conclusion The results show that interdisciplinary SCA-courses successfully increase...

  20. Conversation Analysis in Applied Linguistics

    DEFF Research Database (Denmark)

    Kasper, Gabriele; Wagner, Johannes

    2014-01-01

    on applied CA, the application of basic CA's principles, methods, and findings to the study of social domains and practices that are interactionally constituted. We consider three strands—foundational, social problem oriented, and institutional applied CA—before turning to recent developments in CA research...... on learning and development. In conclusion, we address some emerging themes in the relationship of CA and applied linguistics, including the role of multilingualism, standard social science methods as research objects, CA's potential for direct social intervention, and increasing efforts to complement CA......For the last decade, conversation analysis (CA) has increasingly contributed to several established fields in applied linguistics. In this article, we will discuss its methodological contributions. The article distinguishes between basic and applied CA. Basic CA is a sociological endeavor concerned...

  1. Tacit to explicit knowledge conversion.

    Science.gov (United States)

    Cairó Battistutti, Osvaldo; Bork, Dominik

    2017-11-01

    The ability to create, use and transfer knowledge may allow the creation or improvement of new products or services. But knowledge is often tacit: It lives in the minds of individuals, and therefore, it is difficult to transfer it to another person by means of the written word or verbal expression. This paper addresses this important problem by introducing a methodology, consisting of a four-step process that facilitates tacit to explicit knowledge conversion. The methodology utilizes conceptual modeling, thus enabling understanding and reasoning through visual knowledge representation. This implies the possibility of understanding concepts and ideas, visualized through conceptual models, without using linguistic or algebraic means. The proposed methodology is conducted in a metamodel-based tool environment whose aim is efficient application and ease of use.

  2. Conversion of Ulba Metallurgy Plant

    International Nuclear Information System (INIS)

    Onoprienko, O.

    1996-01-01

    General Information 'Ulba Metallurgical plant' Joint Stock Company successfully operates for more than 46 years. The plant was established by MINSREDMASH, USSR and at the present moment has finished complexes for production of nuclear fuel for atomic power stations, tantalum and superconducting materials production, beryllium, hydrofluoric acid manufacture and engineering production. Problem Essence In spite of the monopoly possession of tantalum manufacture, beryllium and uranium fuel, superconducting materials in Commonwealth of Independent States countries, company has serious financial problems due to the critical situation in Commonwealth of Independent States countries, production ties collapse and fast market demand decrease for the Ulba Metallurgical Plant Joint Stock Company products. The alternative decision is to create substitute productions, conversion integrating and introducing new products to the world market

  3. A Map Enters the Conversation

    DEFF Research Database (Denmark)

    Munk, Anders Kristian

    Over the past decade STS scholars have been engaged in a continuous dialogue about the performativity of their methods and the interventions of their research practices. A frequently posed question is how STS can make a difference to its fields of study, what John Law has called its different...... 'modes of mattering'. In this paper I explore what difference digital cartography can make to STS practice. I draw on three examples from my own work where digitally mediated maps have entered the conversation and made critical, often surprising, differences to the research process. In my first example...... the map is brought along as an ethnographic device on a piece of fieldwork, in my second example it serves as the central collaborative object in a participatory design project, and in my third example the map becomes the object of contestation as it finds itself centre stage in the controversy...

  4. Perceived gender in clear and conversational speech

    Science.gov (United States)

    Booz, Jaime A.

    Although many studies have examined acoustic and sociolinguistic differences between male and female speech, the relationship between talker speaking style and perceived gender has not yet been explored. The present study attempts to determine whether clear speech, a style adopted by talkers who perceive some barrier to effective communication, shifts perceptions of femininity for male and female talkers. Much of our understanding of gender perception in voice and speech is based on sustained vowels or single words, eliminating temporal, prosodic, and articulatory cues available in more naturalistic, connected speech. Thus, clear and conversational sentence stimuli, selected from the 41 talkers of the Ferguson Clear Speech Database (Ferguson, 2004) were presented to 17 normal-hearing listeners, aged 18 to 30. They rated the talkers' gender using a visual analog scale with "masculine" and "feminine" endpoints. This response method was chosen to account for within-category shifts of gender perception by allowing nonbinary responses. Mixed-effects regression analysis of listener responses revealed a small but significant effect of speaking style, and this effect was larger for male talkers than female talkers. Because of the high degree of talker variability observed for talker gender, acoustic analyses of these sentences were undertaken to determine the relationship between acoustic changes in clear and conversational speech and perceived femininity. Results of these analyses showed that mean fundamental frequency (fo) and f o standard deviation were significantly correlated to perceived gender for both male and female talkers, and vowel space was significantly correlated only for male talkers. Speaking rate and breathiness measures (CPPS) were not significantly related for either group. Outcomes of this study indicate that adopting a clear speaking style is correlated with increases in perceived femininity. Although the increase was small, some changes associated

  5. Multichannel spectral mode of the ALOHA up-conversion interferometer

    Science.gov (United States)

    Lehmann, L.; Darré, P.; Boulogne, H.; Delage, L.; Grossard, L.; Reynaud, F.

    2018-06-01

    In this paper, we propose a multichannel spectral configuration of the Astronomical Light Optical Hybrid Analysis (ALOHA) instrument dedicated to high-resolution imaging. A frequency conversion process is implemented in each arm of an interferometer to transfer the astronomical light to a shorter wavelength domain. Exploiting the spectral selectivity of this non-linear optical process, we propose to use a set of independent pump lasers in order to simultaneously study multiple spectral channels. This principle is experimentally demonstrated with a dual-channel configuration as a proof-of-principle.

  6. Coupled field induced conversion between destructive and constructive quantum interference

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xiangqian, E-mail: xqjiang@hit.edu.cn; Sun, Xiudong

    2016-12-15

    We study the control of quantum interference in a four-level atom driven by three coherent fields forming a closed loop. The spontaneous emission spectrum shows two sets of peaks which are dramatically influenced by the fields. Due to destructive quantum interference, a dark line can be observed in the emission spectrum, and the condition of the dark line is given. We found that the conversion between destructive and constructive quantum interference can be achieved through controlling the Rabi frequency of the external fields.

  7. Sensibility to Changes of Vibrational Modes of Excited Electron: Sum Frequency Signals Versus Difference Frequency Signals

    International Nuclear Information System (INIS)

    Gu Anna; Liang Xianting

    2011-01-01

    In this paper, we investigate a two electronic level system with vibrational modes coupled to a Brownian oscillator bath. The difference frequency generation (DFG) signals and sum frequency generation (SFG) signals are calculated. It is shown that, for the same model, the SFG signals are more sensitive than the DFG signals to the changes of the vibrational modes of the electronic two-level system. Because the SFG conversion efficiency can be improved by using the time-delay method, the findings in this paper predict that the SFG spectrum may probe the changes of the microstructure more effectively. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  8. DWDM Fiber-Wireless Access System with Centralized Optical Frequency Comb-based RF Carrier Generation

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Beltrán, Marta; Sánchez, José

    2013-01-01

    We propose and experimentally demonstrate an optical wireless DWDM system at 60 GHz with optical incoherent heterodyne up-conversion using an optical frequency comb. Multiple users with wireline and wireless services are simultaneously supported....

  9. Radio frequency heating in the ion-cyclotron range of frequencies

    International Nuclear Information System (INIS)

    Swanson, D.G.

    1985-01-01

    Both the theory of the absorption process in the ion-cyclotron range of frequencies and some of the experiments which slow the promise and problems with radio frequency plasma heating in this range are discussed. It is shown that mode conversion is invariably involved in the process and so an extensive review of mode conversion theory, expecially as it applies to problems with back-to-back cutoff-resonance pairs, is included. This includes a discussion of the tunneling equation with and without absorption effects and with and without energy conservation. The general theory is applied to various ion-cyclotron harmonics, the two-ion hybrid resonance, and to a case where a wave converts to a Bernstein mode at the plasma edge. The results are given analytically for a variety of cases without absorption, and empirical formulas are given for the second and third harmonics of the ion-cyclotron frequency, which include effects of absorption. Various problem areas in the theory are also discussed with some of the limitations caused by the approximations involved. A number of experiments are also discussed which show effective heating, and some show the features of the mode conversion process, indicating that the general processes of absorption are reasonably well understood. Areas where further work is necessary, both in fundamental theory and in comparing theory with experiment, are also discussed

  10. Conversion of autoimmune hypothyroidism to hyperthyroidism

    OpenAIRE

    Furqan, Saira; Haque, Naeem-ul; Islam, Najmul

    2014-01-01

    Background Graves’ disease and Hashimoto’s thyroiditis are the two autoimmune spectrum of thyroid disease. Cases of conversion from hyperthyroidism to hypothyroidism have been reported but conversion from hypothyroidism to hyperthyroidism is very rare. Although such cases have been reported rarely in the past we are now seeing such conversions from hypothyroidism to hyperthyroidism more frequently in clinical practice. Case presentation We are reporting three cases of middle aged Asian female...

  11. U.S. Domestic Reactor Conversion Programs

    International Nuclear Information System (INIS)

    Woolstenhulme, Eric

    2008-01-01

    The Conversion Projects Include: the revision of the facilities safety basis documents and supporting analysis, the fabrication of new LEU fuel, the change-out of the reactor core, and the removal of the used HEU fuel (by INL University Fuels Program or DOE-NE). The major entities involved are: the U.S. Nuclear Regulatory Commission, the University reactor department, the fuel and hardware fabricators, the Spent fuel receipt facilities, the Spent fuel shipping services, and the U.S. Department of Energy and their subcontractors. Three major Reactor Conversion Program milestones have been accomplished since 2006: the conversion of the TRIGA reactor at Texas A and M University Nuclear Science Center, the conversion of the University of Florida Training Reactor, and the conversion of the Purdue University Reactor. Four Reactor Conversion Program milestones yet to be accomplished in 2008 and 2009: the Washington State University Nuclear Radiation Center reactor, the Oregon State University TRIGA Reactor, the University of Wisconsin Nuclear Reactor, and the Neutron Radiography Reactor Facility. NNSA is committed to doing things cheaper, better, smarter, safer through a 'Lessons Learned' process. The conversion team assessed each major activity grouping: Project Initiation, Conversion Proposal Development, Fuel Fabrication and Hardware, Core Conversion, and Spent Nuclear Fuel Removal. Issues were identified and recommendations were given

  12. Neurologists' understanding and management of conversion disorder.

    Science.gov (United States)

    Kanaan, Richard A; Armstrong, David; Wessely, Simon Charles

    2011-09-01

    Conversion disorder is largely managed by neurologists, for whom it presents great challenges to understanding and management. This study aimed to quantify these challenges, examining how neurologists understand conversion disorder, and what they tell their patients. A postal survey of all consultant neurologists in the UK registered with the Association of British Neurologists. 349 of 591 practising consultant neurologists completed the survey. They saw conversion disorder commonly. While they endorsed psychological models for conversion, they diagnosed it according to features of the clinical presentation, most importantly inconsistency and abnormal illness behaviour. Most of the respondents saw feigning as entangled with conversion disorder, with a minority seeing one as a variant of the other. They were quite willing to discuss psychological factors as long as the patient was receptive but were generally unwilling to discuss feigning even though they saw it as their responsibility. Those who favoured models in terms of feigning were older, while younger, female neurologists preferred psychological models, believed conversion would one day be understood neurologically and found communicating with their conversion patients easier than it had been in the past. Neurologists accept psychological models for conversion disorder but do not employ them in their diagnosis; they do not see conversion as clearly different from feigning. This may be changing as younger, female neurologists endorse psychological views more clearly and find it easier to discuss with their patients.

  13. Conversational Agents in E-Learning

    Science.gov (United States)

    Kerry, Alice; Ellis, Richard; Bull, Susan

    This paper discusses the use of natural language or 'conversational' agents in e-learning environments. We describe and contrast the various applications of conversational agent technology represented in the e-learning literature, including tutors, learning companions, language practice and systems to encourage reflection. We offer two more detailed examples of conversational agents, one which provides learning support, and the other support for self-assessment. Issues and challenges for developers of conversational agent systems for e-learning are identified and discussed.

  14. Single conversion stage amplifier - SICAM

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.

    2005-12-15

    This Ph.D. thesis presents a thorough analysis of the so called SICAM - SIngle Converter stage AMplifier approach to building direct energy conversion audio power amplifiers. The mainstream approach for building isolated audio power amplifiers today consists of isolated DC power supply and Class D amplifier, which essentially represents a two stage solution, where each of the components can be viewed as separate and independent part. The proposed SICAM solution strives for direct energy conversion from the mains to the audio output, by dedicating the operation of the components one to another and integrating their functions, so that the final audio power amplifier represents a single-stage topology with higher efficiency, lower volume, less board space, lower component count and subsequently lower cost. The SICAM approach is both applicable to non-isolated and isolated audio power amplifiers, but the problems encountered in these two cases are different. Non-isolated SICAM solutions are intended for both AC mains-connected and battery-powered devices. In non-isolated mains-connected SICAMs the main idea is to simplify the power supply or even provide integrated power factor correction (PFC) functions, while still maintaining low component stress and good audio performance by generally decreasing the input voltage level to the Class D audio power amplifier. On the other hand, non-isolated battery-powered SICAMs have to cope with the ever changing battery voltage and provide output voltage levels which are both lower and higher than the battery voltage, while still being simple and single-stage energy conversion solutions. In isolated SICAMs the isolation transformer adjusts the voltage level on the secondary side to the desired level, so the main challenges here are decreasing the size of the magnetic core and reducing the number and size of bulky reactive components as much as possible. The main focus of this thesis is directed towards the isolated SICAMs and

  15. Keep Meaning in Conversational Coordination

    Directory of Open Access Journals (Sweden)

    Elena Clare Cuffari

    2014-12-01

    Full Text Available Coordination is a widely employed term across recent quantitative and qualitative approaches to intersubjectivity, particularly approaches that give embodiment and enaction central explanatory roles. With a focus on linguistic and bodily coordination in conversational contexts, I review the operational meaning of coordination in recent empirical research and related theorizing of embodied intersubjectivity. This discussion articulates what must be involved in treating linguistic meaning as dynamic processes of coordination. The coordination approach presents languaging as a set of dynamic self-organizing processes and actions on multiple timescales and across multiple modalities that come about and work in certain domains (those jointly constructed in social, interactive, high-order sense-making. These processes go beyond meaning at the level that is available to first-person experience. I take one crucial consequence of this to be the ubiquitously moral nature of languaging with others. Languaging coordinates experience, among other levels of behavior and event. Ethical effort is called for by the automatic autonomy-influencing forces of languaging as coordination.

  16. NASA thermionic-conversion program

    International Nuclear Information System (INIS)

    Morris, J.F.

    1977-01-01

    NASA's program for applied research and technology (ART) in thermionic energy conversion (TEC) has made worthwhile contributions in a relatively short time: Many of these accomplishments are incremental, yet important. And their integration has yielded gains in performance as well as in the knowledge necessary to point productive directions for future work. Both promise and problems derive from the degrees of freedom allowed by the current programmatic emphasis on out-of-core thermionics. Materials and designs previously prohibited by in-core nucleonics and geometries now offer new potentialities. But as a result a major TEC-ART responsibility is the efficient reduction of the glitter of diverse possibilities to the hard glint of reality. As always high-temperature material effects are crucial to the level and duration of TEC performance: New electrodes must increase and maintain power output regardless of emitter-vapor deposition on collectors. They must also serve compatibly with hot-shell alloys. And while space TEC must face high-temperature vaporization problems externally as well as internally, terrestrial TEC must tolerate hot corrosive atmospheres outside and near-vacuum inside. Furthermore, some modes for decreasing interelectrode losses appear to require rather demanding converter geometries to produce practical power densities. In these areas and others significant progress is being made in the NASA TEC-ART Program

  17. Phase conversion for fusion lasers

    International Nuclear Information System (INIS)

    Kessler, T.; Castle, W.; Sampat, N.; Skupsky, S.; Smith, D.; Swales, S.

    1988-01-01

    An essential requirement for direct drive laser fusion is the uniform irradiation of spherical targets that are located in the quasi-far field of a laser system. A major impediment to irradiation uniformity with high-power solid-state laser systems is the presence of a hot-spot structure at the target plane. The hot-spot intensity nonuniformities are caused by spatial variations in the near-field phase front of each laser beam. Although for many tabletop applications diffraction-limited laser performance can be obtained through static phase correction, adaptive optics, or phase conjugation, such approaches are either excessively expensive, difficult to implement, or not yet available for large-aperture, high-peak-power laser beams. An alternative to phase correcting a wavefront involves modifying the laser beam's coherence properties thereby changing its focusing characteristics. The method of induced spatial incoherence (ISI) involves a reduction in both spatial and temporal coherence. Other methods are based on modifications of only the spatial coherence of a laser beam. A phase conversion technology which incorporates a distribution of near-field phases to either perform static phase correction or induce spatial incoherence offers a route toward increasingly higher levels of irradiation uniformity

  18. Energy Conversion Alternatives Study (ECAS)

    Science.gov (United States)

    1977-01-01

    ECAS compared various advanced energy conversion systems that can use coal or coal-derived fuels for baseload electric power generation. It was conducted in two phases. Phase 1 consisted of parametric studies. From these results, 11 concepts were selected for further study in Phase 2. For each of the Phase 2 systems and a common set of ground rules, performance, cost, environmental intrusion, and natural resource requirements were estimated. In addition, the contractors defined the state of the associated technology, identified the advances required, prepared preliminary research and development plans, and assessed other factors that would affect the implementation of each type of powerplant. The systems studied in Phase 2 include steam systems with atmospheric- and pressurized-fluidized-bed boilers; combined cycle gas turbine/steam systems with integrated gasifiers or fired by a semiclean, coal derived fuel; a potassium/steam system with a pressurized-fluidized-bed boiler; a closed-cycle gas turbine/organic system with a high-temperature, atmospheric-fluidized-bed furnace; a direct-coal-fired, open- cycle magnetohydrodynamic/steam system; and a molten-carbonate fuel cell/steam system with an integrated gasifier. The sensitivity of the results to changes in the ground rules and the impact of uncertainties in capital cost estimates were also examined.

  19. Tropospheric effects of energy conversion

    International Nuclear Information System (INIS)

    Derwent, R.G.

    1992-01-01

    The tropospheric concentrations of a number of trace gases are increasing due to man's activities. For some trace gases, their atmospheric life cycles are not fully understood and it is difficult to be certain about the role of man's activities. Emissions from the energy industries and energy conversion processes represent an important subset of source terms in these life cycles, along with agriculture, deforestation, cement manufacture, biomass burning, process industries and natural biospheric processes. Global Warming Potentials (GWPs) allow the tropospheric effects of a range of climate forcing trace gases to be assessed on a comparable basis. If a short term view of the commitment to global warming is adopted then the contribution from other trace gases may approach and exceed that of carbon dioxide, itself. Over longer time horizons, the long atmospheric lifetime of carbon dioxide shows through as a major influence and the contributions from the other trace gases appear to be much smaller, representing an additional 13-18% contribution on top of that from CO 2 itself

  20. Energy conversion in polyelectrolyte hydrogels

    Science.gov (United States)

    Olvera de La Cruz, Monica; Erbas, Aykut; Olvera de la Cruz Team

    Energy conversion and storage have been an active field of research in nanotechnology parallel to recent interests towards renewable energy. Polyelectrolyte (PE) hydrogels have attracted considerable attention in this field due to their mechanical flexibility and stimuli-responsive properties. Ideally, when a hydrogel is deformed, applied mechanical work can be converted into electrostatic, elastic and steric-interaction energies. In this talk, we discuss the results of our extensive molecular dynamics simulations of PE hydrogels. We demonstrate that, on deformation, hydrogels adjust their deformed state predominantly by altering electrostatic interactions between their charged groups rather than excluded-volume and bond energies. This is due to the hydrogel's inherent tendency to preserve electro-neutrality in its interior, in combination with correlations imposed by backbone charges. Our findings are valid for a wide range of compression ratios and ionic strengths. The electrostatic-energy alterations that we observe in our MD simulations may induce pH or redox-potential changes inside the hydrogels. The resulting energetic difference can be harvested, for instance, analogously to a Carnot engine, or facilitated for sensor applications. Center for Bio-inspired Energy Science (CBES).

  1. Ocean thermal-energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Ford, G; Niblett, C; Walker, L

    1983-03-01

    Ocean thermal-energy conversion (OTEC) is a novel 'alternative' energy technology that has created much interest in a number of countries; namely, the USA, Japan, France, Sweden, Holland, India and most recently, the UK. In particular, the first three of these have had programmes to develop the required technology. However, most interest has been centred in the USA, where the current hiatus in Federal funding provides a timely opportunity to assess progress. This paper offers a survey of the prevailing position there; outlining the outstanding technical and associated problems, and likely future developments. Non-USA programmes are only mentioned to contrast them with the American position. At present, it does not appear that OTEC plants will be commercially viable on a widespread basis even in the tropics. This is particularly true of the larger plants (400 MWe, MWe = megawatts of electrical energy, the final output of a power station) towards which the American programme is ultimately geared. There does seem to be a strong possibility that small OTEC plants, around 40 MWe or less, can be commercial in certain circumstances. This would be possible when one or, preferably, more of the following conditions are met: (i) where a land-based rather than 'at sea' plant is possible, (ii) where alternative energy supplies are at a premium, i.e. islands or regions without indigenous energy supplies, and (iii) where conditions are such that an OTEC plant could operate in conjunction with either or both an aquaculture or desalination plant.

  2. Catalytic conversion of light alkanes

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, J.E.

    1992-06-30

    The second Quarterly Report of 1992 on the Catalytic Conversion of Light Alkanes reviews the work done between April 1, 1992 and June 31, 1992 on the Cooperative Agreement. The mission of this work is to devise a new catalyst which can be used in a simple economic process to convert the light alkanes in natural gas to oxygenate products that can either be used as clean-burning, high octane liquid fuels, as fuel components or as precursors to liquid hydrocarbon uwspomdon fuel. During the past quarter we have continued to design, prepare, characterize and test novel catalysts for the mild selective reaction of light hydrocarbons with air or oxygen to produce alcohols directly. These catalysts are designed to form active metal oxo (MO) species and to be uniquely active for the homolytic cleavage of the carbon-hydrogen bonds in light alkanes producing intermediates which can form alcohols. We continue to investigate three molecular environments for the active catalytic species that we are trying to generate: electron-deficient macrocycles (PHASE I), polyoxometallates (PHASE II), and regular oxidic lattices including zeolites and related structures as well as other molecular surface structures having metal oxo groups (PHASE I).

  3. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel J M

    2010-01-01

    The design of an analog-to-digital converter or digital-to-analog converter is one of the most fascinating tasks in micro-electronics. In a converter the analog world with all its intricacies meets the realm of the formal digital abstraction. Both disciplines must be understood for an optimum conversion solution. In a converter also system challenges meet technology opportunities. Modern systems rely on analog-to-digital converters as an essential part of the complex chain to access the physical world. And processors need the ultimate performance of digital-to-analog converters to present the results of their complex algorithms. The same progress in CMOS technology that enables these VLSI digital systems creates new challenges for analog-to-digital converters: lower signal swings, less power and variability issues. Last but not least, the analog-to-digital converter must follow the cost reduction trend. These changing boundary conditions require micro-electronics engineers to consider their design choices for...

  4. Overcoming difficult conversations in clinical supervision

    Directory of Open Access Journals (Sweden)

    Williams B

    2016-06-01

    Full Text Available Brett Williams,1 Christine King,1 Tanya Edlington,21Department of Community Emergency Health and Paramedic Practice, Monash University, Franskton, VIC, 2The Conversation Clinic Pty Ltd, Melbourne, VIC, Australia Background: Clinical supervisors are responsible for managing many facets of clinical learning and face a range of challenges when the need for "difficult" conversations arises, including the need to manage conflict and relationships. Methods: Spotlight on Conversations Workshop was developed to improve the capacity of clinical supervisors to engage in difficult conversations. They were designed to challenge the mindset of clinical supervisors about difficult conversations with students, the consequences of avoiding difficult conversations, and to offer activities for practicing difficult conversations. Preworkshop, postworkshop, and 4-month follow-up evaluations assessed improvements in knowledge, intent to improve, and confidence along with workshop satisfaction. Results: Nine workshops were delivered in a range of locations across Victoria, Australia, involving a total of 117 clinical supervisors. Preworkshop evaluations illustrated that more than half of the participants had avoided up to two difficult conversations in the last month in their workplace. Postworkshop evaluation at 4 months showed very high levels of satisfaction with the workshop's relevancy, content, and training, as well as participants' intention to apply knowledge and skills. Also shown were significant changes in participants' confidence to have difficult conversations not only with students but also with other peers and colleagues. In follow-up in-depth interviews with 20 of the 117 participants, 75% said they had made definite changes in their practice because of what they learned in the workshop and another 10% said they would make changes to their practice, but had not had the opportunity yet to do so. Conclusion: We conclude that the Spotlight on

  5. Breakfast frequency among adolescents

    DEFF Research Database (Denmark)

    Pedersen, Trine Pagh; Holstein, Bjørn E; Damsgaard, Mogens Trab

    2016-01-01

    OBJECTIVE: To investigate (i) associations between adolescents' frequency of breakfast and family functioning (close relations to parents, quality of family communication and family support) and (ii) if any observed associations between breakfast frequency and family functioning vary...... (n 3054) from a random sample of forty-one schools. RESULTS: Nearly one-quarter of the adolescents had low breakfast frequency. Low breakfast frequency was associated with low family functioning measured by three dimensions. The OR (95 % CI) of low breakfast frequency was 1·81 (1·40, 2......·33) for adolescents who reported no close relations to parents, 2·28 (1·61, 3·22) for adolescents who reported low level of quality of family communication and 2·09 (1·39, 3·15) for adolescents who reported low level of family support. Joint effect analyses suggested that the odds of low breakfast frequency among...

  6. LOW FREQUENCY DAMPER

    Directory of Open Access Journals (Sweden)

    Radu BOGATEANU

    2009-09-01

    Full Text Available The low frequency damper is an autonomous equipment for damping vibrations with the 1-20Hz range.Its autonomy enables the equipment to be located in various mechanical systems, without requiring special hydraulic installations.The low frequency damper was designed for damping the low frequency oscillations occurring in the circuit controls of the upgraded IAR-99 Aircraft.The low frequency damper is a novelty in the aerospace field ,with applicability in several areas as it can be built up in an appropriate range of dimensions meeting the requirements of different beneficiaries. On this line an equipment able to damp an extended frequency range was performed for damping oscillations in the pipes of the nuclear power plants.This damper, tested in INCAS laboratories matched the requirements of the beneficiary.The low frequency damper is patented – the patent no. 114583C1/2000 is held by INCAS.

  7. Effects of nonlinear phase modulation on Bragg scattering in the low-conversion regime

    DEFF Research Database (Denmark)

    Andersen, Lasse Mejling; Cargill, D. S.; McKinstrie, C. J.

    2012-01-01

    In this paper, we consider the effects of nonlinear phase modulation on frequency conversion by four-wave mixing (Bragg scattering) in the low-conversion regime. We derive the Green functions for this process using the time-domain collision method, for partial collisions, in which the four fields...... interact at the beginning or the end of the fiber, and complete collisions, in which the four fields interact at the midpoint of the fiber. If the Green function is separable, there is only one output Schmidt mode, which is free from temporal entanglement. We find that nonlinear phase modulation always...... chirps the input and output Schmidt modes and renders the Green function formally nonseparable. However, by pre-chirping the pumps, one can reduce the chirps of the Schmidt modes and enable approximate separability. Thus, even in the presence of nonlinear phase modulation, frequency conversion...

  8. The Conversion of Wiswesser Line Notations to Ring Codes. I. The Conversion of Ring Systems

    Science.gov (United States)

    Granito, Charles E.; And Others

    1972-01-01

    The computerized conversion of Wiswesser Line Notations to Ring Codes, using a two-part approach, and the set of computer programs generated for the conversion of ring systems are described. (9 references) (Author)

  9. Discourse analysis: Conversational analysis of the internal conversation in Oracle Corporation Malaysia

    Directory of Open Access Journals (Sweden)

    Marwa Marwa

    2017-07-01

    Full Text Available This study highlights the internal conversation which takes place in Oracle CorporationMalaysia. Through the study, it will be shown how conversational analysis is used toanalyze the transcription of a telephone conversation between Oracle staffs. The analysisof the transcriptions will apply a few basic concepts of conversational analysis; turntakingorganization, and the adjacency pair. The objective of the study is to find out howthe internal conversations takes place by focusing on the conversation itself, that is, theconversational structures spontaneously produced by people during talk ranging fromturn-taking strategies, how topics are introduced, conversation closings and so on. Bylooking in detail at such talk, we can gain a detailed understanding of how the staffs seethemselves in relation to the company that influence their daily lives.Keywords: conversational analysis, turn-taking, adjacency pairs

  10. Conversion Matrix Analysis of SiGe HBT Gilbert Cell Mixers

    DEFF Research Database (Denmark)

    Johansen, Tom Keinicke; Vidkjær, Jens; Krozer, Viktor

    2004-01-01

    The frequency response of SiGe HBT active mixers based on the Gilbert cell topology is analyzed theoretically. The time-varying operation of the Gilbert cell mixer is taken into account by applying conversion matrix analysis. The main bandwidth limiting mechanisms experienced in SiGe HBT Gilbert ...

  11. Frequency Hopping Transceiver Multiplexer

    Science.gov (United States)

    1983-03-01

    ATC 17 ULR IHQ OCLI CPCTR ULTRA HIGH "OQS" UP TO 4X HIGHER THAN BEST INDUS- TRY STANDARD (ATC 100). MICROWAVE POWER, CURRENT. AND 0 RATINGS5...Q"W were assigned to element (FigC-2); which will be modelled into the transformer previously ment td . The center frequencies, "Q", frequency range...of the TD 1288 system. Temperature stability, change with time or storage. Flexure Frequency, or non-linear change over bandwidth. * Humidity

  12. Gene conversion and reversion events in Saccharomyces cerevisiae. Model for study of gamma radiation damage

    International Nuclear Information System (INIS)

    Moreno, Damaris; Fuentes, Jorge L.; Prieto Miranda, Enrique F.; Sanchez Lamar, Angel; Baluja, Ligia

    2004-01-01

    Radiosensitivity and kinetics of induction of gene conversion and reversion events in Saccharomyces cerevisiae strain D7 to gamma radiation at dose ranges from 100 to 800 Gy and 50 to 300 Gy respectively were studied. A source of 60Co PX- -30 at a dose rate of 49,43 GY/min was utilized. The cell survival curve showed DL50 of 150 Gy. Cell death kinetics was linear and adjusted over 98 %. The induction of gene conversion events was significant in relation to control from 50 Gy on. However, gene reversion was significant only at 200 Gy. Generally speaking, gene conversion event frequencies were higher than those of reversion, which indicates that gamma radiation preferably induces recombinogenic events. Both the conversion and reversion events showed exponential dependence on gamma radiation dose. The relative benefits of this test for mutagenesis and anti-mutagenesis studies were debated in this paper

  13. Microstructural and electrochemical characterization of environmentally friendly conversion layers on aluminium alloys

    Directory of Open Access Journals (Sweden)

    Palomino Luis Enrique M.

    2003-01-01

    Full Text Available Cerium conversion layers (CeCL have been investigated as a replacement for chromium conversion layers to protect Al alloys against corrosion. In this work the microstructure and the electrochemical behaviour of aluminium alloy 2024 with and without CeCL were investigated using, respectively, SEM-EDX and EIS. EDX results have shown that the presence of dispersed plated Cu particles on the alloy surface enhances the formation of the CeCL increasing the intensity of Ce peaks in the EDX spectra. EIS measurements on conversion-coated samples have shown that the presence of the layer increases the impedance, and that its presence is detected by the presence of a high frequency time constant. Results of potentiodynamic experiments have shown that the corrosion protection afforded by the conversion layer is due to the hindrance of the oxygen reduction reaction and that the pitting potential of the alloy is not changed.

  14. Dominant phonon polarization conversion across dimensionally mismatched interfaces: Carbon-nanotube-graphene junction

    Science.gov (United States)

    Shi, Jingjing; Lee, Jonghoon; Dong, Yalin; Roy, Ajit; Fisher, Timothy S.; Ruan, Xiulin

    2018-04-01

    Dimensionally mismatched interfaces are emerging for thermal management applications, but thermal transport physics remains poorly understood. Here we consider the carbon-nanotube-graphene junction, which is a dimensionally mismatched interface between one- and two-dimensional materials and is the building block for carbon-nanotube (CNT)-graphene three-dimensional networks. We predict the transmission function of individual phonon modes using the wave packet method; surprisingly, most incident phonon modes show predominantly polarization conversion behavior. For instance, longitudinal acoustic (LA) polarizations incident from CNTs transmit mainly into flexural transverse (ZA) polarizations in graphene. The frequency stays the same as the incident mode, indicating elastic transmission. Polarization conversion is more significant as the phonon wavelength increases. We attribute such unique phonon polarization conversion behavior to the dimensional mismatch across the interface, and it opens significantly new phonon transport channels as compared to existing theories where polarization conversion is neglected.

  15. Down-conversion IM-DD RF photonic link utilizing MQW MZ modulator.

    Science.gov (United States)

    Xu, Longtao; Jin, Shilei; Li, Yifei

    2016-04-18

    We present the first down-conversion intensity modulated-direct detection (IM-DD) RF photonic link that achieves frequency down-conversion using the nonlinear optical phase modulation inside a Mach-Zehnder (MZ) modulator. The nonlinear phase modulation is very sensitive and it can enable high RF-to-IF conversion efficiency. Furthermore, the link linearity is enhanced by canceling the nonlinear distortions from the nonlinear phase modulation and the MZ interferometer. Proof-of-concept measurement was performed. The down-conversion IM-DD link demonstrated 28dB improvement in distortion levels over that of a conventional IM-DD link using a LiNbO3 MZ modulator.

  16. Topological energy conversion through the bulk or the boundary of driven systems

    Science.gov (United States)

    Peng, Yang; Refael, Gil

    2018-04-01

    Combining physical and synthetic dimensions allows a controllable realization and manipulation of high-dimensional topological states. In our work, we introduce two quasiperiodically driven one-dimensional systems which enable tunable topological energy conversion between different driving sources. Using three drives, we realize a four-dimensional quantum Hall state which allows energy conversion between two of the drives within the bulk of the one-dimensional system. With only two drives, we achieve energy conversion between the two at the edge of the chain. Both effects are a manifestation of the effective axion electrodynamics in a three-dimensional time-reversal-invariant topological insulator. Furthermore, we explore the effects of disorder and commensurability of the driving frequencies, and show the phenomena are robust. We propose two experimental platforms, based on semiconductor heterostructures and ultracold atoms in optical lattices, in order to observe the topological energy conversion.

  17. Frequency Response Analysis Tool

    Energy Technology Data Exchange (ETDEWEB)

    Etingov, Pavel V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kosterev, Dmitry [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dai, T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-01

    Frequency response has received a lot of attention in recent years at the national level, which culminated in the development and approval of North American Electricity Reliability Corporation (NERC) BAL-003-1 Frequency Response and Frequency Bias Setting Reliability Standard. This report is prepared to describe the details of the work conducted by Pacific Northwest National Laboratory (PNNL) in collaboration with the Bonneville Power Administration and Western Electricity Coordinating Council (WECC) Joint Synchronized Information Subcommittee (JSIS) to develop a frequency response analysis tool (FRAT). The document provides the details on the methodology and main features of the FRAT. The tool manages the database of under-frequency events and calculates the frequency response baseline. Frequency response calculations are consistent with frequency response measure (FRM) in NERC BAL-003-1 for an interconnection and balancing authority. The FRAT can use both phasor measurement unit (PMU) data, where available, and supervisory control and data acquisition (SCADA) data. The tool is also capable of automatically generating NERC Frequency Response Survey (FRS) forms required by BAL-003-1 Standard.

  18. Spontaneous conversion of first onset atrial fibrillation

    DEFF Research Database (Denmark)

    Lindberg, Søren Østergaard; Hansen, Sidsel; Nielsen, Tonny

    2011-01-01

    Background  We studied all patients admitted to hospital with first onset atrial fibrillation (AF) to determine the probability of spontaneous conversion to sinus rhythm and to identify factors predictive of such a conversion. Methods and Results  We retrospectively reviewed charts of 438...

  19. Optimization theory for ballistic energy conversion

    NARCIS (Netherlands)

    Xie, Yanbo; Versluis, Michel; Van Den Berg, Albert; Eijkel, Jan C.T.

    2016-01-01

    The growing demand of renewable energy stimulates the exploration of new materials and methods for clean energy. We recently demonstrated a high efficiency and power density energy conversion mechanism by using jetted charged microdroplets, termed as ballistic energy conversion. Hereby, we model and

  20. Bilingualism and Conversational Understanding in Young Children

    Science.gov (United States)

    Siegal, Michael; Iozzi, Laura; Surian, Luca

    2009-01-01

    The purpose of the two experiments reported here was to investigate whether bilingualism confers an advantage on children's conversational understanding. A total of 163 children aged 3-6 years were given a Conversational Violations Test to determine their ability to identify responses to questions as violations of Gricean maxims of conversation…

  1. Critical Exchange: Religion and Schooling in Conversation

    Science.gov (United States)

    Stern, Julian

    2017-01-01

    Given the complex and messy contexts of schooling, conversations between religion and schooling can be "admitted" as examples of the sort of situated conversation that goes beyond the "false necessity" of universal state-controlled school-based education. There are distinct claims to be made about religion and schooling in…

  2. Jensen's operator inequality and its converses

    DEFF Research Database (Denmark)

    Hansen, Frank; Pecaric, Josip; Peric, Ivan

    2007-01-01

    We give a general formulation of Jensen's operator inequality for unital fields of positive linear mappings, and we consider different types of converse inequalities......We give a general formulation of Jensen's operator inequality for unital fields of positive linear mappings, and we consider different types of converse inequalities...

  3. Improving Teamwork through Awareness of Conversational Styles

    Science.gov (United States)

    Rehling, Louise

    2004-01-01

    Conversational styles can sometimes cause conflicts on problem-solving writing teams. In self-defense, students often resort to blaming and shaming around conversational styles, which can just worsen unproductive group behaviors, limiting idea exchanges and deflecting attention from substantive issues and onto what is often labeled "personality…

  4. Conversion Disorder in Stroke: A Case Report

    Directory of Open Access Journals (Sweden)

    Hsien-Yeh Chou

    2006-11-01

    Full Text Available Conversion disorder is caused by previous severe stress, emotional conflict, or an associated psychiatric disorder, and usually presents with one or more neurologic symptoms. Clinically, it is challenging to diagnose diseases such as transient ischemia attack, stroke, brain tumor, spinal cord injury, and neuropathy. In this case report, we present a male stroke patient who had a typical conversion disorder.

  5. Hypnotic susceptibility in patients with conversion disorder

    NARCIS (Netherlands)

    Roelofs, K.; Hoogduin, C.A.L.; Keijsers, G.P.J.; Näring, G.W.B.; Moene, F.C.; Sandijck, P.

    2002-01-01

    Conversion disorder has been associated with hypnotic susceptibility for over a century and is currently still believed to be a form of autohypnosis. There is, however. little empirical evidence for the relation between hypnotic susceptibility and conversion symptoms. The authors compared 50

  6. Reflection during Portfolio-Based Conversations

    Science.gov (United States)

    Oosterbaan, Anne E.; van der Schaaf, Marieke F.; Baartman, Liesbeth K. J.; Stokking, Karel M.

    2010-01-01

    This study aims to explore the relationship between the occurrence of reflection (and non-reflection) and thinking activities (e.g., orientating, selecting, analysing) during portfolio-based conversations. Analysis of 21 transcripts of portfolio-based conversations revealed that 20% of the segments were made up of reflection (content reflection…

  7. Exergy conversion in the Japanese society

    International Nuclear Information System (INIS)

    Wall, G.

    1989-01-01

    In this paper exergy concept is reviewed as a tool for resource accounting. Conversions of energy and material resources in the Japanese society are described in terms of exergy. Necessary concepts and conventions are introduced. Exergy losses in transformations of material resources and in conversions of various forms of energy are described in some detail

  8. Conversational Memory Employing Cued and Free Recall.

    Science.gov (United States)

    Benoit, Pamela J.; Benoit, William L.

    1988-01-01

    Tests two hypotheses: (1) that cued recall elicits significantly more conversational information than free recall; and (2) that conversational interactants recall more of their partner's utterances than their own. Finds cued recall produced significantly higher amounts of remembering than free recall. (MS)

  9. Abnormal Parietal Function in Conversion Paresis

    NARCIS (Netherlands)

    van Beilen, Marije; de Jong, Bauke M.; Gieteling, Esther W.; Renken, Remco; Leenders, Klaus L.

    2011-01-01

    The etiology of medically unexplained symptoms such as conversion disorder is poorly understood. This is partly because the interpretation of neuroimaging results in conversion paresis has been complicated by the use of different control groups, tasks and statistical comparisons. The present study

  10. Provoking Reflective Thinking in Post Observation Conversations

    Science.gov (United States)

    Kim, Younhee; Silver, Rita Elaine

    2016-01-01

    We present a micro-analysis of post observation conversations between classroom teachers and mentors. Using the approach of conversation analysis, we show how the sequential organization of an episode (i.e., who initiates the interaction, question format used by mentors) could potentially serve to provoke or hinder teacher reflection. Our analysis…

  11. Enhancing Classroom Conversation for All Students

    Science.gov (United States)

    Goldsmith, William

    2013-01-01

    The author, a 5th-grade teacher, offers strategies intended to assist and encourage ELL students to participate in academic conversations. They include insisting that children take part in conversations despite their apprehension and teaching them the language they need to communicate their ideas. One strategy is Think, Pair, Share--a simple…

  12. Large-video-display-format conversion

    NARCIS (Netherlands)

    Haan, de G.

    2000-01-01

    High-quality video-format converters apply motion estimation and motion compensation to prevent jitter resulting from picture-rate conversion, and aliasing due to de-interlacing, in sequences with motion. Although initially considered as too expensive, high-quality conversion is now economically

  13. Teaching communication aid use in everyday conversation

    DEFF Research Database (Denmark)

    Pilesjö, Maja Sigurd; Norén, Niklas

    2017-01-01

    This Conversation Analysis study investigated how a speech and language therapist (SLT) created opportunities for communication aid use in multiparty conversation. An SLT interacted with a child with multiple disabilities and her grandparents in a home setting, using a bliss board. The analyses...

  14. Conversion Disorder in Australian Pediatric Practice

    Science.gov (United States)

    Kozlowska, Kasia; Nunn, Kenneth P.; Rose, Donna; Morris, Anne; Ouvrier, Robert A.; Varghese, John

    2007-01-01

    Objectives: To describe the incidence and clinical features of children presenting to Australian child health specialists with conversion disorder. Method: Active, national surveillance of conversion disorder in children younger than 16 years of age during 2002 and 2003. Results: A total of 194 children were reported on. The average age was 11.8…

  15. Study of a condition for the mode conversion from purely perpendicular electrostatic waves to electromagnetic waves

    Energy Technology Data Exchange (ETDEWEB)

    Kalaee, Mohammad Javad, E-mail: mjkalaee@ut.ac.ir [Space Physics Group, Institute of Geophysics, University of Tehran (Iran, Islamic Republic of); Katoh, Yuto, E-mail: yuto@stpp.gp.tohoku.ac.jp [Department of Geophysics, Graduate School of Science, Tohoku University (Japan)

    2016-07-15

    One of the mechanisms for generating electromagnetic plasma waves (Z-mode and LO-mode) is mode conversion from electrostatic waves into electromagnetic waves in inhomogeneous plasma. Herein, we study a condition required for mode conversion of electrostatic waves propagating purely perpendicular to the ambient magnetic field, by numerically solving the full dispersion relation. An approximate model is derived describing the coupling between electrostatic waves (hot plasma Bernstein mode) and Z-mode waves at the upper hybrid frequency. The model is used to study conditions required for mode conversion from electrostatic waves (electrostatic electron cyclotron harmonic waves, including Bernstein mode) into electromagnetic plasma waves (LO-mode). It is shown that for mode conversion to occur in inhomogeneous plasma, the angle between the boundary surface and the magnetic field vector should be within a specific range. The range of the angle depends on the norm of the k vector of waves at the site of mode conversion in the inhomogeneous region. The present study reveals that inhomogeneity alone is not a sufficient condition for mode conversion from electrostatic waves to electromagnetic plasma waves and that the angle between the magnetic field and the density gradient plays an important role in the conversion process.

  16. The organization of digital conversation on MSN

    Directory of Open Access Journals (Sweden)

    Artarxerxes Tiago Tácito Modesto

    2012-02-01

    Full Text Available The emergence of the Internet has caused a revolution with regard to new forms of interaction between people, offering experiences of real-time communication in so-called virtual environments. Given this scenario, new textual genres emerge, making room for innumerous possibilities of analysis under various approaches. In this paper, we aim at analyzing digital conversations, trying to verify, at first, the extent to which they approach or move away from face-to-face conversations. We also seek to identify, describe and analyze some interactional strategies inherent in this new genre. We base our analyzes on Conversation Analysis theory and Interactional Sociolinguistics to define conversational strategies of the “spoken written text” on the Internet. The corpus used in this work consists of digital conversations coming from the MSN instant messaging software from Microsoft Corporation, chosen because of its wide use among people who use the internet for communication.

  17. Measuring Online Dialogic Conversations: A Scale Development

    DEFF Research Database (Denmark)

    Romenti, Stefania; Valentini, Chiara; Murtarelli, Grazia

    2016-01-01

    Purpose: The scope of this paper is to develop and test a measurement scale for assessing the quality of dialogic conversations among companies and digital publics in social media. It is argued that dialogic conversations are the drivers of dialogic engagement and the result of dialogic...... interactivity. Dialogic conversations are defined as sequences of communicative actions and counteractions taken by social actors for different purposes based on specific linguistic choices and characterised by diverse communicative approaches and the role played by the involved parties. Design....../methodology/approach: A multidimensional scale for measuring dialogic conversations is developed from relevant literature concerning dialogue and public engagement in the fields of corporate communication, public relations, management studies and conversation analysis. The scale was pre-tested to redefine and purify it from irrelevant...

  18. [Management of patients with conversion disorder].

    Science.gov (United States)

    Vermeulen, Marinus; Hoekstra, Jan; Kuipers-van Kooten, Mariëtte J; van der Linden, Els A M

    2014-01-01

    The symptoms of conversion disorder are not due to conscious simulation. There should be no doubt that the symptoms of conversion disorder are genuine, even if scans do not reveal any abnormalities. The management of patients with conversion disorder starts with an explanation of the diagnosis. The essence of this explanation is that patients first hear about what the diagnosis actually means and only after this about what they do not have. When explaining the diagnosis it is a good idea to use metaphors. The treatment of patients with conversion disorder is carried out together with a physical therapist. The collaboration of healthcare professionals who are involved in the treatment of a patient with conversion disorder should preferably be coordinated by the patient's general practitioner.

  19. Conversion Disorder- Mind versus Body: A Review.

    Science.gov (United States)

    Ali, Shahid; Jabeen, Shagufta; Pate, Rebecca J; Shahid, Marwah; Chinala, Sandhya; Nathani, Milankumar; Shah, Rida

    2015-01-01

    In this article, the authors accentuate the signs and symptoms of conversion disorder and the significance of clinical judgment and expertise in order to reach the right diagnosis. The authors review the literature and provide information on the etiology, prevalence, diagnostic criteria, and the treatment methods currently employed in the management of conversion disorder. Of note, the advancements of neuropsychology and brain imaging have led to emergence of a relatively sophisticated picture of the neuroscientific psychopathology of complex mental illnesses, including conversion disorder. The available evidence suggests new methods with which to test hypotheses about the neural circuits underlying conversion symptoms. In context of this, the authors also explore the neurobiological understanding of conversion disorder.

  20. Conversion Disorder— Mind versus Body: A Review

    Science.gov (United States)

    Jabeen, Shagufta; Pate, Rebecca J.; Shahid, Marwah; Chinala, Sandhya; Nathani, Milankumar; Shah, Rida

    2015-01-01

    In this article, the authors accentuate the signs and symptoms of conversion disorder and the significance of clinical judgment and expertise in order to reach the right diagnosis. The authors review the literature and provide information on the etiology, prevalence, diagnostic criteria, and the treatment methods currently employed in the management of conversion disorder. Of note, the advancements of neuropsychology and brain imaging have led to emergence of a relatively sophisticated picture of the neuroscientific psychopathology of complex mental illnesses, including conversion disorder. The available evidence suggests new methods with which to test hypotheses about the neural circuits underlying conversion symptoms. In context of this, the authors also explore the neurobiological understanding of conversion disorder. PMID:26155375

  1. Does pedagogical documentation support maternal reminiscing conversations?

    Directory of Open Access Journals (Sweden)

    Bethany Fleck

    2015-12-01

    Full Text Available When parents talk with their children about lessons learned in school, they are participating in reminiscing of an unshared event. This study sought to understand if pedagogical documentation, from the Reggio Approach to early childhood education, would support and enhance the conversation. Mother–child dyads reminisced two separate times about preschool lessons, one time with documentation available to them and one time without. Transcripts were coded extracting variables indicative of high and low maternal reminiscing styles. Results indicate that mother and child conversation characteristics were more highly elaborative when documentation was present than when it was not. In addition, children added more information to the conversation supporting the notion that such conversations enhanced memory for lessons. Documentation could be used as a support tool for conversations and children’s memory about lessons learned in school.

  2. A Conversation with Adam Heller.

    Science.gov (United States)

    Heller, Adam; Cairns, Elton J

    2015-01-01

    Adam Heller, Ernest Cockrell Sr. Chair in Engineering Emeritus of the John J. McKetta Department of Chemical Engineering at The University of Texas at Austin, recalls his childhood in the Holocaust and his contributions to science and technology that earned him the US National Medal of Technology and Innovation in a conversation with Elton J. Cairns, Professor of Chemical and Biomolecular Engineering at the University of California, Berkeley. Dr. Heller, born in 1933, describes the enslavement of his father by Hungarians in 1942; the confiscation of his family's home, business, and all its belongings in 1944; and his incarceration in a brick factory with 18,000 Jews who were shipped by the Hungarians to be gassed by Germans in Auschwitz. Dr. Heller and his immediate family survived the Holocaust and arrived in Israel in 1945. He studied under Ernst David Bergmann at the Hebrew University, and then worked at Bell Laboratories and GTE Laboratories, where he headed Bell Lab's Electronic Materials Research Department. At GTE Laboratories, he built in 1966 the first neodymium liquid lasers and in 1973 with Jim Auborn conceived and engineered the lithium thionyl chloride battery, one of the first to be manufactured lithium batteries, which is still in use. After joining the faculty of engineering of The University of Texas at Austin, he cofounded with his son Ephraim Heller TheraSense, now a major part of Abbott Diabetes Care, which produced a microcoulometer that made the monitoring of glucose painless by accurately measuring the blood glucose concentration in 300 nL of blood. He also describes the electrical wiring of enzymes, the basis for Abbott's state-of-the-art continuous glucose monitoring system. He discusses his perspective of reducing the risk of catastrophic global warming in a wealth-accumulating, more-energy-consuming world and provides advice for students entering careers in science or engineering.

  3. Visualization of frequency-modulated electric field based on photonic frequency tracking in asynchronous electro-optic measurement system

    Science.gov (United States)

    Hisatake, Shintaro; Yamaguchi, Koki; Uchida, Hirohisa; Tojyo, Makoto; Oikawa, Yoichi; Miyaji, Kunio; Nagatsuma, Tadao

    2018-04-01

    We propose a new asynchronous measurement system to visualize the amplitude and phase distribution of a frequency-modulated electromagnetic wave. The system consists of three parts: a nonpolarimetric electro-optic frequency down-conversion part, a phase-noise-canceling part, and a frequency-tracking part. The photonic local oscillator signal generated by electro-optic phase modulation is controlled to track the frequency of the radio frequency (RF) signal to significantly enhance the measurable RF bandwidth. We demonstrate amplitude and phase measurement of a quasi-millimeter-wave frequency-modulated continuous-wave signal (24 GHz ± 80 MHz with a 2.5 ms period) as a proof-of-concept experiment.

  4. Adaptability of solar energy conversion systems on ships

    Science.gov (United States)

    Visa, I.; Cotorcea, A.; Neagoe, M.; Moldovan, M.

    2016-08-01

    International trade of goods largely uses maritime/transoceanic ships driven by engines using fossil fuels. This two centuries tradition is technologically mature but significantly adds to the CO2 emissions; therefore, recent trends focus on on-board implementation of systems converting the solar energy into power (photovoltaic systems) or heat (solar-thermal systems). These systems are carbon-emissions free but are still under research and plenty of effort is devoted to fast reach maturity and feasibility. Unlike the systems implemented in a specific continental location, the design of solar energy conversion systems installed on shipboard has to face the problem generated by the system base motion along with the ship travelling on routes at different latitudes: the navigation direction and sense and roll-pitch combined motion with reduced amplitude, but with relatively high frequency. These raise highly interesting challenges in the design and development of mechanical systems that support the maximal output in terms of electricity or heat. The paper addresses the modelling of the relative position of a solar energy conversion surface installed on a ship according to the current position of the sun; the model is based on the navigation trajectory/route, ship motion generated by waves and the relative sun-earth motion. The model describes the incidence angle of the sunray on the conversion surface through five characteristic angles: three used to define the ship orientation and two for the solar angles; based on, their influence on the efficiency in solar energy collection is analyzed by numerical simulations and appropriate recommendations are formulated for increasing the solar energy conversion systems adaptability on ships.

  5. Electrothermal frequency reference

    NARCIS (Netherlands)

    Makinwa, K.A.A.; Kashmiri, S.M.

    2011-01-01

    An electrothermal frequency-locked loop (EFLL) circuit is described. This EFLL circuit includes an oscillator in a feedback loop. A drive circuit in the EFLL circuit generates a first signal having a fundamental frequency, and an electrothermal filter (ETF) in the EFLL circuit provides a second

  6. Low frequency noise study.

    Science.gov (United States)

    2007-04-01

    This report documents a study to investigate human response to the low-frequency : content of aviation noise, or low-frequency noise (LFN). The study comprised field : measurements and laboratory studies. The major findings were: : 1. Start-of-takeof...

  7. Single frequency intracavity SRO

    DEFF Research Database (Denmark)

    Abitan, Haim; Buchhave, Preben

    2000-01-01

    Summary form only given. A single resonance optical parametric oscillator (SRO) is inserted intracavity to a CW high power, single frequency, and ring Nd:YVO4 laser. We obtain a stable single frequency CW SRO with output at 1.7-1.9 μm (idler) and a resonating signal at 2.3-2.6 μm. The behavior...

  8. Fast fundamental frequency estimation

    DEFF Research Database (Denmark)

    Nielsen, Jesper Kjær; Jensen, Tobias Lindstrøm; Jensen, Jesper Rindom

    2017-01-01

    Modelling signals as being periodic is common in many applications. Such periodic signals can be represented by a weighted sum of sinusoids with frequencies being an integer multiple of the fundamental frequency. Due to its widespread use, numerous methods have been proposed to estimate the funda...

  9. Frequency control modelling - basics

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela; Sørensen, Poul Ejnar; Zeni, Lorenzo

    2016-01-01

    The purpose of this report is to provide an introduction on how the system balance in an island system can be maintained by controlling the frequency. The power balance differential equation, which is fundamental in understanding the effect on the system frequency of the unbalance between...

  10. Low Frequency Space Array

    International Nuclear Information System (INIS)

    Dennison, B.; Weiler, K.W.; Johnston, K.J.

    1987-01-01

    The Low Frequency Space Array (LFSA) is a conceptual mission to survey the entire sky and to image individual sources at frequencies between 1.5 and 26 MHz, a frequency range over which the earth's ionosphere transmits poorly or not at all. With high resolution, high sensitivity observations, a new window will be opened in the electromagnetic spectrum for astronomical investigation. Also, extending observations down to such low frequencies will bring astronomy to the fundamental limit below which the galaxy becomes optically thick due to free-free absorption. A number of major scientific goals can be pursued with such a mission, including mapping galactic emission and absorption, studies of individual source spectra in a frequency range where a number of important processes may play a role, high resolution imaging of extended sources, localization of the impulsive emission from Jupiter, and a search for coherent emission processes. 19 references

  11. Investigation of the summation of copper-vapour laser frequencies

    International Nuclear Information System (INIS)

    Karpukhin, Vyacheslav T; Konev, Yu B; Malikov, Mikhail M

    1998-01-01

    An investigation was made of the conversion of the copper-vapour laser radiation ( λ 1 = 0.51 μm and λ 2 = 0.578 μm) into UV radiation at the sum frequency (λ 3 = 0.271 μm) in a DKDP crystal. The operation of this frequency converter was compared for two magnifications of the laser cavity: M = 5 and 200. The best results were obtained for M = 200 (average UV radiation power 0.75 W, conversion efficiency 12%). A study was made of the characteristics of the formation of radiation pulses representing the two lines in the laser beam as a whole and in its weakly diverging core. In a low-divergence beam the yellow- and green-line pulses were emitted practically simultaneously with approximately the same peak power, which facilitated the sum-frequency generation. (nonlinear optical phenomena)

  12. Conversion of localized lower hybrid oscillations and fast magnetosonic waves at a plasma density cavity

    International Nuclear Information System (INIS)

    Hall, J.O.

    2004-01-01

    Analytic expressions are presented for conversion of localized lower hybrid oscillations and magnetosonic waves by scattering off a small scale density cavity. The governing equations are solved in slab geometry with wave vectors perpendicular to both the ambient magnetic field and the density gradient associated with density cavity using a scale length separation method. The theory predicts strong excitation of localized lower hybrid oscillations for a set of frequencies between the lower hybrid frequency of the ambient plasma and the minimum lower hybrid frequency inside the cavity. The theory is relevant for the lower hybrid solitary structures observed in space plasmas

  13. Ownership conversions and nursing home performance.

    Science.gov (United States)

    Grabowski, David C; Stevenson, David G

    2008-08-01

    To examine the effects of ownership conversions on nursing home performance. Online Survey, Certification, and Reporting system data from 1993 to 2004, and the Minimum Data Set (MDS) facility reports from 1998 to 2004. Regression specification incorporating facility fixed effects, with terms to identify trends in the pre- and postconversion periods. The annual rate of nursing home conversions almost tripled between 1994 and 2004. Our regression results indicate converting facilities are generally different throughout the pre/postconversion years, suggesting little causal effect of ownership conversions on nursing home performance. Before and after conversion, nursing homes converting from nonprofit to for-profit status generally exhibit deterioration in their performance, while nursing homes converting from for-profit to nonprofit status generally exhibit improvement. Policy makers have expressed concern regarding the implications of ownership conversions for nursing home performance. Our results imply that regulators and policy makers should not only monitor the outcomes of nursing home conversions, but also the targets of these conversions.

  14. Optical analysis of down-conversion OLEDs

    Science.gov (United States)

    Krummacher, Benjamin; Klein, Markus; von Malm, Norwin; Winnacker, Albrecht

    2008-02-01

    Phosphor down-conversion of blue organic light-emitting diodes (OLEDs) is one approach to generate white light, which offers the possibility of easy color tuning, a simple device architecture and color stability over lifetime. In this article previous work on down-conversion devices in the field of organic solid state lighting is briefly reviewed. Further, bottom emitting down-conversion OLEDs are studied from an optical point of view. Therefore the physical processes occurring in the down-conversion layer are translated into a model which is implemented in a ray tracing simulation. By comparing its predictions to experimental results the model is confirmed. For the experiments a blue-emitting polymer OLED (PLED) panel optically coupled to a series of down-conversion layers is used. Based on results obtained from ray tracing simulation some of the implications of the model for the performance of down-conversion OLEDs are discussed. In particular it is analysed how the effective reflectance of the underlying blue OLED and the particle size distribution of the phosphor powder embedded in the matrix of the down-conversion layer influence extraction efficiency.

  15. High-efficiency frequency doubling of continuous-wave laser light.

    Science.gov (United States)

    Ast, Stefan; Nia, Ramon Moghadas; Schönbeck, Axel; Lastzka, Nico; Steinlechner, Jessica; Eberle, Tobias; Mehmet, Moritz; Steinlechner, Sebastian; Schnabel, Roman

    2011-09-01

    We report on the observation of high-efficiency frequency doubling of 1550 nm continuous-wave laser light in a nonlinear cavity containing a periodically poled potassium titanyl phosphate crystal (PPKTP). The fundamental field had a power of 1.10 W and was converted into 1.05 W at 775 nm, yielding a total external conversion efficiency of 95±1%. The latter value is based on the measured depletion of the fundamental field being consistent with the absolute values derived from numerical simulations. According to our model, the conversion efficiency achieved was limited by the nonperfect mode matching into the nonlinear cavity and by the nonperfect impedance matching for the maximum input power available. Our result shows that cavity-assisted frequency conversion based on PPKTP is well suited for low-decoherence frequency conversion of quantum states of light.

  16. Processing of Microalgae: Acoustic Cavitation and Hydrothermal Conversion

    Science.gov (United States)

    Greenly, Justin Michael

    The production of energy dense fuels from renewable algal biomass feedstocks -- if sustainably developed at a sufficiently large scale -- may reduce the consumption of petroleum from fossil fuels and provide many environmental benefits. Achieving economic feasibility has several technical engineering challenges that arise from dilute concentration of growing algae in aqueous media, small cell sizes, and durable cell walls. For microalgae to be a sustainable source of biofuels and co-products, efficient fractionation and conversion of the cellular contents is necessary. Research was carried out to address two processing options for efficient microalgae biofuel production: 1. Ultrasonic cavitation for cell disruption and 2. Hydrothermal conversion of a model algal triglyceride. 1. Ultrasonic cell disruption, which relies on cavitating bubbles in the suspension to produce damaging shock waves, was investigated experimentally over a range of concentrations and species types. A few seconds of high intensity sonication at fixed frequency yielded significant cell disruption, even for the more durable cells. At longer exposure times, effectiveness was seen to decline and was attributed, using acoustic measurements, to ultrasonic power attenuation in the ensuing cloud of cavitating bubbles. Processing at higher cell concentrations slowed cell disintegration marginally, but increased the effectiveness of dissipating ultrasonic energy. A theoretical study effectively predicted optimal conditions for a variety of parameters that were inaccessible in this experimental investigation. In that study, single bubble collapse was modeled to identify operating conditions that would increase cavitation, and thus cell disruption. Simulations were conducted by varying frequency and pressure amplitude of the ultrasound wave, and initial bubble size. The simulation results indicated that low frequency, high sound wave amplitudes, and small initial bubble size generate the highest shock

  17. Linear mode conversion in a toroidal plasma

    International Nuclear Information System (INIS)

    Hellsten, T.

    1980-05-01

    Linear mode conversion at the perpendicular ion cyclotron resonance has been treated for an axially symmetric toroidal plasma. The mode conversion appears between a fast electromagnetic wave and a slow-quasi electrostatic wave, due to finite electron inertia. The problem reduces to the Orr-Sommerfeld equation where the coefficients determining the reflectron, transmission and conversion are functions of the arc length along a poloidal intersection of the resonance surface. These coefficients can be determined from eigenfunctions of an ordinary differential equation. (author)

  18. Entropy fluxes, endoreversibility, and solar energy conversion

    Science.gov (United States)

    de Vos, A.; Landsberg, P. T.; Baruch, P.; Parrott, J. E.

    1993-09-01

    A formalism illustrating the conversion of radiation energy into work can be obtained in terms of energy and entropy fluxes. Whereas the Landsberg equality was derived for photothermal conversion with zero bandgap, a generalized inequality for photothermal/photovoltaic conversion with a single, but arbitrary, bandgap was deduced. This result was derived for a direct energy and entropy balance. The formalism of endoreversible dynamics was adopted in order to show the correlation with the latter approach. It was a surprising fact that the generalized Landsberg inequality was derived by optimizing some quantity W(sup *), which obtains it maximum value under short-circuit condition.

  19. Conversion electron spectroscopy in transfermium nuclei

    International Nuclear Information System (INIS)

    Herzberg, R.D.

    2003-01-01

    Conversion electron spectroscopy is an essential tool for the spectroscopy of heavy deformed nuclei. The conversion electron spectrometer SACRED has been used in conjunction with the gas-filled recoil separator RITU to study conversion electron cascades in 254 No. The spectra reveal the ground state rotational bands down to low spin. A detailed analysis of the background seen for 254 No shows that approximately 40% of the decay path goes via excited high K bands which may be built on an isomer. (orig.)

  20. The conversion factor of α radiation efficiency

    International Nuclear Information System (INIS)

    Wang Weida; Zhou Zhixin; Xia Junding

    1997-01-01

    It is important in fine-grain TL dating that the full α dose must be converted into the equivalent β dose. Although the conversion coefficient K for internal radiation efficiency can not be measured directly for each sample, it is possible to measure the external radiation efficiency K 3.7 . For this purpose a special study for the conversion factor of K to K 3.7 has been made using ultrathin TLD. The results show that the conversion factor of the TLD for archaeological samples is 0.847, which is in agreement with the calculated value 0.85

  1. Energy Conversion & Storage Program, 1993 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, E.J.

    1994-06-01

    The Energy Conversion and Storage Program applies chemistry and materials science principles to solve problems in: production of new synthetic fuels; development of high-performance rechargeable batteries and fuel cells; development of high-efficiency thermochemical processes for energy conversion; characterization of complex chemical processes and chemical species; and the study and application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis.

  2. Energy conversion and management principles and applications

    CERN Document Server

    Petrecca, Giovanni

    2014-01-01

    This book provides an overall view of energy conversion and management in industry and in buildings by following the streams of energy from the site boundaries to the end users. Written for an audience of both practitioners and faculty/students, Energy Conversion and Management: Principles and Applications presents general principles of energy conversion and energy sources, both traditional and renewable, in a broad range of facilities such as electrical substations, boiler plants, heat and power plants, electrical networks, thermal fluid distributions lines and insulations, pumps and fans, ai

  3. [Conversion disorder : functional neuroimaging and neurobiological mechanisms].

    Science.gov (United States)

    Lejeune, J; Piette, C; Salmon, E; Scantamburlo, G

    2017-04-01

    Conversion disorder is a psychiatric disorder often encountered in neurology services. This condition without organic lesions was and still is sometimes referred as an imaginary illness or feigning. However, the absence of organic lesions does not exclude the possibility of cerebral dysfunction. The etiologic mechanisms underlying this disorder remain uncertain even today.The advent of cognitive and functional imaging opens up a field of exploration for psychiatry in understanding the neurobiological mechanisms underlying mental disorders and especially the conversion disorder. This article reports several neuroimaging studies of conversion disorder and attempts to generate hypotheses about neurobiological mechanisms.

  4. Time and frequency applications.

    Science.gov (United States)

    Hellwig, H

    1993-01-01

    An overview is given of the capabilities of atomic clocks and quartz crystal oscillators in terms of available precision of time and frequency signals. The generation, comparison, and dissemination of time and frequency is then discussed. The principal focus is to survey uses of time and frequency in navigation, communication, and science. The examples given include the Global Positioning System, a satellite-based global navigation system, and general and dedicated communication networks, as well as experiments in general relativity and radioastronomy. The number of atomic clocks and crystal oscillators that are in actual use worldwide is estimated.

  5. Passenger and Cell Phone Conversations in Simulated Driving

    Science.gov (United States)

    Drews, Frank A.; Pasupathi, Monisha; Strayer, David L.

    2008-01-01

    This study examines how conversing with passengers in a vehicle differs from conversing on a cell phone while driving. We compared how well drivers were able to deal with the demands of driving when conversing on a cell phone, conversing with a passenger, and when driving without any distraction. In the conversation conditions, participants were…

  6. Intravenous to oral conversion of fluoroquinolones: knowledge versus clinical practice patterns.

    Science.gov (United States)

    Conort, Ornella; Gabardi, Steven; Didier, Marie-Pauline; Hazebroucq, Georges; Cariou, Alain

    2002-04-01

    To assess the knowledge of prescribers regarding intravenous to oral conversions of fluoroquinolones, the frequency and time until conversion, and to compare prescriber knowledge with the data collected concerning the reasons stated for continuation of intravenous fluoroquinolones. Prospective chart review and questionnaire. Large teaching hospital in Paris, France. Fifty-one males and females. Data were collected on in-patients receiving intravenous fluoroquinolone for at least three days and hospitalized in one of six in-patient units. Patients receiving intravenous fluoroquinolone for less than three days were excluded. A questionnaire to assess the awareness of a potential conversion was distributed to those practitioners who had patients reviewed during the data-collection phase. The questionnaire revealed the ten most common reasons for continuing intravenous administration for more than three days. However, the physicians agreed that most patients should be converted as soon as possible. Practice patterns differed, with only 17 of 51 patients actually converted to oral therapy. In theory, the clinicians were aware of when to perform the conversion. However, in practice, the frequency of conversion was lower than optimum. Changes in clinical practice are needed to decrease the costs of intravenous therapy, without jeopardizing quality of care.

  7. Single frequency semiconductor lasers

    CERN Document Server

    Fang, Zujie; Chen, Gaoting; Qu, Ronghui

    2017-01-01

    This book systematically introduces the single frequency semiconductor laser, which is widely used in many vital advanced technologies, such as the laser cooling of atoms and atomic clock, high-precision measurements and spectroscopy, coherent optical communications, and advanced optical sensors. It presents both the fundamentals and characteristics of semiconductor lasers, including basic F-P structure and monolithic integrated structures; interprets laser noises and their measurements; and explains mechanisms and technologies relating to the main aspects of single frequency lasers, including external cavity lasers, frequency stabilization technologies, frequency sweeping, optical phase locked loops, and so on. It paints a clear, physical picture of related technologies and reviews new developments in the field as well. It will be a useful reference to graduate students, researchers, and engineers in the field.

  8. Electric current - frequency converter

    International Nuclear Information System (INIS)

    Kumahara, Tadashi; Kinbana, Setsuro.

    1967-01-01

    Herein disclosed is an improved simple electric current-frequency converter, the input current and output frequency linearity of which is widened to a range of four to five figures while compensating, for temperature. The converter may be used for computor processing and for telemetering the output signals from a nuclear reactor. The converter is an astable multivibrator which includes charging circuits comprising emitter-voltage compensated NPN transistors, a charged voltage detecting circuit of temperature compensated field effect transistors, and a transistor switching circuit for generating switching pulses independent of temperature. The converter exhibited a 0.7% frequency change within a range of 5 - 45 0 C and less than a 0.1% frequency drift after six hours of operation when the input current was maintained constant. (Yamaguchi, T.)

  9. Analytic expressions for mode conversion in a plasma with a parabolic density profile: Generalized results

    International Nuclear Information System (INIS)

    Hinkel-Lipsker, D.E.; Fried, B.D.; Morales, G.J.

    1993-01-01

    This study provides an analytic solution to the general problem of mode conversion in an unmagnetized plasma. Specifically, an electromagnetic wave of frequency ω propagating through a plasma with a parabolic density profile of scale length L p is examined. The mode conversion points are located a distance Δ 0 from the peak of the profile, where the electron plasma frequency ω p (z) matches the wave frequency ω. The corresponding reflection, transmission, and mode conversion coefficients are expressed analytically in terms of parabolic cylinder functions for all values of Δ 0 . The method of solution is based on a source approximation technique that is valid when the electromagnetic and electrostatic scale lengths are well separated. For large Δ 0 , i.e., (cL p /ω) 1/2 much-lt Δ 0 p , the appropriately scaled result [D. E. Hinkel-Lipsker et al., Phys. Fluids B 4, 559 (1992)] for a linear density profile is recovered as the parabolic cylinder functions asymptotically become Airy functions. When Δ 0 →0, the special case of conversion at the peak of the profile [D. E. Hinkel-Lipsker et al., Phys. Fluids B 4, 1772 (1992)] is obtained

  10. Spectrally shaped broadband study of up-conversion in Y2O3:Er3+

    International Nuclear Information System (INIS)

    Lytle, A.L.; Gagnon, E.; Tulchinsky, L.; Krebs, J.K.

    2014-01-01

    We present a novel scheme for studying up-conversion through excited state absorption (ESA) by using a broadband excitation source with spectral shaping capabilities. Up-conversion processes have typically been investigated using a single, narrowband excitation source, when the two steps of the process are coincident in frequency, which is often made possible by broadening mechanisms of the intermediate excited state manifolds. Thus, narrowband sources are limited in the systems they can excite and what material information they can provide. With broadband light, we are able to drive up-conversion with non-coincident frequencies as well. Finally, by windowing the spectrum, we determine the optimal excitation bandwidth for low-concentration (1%) Y 2 O 3 :Er 3+ nanocrystals. - Highlights: • Broadband excitation light is used to drive up-conversion in Y 2 O 3 :Er 3+ . • Broadband light excites all available transitions in the two-photon process. • A spectral shaping technique is used to alter the excitation frequencies present. • The optimal excitation bandwidth is measured by windowing the spectrum. • Broadband excitation reveals information inaccessible by narrowband sources

  11. Demonstration of efficient full-aperture type I/type II third harmonic conversion on Nova

    International Nuclear Information System (INIS)

    Wegner, P.J.; Henesian, M.A.; Marchi, F.T.; Speck, D.R.

    1988-01-01

    The ten arms of the Nova laser system readily deliver 22.5 kJ of third harmonic radiation in 1-ns pulses to targets for fusion experiments. Frequency conversion experiments conducted on a single arm have produced >7.5 kJ of 3ω radiation in longer (2.5-ns) pulses at the output of a Nova crystal array with 15 kJ of 1ω drive. Equivalent on-target energies (40-60 kJ) in 2-3-ns pulses is available at target chamber center when the laser disks in the output section of the Nova amplifier are replaced with new high-damage threshold glass. The remaining issue facing frequency conversion on Nova is to demonstrate similar 3-ω energy (>40 kJ) on-target at shorter (1-ns) pulse lengths with controlled pulse shape at 1→ drive energies up to 9 kJ. Frequency conversion to 40 kJ of 3→ with precisely shaped pulses is required for future experiments. The authors assembled a full-aperture (74-cm) array of these crystals to test on an arm outfitted with the new laser glass. Measurements of conversion efficiency, pulse time history, and optical quality of the converted beam are reported

  12. High frequency breakdown voltage

    International Nuclear Information System (INIS)

    Chu, Thanh Duy.

    1992-03-01

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

  13. Land Conversion, Social Impacts, and Legal Remedies ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Land Conversion, Social Impacts, and Legal Remedies: Understanding the Role of Community Paralegals in Addressing Impacts of Land Use Change in Asia. This project addresses the ... Pays d' institution. United States. Site internet.

  14. Compact Energy Conversion Module, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This STTR project delivers a compact vibration-based Energy Conversion Module (ECM) that powers sensors for purposes such as structural health monitoring (SHM). NASA...

  15. Compact energy conversion module, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This STTR project delivers a compact vibration-based Energy Conversion Module (ECM) that powers sensors for purposes like structural health monitoring (SHM). NASA...

  16. Alternative Fuels Data Center: Conversion Regulations

    Science.gov (United States)

    . Conversion systems must meet the same emissions standards that gasoline or diesel products do. Refer to EPA's manufacturer that holds the relevant emissions-related certifications and tampering exemptions. New and

  17. FLOUTING MAXIMS IN INDONESIA LAWAK KLUB CONVERSATION

    Directory of Open Access Journals (Sweden)

    Rahmawati Sukmaningrum

    2017-04-01

    Full Text Available This study aims to identify the types of maxims flouted in the conversation in famous comedy show, Indonesia Lawak Club. Likewise, it also tries to reveal the speakers‘ intention of flouting the maxim in the conversation during the show. The writers use descriptive qualitative method in conducting this research. The data is taken from the dialogue of Indonesia Lawak club and then analyzed based on Grice‘s cooperative principles. The researchers read the dialogue‘s transcripts, identify the maxims, and interpret the data to find the speakers‘ intention for flouting the maxims in the communication. The results show that there are four types of maxims flouted in the dialogue. Those are maxim of quality (23%, maxim of quantity (11%, maxim of manner (31%, and maxim of relevance (35. Flouting the maxims in the conversations is intended to make the speakers feel uncomfortable with the conversation, show arrogances, show disagreement or agreement, and ridicule other speakers.

  18. Childhood abuse in patients with conversion disorder

    NARCIS (Netherlands)

    Roelofs, K.; Keijsers, G.P.J.; Hoogduin, C.A.L.; Näring, G.W.B.; Moene, F.C.

    2002-01-01

    OBJECTIVE: Despite the fact that the assumption of a relationship between conversion disorder and childhood traumatization has a long history, there is little empirical evidence to support this premise. The present study examined this relation and investigated whether hypnotic susceptibility

  19. Emotional stimuli and motor conversion disorder

    NARCIS (Netherlands)

    Voon, V.; Brezing, C.; Gallea, C.; Ameli, R.; Roelofs, K.; LaFrance, W.C.; Hallett, M.

    2010-01-01

    Conversion disorder is characterized by neurological signs and symptoms related to an underlying psychological issue. Amygdala activity to affective stimuli is well characterized in healthy volunteers with greater amygdala activity to both negative and positive stimuli relative to neutral stimuli,

  20. Expertise in Everyday Nurse–Patient Conversations

    Directory of Open Access Journals (Sweden)

    Lindsay M. Macdonald

    2016-04-01

    Full Text Available A great deal of nursing activity is embedded in what is considered to be everyday conversation. These conversations are important to health professionals because communication can affect health outcomes, and they are important to patients who want to know they are being heard and cared for. How do nurses talk with patients and what are the features of effective communication in practice? In this exploratory study, two expert nurses recorded conversations with patients during domiciliary visits. Linguistic discourse analysis, informed by contextual knowledge of domiciliary nursing shows the nurses skillfully used small talk to support their clinical work. In their conversations, nurses elicit specific information, normalize unpleasant procedures, manage the flow of the interaction, and strengthen the therapeutic relationship. Small talk can be big talk in achieving nursing goals. Critically reflecting on recorded clinical interactions can be a useful method of professional development and a way of demonstrating nursing expertise.

  1. NASA-OAST photovoltaic energy conversion program

    Science.gov (United States)

    Mullin, J. P.; Loria, J. C.

    1984-01-01

    The NASA program in photovoltaic energy conversion research is discussed. Solar cells, solar arrays, gallium arsenides, space station and spacecraft power supplies, and state of the art devices are discussed.

  2. Trends and Challenges in Catalytic Biomass Conversion

    DEFF Research Database (Denmark)

    Osmundsen, Christian Mårup; Egeblad, Kresten; Taarning, Esben

    2013-01-01

    The conversion of biomass to the plethora of chemicals used in modern society is one of the major challenges of the 21st century. Due to the significant differences between biomass resources and the current feedstock, crude oil, new technologies need to be developed encompassing all steps...... in the value chain, from pretreatment to purification. Heterogeneous catalysis is at the heart of the petrochemical refinery and will likely play an equally important role in the future biomass-based chemical industry. Three potentially important routes to chemicals from biomass are highlighted in this chapter....... The conversion of biomass-derived substrates, such as glycerol, by hydrogenolysis to the important chemicals ethylene glycol and propane diols. Secondly, the conversion of carbohydrates by Lewis acidic zeolites to yield alkyl lactates, and finally the conversion of lignin, an abundant low value source of biomass...

  3. Advances in wind energy conversion technology

    CERN Document Server

    Sathyajith, Mathew

    2011-01-01

    The technology of generating energy from wind has significantly changed during the past five years. The book brings together all the latest aspects of wind energy conversion technology - from wind resource analysis to grid integration of generated electricity.

  4. Interfacing feedstock logistics with bioenergy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Sokhansanj, S. [British Columbia Univ., Vancouver, BC (Canada). Oak Ridge National Lab

    2010-07-01

    The interface between biomass production and biomass conversion platforms was investigated. Functional relationships were assembled in a modeling platform to simulate the flow of biomass feedstock from farm and forest to a densification plant. The model considers key properties of biomass for downstream pre-processing and conversion. These properties include moisture content, cellulose, hemicelluloses, lignin, ash, particle size, specific density and bulk density. The model simulates logistical operations such as grinding to convert biomass to pellets that are supplied to a biorefinery for conversion to heat, power, or biofuels. Equations were developed to describe the physical aspects of each unit operation. The effect that each of the process variables has on the efficiency of the conversion processes was described.

  5. 49 CFR 1018.7 - Conversion claims.

    Science.gov (United States)

    2010-10-01

    ... Conversion claims. These procedures are directed primarily to the recovery of money on behalf of the Government. The Board may demand: (a) The return of specific property; or (b) Either the return of property or the payment of its value. ...

  6. Condenser design for AMTEC power conversion

    Science.gov (United States)

    Crowley, Christopher J.

    1991-01-01

    The condenser and the electrodes are the two elements of an alkali metal thermal-to-electric conversion (AMTEC) cell which most greatly affect the energy conversion performance. A condenser is described which accomplishes two critical functions in an AMTEC cell: management of the fluid under microgravity conditions and optimization of conversion efficiency. The first function is achieved via the use of a controlled surface shape, along with drainage grooves and arteries to collect the fluid. Capillary forces manage the fluid in microgravity and dominate hydrostatic effects on the ground so the device is ground-testable. The second function is achieved via a smooth film of highly reflective liquid sodium on the condensing surface, resulting in minimization of parasitic heat losses due to radiation heat transfer. Power conversion efficiencies of 25 percent to 30 percent are estimated with this condenser using present technology for the electrodes.

  7. Solar spectrum conversion for photovoltaics using nanoparticles

    NARCIS (Netherlands)

    Sark, W.G.J.H.M. van; Meijerink, A.; Schropp, R.E.I.

    2012-01-01

    The possibility to tune chemical and physical properties in nanosized materials has a strong impact on a variety of technologies, including photovoltaics. One of the prominent research areas of nanomaterials for photovoltaics involves spectral conversion. Conventional single-junction

  8. Electrochemical conversion of micropollutants in gray water

    NARCIS (Netherlands)

    Butkovskyi, A.; Jeremiasse, A.W.; Hernandez Leal, L.; Zande, van der T.; Rijnaarts, H.; Zeeman, G.

    2014-01-01

    Electrochemical conversion of micropollutants in real gray water effluent was studied for the first time. Six compounds that are frequently found in personal care and household products, namely methylparaben, propylparaben, bisphenol A, triclosan, galaxolide, and 4- methylbenzilidene camphor

  9. Land Conversion, Social Impacts, and Legal Remedies ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Land Conversion, Social Impacts, and Legal Remedies: Understanding the Role of ... There is a recognized need for intermediary institutions, such as media, ... Birth registration is the basis for advancing gender equality and children's rights.

  10. Persuasive Conversational Agent with Persuasion Tactics

    Science.gov (United States)

    Narita, Tatsuya; Kitamura, Yasuhiko

    Persuasive conversational agents persuade people to change their attitudes or behaviors through conversation, and are expected to be applied as virtual sales clerks in e-shopping sites. As an approach to create such an agent, we have developed a learning agent with the Wizard of Oz method in which a person called Wizard talks to the user pretending to be the agent. The agent observes the conversations between the Wizard and the user, and learns how to persuade people. In this method, the Wizard has to reply to most of the user's inputs at the beginning, but the burden gradually falls because the agent learns how to reply as the conversation model grows.

  11. Encoding, storage and judgment of experienced frequency and duration

    Directory of Open Access Journals (Sweden)

    Tilmann Betsch

    2010-08-01

    Full Text Available This paper examines conditions that do or do not lead to accurate judgments of frequency (JOF and judgments of duration (JOD. In three experiments, duration and frequency of visually presented stimuli are varied orthogonally in a within-subjects design. Experiment 1 reveals an asymmetric judgment pattern. JOFs reflected actual presentation frequency quite accurately and were unbiased by exposure duration. Conversely, JODs were almost insensitive to actual exposure duration and were systematically biased by presentation frequency. We show, however, that a tendency towards a symmetric judgment pattern can be obtained by manipulating encoding conditions. Sustaining attention during encoding (Experiment 2 or enhancing richness of the encoded stimuli (Experiment 3 increases judgment sensitivity in JOD and yields biases in both directions (JOF biased by exposure duration, JOD biased by presentation frequency. The implications of these findings for underlying memory mechanisms are discussed.

  12. ALMA High Frequency Techniques

    Science.gov (United States)

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

    2015-12-01

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

  13. Applying linguistic methods to understanding smoking-related conversations on Twitter.

    Science.gov (United States)

    Sanders-Jackson, Ashley; Brown, Cati G; Prochaska, Judith J

    2015-03-01

    Social media, such as Twitter, have become major channels of communication and commentary on popular culture, including conversations on our nation's leading addiction: tobacco. The current study examined Twitter conversations following two tobacco-related events in the media: (1) President Obama's doctor announcing that he had quit smoking and (2) the release of a photograph of Miley Cyrus (a former Disney child star) smoking a cigarette. With a focus on high-profile individuals whose actions can draw public attention, we aimed to characterise tobacco-related conversations as an example of tobacco-related public discourse and to present a novel methodology for studying social media. Tweets were collected 11-13 November 2011 (President Obama) and 1-3 August 2011 (Miley Cyrus) and analysed for relative frequency of terms, a novel application of a linguistic methodology. The President Obama data set (N=2749 tweets) had conversations about him quitting tobacco as well as a preponderance of information on political activity, links to websites, racialised terms and mention of marijuana. Websites and terms about Obama's smoke-free status were most central to the conversation. In the Miley Cyrus data (N=4746 tweets), terms that occurred with the greatest relative frequency were positive, emotional and supportive of quitting (eg, love, and please), with words such as 'love' most central to the conversation. People are talking about tobacco-related issues on Twitter, and semantic network analysis can be used to characterise on-line conversations. Future interventions may be able to harness social media and major current events to raise awareness of smoking-related issues. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  14. Conversion Rate Optimization through Evolutionary Computation

    OpenAIRE

    Miikkulainen, Risto; Iscoe, Neil; Shagrin, Aaron; Cordell, Ron; Nazari, Sam; Schoolland, Cory; Brundage, Myles; Epstein, Jonathan; Dean, Randy; Lamba, Gurmeet

    2017-01-01

    Conversion optimization means designing a web interface so that as many users as possible take a desired action on it, such as register or purchase. Such design is usually done by hand, testing one change at a time through A/B testing, or a limited number of combinations through multivariate testing, making it possible to evaluate only a small fraction of designs in a vast design space. This paper describes Sentient Ascend, an automatic conversion optimization system that uses evolutionary op...

  15. μ- conversion via doubly charged Higgs scalar

    International Nuclear Information System (INIS)

    Picciotto, C.E.; Zahir, M.S.

    1982-10-01

    A new mechanism is used to calculate μ - → e + conversion in nuclei, based on the existence of a doubly charged Higgs scalar. The scalar is part of a triplet which generates the spontaneous breakdown of B-L symmetry in an extension of the standard model, as proposed by Gelmini and Roncadelli. We find a limit for conversion rates which is comparable to those of earlier calculations

  16. Measuring international relations in social media conversations

    OpenAIRE

    Barnett, GA; Xu, WW; Chu, J; Jiang, K; Huh, C; Park, JY; Park, HW

    2017-01-01

    © 2016 Elsevier Inc. This paper examines international relations as perceived by the public in their social media conversations. It examines over 1.8 billion Facebook postings in English and 51 million Chinese posts on Weibo, to reveal the relations among nations as expressed in social media conversations. It argues that social media represent a transnational electronic public sphere, in which public discussions reveal characteristics of international relations as perceived by a foreign publi...

  17. A simple theory of linear mode conversion

    International Nuclear Information System (INIS)

    Cairns, R.A.; Lashmore-Davies, C.N.; Woods, A.M.

    1984-01-01

    A summary is given of the basic theory of linear mode conversion involving the construction of differential equations for the mode amplitudes based on the properties of the dispersion relation in the neighbourhood of the mode conversion point. As an example the transmission coefficient for tunneling from the upper hybrid resonance through the evanescent region to the adjacent cut-off is treated. 7 refs, 3 figs

  18. Mineralogical conversion of asbestos containing materials

    International Nuclear Information System (INIS)

    Pulsford, S.K.; Foltz, A.D.; Ek, R.B.

    1996-01-01

    The principal objective of the Technical Task Plan (TTP) is to demonstrate a thermal-chemical mineralogical asbestos conversion unit at the Hanford Site, which converts non-radiological asbestos containing materials (ACMs) into an asbestos-free material. The permanent thermal-chemical mineralogical conversion of ACMs to a non-toxic, non-hazardous, potentially marketable end product should not only significantly reduce the waste stream volumes but terminate the open-quotes cradle to graveclose quotes ownership liabilities

  19. A Converse of Fermat's Little Theorem

    Science.gov (United States)

    Bruckman, P. S.

    2007-01-01

    As the name of the paper implies, a converse of Fermat's Little Theorem (FLT) is stated and proved. FLT states the following: if p is any prime, and x any integer, then x[superscript p] [equivalent to] x (mod p). There is already a well-known converse of FLT, known as Lehmer's Theorem, which is as follows: if x is an integer coprime with m, such…

  20. Development of high conversion boiling water reactor

    International Nuclear Information System (INIS)

    Yamashita, Jun-ichi; Mochida, Takaaki; Uchikawa, Sadao.

    1988-01-01

    It is expected that the period of LWRs being the main source of electric power supply becomes long, therefore, the development of next generation LWRs placing emphasis on the effective utilization of uranium resources and the improvement of economical efficiency is necessary. In this paper, as the next generation BWRs subsequent to ABWRs, the concept of the core of high conversion type BWRs is reported, in which emphasis is placed on the saving of natural uranium resources by raising the rate of conversion to plutonium. This core is that of realizing the high rate of conversion by utilizing the void in the core, which is the feature of BWRs, and the case of making the change of the core structure relatively small by using cross type control rods and the case of changing the core structure for further heightening the rate of conversion and making control rods into cluster type are described. In order to meet the demand like this, Hitachi Ltd. has engaged in the development of the concept of the core of next generation LWRs. In the high conversion type BWRs, there is not large change in the reactor system and turbine system from the current BWRs. The features and the concept of the core of high conversion type BWRs are described. (Kako, I.)

  1. Coherent Motion Reveals Non‐Ergodic Nature of Internal Conversion between Excited States

    DEFF Research Database (Denmark)

    Kuhlman, Thomas Scheby; Sølling, Theis I.; Møller, Klaus Braagaard

    2012-01-01

    for smaller molecules. Specifically, we focus on the S2→S1 internal conversion in cyclobutanone, cyclopentanone, and cyclohexanone. By means of time‐resolved mass spectrometry and photoelectron spectroscopy the relative rate of this transition is determined to be 13:2:1. Remarkably, we observe coherent......We found that specific nuclear motion along low‐frequency modes is effective in coupling electronic states and that this motion prevail in some small molecules. Thus, in direct contradiction to what is expected based on the standard models, the internal conversion process can proceed faster...

  2. High-accuracy resolver-to-digital conversion via phase locked loop based on PID controller

    Science.gov (United States)

    Li, Yaoling; Wu, Zhong

    2018-03-01

    The problem of resolver-to-digital conversion (RDC) is transformed into the problem of angle tracking control, and a phase locked loop (PLL) method based on PID controller is proposed in this paper. This controller comprises a typical PI controller plus an incomplete differential which can avoid the amplification of higher-frequency noise components by filtering the phase detection error with a low-pass filter. Compared with conventional ones, the proposed PLL method makes the converter a system of type III and thus the conversion accuracy can be improved. Experimental results demonstrate the effectiveness of the proposed method.

  3. Coherent Frequency Shifter, Optical Isolator, Lasers on an Integrated Platform for Cold Atom Microsystems

    Science.gov (United States)

    2017-10-11

    frequency shifting with < 10 % leakage ; (5) experimental demonstration achieving frequency shifting with < 3 dB forward optical loss; (6) 29.3 dBm RF...using heterodyne detection . (b) 100 MHz up-conversion, 20 dB side lobe suppression. (c) 100 MHz down-conversion, 14 dB side lobe suppression...shifting with < 10 % leakage ; (5) experimental demonstration achieving frequency shifting with < 3 dB forward optical loss; (6) 29.3 dBm RF power

  4. Coupling analysis of energy conversion in multi-mode vibration structural control using a synchronized switch damping method

    International Nuclear Information System (INIS)

    Ji, Hongli; Qiu, Jinhao; Xia, Pinqi; Inman, Daniel

    2012-01-01

    Modal coupling is an important issue in the analysis and control of structural systems with multi-degrees of freedom (MDOF). In this paper, modal coupling induced by energy conversion in the structural control of an MDOF system using a synchronized switch damping method is investigated theoretically and validated numerically. In the analysis, it is supposed that the voltage on the piezoelectric actuator is switched at the displacement extrema of a given mode. Two types of coupling in energy conversion are considered. The first is whether the switching action based on one mode induces energy conversion of the other modes. The second is whether the vibration of one mode affects the energy conversion of the other modes. The results indicate that the modal coupling in energy conversion is very complicated. In most cases the switching action based on one mode does induce energy conversion of another mode, but the efficiency depends on the frequency ratio of the two modes. The vibration of one mode affects the energy conversion of another mode only when the frequency ratio of the two modes takes some special values. Discussions are also given on the potential application of the theoretical results in the design of an energy harvesting device. (paper)

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

    Directory of Open Access Journals (Sweden)

    Darius Žižys

    2017-04-01

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

  6. Conversational AI: The Science Behind the Alexa Prize

    OpenAIRE

    Ram, Ashwin; Prasad, Rohit; Khatri, Chandra; Venkatesh, Anu; Gabriel, Raefer; Liu, Qing; Nunn, Jeff; Hedayatnia, Behnam; Cheng, Ming; Nagar, Ashish; King, Eric; Bland, Kate; Wartick, Amanda; Pan, Yi; Song, Han

    2018-01-01

    Conversational agents are exploding in popularity. However, much work remains in the area of social conversation as well as free-form conversation over a broad range of domains and topics. To advance the state of the art in conversational AI, Amazon launched the Alexa Prize, a 2.5-million-dollar university competition where sixteen selected university teams were challenged to build conversational agents, known as socialbots, to converse coherently and engagingly with humans on popular topics ...

  7. Sexy gene conversions: locating gene conversions on the X-chromosome.

    Science.gov (United States)

    Lawson, Mark J; Zhang, Liqing

    2009-08-01

    Gene conversion can have a profound impact on both the short- and long-term evolution of genes and genomes. Here, we examined the gene families that are located on the X-chromosomes of human (Homo sapiens), chimpanzee (Pan troglodytes), mouse (Mus musculus) and rat (Rattus norvegicus) for evidence of gene conversion. We identified seven gene families (WD repeat protein family, Ferritin Heavy Chain family, RAS-related Protein RAB-40 family, Diphosphoinositol polyphosphate phosphohydrolase family, Transcription Elongation Factor A family, LDOC1-related family, Zinc Finger Protein ZIC, and GLI family) that show evidence of gene conversion. Through phylogenetic analyses and synteny evidence, we show that gene conversion has played an important role in the evolution of these gene families and that gene conversion has occurred independently in both primates and rodents. Comparing the results with those of two gene conversion prediction programs (GENECONV and Partimatrix), we found that both GENECONV and Partimatrix have very high false negative rates (i.e. failed to predict gene conversions), which leads to many undetected gene conversions. The combination of phylogenetic analyses with physical synteny evidence exhibits high resolution in the detection of gene conversions.

  8. Effect of echolocation behavior-related constant frequency-frequency modulation sound on the frequency tuning of inferior collicular neurons in Hipposideros armiger.

    Science.gov (United States)

    Tang, Jia; Fu, Zi-Ying; Wei, Chen-Xue; Chen, Qi-Cai

    2015-08-01

    In constant frequency-frequency modulation (CF-FM) bats, the CF-FM echolocation signals include both CF and FM components, yet the role of such complex acoustic signals in frequency resolution by bats remains unknown. Using CF and CF-FM echolocation signals as acoustic stimuli, the responses of inferior collicular (IC) neurons of Hipposideros armiger were obtained by extracellular recordings. We tested the effect of preceding CF or CF-FM sounds on the shape of the frequency tuning curves (FTCs) of IC neurons. Results showed that both CF-FM and CF sounds reduced the number of FTCs with tailed lower-frequency-side of IC neurons. However, more IC neurons experienced such conversion after adding CF-FM sound compared with CF sound. We also found that the Q 20 value of the FTC of IC neurons experienced the largest increase with the addition of CF-FM sound. Moreover, only CF-FM sound could cause an increase in the slope of the neurons' FTCs, and such increase occurred mainly in the lower-frequency edge. These results suggested that CF-FM sound could increase the accuracy of frequency analysis of echo and cut-off low-frequency elements from the habitat of bats more than CF sound.

  9. Temporal mode selectivity by frequency conversion in second-order nonlinear optical waveguides: Erratum

    DEFF Research Database (Denmark)

    Reddy, Dileep V.; Raymer, M. G.; Mckinstrie, C. J.

    2017-01-01

    We correct typographical errors in four equations showing the integral forms of the equations of motion and the corresponding perturbative approximation. Subsequently presented derivations, results, and conclusions remain unchanged.......We correct typographical errors in four equations showing the integral forms of the equations of motion and the corresponding perturbative approximation. Subsequently presented derivations, results, and conclusions remain unchanged....

  10. Analysis of adjusting effects of mounting force on frequency conversion of mounted nonlinear optics.

    Science.gov (United States)

    Su, Ruifeng; Liu, Haitao; Liang, Yingchun; Lu, Lihua

    2014-01-10

    Motivated by the need to increase the second harmonic generation (SHG) efficiency of nonlinear optics with large apertures, a novel mounting configuration with active adjusting function on the SHG efficiency is proposed and mechanically and optically studied. The adjusting effects of the mounting force on the distortion and stress are analyzed by the finite element methods (FEM), as well as the contribution of the distortion and stress to the change in phase mismatch, and the SHG efficiency are theoretically stated. Further on, the SHG efficiency is calculated as a function of the mounting force. The changing trends of the distortion, stress, and the SHG efficiency with the varying mounting force are obtained, and the optimal ones are figured out. Moreover, the mechanism of the occurrence of the optimal values is studied and the adjusting strategy is put forward. Numerical results show the robust adjustment of the mounting force, as well as the effectiveness of the mounting configuration, in increasing the SHG efficiency.

  11. ZnGeP sub 2 crystals for infrared laser radiation frequency conversion

    CERN Document Server

    Andreev, Y M; Gribenyukov, A I; Korotkova, V V

    1998-01-01

    In this parer, we present some recent results on integrated studies concerned with different aspects of ZnGeP sub 2 crystal technology: synthesis, growth, and post-growth treatment. High-yield two-temperature synthesis and subsequent growth of ZnGeP sub 2 crystals are considered. By X-Ray phase analysis it has been found that two-temperature synthesis of ZnGeP sub 2 is realized through binary zinc and germanium phosphides formed at the Zn-Ge mixture temperature of about 900 .deg. C and the P pressure of 7 approx 10 atm. Using the heat-balance equation, a ratio of the thermal conductivity in the solid to that in the liquid ZnGeP sub 2 near the melting point has been determined. The value of the determined ratio is K sub l /K sub s approx =2.3. Analysis of the most favored crystallographic directions for ZnGeP sub 2 growth has been performed. These directions are [116], [132] and [102]. Data for optical absorption of the as-grown and the annealed ZnGeP sub 2 crystals are also presented.

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

    National Research Council Canada - National Science Library

    Nill, Norman B

    2001-01-01

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

  13. Direct conversion of light to radio frequency energy. [using photoklystrons for solar power satellites

    Science.gov (United States)

    Freeman, J. W.; Simons, S.

    1981-01-01

    A description is presented of the test results obtained with the latest models of the phototron. The phototron was conceived as a replacement for the high voltage solar cell-high power klystron combination for the solar power satellite concept. Physically, the phototron is a cylindrical evacuated glass tube with a photocathode, two grids, and a reflector electrode in a planar configuration. The phototron can be operated either in a biased mode where a low voltage is used to accelerate the electron beam produced by the photocathode or in an unbiased mode referred to as self-oscillation. The device is easily modulated by light input or voltage to broadcast in AM or FM. The range of operation of the present test model phototrons is from 2 to 200 MHz.

  14. Pulsed Blue and Ultraviolet Laser System for Fluorescence Diagnostics based on Nonlinear Frequency Conversion

    DEFF Research Database (Denmark)

    Cheng, Haynes Pak Hay

    The motivation for the current thesis work is to build a compact, efficient, pulsed, diode-pumped solid-state (DPSS) laser at 340 nm to be used for autofluorescence imaging and related cancer diagnostic experiments. By exciting endogenous fluorophores in the UV spectrum, autofluorescence imaging...... ns. Comparing this to the 9 ns relative jitter achieved in the passive system shows the performance penalty incurred in using the passive approach. Lastly, practical applications of compact semiconductor and DPSS lasers in the blue and UV spectral region are presented. A CW tapered diode at 808 nm...... applied to other wavelengths; specifically, those in the blue and UV spectral region. Using the passive synchronization technique and the optimization procedure reported for quasi-three-level lasers, a new generation of high peak power, pulsed, blue and UV laser light sources could be realized....

  15. Quantitative feasibility study of magnetocaloric energy conversion utilizing industrial waste heat

    International Nuclear Information System (INIS)

    Vuarnoz, D.; Kitanovski, A.; Gonin, C.; Borgeaud, Y.; Delessert, M.; Meinen, M.; Egolf, P.W.

    2012-01-01

    Highlights: ► We model magnetic energy conversion machine for the use of industrial waste heat. ► Efficiencies and masses of the system are evaluated by a numerical model. ► Excellent potential of profitability is expected with large low-exergy heat sources. -- Abstract: The main objective of this theoretical study was to investigate under which conditions a magnetic energy conversion device (MECD) – utilizing industrial waste heat – is economically feasible. Furthermore, it was evaluated if magnetic energy conversion (MCE) has the potential of being a serious concurrent to already existing conventional energy conversion technologies. Up-today the availability of magnetocaloric materials with a high Curie temperature and a high magnetocaloric effect is rather limited. Therefore, this study was mainly focused on applications with heat sources of low to medium temperature levels. Magnetic energy conversion machines, containing permanent magnets, are numerically investigated for operation conditions with different temperature levels, defined by industrial waste heat sources and environmental heat sinks, different magnetic field intensities and different frequencies of operation (number of thermodynamic cycles per unit of time). Theoretical modeling and numerical simulations were performed in order to determine thermodynamic efficiencies and the exergy efficiencies as function of different operation conditions. From extracted data of our numerical results, approximate values of the total mass and total volume of magnetic energy conversion machines could be determined. These important results are presented dependent on the produced electric power. An economic feasibility study supplements the scientific study. It shows an excellent potential of profitability for certain machines. The most important result of this article is that the magnetic energy conversion technology can be economically and technically competitive to or even beat conventional energy

  16. Teaching Spanish Pragmatics Through Colloquial Conversations

    Directory of Open Access Journals (Sweden)

    Albelda Marco, Marta

    2017-11-01

    Full Text Available This paper focuses on the advantages of teaching and learning a foreign language with and through spoken discursive corpora, and especially colloquial and conversational ones. The benefits of developing oral competence and communicative skills in language learners using colloquial conversations will be exposed and discussed. In this paper, we characterise the colloquial conversation and the features that define this register and discursive genre. Being the most natural and original way to communicate among human beings, the colloquial conversation is the most common means to communicate, and therefore, this genre should have a greater presence in foreign-language classrooms. Secondly, we expound on the advantages of teaching using colloquial conversations corpora, particularly resulting from its contextualisation (the linguistic input is learnt in its real and authentic context and from its oral and conversational features (prosodic elements and interactional mechanisms. Thirdly, the paper provides a list of corpora of colloquial conversations that are available in Spanish, focusing on Val.Es.Co. colloquial corpus (peninsular Spanish oral corpus, Briz et al., 2002; Cabedo & Pons online, www.valesco.es. Finally, a set of pragmatic applications of corpora in foreign-language classroom is offered, in particular using the Val.Es.Co. colloquial corpus: functions of discourse markers and interjections (whose meanings change depending on the context, strategies of turn-takings, ways of introducing new topic in the dialogues, mechanisms of keeping or “stealing” the turn, devices to introduce direct speech, attitudes expressed by the falling and rising intonations, hedges and intensifiers, and so on. In general, this paper pretends to offer ideas, resources and materials to make the students more competent in communication using authentic discursive oral corpora.

  17. Frequency Standards and Metrology

    Science.gov (United States)

    Maleki, Lute

    2009-04-01

    Preface / Lute Maleki -- Symposium history / Jacques Vanier -- Symposium photos -- pt. I. Fundamental physics. Variation of fundamental constants from the big bang to atomic clocks: theory and observations (Invited) / V. V. Flambaum and J. C. Berengut. Alpha-dot or not: comparison of two single atom optical clocks (Invited) / T. Rosenband ... [et al.]. Variation of the fine-structure constant and laser cooling of atomic dysprosium (Invited) / N. A. Leefer ... [et al.]. Measurement of short range forces using cold atoms (Invited) / F. Pereira Dos Santos ... [et al.]. Atom interferometry experiments in fundamental physics (Invited) / S. W. Chiow ... [et al.]. Space science applications of frequency standards and metrology (Invited) / M. Tinto -- pt. II. Frequency & metrology. Quantum metrology with lattice-confined ultracold Sr atoms (Invited) / A. D. Ludlow ... [et al.]. LNE-SYRTE clock ensemble: new [symbol]Rb hyperfine frequency measurement - spectroscopy of [symbol]Hg optical clock transition (Invited) / M. Petersen ... [et al.]. Precise measurements of S-wave scattering phase shifts with a juggling atomic clock (Invited) / S. Gensemer ... [et al.]. Absolute frequency measurement of the [symbol] clock transition (Invited) / M. Chwalla ... [et al.]. The semiclassical stochastic-field/atom interaction problem (Invited) / J. Camparo. Phase and frequency noise metrology (Invited) / E. Rubiola ... [et al.]. Optical spectroscopy of atomic hydrogen for an improved determination of the Rydberg constant / J. L. Flowers ... [et al.] -- pt. III. Clock applications in space. Recent progress on the ACES mission (Invited) / L. Cacciapuoti and C. Salomon. The SAGAS mission (Invited) / P. Wolf. Small mercury microwave ion clock for navigation and radioScience (Invited) / J. D. Prestage ... [et al.]. Astro-comb: revolutionizing precision spectroscopy in astrophysics (Invited) / C. E. Kramer ... [et al.]. High frequency very long baseline interferometry: frequency standards and

  18. Investigating the Optimum Efficiency of Acoustoelectric Conversion Plate Devices

    Directory of Open Access Journals (Sweden)

    Chien-Chih Chen

    2014-04-01

    Full Text Available This study aims to develop the acoustoelectric conversion plate in terms of electromagnetic induction law to convert sound energy to electricity, where the developed apparatus is made of three parts, the thin film coil, the spring, and the high-intensity magnetic framework. In process, the thin film coil receives the injecting sound vibration in connection with the spring to cause the reciprocating motion between the coil and the high-intensity magnet, which yields the electromotive force (EMF. In this study, a pearl plate of length 95 mm, width 95 mm, and thickness 1.5 mm adhered with a PET film of thickness 0.08mm is built as the substrate plate due to it has good properties of light and elasticity. In connection with the substrate plate and the electric coil is the thin film coil. Experiments used the speaker with output frequencies of 30~156 Hz and sound power of 0.5 W (sound intensity 0.32 W/m2, sound pressure level 115 dB as the sound source. The sound energy is captured by the acoustoelectric conversion plate for working efficiency and optimization parameters analysis. The studied parameters content of diameter, turns, and width of electric coil as well as distance between high intensity magnet and coil. The results show that diameter 0.11 mm, turns 220, and width 3 mm of the electric coil, in connection with steel spring of diameter 0.2 mm while input sound is 30 Hz, receives the average output voltage of 0.57 V, the average output current of 5.46 mA, the average output power of 3.13 mW, and the sound electric conversion efficiency of 0.63%. This innovation device could be used in highway, near waterfalls, and some high noise factories to capture energy for immediately charging cell-phone to save human life.

  19. High frequency energy measurements

    International Nuclear Information System (INIS)

    Stotlar, S.C.

    1981-01-01

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

  20. Initiating events frequency determination

    International Nuclear Information System (INIS)

    Simic, Z.; Mikulicic, V.; Vukovic, I.

    2004-01-01

    The paper describes work performed for the Nuclear Power Station (NPS). Work is related to the periodic initiating events frequency update for the Probabilistic Safety Assessment (PSA). Data for all relevant NPS initiating events (IE) were reviewed. The main focus was on events occurring during most recent operating history (i.e., last four years). The final IE frequencies were estimated by incorporating both NPS experience and nuclear industry experience. Each event was categorized according to NPS individual plant examination (IPE) initiating events grouping approach. For the majority of the IE groups, few, or no events have occurred at the NPS. For those IE groups with few or no NPS events, the final estimate was made by means of a Bayesian update with general nuclear industry values. Exceptions are rare loss-of-coolant-accidents (LOCA) events, where evaluation of engineering aspects is used in order to determine frequency.(author)

  1. Hg(+) Frequency Standards

    Science.gov (United States)

    Prestage, John D.; Tjoelker, Robert L.; Maleki, Lute

    2000-01-01

    In this paper we review the development of Hg(+) microwave frequency standards for use in high reliability and continuous operation applications. In recent work we have demonstrated short-term frequency stability of 3 x 10(exp -14)/nu(sub tau) when a cryogenic oscillator of stability 2-3 x 10(exp 15) was used a the local oscillator. The trapped ion frequency standard employs a Hg-202 discharge lamp to optically pump the trapped Hg(+)-199 clock ions and a helium buffer gas to cool the ions to near room temperature. We describe a small Hg(+) ion trap based frequency standard with an extended linear ion trap (LITE) architecture which separates the optical state selection region from the clock resonance region. This separation allows the use of novel trap configurations in the resonance region since no optical pumping is carried out there. A method for measuring the size of an ion cloud inside a linear trap with a 12-rod trap is currently being investigated. At approx. 10(exp -12), the 2nd order Doppler shift for trapped mercury ion frequency standards is one of the largest frequency offsets and its measurement to the 1% level would represent an advance in insuring the very long-term stability of these standards to the 10(exp -14) or better level. Finally, we describe atomic clock comparison experiments that can probe for a time variation of the fine structure constant, alpha = e(exp 2)/2(pi)hc, at the level of 10(exp -20)/year as predicted in some Grand Unified String Theories.

  2. Dynamic Stark shift and alignment-to-orientation conversion

    International Nuclear Information System (INIS)

    Kuntz, Matthew C.; Hilborn, Robert C.; Spencer, Alison M.

    2002-01-01

    We have observed alignment-to-orientation conversion in the (5d6p) 1 P state of atomic barium due to the combined effects of a static Zeeman shift and a dynamic Stark shift associated with the electric field of a pulsed laser beam. The measurements yield a value for the frequency-dependent tensor polarizability of the state in reasonable agreement with a simple perturbation theory calculation. With a tunable laser producing the dynamic Stark shift, we can both enhance the magnitude of the effect by tuning close to a resonance and reverse the sign of the orientation by tuning above or below the resonance. This method of producing an oriented atomic state is quite general, and with easily available field strengths can produce large orientations

  3. Remote Access Unit for Optic-to-Wireless Conversion

    DEFF Research Database (Denmark)

    Chorchos, Łukasz; Rommel, Simon; Turkiewicz, J. P.

    . Growing demand for high speed wireless data transmission and new wireless standards like 5G force network operators to find new solutions for backhaul networks. Presently, to meet this need, attention of many researchers and top network vendors has been directed towards millimeter wave radio links....... Operation in the millimeter wave range brings new possibilities for a channel allocation as well as allows wider radio channels to be used. Moreover this frequency range is lighter licensed than regular GSM. This clearly shows a huge potential of millimeter waves for a high speed wireless data transmission...... was proposed and research projects like IPHOBAC-NG were founded. The aim of the mentioned project is to employ novel RAUs featuring opticto-wireless and wireless-to-optic conversion with a speeds of 1-10Gbit/s for broadband wireless access and up to 3Gbit/s for mobile backhaul. The RAU proposed in this paper...

  4. Ecosystem specific dose conversion factors for Aberg, Beberg and Ceberg

    International Nuclear Information System (INIS)

    Nordlinder, S.; Bergstroem, U.; Mathiasson, Lena

    1999-12-01

    The aim of this study was to calculate ecosystem specific dose conversion factors (EDFs) for three hypothetical sites, Aberg, Beberg and Ceberg, used in the safety analysis SR 97. The EDFs can, in combination with calculated releases of radionuclides from the geosphere, be used to illustrate relative differences in doses to the most exposed individual due to accidental leakage of radionuclides from a deep repository for spent nuclear fuel. Maps of the three sites were studied and subdivided into areas, which were characterised according to an earlier developed module system. For each of the identified modules, ecosystem transport and exposure model calculations were performed for release of 1 Bq per year during 10 000 years. 44 radionuclides contained within a deep repository for spent nuclear fuel were considered. A preliminary comparison of the EDFs for the three sites showed that the highest relative doses can be expected in Ceberg due to the high frequency of peat bog modules

  5. Josephson frequency meter for millimeter and submillimeter wavelengths

    International Nuclear Information System (INIS)

    Anischenko, S.E.; Larkin, S.Y.; Chaikovsky, V.I.

    1994-01-01

    Frequency measurements of electromagnetic oscillations of millimeter and submillimeter wavebands with frequency growth due to a number of reasons become more and more difficult. First, these frequencies are considered to be cutoff for semiconductor converting devices and one has to use optical measurement methods instead of traditional ones with frequency transfer. Second, resonance measurement methods are characterized by using relatively narrow bands and optical ones are limited in frequency and time resolution due to the limited range and velocity of movement of their mechanical elements as well as the efficiency of these optical techniques decreases with the increase of wavelength due to diffraction losses. That requires the apriori information on the radiation frequency band of the source involved. Method of measuring frequency of harmonic microwave signals in millimeter and submillimeter wavebands based on the ac Josephson effect in superconducting contacts is devoid of all the above drawbacks. This approach offers a number of major advantages over the more traditional measurement methods, that is the one based on frequency conversion, resonance and interferrometric techniques. It can be characterized by high potential accuracy, wide range of frequencies measured, prompt measurement and the opportunity to obtain panoramic display of the results as well as full automation of the measuring process

  6. Josephson frequency meter for millimeter and submillimeter wavelengths

    Energy Technology Data Exchange (ETDEWEB)

    Anischenko, S.E.; Larkin, S.Y.; Chaikovsky, V.I. [State Research Center, Kiev (Ukraine)] [and others

    1994-12-31

    Frequency measurements of electromagnetic oscillations of millimeter and submillimeter wavebands with frequency growth due to a number of reasons become more and more difficult. First, these frequencies are considered to be cutoff for semiconductor converting devices and one has to use optical measurement methods instead of traditional ones with frequency transfer. Second, resonance measurement methods are characterized by using relatively narrow bands and optical ones are limited in frequency and time resolution due to the limited range and velocity of movement of their mechanical elements as well as the efficiency of these optical techniques decreases with the increase of wavelength due to diffraction losses. That requires the apriori information on the radiation frequency band of the source involved. Method of measuring frequency of harmonic microwave signals in millimeter and submillimeter wavebands based on the ac Josephson effect in superconducting contacts is devoid of all the above drawbacks. This approach offers a number of major advantages over the more traditional measurement methods, that is the one based on frequency conversion, resonance and interferrometric techniques. It can be characterized by high potential accuracy, wide range of frequencies measured, prompt measurement and the opportunity to obtain panoramic display of the results as well as full automation of the measuring process.

  7. Environmental monitoring program design for uranium refining and conversion operations

    International Nuclear Information System (INIS)

    1984-08-01

    The objective of this study was to develop recommendations for the design of environmental monitoring programs at Canadian uranium refining and conversion operations. In order to develop monitoring priorities, chemical and radioactive releases to the air and water were developed for reference uranium refining and conversion facilities. The relative significance of the radioactive releases was evaluated through a pathways analysis which estimated dose to individual members of the critical receptor group. The effects of chemical releases to the environment were assessed by comparing predicted air and water contaminant levels to appropriate standards or guidelines. For the reference facilities studied, the analysis suggested that environmental effects are likely to be dominated by airborne release of both radioactive and nonradioactive contaminants. Uranium was found to be the most important radioactive species released to the air and can serve as an overall indicator of radiological impacts for any of the plants considered. The most important nonradioactive air emission was found to be fluoride (as hydrogen fluoride) from the uranium hexafluoride plant. For the uranium trioxide and uranium dioxide plants, air emissions of oxides of nitrogen were considered to be most important. The study recommendations for the design of an environmental monitoring program are based on consideration of those factors most likely to affect local air and water quality, and human radiation exposure. Site- and facility-specific factors will affect monitoring program design and the selection of components such as sampling media, locations and frequency, and analytical methods

  8. Hybrid acoustic energy harvesting using combined electromagnetic and piezoelectric conversion

    Science.gov (United States)

    Khan, Farid Ullah; Izhar

    2016-02-01

    This paper reports a novel hybrid acoustic energy harvester. The harvester utilizes both the electromagnetic and piezoelectric conversion mechanisms simultaneously to convert the ambient acoustical noise into electrical power for self-powered wireless sensor nodes. The proposed harvester is comprised of a Helmholtz resonator, two magnets mounted on a piezoelectric plate, and a wound coil located under the magnets. The harvester is characterized both under harmonic and real random acoustical excitations. In-lab, under harmonic acoustical excitation at a sound pressure level of 130 dB and frequency of 2.1 kHz, an optimum power of 2.86 μW (at 114 Ω optimum load) is obtained from electromagnetic conversion and 50 μW (at 1000 Ω optimum load) is generated by the piezoelectric harvester's part. Moreover, in real acoustical environment of a domestic electric generator the peak voltages of 40 and 123 mV are produced by the electromagnetic and piezoelectric portions of the acoustic energy harvester.

  9. Visible light to electrical energy conversion using photoelectrochemical cells

    Science.gov (United States)

    Wrighton, Mark S. (Inventor); Ellis, Arthur B. (Inventor); Kaiser, Steven W. (Inventor)

    1983-01-01

    Sustained conversion of low energy visible or near i.r. light (>1.25 eV) to electrical energy has been obtained using wet photoelectrochemical cells where there are no net chemical changes in the system. Stabilization of n-type semi-conductor anodes of CdS, CdSe, CdTe, GaP, GaAs and InP to photoanodic dissolution is achieved by employing selected alkaline solutions of Na.sub.2 S, Na.sub.2 S/S, Na.sub.2 Se, Na.sub.2 Se/Se, Na.sub.2 Te and Na.sub.2 Te/Te as the electrolyte. The oxidation of (poly) sulfide, (poly)selenide or (poly)telluride species occurs at the irradiated anode, and reduction of polysulfide, polyselenide or polytelluride species occurs at the dark Pt cathode of the photoelectrochemical cell. Optical to electrical energy conversion efficiencies approaching 15% at selected frequencies have been observed in some cells. The wavelength for the onset of photocurrent corresponds to the band gap of the particular anode material used in the cell.

  10. Graphical comparison of calculated internal conversion coefficients

    International Nuclear Information System (INIS)

    Ewbank, W.B.

    1980-11-01

    Calculated values of the coefficients of internal conversion of gamma rays in the K shell and L 1 , L 2 , L 3 subshells from published tabulations by Band and Trzhaskovskaya and by Roesel et al. at Data Nucl. Data Tables, 21, 92-514(1978) are compared with values obtained by computer interpolation among tabulated values of Hager and Seltzer Nucl. Data, A4, 1-235(1968). In some cases, agreement among the three calculations is remarkably good, and differences are generally less than 5%. In a few cases, there are differences as large as 20 to 50%, corresponding to the threshold effect described by Roesel et al. The Z-dependent resonance minimum described by Roesel et al. is also observed in the comparison of E1-E4 conversion in the L 1 subshell. In several cases (notably M1-M4 conversion in the K shell and L 1 subshell), the Band and Roesel calculations show dramatically different dependence on gamma energy and atomic number. For Z = 100, the Band calculation for E4 conversion in the L 3 subshell shows irregular behavior at energies below the K-shell binding energy. A few high-quality measurements of internal conversion coefficients (+-5%) would help greatly to establish a basis for choice among the theoretical calculations. 32 figures

  11. TFTR power conversion and plasma feedback systems

    International Nuclear Information System (INIS)

    Neumeyer, C.

    1985-01-01

    Major components of the Tokamak Fusion Test Reactor (TFTR) power conversion system include 39 thyristor rectifier power supplies, 12 energy storage capacitor banks, and 6 ohmic heating interrupters. These components are connected in various series/parallel configurations to provide controlled pulses of current to the Toroidal Field (TF), Ohmic Heating (OH), Equilibrium (vertical) Field (EF), and Horizontal Field (HF) magnet coil systems. Real-time control of the power conversion system is accomplished by a centralized dedicated computer; local control is minimal. Power supply firing angles, capacitor bank charge and discharge commands, interrupter commands, etc., are all determined and issued by the central computer. Plasma Position and Current Control (PPCC) reference signals to power conversion (OH, EF, HF) are determined by separate analog electronics but invoked through the power conversion computer. Real-time fault sensing of plasma parameters, gas injection, neutral beams, etc., are monitored by a separate Discharge Fault System (DFS) but routed through the power conversion computer for pre-programmed shutdown response

  12. Kinetics of Scheelite Conversion in Sulfuric Acid

    Science.gov (United States)

    Shen, Leiting; Li, Xiaobin; Zhou, Qiusheng; Peng, Zhihong; Liu, Guihua; Qi, Tiangui; Taskinen, Pekka

    2018-02-01

    Complete conversion of scheelite in H2SO4 solution plays a key role in exploration of cleaner technology for producing ammonium paratungstate. In this work, the factors influencing scheelite conversion were investigated experimentally to model its kinetics. The results indicated that the conversion rate increases with increasing temperature and reducing particle size, but is almost independent of stirring speed. Moreover, although the conversion rate increases with increasing initial H2SO4 concentration (≤ 1.25 mol/L), it decreases rapidly at 1.5 mol/L H2SO4 after 10 min due to formation of a H2WO4 layer. The experimental data agree quite well with the shrinking core model under chemical reaction control in ≤ 1.25 mol/L H2SO4 solution, and the kinetic equation was established as: 1- ( 1- α )^{ 1 / 3} = 2 2 2 5 4 6. 6\\cdot C_{{{H}_{ 2} {SO}_{ 4} }}^{ 1. 2 2 6} \\cdot r_{ 0}^{ - 1} \\cdot e^{{ - 3 9 2 6 0/RT}} \\cdot t (t, min). This work could contribute to better understanding of scheelite conversion in H2SO4 solution and development of a new route for ammonium paratungstate production.

  13. VIOLATION OF CONVERSATION MAXIM ON TV ADVERTISEMENTS

    Directory of Open Access Journals (Sweden)

    Desak Putu Eka Pratiwi

    2015-07-01

    Full Text Available Maxim is a principle that must be obeyed by all participants textually and interpersonally in order to have a smooth communication process. Conversation maxim is divided into four namely maxim of quality, maxim of quantity, maxim of relevance, and maxim of manner of speaking. Violation of the maxim may occur in a conversation in which the information the speaker has is not delivered well to his speaking partner. Violation of the maxim in a conversation will result in an awkward impression. The example of violation is the given information that is redundant, untrue, irrelevant, or convoluted. Advertisers often deliberately violate the maxim to create unique and controversial advertisements. This study aims to examine the violation of maxims in conversations of TV ads. The source of data in this research is food advertisements aired on TV media. Documentation and observation methods are applied to obtain qualitative data. The theory used in this study is a maxim theory proposed by Grice (1975. The results of the data analysis are presented with informal method. The results of this study show an interesting fact that the violation of maxim in a conversation found in the advertisement exactly makes the advertisements very attractive and have a high value.

  14. Abnormal parietal function in conversion paresis.

    Directory of Open Access Journals (Sweden)

    Marije van Beilen

    Full Text Available The etiology of medically unexplained symptoms such as conversion disorder is poorly understood. This is partly because the interpretation of neuroimaging results in conversion paresis has been complicated by the use of different control groups, tasks and statistical comparisons. The present study includes these different aspects in a single data set. In our study we included both normal controls and feigners to control for conversion paresis. We studied both movement execution and imagery, and we contrasted both within-group and between-group activation. Moreover, to reveal hemisphere-specific effects that have not been reported before, we performed these analyses using both flipped and unflipped data. This approach resulted in the identification of abnormal parietal activation which was specific for conversion paresis patients. Patients also showed reduced activity in the prefrontal cortex, supramarginal gyrus and precuneus, including hemisphere-specific activation that is lateralized in the same hemisphere, regardless of right- or left-sided paresis. We propose that these regions are candidates for an interface between psychological mechanisms and disturbed higher-order motor control. Our study presents an integrative neurophysiological view of the mechanisms that contribute to the etiology of this puzzling psychological disorder, which can be further investigated with other types of conversion symptoms.

  15. Study on carbon dioxide conversion by radiation

    International Nuclear Information System (INIS)

    Cho, Young Hyun; Park, Geun Il; Cho, Il Hoon; Choi, Sang Do; Hong, Kwang Hee; Lee, Chang Woo

    1999-09-01

    This study was carried out to investigate the synergistic effects on the CO 2 conversion by the application of semiconductor in the field of gamma-ray. Gamma-ray irradiation was performed to examine the effects of semiconductor application on CO 2 conversion in water and the formation of organic material from carbonate solution. From experimental results it is clear that the supplication of semiconductor in the field of gamma-ray increases the efficiency for CO 2 conversion to organic matter. Based on the obtained experimental results it is obvious that the synergistic effects of semiconductor materials in the gamma-ray field leads to increase of the CO 2 conversion yield to organic matter up to 50 percent compared to the gamma-ray irradiation. The way of achieving higher activity is due to the catalytic action of semiconductor by gamma-ray irradiation. Zr-doped TiO 2 catalyst prepared by sol-gel method exhibits the higher efficiency for CO 2 conversion in aqueous solution and carbonate containing solution. This effect of Zr-doping can be explained by the formation of additional defects in surface of TiO 2 film. (author)

  16. Response inhibition in motor conversion disorder.

    Science.gov (United States)

    Voon, Valerie; Ekanayake, Vindhya; Wiggs, Edythe; Kranick, Sarah; Ameli, Rezvan; Harrison, Neil A; Hallett, Mark

    2013-05-01

    Conversion disorders (CDs) are unexplained neurological symptoms presumed to be related to a psychological issue. Studies focusing on conversion paralysis have suggested potential impairments in motor initiation or execution. Here we studied CD patients with aberrant or excessive motor movements and focused on motor response inhibition. We also assessed cognitive measures in multiple domains. We compared 30 CD patients and 30 age-, sex-, and education-matched healthy volunteers on a motor response inhibition task (go/no go), along with verbal motor response inhibition (color-word interference) and measures of attention, sustained attention, processing speed, language, memory, visuospatial processing, and executive function including planning and verbal fluency. CD patients had greater impairments in commission errors on the go/no go task (P conversion. Patients with nonepileptic seizures, a different form of conversion disorder, are commonly reported to have lower IQ and multiple cognitive deficits. Our results point toward potential differences between conversion disorder subgroups. © 2013 Movement Disorder Society. Copyright © 2013 Movement Disorder Society.

  17. Conversion disorder: towards a neurobiological understanding

    Science.gov (United States)

    Harvey, Samuel B; Stanton, Biba R; David, Anthony S

    2006-01-01

    Conversion disorders are a common cause of neurological disability, but the diagnosis remains controversial and the mechanism by which psychological stress can result in physical symptoms “unconsciously” is poorly understood. This review summarises research examining conversion disorder from a neurobiological perspective. Early observations suggesting a role for hemispheric specialization have not been replicated consistently. Patients with sensory conversion symptoms have normal evoked responses in primary and secondary somatosensory cortex but a reduction in the P300 potential, which is thought to reflect a lack of conscious processing of sensory stimuli. The emergence of functional imaging has provided the greatest opportunity for understanding the neural basis of conversion symptoms. Studies have been limited by small patient numbers and failure to control for confounding variables. The evidence available would suggest a broad hypothesis that frontal cortical and limbic activation associated with emotional stress may act via inhibitory basal ganglia–thalamocortical circuits to produce a deficit of conscious sensory or motor processing. The conceptual difficulties that have limited progress in this area are discussed. A better neuropsychiatric understanding of the mechanisms of conversion symptoms may improve our understanding of normal attention and volition and reduce the controversy surrounding this diagnosis. PMID:19412442

  18. Advanced conversion technology review panel report

    International Nuclear Information System (INIS)

    Frazier, T.A.

    1998-01-01

    The Department of Energy (DOE), the National Aeronautics and Space Administration (NASA) and the Jet Propulsion Laboratory (JPL) established a DOE lead management team and an Advanced Conversion Technology Review Panel. The panel was tasked with providing the management team with an assessment and ranking of the three advanced conversion technologies. The three advanced conversion technologies were alkali metal thermal to electric converter (AMTEC), Stirling engine converter (SEC), and thermophotovoltaic (TPV). To rate and rank these three technologies, five criteria were developed: (1) Performance, (2) Development and Cost/Production and Cost/Schedule Risk, (3) Spacecraft Interface and Operations, (4) Ability to Scale Conversion, and (5) Safety. Discussed are the relative importance of each of these criteria and the rankings of the three advanced conversion technologies. It was the conclusion of the panel that the technology decision should be based on the risk that DOE and NASA are willing to accept. SEC is the most mature technology and would provide the lowest risk option. However, if more risk is acceptable, AMTEC not only provides benefits in the spacecraft interface but is also predicted to outperform the SEC. It was proposed that if AMTEC were selected, funding should be provided at a reasonable level to support back-up technology to be developed in a parallel fashion until AMTEC has proven its capability. The panel report and conclusion were provided to DOE in February 1997

  19. Engineering the Frequency Spectrum of Bright Squeezed Vacuum via Group Velocity Dispersion in an SU(1,1) Interferometer

    OpenAIRE

    Lemieux, Samuel; Manceau, Mathieu; Sharapova, Polina R.; Tikhonova, Olga V.; Boyd, Robert W.; Leuchs, Gerd; Chekhova, Maria V.

    2016-01-01

    Bright squeezed vacuum, a promising tool for quantum information, can be generated by high-gain parametric down-conversion. However, its frequency and angular spectra are typically quite broad, which is undesirable for applications requiring single-mode radiation. We tailor the frequency spectrum of high-gain parametric down-conversion using an SU(1,1) interferometer consisting of two nonlinear crystals with a dispersive medium separating them. The dispersive medium allows us to select a narr...

  20. Observation of negative-frequency waves in a water tank: a classical analogue to the Hawking effect?

    Energy Technology Data Exchange (ETDEWEB)

    Rousseaux, Germain [ACRI, Laboratoire Genimar, 260 route du Pin Montard, BP 234, 06904 Sophia-Antipolis Cedex (France); Mathis, Christian; Maissa, Philippe [Universite de Nice-Sophia Antipolis, Laboratoire J-A Dieudonne, UMR CNRS-UNSA 6621, Parc Valrose, 06108 Nice Cedex 02 (France); Philbin, Thomas G; Leonhardt, Ulf [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS, Scotland (United Kingdom)], E-mail: ulf@st-andrews.ac.uk

    2008-05-15

    The conversion of positive-frequency waves into negative-frequency waves at the event horizon is the mechanism at the heart of the Hawking radiation of black holes. In black-hole analogues, horizons are formed for waves propagating in a medium against the current when and where the flow exceeds the wave velocity. We report on the first direct observation of negative-frequency waves converted from positive-frequency waves in a moving medium. The measured degree of mode conversion is significantly higher than that expected from the theory.