WorldWideScience

Sample records for upward frequency shift

  1. Species interactions slow warming-induced upward shifts of treelines on the Tibetan Plateau.

    Science.gov (United States)

    Liang, Eryuan; Wang, Yafeng; Piao, Shilong; Lu, Xiaoming; Camarero, Jesús Julio; Zhu, Haifeng; Zhu, Liping; Ellison, Aaron M; Ciais, Philippe; Peñuelas, Josep

    2016-04-19

    The alpine treeline is commonly regarded as being sensitive to climatic warming because regeneration and growth of trees at treeline generally are limited by low temperature. The alpine treelines of the Tibetan Plateau (TP) occur at the highest elevations (4,900 m above sea level) in the Northern Hemisphere. Ongoing climatic warming is expected to shift treelines upward. Studies of treeline dynamics at regional and local scales, however, have yielded conflicting results, indicating either unchanging treeline elevations or upward shifts. To reconcile this conflict, we reconstructed in detail a century of treeline structure and tree recruitment at sites along a climatic gradient of 4 °C and mean annual rainfall of 650 mm on the eastern TP. Species interactions interacted with effects of warming on treeline and could outweigh them. Densification of shrubs just above treeline inhibited tree establishment, and slowed upward movement of treelines on a time scale of decades. Interspecific interactions are major processes controlling treeline dynamics that may account for the absence of an upward shift at some TP treelines despite continued climatic warming.

  2. Species interactions slow warming-induced upward shifts of treelines on the Tibetan Plateau

    Science.gov (United States)

    Liang, Eryuan; Wang, Yafeng; Piao, Shilong; Lu, Xiaoming; Camarero, Jesús Julio; Zhu, Haifeng; Zhu, Liping; Ciais, Philippe; Peñuelas, Josep

    2016-01-01

    The alpine treeline is commonly regarded as being sensitive to climatic warming because regeneration and growth of trees at treeline generally are limited by low temperature. The alpine treelines of the Tibetan Plateau (TP) occur at the highest elevations (4,900 m above sea level) in the Northern Hemisphere. Ongoing climatic warming is expected to shift treelines upward. Studies of treeline dynamics at regional and local scales, however, have yielded conflicting results, indicating either unchanging treeline elevations or upward shifts. To reconcile this conflict, we reconstructed in detail a century of treeline structure and tree recruitment at sites along a climatic gradient of 4 °C and mean annual rainfall of 650 mm on the eastern TP. Species interactions interacted with effects of warming on treeline and could outweigh them. Densification of shrubs just above treeline inhibited tree establishment, and slowed upward movement of treelines on a time scale of decades. Interspecific interactions are major processes controlling treeline dynamics that may account for the absence of an upward shift at some TP treelines despite continued climatic warming. PMID:27044083

  3. Effects of intergroup upward comparison, trait self-esteem, and identity shift on state self-esteem and affect in upward comparison with in-group members

    OpenAIRE

    Isobe, Chikae; Ura, Mitsuhiro

    2006-01-01

    The present study investigated factors that protect people low in trait self-esteem (Low-SEs), who may be less skilled at constructing information in self-enhancing manners, from threats after interpersonal upward comparison with in-group members. We hypothesized that even Low-SEs can maintain their state self-esteem under intergroup upward comparison. Furthermore, this study explored the possibility that individuals used identity-shift, a strategy to maintain their personal identity, even in...

  4. Global change and upward shift of treeline in the Alps: genetic consequences of pastures colonization

    Directory of Open Access Journals (Sweden)

    Piotti A

    2007-01-01

    Full Text Available In the Alps global warming and change in land use, in particular the drastic reduction in cattle grazing, are causing a progressive treeline ecotone upwards shift. The colonization dynamics of woody species are modulated by high selective pressure on seedlings due to the extreme ecological conditions of this habitat. We studied the colonization dynamics of Norway spruce in a treeline plot, at the upper limit of the Paneveggio forest (Trentino, Italy. We have exhaustively sampled the study stand, collecting needle tissue from all the adults and the juveniles detected, and we have genotyped all the samples (376 with 4 SSR markers. Parentage relationships between the few adults presents in the stand (23 and the juveniles were established. Our results indicate that, in spite of extreme ecological condition of the treeline environment, local adaptations do not seem to favour local parents: only 4% of juveniles have both parents among local adult trees, while 96% of juveniles are completely or partially sired outside the sampling area. Assessing parentage relationship also allowed the estimation of relative reproductive success of local adult trees. Out of a total of 23 adult trees, 5 trees were involved in the 59% of successful reproductive events detected inside the sampling area.

  5. Upward Altitudinal Shifts in Habitat Suitability of Mountain Vipers since the Last Glacial Maximum.

    Directory of Open Access Journals (Sweden)

    Masoud Yousefi

    Full Text Available We determined the effects of past and future climate changes on the distribution of the Montivipera raddei species complex (MRC that contains rare and endangered viper species limited to Iran, Turkey and Armenia. We also investigated the current distribution of MRC to locate unidentified isolated populations as well as to evaluate the effectiveness of the current network of protected areas for their conservation. Present distribution of MRC was modeled based on ecological variables and model performance was evaluated by field visits. Some individuals at the newly identified populations showed uncommon morphological characteristics. The distribution map of MRC derived through modeling was then compared with the distribution of protected areas in the region. We estimated the effectiveness of the current protected area network to be 10%, which would be sufficient for conserving this group of species, provided adequate management policies and practices are employed. We further modeled the distribution of MRC in the past (21,000 years ago and under two scenarios in the future (to 2070. These models indicated that climatic changes probably have been responsible for an upward shift in suitable habitats of MRC since the Last Glacial Maximum, leading to isolation of allopatric populations. Distribution will probably become much more restricted in the future as a result of the current rate of global warming. We conclude that climate change most likely played a major role in determining the distribution pattern of MRC, restricting allopatric populations to mountaintops due to habitat alterations. This long-term isolation has facilitated unique local adaptations among MRC populations, which requires further investigation. The suitable habitat patches identified through modeling constitute optimized solutions for inclusion in the network of protected areas in the region.

  6. Hippocampal theta frequency shifts and operant behaviour

    NARCIS (Netherlands)

    Lopes da Silva, F.H.; Kamp, A.

    1. 1. A shift of hippocampal dominant theta frequency to 6 c/sec has been demonstrated in the post-reward period in two dogs, which occurs consistently related in time to a well defined behavioural pattern in the course of an operant conditioning paradigm. 2. 2. The frequency shift was detected and

  7. A rapid upward shift of a forest ecotone during 40 years of warming in the Green Mountains of Vermont.

    Science.gov (United States)

    Beckage, Brian; Osborne, Ben; Gavin, Daniel G; Pucko, Carolyn; Siccama, Thomas; Perkins, Timothy

    2008-03-18

    Detecting latitudinal range shifts of forest trees in response to recent climate change is difficult because of slow demographic rates and limited dispersal but may be facilitated by spatially compressed climatic zones along elevation gradients in montane environments. We resurveyed forest plots established in 1964 along elevation transects in the Green Mountains (Vermont) to examine whether a shift had occurred in the location of the northern hardwood-boreal forest ecotone (NBE) from 1964 to 2004. We found a 19% increase in dominance of northern hardwoods from 70% in 1964 to 89% in 2004 in the lower half of the NBE. This shift was driven by a decrease (up to 76%) in boreal and increase (up to 16%) in northern hardwood basal area within the lower portions of the ecotone. We used aerial photographs and satellite imagery to estimate a 91- to 119-m upslope shift in the upper limits of the NBE from 1962 to 2005. The upward shift is consistent with regional climatic change during the same period; interpolating climate data to the NBE showed a 1.1 degrees C increase in annual temperature, which would predict a 208-m upslope movement of the ecotone, along with a 34% increase in precipitation. The rapid upward movement of the NBE indicates little inertia to climatically induced range shifts in montane forests; the upslope shift may have been accelerated by high turnover in canopy trees that provided opportunities for ingrowth of lower elevation species. Our results indicate that high-elevation forests may be jeopardized by climate change sooner than anticipated.

  8. Upward Shift and Steepening of the Blood Pressure Response to Exercise in Hypertensive Subjects at High Altitude.

    Science.gov (United States)

    Caravita, Sergio; Faini, Andrea; Baratto, Claudia; Bilo, Grzegorz; Macarlupu, Josè Luis; Lang, Morin; Revera, Miriam; Lombardi, Carolina; Villafuerte, Francisco C; Agostoni, Piergiuseppe; Parati, Gianfranco

    2018-06-09

    Acute exposure to high-altitude hypobaric hypoxia induces a blood pressure rise in hypertensive humans, both at rest and during exercise. It is unclear whether this phenomenon reflects specific blood pressure hyperreactivity or rather an upward shift of blood pressure levels. We aimed at evaluating the extent and rate of blood pressure rise during exercise in hypertensive subjects acutely exposed to high altitude, and how these alterations can be counterbalanced by antihypertensive treatment. Fifty-five subjects with mild hypertension, double-blindly randomized to placebo or to a fixed-dose combination of an angiotensin-receptor blocker (telmisartan 80 mg) and a calcium-channel blocker (nifedipine slow release 30 mg), performed a cardiopulmonary exercise test at sea level and after the first night's stay at 3260 m altitude. High-altitude exposure caused both an 8 mm Hg upward shift ( P blood pressure/oxygen consumption relationship during exercise, independent of treatment. Telmisartan/nifedipine did not modify blood pressure reactivity to exercise (blood pressure/oxygen consumption slope), but downward shifted ( P blood pressure and oxygen consumption by 26 mm Hg, both at sea level and at altitude. Muscle oxygen delivery was not influenced by altitude exposure but was higher on telmisartan/nifedipine than on placebo ( P blood pressure response to exercise. The effect of the combination of telmisartan/nifedipine slow release outweighed these changes and was associated with better muscle oxygen delivery. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01830530. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  9. Hippocampal frequency shifts in different behavioural situations

    NARCIS (Netherlands)

    Kamp, A.; Lopes da Silva, F.H.; Storm van Leeuwen, W.

    1971-01-01

    Electrical activity of the dog's hippocampus was recorded in (a) an operant behaviour situation, and (b) a field situation by a radio-telemetering system. The dominant frequency of the theta rhythm shifted consistently from 4–5 c/sec to 6–7 c/sec when a dog (a) withdrew from a pedal after being

  10. Leapfrogging of tree species provenances? Interaction of microclimate and genetics on upward shifts in tree species' range limits

    Science.gov (United States)

    Reinhardt, K.; Castanha, C.; Germino, M. J.; Kueppers, L. M.

    2011-12-01

    The elevation limit of tree growth (alpine treeline) is considered to be constrained by environmental (i.e., thermal) and genetic (i.e., inability to adapt to climatic conditions) limitations to growth. Warming conditions due to climate change are predicted to cause upward shifts in the elevation of alpine treelines, through relief of cold-induced physiological limitations on seedling recruitment beyond current treeline boundaries. To determine how genetics and climate may interact to affect seedling establishment, we transplanted recently germinated seedlings from high- and low-elevation provenances (HI and LO, respectively) of Pinus flexilis in common gardens arrayed along an elevation and canopy gradient from subalpine forest into the alpine zone at Niwot Ridge, CO. We compared differences in microclimate and seedling ecophysiology among sites and between provenances. During the first summer of growth, frequently cloudy skies resulted in similar solar radiation incidence and air and soil temperatures among sites, despite nearly a 500 m-span in elevation across all sites. Preliminary findings suggest that survival of seedlings was similar between the lowest and highest elevations, with greater survival of LO (60%) compared to HI (40%) seedlings at each of these sites. Photosynthesis, carbon balance (photosynthesis/respiration), and conductance increased more than 2X with elevation for both provenances, and were 35-77% greater in LO seedlings compared to HI seedlings. There were no differences in dark-adapted chlorophyll fluorescence (Fv/Fm) among sites or between provenances. However, in a common-garden study at low elevation, we observed no differences in carbon or water relations between two naturally-germinated mitochondrial haplotypes of P. flexilis (of narrow and wide-ranging distributions). We did observe water-related thresholds on seedling carbon balance and survival that occurred when soil volumetric water content dropped below 10% and seedling water

  11. Frequency shifts in stimulated Raman scattering

    International Nuclear Information System (INIS)

    Zinth, W.; Kaiser, W.

    1980-01-01

    The nonresonant contributions to the nonlinear susceptibility chisup(()3) produce a frequency chirp during stimulated Raman scattering. In the case of transient stimulated Raman scattering, the spectrum of the generated Stokes pulse is found at higher frequencies than expected from spontaneous Raman data. The frequency difference can be calculated from the theory of stimulated Raman scattering. (orig.)

  12. Chirp investigation in EMLs towards frequency shift keying modulation

    DEFF Research Database (Denmark)

    Iglesias Olmedo, Miguel; Vegas Olmos, Juan José; Westergren, Urban

    2014-01-01

    This paper presents a chirp modeling and experimental results that support our vision of enabling frequency shift keying (FSK) exploiting the chirp effect in externally modulated lasers (EMLs).......This paper presents a chirp modeling and experimental results that support our vision of enabling frequency shift keying (FSK) exploiting the chirp effect in externally modulated lasers (EMLs)....

  13. Electro-optical frequency shifting of lasers for plasma diagnostics

    International Nuclear Information System (INIS)

    Forman, P.R.

    1977-07-01

    An electro-optical frequency shifting device is proposed as an aid for plasma physics heterodyne interferometry and heterodyne scattering experiments. The method has the advantage over other electro-optic shifters, that a pure separable frequency shifted beam can be obtained even when less than half wave voltage is applied. (orig.) [de

  14. Laser frequency stabilization and shifting by using modulation transfer spectroscopy

    Science.gov (United States)

    Cheng, Bing; Wang, Zhao-Ying; Wu, Bin; Xu, Ao-Peng; Wang, Qi-Yu; Xu, Yun-Fei; Lin, Qiang

    2014-10-01

    The stabilizing and shifting of laser frequency are very important for the interaction between the laser and atoms. The modulation transfer spectroscopy for the 87Rb atom with D2 line transition F = 2 → F' = 3 is used for stabilizing and shifting the frequency of the external cavity grating feedback diode laser. The resonant phase modulator with electro—optical effect is used to generate frequency sideband to lock the laser frequency. In the locking scheme, circularly polarized pump- and probe-beams are used. By optimizing the temperature of the vapor, the pump- and probe-beam intensity, the laser linewidth of 280 kHz is obtained. Furthermore, the magnetic field generated by a solenoid is added into the system. Therefore the system can achieve the frequency locking at any point in a range of hundreds of megahertz frequency shifting with very low power loss.

  15. Frequency Constrained ShiftCP Modeling of Neuroimaging Data

    DEFF Research Database (Denmark)

    Mørup, Morten; Hansen, Lars Kai; Madsen, Kristoffer H.

    2011-01-01

    The shift invariant multi-linear model based on the CandeComp/PARAFAC (CP) model denoted ShiftCP has proven useful for the modeling of latency changes in trial based neuroimaging data[17]. In order to facilitate component interpretation we presently extend the shiftCP model such that the extracted...... components can be constrained to pertain to predefined frequency ranges such as alpha, beta and gamma activity. To infer the number of components in the model we propose to apply automatic relevance determination by imposing priors that define the range of variation of each component of the shiftCP model...

  16. Lattice-induced nonadiabatic frequency shifts in optical lattice clocks

    International Nuclear Information System (INIS)

    Beloy, K.

    2010-01-01

    We consider the frequency shift in optical lattice clocks which arises from the coupling of the electronic motion to the atomic motion within the lattice. For the simplest of three-dimensional lattice geometries this coupling is shown to affect only clocks based on blue-detuned lattices. We have estimated the size of this shift for the prospective strontium lattice clock operating at the 390-nm blue-detuned magic wavelength. The resulting fractional frequency shift is found to be on the order of 10 -18 and is largely overshadowed by the electric quadrupole shift. For lattice clocks based on more complex geometries or other atomic systems, this shift could potentially be a limiting factor in clock accuracy.

  17. Nonlinear frequency shift of finite-amplitude electrostatic surface waves

    International Nuclear Information System (INIS)

    Stenflo, L.

    1989-01-01

    The problem concerning the appropriate form for the nonlinear frequency shift arising from slow density modulations of electrostatic surface waves in a semi-infinite unmagnetized plasma is reconsidered. The spatial dependence of the wave amplitude normal to the surface is kept general in order to allow for possible nonlinear attenuation behaviour of the surface waves. It is found that if the frequency shift is expressed as a function of the density and its gradient then the result is identical with that of Zhelyazkov, I. Proceedings International Conference on Plasma Physics, Kiev, 1987, Vol. 2, p. 694, who assumed a linear exponential attenuation behaviour. (author)

  18. Modified Pippard relationship describing the Raman frequency shifts ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. We relate in this study the thermal expansivity, αP, to the Raman frequency shift (1/ν)(∂ν/∂P)T for the rotatory lattice (librational) mode in ammonia solid II near its melting point. We have used our calculated Raman frequencies of this mode for pressures of 3⋅65, 5⋅02 and 6⋅57 kbars for this crystalline system.

  19. Frequency-shift vs phase-shift characterization of in-liquid quartz crystal microbalance applications

    International Nuclear Information System (INIS)

    Montagut, Y. J.; Garcia, J. V.; Jimenez, Y.; Arnau, A.; March, C.; Montoya, A.

    2011-01-01

    The improvement of sensitivity in quartz crystal microbalance (QCM) applications has been addressed in the last decades by increasing the sensor fundamental frequency, following the increment of the frequency/mass sensitivity with the square of frequency predicted by Sauerbrey. However, this sensitivity improvement has not been completely transferred in terms of resolution. The decrease of frequency stability due to the increase of the phase noise, particularly in oscillators, made impossible to reach the expected resolution. A new concept of sensor characterization at constant frequency has been recently proposed. The validation of the new concept is presented in this work. An immunosensor application for the detection of a low molecular weight contaminant, the insecticide carbaryl, has been chosen for the validation. An, in principle, improved version of a balanced-bridge oscillator is validated for its use in liquids, and applied for the frequency shift characterization of the QCM immunosensor application. The classical frequency shift characterization is compared with the new phase-shift characterization concept and system proposed.

  20. Tapered amplifier laser with frequency-shifted feedback

    Directory of Open Access Journals (Sweden)

    A. Bayerle, S. Tzanova, P. Vlaar, B. Pasquiou, F. Schreck

    2016-10-01

    Full Text Available We present a frequency-shifted feedback (FSF laser based on a tapered amplifier. The laser operates as a coherent broadband source with up to 370GHz spectral width and 2.3us coherence time. If the FSF laser is seeded by a continuous-wave laser a frequency comb spanning the output spectrum appears in addition to the broadband emission. The laser has an output power of 280mW and a center wavelength of 780nm. The ease and flexibility of use of tapered amplifiers makes our FSF laser attractive for a wide range of applications, especially in metrology.

  1. Initial frequency shift of large amplitude plasma wave, 2

    International Nuclear Information System (INIS)

    Yamanaka, K.; Sugihara, R.; Ohsawa, Y.; Kamimura, T.

    1979-07-01

    A nonlinear complex frequency shift of the ion acoustic wave in the initial phase defined by 0 0 and ωsub(s)/k as long as ωsub(s) >> γsub( l), where phi 0 , ωsub(s), γsub( l) and t sub(c) are the initial value of the potential, the frequency of the wave, the linear Landau damping coefficient and the time for the first minimum of the amplitude oscillation, respectively. A simulation study is also carried out. The results confirm the validity of the theory. (author)

  2. Chemisorption-Induced Resonance Frequency Shift of a Microcantilever

    International Nuclear Information System (INIS)

    Zhang Ji-Qiao; Feng Xi-Qiao; Yu Shou-Wen; Huang Gan-Yun

    2012-01-01

    The autonomy and property of atoms/molecules adsorbed on the surface of a microcantilever can be probed by measuring its resonance frequency shift due to adsorption. The resonance frequency change of a cantilever induced by chemisorption is theoretically studied. Oxygen chemisorbed on the Si(100) surface is taken as a representative example. We demonstrate that the resonant response of the cantilever is mainly determined by the chemisorption-induced bending stiffness variation, which depends on the bond configurations formed by the adsorbed atoms and substrate atoms. This study is helpful for optimal design of microcantilever-based sensors for various applications. (condensed matter: structure, mechanical and thermal properties)

  3. Modeling of Doppler frequency shift in multipath radio channels

    Directory of Open Access Journals (Sweden)

    Penzin M.S.

    2016-06-01

    Full Text Available We discuss the modeling of propagation of a quasi-monochromatic radio signal, represented by a coherent pulse sequence, in a non-stationary multipath radio channel. In such a channel, signal propagation results in the observed frequency shift for each ray (Doppler effect. The modeling is based on the assumption that during propagation of a single pulse a channel can be considered stationary. A phase variation in the channel transfer function is shown to cause the observed frequency shift in the received signal. Thus, instead of measuring the Doppler frequency shift, we can measure the rate of variation in the mean phase of one pulse relative to another. The modeling is carried out within the framework of the method of normal waves. The method enables us to model the dynamics of the electromagnetic field at a given point with the required accuracy. The modeling reveals that a local change in ionospheric conditions more severely affects the rays whose reflection region is in the area where the changes occur.

  4. The perceptual enhancement of tones by frequency shifts.

    Science.gov (United States)

    Demany, Laurent; Carcagno, Samuele; Semal, Catherine

    2013-04-01

    In a chord of pure tones with a flat spectral profile, one tone can be perceptually enhanced relative to the other tones by the previous presentation of a slightly different chord. "Intensity enhancement" (IE) is obtained when the component tones of the two chords have the same frequencies, but in the first chord the target of enhancement is attenuated relative to the other tones. "Frequency enhancement" (FE) is obtained when both chords have a flat spectral profile, but the target of enhancement shifts in frequency from the first to the second chord. We report here an experiment in which IE and FE were measured using a task requiring the listener to indicate whether or not the second chord included a tone identical to a subsequent probe tone. The results showed that a global attenuation of the first chord relative to the second chord disrupted IE more than FE. This suggests that the mechanisms of IE and FE are not the same. In accordance with this suggestion, computations of the auditory excitation patterns produced by the chords indicate that the mechanism of IE is not sufficient to explain FE for small frequency shifts. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Center frequency shift and reduction of feedback in directly modulated external cavity lasers

    DEFF Research Database (Denmark)

    Schiellerup, G.; Pedersen, Rune Johan Skullerud; Olesen, H.

    1989-01-01

    It is shown experimentally and theoretically that a center frequency shift occurs when an external cavity laser is directly modulated. The shift can be observed even when the frequency deviation is small compared to the roundtrip frequency of the external cavity and can qualitatively be explained...... by a reduction in the effective feedback level due to modulation. The frequency shift was measured as a function of modulation frequency and current, and frequency shifts up to 350 MHz were observed...

  6. Frequency shifting approach towards textual transcription of heartbeat sounds.

    Science.gov (United States)

    Arvin, Farshad; Doraisamy, Shyamala; Safar Khorasani, Ehsan

    2011-10-04

    Auscultation is an approach for diagnosing many cardiovascular problems. Automatic analysis of heartbeat sounds and extraction of its audio features can assist physicians towards diagnosing diseases. Textual transcription allows recording a continuous heart sound stream using a text format which can be stored in very small memory in comparison with other audio formats. In addition, a text-based data allows applying indexing and searching techniques to access to the critical events. Hence, the transcribed heartbeat sounds provides useful information to monitor the behavior of a patient for the long duration of time. This paper proposes a frequency shifting method in order to improve the performance of the transcription. The main objective of this study is to transfer the heartbeat sounds to the music domain. The proposed technique is tested with 100 samples which were recorded from different heart diseases categories. The observed results show that, the proposed shifting method significantly improves the performance of the transcription.

  7. Frequency shifting approach towards textual transcription of heartbeat sounds

    Directory of Open Access Journals (Sweden)

    Safar Khorasani Ehsan

    2011-10-01

    Full Text Available Abstract Auscultation is an approach for diagnosing many cardiovascular problems. Automatic analysis of heartbeat sounds and extraction of its audio features can assist physicians towards diagnosing diseases. Textual transcription allows recording a continuous heart sound stream using a text format which can be stored in very small memory in comparison with other audio formats. In addition, a text-based data allows applying indexing and searching techniques to access to the critical events. Hence, the transcribed heartbeat sounds provides useful information to monitor the behavior of a patient for the long duration of time. This paper proposes a frequency shifting method in order to improve the performance of the transcription. The main objective of this study is to transfer the heartbeat sounds to the music domain. The proposed technique is tested with 100 samples which were recorded from different heart diseases categories. The observed results show that, the proposed shifting method significantly improves the performance of the transcription.

  8. Frequency-Shift Detectors Bind Binaural as Well as Monaural Frequency Representations

    Science.gov (United States)

    Carcagno, Samuele; Semal, Catherine; Demany, Laurent

    2011-01-01

    Previous psychophysical work provided evidence for the existence of automatic frequency-shift detectors (FSDs) that establish perceptual links between successive sounds. In this study, we investigated the characteristics of the FSDs with respect to the binaural system. Listeners were presented with sound sequences consisting of a chord of pure…

  9. Gravitational frequency shift effect in the solar system

    International Nuclear Information System (INIS)

    Sarmiento G, A.

    1983-01-01

    An extension of the Parameterized Post-Newtonian (PPN) formalism to third order in the expansion parameter m/r (where m = GM/c 2 denotes the mass of the source of the field and r the distance to its center) is used to derive analytical expressions accurate to the same order for the prediction of the experimental measurments of the frequency shift effect on electromagnetic signals travelling within the solar system. An experimental situation is considered for which it is seen that the consequences of including higher order terms are undetectable by present-day observations or experiments. Some deliberations on issues in the historic context in which the development of the relevant ideas took place is considered necessary to round this work out and is presented in an introductory section. (author)

  10. Initial frequency shift of large amplitude plasma wave

    International Nuclear Information System (INIS)

    Sugihara, Ryo; Yamanaka, Kaoru.

    1979-04-01

    A distribution function which is an exact solution to the collisionless Boltzmann equation is obtained in an expansion form in terms of the potential phi(x, t). A complex nonlinear frequency shift ωsub( n)(t) is obtained by use of the Poisson equation and the expansion. The theory is valid for arbitrary phi 0 and v sub(p) as long as ωsub(p) >> γsub( l), and in the initial phase defined by 0 0 , v sub(p), ωsub(p), γsub( l) and t sub(c) are the initial value of phi, the phase velocity, the Langmuir frequency, the linear Landau damping coefficient and the time for the first minimum of the amplitude oscillation. The ωsub( n)(0) does not vanish and Reωsub( n)(0)/γsub( l) > 1 holds even for e phi 0 /T 1 in the initial phase for v sub( p) > v sub( t). The theory reproduces main features of experimental results and that of simulations. (author)

  11. General phase-frequency shifting in the three-phase inductor-converter bridge

    International Nuclear Information System (INIS)

    Ehsani, M.; Kustom, R.L.; Fuja, R.E.; Barnard, T.J.

    1979-01-01

    A fundamental method of shifting phase frequency in the inductor-converter bridge (ICB) for the purpose of controlling the power in real time is presented. Transient switching sequences needed to implement phase-frequency shifting can be developed by the use of this method and the other five system constraints. Two of the constraints that have been expressed in equation form so far are presented. Finally, an alternative algorithm for computing the frequency shifting transient sequences in real time is suggested

  12. Electrostatics determine vibrational frequency shifts in hydrogen bonded complexes.

    Science.gov (United States)

    Dey, Arghya; Mondal, Sohidul Islam; Sen, Saumik; Ghosh, Debashree; Patwari, G Naresh

    2014-12-14

    The red-shifts in the acetylenic C-H stretching vibration of C-H∙∙∙X (X = O, N) hydrogen-bonded complexes increase with an increase in the basicity of the Lewis base. Analysis of various components of stabilization energy suggests that the observed red-shifts are correlated with the electrostatic component of the stabilization energy, while the dispersion modulates the stabilization energy.

  13. Urbanization causes shifts in species' trait state frequencies

    NARCIS (Netherlands)

    Knapp, S.; Kühn, I.; Wittig, R.; Ozinga, W.A.; Poschlod, P.; Klotz, S.

    2008-01-01

    Urbanization is one of the most extreme forms of land transformation. It is supposed to change the frequencies of species trait states in species assemblages.We hypothesize that the flora of urban and rural areas differs in the frequency of trait states and ask which traits enable a plant to cope

  14. Cancellation of collisional frequency shifts in optical lattice clocks with Rabi spectroscopy

    International Nuclear Information System (INIS)

    Lee, Sangkyung; Park, Chang Yong; Lee, Won-Kyu; Yu, Dai-Hyuk

    2016-01-01

    We analyze both the s- and p-wave collision induced frequency shifts and propose an over-π pulse scheme to cancel the shifts in optical lattice clocks interrogated by a Rabi pulse. The collisional frequency shifts are analytically solved as a function of the pulse area and the inhomogeneity of the Rabi frequencies. Experimentally measured collisional frequency shifts in an Yb optical lattice clock are in good agreement with the analytical calculations. Based on our analysis, the over-π pulse combined with a small inhomogeneity below 0.1 allows a fractional uncertainty on a level of 10 −18 in both Sr and Yb optical lattice clocks by canceling the collisional frequency shift. (paper)

  15. Scheme for efficient extraction of low-frequency signal beyond the quantum limit by frequency-shift detection.

    Science.gov (United States)

    Yang, R G; Zhang, J; Zhai, Z H; Zhai, S Q; Liu, K; Gao, J R

    2015-08-10

    Low-frequency (Hz~kHz) squeezing is very important in many schemes of quantum precision measurement. But it is more difficult than that at megahertz-frequency because of the introduction of laser low-frequency technical noise. In this paper, we propose a scheme to obtain a low-frequency signal beyond the quantum limit from the frequency comb in a non-degenerate frequency and degenerate polarization optical parametric amplifier (NOPA) operating below threshold with type I phase matching by frequency-shift detection. Low-frequency squeezing immune to laser technical noise is obtained by a detection system with a local beam of two-frequency intense laser. Furthermore, the low-frequency squeezing can be used for phase measurement in Mach-Zehnder interferometer, and the signal-to-noise ratio (SNR) can be enhanced greatly.

  16. Frequency shifts in spontaneous emission from two interacting atoms

    International Nuclear Information System (INIS)

    James, D.F.V.

    1993-01-01

    A model radiating system consisting of two atoms in close proximity is analyzed. This system demonstrates the influence of spatial coherence on the spectrum of the radiation field. Explicit expressions for the degree of coherence, the source spectrum, and the spectrum of the radiation field are derived. The results are discussed in terms of Wolf's work [Phys. Rev. Lett. 56, 1370 (1986)] on this effect, which can be considered in terms of a multiple-atom analog of the effects of radiation reaction on a single atom, i.e., spontaneous decay and the Lamb shift

  17. Detection performance improvement of FMCW radar using frequency shift

    NARCIS (Netherlands)

    Wu, Y.; Linnartz, J.P.M.G.

    2011-01-01

    Frequency modulated continuous wave (FMCW) radars have been widely used for measuring target range and speed. In this paper, we present a mathematical model that quantifies the system-level performance of FMCW radar systems. In FMCW radar, the target range is measured through measuring the beat

  18. Simulation of a programmed frequency shift near extraction from the Fermilab Booster

    International Nuclear Information System (INIS)

    Lucas, P.; Kerns, Q.

    1987-03-01

    The longitudinal phase space program ESME has been used to simulate the effects of a linear shift in RF frequency away from that appropriate for the accelerator guide field. This shift takes place in the new Booster low level RF and is used to position the particle bunches in Main Ring buckets in a reproducible fashion. Shifts in frequency are found to generate synchrotron oscillations; however, the simulations show that these can be reduced to acceptable levels by introduction of jumps in RF phase preceding the programmed frequency changes. Lowering the RF voltage near extraction from the Booster, a desirable operational feature, has also been investigated

  19. Frequency dependence of p-mode frequency shifts induced by magnetic activity in Kepler solar-like stars

    Science.gov (United States)

    Salabert, D.; Régulo, C.; Pérez Hernández, F.; García, R. A.

    2018-04-01

    The variations of the frequencies of the low-degree acoustic oscillations in the Sun induced by magnetic activity show a dependence on radial order. The frequency shifts are observed to increase towards higher-order modes to reach a maximum of about 0.8 μHz over the 11-yr solar cycle. A comparable frequency dependence is also measured in two other main sequence solar-like stars, the F-star HD 49933, and the young 1 Gyr-old solar analog KIC 10644253, although with different amplitudes of the shifts of about 2 μHz and 0.5 μHz, respectively. Our objective here is to extend this analysis to stars with different masses, metallicities, and evolutionary stages. From an initial set of 87 Kepler solar-like oscillating stars with known individual p-mode frequencies, we identify five stars showing frequency shifts that can be considered reliable using selection criteria based on Monte Carlo simulations and on the photospheric magnetic activity proxy Sph. The frequency dependence of the frequency shifts of four of these stars could be measured for the l = 0 and l = 1 modes individually. Given the quality of the data, the results could indicate that a physical source of perturbation different from that in the Sun is dominating in this sample of solar-like stars.

  20. Building a good initial model for full-waveform inversion using frequency shift filter

    Science.gov (United States)

    Wang, Guanchao; Wang, Shangxu; Yuan, Sanyi; Lian, Shijie

    2018-05-01

    Accurate initial model or available low-frequency data is an important factor in the success of full waveform inversion (FWI). The low-frequency helps determine the kinematical relevant components, low-wavenumber of the velocity model, which are in turn needed to avoid FWI trap in local minima or cycle-skipping. However, in the field, acquiring data that common point of low- and high-frequency signal, then utilize the high-frequency data to obtain the low-wavenumber velocity model. It is well known that the instantaneous amplitude envelope of a wavelet is invariant under frequency shift. This means that resolution is constant for a given frequency bandwidth, and independent of the actual values of the frequencies. Based on this property, we develop a frequency shift filter (FSF) to build the relationship between low- and high-frequency information with a constant frequency bandwidth. After that, we can use the high-frequency information to get a plausible recovery of the low-wavenumber velocity model. Numerical results using synthetic data from the Marmousi and layer model demonstrate that our proposed envelope misfit function based on the frequency shift filter can build an initial model with more accurate long-wavelength components, when low-frequency signals are absent in recorded data.

  1. The relative importance of fluid and kinetic frequency shifts of an electron plasma wave

    International Nuclear Information System (INIS)

    Winjum, B. J.; Fahlen, J.; Mori, W. B.

    2007-01-01

    The total nonlinear frequency shift of a plasma wave including both fluid and kinetic effects is estimated when the phase velocity of the wave is much less than the speed of light. Using a waterbag or fluid model, the nonlinear frequency shift due to harmonic generation is calculated for an arbitrary shift in the wavenumber. In the limit where the wavenumber does not shift, the result is in agreement with previously published work [R. L. Dewar and J. Lindl, Phys. Fluids 15, 820 (1972); T. P. Coffey, ibid. 14, 1402 (1971)]. This shift is compared to the kinetic shift of Morales and O'Neil [G. J. Morales and T. M. O'Neil, Phys. Rev. Lett. 28, 417 (1972)] for wave amplitudes and values of kλ D of interest to Raman backscatter of a laser driver in inertial confinement fusion

  2. The relative importance of fluid and kinetic frequency shifts of an electron plasma wave

    Science.gov (United States)

    Winjum, B. J.; Fahlen, J.; Mori, W. B.

    2007-10-01

    The total nonlinear frequency shift of a plasma wave including both fluid and kinetic effects is estimated when the phase velocity of the wave is much less than the speed of light. Using a waterbag or fluid model, the nonlinear frequency shift due to harmonic generation is calculated for an arbitrary shift in the wavenumber. In the limit where the wavenumber does not shift, the result is in agreement with previously published work [R. L. Dewar and J. Lindl, Phys. Fluids 15, 820 (1972); T. P. Coffey, Phys. Fluids 14, 1402 (1971)]. This shift is compared to the kinetic shift of Morales and O'Neil [G. J. Morales and T. M. O'Neil, Phys. Rev. Lett. 28, 417 (1972)] for wave amplitudes and values of kλD of interest to Raman backscatter of a laser driver in inertial confinement fusion.

  3. Molecular-level mechanisms of vibrational frequency shifts in a polar liquid.

    Science.gov (United States)

    Morales, Christine M; Thompson, Ward H

    2011-06-16

    A molecular-level analysis of the origins of the vibrational frequency shifts of the CN stretching mode in neat liquid acetonitrile is presented. The frequency shifts and infrared spectrum are calculated using a perturbation theory approach within a molecular dynamics simulation and are in good agreement with measured values reported in the literature. The resulting instantaneous frequency of each nitrile group is decomposed into the contributions from each molecule in the liquid and by interaction type. This provides a detailed picture of the mechanisms of frequency shifts, including the number of surrounding molecules that contribute to the shift, the relationship between their position and relative contribution, and the roles of electrostatic and van der Waals interactions. These results provide insight into what information is contained in infrared (IR) and Raman spectra about the environment of the probed vibrational mode. © 2011 American Chemical Society

  4. Multi-pulse frequency shifted (MPFS) multiple access modulation for ultra wideband

    Science.gov (United States)

    Nekoogar, Faranak [San Ramon, CA; Dowla, Farid U [Castro Valley, CA

    2012-01-24

    The multi-pulse frequency shifted technique uses mutually orthogonal short duration pulses o transmit and receive information in a UWB multiuser communication system. The multiuser system uses the same pulse shape with different frequencies for the reference and data for each user. Different users have a different pulse shape (mutually orthogonal to each other) and different transmit and reference frequencies. At the receiver, the reference pulse is frequency shifted to match the data pulse and a correlation scheme followed by a hard decision block detects the data.

  5. 3D measurement using combined Gray code and dual-frequency phase-shifting approach

    Science.gov (United States)

    Yu, Shuang; Zhang, Jing; Yu, Xiaoyang; Sun, Xiaoming; Wu, Haibin; Liu, Xin

    2018-04-01

    The combined Gray code and phase-shifting approach is a commonly used 3D measurement technique. In this technique, an error that equals integer multiples of the phase-shifted fringe period, i.e. period jump error, often exists in the absolute analog code, which can lead to gross measurement errors. To overcome this problem, the present paper proposes 3D measurement using a combined Gray code and dual-frequency phase-shifting approach. Based on 3D measurement using the combined Gray code and phase-shifting approach, one set of low-frequency phase-shifted fringe patterns with an odd-numbered multiple of the original phase-shifted fringe period is added. Thus, the absolute analog code measured value can be obtained by the combined Gray code and phase-shifting approach, and the low-frequency absolute analog code measured value can also be obtained by adding low-frequency phase-shifted fringe patterns. Then, the corrected absolute analog code measured value can be obtained by correcting the former by the latter, and the period jump errors can be eliminated, resulting in reliable analog code unwrapping. For the proposed approach, we established its measurement model, analyzed its measurement principle, expounded the mechanism of eliminating period jump errors by error analysis, and determined its applicable conditions. Theoretical analysis and experimental results show that the proposed approach can effectively eliminate period jump errors, reliably perform analog code unwrapping, and improve the measurement accuracy.

  6. Influence of Two Photon Absorption on Soliton Self-Frequency Shift

    DEFF Research Database (Denmark)

    Steffensen, Henrik; Rottwitt, Karsten; Jepsen, Peter Uhd

    2011-01-01

    The creation of mid-infrared supercontinua necessitates the use of soft-glass fibers. However, some materials, like chalcogenide, have a substantial two photon absorption. We introduce a model for soliton self-frequency shift that successfully includes this effect.......The creation of mid-infrared supercontinua necessitates the use of soft-glass fibers. However, some materials, like chalcogenide, have a substantial two photon absorption. We introduce a model for soliton self-frequency shift that successfully includes this effect....

  7. Frequency shift of the Bragg and Non-Bragg backscattering from periodic water wave

    Science.gov (United States)

    Wen, Biyang; Li, Ke

    2016-08-01

    Doppler effect is used to measure the relative speed of a moving target with respect to the radar, and is also used to interpret the frequency shift of the backscattering from the ocean wave according to the water-wave phase velocity. The widely known relationship between the Doppler shift and the water-wave phase velocity was deduced from the scattering measurements data collected from actual sea surface, and has not been verified under man-made conditions. Here we show that this ob- served frequency shift of the scattering data from the Bragg and Non-Bragg water wave is not the Doppler shift corresponding to the water-wave phase velocity as commonly believed, but is the water-wave frequency and its integral multiple frequency. The power spectrum of the backscatter from the periodic water wave consists of serials discrete peaks, which is equally spaced by water wave frequency. Only when the water-wave length is the integer multiples of the Bragg wave, and the radar range resolution is infinite, does the frequency shift of the backscattering mathematically equal the Doppler shift according to the water-wave phase velocity.

  8. Circular High-Q Resonating Isotropic Strain Sensors with Large Shift of Resonance Frequency under Stress

    Directory of Open Access Journals (Sweden)

    Hilmi Volkan Demir

    2009-11-01

    Full Text Available We present circular architecture bioimplant strain sensors that facilitate a strong resonance frequency shift with mechanical deformation. The clinical application area of these sensors is for in vivo assessment of bone fractures. Using a rectangular geometry, we obtain a resonance shift of 330 MHz for a single device and 170 MHz for its triplet configuration (with three side-by-side resonators on chip under an applied load of 3,920 N. Using the same device parameters with a circular isotropic architecture, we achieve a resonance frequency shift of 500 MHz for the single device and 260 MHz for its triplet configuration, demonstrating substantially increased sensitivity.

  9. DC space-charge induced frequency up-shift in a quasi-optical gyrotron

    International Nuclear Information System (INIS)

    Alberti, S.; Tran, M.Q.; Tran, T.M.

    1990-10-01

    Recent experiments on a 100GHz quasi-optical gyrotron have shown that for a large resonator set-up the observed frequency up-shift between the starting current and a current of 10A corresponds to a shift of 4-5 longitudinal modes. In this Letter it is shown that the interpretation of this frequency up-shift should involve the current dependent electron beam voltage depression in the beam tunnel and the interaction region for both the single-mode and multi-mode time evolution codes. (author) 7 refs., 5 figs., 1 tab

  10. Frequency Shifts of Micro and Nano Cantilever Beam Resonators Due to Added Masses

    KAUST Repository

    Bouchaala, Adam M.

    2016-03-21

    We present analytical and numerical techniques to accurately calculate the shifts in the natural frequencies of electrically actuated micro and nano (carbon nanotubes (CNTs)) cantilever beams implemented as resonant sensors for mass detection of biological entities, particularly Escherichia coli (E. coli) and prostate specific antigen (PSA) cells. The beams are modeled as Euler-Bernoulli beams, including the nonlinear electrostatic forces and the added biological cells, which are modeled as discrete point masses. The frequency shifts due to the added masses of the cells are calculated for the fundamental and higher-order modes of vibrations. Analytical expressions of the natural frequency shifts under a direct current (DC) voltage and an added mass have been developed using perturbation techniques and the Galerkin approximation. Numerical techniques are also used to calculate the frequency shifts and compared with the analytical technique. We found that a hybrid approach that relies on the analytical perturbation expression and the Galerkin procedure for calculating accurately the static behavior presents the most computationally efficient approach. We found that using higher-order modes of vibration of micro-electro-mechanical-system (MEMS) beams or miniaturizing the sizes of the beams to nanoscale leads to significant improved frequency shifts, and thus increased sensitivities. © 2016 by ASME.

  11. Local time distribution of the SSC-associated HF-Doppler frequency shifts

    International Nuclear Information System (INIS)

    Kikuchi, T.; Sugiuchi, H.; Ishimine, T.

    1985-01-01

    The HF-Doppler frequency shift observed at the storm's sudden commencement is composed of a frequency increase (+) and decrease (-), and classified into four types, SCF(+ -), SCF(- +), SCF(+) and SCF(-). Since the latter two types are special cases of the former two types, two different kinds of electrical field exist in the F region and cause the ExB drift motion of plasma. HUANG (1976) interpreted the frequency increase of SCF(+ -) as due to the westward induction electric field proportional to delta H/ delta t and the succeeding frequency decrease due to the eastward conduction electric field which produces ionospheric currents responsible for the magnetic increase on the ground. In spite of his success in interpreting the SCF(+ -), some other interpretations are needed for the explanation of the whole set of SCF's, particularly SCF(- +). Local time distributions of the SCF's are derived from 41 SCF's which are observed on the HF standard signal (JJY) as received in Okinawa (path length =1600 km) and Kokubunji (60 km). It is shown that the SCF(+ -) appears mainly during the day, whereas the SCF(- +) is observed during the night. The results indicate that the preliminary frequency shift (+) of SCF(+ -) and (-) of SCF(- +) is caused by a westward electric field in the dayside hemisphere, while by an eastward electric field in the nightside hemisphere. The main frequency shift (-) of SCF(+ -) and (+) of SCF(- +) is caused by the reversed electric field. Consequently, the preliminary frequency shift is caused by the dusk-to-dawn electric field, while the main frequency shift by the dawn-to-dusk electric field

  12. Local time distribution of the SSC-associated HF-Doppler frequency shifts

    Science.gov (United States)

    Kikuchi, T.; Sugiuchi, H.; Ishimine, T.

    1985-01-01

    The HF-Doppler frequency shift observed at the storm's sudden commencement is composed of a frequency increase (+) and decrease (-), and classified into four types, SCF(+ -), SCF(- +), SCF(+) and SCF(-). Since the latter two types are special cases of the former two types, two different kinds of electrical field exist in the F region and cause the ExB drift motion of plasma. HUANG (1976) interpreted the frequency increase of SCF(+ -) as due to the westward induction electric field proportional to delta H/ delta t and the succeeding frequency decrease due to the eastward conduction electric field which produces ionospheric currents responsible for the magnetic increase on the ground. In spite of his success in interpreting the SCF(+ -), some other interpretations are needed for the explanation of the whole set of SCF's, particularly SCF(- +). Local time distributions of the SCF's are derived from 41 SCF's which are observed on the HF standard signal (JJY) as received in Okinawa (path length =1600 km) and Kokubunji (60 km). It is shown that the SCF(+ -) appears mainly during the day, whereas the SCF(- +) is observed during the night. The results indicate that the preliminary frequency shift (+) of SCF(+ -) and (-) of SCF(- +) is caused by a westward electric field in the dayside hemisphere, while by an eastward electric field in the nightside hemisphere. The main frequency shift (-) of SCF(+ -) and (+) of SCF(- +) is caused by the reversed electric field. Consequently, the preliminary frequency shift is caused by the dusk-to-dawn electric field, while the main frequency shift by the dawn-to-dusk electric field.

  13. Multiple soliton self-frequency shift cancellations in a temporally tailored photonic crystal fiber

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lai; Kang, Zhe; Li, Qing; Gao, Xuejian; Qin, Guanshi, E-mail: qings@jlu.edu.cn, E-mail: wpqin@jlu.edu.cn; Qin, Weiping, E-mail: qings@jlu.edu.cn, E-mail: wpqin@jlu.edu.cn [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Liao, Meisong; Hu, Lili [Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Ohishi, Yasutake [Research Center for Advanced Photon Technology, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511 (Japan)

    2014-11-03

    We report the generation of multiple soliton self-frequency shift cancellations in a temporally tailored tellurite photonic crystal fiber (PCF). The temporally regulated group velocity dispersion (GVD) is generated in the fiber by soliton induced optical Kerr effect. Two red-shifted dispersive waves spring up when two Raman solitons meet their own second zero-dispersion-wavelengths in the PCF. These results show how, through temporally tailored GVD, nonlinearities can be harnessed to generate unexpected effects.

  14. Frequency shifting at fiber-optical event horizons: The effect of Raman deceleration

    International Nuclear Information System (INIS)

    Robertson, S.; Leonhardt, U.

    2010-01-01

    Pulses in fibers establish analogs of the event horizon [Philbin et al., Science 319, 1367 (2008)]. At a group-velocity horizon, the frequency of a probe wave is shifted. We present a theoretical model of this frequency shifting, taking into account the deceleration of the pulse caused by the Raman effect. The theory shows that the probe-wave spectrum is sensitive to details of the probe-pulse interaction. Our results indicate an additional loss mechanism in the experiment [Philbin et al., Science 319, 1367 (2008)] that has not been accounted for. Our analysis is also valid for more general cases of the interaction of dispersive waves with decelerated solitons.

  15. Frequency-Shift a way to Reduce Aliasing in the Complex Cepstrum

    DEFF Research Database (Denmark)

    Bysted, Tommy Kristensen

    1998-01-01

    The well-known relation between a time signal and its frequency-shifted spectrum is introduced as an excellent tool for reduction of aliasing in the complex cepstrum. Using N points DFTs the frequency-shift property, when used in the right way, will reduce the aliasing error to a size which...... on average is identical to the one normally requiring 2N points DFTs. The cost is an insignificant increase in the number of operations compared to the total number needed for the transformation to the complex cepstrum domain...

  16. A New High Frequency Injection Method Based on Duty Cycle Shifting without Maximum Voltage Magnitude Loss

    DEFF Research Database (Denmark)

    Wang, Dong; Lu, Kaiyuan; Rasmussen, Peter Omand

    2015-01-01

    The conventional high frequency signal injection method is to superimpose a high frequency voltage signal to the commanded stator voltage before space vector modulation. Therefore, the magnitude of the voltage used for machine torque production is limited. In this paper, a new high frequency...... amplitude. This may be utilized to develop new position estimation algorithm without involving the inductance in the medium to high speed range. As an application example, a developed inductance independent position estimation algorithm using the proposed high frequency injection method is applied to drive...... injection method, in which high frequency signal is generated by shifting the duty cycle between two neighboring switching periods, is proposed. This method allows injecting a high frequency signal at half of the switching frequency without the necessity to sacrifice the machine fundamental voltage...

  17. Experimental investigation on electron cyclotron absorption at down-shifted frequency in the PLT tokamak

    International Nuclear Information System (INIS)

    Mazzucato, E.; Fidone, I.; Cavallo, A.; von Goeler, S.; Hsuan, H.

    1986-05-01

    The absorption of 60 GHz electron cyclotron waves, with the extraordinary mode and an oblique angle of propagation, has been investigated in the PLT tokamak in the regime of down-shifted frequencies. The production of energetic electrons, with energies of up to 300 to 400 keV, peaks at values of toroidal field (approx. =29 kG) for which the wave frequency is significantly smaller than the electron cyclotron frequency in the whole plasma region. The observations are consistent with the predictions of the relativistic theory of electron cyclotron damping at down-shifted frequency. Existing rf sources make this process a viable method for assisting the current ramp-up, and for heating the plasma of present large tokamaks

  18. Influence of two-photon absorption on soliton self-frequency shift

    DEFF Research Database (Denmark)

    Steffensen, Henrik; Agger, Christian; Bang, Ole

    2012-01-01

    In this paper we develop an analytical model for the soliton self-frequency shift, which includes second- and thirdorder dispersion, self-steepening, the full Raman term, and, for the first time to our best knowledge, the effect of two-photon absorption (TPA). We show that TPA can have a signific...

  19. Probe-controlled soliton frequency shift in the regime of optical event horizon

    DEFF Research Database (Denmark)

    Gu, Jie; Guo, Hairun; Wang, Shaofei

    2015-01-01

    In optical analogy of the event horizon, temporal pulse collision and mutual interactions are mainly between an intense solitary wave (soliton) and a dispersive probe wave. In such a regime, here we numerically investigate the probe-controlled soliton frequency shift as well as the soliton self...

  20. A Note on the Role of Mean Flows in Doppler-Shifted Frequencies

    NARCIS (Netherlands)

    Gerkema, T.; Maas, L.R.M.; van Haren, H.

    2013-01-01

    The purpose of this paper is to resolve a confusion that may arise from two quite distinct definitions of "Doppler shifts": both are used in the oceanographic literature but they are sometimes conflated. One refers to the difference in frequencies measured by two observers, one at a fixed position

  1. Apparatus for measuring speed through the Doppler frequency shift of sound

    Science.gov (United States)

    Schier, Walter

    2011-04-01

    The Doppler frequency shift of sound apparatus is based on a one meter diameter rotary table with a "button" speaker at its outer edge. A semicircular waveguide encloses half the periphery and has a microphone pickup on its wall at the midpoint. The tangential speed of the button speaker can be determined two ways for comparison. One method calculates speed from the frequency shift of sound, the other uses the repeat sound pattern. Agreement to one percent is possible at speeds of about 25 mph. In the lab the microphone output is fed successively to pairs of students at ten computer stations. Students must also perform an exercise in their lab report that introduces them to the red shifted wavelengths of receding galaxies at determined distances from the earth thus introducing them to Hubble's law, the concept of the "Big Bang", and their estimate of the age of the universe.

  2. Black-body radiation effects and light shifts in atomic frequency standards

    Energy Technology Data Exchange (ETDEWEB)

    Pal' chikov, V G; Domnin, Yu S; Novoselov, A V [Institute of Metrology for Time and Space at National Research Institute for Physical-Technical and Radiotechnical Measurements - IMVP GP VNIIFTRI, Mendeleevo, Moscow Region, 141570 (Russian Federation)

    2003-04-01

    A general method is presented for calculating the higher-order terms of series in powers of the black-body radiation field for the Stark-state wavefunctions, dipole transition matrix elements and corresponding frequency shifts of hyperfine splitting in the ground states for Cs and Rb atoms. A numerical method for calculating the light shifts in Sr atoms is described. It is based on the Green function method for summation over all intermediate states and exact Dirac-Fock wavefunctions for the resonant transitions to the first excited s-, p- and d-states. By comparing the calculated Stark shift with results of measurements employing atomic frequency standards, the black-body radiation effects on the ground state are analysed.

  3. From frequency to time-average-frequency a paradigm shift in the design of electronic system

    CERN Document Server

    Xiu, Liming

    2015-01-01

    Written in a simple, easy to understand style, this book will teach PLL users how to use new clock technology in their work in order to create innovative applications.       Investigates the clock frequency concept from a different perspective--at an application level       Teaches engineers to use this new clocking technology to create innovations in chip/system level, through real examples extracted from commercial products  

  4. The resonance frequency shift characteristic of Terfenol-D rods for magnetostrictive actuators

    International Nuclear Information System (INIS)

    Jin, Ke; Kou, Yong; Zheng, Xiaojing

    2012-01-01

    This paper focuses on the resonance frequency shift characteristic of Terfenol-D rods for magnetostrictive actuators. A 3D nonlinear dynamic model to describe the magneto-thermo-elastic coupling behavior of actuators is proposed based on a nonlinear constitutive model. The coupled interactions among stress- and magnetic-field-dependent variables for actuators are solved iteratively using the finite element method. The model simulations show a good correlation with the experimental data, which demonstrates that this model can capture the coupled resonance frequency shift features for magnetostrictive actuators well. Moreover, a comprehensive description for temperature, pre-stress and bias field dependences of resonance frequency is discussed in detail. These essential and important investigations will be of significant benefit to both theoretical research and the applications of magnetostrictive materials in smart or intelligent structures and systems. (paper)

  5. Motional frequency shifts of trapped ions in the Lamb-Dicke regime

    International Nuclear Information System (INIS)

    Lizuain, I.; Muga, J. G.; Eschner, J.

    2007-01-01

    First order Doppler effects are usually ignored in laser driven trapped ions when the recoil frequency is much smaller than the trapping frequency (Lamb-Dicke regime). This means that the central, carrier excitation band is supposed to be unaffected by vibronic transitions in which the vibrational number changes. While this is strictly true in the Lamb-Dicke limit (infinitely tight confinement), the vibronic transitions do play a role in the Lamb-Dicke regime. In this paper we quantify the asymptotic behavior of their effect with respect to the Lamb-Dicke parameter. In particular, we give analytical expressions for the frequency shift, 'pulling' or 'pushing', produced in the carrier absorption band by the vibronic transitions both for Rabi and Ramsey schemes. This shift is shown to be independent of the initial vibrational state

  6. Frequency shift and hysteresis suppression in contact-mode AFM using contact stiffness modulation

    Directory of Open Access Journals (Sweden)

    Belhaq M.

    2012-07-01

    Full Text Available In this paper the frequency response shift and hysteresis suppression of contact-mode atomic force microscopy is investigated using parametric modulation of the contact stiffness. Based on the Hertzian contact theory, a lumped single degree of freedom oscillator is considered for modeling the cantilever dynamics contact-mode atomic force microscopy. We use the technique of direct partition of motion and the method of multiple scales to obtain, respectively, the slow dynamic and the corresponding slow flow of the system. As results, this study shows that the amplitude of the contact stiffness modulation has a significant effect on the frequency response. Specifically, increasing the amplitude of the stiffness modulation suppresses hysteresis, decreases the peak amplitude and produces shifts towards higher and lower frequencies.

  7. Enhanced statistical damage identification using frequency-shift information with tunable piezoelectric transducer circuitry

    International Nuclear Information System (INIS)

    Zhao, J; Tang, J; Wang, K W

    2008-01-01

    The frequency-shift-based damage detection method entertains advantages such as global detection capability and easy implementation, but also suffers from drawbacks that include low detection accuracy and sensitivity and the difficulty in identifying damage using a small number of measurable frequencies. Moreover, the damage detection/identification performance is inevitably affected by the uncertainty/variations in the baseline model. In this research, we investigate an enhanced statistical damage identification method using the tunable piezoelectric transducer circuitry. The tunable piezoelectric transducer circuitry can lead to much enriched information on frequency shift (before and after damage occurrence). The circuitry elements, meanwhile, can be directly and accurately measured and thus can be considered uncertainty-free. A statistical damage identification algorithm is formulated which can identify both the mean and variance of the elemental property change. Our analysis indicates that the integration of the tunable piezoelectric transducer circuitry can significantly enhance the robustness of the frequency-shift-based damage identification approach under uncertainty and noise

  8. Frequency domain phase retrieval of simultaneous multi-wavelength phase-shifting interferometry

    International Nuclear Information System (INIS)

    Yin, Zhenxing; Zhong, Liyun; Xu, Xiaofei; Zhang, Wangping; Lu, Xiaoxu; Tian, Jindong

    2016-01-01

    In simultaneous multi-wavelength phase-shifting interferometry, we propose a novel frequency domain phase retrieval (FDPR) algorithm. First, using only a one-time phase-shifting operation, a sequence of simultaneous multi-wavelength phase-shifting interferograms (SPSMWIs) are captured by a monochrome charge-coupled device. Second, by performing a Fourier transform for each pixel of SPSMWIs, the wrapped phases of each wavelength can be retrieved from the complex amplitude located in the spectral peak of each wavelength. Finally, the phase of the synthetic wavelength can be obtained by the subtraction between the wrapped phases of a single wavelength. In this study, the principle and the application condition of the proposed approach are discussed. Both the simulation and the experimental result demonstrate the simple and convenient performance of the proposed FDPR approach. (paper)

  9. The Coefficient of the Voltage Induced Frequency Shift Measurement on a Quartz Tuning Fork

    Directory of Open Access Journals (Sweden)

    Yubin Hou

    2014-11-01

    Full Text Available We have measured the coefficient of the voltage induced frequency shift (VIFS of a 32.768 KHz quartz tuning fork. Three vibration modes were studied: one prong oscillating, two prongs oscillating in the same direction, and two prongs oscillating in opposite directions. They all showed a parabolic dependence of the eigen-frequency shift on the bias voltage applied across the fork, due to the voltage-induced internal stress, which varies as the fork oscillates. The average coefficient of the VIFS effect is as low as several hundred nano-Hz per millivolt, implying that fast-response voltage-controlled oscillators and phase-locked loops with nano-Hz resolution can be built.

  10. Computer simulations on the nonlinear frequency shift and nonlinear modulation of ion-acoustic waves

    International Nuclear Information System (INIS)

    Ohsawa, Yukiharu; Kamimura, Tetsuo.

    1976-11-01

    The nonlinear behavior of ion-acoustic waves with rather short wave-length, k lambda sub(De) asymptotically equals 1, is investigated by computer sumulations. It is observed that the nonlinear frequency shift is negative and is proportional to square root of the initial wave amplitude when the amplitude is not too large. This proportionality breaks down and the frequency shift can become positive (for large Te/Ti), when (n tilde sub(i)/n 0 )sup(1/2)>0.25, where n tilde sub(i) is the ion density perturbation and n 0 the average plasma density. Nonlinear modulation of the wave-packet is clearly seen; however, modulational instability was not observed. The importance of the effects of trapped ions to these phenomena is emphasized. (auth.)

  11. Simultaneously measured signals in scanning probe microscopy with a needle sensor: frequency shift and tunneling current.

    Science.gov (United States)

    Morawski, Ireneusz; Voigtländer, Bert

    2010-03-01

    We present combined noncontact scanning force microscopy and tunneling current images of a platinum(111) surface obtained by means of a 1 MHz quartz needle sensor. The low-frequency circuit of the tunneling current was combined with a high-frequency signal of the quartz resonator enabling full electrical operation of the sensor. The frequency shift and the tunneling current were detected simultaneously, while the feedback control loop of the topography signal was fed using one of them. In both cases, the free signal that was not connected to the feedback loop reveals proportional-integral controller errorlike behavior, which is governed by the time derivative of the topography signal. A procedure is proposed for determining the mechanical oscillation amplitude by utilizing the tunneling current also including the average tip-sample work function.

  12. Nonlinear frequency shift of a coherent dust-acoustic wave in the presence of dust-acoustic turbulence

    International Nuclear Information System (INIS)

    Yi Sumin; Ryu, C.-M.; Yoon, Peter H.

    2003-01-01

    The nonlinear frequency shift of a low-frequency, coherent dust-acoustic wave in the presence of higher frequency dust-acoustic turbulence is investigated in the framework of weak turbulence theory. It is found that the frequency shift of the dust-acoustic wave in an unmagnetized dusty plasma is always positive irrespective of the propagation direction of the coherent wave. It is also found that turbulent waves propagating in the same direction as the coherent wave are shown to give rise to a much higher frequency shift than the opposite case. Finally, it is shown that the nonlinear frequency shift of a dust-acoustic wave is more pronounced than in the case of the customary ion-acoustic waves in fully ionized plasmas

  13. Frequency shifts of resonant modes of the Sun due to near-surface convective scattering

    Science.gov (United States)

    Bhattacharya, J.; Hanasoge, S. M.; Antia, H. M.

    Measurements of oscillation frequencies of the Sun and stars can provide important independent constraints on their internal structure and dynamics. Seismic models of these oscillations are used to connect structure and rotation of the star to its resonant frequencies, which are then compared with observations, the goal being that of minimizing the difference between the two. Even in the case of the Sun, for which structure models are highly tuned, observed frequencies show systematic deviations from modeled frequencies, a phenomenon referred to as the ``surface term.'' The dominant source of this systematic effect is thought to be vigorous near-surface convection, which is not well accounted for in both stellar modeling and mode-oscillation physics. Here we bring to bear the method of homogenization, applicable in the asymptotic limit of large wavelengths (in comparison to the correlation scale of convection), to characterize the effect of small-scale surface convection on resonant-mode frequencies in the Sun. We show that the full oscillation equations, in the presence of temporally stationary 3D flows, can be reduced to an effective ``quiet-Sun'' wave equation with altered sound speed, Brünt-Väisäla frequency, and Lamb frequency. We derive the modified equation and relations for the appropriate averaging of 3D flows and thermal quantities to obtain the properties of this effective medium. Using flows obtained from 3D numerical simulations of near-surface convection, we quantify their effect on solar oscillation frequencies and find that they are shifted systematically and substantially. We argue therefore that consistent interpretations of resonant frequencies must include modifications to the wave equation that effectively capture the impact of vigorous hydrodynamic convection.

  14. FREQUENCY SHIFTS OF RESONANT MODES OF THE SUN DUE TO NEAR-SURFACE CONVECTIVE SCATTERING

    International Nuclear Information System (INIS)

    Bhattacharya, J.; Hanasoge, S.; Antia, H. M.

    2015-01-01

    Measurements of oscillation frequencies of the Sun and stars can provide important independent constraints on their internal structure and dynamics. Seismic models of these oscillations are used to connect structure and rotation of the star to its resonant frequencies, which are then compared with observations, the goal being that of minimizing the difference between the two. Even in the case of the Sun, for which structure models are highly tuned, observed frequencies show systematic deviations from modeled frequencies, a phenomenon referred to as the “surface term.” The dominant source of this systematic effect is thought to be vigorous near-surface convection, which is not well accounted for in both stellar modeling and mode-oscillation physics. Here we bring to bear the method of homogenization, applicable in the asymptotic limit of large wavelengths (in comparison to the correlation scale of convection), to characterize the effect of small-scale surface convection on resonant-mode frequencies in the Sun. We show that the full oscillation equations, in the presence of temporally stationary three-dimensional (3D) flows, can be reduced to an effective “quiet-Sun” wave equation with altered sound speed, Brünt–Väisäla frequency, and Lamb frequency. We derive the modified equation and relations for the appropriate averaging of 3D flows and thermal quantities to obtain the properties of this effective medium. Using flows obtained from 3D numerical simulations of near-surface convection, we quantify their effect on solar oscillation frequencies and find that they are shifted systematically and substantially. We argue therefore that consistent interpretations of resonant frequencies must include modifications to the wave equation that effectively capture the impact of vigorous hydrodynamic convection

  15. Improved MIMO radar GMTI via cyclic-shift transmission of orthogonal frequency division signals

    Science.gov (United States)

    Li, Fuyou; He, Feng; Dong, Zhen; Wu, Manqing

    2018-05-01

    Minimum detectable velocity (MDV) and maximum detectable velocity are both important in ground moving target indication (GMTI) systems. Smaller MDV can be achieved by longer baseline via multiple-input multiple-output (MIMO) radar. Maximum detectable velocity is decided by blind velocities associated with carrier frequencies, and blind velocities can be mitigated by orthogonal frequency division signals. However, the scattering echoes from different carrier frequencies are independent, which is not good for improving MDV performance. An improved cyclic-shift transmission is applied in MIMO GMTI system in this paper. MDV performance is improved due to the longer baseline, and maximum detectable velocity performance is improved due to the mitigation of blind velocities via multiple carrier frequencies. The signal model for this mode is established, the principle of mitigating blind velocities with orthogonal frequency division signals is presented; the performance of different MIMO GMTI waveforms is analysed; and the performance of different array configurations is analysed. Simulation results by space-time-frequency adaptive processing proves that our proposed method is a valid way to improve GMTI performance.

  16. LOOP- SIMULATION OF THE AUTOMATIC FREQUENCY CONTROL SUBSYSTEM OF A DIFFERENTIAL MINIMUM SHIFT KEYING RECEIVER

    Science.gov (United States)

    Davarian, F.

    1994-01-01

    The LOOP computer program was written to simulate the Automatic Frequency Control (AFC) subsystem of a Differential Minimum Shift Keying (DMSK) receiver with a bit rate of 2400 baud. The AFC simulated by LOOP is a first order loop configuration with a first order R-C filter. NASA has been investigating the concept of mobile communications based on low-cost, low-power terminals linked via geostationary satellites. Studies have indicated that low bit rate transmission is suitable for this application, particularly from the frequency and power conservation point of view. A bit rate of 2400 BPS is attractive due to its applicability to the linear predictive coding of speech. Input to LOOP includes the following: 1) the initial frequency error; 2) the double-sided loop noise bandwidth; 3) the filter time constants; 4) the amount of intersymbol interference; and 5) the bit energy to noise spectral density. LOOP output includes: 1) the bit number and the frequency error of that bit; 2) the computed mean of the frequency error; and 3) the standard deviation of the frequency error. LOOP is written in MS SuperSoft FORTRAN 77 for interactive execution and has been implemented on an IBM PC operating under PC DOS with a memory requirement of approximately 40K of 8 bit bytes. This program was developed in 1986.

  17. Shifting of wrapped phase maps in the frequency domain using a rational number

    International Nuclear Information System (INIS)

    Gdeisat, Munther A; Abushakra, Ahmad; Qaddoura, Maen; Burton, David R; Lilley, Francis; Arevalillo-Herráez, Miguel

    2016-01-01

    The number of phase wraps in an image can be either reduced, or completely eliminated, by transforming the image into the frequency domain using a Fourier transform, and then shifting the spectrum towards the origin. After this, the spectrum is transformed back to the spatial domain using the inverse Fourier transform and finally the phase is extracted using the arctangent function. However, it is a common concern that the spectrum can be shifted only by an integer number, meaning that the phase wrap reduction is often not optimal. In this paper we propose an algorithm than enables the spectrum to be frequency shifted by a rational number. The principle of the proposed method is confirmed both by using an initial computer simulation and is subsequently validated experimentally on real fringe patterns. The technique may offer in some cases the prospects of removing the necessity for a phase unwrapping process altogether and/or speeding up the phase unwrapping process. This may be beneficial in terms of potential increases in signal recovery robustness and also for use in time-critical applications. (paper)

  18. Soliton self-frequency shift controlled by a weak seed laser in tellurite photonic crystal fibers.

    Science.gov (United States)

    Liu, Lai; Meng, Xiangwei; Yin, Feixiang; Liao, Meisong; Zhao, Dan; Qin, Guanshi; Ohishi, Yasutake; Qin, Weiping

    2013-08-01

    We report the first demonstration of soliton self-frequency shift (SSFS) controlled by a weak continuous-wave (CW) laser, from a tellurite photonic crystal fiber pumped by a 1560 nm femtosecond fiber laser. The control of SSFS is performed by the cross-gain modulation of the 1560 nm femtosecond laser. By varying the input power of the weak CW laser (1560 nm) from 0 to 1.17 mW, the soliton generated in the tellurite photonic crystal fiber blue shifts from 1935 to 1591 nm. The dependence of the soliton wavelength on the operation wavelength of the weak CW laser is also measured. The results show the CW laser with a wavelength tunable range of 1530-1592 nm can be used to control the SSFS generation.

  19. Proposed Sandia frequency shift for anti-islanding detection method based on artificial immune system

    Directory of Open Access Journals (Sweden)

    A.Y. Hatata

    2018-03-01

    Full Text Available Sandia frequency shift (SFS is one of the active anti-islanding detection methods that depend on frequency drift to detect an islanding condition for inverter-based distributed generation. The non-detection zone (NDZ of the SFS method depends to a great extent on its parameters. Improper adjusting of these parameters may result in failure of the method. This paper presents a proposed artificial immune system (AIS-based technique to obtain optimal parameters of SFS anti-islanding detection method. The immune system is highly distributed, highly adaptive, and self-organizing in nature, maintains a memory of past encounters, and has the ability to continually learn about new encounters. The proposed method generates less total harmonic distortion (THD than the conventional SFS, which results in faster island detection and better non-detection zone. The performance of the proposed method is derived analytically and simulated using Matlab/Simulink. Two case studies are used to verify the proposed method. The first case includes a photovoltaic (PV connected to grid and the second includes a wind turbine connected to grid. The deduced optimized parameter setting helps to achieve the “non-islanding inverter” as well as least potential adverse impact on power quality. Keywords: Anti-islanding detection, Sandia frequency shift (SFS, Non-detection zone (NDZ, Total harmonic distortion (THD, Artificial immune system (AIS, Clonal selection algorithm

  20. Cancelation of thermally induced frequency shifts in bimaterial cantilevers by nonlinear optomechanical interactions

    Energy Technology Data Exchange (ETDEWEB)

    Vy, Nguyen Duy, E-mail: nguyenduyvy@tdt.edu.vn [Theoretical Physics Research Group, Ton Duc Thang University, Ho Chi Minh City 756636 (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City 756636 (Viet Nam); Tri Dat, Le [Faculty of Physics and Engineering Physics, University of Science, Ho Chi Minh City 748355 (Viet Nam); Iida, Takuya [Department of Physical Science, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531 (Japan)

    2016-08-01

    Bimaterial cantilevers have recently been used in, for example, the calorimetric analysis with picowatt resolution in microscopic space based on state-of-the-art atomic force microscopes. However, thermally induced effects usually change physical properties of the cantilevers, such as the resonance frequency, which reduce the accuracy of the measurements. Here, we propose an approach to circumvent this problem that uses an optical microcavity formed between a metallic layer coated on the back of the cantilever and one coated at the end of an optical fiber irradiating the cantilever. In addition to increasing the sensitivity, the optical rigidity of this system diminishes the thermally induced frequency shift. For a coating thickness of several tens of nanometers, the input power is 5–10 μW. These values can be evaluated from parameters derived by directly irradiating the cantilever in the absence of the microcavity. The system has the potential of using the cantilever both as a thermometer without frequency shifting and as a sensor with nanometer-controlled accuracy.

  1. Origin of the frequency shift of Raman scattering in chalcogenide glasses

    DEFF Research Database (Denmark)

    Han, X.C.; Tao, H.Z.; Gong, L.J.

    2014-01-01

    of the shift is associated with the topological connectivity of global network and/or the local environment of structural units, (e.g., tetrahedral GeSe4). Here we show the compositional evolution of the main Raman scattering frequency in Ge(SxSe1−x)2 glasses, and then clarify its structural origin. We keep...... units such as GeS4 tetrahedra. The ab-initio calculations of normal Raman mode combined with group theory analysis provide insight into the structural evolution of chalcogenide glasses with varying composition....

  2. Accurate 3He polarimetry using the Rb Zeeman frequency shift due to the Rb-3He spin-exchange collisions

    International Nuclear Information System (INIS)

    Romalis, M.V.; Cates, G.D.

    1998-01-01

    We describe a method of 3 He polarimetry relying on the polarization-dependent frequency shift of the Rb Zeeman resonance. Our method is ideally suited for on-line measurements of the 3 He polarization produced by spin-exchange optical pumping. To calibrate the frequency shift we performed an accurate measurement of the imaginary part of the Rb- 3 He spin-exchange cross section in the temperature range typical for spin-exchange optical pumping of 3 He. We also present a detailed study of possible systematic errors in the frequency shift polarimetry. copyright 1998 The American Physical Society

  3. Investigation of the dynamic NMR frequency shift for Fe57 in FeBO3

    International Nuclear Information System (INIS)

    Bun'kov, Yu.M.; Punkkinen, M.; Yulinen, E.E.

    1978-01-01

    NMR of Fe 57 in FeBO 3 is investigated by pulsed magnetic resonance techniques in the 2 to 70 K temperature range. A dynamic NMR frequency shift is observed which is due to coupling between the NMR oscillations and the low-frequency AFMR mode, the magnitude of which only slightly exceeds the micro-inhomogeneous broadening of the NMR line caused by the spread of the value of hyperfine field at the nuclei. Under these conditions the nuclear spin system possesses a number of unusual properties. Thus, broadening of the magnetic resonance line is uniform, the magnitude of the homogeneous broadening depends on the angle of deviation of the nuclear magnetization from the equilibrium axis, and an echo signal is detected which is similar to the ''solid echo'' in substances with dipole broadening of the magnetic resonance line

  4. Frequency-Shifted Interferometry — A Versatile Fiber-Optic Sensing Technique

    Directory of Open Access Journals (Sweden)

    Fei Ye

    2014-06-01

    Full Text Available Fiber-optic sensing is a field that is developing at a fast pace. Novel fiber-optic sensor designs and sensing principles constantly open doors for new opportunities. In this paper, we review a fiber-optic sensing technique developed in our research group called frequency-shifted interferometry (FSI. This technique uses a continuous-wave light source, an optical frequency shifter, and a slow detector. We discuss the operation principles of several FSI implementations and show their applications in fiber length and dispersion measurement, locating weak reflections along a fiber link, fiber-optic sensor multiplexing, and high-sensitivity cavity ring-down measurement. Detailed analysis of FSI system parameters is also presented.

  5. Measurements of quadrupole frequency shift in the SPS at 26 GeV/c

    CERN Document Server

    Bohl, T; Shaposhnikova, E; Tückmantel, Joachim; CERN. Geneva. AB Department

    2008-01-01

    Measurements of the quadrupole frequency shift with intensity at 26 GeV/c using the peak detected signal were performed in the SPS from 1999 to monitor the evolution of the low-frequency longitudinal impedance [1]. While the large changes, first, due to the impedance reduction and then due to the re-installation of the MKE kickers,are easy to see, to observe small variations of impedance (as shielding or removal of a few kickers) much higher accuracy of measurements is required. This was difficult to achieve so far, mainly due to the insufficient reproducibility of the longitudinal parameters of the injected beam for different intensities as well as for different MDs. In this Note the important role of longitudinal emittance in addition to the bunch length is also revealed.

  6. Electric-field assisted spin torque nano-oscillator and binary frequency shift keying modulation

    Science.gov (United States)

    Zhang, Xiangli; Chen, Hao-Hsuan; Zhang, Zongzhi; Liu, Yaowen

    2018-04-01

    Electric-controlled magnetization precession introduces technologically relevant possibility for developing spin torque nano-oscillators (STNO) with potential applications in microwave emission. Using the perpendicularly magnetized magnetic tunnel junction (MTJ), we show that the magnetization oscillation frequency can be tuned by the co-action of electric field and spin polarized current. The dynamical phase diagram of MTJ-based STNO is analytically predicted through coordinate transformation from the laboratory frame to the rotation frame, by which the nonstationary out-of-plane magnetization precession process is therefore transformed into the stationary process in the rotation frame. Furthermore, using this STNO as a microwave source, we numerically demonstrate that the bit signal can be transmitted by a binary frequency shift keying (BFSK) modulation technique. The BFSK scheme shows good modulation features with no transient state.

  7. On the relation between activity-related frequency shifts and the sunspot distribution over the solar cycle 23

    Directory of Open Access Journals (Sweden)

    Santos Ângela R. G.

    2017-01-01

    Full Text Available The activity-related variations in the solar acoustic frequencies have been known for 30 years. However, the importance of the different contributions is still not well established. With this in mind, we developed an empirical model to estimate the spot-induced frequency shifts, which takes into account the sunspot properties, such as area and latitude. The comparison between the model frequency shifts obtained from the daily sunspot records and those observed suggests that the contribution from a stochastic component to the total frequency shifts is about 30%. The remaining 70% is related to a global, long-term variation. We also propose a new observable to investigate the short-and mid-term variations of the frequency shifts, which is insensitive to the long-term variations contained in the data. On the shortest time scales the variations in the frequency shifts are strongly correlated with the variations in the total area covered by sunspots. However, a significant loss of correlation is still found, which cannot be fully explained by ignoring the invisible side of the Sun when accounting for the total sunspot area. We also verify that the times when the frequency shifts and the sunspot areas do not vary in a similar way tend to coincide with the times of the maximum amplitude of the quasi-biennial variations found in the seismic data.

  8. Precision measurement of the 1S ground-state Lamb shift in atomic hydrogen and deuterium by frequency comparison

    International Nuclear Information System (INIS)

    Weitz, M.; Huber, A.; Schmidt-Kaler, F.; Leibfried, D.; Vassen, W.; Zimmermann, C.; Pachucki, K.; Haensch, T.W.; Julien, L.; Biraben, F.

    1995-01-01

    We have measured the hydrogen and deuterium 1S Lamb shift by direct optical frequency comparison of the 1S-2S and 2S-4S/4D two-photon transitions. Our result of 8172.874(60) MHz for the 1S Lamb shift in hydrogen is in agreement with the theoretical value of 8172.802(40) MHz. For the 1S Lamb shift in deuterium, we obtain a value of 8183.807(78) MHz, from which we derive a deuteron matter radium of 1.945(28) fm. The precision of our value for the 1S Lamb shift has surpassed that of radio frequency measurements of the 2S-2P Lamb shift. By comparison with a recent absolute measurement of the hydrogen 1S-2S transition frequency, we deduce a value for the Rydberg constant R ∞ =109 737.315 684 9(30) cm -1

  9. Frequency Shift of a Rotating Mass-Imbalance Immersed in an Acoustic Fluid

    International Nuclear Information System (INIS)

    Stephen R. Novascone; David M. Weinberg; Michael J. Anderson

    2005-01-01

    In this paper, we describe a physical mechanism that relates a measurable behavior of a vibrating device to the physical properties of a surrounding acoustic medium. The vibrating device under consideration is a rotating imbalance immersed in an unbounded acoustic fluid. It is assumed that the rotating imbalance is driven by an electromagnetic motor excited by a given DC voltage. If nonlinearities are ignored, the steady state operational frequency of such a device is determined by a balance between the applied electromagnetic and opposing frictional torque on the rotating imbalance. If nonlinearities are retained, it is shown that under certain circumstances, the surrounding acoustic medium exerts an additional time-averaged opposing torque on the rotating imbalance that reduces the operational frequency of the device. Consequently, the operational frequency of the device becomes linked to the physical properties of the surrounding medium. Analytical calculations showed that the radiative resistance of an acoustic fluid caused the opposing torque. The shift in frequency is proportional to the radiative resistance and the square of the rotating eccentricity, but inversely proportional the total transducer mass and the damping effect of the DC motor

  10. Time and frequency characteristics of temporary threshold shifts caused by pure tone exposures

    DEFF Research Database (Denmark)

    Ordoñez, Rodrigo Pizarro; Hammershøi, Dorte

    2011-01-01

    The time-frequency characteristics of Temporary Threshold Shifts (TTS) caused by pure tones were determined using the Békésy audiometric method with narrow-band noise of short duration as the probe stimuli. Two experiments were done using exposures of 3 min at 100 dB above threshold. In the first....... In the second experiment, the TTS recovery curve produced by a 1 kHz pure tone exposure was assessed at 1.5 kHz, at approximately 15 s intervals for the first 5 min and at regularly increasing intervals up to 45 min after the exposure. The results showed a maximum in the recovery around 2 min after the exposure....... The data gathered in these experiments were used to construct a mathematical model of TTS recovery. The model describes both the 1/2-octave shift and the 2 min bounce and it can be used in the comparison of temporary changes in auditory function, assessed at different times and frequencies....

  11. On the theory of frequency-shifted secondary emission of light-harvesting molecular systems

    International Nuclear Information System (INIS)

    Morozov, V.A.

    2001-01-01

    The expressions are obtained for the intensity of the frequency-shifted secondary emission of a chromophore playing the role of a reaction center in the simplest model three-chromophore molecular 'light-harvesting' antenna, which is constructed and oriented in space so that the incident photons coherently excite two of its chromophore pigments. The quantum-field formalism was used, which takes into account the generalized (quantum-electrodynamic) dipole-dipole, as well as radiative and nonradiative dissipative interactions between pigments and the reaction center of the antenna. The special features of the excitation spectrum of the Raman scattering line and the frequency-shifted fluorescence spectrum of the reaction center of the molecular antenna under study are discussed. A comparison of the expressions obtained for the excitation and fluorescence spectra and with the corresponding expressions obtained for a bichromophore molecular system, which differs from a three-chromophore antenna by the absence of one of the pigments, revealed the properties of the mechanism of action of light-harvesting molecular antennas that have not been found earlier. In particular, it is shown that 'the light-harvesting' caused by the collective dissipative interactions of pigments with the reaction center of the antenna can substantially exceed a sum of contributions from separate pigments

  12. An improved Q estimation approach: the weighted centroid frequency shift method

    Science.gov (United States)

    Li, Jingnan; Wang, Shangxu; Yang, Dengfeng; Dong, Chunhui; Tao, Yonghui; Zhou, Yatao

    2016-06-01

    Seismic wave propagation in subsurface media suffers from absorption, which can be quantified by the quality factor Q. Accurate estimation of the Q factor is of great importance for the resolution enhancement of seismic data, precise imaging and interpretation, and reservoir prediction and characterization. The centroid frequency shift method (CFS) is currently one of the most commonly used Q estimation methods. However, for seismic data that contain noise, the accuracy and stability of Q extracted using CFS depend on the choice of frequency band. In order to reduce the influence of frequency band choices and obtain Q with greater precision and robustness, we present an improved CFS Q measurement approach—the weighted CFS method (WCFS), which incorporates a Gaussian weighting coefficient into the calculation procedure of the conventional CFS. The basic idea is to enhance the proportion of advantageous frequencies in the amplitude spectrum and reduce the weight of disadvantageous frequencies. In this novel method, we first construct a Gauss function using the centroid frequency and variance of the reference wavelet. Then we employ it as the weighting coefficient for the amplitude spectrum of the original signal. Finally, the conventional CFS is adopted for the weighted amplitude spectrum to extract the Q factor. Numerical tests of noise-free synthetic data demonstrate that the WCFS is feasible and efficient, and produces more accurate results than the conventional CFS. Tests for noisy synthetic data indicate that the new method has better anti-noise capability than the CFS. The application to field vertical seismic profile (VSP) data further demonstrates its validity5.

  13. Shift in cytotype frequency and niche space in the invasive plant Centaurea maculosa.

    Science.gov (United States)

    Treier, Urs A; Broennimann, Olivier; Normand, Signe; Guisan, Antoine; Schaffner, Urs; Steinger, Thomas; Müller-Schärer, Heinz

    2009-05-01

    Polyploidy is often assumed to increase the spread and thus the success of alien plant species, but few empirical studies exist. We tested this hypothesis with Centaurea maculosa Lam., a species native to Europe and introduced into North America approximately 120 years ago where it became highly invasive. We analyzed the ploidy level of more than 2000 plants from 93 native and 48 invasive C. maculosa populations and found a pronounced shift in the relative frequency of diploid and tetraploid cytotypes. In Europe diploid populations occur in higher frequencies than tetraploids and only four populations had both cytotypes, while in North America diploid plants were found in only one mixed population and thus tetraploids clearly dominated. Our results showed a pronounced shift in the climatic niche between tetraploid populations in the native and introduced range toward drier climate in North America and a similar albeit smaller shift between diploids and tetraploids in the native range. The field data indicate that diploids have a predominately monocarpic life cycle, while tetraploids are often polycarpic. Additionally, the polycarpic life-form seems to be more prevalent among tetraploids in the introduced range than among tetraploids in the native range. Our study suggests that both ploidy types of C. maculosa were introduced into North America, but tetraploids became the dominant cytotype with invasion. We suggest that the invasive success of C. maculosa is partly due to preadaptation of the tetraploid cytotype in Europe to drier climate and possibly further adaptation to these conditions in the introduced range. The potential for earlier and longer seed production associated with the polycarpic life cycle constitutes an additional factor that may have led to the dominance of tetraploids over diploids in the introduced range.

  14. Analytic description of Raman-induced frequency shift in the case of non-soliton ultrashort pulses

    International Nuclear Information System (INIS)

    Bugay, Aleksandr N.; Khalyapin, Vyacheslav A.

    2017-01-01

    Raman-induced frequency shift of ultrashort pulses have been studied extensively for the soliton propagation regime. Here we derive explicit analytic expressions for the evolution of Raman-induced frequency shift in much less studied case of non-soliton ultrashort pulses. Pulse spectra may belong to any region of group velocity dispersion including zero group dispersion point. The analysis is based on the moment method. Obtained expressions fit well to the numerical solution of the nonlinear wave equation. - Highlights: • Explicit analytic formulas for the evolution of Raman-induced frequency shift are derived in the case of non-soliton pulses. • Dynamics of non-soliton ultrashort pulses in the cases of positive and zero group dispersion is considered. • The deceleration and the saturation of Raman-induced frequency shift are analyzed. • The calculation relies on the moment method and fit well to the numerical solution of the nonlinear wave equation.

  15. Analytic description of Raman-induced frequency shift in the case of non-soliton ultrashort pulses

    Energy Technology Data Exchange (ETDEWEB)

    Bugay, Aleksandr N., E-mail: bugay_aleksandr@mail.ru [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980, Dubna, Moscow Region (Russian Federation); Khalyapin, Vyacheslav A., E-mail: slavasxi@gmail.com [Immanuel Kant Baltic Federal University, Kaliningrad, 236041 (Russian Federation); Kaliningrad State Technical University, Kaliningrad, 236000 (Russian Federation)

    2017-01-30

    Raman-induced frequency shift of ultrashort pulses have been studied extensively for the soliton propagation regime. Here we derive explicit analytic expressions for the evolution of Raman-induced frequency shift in much less studied case of non-soliton ultrashort pulses. Pulse spectra may belong to any region of group velocity dispersion including zero group dispersion point. The analysis is based on the moment method. Obtained expressions fit well to the numerical solution of the nonlinear wave equation. - Highlights: • Explicit analytic formulas for the evolution of Raman-induced frequency shift are derived in the case of non-soliton pulses. • Dynamics of non-soliton ultrashort pulses in the cases of positive and zero group dispersion is considered. • The deceleration and the saturation of Raman-induced frequency shift are analyzed. • The calculation relies on the moment method and fit well to the numerical solution of the nonlinear wave equation.

  16. Correlations between the resonant frequency shifts and the thermodynamic quantities for the α-β transition in quartz

    Science.gov (United States)

    Lider, M. C.; Yurtseven, H.

    2018-05-01

    The resonant frequency shifts are related to the thermodynamic quantities (compressibility, order parameter and susceptibility) for the α-β transition in quartz. The experimental data for the resonant frequencies and the bulk modulus from the literature are used for those correlations. By calculating the order parameter from the mean field theory, correlation between the resonant frequencies of various modes and the order parameter is examined according to the quasi-harmonic phonon theory for the α-β transition in quartz. Also, correlation between the bulk modulus in relation to the resonant frequency shifts and the order parameter susceptibility is constructed for the α-β transition in this crystalline system.

  17. Frequency shift, damping, and tunneling current coupling with quartz tuning forks in noncontact atomic force microscopy

    Science.gov (United States)

    Nony, Laurent; Bocquet, Franck; Para, Franck; Loppacher, Christian

    2016-09-01

    A combined experimental and theoretical approach to the coupling between frequency-shift (Δ f ) , damping, and tunneling current (It) in combined noncontact atomic force microscopy/scanning tunneling microscopy using quartz tuning forks (QTF)-based probes is reported. When brought into oscillating tunneling conditions, the tip located at the QTF prong's end radiates an electromagnetic field which couples to the QTF prong motion via its piezoelectric tensor and loads its electrodes by induction. Our approach explains how those It-related effects ultimately modify the Δ f and the damping measurements. This paradigm to the origin of the coupling between It and the nc-AFM regular signals relies on both the intrinsic piezoelectric nature of the quartz constituting the QTF and its electrodes design.

  18. Nonlinear laser dynamics induced by frequency shifted optical feedback: application to vibration measurements.

    Science.gov (United States)

    Girardeau, Vadim; Goloni, Carolina; Jacquin, Olivier; Hugon, Olivier; Inglebert, Mehdi; Lacot, Eric

    2016-12-01

    In this article, we study the nonlinear dynamics of a laser subjected to frequency shifted optical reinjection coming back from a vibrating target. More specifically, we study the nonlinear dynamical coupling between the carrier and the vibration signal. The present work shows how the nonlinear amplification of the vibration spectrum is related to the strength of the carrier and how it must be compensated to obtain accurate (i.e., without bias) vibration measurements. The theoretical predictions, confirmed by numerical simulations, are in good agreement with the experimental data. The main motivation of this study is the understanding of the nonlinear response of a laser optical feedback imaging sensor for quantitative phase measurements of small vibrations in the case of strong optical feedback.

  19. Analysis of Weyl-affine theories of gravity in terms of the gravitational frequency shift effect

    International Nuclear Information System (INIS)

    Coley, A.A.; Sarmiento, G.A.

    1986-01-01

    A subclass of nonmetric theories of gravity, called Weyl-affine theories of gravity (WATGs), is analyzed by calculating their predictions for the gravitational frequency shift undergone by a wave signal in a planned solar probe. The analysis is carried out using a formalism in a spherically symmetric and static gravitational field. One of the advantages of the formalism is that any possible ''nonmetricity'' is contained in an arbitrary function, λ, of the Newtonian gravitational potential, U. The numerical results are calculated for a situation modeling a future experiment in the solar system. In the calculations, the metric components and the function, λ, are expanded up to third order in U. Within the limits of the gravitational redshift experiments performed to date, it is found that WATGs must coincide with their metric counterparts (i.e., λ is unity). It is hoped that the planned solar probe will test the nature of the theories under investigation to a higher degree of accuracy

  20. Probe-controlled soliton frequency shift in the regime of optical event horizon.

    Science.gov (United States)

    Gu, Jie; Guo, Hairun; Wang, Shaofei; Zeng, Xianglong

    2015-08-24

    In optical analogy of the event horizon, temporal pulse collision and mutual interactions are mainly between an intense solitary wave (soliton) and a dispersive probe wave. In such a regime, here we numerically investigate the probe-controlled soliton frequency shift as well as the soliton self-compression. In particular, in the dispersion landscape with multiple zero dispersion wavelengths, bi-directional soliton spectral tunneling effects is possible. Moreover, we propose a mid-infrared soliton self-compression to the generation of few-cycle ultrashort pulses, in a bulk of quadratic nonlinear crystals in contrast to optical fibers or cubic nonlinear media, which could contribute to the community with a simple and flexible method to experimental implementations.

  1. Residual stress measurement method in MEMS microbeams using frequency shift data

    International Nuclear Information System (INIS)

    Somà, Aurelio; Ballestra, Alberto

    2009-01-01

    The dynamical behaviour of a set of gold microbeams affected by residual stress has been studied. Experimental frequency shift curves were obtained by increasing the dc voltage applied to the specimens. Comparison with different analytical and numerical models has been carried out in order to identify both analytical and finite element models in the presence of residual stress. Residual strain and stress, due to the fabrication process, have been widely reported in the literature in both out-of-plane microcantilevers and clamped–clamped microbeams by using mainly the value of pull-in voltage and static deflection data. In the case of a microcantilever, an accurate modelling includes the effect of the initial curvature due to microfabrication. In double-clamped microbeams, a pre-load applied by tensile stress is considered. A good correspondence is pointed out between measurements and numerical models so that the residual stress effect can be evaluated for different geometrical configurations

  2. Bragg-Scattering Four-Wave Mixing in Nonlinear Fibers with Intracavity Frequency-Shifted Laser Pumps

    Directory of Open Access Journals (Sweden)

    Katarzyna Krupa

    2012-01-01

    Full Text Available We experimentally study four-wave mixing in highly nonlinear fibers using two independent and partially coherent laser pumps and a third coherent signal. We focus our attention on the Bragg-scattering frequency conversion. The two pumps were obtained by amplifying two Intracavity frequency-shifted feedback lasers working in a continuous wave regime.

  3. Intercomparison of Methods for Determination of Resonant Frequency Shift of a Microstrip Patch Antenna Loaded with Hevea Rubber Latex

    Directory of Open Access Journals (Sweden)

    Nor Zakiah Yahaya

    2014-01-01

    Full Text Available This paper presents an intercomparison between the finite element method, method of moment, and the variational method to determine the effect of moisture content on the resonant frequency shift of a microstrip patch loaded with wet material. The samples selected for this study were Hevea rubber latex with different percentages of moisture content from 35% to 85%. The results were compared with the measurement data in the frequency range between 1 GHz and 4 GHz. It was found that the finite element method is the most accurate among all the three computational techniques with 0.1 mean error when compared to the measured resonant frequency shift. A calibration equation was obtained to predict moisture content from the measured frequency shift with an accuracy of 2%.

  4. Evaluation of the CERN Super Proton Synchrotron longitudinal impedance from measurements of the quadrupole frequency shift

    Directory of Open Access Journals (Sweden)

    A. Lasheen

    2017-06-01

    Full Text Available Longitudinal instabilities are one of the main limitations in the CERN Super Proton Synchrotron (SPS to reach the beam parameters required for the High Luminosity LHC project. In preparation to the SPS upgrade, possible remedies are studied by performing macroparticle simulations using the machine impedance model obtained from electromagnetic simulations and measurements. To benchmark the impedance model, the results of simulations are compared with various beam measurements. In this study, the reactive part of the impedance was probed by measuring the quadrupole frequency shift with intensity, obtained from bunch length oscillations at mismatched injection into the SPS. This method was applied over many last years to follow up the evolution of the SPS impedance, injecting bunches with the same bunch length. A novel approach, giving significantly more information, consists in varying the injected bunch length. The comparison of these measurements with macroparticle simulations allowed us to test the existing model, identify some missing SPS impedance and to obtain its possible dependence on frequency.

  5. Measuring the spin polarization of alkali-metal atoms using nuclear magnetic resonance frequency shifts of noble gases

    Directory of Open Access Journals (Sweden)

    X. H. Liu

    2015-10-01

    Full Text Available We report a novel method of measuring the spin polarization of alkali-metal atoms by detecting the NMR frequency shifts of noble gases. We calculated the profile of 87Rb D1 line absorption cross sections. We then measured the absorption profile of the sample cell, from which we calculated the 87Rb number densities at different temperatures. Then we measured the frequency shifts resulted from the spin polarization of the 87Rb atoms and calculated its polarization degrees at different temperatures. The behavior of frequency shifts versus temperature in experiment was consistent with theoretical calculation, which may be used as compensative signal for the NMRG closed-loop control system.

  6. Analytical study of the frequency shifts of micro and nano clamped–clamped beam resonators due to an added mass

    KAUST Repository

    Bouchaala, Adam M.

    2016-03-18

    We present analytical formulations to calculate the induced resonance frequency shifts of electrically actuated clamped–clamped micro and nano (Carbon nanotube) beams due to an added mass. Based on the Euler–Bernoulli beam theory, we investigate the linear dynamic responses of the beams added masses, which are modeled as discrete point masses. Analytical expressions based on perturbation techniques and a one-mode Galerkin approximation are developed to calculate accurately the frequency shifts under a DC voltage as a function of the added mass and position. The analytical results are compared to numerical solution of the eigenvalue problem. Results are shown for the fundamental as well as the higher-order modes of the beams. The results indicate a significant increase in the frequency shift, and hence the sensitivity of detection, when scaling down to nano scale and using higher-order modes. © 2016 Springer Science+Business Media Dordrecht

  7. 78 FR 18326 - Agency Information Collection Activities; Comment Request; Upward Bound and Upward Bound Math...

    Science.gov (United States)

    2013-03-26

    ...; Comment Request; Upward Bound and Upward Bound Math Science Annual Performance Report AGENCY: The Office... considered public records. Title of Collection: Upward Bound and Upward Bound Math Science Annual Performance...) and Upward Bound Math and Science (UBMS) Programs. The Department is requesting a new APR because of...

  8. Frequency shift of a crystal quartz resonator in thickness-shear modes induced by an array of hemispherical material units.

    Science.gov (United States)

    Yuantai Hu; Huiliang Hu; Bin Luo; Huan Xue; Jiemin Xie; Ji Wang

    2013-08-01

    A two-dimensional model was established to study the dynamic characteristics of a quartz crystal resonator with the upper surface covered by an array of hemispherical material units. A frequency-dependent equivalent mass ratio was proposed to simulate the effect of the covered units on frequency shift of the resonator system. It was found that the equivalent mass ratio alternately becomes positive or negative with change of shear modulus and radius of each material unit, which indicates that the equivalent mass ratio is strongly related to the vibration mode of the covered loadings. The further numerical results show the cyclical feature in the relationship of frequency shift and shear modulus/radius as expected. The solutions are useful in the analysis of frequency stability of quartz resonators and acoustic wave sensors.

  9. Ultrafast OH-stretching frequency shifts of hydrogen- bonded 2-naphthol photoacid-base complexes in solution

    Directory of Open Access Journals (Sweden)

    Batista VictorS.

    2013-03-01

    Full Text Available We characterize the transient solvent-dependent OH-stretching frequency shifts of photoacid 2-naphthol hydrogen-bonded with CH3CN in the S0- and S1-states using a combined experimental and theoretical approach, and disentangle specific hydrogen-bonding contributions from nonspecific dielectric response.

  10. Multiplicity dependence of matrix-induced frequency shifts for atomic transitions of the group 12 metals in rare gas solids

    International Nuclear Information System (INIS)

    Laursen, S.L.; Cartland, H.E.

    1991-01-01

    Atomic resonances of the group 12 metal atoms, Hg, Cd, and Zn, undergo frequency shifts from the gas phase atomic line when trapped in rare gas matrices of Ar, Kr, and Xe at 12 K. As expected, the shifts are approximately linear in polarizability of the rare gas, but the slope of this line depends on whether the transition in question is 1 P 1 left-arrow 1 S 0 or 3 P 1 left-arrow 1 S 0 . Thus the matrix-induced frequency shift is dependent on the singlet or triplet nature of the excited state as well as on the matrix material. This dependence on multiplicity is discussed in terms of interactions between the excited-state atomic orbitals and the matrix. The results are compared to matrix studies of other metals and to related gas-phase work on diatomic van der Waals complexes of group 12 metals with rare gases

  11. The effect of classical and quantum dynamics on vibrational frequency shifts of H2 in clathrate hydrates

    International Nuclear Information System (INIS)

    Plattner, Nuria; Meuwly, Markus

    2014-01-01

    Vibrational frequency shifts of H 2 in clathrate hydrates are important to understand the properties and elucidate details of the clathrate structure. Experimental spectra of H 2 in clathrate hydrates have been measured for different clathrate compositions, temperatures, and pressures. In order to establish reliable relationships between the clathrate structure, dynamics, and observed frequencies, calculations of vibrational frequency shifts in different clathrate environments are required. In this study, a combination of classical molecular dynamics simulations, electronic structure calculations, and quantum dynamical simulation is used to calculate relative vibrational frequencies of H 2 in clathrate hydrates. This approach allows us to assess dynamical effects and simulate the change of vibrational frequencies with temperature and pressure. The frequency distributions of the H 2 vibrations in the different clathrate cage types agree favorably with experiment. Also, the simulations demonstrate that H 2 in the 5 12 cage is more sensitive to the details of the environment and to quantum dynamical effects, in particular when the cage is doubly occupied. We show that for the 5 12 cage quantum effects lead to frequency increases and double occupation is unlikely. This is different for the 5 12 6 4 cages for which higher occupation numbers than one H 2 per cage are likely

  12. Frequency Dependence of Helioseismic Measurements of the Center-to-Limb Effect and Flow-induced Travel-time Shifts

    Science.gov (United States)

    Chen, Ruizhu; Zhao, Junwei

    2018-02-01

    Time–distance helioseismology measures acoustic travel times to infer the structure and flow field of the solar interior; however, both the mean travel times and the travel-time shifts suffer systematic center-to-limb variations, which complicate the interpretation and inversions of the time–distance measurements. In particular, the center-to-limb variation in travel-time shifts (CtoL effect) has a significant impact on the inference of the Sun’s meridional circulation, and needs to be removed from the helioseismic measurements, although the observational properties and the physical cause of the CtoL effect have yet to be investigated. In this study, we measure the CtoL effect in the frequency domain using Doppler-velocity data from the Solar Dynamics Observatory/Helioseismic and Magnetic Imager, and study its properties as a function of disk-centric distance, travel distance, and frequency of acoustic waves. It is found that the CtoL effect has a significant frequency dependence—it reverses sign at a frequency around 5.4 mHz and reaches maximum at around 4.0 mHz before the sign reversal. The tendency of frequency dependence varies with disk-centric distance in a way that both the sign-reversal frequency and the maximum-value frequency decrease closer to the limb. The variation tendency does not change with travel distance, but the variation magnitude is approximately proportional to travel distance. For comparison, the flow-induced travel-time shifts show little frequency dependence. These observational properties provide more clues on the nature of the CtoL effect, and also possibly lead to new ways of effect-removal for a more robust determination of the deep meridional flow.

  13. Frequency Comb Driven Raman Transitions in the THz Range: High Precision Isotope Shift Measurements in Ca+

    DEFF Research Database (Denmark)

    Meyer, Steffen

    2017-01-01

    and frequency resolved optical gating (FROG) are used, and the two frequency comb systems used for the experiments are thoroughly characterized, a Coherent Mira Ti:sapph oscillator and a MenloSystems fiber based frequency comb system. The potential of frequency comb driven Raman transitions is shown...... transition frequencies typically are on the order of a few THz. High precision measurements on these ions have many intriguing applications, for example the test of time-variations of fundamental constants, ultracold chemistry on the quantum level, and quantum information and computing, to name just a few...

  14. Impact of frequency modulation ratio on capacitor cells balancing in phase-shifted PWM based chain-link STATCOM

    DEFF Research Database (Denmark)

    Behrouzian, Ehsan; Bongiorno, Massimo; Teodorescu, Remus

    2014-01-01

    to provide more uniform power distribution among the cells, two different methods called, a) carrier swapping and b) non-integer frequency modulation ratio are studied. In particular, it is shown that the selection of a non-integer frequency modulation ratio helps in providing a more uniform power......The purpose of this paper is to investigate the impact of switching harmonics on the instantaneous power that flows in the cells of a chain-link based STATCOM when using Phase-Shifted PWM. Two different cases are investigated for the converter cells: low, and high switching frequency. It is shown...... that any deviation from the ideal conditions lead to undesired harmonics, which will impact the charge of the dc capacitors. It is also shown that for low switching frequencies, cells voltage sideband harmonics interact with baseband harmonics of the current and causes extra source of unbalance. In order...

  15. An assessment of threshold shifts in nonprofessional pop/rock musicians using conventional and extended high-frequency audiometry.

    Science.gov (United States)

    Schmuziger, Nicolas; Patscheke, Jochen; Probst, Rudolf

    2007-09-01

    The clinical value of extended high-frequency audiometry for the detection of noise-induced hearing loss has not been established conclusively. The purpose of this study was to assess the relative temporary threshold shift (TTS) in two frequency regions (conventional versus extended high frequency). In this exploratory study, pure-tone thresholds from 0.5 to 14 kHz were measured in both ears of 16 nonprofessional pop/rock musicians (mean age, 35 yr; range, 27 to 49 yr), before and after a 90-minute rehearsal session. All had experienced repeated exposures to intense sound levels during at least 5 yr of their musical careers. After the rehearsal, median threshold levels were found to be significantly poorer for frequencies from 0.5 to 8 kHz (Wilcoxon signed rank test, p frequency range from 9 to 14 kHz. Decreases in the median threshold values measured before the rehearsal were present across the conventional frequency range, most notably at 6 kHz, but were not observed in the extended high-frequency range. On the basis of these results, extended high-frequency audiometry does not seem advantageous as a means of the early detection of noise-induced hearing loss.

  16. The effect of the condensed-phase environment on the vibrational frequency shift of a hydrogen molecule inside clathrate hydrates.

    Science.gov (United States)

    Powers, Anna; Scribano, Yohann; Lauvergnat, David; Mebe, Elsy; Benoit, David M; Bačić, Zlatko

    2018-04-14

    We report a theoretical study of the frequency shift (redshift) of the stretching fundamental transition of an H 2 molecule confined inside the small dodecahedral cage of the structure II clathrate hydrate and its dependence on the condensed-phase environment. In order to determine how much the hydrate water molecules beyond the confining small cage contribute to the vibrational frequency shift, quantum five-dimensional (5D) calculations of the coupled translation-rotation eigenstates are performed for H 2 in the v=0 and v=1 vibrational states inside spherical clathrate hydrate domains of increasing radius and a growing number of water molecules, ranging from 20 for the isolated small cage to over 1900. In these calculations, both H 2 and the water domains are treated as rigid. The 5D intermolecular potential energy surface (PES) of H 2 inside a hydrate domain is assumed to be pairwise additive. The H 2 -H 2 O pair interaction, represented by the 5D (rigid monomer) PES that depends on the vibrational state of H 2 , v=0 or v=1, is derived from the high-quality ab initio full-dimensional (9D) PES of the H 2 -H 2 O complex [P. Valiron et al., J. Chem. Phys. 129, 134306 (2008)]. The H 2 vibrational frequency shift calculated for the largest clathrate domain considered, which mimics the condensed-phase environment, is about 10% larger in magnitude than that obtained by taking into account only the small cage. The calculated splittings of the translational fundamental of H 2 change very little with the domain size, unlike the H 2 j = 1 rotational splittings that decrease significantly as the domain size increases. The changes in both the vibrational frequency shift and the j = 1 rotational splitting due to the condensed-phase effects arise predominantly from the H 2 O molecules in the first three complete hydration shells around H 2 .

  17. The effect of the condensed-phase environment on the vibrational frequency shift of a hydrogen molecule inside clathrate hydrates

    Science.gov (United States)

    Powers, Anna; Scribano, Yohann; Lauvergnat, David; Mebe, Elsy; Benoit, David M.; Bačić, Zlatko

    2018-04-01

    We report a theoretical study of the frequency shift (redshift) of the stretching fundamental transition of an H2 molecule confined inside the small dodecahedral cage of the structure II clathrate hydrate and its dependence on the condensed-phase environment. In order to determine how much the hydrate water molecules beyond the confining small cage contribute to the vibrational frequency shift, quantum five-dimensional (5D) calculations of the coupled translation-rotation eigenstates are performed for H2 in the v =0 and v =1 vibrational states inside spherical clathrate hydrate domains of increasing radius and a growing number of water molecules, ranging from 20 for the isolated small cage to over 1900. In these calculations, both H2 and the water domains are treated as rigid. The 5D intermolecular potential energy surface (PES) of H2 inside a hydrate domain is assumed to be pairwise additive. The H2-H2O pair interaction, represented by the 5D (rigid monomer) PES that depends on the vibrational state of H2, v =0 or v =1 , is derived from the high-quality ab initio full-dimensional (9D) PES of the H2-H2O complex [P. Valiron et al., J. Chem. Phys. 129, 134306 (2008)]. The H2 vibrational frequency shift calculated for the largest clathrate domain considered, which mimics the condensed-phase environment, is about 10% larger in magnitude than that obtained by taking into account only the small cage. The calculated splittings of the translational fundamental of H2 change very little with the domain size, unlike the H2 j = 1 rotational splittings that decrease significantly as the domain size increases. The changes in both the vibrational frequency shift and the j = 1 rotational splitting due to the condensed-phase effects arise predominantly from the H2O molecules in the first three complete hydration shells around H2.

  18. Evidence of circadian and extended shift effects on reactor transient frequency

    International Nuclear Information System (INIS)

    Maloney, S.

    1992-01-01

    An extensive body of knowledge exists documenting the significant swings in error rates, perception, judgment, and overall alertness levels in the course of a day. The literature also demonstrates pronounced differences in performance levels whereby night workers routinely underperform day workers in any set of tasks. The performance split widens with task complexity. Rotating shift workers, such as nuclear power plant operators, have been shown to experience performance problems comparable to straight night workers. Finally, sleep research also documents that extended hours, such as the so-called 4-day work week, can undermine alertness levels, particularly in the last 2 to 3 h of a daily shift. These issues suggest that cyclical performance by shift workers may be evident in nuclear plant operators. This paper seeks evidence of such cyclical performance by examining operating transients at nuclear power plants involving human error

  19. Analysis of Power System Low Frequency Oscillation Based on Energy Shift Theory

    Science.gov (United States)

    Zhang, Junfeng; Zhang, Chunwang; Ma, Daqing

    2018-01-01

    In this paper, a new method for analyzing low-frequency oscillation between analytic areas based on energy coefficient is proposed. The concept of energy coefficient is proposed by constructing the energy function, and the low-frequency oscillation is analyzed according to the energy coefficient under the current operating conditions; meanwhile, the concept of model energy is proposed to analyze the energy exchange behavior between two generators. Not only does this method provide an explanation of low-frequency oscillation from the energy point of view, but also it helps further reveal the dynamic behavior of complex power systems. The case analysis of four-machine two-area and the power system of Jilin Power Grid proves the correctness and effectiveness of the proposed method in low-frequency oscillation analysis of power system.

  20. Cortico-pontine theta carrier frequency phase shift across sleep/wake states following monoaminergic lesion in rat.

    Science.gov (United States)

    Kalauzi, Aleksandar; Spasic, Sladjana; Petrovic, Jelena; Ciric, Jelena; Saponjic, Jelena

    2012-06-01

    This study was aimed to explore the sleep/wake states related cortico-pontine theta carrier frequency phase shift following a systemically induced chemical axotomy of the monoaminergic afferents within a brain of the freely moving rats. Our experiments were performed in 14 adult, male Sprague Dawley rats, chronically implanted for sleep recording. We recorded sleep during baseline condition, following sham injection (saline i.p. 1 ml/kg), and every week for 5 weeks following injection of the systemic neurotoxins (DSP-4 or PCA; 1 ml/kg, i.p.) for chemical axotomy of the locus coeruleus (LC) and dorsal raphe (DR) axon terminals. After sleep/wake states identification, FFT analysis was performed on 5 s epochs. Theta carrier frequency phase shift (∆Φ) was calculated for each epoch by averaging theta Fourier component phase shifts, and the ∆Φ values were plotted for each rat in control condition and 28 days following the monoaminergic lesions, as a time for permanently established DR or LC chemical axotomy. Calculated group averages have shown that ∆Φ increased between pons and cortex significantly in all sleep/wake states (Wake, NREM and REM) following the monoaminergic lesions, with respect to controls. Monoaminergic lesions established the pontine leading role in the brain theta oscillations during all sleep/wake states.

  1. Manipulating Electromagnetic Waves in Magnetized Plasmas: Compression, Frequency Shifting, and Release

    International Nuclear Information System (INIS)

    Avitzour, Yoav; Shvets, Gennady

    2008-01-01

    A new approach to manipulating the duration and frequency of microwave pulses using magnetized plasmas is demonstrated. The plasma accomplishes two functions: (i) slowing down and spatially compressing the incident wave, and (ii) modifying the propagation properties (group velocity and frequency) of the wave in the plasma during a uniform in space adiabatic in time variation of the magnitude and/or direction of the magnetic field. The increase in the group velocity results in the shortening of the temporal pulse duration. Depending on the plasma parameters, the frequency of the outgoing compressed pulse can either change or remain unchanged. Such dynamic manipulation of radiation in plasma opens new avenues for manipulating high power microwave pulses

  2. Frequency shift due to blackbody radiation in a cesium atomic fountain and improvement of the clock performances

    International Nuclear Information System (INIS)

    Zhang, S.

    2004-07-01

    FO1 was the first caesium fountain primary frequency standard in the world. The most recent evaluation in 2002 before improvement reached an accuracy of 1*10 -15 when operated with optical molasses. Working as an extremely precise and stable instrument, FO1 has contributed to fundamental physics and technical measurements: - Frequency comparison between Cs and Rb fountains over an interval of 5 years sets an upper limit for a possible variation of the fine structure constant as |alpha/alpha| -15 /y. The resolution is about 5 times better than the previous test in our laboratory. The projected accuracy of the space clock PHARAO is 1*10 -16 . We confirmed its Ramsey cavity performance by testing the phase difference between the two interaction zones in FO1. The measured temperature T dependent frequency shift of the Cs clock induced by the blackbody radiation field is given as nu(T)=154(6)*10 -6 *(T/300) 4 [1+ε(T/300) 2 ] Hz with the theoretical value ε = 0,014. The obtained accuracy represents a 3 times improvement over the previous measurement by the PTB group. Some improvements have been carried out on FO1. The new FO1 version works directly with optical molasses loaded by a laser slowed atomic beam. The application of the adiabatic passage method to perform the state selection allows us to determine the atom number dependent frequency shifts due to the cold collision and cavity pulling effects at a level of of 10 -16 . Recently, the obtained frequency stability is 2,8*10 -14 *τ -1/2 for about 4*10 6 detected atoms. The accuracy is currently under evaluation, the expected value is a few times 10 -16 . (author)

  3. Does urban sprawl hold down upward mobility?

    Science.gov (United States)

    Ewing, R.; Hamidi, Shima; Grace, James B.; Wei, Y.

    2016-01-01

    Contrary to the general perception, the United States has a much more class-bound society than other wealthy countries. The chance of upward mobility for Americans is just half that of the citizens of the Denmark and many other European countries. In addition to other influences, the built environment may contribute to the low rate of upward mobility in the U.S. This study tests the relationship between urban sprawl and upward mobility for commuting zones in the U.S. We examine potential pathways through which sprawl may have an effect on mobility. We use structural equation modeling to account for both direct and indirect effects of sprawl on upward mobility. We find that upward mobility is significantly higher in compact areas than sprawling areas. The direct effect, which we attribute to better job accessibility in more compact commuting zones, is stronger than the indirect effects. Of the indirect effects, only one, through the mediating variable income segregation, is significant.

  4. Using advertisement light-panel and CMOS image sensor with frequency-shift-keying for visible light communication.

    Science.gov (United States)

    Chow, Chi-Wai; Shiu, Ruei-Jie; Liu, Yen-Chun; Liao, Xin-Lan; Lin, Kun-Hsien; Wang, Yi-Chang; Chen, Yi-Yuan

    2018-05-14

    A frequency-shift-keying (FSK) visible light communication (VLC) system is proposed and demonstrated using advertisement light-panel as transmitter and mobile-phone image sensor as receiver. The developed application program (APP) in mobile-phone can retrieve the rolling shutter effect (RSE) pattern produced by the FSK VLC signal effectively. Here, we also define noise-ratio value (NRV) to evaluate the contrast of different advertisements displayed on the light-panel. Both mobile-phones under test can achieve success rate > 96% even when the transmission distance is up to 200 cm and the NRVs are low.

  5. Effect of Shift Work on the Frequency of Depression in Nursing Staff of Yazd University of Medical Sciences

    Directory of Open Access Journals (Sweden)

    Gholam Hossein Halvani

    2012-12-01

    Full Text Available Introduction: Depression as a disorder is relatively common in all societies; several factors are involved in depression development, that shift work is one of these factors. This study compared the frequency of depression in different shifts of nurses in hospitals of Yazd University of medical sciences. Materials & Methods: This study is a descriptive analytical study. Based on statistical methods, 150 nurses participated in this study. The research tool was a questionnaire that included 15 personal questions and 21 questions related to Beck test. The results were analysed by SPSS software. Results: 13.3% of all subjects were males and 86.7% were females. Results showed that, there is no significant relationship between gender, education, type of job, employment status and satisfaction levels of income with depression. Marital status (P-Value = 0.009 and F = 6.93, shift work (day working and shift work (P-Value = 0.032 and F = 1.11, job satisfaction (P-Value = 0.000 and F = 7.641 and the satisfaction of the employer (P-Value = 0.001 and F = 5.414 were significantly associated with depression. 3.49% of the nurses were in normal status, 7.26% had mild depression, 3.9% required consultation with the psychiatrist,% 7.8% suffered from moderate depression, 75.4% from severe depression and 3.1% from very severe depression. Conclusion: It seems that shift work can not cause depression alone, but depression is the result of the interaction of several factors.

  6. Communications: On artificial frequency shifts in infrared spectra obtained from centroid molecular dynamics: Quantum liquid water

    Science.gov (United States)

    Ivanov, Sergei D.; Witt, Alexander; Shiga, Motoyuki; Marx, Dominik

    2010-01-01

    Centroid molecular dynamics (CMD) is a popular method to extract approximate quantum dynamics from path integral simulations. Very recently we have shown that CMD gas phase infrared spectra exhibit significant artificial redshifts of stretching peaks, due to the so-called "curvature problem" imprinted by the effective centroid potential. Here we provide evidence that for condensed phases, and in particular for liquid water, CMD produces pronounced artificial redshifts for high-frequency vibrations such as the OH stretching band. This peculiar behavior intrinsic to the CMD method explains part of the unexpectedly large quantum redshifts of the stretching band of liquid water compared to classical frequencies, which is improved after applying a simple and rough "harmonic curvature correction."

  7. A SSVEP Stimuli Encoding Method Using Trinary Frequency-Shift Keying Encoded SSVEP (TFSK-SSVEP

    Directory of Open Access Journals (Sweden)

    Xing Zhao

    2017-06-01

    Full Text Available SSVEP is a kind of BCI technology with advantage of high information transfer rate. However, due to its nature, frequencies could be used as stimuli are scarce. To solve such problem, a stimuli encoding method which encodes SSVEP signal using Frequency Shift–Keying (FSK method is developed. In this method, each stimulus is controlled by a FSK signal which contains three different frequencies that represent “Bit 0,” “Bit 1” and “Bit 2” respectively. Different to common BFSK in digital communication, “Bit 0” and “Bit 1” composited the unique identifier of stimuli in binary bit stream form, while “Bit 2” indicates the ending of a stimuli encoding. EEG signal is acquired on channel Oz, O1, O2, Pz, P3, and P4, using ADS1299 at the sample rate of 250 SPS. Before original EEG signal is quadrature demodulated, it is detrended and then band-pass filtered using FFT-based FIR filtering to remove interference. Valid peak of the processed signal is acquired by calculating its derivative and converted into bit stream using window method. Theoretically, this coding method could implement at least 2n−1 (n is the length of bit command stimulus while keeping the ITR the same. This method is suitable to implement stimuli on a monitor and where the frequency and phase could be used to code stimuli is limited as well as implementing portable BCI devices which is not capable of performing complex calculations.

  8. Electron-cyclotron heating in net using the ordinary mode at down-shifted frequency

    International Nuclear Information System (INIS)

    Fidone, I.; Giruzzi, G.

    1990-01-01

    A scenario for central heating in NET device is discussed using wave sources and wave launching from the most accessible side of the torus. The method presents two advantages: low wave frequency and side launch of the 0- mode. The maximum wave attenuation occurs for θ different to zero. It is a difficulty which is minimized by the fact that no special polarization is required for the reflected wave, since both modes are absorbed by the plasma core

  9. Evidence for the frequency-shift of the OA A_1g mode in Hg-based superconductors

    Science.gov (United States)

    Yang, In-Sang; Lee, Hye-Gyong

    1996-03-01

    The Hg-based superconductors, HgBa_2Ca_n-1Cu_nO_2n+2+δ (n=1,2,3) have two strong Raman peaks at ~ 570 and 590 cm-1 in the high-frequency region. From the results of Raman measurements of Tl-doped Hg-1223 system, it is concluded that the peak at ~ 570 cm-1 does not arise from the vibration of the interstitial oxygen O_δ in the Hg/Tl-O plane, but from the frequency-shift of the A_1g-type vibration of the apical oxygen O_A. The peak at 570 cm-1 is from the O_As surrounded by the O_δs in the nearest neighbor, while the 590 cm-1 mode is from the O_As without the O_δs in the immediate neighbor. The intensity of the 570 cm-1 mode increases with the O_δ content, but the Raman frequencies of both modes do not change significantly. This suggests that the increase of the frequency of the OA A_1g mode under high pressure (I.-S. Yang et al., Phys. Rev. B 51, 644 (1995)) is independent from the O_δ content, in the Hg-based superconductors.

  10. Electron cyclotron heating of a tokamak reactor at down-shifted frequencies

    International Nuclear Information System (INIS)

    Fidone, I.; Giruzzi, G.; Mazzucato, E.

    1985-01-01

    The absorption of electron cyclotron waves in a hot and dense tokamak plasma is investigated for the case of the extraordinary mode for outside launching. It is shown that, for electron temperatures T/sub e/ greater than or equal to 5 keV, strong absorption occurs for oblique propagation at frequencies significantly below the electron gyrofrequency at the plasma center. A new density dependence of the wave absorption is found which is more favorable for plasma heating than the familiar n/sub e/ -1 scaling

  11. Interaction potential of the H-He system and the hyperfine frequency shift of H in He buffer gas

    International Nuclear Information System (INIS)

    Tang, K.T.; Yang, X.D.

    1990-01-01

    The van der Waals potential of the H-He interaction and the hyperfine frequency shift of H in He are predicted using the Tang-Toennies model. This model damps the long-range ab initio dispersion terms individually using a universal damping function and adds to this a simple Born-Mayer repulsive term. The Born-Mayer parameters are derived from self-consistent-field calculations. The resulting potential is found to be in good agreement with two molecular-beam experiments and its well parameters, in excellent agreement with the complete configuration-interaction calculation. In order to compare with experiment, the hyperfine frequency shift is thermally averaged over the potential both quantum mechanically and classically. The thermally averaged results are in excellent agreement with experiment in the high-temperature range but there are some discrepancies with the measurements at 0.5 and at 1.15 K. These discrepancies may be due to the fact that the long-range coefficient K 10 used is too small. The quantum and classical results are practically identical for temperature above 40 K. The classical statistics fails completely only for temperature below 5 K. Also in the quantum calculation, the isotope effect between 3 He and 4 He is found to show up only for temperature below 10 K. The theoretical isotope effect is in qualitative agreement with experiment

  12. On the intramolecular origin of the blue shift of A-H stretching frequencies: triatomic hydrides HAX.

    Science.gov (United States)

    Karpfen, Alfred; Kryachko, Eugene S

    2009-04-30

    A series of intermolecular complexes formed between the triatomic hydrides HAX and various interaction partners are investigated computationally aiming (1) to demonstrate that either an appearance or nonappearance of a blue shift of the A-H stretching frequency is directly related to the sign of the intramolecular coupling that exists between the two degrees of freedom, the A-H and A-X bond lengths, and (2) to offer the following conjecture: the theoretical protonation of a triatomic neutral molecule HAX at the site X is a simple and rather efficient probe of a red or blue shift that the stretching frequency nu(A-H) undergoes upon complex formation regardless of whether this bond is directly involved in hydrogen bonding or not. In other words, to predict whether this A-H bond is capable to display a blue or red shift of nu(A-H), it suffices to compare the equilibrium structures and vibrational spectra of a given molecule with its protonated counterpart. The two above goals are achieved invoking a series of 11 triatomic molecules: HNO, HSN, HPO, and HPS characterized by a negative intramolecular coupling; HON and HNS as intermediate cases; and HOF, HOCl, HCN, HNC, and HCP with a positive intramolecular coupling. For these purposes, the latter molecules are investigated at the MP2/6-311++G(2p,2d) level in the neutral and protonated HAXH(+) forms as well as their complexes with H(2)O and with the fluoromethanes H(3)CF, H(2)CF(2), and HCF(3).

  13. Pressure broadening and frequency shift of the D 1 and D 2 lines of K in the presence of Ne and Kr

    Science.gov (United States)

    Wang, Xulin; Chen, Yao; Quan, Wei; Chi, Haotian; Fang, Jiancheng

    2018-02-01

    We present the results of pressure broadening and frequency shift of K D 1 and D 2 lines in presence of 1-4 amg of Neon gas and 1-5 amg of Krypton gas by laser absorption spectroscopy. Both pressure broadening and frequency shift are linearly related to gas density with high accuracy. The asymmetry of the absorption line shape caused by van der Waals potential was first found in the near-line wings of large density Kr in the experiment. We have also investigated the temperature dependence of the pressure broadening and frequency shift in a range of 353-403 K in Neon and 373-417 K in Krypton and compared the results of the pressure broadening and frequency shift with previous values.

  14. Analysis of the atmospheric upward radiation in low latitude area

    Science.gov (United States)

    Li, Haiying; Wu, Zhensen; Lin, Leke; Lu, Changsheng

    2016-10-01

    Remote sensing using THz wave has irreplaceable advantage comparing to the microwave and the infrared waves, and study on the THz remote sensing become more and more popular in recent years. The major applications of the remote sensing in THz wavelengths are the retrieval of the atmospheric parameters and the microphysical information of the ice cloud. The remote sensing of the atmosphere is based on the radiation of THz wave along the earth-space path of which the most significant part is the upward radiation of the atmosphere. The upward radiation of the atmosphere in sunny day in the low latitude area is computed and analyzed in this paper. The absorption of THz wave by the atmosphere is calculated using the formulations illustrated in the Recommendation ITU-R P.676 to save machine hour, the frequency range is then restricted below 1THz. The frequencies used for the retrieval of atmospheric parameters such as temperature and water content are usually a few hundred GHz, at the lower end of THz wavelengths, so this frequency range is sufficient. The radiation contribution of every atmospheric layer for typical frequencies such as absorption window frequencies and peak frequencies are analyzed. Results show that at frequencies which absorption is severe, information about lower atmosphere cannot reach the receiver onboard a satellite or other high platforms due to the strong absorption along the path.

  15. Waveguide elliptic polarizers for ECH at down-shifted frequencies on PLT

    International Nuclear Information System (INIS)

    Doane, J.L.

    1986-01-01

    ECH experiments on PLT with resonance frequencies of 80 to 90 GHz at the plasma center use 60 GHz extraordinary mode (X-mode) propagation at 30 0 from the toroidal field. Efficient excitation of this mode requires elliptic polarization of the incident wave at the plasma edge. On PLT the elliptic polarization is achieved outside the vacuum vessel in an elliptically deformed section of circular waveguide propagating TM11, a mode that is intermediate between TE01 and HE11 (which has an ideal radiation pattern). The squeeze and orientation of the TM11 polarizer are adjusted to compensate both for the birefringence of a corrugated bend propagating HE11 and for a flat mirror inside PLT that reverses the sense of rotation of the polarization. 11 refs., 8 figs

  16. Stabilized soliton self-frequency shift and 0.1- PHz sideband generation in a photonic-crystal fiber with an air-hole-modified core.

    Science.gov (United States)

    Liu, Bo-Wen; Hu, Ming-Lie; Fang, Xiao-Hui; Li, Yan-Feng; Chai, Lu; Wang, Ching-Yue; Tong, Weijun; Luo, Jie; Voronin, Aleksandr A; Zheltikov, Aleksei M

    2008-09-15

    Fiber dispersion and nonlinearity management strategy based on a modification of a photonic-crystal fiber (PCF) core with an air hole is shown to facilitate optimization of PCF components for a stable soliton frequency shift and subpetahertz sideband generation through four-wave mixing. Spectral recoil of an optical soliton by a red-shifted dispersive wave, generated through a soliton instability induced by high-order fiber dispersion, is shown to stabilize the soliton self-frequency shift in a highly nonlinear PCF with an air-hole-modified core relative to pump power variations. A fiber with a 2.3-microm-diameter core modified with a 0.9-microm-diameter air hole is used to demonstrate a robust soliton self-frequency shift of unamplified 50-fs Ti: sapphire laser pulses to a central wavelength of about 960 nm, which remains insensitive to variations in the pump pulse energy within the range from 60 to at least 100 pJ. In this regime of frequency shifting, intense high- and low-frequency branches of dispersive wave radiation are simultaneously observed in the spectrum of PCF output. An air-hole-modified-core PCF with appropriate dispersion and nonlinearity parameters is shown to provide efficient four-wave mixing, giving rise to Stokes and anti-Stokes sidebands whose frequency shift relative to the pump wavelength falls within the subpetahertz range, thus offering an attractive source for nonlinear Raman microspectroscopy.

  17. Cover Art: River's Edge: Downward, Outward, Upward

    Directory of Open Access Journals (Sweden)

    Jonee Kulman Brigham

    2017-10-01

    Full Text Available Artist's Statement for the cover art of IJPS volume 4, issue 3: River's Edge: Downward, Outward, Upward, 2015. Mixed Media: photograph, inkjet printed on presentation matte of colored pencil over photograph.

  18. Unsplit complex frequency shifted perfectly matched layer for second-order wave equation using auxiliary differential equations.

    Science.gov (United States)

    Gao, Yingjie; Zhang, Jinhai; Yao, Zhenxing

    2015-12-01

    The complex frequency shifted perfectly matched layer (CFS-PML) can improve the absorbing performance of PML for nearly grazing incident waves. However, traditional PML and CFS-PML are based on first-order wave equations; thus, they are not suitable for second-order wave equation. In this paper, an implementation of CFS-PML for second-order wave equation is presented using auxiliary differential equations. This method is free of both convolution calculations and third-order temporal derivatives. As an unsplit CFS-PML, it can reduce the nearly grazing incidence. Numerical experiments show that it has better absorption than typical PML implementations based on second-order wave equation.

  19. Design of a hybrid reconfigurable Software Defined Radio transceiver based on frequency shift keying using multiple encoding schemes

    Directory of Open Access Journals (Sweden)

    Nikhil Marriwala

    2016-03-01

    The aim of this paper was to analyze Frequency Shift Keying (FSK Transceiver built using Laboratory Virtual Instrumentation Engineering Workbench (LabVIEW and to measure the reduction in data errors in the presence of Forward Error Correction (FEC channel coding algorithms namely the Convolution and the Turbo Codes. Through this design a graphical representation of Bit Error Rate (BER vs Eb/N0 where (Eb is Energy per bit and (N0 is Spectral noise density has been given in the presence of Additive White Gaussian Noise (AWGN introduced in the channel. FSK is widely used for data transmission over band pass channels; hence, we have chosen FSK for the implementation of SDR. The SDR transceiver module designed has been fully implemented and has the ability to navigate over a wide range of frequencies with programmable channel bandwidth and modulation characteristics. We are able to build an interactive FSK based SDR transceiver in a shorter time with the use of LabVIEW. The outputs achieved show a low BER for very high data rates in the presence of AWGN noise.

  20. On the origin of bonding and vibrational frequency shifts for CO adsorbed on neutral, cationic and anionic gold clusters

    International Nuclear Information System (INIS)

    Bagus, P S; Pacchioni, G

    2008-01-01

    We report a detailed analysis of the electronic mechanisms which determine the bond strength and the vibrational frequency of CO molecules adsorbed on neutral or charged gold nanoparticles. To this end we have considered a simple cluster model, Au 5 CO q (q = +1, 0, -1), and decomposed the Au-CO interaction energy into the sum of various contributions according to a Constrained Space Orbital Variation approach. While the adsorption energy is relatively insensitive to the value of q, the C-O stretch frequency, ω e (CO), changes substantially, and allows the use of this molecule as a direct probe of the gold oxidation state. The results show that two major terms contribute to the red or blue shift of ω e (CO) as a function of q: the interaction with the electric field associated to the charged nanoparticle (Stark effect) and the Au → CO Φ back donation. The CO → Au σ donation is about half as important as the Φ back-donation and all other terms are much less important

  1. The Effect of an Added Mass on the Frequency Shifts of a Clamped-Clamped Microbeam for Bio-Mass Detection

    KAUST Repository

    Bouchaala, Adam M.; Nayfeh, Ali H.; Younis, Mohammad I.

    2016-01-01

    We present analytical formulations to calculate the induced resonance frequency shifts of electrically actuated clamped-clamped microbeams due to an added mass. Based on the Euler-Bernoulli beam theory, we investigate the linear dynamic responses of the beams added masses, which are modeled as discrete point masses. Analytical expressions based on perturbation techniques and a one-mode Galerkin approximation are developed to calculate accurately the frequency shifts under a DC voltage as a function of the added mass and position. The analytical results are compared to numerical solution of the eigenvalue problem. Results are shown for the fundamental as well as the higher-order modes of the beams. The results indicate a significant increase in the frequency shift, and hence the sensitivity of detection, when scaling down to nano scale and using higher-order modes.

  2. The Effect of an Added Mass on the Frequency Shifts of a Clamped-Clamped Microbeam for Bio-Mass Detection

    KAUST Repository

    Bouchaala, Adam M.

    2016-12-05

    We present analytical formulations to calculate the induced resonance frequency shifts of electrically actuated clamped-clamped microbeams due to an added mass. Based on the Euler-Bernoulli beam theory, we investigate the linear dynamic responses of the beams added masses, which are modeled as discrete point masses. Analytical expressions based on perturbation techniques and a one-mode Galerkin approximation are developed to calculate accurately the frequency shifts under a DC voltage as a function of the added mass and position. The analytical results are compared to numerical solution of the eigenvalue problem. Results are shown for the fundamental as well as the higher-order modes of the beams. The results indicate a significant increase in the frequency shift, and hence the sensitivity of detection, when scaling down to nano scale and using higher-order modes.

  3. A Study of Upward Influence in Organizations.

    Science.gov (United States)

    Schilit, Warren K.; Locke, Edwin A.

    1982-01-01

    Researchers interviewed 83 subordinate employees and 70 supervisory employees to investigate the ways subordinates try to influence their supervisors. Supervisors and subordinates reported similar agents and methods of influence, causes of success, and outcomes of attempts at upward influence, but different causes of failure. (Author/RW)

  4. Doppler Frequency Shift in Ocean Wave Measurements: Frequency Downshift of a Fixed Spectral Wave Number Component by Advection of Wave Orbital Velocity

    National Research Council Canada - National Science Library

    Hwang, Paul

    2006-01-01

    ... at he expected intrinsic frequency in the frequency spectrum measured by a stationary probe. The advection of the wave number component by the orbital current of background waves produces a net downshift in the encounter frequency...

  5. High-Frequency H-1 NMR Chemical Shifts of Sn-II and Pb-II Hydrides Induced by Relativistic Effects: Quest for Pb-II Hydrides

    Czech Academy of Sciences Publication Activity Database

    Vícha, J.; Marek, R.; Straka, Michal

    2016-01-01

    Roč. 55, č. 20 (2016), s. 10302-10309 ISSN 0020-1669 Institutional support: RVO:61388963 Keywords : hydrides of TlI and PbII * high-frequency 1H chemical shifts * relativistic effects Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.857, year: 2016

  6. High-Frequency C-13 and Si-29 NMR Chemical Shifts in Diamagnetic Low-Valence Compounds of TII and Pb-II: Decisive Role of Relativistic Effects

    Czech Academy of Sciences Publication Activity Database

    Vícha, J.; Marek, R.; Straka, Michal

    2016-01-01

    Roč. 55, č. 4 (2016), s. 1770-1781 ISSN 0020-1669 R&D Projects: GA ČR(CZ) GA14-03564S Institutional support: RVO:61388963 Keywords : high-frequency NMR chemical shifts * HALA effect * relativistic DFT calculations Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.857, year: 2016

  7. Are Millennials with Student Loans Upwardly Mobile?

    OpenAIRE

    Whitaker, Stephan

    2015-01-01

    Students have been amassing ever growing levels of debt to attend college. The situation has raised concerns about whether the debt is high enough that the benefits of borrowing—in terms of students’ future socioeconomic outcomes—are compromised. This Commentary investigates relationships between student debt, mobility, and upward social mobility. The findings suggest that student debts have not become so burdensome that they undo the advantages of higher skills. However, the advantages enjoy...

  8. Effects of asynchrony and ear of presentation on the pitch of mistuned partials in harmonic and frequency-shifted complex tones.

    Science.gov (United States)

    Brunstrom, J M; Roberts, B

    2001-07-01

    When a partial of a periodic complex is mistuned, its change in pitch is greater than expected. Two experiments examined whether these partial-pitch shifts are related to the computation of global pitch. In experiment 1, stimuli were either harmonic or frequency-shifted (25% of F0) complexes. One partial was mistuned by +/- 4% and played with leading and lagging portions of 500 ms each, relative to the other components (1 s), in both monaural and dichotic contexts. Subjects indicated whether the mistuned partial was higher or lower in pitch when concurrent with the other components. Responses were positively correlated with the direction of mistuning in all conditions. In experiment 2, stimuli from each condition were compared with synchronous equivalents. Subjects matched a pure tone to the pitch of the mistuned partial (component 4). The results showed that partial-pitch shifts are not reduced in size by asynchrony. Similar asynchronies are known to produce a near-exclusion of a mistuned partial from the global-pitch computation. This mismatch indicates that global and partial pitch are derived from different processes. The similarity of the partial-pitch shifts observed for harmonic and frequency-shifted stimuli suggests that they arise from a grouping mechanism that is sensitive to spectral regularity.

  9. Synthesis of multi-wavelength temporal phase-shifting algorithms optimized for high signal-to-noise ratio and high detuning robustness using the frequency transfer function

    OpenAIRE

    Servin, Manuel; Padilla, Moises; Garnica, Guillermo

    2016-01-01

    Synthesis of single-wavelength temporal phase-shifting algorithms (PSA) for interferometry is well-known and firmly based on the frequency transfer function (FTF) paradigm. Here we extend the single-wavelength FTF-theory to dual and multi-wavelength PSA-synthesis when several simultaneous laser-colors are present. The FTF-based synthesis for dual-wavelength PSA (DW-PSA) is optimized for high signal-to-noise ratio and minimum number of temporal phase-shifted interferograms. The DW-PSA synthesi...

  10. Bubble Clouds and their Transport within the Surf Zone as Measured with a Distributed Array of Upward-Looking Sonars

    National Research Council Canada - National Science Library

    Dahl, Peter

    2000-01-01

    ... in the surf zone and the effects of these bubbles on acoustic propagation. This paper discusses data gathered by the Applied Physics Laboratory, University of Washington, using a set of four upward-looking sonars (frequency 240 kHz...

  11. Small-Signal Analysis of Single-Phase and Three-phase DC/AC and AC/DC PWM Converters with the Frequency-Shift Technique

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Aquila, A. Dell’; Liserre, Marco

    2004-01-01

    of dc/dc converters via a 50 Hz frequency-shift. The input admittance is calculated and measured for two study examples (a three-phase active rectifier and a single-phase photovoltaic inverter). These examples show that the purpose of a well designed controller for grid-connected converters......A systematic approach to study dc/ac and ac/dc converters without the use of synchronous transformation is proposed. The use of a frequency-shift technique allows a straightforward analysis of single-phase and three-phase systems. The study of dc/ac and of ac/dc converters is reported to the study...... is to minimize the input admittance in order to make the grid converter more robust to grid disturbance....

  12. Correlation of zero-point energy with molecular structure and molecular forces. 3. Approximation for H/D isotope shifts and linear frequency sum rule

    International Nuclear Information System (INIS)

    Oi, T.; Ishida, T.

    1984-01-01

    The approximation methods for the zero-point energy (ZPE) previously developed using the Lanczo's tau method have been applied to the shifts in ZPE due to hydrogen isotope substitutions. Six types of approximation methods have been compared and analyzed on the basis of a weighing function Ω(lambda) varies as lambda/sup k/ and the actual eigenvalue shift spectra. The method generated by the most general optimzation treatment yields a predictable and generally satisfactory precision of the order of 1% or better. A linear frequency sum rule has been derived, which approximately holds for the sets of isotopic molecules which satisfy the second-order frequency sum rule. 19 references, 3 figures, 3 tables

  13. Analysis of the resonance frequency shift in cylindrical cavities containing a sphere and its prediction based on the Boltzmann-Ehrenfest principle

    DEFF Research Database (Denmark)

    Orozco Santillán, Arturo; Cutanda Henriquez, Vicente

    2008-01-01

    of the cavity due to the presence of the levitated object. The Boltzmann-Ehrenfest principle has been used to obtain an analytical expression for the resonance frequency shift in a cylindrical cavity produced by a small sphere, with kR .... The validity of the Boltzmann-Ehrenfest method has been investigated by means of the Boundary Element Method (BEM) and confirmed with experiments....

  14. Finite element analysis and frequency shift studies for the bridge coupler of the coupled cavity linear accelerator of the spallation neutron source.

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z. (Zukun)

    2001-01-01

    The Spallation Neutron Source (SNS) is an accelerator-based neutron scattering research facility. The linear accelerator (linac) is the principal accelerating structure and divided into a room-temperature linac and a superconducting linac. The normal conducting linac system that consists of a Drift Tube Linac (DTL) and a Coupled Cavity Linac (CCL) is to be built by Los Alamos National Laboratory. The CCL structure is 55.36-meters long. It accelerates H- beam from 86.8 Mev to 185.6 Mev at operating frequency of 805 MHz. This side coupled cavity structure has 8 cells per segment, 12 segments and 11 bridge couplers per module, and 4 modules total. A 5-MW klystron powers each module. The number 3 and number 9 bridge coupler of each module are connected to the 5-MW RF power supply. The bridge coupler with length of 2.5 {beta}{gamma} is a three-cell structure and located between the segments and allows power flow through the module. The center cell of each bridge coupler is excited during normal operation. To obtain a uniform electromagnetic filed and meet the resonant frequency shift, the RF induced heat must be removed. Thus, the thermal deformation and frequency shift studies are performed via numerical simulations in order to have an appropriate cooling design and predict the frequency shift under operation. The center cell of the bridge coupler also contains a large 4-inch slug tuner and a tuning post that used to provide bulk frequency adjustment and field intensity adjustment, so that produce the proper total field distribution in the module assembly.

  15. Theoretical and Experimental Study of Light Shift in a CPT-Based RB Vapor Cell Frequency Standard

    Science.gov (United States)

    2001-01-01

    Questions and Answers ROBERT LUTWAK (Datum): When you servo the microwave power to eliminate the light shift, what do you servo to? To what are you...leveling that signal? MIA0 ZHU: Do you mean what I servo to o r where did I do the servo? LUTWAK : What is the error signal that determines the TR

  16. The doppler frequency shift caused by the inhomogeneities of a medium induced by pulses of intense laser radiation

    Science.gov (United States)

    Rozanov, N. N.; Kiselev, Al. S.; Kiselev, An. S.

    2008-08-01

    Self-reflection of pulses of intense laser radiation from an inhomogeneity induced by them in a medium with fast optical nonlinearity is analyzed. The reflected radiation is characterized by a considerable Doppler shift and by a signal magnitude that is sufficient for experimental detection.

  17. A photonic circuit for complementary frequency shifting, in-phase quadrature/single sideband modulation and frequency multiplication: analysis and integration feasibility

    Science.gov (United States)

    Hasan, Mehedi; Hu, Jianqi; Nikkhah, Hamdam; Hall, Trevor

    2017-08-01

    A novel photonic integrated circuit architecture for implementing orthogonal frequency division multiplexing by means of photonic generation of phase-correlated sub-carriers is proposed. The circuit can also be used for implementing complex modulation, frequency up-conversion of the electrical signal to the optical domain and frequency multiplication. The principles of operation of the circuit are expounded using transmission matrices and the predictions of the analysis are verified by computer simulation using an industry-standard software tool. Non-ideal scenarios that may affect the correct function of the circuit are taken into consideration and quantified. The discussion of integration feasibility is illustrated by a photonic integrated circuit that has been fabricated using 'library' components and which features most of the elements of the proposed circuit architecture. The circuit is found to be practical and may be fabricated in any material platform that offers a linear electro-optic modulator such as organic or ferroelectric thin films hybridized with silicon photonics.

  18. Upward creep of the heart: A frequent source of false-positive reversible defects during thallium-201 stress-redistribution SPECT

    International Nuclear Information System (INIS)

    Friedman, J.; Van Train, K.; Maddahi, J.; Rozanski, A.; Prigent, F.; Bietendorf, J.; Waxman, A.; Berman, D.S.

    1989-01-01

    A new cause of artifactual 201 Tl defects on single photon emission computed tomography (SPECT) termed upward creep of the heart is described. In 102 consecutive patients undergoing 201 Tl SPECT, 30 (29%) demonstrated upward creep defined by an upward movement of the heart of greater than or equal to 2 pixels during acquisition. In 45 consecutive patients with a less than 5% likelihood of coronary artery disease, 17 (38%) had upward creep. Of these nine had reversible 201 Tl defects localized to the inferior and basal inferoseptal walls, while none of the 28 without upward creep had defects. The 17 low likelihood patients with upward creep had longer exercise duration and higher peak heart rate than those without upward creep. In five additional low likelihood patients with upward creep in whom imaging was immediately repeated, the upward creep pattern disappeared on the repeated images. After we changed our test protocol to begin imaging 15 min postexercise, only five (14%) of 36 low likelihood patients tested demonstrated upward creep. Upward creep is probably related to a transient increase in mean total lung volume early following exhaustive exercise, resulting in a mean lower position of the diaphragm (and thus the heart) at the beginning of imaging. The frequency of this source of false-positive 201 Tl studies can be reduced by delaying SPECT acquisition until 15 min postexercise

  19. Solid state NMR of proteins at high MAS frequencies: symmetry-based mixing and simultaneous acquisition of chemical shift correlation spectra

    International Nuclear Information System (INIS)

    Bellstedt, Peter; Herbst, Christian; Häfner, Sabine; Leppert, Jörg; Görlach, Matthias; Ramachandran, Ramadurai

    2012-01-01

    We have carried out chemical shift correlation experiments with symmetry-based mixing sequences at high MAS frequencies and examined different strategies to simultaneously acquire 3D correlation spectra that are commonly required in the structural studies of proteins. The potential of numerically optimised symmetry-based mixing sequences and the simultaneous recording of chemical shift correlation spectra such as: 3D NCAC and 3D NHH with dual receivers, 3D NC′C and 3D C′NCA with sequential 13 C acquisitions, 3D NHH and 3D NC′H with sequential 1 H acquisitions and 3D CANH and 3D C’NH with broadband 13 C– 15 N mixing are demonstrated using microcrystalline samples of the β1 immunoglobulin binding domain of protein G (GB1) and the chicken α-spectrin SH3 domain.

  20. Solid state NMR of proteins at high MAS frequencies: symmetry-based mixing and simultaneous acquisition of chemical shift correlation spectra

    Energy Technology Data Exchange (ETDEWEB)

    Bellstedt, Peter [Fritz Lipmann Institute, Biomolecular NMR spectroscopy, Leibniz Institute for Age Research (Germany); Herbst, Christian [Ubon Ratchathani University, Department of Physics, Faculty of Science (Thailand); Haefner, Sabine; Leppert, Joerg; Goerlach, Matthias; Ramachandran, Ramadurai, E-mail: raman@fli-leibniz.de [Fritz Lipmann Institute, Biomolecular NMR spectroscopy, Leibniz Institute for Age Research (Germany)

    2012-12-15

    We have carried out chemical shift correlation experiments with symmetry-based mixing sequences at high MAS frequencies and examined different strategies to simultaneously acquire 3D correlation spectra that are commonly required in the structural studies of proteins. The potential of numerically optimised symmetry-based mixing sequences and the simultaneous recording of chemical shift correlation spectra such as: 3D NCAC and 3D NHH with dual receivers, 3D NC Prime C and 3D C Prime NCA with sequential {sup 13}C acquisitions, 3D NHH and 3D NC Prime H with sequential {sup 1}H acquisitions and 3D CANH and 3D C'NH with broadband {sup 13}C-{sup 15}N mixing are demonstrated using microcrystalline samples of the {beta}1 immunoglobulin binding domain of protein G (GB1) and the chicken {alpha}-spectrin SH3 domain.

  1. Wearable Multi-Frequency and Multi-Segment Bioelectrical Impedance Spectroscopy for Unobtrusively Tracking Body Fluid Shifts during Physical Activity in Real-Field Applications: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Federica Villa

    2016-05-01

    Full Text Available Bioelectrical Impedance Spectroscopy (BIS allows assessing the composition of body districts noninvasively and quickly, potentially providing important physiological/clinical information. However, neither portable commercial instruments nor more advanced wearable prototypes simultaneously satisfy the demanding needs of unobtrusively tracking body fluid shifts in different segments simultaneously, over a broad frequency range, for long periods and with high measurements rate. These needs are often required to evaluate exercise tests in sports or rehabilitation medicine, or to assess gravitational stresses in aerospace medicine. Therefore, the aim of this work is to present a new wearable prototype for monitoring multi-segment and multi-frequency BIS unobtrusively over long periods. Our prototype guarantees low weight, small size and low power consumption. An analog board with current-injecting and voltage-sensing electrodes across three body segments interfaces a digital board that generates square-wave current stimuli and computes impedance at 10 frequencies from 1 to 796 kHz. To evaluate the information derivable from our device, we monitored the BIS of three body segments in a volunteer before, during and after physical exercise and postural shift. We show that it can describe the dynamics of exercise-induced changes and the effect of a sit-to-stand maneuver in active and inactive muscular districts separately and simultaneously.

  2. Sky glint correction in measurements of upward radiance above the sea surface

    Directory of Open Access Journals (Sweden)

    Jerzy Olszewski

    2000-06-01

    Full Text Available An experiment has been performed to determine the upward water-leaving radiance by non-contact measurement of the total upward and downward radiance above the sea surface from a moving ship. The method for achieving this aim is described: the radiance meters are both tilted in such a way that the upward radiance meter can 'see' that part of the measured downward radiance which would be reflected if the water surface were smooth and which is not derived directly from solar glitter. Both meters are firmly fixed in a special frame, which ensures that the required orientation is the most probable one. Time records of the measured parameters are analysed. The results are presented in several forms: frequency (histogram analysis appears to be the most promising one.

  3. Stochastic modelling of shifts in allele frequencies reveals a strongly polygynous mating system in the re-introduced Asiatic wild ass.

    Science.gov (United States)

    Renan, Sharon; Greenbaum, Gili; Shahar, Naama; Templeton, Alan R; Bouskila, Amos; Bar-David, Shirli

    2015-04-01

    Small populations are prone to loss of genetic variation and hence to a reduction in their evolutionary potential. Therefore, studying the mating system of small populations and its potential effects on genetic drift and genetic diversity is of high importance for their viability assessments. The traditional method for studying genetic mating systems is paternity analysis. Yet, as small populations are often rare and elusive, the genetic data required for paternity analysis are frequently unavailable. The endangered Asiatic wild ass (Equus hemionus), like all equids, displays a behaviourally polygynous mating system; however, the level of polygyny has never been measured genetically in wild equids. Combining noninvasive genetic data with stochastic modelling of shifts in allele frequencies, we developed an alternative approach to paternity analysis for studying the genetic mating system of the re-introduced Asiatic wild ass in the Negev Desert, Israel. We compared the shifts in allele frequencies (as a measure of genetic drift) that have occurred in the wild ass population since re-introduction onset to simulated scenarios under different proportions of mating males. We revealed a strongly polygynous mating system in which less than 25% of all males participate in the mating process each generation. This strongly polygynous mating system and its potential effect on the re-introduced population's genetic diversity could have significant consequences for the long-term persistence of the population in the Negev. The stochastic modelling approach and the use of allele-frequency shifts can be further applied to systems that are affected by genetic drift and for which genetic data are limited. © 2015 John Wiley & Sons Ltd.

  4. Dipole, quadrupole, and octupole terms in the long-range hyperfine frequency shift for hydrogen in the presence of inert gases

    International Nuclear Information System (INIS)

    Greenwood, W.G.; Tang, K.T.

    1987-01-01

    The R -6 , R -8 , and R -10 terms in the long-range expansion for the hyperfine frequency shift are calculated for hydrogen in the presence of He, Ne, Ar, Kr, and Xe. The R -6 terms are based on the dipole oscillator strength sums. For helium, the R -8 and R -10 terms are based on quadrupole and octupole oscillator strength sums. For the heavier inert gases, the results for the R -8 and R -10 terms are obtained from the sum rules and the static polarizabilities. Upper bounds are also determined for the R -8 and R -10 terms

  5. Warming-induced upward migration of the alpine treeline in the Changbai Mountains, northeast China.

    Science.gov (United States)

    Du, Haibo; Liu, Jie; Li, Mai-He; Büntgen, Ulf; Yang, Yue; Wang, Lei; Wu, Zhengfang; He, Hong S

    2018-03-01

    Treeline responses to environmental changes describe an important phenomenon in global change research. Often conflicting results and generally too short observations are, however, still challenging our understanding of climate-induced treeline dynamics. Here, we use a state-of-the-art dendroecological approach to reconstruct long-term changes in the position of the alpine treeline in relation to air temperature at two sides in the Changbai Mountains in northeast China. Over the past 160 years, the treeline increased by around 80 m, a process that can be divided into three phases of different rates and drives. The first phase was mainly influenced by vegetation recovery after an eruption of the Tianchi volcano in 1702. The slowly upward shift in the second phase was consistent with the slowly increasing temperature. The last phase coincided with rapid warming since 1985, and shows with 33 m per 1°C, the most intense upward shift. The spatial distribution and age structure of trees beyond the current treeline confirm the latest, warming-induced upward shift. Our results suggest that the alpine treeline will continue to rise, and that the alpine tundra may disappear if temperatures will increase further. This study not only enhances mechanistic understanding of long-term treeline dynamics, but also highlights the effects of rising temperatures on high-elevation vegetation dynamics. © 2017 John Wiley & Sons Ltd.

  6. Shifts in diversification rates and host jump frequencies shaped the diversity of host range among Sclerotiniaceae fungal plant pathogens

    OpenAIRE

    Taylor, Andrew; Clarkson, John; Raffaele, Sylvain; Navaud, Olivier; Barbacci, Adelin

    2017-01-01

    The range of hosts that a parasite can infect in nature is a trait determined by its own evolutionary history and that of its potential hosts. However, knowledge on host range diversity and evolution at the family level is often lacking. Here, we investigate host range variation and diversification trends within the Sclerotiniaceae , a family of Ascomycete fungi. Using a phylogenetic framework, we associate diversification rates, the frequency of host jump events, and host range variation dur...

  7. MR imaging of osteonecrosis using frequency selective chemical shift sequences; Neue Aspekte in der MR-Diagnostik der Osteonekrose: Selektive Fett/Wasser-Bildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Duda, S H [Abt. fuer Radiologische Diagnostik, Tuebingen Univ. (Germany); Laniado, M [Abt. fuer Radiologische Diagnostik, Tuebingen Univ. (Germany); Schick, F [Inst. fuer Physik, Tuebingen Univ. (Germany)

    1994-12-31

    The MR appearance of osteonecrosis was assessed on selective fat- and water images to further evaluate the nature of double-line sign. Conventional T1- and T2-weighted SE and frequency selective chemical shift images of eight patients with avascular necrosis of the femoral head and three patients with bone infarcts were retrospectively reviewed. Eight of 11 patients showed a double-line sign on T2-weighted SE images. In these cases, correlation with selective water images revealed that a chemical shift artifact contributed to appearance and location of the hyperintense line. The authors conclude that chemical shift imaging improves our understanding of the nature of the double-line sign. (orig.) [Deutsch] Das MR-tomographische Erscheinungsbild der Osteonekrose auf selektiven Fett- und Wasserbildern wurde analysiert, um das in der Literatur beschriebene Doppellinienzeichen naeher zu untersuchen. Hierfuer wurden sowohl die herkoemmlichen T1- und T2-gewichteten Spin-Echo-Sequenzen herangezogen, als auch frequenzselektive Bilder, die aufgrund chemischer Verschiebung gewonnen wurden (1,5 T). Es wurden die Untersuchungen von acht Patienten mit avaskulaerer Hueftkopfnekrose und von drei Patienten mit Knocheninfarkten retrospektiv ausgewertet. Acht von 11 Patienten zeigten ein Doppellinienzeichen auf den T2-gewichteten Bildern. Die Korrelation mit den selektiven Wasserbildern ergab, dass durch chemische Verschiebung bedingte Artefakte das Erscheinungsbild und den Ort der hyperintensen Linie beeinflussten. Die Bildgebung mit Hilfe der chemischen Verschiebung verbessert unser Verstaendnis der MRT-Charakteristika der Osteonekrose. (orig.)

  8. A novel femtosecond-gated, high-resolution, frequency-shifted shearing interferometry technique for probing pre-plasma expansion in ultra-intense laser experiments

    Energy Technology Data Exchange (ETDEWEB)

    Feister, S., E-mail: feister.7@osu.edu; Orban, C. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Innovative Scientific Solutions, Inc., Dayton, Ohio 45459 (United States); Nees, J. A. [Innovative Scientific Solutions, Inc., Dayton, Ohio 45459 (United States); Center for Ultra-Fast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Morrison, J. T. [Fellow, National Research Council, Washington, D.C. 20001 (United States); Frische, K. D. [Innovative Scientific Solutions, Inc., Dayton, Ohio 45459 (United States); Chowdhury, E. A. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Intense Energy Solutions, LLC., Plain City, Ohio 43064 (United States); Roquemore, W. M. [Air Force Research Laboratory, Dayton, Ohio 45433 (United States)

    2014-11-15

    Ultra-intense laser-matter interaction experiments (>10{sup 18} W/cm{sup 2}) with dense targets are highly sensitive to the effect of laser “noise” (in the form of pre-pulses) preceding the main ultra-intense pulse. These system-dependent pre-pulses in the nanosecond and/or picosecond regimes are often intense enough to modify the target significantly by ionizing and forming a plasma layer in front of the target before the arrival of the main pulse. Time resolved interferometry offers a robust way to characterize the expanding plasma during this period. We have developed a novel pump-probe interferometry system for an ultra-intense laser experiment that uses two short-pulse amplifiers synchronized by one ultra-fast seed oscillator to achieve 40-fs time resolution over hundreds of nanoseconds, using a variable delay line and other techniques. The first of these amplifiers acts as the pump and delivers maximal energy to the interaction region. The second amplifier is frequency shifted and then frequency doubled to generate the femtosecond probe pulse. After passing through the laser-target interaction region, the probe pulse is split and recombined in a laterally sheared Michelson interferometer. Importantly, the frequency shift in the probe allows strong plasma self-emission at the second harmonic of the pump to be filtered out, allowing plasma expansion near the critical surface and elsewhere to be clearly visible in the interferograms. To aid in the reconstruction of phase dependent imagery from fringe shifts, three separate 120° phase-shifted (temporally sheared) interferograms are acquired for each probe delay. Three-phase reconstructions of the electron densities are then inferred by Abel inversion. This interferometric system delivers precise measurements of pre-plasma expansion that can identify the condition of the target at the moment that the ultra-intense pulse arrives. Such measurements are indispensable for correlating laser pre-pulse measurements

  9. High-resolution quantization based on soliton self-frequency shift and spectral compression in a bi-directional comb-fiber architecture

    Science.gov (United States)

    Zhang, Xuyan; Zhang, Zhiyao; Wang, Shubing; Liang, Dong; Li, Heping; Liu, Yong

    2018-03-01

    We propose and demonstrate an approach that can achieve high-resolution quantization by employing soliton self-frequency shift and spectral compression. Our approach is based on a bi-directional comb-fiber architecture which is composed of a Sagnac-loop-based mirror and a comb-like combination of N sections of interleaved single-mode fibers and high nonlinear fibers. The Sagnac-loop-based mirror placed at the terminal of a bus line reflects the optical pulses back to the bus line to achieve additional N-stage spectral compression, thus single-stage soliton self-frequency shift (SSFS) and (2 N - 1)-stage spectral compression are realized in the bi-directional scheme. The fiber length in the architecture is numerically optimized, and the proposed quantization scheme is evaluated by both simulation and experiment in the case of N = 2. In the experiment, a quantization resolution of 6.2 bits is obtained, which is 1.2-bit higher than that of its uni-directional counterpart.

  10. The electronic donation and frequency shifts on the YCCH⋯BH4- boron-bonded complexes (Y = H, CH3, CF3 and CCl3)

    Science.gov (United States)

    Pordeus, Renato Q.; Rego, Danilo G.; Oliveira, Boaz G.

    2015-06-01

    In this theoretical work, the tetrahydroborate ion (BH4-) was used as proton acceptor in the formation of the YCC-H⋯BH4- complexes (Y = H, CH3, CCl3 and CF3). Using B3LYP/6-311++G(d,p) level of theory, the results of structure corroborate with the analyses of infrared spectra showing that the changes in the bond lengths are in good agreement with the frequency shifts of the HCC-H, H3CCC-H, Cl3CCC-H and F3CCC-H proton donors. Based on the calculations carried out by the Quantum Theory of Atoms in Molecules (QTAIM), the reductions of electronic density corroborate with the red shifts in the frequencies of the C-H bonds. In addition to that, the C-H bonds are polarized because the contributions of s orbital diminish whereas of p increase. In line with this, the variations on the atomic radii computed via QTAIM calculations show that carbon outweigh hydrogen as follows (ΔrC > ΔrH). This scenario is indirectly supported by the Bent's rule of the chemical bonding. Although the interaction energies (corrected with BSSE and ZPE) vary between -19 and -67 kJ mol-1, these complexes interact without covalent character.

  11. The electronic donation and frequency shifts on the YCCH⋯BH₄⁻ boron-bonded complexes (Y=H, CH₃, CF₃ and CCl₃).

    Science.gov (United States)

    Pordeus, Renato Q; Rego, Danilo G; Oliveira, Boaz G

    2015-06-15

    In this theoretical work, the tetrahydroborate ion (BH4(-)) was used as proton acceptor in the formation of the YCC-H⋯BH4(-) complexes (Y=H, CH3, CCl3 and CF3). Using B3LYP/6-311++G(d,p) level of theory, the results of structure corroborate with the analyses of infrared spectra showing that the changes in the bond lengths are in good agreement with the frequency shifts of the HCC-H, H3CCC-H, Cl3CCC-H and F3CCC-H proton donors. Based on the calculations carried out by the Quantum Theory of Atoms in Molecules (QTAIM), the reductions of electronic density corroborate with the red shifts in the frequencies of the C-H bonds. In addition to that, the C-H bonds are polarized because the contributions of s orbital diminish whereas of p increase. In line with this, the variations on the atomic radii computed via QTAIM calculations show that carbon outweigh hydrogen as follows (ΔrC>ΔrH). This scenario is indirectly supported by the Bent's rule of the chemical bonding. Although the interaction energies (corrected with BSSE and ZPE) vary between -19 and -67 kJ mol(-1), these complexes interact without covalent character. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Detailed discussion of a linear electric field frequency shift induced in confined gases by a magnetic field gradient: Implications for neutron electric-dipole-moment experiments

    International Nuclear Information System (INIS)

    Lamoreaux, S.K.; Golub, R.

    2005-01-01

    The search for particle electric dipole moments (EDM's) is one of the best places to look for physics beyond the standard model of electroweak interaction because the size of time reversal violation predicted by the standard model is incompatible with present ideas concerning the creation of the baryon-antibaryon asymmetry. As the sensitivity of these EDM searches increases more subtle systematic effects become important. We develop a general analytical approach to describe a systematic effect recently observed in an electric dipole moment experiment using stored particles [J. M. Pendlebury et al., Phys. Rev. A 70, 032102 (2004)]. Our approach is based on the relationship between the systematic frequency shift and the velocity autocorrelation function of the resonating particles. Our results, when applied to well-known limiting forms of the correlation function, are in good agreement with both the limiting cases studied in recent work that employed a numerical and heuristic analysis. Our general approach explains some of the surprising results observed in that work and displays the rich behavior of the shift for intermediate frequencies, which has not been studied previously

  13. Shifts in diversification rates and host jump frequencies shaped the diversity of host range among Sclerotiniaceae fungal plant pathogens.

    Science.gov (United States)

    Navaud, Olivier; Barbacci, Adelin; Taylor, Andrew; Clarkson, John P; Raffaele, Sylvain

    2018-03-01

    The range of hosts that a parasite can infect in nature is a trait determined by its own evolutionary history and that of its potential hosts. However, knowledge on host range diversity and evolution at the family level is often lacking. Here, we investigate host range variation and diversification trends within the Sclerotiniaceae, a family of Ascomycete fungi. Using a phylogenetic framework, we associate diversification rates, the frequency of host jump events and host range variation during the evolution of this family. Variations in diversification rate during the evolution of the Sclerotiniaceae define three major macro-evolutionary regimes with contrasted proportions of species infecting a broad range of hosts. Host-parasite cophylogenetic analyses pointed towards parasite radiation on distant hosts long after host speciation (host jump or duplication events) as the dominant mode of association with plants in the Sclerotiniaceae. The intermediate macro-evolutionary regime showed a low diversification rate, high frequency of duplication events and the highest proportion of broad host range species. Our findings suggest that the emergence of broad host range fungal pathogens results largely from host jumps, as previously reported for oomycete parasites, probably combined with low speciation rates. These results have important implications for our understanding of fungal parasites evolution and are of particular relevance for the durable management of disease epidemics. © 2018 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

  14. Health State Monitoring of Bladed Machinery with Crack Growth Detection in BFG Power Plant Using an Active Frequency Shift Spectral Correction Method

    Directory of Open Access Journals (Sweden)

    Weifang Sun

    2017-08-01

    Full Text Available Power generation using waste-gas is an effective and green way to reduce the emission of the harmful blast furnace gas (BFG in pig-iron producing industry. Condition monitoring of mechanical structures in the BFG power plant is of vital importance to guarantee their safety and efficient operations. In this paper, we describe the detection of crack growth of bladed machinery in the BFG power plant via vibration measurement combined with an enhanced spectral correction technique. This technique enables high-precision identification of amplitude, frequency, and phase information (the harmonic information belonging to deterministic harmonic components within the vibration signals. Rather than deriving all harmonic information using neighboring spectral bins in the fast Fourier transform spectrum, this proposed active frequency shift spectral correction method makes use of some interpolated Fourier spectral bins and has a better noise-resisting capacity. We demonstrate that the identified harmonic information via the proposed method is of suppressed numerical error when the same level of noises is presented in the vibration signal, even in comparison with a Hanning-window-based correction method. With the proposed method, we investigated vibration signals collected from a centrifugal compressor. Spectral information of harmonic tones, related to the fundamental working frequency of the centrifugal compressor, is corrected. The extracted spectral information indicates the ongoing development of an impeller blade crack that occurred in the centrifugal compressor. This method proves to be a promising alternative to identify blade cracks at early stages.

  15. Exploring the Future of Fuel Loads in Tasmania, Australia: Shifts in Vegetation in Response to Changing Fire Weather, Productivity, and Fire Frequency

    Directory of Open Access Journals (Sweden)

    Rebecca Mary Bernadette Harris

    2018-04-01

    Full Text Available Changes to the frequency of fire due to management decisions and climate change have the potential to affect the flammability of vegetation, with long-term effects on the vegetation structure and composition. Frequent fire in some vegetation types can lead to transformational change beyond which the vegetation type is radically altered. Such feedbacks limit our ability to project fuel loads under future climatic conditions or to consider the ecological tradeoffs associated with management burns. We present a “pathway modelling” approach to consider multiple transitional pathways that may occur under different fire frequencies. The model combines spatial layers representing current and future fire danger, biomass, flammability, and sensitivity to fire to assess potential future fire activity. The layers are derived from a dynamically downscaled regional climate model, attributes from a regional vegetation map, and information about fuel characteristics. Fire frequency is demonstrated to be an important factor influencing flammability and availability to burn and therefore an important determinant of future fire activity. Regional shifts in vegetation type occur in response to frequent fire, as the rate of change differs across vegetation type. Fire-sensitive vegetation types move towards drier, more fire-adapted vegetation quickly, as they may be irreversibly impacted by even a single fire, and require very long recovery times. Understanding the interaction between climate change and fire is important to identify appropriate management regimes to sustain fire-sensitive communities and maintain the distribution of broad vegetation types across the landscape.

  16. Health State Monitoring of Bladed Machinery with Crack Growth Detection in BFG Power Plant Using an Active Frequency Shift Spectral Correction Method.

    Science.gov (United States)

    Sun, Weifang; Yao, Bin; He, Yuchao; Chen, Binqiang; Zeng, Nianyin; He, Wangpeng

    2017-08-09

    Power generation using waste-gas is an effective and green way to reduce the emission of the harmful blast furnace gas (BFG) in pig-iron producing industry. Condition monitoring of mechanical structures in the BFG power plant is of vital importance to guarantee their safety and efficient operations. In this paper, we describe the detection of crack growth of bladed machinery in the BFG power plant via vibration measurement combined with an enhanced spectral correction technique. This technique enables high-precision identification of amplitude, frequency, and phase information (the harmonic information) belonging to deterministic harmonic components within the vibration signals. Rather than deriving all harmonic information using neighboring spectral bins in the fast Fourier transform spectrum, this proposed active frequency shift spectral correction method makes use of some interpolated Fourier spectral bins and has a better noise-resisting capacity. We demonstrate that the identified harmonic information via the proposed method is of suppressed numerical error when the same level of noises is presented in the vibration signal, even in comparison with a Hanning-window-based correction method. With the proposed method, we investigated vibration signals collected from a centrifugal compressor. Spectral information of harmonic tones, related to the fundamental working frequency of the centrifugal compressor, is corrected. The extracted spectral information indicates the ongoing development of an impeller blade crack that occurred in the centrifugal compressor. This method proves to be a promising alternative to identify blade cracks at early stages.

  17. Frequency up-shift in the stimulated thermal scattering under two-photon absorption in liquids and colloids of metal nanoparticles

    Science.gov (United States)

    Smetanin, I. V.; Erokhin, A. I.; Baranov, A. N.

    2018-07-01

    We report the results of the experimental and theoretical study of stimulated temperature scattering in toluene and hexane solutions of Ag-nanoparticles, as well as in pure toluene in the two-photon absorption regime. A four-wave mixing scheme with two counter-propagating pump waves of the same frequency is utilised to demonstrate the lasing effect and the amplification of the backscattered anti-Stokes signal. For the first time, we have measured anti-Stokes spectral shifts which turn out to appreciably exceed the Rayleigh line widths in those liquids. It is shown that the amplification effect is provided predominantly by thermally induced coherent polarisation oscillations, while the dynamic interference temperature grating causes the formation of a self-induced optical cavity inside the interaction region.

  18. An in-building network based on community access television integration with quadrature phase-shift keying orthogonal frequency-division multiplexing

    International Nuclear Information System (INIS)

    Chen, Chia-Yi; Lin, Ying-Pyng; Lu, Hai-Han; Wu, Po-Yi; Lin, Huang-Chang; Wu, Hsiao-Wen

    2012-01-01

    An in-building network based on cable television (CATV) integration with quadrature phase-shift keying (QPSK) orthogonal frequency-division multiplexing (OFDM) transport over a combination of single-mode fibers (SMF) and perfluorinated graded-index plastic optical fibers (GI-POF) is proposed and experimentally demonstrated. In this system, a 1558.5 nm optical signal is directly transmitted along two fiber spans (20 km SMF + 25 m GI-POF). An optimum guard band is carefully established to ensure that no very substantial signal interference is induced between the CATV and QPSK OFDM bands. Error free transmission with sufficiently low bit error rate values was achieved for 1.25 Gbps/771.5 MHz QPSK OFDM signals; also, acceptable carrier-to-noise ratio, composite second-order, and composite triple-beat performances were obtained for CATV signals. This proposed network is significant because it is economical and convenient to install. (paper)

  19. Immersion angle dependence of the resonant-frequency shift of the quartz crystal microbalance in a liquid: effects of longitudinal wave.

    Science.gov (United States)

    Yoshimoto, Minoru; Kobirata, Satoshi; Aizawa, Hideo; Kurosawa, Shigeru

    2007-06-19

    We investigated the effects of the longitudinal wave on the immersion angle dependence of the resonant-frequency shift, deltaF, of the quartz crystal microbalance, QCM. In order to study exactly the effects, we employed the three types of cells: normal cell, cell with the glass beads and cell with sponge. The longitudinal wave exists in the normal cell. On the other hand, both the cell with the glass beads and the cell with sponge eliminate the longitudinal wave. As results, we have found that the tendencies of deltaF are the same in the three types of cells. That is, we conclude that the longitudinal wave does not have effects on the immersion angle dependence of deltaF.

  20. Application of a novel measure of EEG non-stationarity as 'Shannon- entropy of the peak frequency shifting' for detecting residual abnormalities in concussed individuals.

    Science.gov (United States)

    Cao, Cheng; Slobounov, Semyon

    2011-07-01

    The aim of this report was to propose a novel measure of non-stationarity of EEG signals, named Shannon- entropy of the peak frequency shifting (SEPFS). The feasibility of this method was documented comparing this measure with traditional time domain assessment of non-stationarity and its application to EEG data sets obtained from student-athletes before and after suffering a single episode of mild traumatic brain injury (mTBI) with age-matched normal controls. Instead of assessing the power density distribution on the time-frequency plane, like previously proposed measures of signal non-stationarity, this new measure is based on the shift of the dominant frequency of the EEG signal over time. We applied SEPFS measure to assess the properties of EEG non-stationarity in subjects before and shortly after they suffered mTBI. Student-athletes at high risk for mTBI (n=265) were tested prior to concussive episodes as a baseline. From this subject pool, 30 athletes who suffered from mTBI were retested on day 30 post-injury. Additional subjects pool (student-athletes without history of concussion, n=30) were recruited and test-re-tested within the same 30 day interval. Thirty-two channels EEG signals were acquired in sitting eyes closed condition. The results showed that the SEPFS values significantly decreased in subjects suffering from mTBI. Specifically, reduced EEG non-stationarity was observed in occipital, temporal and central brain areas, indicating the possibility of residual brain dysfunctions in concussed individuals. A similar but less statistically significant trend was observed using traditional time domain analysis of EEG non-stationarity. The proposed measure has at least two merits of interest: (1) it is less affected by the limited resolution of time-frequency representation of the EEG signal; (2) it takes into account the neural characteristics of the EEG signal that have not been considered in previously proposed measures of non-stationarity. This new

  1. Widely tunable dispersive wave generation and soliton self-frequency shift in a tellurite microstructured optical fiber pumped near the zero dispersion wavelength

    International Nuclear Information System (INIS)

    Zhang, Lei; Tuan, Tong-Hoang; Liu, Lai; Gao, Wei-Qing; Kawamura, Harutaka; Suzuki, Takenobu; Ohishi, Yasutake

    2015-01-01

    Widely tunable dispersive waves (DW) and Raman solitons are generated in a tellurite microstructured optical fiber (TMOF) by pumping in the anomalous dispersion regime, close to the zero dispersion wavelength (ZDW). The DW can be generated from 1518.3 nm to 1315.5 nm, and the soliton can be shifted from the pump wavelength of 1570 nm to 1828.7 nm, by tuning the average pump power from 3 dBm to 17.5 dBm. After the average pump power is increased to 18.8 dBm, two DW peaks (centered at 1323 nm and 1260 nm) and three soliton peaks (centered at 1762 nm, 1825 nm, and 1896 nm) can be observed simultaneously. When the average pump power is greater than 23.4 dBm, a flat and broadband supercontinuum (SC) can be formed by the combined nonlinear effects of soliton self-frequency shift (SSFS), DW generation, and cross phase modulation (XPM). (paper)

  2. Synthesis of multi-wavelength temporal phase-shifting algorithms optimized for high signal-to-noise ratio and high detuning robustness using the frequency transfer function.

    Science.gov (United States)

    Servin, Manuel; Padilla, Moises; Garnica, Guillermo

    2016-05-02

    Synthesis of single-wavelength temporal phase-shifting algorithms (PSA) for interferometry is well-known and firmly based on the frequency transfer function (FTF) paradigm. Here we extend the single-wavelength FTF-theory to dual and multi-wavelength PSA-synthesis when several simultaneous laser-colors are present. The FTF-based synthesis for dual-wavelength (DW) PSA is optimized for high signal-to-noise ratio and minimum number of temporal phase-shifted interferograms. The DW-PSA synthesis herein presented may be used for interferometric contouring of discontinuous industrial objects. Also DW-PSA may be useful for DW shop-testing of deep free-form aspheres. As shown here, using the FTF-based synthesis one may easily find explicit DW-PSA formulae optimized for high signal-to-noise and high detuning robustness. To this date, no general synthesis and analysis for temporal DW-PSAs has been given; only ad hoc DW-PSAs formulas have been reported. Consequently, no explicit formulae for their spectra, their signal-to-noise, their detuning and harmonic robustness has been given. Here for the first time a fully general procedure for designing DW-PSAs (or triple-wavelengths PSAs) with desire spectrum, signal-to-noise ratio and detuning robustness is given. We finally generalize DW-PSA to higher number of wavelength temporal PSAs.

  3. Submarine Upward Looking Sonar Ice Draft Profile Data and Statistics

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of upward looking sonar draft data collected by submarines in the Arctic Ocean. It includes data from both U.S. Navy and Royal Navy...

  4. Human disturbance and upward expansion of plants in a warming climate

    Science.gov (United States)

    Dainese, Matteo; Aikio, Sami; Hulme, Philip E.; Bertolli, Alessio; Prosser, Filippo; Marini, Lorenzo

    2017-08-01

    Climate change is expected to trigger an upward expansion of plants in mountain regions and, although there is strong evidence that many native species have already shifted their distributions to higher elevations, little is known regarding how fast non-native species might respond to climate change. By analysing 131,394 occurrence records of 1,334 plant species collected over 20 years in the European Alps, we found that non-natives are spreading upwards approximately twice as fast as natives. Whereas the spread of natives was enhanced by traits favouring longer dispersal distances, this was not the case for non-natives. This was due to the non-native species pool already being strongly biased towards species that had traits facilitating spread. A large proportion of native and non-native species seemed to be able to spread upwards faster than the current velocity of climate change. In particular, long-distance dispersal events and proximity to roads proved to be key drivers for the observed rapid spread. Our findings highlight that invasions by non-native species into native alpine communities are a potentially significant additional pressure on these vulnerable ecosystems that are already likely to suffer dramatic vegetation changes with ongoing warming and increasing human activity in mountain regions.

  5. Evaluation of upward migration around a deep injection well

    International Nuclear Information System (INIS)

    Chia, Yeeping; Chiu, J.

    1994-01-01

    The long-term containment of injected wastes in the deep subsurface is expected to be achieved under suitable geologic and hydrologic conditions and by the use of competent engineering practices. Field experiences, however, indicate that waste containment may be affected by hydrologic conduits around the injection well. To assess the potential effects of these conduits, upward migration of injected waste is examined through the use of numerical models under various conditions. Test results indicate that without any preferential hydrologic conduits, most of the injected waste moves laterally in the injection interval, whereas only a small amount of waste migrates upward into the containment interval. When vertical fractures in the disturbed zone or defects in the cement seal around the wellbore exist, the contaminant can move rapidly upward along these conduits to an overlying aquifer, from which it migrates in the lateral direction. The contamination of the overlying aquifer that results from the upward migration of injected waste through these conduits cannot be impeded by a thick, low-permeability containment interval. However, when permeable interbeds exist within the containment interval, a significant portion of the waste migrating upward can be diverted laterally before reaching the overlying aquifer. The front of built-up pressure can reach the aquifer or permeable interbed immediately overlying the injection interval through the preferential hydrologic conduits shortly after the injection starts, but it cannot move farther upward because of pressure dissipation in the permeable formation. This study suggests that the injected waste has the potential to migrate upward into overlying formations through preferential migration conduits around the wellbore

  6. Upward continuation of Dome-C airborne gravity and comparison with GOCE gradients at orbit altitude in east Antarctica

    DEFF Research Database (Denmark)

    Yildiz, Hasan; Forsberg, René; Tscherning, Carl Christian

    2017-01-01

    spherical harmonic models confirmed the quality of the airborne data and that they contain more high-frequency signal than the global models. First, the airborne gravity data were upward continued to GOCE altitude to predict gravity gradients in the local North-East-Up reference frame. In this step...

  7. A self-consistent upward leader propagation model

    International Nuclear Information System (INIS)

    Becerra, Marley; Cooray, Vernon

    2006-01-01

    The knowledge of the initiation and propagation of an upward moving connecting leader in the presence of a downward moving lightning stepped leader is a must in the determination of the lateral attraction distance of a lightning flash by any grounded structure. Even though different models that simulate this phenomenon are available in the literature, they do not take into account the latest developments in the physics of leader discharges. The leader model proposed here simulates the advancement of positive upward leaders by appealing to the presently understood physics of that process. The model properly simulates the upward continuous progression of the positive connecting leaders from its inception to the final connection with the downward stepped leader (final jump). Thus, the main physical properties of upward leaders, namely the charge per unit length, the injected current, the channel gradient and the leader velocity are self-consistently obtained. The obtained results are compared with an altitude triggered lightning experiment and there is good agreement between the model predictions and the measured leader current and the experimentally inferred spatial and temporal location of the final jump. It is also found that the usual assumption of constant charge per unit length, based on laboratory experiments, is not valid for lightning upward connecting leaders

  8. Upwards Intensifiers in the English, German and Croatian Language

    Directory of Open Access Journals (Sweden)

    Anita Pavić Pintarić

    2014-12-01

    Full Text Available This paper investigates the upwards intensifiers (adverbs of intensifying in the English, German and Croatian language. Intensity as an important human cognitive category, and language expressivity is differently treated in grammars and dictionaries of all three languages, especially with respect to different degrees of intensity. In this paper we argue that it is possible to model a typology of upwards adverb intensifiers in the three languages, according to their morphosyntactic and semantic aspects. When it comes to intensifiers, it is necessary to describe which collocates are modified by intensifiers and which semantic fields the collocates belong to. The results of the corpus analysis based on Harry Potter novels show that all the three languages express the category of the upwards intensity in the same way: the number of intensifiers is similar, the collocates mostly belong to the same semantic fields and word classes, they have similar syntactic functions.

  9. Two upward lightning at the Eagle Nest tower

    OpenAIRE

    Montañá Puig, Juan; Van der Velde, Oscar Arnoud; Romero Durán, David; March Nomen, Víctor; Solà de Las Fuentes, Gloria; Pineda Ruegg, Nicolau; Soula, Serge; Hermoso Alameda, Blas

    2012-01-01

    A new instrument composed by a high speed camera, two high energy detectors, a E-field antenna and a VHF antenna were installed at the Eagle Nest tower (northeast of Spain) during summer 2011. With this equipment several lightning flashes to the tower and its vicinity have been observed. This paper presents two examples: the first was an upward negative leader triggered by a close c1oud-to-ground flash and the second was an upward negative flash not associated with previous lightning activity...

  10. Upward Pricing Pressure in Two-Sided Markets

    NARCIS (Netherlands)

    Affeldt, P.; Filistrucchi, L.; Klein, T.J.

    2012-01-01

    Abstract: Pricing pressure indices have recently been proposed as alternative screening devices for horizontal mergers involving differentiated products. We extend the concept of Upward Pricing Pressure (UPP) proposed by Farrell and Shapiro (2010) to two-sided markets. Examples of such markets are

  11. Upward pricing pressure in two-sided markets

    NARCIS (Netherlands)

    Affeldt, P.; Filistrucchi, L.; Klein, T.J.

    2013-01-01

    Measuring upward pricing pressure (UPP) has recently been proposed by Farrell and Shapiro (2010) as an alternative screening device for horizontal mergers. We extend the concept of UPP to two-sided markets. Examples of such markets are the newspaper market, where the demand for advertising is

  12. Upward Mobility Through Job Restructuring. Personnel Management Series No. 26.

    Science.gov (United States)

    Civil Service Commission, Washington, DC.

    The May, 1974, bulletin issued by the Civil Service Commission deals with job restructuring, the process of realigning job duties to develop technician-type or "bridge" jobs in Federal agencies, as a means to provide upward mobility for employees. Besides being highly beneficial to employees in dead end jobs at low grade levels, job restructuring…

  13. "Fist, Stick, Knife, Gun": Getting Real in Upward Bound.

    Science.gov (United States)

    Pace, Barbara G.; Adkins, Theresa A.

    2002-01-01

    Describes how a teacher found literature for Upward Bound students. Presents Geoffrey Canada's "Fist, Stick, Knife, Gun: A Personal History of Violence in America" as a nonfiction work to provide clarity and connections that might not have been available in a fictional work, yet it had elements of literary fiction that made the text…

  14. Managing upwards: a guide for the foundation year doctor.

    Science.gov (United States)

    Hooke, Rachel

    2009-06-01

    The concept of managing your boss sounds peculiar, as people usually only think of managing staff under them. Nevertheless, adept management 'upwards' can reap dividends. It is not manipulative or sly - it is about good working relations. This article is mainly about dealing with consultants. However, the same principles can apply to other doctors more senior than you in the team.

  15. Leadership Behaviour and Upward Feedback: Findings from a Longitudinal Intervention

    NARCIS (Netherlands)

    D. van Dierendonck (Dirk); C. Haynes (Clare); C. Borrill (Carol); C. Stride (Chris)

    2007-01-01

    textabstractA sample of 48 managers and 308 staff members of a community health care organization took part in a study to investigate the influence of participating in an upward feedback program on leadership behaviour, both as indicated be self-ratings and subordinates’ ratings. The research design

  16. Dynamics of rainwater lenses on upward seeping saline groundwater

    NARCIS (Netherlands)

    Eeman, Sara

    2017-01-01

    Fresh water is generally a limited resource in coastal areas which are often densely populated. In low-lying areas, groundwater is mostly saline and both agriculture and freshwater nature depend on a thin lens of rainwater that is formed by precipitation surplus on top of saline, upward seeping

  17. Upward counterfactual thinking and depression: A meta-analysis.

    Science.gov (United States)

    Broomhall, Anne Gene; Phillips, Wendy J; Hine, Donald W; Loi, Natasha M

    2017-07-01

    This meta-analysis examined the strength of association between upward counterfactual thinking and depressive symptoms. Forty-two effect sizes from a pooled sample of 13,168 respondents produced a weighted average effect size of r=.26, pdesign (cross-sectional versus longitudinal). Significant effect size heterogeneity was observed across sample types, methods of assessing upward counterfactual thinking, and types of depression scale. Significant positive effects were found in studies that employed samples of bereaved individuals, older adults, terminally ill patients, or university students, but not adolescent mothers or mixed samples. Both number-based and Likert-based upward counterfactual thinking assessments produced significant positive effects, with the latter generating a larger effect. All depression scales produced significant positive effects, except for the Psychiatric Epidemiology Research Interview. Research and theoretical implications are discussed in relation to cognitive theories of depression and the functional theory of upward counterfactual thinking, and important gaps in the extant research literature are identified. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Shift Colors

    Science.gov (United States)

    Publications & News Shift Colors Pages default Sign In NPC Logo Banner : Shift Colors Search Navy Personnel Command > Reference Library > Publications & News > Shift Colors Top Link Bar Navy Personnel Library Expand Reference Library Quick Launch Shift Colors Shift Colors Archives Mailing Address How to

  19. Upward swimming of a sperm cell in shear flow.

    Science.gov (United States)

    Omori, Toshihiro; Ishikawa, Takuji

    2016-03-01

    Mammalian sperm cells are required to swim over long distances, typically around 1000-fold their own length. They must orient themselves and maintain a swimming motion to reach the ovum, or egg cell. Although the mechanism of long-distance navigation is still unclear, one possible mechanism, rheotaxis, was reported recently. This work investigates the mechanism of the rheotaxis in detail by simulating the motions of a sperm cell in shear flow adjacent to a flat surface. A phase diagram was developed to show the sperm's swimming motion under different shear rates, and for varying flagellum waveform conditions. The results showed that, under shear flow, the sperm is able to hydrodynamically change its swimming direction, allowing it to swim upwards against the flow, which suggests that the upward swimming of sperm cells can be explained using fluid mechanics, and this can then be used to further understand physiology of sperm cell navigation.

  20. Liquid velocity in upward and downward air-water flows

    International Nuclear Information System (INIS)

    Sun Xiaodong; Paranjape, Sidharth; Kim, Seungjin; Ozar, Basar; Ishii, Mamoru

    2004-01-01

    Local characteristics of the liquid phase in upward and downward air-water two-phase flows were experimentally investigated in a 50.8-mm inner-diameter round pipe. An integral laser Doppler anemometry (LDA) system was used to measure the axial liquid velocity and its fluctuations. No effect of the flow direction on the liquid velocity radial profile was observed in single-phase liquid benchmark experiments. Local multi-sensor conductivity probes were used to measure the radial profiles of the bubble velocity and the void fraction. The measurement results in the upward and downward two-phase flows are compared and discussed. The results in the downward flow demonstrated that the presence of the bubbles tended to flatten the liquid velocity radial profile, and the maximum liquid velocity could occur off the pipe centerline, in particular at relatively low flow rates. However, the maximum liquid velocity always occurred at the pipe center in the upward flow. Also, noticeable turbulence enhancement due to the bubbles in the two-phase flows was observed in the current experimental flow conditions. Furthermore, the distribution parameter and the void-weighted area-averaged drift velocity were obtained based on the definitions

  1. Pressure-induced basilar membrane position shifts and the stimulus-evoked potentials in the low-frequency region of the guinea pig cochlea

    NARCIS (Netherlands)

    Fridberger, A; vanMaarseveen, JTPW; Scarfone, E; Ulfendahl, M; Flock, B; Flock, A

    1997-01-01

    We have used the guinea pig isolated temporal bone preparation to investigate changes in the nonlinear properties of the tone-evoked cochlear potentials during reversible step displacements of the basilar membrane towards either the scala tympani or the scala vestibuli. The position shifts were

  2. 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....

  3. Utility Assessment of Specificity in Upward Feedback Instruments for Leadership Development

    National Research Council Canada - National Science Library

    Wardak, Theresa

    2003-01-01

    ...) and the other is the recently developed, non-proprietary Upward Feedback Instrument (2002). The Upward Feedback Instrument was designed to measure leadership behaviors at a more specific level...

  4. Mixing of high density solution in vertical upward flow

    International Nuclear Information System (INIS)

    Kumamaru, Hiroshige; Hosogi, Nobuyoshi; Komada, Toshiaki; Fujiwara, Yoshiki

    1999-01-01

    Experimental and analytical studies have been performed in order to provide fundamental data and a numerical calculation model on the mixing of boric acid solution, injected from the standby liquid control system (SLCS), under a low natural circulation flow during an ATWS in a BWR. First, fundamental experiments on the mixing of high-density solution in vertically-upward water flow have been performed by using a small apparatus. Mixing patterns observed in the experiments have been classified to two groups, i.e. complete mixing (entrainment) and incomplete mixing (entrainment). In the complete mixing, the injected high-density solution is mixed (entrained) completely into the vertically-upward water flow. From the experiments, the minimum water flow rates in which the complete mixing (entrainment) is achieved have been obtained for various solution densities and solution injection rates. Secondly, two-dimensional numerical calculations have been performed. A continuity equation for total fluid, momentum equations in two directions and a continuity equation for solute are solved by using the finite difference method for discretization method and by following the MAC method for solution procedure. The calculations have predicted nearly the minimum water flow rate in which the complete mixing is achieved, while the calculations have been performed only for one combination of the solution density and solution injection rate until now. (author)

  5. Shifting Attention

    Science.gov (United States)

    Ingram, Jenni

    2014-01-01

    This article examines the shifts in attention and focus as one teacher introduces and explains an image that represents the processes involved in a numeric problem that his students have been working on. This paper takes a micro-analytic approach to examine how the focus of attention shifts through what the teacher and students do and say in the…

  6. The collective roots and rewards of upward educational mobility.

    Science.gov (United States)

    Shahrokni, Shirin

    2018-02-02

    Drawing on in-depth interviews with descendants of North African working-class immigrants admitted to elite higher institutions in France, this paper investigates the under-researched role of family dynamics in facilitating upward educational mobility and informing the experience of social ascension. It shows that concrete mobility strategies, such as authoritative parenting and close mentorship from older siblings have been deployed to enable the respondents' educational attainment. Moreover, a set of moral resources transmitted through stories about family-rooted aspirations and stories about post-migration hardships and sacrifices have contributed to forging strong motivational dispositions that have facilitated school success among the respondents. These resources have further shaped the symbolic significance the interviewees associate with mobility. In contrast with the dominant individual-centred narrative of success, for second-generation North African immigrants, mobility represents a powerful way of 'giving back' to former-generation migrants whose mobility dreams often had to be relinquished. The respondents also position themselves as role-models for other youths of racially and socially disadvantaged backgrounds: their mobility pathways are described as vital for collective advancements particularly through the sense of minority empowerment these generate. © London School of Economics and Political Science 2018.

  7. Binaural beats and frequency-coding.

    Science.gov (United States)

    Fritze, W; Köhler, W

    1986-01-01

    Binaural beats were studied before and during a situation of temporary threshold shift, and no frequency shift could be found. In contrast, subjective binaural frequency comparison revealed a distinct shift. These findings demonstrate the two known modes of perception.

  8. Market shifting

    Energy Technology Data Exchange (ETDEWEB)

    Forst, Michael

    2013-11-01

    After years of oversupply and artificially low module pricing, market analysts believe that the solar industry will begin to stabilize by 2017. While the market activities are shifting from Europe to the Asia Pacific region and the United States, the solar shakeout continues to be in full swing including solar cell and module manufacturing. (orig.)

  9. Tough Shift

    DEFF Research Database (Denmark)

    Brewer, Robert S.; Verdezoto, Nervo; Holst, Thomas

    2015-01-01

    people to change their behavior at home. Leveraging prior research on encouraging reductions in residential energy use through game play, we introduce ShareBuddy: a casual mobile game intended to encourage players not only to reduce, but also to shift their electricity use. We conducted two field studies...... real-world resource use into a game....

  10. Chemical shift imaging: a review

    International Nuclear Information System (INIS)

    Brateman, L.

    1986-01-01

    Chemical shift is the phenomenon that is seen when an isotope possessing a nuclear magnetic dipole moment resonates at a spectrum of resonance frequencies in a given magnetic field. These resonance frequencies, or chemical shifts, depend on the chemical environments of particular nuclei. Mapping the spatial distribution of nuclei associated with a particular chemical shift (e.g., hydrogen nuclei associated with water molecules or with lipid groups) is called chemical shift imaging. Several techniques of proton chemical shift imaging that have been applied in vivo are presented, and their clinical findings are reported and summarized. Acquiring high-resolution spectra for large numbers of volume elements in two or three dimensions may be prohibitive because of time constraints, but other methods of imaging lipid of water distributions (i.e., selective excitation, selective saturation, or variations in conventional magnetic resonance imaging pulse sequences) can provide chemical shift information. These techniques require less time, but they lack spectral information. Since fat deposition seen by chemical shift imaging may not be demonstrated by conventional magnetic resonance imaging, certain applications of chemical shift imaging, such as in the determination of fatty liver disease, have greater diagnostic utility than conventional magnetic resonance imaging. Furthermore, edge artifacts caused by chemical shift effects can be eliminated by certain selective methods of data acquisition employed in chemical shift imaging

  11. Frequency shift due to blackbody radiation in a cesium atomic fountain and improvement of the clock performances; Deplacement de frequence du au rayonnement du corps noir dans une fontaine atomique a cesium et amelioration des performances de l'horloge

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S

    2004-07-01

    FO1 was the first caesium fountain primary frequency standard in the world. The most recent evaluation in 2002 before improvement reached an accuracy of 1*10{sup -15} when operated with optical molasses. Working as an extremely precise and stable instrument, FO1 has contributed to fundamental physics and technical measurements: - Frequency comparison between Cs and Rb fountains over an interval of 5 years sets an upper limit for a possible variation of the fine structure constant as |alpha/alpha| < 2*10{sup -15}/y. The resolution is about 5 times better than the previous test in our laboratory. The projected accuracy of the space clock PHARAO is 1*10{sup -16}. We confirmed its Ramsey cavity performance by testing the phase difference between the two interaction zones in FO1. The measured temperature T dependent frequency shift of the Cs clock induced by the blackbody radiation field is given as nu(T)=154(6)*10{sup -6}*(T/300){sup 4}[1+{epsilon}(T/300){sup 2}] Hz with the theoretical value {epsilon} = 0,014. The obtained accuracy represents a 3 times improvement over the previous measurement by the PTB group. Some improvements have been carried out on FO1. The new FO1 version works directly with optical molasses loaded by a laser slowed atomic beam. The application of the adiabatic passage method to perform the state selection allows us to determine the atom number dependent frequency shifts due to the cold collision and cavity pulling effects at a level of of 10{sup -16}. Recently, the obtained frequency stability is 2,8*10{sup -14}*{tau}{sup -1/2} for about 4*10{sup 6} detected atoms. The accuracy is currently under evaluation, the expected value is a few times 10{sup -16}. (author)

  12. Representing or defecting ? : the pursuit of individual upward mobility in low status groups

    NARCIS (Netherlands)

    Bleeker, Dennis

    2010-01-01

    This dissertation investigated the conditions under which the individual upward mobility of mem-bers of low status groups is likely to succeed and when it is likely to meet resistance. In addition, it examines how upwardly mobile individuals can create such beneficial conditions. The results

  13. 34 CFR 645.1 - What is the Upward Bound Program?

    Science.gov (United States)

    2010-07-01

    ... participants the skills and motivation necessary to complete a program of secondary education and to enter and... the following three types of projects: (1) Regular Upward Bound projects. (2) Upward Bound Math and... Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY...

  14. Dual-Polarization Radar Observations of Upward Lightning-Producing Storms

    Science.gov (United States)

    Lueck, R.; Helsdon, J. H.; Warner, T.

    2013-12-01

    The Upward Lightning Triggering Study (UPLIGHTS) seeks to determine how upward lightning, which originates from the tips of tall objects, is triggered by nearby flash activity. As a component of this study we analyze standard and dual-polarization weather radar data. The Correlation Coefficient (CC) in particular can be used to identify and quantify the melting layer associated with storms that produce upward lightning. It has been proposed that positive charge generation due to aggregate shedding at the melting layer results in a positive charge region just above the cloud base. This positive charge region may serve as a positive potential well favorable for negative leader propagation, which initiate upward positive leaders from tall objects. We characterize the horizontal coverage, thickness and height of the melting layer in addition to cloud base heights when upward lightning occurs to determine trends and possible threshold criteria relating to upward lightning production. Furthermore, we characterize storm type and morphology using relevant schemes as well as precipitation type using the Hydrometer Classification Algorithm (HCA) for upward lightning-producing storms. Ice-phase hydrometeors have been shown to be a significant factor in thunderstorm electrification. Only a small fraction of storms produce upward lightning, so null cases will be examined and compared as well.

  15. Quantized beam shifts in graphene

    Energy Technology Data Exchange (ETDEWEB)

    de Melo Kort-Kamp, Wilton Junior [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sinitsyn, Nikolai [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dalvit, Diego Alejandro Roberto [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-10-08

    We predict the existence of quantized Imbert-Fedorov, Goos-Hanchen, and photonic spin Hall shifts for light beams impinging on a graphene-on-substrate system in an external magnetic field. In the quantum Hall regime the Imbert-Fedorov and photonic spin Hall shifts are quantized in integer multiples of the fine structure constant α, while the Goos-Hanchen ones in multiples of α2. We investigate the influence on these shifts of magnetic field, temperature, and material dispersion and dissipation. An experimental demonstration of quantized beam shifts could be achieved at terahertz frequencies for moderate values of the magnetic field.

  16. A case study of lightning attachment to flat ground showing multiple unconnected upward leaders

    Science.gov (United States)

    Cummins, Kenneth L.; Krider, E. Philip; Olbinski, Mike; Holle, Ronald L.

    2018-04-01

    On 10 July 2015, a cloud-to-ground (CG) lightning flash that produced two ground terminations was photographed from inside the safety of a truck in southern New Mexico. An analysis of archived NLDN data verified that this was a two-stroke flash, and a close-up view of the first stroke shows that it also initiated at least 12 unconnected, upward leaders (or "streamers") near the ground termination. No unconnected upward leaders were seen near the second ground attachment. After combining an analysis of the photograph with information provided by the NLDN, we infer that the first stroke was of negative (normal) polarity, had modest peak current, and struck about 460 m (± 24%) from the camera. Attachment occurred when an upward-propagating positive leader reached an inferred height of about 21 m above local ground. The second stroke struck ground about 740 m from the camera, and the height of its attachment leader is estimated to be 15 m. The estimated lengths of the unconnected upward leaders in the two-dimensional (2-D) plane of the first stroke range from 2 to 8 m, and all appear to be located within 15 m (2-D) of the main ground termination, with 24% uncertainty. Many of the unconnected upward leaders (inferred to be positive) exhibit multiple upward branches, and most of those branches have upward-directed forks or splits at their ends. This is the first report showing such extensive branching for positive upward leaders in natural lightning strikes to ground. None of the upward leaders can be seen to emanate from the tops of tall, isolated, or pointed objects on the ground, but they likely begin on small plants and rocks, or flat ground. In terms of lightning safety, this photo demonstrates that numerous upward leaders can be produced near a lightning strike point and have the potential to damage or cause injury at more than one specific point on the ground.

  17. Integrated Design for Geoscience Education with Upward Bound Students

    Science.gov (United States)

    Cartwright, T. J.; Hogsett, M.; Ensign, T. I.; Hemler, D.

    2009-05-01

    Capturing the interest of our students is imperative to expand the conduit of future Earth scientists in the United States. According to the Rising Above the Gathering Storm report (2005), we must increase America's talent pool by improving K-12 mathematics and science education. Geoscience education is uniquely suited to accomplish this goal, as we have become acutely aware of our sensitivity to the destructive forces of nature. The educational community must take advantage of this heightened awareness to educate our students and ensure the next generation rebuilds the scientific and technological base on which our society rests. In response to these concerns, the National Science Foundation advocates initiatives in Geoscience Education such as IDGE (Integrated Design for Geoscience Education), which is an inquiry-based geoscience program for Upward Bound (UB) students at Marshall University in Huntington, West Virginia. The UB program targets low-income under-represented students for a summer academic-enrichment program. IDGE builds on the mission of UB by encouraging underprivileged students to investigate science and scientific careers. During the two year project, high school students participated in an Environmental Inquiry course utilizing GLOBE program materials and on-line learning modules developed by geoscience specialists in land cover, soils, hydrology, phenology, and meteorology. Students continued to an advanced course which required IDGE students to collaborate with GLOBE students from Costa Rica. The culmination of this project was an educational expedition in Costa Rica to complete ecological field studies, providing first-hand knowledge of the international responsibility we have as scientists and citizens of our planet. IDGE was designed to continuously serve educators and students. By coordinating initiatives with GLOBE headquarters and the GLOBE country community, IDGE's efforts have yielded multiple ways in which to optimize positive

  18. Fluid Shifts

    Science.gov (United States)

    Stenger, M. B.; Hargens, A. R.; Dulchavsky, S. A.; Arbeille, P.; Danielson, R. W.; Ebert, D. J.; Garcia, K. M.; Johnston, S. L.; Laurie, S. S.; Lee, S. M. C.; hide

    2017-01-01

    Introduction. NASA's Human Research Program is focused on addressing health risks associated with long-duration missions on the International Space Station (ISS) and future exploration-class missions beyond low Earth orbit. Visual acuity changes observed after short-duration missions were largely transient, but now more than 50 percent of ISS astronauts have experienced more profound, chronic changes with objective structural findings such as optic disc edema, globe flattening and choroidal folds. These structural and functional changes are referred to as the visual impairment and intracranial pressure (VIIP) syndrome. Development of VIIP symptoms may be related to elevated intracranial pressure (ICP) secondary to spaceflight-induced cephalad fluid shifts, but this hypothesis has not been tested. The purpose of this study is to characterize fluid distribution and compartmentalization associated with long-duration spaceflight and to determine if a relation exists with vision changes and other elements of the VIIP syndrome. We also seek to determine whether the magnitude of fluid shifts during spaceflight, as well as any VIIP-related effects of those shifts, are predicted by the crewmember's pre-flight status and responses to acute hemodynamic manipulations, specifically posture changes and lower body negative pressure. Methods. We will examine a variety of physiologic variables in 10 long-duration ISS crewmembers using the test conditions and timeline presented in the figure below. Measures include: (1) fluid compartmentalization (total body water by D2O, extracellular fluid by NaBr, intracellular fluid by calculation, plasma volume by CO rebreathe, interstitial fluid by calculation); (2) forehead/eyelids, tibia, and calcaneus tissue thickness (by ultrasound); (3) vascular dimensions by ultrasound (jugular veins, cerebral and carotid arteries, vertebral arteries and veins, portal vein); (4) vascular dynamics by MRI (head/neck blood flow, cerebrospinal fluid

  19. Preparation of TiC/Ni3Al Composites by Upward Melt Infiltration

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    TiC/Ni3Al composites have been prepared using upward infiltration method. The densificstion was performed by both Ni3Al melt filling and TiC sintering during the infiltration. The dissolution of TiC in liquid Ni3Al has been evidenced by finding Ni3(Al,Ti)C after fast cooling in the TiC/Ni3Al composites. The dissolution may be responsible for the infiltration and sintering. Compared with downward infiltration, the upward infiltration brought about higher strength and fracture toughness and shorter infiltration time. TiC/20 vol. pct Ni3Al composite processed by upward infiltration had a flexural strength of 1476 Mpa with a statistic Weibull modulus of 20.2 and a fracture toughness of 20.4 Mpa(m). Better mechanical properties may be attributed to melt unidirectional movement in upward infiltration.

  20. Atmospheric neutrino oscillations from upward throughgoing muon multiple scattering in MACRO

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosio, M.; Antolini, R.; Bakari, D.; Baldini, A.; Barbarino, G.C.; Barish, B.C.; Battistoni, G.; Becherini, Y.; Bellotti, R.; Bemporad, C.; Bernardini, P.; Bilokon, H.; Bloise, C.; Bower, C.; Brigida, M.; Bussino, S.; Cafagna, F.; Calicchio, M.; Campana, D.; Carboni, M.; Caruso, R.; Cecchini, S.; Cei, F.; Chiarella, V.; Chiarusi, T.; Choudhary, B.C.; Coutu, S.; Cozzi, M.; De Cataldo, G.; Dekhissi, H.; De Marzo, C.; De Mitri, I.; Derkaoui, J.; De Vincenzi, M.; Di Credico, A.; Favuzzi, C.; Forti, C.; Fusco, P.; Giacomelli, G.; Giannini, G.; Giglietto, N.; Giorgini, M.; Grassi, M.; Grillo, A.; Gustavino, C.; Habig, A.; Hanson, K.; Heinz, R.; Iarocci, E.; Katsavounidis, E.; Katsavounidis, I.; Kearns, E.; Kim, H.; Kumar, A.; Kyriazopoulou, S.; Lamanna, E.; Lane, C.; Levin, D.S.; Lipari, P.; Longo, M.J.; Loparco, F.; Maaroufi, F.; Mancarella, G.; Mandrioli, G.; Manzoor, S.; Margiotta, A.; Marini, A.; Martello, D.; Marzari-Chiesa, A.; Mazziotta, M.N.; Michael, D.G.; Mikheyev, S.; Monacelli, P.; Montaruli, T.; Monteno, M.; Mufson, S.; Musser, J.; Nicolo, D.; Nolty, R.; Orth, C.; Osteria, G.; Palamara, O.; Patera, V.; Patrizii, L.; Pazzi, R.; Peck, C.W.; Perrone, L.; Petrera, S.; Popa, V.; Raino, A.; Reynoldson, J.; Ronga, F.; Rrhioua, A.; Satriano, C.; Scapparone, E.; Scholberg, K.; Sciubba, A.; Serra, P.; Sioli, M.; Sirri, G.; Sitta, M.; Spinelli, P.; Spinetti, M.; Spurio, M.; Steinberg, R.; Stone, J.L.; Sulak, L.R.; Surdo, A.; Tarle, G.; Togo, V.; Vakili, M.; Walter, C.W.; Webb, R

    2003-07-24

    The energy of atmospheric neutrinos detected by MACRO was estimated using multiple Coulomb scattering of upward throughgoing muons. This analysis allows a test of atmospheric neutrino oscillations, relying on the distortion of the muon energy distribution. These results have been combined with those coming from the upward throughgoing muon angular distribution only. Both analyses are independent of the neutrino flux normalization and provide strong evidence, above the 4{sigma} level, in favour of neutrino oscillations.

  1. Simulation of upward flux from shallow water-table using UPFLOW model

    Directory of Open Access Journals (Sweden)

    M. H. Ali

    2013-11-01

    Full Text Available The upward movement of water by capillary rise from shallow water-table to the root zone is an important incoming flux. For determining exact amount of irrigation requirement, estimation of capillary flux or upward flux is essential. Simulation model can provide a reliable estimate of upward flux under variable soil and climatic conditions. In this study, the performance of model UPFLOW to estimate upward flux was evaluated. Evaluation of model performance was performed with both graphical display and statistical criteria. In distribution of simulated capillary rise values against observed field data, maximum data points lie around the 1:1 line, which means that the model output is reliable and reasonable. The coefficient of determination between observed and simulated values was 0.806 (r = 0.93, which indicates a good inter-relation between observed and simulated values. The relative error, model efficiency, and index of agreement were found as 27.91%, 85.93% and 0.96, respectively. Considering the graphical display of observed and simulated upward flux and statistical indicators, it can be concluded that the overall performance of the UPFLOW model in simulating actual upward flux from a crop field under variable water-table condition is satisfactory. Thus, the model can be used to estimate capillary rise from shallow water-table for proper estimation of irrigation requirement, which would save valuable water from over-irrigation.

  2. Shifting Sugars and Shifting Paradigms

    Science.gov (United States)

    Siegal, Mark L.

    2015-01-01

    No organism lives in a constant environment. Based on classical studies in molecular biology, many have viewed microbes as following strict rules for shifting their metabolic activities when prevailing conditions change. For example, students learn that the bacterium Escherichia coli makes proteins for digesting lactose only when lactose is available and glucose, a better sugar, is not. However, recent studies, including three PLOS Biology papers examining sugar utilization in the budding yeast Saccharomyces cerevisiae, show that considerable heterogeneity in response to complex environments exists within and between populations. These results join similar recent results in other organisms that suggest that microbial populations anticipate predictable environmental changes and hedge their bets against unpredictable ones. The classical view therefore represents but one special case in a range of evolutionary adaptations to environmental changes that all organisms face. PMID:25688600

  3. Shifting sugars and shifting paradigms.

    Directory of Open Access Journals (Sweden)

    Mark L Siegal

    2015-02-01

    Full Text Available No organism lives in a constant environment. Based on classical studies in molecular biology, many have viewed microbes as following strict rules for shifting their metabolic activities when prevailing conditions change. For example, students learn that the bacterium Escherichia coli makes proteins for digesting lactose only when lactose is available and glucose, a better sugar, is not. However, recent studies, including three PLOS Biology papers examining sugar utilization in the budding yeast Saccharomyces cerevisiae, show that considerable heterogeneity in response to complex environments exists within and between populations. These results join similar recent results in other organisms that suggest that microbial populations anticipate predictable environmental changes and hedge their bets against unpredictable ones. The classical view therefore represents but one special case in a range of evolutionary adaptations to environmental changes that all organisms face.

  4. 34 CFR 645.13 - What additional services do Upward Bound Math and Science Centers provide and how are they...

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false What additional services do Upward Bound Math and... Program? § 645.13 What additional services do Upward Bound Math and Science Centers provide and how are... provided under § 645.11(b), an Upward Bound Math and Science Center must provide— (1) Intensive instruction...

  5. Frequency-Modulation Correlation Spectrometer

    Science.gov (United States)

    Margolis, J. S.; Martonchik, J. V.

    1985-01-01

    New type of correlation spectrometer eliminates need to shift between two cells, one empty and one containing reference gas. Electrooptical phase modulator sinusoidally shift frequencies of sample transmission spectrum.

  6. Mechanism of jet-flutter: self-induced oscillation of an upward plane jet impinging on a free surface

    International Nuclear Information System (INIS)

    Madarame, Haruki; Iida, Masao

    1998-01-01

    An upward plane jet impinging on the free surface of a shallow rectangular tank oscillates without any external periodic force. The movement of the impinging point leaves additional fluid mass on the surface behind the point, which does not balance the momentum supplied by the jet. The imbalance generates propagating waves, and a surface level gap appears there. The level gap is flattened not by the waves but by the vertical motion of water columns. The imbalance causes lateral displacement of jet, which in turn causes the imbalance, forming a positive feedback loop. The above model explains well why the frequency corresponds to that of water column oscillation in a partitioned tank with the same water depth, and the oscillation region has a wide range above a certain velocity limit determined by the water depth. (author)

  7. 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

  8. Look Up for Healing: Embodiment of the Heal Concept in Looking Upward.

    Directory of Open Access Journals (Sweden)

    N D Leitan

    Full Text Available Conceptual processing may not be restricted to the mind. The heal concept has been metaphorically associated with an "up" bodily posture. Perceptual Symbol Systems (PSS theory suggests that this association is underpinned by bodily states which occur during learning and become instantiated as the concept. Thus the aim of this study was to examine whether processing related to the heal concept is promoted by priming the bodily state of looking upwards.We used a mixed 2x2 priming paradigm in which 58 participants were asked to evaluate words as either related to the heal concept or not after being primed to trigger the concept of looking up versus down (Direction--within subjects. A possible dose-response effect of priming was investigated via allocating participants to two 'strengths' of prime, observing an image of someone whose gaze was upward/downward (low strength and observing an image of someone whose gaze was upward/downward while physically tilting their head upwards or downwards in accord with the image (high strength (Strength--between subjects.Participants responded to words related to heal faster than words unrelated to heal across both "Strength" conditions. There was no evidence that priming was stronger in the high strength condition.The present study found that, consistent with a PSS view of cognition, the heal concept is embodied in looking upward, which has important implications for cognition, general health, health psychology, health promotion and therapy.

  9. Technique of the biomechanical analysis of execution of upward jump piked

    Directory of Open Access Journals (Sweden)

    Nataliya Batieieva

    2016-12-01

    Full Text Available Purpose: the biomechanical analysis of execution of upward jump piked. Material & Methods: the following methods of the research were used: theoretical analysis and synthesis of data of special scientific and methodical literature; photographing, video filming, biomechanical computer analysis, pedagogical observation. Students (n=8 of the chair of national choreography of the department of choreographic art of Kiev national university of culture and art took part in carrying out the biomechanical analysis of execution of upward jump piked. Results: the biomechanical analysis of execution of upward jump piked is carried out, the kinematic characteristics (way, speed, acceleration, effort of the general center of weight (GCW and center of weight (CW of biolinks of body of the executor are received (feet, shins, hips, shoulder, forearm, hands. Biokinematic models (phases are constructed. Power characteristics are defined – mechanical work and kinetic energy of links of legs and hands at execution of upward jump piked. Conclusions: it is established that the technique of execution of upward jump piked considerably influences the level of technical training of the qualified sportsmen in gymnastics (sports, in aerobic gymnastics (aerobics, diving and dancing sports.

  10. Effect of Shift Work on Nocturia.

    Science.gov (United States)

    Kim, Jin Wook

    2016-01-01

    To identify the circadian sensitive component of nocturia by comparing nocturia in patients who voluntarily choose a disrupted circadian rhythm, that is, shift workers, with those who maintain normal day-night cycles. Between 2011 and 2013, a total of 1741 untreated patients, 1376 nonshift workers and 365 shift workers, were compared for nocturia indices based on frequency volume charts (FVCs). General linear model of 8-hour interval urine production and frequency were compared between FVCs of nonshift workers, FVCs of night-shift workers, and FVCs of day-shift workers. Nocturia frequency was increased in the night-shift workers (2.38 ± 1.44) compared with nonshift workers (2.18 ± 1.04) (P night-shift workers, 0.34 ± 0.13 for nonshift workers, P = .24), nocturnal bladder capacity index increased significantly (1.41 ± 1.06 for night-shift workers, 1.26 ± 0.92 for nonshift workers, P shift (P shift changes (P = .35). Patients in alternating work shifts showed increased nocturia, especially during their night shift. These changes tended to be more associated with decreased nocturnal bladder capacity than increased nocturnal polyuria. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Upward lightning attachment analysis on wind turbines and correlated current parameters

    DEFF Research Database (Denmark)

    Vogel, Stephan; Ishii, M.; Saito, M.

    2017-01-01

    This work provides insight in the attachment characteristics of upward initiated lightning discharges to wind turbines and their possible consequences for the lightning protection of wind turbine blades. All discharges were recorded at the Japanese coast of the Sea of Japan which is known...... for intense upward lightning activity. 172 video recordings of lightning discharges on rotating wind turbines are analysed and attachment angle, detachment angle, and the resulting angular displacement were determined. A classification between self-initiated and other-triggered upward lightning events...... is performed by means of video analysis. The results reveal that the majority of discharges are initiated on vertical blades; however, also attachments to horizontal blades are reported. Horizontal attachment (or a slightly inclined blade state) is often related with a triggered lightning event prior...

  12. New data on two-phase water-air hydrodynamics in vertical upward and downward tubes

    Energy Technology Data Exchange (ETDEWEB)

    Lau, V [Atomic Energy of Canada Ltd., Saskatoon, SK (Canada); Rezkallah, K S [Saskatchewan Univ., Saskatoon (Canada). Mechanical Engineering Dept.

    1996-12-31

    The three key parameters involved in the analysis of the hydrodynamic characteristics of a two-phase system (i.e. pressure drop, void fraction, and flow pattern associated with the flow) are taken in vertical upward and downward tubes, using water-air mixture at atmospheric pressure. The acquired data set covers a wide range of liquid and gas flow rates, as well as void fractions. Using the acquired data set, two sets of flow pattern maps, for both upward and downward flows, are developed in the present study. Furthermore, a set of correlations for predicting the frictional pressure drop in both upward and downward flow were also developed. (author). 16 refs., 13 figs.

  13. Matter effects in upward-going muons and sterile neutrino oscillations

    CERN Document Server

    Ambrosio, M; Auriemma, G; Bakari, D; Baldini, A; Barbarino, G C; Barish, B C; Battistoni, G; Becherini, Y; Bellotti, R; Bemporad, C; Bernardini, P; Bilokon, H; Bisi, V; Bloise, C; Bower, C; Brigida, M; Bussino, S; Cafagna, F; Calicchio, M; Campana, D; Carboni, M; Caruso, R; Cecchini, S; Cei, F; Chiarella, V; Choudhary, B C; Coutu, S; De Cataldo, G; Dekhissi, H; De Marzo, C; De Mitri, I; Derkaoui, J E; De Vincenzi, M; Di Credico, A; Erriquez, O; Favuzzi, C; Forti, C; Fusco, P; Giacomelli, G; Giannini, G; Giglietto, N; Giorgini, M; Grassi, M; Gray, L; Grillo, A; Guarino, F; Gustavino, C; Habig, A; Hanson, K; Heinz, R; Iarocci, Enzo; Katsavounidis, E; Katsavounidis, I; Kearns, E T; Kim, H; Kyriazopoulou, S; Lammanna, E; Lane, C; Levins, D S; Lipari, P; Longley, N P; Longo, M J; Loparco, F; Maaroufi, F; Mancarella, G; Mandrioli, G; Margiotta, A; Marini, A; Martello, D; Marzari-Chiesa, A; Mazziotta, M N; Michael, D G; Mikheyev, S P; Miller, L; Monacelli, P; Montaruli, T; Monteno, M; Mufson, S L; Musser, J; Nicolò, D; Nolty, R; Orth, C; Osteria, G; Palamara, O; Patera, V; Patrizii, L; Pazzi, R; Peck, C W; Perrone, L; Petrera, S; Pistilli, P; Popa, V; Rainó, A; Reynoldson, J; Ronga, F; Rrhioua, A; Satriano, C; Scapparone, E; Scholberg, K; Sciubba, A; Serra, P; Sioli, M; Sirri, G; Sitta, M; Spinelli, P; Spinetti, M; Spurio, M; Steinberg, R; Stone, J L; Sulak, Lawrence R; Surdo, A; Tarle, G; Togo, V; Vakili, M; Walter, C W; Webb, R

    2001-01-01

    The angular distribution of upward-going muons produced by atmospheric neutrinos in the rock below the MACRO detector shows anomalies in good agreement with two flavor nu /sub mu / to nu /sub tau / oscillations with maximum mixing and Delta m/sup 2/ around 0.0024 eV/sup 2/. Exploiting the dependence of magnitude of the matter effect on the oscillation channel, and using a set of 809 upward-going muons observed in MACRO, we show that the two flavor nu /sub mu / to nu /sub s/ oscillation is disfavored with 99% C.L. with respect to nu /sub mu / to nu /sub tau /. (29 refs).

  14. On the Upward Bias of the Dissimilarity Index and Its Corrections

    Science.gov (United States)

    Mazza, Angelo; Punzo, Antonio

    2015-01-01

    The dissimilarity index of Duncan and Duncan is widely used in a broad range of contexts to assess the overall extent of segregation in the allocation of two groups in two or more units. Its sensitivity to random allocation implies an upward bias with respect to the unknown amount of systematic segregation. In this article, following a multinomial…

  15. Upward Feedback and Its Contribution to Employees' Feeling of Self-Determination

    Science.gov (United States)

    Bauer, Johannes; Mulder, Regina H.

    2006-01-01

    Purpose--The paper seeks to show that self-determination is a widely regarded motivational variable in educational research that relates to intrinsically motivated, self-directed learning at work. This study aimed to find out whether the possibility to provide upward feedback to supervisors contributes to employees' feelings of self-determination.…

  16. UPWARD MOVEMENT OF PLUTONIUM TO SURFACE SEDIMENTS DURING AN 11-YEAR FIELD STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, D.; Beals, D.; Cadieux, J.; Halverson, J.

    2010-01-25

    An 11-y lysimeter study was established to monitor the movement of Pu through vadose zone sediments. Sediment Pu concentrations as a function of depth indicated that some Pu moved upward from the buried source material. Subsequent numerical modeling suggested that the upward movement was largely the result of invading grasses taking up the Pu and translocating it upward. The objective of this study was to determine if the Pu of surface sediments originated from atmosphere fallout or from the buried lysimeter source material (weapons-grade Pu), providing additional evidence that plants were involved in the upward migration of Pu. The {sup 240}Pu/{sup 239}Pu and {sup 242}Pu/{sup 239}Pu atomic fraction ratios of the lysimeter surface sediments, as determined by Thermal Ionization Mass Spectroscopy (TIMS), were 0.063 and 0.00045, respectively; consistent with the signatures of the weapons-grade Pu. Our numerical simulations indicate that because plants create a large water flux, small concentrations over multiple years may result in a measurable accumulation of Pu on the ground surface. These results may have implications on the conceptual model for calculating risk associated with long-term stewardship and monitored natural attenuation management of Pu contaminated subsurface and surface sediments.

  17. Summer Upward Bound, Terre Haute, Indiana. Secondary Program in Compensatory Education, 4.

    Science.gov (United States)

    American Institutes for Research in the Behavioral Sciences, Palo Alto, CA.

    Upward Bound was a precollege program geared for high school students with potential who had been handicapped by economic, cultural, and educational deprivation. It involved a full-time summer program and follow-up programs (counseling, cultural activities, and physical education) during the academic year. Students stayed in the program for three…

  18. 77 FR 37016 - Applications for New Awards: Upward Bound Math and Science Program

    Science.gov (United States)

    2012-06-20

    ... DEPARTMENT OF EDUCATION Applications for New Awards: Upward Bound Math and Science Program AGENCY... Bound Math and Science Program. Notice inviting applications for new awards for fiscal year (FY) 2012.... There are three types of grants under the UB Program: regular UB grants, Veterans UB grants, and UB Math...

  19. UPWARD POWER TENDENCIES IN A HIERARCHY - POWER DISTANCE THEORY VERSUS BUREAUCRATIC RULE

    NARCIS (Netherlands)

    WILKE, HAM

    1993-01-01

    Two contrasting notions concerning upward power tendencies within hierarchically structured groups are investigated. Power Distance Theory assumes that people have a desire for power that results in a tendency to reduce the power distance towards a more powerful other, and this tendency is assumed

  20. Upward Appraisal: A Tool for the Continuous Improvement of Library Managers' Skills.

    Science.gov (United States)

    Stein, Joan E.

    Effective management and the importance of feedback in relation to improvement are becoming critical issues for libraries. Upward appraisal evaluates managers' performance based on input from their staff, rather than the traditional top-down evaluation format in which a manager is evaluated solely by their superior. This paper discusses the…

  1. AIMING AT THE TOP - UPWARD SOCIAL-COMPARISON OF ABILITIES AFTER FAILURE

    NARCIS (Netherlands)

    YBEMA, JF; BUUNK, BP

    1993-01-01

    This study examined the effects of feedback on a task on information seeking and partner preferences as forms of social comparison. It was predicted that subjects who experienced failure and perceived control over future performance would, for reasons of self-improvement, choose more strongly upward

  2. Doing worse, but feeling happy : Social comparison and identification in response to upward and downward targets

    NARCIS (Netherlands)

    Groothof, H.; Siero, F.W.; Buunk, Abraham (Bram)

    2007-01-01

    We investigated people's responses to exposure to downward and upward targets. In Study 1, among 197 participants, it was predicted and found that such exposure led to a contrast effect on self-evaluation, and to an assimilation effect on affect. In Study 2, among 148 participants, it was predicted

  3. Lifting the Veil: A Realist Critique of Sistema's Upwardly Mobile Path

    Science.gov (United States)

    Logan, Owen

    2016-01-01

    El Sistema sits somewhere between a social project and a classical music initiative. However, its promise of delivering upward mobility has not been sufficiently examined as a structural phenomenon which dovetails with critical policy issues in taxation, educational provision, human rights, and welfare. This article argues that Sistema-style…

  4. Upwardly Mobile: Attitudes toward the Class Transition among First-Generation College Students

    Science.gov (United States)

    Hinz, Serena E.

    2016-01-01

    First-generation, working-class college students are on the path to upward mobility and may have social and psychological problems related to cultural differences between the working class and the middle class. In her study, Hurst (2007, 2010) reports that students of working-class origin often choose loyalty to one class. However, I revise…

  5. Feeling bad, but satisfied : the effects of upward and downward comparison upon mood and marital satisfaction

    NARCIS (Netherlands)

    Buunk, B.P.; Ybema, J.F.

    2003-01-01

    In a sample of 135 women from rural areas, the effects of social comparison with the marriage of another woman upon mood, identification and relationship evaluation were examined. Upward targets evoked a more positive mood, and a less negative mood than downward targets, while, in contrast, the

  6. Physical mechanism and numerical simulation of the inception of the lightning upward leader

    International Nuclear Information System (INIS)

    Li Qingmin; Lu Xinchang; Shi Wei; Zhang Li; Zou Liang; Lou Jie

    2012-01-01

    The upward leader is a key physical process of the leader progression model of lightning shielding. The inception mechanism and criterion of the upward leader need further understanding and clarification. Based on leader discharge theory, this paper proposes the critical electric field intensity of the stable upward leader (CEFISUL) and characterizes it by the valve electric field intensity on the conductor surface, E L , which is the basis of a new inception criterion for the upward leader. Through numerical simulation under various physical conditions, we verified that E L is mainly related to the conductor radius, and data fitting yields the mathematical expression of E L . We further establish a computational model for lightning shielding performance of the transmission lines based on the proposed CEFISUL criterion, which reproduces the shielding failure rate of typical UHV transmission lines. The model-based calculation results agree well with the statistical data from on-site operations, which show the effectiveness and validity of the CEFISUL criterion.

  7. Intensity of Upward Muon Flux Due to Cosmic-Ray Neutrinos Produced in the Atmosphere

    Science.gov (United States)

    Lee, T. D.; Robinson, H.; Schwartz, M.; Cool, R.

    1963-06-01

    Calculations were performed to determine the upward going muon flux leaving the earth's surface after production by cosmic-ray neutrinos in the crust. Only neutrinos produced in the earth's atmosphere are considered. Rates of the order of one per 100 sq m/day might be expected if an intermediate boson exists and has a mass less than 2 Bev. (auth)

  8. A Diary Study of Self-Compassion, Upward Social Comparisons, and Body Image-Related Outcomes.

    Science.gov (United States)

    Thøgersen-Ntoumani, Cecilie; Dodos, Louisa; Chatzisarantis, Nikos; Ntoumanis, Nikos

    2017-07-01

    Self-compassion may protect individuals experiencing poor body image and associated maladaptive outcomes. The purpose of the study was to examine within-person associations (whilst controlling for between-person differences) between appearance-related self-compassion, appearance-related threats (operationalised as upward appearance comparisons), and body image-related variables, namely, social physique anxiety, drive for thinness, and body dissatisfaction. A diary methodology was used whereby young women (n = 126; M age = 21.26) responded to brief online surveys three times per day (11am, 3pm, and 7pm) every second day for one week (i.e. a total of 12 measurement points). Results of mixed linear modeling revealed that both state appearance-related upward comparisons and self-compassion independently predicted all three outcomes in a positive and negative fashion, respectively. No significant interaction effects between state appearance-related upward comparisons and self-compassion were found. The results suggested that appearance-based self-compassion was important, not just when there was a potential threat to body image via upward appearance comparisons. The findings highlight the importance of fostering self-compassion on a daily level. © 2017 The International Association of Applied Psychology.

  9. Upward migration of radio-cesium and strontium in a sand-filled lysimeter

    International Nuclear Information System (INIS)

    Sanford, W.E.; Larsen, I.L.; McConnell, J.W.; Rogers, R.D.

    1998-01-01

    The upward migration of 134 Cs, 137 Cs, and 90 Sr was observed in a silica sand-filled lysimeter at the Field Lysimeter Investigations: Low Level Waste Data Base Development experiment site at Oak Ridge National Laboratory. The source of the radionuclides first observed on the surface was identified from isotopic analysis as being from the buried waste. Cores of the sand were collected and analyzed for the vertical distribution of the radionuclides. Results of analyses revealed that pulses (elevated levels) in the activity of the Cs and Sr radioisotopes occurred at the same depths. During the sectioning of the sand core collected from directly above the buried waste form it was discovered that a fine root from an unidentified plant was present throughout all but the upper few centimeters of the core. Because the upward migration was unexpected, information that may lead to the determination of a definitive mechanism of migration was not preserved. The distribution of the radionuclides coupled with the presence of the root suggest that Cs and Sr migrated upward in the evapotranspiration stream of the root. Further study must be undertaken to confirm this phenomenon. Upward migration of radionuclides as observed here could result in direct exposures and offsite releases from underground storage facilities. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. An Extreme-ultraviolet Wave Generating Upward Secondary Waves in a Streamer-like Solar Structure

    Science.gov (United States)

    Zheng, Ruisheng; Chen, Yao; Feng, Shiwei; Wang, Bing; Song, Hongqiang

    2018-05-01

    Extreme-ultraviolet (EUV) waves, spectacular horizontally propagating disturbances in the low solar corona, always trigger horizontal secondary waves (SWs) when they encounter the ambient coronal structure. We present the first example of upward SWs in a streamer-like structure after the passing of an EUV wave. This event occurred on 2017 June 1. The EUV wave happened during a typical solar eruption including a filament eruption, a coronal mass ejection (CME), and a C6.6 flare. The EUV wave was associated with quasi-periodic fast propagating (QFP) wave trains and a type II radio burst that represented the existence of a coronal shock. The EUV wave had a fast initial velocity of ∼1000 km s‑1, comparable to high speeds of the shock and the QFP wave trains. Intriguingly, upward SWs rose slowly (∼80 km s‑1) in the streamer-like structure after the sweeping of the EUV wave. The upward SWs seemed to originate from limb brightenings that were caused by the EUV wave. All of the results show that the EUV wave is a fast-mode magnetohydrodynamic (MHD) shock wave, likely triggered by the flare impulses. We suggest that part of the EUV wave was probably trapped in the closed magnetic fields of the streamer-like structure, and upward SWs possibly resulted from the release of slow-mode trapped waves. It is believed that the interplay of the strong compression of the coronal shock and the configuration of the streamer-like structure is crucial for the formation of upward SWs.

  11. Repetition and Translation Shifts

    Directory of Open Access Journals (Sweden)

    Simon Zupan

    2006-06-01

    Full Text Available Repetition manifests itself in different ways and at different levels of the text. The first basic type of repetition involves complete recurrences; in which a particular textual feature repeats in its entirety. The second type involves partial recurrences; in which the second repetition of the same textual feature includes certain modifications to the first occurrence. In the article; repetitive patterns in Edgar Allan Poe’s short story “The Fall of the House of Usher” and its Slovene translation; “Konec Usherjeve hiše”; are compared. The author examines different kinds of repetitive patterns. Repetitions are compared at both the micro- and macrostructural levels. As detailed analyses have shown; considerable microstructural translation shifts occur in certain types of repetitive patterns. Since these are not only occasional; sporadic phenomena; but are of a relatively high frequency; they reduce the translated text’s potential for achieving some of the gothic effects. The macrostructural textual property particularly affected by these shifts is the narrator’s experience as described by the narrative; which suffers a reduction in intensity.

  12. Assessing the high frequency behavior of non-polarizable electrodes for spectral induced polarization measurements

    Science.gov (United States)

    Abdulsamad, Feras; Florsch, Nicolas; Schmutz, Myriam; Camerlynck, Christian

    2016-12-01

    During the last decades, the usage of spectral induced polarization (SIP) measurements in hydrogeology and detecting environmental problems has been extensively increased. However, the physical mechanisms which are responsible for the induced polarization response over the usual frequency range (typically 1 mHz to 10-20 kHz) require better understanding. The phase shift observed at high frequencies is sometimes attributed to the so-called Maxwell-Wagner polarization which takes place when charges cross an interface. However, SIP measurements of tap water show a phase shift at frequencies higher than 1 kHz, where no Maxwell-Wagner polarization may occur. In this paper, we enlighten the possible origin of this phase shift and deduce its likely relationship with the types of the measuring electrodes. SIP Laboratory measurements of tap water using different types of measuring electrodes (polarizable and non-polarizable electrodes) are carried out to detect the origin of the phase shift at high frequencies and the influence of the measuring electrodes types on the observed complex resistivity. Sodium chloride is used to change the conductivity of the medium in order to quantify the solution conductivity role. The results of these measurements are clearly showing the impact of the measuring electrodes type on the measured phase spectrum while the influence on the amplitude spectrum is negligible. The phenomenon appearing on the phase spectrum at high frequency (> 1 kHz) whatever the electrode type is, the phase shows an increase compared to the theoretical response, and the discrepancy (at least in absolute value) increases with frequency, but it is less severe when medium conductivity is larger. Additionally, the frequency corner is shifted upward in frequency. The dependence of this phenomenon on the conductivity and the measuring electrodes type (electrode-electrolyte interface) seems to be due to some dielectric effects (as an electrical double layer of small

  13. Non-occupational physical activity levels of shift workers compared with non-shift workers

    Science.gov (United States)

    Loef, Bette; Hulsegge, Gerben; Wendel-Vos, G C Wanda; Verschuren, W M Monique; Bakker, Marije F; van der Beek, Allard J; Proper, Karin I

    2017-01-01

    Objectives Lack of physical activity (PA) has been hypothesised as an underlying mechanism in the adverse health effects of shift work. Therefore, our aim was to compare non-occupational PA levels between shift workers and non-shift workers. Furthermore, exposure–response relationships for frequency of night shifts and years of shift work regarding non-occupational PA levels were studied. Methods Data of 5980 non-shift workers and 532 shift workers from the European Prospective Investigation into Cancer and Nutrition-Netherlands (EPIC-NL) were used in these cross-sectional analyses. Time spent (hours/week) in different PA types (walking/cycling/exercise/chores) and intensities (moderate/vigorous) were calculated based on self-reported PA. Furthermore, sports were operationalised as: playing sports (no/yes), individual versus non-individual sports, and non-vigorous-intensity versus vigorous-intensity sports. PA levels were compared between shift workers and non-shift workers using Generalized Estimating Equations and logistic regression. Results Shift workers reported spending more time walking than non-shift workers (B=2.3 (95% CI 1.2 to 3.4)), but shift work was not associated with other PA types and any of the sports activities. Shift workers who worked 1–4 night shifts/month (B=2.4 (95% CI 0.6 to 4.3)) and ≥5 night shifts/month (B=3.7 (95% CI 1.8 to 5.6)) spent more time walking than non-shift workers. No exposure–response relationships were found between years of shift work and PA levels. Conclusions Shift workers spent more time walking than non-shift workers, but we observed no differences in other non-occupational PA levels. To better understand if and how PA plays a role in the negative health consequences of shift work, our findings need to be confirmed in future studies. PMID:27872151

  14. Does upward mobility result in greater well-being? Evidence from a pre-registered study on a large population-based survey

    OpenAIRE

    Cheung, Felix; Jackson, Joshua; Hill, Patrick

    2017-01-01

    Income inequality gained increasing attention in public discourse. Promoting upward mobility is a potential solution to income inequality. The current study tested whether upward mobility predicts greater well-being, whether upward mobility attenuates the negative effects of income inequality, and whether gender differences in upward mobility differentially predict well-being for men and women. Upward mobility was operationalized as changes in income rank across generations for families in th...

  15. 34 CFR 645.20 - How many applications for an Upward Bound award may an eligible applicant submit?

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false How many applications for an Upward Bound award may an eligible applicant submit? 645.20 Section 645.20 Education Regulations of the Offices of the Department of... Does One Apply for An Award? § 645.20 How many applications for an Upward Bound award may an eligible...

  16. 77 FR 21089 - Notice of Submission for OMB Review; Application for Grants Under the Upward Bound Math and...

    Science.gov (United States)

    2012-04-09

    ... Upward Bound Math and Science Program AGENCY: Office of Postsecondary Education, Department of Education. SUMMARY: The Upward Bound Math and Science (UBMS) program provides grants to institutions of higher... for success in a program of postsecondary education that lead to careers in math and science. DATES...

  17. Measurement of the rate of droplet deposition in vertical upward and downward annular flows

    International Nuclear Information System (INIS)

    Murakami, Toshihiro; Okawa, Tomio; Takei, Rei

    2008-01-01

    The deposition rate of droplets was measured for vertical annular two-phase flows in a small diameter tube by means of the double film extraction technique. The test section was a round tube of 5 mm in inside diameter, air and water were used as test fluids, and the flow direction was set to upward and downward; the system pressure and the flow rates of gas and liquid phases were changed parametrically. If the droplet velocity relative to the continuous gas phase is in the equilibrium state, the shear induced lift force acting on droplets is directed toward the tube centerline in upflow while toward the tube wall in downflow. Particular attention was therefore paid to the effect of flow direction. It was shown experimentally that the deposition rate of droplets in downward flow is greater than that in upward flow. The difference in the measured deposition rate may be attributed to the direction of lift force acting on droplets. (author)

  18. High Upward Fluxes of Formic Acid from a Boreal Forest Canopy

    Science.gov (United States)

    Schobesberger, Siegfried; Lopez-Hilifiker, Felipe D.; Taipale, Ditte; Millet, Dylan B.; D'Ambro, Emma L.; Rantala, Pekka; Mammarella, Ivan; Zhou, Putian; Wolfe, Glenn M.; Lee, Ben H.; hide

    2016-01-01

    Eddy covariance fluxes of formic acid, HCOOH, were measured over a boreal forest canopy in spring/summer 2014. The HCOOH fluxes were bidirectional but mostly upward during daytime, in contrast to studies elsewhere that reported mostly downward fluxes. Downward flux episodes were explained well by modeled dry deposition rates. The sum of net observed flux and modeled dry deposition yields an upward gross flux of HCOOH, which could not be quantitatively explained by literature estimates of direct vegetative soil emissions nor by efficient chemical production from other volatile organic compounds, suggesting missing or greatly underestimated HCOOH sources in the boreal ecosystem. We implemented a vegetative HCOOH source into the GEOS-Chem chemical transport model to match our derived gross flux and evaluated the updated model against airborne and spaceborne observations. Model biases in the boundary layer were substantially reduced based on this revised treatment, but biases in the free troposphere remain unexplained.

  19. Freezing of aluminium oxide and iron flowing upward in circular quartz glass tubes

    International Nuclear Information System (INIS)

    Kuhn, D.; Moeschke, M.; Werle, H.

    1983-10-01

    The freezing of aluminium oxide and iron flowing upward in circular quartz glass tubes has been studied in a series of experiments. Several tubes were used in the same test. This demonstrated a good reproducibility and allowed systematic parameter variations, especially of the channel diameter. The time-dependance of the penetration was observed with a film camera and these date provide a good basis for a detailed check of sophisticated models which are in development. (orig.) [de

  20. Air-water upward flow in prismatic channel of rectangular base

    International Nuclear Information System (INIS)

    Carvalho Tofani, P. de.

    1984-01-01

    Experiments had carried out to investigate the two-phase upward air-water flow structure, in a rectangular test section, by using independent measuring techniques, which comprise direct viewing and photography, electrical probes and gamma-ray attenuation. Flow pattern maps and correlations for flow pattern transitions, void fraction profiles, liquid film thickness and superficial average void fraction are proposed and compared to available data. (Author) [pt

  1. The transition from flooding to upwards cocurrent annular flow in a vertical pipe

    International Nuclear Information System (INIS)

    Wallis, G.B.

    1962-02-01

    The limits of countercurrent flow in a vertical pipe are related to the onset of cocurrent upwards annual flow. The results are confirmed by evidence from several sources and lead to the criterion v g =(0.8→0.9)p g -1/2 [D g (p f -p g )] 1/2 for the minimum gas superficial velocity which will support a liquid film in concurrent flow. (author)

  2. Downstream lightening and upward heavying, sorting of sediments of uniform grain size but differing in density

    Science.gov (United States)

    Viparelli, E.; Solari, L.; Hill, K. M.

    2014-12-01

    Downstream fining, i.e. the tendency for a gradual decrease in grain size in the downstream direction, has been observed and studied in alluvial rivers and in laboratory flumes. Laboratory experiments and field observations show that the vertical sorting pattern over a small Gilbert delta front is characterized by an upward fining profile, with preferential deposition of coarse particles in the lowermost part of the deposit. The present work is an attempt to answer the following questions. Are there analogous sorting patterns in mixtures of sediment particles having the same grain size but differing density? To investigate this, we performed experiments at the Hydrosystems Laboratory at the University of Illinois at Urbana-Champaign. During the experiments a Gilbert delta formed and migrated downstream allowing for the study of transport and sorting processes on the surface and within the deposit. The experimental results show 1) preferential deposition of heavy particles in the upstream part of the deposit associated with a pattern of "downstream lightening"; and 2) a vertical sorting pattern over the delta front characterized by a pattern of "upward heavying" with preferential deposition of light particles in the lowermost part of the deposit. The observed downstream lightening is analogous of the downstream fining with preferential deposition of heavy (coarse) particles in the upstream part of the deposit. The observed upward heavying was unexpected because, considering the particle mass alone, the heavy (coarse) particles should have been preferentially deposited in the lowermost part of the deposit. Further, the application of classical fractional bedload transport relations suggests that in the case of mixtures of particles of uniform size and different densities equal mobility is not approached. We hypothesize that granular physics mechanisms traditionally associated with sheared granular flows may be responsible for the observed upward heavying and for the

  3. Experimental study on liquid velocity in upward and downward two-phase flows

    International Nuclear Information System (INIS)

    Sun, X.; Paranjape, S.; Kim, S.; Ozar, B.; Ishii, M.

    2003-01-01

    Local characteristics of the liquid phase in upward and downward air-water two-phase flows were experimentally investigated in a 50.8-mm inner-diameter round pipe. An integral Laser Doppler Anemometry (LDA) system was used to measure the axial liquid velocity and its fluctuations. No effect of the flow direction on the liquid velocity radial profile was observed in single-phase liquid benchmark experiments. Local multi-sensor conductivity probes were used to measure the radial profiles of the bubble velocity and the void fraction. The measurement results in the upward and downward two-phase flows are compared and discussed. The results in the downward flow demonstrated that the presence of the bubbles tended to flatten the liquid velocity radial profile, and the maximum liquid velocity could occur off the pipe centerline, in particular at relatively low flow rates. However, the maximum liquid velocity always occurred at the pipe center in the upward flow. Also, noticeable turbulence enhancement due to the bubbles in the two-phase flows was observed in the current experimental flow conditions. Furthermore, the distribution parameter and the void weighted area-averaged drift velocity were obtained based on the definitions

  4. Interfacial structures and area transport in upward and downward two-phase flow

    International Nuclear Information System (INIS)

    Paranjape, S. S.; Kim, S.; Ishii, M.; Kelly, J.

    2003-01-01

    An experimental study has been carried out for upward and downward two-phase flow to study local interfacial structures and interfacial area transport. The flow studied, is an adiabatic, air-water, co-current, two-phase flow, in 25.4 mm and 50.8 mm ID test sections. Flow regime map is obtained using the characteristic signals obtained from an impedance void meter, employing neural network based identification methodology. A four sensor conductivity probe is used to measure the local two phase flow parameters, in bubbly flow regime. The local profiles of these parameters as well as their axial development reveal the nature of the interfacial structures and the bubble interaction mechanisms occurring in the flow. Furthermore, this study provides a good database for the development of the interfacial area transport equation, which dynamically models the changes in the interfacial area along a flow field. An interfacial area transport equation is used for downward flow based on that developed for the upward flow, with certain modifications in the bubble interaction terms. The area averaged values of the interfacial area concentration are compared with those predicted by the interfacial area transport model. The differences in the interfacial structures and interfacial area transport in co-current downward and upward two-phase flows are studied

  5. Clinical Assessment of Scapula Motion: Scapula Upward Rotation and Relationship with Injury in Swimmers

    Directory of Open Access Journals (Sweden)

    Jo Brown

    2016-01-01

    Full Text Available Abnormal scapulothoracic mechanics and scapulohumeral rhythm are implicated in shoulder pathologies, including glenohumeral impingement and rotator cuff tears. Upward scapula rotation, specifically asymmetry of scapula motion and associations of patterns through range with injury, was investigated in dominant and non-dominant limbs of nationally ranked junior and Paralympic swimmers during competition season. The static and throughout phases measures of upward scapula rotation were: Phase I (start position, 45°, Phase II (45° to 90°, Phase III (90° to 135° and Phase IV (135° to max. Injury was assessed with a validated questionnaire. Differences between side (dominant and non-dominant, group (junior and Paralympic, and phase were examined. Significant differences (P < 0.05 between groups were identified for dominant side at rest, 45° and 135°, and in phases II and IV (including range. Scapulohumeral rhythm was higher in the non-dominant limb of Paralympic swimmers but in the dominant limb of junior swimmers. Greatest differences in upward rotation between injured and non-injured swimmers were found in Phase 1: 43.6% (3.3° Paralympic; 73.1% (8° junior. Results suggest asymmetry of movement in both limbs, through all phases, and at single points in range, should be investigated for assessing injury and developing preventive strategies and rehabilitation protocols.

  6. Pressure broadening and frequency shift of the 5S1/2 → 5D5/2 and 5S1/2 → 7S1/2 two photon transitions in 85Rb by the noble gases and N2

    International Nuclear Information System (INIS)

    Zameroski, Nathan D; Hager, Gordon D; Erickson, Christopher J; Burke, John H

    2014-01-01

    Doppler free two photon absorption spectroscopy was employed to measure the pressure broadening and frequency shift rates of the 5S 1/2 (F = 3) → 5D 5/2 (F = 5, 4, 3, 2, 1) (778.105 nm) and the 5S 1/2 (F = 2) → 7S 1/2 (F = 2) (760.126 nm) two photon transitions in 85 Rb by the noble gases and N 2 . To our knowledge, these rates are reported on for the first time. The self-broadening and shift rate of the 5S 1/2 (F = 3) → 5D 5/2 (F = 5, 4, 3, 2, 1) transition and self -broadening rate of the 5S 1/2 (F = 2) → 7S 1/2 (F = 2) transition were also measured. The temperature dependence of the self-frequency shift (Rb-Rb collisions) of these transitions is presented. Helium diffusion rates through Quartz and Pyrex cells are also calculated and the implication of helium diffusion through glass vapor cells is discussed in regards to atomic frequency standards based on these transitions. Experimental pressure broadening and shift rates are compared to theoretically calculated rates assuming a 6, 8 or 6, 8, 10 difference potential and pseudo potential model. Reasonable agreement is achieved between experimental and theoretical values. (paper)

  7. A study on the upward and downward facing pool boiling heat transfer characteristics of graphene-modified surface

    International Nuclear Information System (INIS)

    Kim, Ji Hoon; Ahn, Ho Seon; Kim, Ji Min

    2016-01-01

    Recently, graphene, carbon in two dimensions, were highlighted as a good heat transfer materials, according to its high thermal conductivity. Lateral conduction and water absorption into the structure helped graphene films to inhibit the formation of hot spots, which means increasing of critical heat flux (CHF) and boiling heat transfer coefficient (BHTC) performances. In this study, we report a promising increase of CHF and BHTC results with 2D graphene films. Furthermore, we tried to observe bubble behavior via high-speed visualization to investigate a relationship between bubble behavior and pool boiling performances in downward facing boiling. The effect of graphene film coating on the pool boiling performances of upward and downward facing heater surface were examined. 2D- and 3D- graphene film showed good enhancement results on the CHF (by 111% and 60%) and BHTC (by 40% and 20-25%) performances. Bubble behavior change was significant factor on the CHF and BHTC performances in downward facing boiling. The amount of evaporation heat flux was calculated from the velocity, bubble diameter, frequency, orientation angle and superheat that the post-products of the high-speed visualization

  8. Micropatch Antenna Phase Shifting

    National Research Council Canada - National Science Library

    Thursby, Michael

    2000-01-01

    .... We have been looking at the ability of embedded element to adjust the phase shift seen by the element with the goal of being able to remove the phase shifting devices from the antenna and replace...

  9. Micropatch Antenna Phase Shifting

    National Research Council Canada - National Science Library

    Thursby, Michael

    1999-01-01

    .... We have been looking at the ability of embedded element to adjust the phase shift seen by the element wit the goal of being able to remove the phase shifting devices from the antenna and replace...

  10. Blue and red shifted temperature dependence of implicit phonon shifts in graphene

    Science.gov (United States)

    Mann, Sarita; Jindal, V. K.

    2017-07-01

    We have calculated the implicit shift for various modes of frequency in a pure graphene sheet. Thermal expansion and Grüneisen parameter which are required for implicit shift calculation have already been studied and reported. For this calculation, phonon frequencies are obtained using force constants derived from dynamical matrix calculated using VASP code where the density functional perturbation theory (DFPT) is used in interface with phonopy software. The implicit phonon shift shows an unusual behavior as compared to the bulk materials. The frequency shift is large negative (red shift) for ZA and ZO modes and the value of negative shift increases with increase in temperature. On the other hand, blue shift arises for all other longitudinal and transverse modes with a similar trend of increase with increase in temperature. The q dependence of phonon shifts has also been studied. Such simultaneous red and blue shifts in transverse or out plane modes and surface modes, respectively leads to speculation of surface softening in out of plane direction in preference to surface melting.

  11. OpenShift Workshop

    CERN Multimedia

    CERN. Geneva; Rodriguez Peon, Alberto

    2017-01-01

    Workshop to introduce developers to the OpenShift platform available at CERN. Several use cases will be shown, including deploying an existing application into OpenShift. We expect attendees to realize about OpenShift features and general architecture of the service.

  12. Modeling on bubbly to churn flow pattern transition for vertical upward flows in narrow rectangular channel

    International Nuclear Information System (INIS)

    Wang Yanlin; Chen Bingde; Huang Yanping; Wang Junfeng

    2011-01-01

    A theoretical model was developed to predict the bubbly to churn flow pattern transition for vertical upward flows in narrow rectangular channel. The model was developed based on the imbalance theory of Helmholtz and some reasonable assumptions. The maximum ideal bubble in narrow rectangular channel and the thermal hydraulics boundary condition leading to bubbly flow to churn flow pattern transition was calculated. The model was validated by experimental data from previous researches. Comparison between predicted result and experimental result shows a reasonable good agreement. (author)

  13. Method of online cleanliness control for upward-facing transport mirrors in integration test bed

    International Nuclear Information System (INIS)

    Zhao Longbiao; Qin Lang; Zhou Guorui; Ye Yayun; Zhang Chuanchao; Miao Xinxiang; Wang Hongbin; Yuan Xiaodong; Wang Xiaohong; Cheng Xiaofeng

    2013-01-01

    An online cleanliness control method based on the online monitoring system was developed for controlling the particle pollution and damage of upward-facing transport mirrors in the integration test bed. By building up gas knife system, the online cleanliness processing was effectively achieved for the particle pollution on the mirror surface. By using the gas screen, the cleanliness of the mirror surface was effectively online maintained. The image processing system was applied to assessing the effect of online cleanliness processing. The experimental results indicate that the particle pollution was reduced by the gas knife and the gas screen was useful to avoid the settlement of particle pollution. (authors)

  14. Experimental Investigation of the Hot Water Layer Effect on Upward Flow Open Pool Reactor Operability

    International Nuclear Information System (INIS)

    Abou Elmaaty, T.

    2014-01-01

    The open pool reactor offers a high degree of reliability in the handling and manoeuvring, the replacement of reactor internal components and the suing of vertical irradiation channels. The protection of both the operators and the reactor hall environment against radiation hazards is considered a matter of interest. So, a hot water layer is implemented above many of the research reactors main pool, especially those whose flow direction is upward flow. An experimental work was carried out to ensure the operability of the upward flow open pool research reactor with / without the hot water layer. The performed experiment showed that, the hot water layer is produced an inverse buoyant force make the water to diffuse downward against the ordinary natural circulation from the reactor core. An upward flow - open pool research reactor (with a power greater than 20 M watt) could not wok without a hot water layer. The high temperature of the hot water layer surface could release a considerable amount of water vapour into the reactor hall, so a heat and mass transfer model is built based on the measured hot water layer surface temperature to calculate the amount of released water vapour during the reactor operating period. The effects of many parameters like the ambient air temperature, the reactor hall relative humidity and the speed of the pushed air layer above the top pool end on the evaporation rate is studied. The current study showed that, the hot water layer system is considered an efficient shielding system against Gamma radiation for open pool upward flow reactor and that system should be operated before the reactor start up by a suitable period of time. While, the heat and mass transfer model results showed that, the amount of the released water vapour is increased as a result of both the increase in hot water layer surface temperature and the increase in air layer speed. As the increase in hot water layer surface temperature could produce a good operability

  15. Experimental Investigation of the Hot Water Layer Effect on Upward Flow Open Pool Reactor Operability

    International Nuclear Information System (INIS)

    Abou Elmaaty, T.

    2015-01-01

    The open pool reactor offers a high degree of reliability in the handling and manoeuvring, the replacement of reactor internal components and the swing of vertical irradiation channels. The protection of both the operators and the reactor hall environment against radiation hazards is considered a matter of interest. So, a hot water layer implemented above many of the research reactors main pool, especially those whose flow direction is upward flow. An experimental work was carried out to ensure the operability of the upward flow open pool research reactor with / without the hot water layer. The performed experiment showed that, the hot water layer produced an inverse buoyant force making the water to diffuse downward against the ordinary natural circulation from the reactor core. An upward flow-open pool research reactor (with a power greater than 20 Mw) could not wok without a hot water layer. The high temperature of the hot water layer surface could release a considerable amount of water vapour into the reactor hall, so a heat and mass transfer model is built based on the measured hot water layer surface temperature to calculate the amount of released water vapour during the reactor operating period. The effects of many parameters like the ambient air temperature, the reactor hall relative humidity and the speed of the pushed air layer above the top pool end on the evaporation rate is studied. The current study showed that, the hot water layer system is considered an efficient shielding system against gamma radiation for open pool upward flow reactor and that system should be operated before the reactor start up by a suitable period of time. While, the heat and mass transfer model results showed that, the amount of the released water vapour is increased as a result of both the increase in hot water layer surface temperature and the increase in air layer speed. As the increase in hot water layer surface temperature could produce a good operability conditions from

  16. [Sleep quality of nurses working in shifts - Hungarian adaptation of the Bergen Shift Work Sleep Questionnaire].

    Science.gov (United States)

    Fusz, Katalin; Tóth, Ákos; Fullér, Noémi; Müller, Ágnes; Oláh, András

    2015-12-06

    Sleep disorders among shift workers are common problems due to the disturbed circadian rhythm. The Bergen Shift Work Sleep Questionnaire assesses discrete sleep problems related to work shifts (day, evening and night shifts) and rest days. The aim of the study was to develop the Hungarian version of this questionnaire and to compare the sleep quality of nurses in different work schedules. 326 nurses working in shifts filled in the questionnaire. The authors made convergent and discriminant validation of the questionnaire with the Athens Insomnia Scale and the Perceived Stress Questionnaire. The questionnaire based on psychometric characteristics was suitable to assess sleep disorders associated with shift work in a Hungarian sample. The frequency of discrete symptoms significantly (pshifts. Nurses experienced the worst sleep quality and daytime fatigue after the night shift. Nurses working in irregular shift system had worse sleep quality than nurses working in regular and flexible shift system (pworking in shifts should be assessed with the Hungarian version of the Bergen Shift Work Sleep Questionnaire on a nationally representative sample, and the least burdensome shift system could be established.

  17. Measurements of the eigenfunction of reversed shear Alfvén eigenmodes that sweep downward in frequency

    International Nuclear Information System (INIS)

    Heidbrink, W. W.; Austin, M. E.; Spong, D. A.; Tobias, B. J.; Van Zeeland, M. A.

    2013-01-01

    Reversed shear Alfvén eigenmodes (RSAEs) usually sweep upward in frequency when the minimum value of the safety factor q min decreases in time. On rare occasions, RSAEs sweep downward prior to the upward sweep. Electron cyclotron emission measurements show that the radial eigenfunction during the downsweeping phase is similar to the eigenfunction of normal, upsweeping RSAEs

  18. Metabolic syndrome in fixed-shift workers

    OpenAIRE

    Raquel Canuto; Marcos Pascoal Pattussi; Jamile Block Araldi Macagnan; Ruth Liane Henn; Maria Teresa Anselmo Olinto

    2015-01-01

    OBJECTIVE To analyze if metabolic syndrome and its altered components are associated with demographic, socioeconomic and behavioral factors in fixed-shift workers. METHODS A cross-sectional study was conducted on a sample of 902 shift workers of both sexes in a poultry processing plant in Southern Brazil in 2010. The diagnosis of metabolic syndrome was determined according to the recommendations from Harmonizing the Metabolic Syndrome. Its frequency was evaluated according to the demographic ...

  19. Metabolic syndrome in fixed-shift workers

    OpenAIRE

    Canuto, Raquel; Pattussi, Marcos Pascoal; Macagnan, Jamile Block Araldi; Henn, Ruth Liane; Olinto, Maria Teresa Anselmo

    2015-01-01

    OBJECTIVE To analyze if metabolic syndrome and its altered components are associated with demographic, socioeconomic and behavioral factors in fixed-shift workers.METHODS A cross-sectional study was conducted on a sample of 902 shift workers of both sexes in a poultry processing plant in Southern Brazil in 2010. The diagnosis of metabolic syndrome was determined according to the recommendations from Harmonizing the Metabolic Syndrome. Its frequency was evaluated according to the demographic (...

  20. Emerging psychopathology moderates upward social mobility: The intergenerational (dis)continuity of socioeconomic status.

    Science.gov (United States)

    Véronneau, Marie-Hélène; Serbin, Lisa A; Stack, Dale M; Ledingham, Jane; Schwartzman, Alex E

    2015-11-01

    Socioeconomic status (SES) is relatively stable across generations, but social policies may create opportunities for upward social mobility among disadvantaged populations during periods of economic growth. With respect to expanded educational opportunities that occurred in Québec (Canada) during the 1960s, we hypothesized that children's social and academic competence would promote upward mobility, whereas aggression and social withdrawal would have the opposite effect. Out of 4,109 children attending low-SES schools in 1976-1978, a representative subsample of 503 participants were followed until midadulthood. Path analyses revealed that parents' SES predicted offspring's SES through associations with offspring's likeability, academic competence, and educational attainment. Interaction effects revealed individual risk factors that moderated children's ability to take advantage of intrafamilial or extrafamilial opportunities that could enhance their educational attainment. Highly aggressive participants and those presenting low academic achievement were unable to gain advantage from having highly educated parents. They reached lower educational attainment than their less aggressive or higher achieving peers who came from a similarly advantaged family background. Growing up with parents occupying low-prestige jobs put withdrawn boys and outgoing girls at risk for low educational attainment. In conclusion, social policies can raise SES across generations, with great benefits for the most disadvantaged segments of the population. However, children presenting with emerging psychopathology or academic weaknesses do not benefit from these policies as much as others, and should receive additional, targeted services.

  1. Evaluation of upward heat flux in ex-vessel molten core heat transfer using MELCOR

    International Nuclear Information System (INIS)

    Park, S.Y.; Park, J.H.; Kim, S.D.; Kim, D.H.; Kim, H.D.

    2000-01-01

    The purpose of this study is to share experiences of MELCOR application to resolve the molten corium-concrete interaction (MCCI) issue in the Korea Next Generation Reactor (KNGR). In the evaluation of concrete erosion, the heat transfer modeling from the molten corium internal to the corium pool surface is very important and uncertain. MELCOR employs Kutateladze or Greene's bubble-enhanced heat transfer model for the internal heat transfer. The phenomenological uncertainty is so large that the model provides several model parameters in addition to the phenomenological model for user flexibility. However, the model parameters do not work on Kutateladze correlation at the top of the molten layer. From our experience, a code modification is suggested to match the upward heat flux with the experimental results. In this analysis, minor modification was carried out to calculate heat flux from the top molten layer to corium surface, and efforts were made to find out the best value of the model parameter based on upward heat flux of MACE test M1B. Discussion also includes its application to KNGR. (author)

  2. Influence of Mining Thickness on the Rationality of Upward Mining in Coal Seam Group

    Directory of Open Access Journals (Sweden)

    Y. Li

    2016-04-01

    Full Text Available This study aimed to determine the influence of mining thickness on the rationality of upward mining in coal seam group. Numerical simulation and theoretical analysis were performed to investigate the influence of the mining thicknesses of initial mining seam on the destruction and pressure relief effect of the upper coal seam in a high-gas coal seam group. The mechanical model of the roof failure based on the mining thickness was established by assuming that the gob formed after adjacent panels have fully been caved is the infinite plane. On the basis of this model, an equation was derived to calculate the roof failure height of the panel. Considering the geological conditions of No. 9 and No. 12 coal seams of Zhaogezhuang Coal Mine, economic effectiveness, and proposed techniques, we concluded that the top layer (4 m of the No. 12 coal seam should be mined first. The top layer of the No. 9 coal seam should be subsequently mined. The topcaving technique was applied to the exploitation of the lower layer of the No. 12 coal seam. Practically monitored data revealed that the deformation and failure of the No. 2699 panel roadway was small and controllable, the amount of gas emission was reduced significantly, and the effect of upward mining was active. The results of this study provide theory basics for mine designing, and it is the provision of a reference for safe and efficient coal exploitation under similar conditions.

  3. Underlying mechanism of precursory activity from analysis of upward earthquake migration

    Directory of Open Access Journals (Sweden)

    O. A. Molchanov

    2011-01-01

    Full Text Available In this paper we analyse the upward earthquake hypocentral migration in the ten known subduction zones and discuss a possible mechanism of such migration. The total time of the migration appears to range from 2.5 to 10 years. It leads to the estimation of the average velocity Vz~ 60−300 km yr−1. It probably corresponds to the movement of the forcing agent like stress or deformation wave from depths of the upper mantle (600–700 km to the level of the lithosphere with subsequent initiation of fluid migration inside the crust to trigger shallow earthquakes. Averaged over all zones upward migration travel time is about 5 years (< Vz > ≈120 km yr−1 that coincides approximately with the period of characteristic temperature variation (El Nino and crustal seismic periodicity in the Pacific region. These findings are helpful for the study of the seismic precursors and analysis of earthquake triggering.

  4. MR chemical shift imaging of human atheroma

    International Nuclear Information System (INIS)

    Mohiaddin, R.H.; Underwood, R.; Firmin, D.; Abdulla, A.K.; Rees, S.; Longmore, D.

    1988-01-01

    The lipid content of atheromatous plaques has been measured with chemical shift MR imaging by taking advantage of the different resonance frequencies of protons in lipid and water. Fifteen postmortem aortic specimens of the human descending aorta and the aortae of seven patients with documented peripheral vascular disease were studied at 0.5 T. Spin-echo images were used to localize the lesions before acquisition of the chemical shift images. The specimens were examined histologically, and the lipid distribution in the plaque showed good correlation with the chemical shift data. Validation in vivo and clinical applications remain to be established

  5. Choice Shifts in Groups

    OpenAIRE

    Kfir Eliaz; Debraj Ray

    2004-01-01

    The phenomenon of "choice shifts" in group decision-making is fairly ubiquitous in the social psychology literature. Faced with a choice between a ``safe" and ``risky" decision, group members appear to move to one extreme or the other, relative to the choices each member might have made on her own. Both risky and cautious shifts have been identified in different situations. This paper demonstrates that from an individual decision-making perspective, choice shifts may be viewed as a systematic...

  6. Implementing OpenShift

    CERN Document Server

    Miller, Adam

    2013-01-01

    A standard tutorial-based approach to using OpenShift and deploying custom or pre-built web applications to the OpenShift Online cloud.This book is for software developers and DevOps alike who are interested in learning how to use the OpenShift Platform-as-a-Service for developing and deploying applications, how the environment works on the back end, and how to deploy their very own open source Platform-as-a-Service based on the upstream OpenShift Origin project.

  7. Insomnia in shift work.

    Science.gov (United States)

    Vallières, Annie; Azaiez, Aïda; Moreau, Vincent; LeBlanc, Mélanie; Morin, Charles M

    2014-12-01

    Shift work disorder involves insomnia and/or excessive sleepiness associated with the work schedule. The present study examined the impact of insomnia on the perceived physical and psychological health of adults working on night and rotating shift schedules compared to day workers. A total of 418 adults (51% women, mean age 41.4 years), including 51 night workers, 158 rotating shift workers, and 209 day workers were selected from an epidemiological study. An algorithm was used to classify each participant of the two groups (working night or rotating shifts) according to the presence or absence of insomnia symptoms. Each of these individuals was paired with a day worker according to gender, age, and income. Participants completed several questionnaires measuring sleep, health, and psychological variables. Night and rotating shift workers with insomnia presented a sleep profile similar to that of day workers with insomnia. Sleep time was more strongly related to insomnia than to shift work per se. Participants with insomnia in the three groups complained of anxiety, depression, and fatigue, and reported consuming equal amounts of sleep-aid medication. Insomnia also contributed to chronic pain and otorhinolaryngology problems, especially among rotating shift workers. Work productivity and absenteeism were more strongly related to insomnia. The present study highlights insomnia as an important component of the sleep difficulties experienced by shift workers. Insomnia may exacerbate certain physical and mental health problems of shift workers, and impair their quality of life. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Laser frequency modulation with electron plasma

    Science.gov (United States)

    Burgess, T. J.; Latorre, V. R.

    1972-01-01

    When laser beam passes through electron plasma its frequency shifts by amount proportional to plasma density. This density varies with modulating signal resulting in corresponding modulation of laser beam frequency. Necessary apparatus is relatively inexpensive since crystals are not required.

  9. Maturational Patterns of Sigma Frequency Power Across Childhood and Adolescence: A Longitudinal Study

    Science.gov (United States)

    Campbell, Ian G.; Feinberg, Irwin

    2016-01-01

    Study Objectives: To further evaluate adolescent brain maturation by determining the longitudinal trajectories of nonrapid eye movement (NREM) sigma (11–15 Hz) power across childhood-adolescence. Methods: The maturational trend for sigma (11–15 Hz) power was evaluated in an accelerated longitudinal study of three overlapping age cohorts (n = 92) covering ages 6 to 18 y. Semiannually, sleep electroencephalography (EEG) was recorded from participants sleeping at home in their normal sleep environment while keeping their current school night schedules. Results: Sigma frequencies became faster with age. The frequency of the 11–15 Hz spectral peak increased linearly. Sigma frequency power (SFP) declined with age, but its trajectory was complex (cubic). Power in a group of low sigma subfrequencies declined with age. Power in a group of high sigma frequencies increased with age. Power in subfrequencies within 11–15 Hz also showed different trends across the night, with lower frequencies increasing across NREM periods and higher frequencies decreasing across NREM periods. The upper and lower boundaries for the sigma frequencies that changed across NREMPs shifted upward with age. Conclusions: We hypothesize that these maturational brain changes result from synaptic elimination which decreases sleep depth and streamlines circuits. SFP displays a maturational trajectory different from both delta and theta power. Theories on the function of sigma must be reconciled with its maturational trajectory. These findings further demonstrate the value of sleep EEG for studying noninvasively the complex developmental brain changes of adolescence. Citation: Campbell IG, Feinberg I. Maturational patterns of sigma frequency power across childhood and adolescence: a longitudinal study. SLEEP 2016;39(1):193–201. PMID:26285004

  10. Automatic oscillator frequency control system

    Science.gov (United States)

    Smith, S. F. (Inventor)

    1985-01-01

    A frequency control system makes an initial correction of the frequency of its own timing circuit after comparison against a frequency of known accuracy and then sequentially checks and corrects the frequencies of several voltage controlled local oscillator circuits. The timing circuit initiates the machine cycles of a central processing unit which applies a frequency index to an input register in a modulo-sum frequency divider stage and enables a multiplexer to clock an accumulator register in the divider stage with a cyclical signal derived from the oscillator circuit being checked. Upon expiration of the interval, the processing unit compares the remainder held as the contents of the accumulator against a stored zero error constant and applies an appropriate correction word to a correction stage to shift the frequency of the oscillator being checked. A signal from the accumulator register may be used to drive a phase plane ROM and, with periodic shifts in the applied frequency index, to provide frequency shift keying of the resultant output signal. Interposition of a phase adder between the accumulator register and phase plane ROM permits phase shift keying of the output signal by periodic variation in the value of a phase index applied to one input of the phase adder.

  11. Far-zone contributions of airborne gravity anomalies' upward/downward continuation

    Directory of Open Access Journals (Sweden)

    Boyang Zhou

    2016-11-01

    Full Text Available Airborne gravimetry has become a vital technique in local gravity field approximation, and upward/downward continuation of gravity data is a key process of airborne gravimetry. In these procedures, the integral domain is divided into two parts, namely the near-zone and the far-zone. The far-zone contributions are approximated by the truncation coefficients and a global geo-potential model, and their values are controlled by several issues. This paper investigates the effects of flight height, the size of near-zone cap, and Remove-Compute-Restore (RCR technique upon far-zone contributions. Results show that at mountainous area the far-zone contributions can be ignored when EIGEN-6C of 360 degree is removed from the gravity data, together with a near-zone cap of 1° and a flight height less than 10 km, while at flat area EIGEN-6C of 180 degree is feasible.

  12. A study of upward going particles with the Extreme Energy Events telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Abbrescia, M. [Museo Storico della Fisica e Centro Studi e Ricerche E. Fermi, Roma (Italy); INFN and Dipartimento di Fisica, Università di Bari, Bari (Italy); Avanzini, C.; Baldini, L. [Museo Storico della Fisica e Centro Studi e Ricerche E. Fermi, Roma (Italy); INFN and Dipartimento di Fisica, Università di Pisa, Pisa (Italy); Ferroli, R. Baldini [Museo Storico della Fisica e Centro Studi e Ricerche E. Fermi, Roma (Italy); INFN Laboratori Nazionali di Frascati, Frascati (RM) (Italy); Batignani, G. [Museo Storico della Fisica e Centro Studi e Ricerche E. Fermi, Roma (Italy); INFN and Dipartimento di Fisica, Università di Pisa, Pisa (Italy); Bencivenni, G. [INFN Laboratori Nazionali di Frascati, Frascati (RM) (Italy); Bossini, E. [Museo Storico della Fisica e Centro Studi e Ricerche E. Fermi, Roma (Italy); INFN Gruppo Collegato di Siena and Dipartimento di Fisica, Università di Siena, Siena (Italy); Chiavassa, A. [INFN and Dipartimento di Fisica, Università di Torino, Torino (Italy); Cicalo, C. [Museo Storico della Fisica e Centro Studi e Ricerche E. Fermi, Roma (Italy); INFN and Dipartimento di Fisica, Università di Cagliari, Cagliari (Italy); Cifarelli, L. [Museo Storico della Fisica e Centro Studi e Ricerche E. Fermi, Roma (Italy); INFN and Dipartimento di Fisica, Università di Bologna, Bologna (Italy); Coccia, E. [INFN and Dipartimento di Fisica, Università di Roma Tor Vergata, Roma (Italy); Corvaglia, A. [Museo Storico della Fisica e Centro Studi e Ricerche E. Fermi, Roma (Italy); INFN and Dipartimento di Matematica e Fisica, Università del Salento, Lecce (Italy); and others

    2016-04-21

    In this paper the first study of the upward going events detected by the telescopes of the Extreme Energy Event (EEE) project is reported. The EEE project consists of a detector array of Multigap Resistive Plate Chambers located at selected sites on the Italian territory. During autumn 2014 the first coordinated data taking period took place and around one billion candidate tracks were collected. Among them, of particular interest is the sample of particles which cross the telescopes from below. The results obtained demonstrate that the EEE telescopes can distinguish the electrons produced as decay products of cosmic muons stopped in the ground, or in the last chamber of the telescopes themselves, confirming the excellent performance of the system for the investigation of intriguing cosmic phenomena.

  13. A Heat Transfer Correlation in a Vertical Upward Flow of CO2 at Supercritical Pressures

    International Nuclear Information System (INIS)

    Kim, Hyung Rae; Bae, Yoon Yeong; Song, Jin Ho; Kim, Hwan Yeol

    2006-01-01

    Heat transfer data has been collected in the heat transfer test loop, named SPHINX (Supercritical Pressure Heat Transfer Investigation for NeXt generation), in KAERI. The facility primarily aims at the generation of heat transfer data in the flow conditions and geometries relevant to SCWR (SuperCritical Water-cooled Reactor). The produced data will aid the thermohydraulic design of a reactor core. The loop uses carbon dioxide, and later the results will be scaled to the water flows. The heat transfer data has been collected for a vertical upward flow in a circular tube with varying mass fluxes, heat fluxes, and operating pressures. The results are compared with the existing correlations and a new correlation is proposed by fine-tuning the one of the existing correlations

  14. Upward nitrate transport by phytoplankton in oceanic waters: balancing nutrient budgets in oligotrophic seas

    Directory of Open Access Journals (Sweden)

    Tracy A. Villareal

    2014-03-01

    Full Text Available In oceanic subtropical gyres, primary producers are numerically dominated by small (1–5 µm diameter pro- and eukaryotic cells that primarily utilize recycled nutrients produced by rapid grazing turnover in a highly efficient microbial loop. Continuous losses of nitrogen (N to depth by sinking, either as single cells, aggregates or fecal pellets, are balanced by both nitrate inputs at the base of the euphotic zone and N2-fixation. This input of new N to balance export losses (the biological pump is a fundamental aspect of N cycling and central to understanding carbon fluxes in the ocean. In the Pacific Ocean, detailed N budgets at the time-series station HOT require upward transport of nitrate from the nutricline (80–100 m into the surface layer (∼0–40 m to balance productivity and export needs. However, concentration gradients are negligible and cannot support the fluxes. Physical processes can inject nitrate into the base of the euphotic zone, but the mechanisms for transporting this nitrate into the surface layer across many 10s of m in highly stratified systems are unknown. In these seas, vertical migration by the very largest (102–103 µm diameter phytoplankton is common as a survival strategy to obtain N from sub-euphotic zone depths. This vertical migration is driven by buoyancy changes rather than by flagellated movement and can provide upward N transport as nitrate (mM concentrations in the cells. However, the contribution of vertical migration to nitrate transport has been difficult to quantify over the required basin scales. In this study, we use towed optical systems and isotopic tracers to show that migrating diatom (Rhizosolenia mats are widespread in the N. Pacific Ocean from 140°W to 175°E and together with other migrating phytoplankton (Ethmodiscus, Halosphaera, Pyrocystis, and solitary Rhizosolenia can mediate time-averaged transport of N (235 µmol N m-2 d-1 equivalent to eddy nitrate injections (242 µmol NO3− m

  15. Two-phase upward air water flow in a prismatic channel with rectangular base

    International Nuclear Information System (INIS)

    Carvalho Tofani, P. de

    1984-01-01

    Two-phase liquid-gas mixtures provide suitable means to simulate water-water vapor flows, which may occur in nuclear reactor cores. The mastery of physical transport phenomena is of great importance, as far as the analysis of such thermal systems is concerned. Within the framework of thermal-hydraulic programs, experiments have been carried out to investigate the two-phase upward air-water flow structure, in a rectangular test section, by using independent measuring techniques, which comprise direct viewing and photography, electrical probes and gamma-ray attenuation. In this paper, flow pattern maps and correlations for flow pattern transitions, void fraction profiles, liquid film thickness and superficial average void fraction are proposed and compared to available data. (Author) [pt

  16. Heat transfer characteristics of supercritical pressure waster in vertical upward annular channels

    International Nuclear Information System (INIS)

    Wang Han; Bi Qincheng; Yang Zhendong; Wu Gang

    2013-01-01

    Within the range of pressure from 23 to 28 MPa, mass flux from 350 to 1000 kg/(m 2 · s), and outside wall heat flux from 200 to 1000 kW/m 2 , experimental investigation was conducted on the heat transfer characteristics of supercritical pressure water in vertical upward annular channels. The effects of heat flux, pressure, mass flux and spiral spacer on heat transfer were analyzed, and two types of heat transfer deterioration occurred in the experiments were compared. The experimental results show that the heat transfer of water can be enhanced by increasing the mass flux or decreasing the wall heat flux. The effect of pressure on heat transfer is not uniform and depends on heat transfer form. It was found that the spiral spacer not only enhances the heat transfer of water, but also delays the heat transfer deterioration which occurs in high heat flux and low mass flux conditions. (authors)

  17. CrossRef A study of upward going particles with the Extreme Energy Events telescopes

    CERN Document Server

    Abbrescia, M; Baldini, L; Ferroli, R Baldini; Batignani, G; Bencivenni, G; Bossini, E; Chiavassa, A; Cicalo, C; Cifarelli, L; Coccia, E; Corvaglia, A; De Gruttola, D; De Pasquale, S; Di Giovanni, A; D׳Incecco, M; Dreucci, M; Fabbri, F L; Fattibene, E; Ferraro, A; Forster, R; Frolov, V; Galeotti, P; Garbini, M; Gemme, G; Gnesi, I; Grazzi, S; Gustavino, C; Hatzifotiadu, D; La Rocca, P; Maggiora, A; Maron, G; Mazziotta, M N; Miozzi, S; Nania, R; Noferini, F; Nozzoli, F; Panareo, M; Panetta, M P; Paoletti, R; Perasso, L; Pilo, F; Piragino, G; Riggi, F; Righini, G C; Rodriguez, A R; Sartorelli, G; Scapparone, E; Schioppa, M; Scribano, A; Selvi, M; Serci, S; Siddi, E; Squarcia, S; Stori, L; Taiuti, M; Terreni, G; Vistoli, M C; Votano, L; Williams, M C S; Zani, S; Zichichi, A; Zuyeuski, R

    2016-01-01

    In this paper the first study of the upward going events detected by the telescopes of the Extreme Energy Event (EEE) project is reported. The EEE project consists of a detector array of Multigap Resistive Plate Chambers located at selected sites on the Italian territory. During autumn 2014 the first coordinated data taking period took place and around one billion candidate tracks were collected. Among them, of particular interest is the sample of particles which cross the telescopes from below. The results obtained demonstrate that the EEE telescopes can distinguish the electrons produced as decay products of cosmic muons stopped in the ground, or in the last chamber of the telescopes themselves, confirming the excellent performance of the system for the investigation of intriguing cosmic phenomena.

  18. Internal causes of radon and its daughters upward migration and cluster phenomenon

    International Nuclear Information System (INIS)

    Jia Wenyi; Fang Fang; Zhou Rongsheng; Ma Yingjie; Qiu Yuande; Hou Xinsheng; Wu Yunping; Zu Xiulan; Wang Xiaoqin

    1999-01-01

    Radon and its daughters have a very big specific gravity. But under laboratory conditions, they have the ability to migrate upward. The phenomenon can't be interpreted by an external cause but by an internal cause. The mechanism is that radon and most of its daughters and parents are decaying bodies able to radiate α-particles. After deceleration, 4He can combine with radon and its daughters and parents to form clusters. When the buoyancy of air is greater than the gravity of the clusters, self-ascending occurs. Accordingly, the distance that Rn covered during 3.825 days (Rn half-life) should not be regarded as Rn and its daughters migrating distance, but should be calculated according to all effects. That clusters can be formed by 4He, Rn and its daughters are valuable to study because of the similarity between Rn and heavy metal particles

  19. A study of upward going particles with the Extreme Energy Events telescopes

    International Nuclear Information System (INIS)

    Abbrescia, M.; Avanzini, C.; Baldini, L.; Ferroli, R. Baldini; Batignani, G.; Bencivenni, G.; Bossini, E.; Chiavassa, A.; Cicalo, C.; Cifarelli, L.; Coccia, E.; Corvaglia, A.

    2016-01-01

    In this paper the first study of the upward going events detected by the telescopes of the Extreme Energy Event (EEE) project is reported. The EEE project consists of a detector array of Multigap Resistive Plate Chambers located at selected sites on the Italian territory. During autumn 2014 the first coordinated data taking period took place and around one billion candidate tracks were collected. Among them, of particular interest is the sample of particles which cross the telescopes from below. The results obtained demonstrate that the EEE telescopes can distinguish the electrons produced as decay products of cosmic muons stopped in the ground, or in the last chamber of the telescopes themselves, confirming the excellent performance of the system for the investigation of intriguing cosmic phenomena.

  20. Peritoneal catheter fixation combined with straight upward tunnel and low implant position to prevent catheter malfunction.

    Science.gov (United States)

    Zhang, Qingyan; Jiang, Chunming; Zhu, Wei; Sun, Cheng; Xia, Yangyang; Tang, Tianfeng; Wan, Cheng; Shao, Qiuyuan; Liu, Jing; Jin, Bo; Zhang, Miao

    2018-03-01

    Catheter malfunction is the main reason for early peritoneal dialysis (PD) technique failure. This study aimed to evaluate the effect of a new surgery technique with catheter fixation to the lower abdominal wall combined with straight upward tunnel and low implant position in reducing catheter malfunction. Patients with end stage renal disease who received PD in our centre from January 2013 to December 2015 were involved in this study. They were randomly divided into three groups according to surgical technique: traditional open surgery group, modified open surgery group and modified open surgery with catheter fixation group. All patients were followed up for six months after surgery. Catheter- related complications were analyzed. A total of 152 patients were involved. Among them, 49 received traditional open surgery (TOS group), 49 received modified open surgery (MOS group), and 54 received modified open surgery with catheter fixation (MOS-F group). During follow-up, no patients (0%) in MOS-F group developed catheter malfunction which was significantly lower than that of the TOS group (0 vs 16.33%, P = 0.002). Although not statistically significant, the incidence of catheter malfunction was lower in MOS-F group than that in MOS group (0 vs 4.08%, P = 0.134). No significant difference was observed in the episodes of infection, bleeding, leakage, inflow or outflow pain, hernia and delayed wound healing among the three groups (all P > 0.05). Catheter fixation combined with straight upward tunnel and low implant position can effectively prevent catheter malfunction in PD catheter placement. © 2016 Asian Pacific Society of Nephrology.

  1. The influence of the unsaturated zone on the upward transport of radionuclides in soils

    International Nuclear Information System (INIS)

    Elert, M.; Lindgren, M.

    1993-07-01

    The transport of radionuclides from the deep soil to the surface soil is an important part of biosphere modelling. In this study the effect of transient hydrological conditions on the upward transport of radionuclides through soils has been studied. The effect of varying soil properties, climate conditions have been considered as well as the effect of a fluctuating groundwater level. It was shown that the soil characteristics influences the radionuclide concentration; an increased hydraulic conductivity leads to increase in the concentration in the root zone. The climate conditions were shown to be of major importance. A dispersion dependent on both velocity and saturation leads to a more effective upward transport of radionuclides to the root zone than if dispersion is assumed to be dependent only on the saturation. The boundary condition used in the case with varying groundwater level may be more realistic than the boundary condition applied for the case with a constant groundwater level. All calculations with varying groundwater level gave lower radionuclide concentration in the root zone. Sorption is redox sensitive for many radionuclides and the redox potential in the soil will be affected by the degree of water saturation. The performed calculations did, however, not result in any significant change in the radionuclide concentration in the root zone due to variation in sorption. A comparison between the results of the two models show that the compartment model in all studied cases predicts a higher annual average radionuclide concentration in the root zone than the numerical model. Annual variation in soil water flow were not included in the compartment model. During the summer the concentration in the root zone may be several times higher than the annual average. This may be important for plant uptake, since this increased concentrations coincides with the plant growing season. The calculations made with the simple compartment model also show that these

  2. Removal of heavy metals from kaolin using an upward electrokinetic soil remedial (UESR) technology

    International Nuclear Information System (INIS)

    Wang, J.-Y.; Huang, X.-J.; Kao, Jimmy C.M.; Stabnikova, Olena

    2006-01-01

    An upward electrokinetic soil remedial (UESR) technology was proposed to remove heavy metals from contaminated kaolin. Unlike conventional electrokinetic treatment that uses boreholes or trenches for horizontal migration of heavy metals, the UESR technology, applying vertical non-uniform electric fields, caused upward transportation of heavy metals to the top surface of the treated soil. The effects of current density, treatment duration, cell diameter, and different cathode chamber influent (distilled water or 0.01 M nitric acid) were studied. The removal efficiencies of heavy metals positively correlated to current density and treatment duration. Higher heavy metals removal efficiency was observed for the reactor cell with smaller diameter. A substantial amount of heavy metals was accumulated in the nearest to cathode 2 cm layer of kaolin when distilled water was continuously supplied to the cathode chamber. Heavy metals accumulated in this layer of kaolin can be easily excavated and disposed off. The main part of the removed heavy metals was dissolved in cathode chamber influent and moved away with cathode chamber effluent when 0.01 M nitric acid was used, instead of distilled water. Energy saving treatment by UESR technology with highest metal removal efficiencies was provided by two regimes: (1) by application of 0.01 M nitric acid as cathode chamber influent, cell diameter of 100 mm, duration of 18 days, and constant voltage of 3.5 V (19.7 kWh/m 3 of kaolin) and (2) by application of 0.01 M nitric acid as cathode chamber influent, cell diameter of 100 cm, duration of 6 days, and constant current density of 0.191 mA/cm 2 (19.1 kWh/m 3 of kaolin)

  3. Experimental heat transfer to supercritical carbon dioxide flowing upward vertical tube with highly conducting surroundings

    International Nuclear Information System (INIS)

    Son, Hyung M.; Suh, Kune Y.

    2012-01-01

    Highlights: ► Performed experiment for the upward SCO 2 flow surrounded by highly conducting metal. ► Selected dimensionless groups representing the property variations and buoyancy. ► Developed the heat transfer correlation for the mixed thermal boundary condition. ► Wrote a finite element heat transfer code to find the appropriate correlation. ► Coupled the 1D convection and 2D heat conduction via heat transfer coefficient. - Abstract: This paper presents heat transfer characteristics of supercritical carbon dioxide flow inside vertical circular pipe surrounded by highly conducting material, and develops an adequate tool to test the performance of available heat transfer correlations with. The possible situations are illustrated for the nuclear power plant to which the above-mentioned geometric configuration might be applicable. An experimental loop with vertical circular geometry is designed and constructed to test the upward flow in supercritical state when the axial heat transfer is enhanced by the surrounding metals, resulting in a wall boundary condition between the constant heat flux and temperature. The set of correlations and important findings are critically reviewed from extensive literature survey. Incorporating nondimensional groups resorting to past insights from the available literature, a convective heat transfer correlation is proposed. The optimization procedure is described which utilizes a random walk method along with the in-house finite element heat transfer code to determine the coefficients of the proposed heat transfer correlation. The proposed methodology can be applied to evaluation of heat transfer when the heat transfer coefficient data cannot directly be determined from the experiment.

  4. Shifted Independent Component Analysis

    DEFF Research Database (Denmark)

    Mørup, Morten; Madsen, Kristoffer Hougaard; Hansen, Lars Kai

    2007-01-01

    Delayed mixing is a problem of theoretical interest and practical importance, e.g., in speech processing, bio-medical signal analysis and financial data modelling. Most previous analyses have been based on models with integer shifts, i.e., shifts by a number of samples, and have often been carried...

  5. Homogeneous bilateral block shifts

    Indian Academy of Sciences (India)

    Douglas class were classified in [3]; they are unilateral block shifts of arbitrary block size (i.e. dim H(n) can be anything). However, no examples of irreducible homogeneous bilateral block shifts of block size larger than 1 were known until now.

  6. OpenShift cookbook

    CERN Document Server

    Gulati, Shekhar

    2014-01-01

    If you are a web application developer who wants to use the OpenShift platform to host your next big idea but are looking for guidance on how to achieve this, then this book is the first step you need to take. This is a very accessible cookbook where no previous knowledge of OpenShift is needed.

  7. Josephson shift registers

    International Nuclear Information System (INIS)

    Przybysz, J.X.

    1989-01-01

    This paper gives a review of Josephson shift register circuits that were designed, fabricated, or tested, with emphasis on work in the 1980s. Operating speed is most important, since it often limits system performance. Older designs used square-wave clocks, but most modern designs use offset sine waves, with either two or three phases. Operating margins and gate bias uniformity are key concerns. The fastest measured Josephson shift register operated at 2.3 GHz, which compares well with a GaAs shift register that consumes 250 times more power. The difficulties of high-speed testing have prevented many Josephson shift registers from being operated at their highest speeds. Computer simulations suggest that 30-GHz operation is possible with current Nb/Al 2 O 3 /Nb technology. Junctions with critical current densities near 10 kA/cm 2 would make 100-GHz shift registers feasible

  8. Non-occupational physical activity levels of shift workers compared with non-shift workers.

    Science.gov (United States)

    Loef, Bette; Hulsegge, Gerben; Wendel-Vos, G C Wanda; Verschuren, W M Monique; Vermeulen, Roel C H; Bakker, Marije F; van der Beek, Allard J; Proper, Karin I

    2017-05-01

    Lack of physical activity (PA) has been hypothesised as an underlying mechanism in the adverse health effects of shift work. Therefore, our aim was to compare non-occupational PA levels between shift workers and non-shift workers. Furthermore, exposure-response relationships for frequency of night shifts and years of shift work regarding non-occupational PA levels were studied. Data of 5980 non-shift workers and 532 shift workers from the European Prospective Investigation into Cancer and Nutrition-Netherlands (EPIC-NL) were used in these cross-sectional analyses. Time spent (hours/week) in different PA types (walking/cycling/exercise/chores) and intensities (moderate/vigorous) were calculated based on self-reported PA. Furthermore, sports were operationalised as: playing sports (no/yes), individual versus non-individual sports, and non-vigorous-intensity versus vigorous-intensity sports. PA levels were compared between shift workers and non-shift workers using Generalized Estimating Equations and logistic regression. Shift workers reported spending more time walking than non-shift workers (B=2.3 (95% CI 1.2 to 3.4)), but shift work was not associated with other PA types and any of the sports activities. Shift workers who worked 1-4 night shifts/month (B=2.4 (95% CI 0.6 to 4.3)) and ≥5 night shifts/month (B=3.7 (95% CI 1.8 to 5.6)) spent more time walking than non-shift workers. No exposure-response relationships were found between years of shift work and PA levels. Shift workers spent more time walking than non-shift workers, but we observed no differences in other non-occupational PA levels. To better understand if and how PA plays a role in the negative health consequences of shift work, our findings need to be confirmed in future studies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  9. A study on the characteristics of upward air-water two-phase flow in a large pipe

    International Nuclear Information System (INIS)

    Shen, Xiuzhong; Mishima, Kaichiro; Nakamura, Hideo

    2003-01-01

    Adiabatic upward air-water two-phase flow in a vertical large pipe (inner diameter, D: 0.2 m, ratio of pipe length to diameter, L/D: 60.5.) was experimentally investigated under various inlet conditions. Flow regime was observed and void fraction, bubble frequency, Sauter mean diameter, interfacial area concentration (IAC) and interfacial direction were measured with optical four-sensor probe. Characteristics of various flow regimes were analyzed carefully. Both the void fraction and the IAC demonstrated radial wall-peak and core-peak distributions in the undisturbed bubbly flow and the other flow regimes, respectively. The existence of bubbly secondary flow accounts for the core-peak distribution in the agitated bubbly, churn bubbly, churn slug and churn froth flow. The bubble frequency showed a wall-peak radial distribution only when the bubbles were small in diameter and the flow was in the undisturbed bubbly flow. The Sauter mean diameter of bubbles did not change much in the main flow of undisturbed bubbly, agitated bubbly and churn bubbly flow regimes and showed a core peak radial distribution in the churn slug flow. In the latter flow regime, the secondary flow disintegrated the bubbles, resulting in the decrease of the Sauter mean diameter. The measurements of the interfacial direction showed that the bubbly main flow and secondary flow can be displayed by the main flow peak and the secondary flow peak, respectively, in the PDF of the interfacial directional angle between the interfacial direction and the z-axis, η zi . The local average η zi at the bubble front hemispheres reflects the local bubble movement and is in direct connection with the flow regimes. Based on the analysis, the authors classified the flow regimes in the vertical large pipe quantitatively by the local average η zi . Bubbles in the liquid phase moved in a zigzag line with no inclination toward any direction in the plane vertical to z-axis in the pipe core. The axial differential

  10. Upward translocation of 14C-amino compounds in xylem and phloem of citrus trees (citrus unshiu marc.)

    International Nuclear Information System (INIS)

    Kato, Tadashi; Yamagata, Makoto; Tsukahara, Sadao

    1985-01-01

    Upward and lateral movements of 14 C-amino compounds in intact trees and excised shoots, and upward translocation of major amino compounds in intact shoots were examined in the early stage of new shoot development. The results were summarized as follows. 1. Uniformly 14 C-labelled arginine, asparagine, aspartic acid and proline were steadily taken up by roots of intact trees, translocated to old leaves and new shoots, and appeared in the fed compound and its metabolized products in these organs. 2. 14 C-arginine, asparagine and proline were translocated upward not only via the xylem but also via the phloem. Lateral movements, from the xylem to the pholoem and from the phloem to the xylem, also occurred. These compounds showed different patterns in their movements. 14 C-arginine and its metabolic products tended to accumulate in the xylem and translocate upward in the xylem. This was in contrast to 14 C-proline and its metabolic products, which tended to accumulate in the phloem and translocate upward in the phloem. These findings were supported by the results obtained in intact shoots. 3. The 14 C-amino compounds were metabolized to soluble and insoluble compounds during the translocation and in the new shoots. However, they differed significantly in the extent of metabolic conversion during translocation; proline was hardly metabolized, arginine and asparagine were moderately metabolized, and aspartic acid was almost completely metabolized. (author)

  11. Six-Year Nitrogen–Water Interaction Shifts the Frequency Distribution and Size Inequality of the First-Order Roots of Fraxinus mandschurica in a Mixed Mature Pinus koraiensis Forest

    Science.gov (United States)

    Wang, Cunguo; Geng, Zhenzhen; Chen, Zhao; Li, Jiandong; Guo, Wei; Zhao, Tian-Hong; Cao, Ying; Shen, Si; Jin, Daming; Li, Mai-He

    2017-01-01

    The variation in fine root traits in terms of size inequality at the individual root level can be identified as a strategy for adapting to the drastic changes in soil water and nutrient availabilities. The Gini and Lorenz asymmetry coefficients have been applied to describe the overall degree of size inequality, which, however, are neglected when conventional statistical means are calculated. Here, we used the Gini coefficient, Lorenz asymmetry coefficient and statistical mean in an investigation of Fraxinus mandschurica roots in a mixed mature Pinus koraiensis forest on Changbai Mountain, China. We analyzed 967 individual roots to determine the responses of length, diameter and area of the first-order roots and of branching intensity to 6 years of nitrogen addition (N), rainfall reduction (W) and their combination (NW). We found that first-order roots had a significantly greater average length and area but had smaller Gini coefficients in NW plots compared to in control plots (CK). Furthermore, the relationship between first-order root length and branching intensity was negative in CK, N, and W plots but positive in NW plots. The Lorenz asymmetry coefficient was >1 for the first-order root diameter in NW and W plots as well as for branching intensity in N plots. The bimodal frequency distribution of the first-order root length in NW plots differed clearly from the unimodal one in CK, N, and W plots. These results demonstrate that not only the mean but also the variation and the distribution mode of the first-order roots of F. mandschurica respond to soil nitrogen and water availability. The changes in size inequality of the first-order root traits suggest that Gini and Lorenz asymmetry coefficients can serve as informative parameters in ecological investigations of roots to improve our ability to predict how trees will respond to a changing climate at the individual root level. PMID:29018474

  12. Six-Year Nitrogen-Water Interaction Shifts the Frequency Distribution and Size Inequality of the First-Order Roots of Fraxinus mandschurica in a Mixed Mature Pinus koraiensis Forest.

    Science.gov (United States)

    Wang, Cunguo; Geng, Zhenzhen; Chen, Zhao; Li, Jiandong; Guo, Wei; Zhao, Tian-Hong; Cao, Ying; Shen, Si; Jin, Daming; Li, Mai-He

    2017-01-01

    The variation in fine root traits in terms of size inequality at the individual root level can be identified as a strategy for adapting to the drastic changes in soil water and nutrient availabilities. The Gini and Lorenz asymmetry coefficients have been applied to describe the overall degree of size inequality, which, however, are neglected when conventional statistical means are calculated. Here, we used the Gini coefficient, Lorenz asymmetry coefficient and statistical mean in an investigation of Fraxinus mandschurica roots in a mixed mature Pinus koraiensis forest on Changbai Mountain, China. We analyzed 967 individual roots to determine the responses of length, diameter and area of the first-order roots and of branching intensity to 6 years of nitrogen addition (N), rainfall reduction (W) and their combination (NW). We found that first-order roots had a significantly greater average length and area but had smaller Gini coefficients in NW plots compared to in control plots (CK). Furthermore, the relationship between first-order root length and branching intensity was negative in CK, N, and W plots but positive in NW plots. The Lorenz asymmetry coefficient was >1 for the first-order root diameter in NW and W plots as well as for branching intensity in N plots. The bimodal frequency distribution of the first-order root length in NW plots differed clearly from the unimodal one in CK, N, and W plots. These results demonstrate that not only the mean but also the variation and the distribution mode of the first-order roots of F. mandschurica respond to soil nitrogen and water availability. The changes in size inequality of the first-order root traits suggest that Gini and Lorenz asymmetry coefficients can serve as informative parameters in ecological investigations of roots to improve our ability to predict how trees will respond to a changing climate at the individual root level.

  13. Nurses' shift reports

    DEFF Research Database (Denmark)

    Buus, Niels; Hoeck, Bente; Hamilton, Bridget Elizabeth

    2017-01-01

    AIMS AND OBJECTIVES: To identify reporting practices that feature in studies of nurses' shift reports across diverse nursing specialities. The objectives were to perform an exhaustive systematic literature search and to critically review the quality and findings of qualitative field studies...... of nurses' shift reports. BACKGROUND: Nurses' shift reports are routine occurrences in healthcare organisations that are viewed as crucial for patient outcomes, patient safety and continuity of care. Studies of communication between nurses attend primarily to 1:1 communication and analyse the adequacy...... and accuracy of patient information and feature handovers at the bedside. Still, verbal reports between groups of nurses about patients are commonplace. Shift reports are obvious sites for studying the situated accomplishment of professional nursing at the group level. This review is focused exclusively...

  14. Shift Verification and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Pandya, Tara M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Evans, Thomas M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Davidson, Gregory G [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Johnson, Seth R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Godfrey, Andrew T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-09-07

    This documentation outlines the verification and validation of Shift for the Consortium for Advanced Simulation of Light Water Reactors (CASL). Five main types of problems were used for validation: small criticality benchmark problems; full-core reactor benchmarks for light water reactors; fixed-source coupled neutron-photon dosimetry benchmarks; depletion/burnup benchmarks; and full-core reactor performance benchmarks. We compared Shift results to measured data and other simulated Monte Carlo radiation transport code results, and found very good agreement in a variety of comparison measures. These include prediction of critical eigenvalue, radial and axial pin power distributions, rod worth, leakage spectra, and nuclide inventories over a burn cycle. Based on this validation of Shift, we are confident in Shift to provide reference results for CASL benchmarking.

  15. Molecular Electronic Shift Registers

    Science.gov (United States)

    Beratan, David N.; Onuchic, Jose N.

    1990-01-01

    Molecular-scale shift registers eventually constructed as parts of high-density integrated memory circuits. In principle, variety of organic molecules makes possible large number of different configurations and modes of operation for such shift-register devices. Several classes of devices and implementations in some specific types of molecules proposed. All based on transfer of electrons or holes along chains of repeating molecular units.

  16. High-speed and supersonic upward plasma drifts: multi-instrumental study

    Science.gov (United States)

    Astafyeva, E.; Zakharenkova, I.; Hairston, M. R.; Huba, J.; Coley, W. R.

    2017-12-01

    Since the pioneering observations by Aggson et al. (1992, JGR, doi: 10.1002/92JA00644), there have been several reports of the occurrence of high-speed (Vz>800 m/s) and supersonic plasma flows in the post-sunset (e.g., Hysell et al., 1994, JGR, doi: 10.1029/94JA00476; Hanson et al., 1997, JGR, doi: 10.1029/96JA03376) and the pre-dawn sector (Astafyeva and Zakharenkova, 2015, GRL, doi:10.1002/2015GL066369). However, despite this observational evidence, these events remain rare and are not well understood. The main issue is to determine the background conditions leading to the occurrence of these high-speed plasma drifts. In this work, we perform a multi-instrumental study of high-speed and supersonic upward plasma drift events/structures. For this purpose, we analyze data from several ground-based and space-borne instruments, including data from the DMSP, Swarm and C/NOFS (IVM instrument) satellites. In addition to the space-borne instruments, we use data from ground-based GPS-receivers and ionosondes to further investigate the background ionosphere conditions, as well as the effects produced by the plasma bubbles and ionospheric irregularities. Besides the observations, we add the SAMI3/ESF modeling results on plasma bubble simulations and high-speed drifts inside plasma bubbles. TIE-GCM runs (from the CCMC, https://ccmc.gsfc.nasa.gov) are used to define the background atmospheric/ionospheric and electrodynamical conditions leading to the occurrence of the high-speed and supersonic plasma drift events. Our search of events with upward plasma drift exceeding 800 m/s in the data of DMSP for the years 2002-2016 shows that such high-speed events are extremely rare. During this period of time, only 6 events were found, two of them occurred during the recovery phase of a geomagnetic storm, while the other four were detected during geomagnetically quiet conditions. Concerning the generation of such events, our preliminary results show that enhanced electric fields are

  17. How does the architecture of a fault system controls magma upward migration through the crust?

    Science.gov (United States)

    Iturrieta, P. C.; Cembrano, J. M.; Stanton-Yonge, A.; Hurtado, D.

    2017-12-01

    The orientation and relative disposition of adjacent faults locally disrupt the regional stress field, thus enhancing magma flow through previous or newly created favorable conduits. Moreover, the brittle-plastic transition (BPT), due to its stronger rheology, governs the average state of stress of shallower portions of the fault system. Furthermore, the BPT may coincide with the location of transient magma reservoirs, from which dikes can propagate upwards into the upper crust, shaping the inner structure of the volcanic arc. In this work, we examine the stress distribution in strike-slip duplexes with variable geometry, along with the critical fluid overpressure ratio (CFOP), which is the minimum value required for individual faults to fracture in tension. We also determine the stress state disruption of the fault system when a dike is emplaced, to answer open questions such as: what is the nature of favorable pathways for magma to migrate? what is the architecture influence on the feedback between fault system kinematics and magma injection? To this end, we present a 3D coupled hydro-mechanical finite element model of the continental lithosphere, where faults are represented as continuum volumes with an elastic-plastic rheology. Magma flow upon fracturing is modeled through non-linear Stoke's flow, coupling solid and fluid equilibrium. A non-linear sensitivity analysis is performed in function of tectonic, rheology and geometry inputs, to assess which are the first-order factors that governs the nature of dike emplacement. Results show that the CFOP is heterogeneously distributed in the fault system, and within individual fault segments. Minimum values are displayed near fault intersections, where local kinematics superimpose on regional tectonic loading. Furthermore, when magma is transported through a fault segment, the CFOP is now minimized in faults with non-favorable orientations. This suggests that these faults act as transient pathways for magma to

  18. A computational investigation of the red and blue shifts in hydrogen

    Indian Academy of Sciences (India)

    The presentwork reports results of computational investigations of hydrogen bonding, with regard to the most common red shift in the vibrational frequency, as well as the less common blue shift in several hydrogen bonded systems. A few new correlations of the frequency shifts with the calculated electrostatic parameters ...

  19. Lifshitz singularities in random harmonic chains: periodic amplitudes near the band edge and near special frequencies

    International Nuclear Information System (INIS)

    Nieuwenhuizen, T.M.; Luck, J.M.

    1987-01-01

    The authors give a complete description of the scaling behavior of the integrated density of states of random harmonic chains with random masses near the band edge omega/sub max/ and near special frequencies omega/sub s/. There are four different situations: omega upward arrow omega/sub max/, omega upward arrow omega/sub s/, omega upward arrow omega/sub s/ (critical case), omega upward arrow omega/sub s/ (general case). Their analytic results have the form of infinite sums involving Fourier coefficients of the scaling behavior of the Dyson-Schmidt function at the special frequency or the band edge. Binary mass distributions are considered in detail in the limit of a small fraction rho of light masses. Their predictions are compared with extensive numerical data

  20. Precise Doppler shift compensation in the hipposiderid bat, Hipposideros armiger.

    Science.gov (United States)

    Schoeppler, Diana; Schnitzler, Hans-Ulrich; Denzinger, Annette

    2018-03-15

    Bats of the Rhinolophidae and Hipposideridae families, and Pteronotus parnellii, compensate for Doppler shifts generated by their own flight movement. They adjust their call frequency such that the frequency of echoes coming from ahead fall in a specialized frequency range of the hearing system, the auditory fovea, to evaluate amplitude and frequency modulations in echoes from fluttering prey. Some studies in hipposiderids have suggested a less sophisticated or incomplete Doppler shift compensation. To investigate the precision of Doppler shift compensation in Hipposideros armiger, we recorded the echolocation and flight behaviour of bats flying to a grid, reconstructed the flight path, measured the flight speed, calculated the echo frequency, and compared it with the resting frequency prior to each flight. Within each flight, the average echo frequency was kept constant with a standard deviation of 110 Hz, independent of the flight speed. The resting and reference frequency were coupled with an offset of 80 Hz; however, they varied slightly from flight to flight. The precision of Doppler shift compensation and the offset were similar to that seen in Rhinolophidae and P. parnellii. The described frequency variations may explain why it has been assumed that Doppler shift compensation in hipposiderids is incomplete.

  1. Excitation of low-frequency electrostatic instability on the auroral ...

    African Journals Online (AJOL)

    Low-Frequency Electrostatic Instability That Is Observed By Both Ground Facilities And Satellites Have Been Studied In The Auroral Acceleration Region Consisting Of Hot Precipitating Electron Beam From The Magnetosphere, Cold Background Electron And Ion Beam Moving Upward Away From The Earth Along The ...

  2. Numerical Simulation on Forced Convective Condensation of Steam Upward Flow in a Vertical Pipe

    Directory of Open Access Journals (Sweden)

    Guo-Dong Qiu

    2014-05-01

    Full Text Available A transient three-dimensional volume of fluid (VOF simulation on condensation of upward flow of wet steam inside a 12 mm i.d. vertical pipe is presented. The effect of gravity and surface tension are taken into account. A uniform wall temperature has been fixed as boundary conditions. The mass flux is 130~6400 kg m−2's−1 and the turbulence inside the vapor phase and liquid phase have been handled by Reynolds stress model (RSM. The vapor quality of fluid is 0~0.4. The numerical simulation results show that, in all the simulation conditions, the bubbly flow, slug flow, churn flow, wispy annular flow, and annular flow are observed; in addition, the results of flow pattern are in good agreement with the regime map from Hewitt and Roberts. The typical velocity field characteristic of each flow pattern and the effect of velocity field on heat transfer of condensation are analyzed, indicating that the slug flow and churn flow have obvious local eddy. However, no obvious eddy is observed in other flow patterns and the streamlines are almost parallel to the flow direction. The simulation results of heat transfer coefficients and frictional pressure drop show good agreement with the correlations from existing literatures.

  3. Surface tension effects on vertical upward annular flows in a small diameter pipe

    Energy Technology Data Exchange (ETDEWEB)

    Sadatomi, Michio, E-mail: sadatomi@mech.kumamoto-u.ac.jp [Dept. of Advanced Mechanical Systems, Kumamoto Univ., 39-1, Kurokami 2-chome, Chuou-ku, Kumamoto 860-8555 (Japan); Kawahara, Akimaro [Dept. of Advanced Mechanical Systems, Kumamoto Univ., 39-1, Kurokami 2-chome, Chuou-ku, Kumamoto 860-8555 (Japan); Suzuki, Aruta [Plant Design & Engineering Dept., Environment, Energy & Plant Headquarters, Hitachi Zosen Corporation, 7-89, Nankokita 1-chome, Suminoe-ku, Osaka, 559-8559 (Japan)

    2016-12-15

    Highlights: • Surface tension effects were clarified on annular flow in a small diameter pipe. • The mean liquid film thickness became thinner with decreasing of surface tension. • The liquid droplet fraction and the interfacial shear stress became higher with it. • New prediction methods for the above parameters were developed and validated. - Abstract: Experiments were conducted to study the surface tension effects on vertical upward annular flows in a 5 mm I.D. pipe using water and low surface tension water with a little surfactant as the test liquid and air as the test gas. Firstly, the experimental results on the mean liquid film thickness, the liquid droplet fraction and the interfacial shear stress in annular flows together with some flow pictures are presented to clarify the surface tension effects. From these, the followings are clarified: In the low surface tension case, the liquid film surface becomes rough, the liquid film thickness thin, the liquid droplet fraction high, and the interfacial shear stress high. Secondary, correlations in literatures for the respective parameters are tested against the present data. The test results show that no correlation for the respective parameters could predict well the present data. Thus, correlations are revised by accounting for the surface tension effects. The results of the experiments, the correlations tests and their revisions mentioned above are presented in the present paper.

  4. On the One-Dimensional Modeling of Vertical Upward Bubbly Flow

    Directory of Open Access Journals (Sweden)

    C. Peña-Monferrer

    2018-01-01

    Full Text Available The one-dimensional two-fluid model approach has been traditionally used in thermal-hydraulics codes for the analysis of transients and accidents in water–cooled nuclear power plants. This paper investigates the performance of RELAP5/MOD3 predicting vertical upward bubbly flow at low velocity conditions. For bubbly flow and vertical pipes, this code applies the drift-velocity approach, showing important discrepancies with the experiments compared. Then, we use a classical formulation of the drag coefficient approach to evaluate the performance of both approaches. This is based on the critical Weber criteria and includes several assumptions for the calculation of the interfacial area and bubble size that are evaluated in this work. A more accurate drag coefficient approach is proposed and implemented in RELAP5/MOD3. Instead of using the Weber criteria, the bubble size distribution is directly considered. This allows the calculation of the interfacial area directly from the definition of Sauter mean diameter of a distribution. The results show that only the proposed approach was able to predict all the flow characteristics, in particular the bubble size and interfacial area concentration. Finally, the computational results are analyzed and validated with cross-section area average measurements of void fraction, dispersed phase velocity, bubble size, and interfacial area concentration.

  5. An assessment of void fraction correlations for vertical upward steam-water flow

    International Nuclear Information System (INIS)

    Vijayan, P.K.; Maruthi Ramesh, N.; Pilkhwal, D.S.; Saha, D.

    1997-01-01

    An assessment of sixteen void fraction correlations have been carried out using experimental void fraction data compiled from open literature for vertical upward steam-water flow. Nearly 80% of all the data pertained to natural circulation flow. This assessment showed that best prediction is obtained by Chexal et al. (1996) correlation followed by Hughmark (1965) and the Mochizuki and Ishii (1992) correlations. The Mochizuki-Ishii correlation is found to satisfy all the three limiting conditions whereas Chexal et al. (1996) correlation satisfies all the limiting conditions at moderately high mass fluxes (greater than 140 kg/m 2 s) while Hughmark correlation satisfies only one of the three limiting conditions. The available void fraction data in the open literature for steam-water two-phase flow lies predominantly in the low quality region. This is the reason why correlations like Hughmark which do not satisfy the upper limiting condition (i.e. at x=1, α=1) perform rather well in assessments. Additional work is required for the generation of high quality (greater than 40%) void fraction data. (author)

  6. Sea ice draft in the Weddell Sea, measured by upward looking sonars

    Directory of Open Access Journals (Sweden)

    A. Behrendt

    2013-06-01

    Full Text Available The presented database contains time-referenced sea ice draft values from upward looking sonar (ULS measurements in the Weddell Sea, Antarctica. The sea ice draft data can be used to infer the thickness of the ice. They were collected during the period 1990–2008. In total, the database includes measurements from 13 locations in the Weddell Sea and was generated from more than 3.7 million measurements of sea ice draft. The files contain uncorrected raw drafts, corrected drafts and the basic parameters measured by the ULS. The measurement principle, the data processing procedure and the quality control are described in detail. To account for the unknown speed of sound in the water column above the ULS, two correction methods were applied to the draft data. The first method is based on defining a reference level from the identification of open water leads. The second method uses a model of sound speed in the oceanic mixed layer and is applied to ice draft in austral winter. Both methods are discussed and their accuracy is estimated. Finally, selected results of the processing are presented. The data can be downloaded from doi:10.1594/PANGAEA.785565.

  7. Theory and observations of upward field-aligned currents at the magnetopause boundary layer.

    Science.gov (United States)

    Wing, Simon; Johnson, Jay R

    2015-11-16

    The dependence of the upward field-aligned current density ( J ‖ ) at the dayside magnetopause boundary layer is well described by a simple analytic model based on a velocity shear generator. A previous observational survey confirmed that the scaling properties predicted by the analytical model are applicable between 11 and 17 MLT. We utilize the analytic model to predict field-aligned currents using solar wind and ionospheric parameters and compare with direct observations. The calculated and observed parallel currents are in excellent agreement, suggesting that the model may be useful to infer boundary layer structures. However, near noon, where velocity shear is small, the kinetic pressure gradients and thermal currents, which are not included in the model, could make a small but significant contribution to J ‖ . Excluding data from noon, our least squares fit returns log( J ‖,max_cal ) = (0.96 ± 0.04) log( J ‖_obs ) + (0.03 ± 0.01) where J ‖,max_cal = calculated J ‖,max and J ‖_obs = observed J ‖ .

  8. Drift-flux parameters for upward gas flow in stagnant liquid

    International Nuclear Information System (INIS)

    Kataoka, Yoshiyuki; Suzuki, Hiroaki; Murase, Michio

    1987-01-01

    The drift-flux model is widely used for gas-liquid two phase flow analysis, because it is applicable to various flow patterns and a wide range of void fractions. The drift-flux parameters for upward gas flow in stagnant liquid, however, have not been well examined. In this study, the distribution parameter C o and the drift velocity V gj for stagnant liquid were derived from the void fraction correlation and boundary conditions of drift-flux parameters, and then compared with C o and V gj for high liquid velocities. Also using the two region model where a circular flow area was divided into an inner region of cocurrent up-flow and an outer annulus region of liquid down flow, C o and V gj for stagnant liquid and for high liquid velocity were compared. The results showed that C o values for stagnant liquid were larger than values for high liquid velocity, while V gj values were almost the same for both cases. (author)

  9. Shift workers have a similar diet quality but higher energy intake than day workers

    NARCIS (Netherlands)

    Hulsegge, Gerben; Boer, Jolanda Ma; van der Beek, Allard J; Verschuren, Wm Monique; Sluijs, Ivonne; Vermeulen, Roel; Proper, Karin I

    2016-01-01

    OBJECTIVE: Shift work is associated with adverse health outcomes, and an unhealthy diet may be a contributing factor. We compared diet quantity and quality between day and shift workers, and studied exposure-response relationships regarding frequency of night shifts and years of shift work. METHODS:

  10. Onward and Upward: Fundraisers Focus on Midlevel Donors to Rise above the Recession

    Science.gov (United States)

    Perry, Michael

    2010-01-01

    The changes and uncertainty people have seen in the economy over the past 20 months have created a paradigm shift in fundraising. This has certainly been the case at Holy Cross, a Jesuit liberal arts college of 2,900 students in Massachusetts, as it has been forced to rethink its strategies and adapt in creative ways to the new reality. Other…

  11. Ethnic diversity and social capital in upward mobility systems: Problematizing the permeability of intra-organizational career boundaries

    NARCIS (Netherlands)

    Ossenkop, C.; Vinkenburg, C.J.; Jansen, P.G.W.; Ghorashi, H.

    2015-01-01

    Purpose – The purpose of this paper is to contribute to a better understanding of the complex relationship between ethnic diversity, social capital, and objective career success in upward mobility systems over time. The authors conceptualize the underlying process of why intra-organizational career

  12. Education as Literacy for Freedom: Implications for Latin America and the Caribbean from an Upward Bound Project.

    Science.gov (United States)

    Dottin, Erskine S.

    The Upward Bound Project for low income youth in Florida emphasizes humanistic education rather than education based on the capitalistic model of production, consumption, and competition. The project, which can serve as a model for education in developing countries, focuses on creating self-concepts and values to counteract those of an acquisitive…

  13. Mindfulness training promotes upward spirals of positive affect and cognition : Multilevel and autoregressive latent trajectory modeling analyses

    NARCIS (Netherlands)

    Garland, Eric L.; Geschwind, Nicole; Peeters, Frenk; Wichers, Marieke

    2015-01-01

    Recent theory suggests that positive psychological processes integral to health may be energized through the self-reinforcing dynamics of an upward spiral to counter emotion dysregulation. The present study examined positive emotion-cognition interactions among individuals in partial remission from

  14. Shift of the spectrum in the non-inertial reference frame

    International Nuclear Information System (INIS)

    Kudykina, T. A.; Pervak, A. I.

    2012-01-01

    We propose a new natural explanation of the spectral redshift (blue shift) arguing that the rotatory non-inertial reference frame of cosmological objects is the main reason of the shift of the frequency of emitting light. (Author)

  15. Self Induced Buoyant Blow Off in Upward Flame Spread on Thin Solid Fuels

    Science.gov (United States)

    Johnston, Michael C.; T'ien, James S.; Muff, Derek E.; Olson, Sandra L.; Ferkul, Paul V.

    2013-01-01

    Upward flame spread experiments were conducted on a thin fabric cloth consisting of 75% cotton and 25% fiberglass. The sample is sandwiched symmetrically with stainless steel plates with the exposed width varying between 2 to 8.8 cm from test to test and >1.5m tall. The bottom edge was ignited resulting in a symmetric two sided flame. For the narrower samples (. 5cm), two sided flame growth would proceed until reaching some limiting value (15-30 cm depending on sample width). Fluctuation or instability of the flame base on one side would initially become visible and then the flame base would retreat downstream and cause extinguishment on one side. Detailed examination of the still images shows that the fuel continues to vaporize from the extinguished side due to the thermally thin nature of the fuel. But, due to the remaining inert fiberglass mesh, which acts as a flashback arrestor, the extinguished side was not able to be reignited by the remaining flame. The remaining flame would then shrink in length due to the reduced heat transfer to the solid to a shorter length. The one-sided flame will spread stably with a constant speed and a constant flame length to the end of the sample. A constant length flame implies that the pyrolysis front and the burnt out fronts move at the same speed. For the wider samples (. 7cm), no one-sided extinction is observed. Two-sided flames spread all the way to the top of the sample. For these wider widths, the flames are still growing and have not reached their limiting length if it exists. Care was taken to minimize the amount of non-symmetries in the experimental configuration. Repeated tests show that blow-off can occur on either side of the sample. The flame growth is observed to be very symmetric during the growth phase and grew to significant length (>10cm) before extinction of the flame on one side. Our proposed explanation of this unusual phenomenon (i.e. stronger two ]sided flame cannot exist but weaker one-sided flame can

  16. Shift Work Disorder and Mental and Physical Effects of Shift Work

    Directory of Open Access Journals (Sweden)

    Pinar Guzel Ozdemir

    2018-03-01

    Full Text Available With the growing prevalence of shift work all over the the world, the relationship between the daily lives of irregular lifestyles and rhythms is being investigated for those working as shift workers and their families. The effect of shift work on physical and mental health is a very important field of research in recent years. The onset and persistence of medical complications in shift workers includes impaired synchronization between work schedule rhythms and circadian clock. In this context, studies have been carried out showing the increased risk of sleep-wake disorders, gastrointestinal problems, and cardiovascular diseases. There is little information about the actual frequency, effect on health and treatment of shift work disorder, known as circadian rhythm sleep disorder. Shift work disorder includes insomnia and/or excessive sleepiness related with the work schedule. The aim of this rewiev, mentioning about the physical and mental effects of shift work, and to provide information about the diagnosis, clinic and treatment methods of shift-work disorder.

  17. Review of Critical Heat Flux Correlations for Upward Flow in a Vertical Thin Rectangular Channel

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Gil Sik; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    From the view point of safety, this type of fuel has higher resistance to earthquake and external impact. The cross section of coolant flow channel in the reactor core composed with the plate fuel is a thin rectangular shape. Thermal-hydraulic characteristics of this thin rectangular channel are different with those of general circular rod fuel bundle flow channel. Accordingly it could be thought that the CHF correlation in a thin rectangular channel is different with that in a circular channel, for which a large number of researches on CHF prediction have been carried out. The objective of this paper is to review previous researches on CHF in a thin rectangular channel, summarize the important conclusion and propose the new simple CHF correlation, which is based on the data set under high pressure and high flow rate condition. The researches on CHF in rectangular channel have been partially carried out according to the pressure, heated surface number, heated surface wettability effect, flow driving force and flow direction conditions. From the literature researches on CHF for upward flow in a vertical thin rectangular channel, some CHF prediction methods were reviewed and compared. There is no universal correlation which can predict CHF at all conditions, but generally, Katto empirical correlation is known to be useful at high pressure and high flow rate. The new simple correlation was developed from the restricted data set, the CHF prediction capacity of which is better than that of Katto. Even though the prediction consistency of the new simple correlation is lower, MAE and RMS error decreased quite. For the more development of the new simple CHF correlation, the more advanced regression analysis method and theoretical analysis should be studied in future.

  18. On the Specification of Upward-Propagating Tides for ICON Science Investigations

    Science.gov (United States)

    Forbes, Jeffrey M.; Zhang, Xiaoli; Hagan, Maura E.; England, Scott L.; Liu, Guiping; Gasperini, Federico

    2017-10-01

    The National Center for Atmospheric Research (NCAR) Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM) will provide a physics-based context for the interpretation of ICON measurements. To optimize the realism of the model simulations, ICON wind and temperature measurements near the ˜97 km lower boundary of the TIEGCM will be used to specify the upward-propagating tidal spectrum at this altitude. This will be done by fitting a set of basis functions called Hough Mode Extensions (HMEs) to 27-day mean tidal winds and temperatures between 90 and 105 km altitude and between 12 °S and 42 °N latitude on a day-by-day basis. The current paper assesses the veracity of the HME fitting methodology given the restricted latitude sampling and the UT-longitude sampling afforded by the MIGHTI instrument viewing from the ICON satellite, which will be in a circular 27° inclination orbit. These issues are investigated using the output from a reanalysis-driven global circulation model, which contains realistic variability of the important tidal components, as a mock data set. ICON sampling of the model reveals that the 27-day mean diurnal and semidiurnal tidal components replicate well the 27-day mean tidal components obtained from full synoptic sampling of the model, but the terdiurnal tidal components are not faithfully reproduced. It is also demonstrated that reconstructed tidal components based on HME fitting to the model tides between 12 °S and 42 °N latitude provide good approximations to the major tidal components expected to be encountered during the ICON mission. This is because the constraints provided by fitting both winds and temperatures over the 90-105 km height range are adequate to offset the restricted sampling in latitude. The boundary conditions provided by the methodology described herein will greatly enhance the ability of the TIEGCM to provide a physical framework for interpreting atmosphere-ionosphere coupling in ICON observations

  19. Review of Critical Heat Flux Correlations for Upward Flow in a Vertical Thin Rectangular Channel

    International Nuclear Information System (INIS)

    Choi, Gil Sik; Chang, Soon Heung

    2014-01-01

    From the view point of safety, this type of fuel has higher resistance to earthquake and external impact. The cross section of coolant flow channel in the reactor core composed with the plate fuel is a thin rectangular shape. Thermal-hydraulic characteristics of this thin rectangular channel are different with those of general circular rod fuel bundle flow channel. Accordingly it could be thought that the CHF correlation in a thin rectangular channel is different with that in a circular channel, for which a large number of researches on CHF prediction have been carried out. The objective of this paper is to review previous researches on CHF in a thin rectangular channel, summarize the important conclusion and propose the new simple CHF correlation, which is based on the data set under high pressure and high flow rate condition. The researches on CHF in rectangular channel have been partially carried out according to the pressure, heated surface number, heated surface wettability effect, flow driving force and flow direction conditions. From the literature researches on CHF for upward flow in a vertical thin rectangular channel, some CHF prediction methods were reviewed and compared. There is no universal correlation which can predict CHF at all conditions, but generally, Katto empirical correlation is known to be useful at high pressure and high flow rate. The new simple correlation was developed from the restricted data set, the CHF prediction capacity of which is better than that of Katto. Even though the prediction consistency of the new simple correlation is lower, MAE and RMS error decreased quite. For the more development of the new simple CHF correlation, the more advanced regression analysis method and theoretical analysis should be studied in future

  20. Upward migration of Vesuvius magma chamber over the past 20,000 years.

    Science.gov (United States)

    Scaillet, B; Pichavant, M; Cioni, R

    2008-09-11

    Forecasting future eruptions of Vesuvius is an important challenge for volcanologists, as its reawakening could threaten the lives of 700,000 people living near the volcano. Critical to the evaluation of hazards associated with the next eruption is the estimation of the depth of the magma reservoir, one of the main parameters controlling magma properties and eruptive style. Petrological studies have indicated that during past activity, magma chambers were at depths between 3 and 16 km (refs 3-7). Geophysical surveys have imaged some levels of seismic attenuation, the shallowest of which lies at 8-9 km depth, and these have been tentatively interpreted as levels of preferential magma accumulation. By using experimental phase equilibria, carried out on material from four main explosive events at Vesuvius, we show here that the reservoirs that fed the eruptive activity migrated from 7-8 km to 3-4 km depth between the ad 79 (Pompeii) and ad 472 (Pollena) events. If data from the Pomici di Base event 18.5 kyr ago and the 1944 Vesuvius eruption are included, the total upward migration of the reservoir amounts to 9-11 km. The change of preferential magma ponding levels in the upper crust can be attributed to differences in the volatile content and buoyancy of ascending magmas, as well as to changes in local stress field following either caldera formation or volcano spreading. Reservoir migration, and the possible influence on feeding rates, should be integrated into the parameters used for defining expected eruptive scenarios at Vesuvius.

  1. Critical heat flux in a vertical annulus under low upward flow and near atmospheric pressure

    International Nuclear Information System (INIS)

    Schoesse, T.; Aritomi, Masanori; Lee, Sang-Ryoul; Kataoka, Yoshiaki; Yoshioka, Yuzuru; Chung, Moon-Ki.

    1997-01-01

    As future boiling water reactors (BWR), concepts of evolutional ABWR (ABWR-IER) and natural circulation BWR (JSBWR) have been investigated in order to reduce their construction cost and simplify their maintenance and inspection procedures. One of the promised features of the design of the evolutional ABWR is to reduce the number of internal pumps and to remove the Motor Generation (MG) sets. These design changes may induce boiling transition in the fuel rods of reactor core during a pump trip transient due to the more rapid flow coastdown characteristics than these of the present design. In addition, the understanding of critical heat flux (CHF) is one important subject to grasp safety margin during the start-up for the natural circulation BWR and to establish the rational start-up procedure in which thermo-hydraulic instabilities can be suppressed. The present study is to clarify CHF characteristics under low velocity conditions. CHF measurements were conducted in a vertical upward annulus channel composed of an inner heated rod and an outer tube made of glass. CHF data were obtained repeatedly under the condition of stable inlet flow to examine statistically their reproducibility. The flow regime was investigated from flow observation and measurement of differential pressure fluctuation. The CHF data are correlated with the flow regime transition. It was clear from the obtained flow pattern and the CHF data that the CHF behavior could be classified into specified regions by the mass flux and inlet subcooling conditions. A CHF correlation was developed and agreed with other researchers' data within acceptable error. (author)

  2. Pattern recognition techniques for horizontal and vertically upward multiphase flow measurement

    Science.gov (United States)

    Arubi, Tesi I. M.; Yeung, Hoi

    2012-03-01

    The oil and gas industry need for high performing and low cost multiphase meters is ever more justified given the rapid depletion of conventional oil reserves that has led oil companies to develop smaller and marginal fields and reservoirs in remote locations and deep offshore, thereby placing great demands for compact and more cost effective solutions of on-line continuous multiphase flow measurement for well testing, production monitoring, production optimisation, process control and automation. The pattern recognition approach for clamp-on multiphase measurement employed in this study provides one means for meeting this need. High speed caesium-137 radioisotope-based densitometers were installed vertically at the top of a 50.8mm and 101.6mm riser as well as horizontally at the riser base in the Cranfield University multiphase flow test facility. A comprehensive experimental campaign comprising flow conditions typical of operating conditions found in the Petroleum Industry was conducted. The application of a single gamma densitometer unit, in conjunction with pattern recognition techniques to determine both the phase volume fractions and velocities to yield the individual phase flow rates of horizontal and vertically upward multiphase flows was investigated. The pattern recognition systems were trained to map the temporal fluctuations in the multiphase mixture density with the individual phase flow rates using statistical features extracted from the gamma counts signals as their inputs. Initial results yielded individual phase flow rate predictions to within ±5% relative error for the two phase airwater flows and ±10% for three phase air-oil-water flows data.

  3. Frequency scaling for angle gathers

    KAUST Repository

    Zuberi, M. A H; Alkhalifah, Tariq Ali

    2014-01-01

    Angle gathers provide an extra dimension to analyze the velocity after migration. Space-shift and time shift-imaging conditions are two methods used to obtain angle gathers, but both are reasonably expensive. By scaling the time-lag axis of the time-shifted images, the computational cost of the time shift imaging condition can be considerably reduced. In imaging and more so Full waveform inversion, frequencydomain Helmholtz solvers are used more often to solve for the wavefields than conventional time domain extrapolators. In such cases, we do not need to extend the image, instead we scale the frequency axis of the frequency domain image to obtain the angle gathers more efficiently. Application on synthetic data demonstrate such features.

  4. Warming-induced upward migration of the alpine treeline in the Changbai Mountains, northeast China

    Czech Academy of Sciences Publication Activity Database

    Du, H.; Liu, J.; Li, M.; Büntgen, Ulf; Yang, Y.; Wang, L.; Wu, Z.; He, Hong S.

    2018-01-01

    Roč. 24, č. 3 (2018), s. 1256-1266 ISSN 1354-1013 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : climate - change * tibetan plateau * pinus-cembra * elevation * dynamics * shifts * forest * growth * line * carbon * altitudinal transect * Betula ermanii * Changbai Mountains * climate change * dendroecology * forest growth * treeline dynamics Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 8.502, year: 2016

  5. Mechanical spectral shift reactor

    International Nuclear Information System (INIS)

    Sherwood, D.G.; Wilson, J.F.; Salton, R.B.; Fensterer, H.F.

    1981-01-01

    A mechanical spectral shift reactor comprises apparatus for inserting and withdrawing water displacer elements from the reactor core for selectively changing the water-moderator volume in the core thereby changing the reactivity of the core. The apparatus includes drivemechanisms for moving the displacer elements relative to the core and guide mechanisms for guiding the displayer rods through the reactor vessel

  6. Mechanical spectral shift reactor

    International Nuclear Information System (INIS)

    Sherwood, D.G.; Wilson, J.F.; Salton, R.B.; Fensterer, H.F.

    1982-01-01

    A mechanical spectral shift reactor comprises apparatus for inserting and withdrawing water displacer elements from the reactor core for selectively changing the water-moderator volume in the core thereby changing the reactivity of the core. The apparatus includes drive mechanisms for moving the displacer elements relative to the core and guide mechanisms for guiding the displacer rods through the reactor vessel. (author)

  7. Two-phase flow characteristics of liquid nitrogen in vertically upward 0.5 and 1.0 mm micro-tubes: Visualization studies

    Science.gov (United States)

    Zhang, P.; Fu, X.

    2009-10-01

    Application of liquid nitrogen to cooling is widely employed in many fields, such as cooling of the high temperature superconducting devices, cryosurgery and so on, in which liquid nitrogen is generally forced to flow inside very small passages to maintain good thermal performance and stability. In order to have a full understanding of the flow and heat transfer characteristics of liquid nitrogen in micro-tube, high-speed digital photography was employed to acquire the typical two-phase flow patterns of liquid nitrogen in vertically upward micro-tubes of 0.531 and 1.042 mm inner diameters. It was found from the experimental results that the flow patterns were mainly bubbly flow, slug flow, churn flow and annular flow. And the confined bubble flow, mist flow, bubble condensation and flow oscillation were also observed. These flow patterns were characterized in different types of flow regime maps. The surface tension force and the size of the diameter were revealed to be the major factors affecting the flow pattern transitions. It was found that the transition boundaries of the slug/churn flow and churn/annular flow of the present experiment shifted to lower superficial vapor velocity; while the transition boundary of the bubbly/slug flow shifted to higher superficial vapor velocity compared to the results of the room-temperature fluids in the tubes with the similar hydraulic diameters. The corresponding transition boundaries moved to lower superficial velocity when reducing the inner diameter of the micro-tubes. Time-averaged void fraction and heat transfer characteristics for individual flow patterns were presented and special attention was paid to the effect of the diameter on the variation of void fraction.

  8. Core shift effect in blazars

    Science.gov (United States)

    Agarwal, A.; Mohan, P.; Gupta, Alok C.; Mangalam, A.; Volvach, A. E.; Aller, M. F.; Aller, H. D.; Gu, M. F.; Lähteenmäki, A.; Tornikoski, M.; Volvach, L. N.

    2017-07-01

    We studied the pc-scale core shift effect using radio light curves for three blazars, S5 0716+714, 3C 279 and BL Lacertae, which were monitored at five frequencies (ν) between 4.8 and 36.8 GHz using the University of Michigan Radio Astronomical Observatory (UMRAO), the Crimean Astrophysical Observatory (CrAO) and Metsähovi Radio Observatory for over 40 yr. Flares were Gaussian fitted to derive time delays between observed frequencies for each flare (Δt), peak amplitude (A) and their half width. Using A ∝ να, we infer α in the range of -16.67-2.41 and using Δ t ∝ ν ^{1/k_r}, we infer kr ∼ 1, employed in the context of equipartition between magnetic and kinetic energy density for parameter estimation. From the estimated core position offset (Ωrν) and the core radius (rcore), we infer that opacity model may not be valid in all cases. The mean magnetic field strengths at 1 pc (B1) and at the core (Bcore) are in agreement with previous estimates. We apply the magnetically arrested disc model to estimate black hole spins in the range of 0.15-0.9 for these blazars, indicating that the model is consistent with expected accretion mode in such sources. The power-law-shaped power spectral density has slopes -1.3 to -2.3 and is interpreted in terms of multiple shocks or magnetic instabilities.

  9. Damping and Frequency Shift of Large Amplitude Electron Plasma Waves

    DEFF Research Database (Denmark)

    Thomsen, Kenneth; Juul Rasmussen, Jens

    1983-01-01

    The initial evolution of large-amplitude one-dimensional electron waves is investigated by applying a numerical simulation. The initial wave damping is found to be strongly enhanced relative to the linear damping and it increases with increasing amplitude. The temporal evolution of the nonlinear...

  10. Relativistic shifts of bound negative-muon precession frequencies

    International Nuclear Information System (INIS)

    Brewer, J.H.; Froese, A. M.; Fryer, B.A.; Ghandi, K.

    2005-01-01

    High-field negative-muon spin precession experiments have been performed using a backward-muon beam with substantial transverse spin polarization, facilitating high-precision measurements of the magnetogyric ratio of negative muons bound to nuclei in the ground states of muonic atoms. These results may provide a testing ground for quantum electrodynamics in very strong electromagnetic fields

  11. Absolute frequency shifts of iodine cells for laser stabilization

    Czech Academy of Sciences Publication Activity Database

    Lazar, Josef; Hrabina, Jan; Jedlička, Petr; Číp, Ondřej

    2009-01-01

    Roč. 46, č. 5 (2009), s. 450-456 ISSN 0026-1394 R&D Projects: GA AV ČR IAA200650504; GA MŠk(CZ) LC06007; GA MŠk 2C06012; GA AV ČR KAN311610701; GA MPO 2A-1TP1/127; GA MPO FT-TA3/133 Institutional research plan: CEZ:AV0Z20650511 Keywords : laser stabilization * Nd :YAG laser Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.634, year: 2009

  12. Nonmetric theories of gravity and the gravitational frequency shift

    International Nuclear Information System (INIS)

    Coley, A.A.; Sarmiento G, A.F.; Universidad Nacional Autonoma de Mexico, Mexico City)

    1988-01-01

    A class of nonmetric theories of gravity called metric-affine theories is investigated, emphasizing a subclass of theories called Weyl-affine theories. An experimental configuration is modeled in which the gravitational redshift of light signals conecting an artificial satellite to the earth is measured. A situation in which both bodies are forced to follow circular orbits around the sun with angular speeds determined by the solar gravitational field is considered along with the more realistic situation in which the artificial satellite and the earth are both allowed to follow general coplanar orbits. The latter is found to give rise to more severe constraints. It is found that theories under investigation must coincide with their metric counterparts up to first order in the Newtonian gravitational potential U and that any nonmetric effects within the solar neighborhood can only manifest themselves at most through small contributions at the U-squared level or at the U-cubed level. 34 references

  13. Dependence of synchronization frequency of Kuramoto oscillators on symmetry of intrinsic frequency in ring network

    Science.gov (United States)

    Saha, Arindam; Amritkar, R. E.

    2014-12-01

    Kuramoto oscillators have been proposed earlier as a model for interacting systems that exhibit synchronisation. In this article we study the difference between networks with symmetric and asymmetric distribution of natural frequencies. We first indicate that the synchronisation frequency of the oscillators is independent of the natural frequency distribution for a completely connected network. Further we analyse the case of oscillators in a directed ring-network where asymmetry in the natural frequency distribution is seen to shift the synchronisation frequency of the network. We also present an estimate of the shift in the frequencies for slightly asymmetric distributions.

  14. Mechanical spectral shift reactor

    International Nuclear Information System (INIS)

    Wilson, J.F.; Sherwood, D.G.

    1982-01-01

    A mechanical spectral shift reactor comprises a reactive core having fuel assemblies accommodating both water displacer elements and neutron absorbing control rods for selectively changing the volume of water-moderator in the core. The fuel assemblies with displacer and control rods are arranged in alternating fashion so that one displacer element drive mechanism may move displacer elements in more than one fuel assembly without interfering with the movement of control rods of a corresponding control rod drive mechanisms. (author)

  15. Prediction, analysis and solution of flow inversion phenomenon in a typical MTR reactor with upward core cooling

    International Nuclear Information System (INIS)

    El-Morshedy, Salah El-Din

    2010-01-01

    Research reactors of power greater than 20 MW are usually designed to be cooled with upward coolant flow direction inside the reactor core. This is mainly to prevent flow inversion problems following a pump coast down. However, in some designs and under certain operating conditions, flow inversion phenomenon is predicted. In the present work, the best-estimate Material Testing Reactors Thermal-Hydraulic Analysis program (MTRTHA) is used to simulate a typical MTR reactor behavior with upward cooling under a hypothetical case of loss of off-site power. The flow inversion phenomenon is predicted under certain decay heat and/or pool temperature values below the design values. The reactor simulation under loss of off-site power is performed for two cases namely; two-flap valves open and one flap-valve fails to open. The model results for the flow inversion phenomenon prediction is analyzed and a solution of the problem is suggested. (orig.)

  16. Measuring proton shift tensors with ultrafast MAS NMR.

    Science.gov (United States)

    Miah, Habeeba K; Bennett, David A; Iuga, Dinu; Titman, Jeremy J

    2013-10-01

    A new proton anisotropic-isotropic shift correlation experiment is described which operates with ultrafast MAS, resulting in good resolution of isotropic proton shifts in the detection dimension. The new experiment makes use of a recoupling sequence designed using symmetry principles which reintroduces the proton chemical shift anisotropy in the indirect dimension. The experiment has been used to measure the proton shift tensor parameters for the OH hydrogen-bonded protons in tyrosine·HCl and citric acid at Larmor frequencies of up to 850 MHz. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. 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

  18. Simultaneous removal of organic contaminants and heavy metals from kaolin using an upward electrokinetic soil remediation process

    International Nuclear Information System (INIS)

    Wang, J.-Y.; Huang, X.-J.; Kao, Jimmy C.M.; Stabnikova, Olena

    2007-01-01

    Kaolins contaminated with heavy metals, Cu and Pb, and organic compounds, p-xylene and phenanthrene, were treated with an upward electrokinetic soil remediation (UESR) process. The effects of current density, cathode chamber flushing fluid, treatment duration, reactor size, and the type of contaminants under the vertical non-uniform electric field of UESR on the simultaneous removal of the heavy metals and organic contaminants were studied. The removal efficiencies of p-xylene and phenanthrene were higher in the experiments with cells of smaller diameter or larger height, and with distilled water flow in the cathode chamber. The removal efficiency of Cu and Pb were higher in the experiments with smaller diameter or shorter height cells and 0.01 M HNO 3 solution as cathode chamber flow. In spite of different conditions for removal of heavy metals and organics, it is possible to use the upward electrokinetic soil remediation process for their simultaneous removal. Thus, in the experiments with duration of 6 days removal efficiencies of phenanthrene, p-xylene, Cu and Pb were 67%, 93%, 62% and 35%, respectively. The experiment demonstrated the feasibility of simultaneous removal of organic contaminants and heavy metals from kaolin using the upward electrokinetic soil remediation process

  19. Phase distribution phenomena in upward cocurrent bubbly flows. A critical review of the experimental and theoretical works

    International Nuclear Information System (INIS)

    Grossetete, C.

    1992-09-01

    The most important and challenging problems in two-phase bubbly flow today are related to the physical understanding and the modeling of multidimensional phenomena such as the distribution of phases in space. We present here a critical review of the available experimental and theoretical studies in gas-liquid adiabatic and non-reactive upward bubbly flows which have been carried out to define and improve the physical models needed to close the three-dimensional two-fluid model equations. It appears that: so far, the axial development of two-phase upward bubbly flows has not been handled thoroughly. Little is known about the way the pressure gradient as well as the gas-liquid mixing conditions affect the distribution of phases, the problems related to the closing of the two-fluid model equations are far from being solved. The physical models proposed seem often to be too much complex considering how little we know about the mechanisms involved, there are still very few multidimensional numerical models whose results have been compared with experimental data on bubbly flows. The boundary conditions introduced in the codes as well as the sensitivity of the results to the parameters of the codes are never precisely stated. To bridge some of those gaps, we propose to perform an experimental and numerical study of the axial development of two-phase air-water upward bubbly flows in vertical pipes

  20. Openness to Experience as a Predictor and Outcome of Upward Job Changes into Managerial and Professional Positions

    Science.gov (United States)

    Nieß, Christiane; Zacher, Hannes

    2015-01-01

    In industrial and organizational psychology, there is a long tradition of studying personality as an antecedent of work outcomes. Recently, however, scholars have suggested that personality characteristics may not only predict, but also change due to certain work experiences, a notion that is depicted in the dynamic developmental model (DDM) of personality and work. Upward job changes are an important part of employees’ careers and career success in particular, and we argue that these career transitions can shape personality over time. In this study, we investigate the Big Five personality characteristics as both predictors and outcomes of upward job changes into managerial and professional positions. We tested our hypotheses by applying event history analyses and propensity score matching to a longitudinal dataset collected over five years from employees in Australia. Results indicated that participants’ openness to experience not only predicted, but that changes in openness to experience also followed from upward job changes into managerial and professional positions. Our findings thus provide support for a dynamic perspective on personality characteristics in the context of work and careers. PMID:26110527

  1. Experimental detection of upward-going cosmic particles and consequences for correction of density radiography of volcanoes

    Science.gov (United States)

    Jourde, Kevin; Gibert, Dominique; Marteau, Jacques; de Bremond d'Ars, Jean; Gardien, Serge; Girerd, Claude; Ianigro, Jean-Christophe; Carbone, Daniele

    2014-05-01

    Muon tomography measures the flux of cosmic muons crossing geological bodies to determine their density. Three acquisitions with different sights of view were made at la soufrière de Guadeloupe. All of them show important density fluctuations and reveal the volcano phreatic system. The telescopes used to perform these measurements are exposed to noise fluxes with high intensities relative to the tiny flux of interest. We give experimental evidences ofa so far never described source of noise caused by a flux of upward-going particles. Data acquired on La soufrière of Guadeloupe and Mount Etna reveal that upward-going particles are detected only when the rear side of the telescope is exposed to a wide volume of atmosphere located below the altitude of the telescope and with a rock obstruction less than several tens of meters. Biases produced on density muon radiographies by upward-going fluxes are quantified and correction procedures are applied to radiographies of la soufrière.

  2. 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

  3. 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

  4. Estimate of the soil water retention curve from the sorptivity and β parameter calculated from an upward infiltration experiment

    Science.gov (United States)

    Moret-Fernández, D.; Latorre, B.

    2017-01-01

    The water retention curve (θ(h)), which defines the relationship between the volumetric water content (θ) and the matric potential (h), is of paramount importance to characterize the hydraulic behaviour of soils. Because current methods to estimate θ(h) are, in general, tedious and time consuming, alternative procedures to determine θ(h) are needed. Using an upward infiltration curve, the main objective of this work is to present a method to determine the parameters of the van Genuchten (1980) water retention curve (α and n) from the sorptivity (S) and the β parameter defined in the 1D infiltration equation proposed by Haverkamp et al. (1994). The first specific objective is to present an equation, based on the Haverkamp et al. (1994) analysis, which allows describing an upward infiltration process. Secondary, assuming a known saturated hydraulic conductivity, Ks, calculated on a finite soil column by the Darcy's law, a numerical procedure to calculate S and β by the inverse analysis of an exfiltration curve is presented. Finally, the α and n values are numerically calculated from Ks, S and β. To accomplish the first specific objective, cumulative upward infiltration curves simulated with HYDRUS-1D for sand, loam, silt and clay soils were compared to those calculated with the proposed equation, after applying the corresponding β and S calculated from the theoretical Ks, α and n. The same curves were used to: (i) study the influence of the exfiltration time on S and β estimations, (ii) evaluate the limits of the inverse analysis, and (iii) validate the feasibility of the method to estimate α and n. Next, the θ(h) parameters estimated with the numerical method on experimental soils were compared to those obtained with pressure cells. The results showed that the upward infiltration curve could be correctly described by the modified Haverkamp et al. (1994) equation. While S was only affected by early-time exfiltration data, the β parameter had a

  5. Upward Bound: An Untapped Fountain Of Youth Wanting To Learn About Math And Science

    Science.gov (United States)

    Gillis-Davis, J. J.; Sherman, S. B.; Gillis-Davis, L. C.; Svelling, K. L.

    2009-12-01

    We developed a two-phased curricula aimed at high school students in Hawaii’s Upward Bound (UB) programs. The course, called “Tour Through the Solar System”, was tested in the summer 2008-2009 programs of two of the four Hawaii UB programs. Authorized by Congress in 1965, UB is a federal program funded by the U.S. Department of Education to serve students underrepresented in higher education. Students enrolled in UB are predominantly low income, or from families in which neither parent holds a bachelor’s degree. UB programs make a measurable improvement in retaining high school students in the education pipeline in part by using innovative educational and outreach programs to spark students’ interest in learning while building academic self-confidence. Curricula developed for UB are sustainable because there are 964 programs in the United States, and U territories. Education and outreach products can be presented at regional and national meetings, which directors of the UB programs attend. Broad regulations and varied instruction formats allow curriculum developers a flexible and creative framework for developing classes. For instance, regulations stipulate that programs must provide participants with academic instruction in mathematics, laboratory sciences, composition, literature, and foreign languages in preparation for college entrance. UB meets these guidelines through school-year academic activities and a six-week summer school program. In designing our curricula the primary goals were to help students learn how to learn and encourage them to develop an interest in the fields of science, technology, engineering and math using NASA planetary data sets in a Problem-Based Learning (PBL) environment. Our focus on planetary science stems from our familiarity with the data sets, our view that NASA data sets are a naturally inspirational tool to engage high school students, and its cross-disciplinary character: encompassing geology, chemistry, astronomy

  6. Are Categorical Spatial Relations Encoded by Shifting Visual Attention between Objects?

    Science.gov (United States)

    Uttal, David; Franconeri, Steven

    2016-01-01

    Perceiving not just values, but relations between values, is critical to human cognition. We tested the predictions of a proposed mechanism for processing categorical spatial relations between two objects—the shift account of relation processing—which states that relations such as ‘above’ or ‘below’ are extracted by shifting visual attention upward or downward in space. If so, then shifts of attention should improve the representation of spatial relations, compared to a control condition of identity memory. Participants viewed a pair of briefly flashed objects and were then tested on either the relative spatial relation or identity of one of those objects. Using eye tracking to reveal participants’ voluntary shifts of attention over time, we found that when initial fixation was on neither object, relational memory showed an absolute advantage for the object following an attention shift, while identity memory showed no advantage for either object. This result is consistent with the shift account of relation processing. When initial fixation began on one of the objects, identity memory strongly benefited this fixated object, while relational memory only showed a relative benefit for objects following an attention shift. This result is also consistent, although not as uniquely, with the shift account of relation processing. Taken together, we suggest that the attention shift account provides a mechanistic explanation for the overall results. This account can potentially serve as the common mechanism underlying both linguistic and perceptual representations of spatial relations. PMID:27695104

  7. Frequency scanning microstrip antennas

    DEFF Research Database (Denmark)

    Danielsen, Magnus; Jørgensen, Rolf

    1979-01-01

    The principles of using radiating microstrip resonators as elements in a frequency scanning antenna array are described. The resonators are cascade-coupled. This gives a scan of the main lobe due to the phase-shift in the resonator in addition to that created by the transmission line phase......-shift. Experimental results inX-band, in good agreement with the theory, show that it is possible to scan the main lobe an angle ofpm30degby a variation of the frequencypm300MHz, and where the 3 dB beamwidth is less than10deg. The directivity was 14.7 dB, while the gain was 8.1 dB. The efficiency might be improved...

  8. The shifting beverage landscape.

    Science.gov (United States)

    Storey, Maureen

    2010-04-26

    STOREY, M.L. The shifting beverage landscape. PHYSIOL BEHAV, 2010. - Simultaneous lifestyle changes have occurred in the last few decades, creating an imbalance in energy intake and energy expenditure that has led to overweight and obesity. Trends in the food supply show that total daily calories available per capita increased 28% since 1970. Total energy intake among men and women has also increased dramatically since that time. Some have suggested that intake of beverages has had a disproportional impact on obesity. Data collected by the Beverage Marketing Corporation between 1988-2008 demonstrate that, in reality, fewer calories per ounce are being produced by the beverage industry. Moreover, data from the National Cancer Institute show that soft drink intake represents 5.5% of daily calories. Data from NHANES 1999-2003 vs. 2003-06 may demonstrate a shift in beverage consumption for age/gender groups, ages 6 to>60years. The beverages provided in schools have significantly changed since 2006 when the beverage industry implemented School Beverage Guidelines. This voluntary action has removed full-calorie soft drinks from participating schools across the country. This shift to lower-calorie and smaller-portion beverages in school has led to a significant decrease in total beverage calories in schools. These data support the concept that to prevent and treat obesity, public health efforts should focus on energy balance and that a narrow focus on sweetened beverages is unlikely to have any meaningful impact on this complex problem. Copyright 2010 Elsevier Inc. All rights reserved.

  9. Mechanical spectral shift reactor

    International Nuclear Information System (INIS)

    Doshi, P.K.; George, R.A.; Dollard, W.J.

    1982-01-01

    A mechanical spectral shift arrangement for controlling a nuclear reactor includes a plurality of reactor coolant displacer members which are inserted into a reactor core at the beginning of the core life to reduce the volume of reactor coolant-moderator in the core at start-up. However, as the reactivity of the core declines with fuel depletion, selected displacer members are withdrawn from the core at selected time intervals to increase core moderation at a time when fuel reactivity is declining. (author)

  10. Spectral shift reactor

    International Nuclear Information System (INIS)

    Carlson, W.R.; Piplica, E.J.

    1982-01-01

    A spectral shift pressurized water reactor comprising apparatus for inserting and withdrawing water displacer elements having differing neutron absorbing capabilities for selectively changing the water-moderator volume in the core thereby changing the reactivity of the core. The displacer elements comprise substantially hollow cylindrical low neutron absorbing rods and substantially hollow cylindrical thick walled stainless rods. Since the stainless steel displacer rods have greater neutron absorbing capability, they can effect greater reactivity change per rod. However, by arranging fewer stainless steel displacer rods in a cluster, the reactivity worth of the stainless steel displacer rod cluster can be less than a low neutron absorbing displacer rod cluster. (author)

  11. A plant distribution shift: temperature, drought or past disturbance?

    Directory of Open Access Journals (Sweden)

    Dylan W Schwilk

    Full Text Available Simple models of plant response to warming climates predict vegetation moving to cooler and/or wetter locations: in mountainous regions shifting upslope. However, species-specific responses to climate change are likely to be much more complex. We re-examined a recently reported vegetation shift in the Santa Rosa Mountains, California, to better understand the mechanisms behind the reported shift of a plant distribution upslope. We focused on five elevational zones near the center of the gradient that captured many of the reported shifts and which are dominated by fire-prone chaparral. Using growth rings, we determined that a major assumption of the previous work was wrong: past fire histories differed among elevations. To examine the potential effect that this difference might have on the reported upward shift, we focused on one species, Ceanothus greggii: a shrub that only recruits post-fire from a soil stored seedbank. For five elevations used in the prior study, we calculated time series of past per-capita mortality rates by counting growth rings on live and dead individuals. We tested three alternative hypotheses explaining the past patterns of mortality: 1 mortality increased over time consistent with climate warming, 2 mortality was correlated with drought indices, and 3 mortality peaked 40-50 years post fire at each site, consistent with self-thinning. We found that the sites were different ages since the last fire, and that the reported increase in the mean elevation of C. greggii was due to higher recent mortality at the lower elevations, which were younger sites. The time-series pattern of mortality was best explained by the self-thinning hypothesis and poorly explained by gradual warming or drought. At least for this species, the reported distribution shift appears to be an artifact of disturbance history and is not evidence of a climate warming effect.

  12. Chemical shift-dependent apparent scalar couplings: An alternative concept of chemical shift monitoring in multi-dimensional NMR experiments

    International Nuclear Information System (INIS)

    Kwiatkowski, Witek; Riek, Roland

    2003-01-01

    The paper presents an alternative technique for chemical shift monitoring in a multi-dimensional NMR experiment. The monitored chemical shift is coded in the line-shape of a cross-peak through an apparent residual scalar coupling active during an established evolution period or acquisition. The size of the apparent scalar coupling is manipulated with an off-resonance radio-frequency pulse in order to correlate the size of the coupling with the position of the additional chemical shift. The strength of this concept is that chemical shift information is added without an additional evolution period and accompanying polarization transfer periods. This concept was incorporated into the three-dimensional triple-resonance experiment HNCA, adding the information of 1 H α chemical shifts. The experiment is called HNCA coded HA, since the chemical shift of 1 H α is coded in the line-shape of the cross-peak along the 13 C α dimension

  13. How Upward Moral Comparison Influences Prosocial Behavioral Intention: Examining the Mediating Role of Guilt and the Moderating Role of Moral Identity

    Directory of Open Access Journals (Sweden)

    Heyun Zhang

    2017-09-01

    Full Text Available Although it has been shown that exceptional good deeds exert influences on people's prosocial behavior and intention, we have known little about how common moral actions in our daily life. The present study aimed to examine how upward moral comparison influenced prosocial behavioral intention as well as to explore the mediating role of guilt and the moderating role of moral identity in the focal relationship. An experimental study was conducted with 162 Chinese undergraduates (103 women, 59 men randomly assigned to an upward moral comparison condition, an upward competence comparison condition or a control condition. Results indicated that participants in the upward moral comparison condition experienced higher levels of guilt and exhibited stronger motivation to act prosocially, relative to participants in the other two conditions. That is to say, upward moral comparison induces guilty experience, and then increases people's prosocial behavioral intention. Moreover, we have found that moral identity internalization moderates the upward moral comparison-guilt relationship, and the indirect effect of upward moral comparison on prosocial behavioral intention via guilt. The implications of these findings were discussed.

  14. How Upward Moral Comparison Influences Prosocial Behavioral Intention: Examining the Mediating Role of Guilt and the Moderating Role of Moral Identity.

    Science.gov (United States)

    Zhang, Heyun; Chen, Sisi; Wang, Rong; Jiang, Jiang; Xu, Yan; Zhao, Huanhuan

    2017-01-01

    Although it has been shown that exceptional good deeds exert influences on people's prosocial behavior and intention, we have known little about how common moral actions in our daily life. The present study aimed to examine how upward moral comparison influenced prosocial behavioral intention as well as to explore the mediating role of guilt and the moderating role of moral identity in the focal relationship. An experimental study was conducted with 162 Chinese undergraduates (103 women, 59 men) randomly assigned to an upward moral comparison condition, an upward competence comparison condition or a control condition. Results indicated that participants in the upward moral comparison condition experienced higher levels of guilt and exhibited stronger motivation to act prosocially, relative to participants in the other two conditions. That is to say, upward moral comparison induces guilty experience, and then increases people's prosocial behavioral intention. Moreover, we have found that moral identity internalization moderates the upward moral comparison-guilt relationship, and the indirect effect of upward moral comparison on prosocial behavioral intention via guilt. The implications of these findings were discussed.

  15. How Upward Moral Comparison Influences Prosocial Behavioral Intention: Examining the Mediating Role of Guilt and the Moderating Role of Moral Identity

    Science.gov (United States)

    Zhang, Heyun; Chen, Sisi; Wang, Rong; Jiang, Jiang; Xu, Yan; Zhao, Huanhuan

    2017-01-01

    Although it has been shown that exceptional good deeds exert influences on people's prosocial behavior and intention, we have known little about how common moral actions in our daily life. The present study aimed to examine how upward moral comparison influenced prosocial behavioral intention as well as to explore the mediating role of guilt and the moderating role of moral identity in the focal relationship. An experimental study was conducted with 162 Chinese undergraduates (103 women, 59 men) randomly assigned to an upward moral comparison condition, an upward competence comparison condition or a control condition. Results indicated that participants in the upward moral comparison condition experienced higher levels of guilt and exhibited stronger motivation to act prosocially, relative to participants in the other two conditions. That is to say, upward moral comparison induces guilty experience, and then increases people's prosocial behavioral intention. Moreover, we have found that moral identity internalization moderates the upward moral comparison-guilt relationship, and the indirect effect of upward moral comparison on prosocial behavioral intention via guilt. The implications of these findings were discussed. PMID:28959221

  16. Shift Work: Improving Daytime Sleep

    Science.gov (United States)

    ... night. Good daytime sleep is possible, though, if shift work is a necessary part of your work life. ... mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/shift-work/faq-20057991 . Mayo Clinic Footer Legal Conditions and ...

  17. Lanthanide shift reagents, binding, shift mechanisms and exchange

    International Nuclear Information System (INIS)

    Boer, J.W.M. de

    1977-01-01

    Paramagnetic lanthanide shift reagents, when added to a solution of a substrate, induce shifts in the nuclear magnetic resonance (NMR) spectrum of the substrate molecules. The induced shifts contain information about the structure of the shift reagent substrate complex. The structural information, however, may be difficult to extract because of the following effects: (1) different complexes between shift reagent and substrate may be present in solution, e.g. 1:1 and 1:2 complexes, and the shift observed is a weighed average of the shifts of the substrate nuclei in the different complexes; (2) the Fermi contact interaction, arising from the spin density at the nucleus, contributes to the induced shift; (3) chemical exchange effects may complicate the NMR spectrum. In this thesis, the results of an investigation into the influence of these effects on the NMR spectra of solutions containing a substrate and LSR are presented. The equations describing the pseudo contact and the Fermi contact shift are derived. In addition, it is shown how the modified Bloch equations describing the effect of the chemical exchange processes occurring in the systems studied can be reduced to the familiar equations for a two-site exchange case. The binding of mono- and bifunctional ethers to the shift reagent are reported. An analysis of the induced shifts is given. Finally, the results of the experiments performed to study the exchange behavior of dimethoxyethane and heptafluorodimethyloctanedionato ligands are presented

  18. An Estimation Method for number of carrier frequency

    Directory of Open Access Journals (Sweden)

    Xiong Peng

    2015-01-01

    Full Text Available This paper proposes a method that utilizes AR model power spectrum estimation based on Burg algorithm to estimate the number of carrier frequency in single pulse. In the modern electronic and information warfare, the pulse signal form of radar is complex and changeable, among which single pulse with multi-carrier frequencies is the most typical one, such as the frequency shift keying (FSK signal, the frequency shift keying with linear frequency (FSK-LFM hybrid modulation signal and the frequency shift keying with bi-phase shift keying (FSK-BPSK hybrid modulation signal. In view of this kind of single pulse which has multi-carrier frequencies, this paper adopts a method which transforms the complex signal into AR model, then takes power spectrum based on Burg algorithm to show the effect. Experimental results show that the estimation method still can determine the number of carrier frequencies accurately even when the signal noise ratio (SNR is very low.

  19. Faktor Dan Penjadualan Shift Kerja

    OpenAIRE

    Maurits, Lientje Setyawati; Widodo, Imam Djati

    2008-01-01

    Work shift has negative effect in physical and mental health, work performance and job accident. Disturbance of circadian rhythms is indicated as source of the problems. This article explores some researches related to the impacts of work shift and establishes basic principles of work shift scheduling that considers human need and limitation.

  20. Isotope shifting capacity of rock

    International Nuclear Information System (INIS)

    Blattner, P.; Department of Scientific and Industrial Research, Lower Hutt

    1980-01-01

    Any oxygen isotope shifted rock volume exactly defines a past throughput of water. An expression is derived that relates the throughput of an open system to the isotope shift of reservoir rock and present-day output. The small isotope shift of Ngawha reservoir rock and the small, high delta oxygen-18 output are best accounted for by a magmatic water source

  1. Experimental study on characteristics of interfacial parameter distribution for upward bubbly flow in inclined tube

    International Nuclear Information System (INIS)

    Xing Dianchuan; Yan Changqi; Sun Licheng; Liu Jingyu

    2013-01-01

    Experimental study on characteristics of interfacial parameter distribution for air-water bubbly flow in an inclined circular tube was performed by using the double sensor probe method. Parameters including radial distributions of local void fraction, bubble passing frequency, interfacial area concentration and bubble equivalent diameter were measured using the probe. The inner diameter of test section is 50 mm, and the liquid superficial velocity is 0.144 m/s, with the gas superficial velocity ranging from 0 to 0.054 m/is. The results show that bubbles obviously move toward the upper wall and congregate. The local interfacial area concentration, bubble passing frequency and void fraction have similar radial distribution profiles. Different from the vertical condition, for a cross-sectional area of the test section, the peak value near the upper side increases, while decreases or even disappears near the underside. The local parameter increases as the radial positions change from lower to upper location, and the increased slope becomes larger as the inclination angles increase. The equivalent bubble diameter doesn't vary with radial position, superficial gas velocity and inclination angle, and bubble aggregation and breaking up nearly doesn't occur. The mechanism of effects of inclination on local parameter distribution for bubbly flow is explained by analyzing the transverse force governing the bubble motion. (authors)

  2. Metabolic syndrome in fixed-shift workers.

    Science.gov (United States)

    Canuto, Raquel; Pattussi, Marcos Pascoal; Macagnan, Jamile Block Araldi; Henn, Ruth Liane; Olinto, Maria Teresa Anselmo

    2015-01-01

    OBJECTIVE To analyze if metabolic syndrome and its altered components are associated with demographic, socioeconomic and behavioral factors in fixed-shift workers. METHODS A cross-sectional study was conducted on a sample of 902 shift workers of both sexes in a poultry processing plant in Southern Brazil in 2010. The diagnosis of metabolic syndrome was determined according to the recommendations from Harmonizing the Metabolic Syndrome. Its frequency was evaluated according to the demographic (sex, skin color, age and marital status), socioeconomic (educational level, income and work shift), and behavioral characteristics (smoking, alcohol intake, leisure time physical activity, number of meals and sleep duration) of the sample. The multivariate analysis followed a theoretical framework for identifying metabolic syndrome in fixed-shift workers. RESULTS The prevalence of metabolic syndrome in the sample was 9.3% (95%CI 7.4;11.2). The most frequently altered component was waist circumference (PR 48.4%; 95%CI 45.5;51.2), followed by high-density lipoprotein. Work shift was not associated with metabolic syndrome and its altered components. After adjustment, the prevalence of metabolic syndrome was positively associated with women (PR 2.16; 95%CI 1.28;3.64), workers aged over 40 years (PR 3.90; 95%CI 1.78;8.93) and those who reported sleeping five hours or less per day (PR 1.70; 95%CI 1.09;2.24). On the other hand, metabolic syndrome was inversely associated with educational level and having more than three meals per day (PR 0.43; 95%CI 0.26;0.73). CONCLUSIONS Being female, older and deprived of sleep are probable risk factors for metabolic syndrome, whereas higher educational level and higher number of meals per day are protective factors for metabolic syndrome in fixed-shift workers.

  3. Metabolic syndrome in fixed-shift workers

    Directory of Open Access Journals (Sweden)

    Raquel Canuto

    2015-01-01

    Full Text Available OBJECTIVE To analyze if metabolic syndrome and its altered components are associated with demographic, socioeconomic and behavioral factors in fixed-shift workers. METHODS A cross-sectional study was conducted on a sample of 902 shift workers of both sexes in a poultry processing plant in Southern Brazil in 2010. The diagnosis of metabolic syndrome was determined according to the recommendations from Harmonizing the Metabolic Syndrome. Its frequency was evaluated according to the demographic (sex, skin color, age and marital status, socioeconomic (educational level, income and work shift, and behavioral characteristics (smoking, alcohol intake, leisure time physical activity, number of meals and sleep duration of the sample. The multivariate analysis followed a theoretical framework for identifying metabolic syndrome in fixed-shift workers. RESULTS The prevalence of metabolic syndrome in the sample was 9.3% (95%CI 7.4;11.2. The most frequently altered component was waist circumference (PR 48.4%; 95%CI 45.5;51.2, followed by high-density lipoprotein. Work shift was not associated with metabolic syndrome and its altered components. After adjustment, the prevalence of metabolic syndrome was positively associated with women (PR 2.16; 95%CI 1.28;3.64, workers aged over 40 years (PR 3.90; 95%CI 1.78;8.93 and those who reported sleeping five hours or less per day (PR 1.70; 95%CI 1.09;2.24. On the other hand, metabolic syndrome was inversely associated with educational level and having more than three meals per day (PR 0.43; 95%CI 0.26;0.73. CONCLUSIONS Being female, older and deprived of sleep are probable risk factors for metabolic syndrome, whereas higher educational level and higher number of meals per day are protective factors for metabolic syndrome in fixed-shift workers.

  4. The shift in windpower

    International Nuclear Information System (INIS)

    Gipe, P.

    1992-01-01

    Despite new production records, the near-term market for new windpower projects in the US remains bleak. Congressional incentives and project proposals in the mid-1990s offer promise, but for now most development has shifted to Europe. During 1992 and 1993 the largest wind projects developed by US companies will not be in the US, but in the United Kingdom and Spain. Indeed, most of the US's windpower industry is going abroad, establishing offices overseas. This move toward Europe comes as little surprise. New project development for US firms has faltered at home while the European market has burgeoned. The topics of the article include the move to Europe, a reduction in California's share of producing wind power plants, a rise in Europe's share of producing wind power plants, the future market for wind power in the US, and reawakening California's market

  5. Michelson interferometer based spatial phase shift shearography.

    Science.gov (United States)

    Xie, Xin; Yang, Lianxiang; Xu, Nan; Chen, Xu

    2013-06-10

    This paper presents a simple spatial phase shift shearography based on the Michelson interferometer. The Michelson interferometer based shearographic system has been widely utilized in industry as a practical nondestructive test tool. In the system, the Michelson interferometer is used as a shearing device to generate a shearing distance by tilting a small angle in one of the two mirrors. In fact, tilting the mirror in the Michelson interferometer also generates spatial frequency shift. Based on this feature, we introduce a simple Michelson interferometer based spatial phase shift shearography. The Fourier transform (FT) method is applied to separate the spectrum on the spatial frequency domain. The phase change due to the loading can be evaluated using a properly selected windowed inverse-FT. This system can generate a phase map of shearography by using only a single image. The effects of shearing angle, spatial resolution of couple charge device camera, and filter methods are discussed in detail. The theory and the experimental results are presented.

  6. An investigation on near wall transport characteristics in an adiabatic upward gas-liquid two-phase slug flow

    Science.gov (United States)

    Zheng, Donghong; Che, Defu

    2007-08-01

    The near-wall transport characteristics, inclusive of mass transfer coefficient and wall shear stress, which have a great effect on gas-liquid two-phase flow induced internal corrosion of low alloy pipelines in vertical upward oil and gas mixing transport, have been both mechanistically and experimentally investigated in this paper. Based on the analyses on the hydrodynamic characteristics of an upward slug unit, the mass transfer in the near wall can be divided into four zones, Taylor bubble nose zone, falling liquid film zone, Taylor bubble wake zone and the remaining liquid slug zone; the wall shear stress can be divided into two zones, the positive wall shear stress zone associated with the falling liquid film and the negative wall shear stress zone associated with the liquid slug. Based on the conventional mass transfer and wall shear stress characteristics formulas of single phase liquid full-pipe turbulent flow, corrected normalized mass transfer coefficient formula and wall shear stress formula are proposed. The calculated results are in good agreement with the experimental data. The shear stress and the mass transfer coefficient in the near wall zone are increased with the increase of superficial gas velocity and decreased with the increase of superficial liquid velocity. The mass transfer coefficients in the falling liquid film zone and the wake zone of leading Taylor bubble are lager than those in the Taylor bubble nose zone and the remaining liquid slug zone, and the wall shear stress associated falling liquid film is larger than that associated the liquid slug. The mass transfer coefficient is within 10-3 m/s, and the wall shear stress below 103 Pa. It can be concluded that the alternate wall shear stress due to upward gas-liquid slug flow is considered to be the major cause of the corrosion production film fatigue cracking.

  7. Connecting theory to fat talk: body dissatisfaction mediates the relationships between weight discrepancy, upward comparison, body surveillance, and fat talk.

    Science.gov (United States)

    Arroyo, Analisa

    2014-06-01

    The fat talk literature is meager in terms of offering theoretical explanations for women's self-disparaging communication. The research presented here sought to establish a relationship between three prominent body image theories - self-discrepancy theory, social comparison theory, and objectification theory - and fat talk by proposing body dissatisfaction as a potential mediating mechanism. Young adult women (N=201) completed an online questionnaire. As predicted, results revealed that body dissatisfaction significantly mediated the relationships between weight discrepancy, upward comparison, body surveillance and fat talk. Effect size estimates indicated that the size of each indirect effect was medium in magnitude. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. The invisible minority: revisiting the debate on foreign-accented speakers and upward mobility in the workplace.

    Science.gov (United States)

    Akomolafe, Soji

    2013-01-01

    Of some of the major types of discrimination, the one that gets the least attention is national origin discrimination and in particular, accent discrimination, especially when it comes to upward mobility in the workplace. Yet, unlike other forms of discrimination, accent discrimination is rarely a subject of any robust public debate. This paper is a modest attempt to help establish a framework for understanding the relative neglect to which the discourse on accent discrimination has been subjected vis-a-vis the overall national debate on diversity. Hopefully, in the process, it will stimulate a more robust conversation on the plight of foreign-accented speakers.

  9. Upward Trend in Catalytic Efficiency of Rare-Earth Triflate Catalysts in Friedel-Crafts Aromatic Sulfonylation Reactions

    DEFF Research Database (Denmark)

    Duus, Fritz; Le, Thach Ngoc; Nguyen, Vo Thu An

    2014-01-01

    A series of 14 lanthanide (Ln) triflates were investigated as sustainable catalysts for aromatic sulfonylation reactions under microwave irradiation. The catalytic efficiency of the early triflates La(OTf)3–Eu(OTf)3 is good for long irradiation times. For the later lanthanides, yields reaching over...... 90 % were achieved for short irradiation periods. This was the case especially for Tm(OTf)3, Yb(OTf)3, and Lu(OTf)3, of which Yb(OTf)3 was the most efficient. The upward trend in catalytic efficiency therefore correlates with the lanthanide sequence in the periodic table. The results can be explained...

  10. 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.

  11. 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.

  12. An improved model to determine the inception of positive upward leader–streamer system considering the leader propagation during dark period

    International Nuclear Information System (INIS)

    Xie Shijun; He Junjia; Chen Weijiang

    2013-01-01

    Stem–leader transition and front-streamer inception are two essential conditions for the inception of positive upward leader–streamer system (LSS). Previous models have not considered the initial-leader propagation during dark period and have not been verified systematically. In this paper, a series of positive upward discharge simulation experiments was designed and carried out. Characteristic parameters of the discharge process related to the inception of positive upward LSS, namely, the first-corona inception voltage, the first-corona charge, the dark period, and the LSS inception voltage, were obtained. By comparing these experiment results with simulation results calculated using previous models, it was found that it is improper to assume that the length of the initial leader is a fixed value. Finally, an improved inception model of positive upward LSS considering the leader propagation during dark period was developed and verified with experiment results.

  13. Cyclotron motion in a microwave cavity: an analog of the Lamb shift

    International Nuclear Information System (INIS)

    Brown, L.S.

    1985-09-01

    The interaction of a bound electron with the radiation field produced by the image charges that represent a surrounding metallic cavity produces a shift in its orbital frequency and in its radiative decay time. This is an analog to the Lamb shift in atomic systems, but it is purely a classical effect. We outline the calculation of the frequency shift and the change in the damping constant for a cyclotron motion at the midpoint of a lossy, cylindrical cavity

  14. Chemical Shift Imaging (CSI) by precise object displacement

    OpenAIRE

    Leclerc, Sebastien; Trausch, Gregory; Cordier, Benoit; Grandclaude, Denis; Retournard, Alain; Fraissard, Jacques; Canet, Daniel

    2006-01-01

    International audience; A mechanical device (NMR lift) has been built for displacing vertically an object (typically a NMR sample tube) inside the NMR probe with an accuracy of 1 Μm. A series of single pulse experiments are performed for incremented vertical positions of the sample. With a sufficiently spatially selective rf field, one obtains chemical shift information along the displacement direction (one dimensional Chemical Shift Imaging – CSI). Knowing the vertical radio-frequency (rf) f...

  15. 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.

  16. Dry-out heat fluxes of falling film and low-mass flux upward-flow in heated tubes

    International Nuclear Information System (INIS)

    Koizumi, Yasuo; Ueda, Tatsuhiro; Matsuo, Teruyuki; Miyota, Yukio

    1998-01-01

    Dry-out heat fluxes were investigated experimentally for a film flow falling down on the inner surface of vertical heated-tubes and for a low mass flux forced-upward flow in the tubes using R 113. This work followed the study on those for a two-phase natural circulation system. For the falling film boiling, flow state observation tests were also performed, where dry-patches appearing and disappearing repeatedly were observed near the exit end of the heated section at the dry-out heat flux conditions. Relation between the dry-out heat flux and the liquid film flow rate is analyzed. The dry-out heat fluxes of the low mass flux upflow are expressed well by the correlation proposed in the previous work. The relation for the falling film boiling shows a similar trend to that for the upflow boiling, however, the dry-out heat fluxes of the falling film are much lower, approximately one third, than those of the upward flow. (author)

  17. Precise optical Lamb shift measurements in atomic hydrogen

    International Nuclear Information System (INIS)

    Weitz, M.; Schmidt-Kaler, F.; Haensch, T.W.

    1992-01-01

    The 1S ground-state Lamb shift in atomic hydrogen has been measured to an accuracy of 1.3 parts in 10 5 by directly comparing the optical frequencies of the 1S-2S and the 2S-4S,4D two-photon transitions. The result, 8172.82(11) MHz, agrees with the theoretical prediction of 8172.94(9) MHz and rivals measurements of the 2S Lamb shift as a test of QED for a bound system. A comparison of the 2S-4S and 2S-4D intervals yields a 4S Lamb shift of 131.66(4) MHz

  18. Chemical shift homology in proteins

    International Nuclear Information System (INIS)

    Potts, Barbara C.M.; Chazin, Walter J.

    1998-01-01

    The degree of chemical shift similarity for homologous proteins has been determined from a chemical shift database of over 50 proteins representing a variety of families and folds, and spanning a wide range of sequence homologies. After sequence alignment, the similarity of the secondary chemical shifts of C α protons was examined as a function of amino acid sequence identity for 37 pairs of structurally homologous proteins. A correlation between sequence identity and secondary chemical shift rmsd was observed. Important insights are provided by examining the sequence identity of homologous proteins versus percentage of secondary chemical shifts that fall within 0.1 and 0.3 ppm thresholds. These results begin to establish practical guidelines for the extent of chemical shift similarity to expect among structurally homologous proteins

  19. Validation of archived chemical shifts through atomic coordinates

    Science.gov (United States)

    Rieping, Wolfgang; Vranken, Wim F

    2010-01-01

    The public archives containing protein information in the form of NMR chemical shift data at the BioMagResBank (BMRB) and of 3D structure coordinates at the Protein Data Bank are continuously expanding. The quality of the data contained in these archives, however, varies. The main issue for chemical shift values is that they are determined relative to a reference frequency. When this reference frequency is set incorrectly, all related chemical shift values are systematically offset. Such wrongly referenced chemical shift values, as well as other problems such as chemical shift values that are assigned to the wrong atom, are not easily distinguished from correct values and effectively reduce the usefulness of the archive. We describe a new method to correct and validate protein chemical shift values in relation to their 3D structure coordinates. This method classifies atoms using two parameters: the per-atom solvent accessible surface area (as calculated from the coordinates) and the secondary structure of the parent amino acid. Through the use of Gaussian statistics based on a large database of 3220 BMRB entries, we obtain per-entry chemical shift corrections as well as Z scores for the individual chemical shift values. In addition, information on the error of the correction value itself is available, and the method can retain only dependable correction values. We provide an online resource with chemical shift, atom exposure, and secondary structure information for all relevant BMRB entries (http://www.ebi.ac.uk/pdbe/nmr/vasco) and hope this data will aid the development of new chemical shift-based methods in NMR. Proteins 2010. © 2010 Wiley-Liss, Inc. PMID:20602353

  20. Shifted-modified Chebyshev filters

    OpenAIRE

    ŞENGÜL, Metin

    2013-01-01

    This paper introduces a new type of filter approximation method that utilizes shifted-modified Chebyshev filters. Construction of the new filters involves the use of shifted-modified Chebyshev polynomials that are formed using the roots of conventional Chebyshev polynomials. The study also includes 2 tables containing the shifted-modified Chebyshev polynomials and the normalized element values for the low-pass prototype filters up to degree 6. The transducer power gain, group dela...

  1. Portable shift register

    International Nuclear Information System (INIS)

    Halbig, J.K.; Bourret, S.C.; Hansen, W.J.; Hicks, D.V.; Klosterbuer, S.F.; Krick, M.S.

    1994-01-01

    An electronics package for a small, battery-operated, self-contained, neutron coincidence counter based on a portable shift-register (PSR) has been developed. The counter was developed for applications not adequately addressed by commercial packages, including in-plant measurements to demonstrate compliance with regulations (domestic and international), in-plant process control, and in-field measurements (environmental monitoring or safeguards). Our package's features, which address these applications, include the following: Small size for portability and ease of installation;battery or mains operation; a built-in battery to power the unit and a typical detector such as a small sample counter, for over 6 h if power lines are bad or noisy, if there is a temporary absence of power, or if portability is desired; complete support, including bias, for standard neutron detectors; a powerful communications package to easily facilitate robust external control over a serial port; and a C-library to simplify creating external control programs in computers or other controllers. Whereas the PSR specifically addresses the applications mentioned above, it also performs all the measurements made by previous electronics packages for neutron coincidence counters developed at Los Alamos and commercialized. The PSR electronics package, exclusive of carrying handle, is 8 by 10 by 20 cm; it contains the circuit boards, battery, and bias supply and weighs less than 2 kg. This instrument package is the second in an emerging family of portable measurement instruments being developed; the first was the Miniature and Modular Multichannel Analyzer (M 3 CA). The PSR makes extensive use of hardware and software developed for the M 3 CA; like the M 3 CA, it is intended primarily for use with an external controller interfaced over a serial channel

  2. Sound field control for a low-frequency test facility

    DEFF Research Database (Denmark)

    Pedersen, Christian Sejer; Møller, Henrik

    2013-01-01

    The two largest problems in controlling the reproduction of low-frequency sound for psychoacoustic experiments is the effect of the room due to standing waves and the relatively large sound pressure levels needed. Anechoic rooms are limited downward in frequency and distortion may be a problem even...... at moderate levels, while pressure-field playback can give higher sound pressures but is limited upwards in frequency. A new solution that addresses both problems has been implemented in the laboratory of Acoustics, Aalborg University. The solution uses one wall with 20 loudspeakers to generate a plane wave...... that is actively absorbed when it reaches the 20 loudspeakers on the opposing wall. This gives a homogeneous sound field in the majority of the room with a flat frequency response in the frequency range 2-300 Hz. The lowest frequencies are limited to sound pressure levels in the order of 95 dB. If larger levels...

  3. The Investigation of Median Frequency Changes in Paraspinal Muscles Following Fatigue

    Directory of Open Access Journals (Sweden)

    Saeed Talebian

    2009-10-01

    Conclusion: Median frequency shift toward low values following fatigue in global and local paraspinal muscles was seen. However, median frequency values for the local stabilizer muscle were higher than median frequency values for the global muscles.

  4. AN UPWARD TREND IN DNA P16INK4A METHYLATION PATTERN AND HIGH RISK HPV INFECTION ACCORDING TO THE SEVERITY OF THE CERVICAL LESION

    Directory of Open Access Journals (Sweden)

    Fernanda Nahoum Carestiato

    2013-09-01

    Full Text Available SUMMARY High-risk human papillomavirus (hr-HPV infection is necessary but not sufficient for cervical cancer development. Recently, P16INK4A gene silencing through hypermethylation has been proposed as an important cofactor in cervical carcinogenesis due to its tumor suppressor function. We aimed to investigate P16INK4A methylation status in normal and neoplastic epithelia and evaluate an association with HPV infection and genotype. This cross-sectional study was performed with 141 cervical samples from patients attending Hospital Moncorvo Filho, Rio de Janeiro. HPV detection and genotyping were performed through PCR and P16INK4A methylation by nested-methylation specific PCR (MSP. HPV frequency was 62.4% (88/141. The most common HPV were HPV16 (37%, HPV18 (16.3% and HPV33/45(15.2%. An upward trend was observed concerning P16INK4A methylation and lesion degree: normal epithelia (10.7%, low grade lesions (22.9%, high grade (57.1% and carcinoma (93.1% (p < 0.0001. A multivariate analysis was performed to evaluate an association between methylation, age, tobacco exposure, HPV infection and genotyping. A correlation was found concerning methylation with HPV infection (p < 0.0001, hr-HPV (p = 0.01, HSIL (p < 0.0007 and malignant lesions (p < 0.0001. Since viral infection and epigenetic alterations are related to cervical carcinoma, we suggest that P16INK4A methylation profile maybe thoroughly investigated as a biomarker to identify patients at risk of cancer.

  5. Mixed convection heat transfer to carbon dioxide flowing upward and downward in a vertical tube and an annular channel

    International Nuclear Information System (INIS)

    Bae, Yoon Y.

    2011-01-01

    Highlights: → Experimental results of heat transfer at a supercritical pressure for a tube with an inner diameter of 4.57 mm and a corresponding annular channel (8 mm x 10 mm, 1 mm gap) were compared each other. → Effect of various parameters such as pressure, flow direction, diameter, channel shape, was investigated. → Existing correlation for supercritical heat transfer were evaluated against the experimental data. → Some unusual characteristics of supercritical heat transfer, such as overshoot and non-monotonic behavior against buoyancy parameter, were discussed. → New correlations were proposed based on the experimental data. - Abstract: This paper addresses three main subjects in supercritical heat transfer: (1) difference in thermal characteristics between upward and downward flows; (2) effect of simulating flow channel shape; (3) evaluation of the existing supercritical heat transfer correlations. To achieve the objectives, a series of experiments was carried out with CO 2 flowing upward and downward in a circular tube with an inner diameter of 4.57 mm and an annular channel created between a tube with an inner diameter of 10 mm and a heater rod with an outer diameter of 8 mm. The working fluid, CO 2 , has been regarded as an appropriate modeling fluid for water, primarily because of their similarity in property variations against reduced temperatures. The mass flux ranged from 400 to 1200 kg/m 2 s. The heat flux was varied between 30 and 140 kW/m 2 so that the pseudo-critical point was located in the middle of the heated section at a given mass flux. The measurements were made at a pressure of 8.12 MPa, which corresponds to 110% of the critical pressure of CO 2 . The difference between the upward and downward flows was observed clearly. The heat transfer deterioration was observed in the downward flow through an annular subchannel over the region beyond the critical point. Several well-known correlations were evaluated against the experimental

  6. Actively Coping with Violation: Exploring Upward Dissent Patterns in Functional, Dysfunctional, and Deserted Psychological Contract End States

    Science.gov (United States)

    Schalk, René; De Ruiter, Melanie; Van Loon, Joost; Kuijpers, Evy; Van Regenmortel, Tine

    2018-01-01

    Recently, scholars have emphasized the importance of examining how employees cope with psychological contract violation and how the coping process contributes to psychological contract violation resolution and post-violation psychological contracts. Recent work points to the important role of problem-focused coping. Yet, to date, problem-focused coping strategies have not been conceptualized on a continuum from constructive to destructive strategies. Consequently, potential differences in the use of specific types of problem-focused coping strategies and the role these different strategies play in the violation resolution process has not been explored. In this study, we stress the importance of focusing on different types of problem-focused coping strategies. We explore how employee upward dissent strategies, conceptualized as different forms of problem-focused coping, contribute to violation resolution and post-violation psychological contracts. Two sources of data were used. In-depth interviews with supervisors of a Dutch car lease company provided 23 case descriptions of employee-supervisor interactions after a psychological contract violation. Moreover, a database with descriptions of Dutch court sentences provided eight case descriptions of employee-organization interactions following a perceived violation. Based on these data sources, we explored the pattern of upward dissent strategies employees used over time following a perceived violation. We distinguished between functional (thriving and reactivation), dysfunctional (impairment and dissolution) and deserted psychological contract end states and explored whether different dissent patterns over time differentially contributed to the dissent outcome (i.e., psychological contract end state). The results of our study showed that the use of problem-focused coping is not as straightforward as suggested by the post-violation model. While the post-violation model suggests that problem-focused coping will most

  7. Actively Coping with Violation: Exploring Upward Dissent Patterns in Functional, Dysfunctional, and Deserted Psychological Contract End States

    Directory of Open Access Journals (Sweden)

    René Schalk

    2018-02-01

    Full Text Available Recently, scholars have emphasized the importance of examining how employees cope with psychological contract violation and how the coping process contributes to psychological contract violation resolution and post-violation psychological contracts. Recent work points to the important role of problem-focused coping. Yet, to date, problem-focused coping strategies have not been conceptualized on a continuum from constructive to destructive strategies. Consequently, potential differences in the use of specific types of problem-focused coping strategies and the role these different strategies play in the violation resolution process has not been explored. In this study, we stress the importance of focusing on different types of problem-focused coping strategies. We explore how employee upward dissent strategies, conceptualized as different forms of problem-focused coping, contribute to violation resolution and post-violation psychological contracts. Two sources of data were used. In-depth interviews with supervisors of a Dutch car lease company provided 23 case descriptions of employee-supervisor interactions after a psychological contract violation. Moreover, a database with descriptions of Dutch court sentences provided eight case descriptions of employee-organization interactions following a perceived violation. Based on these data sources, we explored the pattern of upward dissent strategies employees used over time following a perceived violation. We distinguished between functional (thriving and reactivation, dysfunctional (impairment and dissolution and deserted psychological contract end states and explored whether different dissent patterns over time differentially contributed to the dissent outcome (i.e., psychological contract end state. The results of our study showed that the use of problem-focused coping is not as straightforward as suggested by the post-violation model. While the post-violation model suggests that problem

  8. Actively Coping with Violation: Exploring Upward Dissent Patterns in Functional, Dysfunctional, and Deserted Psychological Contract End States.

    Science.gov (United States)

    Schalk, René; De Ruiter, Melanie; Van Loon, Joost; Kuijpers, Evy; Van Regenmortel, Tine

    2018-01-01

    Recently, scholars have emphasized the importance of examining how employees cope with psychological contract violation and how the coping process contributes to psychological contract violation resolution and post-violation psychological contracts. Recent work points to the important role of problem-focused coping. Yet, to date, problem-focused coping strategies have not been conceptualized on a continuum from constructive to destructive strategies. Consequently, potential differences in the use of specific types of problem-focused coping strategies and the role these different strategies play in the violation resolution process has not been explored. In this study, we stress the importance of focusing on different types of problem-focused coping strategies. We explore how employee upward dissent strategies, conceptualized as different forms of problem-focused coping, contribute to violation resolution and post-violation psychological contracts. Two sources of data were used. In-depth interviews with supervisors of a Dutch car lease company provided 23 case descriptions of employee-supervisor interactions after a psychological contract violation. Moreover, a database with descriptions of Dutch court sentences provided eight case descriptions of employee-organization interactions following a perceived violation. Based on these data sources, we explored the pattern of upward dissent strategies employees used over time following a perceived violation. We distinguished between functional (thriving and reactivation), dysfunctional (impairment and dissolution) and deserted psychological contract end states and explored whether different dissent patterns over time differentially contributed to the dissent outcome (i.e., psychological contract end state). The results of our study showed that the use of problem-focused coping is not as straightforward as suggested by the post-violation model. While the post-violation model suggests that problem-focused coping will most

  9. Scientific evidence contradicts findings and assumptions of Canadian Safety Panel 6: microwaves act through voltage-gated calcium channel activation to induce biological impacts at non-thermal levels, supporting a paradigm shift for microwave/lower frequency electromagnetic field action.

    Science.gov (United States)

    Pall, Martin L

    2015-01-01

    This review considers a paradigm shift on microwave electromagnetic field (EMF) action from only thermal effects to action via voltage-gated calcium channel (VGCC) activation. Microwave/lower frequency EMFs were shown in two dozen studies to act via VGCC activation because all effects studied were blocked by calcium channel blockers. This mode of action was further supported by hundreds of studies showing microwave changes in calcium fluxes and intracellular calcium [Ca2+]i signaling. The biophysical properties of VGCCs/similar channels make them particularly sensitive to low intensity, non-thermal EMF exposures. Non-thermal studies have shown that in most cases pulsed fields are more active than are non-pulsed fields and that exposures within certain intensity windows have much large biological effects than do either lower or higher intensity exposures; these are both consistent with a VGCC role but inconsistent with only a heating/thermal role. Downstream effects of VGCC activation include calcium signaling, elevated nitric oxide (NO), NO signaling, peroxynitrite, free radical formation, and oxidative stress. Downstream effects explain repeatedly reported biological responses to non-thermal exposures: oxidative stress; single and double strand breaks in cellular DNA; cancer; male and female infertility; lowered melatonin/sleep disruption; cardiac changes including tachycardia, arrhythmia, and sudden cardiac death; diverse neuropsychiatric effects including depression; and therapeutic effects. Non-VGCC non-thermal mechanisms may occur, but none have been shown to have effects in mammals. Biologically relevant safety standards can be developed through studies of cell lines/cell cultures with high levels of different VGCCs, measuring their responses to different EMF exposures. The 2014 Canadian Report by a panel of experts only recognizes thermal effects regarding safety standards for non-ionizing radiation exposures. Its position is therefore contradicted by each

  10. Work shifts in Emergency Medicine

    Directory of Open Access Journals (Sweden)

    Roberto Recupero

    2007-06-01

    Full Text Available Emergency Medicine is known as a high stress specialty. The adverse effect of constantly rotating shifts is the single most important reason given for premature attrition from the field. In this work problems tied with night shift work will be taken into account and some solutions to reduce the impact of night work on the emergency physicians will be proposed.

  11. Flexible Schedules and Shift Work.

    Science.gov (United States)

    Beers, Thomas M.

    2000-01-01

    Flexible work hours have gained prominence, as more than 25 million workers (27.6% of all full-time workers) can now vary their schedules. However, there has been little change since the mid-1980s in the proportion who work a shift other than a regular daytime shift. (JOW)

  12. A Heat Transfer Correlation in a Vertical Upward Flow of CO{sub 2} at Supercritical Pressures

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Rae; Bae, Yoon Yeong; Song, Jin Ho; Kim, Hwan Yeol [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2006-07-01

    Heat transfer data has been collected in the heat transfer test loop, named SPHINX (Supercritical Pressure Heat Transfer Investigation for NeXt generation), in KAERI. The facility primarily aims at the generation of heat transfer data in the flow conditions and geometries relevant to SCWR (SuperCritical Water-cooled Reactor). The produced data will aid the thermohydraulic design of a reactor core. The loop uses carbon dioxide, and later the results will be scaled to the water flows. The heat transfer data has been collected for a vertical upward flow in a circular tube with varying mass fluxes, heat fluxes, and operating pressures. The results are compared with the existing correlations and a new correlation is proposed by fine-tuning the one of the existing correlations.

  13. Multivariate multiscale complex network analysis of vertical upward oil-water two-phase flow in a small diameter pipe.

    Science.gov (United States)

    Gao, Zhong-Ke; Yang, Yu-Xuan; Zhai, Lu-Sheng; Dang, Wei-Dong; Yu, Jia-Liang; Jin, Ning-De

    2016-02-02

    High water cut and low velocity vertical upward oil-water two-phase flow is a typical complex system with the features of multiscale, unstable and non-homogenous. We first measure local flow information by using distributed conductance sensor and then develop a multivariate multiscale complex network (MMCN) to reveal the dispersed oil-in-water local flow behavior. Specifically, we infer complex networks at different scales from multi-channel measurements for three typical vertical oil-in-water flow patterns. Then we characterize the generated multiscale complex networks in terms of network clustering measure. The results suggest that the clustering coefficient entropy from the MMCN not only allows indicating the oil-in-water flow pattern transition but also enables to probe the dynamical flow behavior governing the transitions of vertical oil-water two-phase flow.

  14. HYPE: a WFD tool for the identification of significant and sustained upward trends in groundwater time series

    Science.gov (United States)

    Lopez, Benjamin; Croiset, Nolwenn; Laurence, Gourcy

    2014-05-01

    The Water Framework Directive 2006/11/CE (WFD) on the protection of groundwater against pollution and deterioration asks Member States to identify significant and sustained upward trends in all bodies or groups of bodies of groundwater that are characterised as being at risk in accordance with Annex II to Directive 2000/60/EC. The Directive indicates that the procedure for the identification of significant and sustained upward trends must be based on a statistical method. Moreover, for significant increases of concentrations of pollutants, trend reversals are identified as being necessary. This means to be able to identify significant trend reversals. A specific tool, named HYPE, has been developed in order to help stakeholders working on groundwater trend assessment. The R encoded tool HYPE provides statistical analysis of groundwater time series. It follows several studies on the relevancy of the use of statistical tests on groundwater data series (Lopez et al., 2011) and other case studies on the thematic (Bourgine et al., 2012). It integrates the most powerful and robust statistical tests for hydrogeological applications. HYPE is linked to the French national database on groundwater data (ADES). So monitoring data gathered by the Water Agencies can be directly processed. HYPE has two main modules: - a characterisation module, which allows to visualize time series. HYPE calculates the main statistical characteristics and provides graphical representations; - a trend module, which identifies significant breaks, trends and trend reversals in time series, providing result table and graphical representation (cf figure). Additional modules are also implemented to identify regional and seasonal trends and to sample time series in a relevant way. HYPE has been used successfully in 2012 by the French Water Agencies to satisfy requirements of the WFD, concerning characterization of groundwater bodies' qualitative status and evaluation of the risk of non-achievement of

  15. Identification of retinal ganglion cells and their projections involved in central transmission of information about upward and downward image motion.

    Directory of Open Access Journals (Sweden)

    Keisuke Yonehara

    Full Text Available The direction of image motion is coded by direction-selective (DS ganglion cells in the retina. Particularly, the ON DS ganglion cells project their axons specifically to terminal nuclei of the accessory optic system (AOS responsible for optokinetic reflex (OKR. We recently generated a knock-in mouse in which SPIG1 (SPARC-related protein containing immunoglobulin domains 1-expressing cells are visualized with GFP, and found that retinal ganglion cells projecting to the medial terminal nucleus (MTN, the principal nucleus of the AOS, are comprised of SPIG1+ and SPIG1(- ganglion cells distributed in distinct mosaic patterns in the retina. Here we examined light responses of these two subtypes of MTN-projecting cells by targeted electrophysiological recordings. SPIG1+ and SPIG1(- ganglion cells respond preferentially to upward motion and downward motion, respectively, in the visual field. The direction selectivity of SPIG1+ ganglion cells develops normally in dark-reared mice. The MTN neurons are activated by optokinetic stimuli only of the vertical motion as shown by Fos expression analysis. Combination of genetic labeling and conventional retrograde labeling revealed that axons of SPIG1+ and SPIG1(- ganglion cells project to the MTN via different pathways. The axon terminals of the two subtypes are organized into discrete clusters in the MTN. These results suggest that information about upward and downward image motion transmitted by distinct ON DS cells is separately processed in the MTN, if not independently. Our findings provide insights into the neural mechanisms of OKR, how information about the direction of image motion is deciphered by the AOS.

  16. Geographies of High Frequency Trading

    DEFF Research Database (Denmark)

    Grindsted, Thomas Skou

    2016-01-01

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

  17. Mercury Trapped Ion Frequency Standard for Ultra-Stable Reference Applications

    Science.gov (United States)

    Burt, Eric A. (Inventor); Hamell, Robert L. (Inventor); Tucker, Blake C. (Inventor); Larsen, Kameron (Inventor); Tjoelker, Robert L. (Inventor)

    2017-01-01

    An atomic clock including an ion trap assembly, a C-field coil positioned for generating a first magnetic field in the interrogation region of the ion trap assembly, a compensation coil positioned for generating a second magnetic field in the interrogation region, wherein the combination of the first and second magnetic fields produces an ion number-dependent second order Zeeman shift (Zeeman shift) in the resonance frequency that is opposite in sign to an ion number-dependent second order Doppler shift (Doppler shift) in the resonance frequency, the C-field coil has a radius selected using data indicating how changes in the radius affect an ion-number-dependent shift in the resonance frequency, such that a difference in magnitude between the Doppler shift and the Zeeman shift is controlled or reduced, and the resonance frequency, including the adjustment by the Zeeman shift, is used to obtain the frequency standard.

  18. A probabilistic approach for validating protein NMR chemical shift assignments

    International Nuclear Information System (INIS)

    Wang Bowei; Wang, Yunjun; Wishart, David S.

    2010-01-01

    It has been estimated that more than 20% of the proteins in the BMRB are improperly referenced and that about 1% of all chemical shift assignments are mis-assigned. These statistics also reflect the likelihood that any newly assigned protein will have shift assignment or shift referencing errors. The relatively high frequency of these errors continues to be a concern for the biomolecular NMR community. While several programs do exist to detect and/or correct chemical shift mis-referencing or chemical shift mis-assignments, most can only do one, or the other. The one program (SHIFTCOR) that is capable of handling both chemical shift mis-referencing and mis-assignments, requires the 3D structure coordinates of the target protein. Given that chemical shift mis-assignments and chemical shift re-referencing issues should ideally be addressed prior to 3D structure determination, there is a clear need to develop a structure-independent approach. Here, we present a new structure-independent protocol, which is based on using residue-specific and secondary structure-specific chemical shift distributions calculated over small (3-6 residue) fragments to identify mis-assigned resonances. The method is also able to identify and re-reference mis-referenced chemical shift assignments. Comparisons against existing re-referencing or mis-assignment detection programs show that the method is as good or superior to existing approaches. The protocol described here has been implemented into a freely available Java program called 'Probabilistic Approach for protein Nmr Assignment Validation (PANAV)' and as a web server (http://redpoll.pharmacy.ualberta.ca/PANAVhttp://redpoll.pharmacy.ualberta.ca/PANAV) which can be used to validate and/or correct as well as re-reference assigned protein chemical shifts.

  19. Nonlocal optical effects on the Goos–Hänchen shifts at multilayered hyperbolic metamaterials

    International Nuclear Information System (INIS)

    Chen, Chih-Wei; Bian, Tingting; Chiang, Hai-Pang; Leung, P T

    2016-01-01

    The lateral beam shift of light incident on a multilayered hyperbolic metamaterial (HMM) is investigated using a theoretical model which emphasizes the nonlocal optical response of the indefinite material. By applying an effective local response theory formulated recently in the literature, it is found that nonlocal effects only affect p polarized light in this Goos–Hänchen (GH) shift of the incident beam; leading to a blue-shifted peak for positive shifts at high frequencies and red-shifted dip for negative shifts at low frequencies in the GH shift spectrum. An account for the observed phenomenon is given by referring to the ‘Brewster condition’ for the reflected wave from the HMM. This observation thus provides a relatively direct probe for the nonlocal response of the HMM. (paper)

  20. High-frequency Trader Subjectivity

    DEFF Research Database (Denmark)

    Borch, Christian; Lange, Ann-Christina

    2017-01-01

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

  1. Association between rotating night shift work and metabolic syndrome in Korean workers: differences between 8-hour and 12-hour rotating shift work.

    Science.gov (United States)

    Oh, Jae-Il; Yim, Hyeon Woo

    2018-02-07

    This study aimed to analyze the association between the shift work schedule and metabolic syndrome (MetS). This is a retrospective longitudinal study based on the 2015 health checkup data of 2,090 workers evaluated for MetS in 2010 at a general hospital in Korea. The participants were divided according to their shift work schedule into daytime, three-shift (8-h rotation), and two-shift (12-h rotation) workers. The index that indicates the association between the shift work schedule and MetS is the odds ratio (OR) calculated using multivariate logistic regression. The analysis for the entire group of workers indicated that there was positive association between two-shift rotation and MetS (OR=1.58, 95% confidence interval [CI]: 1.09, 2.29). In the analysis of rotating night-shift workers, the years of rotating night shifts, frequency of night-shift work, and sleep disturbance were added to the confounding variables, and two-shift work remained positively associated with MetS (OR=1.72, 95% CI: 1.10, 2.70). The risk of MetS differs based on the shift work schedules they engage in. Hence, structural changes to the shift work schedules are required to prevent MetS in night-shift workers.

  2. Cover Image Innate or learned preference for upward-facing flowers?: implications for the costs of pendent flowers from experiments on captive bumble bees

    Directory of Open Access Journals (Sweden)

    Takashi T Makino

    2012-10-01

    Full Text Available Pollinator preferences for phenotypic characters, including floral orientation, can affect plant reproductive success. For example, hawkmoths and syrphid flies prefer upward- over downward-facing flowers in field experiments. Although such preferences suggest a cost of pendent flowers in terms of pollinator attraction, we cannot rule out the possibility that the preferences have been affected by prior experience: pollinators might choose the same type of flowers to which they have already become accustomed. To test for innate preference, we observed bumble bees foraging on an array of upward- and downward-facing artificial flowers. Without any prior experience with vertical flowers, 91.7% bees chose an upward-facing flower at the very first visit. In addition to this innate preference, we also found that the preference was strengthened by experience, which suggests that the bees learned upward-facing flowers were easier to handle. Although bumble bees may concentrate on pendent flowers in the field, such learned preferences are evidently imposed on a template of upward-facing preference. Because bee-pollinated pendent flowers face particular difficulties in attracting visits, therefore, we expect them to compensate through other means, such as greater floral rewards.

  3. SHIFT: server for hidden stops analysis in frame-shifted translation.

    Science.gov (United States)

    Gupta, Arun; Singh, Tiratha Raj

    2013-02-23

    Frameshift is one of the three classes of recoding. Frame-shifts lead to waste of energy, resources and activity of the biosynthetic machinery. In addition, some peptides synthesized after frame-shifts are probably cytotoxic which serve as plausible cause for innumerable number of diseases and disorders such as muscular dystrophies, lysosomal storage disorders, and cancer. Hidden stop codons occur naturally in coding sequences among all organisms. These codons are associated with the early termination of translation for incorrect reading frame selection and help to reduce the metabolic cost related to the frameshift events. Researchers have identified several consequences of hidden stop codons and their association with myriad disorders. However the wealth of information available is speckled and not effortlessly acquiescent to data-mining. To reduce this gap, this work describes an algorithmic web based tool to study hidden stops in frameshifted translation for all the lineages through respective genetic code systems. This paper describes SHIFT, an algorithmic web application tool that provides a user-friendly interface for identifying and analyzing hidden stops in frameshifted translation of genomic sequences for all available genetic code systems. We have calculated the correlation between codon usage frequencies and the plausible contribution of codons towards hidden stops in an off-frame context. Markovian chains of various order have been used to model hidden stops in frameshifted peptides and their evolutionary association with naturally occurring hidden stops. In order to obtain reliable and persuasive estimates for the naturally occurring and predicted hidden stops statistical measures have been implemented. This paper presented SHIFT, an algorithmic tool that allows user-friendly exploration, analysis, and visualization of hidden stop codons in frameshifted translations. It is expected that this web based tool would serve as a useful complement for

  4. Extension of Newton's Dynamical Spectral Shift for Photons in ...

    African Journals Online (AJOL)

    Extension of Newton's Dynamical Spectral Shift for Photons in Gravitational Fields of Static Homogeneous Spherical Massive Bodies. ... is perfectly in agreement with the physical fact that gravitational scalar potential is negative and increase in recession leads to decrease in kinetic energy and hence decrease in frequency.

  5. Illusion optics via one-dimensional ultratransparent photonic crystals with shifted spatial dispersions.

    Science.gov (United States)

    Yao, Zhongqi; Luo, Jie; Lai, Yun

    2017-12-11

    In this work, we propose that one-dimensional ultratransparent dielectric photonic crystals with wide-angle impedance matching and shifted elliptical equal frequency contours are promising candidate materials for illusion optics. The shift of the equal frequency contour does not affect the refractive behaviors, but enables a new degree of freedom in phase modulation. With such ultratransparent photonic crystals, we demonstrate some applications in illusion optics, including creating illusions of a different-sized scatterer and a shifted source with opposite phase. Such ultratransparent dielectric photonic crystals may establish a feasible platform for illusion optics devices at optical frequencies.

  6. Influences of Fundamental Frequency, Formant Frequencies, Aperiodicity, and Spectrum Level on the Perception of Voice Gender

    Science.gov (United States)

    Skuk, Verena G.; Schweinberger, Stefan R.

    2014-01-01

    Purpose: To determine the relative importance of acoustic parameters (fundamental frequency [F0], formant frequencies [FFs], aperiodicity, and spectrum level [SL]) on voice gender perception, the authors used a novel parameter-morphing approach that, unlike spectral envelope shifting, allows the application of nonuniform scale factors to transform…

  7. Inequalities for scattering phase shifts

    International Nuclear Information System (INIS)

    Baumgartner, B.; Grosse, H.

    1985-01-01

    A recently developed method, which was used to derive bounds on energy levels, is applied to continuous spectra and gives relations between scattering phase shifts of various angular momenta. (Author)

  8. Isotope shifts in unstable nuclei

    International Nuclear Information System (INIS)

    Rebel, H.

    1980-05-01

    Current experimental investigations of isotope shifts in atomic spectra of unstable nuclei and the resulting information about size and shape of nuclei far off stability are discussed with reference to some representative examples. (orig.)

  9. Frequency Correction for MIRO Chirp Transformation Spectroscopy Spectrum

    Science.gov (United States)

    Lee, Seungwon

    2012-01-01

    This software processes the flyby spectra of the Chirp Transform Spectrometer (CTS) of the Microwave Instrument for Rosetta Orbiter (MIRO). The tool corrects the effect of Doppler shift and local-oscillator (LO) frequency shift during the flyby mode of MIRO operations. The frequency correction for CTS flyby spectra is performed and is integrated with multiple spectra into a high signal-to-noise averaged spectrum at the rest-frame RF frequency. This innovation also generates the 8 molecular line spectra by dividing continuous 4,096-channel CTS spectra. The 8 line spectra can then be readily used for scientific investigations. A spectral line that is at its rest frequency in the frame of the Earth or an asteroid will be observed with a time-varying Doppler shift as seen by MIRO. The frequency shift is toward the higher RF frequencies on approach, and toward lower RF frequencies on departure. The magnitude of the shift depends on the flyby velocity. The result of time-varying Doppler shift is that of an observed spectral line will be seen to move from channel to channel in the CTS spectrometer. The direction (higher or lower frequency) in the spectrometer depends on the spectral line frequency under consideration. In order to analyze the flyby spectra, two steps are required. First, individual spectra must be corrected for the Doppler shift so that individual spectra can be superimposed at the same rest frequency for integration purposes. Second, a correction needs to be applied to the CTS spectra to account for the LO frequency shifts that are applied to asteroid mode.

  10. Solute transport with time-variable flow paths during upward and downward flux in a heterogeneous unsaturated porous medium

    Science.gov (United States)

    Cremer, Clemens; Neuweiler, Insa; Bechtold, Michel; Vanderborght, Jan

    2014-05-01

    To acquire knowledge of solute transport through the unsaturated zone in the shallow subsurface is decisive to assess groundwater quality, nutrient cycling or to plan remediation strategies. The shallow subsurface is characterized by structural heterogeneity and strongly influenced by atmospheric conditions. This leads to changing flow directions, strong temporal changes in saturation and heterogeneous water fluxes during infiltration and evaporation events. Recent studies (e.g. Lehmann and Or, 2009; Bechtold et al.,2011) demonstrated the importance of lateral flow and solute transport during evaporation conditions (upward flux). The heterogeneous structure in these studies was constructed using two types of sand with strong material contrasts and arranged in parallel with a vertical orientation. Lateral transport and redistribution of solute from coarse to fine media was observed deeper in the soil column and from fine to coarse close to the soil surface. However, if boundary conditions are reversed due to precipitation, the flow field is not necessarily reversed in the same manner, resulting in entirely different transport patterns for downward and upward flow. Therefore, considering net-flow rates alone is misleading when describing transport under those conditions. In this contribution we analyze transport of a solute in the shallow subsurface to assess effects resulting from the temporal change of heterogeneous soil structures due to dynamic flow conditions. Two-dimensional numerical simulations of unsaturated flow and transport are conducted using a coupled finite volume and random walk particle tracking algorithm to quantify solute transport and leaching rates. Following previous studies (Lehmann and Or, 2009; Bechtold et al., 2011), the chosen domain is composed of two materials, coarse and fine sand, arranged in parallel with a vertical orientation. Hence, one sharp interface of strong material heterogeneity is induced. During evaporation both sands are

  11. Investigation of forced convection heat transfer of supercritical pressure water in a vertically upward internally ribbed tube

    International Nuclear Information System (INIS)

    Wang Jianguo; Li Huixiong; Guo Bin; Yu Shuiqing; Zhang Yuqian; Chen Tingkuan

    2009-01-01

    In the present paper, the forced convection heat transfer characteristics of water in a vertically upward internally ribbed tube at supercritical pressures were investigated experimentally. The six-head internally ribbed tube is made of SA-213T12 steel with an outer diameter of 31.8 mm and a wall thickness of 6 mm and the mean inside diameter of the tube is measured to be 17.6 mm. The experimental parameters were as follows. The pressure at the inlet of the test section varied from 25.0 to 29.0 MPa, and the mass flux was from 800 to 1200 kg/(m 2 s), and the inside wall heat flux ranged from 260 to 660 kW/m 2 . According to experimental data, the effects of heat flux and pressure on heat transfer of supercritical pressure water in the vertically upward internally ribbed tube were analyzed, and the characteristics and mechanisms of heat transfer enhancement, and also that of heat transfer deterioration, were also discussed in the so-called large specific heat region. The drastic changes in thermophysical properties near the pseudocritical points, especially the sudden rise in the specific heat of water at supercritical pressures, may result in the occurrence of the heat transfer enhancement, while the covering of the heat transfer surface by fluids lighter and hotter than the bulk fluid makes the heat transfer deteriorated eventually and explains how this lighter fluid layer forms. It was found that the heat transfer characteristics of water at supercritical pressures were greatly different from the single-phase convection heat transfer at subcritical pressures. There are three heat transfer modes of water at supercritical pressures: (1) normal heat transfer, (2) deteriorated heat transfer with low HTC but high wall temperatures in comparison to the normal heat transfer, and (3) enhanced heat transfer with high HTC and low wall temperatures in comparison to the normal heat transfer. It was also found that the heat transfer deterioration at supercritical pressures was

  12. 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

  13. Experimental investigation on flow patterns of gas-liquid two-phase upward flow through packed channel with spheres

    International Nuclear Information System (INIS)

    Zhang Nan; Sun Zhongning; Zhao Zhongnan

    2011-01-01

    Experiments of visualized two-phase upward flow were conducted in the packed channel, which filled with 3, 5, 8 mm in diameter of glass sphere respectively. The gas superficial velocity ranges from 0.005 to 1.172 m/s. The liquid superficial velocity ranges from 0.004 to 0.093 m/s. Four representative flow patterns were observed as bubbly flow, cluster flow, liquid-pulse flow and churn-pulse flow, and corresponding flow pattern maps were also presented. It is found that the pulse flow region is dominant. The comparisons of flow pattern map between packed channel and non-packed channel show that the bubbly flow region in packed channel is narrower than that of non-packed channel due to the packing. The comparisons of flow pattern maps for three different packing sizes show that the cluster flow region expands with the increase of the packing diameter. In the low liquid superficial velocity, the cluster flow directly changes to churn-pulse flow in the packed channel with 8 mm packing. (authors)

  14. Interfacial area transport of vertical upward air-water two-phase flow in an annulus at elevated pressures

    International Nuclear Information System (INIS)

    Ozar, Basar; Hibiki, Takashi; Ishii, Mamoru; Euh, Dong-Jin

    2009-01-01

    The interfacial area transport of vertical, upward, air-water two-phase flows in an annular channel has been investigated at different system pressures. The inner and outer diameters of the annular channel were 19.1 mm and 38.1 mm, respectively. Twenty three inlet flow conditions were selected, which coverED bubbly, cap-slug, and churn-turbulent flows. These flow conditions also overlapped with twelve conditions of our previous study for comparison. The local flow parameters, such as void fractions, interfacial area concentrations (IAC), and bubble interface velocities, were measured at nine radial positions for the three axial locations (z/D h =52, 149 and 230) and converted into area-averaged parameters. The axial evolutions of local flow structure was interpreted in terms of bubble coalescence, breakup, expansion of the gas-phase due to pressure drop and system pressure. An assessment of interfacial area transport equation (IATE) was made and compared with the experimental data. A discussion of the comparison between model prediction and the experimental results were made. (author)

  15. Churn-annular flow pattern transition in a vertical upward gas-liquid two-phase flow in various conduits

    International Nuclear Information System (INIS)

    Takenaka, Nobuyuki; Ueda, Tadanobu; Asano, Hitoshi

    2008-01-01

    Void fraction was measured by neutron radiography for a vertical upward gas-water two-phase flow in a concentric annular tube with and with out a spacer, 4x4 rod bundle with and without a spacer and a tight rod bundle with and without a wrapping wire for various gas and liquid flow rates. The flow patterns of these two-phase flows were determined by the Mishima-Ishii flow pattern map and void fraction was calculated by the Ishii's drift flux model. The predicted values were compared with the experimental results. The void fraction was well predicted by the Mishima-Ishii flow pattern map and the Ishii's drift flux model except the annular flow region with void fraction lower than 0.8 for conduits with small equivalent diameter. A new churn-annular flow pattern transition condition of the void fraction equal to 0.8 was added. The void fraction for the present experimental condition was successful predicted with the new transition model. (author)

  16. Dryout-type critical heat flux in vertical upward annular flow: effects of entrainment rate, initial entrained fraction and diameter

    Science.gov (United States)

    Wu, Zan; Wadekar, Vishwas; Wang, Chenglong; Sunden, Bengt

    2018-01-01

    This study aims to reveal the effects of liquid entrainment, initial entrained fraction and tube diameter on liquid film dryout in vertical upward annular flow for flow boiling. Entrainment and deposition rates of droplets were included in mass conservation equations to estimate the local liquid film mass flux in annular flow, and the critical vapor quality at dryout conditions. Different entrainment rate correlations were evaluated using flow boiling data of water and organic liquids including n-pentane, iso-octane and R134a. Effect of the initial entrained fraction (IEF) at the churn-to-annular flow transition was also investigated. A transitional Boiling number was proposed to separate the IEF-sensitive region at high Boiling numbers and the IEF-insensitive region at low Boiling numbers. Besides, the diameter effect on dryout vapor quality was studied. The dryout vapor quality increases with decreasing tube diameter. It needs to be pointed out that the dryout characteristics of submillimeter channels might be different because of different mechanisms of dryout, i.e., drying of liquid film underneath long vapor slugs and flow boiling instabilities.

  17. Study of void fraction and mixing of immiscible liquids in a pool configuration by an upward gas flow

    International Nuclear Information System (INIS)

    Casas, J.C.; Corradini, M.L.

    1992-01-01

    In this paper, investigations are performed to study the mixing between immiscible liquids in a pool configuration due to an upward gas flow. A water-R113 system is sued in the bubbly/churn-turbulent regimes to determine the effects of the unagitated pool depth on layer mixing. The superficial gas velocity at which full mixing is attained is observed to increase with the pool depth, although it is concluded that this is a weak dependency. Mixing in the churn-turbulent regime is studied with Wood's metal-water and Wood's metal-silicone fluid (100 cS) as pairs of fluids. Additional past mixing data from six other fluids are also included in the data base. A criterion is proposed to determine if two liquids will entrain in bubbly or churn-turbulent flow. Correlations are derived that, for a set of given conditions, allow prediction of the mixing state (mixed or segregated) of a system. Because of the indirect method of measuring the mixed layer thickness, pool void fraction experiments are also performed. For the case of water and R113, the effect of unagitated pool depth on the void fraction is studied

  18. Observations and Modeling of Thermal Structure in the Lower Atmosphere and the Upward Propagation of Tides into the Thermosphere

    Science.gov (United States)

    Wilson, R. J.; Kahre, M.

    2017-01-01

    Thermal tides are the atmospheric response to diurnally varying thermal forcing resulting from radiative and convective heat transfer from the surface and from aerosol and gaseous heating within the atmosphere. Tides include sun-synchronous (migrating) waves driven in response to solar heating and additional non-migrating waves resulting from longitudinal variations in the distributions of topography, dust aerosol and water ice clouds. The systematic spatial mapping of temperature over 5 Mars years by the Mars Climate Sounder (MCS) has yielded a well-defined climatology of seasonally-varying temperature structures in the lower atmosphere, from 5 to 80 km. Tide theory and Mars global circulation model (MGCM) simulations are a fruitful framework for relating temperature observations to thermal forcing by aerosol fields [1]. The analysis of density and temperature fields derived from MAVEN IUVS and NGIMS observations have revealed the presence of predominantly zonal wave 2 and 3 features at altitudes of 100-170 km that are almost certainly non-migrating tides propagating upward from the lower atmosphere [2,3]. In this presentation we will use the MCS climatology and MGCM simulations to relate the density variations seen by MAVEN with the seasonally varying tide activity in the lower atmosphere. Large amplitude perturbations in density are most sensitive to the tide components with the longest vertical wavelengths in temperature, which are well resolved in MCS observations.

  19. Opportunities for making ends meet and upward mobility: differences in organizational deprivation across urban and suburban poor neighborhoods.

    Science.gov (United States)

    Murphy, Alexandra K; Wallace, Danielle

    2010-01-01

    Objectives. Given the recent rise of poverty in U.S. suburbs, this study asks: What poor neighborhoods are most disadvantageous, those in the city or those in the suburbs? Building on recent urban sociological work demonstrating the importance of neighborhood organizations for the poor, we are concerned with one aspect of disadvantage—the lack of availability of organizational resources oriented toward the poor. By breaking down organizations into those that promote mobility versus those that help individuals meet their daily subsistence needs, we seek to explore potential variations in the type of disadvantage that may exist.Methods. We test whether poor urban or suburban neighborhoods are more likely to be organizationally deprived by breaking down organizations into three types: hardship organizations, educational organizations, and employment organizations. We use data from the 2000 U.S. County Business Patterns and the 2000 U.S. Census and test neighborhood deprivation using logistic regression models.Results. We find that suburban poor neighborhoods are more likely to be organizationally deprived than are urban poor neighborhoods, especially with respect to organizations that promote upward mobility. Interesting racial and ethnic composition factors shape this more general finding.Conclusion. Our findings suggest that if a poor individual is to live in a poor neighborhood, with respect to access to organizational resources, he or she would be better off living in the central city. Suburban residence engenders isolation from organizations that will help meet one's daily needs and even more so from those offering opportunities for mobility.

  20. Moving inwards, moving outwards, moving upwards: the role of spirituality during the early stages of breast cancer.

    Science.gov (United States)

    Swinton, J; Bain, V; Ingram, S; Heys, S D

    2011-09-01

    The paper reflects on a study which explored the role of spirituality in the lives of women during the first year after being diagnosed with breast cancer. The study utilised a qualitative method (hermeneutic phenomenology) designed to provide rich and thick understanding of women's experiences of breast cancer and to explore possible ways in which spirituality may, or may not, be beneficial in enabling coping and enhancing quality of life. The paper draws on the thinking of David Hay and Viktor Frankl to develop a model of spirituality that includes, but is not defined by, religion and that has the possibility to facilitate effective empirical enquiry. It outlines a threefold movement - inwards, outwards and upwards - that emerged from in-depth interviews with women who have breast cancer. This framework captures something of the spiritual movement that women went through on their cancer journeys and offers some pointers and possibilities for better and more person-centred caring approaches that include recognition of the spiritual dimension of women's experiences for the management of those with breast cancer. © 2011 Blackwell Publishing Ltd.

  1. Mud extrusion and ring-fault gas seepage - upward branching fluid discharge at a deep-sea mud volcano.

    Science.gov (United States)

    Loher, M; Pape, T; Marcon, Y; Römer, M; Wintersteller, P; Praeg, D; Torres, M; Sahling, H; Bohrmann, G

    2018-04-19

    Submarine mud volcanoes release sediments and gas-rich fluids at the seafloor via deeply-rooted plumbing systems that remain poorly understood. Here the functioning of Venere mud volcano, on the Calabrian accretionary prism in ~1,600 m water depth is investigated, based on multi-parameter hydroacoustic and visual seafloor data obtained using ship-borne methods, ROVs, and AUVs. Two seepage domains are recognized: mud breccia extrusion from a summit, and hydrocarbon venting from peripheral sites, hosting chemosynthetic ecosystems and authigenic carbonates indicative of long-term seepage. Pore fluids in freshly extruded mud breccia (up to 13 °C warmer than background sediments) contained methane concentrations exceeding saturation by 2.7 times and chloride concentrations up to five times lower than ambient seawater. Gas analyses indicate an underlying thermogenic hydrocarbon source with potential admixture of microbial methane during migration along ring faults to the peripheral sites. The gas and pore water analyses point to fluids sourced deep (>3 km) below Venere mud volcano. An upward-branching plumbing system is proposed to account for co-existing mud breccia extrusion and gas seepage via multiple surface vents that influence the distribution of seafloor ecosystems. This model of mud volcanism implies that methane-rich fluids may be released during prolonged phases of moderate activity.

  2. CFD modelling and validation of upward bubbly flow in an adiabatic vertical pipe using the quadrature method of moments

    International Nuclear Information System (INIS)

    Peña-Monferrer, C.; Passalacqua, A.; Chiva, S.; Muñoz-Cobo, J.L.

    2016-01-01

    Highlights: • A population balance equation solved with QMOM approximation is implemented in OpenFOAM. • Available models for interfacial forces and bubble induced turbulence are analyzed. • A vertical pipe flow is simulated for different bubbly flow conditions. • Two-phase flow characteristics in vertical pipes are properly predicted. - Abstract: An Eulerian–Eulerian approach was investigated to model adiabatic bubbly flow with CFD techniques. In the framework of the OpenFOAM"® software, a two-fluid model solver was modified to include a population balance equation, solved with the quadrature method of moments approximation to predict upward bubbly flow in vertical pipes considering the polydisperse nature of two-phase flow. Some progress have been made recently solving population balance equations in OpenFOAM"® and this research aims to extend its application to the case of vertical pipes under different conditions of liquid and gas velocities. In order to test the solver for nuclear applications, interfacial forces and bubble induced turbulence models were included to provide to this solver the capability to correctly predict the behavior of the continuous and disperse phases. Two-phase flow experiments with different superficial velocities of gas and liquid are used to validate the model and its implementation. Radial profiles of void fraction, gas and liquid velocities, Sauter mean diameter and turbulence intensity are compared to the computational results. These results are in satisfactory agreement with the experiments, showing the capability of the solver to predict two-phase flow characteristics.

  3. Shifting schedules: the health effects of reorganizing shift work.

    Science.gov (United States)

    Bambra, Clare L; Whitehead, Margaret M; Sowden, Amanda J; Akers, Joanne; Petticrew, Mark P

    2008-05-01

    Approximately one fifth of workers are engaged in some kind of shift work. The harmful effects of shift work on the health and work-life balance of employees are well known. A range of organizational interventions has been suggested to address these negative effects. This study undertook the systematic review (following Quality Of Reporting Of Meta [QUORUM] analyses guidelines) of experimental and quasi-experimental studies, from any country (in any language) that evaluated the effects on health and work-life balance of organizational-level interventions that redesign shift work schedules. Twenty-seven electronic databases (medical, social science, economic) were searched. Data extraction and quality appraisal were carried out by two independent reviewers. Narrative synthesis was performed. The review was conducted between October 2005 and November 2006. Twenty-six studies were found relating to a variety of organizational interventions. No one type of intervention was found to be consistently harmful to workers. However, three types were found to have beneficial effects on health and work-life balance: (1) switching from slow to fast rotation, (2) changing from backward to forward rotation, and (3) self-scheduling of shifts. Improvements were usually at little or no direct organizational cost. However, there were concerns about the generalizability of the evidence, and no studies reported on impacts on health inequalities. This review reinforces the findings of epidemiologic and laboratory-based research by suggesting that certain organizational-level interventions can improve the health of shift workers, their work-life balance, or both. This evidence could be useful when designing interventions to improve the experience of shift work.

  4. The Effect of Shift Work on Urogenital Disease: a Systematic Review.

    Science.gov (United States)

    Deng, Nanfu; Haney, Nora M; Kohn, Taylor P; Pastuszak, Alexander W; Lipshultz, Larry I

    2018-05-28

    Non-standard shift work schedules negatively impact the overall health of shift workers, and several studies have shown that shift work, specifically, is detrimental to urogenital health. The aims of this study are to systematically review the literature and determine the effect of shift work on the outcomes of hypogonadism, male infertility, lower urinary tract symptoms, and urogenital cancers. Recent evidence supports associations between non-standard shift work and an increase in the frequency of prostate cancer and the severity of erectile dysfunction, lower urinary tract symptoms, and hypogonadal symptoms, as well as worsening of semen parameters and fertility. These associations are strengthened by the presence of shift work sleep disorder (SWSD) which affects up to 20% of shift workers. No studies have assessed the impact of shift work on the frequency or severity of nephrolithiasis, interstitial cystitis, pelvic pain, prostatitis, or urinary tract infections. Non-standard shift work has been associated with a variety of negative health outcomes and urologic complications, especially with concurrent shift work sleep disorder. Recognition of these elevated risks among shift workers can aid in more effective screening for urologic conditions.

  5. SAT in shift manager training

    International Nuclear Information System (INIS)

    Lecuyer, F.

    1995-01-01

    EDF has improved the organization of the operation shift teams with the replacement of shift supervisor in shift manager function. The shift manager is not only responsible for tasks associated to plant operation (production), but he is also responsible for safety of these tasks and for management of shift team members. A job analysis of this new job position has been performed in order to design the training programme. It resulted in a 10-month training programme that includes 8 weeks in safety-related topics and 12 weeks in soft-skills related topics. The safety related training courses are mandatory, the other courses are optional courses depending on individual trainee needs. The training also includes the development of management competencies. During the 10 month period, each trainee develops an individual project that is evaluated by NPP manager. As well, as group project is undertaken by the trainees and overseen by a steering committee. The steering committee participates in the evaluation process and provides operational experience feedback to the trainee groups and to the overall programme

  6. Masking release with changing fundamental frequency: Electric acoustic stimulation resembles normal hearing subjects.

    Science.gov (United States)

    Auinger, Alice Barbara; Riss, Dominik; Liepins, Rudolfs; Rader, Tobias; Keck, Tilman; Keintzel, Thomas; Kaider, Alexandra; Baumgartner, Wolf-Dieter; Gstoettner, Wolfgang; Arnoldner, Christoph

    2017-07-01

    It has been shown that patients with electric acoustic stimulation (EAS) perform better in noisy environments than patients with a cochlear implant (CI). One reason for this could be the preserved access to acoustic low-frequency cues including the fundamental frequency (F0). Therefore, our primary aim was to investigate whether users of EAS experience a release from masking with increasing F0 difference between target talker and masking talker. The study comprised 29 patients and consisted of three groups of subjects: EAS users, CI users and normal-hearing listeners (NH). All CI and EAS users were implanted with a MED-EL cochlear implant and had at least 12 months of experience with the implant. Speech perception was assessed with the Oldenburg sentence test (OlSa) using one sentence from the test corpus as speech masker. The F0 in this masking sentence was shifted upwards by 4, 8, or 12 semitones. For each of these masker conditions the speech reception threshold (SRT) was assessed by adaptively varying the masker level while presenting the target sentences at a fixed level. A statistically significant improvement in speech perception was found for increasing difference in F0 between target sentence and masker sentence in EAS users (p = 0.038) and in NH listeners (p = 0.003). In CI users (classic CI or EAS users with electrical stimulation only) speech perception was independent from differences in F0 between target and masker. A release from masking with increasing difference in F0 between target and masking speech was only observed in listeners and configurations in which the low-frequency region was presented acoustically. Thus, the speech information contained in the low frequencies seems to be crucial for allowing listeners to separate multiple sources. By combining acoustic and electric information, EAS users even manage tasks as complicated as segregating the audio streams from multiple talkers. Preserving the natural code, like fine-structure cues in

  7. On the physical origin of blue-shifted hydrogen bonds.

    Science.gov (United States)

    Li, Xiaosong; Liu, Lei; Schlegel, H Bernhard

    2002-08-14

    For blue-shifted hydrogen-bonded systems, the hydrogen stretching frequency increases rather than decreases on complexation. In computations at various levels of theory, the blue-shift in the archetypical system, F(3)C-H.FH, is reproduced at the Hartree-Fock level, indicating that electron correlation is not the primary cause. Calculations also demonstrate that a blue-shift does not require either a carbon center or the absence of a lone pair on the proton donor, because F(3)Si-H.OH(2), F(2)NH.FH, F(2)PH.NH(3), and F(2)PH.OH(2) have substantial blue-shifts. Orbital interactions are shown to lengthen the X-H bond and lower its vibrational frequency, and thus cannot be the source of the blue-shift. In the F(3)CH.FH system, the charge redistribution in F(3)CH can be reproduced very well by replacing the FH with a simple dipole, which suggests that the interactions are predominantly electrostatic. When modeled with a point charge for the proton acceptor, attractive electrostatic interactions elongate the F(3)C-H, while repulsive interactions shorten it. At the equilibrium geometry of a hydrogen-bonded complex, the electrostatic attraction between the dipole moments of the proton donor and proton acceptor must be balanced by the Pauli repulsion between the two fragments. In the absence of orbital interactions that cause bond elongation, this repulsive interaction leads to compression of the X-H bond and a blue-shift in its vibrational frequency.

  8. Heat transfer to sub- and supercritical water flowing upward in a vertical tube at low mass fluxes: numerical analysis and experimental validation

    NARCIS (Netherlands)

    Odu, Samuel Obarinu; Koster, P.; van der Ham, Aloysius G.J.; van der Hoef, Martin Anton; Kersten, Sascha R.A.

    2016-01-01

    Heat transfer to supercritical water (SCW) flowing upward in a vertical heated tube at low mass fluxes (G ≤ 20 kg/m2 s) has been numerically investigated in COMSOL Multiphysics and validated with experimental data. The turbulence models, essential to describing local turbulence, in COMSOL have been

  9. The multiplier effect : how the accumulation of cultural and social capital explains steep upward social mobility of children of low-educated immigrants

    NARCIS (Netherlands)

    Crul, Maurice; Schneider, Jens; Keskiner, Elif; Lelie, Frans

    2017-01-01

    We introduce what we have coined the multiplier effect. We explain the steep upward mobility of children of low-educated immigrants by studying how they overcome obstacles on their regular pathway, via alternative routes or through loopholes in the education and labour market system. The idea of the

  10. Does the ARFIMA really shift?

    DEFF Research Database (Denmark)

    Monache, Davide Delle; Grassi, Stefano; Santucci de Magistris, Paolo

    Short memory models contaminated by level shifts have long-memory features similar to those associated to processes generated under fractional integration. In this paper, we propose a robust testing procedure, based on an encompassing parametric specification, that allows to disentangle the level...... the highest power compared to other existing tests for spurious long-memory. Finally, we illustrate the usefulness of the proposed approach on the daily series of bipower variation and share turnover and on the monthly inflation series of G7 countries....... shift term from the ARFIMA component. The estimation is carried out via a state-space methodology and it leads to a robust estimate of the fractional integration parameter also in presence of level shifts.The Monte Carlo simulations show that this approach produces unbiased estimates of the fractional...

  11. Green binary and phase shifting mask

    Science.gov (United States)

    Shy, S. L.; Hong, Chao-Sin; Wu, Cheng-San; Chen, S. J.; Wu, Hung-Yu; Ting, Yung-Chiang

    2009-12-01

    SixNy/Ni thin film green mask blanks were developed , and are now going to be used to replace general chromium film used for binary mask as well as to replace molydium silicide embedded material for AttPSM for I-line (365 nm), KrF (248 nm), ArF (193 nm) and Contact/Proximity lithography. A bilayer structure of a 1 nm thick opaque, conductive nickel layer and a SixNy layer is proposed for binary and phase-shifting mask. With the good controlling of plasma CVD of SixNy under silane (50 sccm), ammonia (5 sccm) and nitrogen (100 sccm), the pressure is 250 mTorr. and RF frequency 13.56 MHz and power 50 W. SixNy has enough deposition latitude to meet the requirements as an embedded layer for required phase shift 180 degree, and the T% in 193, 248 and 365 nm can be adjusted between 2% to 20% for binary and phase shifting mask usage. Ni can be deposited by E-gun, its sheet resistance Rs is less than 1.435 kΩ/square. Jeol e-beam system and I-line stepper are used to evaluate these thin film green mask blanks, feature size less than 200 nm half pitch pattern and 0.558 μm pitch contact hole can be printed. Transmission spectrums of various thickness of SixNy film are inspected by using UV spectrometer and FTIR. Optical constants of the SixNy film are measured by n & k meter and surface roughness is inspected by using Atomic Force Microscope (AFM).

  12. Paradigm Shifts in Ophthalmic Diagnostics.

    Science.gov (United States)

    Sebag, J; Sadun, Alfredo A; Pierce, Eric A

    2016-08-01

    Future advances in ophthalmology will see a paradigm shift in diagnostics from a focus on dysfunction and disease to better measures of psychophysical function and health. Practical methods to define genotypes will be increasingly important and non-invasive nanotechnologies are needed to detect molecular changes that predate histopathology. This is not a review nor meant to be comprehensive. Specific topics have been selected to illustrate the principles of important paradigm shifts that will influence the future of ophthalmic diagnostics. It is our impression that future evaluation of vision will go beyond visual acuity to assess ocular health in terms of psychophysical function. The definition of disease will incorporate genotype into what has historically been a phenotype-centric discipline. Non-invasive nanotechnologies will enable a paradigm shift from disease detection on a cellular level to a sub-cellular molecular level. Vision can be evaluated beyond visual acuity by measuring contrast sensitivity, color vision, and macular function, as these provide better insights into the impact of aging and disease. Distortions can be quantified and the psychophysical basis of vision can be better evaluated than in the past by designing tests that assess particular macular cell function(s). Advances in our understanding of the genetic basis of eye diseases will enable better characterization of ocular health and disease. Non-invasive nanotechnologies can assess molecular changes in the lens, vitreous, and macula that predate visible pathology. Oxygen metabolism and circulatory physiology are measurable indices of ocular health that can detect variations of physiology and early disease. This overview of paradigm shifts in ophthalmology suggests that the future will see significant improvements in ophthalmic diagnostics. The selected topics illustrate the principles of these paradigm shifts and should serve as a guide to further research and development. Indeed

  13. Interplay between spontaneous decay rates and Lamb shifts in open photonic systems

    Science.gov (United States)

    Lassalle, Emmanuel; Bonod, Nicolas; Durt, Thomas; Stout, Brian

    2018-05-01

    In this letter, we describe the modified decay rate and photonic Lamb (frequency) shift of quantum emitters in terms of the resonant states of a neighboring photonic resonator. This description illustrates a fundamental distinction in the behaviors of closed (conservative) and open (dissipative) systems: the Lamb shift is bounded by the emission linewidth in closed systems while it overcomes this limit in open systems.

  14. Morphisms Between Sofic Shift Spaces

    DEFF Research Database (Denmark)

    Nielsen, Jan Agentoft

    The lower entropy factor problem asks for necessary and sufficient conditions for the existence of a factor map from a (mixing) sofic shift space onto another (mixing) sofic subshift of lower entropy. The problem was posed by Mike Boyle in 1984. It remains an open problem, but the present thesis...... gives a re-formulation which can be used to effectively decide the question for a larger class of sofic shifts than all previous results. In addition, the methods are used to make progress on the corresponding embedding problem which asks for necessary and sufficient conditions for the existence...

  15. Shift-Variant Multidimensional Systems.

    Science.gov (United States)

    1985-05-29

    x,y;u,v) is the system response at (x,y) to an unit impulse applied at (u,v). The presence of additive noise in the preceding input-output model of a...space model developed works very effi- ciently to deblur images affected by 2-D linear shift- varying blurs, its use, in presence of noise needs to be...causal linear shift-variant (LSV) system, whose impulse res- ponse is a K-th order degenerate sequence, a K-th order state-space model was obtained

  16. Explaining (Missing) Regulator Paradigm Shifts

    DEFF Research Database (Denmark)

    Wigger, Angela; Buch-Hansen, Hubert

    2014-01-01

    The global financial and economic crisis has prompted some scholars to suggest that a fundamental regulatory shift away from neoliberalism will take place – both in general and in the field of EU competition regulation. This paper shows that so far no radical break with the neoliberal type...... regulation after the crisis in the 1970s, the paper argues that the preconditions for a fundamental shift in this issue area are not present this time around. Several reasons account for this: the current crisis has been construed by economic and political elites as a crisis within and not of neoliberal...

  17. Anxiety about starting three-shift work among female workers: findings from the Female Shift Workers' Health Study.

    Science.gov (United States)

    Kubo, Tatsuhiko; Maruyama, Takashi; Shirane, Kiyoyumi; Otomo, Hajime; Matsumoto, Tetsuro; Oyama, Ichiro

    2008-03-01

    In 1999, the Japanese Law on Equal Employment Opportunity and Conditions was amended and the previous prohibition of the assignment of female workers to night work was abolished. Subsequently, the number of female shift workers has been increasing in Japan, necessitating greater attention to the health care of this population. The aim of the current study is to evaluate the relationship between anxiety expressed about starting three-shift work and background characteristics among female workers who were being assigned to three-shift work for the first time. The subjects were 38 middle-aged female workers (age range: 44 to 59 years) who were working at a chemical plant. The women completed a self-administered questionnaire before starting three-shift work. Levels of anxiety about starting three-shift work were assessed by the question 'Do you feel anxious about starting three-shift work?' The available responses were: 'Very agree', 'Considerably agree', 'Rather agree', 'Slightly agree' and 'Not agree at all', and 63% of the subjects gave one of the first two answers, which were defined as indicating anxiety. We also acquired information regarding lifestyle and occupation for each subject, including the following factors: frequency of breakfast consumption, subjective sleep insufficiency, previous experience of similar work before beginning shift work, previous experience of two-shift work, and responsibility for household duties. In the study, we found a marginally statistically significant trend association between frequent breakfast consumption and anxiety about starting three-shift work (P(trend) = 0.09). Anxiety was also high among subjects with sleep disorders, especially those suffering from subjective sleep insufficiency (P = 0.08). Due to the small study population, these results should be interpreted with caution and confirmed by future studies.

  18. PEAK SHIFTS PRODUCED BY CORRELATED RESPONSE TO SELECTION.

    Science.gov (United States)

    Price, Trevor; Turelli, Michael; Slatkin, Montgomery

    1993-02-01

    Traits may evolve both as a consequence of direct selection and also as a correlated response to selection on other traits. While correlated response may be important for both the production of evolutionary novelty and in the build-up of complex characters, its potential role in peak shifts has been neglected empirically and theoretically. We use a quantitative genetic model to investigate the conditions under which a character, Y, which has two alternative optima, can be dragged from one optimum to the other as a correlated response to selection on a second character, X. High genetic correlations between the two characters make the transition, or peak shift, easier, as does weak selection tending to restore Y to the optimum from which it is being dragged. When selection on Y is very weak, the conditions for a peak shift depend only on the location of the new optimum for X and are independent of the strength of selection moving it there. Thus, if the "adaptive valley" for Y is very shallow, little reduction in mean fitness is needed to produce a shift. If the selection acts strongly to keep Y at its current optimum, very intense directional selection on X, associated with a dramatic drop in mean fitness, is required for a peak shift. When strong selection is required, the conditions for peak shifts driven by correlated response might occur rarely, but still with sufficient frequency on a geological timescale to be evolutionarily important. © 1993 The Society for the Study of Evolution.

  19. Prediction of the critical heat flux for saturated upward flow boiling water in vertical narrow rectangular channels

    International Nuclear Information System (INIS)

    Choi, Gil Sik; Chang, Soon Heung; Jeong, Yong Hoon

    2016-01-01

    A study, on the theoretical method to predict the critical heat flux (CHF) of saturated upward flow boiling water in vertical narrow rectangular channels, has been conducted. For the assessment of this CHF prediction method, 608 experimental data were selected from the previous researches, in which the heated sections were uniformly heated from both wide surfaces under the high pressure condition over 41 bar. For this purpose, representative previous liquid film dryout (LFD) models for circular channels were reviewed by using 6058 points from the KAIST CHF data bank. This shows that it is reasonable to define the initial condition of quality and entrainment fraction at onset of annular flow (OAF) as the transition to annular flow regime and the equilibrium value, respectively, and the prediction error of the LFD model is dependent on the accuracy of the constitutive equations of droplet deposition and entrainment. In the modified Levy model, the CHF data are predicted with standard deviation (SD) of 14.0% and root mean square error (RMSE) of 14.1%. Meanwhile, in the present LFD model, which is based on the constitutive equations developed by Okawa et al., the entire data are calculated with SD of 17.1% and RMSE of 17.3%. Because of its qualitative prediction trend and universal calculation convergence, the present model was finally selected as the best LFD model to predict the CHF for narrow rectangular channels. For the assessment of the present LFD model for narrow rectangular channels, effective 284 data were selected. By using the present LFD model, these data are predicted with RMSE of 22.9% with the dryout criterion of zero-liquid film flow, but RMSE of 18.7% with rivulet formation model. This shows that the prediction error of the present LFD model for narrow rectangular channels is similar with that for circular channels.

  20. Void fraction and interfacial velocity in gas-liquid upward two-phase flow across tube bundles

    International Nuclear Information System (INIS)

    Ueno, T.; Tomomatsu, K.; Takamatsu, H.; Nishikawa, H.

    1997-01-01

    Tube failures due to flow-induced vibration are a major problem in heat exchangers and many studies on the problem of such vibration have been carried out so far. Most studies however, have not focused on two-phase flow behavior in tube bundles, but have concentrated mainly on tube vibration behavior like fluid damping, fluid elastic instability and so on. Such studies are not satisfactory for understanding the design of heat exchangers. Tube vibration behavior is very complicated, especially in the case of gas-liquid two-phase flow, so it is necessary to investigate two-phase flow behavior as well as vibration behavior before designing heat exchangers. This paper outlines the main parameters that characterize two-phase behavior, such as void fraction and interfacial velocity. The two-phase flow analyzed here is gas-liquid upward flow across a horizontal tube bundle. The fluids tested were HCFC-123 and steam-water. HCFC-123 stands for Hydrochlorofluorocarbon. Its chemical formula is CHCl 2 CF 3 , which has liquid and gas densities of 1335 and 23.9 kg/m 3 at a pressure of 0.40 MPa and 1252 and 45.7 kg/m 3 at a pressure of 0.76 MPa. The same model tube bundle was used in the two tests covered in this paper, to examine the similarity law of two-phase flow behavior in tube bundles using HCFC-123 and steam-water two-phase flow. We also show numerical simulation results for the two fluid models in this paper. We do not deal with vibration behavior and the relationship between vibration behavior and two-phase flow behavior. (author)

  1. Electrical Resistivity Tomography Reveals Upward Redistribution of Soil-Water by Coyote Brush in a Shrub-Grassland Ecotone

    Science.gov (United States)

    Manning, J. E.; Schulz, M. S.; Lambrecht, D. S.

    2016-12-01

    Species imbalance within many California plant assemblages may arise due to more intense wildfires as well as climate warming. Given this, coyote brush (Baccharis pilularis DC), a native evergreen shrub known as a ready colonizer of disturbed soil, may become more dominant. While prolonged spring soil moisture is required for seedling establishment, 1+ year-old coyote brush can withstand low soil water potentials (-1.2 MPa). Beyond this, little is known about its soil-water dynamics. Hydraulic redistribution of water within the soil profile by plant roots has been established in numerous species in the past 20 years. Recent quantification of the water quantity re-distributed by root systems are beginning to provide detail that could inform ET, weathering, and carbon cycling models. Electrical resistivity tomography (ERT) has been used to study soil hydraulics in natural as well as cropland settings. This study is the first known to use ERT to investigate hydraulic redistribution in coyote brush. One mid-size shrub surrounded by open grassland was selected at the study site, located on a coastal marine terrace west of Santa Cruz, CA. The soil profile, previously characterized with ERT and auger-based soil-water sampling, includes a clay-rich B horizon and is texturally non-uniform due to bioturbation to 0.6 meter. The 12-m ERT survey transect had 48 semi-permanent electrodes, with the 4-m wide shrub canopy at probes 16 to 32. Five repeats of evening and morning surveys were conducted. Heterogeneous texture and severe soil drying necessitated qualitative comparison across time. Overnight resistivity changes using differences plots of the modelled data revealed increased moisture beneath the shrub canopy during the night. Areas beyond the canopy—presumably outside the root zone—experienced variable overnight changes, with moisture increasing in the clay-rich horizon. Preliminary analysis suggests that coyote brush roots redistribute water upward within the soil

  2. Numerical investigation of heat transfer in upward flows of supercritical water in circular tubes and tight fuel rod bundles

    International Nuclear Information System (INIS)

    Yang Jue; Oka, Yoshiaki; Ishiwatari, Yuki; Liu Jie; Yoo, Jaewoon

    2007-01-01

    Heat transfer in upward flows of supercritical water in circular tubes and in tight fuel rod bundles is numerically investigated by using the commercial CFD code STAR-CD 3.24. The objective is to have more understandings about the phenomena happening in supercritical water and for designs of supercritical water cooled reactors. Some turbulence models are selected to carry out numerical simulations and the results are compared with experimental data and other correlations to find suitable models to predict heat transfer in supercritical water. The comparisons are not only in the low bulk temperature region, but also in the high bulk temperature region. The two-layer model (Hassid and Poreh) gives a better prediction to the heat transfer than other models, and the standard k-ε high Re model with the standard wall function also shows an acceptable predicting capability. Three-dimensional simulations are carried out in sub-channels of tight square lattice and triangular lattice fuel rod bundles at supercritical pressure. Results show that there is a strong non-uniformity of the circumferential distribution of the cladding surface temperature, in the square lattice bundle with a small pitch-to-diameter ratio (P/D). However, it does not occur in the triangular lattice bundle with a small P/D. It is found that this phenomenon is caused by the large non-uniformity of the flow area in the cross-section of sub-channels. Some improved designs are numerically studied and proved to be effective to avoid the large circumferential temperature gradient at the cladding surface

  3. CFD modelling and validation of upward bubbly flow in an adiabatic vertical pipe using the quadrature method of moments

    Energy Technology Data Exchange (ETDEWEB)

    Peña-Monferrer, C., E-mail: cmonfer@upv.es [Institute for Energy Engineering, Universitat Politècnica de València, 46022 València (Spain); Passalacqua, A., E-mail: albertop@iastate.edu [Department of Mechanical Engineering, Iowa State University, Ames, IA 50011 (United States); Chiva, S., E-mail: schiva@emc.uji.es [Department of Mechanical Engineering and Construction, Universitat Jaume I, 12080 Castelló de la Plana (Spain); Muñoz-Cobo, J.L., E-mail: jlcobos@iqn.upv.es [Institute for Energy Engineering, Universitat Politècnica de València, 46022 València (Spain)

    2016-05-15

    Highlights: • A population balance equation solved with QMOM approximation is implemented in OpenFOAM. • Available models for interfacial forces and bubble induced turbulence are analyzed. • A vertical pipe flow is simulated for different bubbly flow conditions. • Two-phase flow characteristics in vertical pipes are properly predicted. - Abstract: An Eulerian–Eulerian approach was investigated to model adiabatic bubbly flow with CFD techniques. In the framework of the OpenFOAM{sup ®} software, a two-fluid model solver was modified to include a population balance equation, solved with the quadrature method of moments approximation to predict upward bubbly flow in vertical pipes considering the polydisperse nature of two-phase flow. Some progress have been made recently solving population balance equations in OpenFOAM{sup ®} and this research aims to extend its application to the case of vertical pipes under different conditions of liquid and gas velocities. In order to test the solver for nuclear applications, interfacial forces and bubble induced turbulence models were included to provide to this solver the capability to correctly predict the behavior of the continuous and disperse phases. Two-phase flow experiments with different superficial velocities of gas and liquid are used to validate the model and its implementation. Radial profiles of void fraction, gas and liquid velocities, Sauter mean diameter and turbulence intensity are compared to the computational results. These results are in satisfactory agreement with the experiments, showing the capability of the solver to predict two-phase flow characteristics.

  4. Earthtech, Dig-Texas and Upward Bound: Outreach to At-Risk Students with Interdisciplinary STEM Activities

    Science.gov (United States)

    Olgin, J. G.; Güereque, M.; Pennington, D. D.; Everett, A.; Dixon, J. G.; Reyes, A.; Houser, P. I. Q.; Baker, J. A.; Stocks, E.; Ellins, K.

    2015-12-01

    The Geological Sciences department at the University of Texas at El Paso (UTEP) hosted the EarthTech outreach program - a one-week intensive summer camp for low-income, at-risk high school students. The EarthTech program engaged students in STEM activities from geological and environmental sciences. Developed and led by university student-mentors with guidance from a supervising faculty member, the course engaged Upward Bound students with lectures, interactive projects, and excursions to local ecological preserves and geological sites around El Paso, Texas. Topics covered plant and animal distribution and diversity, water and soil dynamics, evolution and paleontology, geohazards, and planetary science. Field trips were combined with hands-on activities, including activities from DIG Texas teaching modules. The NSF-funded DIG Texas Instructional Blueprints project is organizing vetted, high quality online educational resources and learning activities into teaching modules. The modules follow a storyline and demonstrate congruency with the Next Generation Science Standards. Selected DIG Texas resources were included in the daily curriculum to complement the field trip and other hands-on activities. EarthTech students created ESRI Online GIS story maps in which they showed the locations of the field trips, incorporated photographs they had taken, and provided written reflections about their camp experiences. The DIG Texas project evaluation collected survey and interview data from the university student mentors throughout the week to ascertain the efficacy of the program. This poster presentation will include an overview of the program, including examples of work and evaluation results.

  5. Leadership Shifts in Changing Field

    Science.gov (United States)

    Zubrzycki, Jaclyn

    2013-01-01

    As groups representing local and state education players struggle to remain relevant in a policy conversation often dominated by foundations, think tanks, new advocacy groups, and political and business figures, a shift in leadership has been under way at major associations. Most of the changes have come as part of the natural churn; former…

  6. Crichton's phase-shift ambiguity

    NARCIS (Netherlands)

    Atkinson, D.; Johnson, P.W.; Mehta, N.; Roo, M. de

    1973-01-01

    A re-examination of the SPD phase-shift ambiguity is made with a view to understanding certain singular features of the elastic unitarity constraint. An explicit solution of Crichton's equations is presented, and certain features of this solution are displayed graphically. In particular, it is shown

  7. Environmental Protection: a shifting focus

    NARCIS (Netherlands)

    Dr. ir. Jan Venselaar

    2004-01-01

    The last two decades have seen a fundamental change in the way chemistry handles environmental issues. A shift in focus has occurred from 'end-of-pipe' to prevention and process integration. Presently an even more fundamental change is brought about by the need for sustainable development. It is

  8. Anthropometric changes and fluid shifts

    Science.gov (United States)

    Thornton, W. E.; Hoffler, G. W.; Rummel, J. A.

    1974-01-01

    Several observations of body size, shape, posture, and configuration were made to document changes resulting from direct effects of weightlessness during the Skylab 4 mission. After the crewmen were placed in orbit, a number of anatomical and anthropometric changes occurred including a straightening of the thoracolumbar spine, a general decrease in truncal girth, and an increase in height. By the time of the earliest in-flight measurement on mission day 3, all crewmen had lost more than two liters of extravascular fluid from the calf and thigh. The puffy facies, the bird legs effect, the engorgement of upper body veins, and the reduced volume of lower body veins were all documented with photographs. Center-of-mass measurements confirmed a fluid shift cephalad. This shift remained throughout the mission until recovery, when a sharp reversal occurred; a major portion of the reversal was completed in a few hours. The anatomical changes are of considerable scientific interest and of import to the human factors design engineer, but the shifts of blood and extravascular fluid are of more consequence. It is hypothesized that the driving force for the fluid shift is the intrinsic and unopposed lower limb elasticity that forces venous blood and then other fluid cephalad.

  9. Gastrointestinal complaints in shift-working and day-working nurses in Iran

    Directory of Open Access Journals (Sweden)

    Moravveji Ali

    2010-10-01

    Full Text Available Abstract Background There is evidence in the scientific literature of the adverse physiological and psychological effects of shift work. The work of nurses in hospitals is connected with shift and night work. Several publications have described gastrointestinal disturbances in shift workers. The aim of this study was to compare the frequency of gastrointestinal (GI complaints of nurses on a rotating shift with that of nurses on a regular day shift. Methods The study involved 160 nurses (133 working in shifts and at night and 27 working on day shifts in the Shahid Beheshti Hospital in Kashan, Iran. These nurses answered a Gastrointestinal Symptom Questionnaire regarding the presence of gastrointestinal symptoms (including heartburn, regurgitation, constipation, diarrhea and bloating. Positive responses required frequent symptom occurrence in the past 4 weeks. Significance of group differences was assessed by chi-square and Fisher-exact tests. Results Prevalence of GI symptoms was significantly higher (p = 0.009 in rotating-shift nurses (81.9% than in day-shift nurses (59.2%. Irregular meal consumption (p = 0.01 and GI medications (p = 0.002 were all significantly higher among the rotating shift nurses. In both groups, regurgitation was the most common symptom. Conclusion Nurses on rotating shifts in Iran experience more GI disturbances than do nurses on day shifts.

  10. Nutrition and health in hotel staff on different shift patterns.

    Science.gov (United States)

    Seibt, R; Süße, T; Spitzer, S; Hunger, B; Rudolf, M

    2015-08-01

    Limited research is available that examines the nutritional behaviour and health of hotel staff working alternating and regular shifts. To analyse the nutritional behaviour and health of employees working in alternating and regular shifts. The study used an ex post facto cross-sectional analysis to compare the nutritional behaviour and health parameters of workers with alternating shifts and regular shift workers. Nutritional behaviour was assessed with the Food Frequency Questionnaire. Body dimensions (body mass index, waist hip ratio, fat mass and active cell mass), metabolic values (glucose, triglyceride, total cholesterol and low- and high-density lipoprotein), diseases and health complaints were included as health parameters. Participants worked in alternating (n = 53) and regular shifts (n = 97). The average age of subjects was 35 ± 10 years. There was no significant difference in nutritional behaviour, most surveyed body dimensions or metabolic values between the two groups. However, alternating shift workers had significantly lower fat mass and higher active cell mass but nevertheless reported more pronounced health complaints. Sex and age were also confirmed as influencing the surveyed parameters. Shift-dependent nutritional problems were not conspicuously apparent in this sample of hotel industry workers. Health parameters did not show significantly negative attributes for alternating shift workers. Conceivably, both groups could have the same level of knowledge on the health effects of nutrition and comparable opportunities to apply this. Further studies on nutritional and health behaviour in the hotel industry are necessary in order to create validated screening programmes. © The Author 2015. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. 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

  12. Predominant natural red-shift of quasi-conservative nonlinear systems

    International Nuclear Information System (INIS)

    Pugno, Nicola Maria; Carpinteri, Alberto; Delsanto, Pier Paolo

    2009-01-01

    Recent discoveries of nonclassical nonlinear phenomena are attracting a large interest in the scientific community, especially in material science. In spite of this, the natural frequency shift related to the appearance of such phenomena remains partially unclear. In this paper, we apply the general and only recently developed Interaction Box Formalism for investigating if a universality in the natural frequency shift of quasi-conservative nonlinear systems exists. Such universality clearly emerges as a rupture in the symmetry, usually leading to a red-shift, quantifiable as a function of the higher- and sub-harmonic generation.

  13. [Effect of the night shift work on micturition patterns of nurses].

    Science.gov (United States)

    Wang, Q; Hu, H; Liang, C; Wang, J; Xu, K X

    2016-08-18

    To compare the effects of rotational night shifts on the micturition patterns of female nurses. A total of 58 nurses without lower urinary tract symptoms were recruited, who worked in the Peking University People's Hospital during January and June in 2014. The nurses aged 20-43 years were divided into two groups, the night-shift group (n=28) and the non-shift group (n=30). The alcohol or coffee intaking were forbidden. In the night-shift group, nurses had worked on rotational shifts for at least 6 months. Their average age was (26.75±4.11) years. In the non-shift group, nurses took regular day-time work, whose average age was (27.80±5.60) years. A voiding diary was kept for 7 consecutive days at the end of 6 months, starting 2 days before their night duties until 4 days after completion of their night duties. For comparison, the non-shift group with regular shifts completed a 7-day voiding diary. In the 7-day recording voiding diary, the nurses were required to have the normal intake of liquid about 1 500-2 000 mL/d. The frequency volume charts of nocturia, the 8-hour interval urine production and frequency were compared between the two groups. Nocturia frequency was increased in the night-shift group [0.5 (0-2.4)] compared with the non-shift group [0 (0-2), P=0.02]. The volume of nocturia was increased in the night-shift group [125 mL (0-660 mL)] compared with the non-shift group [0 mL (0-340 mL), Pshift (Pnight-shift group increased on the day after night shift. When the night-shift nurses returned to daytime duty, the volume of urine decreased but nocturnal urine production remained high, and the frequency of nocturia also increased significantly (Pnight-shift group's voiding volume [(542.35±204.66) mL] and voiding frequency (2.24±0.69) were more than those of the non-shift group at the afternoon time (from 2 pm to 10 pm). During the 8 h interval night time (from 10 pm to 6 am), the volume of nocturia in the night-shift group [(309.74±162.74) mL] was more

  14. Collisional shifts in optical-lattice atom clocks

    International Nuclear Information System (INIS)

    Band, Y. B.; Vardi, A.

    2006-01-01

    We theoretically study the effects of elastic collisions on the determination of frequency standards via Ramsey-fringe spectroscopy in optical-lattice atom clocks. Interparticle interactions of bosonic atoms in multiply occupied lattice sites can cause a linear frequency shift, as well as generate asymmetric Ramsey-fringe patterns and reduce fringe visibility due to interparticle entanglement. We propose a method of reducing these collisional effects in an optical lattice by introducing a phase difference of π between the Ramsey driving fields in adjacent sites. This configuration suppresses site-to-site hopping due to interference of two tunneling pathways, without degrading fringe visibility. Consequently, the probability of double occupancy is reduced, leading to cancellation of collisional shifts

  15. [Burden and health effects of shift work].

    Science.gov (United States)

    Heitmann, Jörg

    2010-10-01

    In Germany aprox. 15% of all employees have irregular or flexible working hours. Disturbed sleep and/or hypersomnia are direct consequences of shift work and therefore described as shift work disorder. Beyond this, shift work can also be associated with specific pathological disorders. There are individual differences in tolerance to shift work. Optimization of both shift schedules and sleep to "non-physiological" times of the day are measures to counteract the negative effects of shift work. There is still not enough evidence to recommend drugs for routine use in shift workers. © Georg Thieme Verlag Stuttgart · New York.

  16. Heat Transfer Characteristics for an Upward Flowing Supercritical Pressure CO{sub 2} in a Vertical Circular Tube

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Deog Ji

    2008-02-15

    The SCWR(Super Critical Water-cooled Reactor) is one of the feasible options for the 4th generation nuclear power plant, which is being pursued by an international collaborative organization, the Gen IV International Forum(GIF). The major advantages of the SCWR include a high thermal efficiency and a maximum use of the existing technologies. In the SCWR, the coolant(water) of a supercritical pressure passes the pseudo-critical temperature as it flows upward through the sub-channels of the fuel assemblies. At certain conditions a heat transfer deterioration occurs near the pseudo-critical temperature and it may cause an excessive rise of the fuel surface temperature. Therefore, an accurate estimation of the heat transfer coefficient is necessary for the thermal-hydraulic design of the reactor core. A test facility, SPHINX(Supercritical Pressure Heat Transfer Investigation for the Next Generation), dedicated to produce heat transfer data and study flow characteristics, uses supercritical pressure CO{sub 2} as a surrogate medium to take advantage of the relatively low critical temperature and pressure: and similar physical properties with water. The produced data includes the temperature of the heating surface and the heat transfer coefficient at varying mass fluxes, heat fluxes, and operating pressures. The test section is a circular tube of ID 6.32 mm: it is almost the same as the hydraulic diameter of the sub-channel in the conceptional design presented by KAERI. The test range of the mass flux is 285 to 1200 kg/m{sup 2}s and the maximum heat flux is 170 kW/m{sup 2}. The tests were mainly performed for an inlet pressure of 8.12 MPa which is 1.1 times of critical pressure. With the test results of the wall temperature and the heat transfer coefficient, effects of mass flux, heat flux, inlet pressure, and the tube diameter on the heat transfer were studied. And the test results were compared with the existing correlations of the Nusselt number. In addition, New

  17. Evidence for Upward Flow of Saline Water from Depth into the Mississippi River Valley Alluvial Aquifer in Southeastern Arkansas

    Science.gov (United States)

    Larsen, D.; Paul, J.

    2017-12-01

    crustal He production. Our model for the system invokes upward migration of Smackover pore fluids and other deep groundwater along faults in SE AR, whereby the saline fluids intrude and mix with dilute water in the MRVA aquifer to create saline conditions. Other processes, such as infiltration of saline irrigation runoff, may also be contributing to the problem.

  18. Special training of shift personnel

    International Nuclear Information System (INIS)

    Martin, H.D.

    1981-01-01

    The first step of on-the-job training is practical observation phase in an operating Nuclear Plant, where the participants are assigned to shift work. The simulator training for operating personnel, for key personnel and, to some extent, also for maintenance personnel and specialists give the practical feeling for Nuclear Power Plant behaviour during normal and abnormal conditions. During the commissioning phase of the own Nuclear Power Plant, which is the most important practical training, the participants are integrated into the commissioning staff and assisted during their process of practical learning by special instructors. The preparation for the licensing exams is vitally important for shift personnel and special courses are provided after the first non-nuclear trial operation of the plant. Personnel training also includes performance of programmes and material for retraining, training of instructors and assistance in building up special training programmes and material as well as training centers. (orig./RW)

  19. Perceptual adaptation of voice gender discrimination with spectrally shifted vowels.

    Science.gov (United States)

    Li, Tianhao; Fu, Qian-Jie

    2011-08-01

    To determine whether perceptual adaptation improves voice gender discrimination of spectrally shifted vowels and, if so, which acoustic cues contribute to the improvement. Voice gender discrimination was measured for 10 normal-hearing subjects, during 5 days of adaptation to spectrally shifted vowels, produced by processing the speech of 5 male and 5 female talkers with 16-channel sine-wave vocoders. The subjects were randomly divided into 2 groups; one subjected to 50-Hz, and the other to 200-Hz, temporal envelope cutoff frequencies. No preview or feedback was provided. There was significant adaptation in voice gender discrimination with the 200-Hz cutoff frequency, but significant improvement was observed only for 3 female talkers with F(0) > 180 Hz and 3 male talkers with F(0) gender discrimination under spectral shift conditions with perceptual adaptation, but spectral shift may limit the exclusive use of spectral information and/or the use of formant structure on voice gender discrimination. The results have implications for cochlear implant users and for understanding voice gender discrimination.

  20. Shift work as an oxidative stressor

    OpenAIRE

    Pasalar Parvin; Farahani Saeed; Sharifian Akbar; Gharavi Marjan; Aminian Omid

    2005-01-01

    Abstract Background Some medical disorders have higher prevalence in shift workers than others. This study was designed to evaluate the effect of night-shift-working on total plasma antioxidant capacity, with respect to the causative role of oxidative stress in induction of some of these disorders. Methods Two blood samples were taken from 44 workers with a rotational shift schedule, one after their day shift and one after their night shift. The total plasma antioxidant capacity of each worke...

  1. Perihelium shifts in central potentials

    International Nuclear Information System (INIS)

    Amorim, A.E.A.; Ferreira, P.L.

    1987-01-01

    Motivated by the rigorous results on level ordering for arbitrary central potentials recently derived in the literature a classical treatment of the perihelium shifts is presented, based on the consideration of those orbits which lie in the vicinity of a circular orbit. The role played by the Laplacian of the potential is emphasized. By the same approach Bertrand's theorem is also discussed, in connection with Arnold's proof. (Author) [pt

  2. Multicolor Holography With Phase Shifting

    Science.gov (United States)

    Vikram, Chandra S.

    1996-01-01

    Prototype apparatus constructed to test feasibility of two-color holographic interferometric scheme in which data for reconstructing holographic wavefront obtained with help of phase-shifting technique. Provides two sets of data needed to solve equations for effects of temperature and concentration. Concept extended to holography at three or more wavelengths to measure three or more phenomena associated with significant variations in index of refraction

  3. Shift Work and Endocrine Disorders

    Directory of Open Access Journals (Sweden)

    M. A. Ulhôa

    2015-01-01

    Full Text Available The objective of this review was to investigate the impact of shift and night work on metabolic processes and the role of alterations in the sleep-wake cycle and feeding times and environmental changes in the occurrence of metabolic disorders. The literature review was performed by searching three electronic databases for relevant studies published in the last 10 years. The methodological quality of each study was assessed, and best-evidence synthesis was applied to draw conclusions. The literature has shown changes in concentrations of melatonin, cortisol, ghrelin, and leptin among shift workers. Melatonin has been implicated for its role in the synthesis and action of insulin. The action of this hormone also regulates the expression of transporter glucose type 4 or triggers phosphorylation of the insulin receptor. Therefore, a reduction in melatonin can be associated with an increase in insulin resistance and a propensity for the development of diabetes. Moreover, shift work can negatively affect sleep and contribute to sedentarism, unhealthy eating habits, and stress. Recent studies on metabolic processes have increasingly revealed their complexity. Physiological changes induced in workers who invert their activity-rest cycle to fulfill work hours include disruptions in metabolic processes.

  4. PSYCHE Pure Shift NMR Spectroscopy.

    Science.gov (United States)

    Foroozandeh, Mohammadali; Morris, Gareth; Nilsson, Mathias

    2018-03-13

    Broadband homodecoupling techniques in NMR, also known as "pure shift" methods, aim to enhance spectral resolution by suppressing the effects of homonuclear coupling interactions to turn multiplet signals into singlets. Such techniques typically work by selecting a subset of "active" nuclear spins to observe, and selectively inverting the remaining, "passive", spins to reverse the effects of coupling. Pure Shift Yielded by Chirp Excitation (PSYCHE) is one such method; it is relatively recent, but has already been successfully implemented in a range of different NMR experiments. Paradoxically, PSYCHE is one of the trickiest of pure shift NMR techniques to understand but one of the easiest to use. Here we offer some insights into theoretical and practical aspects of the method, and into the effects and importance of the experimental parameters. Some recent improvements that enhance the spectral purity of PSYCHE spectra will be presented, and some experimental frameworks including examples in 1D and 2D NMR spectroscopy, for the implementation of PSYCHE will be introduced. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. New flags, upward forces and sheltered harbours: The new ‘Great Game’ in the Pacific Islands region

    OpenAIRE

    Kowasch, Matthias; Lindenmann, Peter

    2014-01-01

    The centre of the global economy and the US-geostrategic focus seem to be shifting to the Asia-Pacific region. The present paper deals with the role of Pacific Island states in this new ‘Great Game’ between China and Western powers. Pacific Island states have a long tradition in building non-confrontational and open ties with rival powers. While only four countries in the Pacific have known mineral resources, others depend mainly on tourism, fisheries and remittances. China is interested in t...

  6. Effect of different cycling frequencies during incremental exercise on the venous plasma potassium concentration in humans.

    Science.gov (United States)

    Zoladz, J A; Duda, K; Majerczak, J; Thor, P

    2002-01-01

    The effect of different muscle shortening velocity was studied during cycling at a pedalling rate of 60 and 120 rev.min(-1) on the [K+]v in humans. Twenty-one healthy young men aged 22.5+/-2.2 years, body mass 72.7+/-6.4 kg, VO2 max 3.720+/-0.426 l. min(-1), performed an incremental exercise test until exhaustion. The power output increased by 30 W every 3 min, using an electrically controlled ergometer Ergoline 800 S (see Zoladz et al. J. Physiol. 488: 211-217, 1995). The test was performed twice: once at a cycling frequency of 60 rev.min(-1) (test A) and a few days later at a frequency of 120 rev. min(-1) (test B). At rest and at the end of each step (i.e. the last 15 s) antecubital venous blood samples for [K+]p were taken. Gas exchange variables were measured continuously (breath-by-breath) using Oxycon Champion Jaeger. The pre-exercise [K+]v in both tests was not significantly different amounting to 4.24+/-0.36 mmol.l(-1) in test A, and 4.37+/-0.45 mmol.l(-1) in test B. However, the [K+]p during cycling at 120 rev. min(-1) was significantly higher (p<0.001, ANOVA for repeated measurements) at each power output when compared to cycling at 60 rev.min(-1). The maximal power output reached 293+/-31 W in test A which was significantly higher (p<0.001) than in test B, which amounted to 223+/-40 W. The VO2max values in both tests reached 3.720+/-0.426 l. min(-1) vs 3.777+/-0.514 l. min(-1). These values were not significantly different. When the [K+]v was measured during incremental cycling exercise, a linear increase in [K+]v was observed in both tests. However, a significant (p<0.05) upward shift in the [K+]v and a % VO2max relationship was detected during cycling at 120 rev.min(-1). The [K+]v measured at the VO2max level in tests A and B amounted to 6.00+/-0.47 mmol.l-1 vs 6.04+/-0.41 mmol.l-1, respectively. This difference was not significant. It may thus be concluded that: a) generation of the same external mechanical power output during cycling at a pedalling

  7. External-field shifts in precision spectroscopy of hydrogen molecular ions

    Energy Technology Data Exchange (ETDEWEB)

    Bakalov, Dimitar, E-mail: dbakalov@inrne.bas.bg [INRNE, Bulgarian Academy of Sciences (Bulgaria); Korobov, Vladimir [Joint Institute for Nuclear Research (Russian Federation); Schiller, Stephan [Heinrich-Heine-Universitat Dusseldorf, Institut fur Experimentalphysik (Germany)

    2015-08-15

    The Effective Hamiltonian of the hydrogen molecular ions is a convenient tool for the evaluation of the shift of the energy levels of the ro-vibrational states and the frequencies of the transitions between them, due to external electric and magnetic fields. Using the Effective Hamiltonian, composite frequencies of suppressed susceptibility to external fields are constructed.

  8. Development of a nonlocal convective mixing scheme with varying upward mixing rates for use in air quality and chemical transport models.

    Science.gov (United States)

    Mihailović, Dragutin T; Alapaty, Kiran; Sakradzija, Mirjana

    2008-06-01

    Asymmetrical convective non-local scheme (CON) with varying upward mixing rates is developed for simulation of vertical turbulent mixing in the convective boundary layer in air quality and chemical transport models. The upward mixing rate form the surface layer is parameterized using the sensible heat flux and the friction and convective velocities. Upward mixing rates varying with height are scaled with an amount of turbulent kinetic energy in layer, while the downward mixing rates are derived from mass conservation. This scheme provides a less rapid mass transport out of surface layer into other layers than other asymmetrical convective mixing schemes. In this paper, we studied the performance of a nonlocal convective mixing scheme with varying upward mixing in the atmospheric boundary layer and its impact on the concentration of pollutants calculated with chemical and air-quality models. This scheme was additionally compared versus a local eddy-diffusivity scheme (KSC). Simulated concentrations of NO(2) and the nitrate wet deposition by the CON scheme are closer to the observations when compared to those obtained from using the KSC scheme. Concentrations calculated with the CON scheme are in general higher and closer to the observations than those obtained by the KSC scheme (of the order of 15-20%). Nitrate wet deposition calculated with the CON scheme are in general higher and closer to the observations than those obtained by the KSC scheme. To examine the performance of the scheme, simulated and measured concentrations of a pollutant (NO(2)) and nitrate wet deposition was compared for the year 2002. The comparison was made for the whole domain used in simulations performed by the chemical European Monitoring and Evaluation Programme Unified model (version UNI-ACID, rv2.0) where schemes were incorporated.

  9. Effect of Shift Work on Sleep, Health, and Quality of Life of Health-care Workers.

    Science.gov (United States)

    Nena, Evangelia; Katsaouni, Maria; Steiropoulos, Paschalis; Theodorou, Evangelos; Constantinidis, Theodoros C; Tripsianis, Grigorios

    2018-01-01

    Shift work is associated with sleep disruption, impaired quality of life, and is a risk factor for several health conditions. Aim of this study was to investigate the impact of shift work on sleep and quality of life of health-care workers (HCW). Tertiary University hospital in Greece. Cross-sectional study. Included were HCW, working either in an irregular shift system or exclusively in morning shifts. All participants answered the WHO-5 Well-Being Index (WHO-5) and a questionnaire on demographics and medical history. Shift workers filled the Shift Work Disorders Screening Questionnaire (SWDSQ). Descriptive statistics, Student's t -test, one-way analysis of variance (ANOVA), Pearson's r correlation coefficient, and multivariate stepwise linear regression analysis were applied. Included were 312 employees (87.9% females), 194 working in irregular shift system and 118 in morning shifts. Most shift-workers (58.2%) were somehow or totally dissatisfied with their sleep quality. Regression analysis revealed the following independent determinants for sleep impairment: parenthood ( P 3 night shifts/week ( P work >5 years in an irregular shift system ( P work impairs quality of life, whereas its duration and frequency, along with age and family status of employees can have adverse effects on sleep.

  10. Bloch-Siegert shift in Dirac-Weyl fermionic systems

    Science.gov (United States)

    Kumar, Upendra; Kumar, Vipin; Enamullah, Setlur, Girish S.

    2018-04-01

    The Bloch-Siegert shift is a phenomenon in quantum optics, typically seen in two-level systems, when the driving field is sufficiently strong. The inclusion of frequency doubling effect (counter rotating term) in the conventional rotating wave approximation (RWA) changes the resonance condition thereby producing a rather small shift in the resonance condition, which is known as the Bloch-Siegert shift (BSS). Rabi oscillations in Dirac-Weyl fermionic systems exhibit anomalous behavior far from resonance, called anomalous Rabi oscillations. Therefore, in the present work, we study the phenomenon of the Bloch-Siegert shift in Weyl semimetal and topological insulator (TI) far from resonance, called anomalous Bloch-Siegert shift (ABSS). It is seen that the change in the resonance condition of anomalous Rabi oscillations is drastic in Weyl semimetal and TI. The ABSS in Weyl semimetals is highly anisotropic, whereas it is isotropic in TI. In case of TI, it is the Chern number which plays a crucial role to produce substantial change in the ABSS.

  11. Prevalence of myopic shifts among patients seeking cataract surgery

    Directory of Open Access Journals (Sweden)

    Rafael Iribarren

    2013-06-01

    Full Text Available Modern cataract surgery by phacoemulsification is a widely accepted procedure with a rapid recovery time. The prescription of specific intraocular lens, implanted during surgery, makes it possible to anticipate whether the patient will need reading glasses after the procedure. The present study analyses a sample of cataract surgery patients to show the frequency of myopic shifts related to nuclear opacity, which can result in clear near vision before surgery. A non-selected sample of consecutive patients who underwent elective cataract surgery in a private clinic was studied retrospectively. The myopic shift in refraction was assessed by comparing the old prescription with the spectacle correction at the time of interviewing.The mean age of the 229 subjects studied was 71.5 ± 10.4 years (109, 47.6%, males. A myopic shift in refraction, defined as at least - 0.5 diopters, was present in 37.1% of subjects (95% CI: 30.8%-43.4%. The mean change in refraction in these subjects was -2.52 ± 1.52 diopters. The percentage of subjects who had developed a myopic shift was significantly greater in those who presented greater nuclear opalescence. There were also differences in the mean myopic shift by refractive group, with the emmetropes having the greatest myopic shift. In this study of patients seeking cataract surgery in a clinical setting, more than one third had myopic shifts in refraction. This must be taken into account in order that patients maintain the benefit of clear near vision after surgery.

  12. Visual attention shifting in autism spectrum disorders.

    Science.gov (United States)

    Richard, Annette E; Lajiness-O'Neill, Renee

    2015-01-01

    Abnormal visual attention has been frequently observed in autism spectrum disorders (ASD). Abnormal shifting of visual attention is related to abnormal development of social cognition and has been identified as a key neuropsychological finding in ASD. Better characterizing attention shifting in ASD and its relationship with social functioning may help to identify new targets for intervention and improving social communication in these disorders. Thus, the current study investigated deficits in attention shifting in ASD as well as relationships between attention shifting and social communication in ASD and neurotypicals (NT). To investigate deficits in visual attention shifting in ASD, 20 ASD and 20 age- and gender-matched NT completed visual search (VS) and Navon tasks with attention-shifting demands as well as a set-shifting task. VS was a feature search task with targets defined in one of two dimensions; Navon required identification of a target letter presented at the global or local level. Psychomotor and processing speed were entered as covariates. Relationships between visual attention shifting, set shifting, and social functioning were also examined. ASD and NT showed comparable costs of shifting attention. However, psychomotor and processing speed were slower in ASD than in NT, and psychomotor and processing speed were positively correlated with attention-shifting costs on Navon and VS, respectively, for both groups. Attention shifting on VS and Navon were correlated among NT, while attention shifting on Navon was correlated with set shifting among ASD. Attention-shifting costs on Navon were positively correlated with restricted and repetitive behaviors among ASD. Relationships between attention shifting and psychomotor and processing speed, as well as relationships between measures of different aspects of visual attention shifting, suggest inefficient top-down influences over preattentive visual processing in ASD. Inefficient attention shifting may be

  13. Final work plan : supplemental upward vapor intrusion investigation at the former CCC/USDA grain storage facility in Hanover, Kansas.

    Energy Technology Data Exchange (ETDEWEB)

    LaFreniere, L. M.; Environmental Science Division

    2008-12-15

    The Commodity Credit Corporation (CCC), an agency of the U.S. Department of Agriculture (USDA), operated a grain storage facility at the northeastern edge of the city of Hanover, Kansas, from 1950 until the early 1970s. During this time, commercial grain fumigants containing carbon tetrachloride were in common use by the grain storage industry to preserve grain in their facilities. In February 1998, trace to low levels of carbon tetrachloride (below the maximum contaminant level [MCL] of 5.0 {micro}g/L) were detected in two private wells near the former grain storage facility at Hanover, as part of a statewide USDA private well sampling program that was implemented by the Kansas Department of Health and Environment (KDHE) near former CCC/USDA facilities. In 2007, the CCC/USDA conducted near-surface soil sampling at 61 locations and also sampled indoor air at nine residences on or adjacent to its former Hanover facility to address the residents concerns regarding vapor intrusion. Low levels of carbon tetrachloride were detected at four of the nine homes. The results were submitted to the KDHE in October 2007 (Argonne 2007). On the basis of the results, the KDHE requested sub-slab sampling and/or indoor air sampling (KDHE 2007). This Work Plan describes, in detail, the proposed additional scope of work requested by the KDHE and has been developed as a supplement to the comprehensive site investigation work plan that is pending (Argonne 2008). Indoor air samples collected previously from four homes at Hanover were shown to contain the carbon tetrachloride at low concentrations (Table 2.1). It cannot be concluded from these previous data that the source of the detected carbon tetrachloride is vapor intrusion attributable to former grain storage operations of the CCC/USDA at Hanover. The technical objective of the vapor intrusion investigation described here is to assess the risk to human health due to the potential for upward migration of carbon tetrachloride and

  14. Red shift, blue shift: investigating Doppler shifts, blubber thickness, and migration as explanations of seasonal variation in the tonality of Antarctic blue whale song.

    Directory of Open Access Journals (Sweden)

    Brian S Miller

    Full Text Available The song of Antarctic blue whales (Balaenoptera musculus intermedia comprises repeated, stereotyped, low-frequency calls. Measurements of these calls from recordings spanning many years have revealed a long-term linear decline as well as an intra-annual pattern in tonal frequency. While a number of hypotheses for this long-term decline have been investigated, including changes in population structure, changes in the physical environment, and changes in the behaviour of the whales, there have been relatively few attempts to explain the intra-annual pattern. An additional hypothesis that has not yet been investigated is that differences in the observed frequency from each call are due to the Doppler effect. The assumptions and implications of the Doppler effect on whale song are investigated using 1 vessel-based acoustic recordings of Antarctic blue whales with simultaneous observation of whale movement and 2 long-term acoustic recordings from both the subtropics and Antarctic. Results from vessel-based recordings of Antarctic blue whales indicate that variation in peak-frequency between calls produced by an individual whale was greater than would be expected by the movement of the whale alone. Furthermore, analysis of intra-annual frequency shift at Antarctic recording stations indicates that the Doppler effect is unlikely to fully explain the observations of intra-annual pattern in the frequency of Antarctic blue whale song. However, data do show cyclical changes in frequency in conjunction with season, thus suggesting that there might be a relationship among tonal frequency, body condition, and migration to and from Antarctic feeding grounds.

  15. Phase-Shift Cyclic-Delay Diversity for MIMO OFDM Systems

    Directory of Open Access Journals (Sweden)

    Young-Han Nam

    2010-01-01

    Full Text Available Phase-shift cyclic-delay diversity (PS CDD scheme and space-frequency-block-code (SFBC PS CDD are developed for multiple-input-multiple-output (MIMO orthogonal frequency division multiplexing (OFDM systems. The proposed PS CDD scheme preserves the diversity advantage of traditional CDD in uncorrelated multiantenna channels, and furthermore removes frequency-selective nulling problem of the traditional CDD in correlated multiantenna channels.

  16. 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

  17. New flags, upward forces and sheltered harbours: The new ‘Great Game’ in the Pacific Islands region

    Directory of Open Access Journals (Sweden)

    Kowasch, Matthias

    2014-03-01

    Full Text Available The centre of the global economy and the US-geostrategic focus seem to be shifting to the Asia-Pacific region. The present paper deals with the role of Pacific Island states in this new ‘Great Game’ between China and Western powers. Pacific Island states have a long tradition in building non-confrontational and open ties with rival powers. While only four countries in the Pacific have known mineral resources, others depend mainly on tourism, fisheries and remittances. China is interested in the vast mineral resources in the Pacific Island region, visible in increasing investment. Nevertheless, Australia remains the principal economic and key security partner for most of the Island states. Besides a painful colonial history, unequal distribution of mining benefits and social disparities are reasons for independence movements. Besides a painful colonial history, unequal distribution of mining benefits and social disparities are reasons for independence movements that are another issue in Pacific Island politics.

  18. 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

  19. Modelling Vulnerability and Range Shifts in Ant Communities Responding to Future Global Warming in Temperate Forests.

    Science.gov (United States)

    Kwon, Tae-Sung; Li, Fengqing; Kim, Sung-Soo; Chun, Jung Hwa; Park, Young-Seuk

    2016-01-01

    Global warming is likely leading to species' distributional shifts, resulting in changes in local community compositions and diversity patterns. In this study, we applied species distribution models to evaluate the potential impacts of temperature increase on ant communities in Korean temperate forests, by testing hypotheses that 1) the risk of extinction of forest ant species would increase over time, and 2) the changes in species distribution ranges could drive upward movements of ant communities and further alter patterns of species richness. We sampled ant communities at 335 evenly distributed sites across South Korea and modelled the future distribution range for each species using generalized additive models. To account for spatial autocorrelation, autocovariate regressions were conducted prior to generalized additive models. Among 29 common ant species, 12 species were estimated to shrink their suitable geographic areas, whereas five species would benefit from future global warming. Species richness was highest at low altitudes in the current period, and it was projected to be highest at the mid-altitudes in the 2080s, resulting in an upward movement of 4.9 m yr-1. This altered the altitudinal pattern of species richness from a monotonic-decrease curve (common in temperate regions) to a bell-shaped curve (common in tropical regions). Overall, ant communities in temperate forests are vulnerable to the on-going global warming and their altitudinal movements are similar to other faunal communities.

  20. Cortisol shifts financial risk preferences.

    Science.gov (United States)

    Kandasamy, Narayanan; Hardy, Ben; Page, Lionel; Schaffner, Markus; Graggaber, Johann; Powlson, Andrew S; Fletcher, Paul C; Gurnell, Mark; Coates, John

    2014-03-04

    Risk taking is central to human activity. Consequently, it lies at the focal point of behavioral sciences such as neuroscience, economics, and finance. Many influential models from these sciences assume that financial risk preferences form a stable trait. Is this assumption justified and, if not, what causes the appetite for risk to fluctuate? We have previously found that traders experience a sustained increase in the stress hormone cortisol when the amount of uncertainty, in the form of market volatility, increases. Here we ask whether these elevated cortisol levels shift risk preferences. Using a double-blind, placebo-controlled, cross-over protocol we raised cortisol levels in volunteers over 8 d to the same extent previously observed in traders. We then tested for the utility and probability weighting functions underlying their risk taking and found that participants became more risk-averse. We also observed that the weighting of probabilities became more distorted among men relative to women. These results suggest that risk preferences are highly dynamic. Specifically, the stress response calibrates risk taking to our circumstances, reducing it in times of prolonged uncertainty, such as a financial crisis. Physiology-induced shifts in risk preferences may thus be an underappreciated cause of market instability.