International Nuclear Information System (INIS)

... edge localized modes h-mode plasma confinement jet tokamak l-mode plasma

International Nuclear Information System (INIS)

Experiments have been performed on the electrically heated rod bundles to investigate the characteristics of the boiling transition under flow oscillation (OSBT) during thermal hydraulic instability. After determining the instability threshold power (Q/sub OS/), the electrical power to the test section was increased further up to the threshold power (Q/sub OSBT/) at which it was detected by the thermocouples that the boiling transition (BT) occurred and the heater rod temperature reached 613 K. Experimental results show that Q/sub OSBT/ is larger than Q/sub OS/ by a certain margin, which depends on the test conditions.

Energy Technology Data Exchange (ETDEWEB)

The low-power operation of a semiconductor buried-heterostructure Raman laser is reported. We are developing these devices for very wide-band optical communication in the terahertz frequency region. It has a structure with a GaP active layer and Al{sub {ital x}}Ga{sub 1{minus}{ital x}}P cladding layers, which are grown by the temperature-difference method under controlled vapor pressure. By making the stripe width 30--40 {mu}m, we have obtained a threshold pump power of 500 mW. A low-threshold semiconductor Raman laser can be pumped by semiconductor injection lasers. We have measured the optical loss of the waveguide and detected the contribution from scattering and leakage at heterointerfaces.

International Nuclear Information System (INIS)

Single-event burnout (SEB) sensitivity was tested for power MOSFET devices, JTMCS081 and JTMCS062, which were made in Institute of Microelectronics, Chinese Academy of Sciences, using californium-252 simulation source. SEB voltage threshold was found for devices under test (DUT). It is helpful for engineers to choose devices used in satellites. (authors)

CERN Document Server

This paper proposes two interference mitigation strategies that adjust the maximum transmit power of femtocell users to suppress the cross-tier interference at a macrocell base station (BS). The open-loop and the closed-loop control suppress the cross-tier interference less than a fixed threshold and an adaptive threshold based on the noise and interference (NI) level at the macrocell BS, respectively. Simulation results show that both schemes effectively compensate the uplink throughput degradation of the macrocell BS due to the cross-tier interference and that the closed-loop control provides better femtocell throughput than the open-loop control at a minimal cost of macrocell throughput.

CERN Document Server

We examine the effect of a threshold bias on the power spectrum and the bispectrum in an ensemble of numerical simulations (Gaussian initial perturbations with power law spectra P(k) \\sim k^n, n=+1, 0, -1, -2) and compare our results with theoretical predictions. Our simulations are evolved sufficiently that on the scale where we apply the threshold the rms fluctuation has developed significantly into the nonlinear regime. Thus, predictions based on perturbation theory do not necessarily apply. Nevertheless, we find our results for the power spectrum, biased power simply amplified by a numerical factor, follow predicted trends, far beyond the regime where perturbation theory is expected to be valid. We find that the biased bispectrum continues to follow the so-called hierarchical form, with reduced three-point amplitude Q \\approx 1 in the strongly nonlinear ...

Energy Technology Data Exchange (ETDEWEB)

The reaction {gamma}d{yields}{pi}{sup +}nn is calculated up to order {chi}{sup 5/2} in chiral perturbation theory, where {chi} denotes the ratio of the pion to the nucleon mass. Special emphasis is put on the role of nucleon recoil corrections that are the source of contributions with fractional power in {chi}. Using the known near-threshold production amplitude for {gamma}p{yields}{pi}{sup +}n as the only input, the total cross-section for {gamma}d{yields}{pi}{sup +}nn is described very well. A conservative estimate suggests that the theoretical uncertainty for the transition operator amounts to 3% for the computed amplitude near threshold. (orig.)

International Nuclear Information System (INIS)

In the last 30 years the production of electricity in the USSR has increased 14-fold, probably attaining 1540 billion kWH in 1985. Nuclear generation will provide the bulk of future increases of consumption, using both water-cooled and uranium/graphite reactors; stations of up to 1.5 million kW are in service. The USSR is also in the fore-front of attempts to exploit thermonuclear power. The USSR is also conducting experiments with renewable sources of energy such as solar, geothermal, wind and wave power and with magnetohydrodynamic generation. (D.A.J.).

Science.gov (United States)

Phenomena in power systems tend to exhibit higher nonlinearity, because efficient operation accompanies severer power transfer. In such cases, there might exist some limitation to the use of conventional linear control design scheme due to the nonlinearity. As for consideration to the nonlinearity, we have developed a nonlinear analysis method based on normal form theory. In this paper, we develop a new control design scheme based on the nonlinear analysis method. The developed method is effective in a case when oscillatory instability occurs. In the developed method, the parameters of control devices are adjusted so as to enlarge the stability limit against the oscillatory instability, unless each eigenvalue exceed its allowable threshold. We verify the effectiveness of the developed method in the IEEJ 10-machine System Model by applying to PSS (Power System Stabilizer). We show that the ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

A high power AlGaInP single quantum well graded index separate confinement heterostructure. It comprises a substrate and a multiplicity of layers deposited thereon comprising a single Ga{sub x}In{sub x}P quantum well where x has a value from about 0.4 to about 0.6; multiple graded index regions on both sides of the quantum well and cladding layers adjacent to each graded region of the well, the graded region comprising Al{sub y}(Ga{sub 1{minus}y}){sub 0.5}In{sub 0.5}P quaternary alloy; wherein the value of y in the graded region varies from about 0.2 at the quantum well/graded region interface to up to about 0.6 for the cladding layers/graded index regions; the heterostructure having a low broad area threshold current with pulsed thresholds in the range from about 1 to about 2 Amps/cm{sup 2} and a differential efficiency of from about 20 to about 60 percent.

International Nuclear Information System (INIS)

The prevailing hypothesis of linear extrapolation from high to low radiation doses without any threshold level is being questioned more and more strongly for radiobiological and epidemiological reasons and, consequently, also on socio-economic and ethical grounds. A cost-benefit analysis based on scientific facts and made plausible to the general public, concentrating on a comparison with demonstrable natural and manmade risks, most probably would result not only in the permissible limits being raised by a considerable margin, but also in billions of costs saved, and in greater acceptance of all peaceful uses of radiation, nuclear power included. (orig.)

Science.gov (United States)

Spectral and energy luminescence characteristics of R6G dye solutions in ethanol with addition of Ag nanoparticle suspensions in different aggregate states are experimentally investigated. It is demonstrated that incorporation of non-aggregated and aggregated nanoparticles causes the superluminescence thresholds in R6G solutions to decrease. It is established that the optical properties of the laser beam propagation channel are transformed when low-power (20 mW) cw laser radiation passes through the suspension of nanoparticles. This is manifested through the occurrence of a region with enhanced nanoparticle density in the laser beam center, on which diffraction of laser radiation is observed.

International Nuclear Information System (INIS)

The following work deals with the realization, characterization and modeling of GaInP / AlGaInP high power semiconductor laser diodes in the visible wavelength range. In addition to the exploration and optimization of efficiency, temperature stability and maximum output power of multi-mode lasers especially methods for longitudinal and lateral mode stabilization of high power laser diodes have been investigated. Although often the focus of optimization is on the threshold current density, in this work the performance of the laser diode for an operation point around 1 Watt under continous wave operation is regarded as the figure of merit. It turns out that low carrier densities are key for an efficient reduction of the heterobarrier leakage currents. In addition, large optical cavity structures with low internal losses enable high external quantum efficiencies even for long cavities. Finally high laser ...

Energy Technology Data Exchange (ETDEWEB)

Room temperature continuous wave operation of red ([lambda][sub 0] [approximately] 660 nm) vertical cavity surface emitting laser arrays is reported. The 1 [times] 64 arrays have a pitch of 100 [mu]m with device diameters of 15 [mu]m with device diameters of 15 [mu]m. Grown by metalorganic vapor phase epitaxy, the devices consist of an AlGaInP strained quantum well optical cavity active region surrounded by AlGaAs distributed Bragg reflectors (DBR's). The top coupling DBR includes a partial dielectric stack, deposited after implanted device fabrication. All 64 devices operation simultaneously with peak output powers >0.45 mW, threshold current <1.5 mA, and threshold voltages [<=] 2.7 V. The differential quantum efficiencies exceed 10%.

International Nuclear Information System (INIS)

III--V based devices such as field effect transistors, heterojunction bipolar transistors, and lasers often have surface leakage and thermal degradation problems due to surface states which pin the Fermi level to the midgap. Sulfur based passivation processes are known to improve device performance by altering surface-state densities. We have developed a voltage-controlled anodic sulfur passivation scheme using Na_2S dissolved in ethylene glycol. Our process has repeatedly produced a #approx#25% improvement in peak output power near the catastrophic damage limit in visible (#lambda#=670 nm) AlGaInP edge-emitting lasers. The threshold current density before and after passivation, and the I--V characteristics before and after catastrophic failure, were essentially unchanged indicating that passivation raises the threshold for facet damage.

Energy Technology Data Exchange (ETDEWEB)

Red laser diodes emitting at 636 nm and 645 nm are studied as a function of pressure up to 20 kbar and temperature from 300 K down to 80 K. The 636 nm samples reveal anomalous L-I-V dependence at low temperatures and at high pressures. The 645 nm samples do not show these anomalies and can be tuned by pressure and temperature down to 575 nm, i.e., in the 70 nm range with powers above 200 mW and low threshold currents. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

International Nuclear Information System (INIS)

The aim of this thesis is the design of a faults diagnosis-aiding system in a nuclear facility of the Cea. Actually the existing system allows the optimization of the production processes in regular operating conditions. Meanwhile during accidental events, the alarms, managed by threshold, are bringing no relevant information. To increase the reliability and the safety, the human operator needs a faults diagnosis-aiding system. The developed system, SECAPI, combines problem solving techniques and automatic learning techniques, that allow the diagnosis and the the simulation of various faults happening on nuclear facilities. Its reasoning principle uses case-based and rules-based techniques. SECAPI owns a learning module which reads out knowledge connected with faults. It can then simulate various faults, using the inductive logical computing. SECAPI has been applied on a radioactive tritium treatment operating channel, at the Cea with good results. (A.L.B.)

Energy Technology Data Exchange (ETDEWEB)

We investigate the reaction pn {yields}d{pi} {pi} in the framework of Chiral Perturbation Theory (ChPT). For the first time a complete calculation of the leading-order contributions is presented. We identify various diagrams that are of equal importance as compared to those recognized in earlier works. The diagrams at leading order behave as expected by the power counting. Also for the first time the nucleon-nucleon interaction in the initial, intermediate and final state is included consistently and found to be very important. Although the perturbative series for the production operator is expected to converge very slowly, this study provides the theoretical basis for a future evaluation of the non-resonant contributions in two-pion production reactions in nucleon-nucleon collisions. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Buried ridge stripe lasers have been grown on InP in two steps by gas source molecular beam epitaxy. The active structure consists of a compressively strained layer multi quantum well with an equivalent wavelength emission at 1.5 [mu]m. The stripe was defined by reactive ion etching. A threshold current of 22 mA was reproducibly obtained on a laser length of 500 [mu]m. A CW output power of 48 mW per facet was achieved. In addition, preliminary accelerated aging tests have shown the high reliability the structure. (orig.)

International Nuclear Information System (INIS)

Russian (Aug 1971). USSR Gulyaev, AP Morgunova, NN Malkhasyan,

International Nuclear Information System (INIS)

The feasibility of developing a fusion power monitor based on a fluid activation detector is considered here. The activation fluid may be either a liquid or a gas and its composition can be selected from a number of candidate materials to provide desired activation and decay characterisitcs. Performance calculations indicate that ordinary water would be a nearly ideal activation fluid. The "1"6O(n,p)"1"6N reaction has a threshold at about 10 MeV and a cross section energy dependence giving it a predominant response for unmoderated D-T fusion neutrons. Adequate activation can be obtained at moderate flow rates for remote counting away from the high radiation area of the reactor. The 7.16 sec half-life of "1"6N is ideal for remote counting with subsequent decay in a small hold-up tank to eliminate activity build-up in the recycled water.

Energy Technology Data Exchange (ETDEWEB)

When a plasma becomes contaminated by foreign particles, generically referred to as dust, the result is called a dusty plasma. At the present time there is a great deal of interest in dusty plasmas because of their roles in terrestrial and extra-terrestrial processes - semiconductor processing, high temperature fusion experiments, stellar formation and the rings of Saturn. This thesis is concerned with the role of dust in processing type plasmas. In the following experiments, artificial dust is introduced into a parallel electrode plasma chamber. Ions and electrons in the plasma charge the dust particles and they become suspended in the plasma due to the balancing of electric and gravitational forces. By illuminating the suspended dust with laser light and using an extremely high speed camera fitted with a macro lens to look at the scattered light, the dust particles are observed directly. Specially written computer software is then able to track and analyse the particles' ...

UK PubMed Central (United Kingdom)

Many patients are currently suffering from nickel (Ni)-induced allergic contact dermatitis (ACD). There have been few Korean studies dealing with the threshold of Ni-induced ACD and quantifying the...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Long crack fatigue threshold ({delta} K{sub th}) and crack closure behaviour of two thermomechanically processed microalloyed (MA) ferrite-pearlite steels are reported. {delta} K{sub th} and crack closure were measured using a dynamic compliance measurement technique. Crack closure was observed at low load ratios (R < 0.5) and the fatigue thresholds decreased with increasing load ratio. In both steels, the closure-free intrinsic threshold ({delta} K{sub eff} {sub th}) was found to be independent of the load ratio. (orig.)

Energy Technology Data Exchange (ETDEWEB)

We investigate the interplay of quark and meson degrees of freedom in a physical state representing a near-threshold resonance for the case of a single continuum channel. We demonstrate that such a near-threshold resonance may possess quite peculiar properties if both quark and meson dynamics generate weakly coupled near-threshold poles in the S -matrix. In particular, the scattering t -matrix may possess zeros in this case. We also discuss possible implications for production reactions as well as studies within lattice QCD. (orig.)

International Nuclear Information System (INIS)

(Apr 1974). Japan Murakami, Akira . Saga Univ. (Japan). Dept. of

International Nuclear Information System (INIS)

The wavelength dependence of the threshold in an InGaP-InAlGaP vertical cavity surface emitting laser is investigated using a microscopic theory of the semiconductor gain medium. Good agreement is found between experiment and theory for the minimum threshold lasing wavelength for a range of laser structures.

Energy Technology Data Exchange (ETDEWEB)

Threshold pump intensity values leading to irreversible damage to colored laser elements based on elastic polymers were measured. The damage to colored elastomers is connected with absorbing microinclusions but is independent of molecular absorption. It is shown that damage to the elastomers has a pronounced threshold character in contrast to the microdamage accumulation effect in glassy polymers. The damage threshold for elastomers is 1.5 times higher, which is connected with the absence of microstresses (characteristics for organic glasses) in the specimens. 13 references.

Science.gov (United States)

The millimeter microwave source of gyrotron-traveling-wave amplifier (gyro-TWT) is capable of generating high power coherent radiation in a broad bandwidth, while its performance is severely deteriorated by the stability problems. This paper focuses on modeling and the stability analysis of the Naval Research Laboratory (NRL) Ka-band TE{sub 01} mode gyro-TWT based on an interaction circuit alternately loaded with lossy ceramic shells and metal rings. The propagation characteristics of the interaction circuit is analyzed first, based on which the boundary impedance method is employed to build an equivalent uniform lossy circuit. Then the stability of the interaction system is studied using linear and nonlinear theories. The analysis reveals that, due to the special waveguide structure and the dielectric loss, the propagation characteristics of the complex waveguide are similar to that of a uniform lossy circuit. The analysis of the absolute instabilities ...

International Nuclear Information System (INIS)

Distributed Bragg reflectors (DBRs) composed of In_0_._5Al_0_._5P/In_0_._5(Al_yGa_1_-_y)_0_._5P quarter-wave layers have been prepared using metalorganic vapor phase epitaxy. The structures were grown over a wide range of high-index layer composition (0#<=#y#<=#0.6) and peak reflectivity wavelength (720 nm#<=##lambda##<=#565 nm, covering the spectrum from deep red to green). In all cases observed and calculated reflectance spectra were in excellent agreement. Using these DBRs, an undoped all-phosphide visible vertical cavity surface-emitting laser structure was grown. Under pulsed optical excitation at room temperature, lasing was obtained at a wavelength of #lambda##approx#670 nm, with a threshold power density comparable to that observed from similar structures prepared using AlAs/AlGaAs DBRs.

International Nuclear Information System (INIS)

Employing a recently developed Monte-Carlo model, we study the fission of 240Pu induced by neutrons with energies from thermal to just below the threshold for second chance fission. Current measurements of the mean number of prompt neutrons emitted in fission, together with less accurate measurements of the neutron energy spectra, place remarkably fine constraints on predictions of microscopic calculations. In particular, the total excitation energy of the nascent fragments must be specified to within 1MeV to avoid disagreement with measurements of the mean neutron multiplicity. The combination of the Monte-Carlo fission model with a statistical likelihood analysis also presents a powerful tool for the evaluation of fission neutron data. Of particular importance is the fission spectrum, which plays a key role in determining reactor criticality. We show that our approach can be used to develop an estimate of the fission spectrum with ...

International Nuclear Information System (INIS)

Modern digital radiographic 'flat panel' detectors can exhibit a progressive form of image degradation arising from non-functioning pixels. The effect of these 'dead pixels' on the quantitative image quality measures of modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE) is investigated by a simulated degradation of images obtained from an Hologic EPEX system. The effects on the semi-quantitive measures obtained from contrast threshold test objects and resolution gratings are also investigated. Results suggest that the contrast-detail tests often employed in quality assurance measures are not sufficient to reveal the presence of dead pixels until well beyond the recommended replacement point for the flat panel detector. However, measurements of spatial resolution using a line pairs phantom were found to be more sensitive to pixel loss. Measurement of the MTF, NPS and DQE can reveal small changes ...

International Nuclear Information System (INIS)

The experiments show that the fluence threshold of 316L SS irradiated by 1.8 MeV alpha particle is between (0.8655-1.3457) x 10"1"8 #alpha#/cm"2, and the threshold decreases in the 1.5 MeV and 1.0 MeV alpha particle irradiation. For the solid solution samples irradiated by 1.5 MeV alpha particle, the threshold is below 0.5595 x 10"1"8#alpha#/cm"2, and for the 20% cold-worked sample, the threshold is between (0.8595-0.5063) x 10"1"8 #alpha#/cm"2. In 1.0 MeV alpha particle irradiation, the threshold for the solid solution sample and 20% cold-worked sample is between (0.3073-0.1024) x 10"1"8 #alpha#/cm"2 and (0.4108-0.3063) x 10"1"8 #alpha#/cm"2 respectively. The difference of threshold of the two kinds of samples shows that the 20% cold-working can influence the occurrence of blistering

Energy Technology Data Exchange (ETDEWEB)

The problem of efficient capture of nonlinear oscillations into resonance is discussed. The capture is guaranteed by passage through resonance when the system starts in equilibrium and the driving amplitude exceeds a threshold. The threshold problem is described by a universal nonlinear Schroedinger-type equation with a single parameter and cannot be analyzed by perturbation methods. A similar threshold phenomenon is a characteristic of two weakly coupled oscillators with a slow parameter if one of the oscillators starts in equilibrium, allowing efficient capture into resonance and subsequent adiabatic (autoresonant) control of strongly excited nonlinear oscillations.

Energy Technology Data Exchange (ETDEWEB)

We report measurements of the temperature dependence of the threshold current of GaAs, 1.3-..mu..m InGaAsP, and 1.5-..mu..m InGaAsP double heterostructure lasers using short electrical pulses. T/sub 0/approx.200 K is observed for all the lasers. These high T/sub 0/ values show that the carrier density at threshold does not increase rapidly with increasing temperature in any of the lasers studied and thus the observed low cw T/sub 0/ of InGaAsP lasers is primarily due to a decrease of the carrier lifetime at threshold with increasing temperature.

UK PubMed Central (United Kingdom)

The rejection thresholds of Phormia regina Meigen for twenty-four glycols have been determined. A definite relationship between the concentration of the test material and the distribution...Full Text Available

DEFF Research Database (Denmark)

Methylisothiazolinone (MI) used alone is a new preservative causing a high prevalence of contact allergy. The eliciting threshold of MI is unknown. The combination of MI and phenoxyethanol enhances the antimicrobial efficacy of MI.

UK PubMed Central (United Kingdom)

The existence of thresholds for toxicants is a matter of debate in chemical risk assessment and regulation. Current risk assessment methods are based on the assumption that, in the absence of sufficient...Full Text Available

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

The threshold values of indicator species and ratios delineating the transition between NO_x and VOC sensitivity of ozone formation are assumed to be universal by various investigators. However, our previous studies suggested that threshold values might vary according to the locations and conditions. In this study, threshold values derived from various model simulations at two different locations (the area of Switzerland by UAM Model and San Joaquin Valley of Central California by SAQM Model) are examined using a new approach for defining NO_x and VOC sensitive regimes. Possible definitions for the distinction of NO_x and VOC sensitive ozone production regimes are given. The dependence of the threshold values for indicators and indicator ratios such as NO_y, O_3/NO_z, HCHO/NO_y, and H_2O_2/HNO_3 on the definition of NO_x and VOC sensitivity is discussed. Then the variations of ...

International Nuclear Information System (INIS)

Muon captures by nucleon pairs via meson-exchange currents produce a high energy excitation tail in heavy nuclei. The muon induced fission by these excitations is calculated in several subactinide nuclei with high threshold fission barriers. The probability for delayed fission ranges from 4 x 10"-"5 to 4 x 10"-"3 for the isotopes considered. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Frequency response measurements are used to determine the carrier lifetime of 1.3-..mu..m InGaAsP buried heterostructure lasers between 1 mA and threshold. The data confirm previous results on the radiative and Auger recombination coefficients and reveal the presence of a nonradiative current which dominates at low currents and contributes 4 mA at threshold.

Science.gov (United States)

We report the first visible (657 nm) vertical-cavity surface-emitting laser. The photopumped undoped structure was grown using low-pressure metalorganic vapor-phase epitaxy in a single-growth sequence on misoriented GaAs substrates. The optical cavity consists of an In{sub 0.54}Ga{sub 0.46}P/In{sub 0.48}(Al{sub 0.7}Ga{sub 0.3}){sub 0.52} P strained quantum-well active region and a lattice-matched In{sub 0.48}(Al{sub {ital y}}Ga{sub 1{minus}{ital y}}){sub 0.52} P (0.7{le}{ital y}{le}1.0) graded spacer region, while the distributed Bragg reflectors are composed of Al{sub 0.5}Ga{sub 0.5}As/AlAs quarter-wave stacks. Room-temperature optically pumped lasing was achieved with a very low-threshold power, clearly demonstrating the viability of this new technology. These results provide the foundation for visible semiconductor laser-diode arrays for a number of applications including laser projection displays, holographic memories, and plastic fiber ...

International Nuclear Information System (INIS)

In this report, I surveyed physics potential of the #gamma##gamma# option of a linear e"+e"- collider with the following questions in mind: What new discovery can be expected at a #gamma##gamma# collider in addition to what will be learned at its 'parent' e"+e"- linear collider? By taking account of the hard energy spectrum and polarization of colliding photons, produced by Compton back-scattering of laser light off incoming e"- beams, we find that a #gamma##gamma# collider is most powerful when new physics appears in the neutral spin-zero channel at an invariant mass below about 80% of the c.m. energy of the colliding e"-e"- system. If a light Higgs boson exists, its properties can be studied in detail, and if its heavier partners or a heavy Higgs boson exists in the above mass range, they may be discovered at a #gamma##gamma# collider. CP property of the scalar sector can be explored in detail by making use of linear polarization of the colliding photons, decay ...

CERN Document Server

High-power pseudospark and BLT switches

CERN Document Server

Finding interesting rule in the sixth strategy step about threshold control on generalized relations in attribute oriented induction, there is possibility to select candidate attribute for further generalization and merging of identical tuples until the number of tuples is no greater than the threshold value, as implemented in basic attribute oriented induction algorithm. At this strategy step there is possibility the number of tuples in final generalization result still greater than threshold value. In order to get the final generalization result which only small number of tuples and can be easy to transfer into simple logical formula, the seventh strategy step about rule transformation is evolved where there will be simplification by unioning or grouping the identical attribute. Our approach to measure interesting rule is opposite with heuristic measurement approach by Fudger and Hamilton where the more complex concept ...

British Library Electronic Table of Contents (United Kingdom)

Odontocetes are believed to receive sounds primarily through the pan bone region of the lower jaw although much variation in jaw morphology exists among species. In order to further examine this jaw hearing hypothesis we tested the head receiving sensitivity and directional hearing of a beluga whale, Delphinapterus leucas. Hearing thresholds were measured using auditory evoked potentials (AEPs). The subject proved to have highly directional hearing for far-field click stimuli similar to that of bottlenose dolphins and more directional than the harbor porpoise. For near-field jawphone stimulation, the beluga's lowest thresholds were found when click stimuli were presented at the rostrum tip (76?dB re: 1??Pa) although thresholds from the pan bone region stimulation were only 2?3?dB higher. S...

CERN Document Server

In cluster-based routing protocol (CBRP), two-level hierarchical structure is successfully used to reduce over-flooding in wireless Ad Hoc networks. As it is vulnerable to a single point of failure, we propose a new adaptive distributed threshold scheme to replace the cluster head by a group of cluster heads within each cluster, called COUNCIL, and distribute the service of single cluster head to multiple cluster heads using (k,n) threshold secret sharing scheme. An Ad Hoc network formed by COUNCIL based clusters can work correctly when the number of compromised cluster heads is smaller than k. To implement this adaptive threshold scheme in wireless Ad Hoc Networks, membership of the clusters should be defined in an adaptive way. In this paper, we mainly discuss our algorithm for forming COUNCIL based clusters using the concept of dominating set from graph theory.

CERN Document Server

In this paper, we investigate the epidemic spreading for SIR model in weighted scale-free networks with nonlinear infectivity, where the transmission rate in our analytical model is weighted. Concretely, we introduce the infectivity exponent $\\alpha$ and the weight exponent $\\beta$ into the analytical SIR model, then examine the combination effects of $\\alpha$ and $\\beta$ on the epidemic threshold and phase transition. We show that one can adjust the values of $\\alpha$ and $\\beta$ to rebuild the epidemic threshold to a finite value, and it is observed that the steady epidemic prevalence $R$ grows in an exponential form in the early stage, then follows hierarchical dynamics. Furthermore, we find $\\alpha$ is more sensitive than $\\beta$ in the transformation of the epidemic threshold and epidemic prevalence, which might deliver some useful information or new insights in the epidemic spreading and the correlative ...

CERN Document Server

It has previously been shown that ensembles of terminated protograph-based low-density parity-check (LDPC) convolutional codes have a typical minimum distance that grows linearly with block length and that they are capable of achieving capacity approaching iterative decoding thresholds on the binary erasure channel (BEC). In this paper, we review a recent result that the dramatic threshold improvement obtained by terminating LDPC convolutional codes extends to the additive white Gaussian noise (AWGN) channel. Also, using a (3,6)-regular protograph-based LDPC convolutional code ensemble as an example, we perform an asymptotic trapping set analysis of terminated LDPC convolutional code ensembles. In addition to capacity approaching iterative decoding thresholds and linearly growing minimum distance, we find that the smallest non-empty trapping set of a terminated ensemble grows linearly with block length.

UK PubMed Central (United Kingdom)

Motivation: Since database retrieval is a fundamental operation, the measurement of retrieval efficacy is critical to progress in bioinformatics. This article points out some issues with...Full Text Available

Science.gov (United States)

These sky images are scanned for point sources above a specified ... The threshold criteria are: a) Gold: >4 sigma in both the Soft AND Hard bands. b) Silver: ... Filtering: Currently, there is no plan for filtering within the GCN based ...

UK PubMed Central (United Kingdom)

The specific white matter location of all the spinal pathways conveying penile input to the rostral medulla is not known. Our previous studies using rats demonstrated the loss of low but not high threshold...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The A(..pi../sup +/,/sup 3/He)B reaction near threshold is studied in a model where the pion is absorbed by an /sup 4/He constituent of the target nucleus. The predictions of this model using harmonic oscillator cluster wave functions agree semi-quantitatively with the experimental data on the inverse reaction.

UK PubMed Central (United Kingdom)

SummaryBody condition affects the timing and magnitude of life history transitions. Therefore, identifying proximate mechanisms...Full Text Available

UK PubMed Central (United Kingdom)

The genetic basis of odorant-specific variations in human olfactory thresholds, and in particular of enhanced odorant sensitivity (hyperosmia), remains largely unknown. Olfactory receptor (OR) segregating...Full Text Available

CERN Document Server

The behavior of silver and lead azides (scaly and threadlike crystals, and compacted powders) in initiation of explosive decomposition by laser pulsed radiation has been investigated. Initiation energy thresholds in irradiation at wavelengths of 1064 nm, 532 nm, 354.7 nm, 266 nm corresponding to four laser radiation harmonics have been measured. Samples both uncovered and covered with a transparent dielectric (a quartz plate) with the compressive force of up to 0.5GPa were initiated. In the transparent spectral region (the first and second laser harmonics) of the heavy metal azide matrix the effect of covering the sample surface with a plate on initiation energy threshold was insignificant, whereas, in the region of bandgap absorption (the fourth harmonic) strong dependence of the initiation threshold on whether the surface under irradiation is uncovered or covered. The results obtained have been considered with the account ...

International Nuclear Information System (INIS)

Cardiac disease research relies increasingly on small animal models and non-invasive imaging methods such as positron emission tomography (PET) and magnetic resonance imaging (MRI). Delayed enhancement magnetic resonance imaging (DE-MRI) using gadolinium-based contrast agents appear to be a visualizing infracted myocardium with high spatial resolution. Polar map (or bull's-eye image) was used to determination of the myocardial infarction area. Polar map is a comprehensive interpretation of the left ventricle. The infarct size was computed as the fraction of the total polar map areas. The threshold was computed as the percentage of mean intensity of the normal region. In other study, 50% predefined threshold value in varying range (30?70%) was most commonly use. However, predefined threshold value isn't acceptance in all case. The purpose of this study was to investigate methodological approach for automatic measurement of ...

UK PubMed Central (United Kingdom)

A common approach used to fuse simultaneously recorded EEG and fMRI is to correlate trial-by-trial variability in the EEG, or variability of components derived therefrom, with the blood oxygenation...Full Text Available

UK PubMed Central (United Kingdom)

AimsTo compare the theoretical retinal threshold time for endoilluminators and experimental phototoxic effect using A2e laden retinal pigment epithelial (RPE) cells.MethodsThe...Full Text Available

International Nuclear Information System (INIS)

Total dose irradiation effects on a VDMOS developed at Institute of Microelectronics, CAS were investigated, particularly the electric parameter changes under different bias conditions. It was found that the breakdown voltage degradation by the irradiation depended mainly on the drain bias, whereas the threshold voltage degradation depended mainly on the gate bias. Thus, an innovative and effective method to domestic VDMOS total dose ionization characterization is that threshold voltage radiation hardening characterization should be tested on gate bias condition, and the breakdown voltage radiation hardening characterization, be tested on the drain bias. (authors)

Energy Technology Data Exchange (ETDEWEB)

Total photon attenuation coefficients near absorption edges are determined in certain suitable elements and compounds. Photoelectric cross sections for elements are deduced from these by subtracting the coherent and incoherent scattering cross sections as well as other elemental cross sections in the cases of compounds. Certain deviations are observed on comparison with the available theoretical and experimental compilations. The I/sub L//sub ..cap alpha..//Il x-ray intensity ratio measured by photon excitation near threshold is found to agree better with the theory than the other available experimental data.

CERN Document Server

The recent measurements by the BES Collaboration of J/psi decays into a photon and a proton-antiproton pair indicate a strong enhancement at the proton-antiproton threshold not observed in the decays into a neutral pion and a proton-antiproton pair. Is this enhancement due to a proton-antiproton quasi-bound state or a baryonium? A natural explanation follows from a traditional model of proton-antiproton interactions based on G-parity transformation. The observed proton-antiproton structure is due to a strong attraction in the 1S0 state, and possibly to a near-threshold quasi-bound state in the 11S0 wave.

Energy Technology Data Exchange (ETDEWEB)

Washboard (WB) modes (Smeulders P et al 1999 Plasma Phys. Control. Fusion 41 1303) are a very common edge instability regularly observed in the H-mode regime in JET. They are detected as (normally several) bands of continuously fluctuating magnetic activity rotating in the direction of the electron diamagnetic drift with typical frequencies in the range of 10-90 kHz. The time evolution of the WB mode frequency is found to follow qualitatively the evolution of the electron temperature measured near the pedestal top, probably due to the strong diamagnetic drift associated with the large pedestal gradients. Evidence for their involvement in the pedestal and ELM dynamics will be presented. Increasing WB mode amplitude is correlated with an increase in the time between consecutive type-I ELMs. In situations in which a sudden increase (decrease) of WB mode activity is observed, the build-up of the pedestal temperature (and, linked to this, also of the pedestal pressure) ...

Energy Technology Data Exchange (ETDEWEB)

This work presents a study of the {sup 1}P{sup 0} excited states of He that can be reached by absorption of a single photon carrying an energy close to the double ionization threshold (DIT) (79 eV). Above the DIT, these states are the double continuum states; below, they are the double excited states. These two types of states are tightly coupled to the single continuum states with or without excitation of the residual ion He{sup +}, owing to their degeneracy in energy. In a one-photon process, these states can only be formed owing to the electronic correlations in the system which must be well described to obtain quantitative good results. Our study is a part of the work which aims at a united description of all these doubly excited, ionized-excited, and double continuum states. We use the Hyperspherical R-Matrix with Semiclassical Outgoing Waves (HRM-SOW) method, initially dedicated to double photoionization studies. We extend it to extract information on the ...

International Nuclear Information System (INIS)

In not infected knee prostheses bone scintigraphy is a possible method to diagnose mechanical loosening, and therefore, to affect treatment regimes in symptomatic patients. However, hitherto studies showed controversial results for the reliability of bone scintigraphy in diagnosing loosened knee prostheses by using asymptomatic control groups. Therefore, the aim of our study was to optimize the interpretation procedure and to evaluate the accuracy using results from revision surgery as standard. Methods: Retrospectively, we were able to examine the tibial component in 31 cemented prostheses. In this prostheses infection was excluded by histological or bacteriological examination during revision surgery. To quantify bone scintigraphy, we used medial and lateral tibial regions with a reference region from the contralateral femur. Results: to differentiate between loosened and intact prostheses we found a threshold of 5.0 for the maximum tibia to femur ratio of the ...

CERN Document Server

We investigate the $D\\bar{D}$ production in $e^+e^-$ annihilations near threshold in an effective Lagrangian approach. It shows that the lineshape of the cross section near threshold is sensitive to the contributions from the $\\psi^\\prime$ though it is below the $D\\bar{D}$ threshold. The recent experimental data from BES and Belle collaborations allow us to determine the $\\psi^\\prime D\\bar{D}$ coupling constant which appears to be consistent with other theoretical studies. As a consequence, the $\\psi^\\prime$-$\\psi(3770)$ mixing parameter can be extracted around the $\\psi(3770)$ mass region. Resonance parameters for $\\psi(3770)$, X(3900), $\\psi(4040)$ and $\\psi(4160)$ are also investigated. The X(3900) appears as an enhancement at around 3.9 GeV in the Belle data. In addition to treating it as a resonance, we also study the mechanism that the enhancement is produced by the $D\\bar{D^*}+c.c.$ open channel ...

CERN Document Server

We improve the steady-state ab initio laser theory (SALT) of Tureci et al. by expressing its fundamental self-consistent equation in a basis set of threshold constant flux states that contains the exact threshold lasing mode. For cavities with non-uniform index and/or non-uniform gain, the new basis set allows the steady-state lasing properties to be computed with much greater efficiency. This formulation of the SALT can be solved in the single-pole approximation, which gives the intensities and thresholds, including the effects of nonlinear hole-burning interactions to all orders, with negligible computational effort. The approximation yields a number of analytic predictions, including a "gain-clamping" transition at which strong modal interactions suppress all higher modes. We show that the single-pole approximation agrees well with exact SALT calculations, particularly for high-Q cavities. Within this range of validity, ...

International Nuclear Information System (INIS)

A merged-beams electron-energy-loss technique is described, by which absolute cross sections can be measured for near-threshold electron-impact excitation of multipy charged ions. Results are reported here for absolute total electron-impact excitation cross sections for the O"5"+(2s#->#2p) transition from below threshold to 1.6 eV above threshold. The experimental data are in good agremeent with a seven-state close-coupling calculation throughout the energy range of the experiment. Results agree with calculations showing that more than 90% of the electrons causing excitation are ejected in the backward direction in the center-of-mass frame. This backscattering is shown in both quantum-mechanical and semiclassical calculations. Evidence is observed for high-lying metastable autoionizing states with a lifetime of approximately 0.9 #mu#s which are made to ionize by electron impact.

Energy Technology Data Exchange (ETDEWEB)

With using artificial neural networks (ANNs), an analytical study related to the heated length effect on critical heat flux (CHF) has been carried out to make an improvement of the CHF prediction accuracy based on local condition correlations or table. It has been carried out to suggest a feasible criterion of the threshold length-to-diameter (L/D) value in which heated length could affect CHF. And within the criterion, a L/D correction factor has been developed through conventional regression. In order to validate the developed L/D correction factor, CHF experiments for various heated lengths have been carried out under low and intermediate pressure conditions. The developed threshold L/D correlation provides a new feasible criterion of L/D threshold value. The developed correction factor gives a reasonable accuracy for the original database, showing the error of -2.18% for average and 27.75% for RMS, and promising results ...

Science.gov (United States)

The primary concern of this work is to study the emission characteristics of a series of chiral nematic liquid crystal lasers doped with different laser dyes (DCM, pyrromethene 580, and pyrromethene 597) at varying concentrations by weight (0.5-2 wt %) when optically pumped at 532 nm. Long-wavelength photonic band-edge laser emission is characterized in terms of threshold energy and slope efficiency. At every dye concentration investigated, the pyrromethene 597-doped lasers exhibit the highest slope efficiency (ranging from 15% to 32%) and the DCM-doped lasers the lowest (ranging from 5% to 13%). Similarly, the threshold was found to be, in general, higher for the DCM-doped laser samples in comparison to the pyrromethene-doped laser samples. These results are then compared with the spectral properties, quantum efficiencies and, where possible, fluorescence lifetimes of the dyes dispersed in a common nematic host. In accordance with the low ...

International Nuclear Information System (INIS)

We have investigated the diffusion enhancement mechanism of boron-enhanced diffusion (BED), wherein boron diffusivity is enhanced four to five times over the equilibrium diffusivity at 1050 ampersand hthinsp;degree C in the proximity of a silicon layer containing a high boron concentration. It is demonstrated that BED is driven by excess interstitials injected from the high boron concentration layer during annealing. For evaporated layers, BED is observed above a threshold boron concentration between 1% and 10%, though it appears to be closer to 1% for B-implanted layers. For sub-keV B implants above the threshold, BED dominates over the contribution from transient-enhanced diffusion to junction depth. For 0.5 keV B, this threshold implantation dose lies between 3x10"1"4 and 1x10"1"5 cm"-"2. It is proposed that the excess interstitials responsible for BED are produced during the formation of a silicon boride phase in the ...

CERN Document Server

The near-threshold enhancement in the ppbar invariant mass spectrum from the B^+ -> K^+ ppbar decay reported recently by the BaBar Collaboration is studied within the J\\"ulich NNbar model. We illustrate that the invariant mass dependence of the ppbar spectrum close to the threshold can be reproduced by the final state interactions. This explanation is in line with our previous analysis of the ppbar invariant mass spectrum from the J/Psi -> gamma ppbar decay measured by the BES Collaboration. We also comment on a structure found recently in the pi^+ pi^- eta' mass spectrum of the radiative J/Psi decay by the BES Collaboration. In particular we argue that one should be rather cautions in bringing this structure in connection with the enhancement found in the ppbar invariant mass spectrum or with the existence of NNbar bound states.

British Library Electronic Table of Contents (United Kingdom)

Abstract We analyse extinction maps of nearby giant molecular clouds to forge a link between driving processes of turbulence and modes of star formation. Our investigation focuses on cloud structure in the column density range above the self-shielding threshold of 1-mag AV and below the star formation threshold - the regime in which turbulence is expected to dominate. We identify clouds with shallow mass distributions as cluster forming. Clouds that form stars in a less clustered or isolated mode show a steeper mass distribution. Structure functions prove inadequate to distinguish between clouds of different star formation mode. They may, however, suggest that the turbulence in the average cloud is governed by solenoidal forcing. The same is found using the -variance analysis which also in...

CERN Document Server

A new property which relies on the linear programming (LP) decoder, the approximate maximum-likelihood certificate (AMLC), is introduced. When using the belief propagation decoder, this property is a measure of how close the decoded codeword is to the LP solution. Using upper bounding techniques, it is demonstrated that the conditional frame error probability given that the AMLC holds is, with some degree of confidence, below a threshold. In channels with low noise, this threshold is several orders of magnitude lower than the simulated frame error rate, and our bound holds with very high degree of confidence. In contrast, showing this error performance by simulation would require very long Monte Carlo runs. When the AMLC holds, our approach thus provides the decoder with extra error detection capability, which is especially important in applications requiring high data integrity.

International Nuclear Information System (INIS)

This paper describes an experiment which has been performed with a somewhat different philosophy in its approach as compared to previous work. (a) The trigger threshold energy was increased by more than a factor of ten on previous experiments reducing the dilution effect of many lower energy showers known not to produce tachyons. 1673 shower were recorded. (b) The exposure time was made longer than previous experiments in order to obtain a reasonably large statistical sample at the higher threshold. Observations were made between February 1979 and June 1980, the total live time being 9768 hours. (c) Records of the detector output amplitude for the 480#mu#s lead time were integrated point by point as is sometimes done in radio astronomy, this gives the integrated energy deposition within the detector.

Energy Technology Data Exchange (ETDEWEB)

I present an overview of the measurement of the proton form factors in the time-like regiun. BABAR has recently measured with great accuracy the e{sup +} e{sup -} {yields} p p-bar reaction from productiun threshold up to an energy of {approx} 4.5 GeV; finding evidence for a ratio of the electric to magnetic form factur greater than unity, contrary to expectation. In agreement with previous measurements. BABAR confirmed the steep rise uf the magnetic form factor close to the p p-bar mass threshold, suggesting the possible presence of an under-threshuld N N-bar vector state. These and uther open questiuns related to the nucleon furm factors both in the time-like and space-like region, wait for more data with different experimental techniques to be possibly solved.

Energy Technology Data Exchange (ETDEWEB)

The dd{yields}{sup 4}He{eta} reaction has been investigated near threshold using the ANKE facility at COSY-Juelich. Both total and differential cross-sections have been measured at two excess energies, Q=2.6 MeV and 7.7 MeV, with a subthreshold measurement being undertaken at Q=-2.6 MeV to study the physical background. While consistent with isotropy at the lower energy, the angular distribution reveals a pronounced anisotropy at the higher one, indicating the presence of higher partial waves. Options for the decomposition into partial amplitudes and their consequences for the determination of the s-wave {eta}{alpha} scattering length are discussed. (orig.)

British Library Electronic Table of Contents (United Kingdom)

An improved singular value decomposition method of gear fault identification based on Hilbert-Huang transform was proposed to overcome the problem of reconstructing a feature matrix of singular value decomposition. The method includes three steps. First, the instantaneous frequency and amplitude matrices were acquired by Hilbert-Huang transform from faulted gear signals. Second, after the matrices were decomposed by singular value decomposition, the defined distances of singular value vectors and the optimal threshold of the distance for classification were calculated. Third, the fault characteristics of a gearbox were identified and classified by the threshold of the distances. The result demonstrates that the proposed method effectively identifies the gear fault and can realize an automa...

International Nuclear Information System (INIS)

We report on the fabrication of nanomechanical devices for shuttling of electrons from one electrode to another. Each device consists of a 20 nm diameter gold nanoparticle embedded within the gap between two gold electrodes. In two different kinds of shuttle-junctions the nanoparticle is attached to the electrodes through either (i) a single layer of 1,8-octanedithiol or (ii) a multilayer of 1-octanethiol molecules. The thiol layers play the role of 'damped springs', such that when a sufficient voltage bias is applied to the junction, the nanoparticle is expected to start oscillating and thereby transferring electrons from one electrode to the other. For both kinds of shuttle-junctions we observed an abrupt increase in the transmitted current above a threshold voltage, which can be attributed to a transition from the stationary to the oscillating regime. The threshold voltage was found to be lower for single-layer shuttle-junctions.

DEFF Research Database (Denmark)

Given a set of users, their friend relationships, and a distance threshold per friend pair, the proximity detection problem is to find each pair of friends such that the Euclidean distance between them is within the given threshold. This problem plays an essential role in friend-locator applications and massively multiplayer online games. Existing proximity detection solutions either incur substantial location update costs or their performance does not scale well to a large number of users. Motivated by this, we present a centralized proximity detection solution that assigns each mobile client with a mobile region. We then design a self-tuning policy to adjust the radius of the region automatically, in order to minimize communication cost. In addition, we analyze the communication cost of our solutions, and provide valuable insights on their behaviors. Extensive experiments suggest that our proposed solution is efficient and robust with respect ...

International Nuclear Information System (INIS)

We study the dynamical evolution of a scalar field coupling to Einstein's tensor in the background of a Reissner-Nordstroem black hole. Our results show that the coupling constant #eta# imprints in the wave dynamics of a scalar perturbation. In the weak coupling, we find that with the increase of the coupling constant #eta# the real parts of the fundamental quasinormal frequencies decrease and the absolute values of imaginary parts increase for fixed charge q and multipole number l. In the strong coupling, we find that for l#not =#0 the instability occurs when #eta# is larger than a certain threshold value #eta#_c which deceases with the multipole number l and charge q. However, for the lowest l=0, we find that there does not exist such a threshold value and the scalar field always decays for arbitrary coupling constant.

International Nuclear Information System (INIS)

Absolute total cross sections for electron-impact excitation of the 3s"2"1S#->#3s3p"3P and 3s"2"1S#->#3s3p"1P transitions in Si"2"+ were measured using the merged electron-ion beams energy-loss technique. The results are compared to R-matrix close-coupling theory, which predicts a strong resonance enhancement of the cross section near the threshold for excitation of the "3P state and this is confirmed by the experiments. The observed disagreement between theory and experiment for the dipole excitation is suggested to be due to resonance interference. copyright 1997 The American Physical Society.

International Nuclear Information System (INIS)

May 1972. United States Warren, FH Federal Power Commission,

International Nuclear Information System (INIS)

This is a manuscript for a lecture contents: 1. Steam power and fundamentals of the steam power process, 2. conventional, nuclear and other steam generation processes, 3. cooling systems for steam power plants, 4. gas turbine power plants and combined-cycle power plants, 5. cogeneration, 6. development of thermal power plants and environmental effects. (orig.).

Medline Plus

English - Downed Power Lines Click to Stop Video Click to Start Video To Listen to the Audio ...

International Nuclear Information System (INIS)

Reactor Power Measurement is an essential part of the Reactor Power Control Loop in PHWRs. None of the available power measuring sensor offers characteristics which allow their direct use in the Reactor Power Control Loop. Thermal power, which is considered as relatively accurate, suffers from measurement delays and is used only as reference. Neutronic power sensors like Ion Chambers and Self Powered Neutron Detectors (SPNDs) which sense instantaneous power suffer from inaccuracies. A technique is required which makes use of both types-reference power and instantaneous power to extract real power information from the signals. This paper describes techniques to calibrate (correct) neutronic power that with the thermal reference ...

International Nuclear Information System (INIS)

The article deals with the effects of various hazardous materials in the working environment. Some of these may be detrimental to the safety and health of the worker. The absorption of hazardous substances by the human body is discussed, as well as the effects of toxic substances. The hazardous substances are classified into the following categories: irritants, asphyxiants, anaesthetics and narcotics, carcinogens, mutagens, teratogens, systemic poisons, hazardous particulate matter and the biotransformation of toxic substances. Examples of hazardous substances include: industrial solvents, fumes and vapours, lead, mercury and uranium.

Science.gov (United States)

The threshold stress itensities for stress corrosion crack propagation in beta titanium alloy 38-6-44, Ti-3Al-8V-6Cr-4Mo-4Zr, has been determined in salt water and methanolic solutions. The alloy was immune to stress corrosion cracking in aqueous sodium c...

International Nuclear Information System (INIS)

The energy distribution of neutrons generated due to bombardment of 40 MeV alpha particles on thick elemental tantalum is measured using threshold activation detectors. A method of unfolding the neutron spectrum from the activation data based on information-entropy weighted average solution is described. The present unfolding method does not require 'a priori' information about the shape of the solution spectrum. 16 refs. (author).

Energy Technology Data Exchange (ETDEWEB)

The authors propose an integrated indicator of pump-rod couplings that allows both the couplings and the pump operations to be appraised according to the given formula. (Formula provided). The dynamic relationships of rod operations were determined with nomographs. These relationships involve such factors as: the type and size of the sucker-rod string; the pressure load at the equalizer head and its correlation to threshold pressure at pump discharge; pump diameter; the rod weight and construction; and integral reliability indicators.

Energy Technology Data Exchange (ETDEWEB)

The influence of MeV electrons irradiation on the gate oxide layers of hydrogenated polysilicon thin film transistors (TFTs) was investigated by measuring gate leakage currents and threshold voltages. The experimental data revealed a decrease of oxide trap density and increase of positive oxide charge. Improvement in the interface roughness and in the oxide quality near the bottom interface was observed.

CERN Document Server

We extend two results on Chow (semi-)stability to positive characteristics. One is on the stability of non-singular projective hypersurfaces of degree greater than 2, and the other is the criterion by Y. Lee in terms of log canonical thresholds. Some properties of log-canonicity in positive characteristics are discussed with a couple of examples, in connection with the proof of the latter one. It is also proven in appendix that the sum of Chow (semi-)stable cycles are again Chow (semi-)stable.

Science.gov (United States)

The kinetics of benzoate degradation by the anaerobic syntrophic bacterium, Syntrophus buswellii, was studied in coculture with Desulfovibrio strain G11. The threshold value for benzoate degradation was dependent on the acetate concentration with benzoate threshold values ranging from 2.4 [mu]M at 20 mM acetate to 30.0 [mu]M at 65 mM acetate. Increasing acetate concentrations also inhibited the rate of benzoate degradation with a apparent K[sub i] for acetate inhibition of 7.0 mM. Lower threshold values were obtained when nitrate rather than sulfate was the terminal electron acceptor. These data are consistent with a thermodynamic explanation for the threshold, and suggest that there is a minimum Gibbs free energy value required for the degradation of benzoate. An acetoacetyl-CoA thiolase has been isolated from Syntrophomonas wolfei; it is apparently a key enzyme controlling the synthesis of ...

Energy Technology Data Exchange (ETDEWEB)

The critical concentrations correspond to contamination thresholds of environments over which noxious effects can occur and deteriorate soils, water and vegetation. They are defined according to the type of pollutants and their mode of action. The aim of this document is to provide a scientific framework to the policies of reduction of atmospheric pollution negotiated at Geneva`s convention. The methodology of evaluation, the results obtained for surface waters and forest soils, the perspectives of French research and the integration of French knowledge in the European database are presented. (J.S.)

International Nuclear Information System (INIS)

1. It is not possible to give a threshold value for the dose - nor for genetic neither for somatic late effects. 2. The linear dose-effect exprapolation is not conservative in the sense of 'fying on the safe side'. 3. There has been found no relative reduction of the effects at chronic radiation exposure in man. 4 The numbers given by authorities and utilities for damage rates per rem received, that are called upper limits, are by far too low. (orig./HP).

International Nuclear Information System (INIS)

A simple model is described to simulate kinetic processes in dielectric barrier discharges for O_2/NO_x mixtures. A threshold of ozone production found experimentally is confirmed by the calculations of this modeling, and the underlying chemical reaction mechanisms are discussed. It is also found that the effects of diffusion processes in the period of the lifetime of O atoms are not important to micro-discharge channels with a large radius, i.e. larger than 150 #mu#m

Energy Technology Data Exchange (ETDEWEB)

Poland intends to construct 2,000 MW of wind power systems during the next four years. This is the start of the Polish wind power industry. (orig.)

Science.gov (United States)

... Those functions are fundamental routines to build a power model for more complex circuits or functional blocks. ... 21 of 54 6. Memory Power Model ...

KoreaScience (Korea)

Full Text Available

Science.gov (United States)

No Abstract Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Norwegian Open Research Archives (NORA)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

No abstract available.

Science.gov (United States)

...2010-10-01 2010-10-01 false Battery or power supply with respect to relay...Signal Systems Standards § 236.206 Battery or power supply with respect to relay; location. The battery or power supply for each signal...

International Nuclear Information System (INIS)

... thermal power plants thermal reactors water cooled reactors WATER

Science.gov (United States)

Sunflower 3 kW mercury Rankine power conversion system

Science.gov (United States)

... Accession Number : ADA350829. Title : Operational Characteristics of a Liquid Nitrogen Powered Automobile. Descriptive Note : Master's thesis. ...

Science.gov (United States)

... measurement. Power spectral density measurements are made by the dynamic signal analyzer for each channel. A cross power ...

International Nuclear Information System (INIS)

The manual presents the fundamentals of thermodynamics and fluid mechanics, the main components of steam power plants, and the power generation process. The following concepts and subjects are discussed at length: steam generator; steam turbines; turbogenerators; condensers; cooling technology; water/steam cycle and water treatment; design data of fossil-fuelled power plants; design and optimisation of nuclear power plant thermodynamics; pipelines and fittings; control systems in steam power plants; connection to the electricity grid and self-supply of thermal power plants; power plant transformer concepts and definitions. (HAG).

International Nuclear Information System (INIS)

Stretch-Out and Extended Low Power Operation is two particular operating modes applied for nuclear electricity generation. The relevant safety analysis and the impacts on plant operation are well illustrated, as well as some operation experiences earned in Daya Bay nuclear power station. The safety analysis and plant practice show that Stretch-Out operation and Extended Low Power Operation are operable in Daya Bay nuclear power station

International Nuclear Information System (INIS)

The invention concerns a procedure for operating reactors in nuclear power plants. It aims at utilizing power reserves in nuclear power plants. This can be achieved by a steam-side connection of the steam generators of two reactors. The amount of steam exchanged between the units is chosen in such a way that power changes at the steam turbines feedback mainly to the corresponding reactor. In order to realize a high power transfer it is necessary to return the amount of condensate produced in the steam receiving unit and corresponding to the power transferred to the feedwater system of the steam donating unit.

Energy Technology Data Exchange (ETDEWEB)

Room-temperature cw operation for InGaP/InGaAlP double heterostructure (DH) laser diodes on GaAs substrates was achieved for the first time. The DH wafers were grown by low-pressure metalorganic chemical vapor deposition using methyl metalorganics. A lasing wavelength of 679 nm and a threshold current of 109 mA at 24C were obtained for an inner stripe structure laser diode with a 250- m-long and 7- m stripe geometry. The laser operated at up to 51C. The characteristic temperature T0 was 87 K at around room temperature. The lowest threshold current density, 5.0 kA/cmS, was obtained with a 20- m stripe width laser diode under room-temperature pulsed operation.

International Nuclear Information System (INIS)

Seven types of shellfish were irradiated by gamma ray at doses of 0, 3 and 6 kGy. Pulse photo-stimulated luminescence (PPSL) and thermoluminescence (TL) methods were employed to detect the radiation treatment. The screening of irradiation was carried out by the PPSL method followed by identification using the TL technique. Most of the irradiated shellfish were screened out correctly and only a few showed photon counts a bit higher than the lower threshold value by much lower than the upper threshold value. The TL method was employed using minerals isolated from all the control and irradiated shellfish samples by density gradient treatment. Three parameters, integrated intensities of first glow curves (TL1), ratios of first to that of second glow curves (TL1/TL2), and the shapes of maxima of first glow curves, were utilized for the identification of gamma ray treatment of shellfish. (author)

International Nuclear Information System (INIS)

The excitation cross sections by electron impact from the Cd II ground state to the laser upper state 5s_2 _2D/sub 5/2/ (Beutler state) and the laser lower state 5p _2P/sub 3/2/ (resonance state) have been measured by using a crossed-beam method of electrons and Cd"+ ions and a photon-counting method. The electron-energy region investigated was from the threshold energy (5.8 eV) for the excitation of the 5p _2P/sub 3/2/ state to 20 eV. It has been shown that the excitation cross section for the ionic Beutler state 5s_2 _2D/sub 5/2/ is of the order of 10"-_1_5 cm_2 and has a sharp peak near the threshold energy for the excitation. The excitation cross section for the resonance state 5p _2P/sub 3/2/ has also been of the order of 10"-_1_5 cm_2 and has a relatively broad maximum.

International Nuclear Information System (INIS)

The combined effects of environment, yield strength and stress state on the cracking susceptibility of beta-extruded Ti-6Al-6V-2Sn have been examined. At a constant yield strength and under plane strain conditions, the stress intensity required for slow crack propagation decreased as the severity of the environment increased, i.e., from laboratory air to 3.5% NaCl. Furthermore, the crack propagation rates were a function of both stress intensity, and environmental severity. Although the fracture toughness and threshold stress intensities for slow crack growth generally decreased with increasing yield strength, aging, which resulted in the precipitation of ordered Ti3Al particles in the primary alpha phase, tended to accentuate the susceptibility of this alloy to sustained load/stress corrosion cracking. Finally, at constant yield strength, the sustained load cracking threshold stress intensity was a function of stress state.

Energy Technology Data Exchange (ETDEWEB)

The cell is modeled as an ellipsoid with shell and the surface stress distribution calculated by means of the Maxwell Stress Tensor. The cell membrane is treated as incompressible material having both bending and shear energies of deformation. Employing the principle of virtual work, cell volume (and hence shape) is computed as a function of the external field strength and orientation with respect to the field. The following results were obtained: (1) The surface stresses that develop or the cell membrane are distributed having both normal and tangential components that act together to produce a rounding of the cell. (2) If the tangential component of the stress is ignored, then higher field strengths are needed to produce similar deformation (shape change) of cells. (3) The threshold value of the applied field, i.e, the field strength at which the volume (shape) of the cell changes abruptly, occurs at approximately 55V/cm. Above the threshold ...

International Nuclear Information System (INIS)

The effects of gate and drain bias stresses on thin film transistors fabricated in polysilicon films crystallized using the advanced sequential lateral solidification excimer laser annealing (SLS ELA) process, which yields very elongated polysilicon grains and allows the fabrication of TFTs without grain boundary barriers to current flow, are investigated as a function of the active layer thickness and of the TFT orientation relative to the grains. The application of hot carrier stress, with a condition of V_G_S = V_D_S/2, was determined to induce threshold voltage, subthreshold swing and transconductance degradation for TFTs in thicker polysilicon films and the associated stress-induced increase in the active layer trap density was evaluated. However, this device degradation was drastically reduced for TFTs fabricated in ultra-thin films. Furthermore, the application of the same stress condition to TFTs oriented vertically to the elongated grains resulted in ...

CERN Document Server

A salient facet of Axelrod's model for culture dissemination or social influence is the existence of many multicultural absorbing states. The dependence of the number $C$ of different, coexisting cultures on the size $A$ of the territory or, equivalently, on the number of agents -- the culture-area relation -- is investigated through extensive simulations. This relation exhibits a strong qualitative dependence on the two parameters of the model, namely, the number $F$ of culture features and the number $q$ of values that each feature can take on. We find that a non-monotonous culture-area relation, for which the number of cultures decreases when the area grows beyond a certain size, occurs for $q$ smaller than a threshold value $q_c = q_c (F)$ provided that $F \\geq 3$. In the limit of infinite area, this threshold value signals the onset of a discontinuous phase transition between a homogeneous regime for which C=1, and a completely disordered ...

CERN Document Server

Spam messes up user's inbox, consumes network resources and spread worms and viruses. Spam is flooding of unsolicited, unwanted e mail. Spam in blogs is called blog spam or comment spam.It is done by posting comments or flooding spams to the services such as blogs, forums,news,email archives and guestbooks. Blog spams generally appears on guestbooks or comment pages where spammers fill a comment box with spam words. In addition to wasting user's time with unwanted comments, spam also consumes a lot of bandwidth. In this paper, we propose a software tool to prevent such blog spams by using Bayesian Algorithm based technique. It is derived from Bayes' Theorem. It gives an output which has a probability that any comment is spam, given that it has certain words in it. With using our past entries and a comment entry, this value is obtained and compared with a threshold value to find if it exceeds the threshold value or not. By using this concept, we ...

Science.gov (United States)

The authors have presented results of an investigation of wettability of SiC particulates by liquid alloys of the Al-Si-Mg system. The evaluation of wetting has been carried out through the determination of the threshold pressure for infiltration of packed SiC particulates by the liquid alloy. The results indicate that whereas Si and Mg additions do not affect wetting, in the case of the ternary alloys the contact angle decreases in an amount proportional to the content of Mg[sub 2]Si.

Energy Technology Data Exchange (ETDEWEB)

The general usefulness of neutron activation analysis (NAA) for samples containing the platinum group elements and Au, either as major or trace constituents, is discussed. Charged particle activation is shown to be a viable or complementary alternative. Proton (6-10 MeV) and alpha particle (9-15 MeV) beams, produced in a Tandem van de Graaff accelerator, have been established to be the most effective choice. By taking advantage of the Coulomb barrier effect and the fact that many charged particle induced reactions have relatively large threshold values, the same instrumental technique can be applied, with minor modifications, to a wide range of materials.

International Nuclear Information System (INIS)

The theoretical hardness against total dose of the six-transistor SRAM cell is investigated in detail. An explicit analytical expression of the maximum tolerable threshold voltage shift is derived for two cross-coupled inverters. A numerical method is used to explore the hardness of the read and write operations. Both N- and P-channel access transistors designs are considered and their respective advantages are compared. The study points out that the radiation hardness mainly relies on the technology. Results obtained with the very robust Gate-All-Around process are finally presented.

British Library Electronic Table of Contents (United Kingdom)

Abstract This paper proposes and analyses the autoregressive conditional root (ACR) time-series model. This multivariate dynamic mixture autoregression allows for non-stationary epochs. It proves to be an appealing alternative to existing nonlinear models, e.g. the threshold autoregressive or Markov switching class of models, which are commonly used to describe nonlinear dynamics as implied by arbitrage in presence of transaction costs. Simple conditions on the parameters of the ACR process and its innovations are shown to imply geometric ergodicity, stationarity and existence of moments. Furthermore, consistency and asymptotic normality of the maximum likelihood estimators are established. An application to real exchange rate data illustrates the analysis.

CERN Document Server

An electroweak singlet scalar can couple to pairs of vector bosons through loop-induced dimension five operators. Compared to a Standard Model Higgs boson, the singlet decay widths in the diphotons and Z gamma channels are generically enhanced, while decays into massive final states like WW and ZZ are kinematically disfavored. The overall event rates into gamma gamma and Z gamma can exceed the Standard Model expectations by orders of magnitude. Such a singlet may appear as a resonant signal in the gamma gamma and Z gamma channels, even with a mass above the WW kinematic threshold.

Energy Technology Data Exchange (ETDEWEB)

Nitrite is to be used to inhibit pitting corrosion during Extended Sludge Processing (ESP) at the Savannah River Plant. The required nitrite concentrations are expressed as a function of the slurries' nitrate ion concentration and temperature. In the most dilute slurries, the nitrite inhibitor requirement is independent of the nitrate ion concentration and depends only on the temperature of the waste. The nitrate-independent concentration ensures that there is sufficient inhibitor, in sludge slurries whose nitrate has been depleted by radiolysis, to prevent pitting corrosion induced by other corrosive anions (e.g., sulfate and chloride). The threshold nitrate concentration at which the nitrite level is expressed as a function only of temperature is 0.02 M.

British Library Electronic Table of Contents (United Kingdom)

Recent research developments in common-pool resource models emphasize the importance of links with ecological systems and the presence of non-linearities, thresholds and multiple steady states. In a recent paper Kossioris et al. (2008) develop a methodology for deriving feedback Nash equilibria for non-linear differential games and apply this methodology to a common-pool resource model of a lake where pollution corresponds to benefits and at the same time affects the ecosystem services. This paper studies the structure of optimal state-dependent taxes that steer the combined economic-ecological system towards the trajectory of optimal management, and provides an algorithm for calculating such taxes.

International Nuclear Information System (INIS)

In radiation risk assessment it must be differentiated between somatic and genetic effect on the one hand as well as between stochastic and non-stochastic effect on the other. According to definitions of the ICRP report 26 the limit for the dose equivalent of all tissues prevents non-stochastic radiation effects. With stochastic radiation effects probably exist no threshold doses; therefore the ALARA principle must be applied concerning radiation protection. The individual risk by stochastic radiation effects in its linear, linear-quadratic and quadratic extrapolations, respectively, is discussed in detail. The effective stochastic dose equivalent (H/sub eff/) as well as collective dose and collective damage are outlined.

Energy Technology Data Exchange (ETDEWEB)

The first measurement of the pn{yields}d{omega} total cross-section has been achieved at mean excess energies Q{approx}28 and 57 MeV by using a deuterium cluster-jet target. The momentum of the fast deuteron was measured in the ANKE spectrometer at COSY-Juelich and that of the slow ''spectator'' proton (p{sub sp}) from the pd{yields}p{sub sp}d{omega} reaction in a silicon telescope placed close to the target. The cross-sections lie above those measured for pp{yields}pp{omega} but seem to be below theoretical predictions. (orig.)

Energy Technology Data Exchange (ETDEWEB)

It has been observed that dislocation loops form and grow during annealing of silicon wafers implanted at doses above the amorphization threshold. Dislocation loops can act to store interstitials for prolonged periods of anneals, sustaining an interstitial super-saturation and thus causing substantial transient enhanced diffusion (TED). The authors have developed a comprehensive model which, in combination with a model and parameters for {l_brace}311{r_brace} defects from previous work, accounts for the formation and evolution of dislocation loops during ion implant annealing, as well as giving the correct TED behavior.

Energy Technology Data Exchange (ETDEWEB)

This invention refers to the organic geochemistry and can be used in prospecting for oil and gas. The method includes taking samples of rocks, extracting from them the chloroform bitumoid and its thermal processing. In order to improve the accuracy, the equal quantities of bitumoid taken are exposed to gradual thermal treatment to temperatures exceeding the thresholds of thermal stability of sulfur-containing compounds, in each temperature interval, the content of hydrogen sulfide released in this case is revealed, and by its drastic increase at temperatures corresponding to the temperatures of the productive part of the section, a conclusion is drawn about the epigenetic nature of the bitumoid. The method makes it possible to improve the resolution of the bituminological prospecting for oil and gas.

International Nuclear Information System (INIS)

The sensitivity of the primary circuit material was examined at the Mochovce and Dukovany NPPs. No significant sensitivity of the base material or the weld metal to the initiation of corrosion cracking was observed. Thermal aging was found to accelerate significantly the corrosion fatigue kinetics in the material of the heat affected zone. The threshold values of the double amplitudes of the stress intensity factor were below 8 MPa/m"2 for the materials examined, with a cycle asymmetry coefficient of 0.65. The tests revealed no appreciable sensitivity to general corrosion, pitting, or intergranular corrosion. (J.B.). 7 tabs., 26 figs., 11 refs.

Science.gov (United States)

Continuous wave lasing operation with the shortest wavelength for semiconductor lasers was obtained from AlGaInP double heterostructure lasers at 77 K. The structure was grown by metalorganic vapor phase epitaxy. Lasing wavelength was 583.6 nm (yellow). Threshold current was 43 mA (1.9 kA/cm/sup 2/). Magnesium was adopted as a p-type dopant, and was proved to be preferable for a high aluminum composition AlGaInP cladding layer.

International Nuclear Information System (INIS)

A historical background is first given in which the role of biomass is described in relation to its competition with fossil biomass for the production of chemicals and energy. Occurrences of reserves from both sources are then compared. Petrochemical and biomass routes are then analyzed in terms of their relative competitive advantages. The oleochemical and biotechnology cases are analyzed in more detail as examples of biomass utilization. Latin American examples of industrial manufacturing of biomass derived chemicals are then provided. Alcochemicals are analyzed in detail as well as essential oils and other chemicals. Finally, references are made to regional Latin American initiatives regarding biomass and the objectives, organization and nature of the initiative are presented.

CERN Document Server

We entertain the idea that a suitable background of cold (very low momentum) pseudoscalar particles or condensate, may trigger a background that effectively generates Lorentz-invariance violation. This aether-like background induces a Chern-Simons modification of QED. Physics is different in different frames and, in the rest frame of the pseudoscalar background, high momentum photons can decay into pairs. The threshold for such decay depends quadratically on the rest mass of the particles. This mechanism could explain in a natural way why antiprotons are absent in recent cosmic ray measurements. A similar signal could be used as a probe of pseudoscalar condensation in heavy ion collisions.

Energy Technology Data Exchange (ETDEWEB)

Carbonyl sulfide (COS), a colorless gas, is a side product of industrial procedures sure as coal hydrogenation and gasification. It is structurally related to and is a metabolite of carbon disulfide. COS is metabolized in the body by carbonic anhydrase to hydrogen sulfide (H{sub 2}S), which is thought to be responsible for COS toxicity. No threshold limit value for COS has been established. Results of these studies indicate COS (with an LC{sub 50} of 590 ppm) is slightly less acutely toxic than H{sub 2}S (LC{sub 50} of 440 ppm).

CERN Document Server

This paper describes an effective unsupervised speaker indexing approach. We suggest a two stage algorithm to speed-up the state-of-the-art algorithm based on the Bayesian Information Criterion (BIC). In the first stage of the merging process a computationally cheap method based on the vector quantization (VQ) is used. Then in the second stage a more computational expensive technique based on the BIC is applied. In the speaker indexing task a turning parameter or a threshold is used. We suggest an on-line procedure to define the value of a turning parameter without using development data. The results are evaluated using 10 hours of audio data.

CERN Document Server

Reactive power plays an important role in supporting the real power transfer by maintaining voltage stability and system reliability. It is a critical element for a transmission operator to ensure the reliability of an electric system while minimizing the cost associated with it. The traditional objectives of reactive power dispatch are focused on the technical side of reactive support such as minimization of transmission losses. Reactive power cost compensation to a generator is based on the incurred cost of its reactive power contribution less the cost of its obligation to support the active power delivery. In this paper an efficient Particle Swarm Optimization (PSO) based reactive power optimization approach is presented. The optimal reactive power dispatch problem is a nonlinear optimization problem with several ...

Science.gov (United States)

Room-temperature continuous-wave (cw) operation is achieved in the MBE (molecular-beam epitaxy)-grown InGaP/InGaAlP double-heterostructure (DH) visible laser diodes with a threshold current of 110 mA. The lasing wavelength and threshold current density under pulsed operation are 666 nm and as low as 3.9 kA/cm/sup 2/, respectively. This result is achieved by the introduction of H/sub 2/ into the growth chamber during growth, the continuous growth from one layer to the next layer, and the introduction of a GaAs buffer layer. InGaP/InGaAlP quantum well structures are also grown. From photoluminescence measurements, the conduction-band discontinuity ..delta..E/sub c/ is estimated to be 0.43 of the band-gap difference ..delta..E/sub g/. Furthermore, the multiquantum-well (MQW) structure is found to be stable under thermal treatment at temperatures as high as 750 /sup 0/C. Room-temperature pulsed operation of InGaP/InGaAlP MQW laser diodes is ...

International Nuclear Information System (INIS)

The paper describes transportation cost of the nuclear off-peak power for a hydrogen production based on water electrolysis in Japan. The power could be obtainable by substituting hydropower and/or fossil fueled power supplying peak and middle demands with nuclear power. The transportation cost of the off-peak power was evaluated to be 1.42 yen/kWh when an electrolyser receives the off-peak power from a 6kV distribution wire. Marked reduction of the cost was caused by the increase of the capacity factor. (author)

Energy Technology Data Exchange (ETDEWEB)

All power plant engineers face the problem of peak power demands. Pumped storage plants are used to generate peak load power by pumping up water utilizing off-peak energy of hydrothermal and thermonuclear plants. This is the first accessible text/reference to cover hydroelectric power generation with emphasis on engineering to meet peak power demands by means of pumped storge plants, tidal power plants, and low head power generation. Text covers hydrology, mechanical and electrical equipment, accessories such as penstocks and valves, and civil engineering considerations. Contains descriptions of several existing plants. Includes 200 diagrams and 50 photographs.

International Nuclear Information System (INIS)

The European Union (EU) market integration is leading to increasingly monopolistic electricity market infrastructures, which has opened a debate on the regulation of these so-called power exchanges. In this paper, we start by stating that there are two types of power exchanges in Europe, i.e. 'merchant' and 'cost-of-service regulated' power exchanges. We then discuss how regulation can be used to better align their incentives with the main power exchange tasks. We conclude that adopting the cost-of-service regulated model for all power exchanges in Europe could be counterproductive in the current context, but that regulation can help ensure that the benefits of the EU market integration materialize. Promising regulatory actions include tempering the reinforced market power of power exchanges, and quality-of-service regulation for the ongoing ...

Energy Technology Data Exchange (ETDEWEB)

The study examines advances in Chinese High Power Microwaves (HPM) research and its associated technologies: pulsed power, high-power microwave sources, and high-power microwave components. It draws from open literature published in Chinese and English, communication with US scholars who have visited China recently, and communication with Chinese researchers in the United States. The study is limited to frequencies ranging from 1 GHz to 300 GHz. It includes both high peak power microwaves and high average power microwaves. The technical review section of this study is ordered in technological sequence, starting with the pulsed-power systems required to form the intense relativistic electron beams, then assessing microwave source research and development, and finally discussing high-power microwave components.

International Nuclear Information System (INIS)

A LOss of Electric Power(LOEP) experiment was conducted after a 30MW full power operation as one of the reactor performance tests to verify the design characteristics of the HANARO. The objective of LOEP test was to investigate the integral behaviors of the system and the components as well as the cooling characteristics when the electric power was lost unexpectedly. Through the test, it was confirmed that the residual heat from the core was safely removed by the natural convection cooling and the assistant power systems operated normally

Energy Technology Data Exchange (ETDEWEB)

This work presents the project and relates the implementation of a power system stabilizer in Itauba hydroelectric power plant, Brazil. Some forecasts and field experiments are also presented. 10 refs., 19 figs.

International Nuclear Information System (INIS)

For the first time in China, Daya Bay Nuclear Power Station applied the advanced technology of worldwide commercial pressurized reactors to the in-core detectors, the leading excore six-chamber instrumentation for precise axial power distribution, and the related data processing. Described in this article are the neutron flux measurement in Daya Bay Nuclear Power Station, and the detailed data processing.

International Nuclear Information System (INIS)

The article gives a brief description of the state of the nuclear power engineering in Ukraine and in the world as of today. There are basic organizational and practical actions on scientific and technical maintenance of the Ukraine nuclear power complex presented in the article.

Science.gov (United States)

... trees, data showing a better fit to a power model than to a negative exponential model. Invading Pinus ... power law models were significantly negative. The inverse power model accounted for a considerabl...

International Nuclear Information System (INIS)

Papers are presented on space power requirements and issues, space photovoltaic systems, space solar dynamic systems, space thermal systems, manned and unmanned space power systems, thermionics, and thermoelectrics. Also considered are high power devices for space power systems, high power conversion for space power systems, 1-10 kWe nuclear space power sources, 100-kW class nuclear power concepts, space reactor safety, and multimegawatt space nuclear power systems. Other topics include space power systems automation, space kilovolt technology, space power electronics, space lithium and nickel-cadmium batteries, lithium sodium storage, and space fuel cells. Papers are also presented on space nickel hydrogen batteries, alternative energy concepts and fuels, ...

Science.gov (United States)

The frequency dependence of the lasing power of a He-Ne laser was studied using the electrooptic effect in a KDP crystal. The gain profile of the power curve was found to differ noticeably between the high-frequency and low-frequency edges. (AIP). (AIP)

Energy Technology Data Exchange (ETDEWEB)

Deregulation of the electric power industry in Alberta holds the prospect of providing greater choice for customers. One such option will be `green power` which is provided by renewable energy technologies. The energy produced would be without environmental impacts such as air emissions, water pollution, flooding, thermal emissions or waste by-products. Wind power, small scale hydro power, photovoltaics and biomass technologies have been termed as `green power`. The choices that customers make will not be focused on price alone. Market forces are emerging to demand reduction in emissions which will result in a market for `green energy` products and facilitate achieving goals for a sustainable future.

Energy Technology Data Exchange (ETDEWEB)

In response to the need of the Strategic Defence Initiative (SDI) and long range space exploration and extra-terrestrial basing by the National Air and Space Administration (NASA), concepts for nuclear power systems in the multi-megawatt levels are being evaluated. The requirements for these power systems are being driven primarily by the need to minimize weight and maximize safety and reliability. This paper discusses the present requirements for space based advanced power systems, technological issues associated with the development of these advanced nuclear power systems, and some of the concepts proposed for generating large amounts of power in space. (author).

Energy Technology Data Exchange (ETDEWEB)

Large scale steam storage power generation, one of the new energy storage systems for the future of inflexible electric power sources consisting of nuclear and coal power plants has been studied on the subjects of the systems to be attached to coal and nuclear power units, of the definition of storage efficiency and of the vertical steam storage vessel technology. Steam storage power generation may be hopeful for its higher efficiency similarly defined as of pumped storage plants while high temperature heat storage and the internal structure of large vertical steam storage vessel (accumulator) need to be developed.

Energy Technology Data Exchange (ETDEWEB)

A probabilistic method for assessing the profitability of reactive power compensation devices such as capacitors, static VAR compensators and generators, which improve network security, was described. Since network development is limited by environmental constraints, power networks are operated close to their limits. Because of this fact transmission network planning increasingly relies on techno-economic models to improve network security and profitability. The proposed method consists of analyzing large numbers of constrained power system states, extracted from power system simulation exercises. The paper describes details of the method and provides an example of a numerical application on a part of the French power transmission system. 10 refs., 8 figs.

Energy Technology Data Exchange (ETDEWEB)

The article presents briefly the plans of the British Petroleum Oil Company for a new hydrogen power plant that includes an offshore platform in the North Sea.

International Nuclear Information System (INIS)

... californium 252 fftf reactor mockup power density reactor cores reactor noise

International Nuclear Information System (INIS)

Data on French nuclear electricity generation sites, nuclear power plant operations personnel, operation simulators, nuclear training centers and training statistics are presented.

International Nuclear Information System (INIS)

(Nov 1973). United States Keeley, GS Consumer Power Co., Jackson,

International Nuclear Information System (INIS)

... reactor intake canals intake structures nuclear power plants safety seismic

UK PubMed Central (United Kingdom)

Over the past decade, dramatic increases in computational power and improvement in image analysis algorithms have allowed the development of powerful computer-assisted analytical approaches...Full Text Available

CERN Document Server

Development of High Field Dipole and High Current Pulse Power Supply for Compact Proton Synchrotron

Science.gov (United States)

FIG. 4. Power Spectral Density of the MAP W11 radiometer. The red and black traces are the power spectral density measurements of the two detectors on the ...

Science.gov (United States)

Externally powered prostheses have been studied for many years, to provide more effective rehabilitation of amputees. To take advantage of the benefits offered by external power in prostheses, however, the mode of control of the prosthesis by the amputee ...

International Nuclear Information System (INIS)

Published in summary form only.

International Nuclear Information System (INIS)

Due to its important hydroelectric power generation facilities (about 525 plants with a total power of 13,314 MW producing about 35.3 TWh annually) Switzerland plays an important role in the interconnected European power system. Large artificial storage lakes in the Swiss Alps can generate peak power during hours of highest demand: 9700 MW are available from accumulated energy and the total power of pumped-storage facilities amounts to 1700 MW. The latter allow refilling the reservoirs at periods of low power demand and generating power at periods of peak demand. In the case of favorable conditions, the yearly average power production could be increased by 6% and the production during the winter period (October to March) by 20% by the year 2020. However, looking forward to the year 2050, the annual production is expected ...

Energy Technology Data Exchange (ETDEWEB)

Solid polymer fuel cell (SPFC) systems are compared to spark ignition (SI) engine power systems for utility vehicle applications. Utility vehicles provide crew and payload transport and electrical power at work sites lacking grid supply. The methodology emphasizes comparison on an equal service basis. Using power system component models and numerical analysis, power systems are designed using SI engine and SPFC technologies. The power systems are compared on the basis of fuel energy consumed and life cycle cost (LCC). Gasoline is the fuel for the SI engines, while liquid hydrogen is used for the SPFC. Three types of SPFC power system configurations are studied. The superior SPFC in terms of LCC is a fuel cell/battery hybrid where the fuel cell is sized to provide average driving power. Using today's technology, SPFC ...

CERN Document Server

We make a complete analysis of the Yukawa coupling unification in SU(5) extensions of the MSSM in the framework of the radiative symmetry breaking scenario. Both logarithmic and finite threshold corrections of sparticles have been included in the determination of the gauge and Yukawa couplings at M_Z. The effect of the heavy masses of each model in the renormalization group equations is also included. We find that in the minimal SU(5) model b-tau Yukawa unification can be achieved for too large a value of alpha_s. On the other hand the Peccei-Quinn version of the Missing Doublet model, with the effect of the right handed neutrino also included, exhibits b-tau unification in excellent agreement with all low energy experimental data. Unification of all Yukawa couplings is also discussed.

British Library Electronic Table of Contents (United Kingdom)

According to the environmental Kuznets curve hypothesis, environmental degradation increases in the early stages of growth, but it eventually decreases as income exceeds a threshold level. It is thus often argued that if international trade increases incomes then it can also have a positive impact on environmental quality. So far, these hypotheses have been widely empirically tested for the developed countries. However, it is still uncertain whether positive effects of international trade on growth and on the environment may also hold in developing countries. One of the major difficulties in testing these relations in developing countries is the poor quality of environment related data. In this analysis this problem is reduced by constructing a structural equation model (SEM) with three la...

International Nuclear Information System (INIS)

A series of six transient tests was performed on FFTF irradiated fuel pins to demonstrate their transient performance capability. The tests were performed in the TREAT reactor using sodium loops and instrumented test trains. The TEMECH computer code was used to design overpower transients which would simulate FFTF fuel pin thermal conditions during slow and fast unprotected transients. Some tests were run to substantial overpower levels but terminated prior to fuel pin failure, while other tests were intentionally extended to fuel failure to establish failure thresholds and characteristics. Post-test examination data provided significant cladding strain and fuel melting information used for performance code calibration and validation. These data showed that cladding damage caused by fuel melting is related to the steady state condition of the fuel.

Energy Technology Data Exchange (ETDEWEB)

Describes temperature and humidity sensing devices used in mine rescue operations. Chemical indicators use chemical substances that melt at predetermined temperatures and display the actual temperature in the range of 40-50 C. Electronic temperature monitoring devices release acoustic signals as soon as a temperature of 40 or 45 C has been exceeded. A more recent piece of equipment combines the ULR rescue communication set with remote temperature sensing. A digital meter that measures temperature and humidity in the range of -100 to +200 C and 3 to 98% respectively has also been developed. The Central Mine Rescue Station in Bytom, Poland has developed equipment that permits body temperature and pulse rate of a rescuer to be measured and transmitted by radio over a distance of up to 50 m. Safe threshold values can be set for each individual rescuer.

Energy Technology Data Exchange (ETDEWEB)

The magnetic ordering temperature of some rare-earth-based heavy-fermion compounds is strongly pressure dependent and can be completely suppressed at a critical pressure, p{sub c}, making way for novel correlated electron states close to this quantum critical point. We have studied the clean heavy-fermion antiferromagnets CePd{sub 2}Si{sub 2} and CeIn{sub 3} in a series of resistivity measurements at high pressures up to 3.2 GPa and down to temperatures in the mK region. In both materials, superconductivity appears in a small window of a few tenths of a GPa on either side of p{sub c}. We present detailed measurements of the superconducting and magnetic temperature-pressure phase diagram, which indicate that superconductivity in these materials is enhanced, rather than suppressed, by the closeness to magnetic order. (author)

British Library Electronic Table of Contents (United Kingdom)

Metal iodates with a lone-pair containing I(V) that is in an asymmetric coordination geometry can form a diversity of unusual structures and many of them are promising new second homonic generation (SHG) materials. They exhibit wide transparency wavelength regions, large SHG coefficients and high optical-damage thresholds as well as moderately high thermal stability. In this paper, the structures and properties of the metal iodates are reviewed. The combination of d0 transition-metal cations with the iodate groups afforded a large number of metal iodates, with cations covering alkali metal, alkaline earth and lanthanide elements. Many of them are noncentrosymmetric (NCS) and display excellent SHG properties due to the additive effects of polarizations from both types of the asymmetric unit...

Science.gov (United States)

The spectrum, angular distribution, polarization and coherence properties of the radiation emitted by relativistic electrons undulating through a quasiperiodic tapered magnetic field are studied. Tapering the wavelength and/or field strength along the undulator's axis has the effect of spreading the spectral line to higher frequencies; interference over this broader spectral range results in a more complex line shape. The angular dependence, on the other hand, is not affected by the amount of taper. The polarization of the radiation in the forward direction is determined by the transverse polarization of the undulator, but the polarization changes off axis. The radiation patterns predicted here are distinct from those of untapered undulators, and their detection is now feasible. They will provide useful diagnostics of electron trajectories and threshold behavior in free-electron-laser oscillators using tapered undulators.

CERN Document Server

Mining association rules is a popular and well researched method for discovering interesting relations between variables in large databases. A practical problem is that at medium to low support values often a large number of frequent itemsets and an even larger number of association rules are found in a database. A widely used approach is to gradually increase minimum support and minimum confidence or to filter the found rules using increasingly strict constraints on additional measures of interestingness until the set of rules found is reduced to a manageable size. In this paper we describe a different approach which is based on the idea to first define a set of ``interesting'' itemsets (e.g., by a mixture of mining and expert knowledge) and then, in a second step to selectively generate rules for only these itemsets. The main advantage of this approach over increasing thresholds or filtering rules is that the number of rules found is significantly reduced while ...

Science.gov (United States)

Room-temperature continuous-wave (cw) operation of a GaInP/AlGaInP multiquantum well (MQW) laser was achieved for the first time. The threshold current was 70 mA at 22 /sup 0/C for a device with an 8-..mu..m-wide and a 250-..mu..m-long planar stripe. The emission wavelength was 668 nm. The characteristic temperature T/sub 0/ was 138 K under cw operation. The wafer with the MQW structure composed of 100-A-thick GaInP wells and 40-A-thick AlGaInP barrier layers was grown by atmospheric pressure metalorganic chemical vapor deposition.

British Library Electronic Table of Contents (United Kingdom)

Integrative and firing properties are important characteristics of neuronal circuits and these responses are determined in large part by the repertoire of ion channels they express, which can vary considerably between cell types. Recently, a new mode of operation of voltage dependent sodium channels has been described that generates a so-called resurgent Na^+ current. Accumulating evidence suggests resurgent Na current participates in the generation of sub-threshold inward Na^+ current causing membrane depolarization which provides the necessary drive to fire high-frequency action potentials. Recent studies indicate that resurgent Na^+ current could be a more widespread feature than previously thought.

International Nuclear Information System (INIS)

In the group of persistent aromatic hydrocarbons, the highest values were determined for polychlorinated biphenyls (PCB), total DDT and hexachlorobenzene (HBC). Comparisons of the relevant median values for the past six years led to the conclusion that the steep initial decline in the breast milk concentrations of DDT and HBC was followed by reductions at a much lower pace in the years after 1987. The time course of the concentration of the total PCB did not appear to follow any particular pattern. The mean contents of lead and cadmium remained by a wide margin below the threshold values for these heavy metals and thus were of no relevance from the toxicological point of view. It was found that the 134 and 137 cesium isotopes constituted no particular health hazard for breast-fed infants, as the relevant concentrations in breast milk were low. (VHE).

British Library Electronic Table of Contents (United Kingdom)

Abstract In this first systematic attempt to characterize the intranight optical variability (INOV) of TeV-detected blazars, we have monitored a well-defined set of nine TeV blazars on total 26 nights during 2004-10. In this R- or V-band-monitoring programme only one blazar was monitored per night and the minimum duration was close to 4-h, the average being 5.3 h per night. Using the CCD for strictly simultaneous photometry of the blazar and nearby reference stars (N-star photometry), an INOV detection threshold of -1-2-per cent was achieved in the densely sampled differential light curves derived from our data. We have further expanded the sample by including another 13 TeV blazars, taking advantage of the availability in the literature of INOV data, including those published earlier in o...

Science.gov (United States)

An analysis is made of the basic principles and methods of construction of integrated optical circuits (IOC) for data processing, which are optical waveguide processors in the integrated form. A classification is provided of IOC in accordance with the nature of the input connections to optical components and in accordance with their intended function. An analysis is made of the current status of research and development of analog IOC for handling analog and digital signals, IOC for computing technology, and switching IOC. A detailed analysis is made of IOC with different functions in data processing: spectrum analyzers and correlators, analog-digital converters, circuits for identification of data sets and for encoding of signals, threshold and multistable circuits, logic and arithmetic units, and switching arrays. Descriptions are given of IOC for optically controlled data handling: bistable purely optical logic circuits, multivibrators, flip-flops, and optical ...

British Library Electronic Table of Contents (United Kingdom)

A study was conducted to determine the fitting soil moisture for the normal growth of two-year-old W. sinensis (Sims) Sweets by using gas exchange technique. Remarkable threshold values of net photosynthetic rate (Pn), transpiration rate (Tr) and water use efficiency (WUE) were observed in the W. sinensis leaves treated by various soil moisture and photosynthetic available radiation (PAR). The fitting soil moisture for maintaining a high level of Pn and WUE was in range of 15.3%?26.5% of volumetric water content (VWC), of which the optimal VWC was 23.3%. Under the condition of fitting soil moisture, the light saturation point of leaves occurred at above 800?mol?m?2?s?1, whereas under the condition of water deficiency (VWC, 11.9% and 8.2%) or oversaturation (VWC, 26.5%), the light saturatio...

Science.gov (United States)

This is a continuation of our paper [Liu, M., Wang, K., 2010. Persistence and extinction of a stochastic single-species model under regime switching in a polluted environment, J. Theor. Biol. 264, 934-944]. Taking both white noise and colored noise into account, a stochastic single-species model under regime switching in a polluted environment is studied. Sufficient conditions for extinction, stochastic nonpersistence in the mean, stochastic weak persistence and stochastic permanence are established. The threshold between stochastic weak persistence and extinction is obtained. The results show that a different type of noise has a different effect on the survival results. PMID:20816991

British Library Electronic Table of Contents (United Kingdom)

Nomographs that calculate the threshold values of surface fire parameters which lead to crown fire initiation were created by linking two separate fire behavior models: Van Wagner?s crown fire ignition criteria and Byram?s surface fire model. The nomographs were also based on the existing surface (fuel load, fuel heat content) and canopy (foliar moisture content, live crown base height) fuel models of Aleppo (Pinus halepensis Mill.) pine forests of Mediterranean Greece. The most important fire parameters for crown fire initiation that are calculated by the nomographs are the critical flame length and the forward spread rate of the surface fire. These parameters are readily observable in the field during fires. The nomographs provide a judicious way to assess whether a crown fire is likely ...

British Library Electronic Table of Contents (United Kingdom)

The objective of this study was to determine whether walking and running at different treadmill speeds resulted in different metabolic and cardiovascular responses in the vastus lateralis (VL) and lateral gastrocnemius (LG) by examining metabolite accumulation and tissue oxygen saturation. Ten healthy subjects (6 males, 4 females) completed a submaximal treadmill exercise test, beginning at 3.2?km?h?1 and increasing by 1.6?km?h?1 increments every 3?min until reaching 85% of age-predicted maximal heart rate. Muscle tissue oxygenation (SO2), total hemoglobin (HbT) and interstitial hydrogen ion concentration ([H+]) were calculated from near infrared spectra collected from VL and LG. The [H+] threshold for each muscle was determined using a simultaneous bilinear regression. Muscle and treadmil...

British Library Electronic Table of Contents (United Kingdom)

This study highlights a methodology to detect the transplanting operation of wetland rice at a regional scale using SSM/I brightness temperature in frequencies like 19, 37 and 85 GHz with vertical polarization. A cloud removal algorithm was used to make weekly composites of the brightness temperature, which were used to estimate the soil wetness index (SWI). Flooding of rice fields with water for transplanting induces very high change in SWI due to contrasting dielectric constant of water (80) and soil (4). Different weather conditions and fractional wet area under the footprint of sensor affect SWI, hence absolute value of SWI was not adequate. Therefore, multi-year SWI anomaly was used to generate a threshold value of SWI change to detect when SWI change between two consecutive weeks was...

CERN Document Server

Cosmic ray antiprotons provide an important probe for the study of cosmic ray propagation in the interstellar space and to investigate the existence of Galactic dark matter. The ARGO-YBJ experiment is observing the Moon shadow with high statistical significance at an energy threshold of a few hundred GeV. Using all the data collected until November 2009, we set two upper limits on the antip/p flux ratio: 5% at an energy of 1.4 TeV and 6% at 5 TeV with a confidence level of 90%. In the few-TeV range the ARGO-YBJ results are the lowest available, useful to constrain models for antiproton production in antimatter domains.

International Nuclear Information System (INIS)

A crossed-electron-ion-beam experiment was used to measure the total ionization cross section for Ar"8"+ in the energy range from 50 to 600 eV. The present results are roughly in agreement with the previous measurements of Defrance et al. [Nucl. Instrum. Methods Phys. Res. B 23, 256 (1987)] above 450 eV. However, the present measurements show a significant contribution below the threshold for direct ionization. The present measurements agree with the distorted-wave calculations of Pindzola et al. [Phys. Rev. A 41, 1375 (1990)] when 3% of the incident ion beam is assumed to be in metastable states and excitation autoionization from metastable states is included.

Energy Technology Data Exchange (ETDEWEB)

The influence of common welding defects such as internal under-cut, incomplete penetration of the root bead, internal concavity and hollow bead have been evaluated in a sour environment. Tests were performed on samples cut from actual pipeline welds. The individual defects were subjected to slow strain rate testing. The samples were then examined by metallography, scanning electron microscopy, and hardness testing. It was established that a threshold stress intensity exists for sulphide stress cracking. The test results were compared to those obtained from samples of the weld and pipe which did not contain any defects. This comparison indicated that the metallurgical variations associated with the presence of a weld are the main factor for sulphide stress cracking rather than any specific defects or geometry. 5 tabs., 9 figs.

International Nuclear Information System (INIS)

The program introduced here for determining and describing the multi-axial creep of pipes is based, on the one hand, on the results of the nuclear process heat prototype plant material program and, on the other hand, on the possible load conditions which arise for evaluating accidents or extreme working situations. The basis of a theoretical description of multi-axial creep is the invariant theory in which both the von Mises configuration change hypothesis and the Norton creep law are included. Combined tension and torsion are also considered in detail, the superimposition of cyclic stresses in the tensile threshold area is discussed and cases of partial relaxation are explained. Experimental results for the discussed loads are introduced, which have led to satisfactory agreement between theory and experiment. (orig./MM).

British Library Electronic Table of Contents (United Kingdom)

Fault symptoms of running gearboxes must be detected as early as possible to avoid serious accidents. Diverse advanced methods are developed for this challenging task. However, for multiwavelet transforms, the fixed basis functions independent of the input dynamic response signals will possibly reduce the accuracy of fault diagnosis. Meanwhile, for multiwavelet denoising technique, the universal threshold denoising tends to overkill important but weak features in gear fault diagnosis. To overcome the shortcoming, a novel method incorporating customized (i.e., signal-based) multiwavelet lifting schemes with sliding window denoising is proposed in this paper. On the basis of Hermite spline interpolation, various vector prediction and update operators with the desirable properties of biorthog...