British Library Electronic Table of Contents (United Kingdom)

Harmonics bred from loads are mainly odd order because the current waveforms have half-wave symmetry. Since the even harmonics are negligibly small, they generally are not measured in electric power systems. However, even harmonics were measured at a 500/275/154 kV substation in Hokuriku Electric Power Company after a transmission line fault was corrected. The even harmonics caused malfunctions of protective digital relays because the relays used 4th harmonics at the input filter as the automatic supervisory signal. This paper describes mechanisms of generation of the even harmonics by comparing the measured waveforms with the ATP-EMTP simulation results. Analysis of these results has clearly shown that there are three different mechanisms of generation of even harmonics. The first mechani...

Science.gov (United States)

This report discusses the following topics on superconductivity: nonlinearities in hard superconductors such as surface impedance of a type II superconductimg half space and harmonic generation and intermodulation due to alternating transport currents; and nonlinearities in superconducting weak links such as harmonic generation by a long Josephson Junction in a superconducting slab.

International Nuclear Information System (INIS)

We studied the optimum plasma conditions that are required for efficient high-order harmonic generation in platinum plume. Harmonics up to the 49th order (?=16.32 nm) are analyzed under various conditions of laser-plasma interaction. Time-resolved ultraviolet spectra of platinum plasma at both optimum and nonoptimum conditions of harmonic generation are presented. We calculated the ionization states of the plasma, free electron density, and singly charged ion density at different prepulse intensities and compared them with experimental results.

International Nuclear Information System (INIS)

Single crystals of semi-organic L-histidine hydrobromide have been grown by slow evaporation technique from a mixture of L-histidine and hydrobromic acid in aqueous solution at ambient temperature. From high-resolution X-ray diffraction analysis, the crystalline perfection of the grown crystal has been studied. Single crystal X-ray diffraction analyses, Nuclear Magnetic Resonance spectral analysis, Thermo-Gravimetry (TG), Differential Thermal Analysis (DTA) and hardness test have been employed to characterize the as-grown crystals. The UV cutoff wavelength of the grown crystal is below 300 nm and has a wide transparency window, which is suitable for second harmonic generation of laser in the blue region. Nonlinear optical characteristics have been studied using Q switched Nd:YAG laser (#lambda#=1064 nm). The second harmonic generation conversion efficiency of the grown crystals ...

CERN Document Server

We present a unified self-consistent review of the approach to spherical harmonics developed in the second half of the 19th century by Maxwell and by Thomson and Tait. We remark how this spherical coordinate-free approach straightforwardly leads to physically very important results of the theory of solid and surface harmonics which become rather tedious to work out when using spherical coordinates and associated Legendre functions. These results include, among others, the addition theorem, spherical wave expansions, the construction of the standard set of normalized spherical harmonics, Y_lm - together with their rotational properties-, and recursion relations. We provide new proofs for Maxwell's theorem, the addition theorem and Hobson's theorem, respectively, using in the latter some elementary notions of the symbolic techniques proper of the theory of invariants. Also, we give an approach based on ...

International Nuclear Information System (INIS)

We present and characterize a very efficient optical device that employs the plasma mirror technique to increase the contrast of high-power laser systems. Contrast improvements higher than 104 with 50% transmission are shown to be routinely achieved on a typical 10 TW laser system when the pulse is reflected on two consecutive plasma mirrors. Used at the end of the laser system, this double plasma mirror preserves the spatial profile of the initial beam, is unaffected by shot-to-shot fluctuations, and is suitable for most high peak power laser systems. We use the generation of high-order harmonics as an effective test for the contrast improvement produced by the double plasma mirrors. (authors)

Energy Technology Data Exchange (ETDEWEB)

This paper describes nonlinear effect recognized in Vibroseis data. Harmonics is a wave of frequency in integer factors generated in association with basic sweep vibrated by Vibroseis. Harmonics is generated because vibration in the vicinity of seismic source contains nonlinear terms. Seismic exploration using the reflection method often discusses propagation of seismic waves hypothesized as a linear phenomenon. Vibroseis data analysis, however, requires evaluation of the effect of the harmonics on accuracy. Vibroseis investigation measures may be taken by eliminating n-order harmonics by using the phase control method, and generating seismic source sweep in which the phase is shifted by 180/(n-1) each time in order to leave the basic sweep. Methods to increase the sweep length include a method to expel strain to a location outside the range ...

International Nuclear Information System (INIS)

Coherent x-ray production by a seeded free electron laser (FEL) is important for next generation synchrotron light sources. The authors examine the feasibility and features of FEL emission seeded by a high-order harmonic generation (HHG) of an infrared laser. In addition to the intrinsic FEL chirp, the longitudinal profile and spectral bandwidth of the HHG seed are modified significantly by the FEL interaction well before saturation. This smears out the original attosecond pulselet structure. The authors introduce criteria for this smearing effect on the pulselet and the stretching effect on the entire pulse. They discuss the noise issue in such a seeded FEL.

British Library Electronic Table of Contents (United Kingdom)

Non-linear optics encompasses a range of optical phenomena, including two- and three-photon fluorescence, second harmonic generation (SHG), sum frequency generation (SFG), difference frequency generation (DFG), third harmonic generation (THG), coherent anti-Stokes Raman scattering (CARS), and stimulated Raman scattering (SRS). The combined advantages of using these phenomena for imaging complex pharmaceutical systems include chemical and structural specificities, high optical spatial and temporal resolutions, no requirement for labels, and the ability to image in an aqueous environment. These features make such imaging well suited for a wide range of pharmaceutical and biopharmaceutical investigations, including material and dosage form characterisation, dosage form digestion and drug rele...

International Nuclear Information System (INIS)

Consensus reached in the last few years that fourth generation light source will most likely be a X-ray or a UV coherent source based on single-pass high-gain free electron laser (FEL), such as Self Amplified Spontaneous Emission (SASE), or seeded high-gain harmonic-generation (HGHG) free electron lasers. High-gain (>10"7) required for single-pass FEL puts great constrain on the quality of electron beam, and demands detailed distribution information of electron beam in six-dimension. The typical accelerator system for single-pass FEL consists of a photocathode RF gun injection system, a linac and magnetic bunch compressors, and a long undulator. The major challenges in beam diagnostics for single-pass FEL are to characterize the pico-seconds high-brightness electron beam in six-dimension produced by photocathode RF gun injector, and improve the stability and reliability of the photocathode RF gun injection system. Characterization of short ...

CERN Document Server

Multi-Harmonic RF Control System for J-PARC RCS

International Nuclear Information System (INIS)

Tunable output wavelength is an important character of a free electron laser (FEL). As generally understood, to alter the wavelength of a high-gain harmonic generation (HGHG) FEL laser, the seed laser must be tunable. A few-cycle, high intensity laser obtained by optical compression usually has pretty broad bandwidth in the spectral domain, which can be used as the seed laser of a HGHG and may open the possibility to approach a HGHG scheme with fully tunable wavelength. In this paper, a HGHG FEL seeded by a few-cycle laser is theoretically discussed and numerically investigated. A few-cycle seed laser significantly influences HGHG FEL performance, especially in output wavelength tuning. For a HGHG FEL seeded by a 4-cycle 786 nm laser, output wavelength tunability range up to 14.9% of the central wavelength 262 nm is observed by adjusting the resonant condition.

International Nuclear Information System (INIS)

One-velocity angular flux of a neutron field generated by a polarly anisotropic point source in an infinite homogeneous region is calculated in P3 approximation, using the spherical harmonics operator formalism adapted to two-dimensional spherical geometry. The problem is reduced to simple algebraic equations. For weak absorption and linearly anisotropic scattering, the solution is given in closed form. (orig.).

Energy Technology Data Exchange (ETDEWEB)

The authors report an extension of the source imaging method for analyzing three-dimensional sources from three-dimensional correlations. The technique consists of expanding the correlation data and the underlying source function in spherical harmonics and inverting the resulting system of one-dimensional integral equations. With this strategy, they can image the source function quickly, even with the extremely large data sets common in three-dimensional analyses.

International Nuclear Information System (INIS)

The present communication deals with the synthesis, single crystal growth and characterization of a new nonlinear optical material L-proline strontium chloride monohydrate (L-PSCM). Single crystals have been grown using the slow solvent evaporation technique. Single crystal XRD analysis confirmed that the crystal belongs to the orthorhombic structure with lattice parameter a=6.6966(3) A, b=12.4530(5) A, c=15.2432(5) A and space group P2_12_12_1. Presence of various functional groups in L-PSCM and protonation of the ions were confirmed by Fourier transform infrared spectroscopy (FT-IR) analysis. The melting point of the single crystal was found to be 126 "oC using DSC. Ultraviolet-visible spectral analyses showed that the crystal has low UV cut-off at 226 nm combined with very good transparency of 90% in a wide range. The optical band gap was estimated to be 5.82 eV. Capacitance and dielectric-loss measurements were carried out at different temperatures in the ...

International Nuclear Information System (INIS)

Measurements of low-energy (#approx#10"- "1"0 J) femtosecond laser pulse durations have been carried out on the basis of second-order autocorrelation function analysis. The scheme of non collinear second harmonic generation realized in KDP crystal has been used for increasing of the measurement contrast and accuracy. Proposed scheme can be used for measurements in wide enough ranges of laser pulse durations (from tens femto seconds to hundreds picoseconds) and energies. (authors)

Energy Technology Data Exchange (ETDEWEB)

The LCLS, a Free-Electron Laser (FEL) designed for operation at a first harmonic energy of 300 eV ({lambda} {congruent} 40{Angstrom}) in the Self-Amplified Spontaneous Emission (SASE) regime, will utilize electron bunches compressed down to durations of <0.5ps, or lengths of <150 {mu}. It is natural to inquire whether coherent radiation of this (and longer) wavelength will constitute a significant component of the total coherent output of the FEL. In this paper a determination of a simple upper bound on the IR that can be generated by the compressed bunches is outlines. Under the assumed operating parameters of the LCLS undulator, it is shown that that IR component of the coherent output should be strongly dominated by the x-ray component.

Energy Technology Data Exchange (ETDEWEB)

A design of a compact free-electron laser (FEL), generating ultra-fast, high-peak flux, XUV pulses is presented. The FEL is driven by ahigh-current, 0.5 GeV electron beam from the Lawrence Berkeley National Laboratory (LBNL) laser-plasma accelerator, whose active acceleration length is only a few centimeters. The proposed ultra-fast source (~;;10 fs) would be intrinsically temporally synchronized to the drive laser pulse, enabling pump-probe studies in ultra-fast science. Owing to the high current (>10 kA) of the laser-plasma-accelerated electron beams, saturated output fluxes are potentially greater than 10^13 photons/pulse. Devices based both on self-amplified spontaneous emission and high-harmonic generated input seeds, to reduce undulator length and fluctuations, are considered.

Energy Technology Data Exchange (ETDEWEB)

This paper describes a simple analysis procedure that transforms a set of beamline orbit data into a set of harmonic orbits of first, second, and third order or higher. Each harmonic orbit can be studied individually to identify errors of the specific order with minimum interference from other orders. Effectively these are orbits caused by kicks, due to harmonic errors, propagated through linear lattice. Examples from accelerator study will be presented. The application and inherent limitations of this analysis procedure are discussed.

British Library Electronic Table of Contents (United Kingdom)

A three-dimensional numerical study is performed to explore the effect of pulsed spanwise-periodic surface thermal perturbation (also denoted as thermal bump) in a Mach 1.5 flat plate laminar boundary layer. A high-resolution upwind-biased Roe method is used with the compressive Van Leer harmonic limiter on a suitably refined mesh. The dependence of flow stability characteristics on the variation of thermal bump geometry (shape and dimension) and pulsing properties (disturbance amplitude and frequency) is assessed. It is shown that the finite-span thermal bumps generate streamwise vortices. When the thermal bump is pulsed, vortex shedding is observed, and the streamwise vorticity grows with the downstream distance. Analysis of the integrated disturbance energy indicates that the streamwise...

International Nuclear Information System (INIS)

In the early sixties it was decided to investigate salt formations on its suitability to host heat generating radioactive waste in Germany. In the reference repository concept consequently the emplacement of vitrified waste canisters in deep vertical boreholes inside a salt mine was considered whereas spent fuel should be disposed of in self shielding casks (type POLLUX) in horizontal drifts. The POLLUX casks, 65 t heavy carbon steel casks, will be laid down on the floor of a horizontal drift in one of the disposal zones to be constructed in the salt dome at the 870 m level. The space between casks and drift walls will be backfilled with crushed salt. The transport, the handling und the emplacement of POLLUX casks were subject of successfully performed demonstration and in situ tests in the nineties and resulted in an adjustment of the atomic law. The borehole disposal concept comprises the emplacement of unshielded canisters with vitrified HLW in boreholes with a ...

International Nuclear Information System (INIS)

We describe a panoramic stigmatic spectrograph comprising a grazing-incidence toroidal mirror and a large-aperture free-standing transmission diffraction grating (5000 lines mm-1 ). Two spectrograph versions were constructed, with grazing angles of 7.6 and 40 and the short-wavelength spectral limits near 4 and 1.5 nm. The spectrograph aberrations were studied by numerical ray tracing. The spectrograph was used to record line and quasi-continuous spectra (1.5 - 30 nm) of multiply charged ions in a plasma generated by the second-harmonic pulses of an yttrium aluminate laser (Q = 0.15 J, ? = 5 ns, ? = 0.54 ?m, repetition rate = 0.5 Hz). In combination with a laser-produced plasma radiation source, the arrangement was used to characterise soft x-ray optical components and to generate collimated beams of polarised radiation in the 14 - 20 nm range. (laser applications and other topics in quantum electronics)

Science.gov (United States)

... and flashtube. Unfortunately, we had insufficient laser intensity to use the harmonic from a KDP crystal as a monitor. This ...

International Nuclear Information System (INIS)

An explicite PN solution of the multi-dimensional homogeneous neutron transport equation is given by expanding the angular flux into a series of geometry-independent spherical harmonics operators. An algorithm is developed for representing the spherical harmonic operators in orthogonal curvilinear coordinates. The general formulae are applied to two-dimensional spherical geometry; detailed P3 formulae are given. (orig.).

Energy Technology Data Exchange (ETDEWEB)

In this report the effects of harmonics in marine power systems is discussed and a comparison is given between the most typical converter types, including pulse width modulated drives, load commutated inverters and cycloconverters. The effect of harmonic distortion on the power system equipment and loads is first briefly discussed. Special attention is given to the circumstances in the low voltage distribution system, where general load equipment is connected. In addition to the total harmonic distortion the effect of voltage deviation to the supply quality is also considered. The origin of harmonics in the load currents of the three converter types is then considered. The differences between the converters are outlined, and the most typical spectra are presented. The possible means for reducing the harmonic distortion are also studied. The solutions considered are the increasing of ...

International Nuclear Information System (INIS)

Various electrochemical techniques are available to continuously monitor corrosion in conditions simulating those on the secondary side of PWR steam generators. This paper reviews those electrochemical techniques which are potentially useful to measure denting in tube-support crevices in situ. Attention is also given to corollary needs for monitoring the water chemistry which leads to corrosive attack. Finally some suggestions are offered for corrosion monitoring in autoclaves, model boilers and operating steam generators.

Energy Technology Data Exchange (ETDEWEB)

Since the earliest papers on undulaters were published, it has been known how to calculate the spontaneous emission spectrum from ''short'' undulaters when the magnetic field strength parameter is small compared to unity, or in ''single'' frequency sinusoidal undulaters where the magnetic field strength parameter is comparable to or larger than unity, but where the magnetic field amplitude is constant throughout the undulater. Fewer general results have been obtained in the case where the insertion device is both short, i.e., the magnetic field strength parameter changes appreciably throughout the insertion device, and the magnetic field strength is high enough that ponderomotive effects, radiation retardation, and harmonic generation are important physical phenomena. In this paper a general method is presented for calculating the radiation spectrum for short, high-field ...

International Nuclear Information System (INIS)

Nuclear energy provides a third of Europe's electricity with nearly no greenhouse-gas emissions. Sustained efforts are now being conducted to harmonize regulations all over Europe through WENRA and to converge on technical nuclear safety practices within the TSO network ETSON (European Technical Safety Organizations Network). In CANDU type NPP the tritiated water occurs by the neutron bombardment of deuterium. The tritiated water vapors imply health hazard (in the critical organs of the body the water presents a 10 day average biological half-life) and the early detection in nuclear plants of tritium emissions is important because the tritiated water vapors have the same characteristics as of atmospheric water vapors. By detecting tritiated vapors, the monitoring system ensures the following objectives: (a) indicates levels of tritium generally due to heavy water leakage, (b) reduces the possibility of health hazard. In order to attain this goal of safety function, ...

Science.gov (United States)

We have calculated the on-axis spectrum of spontaneous radiation emitted by an electron moving along a planar undulator that has a magnetic profile along the axis that approximates a square wave. (This could be obtained in practice by driving a ferromagnetic undulator into saturation by excessive current in the windings.) We find considerable enhancement of the harmonic radiation spectrum. We compare the harmonic power emitted by an electron moving through an undulator having a sine-wave field profile with the radiation emitted from an undulator having a square-wave profile; the latter is approximated by the first three Fourier components of the undulator magnetic field profile along the axial direction. Examples are computed for 40MeV electrons taking K < 1, for spontaneous radiation emitted along the axis of the system. The emission at harmonics f > 1 is greatly enhanced for the approximate square-wave magnetic ...

Energy Technology Data Exchange (ETDEWEB)

A robust adaptive Power System Stabilizer algorithm using a Generalized Multivariable Pole Shifting (GMPS) technique is presented in this paper. The algorithm handles systems with equal or unequal numbers of inputs and outputs, therefore both shaft speed as well as the generator power are used to derive the stabilizing control. The technique also provides a simple scheme of on-line self-searching pole shifting factor to meet the excitation control limits. The application of the proposed stabilizer to a simulated generator excitation control under a wide range of operating and disturbance conditions demonstrates that the new control strategy is superior to conventional Power System Stabilizer (PSS) and the widely accepted Minimum Variance Self-Tuning Controller (MVSTC).

Energy Technology Data Exchange (ETDEWEB)

Ontario's electricity industry restructuring program is reviewed, with a view to identify the reasons behind the failure of deregulation which was expected to create competition, to stabilize, or even reduce, prices to consumers, and attract serious private sector investment for the construction of new generating capacity. The report painstakingly reviews the series of events which resulted in a steep rise in electricity rates during the summer of 2002, immediately after deregulation came into effect, which led to freezing retail electricity rates and related charges by the then Conservative provincial government, and the reversal of that decision by the newly-elected Liberal government in the fall of 2003, and plans to bring back retail hydro rates that reflect the cost of production. The authors provide a discussion of policy options and a series of recommendations that are expected to create incentives to reduce and shift demand, encourage the use of ...

UK PubMed Central (United Kingdom)

The geographical arrangement of people on the surface of the earth is approximated by a mathematical equation of 361 terms. This is a convenient form for comparison with other distributions and for...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The techniques in order to measure the depth of defect in weldment and structure accurately have been developed. Many researches have made efforts to develop the methods for the accurate depth sizing of defect. TOFD is known as the most accurate method of various methods for measuring depth sizing. However, there is a possibility to miss defects because of the limitation of beam coverage for the ultrasound incident angle. In this study, the results for detectability and depth sizing using phased array ultrasonic technique for thick body were compared with those of conventional TOFD technique. It was experimentally confirmed that the phased array ultrasonic TOFD technique gives good detectability and accurate depth measurement for the various types of defects. The phased array ultrasonic TOFD technique developed in this study will contribute to increase the inspection reliability in ...

Science.gov (United States)

Results of feasibility experiments for determining the mineral content of individual stains on special Sensitized Paper are presented. The stains were formed on the paper by the impaction of laboratory generated salt water droplets. Of the techniques exam...

Energy Technology Data Exchange (ETDEWEB)

Temperature and concentration profiles of CO in a laminar, axisymmetric, premixed methane-air Bunsen flame are measured using line-of-sight diode laser absorption spectroscopy and computer tomographic (CT) reconstruction. Absorption spectra for P(20) (v=2<-1) and P(27) (v=1<-0) vibrotational transitions of CO were measured at 21 evenly spaced positions over a 1.33 cm span for a 1.3 cm radius flame. CT reconstruction algorithm was based on Fourier convolution. The tomographically reconstructed normalized transmission profiles derived from absorption spectra, in conjunction with a quantum mechanical model for vibrotational behavior of CO, yielded both temperature and concentration profiles. The Bunsen flame had 3 distinct zones: an inner rich-premixed flame zone, an outer non-premixed flame zone and an unburnt core region. The reconstructed temperature profile showed that the core region temperature was close to ambient and rapidly increased to adiabatic flame temperature at the ...

International Nuclear Information System (INIS)

The approach estimating the leak probability of flanged joint due to the destruction of fastening studs is described. The mentioned approach consists of two stages. The probability of destroying one stud is calculated at the first stage, and the probability of different combination interpositions of intact and destroyed studs is calculated at the second one. The probability calculation of leak in the area of collector cover of steam generator PGV-1000 is used as an example of developed approach

Energy Technology Data Exchange (ETDEWEB)

During thirty years the techniques used for sensing the environment have changed dramatically. This paper describes the latest generation of sensors available. This new generation of sensors includes those two most critical gas sensors for methane and carbon monoxide and new sensors for airflow and air temperature. When these sensors are combined with the new sensors for machine condition monitoring it forms the heart of the Sentex system. 2 figs.

International Nuclear Information System (INIS)

In order to understand the detail transient two-phase flow structure, more advanced two-phase flow instrumentation is required. One advanced technique for flow visualization is real-time neutron radiography. Reconstruction method of visualized radiographic image of liquid metal two-phase flow generated by the real-time neutron radiography system is proposed in this paper. Image processing techniques for noise reduction and image enhancement are discussed in detail. (author).

Energy Technology Data Exchange (ETDEWEB)

System instability as result of high power generation of one of the largest plants of the Iranian electric power grid prevented the plant to be fully utilized. PSSs were installed on the generating units of the power station, to improve its small signal stability, and enhance the stable generation limit. Domain separation and pole assignment techniques were applied for the PSS design. Several field tests were also carried out to verify its effectiveness. This paper presents the PSS tuning procedure, including the design criteria and some of the field test results.

Energy Technology Data Exchange (ETDEWEB)

A new test methodology is described which allows access to loading rates that lie between split Hopkinson bar and shock-loading techniques. Gas gun experiments combined with velocity interferometry techniques have been used to experimentally determine the intermediate strain-rate loading behavior of Coors AD995 alumina and Cercom silicon-carbide rods. Graded-density materials have been used as impactors; thereby eliminating the tension states generated by the radial stress components during the loading phase. Results of these experiments demonstrate that the time-dependent stress pulse generated during impact allows an efficient transition from the initial uniaxial strain loading to a uniaxial stress state as the stress pulse propagates through the rod. This allows access to intermediate loading rates over 5 x 10{sup 3}/s to a few times 10{sup 4}/s.

Energy Technology Data Exchange (ETDEWEB)

Power system stabilizers (PSSs) are used to enhance damping of power system oscillations through excitation control of synchronous generator. The objective of the PSS is to generate a stabilizing signal, which produces a damping torque component on the generator shaft. Conventional PSSs are designed with the phase compensation technique in the frequency domain and include the lead-lag blocks whose parameters are determined according to a linearized power system model. The performance of conventional PSSs (CPSSs) depends upon the generator operating point and the system parameters, but a reasonable level of robustness can be achieved depending on the tuning method. This paper presents a new three-dimensional PSS (3D PSS), which uses rotor speed deviation, rotor acceleration and load angle deviation as input signals. The 3D PSS attempts to return the generator to ...

International Nuclear Information System (INIS)

Nanocrystalline powders of GaN with grain sizes ranging from 2 to 30 nm were examined under high external pressures by in situ diffraction techniques in a diamond anvil cell at DESY (HASYLAB, Station F3). The experiments on densification of pure powders under high pressure were performed without a pressure medium. The mechanism of generation and relaxation of internal strains and their distribution in nanoparticles was deduced from Bragg reflections recorded in situ under high pressures at room temperature. The microstrain was calculated from the full-width at half-maximum (FWHM) values of the Bragg lines. It was found that microstrains in GaN crystallites are generated and subsequently relaxed by two mechanisms: generation of stacking faults and change of the size and shape of the grains occurring under external stress. (author)

CERN Document Server

The interaction energies between the different types of bases of a single strand of DNA molecule have been calculated. Using these original values of energies the harmonic behavior of a number of base patterns of DNA has been studied. In view of the great interest aroused by the discovery of the role of the telomere segment of the DNA in the replication process and its possible link with the aging process, we have investigated, with simple models, the harmonic behavior of the telomeric pattern of bases as well as the thermodynamic response in the biological system. With these results a conclusion on the probable role of the telomeric pattern on aging has also been drawn. Here the calculated values of harmonic frequencies of the telomeric pattern of bases and of other possible patterns show that the telomeric pattern is associated with the highest vibrational frequency among all patterns of base combinations at the ...

Energy Technology Data Exchange (ETDEWEB)

We have observed resonant changes in the current-voltage characteristics of miniband semiconductor superlattices when the Bloch frequency is resonant with a terahertz field and its harmonics: the inverse Bloch oscillator effect. The resonant feature consists of a peak in the current which grows with increasing laser intensity accompanied by a decrease of the current at the low bias side. The peak position moves linearly with the laser frequency. When the intensity is increased further the first peak starts to decrease and a second peak at about twice the voltage of the first peak is observed due to a two photon resonance. At the highest intensities we observe up to a four photon resonance. A superlattice is expected to show negative differential conductance due to the strong nonparabolicity of the miniband. In this situation the carriers should undergo Bloch oscillations with a frequency {omega}{sub B} = eEd/h. Transient Bloch oscillations of photo excited carriers ...

Science.gov (United States)

... Highly-Functional Materials" was launched in JFY1996 under the New Materials field. This project was ... Bio-mimetic materials" (1) Advanced stimuli responsive materials (2) Harmonized molecular materials ...

UK PubMed Central (United Kingdom)

Several studies have demonstrated that telephone use presents a challenge for most cochlear implant (CI) users, and this is attributed mainly to the narrow bandwidth (300–3400 Hz) introduced...Full Text Available

Science.gov (United States)

This paper proposes a new pattern recognition system employing optical joint transform correlation (JTC) technique which offers a great number of advantages over similar digital techniques, including very fast operation, simple architecture and capability of updating the reference image in real time. The proposed JTC technique incorporates a synthetic discriminant function (SDF) of the target image estimated from different training images to make the pattern recognition performance invariant to noise and distortion. It then involves four different phase-shifted versions of the same target SDF reference image, which are individually joint transform correlated with the given input scene. When the correlation signals are combined, it produces a single cross-correlation peak corresponding to each potential target present in the given input scene. The proposed technique also includes a fringe-adjusted filter ...

Energy Technology Data Exchange (ETDEWEB)

New technologies make multi-megajoule glass lasers economically feasible. Laser architectures using harmonic switchout, target plane holographic injection, phase conjugation, continuous apodization and higher amplifier efficiencies have been devised. A plan for a multi-megajoule laser which can be built for an acceptable cost relies on manufacturing economies of scale and the demonstration of the new technologies presented here. These include continuous pour glass production, rapid harmonic crystal growth, switching of large blocks of power using larger capcaitors packed more economically and by using large identical parts counts.

Energy Technology Data Exchange (ETDEWEB)

The non linear electrical loads can give rise to a number of disturbances in electrical power networks. Among them, the high consumption of relative power is to be noted and so is the several harmonic components which may be injected in the industry system and very often in the utility system. So, by using appropriate technical considerations, as well as measurements in typical special electrical loads, such negative effects are analyzed and ways of minimizing them are suggested. (author) 3 refs., 11 figs., 6 tabs.

International Nuclear Information System (INIS)

CANDU steam generators and heat exchangers have been afflicted with a significant variety of degradation mechanisms. Until recently, detection and characterization of most of the varieties of flaws required usage of several different eddy current techniques. Tubes needed to be scanned multiple times to ensure they were inspected for all possible degradation mechanisms. The time required to deploy so many different types of techniques to inspect the steam generator tubes has had a significant impact on the inspection schedules. The X-Probe was designed with an array of eddy current coils capable of detecting, characterizing and sizing axial, circumferential and volumetric flaws. The X-Probe is a fast-scanning probe with scanning speed equivalent to speeds typically used for simple bobbin coil probes. With its capability of fulfilling most if not all of the functions of the other tube-testing eddy current ...

Energy Technology Data Exchange (ETDEWEB)

A technique has been developed which enables the direct sputter generation of atomic negative ion beams of all members of the Group IA elements (Li, Na, K, Rb and Cs). The method is based on the use of sputter samples formed by pressing mixtures of the carbonates of the Group IA elements and 10% (atomic) Cu, Ag or other metal powders. The following intensities are typical of those observed from carbonate samples subjected to approx. = 3 keV cesium ion bombardment: Li/sup -/: greater than or equal to 0.5 ..mu..A; Na/sup -/: greater than or equal to 0.5 ..mu..A; K/sup -/: greater than or equal to 0.5 ..mu..A; Rb/sup -/: greater than or equal to 0.5 ..mu..A; Cs/sup -/: greater than or equal to 0.2 ..mu..A.

Energy Technology Data Exchange (ETDEWEB)

We report experimental evidence of a previously unseen species-dependent effect in the transverse emittances of momentum analysed /sup 28/Si/sup -/, /sup 58/Ni/sup -/ and /sup 197/Au/sup -/ ion beams generated by caesium ion sputtering. The high-resolution emittance measurement techniques employed in this work have enabled us to estimate the energy spreads of these ion beams; differences in the widths of the energy distributions are the origin of the observed differences in emittances of the ion beams investigated. (author).

International Nuclear Information System (INIS)

The objectives of the project were to develop operational techniques for promoting contaminant hideout return from tube support crevices and to identify the effect of chemical inhibitor application on corrodent transport. The implementation of routine procedures for promoting the return of sequestered corrodents could retard the progression of denting or other corrosion processes and improve steam generator availability. Tests also quantified the effect of inhibitor application on crevice hideout and hideout return processes, with the intention of developing a better understanding of the inhibition mechanism. By carefully monitoring the hideout and hideout return inventories, the program also has provided the opportunity to study steam generator concentration processes in general.

Energy Technology Data Exchange (ETDEWEB)

Average emittance data for ion beams extracted from cesium-sputter negative ion sources equipped with spherical, ellipsoidal, and cylindrical geometry cesium-surface ionizers are presented. The attributes of the respective source geometries are described in terms of their cesium ion optical properties. The results of recent measurement of the emittances of momentum-analyzed beams extracted from the ellipsoidal geometry source are also presented. These measurements indicate the presence of a species-dependent effect. The effect is believed to be attributable to differences in the energy spreads of the respective negative ion beams introduced by the sputter generation process. 11 refs., 8 figs.

International Nuclear Information System (INIS)

In dual-energy projection radiography with double exposures, rapid energy switching is mandatory to eliminate motion artifacts, but it is costly for use in a clinical environment. We developed a system with practical exposure intervals at reasonable cost by modifying a condenser-type X-ray generator. A commercially available system for digital radiography (Fuji Computed Radiography, FCR) was used to subtract images. This report dealt with technical factors to obtain adequate kV and mAs settings in this technique. (author).

Energy Technology Data Exchange (ETDEWEB)

The Dynamic Transmission Electron Microscope (DTEM) is introduced as a novel tool for in situ processing of materials. Examples of various types of dynamic studies outline the advantages and differences of laser-based heating in the DTEM in comparison to conventional (resistive) heating in situ TEM methods. We demonstrate various unique capabilities of the drive laser, namely, in situ processing of nanoscale materials, rapid and high temperature phase transformations, and controlled thermal activation of materials. These experiments would otherwise be impossible without the use of the DTEM drive laser. Thus, the potential of the DTEM to as a new technique to process and characterize the growth of a myriad of micro and nanostructures is demonstrated.

International Nuclear Information System (INIS)

There are a total of nine operational nuclear plants in Spain totalling 7.350 MWe. These units produced 54.265 x 106 KWh in 1990, 36% of the total generation in Spain. Seven of these plants are of the PWR type. The first plant in operation was Jose Cabrera (ZORITA) in 1968, one loop Westinghouse plant with a model 24 Steam Generator. Due to the design margin and careful operation of the Steam Generator of this plant its performance have been very good, with only 5% tubes plugged after 23 years of operation. This is one of the few units in the world that remains in phosphate chemistry. During the period 1981-1985 a total of four units, two in Almaraz and two in Asco entered in operation. These three loop s Westinghouse units use model D-3 preheater Steam Generators. The poor design and manufacture of the Steam Generators of these units have caused a large number of problems: ...

International Nuclear Information System (INIS)

This paper presents some situations, in which measurements of electromagnetic fields generated by transmission lines and substations should be performed. The range of measurements may differ, but maximum values of electric and magnetic fields and flux density must be identified in all situations. The area with electric field exceeding 1 kV/m should be identified as well. The author also presents basic requirements to be met by the measurement technique. These requirements are specified according to the national standard. Special attention should be paid to the identification of the spatial distribution of electric field and flux density generated in the vicinity of high voltage transmission lines. To verify the measurement results, it is necessary to calculate the distribution of both aforesaid field components. For environmental protection purposes, it is also proposed that the report should include measurements of ...

CERN Document Server

Term extraction is one of the layers in the ontology development process which has the task to extract all the terms contained in the input document automatically. The purpose of this process is to generate list of terms that are relevant to the domain of the input document. In the literature there are many approaches, techniques and algorithms used for term extraction. In this paper we propose a new approach using particle swarm optimization techniques in order to improve the accuracy of term extraction results. We choose five features to represent the term score. The approach has been applied to the domain of religious document. We compare our term extraction method precision with TFIDF, Weirdness, GlossaryExtraction and TermExtractor. The experimental results show that our propose approach achieve better precision than those four algorithm.

Energy Technology Data Exchange (ETDEWEB)

Theoretical assessment on the chromatographic {sup 99m}Tc generator preparation using (n, {gamma}) {sup 99}Mo produced ex-natural molybdenum was carried out. The relationship between the neutron flux for MoO{sub 3} target activation, Mo-content or Mo adsorption capacity of column packing material, {sup 99m}Tc pertechnetate concentration and/or {sup 99m}Tc radioactivity of eluate was established. The reasonably lower limit of neutron flux of reactor and Molybdenum content of column packing material were found out to estimate the production of portable chromatographic generators available for nuclear medicine application. The concentration of {sup 99m}Tc pertechnetate eluate of low {sup 99m}Tc concentration using the column elution technique was also evaluate theoretically and conducted successfully in practice. Three options of {sup 99m}Tc generator using Titanium-Molybdate, Zirconium-Molybdate and ...

Energy Technology Data Exchange (ETDEWEB)

The hydro-generators suffer during its operative useful life a combination of stresses of nature thermal, electric, mechanics and environmental. With the time, they are going losing the capacity to support those stresses and the power plants suffer, more and more frequently, undesirable stops for repair services and maintenance. In function of the high costs incurred with these stopped, the operation of the power plant can be economically impracticable. That unavailability of the generation for the electric system, it results in reduction of the reliability, burdening the politics of load ruling. The re-potentiation is a proposal that seeks to extend the useful life of hydro-generators, at the same time that it try to rescue the reliability and the readiness of the plant, with larger power. The power increase is usually made possible, or for the surplus of the hydro resources in excess, or for the reduction of the losses of ...

Energy Technology Data Exchange (ETDEWEB)

CdTe/SnTe heterojunctions, prepared by EDRI (evaporation-diffusion en regime isotherme) and CSVT (close spaced vapour transport) techniques, have a spectral response in a wide wavelength range (0.3 - 1.5 ..mu..m) which exhibits two distinct bands, corresponding to carrier generation in each material of the couple. Experimental results are interpreted in terms of a Schottky diode model. (orig.).

UK PubMed Central (United Kingdom)

A new proprietary de novo peptide design technique generated ten 15-residue peptides targeting and containing the leading nontransmembrane hydrophobic autocorrelation wavelengths, “modes”,...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Computer programs have been written to allow the analysis of different types of eddy-current probes and their performance under different steam generator test conditions. The probe types include the differential bobbin probe, the absolute bobbin probe, the pancake probe and the reflection probe. The generator test conditions include tube supports, copper deposits, magnetite deposits, denting, wastage, pitting, cracking and IGA. These studies are based mostly on computed values, with the limited number of test specimens available used to verify the computed results. The instrument readings were computed for a complete matrix of the different test conditions, and then the test conditions determined as a function of the readings by a least-squares technique. A comparison was made of the errors in fit and instrument drift for the different probe types. The computations of the change in instrument reading due to the defects have ...

Energy Technology Data Exchange (ETDEWEB)

Radio interference and TV interference are being a problem in urban and rural areas. This interference is generated by high voltage transmission lines as well as distribution lines. The radio noise can be produced by polluted or damaged insulators, and by metal parts of the distribution lines. The corona effect on the surface of the dielectric material produces high frequency electromagnetic fields during the ionization and during the recombination period. Fields of different intensity are produced by positive voltage and negative voltage. The insulator flashover (leaking current) also produces electromagnetic fields. A new technique to measure these fields was developed. This technique measures the radiated fields on time domain and on frequency domain. This permits us to characterize the radiated field and thus identify the type of the source. Several measurements were done varying the type of the RF ...

Science.gov (United States)

This report describes the results of EPRI Program S404-28, titled Experimental Modeling of Eddy Current Response'', conducted by the Westinghouse Science and Technology Center (STC). The Westinghouse STC demonstrates that its mercury modeling technique provides an unique bridge between steam generator eddy current field inspection conditions and predictions obtained using recently developed analytical models. The mercury modeling technique was used systematically to explore factors which contribute to primary water stress corrosion cracking (PWSCC) sizing inaccuracy, including probe design, coil excitation frequency, crack length, and crack morphology. Two new proposed techniques for inverting crack lengths from eddy current data are compared with the technique commonly used in field data analysis for PWSCC. The performance of uniform field eddy current probes is ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

The permeation of hydrogen through steam generator tubes at high temperatures ({approx} 300 degrees C) has been studied using an electrochemical technique. With this technique, hydrogen is generated on one side of the tube and monitored on the other side. The time for the hydrogen to reach the other side is used to determine the diffusion coefficient of hydrogen in the tube. Boundary conditions at the entry and exit sides have been investigated separately. Preliminary studies were performed on Stainless Steel 316 and Nickel Alloy 800 to better understand the influence of the solution chemistry on the electrochemical evolution of hydrogen. The surface phenomena effect and the trapping effect are discussed to account for differences observed in the permeation response. The hydrogen permeation through oxides at the exit side has been studied. Two nickel alloys (Alloy 800 and Alloy 600), materials widely ...

International Nuclear Information System (INIS)

We have studied the features of formation and the possible stationary structures of a self-consistent magnetic field in a relativistic collisionless plasma, which are characteristic of a simple geometry of the Weibel instability that is well known in the nonrelativistic case. The universal condition is established, the growth rate is determined, and the criteria of saturation of the Weibel instability are analyzed for a broad class of anisotropic particle distribution functions (for definiteness, in application to an electron-positron plasma). A nonlinear equation of the Grad-Shafranov type describing the potential current structures is derived and its solutions are analytically studied. Special attention is paid to spatially harmonic, nonlinear current configurations with parameters determined by the properties of the initial homogeneous plasma subject to the Weibel instability. It is demonstrated that the magnetic field energy density in the obtained solutions ...

CERN Document Server

The unavoidable irreversible losses of power in a heat engine are found to be of quantum origin. Following thermodynamic tradition a model quantum heat engine operating by the Otto cycle is analyzed. The working medium of the model is composed of an ensemble of harmonic oscillators. A link is established between the quantum observables and thermodynamical variables based on the concept of canonical invariance. These quantum variables are sufficient to determine the state of the system and with it all thermodynamical variables. Conditions for optimal work, power and entropy production show that maximum power is a compromise between the quasistatic limit of adiabatic following on the compression and expansion branches and a sudden limit of very short time allocation to these branches. At high temperatures and quasistatic operating conditions the efficiency at maximum power coincides with the endoreversible result. The optimal compression ratio varies from the square ...

International Nuclear Information System (INIS)

Hyperspherical-harmonics method to investigate the lightest nuclei having three-cluster structure is discussed together with recent experiments. Properties of bound states and methods to explore three-body continuum are presented. The challenges created by large neutron excess and halo phenomena are highlighted. Astrophysical aspects of the "7Li + n "#-># "8Li + #gamma# reaction and the solar-boron-neutrinos problem are analyzed. Three-cluster structure of highly excited states in "8Be is shown to be responsible for extreme isospin mixing. Progress in studies of "6He- and "1"1Li-induced inclusive and exclusive nuclear reactions is demonstrated, providing information on the nature of continuum structures of Borromean nuclei.

Energy Technology Data Exchange (ETDEWEB)

Vacuum pressure standards of the orifice-flow type require known gas flows of 10/sup -6/ mol/s (10/sup -2/ atm cm/sup 3//s at 0 /sup 0/C) and less. Known gas flows can also be used to calibrate ''standard'' leaks by comparing the pressures generated when flows from the leak and the flowmeter are alternately passed through a constant conductance. Two constant-pressure, piston displacement flowmeters developed at the National Bureau of Standards are described that can generate flows between 10/sup -6/ and 10/sup -10/ mol/s with an estimated uncertainty of 0.8% to 2%. Comparisons of the flowmeters with alternate calibration techniques, and repeated low-range leak and vacuum gauge calibrations, have been used to confirm the estimated uncertainty and random errors of the flowmeter.

Energy Technology Data Exchange (ETDEWEB)

Genetic mapping is approached using the techniques of high resolution fluorescence in situ hybridization (FISH). This technology and the results of its application are designed to rapidly generate whole genome as tool box of expressed sequence to speed the identification of human disease genes. The results of this study are intended to dovetail with and to link the results of existing technologies for creating backbone YAC and genetic maps. In the first eight months, this approach generated 60--80% of the expressed sequence map, the remainder expected to be derived through more long-term, labor-intensive, regional chromosomal gene searches or sequencing. The laboratory has made significant progress in the set-up phase, in mapping fetal and adult brain and other cDNAs, in testing a model system for directly linking genetic and physical maps using FISH with small fragments, in setting up a database, and in establishing the ...

Energy Technology Data Exchange (ETDEWEB)

We report experimental evidence of a previously unseen species-dependent effect in the transverse emittances of momentum-analyzed {sup 28}Si{sup {minus}}, {sup 58}Ni{sup {minus}}, and {sup 197}Au{sup {minus}} negative-ion beams generated by cesium-ion sputtering. The differences in the emittances are found to be principally correlated with differences in the energy spreads in the respective ion beams, which have their origins in the sputter-ejection negative-ion formation process. The experimental equipment and techniques utilized for emittance data acquisition and analysis, and evidence for a species-dependent effect in the emittances and brightnesses of the subject ion beams, are presented in this paper.

CERN Document Server

A transformation monoid on a set Omega is called synchronizing if it contains an element of rank 1 (that is, mapping the whole of Omega to a single point). In this paper, I tackle the question: given n and k, what is the probability that the submonoid of the full transformation monoid T_n generated by k random transformations is synchronizing? This question is analogous to Dixon's Theorem that two random permutations generate the symmetric or alternating group with high probability. Following the technique of Dixon's theorem, we need to analyse the maximal non-synchronizing submonoids of T_n. I develop a very close connection between transformation monoids and graphs, from which we obtain a description of non-synchronizing monoids as endomorphism monoids of graphs satisfying some very strong conditions. However, counting such graphs, and dealing with the intersections of their endomorphism monoids, seems difficult.

International Nuclear Information System (INIS)

A Quantitative Computed Tomography (QCT) method, simplifying the well-known technique proposed by Genant (1982) and applied to a standard third generation whole body CT scanner is described. This technique was applied in the measurement of the trabecular bone which has high sensitivity for metabolic changes. The BMC (Bone Mineral Content) measured in different groups of subjects (healthy postmenopausal patients versus women with postmenopausal osteoporosis) showed a highly significant difference (p<0.001). The precision of repositioning (coefficient of variation 1.8% to 2.3%, obtained in healty male patients) and the good, linear relationship computed from the phantom values, minimize measurement errors. Since this method is quickly applied and involves low-dose radiation-exposure, it could be introduced in the clinical study of metabolic bone diseases.

International Nuclear Information System (INIS)

An ultrasonic signal processing technique is applied to multi-mode arrival time estimation from Lamb waveforms. The basic tool is a simplified time-scale projection called a dynamic wavelet fingerprint (DWFP) which enables direct observation of the variation of features of interest in non-stationary ultrasonic signals. The DWFP technique was used to automatically detect and evaluate each candidate through-transmitted Lamb mode. The area of the dynamic wavelet fingerprint was then used as a feature to distinguish false modes caused by noise and other interference from the true modes of interest. The set of estimated arrival times were then used as inputs for tomographic reconstruction. The Lamb wave tomography images generated with these estimated arrival times were able to indicate different defects in aluminum plates.

Energy Technology Data Exchange (ETDEWEB)

A technique is proposed to generate electron beam with ultralow transverse emittance through laser assisted transverse-to-longitudinal emittance exchange. In the scheme a laser operating in the TEM10 mode is used to interact with the electron beam in a dispersive region and to initiate the emittance exchange. It is shown that with the proposed technique one can significantly downsize an x-ray free electron laser (FEL), which may greatly extend the availability of these light sources. A hard x-ray FEL operating at 1.5 {angstrom} with a saturation length within 30 meters using a 3.8 GeV electron beam is shown to be practically feasible.

CERN Document Server

A growing number of applications that generate massive streams of data need intelligent data processing and online analysis. Real-time surveillance systems, telecommunication systems, sensor networks and other dynamic environments are such examples. The imminent need for turning such data into useful information and knowledge augments the development of systems, algorithms and frameworks that address streaming challenges. The storage, querying and mining of such data sets are highly computationally challenging tasks. Mining data streams is concerned with extracting knowledge structures represented in models and patterns in non stopping streams of information. Generally, two main challenges are designing fast mining methods for data streams and need to promptly detect changing concepts and data distribution because of highly dynamic nature of data streams. The goal of this article is to analyze and classify the application of diverse data mining ...

Energy Technology Data Exchange (ETDEWEB)

A CANDU nuclear reactor was shut down for over one year because steam generator (SG) tubes had failed with outer diameter stress-corrosion cracking (ODSCC) in the U-bend section. Novel, single-pass eddy current transmit-receive probes, denoted as C3, were successful in detecting all significant cracks so that the cracked tubes could be plugged and the unit restarted. Significant numbers of tubes with SCC were removed from a SG in order to validate the results of the new probe. Results from metallurgical examinations were used to obtain probability-of-detection (POD) and sizing accuracy plots to quantify the performance of this new inspection technique. Though effective, the above approach of relying on tubes removed from a reactor is expensive, in terms of both economic and radiation-exposure costs. This led to a search for more affordable methods to validate inspection techniques and procedures. Methods are presented for ...

International Nuclear Information System (INIS)

Low-temperature #gamma# radiolysis and photolysis of crystalline 2,4,6-triazido-3,5-dichloropyridine (TAP) were studied by means of the ESR technique. It was found that the long-term irradiation of TAP at 77 K leads to the appearance of characteristic signals of quintet 2,6-dinitreno-4-azido-3,5-dichloropyridine and 2,4-dinitreno-6-azido-3,5-dichloropyridine; the radiation-chemical yield was 0.035 and 0.012 molecule/100 eV, respectively. The photolysis of crystalline 2,4,6-triazido-3,5-dichloropyridine proceeded less effectively, producing only quintet 2,6 dinitrene with a quantum yield of #approx#4.5 x 10"-"4. The study showed that the generation of high-spin nitrenes via radiolysis of crystalline azides is much superior to the photochemical technique in efficiency and may be of practical importance for the preparation of magnetically active organic materials

Energy Technology Data Exchange (ETDEWEB)

In the paper, a fuzzy decision-making methodology is presented to decide the generation schedule of long-term hydrothermal problems with explicit recognition of statistical uncertainties in system production cost data, NO{sub x} emission data, system load demand and hydro reservoir water inflows. In deciding the optimal operation, three objectives operating cost, NO{sub x} emission and unsatisfied load demand over the whole of the planning period are simultaneously minimised. Specific technique is put forth to convert the stochastic models into their deterministic equivalents. The weighted minimax method is used to simulate the tradeoff relation between the conflicting objectives in the non-inferior domain. The fuzzy set theory is exploited to choose the best operating point over the tradeoff curve. An efficient decomposition technique is applied to reduce the complexity of the problem. In each subproblem, thermal ...

International Nuclear Information System (INIS)

Techniques for reducing computation time in 3D photon dose calculations are addressed with specific emphasis given to the convolution/superposition approach. A single polyenergetic superposition model calculating absorbed dose per incident photon fluence (Gy cm"2) was developed in terms of TERMA and a total energy deposition kernel (a total point spread function). A novel approach was devised for reducing calculation time. The method, named the CF method, was based on the use of a conventional, fast model (here a modified power-law method was used) for the generation of 3D dose distributions on a fine dose matrix. Superposition calculations were carried out on a coarse matrix and calculation speed was increased simply by reducing the number of calculations. A set of correction factors was derived on the coarse grid from the ratio of the dose values from superposition to those from the conventional algorithm. These were interpolated onto the ...

Energy Technology Data Exchange (ETDEWEB)

A brief overview is given of the geological characteristics of each region of the state as they relate to potential geothermal development. Those exploration methods which can lead to the siting of a deep exploration well are described. Requirements and techniques needed for drilling deeper higher temperature exploration and production wells are presented. Electrical generation, direct utilization, and indirect utilization are reviewed. Economic factors of direct use projects are presented. A general guide to the regulatory framework affecting geothermal energy development is provided. The general steps necessary to gain access to explore, develop, distribute, and use geothermal resources are outlined. (MHR)

British Library Electronic Table of Contents (United Kingdom)

The Dynamic Analog Scale (DAS) is introduced as a technique for generating single-item measures of personality traits. The DAS is comprised of extensive trait definitions and an analog scale on which respondents simultaneously rate themselves and others. In two studies the Big Five personality traits were assessed with the DAS and compared to a multiple-item questionnaire that measured the same traits. Statistical analysis supported the validity of the DAS for predicting self-reported behavioral acts, drinking behaviors, affect, and religiosity in ways similar to the multiple-item questionnaire. Consistent with previous research, both studies supported the viability of measuring personality traits with single items.

International Nuclear Information System (INIS)

A technique for quantitative analysis of growth plates in varus or valgus deformity about the knee has been developed. Computer-generated regions of interest are placed on magnification scintigraphs to divide distal femoral and proximal tibial physes into four equal segments. The ratio of counts in the medial half to counts in the lateral half was studied in 31 children (22 normal, 9 with angular deformity). Normal ratios were 0.74 to 0.98 for femora and 0.98 to 1.20 for tibias. In eight of nine patients with deformity, the ratio was abnormal; in two patients the ratio returned to normal when the deformity ceased to progress.

Science.gov (United States)

Deformation experiments performed in-situ in the transmission electron microscope have led to an increased understanding of dislocation dynamics. To illustrate the capability of this technique two examples will be presented. In the first example, the processes of work hardening in Mo at room temperature will be presented. These studies have improved our understanding of dislocation mobility, dislocation generation, and dislocation-obstacle interactions. In the second example, the interaction of matrix dislocations with grain boundaries will be described. From such studies predictive criteria for slip transfer through grain boundaries have been developed.

Energy Technology Data Exchange (ETDEWEB)

The wind industry has experienced premature turbine component failures during the past years. With the increase in turbine size, these failures, especially those found in the major drivetrain components, i.e. main shaft, gearbox, and generator, have become extremely costly. Given that the gearbox is the most costly component in the drivetrain to fix, the National Renewable Energy Laboratory (NREL) initiated the Gearbox Reliability Collaborative (GRC) to determine the causes for premature gearbox failures and subsequently, recommend improvements to gearbox design, manufacture, and operational practices. The GRC has two identical test gearboxes, which are planned for a dynamometer and a field test, respectively.

Energy Technology Data Exchange (ETDEWEB)

The aim of this document is to make a state-of-the-art of the techniques of heating-cooling ceilings and cold beams. These systems offer many advantages: they generate a high quality thermal comfort, they are energy efficient, and offer important room saving, particularly interesting in the case of building renovation. The document comprises 5 parts dealing with: 1 - the heating-cooling ceilings; 2 - the cold beams; 3 - the elements necessary for the dimensioning (building-system interactions, ventilation, temperature regulation and safety systems); 4 - dimensioning method; 5 - design, realization and operation: the rules to follow. (J.S.)

CERN Document Server

Data generated in the fields of science, technology, business and in many other fields of research are increasing in an exponential rate. The way to extract knowledge from a huge set of data is a challenging task. This paper aims to propose a hybrid and viable method to deal with an information system in data mining, using topological techniques and the significance of the attributes measured using rough set theory, to compute the reduct, This will reduce the randomness in the process of elimination of redundant attributes, which, in turn, will reduce the complexity of the computation of reducts of an information system where a large amount of data have to be processed.

Energy Technology Data Exchange (ETDEWEB)

A brief overview is given of the geological characteristics of each region of the state as they relate to potential geothermal development. Those exploration methods which can lead to the siting of a deep exploration well are described. Requirements and techniques needed for drilling deeper higher temperature exploration and production wells are presented. Electrical generation, direct utilization, and indirect utilization are reviewed. Economic factors of direct use projects are presented. A general guide to the regulatory framework affecting geothermal energy development is provided. The general steps necessary to gain access to explore, develop, distribute, and use geothermal resources are outlined. (MHR)

International Nuclear Information System (INIS)

The nuclear shapes of transitional Mo isotopes are calculated by means of a model based on the cranking approximation and the Strutinksy method. The recent experimental results of the high-spin spectroscopy and lifetime measurement of "8"7Mo are studied in detail and explained by the evolution of the #gamma#-deformation with the quasiparticle configurations. The shape calculations with the modified-harmonic-oscillator potential give a critical neutron number N #>=# 47 for the spherical shape of the Mo isotopes. (orig.).

International Nuclear Information System (INIS)

The case of spontaneous radiation of channeled ultrarelativistic particles is considered when the dipolarity condition is not satisfied. The change of the particle longitudinal velocity affecting the maximum radiation frequency is included. The angular and frequency characteristics of the radiation for superhigh energies are studied for the first time. It is shown that there is an optimum energy at which the radiation density is maximum. The influence of the angle at which electrons enter a crystal and of the beam divergence on the radiation is investigated. The problem of quasichanneled particle radiation and also the radiation in axis-plane transitions are considered. (author).

International Nuclear Information System (INIS)

Coherent oscillator radiation is considered. A comparison is made with classical particle radiation with gauss distribution. Decay probability for coherent state in spontaneous radiation is estimated. The method suggested for describing harmonic oscillator allows to separate the effect of classical field radiation from quantum description of particle state within the framework of a self-consistent quantum mechanical problem.

International Nuclear Information System (INIS)

We study the spin dependence of accretion onto rotating Kerr black holes using analytic techniques. In its linear regime, angular momentum transport in MHD turbulent accretion flow involves the generation of radial magnetic field connecting plasma in a differentially rotating flow. We take a first principles approach, highlighting the constraint that limits the generation and amplification of radial magnetic fields, stemming from the transfer of energy from mechanical to magnetic form. Because the energy transferred in magnetic form is ultimately constrained by gravitational potential energy or Killing energy, the spin dependence of the latter allows us to derive spin-dependent constraints on the success of the accreting plasma to expel its angular momentum. We find an inverse relationship between this ability and black hole spin. If this radial magnetic field generation forms the basis for angular ...

International Nuclear Information System (INIS)

In this paper we apply stochastic programming modelling and solution techniques to planning problems for a consortium of oil companies. A multiperiod supply, transformation and distribution scheduling problem - the Depot and Refinery Optimization Problem (DROP) - is formulated for strategic or tactical level planning of the consortium's activities. This deterministic model is used as a basis for implementing a stochastic programming formulation with uncertainty in the product demands and spot supply costs (DROPS), whose solution process utilizes the deterministic equivalent linear programming problem. We employ our STOCHGEN general purpose stochastic problem generator to 'recreate' the decision (scenario) tree for the unfolding future as this deterministic equivalent. To project random demands for oil products at different spatial locations into the future and to generate random fluctuations in their future prices/costs a ...

Energy Technology Data Exchange (ETDEWEB)

A multivariate adaptive power system stabilizer is proposed. The advantages of using coordinated governor and excitation control are discussed, and the problems associated with constant parameter power system stabilizers (CPSS) are highlighted. The proposed multi-input multi-output (MIMO) power system stabilizer can coordinate the governor and excitation control and can overcome the problems associated with CPSS in power system stabilization. Selective multivariable state modelling, identification and control methods are investigated and the MIMO least squares technique with variable forgetting factor is used for system identification, guaranteeing good parameter tracking after a disturbance. Two multivariable self-tuning algorithms are investigated, the generalized minimum variance control and pole-shifting control algorithms. The multivariable self-searching pole-shifting algorithm is developed. Models of a single machine connected to an infinite bus through a ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes a technique for implementing the ultrasonic inside diameter (ID) creeping wave technique for detection and sizing ID connected defects using a phased array ultrasonic system. The technique uses multiple focal laws to produce the examination modes. The first focal law is designed to create a shear wave nominally at the critical angle for mode conversion to a longitudinal wave at the ID of a part, thus creating a creeping wave. This focal law is focused at the ID to improve sensitivity. The rest of the laws are designed to create tandem sound paths that progress up a vertical surface directly above the focal point of the creeping wave generation point. When a defect on the inner surface is detected with the creeping wave, the height of the defect can be measured from the response of a set of tandem laws without readjusting the position of the probe. Results from standard one-inch long ...

Energy Technology Data Exchange (ETDEWEB)

Techniques for fabricating P-type (Cu,Ag)/sub 2/Se with mesh-type bonds have been developed and are being evaluated for long-term use. In addition, methods for reducing vapor suppression by the use of coatings and/or baffling continue to show gains. The N-type alloy Gd/sub 2/Se/sub 3/ has been shown to be thermally unstable. It undergoes a sluggish cubic-to-orthorhombic phase change below 1000/sup 0/C, with an accompanying degradation in mechanical and thermoelectric properties. Fabrication studies conducted with the (Bi,Sb)/sub 2/(Se,Te)/sub 3/ alloys showed these materials to be sensitive to oxygen contamination if reproducible properties are to be obtained. Preparation of powdered material by explosive techniques was investigated. This technique appears to be useful in preparing homogeneous -325 mesh material, but it does not yield a useful amount of submicron-size powder.

Science.gov (United States)

An advanced experimental technique has been developed to simulate two-phase flow behavior in a light water reactor (LWR). The technique applies three kinds of methods; (1) use of sulfur-hexafluoride (SF6) gas and ethanol (C2H5OH) liquid at atmospheric temperature and a pressure less than 1.0MPa, where the fluid properties are similar to steam-water ones in the LWR, (2) generation of bubble with a sintering tube, which simulates bubble generation on heated surface in the LWR, (3) measurement of detailed bubble distribution data with a bi-optical probe (BOP), (4) and measurement of liquid velocities with the tracer liquid. This experimental technique provides easy visualization of flows by using a large scale experimental apparatus, which gives three-dimensional flows, and measurement of detailed spatial distributions of two-phase flow. With this technique, we ...

Energy Technology Data Exchange (ETDEWEB)

Maintaining uniformity of properties over long distances is one of the fabrication problems encountered with the new high {Tc} superconductors. Uniform properties are crucial in long tapes or wires with high critical current since local nonuniformities can limit the current carrying capacity of the whole piece. Transport critical currents in high {Tc} superconductors are conventionally measured with the contact 4-point probe DC current-voltage technique. This technique requires contact with the sample and and spatially averages over the region between the two voltage contacts. Two techniques have been used to infer the critical state model. The first uses the net magnetization of a suitably shaped sample in an external magnetic field. The second combines a DC magnetic field with AC induced currents to infer spatial flux profiles. The AC magnetization technique offers an advantage in that it is ...

International Nuclear Information System (INIS)

The bobbin probe technique is basically one of the important ECT methods for the steam generator tube integrity assessment that is practiced during each plant outage. The bobbin probe also is the essential component which consists of the whole ECT examination system, and provides a decisive data for the evaluation of tube integrity in compliance with acceptance criteria described in specific procedures. The selection of probe is especially important because the quality of acquired ECT data is determined by the probe design characteristics, such as geometry and operation frequency, and has an important effect on examination results. The Electric Power Research Institute (EPRI) has recently defined the procedures for the qualification of eddy current hardware and technique. These procedures provide two basic methods for qualification. Flawed tube removed from operation, or artificial flaw is required for the original ...

Science.gov (United States)

This Dissertation presents the author's investigation and development of a systematic method for evaluating the aerodynamic performance of Vertical Axis Wind Energy Capture Systems (WECS) apart from their electrical generation capability. The current standard method for specifying a wind energy machine is to discuss its rated power in kilowatts (or megawatts when capacity exceeds 100 kW). While this holistic method is effective for comparing machines it does not reveal the essential characteristics necessary for optimization of individual machine components. The method developed herein separates the performance characteristics of the WECS from the generation characteristics and isolates them for benchmarking and optimization. In order to develop an evaluation criterion, it was essential to evaluate and benchmark the current state of the art for wind energy capture. A thorough history of Vertical Axis Wind Turbine (VAWT) development and ...

International Nuclear Information System (INIS)

Since 1975 All Volatile Treatment (AVT) has been the preferred method for controlling the secondary system operating environment in Westinghouse PWR plants. However, since AVT provides no buffering action against corrodent species present in the water as trace contaminants, utilities have initiated programs which combine control of contaminant ingress with total steam generator sludge management. The earliest applications of boric acid, to control denting type corrosion, began in 1978 and have continued up to the present time. Boric Acid has also been added as an inhibitor for SCC/IGA type corrosion since 1985. There are now approximately 30 plants operating with boric acid or boric acid/morpholine chemistry in the secondary system, and a growing number of plants where morpholine is being used as an additive to maintain pH and reduce iron transport attributable to erosion/corrosion. The impact of these modifications in the operating chemistry environment are ...

CERN Document Server

In this paper we study half-BPS type IIB supergravity solutions with multiple $AdS_3\\times S^3\\times M_4$ asymptotic regions, where $M_4$ is either $T^4$ or $K_3$. These solutions were first constructed in [1] and have geometries given by the warped product of $AdS_2 \\times S^2 \\times M_4 $ over $\\Sigma$, where $\\Sigma$ is a Riemann surface. We show that the holographic boundary has the structure of a star graph, i.e. $n$ half-lines joined at a point. The attractor mechanism and the relation of the solutions to junctions of self-dual strings in six-dimensional supergravity are discussed. The solutions of [1] are constructed introducing two meromorphic and two harmonic functions defined on $\\Sigma$. We focus our analysis on solutions corresponding to junctions of three different conformal field theories and show that the conditions for having a solution charged only under Ramond-Ramond three-form fields reduce to relations involving the positions of the poles ...

Energy Technology Data Exchange (ETDEWEB)

A highly efficiency partial smoothing method is proposed to be used for inverters for 40W class household fluorescent inverters. In this system, the input current from the commercial AC power source is accumulated in a capacitor with comparatively small capacity as the electric charge, and then the lamp circuit is driven by the inverter utilizing the charging voltage of the capacitor and the charging voltage of the separately prepared partial smoothing capacitor. By this method, the RF harmonic components in the supply current can be decreased to improve the power factor with no complicated feedback controlling device. In addition, comparatively small capacity coils and capacitors can be used. The structure of the circuit and the operation of this proposed method are described, and the operational characteristic of the prototype circuit and the result of analysis are shown. Furthermore, problems and improving method of the actual circuit are investigated by an ...

International Nuclear Information System (INIS)

As a continuation of its efforts to provide methodologies and tools to Member States to carry out comparative assessment and analyse priority environmental issues related to the development of the electric power sector, the IAEA has completed a new version of the Wien Automatic System Planning (WASP) Package WASP-IV for carrying out power generation expansion planning taking into consideration fuel availability and environmental constraints. This manual constitutes a part of this work and aims to provide users with a guide to use effectively the new version of the model WASP-IV. WASP was originally developed in 1972 by the Tennessee Valley Authority and the Oak Ridge National Laboratory in the USA to meet the IAEA needs to analyse the economic competitiveness of nuclear power in comparison to other generation expansion alternatives for supplying the future electricity requirements of a country or region. Previous versions of the model were used ...

Scientific Electronic Library Online (English)

Abstract in english We consider the three dimensional electromagnetic inverse scattering problem of determining information about a buried coated object from a knowledge of the electric and magnetic fields measured on the surface of the earth corresponding to time harmonic electric dipoles as incident fields. We assume that the buried object is a perfect conductor that is (possibly) partially coated by a thin dielectric layer. No a priori assumption is made on the extent of the coating, i.e. (more) the object can be fully coated, partially coated or not coated at all. We present an algorithm based on the linear sampling method and reciprocity gap functional for reconstructing the shape of the scattering obstacle together with an estimate of the surface impedance of the coating.

International Nuclear Information System (INIS)

To investigate the magnetic fluctuations and for further transport study, the poloidal and radial magnetic field measurement is conducted on the Sino United Spherical Tokamak (SUNIST). Auto-power spectral density indicates that the magnetic fluctuation energy mainly concentrates in the frequency region lower than 10 kHz. The magnetic field oscillations, which are characterized by harmonic frequencies of 40 kHz, are observed in the scrape-off layer; by contrast, in the plasma core, the magnetic fluctuations are of Gaussian type. The time-frequency profiles show that the poloidal magnetic fluctuations are temporally intermittent. The autocorrelation calculation indicates that the fluctuations in decorrelation time vary between the core and the edge. (authors)

International Nuclear Information System (INIS)

The electromagnetic properties of a prototype gravitational wave detector, based on two coupled superconducting microwave cavities, were tested. The radio-frequency (rf) detection system was carefully analysed. With the use of piezoelectric crystals small harmonic displacements of the cavity walls were induced and the parametric conversion of the electromagnetic field inside the cavities explored. Experimental results of bandwidth and sensitivity of the parametric converter versus stored energy and voltage applied to the piezoelectric crystal are reported. A rf control loop, developed to stabilize phase changes on signal paths, gave a 125 dBc rejection of the drive mode on a time scale of 1 h.

International Nuclear Information System (INIS)

In laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS), the properties of laser-generated aerosols, such as size and composition, are crucial for matrix-independent quantification. In this study, the aerosol particle morphology and elemental composition generated by two state-of-the-art laser systems (ArF excimer nanosecond-UV laser and Ti:sapphire femtosecond-IR laser) were investigated by electron microscopic techniques. Electrostatic sampling of the aerosols directly onto transmission electron microscopy (TEM) grids allowed us to study the morphology and elemental composition of the aerosols using TEM and TEM-EDX (energy dispersive X-ray spectroscopy) analyses, respectively. The results of the electron microscopic studies were finally compared to the LA-ICPMS signals of the main matrix components. The investigations were carried out for non-conducting materials (glass and zircon), metallic samples ...

Energy Technology Data Exchange (ETDEWEB)

Acid mine drainage represents one of the most important environmental problem facing the mining industry. If the tailings contain sulphur, acid mine drainage will be generated as soon as the tailings are exposed to oxygen. In this paper, the authors discussed a technique for the storage of acid mine drainage generating tailings that delays and even eliminates the occurrence. It was suggested that tailings should be piled by incorporating, at regular intervals, compacted waste rock. Thermal convection and diffusion will prevent oxygen from reaching the tailings, and limit water circulation. The modelling of transfer processes (heat, water, oxygen) in a well known tailings dump, the Doyon Mine, was performed, and the results compared to the modelling where compacted waste rock had been incorporated at regular intervals. The results indicated that by remaining saturated, the layers acted as capillary barriers preventing oxygen ...

International Nuclear Information System (INIS)

The UK Energy Research Centre (UKERC) in it's submission to the DTI's 2006 Energy Review reminded us that the 'UK has abundant wind, wave and tidal resources available; its mild climate lends itself to bio-energy production, and solar radiation levels are sufficient to sustain a viable solar industry'. These technologies are at different stages of development but they all draw on basic and applied Science and Engineering. The paper will briefly review the renewable energy technologies and their potential for contributing to a sustainable energy supply. Three research topics will be highlighted that bridge the gap between the physics underpinning the energy conversion, and the engineering aspects of development and deployment; all three are highly relevant to the Government's programme on micro-generation. Two are these are taken from field of thin film photovoltaics (PV), one related to novel device development and the other to a measurement ...

International Nuclear Information System (INIS)

We describe in a comprehensive fashion the Los Alamos second-generation system for passive and active neutron assays of drum-size containers. The developmental history of this 7-year project is presented with emphasis on the pulsed active neutron technique (differential dieaway), which has achieved milligram levels of assay sensitivity for both plutonium and uranium wastes. We describe in detail the matrix effects for both passive and active neutron assays. We present in a thorough fashion our novel approach to achieving comprehensive corrections for these matrix effects using measurements made during the assays. We develop a matrix correction formalism based on separate neutron absorption and moderator indices determined from these measurements. These are presented as a series of analytic functions fitted to the data. Absolute calibrations and calibration standards are discussed, as is a practical means (pink drum measurements) of achieving ...

Energy Technology Data Exchange (ETDEWEB)

Anisotropy has been investigated using S-wave as a technique for detecting fractures. In this study, fundamental experiments were carried out with slightly changing the measuring conditions at a place where anisotropy was expected. This paper describes the fundamental data acquisition of anisotropy analysis using S-wave, and a part of the results. The experiments were conducted on the agricultural road in Yamadera district, Matsuyama-machi, Yamagata Prefecture. Two flat unpaved roads meeting at right angles were used as traverse lines. In this place, several reflection surfaces were certainly detected by P-wave, and anisotropy of S-wave was confirmed from the velocity of refracted wave of S-wave. Data were processed for individual traverse lines meeting at right angles. Firstly, signal sweeping, correlation, and vertical superposition were made. Six kinds of data were prepared, i.e., three-component receiving records of data at 0{degree} of ...

Energy Technology Data Exchange (ETDEWEB)

Steam generator tubes in nuclear power plants are periodically checked by means of eddy current probes. The output of a probe is composed of three types of signals: known events (rolling zone, support plates, U-bend part), noise (mainly metallurgical noise) and possible flaws. The latter are random transients, both in arrival time and in shape: they have to be detected and then estimated, before to be fed to the high level stages of a diagnostics system. The objective of the study presented is to develop a semi-automatic system, which could manage and process more than 1 M-bytes of data per tube and provide an operator with reliable diagnostics proposals within a few minutes. This can be achieved only by cooperation of several digital signal processing techniques: detection, segmentation, estimation, noise subtraction, adaptive filtering, modelization, pattern recognition. The paper describes some of these items.

Energy Technology Data Exchange (ETDEWEB)

Radiographic images generated by the real-time neutron radiography system (RTNR) are analyzed by customized image processing software of the determination of instantaneous void fraction distribution. The cross-sectional averaged axial void fraction profiles and the two-dimensional void fraction profiles are determined simultaneously for each image. Various flow regimes are generated to determine if the RTNR system can accurately predict the void distribution in the radial, axial, and temporal coordinates. The results show the RTNR system correctly determines the void fraction distribution for each flow regime; however, accuracy decreases with decreasing void fraction. For net water thicknesses > 1.0 cm, the accuracy decreases with increasing water thickness due to the extreme sensitivity of thermal neutron interactions with light water. Heavy water is a more suitable fluid than light water for void fraction measurements in large-diameter ...

Energy Technology Data Exchange (ETDEWEB)

Red mud (Rm) is the main by-product of the Bayer process for alumina extraction from bauxite, and grey slurries (GS) are generated during the granite rocks transformation processes. the huge volume of those wastes generated every year suppose a serious environmental problem. Recent works by our group demonstrate the efficiency of both types of muds as corrosion inhibitors for iron and steel in alkaline media containing chlorides. The elemental analysis of these slurried shows that Al{sup 3}+ is the main common element. Therefore, the aim of this paper is to study the effect of the soluble Al{sup 3}+ in the electrochemical behaviour of iron in alkaline media, in presence and absence of chlorides. The electrochemical study using Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) together with surface analysis techniques allowed to conclude that Al{sup 3}+ blocks the surface of steel in alkaline media ...

Energy Technology Data Exchange (ETDEWEB)

This report describes the work performed during FY 1995 by Pacific Northwest Laboratory in developing and optimizing analysis techniques for identifying organics present in Hanford waste tanks. The main focus was to provide a means for rapidly obtaining the most useful information concerning the organics present in tank waste, with minimal sample handling and with minimal waste generation. One major focus has been to optimize analytical methods for organic speciation. Select methods, such as atmospheric pressure chemical ionization mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry, were developed to increase the speciation capabilities, while minimizing sample handling. A capillary electrophoresis method was developed to improve separation capabilities while minimizing additional waste generation. In addition, considerable emphasis has been placed on developing a rapid screening tool, based ...

International Nuclear Information System (INIS)

In the convolution/superposition method of photon beam dose calculations, inhomogeneities are usually handled by using some form of scaling involving the relative electron densities of the inhomogeneities. In this paper the accuracy of density scaling as applied to primary electrons generated in photon interactions is examined. Monte Carlo calculations are compared with density scaling calculations for air and cork slab inhomogeneities. For individual primary photon kernels as well as for photon interactions restricted to a thin layer, the results can differ significantly, by up to 50%, between the two calculations. However, for realistic photon beams where interactions occur throughout the whole irradiated volume, the discrepancies are much less severe. The discrepancies for the kernel calculation are attributed to the scattering characteristics of the electrons and the consequent oversimplified modeling used in the density scaling method. A ...

International Nuclear Information System (INIS)

Full text.Increased environmental concerns and the emphasis on material and energy recovery are gradually changing the orientation of municipal solid waste (MSW) management and planning. In this context, the application of optimization techniques have been introduced to design the least cost solid waste management systems, considering the variety of management processes (recycling, composting, anaerobic digestion, incineration and land filling) and the existence of uncertainties associated with the number of system components and their interrelations. This study presents a model that was developed and applied to serve as a solid socio-economic and environmental considerations. The model accounts for solid waste generation rates, composition, collection, treatment, disposal as well as potential environmental impacts of various MSW management techniques. The model follows a linear programming formulation with the framework of ...

International Nuclear Information System (INIS)

The B test series from the course of ISP Nr. 43 was analysed. The boundary conditions measured include the initial temperature of the primary system, the front/slug injection flowrate and temperature, and the pressure drop across the core. Temperature data were collected at 185 thermocouple positions in the downcomer and 38 positions in the lower plenum. The frequency of data acquisition for code predictions was set to 2 Hz, which corresponds to the acquisition frequency of the two experimental setups. Calculations were performed using the FLUENT Computational Fluid Dynamics (CFD) code. This program is based on the finite volume method, The computational mesh was generated by the pre-processor - GAMBIT program. FLUENT uses a control-volume-based technique to convert the governing equations to algebraic equations, which can be solved numerically. This control volume technique consists of integrating the governing equations ...

International Nuclear Information System (INIS)

In this paper, we propose to characterize boron transient enhanced diffusion (TED) for processes currently used for P"+/N ultra-shallow junctions (USJ) fabrication. Indeed, the fundamental understanding of boron diffusion for low energy boron implantation is mandatory to evaluate the scalability of such processes for the coming complementary metal-oxide-semiconductor (CMOS) transistor generations. In these experiments, we characterize the boron anomalous diffusion, thanks to boron buried marker-layers obtained by epitaxial growth. B"+ and BF_2"+ ultra-low energy (ULE) implantations and plasma doping (PLAD) using BF_3 as precursor gas are carried out to compare the two techniques used for advanced USJ fabrication. Boron diffusion behaviors are analyzed via secondary ion mass spectrometry for annealing at 700 deg. C for 5 min and 15 min. Finally this paper brings some physical insights explaining the technological benefit coming from PLAD ...

Energy Technology Data Exchange (ETDEWEB)

A multi-faceted research program has been performed to investigate in detail several aspects of free and forced convective cooling of underground electric cable systems. There were two main areas of investigation. The first one, reported in Volume 1, dealt with the fluid dynamic and thermal aspects of various components of the cable system. In particular, friction factors for laminar flow in the cable pipes with various configurations were determined using a finite element technique; the temperature distributions and heat transfer in splices were examined using a combined analytical numerical technique; the pressure drop and heat transfer characteristics of cable pipes in the transitional and turbulent flow regime were determined experimentally in a model study; and full-scale model experimental work was carried out to determine the fluid dynamic and thermal characteristics of entrance and exit chambers for the cooling oil. The second major ...

Science.gov (United States)

This paper presents a novel feature extraction scheme for roller bearing fault diagnosis utilizing generalized S transform and two-dimensional non-negative matrix factorization (2DNMF). The generalized S transform, which can make up the poor energy concentration of the standard S transform, is introduced to generate the time-frequency representation (TFR). Experiment results on simulated signal and vibration signals measured from rolling element bearings have revealed that the generalized S transform can obtain a more satisfactory TFR than other similar techniques. Furthermore, a new technique called two-dimensional non-negative matrix factorization (2DNMF), which can reduce the computation cost and preserve more structure information hiding in original 2D matrices compared to the NMF, is developed to extract more informative features from the time-frequency matrixes for accurate fault classification. Experimental results ...

Energy Technology Data Exchange (ETDEWEB)

During 17 years since the start of operation of the first commercial LWR in Japan, many LWRs have experienced various corrosion damages, but the causes of them were clarified, and the counter-measures were executed effectively in actual plants, as the results, the cause of corrosion damage decreased remarkably, and now, the high rate of operation has become to be maintained. In this paper, the major cases of corrosion damage experienced in LWRs in Japan and foreign countries, the causes of them and the countermeasures, the problems of hereafter and so on are described. The corrosion damage of metallic materials in the environment of LWRs occurs in the parts in contact with high temperature, high pressure water and steam, such as stainless steel piping in the primary cooling system of BWRs, and nickel alloy heating tubes of steam generators, carbon steel feed water piping and zirconium alloy fuel cladding tubes in PWRs. Recently, accompanying the advance of LWR ...

International Nuclear Information System (INIS)

Industrial segments as plant of mining, hospitals and university generate considerable volumes of radioactive wastewater containing uranium. The increasing development of the use of the nuclear energy to lead away to an expansion of the sectors of the nuclear fuel cycle, but it leads to security problems and it appears the necessity of control of the removing of uranium and radioactive effluent treatments. Researches evaluate if the technique of the biosorption would promote an alternative process with attractive characteristics of cost-benefit. The residual biomass from agricultural activities has been studied and used as adsorbent of metals and organic composts by low cost, abundance and for being biodegradable. In this work, it is presented the efficiency of the coir pith for the adsorption of ions UO_2"2"+. The coir pith is a by-product of the harvest of the coconut, a renewable natural source. The study was accomplished using the batch ...

Energy Technology Data Exchange (ETDEWEB)

This report is a summary of the Steam Generator Group Project progress for 1985. Statistical analyses are presented of data from nondestructive examination (NDE) round robin tests that were performed on the Surry generator in 1984. In the first round robin, teams acquired and analyzed their own data on a selected 10% subset of tubes. In the second round robin, analysts from each participating team analyzed identical sets of data which were provided to them by the Project. Results from several examinations utilizing advanced/alternate NDE technologies including alternate eddy current probes and techniques, ultrasonics, and profilometry are also reported. Criteria are listed for selecting tube specimens that will be removed from the generator. A sampling plan based on these criteria is detailed graphically in the report. The initial steps that have been taken to carry out the plan are described; tooling ...

Energy Technology Data Exchange (ETDEWEB)

The abatement of CO{sub 2} emissions is a huge technical and economical challenge. Fossil fuels, which represent 88% of the world primary energy consumption, are the main source of the 25 billions of CO{sub 2} released each year in the atmosphere. The mastery of CO{sub 2} emissions cannot come from a single technology but must result from the simultaneous implementation of several means, like the development of carbon-free energies and the mastery of fossil fuel emissions. The opportunities of progress are numerous and compatible with the economic development. This document presents, first, the different greenhouse gases, the CO{sub 2} emissions per country and the main sources of CO{sub 2} emissions (power and heat generation, transports). Then it presents different ways of abatement of CO{sub 2} emissions: clean coal technologies, gas combined cycles, CO{sub 2} sequestration, reduction of fuel consumption in transports, development of carbon-free energies: wind ...

International Nuclear Information System (INIS)

In Japan, the development of next-generation Light Water Reactor has been launched since April 2008. The development program will be completed in 2015. The purpose of development is to cope with the replacement for existing nuclear power plants after 2030 in Japan and the expanding demand for nuclear power in the world; 'Nuclear Renaissance.' The reactor also aims to be global standard at around 2030. The requirements for global standard and domestic users have been investigated through the feasibility study of past 2 years, 2006-2007, and six innovative features or 'Core-Concepts' were established as follows. A) Reactor core system with uranium enrichment above 5% for significant decrease of spent fuel discharge and prominent higher availability B) Long-life materials and innovative water chemistry technologies for 80 years plant lifetime and significant reduction of occupational dose C) Seismic isolation technologies to standardize plant design independent from ...

Energy Technology Data Exchange (ETDEWEB)

Ternary diagrams are commonly used to provide a graphic representation of equilibrium fluid phase behavior for systems as diverse as distillation columns and miscible gas floods of oil reservoirs. The phase envelope, and the position of the critical point on it, are important to enhanced oil recovery engineers who are involved with miscible gas flood design. In the past, phase equilibrium data were laboriously plotted on the ternary diagram and special graphic techniques were utilized to locate the critical point on the phase envelope. This work presents a computerized curve fitting method to generate the phase envelope from a given set of phase equilibrium data and then use the tie-line slopes to position the critical point. Experimental data are included and show excellent agreement with this new method.

Energy Technology Data Exchange (ETDEWEB)

The new generation of performing rechargeable lithium-ion batteries (``rocking-chair``-type) are penalized by important self-output phenomena linked with the use of highly oxidizing positive electrodes. In order to limit this problem in LiMn{sub 2}O{sub 4}/C batteries, two different passivation techniques were used in order to limit the surface contact between the positive electrode and the electrolyte. Thanks to these treatments, a significant reduction of the percentage of irreversible capacity losses is effectively observed. (J.S.) 3 refs.

Environmental Research Database

ObjectivesFor thermoelectricity both low thermal conductivity and high electrical conductivity are required. High electrical conductivity should be established via a high carriers concentration and a high mobility.~%~The aim of this feasibility study is to investigate a method of modulation doping of Si nanowires in order to generate high carrier concentrations without the need for impurity doping, thus retaining high mobilities.~%~~%~The objectives are (in chronological order):~%~- reduction of the wire [continued...]DescriptionIn recent years, the increasing dependence of society on fossil fuels for socio-economical development has become a cause of great concern. The possibility of a reduced availability of fossil fuels, and the effect of these fuels on climate change, have encouraged research into alternative energy sources. Many of these alternatives are old ideas, implemented using modern techniques. This proposal plans ...

Energy Technology Data Exchange (ETDEWEB)

A real time neutron radiography system has been developed at the University of Michigan Phoenix Memorial Laboratory (PML) and has recently been used to test the imaging capabilities of a neutron imaging device developed by Lixi, Inc. of Downers Grove, Illinois. This device uses an input phosphor that is high in gadolinium to generate a light image which is then sent through an intensifier stage to provide images that can be viewed by eye, video camera, or standard 35 mm camera. It was determined that this device provides images of much higher resolution and sensitivity than those obtained with the imaging system currently being used at PML. Using computerized image enhancement techniques, the images obtained with the Lixi neutron imaging device can then be further enhanced or processed to obtain quantitative information on the object being imaged.

Energy Technology Data Exchange (ETDEWEB)

Using phantoms of children simulating a child of 6 months of age and another one aged 6 years, the authors measured the amount of radioexposure of the lens of the eye, the thyroid and of the gonads. The two computer tomographs Somatom SF and Tomoscan 300 under examination, produced radiodoses of comparable magnitudes. Both devices allow additional examination techniques of particularly high economy. It was found that in cranial CT the exposure of the lens to radiation is generally below 1 R if the orbitae are not situated in the plane of section. If a distance of 2-3 cm is maintained from the orbitae, the dose remains below 0.5 R. Protecting the gonads is meaningful in a 6-year-old boy, whereas covering-up of the thyroid reduced the dose only slightly.

International Nuclear Information System (INIS)

The time and dose characteristics of the electron and X-ray radiations of a tube, connected to a subnanosecond mega volt accelerator, are measured. By the pulse of the accelerating voltage of #>=# 600 kV with duration of #approx =# 0.3 ns the tube generates approximately 5 x 10"1"2 electrons pulse. The current amplitude equals approximately 5 kA/pulse and the radiation dose-about 5 kGy/pulse. The X-ray radiation dose from the tantalum external target constitutes 0.15 Gy/pulse. The prototypes of the electron and X-ray tubes sufficiently lower volumes, opening new applications in the technique and medicine, are developed

Energy Technology Data Exchange (ETDEWEB)

A process is described for converting organic waste into a combustible gas for use in a heavy duty thermal engine. The engines best suited for this operation are of the dual-fuel type whose output power results from the simultaneous work of 2 combustibles. The gas flow rate is controlled by the desired power output, while diesel fuel injection remains constant regardless of engine load. The low BTU gas produced by the gasification of dry wastes is a mixture of CO, H/sub 2/ CH/sub 4/, CO/sub 2/ and N/sub 2/. Diesel fuel savings under usual operating conditions is no less than 80% of the consumption of conventional diesel engines of identical power. Characteristics of the low Btu gas engines are described as are the characteristics of the gasifying equipment. Applications for this process are suggested. (DMC)

British Library Electronic Table of Contents (United Kingdom)

Objective: To describe the meaning of the theme of empowerment from research on health promotion in nursing from the perspective of nurses participating in the study. Methods: Manual data analysis and QSR NUD*IST Vivo were used to analyse the data generated by individual and focus group interviews and the critical incident technique with 32 qualified nurses working in an acute hospital setting in the UK. Results: The participants identified a number of issues related to the theme of empowerment. These included the nurse as patient informer, psychological supporter and rapport builder and the concepts of informed choice/decision making, gatekeeping, coping, patient assertiveness, self-esteem and confidence. Conclusion: Empowerment is a complex, multi-dimensional, contested concept which can...

Energy Technology Data Exchange (ETDEWEB)

A new surveillance system for Oil-Filled cable, which can provide continuous monitoring, using a newly developed optical gas sensor that can detect the concentration of the gas dissolved in the oil with extremely high sensitivity has been developed. It was proved that the degree of deterioration of the insulating oil can be detected by measuring C{sub 2}H{sub 2} and CH{sub 4} by investigating the relation between the degree of deterioration and amount of combustible gas generated. In order to detect extremely small amounts of gas, a new gas detecting method using absorption line of the gas using a frequency modulated technique has been developed. The gas detection ability was also confirmed by examination using a 66 kV of cable and the possibility of detection at an early stage is expected.

International Nuclear Information System (INIS)

Designs of nuclear reactor plants aim for high performance under safety consideration. Because of large scale and high pressure/temperature conditions, data from costly mockup tests have been required to verify simulation codes of systems and components. Establishment of design by analysis (DBA) in nuclear engineering is required for development of next generation nuclear reactors. Recent powerful computers and simulation technique enable numerical analyses to predict realistic behaviors of thermo-fluid flow, structure and do on. The present report describes resent simulation results of complex gas-liquid two-phase flow, large scale structure dynamics and fluid-structure interaction. (author)

CERN Document Server

An algorithm for creating synthetic telescope images of Smoothed Particle Hydrodynamics (SPH) density fields is presented, which utilises the adaptive nature of the SPH formalism in full. The imaging process uses Monte Carlo Radiative Transfer (MCRT) methods to model the scattering and absorption of photon packets in the density field, which then exit the system and are captured on a pixelated image plane, creating a 2D image (or a 3D datacube, if the photons are also binned by their wavelength). The algorithm is implemented on the density field directly: no gridding of the field is required, allowing the density field to be described to an identical level of accuracy as the simulations that generated it. Some applications of the method to star and planet formation simulations are presented to illustrate the advantages of this new technique, and suggestions as to how this framework could support a Radiative Equilibrium algorithm are also given ...

CERN Document Server

In this paper we present results of using parallel supercomputers to simulate beam dynamics in next-generation high intensity ion linacs. Our approach uses a three-dimensional space charge calculation with six types of boundary conditions. The simulations use a hybrid approach involving transfer maps to treat externally applied fields (including rf cavities) and parallel particle-in-cell techniques to treat the space-charge fields. The large-scale simulation results presented here represent a three order of magnitude improvement in simulation capability, in terms of problem size and speed of execution, compared with typical two-dimensional serial simulations. Specific examples will be presented, including simulation of the spallation neutron source (SNS) linac and the Low Energy Demonstrator Accelerator (LEDA) beam halo experiment.

Energy Technology Data Exchange (ETDEWEB)

Encouragement and incentives ar being given in many counties to the electricity industry and private sector to install, own and operate renewable energy systems. The impact of renewable energy installations connected to the grid or operating independently is an important issue concerning the technical and economic viability of harnessing these emerging energy sources. This paper brings out the need for developing and implementing a strategy for comprehensive and accurate protection and control systems for these dispersed generator installations. It appears that a combination of discrete and fuzzy logic devices on an integrated platform will be a novel technique for the protection and control schemes. This development has the potential to be cost effective and suits the requirements for operating renewable energy systems safety. (author). 2 figs., 16 refs.

CERN Document Server

The Goldstone-Brueckner perturbation theory is extended to incorporate in a simple way correlations associated with large amplitude collective motions in nuclei. The new energy expansion making use of non-orthogonal vacua still allows to remove the divergences originating from the hard-core of the bare interaction. This is done through the definition of a new Brueckner matrix summing generalized Brueckner ladders. At the lowest-order, this formalism motivates variational calculations beyond the mean-field such as the Generator Coordinate Method (GCM) and the Projected Mean-Field Method from a perturbative point of view for the first time. Going to higher orders amounts to incorporate diabatic effects in the GCM and to extend the projection technique from product states to well-defined correlated states.

Energy Technology Data Exchange (ETDEWEB)

Focused Ion Beam (FIB) repairs and modifications to integrated circuits have been somewhat limited in the past due to the physical limitations imposed by the nodes of interest being buried under metal layers, the need for multiple layers of FIB generated interconnects, and the like. With the advent of FIB deposited INSULATOR materials, integrated circuit modifications can now be much more complex. The two primary goals of this project were (1) to determine the appropriateness of FIB insulator deposition for aiding FIB connections to metal nodes buried under power busses, and (2) development of a technique to do this. The work presented in this paper includes the development and characterization phases of adding INSULATION DEPOSITION to a FEI 611 FIB system, the problems encountered, their work around, and the aforementioned application of this technology.

Energy Technology Data Exchange (ETDEWEB)

We suggest a procedure for estimating uncertainties in neutron cross sections calculated with a nuclear model descriptive of a specific mass region. It applies standard error propagation techniques, using a model-parameter covariance matrix. Generally, available codes do not generate covariance information in conjunction with their fitting algorithms. Therefore, we resort to estimating a relative covariance matrix a posteriori from a statistical examination of the scatter of elemental parameter values about the regional representation. We numerically demonstrate our method by considering an optical-statistical model analysis of a body of total and elastic scattering data for the light fission-fragment mass region. In this example, strong uncertainty correlations emerge and they conspire to reduce estimated errors to some 50% of those obtained from a naive uncorrelated summation in quadrature. 37 references.

CERN Document Server

Magnetic fields appear to be a generic feature of the early universe and are a natural source of secondary CMB non-Gaussianity. In recent years the statistical nature of the stresses of a primordial magnetic field has been well studied. In this paper we confirm and extend these studies at one- and two-point level, and present analytical results for a wide range of power-law spectra. We also consider two non-power law cases of interest: a blue spectrum with an extended damping tail on small scales, which could be generated by the non-linear mixing of density and vorticity; and a red spectrum with a damping tail on large scales. We then briefly consider the CMB impacts that result from such fields. While this paper focuses on the one- and two-point moments, the techniques we employ are designed to ease the analysis of the full bispectra induced by primordial magnetic fields.

CERN Document Server

Real-time object detection is one of the core problems in computer vision. The cascade boosting framework proposed by Viola and Jones has become the standard for this problem. In this framework, the learning goal for each node is asymmetric, which is required to achieve a high detection rate and a moderate false positive rate. We develop new boosting algorithms to address this asymmetric learning problem. We show that our methods explicitly optimize asymmetric loss objectives in a totally corrective fashion. The methods are totally corrective in the sense that the coefficients of all selected weak classifiers are updated at each iteration. In contract, conventional boosting like AdaBoost is stage-wise in that only the current weak classifier's coefficient is updated. At the heart of the totally corrective boosting is the column generation technique. Experiments on face detection show that our methods outperform the state-of-the-art asymmetric ...

Energy Technology Data Exchange (ETDEWEB)

This paper discusses a database of information collected and organized during the past eight years from 2,000 producing oil wells in the United States, all of which have been treated with special applications techniques developed to improve the effectiveness of MEOR technology. The database, believed to be the first of its kind, has been generated for the purpose of statistically evaluating the effectiveness and economics of the MEOR process in a wide variety of oil reservoir environments, and is a tool that can be used to improve the predictability of treatment response. The information in the database has also been evaluated to determine which, if any, reservoir characteristics are dominant factors in determining the applicability of MEOR.

CERN Document Server

This contribution deals with identification of fractional-order dynamical systems. System identification, which refers to estimation of process parameters, is a necessity in control theory. Real processes are usually of fractional order as opposed to the ideal integral order models. A simple and elegant scheme of estimating the parameters for such a fractional order process is proposed. This method employs fractional calculus theory to find equations relating the parameters that are to be estimated, and then estimates the process parameters after solving the simultaneous equations. The said simultaneous equations are generated and updated using particle swarm optimization (PSO) technique, the fitness function being the sum of squared deviations from the actual set of observations. The data used for the calculations are intentionally corrupted to simulate real-life conditions. Results show that the proposed scheme offers a very high degree of ...

Science.gov (United States)

No abstract available.

Energy Technology Data Exchange (ETDEWEB)

Free-electron laser (FEL) experiments have been conducted with the 38-MeV L-band electron linac at the Institute of Scientific and Industrial Research, Osaka University. It is a 1.3 GHz RF linac with a thermoionic gun, and equipped with two 12th and one 6th sub-harmonic prebunchers for producing the high-intensity single-bunch beam with a charge up to 67 nC/bunch. For oscillation experiments of FEL, the gun is replaced with that with a smaller cathode area in order to reduce the emittance of the beam. The normalized emittance has been measured to be 200 {pi} mm-mrad. The linac is operated in the long-pulse mode and one of the 12th sub-harmonic bunchers and the 6th sub-harmonic buncher are operated, so that the time duration of the macropulse is 4 {mu}s and the spacing between micropulses is 9.2 ns. The length of the micropulse is 30-40 ps and the charge in each micropulse is 2 nC. The electron beam from the linac is ...

Energy Technology Data Exchange (ETDEWEB)

Aqueous solutions (mixed waste) generated from various LLNL operations, such as debris washing, sample preparation and analysis, and equipment maintenance and cleanout, were combined for storage in the B695 tank farm. Prior to combination the individual waste streams had different codes depending on the particular generating process and waste characteristics. The largest streams were CWC 132, 791, 134, 792. Several smaller waste streams were also included. This combined waste stream was treated at LLNL's waste treatment facility using a vacuum filtration and cool vapor evaporation process in preparation for discharge to sanitary sewer. Prior to discharge, the treated waste stream was sampled and the results were reviewed by LLNL's water monitoring specialists. The treated solution was discharged following confirmation that it met the discharge criteria. A major source, accounting for 50% for this waste stream, is metal ...

CERN Document Server

Next Generation SSH2 Implementation

Energy Technology Data Exchange (ETDEWEB)

As the penetration of wind energy continues to increase around the world, with a trend towards large utility-scale wind farms (greater than 100 MW), effective wind energy forecasting will become increasingly important. Previous work by GH has estimated the trading benefit of high quality short-term forecasting to be EUR 7/MWh. Depending on market conditions, for a 100 MW wind farm with a capacity factor of 30%, this equates to an estimated annual trading benefit of up to EUR 1.8m. To date, a number of studies have focused on the mathematical modelling techniques for forecasting the production from wind farms, looking predominantly at the task of predicting the meteorological conditions at the site. This paper focuses on the final stage of the forecasting process, conversion from a meteorological forecast to a power production forecast. This challenge is particularly significant for utility-scale wind farms. The main body of research in short-term forecasting in ...

International Nuclear Information System (INIS)

A next generation e"+-e"- linear collider in the TeV range can be converted into a #gamma#-#gamma# collider by converting it to e"--e"- operation and then generating #gamma#-rays via Compton backscattering with optical beams. This provides unique access to some areas of fundamental physics as well as highly desirable redundancy to the collisions. The required optical beam (with a wavelength of about 1 micron) must have very high peak power, (about 1 TW) as well as average power (about 10 kW). To achieve a 1 : 1 conversion from an electron to #gamma#-quantum, each micropulse must contain about one Joule and must be about one picosecond long, the micropulse peak power being about one Terawatt. To match the electron beam pulse structure, a macropulse consists of a sequence of about one hundred micropulses separated by about one nanosecond, and the macropulses am repeated at a rate of about 100 Hz. Thus, the time average power is about 10 kW ...

International Nuclear Information System (INIS)

Several types of corrosion have damaged alloy 600 tubing in the secondary side of steam generators. The types of corrosion include wastage, denting, intergranular attack, stress corrosion, erosion-corrosion, etc. The environments which cause attack may originate from leaks of cooling water into the condensate, etc. When the contaminated feedwater is pumped into the generator, the impurities may concentrate first 200 to 400 fold in the bulk water, depending on the blowdown, and then further to saturation and dryness in heated tube support plate crevices. Characterization of local solution chemistries is the first step to predict and correct the type of corrosion that can occur. The pH is of particular importance because it is a major factor governing the rate of corrosion reactions. The pH of a solution at high temperature is not the same as the ambient temperature, since ionic dissociation constants, solubility and solubility products, activity ...

Energy Technology Data Exchange (ETDEWEB)

The mass generation in the Standard Model of Particles Physics relies on a spontaneous symmetry breaking mechanism. Its implementation is recalled, along with its constraints, both theoretical (Naturalness, Stability, Triviality, Unitarity) and experimental (limits of direct and indirect searches, prospects). Calculation techniques for observables evaluation in Perturbative Field Theory are described, particularly Helicity Amplitude method, which is given in details: fermions and vector bosons, massless and massive. Monte-Carlo integration, and structure functions approximations (which allows non-perturbative calculations) are also detailed. With these tools, a process giving to Physics beyond the Standard Model is studied: it leads to an experimental prediction for the LEP collision ring, taking the classical background into account. Technical aspects of a future photon linear collider are reviewed. The production of heavy vector bosons, ...

Energy Technology Data Exchange (ETDEWEB)

A technique involving shifting of core fuel loadings was investigated as a method for reducing the neutron flux at points of high damage accumulation in the pressure vessel wall of a light water reactor. Calculations were run for six types of commercial generic PWR. Information is provided on the progress being made to develop and apply the Solid State Track Recorder (SSTR) method for in-situ in- and ex-vessel measurements of neutron exposure parameter values, such as fluence (E > 1.0 MeV) and dpa in iron. A new technique of quantitative track counting, the Buffon needle method, is advanced. It is based on random sampling of the SSTR surface. A desensitized etching technique was developed that resulted in an excellent differential energy response for alpha particles in the 3- to 14-MeV energy range. The optical efficiency of Muscovite mica for manual fission track counting is being redetermined to form a data base for ...

International Nuclear Information System (INIS)

The design characteristic of the autocontrol technique of the combined centrifuge is introduced. Digital technique, vary structure control and interface technique, graphical display techniques, digital communication technique as well as electronic technique are applied in the course of research. Automation in the operation of large scale combined centrifuges and the course of combined test has been realized and it can coordinate with other systems of status monitoring, data collecting and centrifugal force-aerodynamic force matched load automatically

Energy Technology Data Exchange (ETDEWEB)

Full text of publication follows: Energy and environment are two major concerns in our modern society due to the coming shortage in fossil energy sources and the growing of greenhouse gas emissions. The challenge for the coming years is to discover new energy resources and to develop devices that are compatible with a sustainable development and generate few (or zero) emission. One of these devices is the fuel cell feed by hydrogen, whose application fields are very large. In particular, the proton exchange membrane fuel cell (PEMFC) is the most realistic device for automotive application. However, hydrogen storage remains one of the most important challenges regarding its development. Although different techniques are available for storing hydrogen, no ideal solution has been found yet. Compression needs elaborated tanks in shape for supporting high pressures, liquefaction requires an expensive hydrogen cooling and adapted tanks. Chemical ...

International Nuclear Information System (INIS)

The operation and safety of both fossil-fuel and nuclear power stations depend on adequate cooling of the thermal source involved. This is usually accomplished using liquid coolants that are forced through the high temperature regions by a pumping system; this fluid then transports the thermal energy to another section of the power station. However, fluids that undergo boiling during this process create vapor that can be detrimental, and influence safe operation of other system components. The behavior of this vapor, or void, as it is generated and transported through the system is critical in predicting the operational and safety performance. This study uses two advanced penetrating radiation techniques, Real Time Neutron Radiography (RTNR), and High Speed X-Ray Tomography (HS-XCT), to examine void generation and transport behavior in a flow boiling system. The geometries studied were tube side flow boiling in a ...

International Nuclear Information System (INIS)

An overview of different Ion Beam Analysis (IBA) techniques is given. Examples of applications of the PIXE techniques to various types of samples are presented. (author)

CERN Document Server

We study the dynamics of states perturbatively expanded about a harmonic system of loop quantum cosmology, exhibiting a bounce. In particular, the evolution equations for the first and second order moments of the system are analyzed. These moments back-react on the trajectories of the expectation values of the state and hence alter the energy density at the bounce. This analysis is performed for isotropic loop quantum cosmology coupled to a scalar field with a small but non-zero constant potential, hence in a regime in which the kinetic energy of matter dominates. Analytic restrictions on the existence of dynamical coherent states and the meaning of semi-classicality within these systems are discussed. A numerical investigation of the trajectories of states that remain semi-classical across the bounce demonstrates that, at least for such states, the bounce persists and that its properties are similar to the standard case, in which the moments of the states are ...

British Library Electronic Table of Contents (United Kingdom)

Background: Mechanisms underlying the association between myocardial bridge (MB)-stenting and in-stent restenosis (ISR) are still unclear. Objective: To assess the impact of MB on ISR using intravascular ultrasound (IVUS). Methods: In the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial, 100 left anterior descending artery (LAD) culprit lesions (79 treated with paclitaxel-eluting stents [PES] and 21 treated with bare metal stents) were imaged with serial IVUS immediately postprocedure and at 13 months. Results: At baseline the LAD stent extended into the MB segment beyond the culprit lesion in seven patients (MB-stent group). In the remaining 93 patients the LAD stent was implanted only in the culprit lesion without extending into t...

Energy Technology Data Exchange (ETDEWEB)

At Los Alamos, we are building a free-electron laser (FEL) for industrial, medical, and research applications. This FEL, which will incorporate many of the new technologies developed over the last decade, will be compact in size, robust, and user-friendly. Electrons produced by a photocathode will be accelerated to 20 MeV by a high-brightness accelerator and transported using permanent-magnet quadrupoles and dipoles. They will form an electron beam with an excellent instantaneous beam quality of 10 {pi} mm mrad in transverse emittance and 0.3% in energy spread at a peak current up to 300 A. Including operation at higher harmonics, the laser wavelength extends form 3.7 {mu}m to 0.4 {mu}m. In this paper, we will describe the project and the programs to date. 10 refs., 10 figs., 1 tab.

British Library Electronic Table of Contents (United Kingdom)

Abstract Results of numerous experiments conducted over the past 15-years by using behavioural as well as brain imaging methods have shown that musical expertise influences brain anatomy, brain functions and behaviour. The musician- brain is thus considered as a very good model of brain plasticity. Moreover, many results have demonstrated that musical expertise not only impacts on music processing but also on several aspects of speech processing including lexical pitch, sentence intonation and the metric structure of words. Conversely, recent results indicated that linguistic expertise with tone or quantity languages such as Mandarin Chinese, Thai, Finnish and Japanese, influences the processing of harmonic tones and musical intervals. We discuss possible interpretations of these findings ...

Energy Technology Data Exchange (ETDEWEB)

Every Bianchi type-IX universe can be interpreted as a closed Friedmann universe on which is superimposed circularly polarized gravitational waves with the longest wavelength that will fit into a closed universe. In this paper, I give a new derivation of this result based on the concept of homogeneous tensor fields on the three-sphere. Every homogeneous symmetric traceless tensor field is shown to be a longest-wavelength three-sphere harmonic. Contrary to previous authors, I show that the wavelength of these gravitational waves is one-half the circumference of the universe. In order to maintain homogeneity, the gravitational waves must all have the same polarization. There are five longest-wavelength modes for each polarization. This interpretation is an {ital exact} description that is valid for every Bianchi type-IX universe---it is in no way limited to first-order perturbations of a Friedmann universe.

International Nuclear Information System (INIS)

We investigate the effects of the velocity-dependent force on the magnetic form factors and magnetic moments of odd-Z nuclei. The form factors are calculated with the harmonic-oscillator wavefunctions. It is found that the contributions of the velocity-dependent force manifest themselves in the very large momentum transfer region (q?4 fm-1). In the low and medium q region the contributions of the velocity-dependent force are very small compared with those without this force. However, in the high-q region the contributions of the velocity-dependent force are larger than the normal form factors. The diffraction structures beyond the existing experimental data are found after the contributions of the velocity-dependent force are included. The formula of the correction to the single particle magnetic moment due to the velocity-dependent force is reproduced exactly in the long-wavelength limit (q=0) of the M1 form factor. (authors)

British Library Electronic Table of Contents (United Kingdom)

The (simplified) Backus? Problem (BP) consists in finding a harmonic function u on the domain exterior to the three dimensional unit sphere S, such that u tends to zero at infinity and the norm of the gradient of u takes prescribed values g on S. Except for a change of sign, the solution is not unique in general. However, there is uniqueness of solutions in the class of functions with the additional property that the radial component of the gradient of u on S is nonpositive. This is the geodetically relevant case. If a solution u with this property exists, then u is the maximal solution of the problem (and -u the minimal one). In this paper we propose a method of successive approximations to get this particular solution of BP and prove the convergence for functions g close to a constant fu...

CERN Document Server

This contribution reviews a selection of findings on atomic density functions and discusses ways for reading chemical information from them. First an expression for the density function for atoms in the multi-configuration Hartree--Fock scheme is established. The spherical harmonic content of the density function and ways to restore the spherical symmetry in a general open-shell case are treated. The evaluation of the density function is illustrated in a few examples. In the second part of the paper, atomic density functions are analyzed using quantum similarity measures. The comparison of atomic density functions is shown to be useful to obtain physical and chemical information. Finally, concepts from information theory are introduced and adopted for the comparison of density functions. In particular, based on the Kullback--Leibler form, a functional is constructed that reveals the periodicity in Mendeleev's table. Finally a quantum similarity measure is ...

CSIR Research Space (South Africa)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

The performance of a geologic repository for high-level nuclear waste will be influenced to a large degree by thermohydrologic phenomena created by the emplacement of heat-generating radioactive waste. The importance of these phenomena is manifest in that they can greatly affect the movement of moisture and the resulting transport of radionuclides from the repository. Thus, these phenomena must be well understood prior to a definitive assessment of a potential repository site. An investigation has been undertaken along three separate avenues of analysis: (i) laboratory experiments, (ii) mathematical models, and (iii) similitude analysis. A summary of accomplishments to date is as follows. (1) A review of the literature on the theory of heat and mass transfer in partially saturated porous medium. (2) A development of the governing conservation and constitutive equations. (3) A development of a dimensionless form of the governing equations. (4) A numerical study of ...

International Nuclear Information System (INIS)

We developed a new TLD array for precise dose measurement and verification of the spatial dose distribution in small radiation targets. It consists of a hemicylindrical, tissue-equivalent rod made of polystyrene with 17 parallel moulds for an exact positioning of each TLD. The spatial resolution of the TLD array was evaluated using the Leskell spherical phantom. Dose planning was performed with KULA 4.4 under stereotactic conditions on axial CT images. In the Leksell gamma unit the TLD array was irradiated with a maximal dose of 10 Gy with an unplugged 14 mm collimator. The doses delivered to the TLDs were rechecked by diode detector and film dosimetry and compared to the computer-generated dose profile. We found excellent agreement of our measured values, even at the critical penumbra decline. For the 14 mm and 18 mm collimator and for the 11 mm collimator combination we compared the measured and calculated data at full width at half maximum. This TLD array may be ...

Energy Technology Data Exchange (ETDEWEB)

We describe a stochastic inversion method for mapping subsurface regions where the electrical resistivity is changing. The technique combines prior information, electrical resistance data and forward models to produce subsurface resistivity models that are most consistent with all available data. Bayesian inference and a Metropolis simulation algorithm form the basis for this approach. Attractive features include its ability to: (1) provide quantitative measures of the uncertainty of a generated estimate and, (2) allow alternative model estimates to be identified, compared and ranked. Methods that monitor convergence and summarize important trends of the posterior distribution are introduced. Results from a physical model test and a field experiment were used to assess performance. The stochastic inversions presented provide useful estimates of the most probable location, shape, and volume of the changing region, and the most likely resistivity ...

Environmental Research Database

ObjectivesThe overall objective is to establish rigorous and verified means of deploying FACTS devices as damping controllers so that stability limits of a congested grid can be expanded, with confidence, toward to the thermal limits. A key to this is to ensure that damping of oscillatory modes of the system are robust to the acknowledged variations of the system.~%~~%~The goals are:~%~~%~a) to apply model order reduction techniques to realistic grid systems and verify modes are adequately expressed,~%~~% [continued...]DescriptionTraditionally, the phenomena of inter-area oscillation between generation groups, e.g. England and Scotland, has been avoided through operating point constraints on tie-lines and acceptance of operation at less than thermal capacity. The need to support long distance trading makes such constraints unacceptable. Stability problems can be solved dynamically, rather ...

Energy Technology Data Exchange (ETDEWEB)

In the context of the research project, the physical basis of the direct decoupling of highly concentrated solar radiation in materials without the detour via absorbing heat exchanger walls was examined. Also, the first chemical processes suitable for the effective long-term storage of solar energy were analysed, relevant experiments were carried out and the necessary receiver techniques for high temperature applications were provided. The principle of direct coupling was examined on fluidized beds on the one hand and on cavity receivers, on the other hand. The contribution shows the results achieved in detail. It is recorded that first processes for storing solar energy in chemical reactions were able to be examined. Alkaline earth hydroxides accommodated in ceramic honeycomb structures seem to be possible as stores for medium temperature ranges around 500deg C. Investigations on receiver structure materials are also making progress. Highly transparent, high ...

Energy Technology Data Exchange (ETDEWEB)

A number of amines can be employed for all volatile treatment (AVT) of steam generator (SG) systems of nuclear power reactors. These amines form complexes with Cu{sup 2+} and Ni{sup 2+} ions which come into water due to corrosion. The redox reactions of a number of Cu(II)-AVT amine complexes and the stability of the transient species formed have been studied by pulse radiolysis technique. Rate constants for the reaction of e{sub aq}{sup -} with a number of Cu(II)-amine complexes have been determined by following the decay of e{sub aq}{sup -} absorption. Stability of Cu(I)-amine complexes was studied by following the kinetics of the bleaching signal formed at the {lambda}{sub max} of the Cu(II) amine complex. Except for Cu(I)-triethanolamine complex all other Cu(I)-amine complexes were found to be stable. One-electron oxidation of Cu(II) amine complexes was studied using azidyl radicals for the oxidation reaction as OH radicals react with the ...

Energy Technology Data Exchange (ETDEWEB)

We aim to isolate cDNAs mapping to human chromosome 16 and localise such cDNAs on the high resolution physical map. In collaboration with LANL, PCR primers will be synthesised from cDNA sequences mapped to chromosome 16 and used as ESTs in the generation of mega-YAC contigs for this chromosome. Probing of high density cosmid grids will enable integration of the ESTs into cosmid contigs and location of the cosmid contigs on the YAC contig. A hn-cDNA library has been constructed from the hybrid CY18 which contains chromosome 16 as the only human chromosome. A modified screening protocol has been successfully developed and 15 hn-cDNA clones have been sequenced and localised on the hybrid map. Sequence analysis of four of these revealed that they were known cDNAs, which are now mapped to chromosome 16. Development of techniques to allow the isolation of longer cDNAs from the identified exons is in progress. This will depend on PCR amplification of ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes the effects of SiC coating on the oxidation resistance of C/C composites in combusting fields, which are expected to be applied to high temperature structural materials at over 1770K. The coating methods employed were CVD and pack cementation. The time changes in weight loss of the specimens were measured at temperatures of 1770K and 1900K under the equivalence ratio of 0.9 generated by methane-air combustion, and the surface of the specimens before and after the experiment was observed by SEM. Although the weight loss of the specimens coated by the CVD method was minimal, the coating layer was easily peeled off from the substrate. On the other hand, the layer of the specimens coated by the pack cementation method was stable and adhered to the substrate, but the substrate was degraded because of penetration of oxygen through the pores in the layer. To cover the pores, the specimens were additionally coated with glass materials comprised of ...

Science.gov (United States)

Staggered arrays of dimples printed on opposite surfaces of a cooling channel is formulated numerically and optimized with hybrid multi-objective evolutionary algorithm and Pareto optimal front. As Pareto optimal front produces a set of optimal solutions, the trends of objective functions with design variables are predicted by hybrid multi-objective evolutionary algorithm. The problem is defined by three non-dimensional geometric design variables composed of dimpled channel height, dimple print diameter, dimple spacing, and dimple depth, to maximize heat transfer rate compromising with pressure drop. Twenty designs generated by Latin hypercube sampling were evaluated by Reynolds-averaged Navier-Stokes solver and the evaluated objectives were used to construct Pareto optimal front through hybrid multi-objective evolutionary algorithm. The optimum designs were grouped by k-means clustering technique and some of the clustered points were evaluated ...

Energy Technology Data Exchange (ETDEWEB)

Acid Rock Drainage (ARD) is the product formed by the atmospheric oxidation of the relatively common pyrite and pyrrhotite. Waste rock dumps and tailings containing sulfide mineral have been reported at toxic materials producing ARD. Mining in sulphide bearing rock is one of activity which may lead to generation and release of ARD. ARD has had some major detrimental affects on mining areas. The purpose of this study was carried out to develop disposal method for preventing contamination of water and soil environment by waste rocks dump and tailings, which could discharge the acid drainage with high level of metals. Scope of this study was as following: environmental impacts by mine wastes, geochemical characteristics such as metal speciation, acid potential and paste pH of mine wastes, interpretation of occurrence of ARD underneath tailings impoundment, analysis of slope stability of tailings dam etc. The following procedures were used as part of ARD evaluation and ...

Energy Technology Data Exchange (ETDEWEB)

A technique capable of measuring the electron energy fluence spectra in a scattering medium was designed. These measurements were performed by setting a bremsstrahlung conversion target on the surface of a phantom, at an intermediate depth, and at a depth equal to electron mean range. The bremsstrahlung produced by the deceleration of electrons in the target was passed through an air channel in the phantom and passed forward by a pinhole collimator into a Na(Tl) detector. The measured pulse height data were unfolded to correct for the distortion of the spectrometer system by using the FORIST unfolding code. The unfolded bremsstrahlung spectra represent the electron energy fluence spectra convolution with the bremsstrahlung produced in the target. To generate the electron energy fluence spectra, the unfolded bremsstrahlung spectra were deconvoluted by using the MAZE2 unfolding code. CYLTRAN, a coupled electron-photon Monte Carlo transport code, ...

Energy Technology Data Exchange (ETDEWEB)

Two novel organic n-type semiconductors are investigated due to their function as electron acceptor for applications in organic electronic devices to widen the knowledge of how molecule structure influences the excitation processes in organic electronics. Bispyrenylfullerene and Octadecyl-Capronacidesterfullerene are C{sub 60} derivates with sidechains more featured compared to the commonly used[6,6] phenyl-C{sub 61}-butyric acid methyl ester (PCBM). In bulk heterojunction devices regioregular poly(3-hexylthiophene) (P3HT) was used as donor. The materials, pristine and in blend, were studied in view of light absorption, their quenching abilities of the P3HT photoluminescence as well as excited states. Furthermore, the spin state of the excited states was determined by light-induced electron spin resonance. Combining these complimentary experimental techniques, we obtained information on the generation of excited states, their nature, and the ...

International Nuclear Information System (INIS)

In the present paper, the chemical composition of passive films formed on both phases of two types of duplex stainless steels (UNS S31803 and UNS S32304) is determined at the micro-scale using Auger electron spectroscopy (AES). Samples were either mechanically polished (down to diamond pastes) or electrochemically etched in acidic solutions. The micro-electrochemical behavior of samples was then determined in sodium chloride media by means of the electrochemical micro-cell technique (capillary diameters of 30 ?m). The results obtained were analyzed considering the passive film chemical composition. Quantitative relationships between electrochemical parameters and the distribution of chromium and iron in the oxide layer were found. Due to differences in mechanical properties between ferrite and austenite, a heterogeneous stress distribution is generated in both phases. A method based on thermal-mechanical simulation was used to quantify surface ...

Energy Technology Data Exchange (ETDEWEB)

A technique has been developed for high resolution alpha particle spectroscopy from track length determination in CR-39 plastic. On individual tracks an energy resolution deltaE close to the range straggling limit is obtainable. For 6 MeV alpha-particle deltaE is proportional 35 keV on individual particles and for groups of particles deltaE proportional 20 keV can be achieved using certain data selection criteria. At 100 keV on individual particles deltaE is proportional 20 keV. The analysis requires 1) a knowledge of the track-etch rate (Vsub(T))-range relationship and 2) a theoretical understanding of alpha-particle track structure in CR-39 as a function of particle energy, dip angle and degree of etching. The structure of alpha-particle etched tracks in CR-39 is described and two methods of analysis discussed. Examples are given of the resolution attainable on tracks of alpha-particles as natural decay energy and from alpha-particles ...

Environmental Research Database

Objectives- Investigate the potential for the use of enzymes to bring about improvements in the recycling of recovered waste paper sources~%~~%~- Optimise enzyme formulations and process conditions to maximise benefits. - Produce recovered fibre at lower energy and chemical costs than is currently achievable using 'classical' de-inking techniques.~%~~%~- Improve recycled fibre quality and~%~~%~- All of the above will allow a greater use of recovered paper resources, which would otherwise be diposed of by [continued...]DescriptionThe project proposes to carry out an initial literature review to update the consortium on the currently available publications relating to the use of enzymes in de-inking.. This will be followed by an intensive laboratory study in an upgraded facility which will allow enzyme formulations and mechanisms to be studied. This work will also eliminate the need for an initial round of pilot ...

International Nuclear Information System (INIS)

The principle and history of free-electron laser (FEL), first evidenced in 1977, the relationship between FEL wavelength and output power, the high-power FEL driven by the superconducting linac, the X-ray FEL by the linac, and the medical use are described. FEL is the vacuum oscillator tube and essentially composed from the high-energy linac, undulator and light-resonator. It utilizes free electrons in the vacuum to generate the beam with wavelength ranging from microwave to gamma ray. The first high-power FEL developed in Japanese Atomic Energy Research Institute (JAERI) is based on the development of superconducting linac for oscillating the highest power beam. In the medical field, applications to excise brain tumors (in US) and to reconstruct experimentally blood vessels in the pig heart (in Gunma University) by lasing and laser coagulator are in progress with examinations to remove intra-vascular cholesterol mass by irradiation of 5.7#mu#m FEL beam. Cancer ...