Energy Technology Data Exchange (ETDEWEB)

A comparitive analysis is made of the principal characteristics of narrow-band and conventional semiconductor light amplifiers. It is shown that quasi-distributed filtering of the spontaneous radiation ensures a high gain and a low level of the spontaneous noise at the amplifier output.

International Nuclear Information System (INIS)

The results of experiments with a short period (9.6 mm) wiggler sheet electron beam (1.0 mm x 2.0 cm) millimeter-wave free electron laser (FEL) amplifier are presented. This FEL amplifier utilized a strong wiggler field for sheet beam confinement in the narrow beam dimension and an offset-pole side-focusing technique for the wide dimension beam confinement. The beam analysis herein includes finite emittance and space-charge effects. High-current beam propagation was achieved as a result of extensive analytical studies and experimental optimization. A design optimization resulted in a low sensitivity to structure errors and beam velocity spread, as well as a low required beam energy. A maximum gain of 24 dB was achieved with a 1-kW injected signal power at 86 GHz, a 450-kV beam voltage, 17-A beam current, 3.8-kG wiggler magnetic field, and a 74-period wiggler length. The maximum gain ...

International Nuclear Information System (INIS)

The simplest high gain free electron laser (FEL) amplifier concept is proposed. A klystron amplifier has the useful property that the various electronic processes take place in separate portions of the amplifier, rather than overlapping as in FEL amplifier with an uniform undulator. The klystron consists of two fundamental parts: succession of 2-3 cascades (modulator), and an output undulator (radiator) in which the modulated electron beam coherently radiates. Each cascade consists of uniform undulator and dispersion section. Unlike distributed optical klystrons, we have a high gain per cascade pass. This has a few consequences. First, klystron gain does not depend on the bunch compression in the injector linac, i.e. maximum gain per cascade pass at high peak beam current is the same at low peak beam current, without ...

International Nuclear Information System (INIS)

We have studied both theoretically and experimentally a new scheme of active pulse compression in a free electron laser (FEL) amplifier. The pulse compression scheme presented here is the following. A frequency-chirped pulse is injected into the FEL interaction region. Because of the high gain and narrow bandwidth of the FEL interaction, only the resonant frequency band of the pulse is actively amplified, resulting in a short pulse of high power coherent radiation at the output of the laser. For our experimental parameters (beam voltage #approx =# 150 kV, current #approx =# 5.0 A, wiggler period #approx =# 3.5 cm and gain #approx =# 10 dB), pulses of a few nanoseconds were generated at #approx =# 10 GHz after an interaction length of 2.30 m, in good agreement with theoretical expectations. For the same input pulses (width > 100 ns, frequency chirp #alpha#/2#pi# #approx =# 5 MHz/ns), the obtention of ...

Energy Technology Data Exchange (ETDEWEB)

A fully quantized many-particle theory of the standard free-electron laser in the small-signal, cold-beam regime is presented. The approach is based on an evaluation of the time-evolution operator in the interaction picture to first order in the quantum-mechanical recoil. For algebraic convenience we use the moving (Bambini-Renieri) frame, in which resonance occurs for zero electron momentum. Though we neglect space-charge effects, genuine many-particle contributions still show up, because the radiation emitted by one electron can be amplified by another electron. Our main results are gross features of the amplification, such as gain and spread, are virtually without many-particle effects. These effects are mainly important in the case of spontaneous emission. For a sufficiently high current, the buildup of the laser field from vacuum is enhanced by amplified spontaneous emission. Incoherence of the spontaneous radiation ...

Science.gov (United States)

This is a multi-color 230-page textbook covering analog electronics at the upper-division level. Text material is intended for a full-year sequence at 2-3 credits per term. Topics include: amplifier thermal considerations; class A IC output stage; class B complementary amplifier; class A and Class B single-ended amplifiers; feedback amplifiers; gain margin and phase margin; compensation; oscillators (Wien-bridge, Hartley, Colpitts, Pierce); piezoelectric crystals, single-pole circuits; single-pole pulse response; single-pole rectangular wave response; comparators; Schmitt triggers; 555 timers; multivibrators; RC attenuators; compensated attenuators; principles of dc-dc conversion; capacitor-based converters; buck converter; boost converter; buck-boost converter. The text is in Adobe Acrobat 4.0 format, complete with Acrobat index. Large font size allows the text to be used with ...

Energy Technology Data Exchange (ETDEWEB)

An FEL amplifier to generate a laser power of the order of TW at 4 {mu}m wavelength is investigated for a {gamma}-{gamma} collider. A concept of an amplifier chain consisting of a phase-displacement deceleration FELs is proposed to increase the FEL efficiency and to mitigate the requirement for the beam energy spread. The feasibility of the driving linac for the FEL system is also discussed. ((orig.)).

Energy Technology Data Exchange (ETDEWEB)

The high repetition rate and low single-pass gain inherent in an rf-driven Free Electron Laser (FEL) dictate that the laser system be configured as an oscillator. This allows the laser's electric field to build up over many passes around a high Q cavity. By way of contrast, the high-current capability of the Induction Linac (IL) system permits high single-pass optical gain, but the relatively low duty factor precludes oscillator operation; the pulses are neither long enough nor often enough to permit a field to accumulate in a cavity. The IL is thus configured as a MOPA (master oscillator/power amplifier) with a conventional laser serving as the MO. This report concentrates on the status of IL-driven FEL research at LLNL and gives a description of several applications for the high-peak-power radiation produced by an induction linac FEL.

Energy Technology Data Exchange (ETDEWEB)

An overview of particle and photon beam bunch length measurements is presented in the context of free-electron laser (FEL) challenges. Particle-beam peak current is a critical factor in obtaining adequate FEL gain for both oscillators and self-amplified spontaneous emission (SASE) devices. Since measurement of charge is a standard measurement, the bunch length becomes the key issue for ultrashort bunches. Both time-domain and frequency-domain techniques are presented in the context of using electromagnetic radiation over eight orders of magnitude in wavelength. In addition, the measurement of microbunching in a micropulse is addressed.

Energy Technology Data Exchange (ETDEWEB)

An FEL based energy driver for Inertial Confinement Fusion (ICF) is proposed. The key element of the scheme is free electron laser system. Novel technical solutions, namely, using of multichannel, multi-stage FEL amplifier with diaphragm focusing line, reveal a possibility to construct the FEL system operating at radiation wavelength {lambda} = 0.5 {mu}m and providing flush energy E = 1 MJ and brightness 4 x 10{sup 22} W cm{sup -2} sr{sup -1} within steering pulse duration {tau} {approximately} 0.1-2 ns. Total energy efficiency of the proposed ICF energy driver is about of 11% and repetition rate is 40 Hz. It is shown that the FEL based ICF energy driver may be constructed at the present level of accelerator technique R& D.

Energy Technology Data Exchange (ETDEWEB)

The authors report a two-temperature RF bias stress test on nominal 1.2 W 7.5 GHz GaAs/AlGaAs HBT unit cell amplifiers. MTTF`s of 2020 and 1340 hours were obtained at Tj = 218{degrees}C and 245{degrees}C, respectively, under nominal input bias. An activation energy of 0.42 eV is estimated, consistent with published results for similar devices under DC bias stress.

International Nuclear Information System (INIS)

An analytic solution is obtained for the equations of resonance coherent SRS by neglecting the population of the final level of the Raman transition for the systems with the active-medium length that is smaller than the wavelength of the incident light. For the extended systems, a numerical solution is obtained. The energy distribution of the Stokes pulses is found. The large-scale (about 100%) fluctuations of the Stokes radiation energy were observed in the case of unsaturated amplified spontaneous emission. (nonlinear optical phenomena)

International Nuclear Information System (INIS)

Reducing count losses and pile-up pulse effects in quantitative and qualitative analysis is necessary for accuracy of analysis. Therefore, the optimum peaking time for particular detector systems is important. For this purpose, pure Se and Zn elements were excited by 59.5 keV ?-rays from a 50 mCi 241Am annular radioactive source in this study. The characteristic x-rays emitted from pure Se and Zn elements were detected by using an ultra low energy Ge (Ultra-LEGe) detector connecting Tennelec TC 244 spectroscopy amplifier at different peaking time modes. Overall pulse widths were determined by HM 203-7 oscilloscope connecting amplifier. The proper peaking time for ultra low energy germanium detector (Ultra-LEGe) is determined about 4 ?s.

International Nuclear Information System (INIS)

The advances in laser technology have made available very short and intense laser pulses which can be used to seed a high-gain single-pass free-electron laser (FEL) amplifier. With these seed pulses, a regime of the FEL interaction where the radiation evolution is simultaneously dominated by nonlinear effects (saturation) and time-dependent effects (slippage) can be explored. This regime is characterized by the propagation of a solitary wavelike pulse where the power of the optical wave grows quadratically with time, its pulse length decreases and the spectral bandwidth increases. We analyze the interplay between the field and particle dynamics of this propagation regime which was studied before and termed super-radiance. Furthermore we analyze the properties of the strong higher-order harmonic emission from this wave and its behavior when propagating in a cascade FEL. The super-radiant pulse is indeed capable of passing through the stages of a ...

Energy Technology Data Exchange (ETDEWEB)

In 1992, the Federal Energy Regulatory Commission (FERC) began using a Flow Duration Analysis (FDA) methodology to assess headwater benefits in river basins where use of the Headwater Benefits Energy Gains (HWBEG) model may not result in significant improvements in modeling accuracy. The purpose of this study is to validate the accuracy and appropriateness of the FDA method for determining energy gains in less complex basins. This report presents the results of Oak Ridge National Laboratory`s (ORNL`s) validation of the FDA method. The validation is based on a comparison of energy gains using the FDA method with energy gains calculated using the MWBEG model. Comparisons of energy gains are made on a daily and monthly basis for a complex river basin (the ...

Energy Technology Data Exchange (ETDEWEB)

Previous analyses of binary cycles for conversion of geothermal energy from moderate temperature resources to electrical energy have shown potential gains in net geofluid effectiveness of on the order of 8%, resulting from selection of turbine-expansion processes whose equilibrium states pass through the two-phase region (assuming major condensation does not occur). If condensation occurs, this gain could be reduced or eliminated by the resulting loss in turbine efficiency. Experience with many fluids, however, indicates that vapor supersaturation (or subcooling) permits metastable pure-vapor states to exist at temperatures considerably below the saturation temperature at a given pressure; thus, by better understanding the condensation process, and properly structuring the cycle, substantial performance gains may be achievable. The present study assessed, qualitatively, the ...

International Nuclear Information System (INIS)

A network of second-generation low-temperature gravitational radiation detectors is nearing completion. These detectors, sensitive to mechanical strains of order 10"-"1"8, are possible because of a variety of technical innovations that have been made in cryogenics, low-noise superconducting instrumentation, and vibration isolation techniques. Another five orders of magnitude improvement in energy sensitivity of resonant-mass detectors is possible before the linear amplifier quantum limit is encountered. 33 references, 3 figures, 1 table.

International Nuclear Information System (INIS)

Recent advances in self-amplified spontaneous emission (SASE) experiments stimulate interest in quantitative comparison of measurements with theory. In this paper we show that the widely used simulation code TDA3D, developed by Tran and Wurtele [Comput. Phys. Commun. 54, 263 (1989)] even though a single frequency code, can be used to determine the output power in the SASE process with excellent approximation in the exponential growth regime. The method applies when the gain is not very high, which is a special advantage, because when the gain is not very high, the analytical calculation is particularly difficult since the exponential growing term does not dominate. The analysis utilizes a scaling relation between the output power and the number of simulation particles in the code TDA3D: left-angle P right-angle=N_#lambda#"'/N_#lambda# left-angle P"'right-angle, where left-angle P right-angle is the output power and ...

Energy Technology Data Exchange (ETDEWEB)

Previous analyses of binary cycles for conversion of geothermal energy from moderate temperature resources to electrical energy have shown potential gains in net geofluid effectiveness on the order of 8%, resulting from selection of turbine-expansion processes whose equilibrium states pass through the two-phase region. If condensation occurs, this gain could be reduced or eliminated by the resulting loss in turbine efficiency. Experience with many fluids, however, indicates that vapor supersaturation permits metastable pure-vapor states to exist at temperatures considerably below the saturation temperature at a given pressure; thus, by better understanding the condensation process, and properly structuring the cycle, substantial performance gains may be possible. The purpose of the present study was to assess the probability for attaining this performance gain ...

International Nuclear Information System (INIS)

In a seeded high-gain free-electron laser (FEL), where a coherent laser pulse interacts with an ultrarelativistic electron beam, the seed laser pulse can be frequency chirped, and the electron beam can be energy chirped. Besides these two chirps, the FEL interaction introduces an intrinsic frequency chirp in the FEL even if the above-mentioned two chirps are absent. We examine the interplay of these three chirps. The problem is formulated as an initial value problem and solved via a Green function approach. Besides the chirp evolution, we also give analytical expressions for the pulse duration and bandwidth of the FEL, which remains fully longitudinally coherent in the high-gain exponential growth regime. Because the chirps are normally introduced for a final compression of the FEL pulse, some conceptual issues are discussed. We show that to get a short pulse duration, an energy chirp in the electron ...

Energy Technology Data Exchange (ETDEWEB)

The Bragg Curve Spectrometer (BCS) is an ionization chamber long enough to stop particles of interest. Particles enter through the cathode window and leave an ionization track parallel to the electric field. The ionization electrons drift through a Frisch grid and are collected on an anode. The anode current, as a function of time, is split and used as input for two amplifiers, one with a long integration time constant for energy measurement, and one with a short time constant to pick off the maximum ionization or Bragg peak. The Bragg peak, which is proportional to the nuclear charge, is used for particle identification. We have constructed and tested several versions of the BCS. The results are described.

CERN Document Server

The effect of pair-binding energy variations on the denaturation of double stranded DNAs is investigated. Using a two-parameter renormalization group (RG) analysis and extensive transfer matrix calculations, we find a random quenched-in variations to be marginally irrelevant, indicating that the system is self-averaging at the transition. The effect of a recently-proposed variable backbone stiffness is also investigated. Although irrelevant in the RG sense, it dramatically amplifies the randomness, leading to the appearance of ``multi-step melting'' for realistic sequences. These results are relevant to the adsorption of random heteropolymers and the wetting of disordered substrates.

Science.gov (United States)

... spontaneous radiation of amplifiers within a relatively w~de range of ... pulse widths are 20-30ns, while amplified spontaneous radiation pulse ...

Energy Technology Data Exchange (ETDEWEB)

APEX (ATLAS Positron EXperiment), a collaborative effort of ANL, FSU, MSU/NSCL, Princeton, Queen`s, Rochester, Washington and Yale, is an experiment to study positron and electron production in very heavy ion collisions. The electrons and positrons are detected with two detector arrays, each consisting of 216 1 mm thick Si PIN diodes, and their energy and time-of-flight are measured. The number of detectors and limited space made it necessary to develop a system that could efficiently process and transfer signals from the detectors to the charge sensing ADC`s and data readout electronics as well as monitor the condition of the detectors. The discussion will cover the electronics designed for the Si detectors, including the charge amplifier, ``Mother board`` for the charge amplifiers, 8 channel Shaper, 16 channel Constant Fraction Discriminator (CFD), 16 channel Peak-to-FERA (PTF) and the integration of the CFD and PTF with ...

Science.gov (United States)

... multivibrators and amplifiers arranged to operate as described above. ... The first of the multivibrators is triggered by the trailing edge of the ...

International Nuclear Information System (INIS)

Development of renewable energy systems for remote communities is gaining interest among government, utilities, NGOs and the communities themselves as a means of improving lifestyles of community members and showcasing renewable energy systems. The Huu-ay-aht First Nation, whose traditional territory is located on the west side of Vancouver Island in British Columbia, is a community which has energy related problems and energy related opportunities. The objective of this study is to assess possible energy options for the Huu-ay-aht First Nation traditional territory. Current and future energy services within the territory were used as the starting point for developing energy system options. Extensive consultation with community members was instrumental in clearly defining the objectives of the study and understanding the ...

International Nuclear Information System (INIS)

A model for the simulation of the time dependent behavior and the analysis of the equilibrium of the coupled system of storage ring and Free Electron Laser (FEL) is presented. The analysis comprises both amplifier and oscillator FEL. Bunch lengthening and energy widening due to wake forces are taken into account in a self-consistent way. The method is based on a mapping algorithm for means and correlations of the electron distribution function, pioneered by K. Hirata. The evolution of the laser field in the oscillator FEL is described by K. Hirata. The evolution of the laser field in the oscillator FEL is described by supermodes. The model is used to simulate an FEL in a small 500 MeV storage ring with 100 m circumference. Typical values for the output power, spatial, and spectral characteristics of the emitted radiation are presented.

International Nuclear Information System (INIS)

The Bragg Curve Spectrometer (BCS) is an ionization chamber long enough to stop particles of interest. Particles enter through the cathode window and leave an ionization track parallel to the electric field. The ionization electrons drift through a Frisch grid and are collected on an anode. The anode current, as a function of time, is proportional to the specific ionization along the track. The preamp output is split and used as input for two amplifiers, one with a long integration time constant for energy measurement, and one with a short time constant to pick off the maximum ionization or Bragg peak. The Bragg peak, which is proportional to the nuclear charge, is used for particle identification. Several versions of the BCS have been constructed and tested. Test results, detector characteristics and some design problems are discussed.

International Nuclear Information System (INIS)

Coherent spontaneous radiation has now been observed in several FELs, and is a subject of great importance to the design of self-amplified spontaneous emission (SASE) devices. We report observations of coherent spontaneous radiation in both FIREFLY and the mid-infrared FEL at the Stanford Picosecond FEL Center. Coherent emission has been observed at wavelengths as short as 5 microns, and enhancement over incoherent levels by as much as a factor of 4x10"4 has been observed at longer wavelengths. The latter behavior was observed at 45 microns in FIREFLY with short bunches produced by off-peak acceleration and dispersive compression. We present temporal measurements of the highly bunched electron distributions responsible for the large enhancements, using both transition radiation and energy-phase techniques.

Energy Technology Data Exchange (ETDEWEB)

This investigation involves a study of the influence of key processing parameters on the heating of materials using microwave energy. Selective and localized heating characteristics of microwaves will be utilized in the sintering of ceramics without hydrostatic pressure. In addition, combustion synthesis will be studied for the production of powders, carbides, and nitrides by combining two or more solids or a solid and a gas to form new materials. The insight gained from the interaction of microwaves with various materials will be utilized in the mobilization and subsequent redeposition of uranium.

Energy Technology Data Exchange (ETDEWEB)

This 2001 edition of the guide to UK renewable energy companies examines the geothermal heat pump sector, and discusses the technology involved, installations of geothermal heat pumps, the activity in the UK market with increased interest in UK geothermal heat pump products from abroad, and developments in the building sector. The UK government's increased support for the industry including its sponsorship of the Affordable Warmth programme, and the future potential of ground source systems are discussed.

Energy Technology Data Exchange (ETDEWEB)

Since many years, people take care of hazardous consequences of a non controlled economic growth and the sustainable development concept gains on one. This situation leads to consequences in the building industry and in the energy policy: buildings insulation in consideration, demand of consultants. In this framework, the partnership between Gaz De France and CICF has to be built. (A.L.B.)

UK PubMed Central (United Kingdom)

We report the first quantitative assessment of electrosprayed droplet/ion focusing enabled by the use of a voltage-assisted air amplifier between an electrospray ionization emitter and a hybrid...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The relaxation oscillation of the amplified spontaneous radiation pulses emitted from a single-mirror Cu/CuBr laser has been observed for the first time and the experimental characteristics of the relaxation oscillation were obtained. In addition, the spatial and temporal distributions of the light pulse intensity of the amplified spontaneous radiation were also measured and found to be comparatively and uniform. The spatial coherence of the amplified spontaneous radiation was found to be better than that of the laser with the same lasant.

International Nuclear Information System (INIS)

The electron-beam qualities with and without free electron laser (FEL) oscillations were investigated in the compact storage ring NIJI-IV. The peak-electron density in a bunch was suppressed by beam instabilities, so that it was limited to about 1.0 x 10"1"7 m"-"3. The maximum FEL gain estimated for 215 and 300 nm using a well-known one-dimension theory was about 2.8% and 4.6%. The cavity loss at 300 nm was evaluated to be about 2% from the threshold beam current. The bunch length and energy spread with FEL oscillations increased by 1.3 times or more due to bunch heating. The ratio of the FEL gain to a cavity loss estimated from the beam qualities with and without FEL oscillations was almost in accord with the ratio evaluated directly with the measured data of the FEL gain and the cavity loss. (author)

Energy Technology Data Exchange (ETDEWEB)

Beginning with an overview of renewable energy sources including biomass, hydroelectricity, geothermal, tidal, wind and solar power, this book explores the fundamentals of different renewable energy systems. The main focus is on technologies with high development potential such as solar thermal systems, photovoltaics and wind power. This text not only describes technological aspects, but also deals consciously with problems of the energy industry. In this way, the topics are treated in a holistic manner, bringing together maths, engineering, climate studies and economics, and enabling readers to gain a broad understanding of renewable energy technologies and their potential. The book also contains a free CD-ROM resource, which includes a variety of specialist simulation software and detailed figures from the book. (Author)

Energy Technology Data Exchange (ETDEWEB)

The first part of this article in two parts deals with the cupola furnace process regarding the energy consumption figures and efficiencies. The splitting of heat transfer into the two stages of melting and superheating makes the poor use of energy in superheating clear. For this reason the previously published idea of duplication, i.e. melting in a cupola furnace and superheating in an induction channel furnace or coreless induction furnace, has gained in interest. The last section of part I examines and compares cupola and electrode furnaces regarding the use of primary energy, where, surprisingly, roughly equal efficiencies of 20 to 25% are found for the melting processes considered.

DEFF Research Database (Denmark)

OBJECTIVE: To evaluate the association between fatty acid (alpha-linolenic acid (ALA), EPA, DHA, palmitic, stearic, oleic, linoleic and arachidonic acids) intake and prospective weight change in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition. DESIGN: Prospective cohort study with mean follow-up time of 6.5 years. In a total of 9182 men and 10867 women aged 35 to 64 years, from body weight measurement at recruitment and calibrated body weight during follow-up, weight change was expressed as mean annual weight change relative to baseline weight (%/year) and categorised into four groups (weight loss, or =2.5 to or =7.5%/5 years). Energy-adjusted dietary fatty acid intake data were estimated from the FFQ completed at baseline. Multivariate linear regression models as well as multinomial logistic regression analyses (carbohydrate replacement models) were conducted. RESULTS: Stearic acid intake was linearly associated with ...

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)

Energy Technology Data Exchange (ETDEWEB)

Abstract: The Hanford Tanks Initiative (HTI) is a five-year project resulting from the technical and financial partnership of the U.S. Department of Energy`s Office of Waste Management (EM-30) and Office of Science and Technology Development (EM-50). The HTI project accelerates activities to gain key technical, cost performance, and regulatory information on two high-level waste tanks. The HTI will provide a basis for design and regulatory decisions affecting the remainder of the Tank Waste Remediation System`s tank waste retrieval Program.

Energy Technology Data Exchange (ETDEWEB)

In Canada, the cost of heating is a major expense in the operation of greenhouses in the winter season, inhibiting greenhouse production in winter months in most part of the country. Alternative energy sources, such as solar energy and biomass energy may offer an economically feasible heating alternative. A solar energy greenhouse technology developed in northern China for winter vegetable production has demonstrated good potential for Manitoba winter conditions. The design and performance of solar energy greenhouses depend on the geographical location. Therefore, in order to optimize the design of solar greenhouses with respect to the latitude of the location for maximum solar radiation gain, a theoretical analysis was performed that analyzed parameters such as greenhouse length and the roof slope. This paper described the methodology of the study, including a ...

Energy Technology Data Exchange (ETDEWEB)

The MTX explored the plasma heating effects of 140 GHz microwaves from both Gyrotrons and from the IMP FEL wiggler. The Gyrotron was long pulse length (0.5 seconds maximum) and the FEL produced short-pulse length, high-peak power, single and burst modes of 140 GHZ microwaves. Full-power operations of the IMP FEL wiggler were commenced in April of 1992 and continued into October of 1992. The Experimental Test Accelerator H (ETA-II) provided a 50-nanosecond, 6-MeV, 2--3 kAmp electron beam that was introduced co-linear into the IMP FEL with a 140 GHz Gyrotron master oscillator (MO). The FEL was able to amplify the MO signal from approximately 7 kW to peaks consistently in the range of 1--2 GW. This microwave pulse was transmitted into the MTX and allowed the exploration of the linear and non-linear effects of short pulse, intense power in the MTX plasma. Single pulses were used to explore and gain operating experience in the parameter space of the ...

British Library Electronic Table of Contents (United Kingdom)

In light of the global focus on greenhouse gas emissions, energy consumption of communication networks has become an important research area. Networks are major energy consumers and are generally dimensioned for peak loads. For extended periods, resources consume power, but are lightly or unused. This research investigates the concept of dynamic topologies, i.e. networks that adapt their topology according to traffic volume. The key aim of this study is to investigate power reductions that can be achieved by dynamic topologies. It proposes a network transformation and introduces mathematical programming models that results in energy optimal topologies for given traffic loads. This paper focuses on the optimisation problems and investigates gains in static environments. Numerical results ar...

Energy Technology Data Exchange (ETDEWEB)

Large area, single-element Si(Li) detectors have been fabricated using a novel geometry which yields detectors with reduced capacitance and hence reduced noise at short amplifier pulse-processing times. A typical device employing the new geometry with a thickness of 6 mm and an active area of 175 mm 2 has a capacitance of only 0.5 pf, compared to 2.9 pf for a conventional planar device with equivalent dimensions. These new low capacitance detectors, used in conjunction with low capacitance field effect transistors, will result in x-ray spectrometers capable of operating at very high count rates while still maintaining excellent energy resolution. The spectral response of the low capacitance detectors to a wide range of x-ray energies at 80 K is comparable to typical state-of-the-art conventional Si(Li) devices. In addition to their low capacitance, the new devices offer other advantages over conventional detectors. Detector ...

International Nuclear Information System (INIS)

Postulated impacts of large energy releases were examined in the light of existing technical information. The magnitudes of direct atmospheric modifications were estimated, and the ecological and economic implications of the modifications were explored. Energy releases from energy centers (10 to 40 power plants at a single site) and individual power plant clusters (1 to 4 power plants) were considered. In the atmosphere the energy will exist initially as increased temperature (sensible heat), moisture (latent heat), and air motion (kinetic energy). Addition of energy could result in increased cloudiness and fog, and changed precipitation patterns. A framework for economic analysis of the impacts of the postulated atmospheric modifications was established on the basis of costs and benefits. Willingness-to-pay was selected as the appropriate measure for valuing ...

Energy Technology Data Exchange (ETDEWEB)

This paper deals with conversions of solar energy efficiently into electricity and into gas laser radiation. In the first section, a review study of the possibility of a solar-electric thermophotovoltaic (TPV) device has been done. In a proposed extension of the TPV concept, a Cassagranian optical system concentrates solar radiation to heat a blackbody cavity to 2400/sup 0/K. A double-layer solar cell, GaAs and Si, forming the cylindrical surface concentric to the blackbody cavity, receives the blackbody radiation and converts it into electricity efficiently. A cell conversion efficiency of 50% or more would be possible with the TPV system. The second section explores the concept of blackbody radiation pumping of gas laser media as a step toward utilization of solar energy as a laser pumping source. To demonstrate this concept, an experiment was performed in which various gas mixtures of CO/sub 2/ and He were exposed to 1500/sup 0/K thermal ...

International Nuclear Information System (INIS)

Shell Oil's exploration of profitable business opportunities afforded by fuel cells and by the emergence of a viable hydrogen economy is discussed. The emphasis in this paper is on the transportation sector, particularly the importance of a refueling infrastructure and the influence that consumer attitudes will have on which technological solution will gain the upper hand in hydrogen-powered vehicle development. Key issues facing the oil industry with regard to development of hydrogen as the new energy carrier are also reviewed. Methanol reformer fuel cell cars are the most likely to gain acceptability in the short term, but the probability of methanol fuel cell vehicles being replaced by gasoline or hydrogen fuelled fuel cell vehicles or be superseded by advances in internal combustion engine and after-treatment technology, are very real. Government regulations, fiscal incentives and societal pressures will be the ...

Energy Technology Data Exchange (ETDEWEB)

This book applies the Los Alamos Solar Load Ratio (SLR) method to the design of passive solar heating systems, with an emphasis on the average annual heating energy consumption. Recommendations are given on minimizing heating energy consumption by appropriate choices of conservation level and solar system parameters. Analytical methods and supporting tables are presented which enable simple, fast estimates of the heating energy consumption as part of the design process. Topics considered include SLR correlations, the load collector ratio (LCR) method, sensitivity data, cooling considerations, conservation formulas, design procedure, life-cycle costs, high-mass direct gain buildings, low-mass sun-tempered buildings, sunspaces, off-reference night insulation, correlation equations, and mixed systems.

International Nuclear Information System (INIS)

Among others, one of the main activities in the Nuclear Engineering and Fluid Mechanics Department of the Engineering School in Bilbao, is the study of liquid metals behavior. And for this purpose the CFD code FLUENT is being used. Currently, the code is being applied to the use of Lead-Bismuth eutectic (LBE) as the coolant of an accelerator driven system (ADS) and also as the target for a neutron source. In this paper, ANSALDO's Energy Amplifier Demonstration Facility is simulated, paying attention only on the coolant. As it will be later explained, natural convection is a very important issue, because the philosophy for safety systems in nuclear devices tends to consider passive technologies. The purpose is to avoid electrical machines like pumps, so the core should remain coolable, even if there is a blackout. To get this natural circulation, heat transfer plays a main role, and as turbulence enhances the heat transfer, it is important to ...

UK PubMed Central (United Kingdom)

Diverse cell polarity networks require positive feedback for locally amplifying distributions of signalling molecules at the plasma membrane1. Additional...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Like other Central European countries, Poland faces the twin challenges of improving environmental quality while also fostering sustainable economic development. In this study we examine the costs of different standards for air pollution control, and the cost savings from using incentive-based policy instruments in lieu of more rigid command-and-control policies. The comparisons are based on the results of a simulation model of energy use and air pollution control for the Polish economy over 1990-2015. The model simulates least-cost energy supply decisions under different environmental policy assumptions, the corresponding emissions, and the cost of achieving the specified policy objectives. The model results suggest that incentive-based policies will have efficiency gains over command policies that are at least worthy of consideration and may be quite substantial. The size of the gains in practice ...

Energy Technology Data Exchange (ETDEWEB)

This article reports on the UN Environment Programme's (UNEP's) work in supporting the banking and financing sector by creating clean energy finance markets in developing countries. Details are given of the shifting of cash markets to credit, financing solar home systems in India, solar thermal lending in Tunisia, the financing of hotel based solar water heating in Morocco, and the Green Village Credit initiatives in the Yunnan province of China. The importance of providing banks with information needed to gain awareness and experience of renewable energy systems is stressed. The fundamentals of a bank engagement programme, financial catalysts, structuring market oriented approaches, and linking bank lending to policy making are discussed along with the need to shift to credit enhancements to help banks set up their first loan portfolios.

International Nuclear Information System (INIS)

A Smith-Purcell oscillator with a thick electron beam is analyzed in its exponential gain regime. A threshold current less than 1[A] is found for a 1 mm wavelength; this threshold is much lower than that of a similar oscillator operating in a linear gain regime.

Science.gov (United States)

Charge flow and valence/d-band behavior in ion-beam-mixed (IBM) Pd1-xAgx (x = 0.5-0.9) alloys have been studied by X-ray photoemission measurement of the valence bands and of core-level binding energy shifts and X-ray absorption near-edge structure. We correlated the observed Ag 3d5/2 core-level shifts in these IBM alloys, relative to the elemental Ag, with the White Line area changes at the Pd and Ag L3-edge to investigate the charge redistribution at the Ag site. The results indicate that there is a decrease in sp-like conduction electron and a negligible change in the number of d-electrons at the Ag site upon alloying. These results are in line with our previous results in which Pd gains d-charges and loses sp-type charges. This electron redistribution due to hybridization in the alloy leads small net charge transfer from the Ag site to the Pd site in accordance with electronegativity predictions. This result is consistent with the result of ...

Energy Technology Data Exchange (ETDEWEB)

Data resulting from a continuing effort to provide system/subsystem definition data to aid in the evaluation of the SPS program concept is presented. The specific data described relate to the proposed use of solid state devices as microwave power amplifiers in the satellite microwave power transmission subsystem.

Energy Technology Data Exchange (ETDEWEB)

The research supported by this Department of Energy contract has primarily been devoted to the study of the electronic properties of surfaces with sub-micron size. In previous years, we have studied the photoexcitation of electrons from field emission tips by a focussed Argon-ion laser beam tuned to operate at specific photon energy. The photoexcited electrons escape into the vacuum by tunneling through a surface potential barrier which is distorted by the application of a strong electric field. The interest in these experiments lies in a better understanding of the photoexcitation process at low photon energies. The techniques that have been developed directly measure the excited state energy distribution of electrons emitted through the surface potential barrier. The basic information gained from this research is relevant to opto-electronic devices which rely on photoexcitation of ...

International Nuclear Information System (INIS)

A high power Free-Electron Laser (FEL) has lased at a wavelength of 22 #mu#m at the Japan Atomic Energy Research Institute (JAERI). The maximum power on a macro-pulse average is 1.7 kW, and it corresponds to an FEL energy of 160 #mu#J/micro-pulse. Extraction efficiency from the electron beam to the FEL radiation was measured to be 5.3% by an energy analyzer, when the maximum FEL power was coupled out. The rms wavelength spread was measured to be 4.6% at the same time. The extraction efficiency, in general, has a maximum value near the zero detuning length of an optical cavity, where (in contrast) the single-pass gain becomes smallest. A high peak current and a long macro-pulse duration are therefore indispensable for realizing high efficiency. The electron beam energy is 16.5 MeV, and the average current is 5.3 mA at a micro-pulse repetition rate of 10.4 MHz. The macro-pulse ...

International Nuclear Information System (INIS)

United States Taur, Y. Claassen, JH Richards, PL Department of Physics,

Energy Technology Data Exchange (ETDEWEB)

In this systematic examination of some of the spectroscopic properties of the f-elements we deal with both the trivalent lanthanides and actinides. We summarize the present status of our energy level calculations in single crystal matrices and in aqueous solution, and compare the predicted crystal-field structure in certain low-symmetry sites with that observed. Some interesting new structural insights are thereby gained. The state eigenvectors from these calculations are then used in part in reassessing and interpreting the intensities of transitions in aqueous solution via the Judd-Ofelt theory. The parameters of this theory derived from fitting experimental data are compared with those computed from model considerations. Finally, we discuss some recent contributions to the interpretation of excited state relaxation processes in aqueous solution. 79 references, 23 figures, 17 tables.

Science.gov (United States)

Photoelectron resonance capture ionization (PERCI) is a soft and sensitive ionization method, based on the attachment of low-energy (<1 eV) photoelectrons to organic analyte molecules. PERCI has been developed in our laboratory for the real-time analysis of organic particles by mass spectrometry, and is employed here to monitor the heterogeneous reaction of ozone with oleic acid. Simplified identification of the reaction products is possible as a result of the soft nature of PERCI, giving predominantly the [M--H](-) ions. The major particle-phase products are identified as: 1-nonanal, nonanoic acid, 9-oxononanoic acid, and azelaic acid, consistent with proposed mechanisms. New insight into this well-studied heterogeneous reaction is gained as additional minor particle-phase products, consistent with the Criegee mechanism, are readily detected. PMID:15468105

Energy Technology Data Exchange (ETDEWEB)

In the international study of IEA Annex 27 `Demonstration and evaluation of domestic ventilation systems` a number of simple tools to gain insight into the characteristics of ventilation systems for dwellings are presented. The assessment is made with respect to e.g. indoor air quality, comfort, noise, energy, costs and reliability. In three articles the results of Annex 27 will be discussed. In the first article background information of IEA Annex 27 was given as well as applications in the Netherlands. In this second article attention is paid to the assessment models (`simplified tools`) for indoor air quality, thermal comfort and noise. 6 refs.

Energy Technology Data Exchange (ETDEWEB)

To gain in efficiency, lightness and volume, the hybrid and electric-powered cars will certainly follow the cellular phone path. The key of success of todays hybrid cars is the Ni-MH battery developed by Matsushita (87.5% of the market in 2004). The lithium-ion batteries will be the next step and would allow to supply 80 to 100% of the energy of the vehicle, the thermal engine becoming just an auxiliary system for additional power, autonomy and air-conditioning. Prototypes can reach today 200 to 450 km of autonomy and 130 km/h speeds with batteries of about 200 kg. If most of the safety problems linked with the Li technology have been solved, the main drawback remains the cost of the Li-ion technology. Short paper. (J.S.)

Energy Technology Data Exchange (ETDEWEB)

Current decisions on greenhouse gas emissions may have effects on human well being for centuries. This project has aimed to extend the economic models designed for analyzing this particular issue. A closely related topic follows from the fact that emitting CO{sub 2} can be interpreted as a utilization of a free access resource, i.e., when countries gain from utilizing cheap fossil fuels (relative to noncarbon energy sources), the possible loss any country suffers from climate change is only a negligible fraction of the total loss of all countries. Thus, from a global point of view, the incentives for an individual country to abate emissions is low. Economic understanding of these problems calls for dynamic game-theoretical models

British Library Electronic Table of Contents (United Kingdom)

The aim of this study is to evaluate the specificities of the irradiation of drugs in frozen aqueous solution. The structures of the degradation products were determined to gain insight into the radiolysis mechanisms occurring in frozen aqueous solutions. Metoclopramide hydrochloride and metoprolol tartrate were chosen as models. The frozen solutions were irradiated at dry ice temperature by high energy electrons at various doses. The drug purity (chemical potency) and the radiolysis products were quantified by HPLC-DAD. Characterization of the degradation products was performed by LC-APCI-MS-MS. The structures of the radiolysis products detected in irradiated frozen aqueous solutions were compared to those detected in solid-state and aqueous solutions (previous studies). For both metoclop...

Energy Technology Data Exchange (ETDEWEB)

In 1986, following comprehensive preliminary studies, a 17 MW battery energy storage plant was set up in the insular power supply system of Berlin (West) for the purpose of frequency and output control and provision of immediate reserve capacities. The present paper reports on the initial task, and the dimensioning and construction of this large-scale demonstration as well as the costs entailed in this. It also relates the experiences gained with the operation of the battery energy storage plant in its function as a fast-responding control unit and gives an account of its economic efficiency. Recent studies on the economic efficiency of the plant in conditions as they exist in the present interconnected power supply system are presented. Finally the author reports on the experiences gained with individual plant components, i.e., battery, battery periphery, and power converter and quantifies the cost of ...

Energy Technology Data Exchange (ETDEWEB)

The report sums up the experience gained with energy efficiency pilot campaigns in Schleswig-Holstein (Schoeth et al., to appear, and Wortman et al., 2000, 2001). The information is to help other actors in this field to develop and optimize their own campaigns. [German] Dieser Bericht resuemiert die wesentlichen Erkenntnisse und Erfahrungen mit wirkungsvoller Umweltwerbung auf Basis der ausfuehrlichen Werbewirkungskontrollen zu den Energieeffizienz-Pilotkampagnen in Schleswig-Holstein (vgl. ausfuehrlicher Schoetz et al., im Druck sowie Wortmann et al., 2000, 2001). Die abschliessenden Abschnitte 'Empfehlungen' und 'Ausblick' kennzeichnen den aktuellen Stand des Wissens und sollen anderen Akteuren mit gleicher oder aehnlicher Zielsetzung Hilfestellung und Anregung fuer die optimierte eigene Planung von Kampagnen geben. (orig.)

Energy Technology Data Exchange (ETDEWEB)

The Geothermal Heat Pump (GHP) concept was originally developed in the 1940`s. Recently, because of increasing energy costs, utility interest, and the development of simple and durable ground source heat exchangers, GHP`s have gained international attention as a proven means of energy conservation and electrical peak power demand reduction. GHP systems require installation of a buried heat exchanger to utilize the nearly constant ground temperature making them more efficient than conventional air source heat pumps. However, the high installation cost for both residential and commercial applications is a major obstacle to their market penetration. Sandia National Laboratories (SNL) through its sponsors, the Department of Energy (DOE), and the Department of Defense (DOD), has embarked on a research program to find ways to reduce GHP installation costs and improve performance, thereby increasing their ...

Energy Technology Data Exchange (ETDEWEB)

This paper reported on a life cycle assessment (LCA) study that compared the environmental impacts of business-as-usual manure management with those of a manure management operation incorporating anaerobic digestion with combined heat and power generation. The case study was based on a medium sized dairy farm in northern New York State. The study identified the benefits resulting from the displacement of fossil fuels, and reduction of related emissions. Although anaerobic digestion of dairy manure with energy recovery through biogas combustion is viewed as a positive environmental approach to increase the use of renewable energy, there are potential negative impacts that can counteract the environmental benefits. The negative impacts are associated with emissions of methane and nitrogen species during digestion and after spreading of digester effluent. The environmental impacts and their causes should be evaluated in order to promote best ...

Energy Technology Data Exchange (ETDEWEB)

By contrast to the large mass, complexity and recirculating power of conventional drivers for inertial confinement fusion (ICF), antiproton annihilation offers a specific energy of 90MJ/{micro}g and thus a unique form of energy packaging and delivery. In principle, antiproton drivers could provide a profound reduction in system mass for advanced space propulsion by ICF. We examine the physics underlying the use of antiprotons ({bar p}) to drive various classes of high-yield ICF targets by the methods of volumetric ignition, hotspot ignition and fast ignition. The useable fraction of annihilation deposition energy is determined for both {bar p}-driven ablative compression and {bar p}-driven fast ignition, in association with 0-D and 1-D target burn models. Thereby, we deduce scaling laws for the number of injected antiprotons required per capsule, together with timing and focal spot requirements. The kinetic ...

UK PubMed Central (United Kingdom)

An improved method of counting acoustic emission (AE) events from water-stressed stems of cedar (Thuja occidentalis L.) is presented. Amplified AEs are analyzed on a real time basis...Full Text Available

UK PubMed Central (United Kingdom)

Randomly amplified polymorphic DNA (RAPD) analysis and the PCR assay were used in combination with dilution plating on a semiselective medium to detect and enumerate propagules of Trichoderma...Full Text Available

UK PubMed Central (United Kingdom)

DNA from the peripheral blood mononuclear cells of 17 different individuals infected with human T-cell lymphoma/leukemia virus type II (HTLV-II) was successfully amplified by the polymerase chain reaction...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundDeveloping lepidopteran microsatellite DNA markers can be problematical, as markers often exhibit multiple banding patterns and high frequencies of non-amplifying "null"...Full Text Available

UK PubMed Central (United Kingdom)

The Tetrahymena thermophila origin recognition complex (ORC) contains an integral RNA subunit, 26T RNA, which confers specificity to the amplified ribosomal DNA (rDNA) origin by base...Full Text Available

Science.gov (United States)

... 19. AmSTR.ACT (Continuq 9n =usff i En " Adentity by bo nwnb Agallumarsemoe t(a.") MEtFET ... 2%ITE 4T (Include Area Code) InghE SMO ...

British Library Electronic Table of Contents (United Kingdom)

We propose and demonstrate experimentally a singlelongitudinal-mode (SLM) fiber double-ring laser using an Erbium-doped waveguide amplifier (EDWA), polarization controller (PC), and a fiber Fabry-Perot tunable filter (FFP-TF) into the ring cavity. In addition, the output power, side-mode suppression ratio (SMSR), and the stabilities of power and wavelength of the laser also are investigated. (Copyright 2007 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA)

International Nuclear Information System (INIS)

A high-power microwave Free Electron Laser (FEL) experiment has been performed to study the inherent electron beam bunching that occurs in the FEL interaction. An induction linac delivered a 1 kA, 2.2 MeV electron beam to a FEL amplifier. In the process of amplifying the input signal of frequency 35 GHz to power levels of the order of 10 MW, the electron beam was bunched by the ponderomotive force. In this paper we describe the FEL experiment and the optical technique that was used to observe the bunches. Their properties as functions of the basic FEL parameters are discussed. copyright 1996 American Institute of Physics.

CERN Document Server

We consider relay selection technique in a cooperative cellular network where user terminals act as mobile relays to help the communications between base station (BS) and mobile station (MS). A novel relay selection scheme, called Joint Uplink and Downlink Relay Selection (JUDRS), is proposed in this paper. Specifically, we generalize JUDRS in two key aspects: (i) relay is selected jointly for uplink and downlink, so that the relay selection overhead can be reduced, and (ii) we consider to minimize the weighted total energy consumption of MS, relay and BS by taking into account channel quality and traffic load condition of uplink and downlink. Information theoretic analysis of the diversity-multiplexing tradeoff demonstrates that the proposed scheme achieves full spatial diversity in the quantity of cooperating terminals in this network. And numerical results are provided to further confirm a significant energy efficiency ...

International Nuclear Information System (INIS)

Nanoporous materials have become indispensable in many fields ranging from photonics, catalysis and semiconductor processing to biosensor infrastructure. Rapid and energy efficient process fabrication of these materials is, however, nontrivial. In this communication, we describe a simple method for the rapid fabrication of these materials from colloidal dispersions of Polymethyl Silsesquioxane nanoparticles. Nanoparticle-polymer composites above the decomposition temperature of the polymer are examined and the entropic gain experienced by the nanoparticles in this rubric is harnessed to fabricate novel highly porous films composed of nanoparticles. Optically smooth, hydrophobic films with low refractive indices (as low as 1.048) and high surface areas (as high as 1325 m2 g-1) have been achieved with this approach. In this communication we address the behavior of such systems that are both temperature and substrate surface ...

Energy Technology Data Exchange (ETDEWEB)

The present paper is concerned with development and application of a so-called Effective Convection Model (ECM), which aims to provide a detailed, mechanistic description of heat transfer processes in a BWR lower plenum. The ECM is a Computational Fluid Dynamics (CFD)-like tool which employs a simpler and more effective approach to compute heat transfer by solving only energy conservation equation instead of solving the full set of Navier-Stokes and energy equations by a CFD code. We implement the ECM in a CFD code (Fluent), with detailed description of the ECM development, implementation and validation. A dual approach is used to validate the ECM, namely validation against experimental data and against heat transfer results obtained by CFD predictions in the same geometries and conditions. Insights gained from CFD simulations are also used to improve ECM. The ECM capability as an effective tool to simulate heat transfer of ...

Energy Technology Data Exchange (ETDEWEB)

The aim was to gain experience on how to produce Alkali Metal Thermo-Electric-Converter (AMTEC) cells, for the demonstration of their principles and potentials, as a basis for future commercialization. These cells should be able to present an efficient and direct conversion of thermal energy to electric energy. The system is based on an electro-chemical concentration cell built around a {beta}`` aluminium oxide membrane that separates the two chambers. This material is a good conductor of sodium and a bad conductor of electrons, and it is this property which is taken advantage of. In the two chambers of the cell is found saturated sodium vapour at two temperatures. The motive power is the expansion over the membrane where the sodium ions are transported through it whilst the electrons are forced through the outer cycle. This concept is described in detail in addition to the choice of materials, performance testing and ...

Energy Technology Data Exchange (ETDEWEB)

We propose that a search for extra-terrestrial life can be approached as a Search for Extra-Terrestrial Homochirality{emdash}SETH. Homochirality is probably a pre-condition for life, so a chiral influence may be required to get life started. We explain how the weak force mediated by the {ital Z}{sup 0} boson gives rise to a small parity-violating energy difference (PVED) between enantiomers, and discuss how the resulting small excess of the more stable enantiomer may be amplified to homochirality. Titan and comets are good places to test for emerging pre-biotic homochirality, while on Mars there may be traces of homochirality as a relic of extinct life. Our calculations of the PVED show that the natural L-amino acids are indeed more stable than their enantiomers, as are several key D-sugars and right-hand helical DNA. Thiosubstituted DNA analogues show particularly large PVEDs. L-quartz is also more stable than D-quartz, and we believe that ...

Energy Technology Data Exchange (ETDEWEB)

The Asian countries are expected to generate 45% of the world energy consumption and Japan is the absolutely greatest consumer in Asia, but China is the country that will be most important as a new consumer on the world energy markets. China, like India and later possibly even Japan try to change to natural gas as a source of energy as much as possible. This is causing a competition about the resources that can be reached by pipelines for gas, which in practice means those in Russia and Central Asia. Russia is trying to control the gas in Central Asia. The competition is also increasing about oil. China is becoming heavily dependent on Muslim countries in the Middle East and Central Asia. This also leads to an effort to increase the safety along the sea lanes, which may collide with the interests of other countries. Territorial conflicts with gas and oil as underlying elements exist in Asia. USA is a player on the ...

UK PubMed Central (United Kingdom)

OBJECTIVETo estimate the relationship between the rate of gestational weight gain before the 50-g, 1-hour oral glucose challenge test screening for gestational diabetes...Full Text Available

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

Boron Neutron Capture Therapy (BNCT) is a promising binary treatment modality for high-grade primary brain tumors (glioblastoma multiforme, GM) and other cancers. BNCT employs a boron-10 containing compound that preferentially accumulates in the cancer cells in the brain. Upon neutron capture by {sup 10}B energetic alpha particles and triton released at the absorption site kill the cancer cell. In order to gain penetration depth in the brain Fairchild proposed, for this purpose, the use of energetic epithermal neutrons at about 10 keV. Phase I/II clinical trials of BNCT for GM are underway at the Brookhaven Medical Research Reactor (BMRR) and at the MIT Reactor, using these nuclear reactors as the source for epithermal neutrons. In light of the limitations of new reactor installations, e.g. cost, safety and licensing, and limited capability for modulating the reactor based neutron beam energy spectra alternative neutron sources are being ...

Energy Technology Data Exchange (ETDEWEB)

The cooperative project was a joint development program between Ceradyne and Oak Ridge National Laboratory through Lockheed Martin Energy Research (LMER). Cooperative work was of benefit to both parties. ORNL was able to assess the effect of the microwave nitridation process coupled with gas-pressure sintering for fabrication of parts for advanced diesel engines. Ceradyne gained access to gelcasting expertise and microwave facilities and experience for the nitridation of SRBSN materials. The broad objective of the CRADA between Ceradyne and OIWL was to (1) examine the applicability of the gelcasting technology to fabricate parts from SRBSN, and (2) to assess the effect of the microwave nitridation of silicon process coupled with gas-pressure sintering for fabrication of parts for advanced diesel engines. The following conclusions can be made from the work performed under the CRADA: (1) Gelcasting is a viable method to fabricate SRBSN parts ...

Energy Technology Data Exchange (ETDEWEB)

In this study, isothermal torsion tests were carried out on magnesium AZ31B alloy under constant strain rate conditions, in the range of 250 to 400 C at 0.01, 0.1, and 1.0 s{sup -1}. Alloy flow stress dependence on strain rate and temperature can be described by a power law with activation energy of 130 kJ/mol. Microstructural examination of hot deformed samples shows very fine recrystallized grains decorating grain boundaries of larger gains in the form of a necklace. These fine grains are produced by dynamic recrystallization at the grain boundaries of original grains. Microstructure evolution, based on samples quenched at different strain levels, indicates that increasing deformation strain has little effect on recrystallized grain size but widens the recrystallized region, with full recrystallization achieved at a certain high strain level. Recrystallized grain size increases with increasing deformation temperature and strain rate. The ...

Energy Technology Data Exchange (ETDEWEB)

Obtaining precise values of the undulator parameter, K, is critical for producing high-gain FEL radiation. At the LCLS [1], where the FEL wavelength reaches down to 1.5 {angstrom}, the relative precision of K must satisfy ({Delta}K/K){sub rms} {approx}< 0.015% over the full length of the undulator. Transverse misalignments, construction errors, radiation damage, and temperature variations all contribute to errors in the mean K values among the undulator segments. It is therefore important to develop some means to measure relative K values, after installation and alignment. We propose a method using the angle-integrated spontaneous radiation spectrum of two nearby undulator segments, and the natural shot-to-shot energy jitter of the electron beam. Simulation of this scheme is presented using both ideal and measured undulator fields. By ''leap-frogging'' to different pairs of segments with extended ...

Energy Technology Data Exchange (ETDEWEB)

In the 150 kV power system of the Dutch energy utility MEGA Limburg cross-country faults have caused problems in the protection of high voltage transmission lines. A cross-country fault is the simultaneous presence of two single-phase earth connections in different phases and places within the grid. These cross-country faults can lead to the incorrect operation of a number of distance relays, which could result in the faulty disconnection of high voltage transmission lines. To gain an insight into these problems, the transient phenomenon in the power system during cross-country faults were studied. For this purpose, the simulation program EMTP (ElectroMagnetic Transients Program) has been used. Simulation models of the 150 kV power system and the measuring system of a distance relay were developed within EMTP. 7 figs., 1 ill.

Energy Technology Data Exchange (ETDEWEB)

The indoor climate of school buildings have been much debated recently. Many problems connected with air quality and thermal comfort are caused by bad maintenance, fitted carpets and no sunshades. Mechanical ventilation in schools has gained a bad reputation and many municipalities are seeking other solutions when building new schools. Natural ventilation according to the ''Swedish model'' does not use air filters or heat recovery from the outgoing air and achieve low energy consumption by reducing the airflow substantially in cold weather. Most of the naturally ventilated schools have supply air culverts of concrete below ground outside the building and in the basement. This is also true of schools using hybrid ventilation, where natural and mechanical ventilation is combined. The naturally ventilated schools often use manual control of the ventilation, which may not always be a good solution for buildings ...

Energy Technology Data Exchange (ETDEWEB)

This paper examines the global impacts of a policy that internalizes the external costs (related to air pollution damage, excluding climate costs) of electricity generation using a combined energy systems and macroeconomic model. Starting point are estimates of the monetary damage costs for SO{sub 2}, NOX, and PM per kWh electricity generated, taking into account the fuel type, sulfur content, removal technology, generation efficiency, and population density. Internalizing these externalities implies that clean and advanced technologies increase their share in global electricity production. Particularly, advanced coal power plants, natural gas combined cycles, natural gas fuel cells, wind and biomass technologies gain significant market shares at the expense of traditional coal- and gas-fired plants. Global carbon dioxide emissions are lowered by 3% to 5%. Sulfur dioxide emissions drop significantly below the already low level. The policy ...

International Nuclear Information System (INIS)

Electricite de France, (EDF) in the late sixties and China through 10. 5-year Plan adopted the same approach of standardized NPPs to benefit from the series effect and to increase and speed up self reliance and localization. This approach also allows to continuously gather the feedback from design, construction and operation and to use it to constantly improve future and present nuclear power plants, by optimizing design features, construction phase and generation performances for safety, quality, cost and schedule aspects. Daya Bay NPP put into commercial operation in 1994 is posting high level safety and operation results. At Ling Ao NPP Chinese engineers of LANPC, with the contribution of the Chinese industry, have efficiency and successfully managed engineering, construction and operation preparation. GNPJVC / LANPC and EDF are developing permanent and mutual experience feedback exchanges in all areas of engineering, maintenance and operation. The results of the cooperation and ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this project was to investigate the feasibility of an antiproton catalyzed fission fragment rocket (FFR). The FFR is characterized by the extraction of fission fragments from the fissile fuel, and the utilization of their kinetic energy for thrust generation. A significant drawback to previous FFR designs was the requirement to maintain a critical nuclear pile as the fission fragment source. The author examined the possibility of replacing the critical pile with a sub-critical pile driven by antiprotons. Recent experiments have revealed that antiprotons stimulate highly energetic fissions in {sup 238}U, with a neutron multiplicity of 13.7 neutrons per fission. This interaction was used as a throttled neutron source. The pile consisted of layers of fissile coated fibers which are designed to allow fission fragments to escape them, where the fragments collide with a fluid. The heated fluid is then ejected from the rocket to provide thrust. The ...

Energy Technology Data Exchange (ETDEWEB)

In this paper the authors present some final results from a research project focused on introducing automatic control to the operation of cupola iron furnaces. The main aim of this research is to improve the operational efficiency and performance of the cupola furnace, an important foundry process used to melt iron. Previous papers have described the development of appropriate control system architectures for the cupola. In this paper experimental data is used to calibrate the model, which is taken as a first-order multivariable system with time delay. Then relative gain analysis is used to select loop pairings to be used in a multiloop controller. The resulting controller pairs melt rate with blast volume, iron temperature with oxygen addition, and carbon composition with metal-to-coke ratio. Special (nonlinear) filters are used to compute melt rate from actual scale readings of the amount of iron produced and to smooth the temperature measurement. The temperature ...

Energy Technology Data Exchange (ETDEWEB)

To significantly improve the simulation of climate by general circulation models (GCMs), systematic errors in representations of relevant processes must first be identified, and then reduced. This endeavor demands that the GCM parameterizations of unresolved processes, in particular, should be tested over a wide range of time scales, not just in climate simulations. Thus, a numerical weather prediction (NWP) methodology for evaluating model parameterizations and gaining insights into their behavior may prove useful, provided that suitable adaptations are made for implementation in climate GCMs. This method entails the generation of short-range weather forecasts by a realistically initialized climate GCM, and the application of six-hourly NWP analyses and observations of parameterized variables to evaluate these forecasts. The behavior of the parameterizations in such a weather-forecasting framework can provide insights on how these schemes might be improved, and ...

Science.gov (United States)

The financial evaluation of capital and operating cost estimates for a dry coke quenching facility installation indicates a marginal return on investment if the evaluation is based exclusively on steam credits. However, the potential improvements in environmental emissions and reported, but unverified, blast furnace operations may justify the expenditure. The Russian and Japanese claim of 2 to 4% reduction in blast furnace coke usage with up to 4% increase in iron production has not been demonstrated in the domestic steel industry and, therefore, is not included in the financial analysis. A 2% coke reduction represents a savings of approximately $0.81 per ton of hot metal produced or an additional annual credit of $1,800,000 for dry coke quenching, exclusive of productivity gains. Additional credit of this magnitude would increase the estimated discounted cash flow return from 10% to approximately 16% for the estimated capital expenditure of $21,742,652. The ...

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

In addition to the goal of ensuring waste disposal, thermal waste treatment has always been aimed at the energy-efficient utilisation of wastes. Developments in waste management have led to an increase in high-calorific waste arisings. This is attributable to the use of mechanical-biological waste treatment as well as to segregated waste collection systems. High-calorific wastes are equivalent to fossil fuels in terms of their calorific content. Furthermore, they fulfil the legal requirements for conversion to energy. Another source of high-calorific wastes suitable for conversion to energy can be made available through the segregated disposal of industrial wastes, in many cases at low cost. These high-calorific fractions of varying origin and composition are referred to generically as substitute fuels, a term which implies quality and availability by reference to other fuels. Specifically, the term substitute fuel implies ...

Science.gov (United States)

Self-amplifying spontaneous radiation free-electron lasers, such as the LCLS or the European X-FEL, rely on the incoherent, spontaneous radiation as the seed for the amplifying process. Though this method overcomes the need for an external seed source one drawback is the incoherence of the effective seed signal. The FEL process allows for a natural growth of the coherence because the radiation phase information is spread out within the bunch due to slippage and diffraction of the radiation field. However, at short wavelengths this spreading is not sufficient to achieve complete coherence. In this presentation we report on the results of numerical simulations of the LCLS X-ray FEL. From the obtained radiation field distribution the coherence properties are extracted to help to characterize the FEL as a light source.

Energy Technology Data Exchange (ETDEWEB)

The Lesch-Nyhan (LN) syndrome is a severe X chromosome-linked disease that results from a deficiency of the purine salvage enzyme hypoxanthine phosphoribosyltransferase (HPRT). The mutations leading to the disease are heterogeneous and frequently arise as de novo events. The authors have identified nucleotide alterations in 15 independently arising HPRT-deficiency cases by direct DNA sequencing of in vitro amplified HPRT cDNA. They also demonstrate that the direct DNA sequence analysis can be automated, further simplifying the detection of new mutations at this locus. The mutations include DNA base substitutions, small DNA deletions, a single DNA base insertion, and errors in RNA splicing. The application of these procedures allows DNA diagnosis and carrier identification by the direct detection of the mutant alleles within individual families affected by LN.

Energy Technology Data Exchange (ETDEWEB)

During a Workshop on Gamma-Gamma Colliders in Lawrence Berkeley Laboratory, it was pointed out that an 1-{mu}m laser that can produce 1-J, 1-ps pulses at a few hundred hertz is required. With high-power scalability and ease of formatting, an FEL can be a promising candidate for such a laser. The authors propose an FEL scheme based on chirped-pulsed regenerative amplification to achieve this high peak-power laser. The 1-ps pulse of a solid-state laser will be stretched, amplified, and recompressed to achieve the high peak power. The system is relatively simple and consists of mostly components that have already been demonstrated. This paper will describe the proposal and the important issues of such a scheme.

Science.gov (United States)

An abundance of waste corn, a key food of many wildlife species, has helped make possible the widespread success of wildlife management in the United States over the past half century. We found waste corn post harvest in Nebraska declined by 47% from 1978 to 1998 due primarily to improvements in combine headers resulting in a marked decline in ear loss. The reduction in waste coincided with major declines in fat storage by sandhill cranes and white-fronted geese during spring migration. Sandhill cranes, northern pintails, white-fronted geese, and lesser snow geese avoided soybeans while staging in spring in the Rainwater Basin Area and Central Platte River Valley. These findings and other literature suggest soybeans are a marginal food for wildlife particularly during periods of high energy requirements. Soybean acreage has increased by 600% in the United States since 1950 and now comprises nearly one-quarter of the nation>'s cropland. With over 80% of the ...

Science.gov (United States)

... upland development or destroyed during sand and gravel pit mining operations. Gains Increases in nonvegetated wetlands mainly through pond ... ...

Science.gov (United States)

Based on a collisional-radiative model, an atomic-kinetic calculation of the gains on the 41.8-nm transitions of Pd-like xenon was performed for the plasma produced due to the interaction of a femtosecond laser pulse with gaseous xenon. The gains g(z,{tau}) averaged over the spatial and temporal coordinates were compared with the known gains which had been measured experimentally in Xe{sup 8+}. The amplification was shown to occur under the conditions of ionisation of the working ions, and the time of output radiation saturation depends on the time of Xe{sup 8+} transformation to higher-ionised ions. Our theoretical investigation enables determining the optimal pump parameters, at which the product of the gain g by the active medium length L is about 20, which exceeds the experimental gL value. (active media)

UK PubMed Central (United Kingdom)

Background:Percutaneous tracheostomy (PT) has gained an increasing acceptance as an alternative to the conventional surgical tracheostomy (ST). In experienced hands, and with...Full Text Available

UK PubMed Central (United Kingdom)

Experience gained with a wide variety of missile injuries of the brain is presented. Clinical signs and intracranial pressure (ICP) studied in the early post-injury period have been correlated with...Full Text Available

UK PubMed Central (United Kingdom)

The protein “amplified in osteosarcoma-9” (OS-9) has been shown previously to interact with the prolyl hydroxylases PHD2 and PHD3. These enzymes initiate oxygen-dependent degradation...Full Text Available

UK PubMed Central (United Kingdom)

The Epstein-Barr virus protein, LMP1, is a functional mimic of the cellular receptor CD40, but signals to B lymphocytes in an amplified and sustained manner compared to CD40. LMP1 contributes...Full Text Available

UK PubMed Central (United Kingdom)

A two-step polymerase chain reaction (PCR) procedure with two nested pairs of primers specific for the yadA gene of Yersinia enterocolitica was developed. The PCR assay identified all common pathogenic...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

In the fall of 2003, the operators noticed that in the recently-refurbished Bruce A Shutdown System no. 1 (SDS1) the noise level in Log Rate signals were much larger than before. At the request of the Canadian Nuclear Safety Commission (CNSC), all Canadian CANDU reactors took action to characterize their Log Rate noise. Staff of the Inspection and Maintenance Services division of Ontario Power Generation (OPG) has collected high-speed high-accuracy noise data from nearly all 16 Ontario reactors, either as part of routine measurements before planned outages or as a dedicated noise recording. This paper gives the results of examining a suitable subset of this data, with respect to the characteristics and possible causes of Log Rate noise. The reactor and instrumentation design is different at each station: the locations of the moderator injection nozzles, the location of the ion chambers for each system, and the design of the Log Rate amplifiers. It was found that ...

Energy Technology Data Exchange (ETDEWEB)

A new technique is described in this paper for a general active radio frequency (RF) filter trap that can be used for suppressing noise or interference on high voltage (HV) transmission lines. The technique exploits the Miller effect of an RF amplifier in conjunction with a special sensing circuit, and is potentially far more economical to implement than conventional techniques that use passive HV filter components.

Energy Technology Data Exchange (ETDEWEB)

The Northeast Gateway Energy Bridge Deepwater Port project was commissioned in 2005 and is based on a proprietary energy bridge shipboard regasification technology. The offshore liquefied natural gas (LNG) facility will be located in federal waters 13 miles southeast of Gloucester and was designed to cope with the extreme weather of the Massachusetts Bay. A dual-buoy system will be capable of ensuring continuous delivery of natural gas. Throughput capacity will range from 400 to over 800 MMcf/d. Vessels used at the port have capacities of 138,000 m{sup 3} and 150,900 m{sup 3} with peak sendout rates of 600 MMcf/d. The vessels have the capacity to rapidly increase and decrease their delivery rates. During periods of peak demand, 2 vessels can be simultaneously accommodated at the port, which has been designed to accommodate larger vessels to maximize future throughput. This presentation presented details of the port's design phases and ...

International Nuclear Information System (INIS)

Focused ion beam (FIB) microscopes have become well-established in the semiconductor industry during the past decade, and are rapidly gaining attention in the field of materials science, both as a tool for producing site specific, parallel sided transmission electron microscope (TEM) specimens and as stand alone specimen preparation and imaging systems. FIB secondary electron imaging (SEI) of nickel-based alloys, such as commercially produced Alloy 600 (approximately Ni 15Cr 10Fe 0.5C), has been demonstrated to show a high degree of sensitivity to the presence of deformation in the alloy, and FIB secondary ion imaging (SII) is particularly useful for identifying the presence of grain boundary corrosion, as secondary ion yields from metallic specimens can increase by three orders of magnitude in the presence of oxygen. This 'oxygen enhanced yield', makes FIB SII ideal for detection of corrosion at grain boundaries down to thicknesses of only a few tens of ...

International Nuclear Information System (INIS)

A CIEP analysis of the recent development of demand and supply for crude oil indicates that the mismatch in supply and demand growth could cause tighter oil markets than we already experience today. In the World Energy Outlook 2007, the International Energy Agency (IEA) warned of a possible 'energy crunch'. But what was anticipated to happen in the first part of the next decade has been fast-forwarded to today, more than 5 years earlier, and could shake the very foundation of our energy systems if no action is undertaken. Without exaggeration, the recent developments in the international oil market are ground-breaking: a little over a year ago, in January 2007, the West Texas Intermediate crude oil price (WTI) traded for USD50 dollar a barrel. Within a year, the price doubled to USD100 per barrel in January 2008 and pushed through to over USD135 in June 2008, against the backdrop of the fresh market ...

International Nuclear Information System (INIS)

An original evaluating method of gain degradation has been found for neutron irradiated transistors. It establishes a correlation between degradation and the product of two coefficients: spectra factor and an electrical parameter which is measured or directly deduced from manufacturer's data. Equivalence for several type of spectra (fission, 14MeV and degradation sensitivity to electrical parameters values of individual components of a batch are obtained.

Energy Technology Data Exchange (ETDEWEB)

A robust fusion of the agricultural, industrial biotechnology, and energy industries can create a new strategic national capability for energy independence and climate protection. In his State of the Union Address (Bush 2006), President George W. Bush outlined the Advanced Energy Initiative, which seeks to reduce our national dependence on imported oil by accelerating the development of domestic, renewable alternatives to gasoline and diesel fuels. The president has set a national goal of developing cleaner, cheaper, and more reliable alternative energy sources to substantially replace oil imports in the coming years. Fuels derived from cellulosic biomass - the fibrous, woody, and generally inedible portions of plant matter - offer one such alternative to conventional energy sources that can dramatically impact national economic growth, national energy security, ...

International Nuclear Information System (INIS)

The renewed interest for using wind energy commercially is not more than twenty-five years old. From an experimental stage of turning wind energy into electricity in the 1970s, a new industry for producing standardised windmills gained foothold in the beginning of the 1980s and since then it has developed rapidly through the 1980s and the 1990s. The Danish innovators of the new windmill technology have been the pioneers behind this development, and Denmark has succeeded in acquiring a first mover advantage on the world market. This position has been maintained and at present Denmark satisfies more than half of the world market's demand for windmills. There are at least two reasons for this pioneering position of the Danish windmill industry. First, Denmark is by nature very 'abundant' in wind energy due to its geographical position at the nexus between the Gulf Stream and the European continent. The ...

Energy Technology Data Exchange (ETDEWEB)

This document is intended as an addendum to the Remedial Investigation and Feasibility Study (RI/FS) Work Plan for the Salmon Site (SS) (formerly the Tatum Dome Test Site) Lamar County, Mississippi. The original work plan - Remedial Investigation and Feasibility Study of the Tatum Dome Test Site, Lamar County, Mississippi (herein after called the Work Plan) was approved by the state of Mississippi in 1992 and was intended as the operative document for investigative activities at the Tatum Dome Test Site. Subsequent to the approval of the document a series of activities were undertaken under the auspices of the work plan. This document is organized in the same manner as the original work plan: (1) Introduction; (2) Site Background and History; (3) Initial Evaluation; (4) Data Quality Objectives; (5) RI/FS Tasks; (6) Project Schedule; (7) Project Management; and (8) Reference. This addendum will identify changes to the original work plan that are necessary because of additional ...

International Nuclear Information System (INIS)

The slow or stagnant rate of nuclear power generation development in many developed countries over the last two decades has resulted in a significant shortage in the population of mid-career nuclear industry professionals. This shortage is even more pronounced in some specific areas of expertise such as radiological protection, waste management and decommissioning. This situation has occurred at a time when the renaissance of nuclear power and the globalization of the nuclear industry are steadily gaining momentum and when the industry's involvement in international and national debates in these three fields of expertise (and the industry's impact on these debates) is of vital importance. This paper presents the World Nuclear Association (WNA) approach to building and enhancing worldwide industry cooperation in radiological protection, waste management and decommissioning, which is manifested through the activities of the two WNA working groups on radiological ...

Energy Technology Data Exchange (ETDEWEB)

An update of Toronto Hydro's smart metering program was presented. Electricity demand is expected to keep increasing, and there is presently insufficient generation to match supply needs in Ontario. The smart metering program was introduced to aid in the Ontario government's energy conservation strategy, as well as to address peak supply problems that have led to power outages. It is expected that the smart metering program will reduce provincial peak supply by 5 per cent, as the meters support both time-of-use rates and critical peak pricing. Over 800,000 smart meters will be supplied to customers by 2007, and all 4.3 million homes in Toronto will have a smart meter by 2010. In order to meet targets for 2010, the utility will continue to install more 15,000 meters each month for the next 4 years. While the Ontario government has planned and coordinated the rollout and developed smart metering specifications and standards, Toronto Hydro is ...

International Nuclear Information System (INIS)

Pipe whip restraints are used in nuclear power plants in order to limit the consequences of ruptured pipe whip effects and are thus an important part of the plant safety concept. The design of these devices is based on the choice of adequate construction and computational analysis supported by experimental investigation. Pipe whip restraints should, by means of deforming components, be able to absorb the energy of a ruptured pipe accelerated by the fluid reaction force. Since the elastic deformation of the restraint material is not sufficient for this purpose, or would result in excessive anchor loads, pipe whip restraints must generally be designed to work in the plastic range. Two types of restraints are presented in this paper, including the description of their mode of operation, design and computation. A comparison and critical evaluation of the calculation methods presently available are also given. The range of methods covers those developed for very simple ...

International Nuclear Information System (INIS)

The FFTF is a 400-MWt sodium-cooled fast neutron flux test reactor located on the US government-owned Hanford Site in southeastern Washington state. The reactor is operated for the US Department of Energy by the Westinghouse Hanford Company. Since FFTF started routine operation in 1982, the commercially fabricated driver fuel has performed flawlessly to well beyond the design goal peak burnup of 80 MWd/kgM. The core average discharge exposure is now some 60% beyond the original design expectations and attests to the ruggedness and reliability of the mixed oxide fuel system. In Cycle 9 sixteen long-life assemblies were installed to begin the irradiation of mixed oxides in the advanced low-swelling alloy HT-9 as the Core Demonstration Experiment (CDE). Operation of the plant from initial startup testing to ten cycles of operation has confirmed that the nuclear characteristics are well within the design predictions, and all parameters have remained inside the ...

Energy Technology Data Exchange (ETDEWEB)

Competition to produce cast parts of higher quality, lower rejection rate, and lower cost is a fundamental factor in the global economy. To gain an edge on foreign competitors, the US casting industry must cut manufacturing costs and reduce the time from design to market. Casting research and development (R&D) are the key to increasing US compentiveness in the casting arena. Lawrence Livermore National Laboratory (LLNL) is the home of a wide range of R&D projects that push the boundaries of state-of-the art casting. LLNL casting expertise and technology include: casting modeling research and development, including numerical simulation of fluid flow, heat transfer, reaction/solidification kinetics, and part distortion with residual stresses; special facilities to cast toxic material; extensive experience casting metals and nonmetals; advanced measurement and instrumentation systems. Department of Energy (DOE) funding provides the ...

Science.gov (United States)

In this paper we present some final results from a research project focused on introducing automatic control to the operation of cupola iron furnaces. The main aim of this research is to improve the operational efficiency and performance of the cupola furnace, an important foundry process used to melt iron. Previous papers have described the development of appropriate control system architectures for the cupola. These results are summarized. Then we describe the experimental results obtained with the U.S. Department of Energy Albany Research Center`s research cupola. First, experimental data is used to calibrate the model, which is taken as a first-order multivariable system with time delay. Then relative gain analysis is used to select loop pairings to be used in a multi-loop controller. The resulting controller pairs meltrate with blast volume, iron temperature with oxygen addition, and carbon composition with percent coke. Special ...

Energy Technology Data Exchange (ETDEWEB)

A working visit was made to the National Laboratory for High Energy Physics, Tsukuba, Japan, during the time periods May 16, 1988--June 15, 1988 for the purposes of further evaluation of the high intensity plasma sputter negative ion source and to test the response of the University of Tsukuba 13-MV tandem accelerator to mA intensity level pulsed mode heavy negative ion beams. During the visit, the traveler worked in collaboration with Japanese scientists in installing and testing of the source on the University of Tsukuba tandem electrostatic accelerator injector. During the course of preliminary testing of the ion source and prior to actual injection into the accelerator, sparking began in one or more tube sections, which ultimately led to the decision to replace the damaged tube sections. This problem led to postponement of the scheduled tandem accelerator tests. The traveler attended the Seventh International Conference on Ion Implantation Technology held in ...

International Nuclear Information System (INIS)

We report on the first measurements of the z-dependent evolution of electron-beam microbunching as revealed through coherent transition radiation (CTR) measurements in a visible self-amplified spontaneous emission free-electron laser experiment. The increase in microbunching was detected by tracking the growth of the visible CTR signals as generated from insertable metal mirrors/foils after each of the last three undulators. The same optical imaging diagnostics that were used to track the z-dependent intensity of the undulator radiation (UR) were also used to track the electron beam/CTR information. Angular distribution, beam size, and intensity data were obtained after each of the last three undulators in the five-undulator series, and spectral information was obtained after the last undulator. The exponential growth rate of the CTR was found to be very similar to that of the UR and consistent with simulations using the code GENESIS.

International Nuclear Information System (INIS)

The FEL rf system was designed for 3.6-MW rf pulses from two klystrons to drive two linacs and one deflection cavity at 1300 MHz. Two 108.33-MHz subharmonic buncher cavities and one fundamental buncher were also built, each powered by a 5-kW amplifier. A single phase-coherent source drives the various amplifiers as well as the grid of the electron gun, which is pulsed at 21.67 MHz. The initial buncher system did not work as well as expected, and the first linac tank required more rf power than anticipated. The light output was extremely sensitive to amplitude and phase errors. More powerful klystrons were developed and installed, and a method was discovered for operating a single subharmonic buncher and allowing the first linac to complete the bunching process. This paper shows the actual configuration used to operate the laser and discusses future improvements.

International Nuclear Information System (INIS)

The millimeter microwave source of gyrotron-traveling-wave amplifier (gyro-TWT) is capable of generating high power coherent radiation in a broad bandwidth, while its performance is severely deteriorated by the stability problems. This paper focuses on modeling and the stability analysis of the Naval Research Laboratory (NRL) Ka-band TE01 mode gyro-TWT based on an interaction circuit alternately loaded with lossy ceramic shells and metal rings. The propagation characteristics of the interaction circuit is analyzed first, based on which the boundary impedance method is employed to build an equivalent uniform lossy circuit. Then the stability of the interaction system is studied using linear and nonlinear theories. The analysis reveals that, due to the special waveguide structure and the dielectric loss, the propagation characteristics of the complex waveguide are similar to that of a uniform lossy circuit. The analysis of the absolute instabilities characterizes the ...

International Nuclear Information System (INIS)

Object: To control the average liquid level of each steam generator at a constant level irrespective of the flow rate of sodium thereby to decrease change in the retained amount of sodium and at the same time to improve the load response characteristic. Construction: A method for decreasing to as large an extent as possible a change in the amount of sodium retained in a steam generator due to change in the flow rate, which comprises the steps of detecting the main recirculating flow rate of liquid sodium by the use of a sodium flow rate detector, amplifying the detected flow rate signal depending upon the ratio between the flow rates respectively in a super-heater and a re-heater (distribution ratio), delivering the amplified signal to a function generator which generates a liquid level setting signal for maintaining the respective average liquid levels of the super-heater and the re-heater at constant levels irrespective of the flow rates, and ...

Energy Technology Data Exchange (ETDEWEB)

Fetal nucleated cells within maternal blood represent a potential source of fetal genes obtainable by venipuncture. The authors used monoclonal antibody against the transferrin receptor (TIR) to identify nucleated erythrocytes in the peripheral blood of pregnant women. Candidate fetal cells from 19 pregnancies were isolated by flow sorting at 12 1/2-17 weeks gestation. The DNA in these cells was amplified for a 222-base-pair (bp) sequence present on the short arm of the Y chromosome as proof that the cells were derived from the fetus. The amplified DNA was compared with standardized DNA concentrations. In the case of the female fetus, DNA prepared from samples at 32 weeks of gestation and cord blood at delivery also showed the presence of the Y chromosomal sequence, suggesting Y sequence mosaicism or translocation. In 10/12 cases where the 222-bp band was absent, the fetuses were female. Thus, they were successful in detecting the Y chromosomal ...

CERN Document Server

The front-end electronics system for the anode signals of the CMS Endcap Muon cathode strip chambers has about 183000 channels. The purposes of the anode front-end electronics are to acquire precise muon timing information for bunch crossing number identification at the Level-1 muon trigger system and to provide a coarse radial position of the muon track. Each anode channel consists of an input protection network, amplifier, shaper, constant-fraction discriminator, and a programmable delay. The essential parts of the electronics include a 16-channel amplifier-shaper-discriminator ASIC CMP16 and a 16-channel ASIC D16G providing programmable time delay. The ASIC CMP16 was optimized for the large cathode chamber size (up to 3 x 2.5 m2) and for the large input capacitance (up to 200 pf). The ASIC combines low power consumption (30 mW/channel) with good time resolution (2 - 3 ns). The del ay ASIC D16G makes possible the alignment of signals with an ...

Energy Technology Data Exchange (ETDEWEB)

The light gain due to S/sub 2/ molecules in a supersonically cooled gas mixture is calculated. The S/sub 2/ molecules formed due to the recombination of the sulfur atoms, and the combustion gas mixture was preheated in a precombustion chamber. Optimal gas flow and nozzle parameters are found which correspond to the highest possible light gain using Cs/sub 2/-Ar and S/sub 2/-Ar gas mixtures. The steady state gas flow in the nozzle was calculated, taking into account the chemical reactions in the one-dimensional approximation. It is shown that the maximum gain values vary in the 0.0001-0.002 range for gas pressures in the precombustion chamber in the range 10-100 atm. The optimal initial relative concentration of Cs/sub 2/ molecules and S/sub 2/ molecules are given. 32 references.

Energy Technology Data Exchange (ETDEWEB)

In the previous paper, we have derived a dispersion relation for the free electron laser (FEL) gain in the exponential regime taking account the diffraction and electron`s betatron oscillation. Here, we compare the growth rates obtained by solving the dispersion relation with those obtained by simulation calculation for the waterbag and the Gaussian models for the electron`s transverse phase space distribution. The agreement is found to be good except for the limiting case where the Rayleigh length is much longer than the gain length (1-D limit). We also generalize the analysis to the case where the electron beam cross section is elliptical as is usually the case in storage rings, and derive the first-order dispersion relation.

Energy Technology Data Exchange (ETDEWEB)

The RF system for the SuperHILAC injector linac was designed and constructed for minimum system complexity, wide dynamic range, and ease of maintenance. The final amplifier is close coupled to the linac and operates in an efficient semilinear mode, eliminating troublesome transmission lines, modulators, and high level regulators. The system has been operated at over 250 kW, 23 MHz with good regulation. The low level RF electronics are contained in a single chassis adjacent to the RF control computer, which monitors all important operating parameters. A unique 360/sup 0/ phase and amplitude modular is used for precise control and regulation of the accelerating voltage.

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.

CERN Document Server

We report on the design, fabrication and testing of two superconducting passive microwave components, a quadrature hybrid and a 20 dB directional coupler. These components are designed to be integrated with superconducting qubits or Josephson parametric amplifiers and used in quantum information processing applications. For the coupler, we measure return loss and isolation > 20 dB, and insertion loss 20 dB and insertion loss < 0.3 dB in a 10% band around 6.5 GHz. These values are within the design specifications of our application; however, we find a 7% difference between the designed and measured center frequency for the hybrid.

UK PubMed Central (United Kingdom)

The paper describes the possibilities of using data warehousing and OLAP technologies in public health care in general and then our own experience with these technologies gained during the implementation...Full Text Available

UK PubMed Central (United Kingdom)

PurposeIn order to gain insight into the physicians' awareness of and attitude towards management of overactive bladder (OAB) in males, we performed a nationwide survey of the current...Full Text Available

Science.gov (United States)

This presentation from the 2006 PTEC Conference presents education research on topics in thermodynamics. Student responses to conceptual thermodynamics questions, and the conceptions they reveal, are presented. Tutorial materials developed to help students gain a better understanding of the topic are also presented.

Energy Technology Data Exchange (ETDEWEB)

A description of the FEL experiment underway at the 10 kA, 5 MeV Experimental Test Accelerator (ETA) is described. The facility has been designed to investigate the high-gain operation of an FEL.

UK PubMed Central (United Kingdom)

Computer-aided diagnosis of neural diseases from EEG signals (or other physiological signals that can be treated as time series, e.g., MEG) is an emerging field that has gained much attention in past...Full Text Available

UK PubMed Central (United Kingdom)

Outpatient practice after percutaneous coronary intervention (PCI) is gaining momentum due to constantly optimizing results. Furthermore, the availability of limited beds to handle the large volume...Full Text Available

UK PubMed Central (United Kingdom)

To gain insight into the process of mitochondrial transmission in yeast, we directly labeled mitochondrial proteins and mitochondrial DNA (mtDNA) and observed their fate after the fusion of two cells....Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Statistical data on experience gained from operation of steam generators around the world are presented, problems arising in vertical and horizontal steam generators are described, and the conditions of heattransfer tubes used in them are compared.

British Library Electronic Table of Contents (United Kingdom)

Main results of the 40-year experience gained from operation of horizontal steam generators in VVER-type reactor installations used in Russia and many foreign countries are described. Existing unresolved problems are pointed out.

UK PubMed Central (United Kingdom)

The discovery that aerobic exercise increases adult hippocampal neurogenesis and can enhance cognitive performance holds promise as a model for regenerative medicine. This study adds two new...Full Text Available

UK PubMed Central (United Kingdom)

Epicuticular wax production was evaluated along the length of expanding leek (Allium porrum L.) leaves to gain insight into the regulation of wax production. Leaf segments from the...Full Text Available

UK PubMed Central (United Kingdom)

The use of spatially referenced data in cancer studies is gaining in prominence, fueled by the development and availability of spatial analytic tools and the broadening recognition of the linkages between...Full Text Available

Science.gov (United States)

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

UK PubMed Central (United Kingdom)

This article reports on a one-semester Advanced Cell Biology course that endeavors to bridge the gap between gaining basic textbook knowledge about cell biology and learning to think and work as a researcher....Full Text Available

UK PubMed Central (United Kingdom)

Dictyostelium discoideum (Dd) is a widely studied model system from which fundamental insights into cell movement, chemotaxis, aggregation and pattern formation can be gained. In this system aggregation...Full Text Available

Science.gov (United States)

This paper presents a systematic study on the stability of a two-dimensional vibration isolation floating raft system with a time-delayed feedback control. Based on the generalized Sturm criterion, the critical control gain for the delay-independent stability region and critical time delays for the stability switches are derived. The critical conditions can provide a theoretical guidance of chaotification design for line spectra reduction. Numerical simulations verify the correctness of the approach. Bifurcation analyses reveal that chaotification is more likely to occur in unstable region defined by these critical conditions, and the stiffness of the floating raft and mass ratio are the sensitive parameters to reduce critical control gain.

International Nuclear Information System (INIS)

Laser gain of the NIJI-IV compact storage-ring-based Free Electron Laser (FEL) system at AIST reached #approx#9% at 200 nm for an average beam current of 16.3 mA. In addition to such a drastic gain enhancement, improvement of the laser-cavity performance has led to successful FEL lasing in the vacuum ultraviolet below 200 nm even in a compact system. Temporal and spectral characteristics of the NIJI-IV FEL were examined around 200 nm. FEL performance will be briefly discussed from the application point of view.

Energy Technology Data Exchange (ETDEWEB)

This paper details the design, construction and testing of a bayonet tube heat exchanger for use in the process industry and potentially as part of an externally fired combined cycle. Detailed analysis of the system has been undertaken, in particular on the tube side. The data is reported in terms of temperature, pressure, heat gain and heat exchanger effectiveness, over a range of Reynolds numbers and shell side mixture ratios. Much of the heat gained by the tubes is in the annular flow of the bayonet tube. Overall the effectiveness of this system could exceed 70%. (Author)

Energy Technology Data Exchange (ETDEWEB)

Recently, the public has become aware of keywords like ''Quantum computer'' or ''Quantum cryptography''. Regarding their potential application in solid state based quantum information processing and their overall benefit in fundamental research quantum dots have gained more and more public interest. In this context, quantum dots are often referred to as ''artificial atoms'', a term subsuming their physical properties quite nicely and emphasizing the huge potential for further investigations. The basic mechanism to be considered is the theoretical model of a two-level system. A quantum dot itself represents this kind of system quite nicely, provided that only the presence or absence of a single exciton in the ground state of that structure is regarded. This concept can also be expanded to the presence of two excitons (bi-exciton). Transitions between the ...

Energy Technology Data Exchange (ETDEWEB)

The Petroleum Technology Transfer Council (PTTC) and cooperating Regional Lead Organizations (RLOs) in its South Midcontinent (Oklahoma Geological Survey, Norman, Oklahoma) and West Coast (University of Southern California, Los Angeles, California) regions conducted a ''Mentor-Based Effort to Advance Implementation of Preferred Management Practices (PMPs) For Oil Producers'' (DE-FC26-01BC15272) under an award in Phase I of Department of Energy's (DOE's) PUMP (Preferred Upstream Management Practices) program. The project's objective was to enable producers in California, Oklahoma and Arkansas to increase oil production, moderating or potentially reversing production declines and extending the life of marginal wells in the near term. PTTC identified the primary constraints inhibiting oil production through surveys and PUMPer direct contacts in both regions. The leading common constraint was excess ...

Science.gov (United States)

Buildings Energy-Efficient Research Laboratories Energy Efficiency in Federal Facilities Energy Efficiency Standards Group Energy Efficient Windows Collaborative Energy &...

Energy Technology Data Exchange (ETDEWEB)

The Interstate Oil and Gas Compact Commission (IOGCC) engaged in numerous projects outlined under the scope of work discussed in the United States Department of Energy (DOE) grant number DE-FG26-01BC15336 awarded to the IOGCC. Numerous projects were completed that were extremely valuable to state oil and gas agencies as a result of work performed utilizing resources provided by the grant. There are numerous areas in which state agencies still need assistance. This additional assistance will need to be addressed under another grant because funding resources have been exhausted under The scope of work objectives for the eight projects covered under this grant is as follows: (1) Improve uniformity within state oil and gas data management efforts. (2) Conduct environmental compliance workshops and related educational projects on natural gas and oil exploration and production. (3) Improve regulatory efficiency through partnering opportunities provided by the Appalachian ...

British Library Electronic Table of Contents (United Kingdom)

We investigate optimal horizons for targeting inflation in response to different shocks and their properties. Our analysis is based on a well specified macroeconometric model of Norway. We find that optimal horizons are highly shock-specific and do not increase with concern for output and/or interest rate fluctuations beyond some shock-specific levels. Optimal horizons increase with the degree of persistence in shocks while they are not affected by the size of a shock unless the central bank is averse to interest rate volatility. In the face of multiple shocks, however, sizes as well as signs of shocks become important for optimal horizons even when the central bank is not averse to interest rate volatility. This is because shocks of different signs and sizes may amplify or outweigh each o...

Energy Technology Data Exchange (ETDEWEB)

In a shipping terminal, the pipeline in the pier usually has a diameter smaller than the main pipeline diameter. This diameter reduction amplifies the effects caused by hydraulic transients. It was noticed during simulations that check valves placed in the pier may introduce some error in the maximum pressure when it was modeled in a conventional fashion. The dynamic check valve model had been added to a commercial pipeline simulation software and the results was compared with a similar model using the method of characteristics. Considering a real state shipping terminal case, it was proved even a pipeline that works with low pressure and smooth elevation profile needs a detailed valve modeling to prevent the calculation of unreal pressure values in the region with diameter reduction. (author)

Energy Technology Data Exchange (ETDEWEB)

Greenhouse-effect induced climate change repercussions will, via the catchment areas of big rivers, eventually arrive in amplified form at the far downstream coastal zones of the world. In the coastal zone these imported problems will add to the locally exerted climate change effects, while the climate change induced sea-level rise will attack the coastal zone from the other side, both by flooding and by saline groundwater intrusion. These multiple problems will hit the coastal zone, which is already under increasing stress. The combined threats require fast and massive support for national Coastal Zone Management capabilities, which could help to limit the damage and to support planning for sustainable development. Recommendations are presented to facilitate implementation of Coastal Zone Management units in all coastal countries by the year 2000.

International Nuclear Information System (INIS)

The proposal made in this paper refers to a free electron laser FEL with small-period electromagnet undulator in SASE regime and a FEL transverse optical klystron in the amplifier regime. The relativistic electron beam source for this FEL is the 7 MeV electron linac of the National Institute for Laser, Plasma and Physics Radiation (NILPRP) in Bucharest. The paper presents the main features of the design and performance of both FELs and discusses the improvements which must be made to the accelerator in order to use it as a free electron source concerning the injection system of electrons and formation of accelerated electron beam. The findings show that this FEL can be employed as a coherent radiation source in the IR range. (author)

International Nuclear Information System (INIS)

In order to get fully coherent radiation from the Free Electron Laser (FEL) amplifier starting from the shot noise, it is foreseen to implement a seeding option into the VUV FEL being under construction at DESY (DESY print TESLA-FEL 95-03, Hamburg, DESY, 1995, Seeding option for the VUV free electron laser at DESY: joint DESY and GKSS proposal; Available at DESY upon request only). It consists of an additional undulator, a bypass for electrons and an X-ray monochromator. This paper presents the results of optimization of the seeding option for the VUV FEL providing maximal spectral brightness at minimal shot-to-shot intensity fluctuations. Calculations are performed with three-dimensional, time-dependent simulation code FAST (Nucl. Instr. and Meth. A 429 (1999) 233).

British Library Electronic Table of Contents (United Kingdom)

Summary CAG trinucleotide repeat length in the nuclear polymerase gamma gene (POLg) has been shown to be associated with men with reduced fertility. The present study investigated the frequency of CAG repeat length genotypes and three exonuclease motifs of the POLg in relation to the frequency of mitochondrial nucleotide substitutions. DNA from semen samples of 93 normozoospermic men and 192 non-normozoospermic men was isolated and the specific regions of the genes were amplified by polymerase chain reactions (PCR) and sequenced to identify mutations. The genotypic frequencies of pooled POLg CAG repeat lengths, =10/!=10 heterozygotes and !=10/!=10 homozygotes, were significantly different between normozoospermic and non-normozoospermic men (p p POLg genotype. Of the 17 men with non-synonym...

Energy Technology Data Exchange (ETDEWEB)

A laser beam apparatus and method for analyzing, inter alia, the current versus voltage curve at the point of illumination on a solar cell and the open circuit voltage of a solar cell. The apparatus incorporates a lock-in amplifier, and a laser beam light chopper which permits the measurement of the AC current of the solar cell at an applied DC voltage at the position on the solar cell where the cell is illuminated and a feedback scheme which permits the direct scanning measurements of the open circuit voltage. The accuracy of the measurement is a function of the intensity and wavelength of the laser light with respect to the intensity and wavelength distribution of sunlight and the percentage the dark current is at the open circuit voltage to the short circuit current of the solar cell.

Science.gov (United States)

Sensitive and quick-response nonlinear inductance characteristics are found for high Tc superconducting (YBa/sub 2/Cu/sub 3/O/sub 7-chi/) disk cores at 77K in which soft magnetic BH hysteresis loops are observed. Various quick response magnetic devices such as modulators, amplifiers and sensors are built using these cores. The magnetizing frequency can be set to more than 20 MHz, which is difficult for conventional ferromagnetic bulk materials such as Permalloy amorphous alloys and ferrite. New quick-response fluxgate type magnetic-field sensors are made using ac and dc voltage sources. The former is used for second-harmonic type sensors, while the latter is for voltage-output multivibrator type sensors. Stable and quick-response sensor characteristics were obtained for two-core type multivibrators.

British Library Electronic Table of Contents (United Kingdom)

Abstract To investigate the link between the functionality and the diversity of microbial communities under strong selective pressure from pollutants, two types of mesocosms that simulate natural attenuation and phytoremediation were generated using soil from a site highly contaminated with jet fuel and under air-sparging treatment. An increase in the petroleum hydrocarbon concentration from 4900 to 18-500-mg-kg-1-dw soil simulated a pollutant rebound (postremediation pollutant reversal due to residual contamination). Analysis of soil bacterial communities by denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA gene fragments showed stronger changes and selection for a phylogenetically diverse microbial population in the mesocosms with pollutant-tolerant willow trees. Enumerat...

Energy Technology Data Exchange (ETDEWEB)

In the process of backward Raman amplification (BRA), the leading layers of the seed laser pulse can shadow the rear layers, thus weakening the effective seeding power and affecting parameters of output pulses in BRA. We study this effect numerically and also analytically by approximating the pumped pulse by the ''*-pulse'' manifold of self-similar solutions. We determine how the pumped pulse projection moves within the *-pulse manifold, and describe quantitatively the effective seeding power evolution. Our results extend the quantitative theory of BRA to regimes where the effective seeding power varies substantially during the amplification. These results might be of broader interest, since the basic equations, are general equations for resonant 3-wave interactions.

Energy Technology Data Exchange (ETDEWEB)

Comparative indices are given for the efficiency of phase control of remote-controlled self-compensating high-voltage transmission lines, including a consideration of the power transfer effect between high-voltage line circuits. A description is given of certain circuit variations for performing the technical means of regulating phase shift, and their characteristics which make it possible to evaluate the effect of the phase regulators on the electrical transmission system are also given. An examination is made of problems concerned with the design of lines, relay protection, computation of transfer processes and dynamic stability as well as the computation of over-voltage when shutting off short circuits during amplified electromagnetic ties between line circuits.

Energy Technology Data Exchange (ETDEWEB)

Realization of the scale of spectral responsivity of the detectors in the Directorate of Measures and Precious Metals (DMDM) is based on silicon detectors traceable to LNE-INM. In order to realize the unit of spectral irradiance in the laboratory for photometry and radiometry of the Bureau of Measures and Precious Metals, the new method based on the calibration of the spectroradiometer by comparison with standard detector has been established. The development of the method included realization of the System of Spectral Comparisons (SSC), together with the detector spectral responsivity calibrations by means of a primary spectrophotometric system. The linearity testing and stray light analysis were preformed to characterize the spectroradiometer. Measurement of aperture diameter and calibration of transimpedance amplifier were part of the overall experiment. In this paper, the developed method is presented and measurement results with the associated measurement ...

International Nuclear Information System (INIS)

FELs require tight control of the amplitudes and phase of the fields in two linear accelerator tanks to obtain stable lasing. The accelerator control loops must establish constant, stable, repeatable amplitudes and phases of the rf fields and must have excellent bandwidth to control high-frequency noise components. A model of the feedback loops has been developed that agrees well with measurements and allows easy substitution of components and circuits, thus reducing breadboarding requirements. The model permits both frequency and time-domain analysis. The accelerator control scheme and model are described and the control of noise in feedback loops is discussed, showing how low-frequency-noise components (errors) can be corrected, but high-frequency-noise components (errors) are actually amplified by the feedback circuit. Measurements of noise in both open- and closed-loop modes is shown and comparison is made with results from the model calculations.

International Nuclear Information System (INIS)

Fluidic two diode pumps have been developed for moving highly toxic and for radioactive waste liquors about chemical plant. The pumps have a cylinder into which liquor is initially sucked and then expelled. For situations where no maintenance can be carried out the need has arisen for a fluidic alternator to the solenoid ejector system used on top of the pump cylinder to supply an alternating negative/positive air supply. A fluidic air alternator has been constructed by modifying a small vortex amplifier and inserting an ejector opposite to the throat of the outlet diffuser. The vortex valve ejector is described and performance characteristics are presented. Several developments of the V.V.E. for fluidic pumping and other applications are also reported. (author).

British Library Electronic Table of Contents (United Kingdom)

Evidence suggests that insertion of the IS6110 element is not without consequence to the biology of Mycobacterium tuberculosis complex strains. Thus, mapping of multiple IS6110 insertion sites in the genome of biomedically relevant clinical isolates would result in a better understanding of the role of this mobile element, particularly with regard to transmission, adaptability and virulence. In the present paper, we describe a versatile strategy, referred to as GL-PCR, that amplifies IS6110-flanking sequences based on the construction of a genomic library. M. tuberculosis chromosomal DNA is fully digested with HincII and then ligated into a plasmid vector between T7 and T3 promoter sequences. The ligation reaction product is transformed into Escherichia coli and selective PCR amplification...

Science.gov (United States)

Our long-term goal is to enable highly productive plant species to extract, resist, detoxify, and/or sequester toxic heavy metal pollutants as an environmentally friendly alternative to physical remediation methods. We have focused this phytoremediation research on soil and water-borne ionic and methylmercury. Mercury pollution is a serious world-wide problem affecting the health of human and wild-life populations. Methylmercury, produced by native bacteria at mercury-contaminated wetland sites, is a particularly serious problem due to its extreme toxicity and efficient biomagnification in the food chain. We engineered several plant species (e.g., Arabidopsis, tobacco, canola, yellow poplar, rice) to express the bacterial genes, merB and/or merA, under the control of plant regulatory sequences. These transgenic plants acquired remarkable properties for mercury remediation. (1) Transgenic plants expressing merB (organomercury lyase) extract methylmercury from their growth substrate and ...

Energy Technology Data Exchange (ETDEWEB)

We will describe recent improvements to the SPEAR reflectometer at the Manuel Lujan Jr. Neutron Scattering Center at Los Alamos. One of the changes consists of wider convergent, incident-beam, collimation to take advantage of optical imaging for specular scattering. In addition, the instrument now views a partially coupled liquid hydrogen moderator as opposed to the decoupled moderator that was previous in-place. While the wavelength distribution is poorer, it matches the time (wavelength) resolution of the reflectometer more closely with the angular resolution. Since the integrated intensity of the partially coupled moderator is higher than the decoupled moderator, we show a similar gain in incident beam flux on the sample without loss of the ability to separate fringes. The increases in intensity from the moderator gain and the improved collimation combine to allow us to measure reflectivities with good statistics down to 10{sup -4} in a ...

CERN Document Server

We consider the wireless Rayleigh fading relay channel with finite complex input constellations. Assuming global knowledge of the channel state information and perfect synchronization, upper and lower bounds on the achievable rate, for the full-duplex relay, as well as the more practical half-duplex relay (in which the relay cannot transmit and receive simultaneously), are studied. Assuming the power constraint at the source node and the relay node to be equal, the gain in rate offered by the use of relay over the direct transmission (without the relay) is investigated. It is shown that for the case of finite complex input constellations, the relay gain attains the maximum at a particular SNR and at higher SNRs the relay gain tends to become zero. Since practical schemes always use finite complex input constellation, the above result means that the relay offers maximum advantage over the direct transmission when we operate ...

British Library Electronic Table of Contents (United Kingdom)

The purpose of this study was to evaluate the toxicological effects of feeding the oils of Calophyllum inophyllum, Pentaclethra macrophylla and Terminalia catappa to rats. The effects on physical appearance, feed intake, weight gain, plasma and tissue cholesterol and triacyglycerol levels in rats with 5% of the oils in normal rat feed were determined. Weekly monitoring of the rats showed good physical appearance and steady weight gain, with no mortality recorded for the period of the study. Haematological analysis of the rats indicated that they were not anaemic. Histopathotogical examination of the sections of the heart, liver, kidney and spleen revealed moderate (T. catappa oil) to severe fatty change and necrosis in the liver. Glomerulonephrotic changes in the kidneys of rats fed with T...

British Library Electronic Table of Contents (United Kingdom)

Motivation: High-throughput transcriptomics, proteomics and metabolomics methods have revolutionized our knowledge of biological systems. To gain knowledge from comparative omics studies, strong data integration and visualization features are required. Knowledge gained from these studies is often available in the form of graphs, and their visualization is especially useful in a wide range of systems biology topics, including pathway analysis, interaction networks or gene models. Especially, it is necessary to compare biological models with measured data. This allows the identification of new models and new insights into existing ones. Results: We present MGV, a versatile generic graph viewer for multiomics data. MGV is integrated into Mayday (Battke et al., 2010). It extends Maydays visual...

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.

British Library Electronic Table of Contents (United Kingdom)

Philosophy of science was once a much more socially engaged endeavor, and can be so again. After a look back at philosophy of science in the 1930s?1950s, I turn to discuss the current potential for returning to a more engaged philosophy of science. Although philosophers of science have much to offer scientists and the public, I am skeptical that much can be gained by philosophers importing off-the-shelf discussions from philosophy of science to science and society. Such efforts will likely look like efforts to do applied ethics by merely applying ethical theories to particular contexts and problems. While some insight can be gained by these kinds of endeavors, the most interesting and pressing problems for the actual practitioners and users of science are rarely addressed. Instead, I recom...

British Library Electronic Table of Contents (United Kingdom)

Research in concentrated thermal solar power plants of all types and, in particular, those based on central receiver, namely solar tower plants, has experienced great impetus in the last decade, reaching full commercial operation with the PS10 plant in Spain. In spite of previous demonstration plants testing different receivers and power cycle layouts, this first commercial power plant adopted a cavity receiver generating saturated steam and therefore penalising cycle efficiency in order to gain plant reliability. According to the experience gained, if a competitive Levelised Cost of Electricity is to be reached, capital and maintenance costs must be reduced and efficiencies must be increased. To achieve these goals, modifying the power cycle is deemed essential, whether using superheated ...

International Nuclear Information System (INIS)

In this paper, a neural networks (NN) based adaptive sliding mode controller (SMC) is introduced. The selection of SMC feedback gains is normally based on one operating point and thus the performance of the controller away from the design operating point is, of necessity, a compromise. The adaptive SMC is proposed to overcome the limitations imposed on the effectiveness of the SMC under different operating conditions. Neural networks are used for online prediction of the optimal SMC gains when the operating point changes. The proposed method has been applied to a power system stabilizer (PSS) of a single machine power system. Simulation results are included to demonstrate the performance of the proposed control scheme.

Science.gov (United States)

Using the phasmid vector pSL5, the genomic DNA fragment of T. aquaticus YT1 which contained the thermostable DNA polymerase (Taq-polymerase) gene was cloned. The BglII fragment of this genome locus was subcloned in the BamHI site of the pUC19 plasmid. To optimize the Taq-polymerase gene expression in E. coli cells, the gene was cloned in the correct reading frame regarding the initiation ATG codon of the pPR-TGATG-1 expression vector. The gene expression in this vector was controlled by the phage lambda PR promoter and the temperature-sensitive phage lambda repressor. We used PCR to amplify the short 5'-end fragment of the Taq-polymerase gene coding for the part into which an artificial SacI site was introduced. This site has been used for cloning the PCR product into the pPR-TGATG-1 vector, and the missing gene part was cloned into the KpnI site of the PCR product from the natural cloned gene. The cells of the E. coli PVG-A1 strain, which was obtained in the end, ...

International Nuclear Information System (INIS)

This study demonstrates amplified spontaneous emission (ASE) of the ultraviolet (UV) electroluminescence (EL) from ZnO at #lambda##approx#380 nm in the n-ZnO/ZnO nanodots-SiO_2 composite/p- Al_0_._1_2Ga_0_._8_8N heterojunction light-emitting diode. A SiO_2 layer embedded with ZnO nanodots was prepared on the p-type Al_0_._1_2Ga_0_._8_8N using spin-on coating of SiO_2 nanoparticles followed by atomic layer deposition (ALD) of ZnO. An n-type Al-doped ZnO layer was deposited upon the ZnO nanodots-SiO_2 composite layer also by the ALD technique. High-resolution transmission electron microscopy (HRTEM) reveals that the ZnO nanodots embedded in the SiO_2 matrix have diameters of 3-8 nm and the wurtzite crystal structure, which allows the transport of carriers through the thick ZnO nanodots-SiO_2 composite layer. The high quality of the n-ZnO layer was manifested by the well crystallized lattice image in the HRTEM picture and the low-threshold optically pumped stimulated ...

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 by Member States in many national and ...

UK PubMed Central (United Kingdom)

Background: Little is known about the effectiveness of behavioral strategies to prevent long-term weight gain among adolescents and young adults.Objective: The objective...Full Text Available

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

This book provides the information required to design and prepare construction drawings, and to install, inspect, test, and commission buried piping. Both pressure and gravity piping are covered, including water, steam, gases, and sewers. Directed primarily toward underground industrial piping systems, this is a succinct, well-organized compilation of practical knowledge. Checklists, examples, tables, charts, nomographs, short cuts, and helpful hints gained through years of experience complete this timely and useful ''how to'' book.

CERN Document Server

We discuss the Sundman-Weierstrass theorem of total collapse in its historical context. This remarkable and relatively simple result, a type of stability criterion, is at the crossroads of some interesting developments in the gravitation Newtonian N-body problem. We use it as motivation to explore the connections to such important concepts as integrability, singularities and tyipicality in order to gain some insight on the transition from a predominantly quantitative to a novel qualitative approach to dynamical problems that took place at the end of the 19th century.