gain geometrical principles: Topics by WorldWideScience.org

Dimension reduction in fluid dynamics equations

A basic treatment of the principle of the linac-driven free-electron laser (FEL) is given. The first part of the paper describes the FEL in low-gain approximation, and in the second part the high-gain FEL theory is given. The majority of the treatment describes FELs in one dimensional approximation, neglecting effects by diffraction of radiation and by electron beam emittance. Only in the final section a few remarks on these issues are given. The ambition of the paper is by no means any progress in FEL theory but a clear presentation of basic FEL theory concepts with explicit derivation of the formulae from first principles. (orig.)

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British Library Electronic Table of Contents (United Kingdom)

A method for transforming the Euler and Navier-Stokes equations and a complete system of fluid dynamics equations in three dimensions to a closed system on any moving surface is proposed. As a result, for an arbitrary geometric configuration, the dimension of the equations is reduced by one, which makes them convenient for numerical simulation. The general principles of the method are described, and verifying examples are presented.

2011-01-01

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Principe local-global pour les z\\'ero-cycles sur certaines fibrations au-dessus d'une courbe: II

Free electron laser: general concepts and present state of practical importance

We consider an admissible fibration $\\pi:X\\to\\mathbb{P}^1$ over a curve over a number field, of which the generic fiber $X_\\eta$ is geometrically rationally connected. We suppose that there exists a generalized Hilbertian subset $\\textsf{Hil}$ of $\\mathbb{P}^1$, such that the Brauer-Manin obstruction is the only obstruction to the Hasse principle (resp. to the weak approximation) for $X_\\theta(\\theta\\in \\textsf{Hil}).$ We prove that the Brauer-Manin obstruction is the only obstruction to the Hasse principle (resp. to the strong approximation) for zero-cycles of degree 1 on $X$ in the following cases: $(B_1)$ the index of the generic fibre $X_\\eta$ is equal to 1; $(B_2)$ all fibers are geometrically integral. Then, we obtain some similar results for certain fibrations over $\\mathbb{P}^n$. As a consequence, we obtain the following result: let $X$ be a smooth projective ...

2010-01-01

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Small hemielliptic dielectric lens antenna analysis in 2-D: boundary integral equations versus geometrical and physical optics

Since the advent of the first free electron laser (FEL) in 1976 up to now, a series of principles, configurations and operation modes of these FELs have been devised and partially implemented. The principles refer to transverse FEL, longitudinal FEL, combined FEL, and transverse optical klystron FEL. Configurations may be standard or many-stage and the undulators may be magnetostatic, electrostatic or electromagnetic. The operation regimes may be low-gain Compton type, high-gain Compton type, Raman type, with and without space charge. The operation modes may be the amplification of an external coherent EM radiation, a self-amplified spontaneous emission (SASE), or an oscillator. The paper presents in detail these concepts and the limit between classical approach and the quantum approach of FEL. (Author).

1994-09-21

6

Design of the electromagnetic actuator for vibration control of a flexible rotor

We assess the accuracy and relevance of the numerical algorithms based on the principles of Geometrical Optics (GO) and Physical Optics (PO) in the analysis of reduced-size homogeneous dielectric lenses prone to behave as open resonators. As a benchmark solution, we use the Muller boundary integral equations discretized with trigonometric Galerkin scheme that has guaranteed and fast convergence as well as controllable accuracy. The lens cross-section is chosen typical for practical applications, namely an extended hemiellipse whose eccentricity satisfies the GO focusing condition. The analysis concerns homogeneous lenses made of rexolite, fused quartz, and silicon with the size varying between 3 and 20 wavelengths in free space. We consider the 2-D case with both E- and H-polarized plane waves under normal and oblique incidence, and compare characteristics of the near fields.

2010-01-01

7

Data Mining on Crash Simulation Data

In order to suppress resonance vibrations of a rotor-shaft of rotating machinery, a rotor-shaft system elastically supported by ball bearings which are installed in electromagnetic actuators are proposed and the design method of some compensatory circuits in the controller to control the electromagnetic actuators in the system are explained. These actuators are controlled by the analog PID (proportional, integral, and derivative) controller. The compensation for nonlinearity of electromagnetic force, the negative stiffness of electromagnet, and the time lag of the coil current are discussed and the effective control circuits are proposed. The rotor-shaft system is replaced by the equivalent two-degree-of-freedom system and both impulse and frequency responses are numerically simulated for several parameters of PD-controller gain. By applying the principle of dynamic absorbers, optimum parameters are calculated. The gains of ...

1994-12-21

8

The Principles of Radioactive Waste Management

The work presented in this paper is part of the cooperative research project AUTO-OPT carried out by twelve partners from the automotive industries. One major work package concerns the application of data mining methods in the area of automotive design. Suitable methods for data preparation and data analysis are developed. The objective of the work is the re-use of data stored in the crash-simulation department at BMW in order to gain deeper insight into the interrelations between the geometric variations of the car during its design and its performance in crash testing. In this paper a method for data analysis of finite element models and results from crash simulation is proposed and application to recent data from the industrial partner BMW is demonstrated. All necessary steps from data pre-processing to re-integration into the working environment of the engineer are covered.

2005-01-01

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Probing dark energy with the shear-ratio geometric test

The Principles of Radioactive Waste Management

1995-01-01

10

Variational method for estimating the rate of convergence of Markov Chain Monte Carlo algorithms

We adapt the Jain-Taylor (2003) shear-ratio geometric lensing method to measure the dark energy equation of state, w = pv/?v and its time derivative from dark matter haloes in cosmologies with arbitrary spatial curvature. The full shear-ratio covariance matrix is calculated for lensed sources, including the intervening large-scale structure and photometric redshift errors as additional sources of noise, and a maximum likelihood method for applying the test is presented. Decomposing the lensing matter distribution into dark matter haloes we calculate the parameter covariance matrix for an arbitrary experiment. Combining with the expected results from the cosmic microwave background (CMB) we design an optimal survey for probing dark energy. This shows that a targeted survey imaging 60 of the largest clusters in a hemisphere with five-band optical photometric redshifts to a median galaxy depth of zm = 0.9 could measure w0 ? w(z = 0) to a marginal 1? error of ?w0 = ...

2007-02-01

11

Revisited the mathematical derivation wall thickness measurement of pipe for radiography

We demonstrate the use of a variational method to determine a quantitative lower bound on the rate of convergence of Markov Chain Monte Carlo (MCMC) algorithms as a function of the target density and proposal density. The bound relies on approximating the second largest eigenvalue in the spectrum of the MCMC operator using a variational principle and the approach is applicable to problems with continuous state spaces. We apply the method to one dimensional examples with Gaussian and quartic target densities, and we contrast the performance of the basic Metropolis-Hastings algorithms with a ``smart'' variant that incorporates gradient information into the trial moves. We find that the variational method agrees quite closely with numerical simulations. We also see that the smart MCMC algorithm often fails to converge geometrically in the tails of the target density except in the simplest case we examine, and even then care must be taken to choose ...

2006-01-01

12

Estimating hip fracture risk from digital x-ray image data

Wall thickness measurement of pipe is very important of the structural integrity of the industrial plant. However, the radiography method has an advantage because the ability of penetrating the insulated pipe. This will have economic benefit for industry. Moreover, the era of digital radiography has more advantages because the speed of radiographic work, less exposure time and no chemical used for film development. Either the conventional radiography or digital radiology, the wall thickness measurement is using the tangential radiography technique (TRT). In case, of a large diameter, pipe (more than inches) the determination maximum penetration wall thickness must be taken into the consideration. This paper is revisited the mathematical derivation of the determination of wall thickness measurement based on tangential radiography technique (TRT). The mathematical approach used in this derivation is the Pythagoras theorem and geometrical ...

2007-07-01

13

Monitoring processes and measuring the effectiveness of the management system

The authors propose a method for determining the risk of femoral neck fracture in osteoporotic patients that is not based on densitometric techniques. The method is based on a structural analysis performed by a computer on data taken from a single digital anteroposterior projection of the hip. From the image, the effective cross-sectional area and cross-sectional moment of inertia are computed from attenuation principles. Together with other geometric measurements, these data are used in an engineering analysis to compute the yield strength of the proximal femur, under stress applied through the acetabulum in a one-legged stance. An index of fracture risk based on the ratio of estimated yield strength to body weight is proposed. Ultimately it is expected that this work will allow the clinician to estimate hip fracture risk in osteoporotic patient using widely available existing technology, a goal which has eluded bone density-based methods.

14

Initiation of conformal radiotherapy with a multileaf-collimator - An approach to clinical routine

This document presents the way which the 8th principle of the quality management system 'Process approach' is applied, the principle that is identified and used by international standard ISO 9000. In order to understand the evolution of the management system requirements, as used today in different activities namely, industry, services, and nuclear activities, the authors present an evolution of the quality concept and its traceability to different standards, applicable in time. There are described the requirements of ISO 9001 standard, that represents the most widely spread model for modern organization management and the IAEA concerns related to integration of the above standard requirements into the most recent safety IAEA standard 'The Management System for facilities and activities'. The IAEA Safety Standard GS-R-3 describes a management model considering both the evolution of the quality requirements into the modern management and the ...

2009-10-12

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Study of the Smith-Purcell effect in the relativistic regime

The implementation of a three-dimensional conformal radiotherapy facility in the radiotherapy department of the Heinrich Heine University is described. Complex radiotherapy techniques with commercially available networked systems are introduced to improve clinical work. Over 18 month we have gained clinical experience with a PHILIPS Multileaf Collimator (MLC) mounted on a SL 25 linear accelerator. For a limited period the MLC was used as a conventional blocking device. The standard MLC-shapes are controlled with a stand-alone computer system. In addition, a three-dimensional treatment planning system (3-D-TPS / TMS-Radix, Helax AB) based on convolution/superposition algorithms was recently installed. Treatment optimization is achieved using static field arrangements with complete volumetric computerized tomographic patient data for 3-D-TPS. Conformal adaptation of the 95%-isodose to the Planning Target Volume (PTV, ICRU 50) results in MLC-field-shaping concerning ...

1995-10-01

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Potential of high-average-power solid state lasers

We propose to investigate the spontaneous emission of radiation arising out of the interaction of a relativistic electron beam with a metallic grating (the Smith-Purcell effect). The work will concentrate, primarily, in the 50-120 #mu#m part of the infrared spectrum and will be an extension of the work begun by the Oxford-Dartmouth-Essex collaboration; one of the early objectives of the project will be to develop a quantitative understanding of the power spectrum of the emitted radiation over a wide range of emission angles. In particular, the limits of relativistic peaking of forward directed emission will be investigated. The electron beam will be produced by laser irradiation of a metallic cathode in the terminal of a small Van de Graff accelerator located in the Technische Universitaet, Muenchen. Beam energies will be in the range of 2 - 4 MeV. Initial tests on photoproduction of electrons have yielded 10 mA pulses with a width of about 20 ns. The electron pulse length is long ...

1995-08-21

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Designing a healthy house - an overview

We discuss the possibility of extending solid state laser technology to high average power and of improving the efficiency of such lasers sufficiently to make them reasonable candidates for a number of demanding applications. A variety of new design concepts, materials, and techniques have emerged over the past decade that, collectively, suggest that the traditional technical limitations on power (a few hundred watts or less) and efficiency (less than 1%) can be removed. The core idea is configuring the laser medium in relatively thin, large-area plates, rather than using the traditional low-aspect-ratio rods or blocks. This presents a large surface area for cooling, and assures that deposited heat is relatively close to a cooled surface. It also minimizes the laser volume distorted by edge effects. The feasibility of such configurations is supported by recent developments in materials, fabrication processes, and optical pumps. Two types of lasers can, in ...

1984-09-25

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Second-law efficiency of solar-thermal cavity receivers

There are certain factors to take into account when determining the suitability of a healthy house site. Power lines, agricultural spraying, vehicle exhaust, and industrial pollution are all potential sources of indoor air contamination. It is recommended that a environmental assessment be done to determine whether there are specific sources of contamination. Good drainage is required. The surrounding landscaping should be open and sunlit, and with low maintenance requirements. Decks and fences made from pressure-treated or chemical treated lumber should be avoided. One of the early decisions in the design process is the choice of the structural system. The key with all foundation types is to control moisture, whether from rain, from the ground, or the condensation of moisture from the air with cooling. The construction frame is sealed away from the occupants by the air/vapor barrier, so only in extreme cases is it essential to use alternatives to softwood lumber for framing exterior ...

1999-11-01

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The frequency map for billiards inside ellipsoids

Properly quantified performance of a solar-thermal cavity receiver must not only account for the energy gains and losses as dictated by the First Law of thermodynamics, but it must also account for the quality of that energy. However, energy quality can only be determined from the Second Law. In this paper an equation for the Second-Law efficiency of a cavity receiver is derived from the definition of available energy or availability (occassionally called exergy), which is a thermodynamic property that measures the maximum amount of work obtainable when a system is allowed to come into unrestrained equilibrium with the surrounding environment. The fundamental concepts of the entropy and availability of radiation are explored from which a convenient relationship among the reflected cone half angle, the insolation, and the concentrator geometric characteristics is developed as part of the derivation of the Second-Law efficiency. A comparison is ...

1983-10-01

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Algebraic Principles of Quantum Field Theory II: Quantum Coordinates and WDVV Equation

The billiard motion inside an ellipsoid $Q \\subset \\Rset^{n+1}$ is completely integrable. Its phase space is a symplectic manifold of dimension $2n$, which is mostly foliated with Liouville tori of dimension $n$. The motion on each Liouville torus becomes just a parallel translation with some frequency $\\omega$ that varies with the torus. Besides, any billiard trajectory inside $Q$ is tangent to $n$ caustics $Q_{\\lambda_1},...,Q_{\\lambda_n}$, so the caustic parameters $\\lambda=(\\lambda_1,...,\\lambda_n)$ are integrals of the billiard map. The frequency map $\\lambda \\mapsto \\omega$ is a key tool to understand the structure of periodic billiard trajectories. In principle, it is well-defined only for nonsingular values of the caustic parameters. We present four conjectures, fully supported by numerical experiments. The last one gives rise to some lower bounds on the periods. These bounds only depend on the type of the caustics. We describe the ...

2010-01-01

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Natural and hybrid ventilation in schoolhouses. Requirements on air quality and thermal conditions; Naturlig og hybrid ventilasjon i skolebygninger

This paper is about algebro-geometrical structures on a moduli space $\\CM$ of anomaly-free BV QFTs with finite number of inequivalent observables or in a finite superselection sector. We show that $\\CM$ has the structure of F-manifold -- a linear pencil of torsion-free flat connection with unity on the tangent space, in quantum coordinates. We study the notion of quantum coordinates for the family of QFTs, which determines the connection 1-form as well as every quantum correlation function of the family in terms of the 1-point functions of the initial theory. We then define free energy for an unital BV QFT and show that it is another avatar of morphism of QFT algebra. These results are consequences of the solvability of refined quantum master equation of the theory. We also introduce the notion of a QFT integral and study some properties of BV QFT equipped with a QFT integral. We show that BV QFT with a non-degenerate QFT integral leads to the WDVV equation---the ...

2011-01-01

22

Heating and cooling with geothermal energy: trends and accomplishments; Solutions de chauffage et de climatisation utilisant l`energie geothermique: tendances et realisations

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 with changing types of ...

2000-07-01

23

Fast diagnosis and treatment of crack-like defect injuriousness in nuclear power plant equipment

Recent developments in heat pump technology have made geothermal-based heat exchange systems particularly well-suited for the heating and cooling needs of buildings even in cold climates. The principles of geothermally-coupled heat pump heating and cooling systems were presented. Results of an in-situ study conducted by Hydro-Quebec on the efficiency of the geothermal heat pump system installed at the Saint-Hyacinthe professional school were summarized. This investigation was meant to be a case study of the applicability of these new technologies to the needs of the Quebec market. After the first year of service, the Saint-Hyacinthe system clearly demonstrated its cost effectiveness over conventional systems. It was predicted that geothermal heat pump systems will gain in popularity in Quebec because they can fully meet the heating and cooling needs of public buildings at considerable cost reductions, besides offering considerable environmental ...

1996-03-01

24

Exemplification of the Game Theory application in auctions of exploratory blocks; Um exemplo de aplicacao de Teoria dos Jogos em leiloes de blocos exploratorios

Increasingly stringent safety requirements governing the nuclear industry have made it essential to gain in-depth knowledge of the injuriousness of cracking phenomena in auxiliary and secondary nuclear power plant systems, and to devise methods of rapidly evaluating potentially injurious flaws. The Defect Injuriousness Diagnosis and Treatment Package (DIDTP) discussed in this paper was developed by Framatome, a French-based PWR builder, with this goal in mind. A general description is given of the DIDTP, which is made up of tables and nomographs illustrating the injuriousness of flaws liable to be encountered in the most severely loaded regions of plant systems. The basic principles underlying the DIDTP, together with computational methods and application procedure, are detailed. Two practical examples illustrating the use of the diagnostic system are presented, one applied to the main steam line, the other to gate valve wedges. The types of ...

1985-01-01

25

Entropy driven spontaneous formation of highly porous films from polymer-nanoparticle composites

This article describes a methodology to determine the best strategy in an open bid, where oil and gas fields are the targets for exploration. Based upon the previous bid rounds for a given specific area - the Campos Basin, for that matter -, the data were statistically treated to fit a probability density function, modelling the value of bids offered by the competing companies. By means of techniques and concepts pertaining to Game Theory a balance matrix was built for values of bids made by companies as a function of the company alone in assumed bid rounds. At the end of each british auction, participants of this simultaneous game, using the rationality principle, aimed at winning the tender on the oil field aimed for, through the use of better answers with respect to its rival competitor. The game goal was maximize return on investment purchase in the decisions of lease blocks purchases in the auctions, or to try minimize its opponents gains. ...

2003-07-01

26

Electronic Applications: An Online Text (tm)

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 dependent. The method is applicable, ...

2009-10-21

27

AMTEC thermo-electric conversion. Final report; AMTEC termo-elektrisk konvertering. Slutrapport

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 overhead transparencies, on screen with an Acrobat Reader, or in ...

1999-08-01

28

Statistical modelling for social researchers principles and practice

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 results. It was found ...

1994-10-15

29

Digital Libraries Principles and Practice in a Global Environment

Statistical modelling for social researchers

2008-01-01

30

Factors affecting public and political acceptance for the implementation of geological disposal

Digital Libraries

2004-01-01

31

Scaling of swim speed and stroke frequency in geometrically similar penguins: they swim optimally to minimize cost of transport

This publication identifies conditions which affect (either increase or decrease) public concern for and political acceptance of the development and implementation of programmes for geological disposal of long lived radioactive waste. It also looks at how interested citizens can be associated in the decision making process in such a way that their input enriches the outcome of a more socially robust and sustainable solution. The publication also considers how to optimize risk management, addressing the needs and expectations of the public and of other relevant stakeholders. Factors of relevance for societal acceptance conditions are identified for the different stages of a repository programme and implementation process, from policy development to the realization of the repository itself. Further, they are described and analysed through case studies from several countries, illustrating the added value of broadening the technical dimension with social dialogue and insight into value ...

2009-09-01

32

Spectral properties of cylindrical quasioptical cavity resonator with random inhomogeneous side boundary.

It has been predicted that geometrically similar animals would swim at the same speed with stroke frequency scaling with mass^−1/3. In the present study, morphological and behavioural...Full Text Available

2010-03-07

33

Numerical analysis of the mixing and recombination in the downcomer of an internal pump BWR

A rigorous solution for the spectrum of a quasioptical cylindrical cavity resonator with a randomly rough side boundary has been obtained. To accomplish this task, we have developed a method for the separation of variables in a wave equation, which enables one, in principle, to rigorously examine any limiting case-from negligibly weak to arbitrarily strong disorder at the resonator boundary. It is shown that the effect of disorder-induced scattering can be properly described in terms of two geometric potentials, specifically, the "amplitude" and the "gradient" potentials, which appear in wave equations in the course of conformal smoothing of the resonator boundaries. The scattering resulting from the gradient potential appears to be dominant, and its impact on the whole spectrum is governed by the unique sharpness parameter ?, the mean tangent of the asperity slope. As opposed to the resonator with bulk disorder, the distribution of ...

2011-08-30

34

X-ray microdiffraction and strain gradient crystal plasticity studies of geometrically necessary dislocations near a Ni bicrystal grain boundary

The mixing process of feedwater and reactor water in the downcomer of an internal-pump BWR (Forsmark 1 and 2) has been numerically modelled by means of a CFD-code (FLUENT/UNS). Earlier studies with a very rough model, have shown that a new sparger design is necessary to achieve an effective HWC through improved mixing in the downcomer,. This requires detailed and accurate modelling of the flow, not only for determining the mixing quality but for avoiding negative effects like increased thermal loading of internal parts. Through three 22.5deg models containing a sparger end and half the region between spargers, the principles of a new design have been defined. Their length scales range from 7-14 mm to ca 12 m. Also the steam separator region has been incorporated in the models. A 90deg model shows that they are sufficiently accurate for the actual region. The results cannot be generalised to other regions between spargers due to geometrical ...

1997-12-31

35

Geometric and topological methods for quantum field theory

Abstract not provided

2009-09-30

36

Determination methods of alpha activity ratio

An introduction to recent developments in several active topics at the interface between algebra, geometry, topology and quantum field theory

2010-01-01

37

Smith-Purcell oscillator in an exponential gain regime

The three determination methods of alpha activity ration are described, namely geometric progression method, extrapolation method and curve fitting method. The validity of the geometric progression method is demonstrated in the present work. The "2"3"8Pu/("2"3"9Pu + "2"4"0Pu) evaluated by extrapolation method is compared with that by geometric progression method. Also, the "2"3"8Pu/("2"3"9Pu + "2"4"0Pu)evaluated by curve fitting method is compared with that by geometric progression.

38

A Monograph Assignment as an Integrative Application of Evidence-Based Medicine and Pharmacoeconomic Principles

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.

1988-11-02

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Conversion gain in a Josephson effect mixer

ObjectiveTo describe the development and assessment of monographs as an assignment to incorporate evidence-based medicine (EBM) and pharmacoeconomic principles into a third-year...Full Text Available

2011-02-10

40

Sustainable development, value creation and the capital markets

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

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41

Study on Control of Brain Temperature for Brain Hypothermia Treatment

The minimization of the environmental footprint is the underlying principle of companies involved in sustainable development. At the same time, those companies seek to contribute to the economic and social development of the communities in which they have a presence. The evidence linking sustainable development and value creation are examined in this report targeted to the investment community, which is part of an overall leadership initiative undertaken by the Conference Board of Canada. The benchmarks of companies committed to sustainable development have, on the whole, been matched or exceeded, as shown by recent evidence based on the performance of seven prominent funds and indices managed in Canada, the United States, and western Europe. They are: the Domini Social Equity Fund (American focus), the EcoValue 21{sup TM} (American focus), the Dow Jones Sustainability Group Index (international focus), Storebrand Scudder Environmental Value Fund (European focus), ...

2001-07-01

42

On the Utility of Antiprotons as Drivers for Inertial Confinement Fusion

The brain hypothermia treatment is an attractive therapy for the neurologist because of its neuroprotection in hypoxic-ischemic encephalopathy patients. The present paper deals with the possibility of controlling the brain and other viscera in different temperatures from the viewpoint of system control. It is theoretically attempted to realize the special brain hypothermia treatment to cool only the head but to warm the body by using the simple apparatus such as the cooling cap, muffler and warming blanket. For this purpose, a biothermal system concerning the temperature difference between the brain and the other thoracico-abdominal viscus is synthesized from the biothermal model of hypothermic patient. The output controllability and the asymptotic stability of the system are examined on the basis of its structure. Then, the maximum temperature difference to be realized is shown dependent on the temperature range of the apparatus and also on the maximum gain ...

2003-01-01

43

Large dual-fuel engines with high efficiency and low environmental pollution

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 energy of the injected antiproton beam required to ...

2003-10-20

44

Coherence and statistical properties of photon beams with application to the free-electron laser

This paper deals with the combustion process of the turbocharged dual-fuel engine with regard to improvement to thermal efficiency and exhaust gas emissions. It describes the method of charge-air control used to achieve optimal operation in either a pure diesel engine or a gas engine using the pilot-ignition process (dual-fuel principle). The change-over from gas to diesel operation and vice versa can be made automatically even under full load, i. e. the engine can be changed over from one mode of operation to the other without interruption. The exhaust gas constituents emitted by the dual-fuel engine are less detrimental to the environment than those of other internal-combustion engines: CO is hardly present at all; NOx is no higher than that from good diesel engines, or even lower; SO/sub 2/ does not occur since the natural gas, which is used most frequently, and the pilot fuel are practically free of sulfur; CH (hydrocarbons) in this case are non-toxic and ...

1985-06-01

45

A Geometrical Model for Non-Zero $\\theta_{13}$

The subject of quantum optics has undergone considerable development in the last twenty-five years. Spurred by the invention of the laser, the theoretical understanding of the coherence and statistical properties of optical beams has now attained a stage of maturity where it is possible to treat different kinds of light sources. Over approximately the latter half of this period of development in quantum optics, the free-electron laser (FEL) has been developed to the point where it is now regarded as a tunable light source of considerable versatility, with prospects of producing radiation over a wide range of wavelengths at large levels of power. Since the basic mechanism for radiation gain in an FEL can be understood in classical terms, much of the literature on the subject does not need to venture outside the domain of classical physics. However, it is natural that the coherence and statistical properties of photon beams produced by FEL's should be investigated as ...

46

First-principles investigation of Co wires at Pt(111) step-edges

Based on Friedberg and Lee's geometric picture by which the tribimaximal PMNS leptonic mixing matrix is constructed, namely corresponding mixing angles correspond to the geometric angles among the sides of a cube. We suggest that the three realistic mixing angles which slightly deviate from the values determined for the cube, are due to a viable deformation from the perfectly cubic shape. Taking the best fitted results of $\\theta_{12}$ and $\\theta_{23}$ as inputs, we determine the central value of $\\sin^22\\theta_{13}$ should be 0.0238 with a relatively large error tolerance, this value lies in the range of measurement precision of the Daya Bay experiment.

2011-01-01

47

SS 433 as a black hole candidate

No abstract prepared.

2006-07-01

48

Influence of the curved geometrical shape on the thin shell buckling phenomenon behaviour

The inverse problem of interpreting the SS 433 optical light curves is solved for a geometrically thick model accretion disk around the compact relativistic object: most likely a black hole.

1985-01-01

49

British Library Electronic Table of Contents (United Kingdom)

The present paper deals with instabilities of long homogeneous and isotropic thin shells, characterized by geometrical non-linearities and imperfections, with reference to a bent helicoidally geometrical shape of particular interest for the helicoidal steam generators tube bundle. Apparently no data exist in the literature to describe the non-linear buckling behaviour of curved thin shells under external pressure, thus, the theoretical analyses based on the classical linear elastic theory, as expected, might be inadequate to evaluate the collapse load especially if the curvature is rather large. To the purpose of determining the buckling pressure load the effects of a pre-existing level of geometrical and technological imperfection, unavoidably caused by various manufacturing processes wer...

2009-01-01

50

Intrinsic plasticity complements LTP in parallel fiber input gain control in cerebellar Purkinje cells

Gestational Weight Gain and Risk of Gestational Diabetes Mellitus

Synaptic gain control and information storage in neural networks are mediated by alterations in synaptic transmission, such as in long-term potentiation (LTP). Here, we show using both in...Full Text Available

2010-10-13

51

Effects of Collaborative Group Composition and Inquiry Instruction on Reasoning Gains and Achievement in Undergraduate Biology

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

2010-03-01

52

A research of the development of electricity and natural gas markets and the experiences gained from implementation of the electricity and natural gas market laws

This study compared the effectiveness of collaborative group composition and instructional method on reasoning gains and achievement in college biology. Based on initial student reasoning ability (i.e.,...Full Text Available

2011-03-01

53

The Effects of Dietary Chinese Cabbage Kimchi Juice on the Lipid Metabolism and Body Weight Gain in Rats Fed High-Calories-Diet

In the beginning of 2005 several changes in the electricity and natural gas market law came into effect. This report examines the influence and impact of these changes on the behaviour and development of these markets, looking at the role and position of both the energy industry and customers. The report combines existing data with new research data collected during spring and summer 2006. Whilst the recency of the law changes, along with the simultaneous impact of other market variables limits the salience of any impact, the report nevertheless provides clear and interesting conclusions. In the electricity market, one major legislative change that came into force in the beginning of 2005 concerned the supervision of the reasonableness of electricity distribution pricing. According to the newly adopted ex ante regulation principles, the regulatory authority now determines the guidelines for reasonable pricing prior the start of a predefined regulatory period. So ...

54

KoreaScience (Korea)

Full Text Available

2004-01-01

55

High gain 10.6-micron free-electron laser amplifier

Principles of quantum computing

A 10.6-micron wavelength free-electron laser (FEL) amplifier has been operated using a 45-MeV, 600-A electron beam from the Advanced Test Accelerator (ATA) and a 15.36-meter long electromagnetic wiggler. The peak small signal power gain was 27 dB(500). Gain guiding was observed to confine the amplified laser beam.

1988-11-02

56

Maximization of the connectivity repertoire as a statistical principle governing the shapes of dendritic arbors

This contribution is intended to introduce the principles of quantum computing to those who always wanted to know about quantum computing but never dared to ask. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

2007-11-15

57

Basic Principles of Information Technology Organization in Health Care Institutions

The shapes of dendritic arbors are fascinating and important, yet the principles underlying these complex and diverse structures remain unclear. Here, we analyzed basal dendritic arbors of 2,171 pyramidal...Full Text Available

2009-07-28

58

Principles of air pollution meteorology

Abstract This paper focuses on the basic principles of information technology (IT) organization within health sciences centers. The paper considers the placement of the leader of the...Full Text Available

1997-03-01

59

Principles and Algorithms for Causal Reasoning with ...

This book is divided into the following chapters: the atmospheric boundary layer; atmospheric diffusion; pollutants and their properties; and environmental monitoring and impact.

1990-01-01

60

Meteorological Measurement Guide

... Missionaries and Cannibals, etc.) Since the shooting example is intended to be an example of general autonomous reasoning, we will avoid such ...

1989-05-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

61

Determination of active principle of seeds from Annona muricata L; Determinacao do principio ativo das sementes de Annona muricata L

... 2-22 Page 31. The mercury barometer operates on the principle of air pressure forcing the mercury column up an evacuated tube. ...

1992-01-01

62

X-ray Microdiffraction and Strain Gradient Crystal Plasticity Studies of Geometrically Necessary Dislocations Near a Ni Bicrystal Grain Boundary

No abstract prepared.

2002-07-01

63

Principles of protection: a formal approach for evaluating dose distributions

We compare experimental measurements of inhomogeneous plastic deformation in a Ni bicrystal with crystal-plasticity simulations. Polychromatic X-ray microdiffraction, orientation imaging microscopy and scanning electron microscopy, were used to characterize the geometrically necessary dislocation distribution of the bicrystal after uniaxial tensile deformation. Changes in the local crystallographic orientations within the sample reflect its plastic response during the tensile test. Elastic strain in both grains increases near the grain boundary. Finite element simulations were used to understand the influence of initial grain orientation and structural inhomogeneities on the geometrically-necessary dislocations arrangement and distribution and to understand the underlying materials physics.

2009-01-01

64

Verification of MLC based real-time tumor tracking using an electronic portal imaging device

One of the central issues in radiation protection consists in determining what weight should be given to individual doses in relation to collective or aggregated doses. A mathematical framework is introduced in which such assessments can be made precisely in terms of comparisons between alternative distributions of individual doses. In addition to evaluation principles that are well known from radiation protection, a series of principles that are derived from parallel discussions in moral philosophy and welfare economics is investigated. A battery of formal properties is then used to investigate the evaluative principles. The results indicate that one of the new principles, bilinear prioritarianism, may be preferable to current practices, since it satisfies efficiency-related properties better without sacrificing other desirable properties.

2006-03-01

65

Theoretical Study of Tautomerization Reactions for the Ground and First Excited Electronic States of Adenine.

Purpose: The authors have developed a novel technique using an electronic portal imaging device (EPID) to verify the geometrical accuracy of delivery of dose-rate-regulated tracking (DRRT)....Full Text Available

2010-06-01

66

Subject-specific, multiscale simulation of electrophysiology: a software pipeline for image-based models and application examples

Geometrical structures and energetic properties for different tautomers of adenine are calculated in this study, using multi-configurational wave functions. Both the ground and the lowest singlet excited state potential energy surfaces are studied. Four t...

2002-01-01

67

Retinal Fundus Image Registration via Vascular Structure Graph Matching

Many simulation studies in biomedicine are based on a similar sequence of processing steps, starting from images and running through geometric model generation, assignment of tissue properties, numerical...Full Text Available

2009-06-13

68

Predictive Value of Kushida Index and Acoustic Pharyngometry for the Evaluation of Upper Airway in Subjects With or Without Obstructive Sleep Apnea

Motivated by the observation that a retinal fundus image may contain some unique geometric structures within its vascular trees which can be utilized for feature matching, in this paper, we proposed...Full Text Available

2010-01-01

69

Performance of Buried Pipe Installations, Summary.

Acoustic pharyngometry is a relatively new noninvasive method that quantifies geometrically complexed pharyngeal dimensions. Our study aimed to investigate the predictability and usefulness of acoustic...Full Text Available

2004-10-01

70

Parallel Arrays of Geometric Nanowells for Assembling Curtains of DNA with Controlled Lateral Dispersion

The goal of this research project was to determine the eff ects of geometric and mechanical parameters characterizing the soil-structure interaction developed in a buried pipe installation. Parameters such as pipe ring stiff ness, bedding thickness, trenc...

2010-01-01

71

Model Study of Instant Vehicular Camouflage.

The analysis of individual molecules is evolving into an important tool for biological research, and presents conceptually new ways of approaching experimental design strategies. However, more...Full Text Available

2008-10-07

72

In-vivo coronary flow profiling based on biplane angiograms: influence of geometric simplifications on the three-dimensional reconstruction and wall shear stress calculation

A feasibility study to determine what materials and geometric systems would be required for fabrication of a camouflage system that would instantaneously cover a military vehicle in order to disrupt its characteristic shape or outline. The program involve...

1973-01-01

73

Geometry optimization of Fresnel-collectors with economic assessment

BackgroundClinical studies suggest that local wall shear stress (WSS) patterns modulate the site and the progression of atherosclerotic lesions. Computational fluid dynamics (CFD)...Full Text Available

74

Geometrical Symmetry in Symmetric Galerkin BEM.

The Fresnel solar collector is a promising concept to reduce the electricity cost price in solar thermal power plants. The optical performance of a Fresnel collector depends on material properties, on its geometric layout and on the level of optical accuracy that can be obtained. A variety of geometric parameters, e.g. the height of the absorber, the number, size and distance of primary mirrors in.uence the shading and blocking of rays and the amount of rays missing the absorber. To evaluate the in.uence of the parameter variation regarding the electricity cost price and to yield an optimization, the optical performance is assessed with an annual simulation based on hourly weather-data. To permit a consideration of changes in collector cost according to different geometric layouts, cost factors where allocated to geometric parameters. The paper presents the method and the simulation results of the ...

2004-07-01

75

Environment influences on the aromatic character of nucleobases and amino acids

We consider a symmetric boundary integral formulation associated with a mixed boundary value problem defined on a domain Omega is an element of the set of real numbers(2) with piecewise smooth boundary Gamma. We assume that Omega is mapped onto itself by ...

2001-01-01

76

Age- and Gender-Related Differences in the Geometric Properties and Biomechanical Significance of Intracortical Porosity in the Distal Radius and Tibia

Geometric (HOMA) and magnetic (NICS) indices of aromaticity were estimated for aromatic rings of amino acids and nucleobases. Cartesian coordinates were taken directly either from PDB files deposited...Full Text Available

2010-11-01

77

Aeroelasticity Benchmark ... - NASA Technical Reports Server

Cortical bone contributes the majority of overall bone mass and bears the bulk of axial loads in the peripheral skeleton. Bone metabolic disorders often are manifested by cortical microstructural changes...Full Text Available

2010-05-01

78

A frequency-based approach to locate common structure for 2D-3D intensity-based registration of setup images in prostate radiotherapy

include modeling geometric complexities, coupling between the flow and the .... noted that the AGARD 445.6 wing data set, which has been widely used for .... higher-level computational aeroelastic code validations at transonic flow separation ...

79

Group classification of the Sachs equations for a radiating axisymmetric, non-rotating, vacuum space-time

In many radiotherapy clinics, geometric uncertainties in the delivery of 3D conformal radiation therapy and intensity modulated radiation therapy of the prostate are reduced by aligning the...Full Text Available

2007-07-01

80

Algorithmic tangent stiffness in elastoplasticity and elastoviscoplasticity: A geometric insight

We carry out a Lie group analysis of the Sachs equations for a time-dependent axisymmetric non-rotating space-time in which the Ricci tensor vanishes. These equations, which are the first two members of the set of Newman-Penrose equations, define the characteristic initial-value problem for the space-time. We find a particular form for the initial data such that these equations admit a Lie symmetry, and so defines a geometrically special class of such spacetimes. These should additionally be of particular physical interest because of this special geometric feature.

2006-01-01

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81

British Library Electronic Table of Contents (United Kingdom)

The algorithmic, or consistent, tangent stiffness was introduced to improve the asymptotic convergence rate of the iterative correction algorithm for the evolutive analysis of elastoplastic structures. The original approach is based on a formulation of the elastoplastic law in terms of a plastic multiplier with an analysis which, in general, requires an operator inversion. A geometric description of the method, based on hypersurface theory, is proposed here to provide a clear picture of the algorithmic properties. An estimate of the tangent stiffness associated with finite step elastoplastic and elastoviscoplastic constitutive models is given. It is based on the properties of the projection operator on the elastic domain and avoids operator inversions retaining the beneficial properties of...

2010-01-01

82

Development of a geometrically accurate imaging protocol at 3 Tesla MRI for stereotactic radiosurgery treatment planning

Self-seeded injection-locked FEL amplifier

The purpose of this study is to develop a geometrically accurate imaging protocol at 3 T magnetic resonance imaging (MRI) for stereotactic radiosurgery (SRS) treatment planning. In order to achieve this purpose, a methodology is developed to investigate the geometric accuracy and stability of 3 T MRI for SRS in phantom and patient evaluations. Forty patients were enrolled on a prospective clinical trial. After frame placement prior to SRS, each patient underwent 3 T MRI after 1.5 T MRI and CT. MR imaging protocols included a T1-weighted gradient echo sequence and a T2-weighted spin echo sequence. Phantom imaging was performed on 3 T prior to patient imaging using the same set-up and imaging protocols. Geometric accuracy in patients and phantoms yielded comparable results for external fiducial reference deviations and internal landmarks between 3 T and 1.5 T MRI (mean ?0.6 mm; standard deviation ?0.3 mm). Mean stereotactic ...

2010-11-21

83

Wetland Trends in the Greater Buffalo Area, New York: 1980-2002

A self-seeded free electron laser (FEL) provides a high gain and extraction efficiency for the emitted light. An accelerator outputs a beam of electron pulses to a permanent magnet wiggler having an input end for receiving the electron pulses and an output end for outputting light and the electron pulses. An optical feedback loop collects low power light in a small signal gain regime at the output end of said wiggler and returns the low power light to the input end of the wiggler while outputting high power light in a high signal gain regime.

1998-12-01

84

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

85

Walther process

Theoretical search for optimal pump parameters for observing spontaneous radiation amplification on the {lambda}=41.8-nm transition of Xe IX in plasma

The article focusses on operational experience gained with the following items: scrubbing system with oxidation, regenerative gas preheater, blower/fan, aerosol filter, and product processing. (orig./PW).

1985-09-01

86

Theoretical search for optimal pump parameters for observing spontaneous radiation amplification on the ?=41.8-nm transition of Xe IX in plasma

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)

2004-11-30

87

Preliminary assessment of condensation behavior for hydrocarbon-vapor expansions which cross the saturation line near the critical point

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,?) averaged over the spatial and temporal coordinates were compared with the known gains which had been measured experimentally in Xe8+. 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 Xe8+ 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)

2004-11-30

88

Percutaneous tracheostomy

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 probability for attaining this performance ...

1982-07-01

89

Combined Radiation and Thermal Injury after Nuclear Attack

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

1999-01-01

90

Bullet injuries of the brain

... Except for isolated radiation accidents over the ensuing years, little practical experience has been gained in the treatment of thermal injuries ...

2011-05-13

91

AlGaInP visible vertical cavity surface emitting lasers operating with gain contributions from the [ital n]=2 quantum well transition

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

1974-09-01

92

We report the characteristics of visible vertical cavity surface emitting laser diodes. Wafers are grown such that the Fabry--Perot resonance wavelength changes with position from 690 to 620 nm, overlapping to varying degrees with the [ital n]=1 and [ital n]=2 quantum well gain peaks at [similar to]670 and 650 nm. Gain guided devices are tested across the entire wafer, and pulsed room temperature lasing is observed from 634.6 to 663.2 nm. Our results suggest that gain contributions from the second quantized state are required to overcome high cavity losses in order to achieve lasing.

1993-12-20

93

HORIZON SENSING

Why we don`t need quantum planetary dynamics, or on decoherence and the correspondence principle for chaotic systems

With the aid of a DOE grant (No. DE-FC26-01NT41050), Stolar Research Corporation (Stolar) developed the Horizon Sensor (HS) to distinguish between the different layers of a coal seam. Mounted on mining machine cutter drums, HS units can detect or sense the horizon between the coal seam and the roof and floor rock, providing the opportunity to accurately mine the section of the seam most desired. HS also enables accurate cutting of minimum height if that is the operator's objective. Often when cutting is done out-of-seam, the head-positioning function facilitates a fixed mining height to minimize dilution. With this technology, miners can still be at a remote location, yet cut only the clean coal, resulting in a much more efficient overall process. The objectives of this project were to demonstrate the feasibility of horizon sensing on mining machines and demonstrate that Horizon Sensing can allow coal to be cut cleaner and more efficiently. Stolar's primary goal was ...

2003-03-18

94

Unbiased estimation of particle number using sections--an historical perspective with special reference to the stereology of glomeruli.

Violation of correspondence principle may occur for very macroscopic byt isolated quantum systems on rather short timescales as illustrated by the case of Hyperion, the chaotically tumbling moon of Saturn, for which quantum and classical predictions are expected to diverge on a timescale of approximately 20 years. Motivated by Hyperion, we review salient features of ``quantum chaos`` and show that decoherence is the essential ingredient of the classical limit, as it enables one to solve the apparent paradox caused by the breakdown of the correspondence principle for classically chaotic systems.

1995-08-01

95

Legal Analysis of the Korea Radioactive Waste Management Act in the aspect of IAEA Principles

Methods for estimating particle number may be based on at least three different principles. Two of them, isolation of particles and indirect counting, have been predominant until recently. The new methods based on section pairs (disectors) are unbiased and far more efficient. The three principles and their historical developments are described, emphasizing that the newly developed principles have old roots, which were forgotten until recently. It is concluded, that 'learned societies' combined with individual enthusiasm are material for the spread and development of new ideas.

1989-01-01

96

Displacement ventilation in industry - a design principle for improved air quality

According to the Principles of Radioactive Waste Management, the IAEA SAFETY SERIES NO-111-F, IAEA declared 9 doctrines. The IAEA advised a country that operates nuclear power plant to adopt the principles. As a member of the IAEA, Korea has also discussed about a unified policy and enacting law for radioactive waste management to follow the doctrines. This study analyzed the recently enacted Korea Radioactive Waste Management Act and verified whether the Act successfully follows the doctrine or not

2009-05-01

97

Workshop on Dynamics and Aeroelastic Stability Modeling of ...

There is very little quantitative documentation of actual improvements resulting from the installation of new general ventilation systems in industrial settings. Therefore the performance of the common mixing design principle was compared to the displacement design principle by means of an intervention study in a workshop (V = 12,000 m[sup 3]), where thermoplastics were moulded. An experimental signal-response tracer gas technique was used. In terms of supplying fresh air to the zone of occupancy the displacement system was better than the mixing system by a factor of 2. In terms of the exposure level to a simulated contaminant (tracer gas) the displacement system was better by a factor 1.5-18. (author)

1992-10-01

98

Untitled - NASA Technical Report Server (NTRS)

... Each beam finite element was derived using Hamilton's principle and the following basic assumptions: the beam has an arbitrary amount of pretwist ...

1990-03-14

99

Treatment of persons exposed in radiation accidents or nuclear explosions. Omhaendertagande av skadade vid radiakolyckor och kaernvapenexplosioner

Principle advantages of magnetic forming for part manufacture appear to lie ... to be an area of great potential for the magnetic forming process. We have a ...

100

Standardization of Ajmodadi churna, a polyherbal formulation

The report gives general principles of treatment and care of casualties caused by radiation accidents or nuclear explosions.

1991-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

101

Sensor for monitoring the angle of rotation of a drag

Standardization of herbal formulations is essential in order to assess the quality of drugs, based on the concentration of their active principles. This article reports on standardization of Ajmodadi...Full Text Available

2010-03-01

102

Reenergizing Public Health Through Precaution

The operating principle is examined for an optical sensor for the angle of rotation of the drag ODUP-1 developed and manufactured by the VNII-1. Basic technical data are presented for the experimental model.

1980-01-01

103

Radionuclide X-ray fluorescence analysis. 1: Excitation of X-ray fluorescense radiation by nuclear radiation

The precautionary principle has provoked a spirited debate among environmentalists worldwide, but it is equally relevant to public health and shares much with primary prevention. Its central components...Full Text Available

2001-09-01

104

Quantitative investigation of the crowding effect of Hymenolepis diminuta in Rattus norvegicus

The principles of radionuclide excitation of X-ray fluorescence radiation and its application in

1972-01-01

105

Principles of antibody therapy.

This laboratory exercise demonstrates some basic principles in parasitology by using experimental studies of the relationship of Hymenolepis diminuta with its rodent host.

2000-01-01

106

Nutating Mechanical Transmission (Maroth Drive Principle)

The success of monoclonal antibodies in clinical practice is dependent on good design. Finding a suitable target is the most important part as other properties of the antibody can be altered by genetic...Full Text Available

1992-12-05

107

NASA Technical Reports Server - Radionuclide X-ray fluorescence ...

... d Diameter of ro.'ling element of a cylindrical roller bearing ... L Life (B-10) of a cyl.ndrical roller bearing LACA Contact ratio ...

1974-01-01

108

K-matix theory in relation to MQDT and applications to atomic spectra

Aug 1, 1972 ... The principles of radionuclide excitation of X-ray fluorescence radiation and its application in analytic chemistry are discussed.

109

Foundational Principles for Organizing a Joint Force Staff

A summary of the basic principles of K-matrix theory and examples of its applications to atomic spectra are discussed. (AIP)

1990-04-01

110

Feasibility assessment of performing FFTF unscrammed LOF proof-of-principle and verification data base tests

... Chiefs of Staff, Joint Operation Planning and Execution System (JOPES) Volume I, Planning and Procedures, CJCSM 3122.01A (Washington, DC ...

2009-03-18

111

Dynamic Clamp Analysis of Synaptic Integration in Sympathetic Ganglia

... feasibility studies fftf reactor loss of flow reactor control systems reactor core

1985-06-09

112

Trusts : Directgov - Money, tax and benefits

Advances in modern neuroscience require the identification of principles that connect different levels of experimental analysis, from molecular mechanisms to explanations of cellular functions,...Full Text Available

2007-11-01

113

Wastenet

...events Completing the Trust and Estate Tax Return Completing and filing the trust tax return - filing online, avoiding common mistakes, tax return deadlines and penalties Trusts and Income Tax How different types of trust income are taxed, what management expenses and reliefs can be deducted, understanding the tax pool Trusts and Capital Gains Tax Capital Gains Tax exemptions and reliefs for trustees and notifying HMRC about a trust disposal or ...

114

Prediction of the gain degradation induced by neutrons in dipolar transistors: spectrum dependence, electrical characteristic correlations

Polarization characteristics of spontaneous emission and off-axis coherent gain in a free-electron laser

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.

1974-06-01

115

Particle acceleration by stimulated emission of radiation near a solid-state active medium

The polarization characteristics of spontaneous radiation from relativistic electrons moving through helical and planar wiggler fields are evaluated for imperfect beam injection. Maximum coherent gain in free-electron laser systems are seen to occur in optical fields having these polarization characteristics rather than those of the wiggler magnets. Coupling coefficients for an electron beam skewed at an angle to the optical mode are presented.

1995-11-01

116

British Library Electronic Table of Contents (United Kingdom)

We report acceleration of electrons moving in free space near an active Nd:YAG slab. The power of a non-relativistic beam of electrons has increased by more than 30% when the medium was excited. It is demonstrated experimentally that the energy gained by the electrons is linearly proportional to the energy stored in the medium. Moreover, the energy gain traces closely the population inversion inferred by monitoring the spontaneous radiation.

2011-01-01

117

Preliminary assessment of condensation behavior for hydrocarbon-vapor expansions which cross the saturation line near the critical point

Alternative methods to determine headwater benefits

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 by estimating the extent of condensation ...

1983-01-01

118

On Geometrical Interpretation of Non-Abelian Flat Direction Constraints

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 Alabama River Basin) and a basin that is considered relatively simple hydrologically (the Stanislaus River Basin). In addition to ...

1997-11-10

119

Geometrically anisotropic probes: an improved eddy current technique

In order to produce a low energy effective field theory from a string model, it is necessary to specify a vacuum state. In order that this vacuum be supersymmetric, it is well known that all field expectation values must be along so-called flat directions, leaving the F- and D-terms of the scalar potential to be zero. The situation becomes particularly interesting when one attempts to realize such directions while assigning VEVS to fields transforming under non-Abelian representations of the gauge group. Since the expectation value is now shared among multiple components of a field, satisfaction of flatness becomes an inherently geometrical problem in the group space. Furthermore, the possibility emerges that a single seemingly dangerous F-term might experience a self-cancellation among its components. The hope exists that the geometric language can provide an intuitive and immediate recognition of when the D and F conditions are simultaneously ...

2005-01-01

120

The holographic principle and the language of genes

Geometrically anisotropic eddy current probes are a type of separate function probes especially fit to the detection of defects showing a preferential direction. This kind of flaw induces a coupling between the transmitter and the receiver by guiding eddy currents from the one to the other. On the other hand, this coupling will be almost non-existent in the presence of defects or spurious effects not displaying this geometrical particularity. Basic studies on an elementary two-coil set-up allow the acknowledgment of the intrinsic qualities of such probes: good signal-to-noise ratio, influence field practically constant on the whole defect length, ability to detect bridged defects, insensitivity to lift off. These results can be improved by achieving multicoils probes adapted to different kinds of problems. An application to continuous casting slabs testing yields very interesting results in the detection of cracks, while getting rid of the ...

1987-06-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

121

Tachyons and the search for a preferred frame

We show that the holographic principle in quantum gravity imposes a strong constraint on life. The degrees of freedom of an organism can be estimated according to the theory of Boolean networks, which is constrained by the entropy bound. Hence we can explain the languages in protein sequences or in DNA sequences. The overall evolution of biological complexity can be illustrated. And some general properties of protein length distributions can be explained by a linguistic mechanism.

2008-01-01

122

State of coal gasification for production of fuel gas and synthesis gas

The essential properties of tachyons are described briefly and the 'reinterpretation principle' for tachyons is discussed. The possibility of conducting an experiment analogous to the Michelson-Morley experiment in which a preferred frame may be detected is considered. The existance of a tachyon prefered frame is consistent with the principles of relativity and, if suitable experiments were devised, could provide important evidence for the existence of tachyons. (W.D.L.).

123

Relativistic semigroup, Lorentz group and tachyons. 1

The fundamental principles of coal gasification are discussed including the reactions, their course and influencing parameters. Said principles are illustrated considering heat balance as well as process performance. Coal gasification processes are presented which are under development on a pilot plant scale or which are approved on an industrial scale.

1984-04-01

124

Principles of photon colliders

It is confirmed that actuality of tachyons and some unusual properties may be due to inadequate mathematical formalism based on the Lorentz group. Insertion of tachyons requires in addition to generalization of the causality principle also an extension of the relativistic invariance principle. It is proposed a way in the paper which removes a number of problematic situations in the tachyon problem.

125

Principles of ground relaying for high voltage and extra high voltage transmission lines

Future linear colliders offer unique opportunities to study {gamma}{gamma}, {gamma}e interactions. Using the laser backscattering method one can obtain {gamma}{gamma}, {gamma}e colliding beams with energy and luminosity comparable to the electron-position luminosity or even higher. In this review physical principles of photon colliders are described and various problems, concerning the accelerator, laser, interaction region and luminosity are discussed. Some examples of physical processes are given. ((orig.)).

1995-02-01

126

Anodic protection: theory and practice in the prevention of corrosion

This paper is a tutorial discussion of the basic principles of ground relaying for high voltage and extra high voltage transmission lines. Three different HV configurations are considered: Long lines, lines with a weak mid-point station, and mutually-coupled lines. Application criteria for EHV circuits are also discussed, and specific setting calculations are included where appropriate.

1983-02-01

127

What are $E_{\\infty}$ ring spaces good for?

Theoretical and practical aspects of anodic protection for control of corrosion by a wide range of acidic and alkaline solutions are discussed. Chapters are included concerning strategic importance of metals and alloys in modern industry, applications to industrial equipment, descriptions of equipment used in the technique; design, operation and maintenance; economics, scientific principles, characteristics of potentiostats, laboratory tests and procedures, selected application examples and projected future uses. A section is devoted to electrochemical principles.

1981-01-01

128

Quantum probabilities: an information-theoretic interpretation

Infinite loop space theory, both additive and multiplicative, arose largely from two basic motivations. One was to solve calculational questions in geometric topology. The other was to better understand algebraic K-theory. The Adams conjecture is intrinsic to the first motivation, and Quillen's proof of that led directly to his original, calculationally accessible, definition of algebraic K-theory. In turn, the infinite loop understanding of algebraic K-theory feeds back into the calculational questions in geometric topology. For example, use of infinite loop space theory leads to a method for determining the characteristic classes for topological bundles (at odd primes) in terms of the cohomology of finite groups. We explain just a little about how all that works, focusing on the central role played by E infinity ring spaces.

2009-01-01

129

Non-relativistic Fermions, Coadjoint Orbits of \\winf\\ and String Field Theory at $c=1$

This Chapter develops a realist information-theoretic interpretation of the nonclassical features of quantum probabilities. On this view, what is fundamental in the transition from classical to quantum physics is the recognition that \\emph{information in the physical sense has new structural features}, just as the transition from classical to relativistic physics rests on the recognition that space-time is structurally different than we thought. Hilbert space, the event space of quantum systems, is interpreted as a kinematic (i.e., pre-dynamic) framework for an indeterministic physics, in the sense that the geometric structure of Hilbert space imposes objective probabilistic or information-theoretic constraints on correlations between events, just as the geometric structure of Minkowski space in special relativity imposes spatio-temporal kinematic constraints on events. The interpretation of quantum probabilities is more subjectivist in spirit ...

2010-01-01

130

Modelling gas dynamics in 1D ducts with abrupt area change

We apply the method of coadjoint orbits of \\winf-algebra to the problem of non-relativistic fermions in one dimension. This leads to a geometric formulation of the quantum theory in terms of the quantum phase space distribution of the fermi fluid. The action has an infinite series expansion in the string coupling, which to leading order reduces to the previously discussed geometric action for the classical fermi fluid based on the group $w_\\infty$ of area-preserving diffeomorphisms. We briefly discuss the strong coupling limit of the string theory which, unlike the weak coupling regime, does not seem to admit of a two dimensional space-time picture. Our methods are equally applicable to interacting fermions in one dimension.

1992-01-01

131

British Library Electronic Table of Contents (United Kingdom)

Most gas dynamic computations in industrial ducts are done in one dimension with cross-section-averaged Euler equations. This poses a fundamental difficulty as soon as geometrical discontinuities are present. The momentum equation contains a non-conservative term involving a surface pressure integral, responsible for momentum loss. Definition of this integral is very difficult from a mathematical standpoint as the flow may contain other discontinuities (shocks, contact discontinuities). From a physical standpoint, geometrical discontinuities induce multidimensional vortices that modify the surface pressure integral. In the present paper, an improved 1D flow model is proposed. An extra energy (or entropy) equation is added to the Euler equations expressing the energy and turbulent pressure ...

2011-01-01

132

Local binary pattern based features for sign language recognition

British Library Electronic Table of Contents (United Kingdom)

In this paper we focus on appearance features describing the manual component of Sign Language particularly the Local Binary Patterns. We compare the performance of these features with geometric moments describing the trajectory and shape of hands. Since the non-manual component is also very important for sign recognition we localize facial landmarks via Active Shape Model combined with Landmark detector that increases the robustness of model fitting. We test the recognition performance of individual features and their combinations on a database consisting of 11 signers and 23 signs with several repetitions. Local Binary Patterns outperform the geometric moments. When the features are combined we achieve a recognition rate up to 99.75% for signer dependent tests and 57.54% for signer indep...

2011-01-01

133

Jacobi stability analysis of dynamical systems -- applications in gravitation and cosmology

Geometric configuration factors for polygonal zones using Nusselt's unit sphere

The Kosambi-Cartan-Chern (KCC) theory represents a powerful mathematical method for the analysis of dynamical systems. In this approach one describes the evolution of a dynamical system in geometric terms, by considering it as a geodesic in a Finsler space. By associating a non-linear connection and a Berwald type connection to the dynamical system, five geometrical invariants are obtained, with the second invariant giving the Jacobi stability of the system. The Jacobi (in)stability is a natural generalization of the (in)stability of the geodesic flow on a differentiable manifold endowed with a metric (Riemannian or Finslerian) to the non-metric setting. In the present paper we review the basic mathematical formalism of the KCC theory, and present some specific applications of this method in general relativity, cosmology and astrophysics. In particular we investigate the Jacobi stability of the general relativistic static fluid sphere with a ...

2010-01-01

134

Extraction methods of phase information for X-ray diffraction enhanced imaging

The Energy Laboratory of the University of Houston has developed a computer simulation program called CREAM (Cavity Radiation Exchange Analysis Model) for application to the solar central receiver system. CREAM contains a geometric configuration factor generator based on Nusselt's method. A formulation of Nusselt's method provides the basis for a FORTRAN subroutine NUSSELT. Numerical results from NUSSELT are compared to analytic values and values from Sparrow's method. Sparrow's method is based on a double contour integral and its reduction to a single integral which is a approximated by Gaussian methods. Nusselt's method is adequate for the intended engineering applications, but Sparrow's method is an order of magnitude more efficient in many situations.

1983-05-01

135

Extraction methods of phase information for X-ray diffraction enhanced imaging

X-ray diffraction enhanced imaging (DEI) is one of X-ray phase-contrast imaging methods, which is applied to inspect internal structures of weakly absorbing low-Z samples. The key problem of the DEI is how to extract phase information which is expressed by refraction-angle images from a series of DEI images measured in different positions of the rocking curve of the analyzer. Three effective extraction methods are presented in this paper: the statistical geometric-optics-approximation method, the maximum refraction-angle method and the Gaussian curve fitting method. They are compared with the existing methods, such as the D. Chapman's geometric optics approximation method and the multiple-images statistical method. A 2D computer simulation experiment is performed to draw comparisons of these methods. The experimental results prove that the above three methods have more precision of refraction-angle values than existing methods.

2007-08-21

136

Effects of indirect ionization on the charge state distributions observed with highly charged ion sources

X-ray diffraction enhanced imaging (DEI) is one of X-ray phase-contrast imaging methods, which is applied to inspect internal structures of weakly absorbing low-Z samples. The key problem of the DEI is how to extract phase information which is expressed by refraction-angle images from a series of DEI images measured in different positions of the rocking curve of the analyzer. Three effective extraction methods are presented in this paper: the statistical geometric-optics-approximation method, the maximum refraction-angle method and the Gaussian curve fitting method. They are compared with the existing methods, such as the D. Chapman's geometric optics approximation method and the multiple-images statistical method. A 2D computer simulation experiment is performed to draw comparisons of these methods. The experimental results prove that the above three methods have more precision of refraction-angle values than existing methods.

2007-08-21

137

Did Lobachevsky Have A Model Of His "imaginary Geometry"?

Presently, most charge state distributions produced with highly charged ion sources are predicted with models that approximate the ionization process with the Lotz formula. The Lotz ionization cross sections decrease approximately geometrically with increasing charge state except for ions with very few vacancies, for ions with very few electrons, and for electron impact energies which barely exceed the ionization energy. The geometrical decrease causes these models to predict a maximum abundance for most of the charge states, which is only weakly dependent on the charge state. Experimental results, however, yield much higher abundances for ions with an empty M shell than ions with a partly filled M shell. This difference is explained with indirect ionization processes that are neglected by the Lotz approximation, and normally can be neglected for the ionization of the L shell, but can dominate the ionization of the M shell. (c) 2000 American ...

2000-02-01

138

Design of Reactor Head Structure Assembly Using Axiomatic Design

The invention of non-Euclidean geometries is often seen through the optics of Hilbertian formal axiomatic method developed later in the 19th century. However such an anachronistic approach fails to provide a sound reading of Lobachevsky's geometrical works. Although the modern notion of model of a given theory has a counterpart in Lobachevsky's writings its role in Lobachevsky's geometrical theory turns to be very unusual. Lobachevsky doesn't consider various models of Hyperbolic geometry, as the modern reader would expect, but uses a non-standard model of Euclidean plane (as a particular surface in the Hyperbolic 3-space). In this paper I consider this Lobachevsky's construction, and show how it can be better analyzed within an alternative non-Hilbertian foundational framework, which relates the history of geometry of the 19th century to some recent developments in the ?eld.

2010-01-01

139

Body-and-cad Geometric Constraint Systems

The Reactor Head Structure Assembly(RHSA) is the structure located on the reactor assembly. The purpose of the assembly is providing interface location for cables, preventing pipe whips, prohibiting instruments from becoming missiles, and restraining CEDMs' horizontal motion. On the RHSA, Reactor Disconnect Panels(RDP) are installed. The installation location of RDP is to be decided to minimize the geometric interface with other components. Since the neighborhood of RHSA is crowded due to many connectors and cables, it is necessary to find the good design of RHSA to make an intricate situation attenuated and the required function maintained. The geometric shape and overall configuration of RHSA are determined by axiomatic design approach. The FRs of RHSA are specified and the corresponding DPs are found to satisfy FRs in sequence. The finite element analysis is carried out based on the result of the axiomatic design to evaluate the ...

2007-07-01

140

Performance of hole coupling resonator in the presence of asymmetric modes and FEL gain

Motivated by constraint-based CAD software, we develop the foundation for the rigidity theory of a very general model: the body-and-cad structure, composed of rigid bodies in 3D constrained by pairwise coincidence, angular and distance constraints. We identify 21 relevant geometric constraints and develop the corresponding infinitesimal rigidity theory for these structures. The classical body-and-bar rigidity model can be viewed as a body-and-cad structure that uses only one constraint from this new class. As a consequence, we identify a new, necessary, but not sufficient, counting condition for minimal rigidity of body-and-cad structures: nested sparsity. This is a slight generalization of the well-known sparsity condition of Maxwell.

2010-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

141

Light amplification by S/sub 2/ molecules in the visible spectrum under supersonic cooling of a sulfur-containing gas mixture

We continue the study of the hole coupling resonator for free electron laser (FEL) application. The previous resonator code is further developed to include the effects of the azimutally asymmetric modes and the FEL gain. The implication of the additional higher order modes is that there are more degeneracies to be avoided in tuning the FEL wavelengths. The FEL interaction is modeled by constructing a transfer map in the small signal regime and incorporating it into the resonator code. The FEL gain is found to be very effective in selecting a dominant mode from the azimuthally symmetric class of modes. Schemes for broad wavelength tuning based on passive mode control via adjustable apertures are discussed. 12 refs., 7 figs., 1 tab.

1991-08-01

142

Interplay of the chirps and chirped pulse compression in a high-gain seeded free-electron laser

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.

1985-08-01

143

High-Gain Lasing and Polarization Switch with a Distributed Optical-Klystron Free-Electron Laser

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 beam is important.

2007-03-01

144

Calculation of 3-D free electron laser gain: Comparison with simulation and generalization to elliptical cross section

This Letter reports the first experimental results from the world's first distributed optical-klystron (DOK) free-electron laser (FEL), the DOK-1 FEL, at Duke University. The DOK-1 FEL is a hybrid system, comprised of four wigglers: two horizontal and two helical. With the DOK-1 FEL, we have obtained the highest FEL gain among all storage ring based FELs at 47.8% (#+-#2.7%) per pass. We have also demonstrated that the FEL gain can be enhanced by increasing electron bunching using wigglers with a different polarization. Furthermore, we have realized controlled polarization switches of the FEL beam by a nonoptical means through the manipulation of a buncher magnet.

2006-06-09

145

Statistical study of pulsar rotational braking

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.

1992-08-01

146

Solar flux distribution in cavity receivers with parabolic dish collector

Pacini (1973) has considered basic theoretical expectations regarding the magnetic dipole radiation and unipolar induction of pulsars, taking into account observational results. The present investigation is concerned with the difference between the two braking mechanisms. Attention is also given to a statistical study involving a comparison of the two braking mechanisms with observations. The study makes use of the observational data for the distribution of apparent beamwidth, and a geometrical method. The obtained results agree with the theory of magnetic dipole radiation.

147

Separation of isomers of saturated polycyclic hydrocarbons in packed capillary columns with graphitized thermal carbon black

Thermal absorption with its combined thermal and mechanical loads in a solar receiver does depend significantly on the distribution of incident solar radiation. For a cavity receiver with paraboloid collectar a method is derived which enables the calculation of solar radiation distribution on the areas inside the receiver. The theoretical bases are presented first, and a subsequent example shows the influence of the most important geometric parameters on the distribution of solar radiation.

1982-01-01

148

Recovering quantum graphs from their Bloch spectrum

Using the example of perhydrophenanthrene, perhydroanthracene and cyclopentanodecalin isomers a possibility is shown to use packed capillary columns containing graphitized thermal carbon black for a complete separation of high-boiling mixtures of polycyclic saturated hydrocarbon isomers in accordance with the geometric structure of their molecules.

1981-03-01

149

Proceedings: Image Understanding Workshop

We define the Bloch spectrum of a quantum graph to be the collection of the spectra of a family of Schr\\"odinger operators parametrized by the cohomology of the quantum graph. We show that the Bloch spectrum determines the Albanese torus, the block structure and the planarity of the graph. It determines a geometric dual of a planar graph. This enables us to show that the Bloch spectrum completely determines planar 3-connected quantum graphs.

2011-01-01

150

PhET Teacher Ideas and Activities: Images from Convex Lenses

Sponsored by the Defense Advanced Research Projects Agency the Image Understanding Workshop is a forum for the presentation of new research in vision, image analysis, and geometric modeling. Leading scientists present overviews of projects underway at major universities and corporate research sites, as well as results of individual work. The 1987 volume contains 94 articles and technical reports in two volumes.

1987-01-01

151

On the homology of exotic Springer fibers

This is an inquiry-based module created specifically for use with the PhET simulation Geometric Optics. It includes a lesson plan for teaching about convex lenses, step-by-step student directions, and a set of Power Point "clicker" questions for use as warm-up questions or informal assessment. This resource is part of a larger collection of interactive Java simulations for students of physics, developed by the Physics Education Technology project at the University of Colorado.

2009-05-20

152

Geometrically relating momentum cut-off and dimensional regularization

We determine the structure of the total homology groups of exotic Springer fibers as affine Weyl group representations. As applications, we provide single top/socle property of standard modules in the exotic Deligne-Langlands correspondence (except for root of unity case), an analogue of Verma's theorem, the coincidence of analytic/geometric gradings in the $C ^{\\infty}$-realization of anti-spherical modules of graded Hecke algebras of type $\\mathsf{BC}$ with unequal parameters, among others.

2011-01-01

153

Friction between different wire-bracket configurations and materials.

The $\\beta$ function for a scalar field theory describes the dependence of the coupling constant on the renormalization mass scale. This dependence is affected by the choice of regularization scheme. I explicitly relate the $\\beta$-functions of momentum cut-off regularization and dimensional regularization on scalar field theories by a gauge transformation using the Hopf algebras of the Feynman diagrams of the theories.

2011-01-01

154

Bosonization of conformal ghosts in Witten's string theory

Friction opposes tooth motion whenever sliding mechanics is employed. Understanding what friction is and how to manage it is of paramount importance to the successful practitioner. In this article, the coefficients of friction are summarized between different arch wire-bracket couples as a function of material, geometric, and external parameters. From this vantage point, friction can then be evaluated within the context of other factors that affect sliding-binding and notching. PMID:9573878

1997-09-01

155

Annual average and seasonal variations of residential radon concentration for all the Italian Regions

It is formulated Witten's proposal of a covariant open-string theory in terms of oscillator modes and shown that some basic axioms for the noncommutative geometry are obeyed as algebraic operations, which were defined previously from a geometrical point of view. Our strategy is based on the proper bosonization of the conformal ghost fields.

156

A statistical study of pulsar rotational braking

A representative National Survey to evaluate the exposure to natural sources of ionizing radiation in dwellings was conducted in all the 21 Italian Regions from 1989 to 1998, and the complete results are reported in this paper. Radon concentration was measured for two consecutive 6-month periods (generally covering the spring-summer and autumn-winter seasons) in one room, usually the main bedroom, of each surveyed dwelling. Validated radon concentration measurements were obtained for a total of 5631 dwellings, distributed in 232 towns (all the 50 towns with more than 100,000 inhabitants and 182 randomly sampled smaller towns). The national average, weighted by the population of each Region, of the annual radon concentration is 70Bqm{sup -3}, the geometric mean is 52Bqm{sup -3}, and the geometric standard deviation is 2.1. The fraction of dwellings with a radon concentration exceeding the reference levels of 150, 200, 400, and 600Bqm{sup -3} are ...

2005-11-15

157

A simple model of dimensional collapse

A previous study described the basic theoretical expectations of the magnetic dipole radiation and unipolar induction of pulsars and presented observational results. This paper further discusses the difference between the two braking mechanisms and analyses the results of a statistical study through observed data of apparent beamwidth's distributions and a geometrical method. The theory of magnetic dipole radiation of pulsars agrees with the observations. Unipolar induction as a braking mechanism is not consistent with the observations.

158

ch6-1 - NASA's History Office

We consider a simple model of d families of scalar field interacting with geometry in two dimensions. The geometry is locally flat and has only global degrees of freedom. When d0 it collapses to a one dimensional manifold. The model has some, but not all, of the characteristics believed to be features of the full theory of conformal matter interacting with quantum gravity which has local geometric degrees of freedom.

1996-01-01

159

Using data warehousing and OLAP in public health care.

Composed of Sun sensors, the Canopus sensor, the inertial reference unit, ... The heart of the system was a 100-pound-thrust rocket whose hypergolic, ... The spacecraft's low-gain antenna picked up all incoming signals from the NASA-JPL ...

160

The influence of tethered epidermal growth factor on connective tissue progenitor colony formation

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

2000-01-01

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161

The Urologist's View of Male Overactive Bladder: Discrepancy between Reality and Belief in Practical Setting

Strategies to combine aspirated marrow cells with scaffolds to treat connective tissue defects are gaining increasing clinical attention and use. In situations such as large defects where initial...Full Text Available

2009-09-01

162

System Design and Applications of the Ultra Small ... - GLTRS - NASA

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

2010-05-01

163

Student Understanding of the First and Second Laws of Thermodynamics

The advanced technologies of Ka-Band systems such as high gain spot .... sometimes used based on link requirements for a specific application. .... received at NASA LeRC from a Ku-band satellite and retransmitted to the USAT at Ka-Band. .... and to the Office of Management and Budget, Paperwork Reduction Project ...

164

Structural basis of growth-related gain and age-related loss of bone strength

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.

2006-09-30

165

Status of the Lawrence Berkeley Laboratory and Lawrence Livermore National Laboratory free electron laser (FEL)

If bone strength was the only requirement of skeleton, it could be achieved with bulk, but bone must also be light. During growth, bone modelling and remodelling optimize strength, by depositing bone...Full Text Available

2008-07-01

166

Sp1/NF?B/HDAC/miR-29b Regulatory Network in KIT-driven Myeloid Leukemia

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.

1983-09-19

167

Rapid, reversible activation of AgRP neurons drives feeding behavior in mice

SUMMARYThe biologic and clinical significance of KIT overexpression that associates with KIT gain-of- function mutations occurring in subsets...Full Text Available

2010-04-13

168

PyEEG: An Open Source Python Module for EEG/MEG Feature Extraction

Several different neuronal populations are involved in regulating energy homeostasis. Among these, agouti-related protein (AgRP) neurons are thought to promote feeding and weight gain; however, the...Full Text Available

2011-04-01

169

PYRROLO[1,2-b][1,2,5]BENZOTHIADIAZEPINES (PBTDs) induce apoptosis in K562 cells

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

2011-01-01

170

Outpatient percutaneous coronary intervention: Ready for prime time?

BackgroundThe objective of this study was to gain insight into the molecular mechanism of induced cell death (apoptosis) by PYRROLO [1,2-b][1,2,5]BENZOTHIADIAZEPINES...Full Text Available

171

NASA TN D-7790 - NASA Technical Report Server (NTRS)

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

2007-10-01

172

Mitochondrial transmission during mating in Saccharomyces cerevisiae is determined by mitochondrial fusion and fission and the intramitochondrial segregation of mitochondrial DNA.

Pedel. 24.8. 0. 0. 38.0. 21.7. 35. Page 38. TABLE VII.- PREFILTER AND FEEDBACK GAIN MATRICES G AND F. FOR DECOUPLED LATERAL AND LONGITUDINAL CONTROLS ...

173

Maternal Overweight Programs Insulin and Adiponectin Signaling in the Offspring

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

1997-07-01

174

Light amplifier with filtering of spontaneous background

Gestational exposure to maternal overweight (OW) influences the risk of obesity in adult life. Male offspring from OW dams gain greater body weight and fat mass and develop insulin resistance when fed...Full Text Available

2010-06-01

175

Integrity of the tubes used in vertical and horizontal steam generators

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.

1980-06-01

176

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.

2011-01-01

177

Increased expression of cholesterol transporter ABCA1 is highly correlated with severity of dementia in AD hippocampus

Horizontal steam generators: Problems and prospects

To gain insight into ATP-binding cassette transporter A1 (ABCA1) function and its potential role in AD pathology, we analyzed the expression of the cholesterol transporter ABCA1...Full Text Available

2010-03-08

178

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.

2011-01-01

179

Gene-Environment Interactions and Epigenetic Basis of Human Diseases

Functional Analysis of Neurovascular Adaptations to Exercise in the Dentate Gyrus of Young Adult Mice Associated With Cognitive Gain

Most human diseases are related in some way to the loss or gain in gene functions. Regulation of gene expression is a complex process. In addition to genetic mechanisms, epigenetic causes are...Full Text Available

2008-01-01

180

Fully quantized many-particle theory of a free-electron laser

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

2009-10-01

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181

FGF18 is required for normal cell proliferation and differentiation during osteogenesis and chondrogenesis

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 from several electrons induces deviations ...

1983-02-01

182

Epicuticular Wax Accumulation and Fatty Acid Elongation Activities Are Induced during Leaf Development of Leeks1

Fibroblast growth factor (FGF) signaling is involved in skeletal development of the vertebrate. Gain-of-function mutations of FGF receptors (FGFR) cause craniosynostosis, premature fusion of the skull,...Full Text Available

2002-04-01

183

DEMONSTRATION/EVALUATION OF THE CAT-OX FLUE GAS DESULFURIZATION SYSTEM

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

1998-03-01

184

Current practices in spatial analysis of cancer data: data characteristics and data sources for geographic studies of cancer

The report gives a comprehensive summary of the experience gained and the problems encountered during the Cat-Ox demonstration program. The report outlines the process design and construction, as well as operating experience and problems. Test results and conclusions derived from...

185

Computer code analysis of steam generator in thermal-hydraulic test facility simulating nuclear power plant.

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

186

Average output lasing power of a He-Ne laser as a function of the modulation frequency of resonator losses

In the study three loss-of-feedwater type experiments which were preformed with the PACTEL facility has been calculated with two computer codes. The purpose of the experiments was to gain information about the behaviour of horizontal steam generator in a ...

1995-01-01

187

Animal models of human amyloidoses: Are transgenic mice worth the time and trouble?

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)

1976-09-01

188

An Undergraduate Course to Bridge the Gap between Textbooks and Scientific Research

The amyloidoses are the prototype gain of toxic function protein misfolding diseases. As such, several naturally occurring animal models and their inducible variants provided some of the first...Full Text Available

2009-08-20

189

AEROSPACE MEDICINE AND BIOLOGY - NASA Technical Reports Server

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

2011-03-01

190

A discrete cell model with adaptive signalling for aggregation of Dictyostelium discoideum.

Learning curve models have gained widespread acceptance as a technique for analyzing and ...... flight segment in F4 pilots p 163 A91-30966. WILSON, JOHN W . ...

191

A case of an uncommon anatomic variation of the middle turbinate associated with headache

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

1997-03-29

192

Stability and chaotification of vibration isolation floating raft systems with time-delayed feedback control

SummaryHeadache due to the pressure of nasal mucosa in the absence of inflammation of the nose and paranasal sinuses is a clinical entity that has gained wide acceptance. Concha bullosa...Full Text Available

2010-06-01

193

Lasing below 200 nm in the NIJI-IV compact storage-ring-based free electron laser

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.

2011-09-01

194

Improved economies in the use of natural gas

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.

2004-08-01

195

Energy-spectroscopic studies of electron-capture processes of low-energy, highly stripped F and Ne ions in collisions with He atoms

Preheating processed materials and combustion air can result in processing and fuel-efficiency gains in industrial smelting furnaces. For example, fuel consumption in reverberatory furnaces used in copper smelting would drop by as much as 63% at the same throughput by preheating the charge in a countercurrent mode to 1400/sup 0/F by exhaust gases that have an initial temperature of 2500/sup 0/F. Concurrent charge preheating would result in a maximum decrease of 46% in natural gas consumption. An analysis of these gains also provides equations for calculating investment returns and nomographs for optimizing charge-preheating temperatures for reverberatory furnaces.

1981-12-01

196

Analysis of a bayonet tube heat exchanger

The electron-capture processes of highly stripped ions of Fq+ (q=6,7,8) and Neq+ (q=7,8,9) in collisions with He atom were investigated using the energy-gain spectroscopy technique. A single dominant peak is observed in most of the energy-gain spectra except for the Ne7+ and Ne9+ spectra, in which two peaks are observed corresponding to the one-electron capture process into levels with different principal quantum number n.

1984-03-01

197

A strategic risk approach to knowledge management

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)

2001-01-01

198

British Library Electronic Table of Contents (United Kingdom)

In today's business environment, strong forces of competition and globalization have created an urgency to focus how an organization controls and nurtures its intellectual capital. The concept of knowledge and its management has gained currency and momentum as technology has enabled thoughts and ideas to be more easily generated and distributed. With increased application of technologies such as the Internet, Customer Relationship Management (CRM), and advanced software capabilities, it has been suggested the time has come for discussion of a new paradigm for knowledge management. Toward that end, this article examines the knowledge literature and reviews the experience of a leading private healthcare group, with the objective of gaining a better understanding of the issues that confront e...

2007-01-01

199

Remodeled Relativity Theory

Is Gold Really Softer than Silver? HSAB Principle Revisited

This remodeled form of Einstein's relativity theories retains and incorporates only experimentally proven principles. It is based on a generalized law for spinning and rotational motions, which is in fact the conservation law of momentum vector direction, and can be successfully used for the precision computation of planetary and lunar orbits. The most fundamental principles of the remodeled relativity theory are the conservation laws of energy and momentum. Based on experience of relativity experiments, we adopted the principles that energy level is the underlying cause for relativistic effects, and that mass is expressed by the relativistic energy equation from Einstein. From space age ephemeris generation experience and following nature's way to conserve energy and momentum, we found reason to replace the concept of "relativity of all frames" with that of "nature's preferred frame", which helped us to escape Einstein's ...

2007-01-01

200

The free electron laser klystron amplifier concept

A detailed comparison of the softness of gold and silver has been reported in the light of hard soft acid base (HSAB) principle. Gold and silver nanoparticles in organic media (i.e., organosol) have been exploited individually to establish the principle. Sulfur and nitrogen were employed as soft and borderline donating atoms to examine the metal-ligand interactions. In this regard, thiols and amines have been considered as interacting ligands with sulfur and nitrogen donor atoms respectively. The stronger affinity of gold towards softer sulfur donor as compared to nitrogen and conversely a reasonable interaction of silver nanoparticles with both the atoms authenticate the softer nature of gold nanoparticle as compared to silver one.

2006-02-15

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201

Yield improvement for lost mould rapid infiltration forming process by a multistage fractional factorial split plot design

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 compression. Conventional, short-wavelength FEL amplifier and distributed optical ...

202

Who Should Receive Life Support During a Public Health Emergency? Using Ethical Principles to Improve Allocation Decisions

Statistical design of experiments is widely used among scientists and engineers to understand influential factors in a laboratory or manufacturing process. One of the underlying principles of...Full Text Available

2009-07-01

203

Utilization of a Marketing Strategy at Naval Regional Medical Center Great Lakes, Great Lakes, Illinois.

A public health emergency such as an influenza pandemic will lead to shortages of mechanical ventilators, critical care beds, and other potentially life saving treatments. This will raise difficult...Full Text Available

2009-01-20

204

Underlying Principles of Natural Selection in Network Evolution: Systems Biology Approach

The study examines the question of whether or not civilian marketing practices and principles can be applied in the military care setting. Using the NRMC Great Lakes as a basis, the answer is yes--consumers of military medical care are ready to be the rec...

1983-01-01

205

Theory of chemical reaction dynamics. Volume 3

Systems biology is a rapidly expanding field that integrates diverse areas of science such as physics, engineering, computer science, mathematics, and biology toward the goal of elucidating the underlying...Full Text Available

206

Theoretical study of lithium isotope separation by displacement chromatography

This book examines some of the basic principles behind chemical reaction kinetics. Topics considered include the classical trajectory approach to reactive scattering; periodic orbits and theory of reactive scattering; and semiclassical reactive scattering.

1985-01-01

207

The healthy communities movement and the coalition for healthier cities and communities.

Lithium isotope separation by displacement chromatography is studied using fundamental principles; the equations are derived assuming theoretical stages in lithium adsorption bands. The concentration profiles in the band are calculated numerically under unsteady state.

1982-01-01

208

Tachyons and the instability of physical systems

Part One of this article describes the principles and origins of the Healthy Communities movement. Part Two describes the Coalition for Healthier Cities and Communities, a national network of partnerships...Full Text Available

2000-03-01

209

Strategic principles workshops: Discussion drafts and workshop notes

The problem on the ratio between the instability of physical systems and tachyons is discussed. It is shown that the tachyons participation in the real physical process of the system rearranging does not contradict any principles. It is noted that the tachyons constitute the most significant element of the systems, identifying the instability relative to the phase transition into the stable state.

210

Soft commutated direct current motor [summary of proposed paper

The Office of Civilian Radioactive Waste-Management in the Department of Energy (DOE) is responsible for disposing of this nation`s spent fuel and high-level radioactive waste in a manner that protects the health and safety of the public and the quality of the environment. Although embodied in the Federal repository program that began with studies in the late 1950s, this mission was explicitly established by the Nuclear Waste Policy Act of 1982 and reaffirmed by the Nuclear Waste Policy Amendments Act of 1987. To fulfill our mission, we are developing a waste management system consisting of a geologic repository for permanent disposal deep beneath the surface of the earth, a facility for monitored retrievable storage, and a system for transporting the waste. This discussion draft was developed to help involve parties affected by or interested in the waste-management program in the formulation of the basic principles on which the program will be based. It reviews ...

1991-09-01

211

Short rotation coppice: a guide to cold storage of planting material

A novel soft commutated direct current (DC) motor is introduced. The current of the commutated coil is intentionally drained before the brush disconnects the coil. This prevents the spark generation that normally occurs in conventional DC motors. A similar principle can be applied for DC generators.

1998-10-22

212

Recovering casuality for tachyons even in macrophysics

This guide has been written to introduce growers of Short Rotation Coppice (SRC) to the principles and need for cold storage of planting material. The main types of cold store are described. It also provides assistance in the selection of suitable stores and how these are located nationally. (author)

1999-07-01

213

Quantum computing and the chaotic amplifier

In this paper it is shown that the ''third postulate'' of special relativity (i.e. the so-called ''Reinterpretation principle'' by Stueckelberg and by Faynmam) is enough to implement the law of retarded casuality for tachyons even in macro-physics, when usual macro-objects interact with micro-tachyons and macro-tachyons.

214

QED processes on e"+e"#+-#-, ep-, #gamma##gamma#-colliders

A new model for computations is considered which combines the quantum computer with the chaotic dynamics amplifier, based on the logistic map. We discuss the satisfiability problem and argue that the problem can, in principle, be solved in polynomial time if one uses the new model for computations.

2003-12-01

215

Protons, heavy ions, radioactive beams: new ways for radiotherapy. Protons, ions lourds, faisceaux radioactifs: de nouvelles voies pour la radiotherapie

The present status of theoretical description of deep-inelastic lepton-nucleon as well as large angle Bhabha scattering with account for radiative corrections in the leading and next-to-leading approximations are reviewed. Also considered is a build-up principle and physical programme of the photon-photon colliders

216

Principles of room air flow; Grundlagen der Raumluftstroemung

In this article, the author presents the principles, applications and advantages of proton and heavy ion beams used for radiotherapy.

1993-07-01

217

Principle of pulse frequency measurement and methods for improving frequency meters accuracy

The following subjects are dealt with: physics of indoor air flow, flow in individual rooms, exchange of air and pollution between individual building zones and with the outside world, thermal coupling with the building shell, thermal comfort and air quality, evaluation of the ventilation. figs., tabs., refs.

1994-12-31

218

Principle of pulse frequency measurement and methods for improving frequency meters accuracy

Specificity of the pulses mean frequency measurement (the pulses being generated in a stochastic process) is described. Status of the domain of analog frequency meters is presented. Methods of increasing accuracy of such meters are discussed.

1980-01-01

219

Path integral of the hydrogen atom, Jacobi's principle of least action and one-dimensional quantum gravity

Specificity of the pulses mean frequency measurement (the pulses being generated in a stochastic process) is described. Status of the domain of analog frequency meters is presented. Methods of increasing accuracy of such meters are discussed. (author).

1980-01-01

220

Monitoring potential neurotoxic effects of hazardous waste disposal

A path integral evaluation of the Green's function for the hydrogen atom initiated by Duru and Kleinert is studied by recognizing it as a special case of the general treatment of the separable Hamiltonian of Liouville type. The basic dynamical principle involved is identified as Jacobi's principle of least action for given energy which is reparametrization invariant, and thus the appearance of a gauge freedom is naturally understood. The separation of variables in the operator formalism corresponds to a choice of gauge in the path integral, and the Green's function is shown to be gauge independent if the operator ordering is properly taken into account. Unlike the conventional Feynman path integral, which deals with a space-time picture of particle motion, the path integral on the basis of Jacobi's principle sums over orbits in space. We illustrate these properties by evaluating an exact path integral of the Green's ...

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

221

Magnetic mirror fusion systems: Characteristics and distinctive features

This report reviews neurotoxicological principles relevant to situations of hazardous waste disposal. Some of the diagnostic techniques currently used for field assessment of nervous system dysfunction...Full Text Available

1983-02-01

222

Magnetic and chemical changes in marine sediments

A tutorial account is given of the main characteristics and distinctive features of conceptual magnetic fusion systems employing the magnetic mirror principle. These features are related to the potential advantages that mirror-based fusion systems may exhibit for the generation of economic fusion power.

1987-08-10

223

Impossibility of a scalar tachyon

A considerable amount of chemical knowledge of marine sediments has been acquired in recent years but has not yet been utilized by paleomagnetists. On the other hand, geochemists are often unaware of the usefulness of numerous magnetic techniques. In this review we try to bridge this gap, and in particular, we outline many of the chemical and magnetic principles that should allow paleomagnetists to better identify and undertand chemical changes that affect the magnetic properties of marine sediments. The chemical principles include those for distinguishing the four major sources of sediments (continental, biological, authigenic/hydrogenous, volcanic/hydrothermal) from one another by determining elemental abundance distributions, as well as for investigating the stabilities of mineral phases relative to changes in pE and pH. The magnetic principles include the effects of authigenesis and diagenesis on magnetic properties, ...

1980-05-01

224

How to play fair in an environmental context

It is the purpose of this paper to prove that a preferred space direction is coupled with each tachyon and, consequently, scalar tachyons, are impossible in principle. Even the notion of a scalar faster-than-light particle cannot be defined in a relativistically invariant way.

1982-06-01

225

Wastenet

The principle of need selecting the game of Chicken ... The Chicken (e.g.Rasmusen, 1994) tells the story of two car drivers ...6 Therefore the Chicken is also characterised as a dilemma of common aversion (Rapoport &

226

First Measurements of the Inclined Boron Layer Thermal-Neutron Detector for Reflectometry

First Measurements of the Inclined Boron Layer Thermal-Neutron Detector for Reflectometry

A prototype detector based on the inclined boron layer principle is introduced. For typical measurement conditions at the Liquids Reflectometer at the Spallation Neutron Source, its count rate capability is shown to be superior to that of the current detector by nearly two orders of magnitude.

2010-01-01

227

Feynman lectures on physics, quantum mechanics; Le cours de physique de Feynman mecanique quantique

A prototype detector based on the inclined absorber layer principle is introduced. For the Liquids Reflectometer at the Spallation Neutron Source, it is shown to be a significant improvement over its current detector, which imposes an instantaneous count rate limitation of 50 kcps.

2008-10-01

228

Energy extraction (a reversible process) from a Kerr source by tachyons

This course is based upon lectures in physics given by Professor Feynman at the California institute of technology during 1961 and 1962. This volume is dedicated to quantum physics, semiconductors, symmetry and advanced principles of physics.

2000-07-01

229

The author demonstrates through a specific example that it is possible to extract rotational energy from a Kerr source (in principle, of arbitrary size but not turned black) through a reversible process by suitably injecting tachyons. (Auth.).

230

Defect modelling

DESIGN PRINCIPLES OF INSECT AND VERTEBRATE VISUAL SYSTEMS

Calculations, drawing principally on developments at AERE Harwell, of the relaxation about lattice defects are reviewed with emphasis on the techniques required for such calculations. The principles of defect modelling are outlined and various programs developed for defect simulations are discussed. Particular calculations for metals, ionic crystals and oxides, are considered. (UK).

1980-03-01

231

Compact Image Slicing Spectrometer (ISS) for hyperspectral fluorescence microscopy

A century ago, Cajal noted striking similarities between the neural circuits that underlie vision in vertebrates and flies. Over the past few decades, structural and functional studies have...Full Text Available

2010-04-15

232

Climatology: An atmospheric science

An image slicing spectrometer (ISS) for microscopy applications is presented. Its principle is based on the redirecting of image zones by specially organized thin mirrors within a custom fabricated...Full Text Available

2009-07-20

233

Circadian Rhythm Sleep Disorders: Part I, Basic Principles, Shift Work and Jet Lag DisordersAn American Academy of Sleep Medicine Review

In this college-level introductory text the authors outline the fundamental principles of meteorology. The text is divided into three sections: meteorology, regionalization of climate, and climate change. Numerous charts, graphs, and photographs are displayed with each subject. A glossary of terms is also provided at the end of the book.

1993-01-01

234

Characterization of discrete classes of binding sites of human serum albumin by application of thermodynamic principles.

Objective:This the first of two articles reviewing the scientific literature on the evaluation and treatment of circadian rhythm sleep disorders (CRSDs), employing the methodology...Full Text Available

2007-11-01

235

Biobank resources for future patient care: developments, principles and concepts

The binding interactions of four ligands differing in acid-base properties with human serum albumin (HSA) were examined as a function of temperature. Binding to HSA decreased with increasing temperature...Full Text Available

1994-08-15

236

Atomic-scale insight and design principles for turbine engine thermal barrier coatings from theory

The aim of the overview is to give a perspective of global biobank development is given in a view of positioning biobanking as a key resource for healthcare to identify new potential markers that can...Full Text Available

237

An Introduction to Malware

To maximize energy efficiency, gas turbine engines used in airplanes and for power generation operate at very high temperatures, even above the melting point of the metal alloys from which they are...Full Text Available

2011-04-05

238

Airborne dial remote sensing of the Arctic ozone layer

These notes intended for use in DTU course 02233 on Network Security give a short introduction to the topic of malware. The most important types of malware are described, together with their basic principles of operation and dissemination, and defences against malware are discussed.

239

Air shifting diffusion; Diffusion d'air par deplacement

A combined ozone and aerosol LIDAR was developed at the Institute of Physics of the Atmosphere at the DLR in Oberpfaffenhofen. It is an airborne version, that, based on the DIAL-principle, permits the recording of two-dimensional ozone profiles. This presentation will focus on the ozone-part; the aerosol subsection will be treated later.

1992-01-01

240

ARISE: American renaissance in science education

The technique of air diffusion by shifting presents several advantages in terms of thermal comfort, indoor air quality and energy conservation. This book presents the principle, dimensioning, and implementation of air shifting diffusion systems. (J.S.)

2001-07-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

241

A path model of factors influencing morbidity and mortality in Ontario feedlot calves.

The national standards and state derivatives must be reinforced by models of curricular reform. In this paper, ARISE presents one model based on a set of principles--coherence, integration of the sciences, movement from concrete ideas to abstract ones, inquiry, connection and application, sequencing that is responsive to how people learn.

1998-09-14

242

Various clinical situations and their influence on linear occlusion in treating combination syndrome: a discussion of treatment options.

The principles of path analysis and causal modelling are discussed. Path analysis was applied to three data sets to assess the relationship between group characteristics (number per group and "mixing"...Full Text Available

1986-01-01

243

Toward a predictive atomistic model of ion implantation and dopant diffusion in silicon

Eliminating anterior tooth contact is paramount when treating combination syndrome. It is possible to do so through the use of linear occlusion with a non-interceptive arrangement and the bilateral fulcrum of protrusive stability. The presence of mandibular anterior teeth often complicates this procedure. When establishing the horizontal plane of occlusion, clinical circumstances often necessitate modifications; nevertheless, certain principles must be incorporated into the design of the prostheses. Clinical circumstances may dictate altering the approach but these principles must be maintained to eliminate anterior hyperfunction. PMID:15055634

244

R and D on Control Rod Magnetic Suspension Drive Mechanism of CARR

We review the development and application of kinetic Monte Carlo simulations to investigate defect and dopant diffusion in ion implanted silicon. In these type of Monte Carlo models, defects and dopants are treated at the atomic scale, and move according to reaction rates given as input principles. These input parameters can be obtained from first principles calculations and/or empirical molecular dynamics simulations, or can be extracted from fits to experimental data. Time and length scales differing several orders of magnitude can be followed with this method, allowing for direct comparison with experiments. The different approaches are explained and some results presented.

1998-09-18

245

Quenched large deviations for random walk in a random environment

This paper deal with the research and develop (R and D) on Control Rod Magnetic Suspension Drive Mechanism (MSDM) of CARR. The MSDM is made up of tube, coil, armature, step motor, lead screw etc. The MSDM use electromagnetics as its main principle. The open solenoid electromagnet technique is employed to implement suspension function. It has advantages of high drive precision, high safety feature, good running reliability, easy maintenance and good economical property. The R and D process of MSDM has three phases including single coil electromagnet, principle prototype and engineering prototype. (author)

2011-07-01

246

Principles for occupational exposure control; Principes pour le controle des expositions professionnelles

We take the point of view of a particle performing random walk with bounded jumps on Z^d in a stationary and ergodic random environment. We prove the quenched large deviation principle (LDP) for the pair empirical measure of the environment Markov chain. By the contraction principle, we deduce the quenched LDP for the mean velocity of the particle and obtain a variational formula for the corresponding rate function. We propose an Ansatz for the minimizer of this formula. We verify this Ansatz for nearest-neighbor walks on Z. As a separate result, we give a probabilistic formula for the ergodic invariant density of the environment Markov chain in the case of ballistic random walk with bounded jumps on Z.

2008-01-01

247

Optimal oscillation-center transformations

A major component of the 1990 recommendations of ICRP (ICRP, 1991a) was the revision of the dose limits. But other changes were introduced which necessitated a review of earlier guidance. In particular, ICRP set up a Task Group in 1993 to prepare a report on the principles for the protection of workers. The report was adopted in 1997 and has now been published as ICRP Publication 75 (ICRP, 1997). It is for others to judge the real significance of the guidance provided; what follows are some of the main points. (author)

1997-10-01

248

Experimental Proof Of Principle For The Link-Up Of A Solid Oxide Fuel Cell With A Counter-Current Wood Gasifier

A variational principle is proposed for defining that canonical transformation, continuously connected with the identity transformation, which minimizes the residual, coordinate-dependent part of the new Hamiltonian. The principle is based on minimization of the mean-square generalized force. The transformation reduces to the action-angle transformation in that part of the phase space of an integrable system where the orbit topology is that of the unperturbed system, or on primary KAM surfaces. General arguments in favor of this definition are given, based on Galilean invariance, decay of the Fourier spectrum, and its ability to include external fields or inhomogeneous systems. The optimal oscillation-center transformation for the physical pendulum, or particle in a sinusoidal potential, is constructed.

1984-08-01

249

CRC handbook of lubrication. Theory and practice of tribology: Volume II: Theory and design

The combination of wood gasification and high temperature fuel cells like solid oxide fuel cells (SOFC) is an interesting approach to achieve high electrical efficiencies (40%) in small scale combined heat and power plants. This combination is called 'Biomass - Integrated Gasification Fuel Cell System' (B-IGFC). The main challenge is the adjustment of the three main components gasification, gas cleaning and fuel cell. In this technology, the first proof of principle by combining a gasifier with a SOFC in a laboratory scale for more than 100 hours was achieved. During this period, no deactivation of the system was found. (author)

2005-03-01

250

Effect of dietary fatty acid intake on prospective weight change in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition

This handbook covers the general area of lubrication and tribology in all its facets: friction, wear lubricants (liquid, solid, and gas), greases, lubrication principles, applications to various mechanisms, design principles of devices incorporating lubrication, maintenance, lubrication scheduling, and standardized tests; as well as environmental problems and conservation. The information contained in these two volumes will aid in achieving effective lubrication for control of friction and wear, and is another step to improve understanding of the complex factors involved in tribology. Both metric and English units are provided throughout both volumes.

1984-01-01

251

X-ray phase imaging using a X-ray tube with a small focal spot. Improvement of image quality in mammography

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 weight ...

2010-01-01

252

The thermodynamic characteristics of retention of tricyclo[5.2.1.02,6]decane isomer molecules on different sorbents in gas chromatography

Phase contrast X-ray imaging has been studied intensively using X-rays from synchrotron radiation and micro-focus X-ray tubes. However, these studies have revealed the difficulty of this technique's application to practical medical imaging. We have created a phase contrast imaging technique using a molybdenum X-ray tube with a small focal spot size for mammography. We identified the radiographic conditions in phase contrast magnification mammography with a screen-film system, where edge effect due to phase contrast overcomes geometrical unsharpness caused by the 0.1 mm-focal spot of a molybdenum X-ray tube. The edge enhancement due to phase imaging was observed in an image of a plastic tube, and then geometrical configuration of the X-ray tube, the object and the screen-film system was determined for phase imaging of mammography. In order to investigate a potential for medical application of this method, we conducted evaluation of the images of ...

2002-03-01

253

Structural adaptation and intracortical bone turnover in an ovine model of osteoporosis.

The thermodynamic characteristics of sorption of the isomeric tricyclo[5.2.1.02.6]decane (tetrahydrodicyclopentadiene, TDCPD) molecules were for the first time determined experimentally and by molecular statistical methods under the conditions of gas-adsorption chromatography on graphitized thermal carbon black and gas-liquid chromatography on stationary liquid phases of different polarities (Apiezon L and Carbowax 20M). The effects of the chemical nature of sorbents on the retention of the TDCPD isomers are considered. A procedure for calculating the thermodynamic characteristics of adsorption of molecules with a complex structure is suggested within the framework of the atom-atom approximation of the semiempirical molecular statistical theory of adsorption for the example of isostructural norbornane molecules. The procedure involves simultaneous variation of geometric parameters and refinement of the parameters that determine the special features of the ...

2008-07-01

254

Stabilization and limit theorems for geometric functionals of Gibbs point processes

Compact bone makes up approximately 80% of the human skeletal mass. This study examines the effect of estrogen deficiency on compact bone turnover and associated geometrical structural adaptation over a 31-month period in a large animal model. Twenty-seven skeletally mature sheep were divided into control (n = 16) and ovariectomy group (OVX, n = 11). Animals were administered five different fluorochrome dyes to label intracortical bone turnover, and sacrificed at 31 months. Compact bone samples were analyzed for cortical geometry, intracortical turnover at five time points, resorption cavities, porosity, and compressive strength. Intracortical bone turnover was significantly increased in OVX, which demonstrated seasonal variation. Cross-sectional area in OVX was significantly greater than control and was associated with an increased section modulus. Intracortical porosity was significantly increased in OVX, however, there was no significant difference in ultimate ...

2010-02-01

255

Optoelectronic multipoint liquid level sensor for light petrochemical products

Given a Gibbs point process $\\P^{\\Psi}$ on $\\R^d$ having a weak enough potential $\\Psi$, we consider the random measures $\\mu_\\la := \\sum_{x \\in \\P^{\\Psi} \\cap Q_\\la} \\xi(x, \\P^{\\Psi} \\cap Q_\\la) \\delta_{x/\\la^{1/d}}$, where $Q_{\\la} := [-\\la^{1/d}/2,\\la^{1/d}/2]^d$ is the volume $\\la$ cube and where $\\xi(\\cdot,\\cdot)$ is a translation invariant stabilizing functional. Subject to $\\Psi$ satisfying a localization property and translation invariance, we establish weak laws of large numbers for $\\la^{-1} \\mu_\\la(f)$, $f$ a bounded test function on $\\R^d$, and weak convergence of $\\la^{-1/2} \\mu_\\la(f),$ suitably centered, to a Gaussian field acting on bounded test functions. The result yields limit laws for geometric functionals on Gibbs point processes including the Strauss and area interaction point processes as well as more general point processes defined by the Widom-Rowlinson and hard-core model. We provide applications to random ...

2008-01-01

256

Non-Riemannian geometrical asymmetrical damping stresses on the Lagrange instability of shear flows

In this article we describe an optoelectronic sensor for assessing the level of light petrochemical products in technological tanks at the oil refineries. This sensor employs the multi-element vertical array of discrete micro- optical refractometric transducers. The transducers are made of silica glass and have the conical shape. In the air, each transducer operates as a tiny retro-reflector that optically couple together two multimode optical fibers. The optical coupling in the transducer is due to the internal reflection at the conical surface. The amount of the coupling depends on the refractive index of the surrounding media. In a fluid, the total internal reflection vanishes and the coupling becomes negligibly small. The number of immersed transducers is a measure of the fluid level in the reservoir. Because of the significance of the transducer transmission function, it is evaluated in detail under various combinations of the geometrical parameters of the ...

2000-06-01

257

Localized tachyons in C{sup 3}/Z{sub N}

It is shown that the physical interpretation of Elie Cartan three-dimensional space torsion as couple asymmetric stress, has the effect of damping, previously Riemannian unstable Couette planar shear flow, leading to stability of the flow in the Lagrangean sense. Actually, since the flow speed is inversely proportional to torsion, it has the effect of causing a damping in the planar flow atenuating the instability effect. In this sense we may say that Cartan torsion induces shear viscous asymmetric stresses in the fluid, which are able to damp the instability of the flow. The stability of the flow is computed from the sectional curvature in non-Riemannian three-dimensional manifold. Marginal stability is asssumed by making the sectional non-Riemannian curvature zero, which allows us to determine the speeds of flows able to induce this stability. The ideas discussed here show that torsion plays the geometrical role of magnetic field in hydromagnetic instability of ...

2007-01-01

258

We study the condensation of localized closed string tachyons in C{sup 3}/Z{sub N} non-supersymmetric noncompact orbifold singularities via renormalization group flows that preserve supersymmetry in the worldsheet conformal field theory and their interrelations with the toric geometry of these orbifolds. We show that for worldsheet supersymmetric tachyons, the endpoint of tachyon condensation generically includes 'geometric' terminal singularities (orbifolds that do not have any marginal or relevant Kahler blowup modes) as well as singularities in co-dimension two. Some of the various possible distinct geometric resolutions are related by flip transitions. For Type II theories, we show that the residual singularities that arise under tachyon condensation in various classes of Type II theories also admit a Type II GSO projection. We further show that Type II orbifolds entirely devoid of marginal or relevant blowup modes (Kahler ...

2004-08-01

259

Geometric optimization

Focused ion beam techniques for fabricating geometrically-complex components and devices.

An algorithm is presented which describes an application independent method for reducing the number of polygonal primitives required to faithfully represent an object. Reducing polygon count without a corresponding reduction in object detail is important for: achieving interactive frame rates in scientific visualization, reducing mass storage requirements, and facilitating the transmission of large, multi-timestep geometric data sets. This paper shows how coplanar and nearly coplanar polygons can be merged into larger complex polygons and re-triangulated into fewer simple polygons than originally required. The notable contributions of this paper are: (1) a method for quickly grouping polygons into nearly coplanar sets, (2) a fast approach for merging coplanar polygon sets and, (3) a simple, robust triangulation method for polygons created by 1 and 2. The central idea of the algorithm is the notion of treating polygonal data as a collection of segments and removing ...

1993-09-01

260

Experimental simulation of heat transfer augmentation by break-jets in passive containment cooling system

We have researched several new focused ion beam (FIB) micro-fabrication techniques that offer control of feature shape and the ability to accurately define features onto nonplanar substrates. These FIB-based processes are considered useful for prototyping, reverse engineering, and small-lot manufacturing. Ion beam-based techniques have been developed for defining features in miniature, nonplanar substrates. We demonstrate helices in cylindrical substrates having diameters from 100 {micro}m to 3 mm. Ion beam lathe processes sputter-define 10-{micro}m wide features in cylindrical substrates and tubes. For larger substrates, we combine focused ion beam milling with ultra-precision lathe turning techniques to accurately define 25-100 {micro}m features over many meters of path length. In several cases, we combine the feature defining capability of focused ion beam bombardment with additive techniques such as evaporation, sputter deposition and electroplating in order to build ...

2004-03-01

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261

Development of a GIUH model based on river fractal characteristics

The studies of forced jet augmentation of natural convection heat transfer are introduced. It investigates experimentally mixed convection and heat transfer augmentation by forced jets in a large rectangular enclosure with a vertical cooling surface. The experiment is designed to measure the key parameters governing the heat transfer augmentation by a forced jet, and to investigate the effects of geometric factors, including the jet diameter, jet injection orientation, interior structures, and enclosure aspect ratio, on conditions simulating those of actual passive containment cooling systems and scales approaching those of actual containment buildings or compartments. The tests that cover a variety of injection modes will contribute to reveal the nature of mixing and stratification phenomena under accident conditions to a new generation of inherently safe reactors. With similarity considerations on governing equations, the heat transfer of mixed convection can be ...

2010-02-01

262

An Upper Limit on the Albedo of HD 209458b: Direct Imaging Photometry with the MOST Satellite

The geometric patterns of a stream network in a drainage basin can be viewed as a 'fractal' with fractal dimensions. Fractals provide a mathematical framework for treatment of irregular, ostensively complex shapes that show similar patterns or geometric characteristics over a range of scale. GIUH (Geomorphological Instantaneous Unit Hydrograph) is based on the hydrologic response of surface runoff in a catchment basin. This model incorporates geomorphologic parameters of a basin using Horton's order ratios. For an ordered drainage system, the fractal dimensions can be derived from Horton's laws of stream numbers, stream lengths and stream areas. In this paper, a fractal approach, which is leading to representation of a 2-parameter Gamma distribution type GIUH, has been carried out to incorporate the self-similarity of the channel networks based on the high correlations between the Horton's order ...

1999-10-31

263

AP Theory IV: Intrinsic Topological Quantum Langlands Theory

We present space-based photometry of the transiting exoplanetary system HD 209458 obtained with the MOST (Microvariablity and Oscillations of STars) satellite, spanning 14 days and covering 4 transits and 4 secondary eclipses. The HD 209458 photometry was obtained in MOST's lower-precision Direct Imaging mode, which is used for targets in the brightness range $6.5 < V < 13$. We describe the photometric reduction techniques for this mode of observing, in particular the corrections for stray Earthshine. We do not detect the secondary eclipse in the MOST data, to a limit in depth of 0.053 mmag (1 \\sigma). We set a 1 \\sigma upper limit on the planet-star flux ratio of 4.88 x 10^-5 corresponding to a geometric albedo upper limit in the MOST bandpass (400 to 700 nm) of 0.25. The corresponding numbers at the 3 \\sigma level are 1.34 x 10^-4 and 0.68 respectively. HD 209458b is half as bright as Jupiter in the MOST bandpass. This low geometric ...

2006-01-01

264

Twisted cscK metrics and K\\"ahler slope stability

Without using any moduli, sheaves, stacks, nor any analytic, nor category-type arguments, we exhibit an analogue to Geometric Langlands Theory in an entirely model-independent, non-perturbative,purely smooth topological context in Artin Presentation Theory. A basic initial feature is that AP Theory, as a whole, is already, ab initio, a universal canonical 2D sigma-model, targeting smooth, compact, simply-connected 4-manifolds with a connected boundary, and its topological Planckian quantum starting point, as well as its cone-like, infinitely-generated at each stage, graded group of homology-preserving, but topology-changing transitions/interactions, exhibit the most general qualitative S-duality. We first point out the numerous mathematically rigorous, model-free, (i.e., intrinsic), topological AP analogues with the heuristic Kapustin-Witten version of Geometric Langlands theory, as well as the crucial differences between the two theories. The ...

2010-01-01

265

Triangle identity and free differential algebra of massless higher spins

We introduce a cohomological obstruction to solving the constant scalar curvature K\\"ahler (cscK) equation twisted by a semipositive form, appearing in works of Fine and Song-Tian. Geometrically this gives an obstruction for a manifold to be the base of a holomorphic submersion carrying a cscK metric in certain ``adiabatic'' classes. In turn this produces many new examples of general type threefolds with classes which do not admit a cscK representative. When the twist vanishes our obstruction extends the slope stability of Ross-Thomas to effective divisors on a K\\"ahler manifold. Thus we find examples of non-projective slope unstable manifolds.

2008-01-01

266

The implications of tolerance system interpretation on past and present dimensional variability studies

In terms of Berezins's theory of symbols of operators, the integral formulation is suggested for the free differential algebra which gives rise to consistent equations of motion of interacting massless fields of all spins 0#<=#s<#infinity# in the frameworks of gravity. In the first nontrivial order of the expansion in powers of curvatures, Frobenius consistency conditions for higher-spin equations of motion are shown to reduce to the simple geometrical fast that there are two ways for splitting any quadrangle in two triangles. To clarify our construction, we illustrate how it works in the simplest case of pure gravity. (orig.).

1989-09-01

267

The effect of ductile connectors on the behaviour of timber-concrete composite beams

Dimensional variability studies and published dimensional variability standards have been used by the foundry industry for years as an indicator of the casting process` ability to produce uniform parts. These studies are an extremely useful tool in the continuous ``dimensional dialogue`` between foundries and customers. The nature of these studies, and of the current tolerancing systems used by casting designers, leaves room for some misinterpretation and misuse of these study results. This paper contains two important discussions. The first part explains exactly what these studies represent. Following this is a brief explanation on dimensional and geometric tolerances and how they communicate dimensional requirements.

1994-12-31

268

British Library Electronic Table of Contents (United Kingdom)

The load-carrying capacity and ultimate deformation capacity of timber-concrete composite systems can be significantly influenced by the ductility of the connection between the two materials. The use of more ductile connections can increase the load-carrying capacity of the composite system as well as its ultimate deformation capacity. In this work, the potential increase that might be expected for these two parameters due to the use of ductile connections will be assessed through numerical simulations, taking the non-linear behaviour of the connections into account. Furthermore, the connection ductility required to achieve the maximum load capacity depends on the mechanical properties of the connection as well as on the geometric and mechanical properties of the composite system. There ar...

2011-01-01

269

The double crystal technique - its application to resconstructed InSb (001) and Xe layers

The ACR Model: A Multivariate Dynamic Mixture Autoregression

The early work of Stern has been reviewed briefly along with some of our experiments carried out later with similar geometrical arrangements in order to highlight his successes at the time and the future developments of his findings and predictions. The double crystal technique, developed by Stern has been used for energy analysis of He beams and results are shown for scattering from a rough reconstructed (001) InSb surface and Xe adsorbed layers. Surface phonons were not observed in the case of InSb probably as a result of the rough surface. (orig.).

1988-01-01

270

British Library Electronic Table of Contents (United Kingdom)

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

2008-01-01

271

SU(2) potentials in quantum gravity

Real time neutron dosemeter response calculations

We present investigations of the potential between static charges from a simulation of quantum gravity coupled to an SU(2) gauge field on 6^{3}\\times 4 and 8^{3}\\times 4 simplicial lattices. In the well-defined phase of the gravity sector where geometrical expectation values are stable, we study the correlations of Polyakov loops and extract the corresponding potentials between a source and sink separated by a distance R. In the confined phase, the potential has a linear form while in the deconfined phase, a screened Coulombic behavior is found. Our results indicate that quantum gravitational effects do not destroy confinement due to non-abelian gauge fields.

1994-01-01

272

Perturbing the ground ring of 2D string theory

The response of a real time neutron dosemeter using a thin LiF target sandwiched between tow parallel surface barrier semiconductor detectors is studied for different neutron distributions and different angles of incidence. Calculations of the response function defined for a simultaneous detection by the two detectors of the particles emitted when the reaction "6Li(n,t)#alpha# occurs in the target are fulfilled by geometrical considerations of the reaction kinematics and the differential cross section variations. Finally, the efficiency of the studied detection systems is analyzed for dosimetric uses. (author).

1996-04-01

273

Modelling heat and mass transfer in drying of biological materials. A simplified approach to materials with small dimensions

In this paper, the authors use free field techniques in D = 2 string theory t calculate the perturbation of the special state algebras when the cosmological constant is turned on. In particular, the authors find that the 'ground cone' preserved by the ring structure is promoted to a three-dimensional hyperboloid as conjectured by Witten. On the other hand, the perturbed (1,1) current algebra of moduli deformations is computed completely, and no simple geometrical interpretation is found. The authors also quote some facts concerning the Liouville matrix a model dictionary in this class of theories.

1992-12-10

274

Local central limit theorems in stochastic geometry

A simplified approach has been proposed to model the drying of capillary-porous materials with small geometric parameters for practical purposes. Luikov`s theory of mass and heat transfer for capillary-porous bodies was applied to drying of biological materials and it was shown that the thermo diffusion effect can be neglected if the thermal gradient remains small during the whole period of drying. The resulting simplified equations can then be solved using available mathematical software. The simplified equations were applied to drying of wood and a peanut pod

1996-04-17

275

Interplay between the ray and mode effects in electromagnetic behavior of small-size hemielliptic dielectric lenses

We give a general local central limit theorem for the sum of two independent random variables, one of which satisfies a central limit theorem while the other satisfies a local central limit theorem with the same order variance. We apply this result to various quantities arising in stochastic geometry, including: size of the largest component for percolation on a box; number of components, number of edges, or number of isolated points, for random geometric graphs; covered volume for germ-grain coverage models; number of accepted points for finite-input random sequential adsorption; sum of nearest-neighbour distances for a random sample from a continuous multidimensional distribution.

2010-01-01

276

Inner ring structures in galaxies as distance indicators. III. Distances to 453 spiral and lenticular galaxies

Focusing and resonance properties of two-dimensional small-size hemielliptic lenses made of different materials are studied numerically in order to estimate the influence of internal reflections on the radiation characteristics of dielectric lens antennas. Accuracy of in-house made algorithms based on combination of geometrical and physical optics and FDTD in the analysis of optical and modal effects in the behavior of such lenses is tested by comparison with the exact solution obtained using the Muller boundary integral equations. The range of applicability for the approaches is discussed.

2010-01-01

277

Influence of surface layers on the formation of the electrophysical properties of heterogeneous polymer systems

The diameters d/sub r/ of inner ring structures in disk galaxies are used as geometric distance indicators to derive the distances of 453 spiral and lenticular galaxies, mainly in the distance interval 4<#delta#<63 Mpc. The diameters are weighted means from the catalogs to Kormendy, Pedreros and Madore, and the authors. The distances are calculated by means of the two- and three-parameter formulae of Paper II; the adopted mean distance moduli #mu#"0(r) have mean errors from all sources of 0.6--0.7 mag for the well-observed galaxies.

278

British Library Electronic Table of Contents (United Kingdom)

There is investigated the role of polymer layers on the metal surface of a fine filler in the formation of a PVC system with electrophysical properties. It is shown that a physicochemical polymer modification takes place under the surface active center influence. Thus, the surface layer properties (density and geometrical characteristics) differ from the PVC ones. The correlation between the electrophysical properties of the PVC composite and the surface layer in the range of the fine copper fraction of 0?11.3 vol % at E ? 106 V m?1 and a frequency response of 20?2 ? 105 Hz is determined. An explanation of the investigated relation is presented.

2008-01-01

279

Hydrothermal coupling in a rough fracture

Geometry of supersymmetric gauge theories

Heat exchange during laminar flow is studied at the fracture scale on the basis of the Stokes equation. We used a synthetic aperture model (a self-affine model) that has been shown to be a realistic geometrical description of the fracture morphology. We developed a numerical modelling using a finite difference scheme of the hydrodynamic flow and its coupling with an advection/conduction description of the fluid heat. As a first step, temperature within the surrounding rock is supposed to be constant. Influence of the fracture roughness on the heat flux through the wall, is estimated and a thermalization length is shown to emerge. Implications for the Soultz-sous-For\\^{e}ts geothermal project are discussed.

2006-01-01

280

Geometrical aspects of reaction cross sections for {sup 3}He, {sup 4}He and {sup 12}C projectiles

This monograph gives a detailed and pedagogical account of the geometry of rigid superspace and supersymmetric Yang-Mills theories. While the core of the text is concerned with the classical theory, the quantization and anomaly problem are briefly discussed following a comprehensive introduction to BRS differential algebras and their field theoretical applications. Among the treated topics are invariant forms and vector fields on superspace, the matrix-representation of the super-Poincare group, invariant connections on reductive homogeneous spaces and the supermetric approach. Various aspects of the subject are discussed for the first time in textbook and are consistently presented in a unified geometric formalism.

1988-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

281

Direct observations of dislocation substructures formed by nano-indentation of the #alpha#-phase in an #alpha#/#beta# titanium alloy

A black-disc model combined with accurate matter densities has been used for an investigation of reaction cross sections for {sup 3}He, {sup 4}He and {sup 12}C projectiles. A simple relation is derived between the energy dependence of the reaction cross sections and the strength of the nucleon-nucleon interaction. A comparison is also made of the reaction cross sections for {sup 3}He and {sup 4}He for six different nuclei {sup 12}C, {sup 16}O, {sup 40}Ca, {sup 58,60}Ni and {sup 208}Pb.

2003-04-01

282

Crossing Zones in the Vestibulocerebellum: A Commentary

Nano-indentation has been used to assess the hardness of equiaxed grains of #alpha#-Ti as a function of orientation. Surface normals of these grains in metallographic sections were assessed using orientation imaging microscopy. Thin membranes of material from below a series of nano-indentations were excised by use of a dual-beam focused ion beam instrument. In this way, the dislocation substructures beneath individual indentations were characterized using transmission electron microscopy, permitting an identification of both statistically stored and geometrically necessary dislocations.

2005-07-25

283

British Library Electronic Table of Contents (United Kingdom)

The contention of this commentary, focused on the vestibulocerebellum (particularly the flocculus), is that the great importance for our understanding of cerebellar organization in terms of climbing fiber zones, begun years ago by Voogd [1969, 2011] and Oscarsson [1969], needs to be matched by coming more to grips with the other fundamental geometrical organization of the cerebellum, the parallel fibers. The central issue is the selection of those parallel fiber signals to be transformed into Purkinje cell activity in the different zones. At present, in comparison to our knowledge of vestibulocerebellar climbing fiber inputs, the deficiencies in our knowledge of the zonal anatomy and physiology of vestibulocerebellar mossy fibers and granule cells are glaring. The recent emphasis on molecu...

2011-01-01

284

Behavior of the cooling towers as a function of the time

Affine cones over Fano threefolds and additive group actions

In the scope of the nuclear plants lifetime study, the behavior of the cooling towers is discussed. The main geometrical characteristics of the cooling towers in the French nuclear power plants, are presented. The surveyance program, the risks of accident, the research and development actions are considered. The results of the investigations of the cooling tower structure show that it is a multidiciplinary problem and needs the development of experimental and theoretical methods. Concerning the regenerators, the surveyance actions under operating conditions, the accelerated aging tests, and some aspects of the mechanical resistance, are underlined. It is shown that mainly the creep tests will allow the lifetime estimation of the materials developed for the regenerators.

1988-12-01

285

Infinite Dimensional Groups and Riemann Surface Field Theories

We address the following question: When an affine cone over a smooth Fano threefold admits an effective action of the additive group? In this paper we deal with Fano threefolds of index 1 and Picard number 1. Our approach is based on a geometric criterion from our previous paper, which relates the existence of an additive group action on the cone over a smooth projective variety X with the existence of an open polar cylinder in X. Non-trivial families of Fano threefolds carrying a cylinder were found in loc. cit. Here we provide new such examples.

2011-01-01

286

Real time neutron reflectometry using neutron optical imaging

We show how to obtain positive energy representations of the group G of smooth maps from a union of circles to U(N) from geometric data associated with a Riemann surface having these circles as boundary. Using covering spaces we can reduce to the case where N=1. Then our main result shows that Mackey induction may be applied and yields representations of the connected component of the identity of G which have the form of a Fock representation of an infinite dimensional Heisenberg group tensored with a finite dimensional representation of a subgroup isomorphic to the first cohomology group of the surface obtained by capping the boundary circles with discs. We give geometric sufficient conditions for the correlation functions to be positive definite and derive explicit formulae for them and for the vacuum (or cyclic) vector. (This gives a geometric construction of correlation functions which had been obtained earlier using ...

1996-01-01

287

Real time neutron reflectometry using neutron optical imaging

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"-"4 in a matter ...

2001-03-01

288

Modeling paraxial wave propagation in free-electron laser oscillators

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 ...

2001-03-01

289

Electron beam qualities with and without free electron laser oscillations in the compact storage ring NIJI-IV

Modeling free-electron laser (FEL) oscillators requires calculation of both the light-beam interaction within the undulator and the light propagation outside the undulator. We have developed a paraxial optical propagation code that can be combined with various existing models of gain media, for example, Genesis 1.3 for FELs, to model oscillators with full paraxial wave propagation within the resonator. A flexible scripting interface is used both to describe the optical resonator and to control the codes for propagation and amplification. To illustrate its capabilities, we numerically investigate two significantly different FEL oscillators: the free-electron laser for infrared experiments (FELIX) system and the vacuum-ultraviolet (VUV)-FEL oscillator of the proposed high-gain fourth generation light source. For the FELIX system, we find that diffraction losses are a considerable part of the single-pass cavity loss (at a wavelength of 40 #mu#m). ...

2006-11-01

290

Bounds on the Achievable Rate for the Fading Relay Channel with Finite Input Constellations

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)

2003-09-01

291

Tax management strategies with multiple risky assets

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 ...

2011-01-01

292

British Library Electronic Table of Contents (United Kingdom)

We study the consumption-portfolio problem in a setting with capital gain taxes and multiple risky stocks to understand how short selling influences portfolio choice with a shorting-the-box restriction. Our analysis uncovers a novel trading flexibility strategy whereby, to minimize future tax-induced trading costs, the investor optimally shorts one of the stocks (or equivalently, buys put options) even when no stock has an embedded gain. Alternatively, an imperfect form of shorting the box can reduce aggregate equity exposure ex post. Given these two short selling strategies, it is common for an unconstrained investor to short some equity while a constrained investor holds a positive investment in all stocks. With no shorting, the benefit of trading separately in multiple stocks is not eco...

2006-01-01

293

Short-term toxicological evaluation of Terminalia catappa, Pentaclethra macrophylla and Calophyllum inophyllum seed oils in rats

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...

2008-01-01

294

Noise in Josephson mm-wave mixers

MGV: a generic graph viewer for comparative omics data

Point contact Josephson junctions can function as millimeter wave heterodyne mixers with conversion gain. The best results achieved thus far show a single sideband conversion gain of 1.3 and a mixer contribution to the system noise temperature of 54"0K. Both of these results are approximately 5 times better than the best published figures for cooled Schottky barrier diode mixers operated at the same frequency. The measured noise for a variety of junctions can be expressed as a universal function of the normalized rf frequency #OMEGA# = h#omega#/2eI/sub c/R. It is about a factor 2 larger than the calculated noise arising from the thermal noise in the junction shunt resistance, R. The noise calculation was done for the resistively shunted junction model using an analog junction simulator.

1974-09-30

295

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...

2011-01-01

296

Linewidth-broadened Fabry-Perot cavities within future gravitational wave detectors

Induction linac-driven free-electron lasers: Status and future prospects

The bandwidth of LIGO-like terrestrial interferometric gravitational wave detectors is set by the pole of the Fabry-Perot cavities within the arms of the Michelson interferometer. This constraint arises because the gain of gravitational wave-induced signal sidebands is limited to frequencies within the linewidth of the cavities. The nature of standard Fabry-Perot cavities is such that one cannot independently adjust for increased gain without suffering a loss of bandwidth. If these quantities could be decoupled, the resulting improvement in bandwidth may lead to viable high frequency detectors. A pair of anti-parallel diffraction gratings within a Fabry-Perot cavity can increase the bandwidth of a LIGO-scale detector by a factor of #approx#1000.

2004-03-07

297

High-gain harmonic generation free electron laser seeded by few-cycle laser

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.

1987-01-11

298

Good plant design and operation for onshore carbon capture installations and onshore pipelines. A recommended practice guidance document. 1st. ed.

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.

2008-06-07

299

Engagement for progress: applied philosophy of science in context

The document provides: An overview of CCS technology including what plant equipment is novel and what is currently in use within the CCS or other industries; An in depth guide to carbon dioxide to broaden the readers understanding of the material and its health and safety issues; Key design features of plant and pipelines for carbon dioxide service including experience gained from the industrial gases sector; and Key operational information for plant and pipelines for carbon dioxide service including experience gained from the industrial gases sector to ensure that your operating practices take into account the latest operational experiences from carbon dioxide plant. 45 figs., 18 tabs.

2010-09-15

300

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...

2010-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

301

Alternative cycles based on carbon dioxide for central receiver solar power plants

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 ...

2011-01-01

302

A neural network based adaptive sliding mode controller: Application to a power system stabilizer

A neural network based adaptive sliding mode controller: Application to a power system stabilizer

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.

2011-02-15

303

A Virtual Dielectric Waveguide Mode Description of a High-Gain Free-Electron Laser I: Theory

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.

2011-02-01

304

Local structure of Ca dopant in BaTiO_3 by Ca K-edge X-ray absorption near-edge structure and first-principles calculations

A set of mode-coupled excitation equations for the slowly-growing amplitudes of dielectric waveguide eigenmodes is derived as a description of the electromagnetic signal field of a high-gain free-electron laser, or FEL, including the effects of longitudinal space-charge. This approach to describing the field basis set has notable advantages for FEL analysis in providing an efficient characterization of such eigenmodes, and in allowing a clear connection to free-space propagation of the input (seeding) and output radiation. A simple transformation converts the coupled differential excitation equations into a set of coupled algebraic equations and yields a matrix determinant equation for the FEL eigenmodes. A quadratic index medium is used as a model dielectric waveguide to obtain an expression for the predicted spot size of the dominant eigenmode, in the approximation that it consists of a single gaussian mode.

2008-01-01

305

Interacting tachyons in classical and quantum physics

The local environment of Ca dopants in barium titanate, BaTiO_3, is investigated by Ca K-edge X-ray absorption near-edge structure (XANES) spectroscopy. In conjunction with experiments, first-principles calculations by two methods are systematically made. The projector-augmented wave (PAW) method is used to optimize the local structure and obtain the formation energy. The augmented plane wave plus local orbitals method is adopted to obtain theoretical XANES spectra. A comparison between experimental and theoretical XANES spectra shows that Ca dopants are located at the Ba"2"+ sites forming Ca"2"+. Formation energy calculations of Ca doped BaTiO_3 by the PAW method also give the same results. The Ca atom in BaTiO_3 is off-centering in comparison with the Ba site in BaTiO_3. The off-centering of Ca atom is newly revealed by the combination of XANES spectroscopy and first-principles DFT calculations.

2010-06-01

306

Application of variational methods to fusion reactor blanket studies

It is demonstrated that tachyons do not violate the principles of relativity, and that, with the aid of a reinterpretation principle to eliminate negative energies, tachyons can be characterized as particles of real, spacelike 4-momentum. The classical, charged tachyon is treated within conventional electromagnetic theory, and in an explicitly Lorentz-invariant way. It is shown that a charged tachyon would not emit electromagnetic radiation in a vacuum regardless of its state of motion. A theory based on the real-energy solutions of the Klein-Gordon equation with imaginary mass is shown to provide the best opportunity for describing spinless tachyons in quantum field theory. The theory should be Lorentz-invariant, incorporate the reinterpretation principle to remove negative energies, and be as close as possible to conventional quantum theory. The proposal of Arons and Sudarshan is adopted as best fulfilling these ...

307

The novel 'OLGA' technology for complete tar removal from biomass producer gas

The general development of variational methods for fusion reactor blanket studies is given. Important quantities such as tritium breeding ratio and total nuclear heating are linear functionals of the solutions to the Boltzmann transport equation. To estimate a neutronic quantity by variational methods is, in general, to carry out the scalar product formulation of the Roussopoulos variational principle, or the Schwinger variational principle, with the help of the associated adjoint transport equation where the appropriate response function for the estimate is taken as the source. A multipoint interpolation method based on the above variational principles has been developed and compared to other variational approaches. The method of variational interpolation removes the need to compute both forward and adjoint solutions while the error has the characteristic of cancellation of errors between interpolation reference points. ...

308

Studies on thermodynamic properties of III-V compounds by first-principles response-function calculation

A new process for the removal of tar from biosyngas, OLGA (Oil and Gas Washer), is presented. This gas cleaning technology is based on physical principles and is designed to eliminate tar problems that relate to fouling and er pollution. The applied principles are confirmed by experimental validation. OLGA can be operated without suffering from harmful effects on important gasification characteristics as cold gas efficiency, gasifier simplicity, and feedstock flexibility. Some fundamental considerations in the development of OLGA are discussed. Amongst these is a different approach to the tar problem. This approach does not consider the total tar content as decisive in the evaluation of gas cleaning equipment. Instead, evaluation is focussed on whether tar properties as condensation behaviour and water solubility can still occur. A biosyngas free of tar should therefore be synonymous to a biosyngas that is free of tar related problems.

2002-10-14

309

Rapid and precise measurement of flatband voltage

The temperature dependences of the Grueneisen parameter, heat capacity, bulk modulus and linear thermal expansion coefficient of sixteen III-V zincblende compounds are studied by first-principles response-function calculations. The fundamental relationships among these physical parameters are explored. Negative thermal expansions at lower temperature are found in most of these III-V phases except for the nitrides and boron compounds. By analyzing the cell-volume dependences of the phonon spectrum, it is found that the phases with a negative thermal expansion show a significant acoustic phonon weakening at the X-point in their phonon dispersion, while slight weakening is only seen around the L-point for those boron phases. There is no sign of phonon weakening in the nitrides. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

2009-07-01

310

Nuclear fission with mean-field instantons

The paper outlines the design, principles of operation, and calibration of a five-IC network intended to give a rapid, precise, and automatic determination of the flatband voltage of MOS capacitors. The basic principle of measurement is to compare the analog output voltage of a capacitance meter - which is directly proportional to the capacitance being measured - with a preset or dialed-in voltage proportional to the calculated flatband capacitance by means of a comparator circuit. The bias to the MOS capacitor supplied through the capacitance meter is provided by a ramp voltage going from a negative toward a positive voltage level and vice versa. The network employs two monostable multivibrators for reading and recording the flatband voltage and for resetting the initial conditions and restarting the ramp. The flatband voltage can be held and read on a digital voltmeter.

1976-05-01

311

How to recover casuality for tachyons even in macrophysics

We present a description of nuclear spontaneous fission, and generally of quantum tunneling, in terms of instantons - periodic imaginary-time solutions to time-dependent mean-field equations - that allows for a comparison with more familiar and used generator coordinate (GCM) and adiabatic time-dependent Hartree-Fock (ATDHF) methods. It is shown that the action functional whose value for the instanton is the quasiclassical estimate of the decay exponent fulfils the minimum principle when additional constraints are imposed on trial fission paths. In analogy with mechanics, these are conditions of energy conservation and the velocity-momentum relations. In the adiabatic limit the instanton method reduces to the time-odd ATDHF equation, with collective mass including the time-odd Thouless-Valatin term, while the GCM mass completely ignores velocity-momentum relations. This implies that GCM inertia generally overestimates instanton-related decay rate. The very ...

2007-01-01

312

Generation of number-phase minimum uncertainty states

The postulate that negative-energy particles do not exist (travelling forward in time) leads automatically to the 'Reinterpretation Principle' by Stueckelberg and by Feynman. It has been already shown that such a 'principle', assumed as the Third postulate of special relativity, ensures the validity of the law of (retarded) casuality both in standard relativity and in (extended) relativity with tachyons and with Superluminal inertial frames. Our Thir postulate, moreover, allows predicting antiparticle existence in a purely relativistic context. In this paper it is shown that the Third postulate is enough to implement the law of casuality even in macrophysics, when usual macro-objects interact with micro-tachyons and macrotachyons. To that aim, some tachyon kinematics is further developed, which can be useful even in understanding elementary-particle interactions (and may be hadron structure). Many other related problems are discussed.

313

First-principles derivation of the AdS/CFT Y-systems

The difference between the two nonclassical lights, i.e., the squeezed state and number-phase minimum uncertainty state (NUS) is discussed. The four different generation principles for NUS are described. They are: unitary evolution using self-phase modulation; nonunitary state reduction by the first kind measurement; controlled state reduction by quantum correlation measurement-feedback, and high saturated laser oscillation with suppressed-pump-noise. The constant current-driven semiconductor laser based on the last principle generated the NUS with photon number noise reduced below the standard quantum limit by 40 percent in the entire frequency region from dc to 1.1 GHz. Several applications of NUS including quantum communication, quantum mechanical computers and interferometric gravitational detection are discussed briefly. This presentation is represented by viewgraphs only.

1987-01-01

314

First principles investigations of formation of ordered omega phases in Zr-Al alloys

We provide a first-principles, perturbative derivation of the AdS5/CFT4 Y-system that has been proposed to solve the spectrum problem of N=4 SYM. The proof relies on the computation of quantum effects in the fusion of some loop operators, namely the transfer matrices. More precisely we show that the leading quantum corrections in the fusion of transfer matrices induce the correct shifts of the spectral parameter in the T-system. As intermediate steps we study UV divergences in line operators up to first order and compute the fusion of line operators up to second order for the pure spinor string in AdS5xS5. We also argue that the derivation can be easily extended to other integrable models, some of which describe string theory on AdS4, AdS3 and AdS2 spacetimes.

2011-01-01

315

Enhancing supply chain solutions with the application of chaos theory

First-principles density functional theory (DFT) based calculations were performed to study the electronic and cohesive properties of all the intermediate ordered phases appearing in the transformation from bcc-based #beta# to hexagonal ordered #omega# phase in Zr_3Al alloy. Full-potential linear augmented plane wave (FPLAPW) method under the GGA was employed to establish the stability hierarchy and structure-property correlations. Further, effective pair potentials upto the fourth nearest neighbours were extracted, which, subsequently, were used for the thermodynamics analysis of the thermally-induced #beta##->##omega# transformation. The lattice collapse mechanism involving the concept of the onset of a displacement wave where the extent of collapse is viewed as an amplification of the displacement wave was employed for further analysis. (author)

2005-12-05

316

British Library Electronic Table of Contents (United Kingdom)

Purpose ? The purpose of this article is to expand the base of supply chain knowledge by applying chaos theory principles to selected supply chain functions. Design/methodology/approach ? Researchers borrow chaos theory from the natural sciences, provide a basic explanation, and then examine how it may be applied to enhance supply chain management techniques. Findings ? Chaos theory principles are used to assist in the examination of forecasting, product design, and inventory management challenges currently facing supply chain practitioners. Research limitations/implications ? Application of chaos theory to various supply chain issues and key functional areas may produce an increase in the level of understanding of supply chain ambiguity and how chaos theory may provide valuable insight in...

2006-01-01

317

Design principles for CANDU control centres in response to evolving utility business needs

Corrosion: Understanding the basics

Nuclear generation operators are facing a challenging business environment at the beginning of the new millennium. Evolving changes in business context, competitive commercial pressures, and changes in technology have dictated recurring evaluation of operational practices and the adequacy of supporting tools, and the pursuit of opportunities for operational improvement. A key area of utility operations that has been impacted by these changes is the nuclear plant control centre. Changes to workspace layout, equipment provisions, staffing, and work organization are examples of some of the adjustments being introduced to improve operational and safety effectiveness. This paper discusses some of the key factors influencing these changes and identifies additional design principles for CANDU control centres that will enable new control centre designs and retrofits of existing control centres to remain relevant and responsive to utility needs. (author)

2002-07-01

318

Characterizing the time variability in magnetized neutrino--cooled accretion disks: signatures of the gamma-ray burst central engine

This new book presents a practical how to approach to understanding and solving the problems of corrosion of structural materials. Although it is written mainly for those having a limited technical background in corrosion, it also provides more experienced engineers with a useful overview of the principles of corrosion and can be used as a general guide for developing a corrosion-control program. Contents include: the effects and economic impact of corrosion; basic concepts important to corrosion; principles of aqueous corrosion; forms of corrosion: recognition and prevention; types of corrosive environments; corrosion characteristics of structural materials; corrosion control by proper design; corrosion control by materials selection; corrosion control by protective coatings and inhibitors; corrosion control by cathodic and anodic protection; corrosion testing and monitoring; techniques for diagnosis of corrosion failures; and glossary of ...

2000-07-01

319

Basic environmental questions concerning lawsuits of neighboring power plant dwellers. Grundfragen umweltrechtlicher Nachbarklagen. Zum verwaltungsrechtlichen Drittschutz im Bauplanungsrecht, Immissionsschutzrecht und Kernenergierecht

The central engine of Gamma Ray Bursts is hidden from direct probing with photons mainly due to the high densities involved. Inferences on their properties are thus made from their cosmological setting, energetics, low-energy counterparts and variability. If GRBs are powered by hypercritical accretion onto compact objects, on small spatial scales the flow will exhibit fluctuations, which could in principle be reflected in the power output of the central engine and ultimately in the high energy prompt emission. Here we address this issue by characterizing the variability in neutrino cooled accretion flows through local shearing box simulations with magnetic fields, and then convolving them on a global scale with large scale dynamical simulations of accretion disks. The resulting signature is characteristic, and sensitive to the details of the cooling mechanism, providing in principle a discriminant for GRB central engine properties.

2010-01-01

320

Application of nuclear energy for power generation at TAPS 3 and 4

In conjunction with the constellation of lawsuits within the administrative court system, and based on modern environmental protection laws, emission control laws, and foremost, the atomic energy laws, we are confronted with a variety of constitutional and administrative problems. However, the fundamental questions of individual rights within the potentially incriminating environmental utilization or exploitation by individuals could be relatively clearly answered by observing the basic principles of our legal order. It is to be expected that the administrative courts will arrive at acceptable decisions reflecting the full protection of the law and the basic constitutional principles, and that these - once made - may serve as orientation in superior court actions.

1982-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

321

Application of hazard analysis - Critical control point (HACCP) principles to primary production: What is feasible and desirable?

Tarapur Atomic Power Station, Unit 3 and 4 is located on the West Coast of the Arabian Sea near the existing Tarapur Atomic Power Station Unit 1 and 2. The nearest railway station is Boisar at a distance of 12 km from the site, which is on the main Western Railway Mumbai-Delhi route. The site is well connected by road and is about 30 Km from Mumbai-Ahmedabad National Highway-NH-8. The paper describes the land acquisition and rehabilitisation of the affected families, importance of project in the western grid, how it works, working principles of PHWR, principle of operation, major components/equipment, important systems, safety features, and waste management

2010-10-01

322

British Library Electronic Table of Contents (United Kingdom)

We show that the HACCP system is not fully applicable at the primary production level, and that food safety is obtained through the careful implementation of good hygiene practice (GHP) at the farm. Guides to GHP intended at primary productions cover one activity, such as cattle rearing or corn production. Yet most farms have more than one activity. Hazards from one activity can be transferred to another activity, and in general this is not considered in one-activity guides. There is a need therefore for farmers to be able to detect and control such transfers. We suggest a horizontal complement to the Guides to GHP that would consider only the application of the Step 6 and Principle 1 of the HACCP system amended as follows: ''List all potential hazards transferred from one activity to anot...

2011-01-01

323

Alcohol Use During Pregnancy. [and] Fast Food and the American Diet. [and] Food Additives and Hyperactivity.

A review of the effect of different application rates on pesticide residue levels in supervised residue trials

These three separate pamphlets provide background information, brief discussions of research findings, and guidelines and recommendations concerning selected aspects of diet. The first pamphlet discusses food additives and hyperactivity, focusing on both the Feingold theory and controlled experiments which do not support Feingold's clinical observations and case reports. (The Feingold theory claims that artificial food flavors and colors and antioxidant preservatives cause hyperactivity in genetically predisposed individuals.) The second pamphlet discusses fast food and the American diet as they are related to sound nutritional principles. The third pamphlet, focusing on alcohol use during pregnancy, lists principles and associated features of the fetal alcohol syndrome and presents research findings and recommendations concerning alcohol use during pregnancy. (RH)

1980-12-01

324

British Library Electronic Table of Contents (United Kingdom)

Abstract Residue trial data reported by the Joint FAO/WHO Meeting on Pesticide Residues (JMPR) have been reviewed to establish whether or not the resulting residues in harvested commodities are proportional to the pesticide application rate used on the crop. Numerous sets of trials were identified where the only parameter varied was application rate or spray concentration. Analysis of this database in terms of application rate, spray concentration, formulation type, preharvest interval, crop, pesticide, residue level and application type confirms that residues scale with application rate (proportionality principle). It is anticipated that use of the proportionality principle by regulators and those interested in evaluating pesticide residue data will improve pesticide risk assessment. Copy...

2011-01-01

325

A principle of charged particle trapping by RF electromagnetic field in the spherical cavity

A first principles study on optical transparency mechanism in Dy doped #alpha#-SiAlON ceramics

A new principle of particle trapping in the simple spherical cavity using both electric and magnetic components of radiofrequency electromagnetic field is proposed. The electric component of H {sub 12} oscillating mode drives the fast particle oscillations, while the magnetic component synchronously bends the trajectories to the cavity center. A specially developed theory of particle stability predicts dense and energetic electron cluster in the trap. Numerical simulations of particle dynamics in the complete electromagnetic field taking into account both space charge and particle-induced magnetic field are in good agreement with the analytic results, giving a density of 2.6*10{sup 1} electrons/cm{sup 3} and an average kinetic energy of around 30 keV at an operating frequency of 3 GHz. Being used at lower frequency, spherical cavity can trap protons and heavier ions too, but with lower density and kinetic energy.

2005-11-21

326

[Heart injuries: diagnosis and therapy].

Dy doped #alpha#-SiAlON ceramics prepared by the hot-pressing method show a high optical transmittance value, >70%, in the infrared region of 1.5-4.5 #mu#m. First principles calculations have been carried out to reveal the underlying transparency mechanism. It is found that the valence shell of doped Dy atoms interacts strongly with the doping states of #alpha#-SiAlON, resulting in the increase in the optical gap from 0.4 to 1.1 eV, which suppresses the photoabsorption in the wavelength region longer than 1.0 #mu#m and leads to the good transparency property. The calculated optical transmission spectra are in good agreement with the corresponding experiments.

2009-11-01

327

Weight-control behaviors and subsequent weight change among adolescents and young adult females¹²³

The clinical manifestation of wounds of the heart is determined by the mode, site and size of the injury as well as the structure of the pericardial and myocardial lesion. Diagnosis can be confirmed by ECG and echocardiography. Only 20% of the patients with penetrating wounds of the heart live for more than 30 minutes. Pericardio-centesis should be used only to gain time for a safe sternotomy, cardiac decompression and suture of the wound of the heart. An aggressive surgical approach is mandatory. Cardiopulmonary bypass is necessary only to correct of concomitant lesions. PMID:1983618

1990-01-01

328

Wavelength dependence of the threshold in an InGaP-InAlGaP vertical cavity surface emitting laser

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

2010-01-01

329

Wavelength dependence of the threshold in an InGaP-InAlGaP vertical cavity surface emitting laser

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.

1994-07-11

330

Using decoupled characteristic in the synthesis of stabilizers in multimachine systems

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.

331

Underground piping handbook

A decoupled characteristic between the damping of a specific swing mode and the stabilizer gain of the corresponding machine in multimachine power systems is identified. Using this decoupled characteristic a power system stabilizer (PSS) synthesis approach which is based on the phase compensation concept is verified on a 9-machine system and the dynamic performance of this system is significantly improved. This method is proved to be effective, simple and it can provide useful guidance for the PSS field tuning.

1987-02-01

332

Theory of bistability in the face-pumped laser with bimolecular recombination

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.

1985-01-01

333

Some insights from total collapse

Steady-state and transient behavior of the longitudinally pumped semiconductor laser is theoretically investigated by using a rate-equation model with distributed gain and photon density. Conditions necessary for bistable operation are derived. Dependencies of such major switching characteristics as turn-on and turn-off powers, delay, and rise times on laser parameters are examined. Influences of spontaneous radiation, impurities, and Auger recombination are studied. The results offer an explanation for the observed nonlinear behavior of face-pumped lasers.

1987-01-01

334

Solar collectors with tubes partially filled with porous substrates

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.

2008-01-01

335

Single-pass high-gain free electron laser electron beam diagnostics

In this work, the thermal performance of a conventional collector is improved by inserting porous substrates at the inner walls of the collector tubes. The porous substrates improve the convective heat transfer coefficient between the tube wall and the fluid. This improvement is investigated numerically and its effects on the efficiency and the useful gain of the collector are evaluated. It is found that inserting the porous substrate may raise the collector efficiency considerably, especially at high values of the overall heat loss coefficient.

1999-02-01

336

Prostaglandin E₂ Signals Through PTGER2 to Regulate Sclerostin Expression

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

2000-11-27

337

Pitting corrosion of aluminized seals in molten carbonate fuel cells

The Wnt signaling pathway is a robust regulator of skeletal homeostasis. Gain-of-function mutations promote high bone mass, whereas loss of Lrp5 or Lrp6 co-receptors decrease bone mass. Similarly, mutations...Full Text Available

338

Microwave Combustion and Sintering Without Isostatic Pressure

The objective of this research is to gain a better understanding of the corrosion of the aluminized type 316 stainless steel employed in the seal areas of the molten carbonate fuel cell. The seals are formed between the aluminized Type 316 SS surface and the electrolyte (generally a mixture of molten alkali carbonates and lithium aluminate).

1994-08-01

339

Microturbine applications for the oil and gas industries of South America

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.

1998-10-20

340

Maintenance viewpoint of a successful reactor program

This paper will describe the application of power generation by the use of microturbine technology by Capstone Turbine Corporation throughout South America. The purpose of this paper is to describe the technology and the experience gained over the last six years. The microturbines are power generation systems that produce energy from a diverse range of liquid or gaseous fuels. The generator is driven by a small gas turbine with a common shaft for the rotors of the generator and the engine. (author)

2008-07-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

341

Longitudinal and transverse mode evolution in free electron laser

As the Operating and Support staffs of the FFTF organization have gained experience, the plant reliability and capacity factors have shown a steadily improving trend. The plant capacity factor for Cycle 4 was 99.5%. It is the purpose of this report to describe the evolution of the maintenance organization at the FFTF site from a general support organization to a technically proficient organization playing a major role in planning and performance of plant maintenance evolutions.

1984-06-03

342

Josephson junctions as heterodyne detectors

We use the method of Padg approximants and Fourier transform techniques to treat analytically the problem of transverse and longitudinal mode evolution in FELs. We obtain simple relations providing a transparent understanding of the dynamic of pulse propagation effects and of transverse mode guiding. We discuss the interplay with inhomogeneous broadening effects and derive gain formulae including longitudinal and transverse mode couplings.

1995-12-31

343

Geothermal heat pumps - gaining ground in the UK and worldwide

Heterodyne detection with a point-contact Josephson junction has been investigated both experimentally and theoretically. The measured performance of the device at 36 GHz is in good agreement with the theory. By operating vanadium point contacts at 1.4 K, the authors have achieved a single-sideband (SSB) mixer noise temperature of 54 K with a conversion gain of 1.35 and a signal bandwidth on the order of 1 GHz. A potentially impressive performance for these devices at submillimeter wavelengths can be extrapolated from the results.

344

Geothermal heat pumps - gaining ground in the UK and worldwide

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.

2001-07-01

345

Genome Sequence of a Lancefield Group C Streptococcus zooepidemicus Strain Causing Epidemic Nephritis: New Information about an Old Disease

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.

346

First tests of "bulk" MICROMEGAS with resistive cathode mesh

Outbreaks of disease attributable to human error or natural causes can provide unique opportunities to gain new information about host-pathogen interactions and new leads for pathogenesis research....Full Text Available

347

Evolution of longitudinal modes in low voltage FEL

We present the first results from tests of a MICROMEGAS detector manufactured using the so-called "bulk" technology and having a resistive cathode mesh instead of the conventional metallic one. This detector operates as usual MICROMEGAS, but in the case of sparks, which may appear at high gas gains, the resistive mesh reduces their current and makes the sparks harmless. This approach could be complementary to the ongoing efforts of various groups to develop spark-protected MICROMEGAS with resistive anode planes.

2010-01-01

348

Evaluating the metrology of the standard method of determining blast furnace coke strength

A low voltage FEL operating at 130 kV which can be run cw with a continuous electron beam current level up to 12 mA has been constructed for the X-Band microwave range (8-12 GHz). In this poster, we will report on the dependence on time, after the electron beam is switched on, of the growth and competition of those longitudinal modes in the cavity having nett gain.

1995-12-31

349

Engineering Assistance and sustainable development; Ingenierie conseil et developpement durable

Coke strength increases in significance as blast furnace and metallurgical plant gain in size and output requirement. The article underlines the need to apply error computation standards to strength testing routines. The mean square deviation was found for cokes from different plants, related to a single strength determination for M25 and M10, and amounted to 0.61 and 0.35% respectively. The future standards should include a correlation factor for permitted tolerance as between parallel determinations.

1981-03-01

350

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.)

2002-07-01

351

Eddy current imaging

Diversity and Multiplexing Tradeoff in the Uplink of Cellular Systems with Linear MMSE Receiver

Image representations have gained wide acceptance in displaying data collected during optical, ultrasonic, radiographic, and thermographic inspections. Applying imaging techniques to eddy current testing is explored in this article. The authors show that flaw interpretation and characterization are made considerably simpler when images are used to visualize the impedance changes in eddy current probes.

1993-04-01

352

Crystallization and preliminary X-ray diffraction studies of two thermostable ?-galactosidases from glycoside hydrolase family 36

In this paper, we extend the diversity and multiplexing tradeoff (DMT) analysis from point-to-point channels to cellular systems to evaluate the impact of inter-cell interference on the system reliability and efficiency. Fundamental tradeoff among diversity order, multiplexing gain and inter-cell interference intensity is characterized to reveal the capability of multiple antennas in cellular systems. And the detrimental effects of the inter-cell interference on the system performance of diversity and multiplexing is presented and analyzed.

2011-01-01

353

Coradia LIREX X 60 for Sweden; Coradia LIREX X 60 fuer Schweden

α-Galactosidases from thermophilic organisms have gained interest owing to their applications in the sugar industry. The α-galactosidases AgaA, AgaB and AgaA A355E mutant from Geobacillus...Full Text Available

354

CLIC High-Gradient Test Results

The new power cars currently being built for commuter services in the Stockholm area have a number of innovative features. Manufacturer Alstom-LHB, who developed the vehicle based on experience gained with the LIREX experimental train, is also offering this model in continental Europe. (orig.)

2005-07-01

355

Assisting Eastern European countries in the setting up of a national response to nuclear smuggling

The CLIC (Compact Linear Collider) high-gradient RF structure testing program has been carried out in order to gain insight into the physical processes involved in RF breakdown, determine the mechanisms that limit gradient and produce damage so that technical concepts can be developed which allow higher accelerating gradients. Two main paths towards higher gradients have emerged from this program, and the performances of two new structures which incorporate them are presented.

2002-01-01

356

All wired up and ready to go

The paper will report the experience gained in the implementation of the national assistance projects, including the detailed assessment of the national situation compared to the ITWG Model Action Plan, the upgrading of the technical skills, the training of national experts and the joint analysis of nuclear material at ITU. The status of the work with the 13 future Member States to the European Union will also be reported on during the conference

2001-10-01

357

A two-frequency Wiggler for a better control of a free-electron-laser dynamics

Electric cars have long been seen as science fiction. This may be changing. As the 1990s began, several companies chose to launch publicity campaigns for electric vehicles. In California, experimental programmes are gaining momentum, in the context of LA's appalling air pollution problems and tightening clean air standards. Supporters claim that electric motive power is a key to solving several environmental problems involving atmospheric pollution. These claims are examined. (author).

1990-01-01

358

A numerical weather prediction model--Computational aspects on the CRAY-1

In the paper is studied the physics of a free electron laser (FEL) based on a two-frequency undulator (TFU) which induces large non linear effects, especially on the spectral dynamics. These effects are analyzed in an extended formalism where the spontaneous emission, the low-gain regime and the strong-field saturation regime are studied. Numerical simulations show that the optimized TFU generates a laser field having both a large extraction efficiency and a narrow spectrum.

1991-12-31

359

Wood and polymer chemistry. Khimiya drevesiny i polimerov

This paper presents a case study in the design and implementation of a numerical weather prediction model on a supercomputer (CRAY-1). Following a historical introduction to the evolution of the model, the governing equations of the model are presented and the numerical solution of these forecast equations is described. A brief tutorial on the architecture of the CRAY-1 is presented with a discussion of how it affects the choice of algorithms and code design of the model. A summary of the advantages gained by use of the vector aspects of the CRAY-1 is included.

1984-01-01

360

Usability Studies and User-Centered Design in Digital Libraries

Information is given on the theoretical principles underlying the technology of producing fibrous plastics and wood slabs. An examination is made of the most important characteristics of the physics and chemistry of polymers, and the properties of synthetic polymers used in the wood processing industry. A description is given of the chemical composition and properties of wood and its components as well as of synthetic polymers made of cellulose. The book is designed for students of technical schools of the wood and pulp processing industry. 7 references, 14 figures, 1 table.

1980-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

361

Tumorigenic and tumoricidal actions of ionizing radiations

Digital libraries continue to flourish. At the same time, the principles of user-centered design and the practice of usability testing have been growing in popularity, spreading their influence into the library sphere. This article explores the confluence of these two trends by surveying the current literature on usability studies of digital libraries. This article focuses on the methodology of studies of multimedia digital libraries. (Contains 1 table and 45 notes.)

2007-12-01

362

Tropospheric sampling with aircraft

The book is divided into two approximately equal parts. The first four chapters are relatively lengthy and cover the basic principles of radiation biology, carcinogenesis and therapy, along with a brief introduction to radiological physics to orient the reader without background in this specialized related discipline. The remainder consists of twenty-four relatively brief chapters, each covering the radiation biology of a specific organ, tissue, or systems tissues, with emphasis on the tumorigenic and tumoricidal action of ionizing radiations.

1983-01-01

363

Theory of chemical reaction dynamics. Volume 1

Aircraft constitute a unique environment which places stringent requirements on the instruments used to measure the concentrations of atmospheric trace gases and aerosols. Some of these requirements such as minimization of size, weight, and power consumption are general; others are specific to individual techniques. This review presents the basic principles and considerations governing the deployment of trace gas and aerosol instrumentation on an aircraft. An overview of common instruments illustrates these points and provides guidelines for designing and using instruments on aircraft-based measurement programs.

1991-03-01

364

The physics of tachyons. Pt.1

This book examines some of the basic principles behind chemical reactions kinetics. Topics considered include ab initio determination of potential energy for chemical reactions; semi-empirical potential energy surfaces; general theory of reactive scattering: different equation approach; and integral equation approach to reactive scattering.

1985-01-01

365

The liquid phase oxidation of n-butane: a search for plausible mechanisms

A new formulation of the theory of tachyons is developed using the same two postulates as in special relativity. Use is made of a 'switching principle' to show how tachyons automatically obey the laws of conservation of energy, momentum and electric charge. Tachyonic mechanics is further developed by a consideration of tachyonic rods and clocks. There follows a discussion of the conservation of electric charge and the apparent visual appearance of a tachyonic cube. 19 refs., 9 figs.

366

The characteristic and relevant fault analysis for the microgovernor synchronization of Daya Bay Nuclear Power Station and Ling'ao Nuclear Power Station

This articles deals with an approach that has given some key information about the mechanisms of the liquid phase oxidation of butane to acetic acid. This procedure has been developed over the last 34 years; however, much of what will be discussed represents a synthesis of previous insights. Many of the observations are relatively recent and have not been previously published. In principle, this approach should be applicable to many oxidation processes. (orig.)

1998-12-31

367

The application of virtual instruments technique in U-H_2 experimental system

In Daya Bay and Ling'ao Nuclear Power Station, the Microgovernor has the control functions such as synchronization, block loading etc. The control principle of the Microgovernor is right described by sequence diagram for the first time. That the fault occurred in the synchronization process of Daya Bay Nuclear Power Station unit 1 is also analyzed and illustrated. (author)

2005-09-01

368

The European volcanic ash crisis: Between international and European law | EurActiv

The concept of the modern data acquisition system and some functional specialties of the programming software--Visual Basic 6.0 are introduced. The construction and theory of the hardware and the designing principle of the software are described. Experimental results showed that the real-time data acquisition rate was as high as 10 times per second in the system. And the relative standard uncertainty of the measurement was less than 0.5%. (authors)

2004-11-01

369

Wastenet

... Carbon capture and storage Waste Prevention and Recycling EU clean air strategy Environmental liability: Applying the 'polluter pays' principle What goes around ...comes around: Recycling and climate change Behind closed doors: Air quality in buildings Keeping cool with refrigerants: The F-gas review Regions fighting climate ...

370

Technical-ecologic principles of efficient use of open pit mine motor transport

Tachyons without paradoxes

The effect of open pit mine motor transport with ICE on the air basin is examined using the example of shale mines and open pits of the production association ''Estonslanets''. Efficient areas of use of different types of open pit mine motor transport, diesel-trolley tracks and electric cars are determined based on technical-economic and ecologic feasibility.

1981-01-01

371

Tachyons and the radiation of an accelerated charge

Tachyon paradoxes, including causality paradoxes, have persisted within tachyon theories and left little hope for the existence of observable tachyons. A way is presented to solve the causality paradoxes, along with two other paradoxes, by the introduction of an absolute frame of reference in which a tachyon effect may never precede its cause. Relativity for ordinary matter is unaffected by this, even if the tachyons couple to ordinary particles. Violations of the principle of relativity due to the absolute frame would appear only in the case of free tachyons.

372

Tachyons - particles faster than light

The motion of an accelerated charge in a vacuum is analyzed, via the superposition principle and Fourier analysis, into uniform-motion components, which include bradyonic as well as tachyonic contributions. It is shown that the former contribute only to the induction fields whereas the latter are the source of the radiation emitted by the charge, via the Sommerfeld-Cerenkov mechanism. This result calls for a reexamination of some recently formulated theories of superluminal particles.

1982-10-15

373

Study on carbonization of spherical fuel elements for 10 MW high temperature gas-cooled reactor

This paper shows that there is no possibility to see tachyons moving backwards in time, because such a tachyon would contradict the principle of entropy. And whenever a law would be hurt in particle physics, the possibility of this interaction tends to zero. Therefore you can only see tachyons moving ahead in time. Further more, it can be shown, that it is impossible to prove the existence of tachyons using Cerenkov radiation in vacuo. They are not able to emit Cerenkov radiation in vacuo because of their symmetrical electric fields. Remember gluons. (orig.).

374

Steel microstructure engineering for large diameter tubes; Engenharia de microestrutura de acos para tubos de grande diametro

The principle for working out the time-temperature schedule of the carbonization was determined through the investigation on the carbonization process of the green body and the phenol formaldehyde resin. During the carbonization process, the crack at lower temperatures is due to strain inhomogeneity produced in press. But the crack at higher temperatures results from the improper increasing rate of temperature. The application of the autoclave-carbonization process can increase the mechanical properties of the spherical fuel elements.

375

Steam turbines. Dampfturbinen

High and ultra-high strength steels for pipelines are produced by properly handling the steel microstructure. The metallurgical principles involved in the microstructure control are presented, with emphasis on TMCP processing, that comprises conventional controlled rolling followed by accelerated cooling. (author)

2008-05-15

376

Stabilization of measuring channel of reflective gamma thickness gage by light pulses from additional scintillator

In spite of the fact that market requirements for new plants continue to be restricted, steam turbine technology and operation engineers have left nothing undone to improve products and operating characteristics. They are generally guided by the principle of optimum economic power supplies but lowest pollution. The new eastern markets are expected to give new impulses to steam turbine design. Cogeneration is of special future importance. (orig.).

1991-04-01

377

Solar receiver enclosure enhancement by controlled directional scattering

Possibility for using a sodium iodide scintillator as a reference signal source is considered. Experimental data on studying the performance of a gamma thickness gage with an additional scintillator are given. Results of experimental investigations of a thickness gage dummy proved practical expediency of the principle being considered. It is established, in particular, that the device is ready to operate without warm-up with a constant sensitivity, the deviation not exceeding 0.5%, in the ambient temperature range of 15-25 deg C.

378

The interest in efficient solar collector design has stimulated investigation of two-dimensional (trough-like) cavity structures. A novel principle for designing cavity enclosures is described. The present method maintains high transmission albeit at the expense of some concentration in the presence of gaps as large as the radius between reflector and receiver. The new method can be applied to advantage to nonimaging concentrator design as well as to line focus concentrators.

1980-01-01

379

Solar cells

Software for Data Analysis Programming with R

The article is the second part of a review dealing with latest developments in the area of solar cell technologies and application. Physical principles, design and efficiency as well as advantages and disadvantages of GaAs- and CdS-solar cells are described. Power generation solar cell systems with voltage converters, combined solar cell/solar collector systems and thermoelectric solar systems are presented in the second part of the article.

1983-04-01

380

Semi-automatic system for designing operations in a face

Although statistical design is one of the oldest branches of statistics, its importance is ever increasing, especially in the face of the data flood that often faces statisticians. It is important to recognize the appropriate design, and to understand how to effectively implement it, being aware that the default settings from a computer package can easily provide an incorrect analysis. The goal of this book is to describe the principles that drive good design, paying attention to both the theoretical background and the problems arising from real experimental situations. Designs are motivated t

2008-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

381

Revisit to the helicity and the generalized self-organization theory

A semi-automatic system which considers operation in a face by monitoring technological parameters of an extraction vehicle and a longwall conveyor is examined. The system records in tabular form the location, progress made, operating and down time of an extraction vehicle and operating and down time of the conveyor. A description of the operating principle system and systems for arrangement of the remote sensing and central recording device are presented. (Note: extraction vehicle not identified: LTN)

1980-01-01

382

Radiation protection in connection with the decommissioning of nuclear plants

It is clarified that the so-caned 'helicity conservation law' is never the conservation equation of the helicity K itself', but is merely 'the time change rate equation of K', which is passively and resultantly determined by the mutually independent volume and surface integral terms. It is shown that since the total helicity K can never be conserved in the real experimental systems, the conjecture of the total helicity invariance is not physically available to real magnetized plasmas in an exact sense. The well-known relaxation theory by Dr. J. B. Taylor is clarified to be neither the variational principle nor the energy principle, but be merely a mathematical calculation, using the variational calculus in order to find the minimum magnetic energy solution from the set of solutions having the same value of K. With the use of auto-correlations for physical quantities, it is presented that a novel ...

2000-09-01

383

Quantum Cloning for Absolute Radiometry

This document presents the SSI preliminary views and position concerning the decommissioning of nuclear plants. To prevent the exposure of the decommissioning personnel and the general public to unacceptable levels of radiation and to protect the environment and future generations, it is SSI`s task to formulate and issue the necessary terms and regulations with which the reactor licensees must comply during the decommissioning work. The views and principles presented here are the basis of SSI`s continued work on guidelines and regulations for the decommissioning of nuclear plants.

1997-04-01

384

Quality assurance requirements for the computer software and safety analyses

In the quantum regime information can be copied with only a finite fidelity. This fidelity gradually increases to 1 as the system becomes classical. In this Letter we show how this fact can be used to directly measure the amount of radiated power. We demonstrate how these principles can be used to build a practical primary standard.

2010-08-20

385

The requirements are given as placed on the development, procurement, maintenance, and application of software for the creation or processing of data during the design, construction, operation, repair, maintenance and safety-related upgrading of nuclear power plants. The verification and validation processes are highlighted, and the requirements put on the software documentation are outlined. The general quality assurance principles applied to safety analyses are characterized. (J.B.). 1 ref.

386

Pumped storage plants

Progress of magnetic-suspension systems and magnetic bearings in the USSR

Pumping is one of the means for storing vast quantities of energy. This article analyses its principles and ways of implementation with emphasis on its double aspect, e.g., on the one hand, off-peak power is transferred to the periods of heaviest load and is thus valorized, even when taking into account losses due to poor efficiency of operations in the pumping and turbine modes, and on the other hand, plants have great flexibility in operation, faciliting the permanent fitting of generation to demand.

1982-09-01

387

Proceedings of the tenth annual DOE low-level waste management conference: Session 1: Institutional and regulatory issues

This paper traces the development and progress of magnetic suspension systems and magnetic bearings in the USSR. The paper describes magnetic bearings for turbomachines, magnetic suspension systems for vibration isolation, some special measuring devices, wind tunnels, and other applications. The design, principles of operation, and dynamic characteristics of the system are presented.

1992-05-01

388

Problems of development and putting into education process an electronic textbook on special discipline 'General theory and construction of heat-and-power engineering facilities'

This document contains eleven papers on various aspects of low-level radioactive waste regulation. Topics include: EPA environmental standards; international exemption principles; the concept of below regulatory concern; envirocare activities in Utah; mixed waste; FUSRAP and the Superfund; and a review of various incentive programs. Individual papers are processed separately for the data base. (TEM)

1988-12-01

389

Principles of the coprecipitation of thorium and yttrium with organicinorganic salts of molybdenum polyacids

The results of work of making the electronic textbook of special discipline ('General theory and construction of heat-and-power engineering facilities' are brought. The principles and requirements, presented towards literature of such type, are outlined. (author)

2005-01-01

390

Practical design methods for barrier pillars. Information circular/1995

This paper advances hypotheses on the chemistry of the interaction of thorium and yttrium with organic-inorganic salts of molybdenum polyacids. On the basis of an analysis of the data of an adsorption experiment and the quantitative relationships that follow from the law of mass action, it is shown that thorium is absorbed by the solid phase by coprecipitation with the participation of complex formation, while the coprecipitation of yttrium with salts of polyacids is due to a reaction of ion exchange chemisorption.

1986-03-01

391

Optical measurement of electron bunching in vacuum

Effective barrier pillar design is essential for safe and productive underground coal mining. This U.S. Bureau of Mines report presents an overview of available barrier pillar design methodologies that incorporate sound engineering principles while remaining practical for everyday usage. Nomographs and examples are presented to assist in the determination of proper barrier pillar sizing. Additionally, performance evaluation techniques and criteria are included to assist in determining the effectiveness of selected barrier pillar configurations.

1995-11-01

392

On the unfreezing of color in fluctons

We report the homodyne detection of phase modulation sidebands induced on a laser beam by a coherently bunched electron beam. This provides a sensitive and nonperturbing measurement of complex Fourier time series components of the electron density. A proof-of-principle measurement of the microwave frequency component of electron density in a crossed-field device, which agrees well with a calculation of the same quantity, is reported.

393

On the Effects of Idiotypic Interactions for Recommendation Communities in Artificial Immune Systems

It is shown that account of nuclear effects in nucleon channel is of principle importance when analyzing hadron-nucleon process at high energies. This enables to make correct conclusions both about the contribution of multiquark systems - fluctons - to nuclear wave function and about quark distribution in them. Analysis of these distributions shows that color degrees of freedom in flucton are partially unfrozen and flucton contains with high probability one or two quarks.

394

Nucleon transfer contribution to the absorptive heavy ion potential by the Monte Carlo simulation method

It has previously been shown that a recommender based on immune system idiotypic principles can out perform one based on correlation alone. This paper reports the results of work in progress, where we undertake some investigations into the nature of this beneficial effect. The initial findings are that the immune system recommender tends to produce different neighbourhoods, and that the superior performance of this recommender is due partly to the different neighbourhoods, and partly to the way that the idiotypic effect is used to weight each neighbours recommendations.

2008-01-01

395

Nuclear power generation. Chapter 14

The Monte Carlo simulation method is applied to calculate the nucleon transfer part of the imaginary optical-model potential in colliding heavy ions. In the process of transfer of nucleons from one nucleus to the other, forward and backward neutrons and protons are treated separately by taking into consideration the effect of the Coulomb forces and the potential energy surfaces (driving forces). The Pauli exclusion principle is also incorporated properly in the calculation.

1988-08-08

396

Multidipole magnetic fields for plasma confinement

As part of a handbook on the efficient use of energy a chapter is included which is intended to give an appreciation of the principles and problems involved in the generation of nuclear power. The subject is discussed under the following headings: introductory nuclear physics; basic reactor physics; thermal reactors; fast reactors; fuel reserves and utilization; environmental considerations; nuclear fusion. (U.K.).

1975-01-01

397

Modification of reference spectrum method for solving the Bethe-Goldstone equation for finite nuclei

Plasma confinement by permanent magnets has been studied. An analytic formula for the field of a single bar magnet has been obtained. Generalization to various configurations of multidipole fields has also been found. Any two-dimensional field may now be completely described by a simple function of complex variables in closed form. Vector potential has also been obtained by integrating over a prescribed Riemann surface. The confinement of plasma by multidipole fields then becomes obvious through conservation principles.

1983-07-01

398

Moderate deviations for stationary sequences of Hilbert valued bounded random variables

A method of auxiliary spectrum is modified so that matrix elements of the reaction matrix in final nuclei are determined by means of algebraic operations alone (inversion of matrices). No differential equations need to be solved; Pauli's exclusion principle is accurately taken into account. A single-particle potential may be of any kind, but a two-particle interaction must have no solid core.

399

Modeling Transient Discharge into a Tunnel Drilled in a Heterogeneous Formation

In this paper, we derive the moderate deviation principle for stationary sequences of bounded random variables with values in a Hilbert space. The conditions obtained are expressed in terms of martingale-type conditions. The main tools are martingale approximations and a new Hoeffding inequality for non adpated sequences of Hilbert-valued random variables. Applications to Cramer-Von Mises statistics, functions of linear processes and stable Markov chains are given.

2008-01-01

400

British Library Electronic Table of Contents (United Kingdom)

Abstract An analytical model is developed to predict transient discharge flow into a tunnel drilled at various speeds through a heterogeneous formation. This model relies on simplifying assumptions commonly enforced in hydrogeologic engineering, and combines the convolution and superposition principles to account for composite sections with arbitrary parametric contrasts. An application to the data monitored during the exploratory drilling of an Alpine tunnel confirms the validity of the approach.

2007-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

401

Measurement of the half-life of "1"0"1Mo

Main concepts of modern methods for substantiating extractable reserves and coefficients of oil extraction from the depths

"1"0"1Mo is an important radionuclide to determine the burn-up of nuclear fuels, but its half-life reference values had marked differences. It is described in detail the principles and processes of the position normalization method by two high purity germanium detectors to determinate the half-life of "1"0"1Mo. (authors)

2006-11-01

402

Magnetic electronic lenses, quadrupole and octupole for microsystem electron beam techniques

General conclusions, principles and order of substantiating the extractable reserves and coefficients of oil extraction from oil and oil and gas fields are presented. Recommendations are made for solving questions of constructing calculation models for heterogeneous beds, schematization of the working conditions, selection of mathematical models for oil extraction for different geological-field conditions and different stages of ''life'' of the field.

1984-01-01

403

Liability problems related to backfitting of nuclear installations in Eastern Europe

The MOS-technology allows to make tiny electronic lenses for multibeam electron systems. In the paper results of research and principles of designing of tiny magnetic electron lenses are submitted. Electronic lenses with a nonconventional configuration of tiny magnetic circuit and electronic lenses with coincident electric and magnetic fields in nonconventional tiny performance are considered

2006-09-01

404

Large-Scale Computations Leading to a First-Principles Approach to Nuclear Structure

The paper shortly recapitulates the background to and the importance of the principle of channeling of liability to the operator, contained in the international Conventions in the field of nuclear liability. It tries to outline the main problems involved in the process of backfitting in some more detail and to describe part of the work that has been done in Sweden and elsewhere to try to solve them. Finally, the paper contains some concluding remarks indicating that no entirely satisfactory solution to the problem is presently at hand. (orig./HP)

1995-12-31

405

Industrial ecology at Lawrence Livermore National Laboratory summary statement

We report on large-scale applications of the ab initio, no-core shell model with the primary goal of achieving an accurate description of nuclear structure from the fundamental inter-nucleon interactions. In particular, we show that realistic two-nucleon interactions are inadequate to describe the low-lying structure of {sup 10}B, and that realistic three-nucleon interactions are essential.

2003-08-18

406

Importance of the chemical reaction of coke in the operation of shaft furnaces

At Livermore our hope and our intention is to make important contributions to global sustainability by basing both our scientific and technological research and our business practices on the principles of industrial ecology. Current efforts in the following fields are documented: global security, global ecology, energy for transportation, fusion energy, materials sciences, environmental technology, and bioscience.

1996-06-04

407

GS1 - radiological protection objectives for the disposal of solid radioactive wastes

The principle of operation of shaft furnaces is explained and demonstrated in four practical examples. The conditions and parameters determining coke conversion in the combustion zone and in the Boudouard reaction range are described. The combustion process is treated as a whole while the reduction process is discussed separately for the blast furnace, the cupola furnace, and the shaft furnace. The possibilities describing the Boudouard reaction as a function of the temperature level are discussed and consequences are derived for further experimental and theoretical studies.

1984-11-01

408

First-principles nonlocal-pseudopotential approach in the density-functional formalism. II. Application to electronic and structural properties of solids

A summary is given of the 1983 NRPB-GS1 Report on the 'Radiological protection objectives for the disposal of solid radioactive wastes'. The two principal difficulties in applying the ICRP system of dose limitation to some solid waste disposal methods are outlined. Despite these difficulties three radiological protection objectives for waste disposal were recommended based on the same fundamental principle as ICRP recommendations.

1984-01-01

409

Environmental #gamma# dose rate monitoring system around Guangdong Daya Bay Nuclear Power Station

We apply our previously developed first-principles nonlocal pseudopotentials (obtained for all atoms of rows 1--5 in the Periodic Table) to study self-consistently the electronic structure of Si and Ge and the transition metals Mo and W. For Si and Ge we find that the first-principles pseudopotentials yield valence-band states in good agreement with the empirically adjusted pseudopotential and photoemission data, whereas the low conduction-band states appear to be consistently lower in energy due apparently to incomplete cancellation of the self-interaction effects. The calculated x-ray scattering factors (obtained by core orthogonalization of the pseudo-wave-functions) are in excellent agreement with experiment. The self-consistent valence charge density shows a distinct elongation of the covalent bond along the internuclear axis, in good agreement with the experimentally synthesized density. The systematic deviations of the empirical ...

410

Dynamics of electrooptic bistable devices with delayed feedback

This article introduces the composition, monitoring methods and working principles of environmental #gamma# dose rate continuous monitoring system at Guangdong Daya Bay Nuclear Power Station. The #gamma# dose rate monitoring status after modification of measurement conditions is introduced too.

411

Determination of ash in coal by X-ray backscattering and X-ray fluorescence analysis and apparatus by the PAR company

The dynamic behavior of electrooptic bistable devices with delayed feedback is investigated theoretically and experimentally. The operation principle of the system is analyzed by the method of iterated maps. Stable, bistable, periodic, higher periodic, and chaotic solutions are discussed and realized experimentally by using an integrated Mach-Zehnder interferometer on LiNbO3 as a basic nonlinear element. Taking into account the periodic modulator characteristic, the application of this device as a simple and fast bistable and monostable multivibrator is demonstrated. In addition, the synchronization properties of the astable multivibrator are investigated.

1982-12-01

412

DOUBLE-SHELL TANK (DST) HYDROXIDE DEPLETION MODEL FOR CARBON DIOXIDE ABSORPTION

The basic principles of determination of the ash content of coal by the title methods are outlined. A brief technical characteristic of the ash meters and radionuclide X-ray fluorescence analyzers manufactured by the PAR company is presented. (Z.S.). 4 figs., 7 refs.

1993-01-01

413

Cross Entropy Approximation of Structured Covariance Matrices

This document generates a supernatant hydroxide ion depletion model based on mechanistic principles. The carbon dioxide absorption mechanistic model is developed in this report. The report also benchmarks the model against historical tank supernatant hydroxide data and vapor space carbon dioxide data. A comparison of the newly generated mechanistic model with previously applied empirical hydroxide depletion equations is also performed.

2009-04-30

414

Control of radon daughters in underground uranium mines

We apply two variations of the principle of Minimum Cross Entropy (the Kullback information measure) to fit parameterized probability density models to observed data densities. For an array beamforming problem with P incident narrowband point sources, N > P sensors, and colored noise, both approaches yield eigenvector fitting methods similar to that of the MUSIC algorithm[1]. Furthermore, the corresponding cross-entropies are related to the MDL model order selection criterion[2].

2006-01-01

415

Contribution of first-principles energetics to the Ca-Mg thermodynamic modeling

Many factors influence radon-222 influx and radon-daughter concentrations in underground uranium mines. A brief review of some of these factors is presented. Current radon-222 and radon-daughter control principles and practices for US underground uranium mine atmospheres are discussed and a brief review of the applicability of other possible control methods such as rock sealants, radon-222 removal, and radon-daughter removal is given.

416

Collective acceleration of electrons and ions in a high current relativistic electron beam. Final report

The first-principles energetics of the constituent elements Ca and Mg and the Mg_2Ca C14 laves phase (C14) in the Ca-Mg binary system were used in the computational thermodynamic modeling, with models for the Gibbs energy of individual phases. C14 was modeled as (Ca,Mg)_2(Ca,Mg)_1 with four end-members. The first-principles calculations were performed using two computer codes: (i) WIEN2K based on the full-potential linearized augmented plane-wave (FLAPW) method and (ii) VASP based on the pseudo-potentials and a plane wave basis set. The total energies of the pure Ca and Mg in the fcc, bcc, and hcp structures, three laves phase structures of Mg_2Ca, and the four end-members of C14 were calculated at 0 K. The enthalpies of formation of the four end-members were obtained accordingly and used as input data in evaluating the Gibbs energy functions of C14. The entropy contribution in the Gibbs energy function for C14 was obtained through its liquidus ...

2006-08-31

417

The original purpose of this research was an investigation into the use of slow space charge waves on weakly relativistic electron beams for ion acceleration. The work had three main objectives namely, the development of a suitable ion injector, the growth and study of the properties of slow space charge waves on an electron beam, and a combination of the two components parts into a suitable proof of principle demonstration of the wave accelerator. This work focusses on the first two of these objectives.

418

Catalytic chemistry

Bragg curve spectroscopy detector for particle identification

Most chemical reactions in industry and biology are catalytic and play a role at some stage of the processing of about 80% of the goods manufactured in the U.S., yet catalysis is a neglected subject in chemical education. This book integrates the fragmentary treatment accorded the topic until now. It covers, in a unified way, catalysis in solutions, by enzymes, in synthetic polymers within the molecular scale cages of zeolites and other molecular sieves, and on surfaces of inorganic solids. The central ideas are chemical; and principles are illustrated by emphasizing industrial reactions and catalysts.

1991-01-01

419

Bianchi type-IX quantum cosmology of the heterotic string

The operation principle, construction and characteristics of the Bragg curve spectroscopy detector (BCS detector) are described. The electric field of the BCS detector is parallel to the particle trajectories. The detector was tested by 8.78 MeV and 6.02 MeV #alpha# particles from a ThC-ThC's source. The energy resolutions are 1.5% and 2.6% respectively for two groups of #alpha# particles, and the charge resolution is 2.7%. Further test experiments with heavy ions will be arranged.

420

Bianchi type-IX quantum cosmology of the heterotic string

The dimensionally reduced effective action of the bosonic sector of the heterotic string in critical dimensions is employed to derive a Wheeler-DeWitt equation for the Bianchi type-IX cosmology. An exact solution is found that becomes strongly peaked around the isotropic limit as the volume of the three-geometry increases. In principle the global O(6,6) symmetry of the effective action can be employed to generate new solutions from the one presented here.

1994-01-15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

421

Beam-beam compensation activities at Fermilab. R and D status

The dimensionally reduced effective action of the bosonic sector of the heterotic string in critical dimensions is employed to derive a Wheeler-DeWitt equation for the Bianchi type-IX cosmology. An exact solution is found that becomes strongly peaked around the isotropic limit as the volume of the three-geometry increases. In principle the global O(6,6) symmetry of the effective action can be employed to generate new solutions from the one presented here.

422

An ultrasonic goniometer for surface stress measurement

The beam-beam interaction in the Tevatron produce the betatron tune spread in each bunch and a bunch-to-bunch tune spread. The tune spread sets limits on bunch intensity and luminosity. The beam-beam effects for antiprotons are usually more severe since the proton bunch population is higher. The beam-beam effects for antiprotons can in principle be compensated with the use of an electron beam with a corresponding charge density. The status of studies of possibilities of the beam-beam compensation is reviewed in this paper.

1999-06-09

423

An online monitoring system for nuclear waste storage

An instrument has been constructed for the measurement of residual stress in steel. If necessary, large objects can be examined in situ. An account is given of the principles and construction. A special stressing frame provides for calibration. An application to residual stress in gear blanks has established a systematic variation of surface stress with nickel content and confirmed the overall effect of the surface hardening treatment.

1978-09-01

424

An instrument for measuring spatial and time characteristics of sea agitation in coastal zones

We propose a system for the on-line monitoring of short and medium term radioactive waste repositories. Such a system is distributed, fine-grained, robust, reliable, and must be based on low-cost components. It could, in principle, open new perspectives on the modality of waste packaging and storage. In particular we propose to employ a new family of cheap and powerful micro sensors to be placed in shape of a fine grid around each single drum. (authors)

2009-06-07

425

Ab initio calculations in a uniform magnetic field using periodic supercells

Resistive analogous meters for spatial and time characteristics in ocean agitation are most often used in practical oceanography in coastal zones but are based on bridge circuits determined to have shortcomings in their linearity range. This shortcoming is eliminated in the circuit of an instrument developed in an oceanographic laboratory (IMIO, Vana). Principle and block circuits are indicated, and static calibration curves are presented as are the correlative functions in the frequency spectrums obtained with the help of sea agitation recorded at a fixed point and at a depth of 6 meters.

1981-01-01

426

ALARA Center of Technology -- resource guide

We present a formulation of ab initio electronic structure calculations in a finite magnetic field, which retains the simplicity and efficiency of techniques widely used in first principles molecular dynamics simulations, based on plane-wave basis sets and Fourier transforms. In addition we discuss results obtained with this method for the energy spectrum of interacting electrons in quantum wells, and for the electronic properties of dense fluid deuterium in a uniform magnetic field.

2003-10-21

427

A simple, high efficiency, negative surface ionization source

The purpose is to provide a source of information that can be used to assist personnel in the planning, training, and execution of radiological work using the principles of ALARA. This document is not intended to replace HNF or WHC Control Manual requirements. The ALARA Tools-List provides detailed information on the use and procurement of engineered controls, mockup training guidelines, and good radiological work practices that have been proven to be ALARA.

1998-02-05

428

A derivation of the electromagnetic coupling ?0?137.036

A spherical-geometry, self-extraction negative ion source has been designed and fabricated. The source utilizes direct surface ionization to form negative ion beams resulting from interactions between high electron affinity gaseous elemental or molecular materials and a negatively biased, spherical-sector LaB{sub 6} surface ionizer maintained at {similar to}1300 K. The design features of this source and principles upon which the source is based are discussed in this report.

1992-04-01

429

X-ray magnetic form factor of UTe

A consistent mathematical derivation is given for the Sommerfeld fine structure electromagnetic coupling 1/?-bar 0=?0-bar 1/137.036. Following 't Hooft's holographic principle two complimentary forms of the derivation are given both leading to the E(?) theoretical value, namely ?-bar 0=(20)(1/?)4=137.082039311. The experimental value is subsequently found by projection as ?-bar 0(exp)=137/[cos(?/?-bar 0)]-bar 137.036.

2007-02-01

430

X-ray magnetic form factor of UTe

A measurement of the magnetic form factor of a ferromagnetic actinide compound of UTe with circularly polarized X-rays is reported. The present geometrical configuration of the measurement gives a form factor of L(k)+0.3S(k), where L(k) and S(k) are the form factors of the orbital and the spin magnetic moment, respectively. We have combined the X-ray magnetic form factor with the neutron one which gives L(k)+2S(k) (G. Busch et al.: J. Phys. C 12 (1979) 1391), and have deduced L(k) and S(k) separately. The obtained profiles of L(k) and S(k) show that the orbital and the spin magnetic moments are spatially spread out more than those calculated for a free uranium ion. (author).

1995-07-01

431

Weld integrity of the superconducting cable aluminium jackets of W7-X

A measurement of the magnetic form factor of a ferromagnetic actinide compound of UTe with circularly polarized X-rays is reported. The present geometrical configuration of the measurement gives a form factor of L(k)+0.3S(k), where L(k) and S(k) are the form factors of the orbital and the spin magnetic moment, respectively. We have combined the X-ray magnetic form factor with the neutron one which gives L(k)+2S(k) (G. Busch et al.: J. Phys. C 12 (1979) 1391), and have deduced L(k) and S(k) separately. The obtained profiles of L(k) and S(k) show that the orbital and the spin magnetic moments are spatially spread out more than those calculated for a free uranium ion. (author).

432

British Library Electronic Table of Contents (United Kingdom)

The Wendelstein 7-X (W7-X) modular stellarator is under construction at the Max-Planck-Institut fur Plasmaphysik in Greifswald, Germany. The W7-X magnet system contains 70 coils made up from helium cooled superconducting cables in aluminium alloy (EN AW-6063) jackets. Several hundred connections of the jacket to the cable joints are made by aluminium-to-aluminium welds. Due to geometrical and thermal boundary conditions these welds cannot be accomplished free from defects. Microscopic analyses of the welds show that a variety of small flaws such as cracks and pores develop during welding. The welds have thus to be dimensioned accordingly, and appropriate weld qualification, investigation and testing has to be done in order not to jeopardise the structural integrity and leak tightness. The ...

2009-01-01

433

The geometry emerging from the symmetries of a quantum system

The cohomology ring of the GKM graph of a flag manifold of classical type

We investigate the relation between the symmetries of a quantum system and its topological quantum numbers, in a general C*-algebraic framework. We prove that, under suitable assumptions on the symmetry algebra, there exists a generalization of the Bloch-Floquet transform which induces a direct-integral decomposition of the algebra of observables. Such generalized transform selects uniquely the set of "continuous sections" in the direct integral, thus yielding a Hilbert bundle. The emerging geometric structure provides some topological invariants of the quantum system. Two running examples provide an Ariadne's thread through the paper. For the sake of completeness, we review two related theorems by von Neumann and Maurin and compare them with our result.

2009-01-01

434

The Nuclear Outflow in NGC 2110

If a closed smooth manifold $M$ with an action of a torus $T$ satisfies certain conditions, then a labeled graph $\\mG_M$ with labeling in $H^2(BT)$ is associated with $M$, which encodes a lot of geometrical information on $M$. For instance, the "cohomology" ring $\\mHT^*(\\mG_M)$ of $\\mG_M$ is defined to be a subring of $\\bigoplus_{v\\in V(\\mG_M)}H^*(BT)$, where $V(\\mG_M)$ is the set of vertices of $\\mG_M$, and is known to be often isomorphic to the equivariant cohomology $H^*_T(M)$ of $M$. In this paper, we determine the ring structure of $\\mHT^*(\\mG_M)$ when $M$ is a flag manifold of classical type directly without using the fact that $\\mHT^*(\\mG_M)$ is isomorphic to $H^*_T(M)$.

2011-01-01

435

Target space duality I: general theory

We present a HST/STIS spectroscopic and optical/radio imaging study of the Seyfert NGC 2110 aiming to measure the dynamics and understand the nature of the nuclear outflow in the galaxy. Previous HST studies have revealed the presence of a linear structure in the Narrow-Line Region (NLR) aligned with the radio jet. We show that this structure is strongly accelerated, probably by the jet, but is unlikely to be entrained in the jet flow. The ionisation properties of this structure are consistent with photoionisation of dusty, dense gas by the active nucleus. We present a plausible geometrical model for the NLR, bringing together various components of the nuclear environment of the galaxy. We highlight the importance of the circum-nuclear disc in determining the appearance of the emission line gas and the morphology of the jet. From the dynamics of the emission line gas, we place constraints on the accelerating mechanism of the outflow and discuss the relative ...

2010-01-01

436

Subspace estimation and prediction methods for hidden Markov models

We develop a systematic framework for studying target space duality at the classical level. We show that target space duality between manifolds M and M-tilde arises because of the existence of a very special symplectic manifold. This manifold locally looks like MxM-tilde and admits a double fibration. We analyze the local geometric requirements necessary for target space duality and prove that both manifolds must admit flat orthogonal connections. We show how abelian duality, nonabelian duality and Poisson-Lie duality are all special cases of a more general framework. As an example we exhibit new (nonlinear) dualities in the case M=M-tilde=R{sup n}.

2000-09-25

437

Spontaneous excitation of an accelerated atom in a spacetime with a reflecting plane boundary

Hidden Markov models (HMMs) are probabilistic functions of finite Markov chains, or, put in other words, state space models with finite state space. In this paper we examine subspace estimation methods for HMMs whose output lies a finite set as well. In particular we study the geometric structure arising from the non-minimality of the linear state space representation of HMMs, and consistency of a subspace algorithm arising from a certain factorisation of the singular value decomposition of the estimated linear prediction matrix. For this algorithm we show that the estimates of the transition and emission probability matrices are consistent up to a similarity transformation, and that the m-step linear predictor computed from the estimated system matrices is consistent, i.e. converges to the true optimal linear m-step predictor.

2009-01-01

438

Spatial distribution of IGC-30 Ge-detector's efficiency

We study a two-level atom in interaction with a real massless scalar quantum field in a spacetime with a reflecting boundary. The presence of the boundary modifies the quantum fluctuations of the scalar field, which in turn modifies the radiative properties of atoms. We calculate the rate of change of the mean atomic energy of the atom for both inertial motion and uniform acceleration. It is found that the modifications induced by the presence of a boundary make the spontaneous radiation rate of an excited inertial atom oscillate near the boundary and this oscillatory behavior may offer a possible opportunity for experimental tests for geometrical (boundary) effects in flat spacetime. While for accelerated atoms, the transitions from ground states to excited states are found to be possible even in a vacuum due to changes in the vacuum fluctuations induced by both the presence of the boundary and the acceleration of atoms, and this can be regarded as an actual ...

2005-09-15

439

Semiclassical calculation of photon-stimulated Schwinger pair creation

The dependence of the efficiency of a coaxial IGC-30 Ge detector on the direction of gamma quanta entry, their energy and the distance from the source is examined. A set of point sources QCR-2 (Amersham, UK) has been used which is arranged consecutively in two perpendicular planes passing through the detector axis, at a distance of 0.1 - 1.3 m (pace 0.1) from its geometric centre for 16 different angles in every plane. Dependence curves of the efficiency on the angle of gamma-quanta hits are obtained for energies 60, 81, 122, 356, 662, 834, 1173 and 1332 keV. Changes in efficiency connected with spatial dividing ability are found out. Using the least squares' method the expected spatial distribution of efficiency is examined with a level of authenticity P > 0.9. The possible causes for the efficiency change and its possible effect on the measurements' precision are discussed. (author).

1993-12-02

440

Self-inhibited rate in gas-solid noncatalytic reactions. The shrinking core model

We consider the electron-positron pair creation by a photon in an external constant electric field. The presented treatment is based on a purely quasiclassical calculation of the imaginary part of the on-shell photon polarization operator. By using this approach we find the pair production rate for photons with polarization parallel as well as orthogonal to the external electric field in the leading order in the parameter eE/m"2, which has been recently found by other methods. For the orthogonal polarization we also find a new contribution to the rate, which is leading in the ratio of the photon energy to the electron mass #omega#/m. We also reproduce by a purely geometrical calculation the exponential factor in the probability of the stimulated pair creation at arbitrary energy of the photon.

2010-04-15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

441

Safety calculation for an underground repository for radioactive waste: the first objective of the alliances calculation software platform

The shrinking core model is examined for gas-solid noncatalytic reactions with a self-inhibited rate form and it is shown that multiple reaction pathways are possible for solid particles reacted under identical conditions. The observed reaction rate can have up to two discontinuities (jumps) during reaction for particles of spherical and cylindrical shape. The geometric instability analysis reveals that the reaction interface is stable under a very limited set of conditions only for solid particles of slab geometry. For a sphere or cylinder at large Biot numbers the reaction interface is always potentially unstable. This model provides a plausible explanation for gas-solid reactions which exhibit erratic shrinking core behavior.

1984-02-01

442

Removal of scattered thermal neutrons using antiscatter grid

The aim of the safety calculation is to quantify through numerical modelling the radiological impact (molar flow, human dose) of a potential repository for radioactive waste on the Meuse/Haute Marne site at Bure. A selection process is underway for safety scenarios and their phenomenological and numerical conceptual models upstream from the safety calculation. This involves defining and quantifying the geometric and dimensional representations of the repository for each scenario plus the physical, mathematical and numerical models that reflect its behaviour and the uncertainties associated with all the parameters required to quantify the impact. A summary will be given of these various aspects. The numerical simulations are then performed on the Alliances platform which integrates the various computer codes required for the physical representation of the system. (authors)

2005-03-14

443

Reconstructions of archaeological contexts in OpenGl environments; Intelligenza artificiale per i beni culturali e le biblioteche digitali. Atti del Workshop

One of the significant factors of neutron radiographic image degradation is scattering blur from the object. A practical method is described to enhance image quality by eliminating the overlapping of scattered thermal neutrons component from the objects in ETRR-2 neutron radiography facility, using aluminum Gd-coated antiscatter grid. The MCNP code was used to determine the optimum grid dimensions that will reduce the scattered thermal neutrons from the object. An experiment was performed to determine the optimum grid height and irradiation time that gives the best image with acceptable geometric unsharpness. Using the MCNP code it was found that 97% of the scattered neutrons were removed by the grid. The wall dimensions and Gd coating are so small that the facility resolution cannot detect the image pattern superposition on the film.

2006-12-01

444

Quick. How much material in that pile

DVR project concerns the creation of a virtual reality OpenGL system for desktop applications in archaeology. The main goal is the creation of a 3D information system using the real time interaction of OpenGL environments. The first case study implemented is the Vettii House, one of the most important and outstanding monuments in Pompei. The virtual reconstruction of these architectural models is based on very detailed photogrammetric surveys and it is connected with information layers and archaeometric data-bases regarding the state of conservation of walls, structures and any type of materials of the monument. A full 3D interface characterizes the system, comprising a high resolution texturing with detailed volumetric and geometric data. Finally, for the future, the project plans to fit the system for scientific and end users through the installation of stations on site.

2001-07-01

445

Probing the origin of inertia behind spacetime deformation

Presented are nomographs for calculating volume of bulk materials (e.g. coal, ores, sand, limestone) in conical or oblong piles formed by means of throwers and other mechanical transporting devices. The author explains that when a thrower is stationary, the pile formed resembles a cone and its projection on the ground is roughly circular. If thrower is moving, in general along a straight path, the final shape is more oblong, resulting from overlapping of separately formed cones. Slope of piles depends on the angle of repose which material makes with the horizontal when piled. This angle depends on such factors as internal friction of material stored, the throwing impact, fineness of grains, and moisture content. Volume is determined from the angle of repose and geometrical data on the area occupied by the pile.

1982-10-01

446

Power correlation for vertical axis wind turbines with varying geometries

To investigate the origin and nature of inertia, we introduce a new concept of hypothetical 2D, so-called, "master-space" (MS), subject to certain rules. The MS, embedded in the background 4D-spacetime, is an indispensable individual companion to the particle of interest, without relation to every other particle. We argue that a deformation/(distortion of local internal properties) of MS is the origin of inertia. With this perspective in sight, we construct the alternative relativistic theory of inertia (RTI), which allows to compute the relativistic inertial force acting on an arbitrary point-like observer due to its "absolute acceleration". We go beyond the hypothesis of locality with an emphasis on distortion of MS, which allows to improve essentially the standard metric and other relevant geometrical structures related to the noninertial reference frame of an arbitrary accelerated observer. We compute the inertial force exerted on the photon in a gravitating ...

2011-01-01

447

British Library Electronic Table of Contents (United Kingdom)

Abstract In this paper, a new predictive model that can forecast the performance of a vertical axis wind turbine (VAWT) is presented. The new model includes four primary variables (rotor velocity, wind velocity, air density, and turbine power output) as well as five geometrical variables (rotor radius, turbine height, turbine width, stator spacing, and stator angle). These variables are reduced to include the power coefficient (Cp) and tip speed ratio (TSR). A power coefficient correlation for a novel VAWT (called a Zephyr Vertical axis Wind Turbine (ZVWT)) is developed. The turbine is an adaptation of the Savonius design. The new correlation can predict the turbine's performance for altered stator geometry and varying operating conditions. Numerical simulations with a rotating reference f...

2011-01-01

448

Pickup and delivery network segmentation using contiguous geographic clustering

British Library Electronic Table of Contents (United Kingdom)

This paper addresses the problem of partitioning a local service region into nonoverlapping work areas in which pickups and deliveries are made throughout the day. For a fleet of homogeneous vehicles, a given set of customers, and expected demand for service, the objective is to find the least number of work areas or clusters that satisfy a variety of geometric and capacity constraints. Using rectangles as the basic shape, each cluster must have an aspect ratio that falls within certain bounds, as well as meet load and time requirements dictated by the capacity of a vehicle and the working hours in a day, respectively. The latter requirement presents a unique hurdle because travel times are a function of the actual routes followed by the drivers, and are not known, even in a probabilistic ...

2011-01-01

449

Parallel MRI reconstruction using variance partitioning regularization

British Library Electronic Table of Contents (United Kingdom)

Multiple receivers can be utilized to enhance the spatiotemporal resolution of MRI by employing the parallel imaging technique. Previously, we have reported the L-curve Tikhonov regularization technique to mitigate noise amplification resulting from the geometrical correlations between channels in a coil array. Nevertheless, one major disadvantage of regularized image reconstruction is lengthy computational time in regularization parameter estimation. At a fixed noise level, L-curve regularization parameter estimation was also found not to be robust across repetitive measurements, particularly for low signal-to-noise ratio (SNR) acquisitions. Here we report a computationally efficient and robust method to estimate the regularization parameter by partitioning the variance of the noise-white...

2007-01-01

450

PERFORMANCE-LIMITING DEFECTS IN CDZNTE DETECTORS.

PCA consistency in high dimension, low sample size context

We studied the effects of small, <20 {micro}m, Te inclusions on the energy resolution of CdZnTe gamma-ray detectors using a highly collimated X-ray beam and gamma-rays, and modeled them via a simplified geometrical approach. Previous reports demonstrated that Te inclusions of about a few microns in diameter degraded the charge-transport properties and uniformity of CdZnTe detectors. The goal of this work was to understand the extent to which randomly distributed Te-rich inclusions affect the energy resolution of CZT detectors, and to define new steps to overcome their deleterious effects. We used a phenomenological model, which depends on several adjustable parameters, to reproduce the experimentally measured effects of inclusions on energy resolution. We also were able to hound the materials-related problem and predict the enhancement in performance expected by reducing the size and number of Te inclusions within the crystals.

2006-10-29

451

Ordered magnetic nanohole and antidot arrays prepared through replication from anodic alumina templates

Principal Component Analysis (PCA) is an important tool of dimension reduction especially when the dimension (or the number of variables) is very high. Asymptotic studies where the sample size is fixed, and the dimension grows [i.e., High Dimension, Low Sample Size (HDLSS)] are becoming increasingly relevant. We investigate the asymptotic behavior of the Principal Component (PC) directions. HDLSS asymptotics are used to study consistency, strong inconsistency and subspace consistency. We show that if the first few eigenvalues of a population covariance matrix are large enough compared to the others, then the corresponding estimated PC directions are consistent or converge to the appropriate subspace (subspace consistency) and most other PC directions are strongly inconsistent. Broad sets of sufficient conditions for each of these cases are specified and the main theorem gives a catalogue of possible combinations. In preparation for these results, we show that the ...

2009-01-01

452

Ordered magnetic nanohole and antidot arrays prepared through replication from anodic alumina templates

Highly ordered arrays of Ni nanoholes and Fe{sub 20}Ni{sub 80} antidots have been prepared, respectively, by replica/antireplica processing and sputtering techniques using nanoporous alumina membranes as templates. Geometrical characteristics as nanohole/antidot diameter, interpore distance and the overall hexagonal symmetry of arrays are controlled through the original templates. Experimental data on their hysteresis and magnetic domain structure have been taken by vibrating sample magnetometry and magnetic force microscopy, respectively. An analysis of the magnetization process, resulting magnetic anisotropy and magnetic domain structure is summarized considering the influence of those geometry aspects. In particular, the hexagonal symmetry and the density of nanohole/antidots determine the overall magnetic behavior, which is of interest in future high-density magnetic storage systems.

2008-07-15

453

Optimum aspect ratio for heat transfer enhancement in curved rectangular channels

Highly ordered arrays of Ni nanoholes and Fe20Ni80 antidots have been prepared, respectively, by replica/antireplica processing and sputtering techniques using nanoporous alumina membranes as templates. Geometrical characteristics as nanohole/antidot diameter, interpore distance and the overall hexagonal symmetry of arrays are controlled through the original templates. Experimental data on their hysteresis and magnetic domain structure have been taken by vibrating sample magnetometry and magnetic force microscopy, respectively. An analysis of the magnetization process, resulting magnetic anisotropy and magnetic domain structure is summarized considering the influence of those geometry aspects. In particular, the hexagonal symmetry and the density of nanohole/antidots determine the overall magnetic behavior, which is of interest in future high-density magnetic storage systems.

2008-07-01

454

Multi-domain, higher order level set scheme for 3D image segmentation on the GPU

Enhanced heat transfer in curved rectangular channels depends on at least two geometric factors, the radius of curvature of the duct and the aspect ratio, which is the width/depth ratio of the duct. In this work, an expression for optimum aspect ratio is derived mathematically from a correlation that includes both aspect ratio and bend curvature parameters. Enhancement factors are developed that show optimal, near-optimal, and nonoptimal aspect ratios for curved rectangular ducts. Predicted enhancements are within 25% of published literature results for individual designs, two of which show heat transfer enhancement of 200% over that of a straight duct with turbulent flow. The theoretical maximum enhancement is shown to be about 480% over a straight-duct, turbulent-flow situation. This is not achievable in practice, but near-optimal solutions are achievable, yielding enhancements on the order of 200--300%.

455

Laser-generated PuO_2--UO_2 condensation aerosols

Level set method based segmentation provides an efficient tool for topological and geometrical shape handling. Conventional level set surfaces are only $C^0$ continuous since the level set evolution involves linear interpolation to compute derivatives. Bajaj et al. present a higher order method to evaluate level set surfaces that are $C^2$ continuous, but are slow due to high computational burden. In this paper, we provide a higher order GPU based solver for fast and efficient segmentation of large volumetric images. We also extend the higher order method to multi-domain segmentation. Our streaming solver is efficient in memory usage.

2010-01-01

456

Laser-assisted asymmetric incremental sheet forming of titanium sheet metal parts

A 340-watt CO_2 laser is being used to generate PuO_2-UO_2 condensation aerosol from the surface of a Liquid Metal Fast Breeder Reactor (LMFBR) fuel pellet. A wide range of concentrations is achieved by varying the laser power, pulse width, and/or pulse period. The resulting aerosol is composed of branch chain-like aggregates, with the primary particle size ranging between 0.005 and 0.15 #mu#m. X-ray diffraction analyses show that these aerosols condense into a face-centered cubic crystal structure. The activity mean aerodynamic diameter (AMAD), for most power levels, is approximately 0.85 #mu#m with a geometric standard deviation of 1.5.

1977-05-01

457

British Library Electronic Table of Contents (United Kingdom)

Asymmetric Incremental Sheet Forming (AISF) is a relatively new manufacturing process. In AISF, a CNC driven forming tool imposes a localized plastic deformation as it moves along the contour of the desired part. Thus, the final shape is obtained by a sequence of localized plastic deformations. AISF is suitable for small series production of sheet metal parts as needed in aeronautical and medical applications. Two main process limits restrict the range of application of AISF in these fields. These are the low geometrical accuracy of parts made from titanium alloys or high strength steels and, for titanium alloys, the limited formability at room temperature. In this paper a new concept for laser-assisted AISF is introduced including the required components. Furthermore, the CAX tools used f...

2011-01-01

458

J{sup {asterisk}} optimization of small aspect ratio stellarator/tokamak hybrid devices

J* optimization of small aspect ratio stellarator/tokamak hybrid devices

A new class of low aspect ratio toroidal hybrid stellarators is found using a more general plasma confinement optimization criterion than quasisymmetrization. The plasma current profile and shape of the outer magnetic flux surface are used as control variables to achieve near constancy of the longitudinal invariant J{sup {asterisk}} on internal flux surfaces (quasiomnigeneity), in addition to a number of other desirable physics target properties. A range of compact (small aspect ratio A), low plasma current devices have been found with significantly improved confinement, both for thermal as well as energetic (collisionless) particle components. With reasonable increases in magnetic field and geometric size, such devices can also be scaled to confine 3.5 MeV alpha particle orbits.

1998-05-01

459

Investigation of mixed convection in a large rectangular enclosure

A new class of low aspect ratio toroidal hybrid stellarators is found using more general plasma confinement optimization criterion than quasi-symmetrization. The plasma current profile and shape of the outer magnetic flux surface are used as control variables to achieve near constancy of the longitudinal invariant J* on internal flux surfaces (quasi-omnigeneity), in addition to a number of other desirable physics target properties. We find that a range of compact (small aspect ratio A), high {beta} (ratio of thermal energy to magnetic field energy), low plasma current devices exist which have significantly improved confinement both for thermal as well as energetic (collisionless) particle components. With reasonable increases in magnetic field and geometric size, such devices can also be scaled to confine 3.5 MeV alpha particle orbits.

1997-12-31

460

Investigation of mixed convection in a large rectangular enclosure

This experimental research investigates mixed convection and heat transfer augmentation by gaseous forced jets in a large enclosure, at conditions simulating those of passive containment cooling systems for Gen III+ passively safe reactors. The experiment is designed to measure the key parameters governing heat transfer augmentation by forced jets, and to investigate the effects of geometric factors, including the jet diameter, jet injection orientation, interior structures, and enclosure aspect ratio. The tests cover a variety of injection modes leading to flow configurations of interest for mixing and stratification phenomena in containments under accident conditions. Correlations for heat transfer augmentation by forced jets are developed and compared with experimental data. The characteristic recirculation speed inside the enclosure is introduced and analyzed. Steady stratified temperature distributions are compared with model simulations of the BMIX++ code.

2007-05-15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

461

International Lens Design Conference, Monterey, CA, June 11-14, 1990, Proceedings

This experimental research investigates mixed convection and heat transfer augmentation by gaseous forced jets in a large enclosure, at conditions simulating those of passive containment cooling systems for Gen III+ passively safe reactors. The experiment is designed to measure the key parameters governing heat transfer augmentation by forced jets, and to investigate the effects of geometric factors, including the jet diameter, jet injection orientation, interior structures, and enclosure aspect ratio. The tests cover a variety of injection modes leading to flow configurations of interest for mixing and stratification phenomena in containments under accident conditions. Correlations for heat transfer augmentation by forced jets are developed and compared with experimental data. The characteristic recirculation speed inside the enclosure is introduced and analyzed. Steady stratified temperature distributions are compared with model simulations of the BMIX++ code.

2007-05-01

462

Internal heat transfer augmentation in a channel using an alternate set of porous cavity-block obstacles

The present conference on lens design encompasses physical and geometrical optics, diffractive optics, the optimization of optical design, software packages, ray tracing, the use of artificial intelligence, the achromatization of materials, zoom optics, microoptics and GRIN lenses, and IR lens design. Specific issues addressed include diffraction-performance calculations in lens design, the optimization of the optical transfer function, a rank-down method for automatic lens design, applications of quadric surfaces, the correction of aberrations by using HOEs in UV and visible imaging systems, and an all-refractive telescope for intersatellite communications. Also addressed are automation techniques for optics manufacturing, all-reflective phased-array imaging telescopes, the thermal aberration analysis of a Nd:YAG laser, the analysis of illumination systems, athermalized FLIR optics, and the design of array systems using shared symmetry.

1990-01-01

463

Impact of Hight Velocity Cold Spray Particles

A numerical investigation for forced convection in a constant-temperature parallel plate channel with porous cavity and block alternately emplaced on the bottom plate is presented in this work. The Brinkman-Forchheimer-extended Darcy model, which accounts for the effects of impermeable boundary and inertia, is used to characterize the flow field inside the porous region. Solutions of the coupled governing equations are carried out through the stream function-vorticity analysis. The characteristics of fluid flow and forced convection heat transfer have been obtained by the examinations of various governing parameters, such as the Reynolds number, Darcy number, inertial parameter, Prandtl number, and two geometric parameters. Several interesting phenomena such as the heat transfer augmentation in the channel were presented and discussed. The results of this investigation indicate that the size of recirculation caused by porous block will have a profound effect on the ...

1994-05-01

464

Idealized gas turbine combustor for performance research and validation of large eddy simulations.

This paper presents experimental data and an computational model of the cold spray solid particle impact process. Copper particles impacting onto a polished stainless steel substrate are examined. The high velocity impact causes significant plastic deformation of both the particle and the sub- strate, but no melting is observed. The plastic deformation exposes clean surfaces that, under the high impact pressures, result in significant bond strengths between the particle and substrate. Experimental measurements of the splat and crater sizes compare well with the numerical calculations. It is shown that the crater depth is significant and increases with impact velocity. However, the splat diameter is much less sensitive to the impact velocity. It is also shown that the geometric lengths of the splat and crater scale linearly with the diameter of the impacting particle. It is hoped that the results presented will allow better understanding of the bonding process ...

1998-12-01

465

How do mathematicians learn math?: resources and acts for constructing and understanding mathematics

This paper details the design of a premixed, swirl-stabilized combustor that was designed and built for the express purpose of obtaining validation-quality data for the development of large eddy simulations (LES) of gas turbine combustors. The combustor features nonambiguous boundary conditions, a geometrically simple design that retains the essential fluid dynamics and thermochemical processes that occur in actual gas turbine combustors, and unrestrictive access for laser and optical diagnostic measurements. After discussing the design detail, a preliminary investigation of the performance and operating envelope of the combustor is presented. With the combustor operating on premixed methane/air, both the equivalence ratio and the inlet velocity were systematically varied and the flame structure was recorded via digital photography. Interesting lean flame blowout and resonance characteristics were observed. In addition, the combustor exhibited a large region of ...

2007-03-01

466

British Library Electronic Table of Contents (United Kingdom)

In this paper, we present an analytic framework for investigating expert mathematical learning as the process of building a network of mathematical resources by establishing relationships between different components and properties of mathematical ideas. We then use this framework to analyze the reasoning of ten mathematicians and mathematics graduate students that were asked to read and make sense of an unfamiliar, but accessible, mathematical proof in the domain of geometric topology. We find that experts are more likely to refer to definitions when questioning or explaining some aspect of the focal mathematical idea and more likely to refer to specific examples or instantiations when making sense of an unknown aspect of that idea. However, in general, they employ a variety of types of m...

2011-01-01

467

Heat transfer augmentation in an axisymmetric impinging jet

Ground state energies and nuclear density distribution in the coherent flucton model

This paper presents the experimental results of heat transfer augmentation in an axisymmetric jet impinging normally on a flat plate surface without the requirement of additional pumping power. The present technique of augmentation utilizes only a punched plate with circular holes arranged in a triangular array, fixed parallel to, just in front of the heated target plate. Near the optimum conditions determined, the heat transfer coefficient at the geometrical stagnation point can be increased 4 times. Additional flow visualization study indicates that this augmentation mechanism creates an improved flow field where the punched plate acts as a detached fin, the conductivity of which may be exploited for further augmentation. Besides augmentation, the present investigation foresees the possibility of manipulating the distribution of local heat transfer rate by varying few parameters.

1982-01-01

468

Ground state energies and nuclear density distribution in the coherent flucton model

The coherent flucton model is applied to the description of some basic nuclear properties, such as: ground state energies, bond energies, nucleon momentum spectra, and nuclear density distributions. It is shown that the momentum distributions of the nucleons coincide with the Fermi distribution for small momenta and exhibit a well pronounced high energy ''tail'', thus providing inclusive reactions of pi-meson generations in kinematically forbidden areas at nucleon-nucleon collisions. Analytical expressions for the bond energy and nuclear density distribution are derived. An agreement with the experimentally obtained data is achieved. The model features are discussed referring to the processes, characterized mainly by the geometric and dynamic properties of the nuclei, as well as by nuclear density distribution. In particular, ion-ion scattering processes at high energy are considered.

1980-01-01

469

Gravity Dual for a Model of Perception

The coherent flucton model is applied to the description of some basic nuclear properties, such as: ground state energies, bond energies, nucleon momentum spectra, and nuclear density distributions. It is shown that the momentum distributions of the nucleons coincide with the Fermi distribution for small momenta and exhibit a well pronounced high energy ''tail'', thus providing inclusive reactions of pi-meson generations in kinematically forbidden areas at nucleon-nucleon collisions. Analytical expressions for the bond energy and nuclear density distribution are derived. An agreement with the experimentally obtained data is achieved. The model features are discussed referring to the processes, characterized mainly by the geometric and dynamic properties of the nuclei, as well as by nuclear density distribution. In particular, ion-ion scattering processes at high energy are considered.

470

Geometric group theory and arithmetic diameter

One of the salient features of human perception is its invariance under dilatation in addition to the Euclidean group, but its non-invariance under special conformal transformation. We investigate a holographic approach to the information processing in image discrimination with this feature. We claim that a strongly coupled analogue of the statistical model proposed by Bialek and Zee can be holographically realized in scale invariant but non-conformal Euclidean geometries. We identify the Bayesian probability distribution of our generalized Bialek-Zee model with the GKPW partition function of the dual gravitational system. We provide a concrete example of the geometric configuration based on a vector condensation model coupled with the Euclidean Einstein-Hilbert action. From the proposed geometry, we study sample correlation functions to compute the Bayesian probability distribution.

2010-01-01

471

FFTF scale-model characterization of flow-induced vibrational response of reactor internals

Let X be a group with identity e, let A be an infinite set of generators for X, and let (X,d_A) be the metric space with the word metric d_A induced by A. It is proved that if the diameter of the space is infinite, then for every positive integer h there are infinitely many elements x in X with d_A(e,x)=h. It is proved that if P is a nonempty finite set of prime numbers and A is the set of positive integers whose prime factors all belong to P, then the diameter of the metric space (\\Z,d_A) is infinite. Let \\lambda_A(h) denote the smallest positive integer x with d_A(e,x)=h. It is an open problem to compute \\lambda_A(h) and estimate its growth rate.

2011-01-01

472

Extremum-Preserving Limiters for MUSCL and PPM

As an integral part of the Fast Test Reactor Vibration Program for Reactor Internals, the flow-induced vibrational characteristics of scaled Fast Test Reactor core internal and peripheral components were assessed under scaled and simulated prototype flow conditions in the Hydraulic Core Mockup. The Hydraulic Core Mockup, a 0.285 geometric scale model, was designed to model the vibrational and hydraulic characteristics of the Fast Test Reactor. Model component vibrational characteristics were measured and determined over a range of 36 percent to 111 percent of the scaled prototype design flow. Selected model and prototype components were shaker tested to establish modal characteristics. The dynamic response of the Hydraulic Core Mockup components exhibited no anomalous flow-rate dependent or modal characteristics, and prototype response predictions were adjudged acceptable.

473

Experimental modeling of the explosion mechanism of basaltic magmas

Limiters are nonlinear hybridization techniques that are used to preserve positivity and monotonicity when numerically solving hyperbolic conservation laws. Unfortunately, the original methods suffer from the truncation-error being first-order accurate at all extrema despite the accuracy of the higher-order method. To remedy this problem, higher-order extensions were proposed that relied on elaborate analytic and geometric constructions. Since extremum-preserving limiters are applied only at extrema, additional computational cost is negligible. Therefore, extremum-preserving limiters ensure higher-order spatial accuracy while maintaining simplicity. This report presents higher-order limiting for (i) computing van Leer slopes and (ii) adjusting parabolic profiles. This limiting preserves monotonicity and accuracy at smooth extrema, maintains stability in the presence of discontinuities and under-resolved gradients, and is based on constraining the interpolated ...

2009-01-01

474

British Library Electronic Table of Contents (United Kingdom)

Processes in the feeders of basaltic volcanoes during Strombolian-type eruptions were examined with the use of a complex apparatus for modeling basaltic eruptions (CAMBE), which was designed and manufactured by the authors for this purpose. The experimental setup consists of modeling and registering units and has a height of 18 m. It was designed with regard for the geometric dimensions of a natural feeding volcanic system: the ratio of the inner diameter of the feeder to its height is approximately 1: 1000. CAMBE was the first modeling equipment making possible passing a flow of gas-saturated liquid through the conduit, which allowed us to study the nucleation of gas bubbles, their growth, coalescence, transformations of the gas structures, and the kinetics of the gas phase. The experimen...

2009-01-01

475

Experimental investigations of plasma bullets

Experimental demonstration of a trumpet secondary concentrator for the Cummins Power Generation (CPG) 7.5 kW(e) dish-Stirling system

Recently several investigators reported on various means of generating cold plasma jets at atmospheric pressure. More interestingly, these jets turned out to be not continuous plasmas but trains of small high velocity plasma packets/bullets. However, until now little is known of the nature of these 'bullets'. Here we present experimental insights into the physical and chemical characteristics of bullets. We show that their time of initiation, their velocity and the distance they travel are directly dependent on the value of the applied voltage. We also show that these bullets can be controlled by the application of an external electric field. Using an intensified charge coupled device camera we report on their geometrical shape, which was revealed to be 'donut' shaped, therefore giving an indication that solitary surface ionization waves may be responsible for the creation of these bullets. In addition, using emission spectroscopy, we follow the evolution of ...

2009-03-07

476

Empirical relationship between track diameter and etching time for fission fragments incident on a glass SSNTD at various angles of incidence

A prototype trumpet type nonimaging secondary concentrator has been designed and fabricated for use with the Cummins Power Generation (CPG) 7.5 kW(e) dish-Stirling system and a preliminary set of operating tests has been carried out. The secondary is 26.7 cm (10.5 in.) deep by about 69 cm (27 in.) wide, and has a geometric concentration of 1.7X. The test units were fabricated from polished copper spinnings, overcoated with vapor deposited aluminum and aluminum oxide layers and are water cooled. The basic design considerations are reviewed, the objectives and test procedures for the experiment are summarized and some preliminary results are presented.

1996-11-01

477

Elucidating two-phase transport in a polymer electrolyte fuel cell, Part 1: Characterizing flow regimes with a dimensionless group

Geometrical shapes and diameter of nuclear tracks changes continuously during the process of etching for various incident angles. Besides, there is also a marked difference amongst their profiles, as evidenced by the SEM analysis, when the incoming particles fall on the detector at different angles of incidence. This work outlines this aspect of fission fragment tracks in a glass detector and has set out a few empirical relationships between the mean track diameter, d-bar and the etching time, t, within experimental limits. This study, therefore, sheds some light in the follow up the origins and characteristics of heavy ions in some terrestrial and extra-terrestrial materials and also in studying the collimation accuracy of heavy ion bombardments. The implications of the results in discerning the measurements of incident angles of various types of ions are described in detail in the paper.

1983-09-01

478

British Library Electronic Table of Contents (United Kingdom)

This paper explores the through-/in-plane characteristics of water transport in the cathode gas diffusion layer (GDL) of a polymer electrolyte fuel cell (PEFC). Theoretical analysis is performed on the non-isothermal two-phase flow under flow channels. A dimensionless group Da (Damkohler number for PEFC operation), defined as the ratio of water generation rate to water vapor-phase removal rate, is formulated to characterize the flow regimes in a PEFC. This group, lumping geometrical parameters and physical properties, compares the water vapor-phase removal capability (via water diffusion and holding capacity) with the rate of water production by the oxygen reduction reaction. We find that this dimensionless group can be used to characterize the non-isothermal, two-phase phenomena: when Da&...

2011-01-01

479

Effect of charge dilution on gaseous and particulate emissions from a diesel engine fueled with biodiesel and biodiesel blended with methanol and ethanol

British Library Electronic Table of Contents (United Kingdom)

In this study, the effect of intake charge dilution with carbon dioxide on the combustion and emission characteristics of a 4-cylinder direct-injection diesel engine fueled with biodiesel, ethanol-biodiesel and methanol-biodiesel were investigated. With increase of intake CO"2 concentration, CO, HC, particulate mass concentration, particle number concentration and geometric diameter (GMD) of all fuels increased while NO"x decreased obviously. After addition of methanol and ethanol in biodiesel, the NO"x, particulate mass concentration and particle number concentration decreased at each intake CO"2 concentration, compared with biodiesel. Moreover, as the intake CO"2 concentration increased from 2% to 5.6%, particulate mass concentration of the alcohol-biodiesel blends remained almost unchan...

2011-01-01

480

Double peak effect in microdosimetric proportional counters and its interpretation

Discretization of complex 3-D flow domains with adaptive hybrid grids

In calibration measurements with low energy X-rays, a double peak effect appears in low pressure proportional counters with a helix, when used for simulation of tissue equivalent diameters considerably larger than 2 m. An interpretation of this phenomenon is discussed, based upon electron capture and electric field perturbation at the counter helix. A description of the physical processes is presented showing that the double peak effect is a problem in the case of helix counters (called also Rossi counters) for all simulated diameters. Conclusions are drawn on systematic errors introduced by the counter helix into microdosimetric spectra and anti y/sub D/ of photons and neutrons. The authors recommend to use cylindrical counters with optimized geometrical and electronic parameters rather than the spherical counters with a helix discussed.

1989-01-01

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481

Development of an advanced power system stabilizer using a strict linearization approach

There is an ever increasing demand to perform flow simulations that incorporate the complete details of geometry as well as sophisticated flow physics. This has led to the development of numerical algorithms that can simulate the actual flow phenomena with greater fidelity. However, the success of these algorithms hinges on the grid that models the geometry. Grid generation methods for 2-D models have long existed and the general lack of complexity of the simpler 2-D models has not quite challenged the efforts in this area. However, demands for generating better 3-D geometric models for flow simulations involving complex geometries have completely changed the perspective of grid generation strategies. As a consequence, grid generation efforts have earned equal significance as that of numerical solver efforts.

1996-12-31

482

Controlled Synthesis of Water-Dispersible Faceted Crystalline Copper Nanoparticles and Their Catalytic Properties

This paper presents a practical design for a power system stabilizer using the differential geometric linearization approach. This stabilizer uses the information at the secondary bus of the step-up transformer as input signals, enabling its application to multi-machine power systems. The stabilizer makes it possible to obtain all necessary information within its own power station without observing an equivalent reactance in other power systems. To evaluate the dynamic performance of this stabilizer, the authors tested it on a multi-machine system model using the computer. The simulation results showed that the stabilizer offered good dynamic performance and robustness compared with conventional power system stabilizers, thus confirming its very effective and practical application in power system stabilization.

1996-05-01

483

British Library Electronic Table of Contents (United Kingdom)

We report a solution-phase synthetic route to copper nanoparticles with controllable size and shape. The synthesis of the nanoparticles is achieved by the reduction of copper(II) salt in aqueous solution with hydrazine under air atmosphere in the presence of poly(acrylic acid) (PAA) as capping agent. The results suggest that the pH plays a key role for the formation of pure copper nanoparticles, whereas the concentration of PAA is important for controlling the size and geometric shape of the nanoparticles. The average size of the copper nanoparticles can be varied from 30 to 80 nm, depending on the concentration of PAA. With a moderate amount of PAA, faceted crystalline copper nanoparticles are obtained. The as-synthesized copper nanoparticles appear red in color and are stable for weeks, ...

2010-01-01

484

Chern classes of graph hypersurfaces and deletion-contraction

Capacity-coupled multidischarge for atmospheric plasma production

We study the behavior of the Chern classes of graph hypersurfaces under the operation of deletion-contraction of an edge of the corresponding graph. We obtain an explicit formula when the edge satisfies two technical conditions, and prove that both these conditions hold when the edge is multiple in the graph. This leads to recursions for the Chern classes of graph hypersurfaces for graphs obtained by adding parallel edges to a given (regular) edge. Analogous results for the case of Grothendieck classes of graph hypersurfaces were obtained in previous work. Both Grothendieck classes and Chern classes were used to define `algebro-geometric' Feynman rules. The results in this paper provide further evidence that the polynomial Feynman rule defined in terms of the Chern-Schwartz-MacPherson class of a graph hypersurface reflects closely the combinatorics of the corresponding graph. The key to the proof of the main result is a more general formula for the ...

2011-01-01

485

Calculation of electromagnetic force in electromagnetic forming process of metal sheet

We propose a method of plasma production by capacity-coupled multidischarge (CCMD) at atmospheric pressure. The discharge gaps in the CCMD consist of a common electrode and a number of compact electrodes (CCE) which are directly coupled with small capacitors for quenching the discharge. A simple CCE structure is provided by a cylindrical capacitor, the inner conductor of which is used as a gap electrode. A short pulse discharge is observed to appear homogeneously at each CCE. A charge transfer for the single-pulsed discharge is 10-100 times as large as that of the conventional dielectric barrier discharge. A high efficiency of ozone production has been confirmed in the CCMD using O_2 gas. A device configuration of the CCMD is quite flexible with respect to its geometrical shape and size. The CCMD could be used to produce plasmas for various kinds of industrial applications at atmospheric pressure.

2003-12-29

486

Calculation model testing for the case of rcs hot collector rupture inside the horizontal steam generator of VVER-440 NPP

Electromagnetic forming (EMF) is a forming process that relies on the inductive electromagnetic force to deform metallic workpiece at high speed. Calculation of the electromagnetic force is essential to understand the EMF process. However, accurate calculation requires complex numerical solution, in which the coupling between the electromagnetic process and the deformation of workpiece needs be considered. In this paper, an appropriate formula has been developed to calculate the electromagnetic force in metal work-piece in the sheet EMF process. The effects of the geometric size of coil, the material properties, and the parameters of discharge circuit on electromagnetic force are taken into consideration. Through the formula, the electromagnetic force at different time and in different positions of the workpiece can be predicted. The calculated electromagnetic force and magnetic field are in good agreement with the numerical and experimental results. The accurate ...

2010-06-15

487

Calculation model testing for the case of rcs hot collector rupture inside the horizontal steam generator of VVER-440 NPP

The calculations presented are based on RELAP5/MOD2-3 input for VVER 440/213 Bohunice NPP, developed within the framework of IAEA TC Project by an international team of specialists from CSFR, Hungary, Bulgaria and Poland. Project activities were condentrated on input data refinement and testing. Several cases were calculated using the latest version of RELAP5/MOD2 provided by RMA, Albuquerque to investigate some modelling assumptions, such as break location, geometrical representation of secondary circuit piping as well as the effect of deactivation of the signal controlling the SG isolation valves. (2 refs., 21 figs., 2 tabs.).

1993-12-31

488

Acoustic band gaps in arrays of neutral inclusions

The calculations presented are based on RELAP5/MOD2-3 input for VVER 440/213 Bohunice NPP, developed within the framework of IAEA TC Project by an international team of specialists from CSFR, Hungary, Bulgaria and Poland. Project activities were condentrated on input data refinement and testing. Several cases were calculated using the latest version of RELAP5/MOD2 provided by RMA, Albuquerque to investigate some modelling assumptions, such as break location, geometrical representation of secondary circuit piping as well as the effect of deactivation of the signal controlling the SG isolation valves. (2 refs., 21 figs., 2 tabs.).

1992-09-29

489

British Library Electronic Table of Contents (United Kingdom)

We analyse numerically the acoustic stop band properties of an array of orthotropic coated cylinders whose elastic parameters are deduced from a geometric transform [H. Chen, C.T. Chan, Acoustic cloaking in three dimensions using acoustic metamaterials, Appl. Phys. Lett. 91 (2007) 183518]. We find that whereas a single coated inclusion is acoustically neutral at any frequency, an array of them might display some stop bands. More precisely, an array of freely vibrating coated voids is always neutral, whereas an array of clamped coated inclusions might display a zero frequency stop band. Interestingly, an array of radially symmetric coated inclusions behaves as local Helmholtz resonators, for which the eigenfield within each cloak is obtained in closed form, leading to a frequency estimate a...

2010-01-01

490

A novel approach to the dynamics of Szekeres dust models

A multi-criteria interval-valued intuitionistic fuzzy group decision making with Choquet integral-based TOPSIS

We obtain an elegant and useful description of the dynamics of Szekeres dust models (in their full generality) by means of "quasi--local" scalar variables constructed by suitable integral distributions that can be interpreted as weighed proper volume averages of the local covariant scalars. In terms of these variables, the field equations and basic physical and geometric quantities are formally identical to their corresponding expressions in the spherically symmetric LTB dust models. Since we can map every Szekeres model to a unique LTB model, rigorous results valid for the latter models can be readily generalized to a non--spherical Szekeres geometry. The new variables lead naturally to an initial value formulation in which all scalars are expressed as scaling laws in terms of their values at an arbitrary initial space slice. These variables also yield a significant simplification of numerical work, since the fluid flow evolution equations become a system of ...

2011-01-01

491

British Library Electronic Table of Contents (United Kingdom)

An extension of TOPSIS, a multi-criteria interval-valued intuitionistic fuzzy decision making technique, to a group decision environment is investigated, where inter-dependent or interactive characteristics among criteria and preference of decision makers are taken into account. To get a broad view of the techniques used, first, some operational laws on interval-valued intuitionistic fuzzy values are introduced. Based on these operational laws, a generalized interval-valued intuitionistic fuzzy geometric aggregation operator is proposed which is used to aggregate decision makers? opinions in group decision making process. In addition, some of its properties are discussed. Then Choquet integral-based Hamming distance between interval-valued intuitionistic fuzzy values is defined. Combining ...

2011-01-01

492

A density Functional Calculations on The Geometrical Electronic and Nonlinear Optical Properties of Thienyl Oxazoles and Thienyl Isoxazoles

Simulation of uranium oxides reduction kinetics by hydrogen. Reactivities of germination and growth; Modelisation de la cinetique de reduction d`oxydes d`uranium par l`hydrogene. Reactivites de germination et de croissance

Thienyl oxazoles and thienyl isoxazoles, are composite molecules having two subsystems thiophene and oxazole molecules connected together by a single bond that they have 13 isomers. They are potential candidates for many kinds of applications such as OLED and nonlinear optical materials. Initially equilibrium geometries of title compounds have been obtained without any restriction using density functional theory with 6-311++g(2d,p) basis set. We obtained structural parameters, dipole moment and electronic energy. At the second stage, we have calculated some electronic and nonlinear optical properties such as HOMO and LUMO energies, polarizability, anisotropic polarizability and hyper polarizability using same level of theory.

2008-08-25

493

Experimental investigation of mixed convection heat transfer caused by forced-jets in large enclosure

The aim of this work is to simulate the reduction by hydrogen of the tri-uranium octo-oxide U{sub 3}O{sub 8} (obtained by uranium trioxide calcination) into uranium dioxide. The kinetics curves have been obtained by thermal gravimetric analysis, the hydrogen and steam pressures being defined. The geometrical modeling which has allowed to explain the trend of the kinetics curves and of the velocity curves is an anisotropic germination-growth modeling. The powder is supposed to be formed of spherical grains with the same radius. The germs of the new UO{sub 2} phase appear at the surface of the U{sub 3}O{sub 8} grains with a specific germination frequency. The growth reactivity is anisotropic and is very large in the tangential direction to the grains surface. Then, the uranium dioxide growths inside the grain and the limiting step is the grain surface. The variations of the growth reactivity and of the germination specific frequency in terms of the gases partial ...

1997-12-04

494

Development of an efficient parallel FEM analysis program for large structural problems over several millions of DOF

This research investigates experimentally mixed convection and heat transfer augmentation by forced jets in a large enclosure, at conditions simulating those of actual passive containment cooling systems and scales approaching those of actual containment buildings or compartments. The experiment was designed to measure the key parameters governing the heat transfer augmentation by forced jets and investigate the effects of geometric factors, including the jet diameter, jet injection orientation, interior structures, and enclosure aspect ratio. The tests cover a variety of injection modes leading to flow configurations of interest that contribute to reveal the nature of mixing and stratification phenomena in the containment under accident conditions of interest. The heat transfer of mixed convection can be predicted to be controlled by jet Archimedes number and geometric factors. Using a combining rule for mixed convection and appropriate forced ...

2004-07-01

495

A campaign of discrete radon concentration measurements in soil of Niska Banja town, Serbia

In order to predict or to evaluate the structural reliability of a variety of nuclear components under actual changing operating conditions, it is necessary to take the detailed geometrical features of components into consideration on one hand, and thermo-mechanical loading conditions with space and time variations during the lifetime, on the other hand. This consideration leads the authors to develop a super large-scale structural analysis program based on a parallel computational FEM with a variable scale of PC cluster architecture, whose prototype system is presented in a companion paper in this Symposium. Development of the PC cluster technology is one of the most important subjects in large-scale structural simulation, reducing computer costs and thus making simulation more acceptable to the engineering community. This paper presents the developmental status of the parallel FEM solver, demonstrating computational capabilities with three dimensional effects ...

2000-09-01

496

A campaign of discrete radon concentration measurements in soil of Niska Banja town, Serbia

The first radon soil gas survey in Serbia, using passive detectors (SSNTD, CR-39), was carried out in June 2005 at field sites in Niska Banja town. The aim of the survey was to identify risk zones characterised by high levels of this radioactive gas. Radon measurements were made at the depth of 50 cm, in the ground according to a systematic grid pattern. Furthermore, at all 48 measurement points, the surface gamma dose rates in the air was also measured at the same locations and soil samples were collected for gamma spectrometric analysis for the radionuclides {sup 226}Ra, {sup 228}Th and {sup 40}K. Radon concentrations were found to range from 1270 to 155000Bqm{sup -3} with an average of 33765Bqm{sup -3} and a median value of 12626Bqm{sup -3}. The geometrical mean value and geometrical standard deviation were calculated as 16160Bqm{sup -3} and 3.5Bqm{sup -3}, respectively. Gamma dose rate varies from 92 to 316nGyh{sup -1}, with an average of ...

2007-11-15

497